fs/btrfs/inode.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/highmem.h>
  26 #include <linux/time.h>
  27 #include <linux/init.h>
  28 #include <linux/string.h>
  29 #include <linux/backing-dev.h>
  30 #include <linux/mpage.h>
  31 #include <linux/swap.h>
  32 #include <linux/writeback.h>
  33 #include <linux/compat.h>
  34 #include <linux/bit_spinlock.h>
  35 #include <linux/xattr.h>
  36 #include <linux/posix_acl.h>
  37 #include <linux/falloc.h>
  38 #include <linux/slab.h>
  39 #include <linux/ratelimit.h>
  40 #include <linux/mount.h>
  41 #include <linux/btrfs.h>
  42 #include <linux/blkdev.h>
  43 #include <linux/posix_acl_xattr.h>
  44 #include <linux/uio.h>
  45 #include <linux/magic.h>
  46 #include <linux/iversion.h>
  47 #include "ctree.h"
  48 #include "disk-io.h"
  49 #include "transaction.h"
  50 #include "btrfs_inode.h"
  51 #include "print-tree.h"
  52 #include "ordered-data.h"
  53 #include "xattr.h"
  54 #include "tree-log.h"
  55 #include "volumes.h"
  56 #include "compression.h"
  57 #include "locking.h"
  58 #include "free-space-cache.h"
  59 #include "inode-map.h"
  60 #include "backref.h"
  61 #include "props.h"
  62 #include "qgroup.h"
  63 #include "dedupe.h"
  64
  65 struct btrfs_iget_args {
  66         struct btrfs_key *location;
  67         struct btrfs_root *root;
  68 };
  69
  70 struct btrfs_dio_data {
  71         u64 reserve;
  72         u64 unsubmitted_oe_range_start;
  73         u64 unsubmitted_oe_range_end;
  74         int overwrite;
  75 };
  76
  77 static const struct inode_operations btrfs_dir_inode_operations;
  78 static const struct inode_operations btrfs_symlink_inode_operations;
  79 static const struct inode_operations btrfs_dir_ro_inode_operations;
  80 static const struct inode_operations btrfs_special_inode_operations;
  81 static const struct inode_operations btrfs_file_inode_operations;
  82 static const struct address_space_operations btrfs_aops;
  83 static const struct address_space_operations btrfs_symlink_aops;
  84 static const struct file_operations btrfs_dir_file_operations;
  85 static const struct extent_io_ops btrfs_extent_io_ops;
  86
  87 static struct kmem_cache *btrfs_inode_cachep;
  88 struct kmem_cache *btrfs_trans_handle_cachep;
  89 struct kmem_cache *btrfs_path_cachep;
  90 struct kmem_cache *btrfs_free_space_cachep;
  91
  92 #define S_SHIFT 12
  93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
  94         [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
  95         [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
  96         [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
  97         [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
  98         [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
  99         [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
 100         [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
 101 };
 102
 103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
 104 static int btrfs_truncate(struct inode *inode, bool skip_writeback);
 105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
 106 static noinline int cow_file_range(struct inode *inode,
 107                                    struct page *locked_page,
 108                                    u64 start, u64 end, u64 delalloc_end,
 109                                    int *page_started, unsigned long *nr_written,
 110                                    int unlock, struct btrfs_dedupe_hash *hash);
 111 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
 112                                        u64 orig_start, u64 block_start,
 113                                        u64 block_len, u64 orig_block_len,
 114                                        u64 ram_bytes, int compress_type,
 115                                        int type);
 116
 117 static void __endio_write_update_ordered(struct inode *inode,
 118                                          const u64 offset, const u64 bytes,
 119                                          const bool uptodate);
 120
 121 /*
 122  * Cleanup all submitted ordered extents in specified range to handle errors
 123  * from the fill_dellaloc() callback.
 124  *
 125  * NOTE: caller must ensure that when an error happens, it can not call
 126  * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
 127  * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
 128  * to be released, which we want to happen only when finishing the ordered
 129  * extent (btrfs_finish_ordered_io()). Also note that the caller of the
 130  * fill_delalloc() callback already does proper cleanup for the first page of
 131  * the range, that is, it invokes the callback writepage_end_io_hook() for the
 132  * range of the first page.
 133  */
 134 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
 135                                                  const u64 offset,
 136                                                  const u64 bytes)
 137 {
 138         unsigned long index = offset >> PAGE_SHIFT;
 139         unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
 140         struct page *page;
 141
 142         while (index <= end_index) {
 143                 page = find_get_page(inode->i_mapping, index);
 144                 index++;
 145                 if (!page)
 146                         continue;
 147                 ClearPagePrivate2(page);
 148                 put_page(page);
 149         }
 150         return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
 151                                             bytes - PAGE_SIZE, false);
 152 }
 153
 154 static int btrfs_dirty_inode(struct inode *inode);
 155
 156 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 157 void btrfs_test_inode_set_ops(struct inode *inode)
 158 {
 159         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 160 }
 161 #endif
 162
 163 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
 164                                      struct inode *inode,  struct inode *dir,
 165                                      const struct qstr *qstr)
 166 {
 167         int err;
 168
 169         err = btrfs_init_acl(trans, inode, dir);
 170         if (!err)
 171                 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
 172         return err;
 173 }
 174
 175 /*
 176  * this does all the hard work for inserting an inline extent into
 177  * the btree.  The caller should have done a btrfs_drop_extents so that
 178  * no overlapping inline items exist in the btree
 179  */
 180 static int insert_inline_extent(struct btrfs_trans_handle *trans,
 181                                 struct btrfs_path *path, int extent_inserted,
 182                                 struct btrfs_root *root, struct inode *inode,
 183                                 u64 start, size_t size, size_t compressed_size,
 184                                 int compress_type,
 185                                 struct page **compressed_pages)
 186 {
 187         struct extent_buffer *leaf;
 188         struct page *page = NULL;
 189         char *kaddr;
 190         unsigned long ptr;
 191         struct btrfs_file_extent_item *ei;
 192         int ret;
 193         size_t cur_size = size;
 194         unsigned long offset;
 195
 196         if (compressed_size && compressed_pages)
 197                 cur_size = compressed_size;
 198
 199         inode_add_bytes(inode, size);
 200
 201         if (!extent_inserted) {
 202                 struct btrfs_key key;
 203                 size_t datasize;
 204
 205                 key.objectid = btrfs_ino(BTRFS_I(inode));
 206                 key.offset = start;
 207                 key.type = BTRFS_EXTENT_DATA_KEY;
 208
 209                 datasize = btrfs_file_extent_calc_inline_size(cur_size);
 210                 path->leave_spinning = 1;
 211                 ret = btrfs_insert_empty_item(trans, root, path, &key,
 212                                               datasize);
 213                 if (ret)
 214                         goto fail;
 215         }
 216         leaf = path->nodes[0];
 217         ei = btrfs_item_ptr(leaf, path->slots[0],
 218                             struct btrfs_file_extent_item);
 219         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
 220         btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
 221         btrfs_set_file_extent_encryption(leaf, ei, 0);
 222         btrfs_set_file_extent_other_encoding(leaf, ei, 0);
 223         btrfs_set_file_extent_ram_bytes(leaf, ei, size);
 224         ptr = btrfs_file_extent_inline_start(ei);
 225
 226         if (compress_type != BTRFS_COMPRESS_NONE) {
 227                 struct page *cpage;
 228                 int i = 0;
 229                 while (compressed_size > 0) {
 230                         cpage = compressed_pages[i];
 231                         cur_size = min_t(unsigned long, compressed_size,
 232                                        PAGE_SIZE);
 233
 234                         kaddr = kmap_atomic(cpage);
 235                         write_extent_buffer(leaf, kaddr, ptr, cur_size);
 236                         kunmap_atomic(kaddr);
 237
 238                         i++;
 239                         ptr += cur_size;
 240                         compressed_size -= cur_size;
 241                 }
 242                 btrfs_set_file_extent_compression(leaf, ei,
 243                                                   compress_type);
 244         } else {
 245                 page = find_get_page(inode->i_mapping,
 246                                      start >> PAGE_SHIFT);
 247                 btrfs_set_file_extent_compression(leaf, ei, 0);
 248                 kaddr = kmap_atomic(page);
 249                 offset = start & (PAGE_SIZE - 1);
 250                 write_extent_buffer(leaf, kaddr + offset, ptr, size);
 251                 kunmap_atomic(kaddr);
 252                 put_page(page);
 253         }
 254         btrfs_mark_buffer_dirty(leaf);
 255         btrfs_release_path(path);
 256
 257         /*
 258          * we're an inline extent, so nobody can
 259          * extend the file past i_size without locking
 260          * a page we already have locked.
 261          *
 262          * We must do any isize and inode updates
 263          * before we unlock the pages.  Otherwise we
 264          * could end up racing with unlink.
 265          */
 266         BTRFS_I(inode)->disk_i_size = inode->i_size;
 267         ret = btrfs_update_inode(trans, root, inode);
 268
 269 fail:
 270         return ret;
 271 }
 272
 273
 274 /*
 275  * conditionally insert an inline extent into the file.  This
 276  * does the checks required to make sure the data is small enough
 277  * to fit as an inline extent.
 278  */
 279 static noinline int cow_file_range_inline(struct inode *inode, u64 start,
 280                                           u64 end, size_t compressed_size,
 281                                           int compress_type,
 282                                           struct page **compressed_pages)
 283 {
 284         struct btrfs_root *root = BTRFS_I(inode)->root;
 285         struct btrfs_fs_info *fs_info = root->fs_info;
 286         struct btrfs_trans_handle *trans;
 287         u64 isize = i_size_read(inode);
 288         u64 actual_end = min(end + 1, isize);
 289         u64 inline_len = actual_end - start;
 290         u64 aligned_end = ALIGN(end, fs_info->sectorsize);
 291         u64 data_len = inline_len;
 292         int ret;
 293         struct btrfs_path *path;
 294         int extent_inserted = 0;
 295         u32 extent_item_size;
 296
 297         if (compressed_size)
 298                 data_len = compressed_size;
 299
 300         if (start > 0 ||
 301             actual_end > fs_info->sectorsize ||
 302             data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
 303             (!compressed_size &&
 304             (actual_end & (fs_info->sectorsize - 1)) == 0) ||
 305             end + 1 < isize ||
 306             data_len > fs_info->max_inline) {
 307                 return 1;
 308         }
 309
 310         path = btrfs_alloc_path();
 311         if (!path)
 312                 return -ENOMEM;
 313
 314         trans = btrfs_join_transaction(root);
 315         if (IS_ERR(trans)) {
 316                 btrfs_free_path(path);
 317                 return PTR_ERR(trans);
 318         }
 319         trans->block_rsv = &BTRFS_I(inode)->block_rsv;
 320
 321         if (compressed_size && compressed_pages)
 322                 extent_item_size = btrfs_file_extent_calc_inline_size(
 323                    compressed_size);
 324         else
 325                 extent_item_size = btrfs_file_extent_calc_inline_size(
 326                     inline_len);
 327
 328         ret = __btrfs_drop_extents(trans, root, inode, path,
 329                                    start, aligned_end, NULL,
 330                                    1, 1, extent_item_size, &extent_inserted);
 331         if (ret) {
 332                 btrfs_abort_transaction(trans, ret);
 333                 goto out;
 334         }
 335
 336         if (isize > actual_end)
 337                 inline_len = min_t(u64, isize, actual_end);
 338         ret = insert_inline_extent(trans, path, extent_inserted,
 339                                    root, inode, start,
 340                                    inline_len, compressed_size,
 341                                    compress_type, compressed_pages);
 342         if (ret && ret != -ENOSPC) {
 343                 btrfs_abort_transaction(trans, ret);
 344                 goto out;
 345         } else if (ret == -ENOSPC) {
 346                 ret = 1;
 347                 goto out;
 348         }
 349
 350         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
 351         btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
 352 out:
 353         /*
 354          * Don't forget to free the reserved space, as for inlined extent
 355          * it won't count as data extent, free them directly here.
 356          * And at reserve time, it's always aligned to page size, so
 357          * just free one page here.
 358          */
 359         btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
 360         btrfs_free_path(path);
 361         btrfs_end_transaction(trans);
 362         return ret;
 363 }
 364
 365 struct async_extent {
 366         u64 start;
 367         u64 ram_size;
 368         u64 compressed_size;
 369         struct page **pages;
 370         unsigned long nr_pages;
 371         int compress_type;
 372         struct list_head list;
 373 };
 374
 375 struct async_cow {
 376         struct inode *inode;
 377         struct btrfs_root *root;
 378         struct page *locked_page;
 379         u64 start;
 380         u64 end;
 381         unsigned int write_flags;
 382         struct list_head extents;
 383         struct btrfs_work work;
 384 };
 385
 386 static noinline int add_async_extent(struct async_cow *cow,
 387                                      u64 start, u64 ram_size,
 388                                      u64 compressed_size,
 389                                      struct page **pages,
 390                                      unsigned long nr_pages,
 391                                      int compress_type)
 392 {
 393         struct async_extent *async_extent;
 394
 395         async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
 396         BUG_ON(!async_extent); /* -ENOMEM */
 397         async_extent->start = start;
 398         async_extent->ram_size = ram_size;
 399         async_extent->compressed_size = compressed_size;
 400         async_extent->pages = pages;
 401         async_extent->nr_pages = nr_pages;
 402         async_extent->compress_type = compress_type;
 403         list_add_tail(&async_extent->list, &cow->extents);
 404         return 0;
 405 }
 406
 407 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
 408 {
 409         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 410
 411         /* force compress */
 412         if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
 413                 return 1;
 414         /* defrag ioctl */
 415         if (BTRFS_I(inode)->defrag_compress)
 416                 return 1;
 417         /* bad compression ratios */
 418         if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
 419                 return 0;
 420         if (btrfs_test_opt(fs_info, COMPRESS) ||
 421             BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
 422             BTRFS_I(inode)->prop_compress)
 423                 return btrfs_compress_heuristic(inode, start, end);
 424         return 0;
 425 }
 426
 427 static inline void inode_should_defrag(struct btrfs_inode *inode,
 428                 u64 start, u64 end, u64 num_bytes, u64 small_write)
 429 {
 430         /* If this is a small write inside eof, kick off a defrag */
 431         if (num_bytes < small_write &&
 432             (start > 0 || end + 1 < inode->disk_i_size))
 433                 btrfs_add_inode_defrag(NULL, inode);
 434 }
 435
 436 /*
 437  * we create compressed extents in two phases.  The first
 438  * phase compresses a range of pages that have already been
 439  * locked (both pages and state bits are locked).
 440  *
 441  * This is done inside an ordered work queue, and the compression
 442  * is spread across many cpus.  The actual IO submission is step
 443  * two, and the ordered work queue takes care of making sure that
 444  * happens in the same order things were put onto the queue by
 445  * writepages and friends.
 446  *
 447  * If this code finds it can't get good compression, it puts an
 448  * entry onto the work queue to write the uncompressed bytes.  This
 449  * makes sure that both compressed inodes and uncompressed inodes
 450  * are written in the same order that the flusher thread sent them
 451  * down.
 452  */
 453 static noinline void compress_file_range(struct inode *inode,
 454                                         struct page *locked_page,
 455                                         u64 start, u64 end,
 456                                         struct async_cow *async_cow,
 457                                         int *num_added)
 458 {
 459         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 460         u64 blocksize = fs_info->sectorsize;
 461         u64 actual_end;
 462         u64 isize = i_size_read(inode);
 463         int ret = 0;
 464         struct page **pages = NULL;
 465         unsigned long nr_pages;
 466         unsigned long total_compressed = 0;
 467         unsigned long total_in = 0;
 468         int i;
 469         int will_compress;
 470         int compress_type = fs_info->compress_type;
 471         int redirty = 0;
 472
 473         inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
 474                         SZ_16K);
 475
 476         actual_end = min_t(u64, isize, end + 1);
 477 again:
 478         will_compress = 0;
 479         nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
 480         BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
 481         nr_pages = min_t(unsigned long, nr_pages,
 482                         BTRFS_MAX_COMPRESSED / PAGE_SIZE);
 483
 484         /*
 485          * we don't want to send crud past the end of i_size through
 486          * compression, that's just a waste of CPU time.  So, if the
 487          * end of the file is before the start of our current
 488          * requested range of bytes, we bail out to the uncompressed
 489          * cleanup code that can deal with all of this.
 490          *
 491          * It isn't really the fastest way to fix things, but this is a
 492          * very uncommon corner.
 493          */
 494         if (actual_end <= start)
 495                 goto cleanup_and_bail_uncompressed;
 496
 497         total_compressed = actual_end - start;
 498
 499         /*
 500          * skip compression for a small file range(<=blocksize) that
 501          * isn't an inline extent, since it doesn't save disk space at all.
 502          */
 503         if (total_compressed <= blocksize &&
 504            (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
 505                 goto cleanup_and_bail_uncompressed;
 506
 507         total_compressed = min_t(unsigned long, total_compressed,
 508                         BTRFS_MAX_UNCOMPRESSED);
 509         total_in = 0;
 510         ret = 0;
 511
 512         /*
 513          * we do compression for mount -o compress and when the
 514          * inode has not been flagged as nocompress.  This flag can
 515          * change at any time if we discover bad compression ratios.
 516          */
 517         if (inode_need_compress(inode, start, end)) {
 518                 WARN_ON(pages);
 519                 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
 520                 if (!pages) {
 521                         /* just bail out to the uncompressed code */
 522                         goto cont;
 523                 }
 524
 525                 if (BTRFS_I(inode)->defrag_compress)
 526                         compress_type = BTRFS_I(inode)->defrag_compress;
 527                 else if (BTRFS_I(inode)->prop_compress)
 528                         compress_type = BTRFS_I(inode)->prop_compress;
 529
 530                 /*
 531                  * we need to call clear_page_dirty_for_io on each
 532                  * page in the range.  Otherwise applications with the file
 533                  * mmap'd can wander in and change the page contents while
 534                  * we are compressing them.
 535                  *
 536                  * If the compression fails for any reason, we set the pages
 537                  * dirty again later on.
 538                  *
 539                  * Note that the remaining part is redirtied, the start pointer
 540                  * has moved, the end is the original one.
 541                  */
 542                 if (!redirty) {
 543                         extent_range_clear_dirty_for_io(inode, start, end);
 544                         redirty = 1;
 545                 }
 546
 547                 /* Compression level is applied here and only here */
 548                 ret = btrfs_compress_pages(
 549                         compress_type | (fs_info->compress_level << 4),
 550                                            inode->i_mapping, start,
 551                                            pages,
 552                                            &nr_pages,
 553                                            &total_in,
 554                                            &total_compressed);
 555
 556                 if (!ret) {
 557                         unsigned long offset = total_compressed &
 558                                 (PAGE_SIZE - 1);
 559                         struct page *page = pages[nr_pages - 1];
 560                         char *kaddr;
 561
 562                         /* zero the tail end of the last page, we might be
 563                          * sending it down to disk
 564                          */
 565                         if (offset) {
 566                                 kaddr = kmap_atomic(page);
 567                                 memset(kaddr + offset, 0,
 568                                        PAGE_SIZE - offset);
 569                                 kunmap_atomic(kaddr);
 570                         }
 571                         will_compress = 1;
 572                 }
 573         }
 574 cont:
 575         if (start == 0) {
 576                 /* lets try to make an inline extent */
 577                 if (ret || total_in < actual_end) {
 578                         /* we didn't compress the entire range, try
 579                          * to make an uncompressed inline extent.
 580                          */
 581                         ret = cow_file_range_inline(inode, start, end, 0,
 582                                                     BTRFS_COMPRESS_NONE, NULL);
 583                 } else {
 584                         /* try making a compressed inline extent */
 585                         ret = cow_file_range_inline(inode, start, end,
 586                                                     total_compressed,
 587                                                     compress_type, pages);
 588                 }
 589                 if (ret <= 0) {
 590                         unsigned long clear_flags = EXTENT_DELALLOC |
 591                                 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
 592                                 EXTENT_DO_ACCOUNTING;
 593                         unsigned long page_error_op;
 594
 595                         page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
 596
 597                         /*
 598                          * inline extent creation worked or returned error,
 599                          * we don't need to create any more async work items.
 600                          * Unlock and free up our temp pages.
 601                          *
 602                          * We use DO_ACCOUNTING here because we need the
 603                          * delalloc_release_metadata to be done _after_ we drop
 604                          * our outstanding extent for clearing delalloc for this
 605                          * range.
 606                          */
 607                         extent_clear_unlock_delalloc(inode, start, end, end,
 608                                                      NULL, clear_flags,
 609                                                      PAGE_UNLOCK |
 610                                                      PAGE_CLEAR_DIRTY |
 611                                                      PAGE_SET_WRITEBACK |
 612                                                      page_error_op |
 613                                                      PAGE_END_WRITEBACK);
 614                         goto free_pages_out;
 615                 }
 616         }
 617
 618         if (will_compress) {
 619                 /*
 620                  * we aren't doing an inline extent round the compressed size
 621                  * up to a block size boundary so the allocator does sane
 622                  * things
 623                  */
 624                 total_compressed = ALIGN(total_compressed, blocksize);
 625
 626                 /*
 627                  * one last check to make sure the compression is really a
 628                  * win, compare the page count read with the blocks on disk,
 629                  * compression must free at least one sector size
 630                  */
 631                 total_in = ALIGN(total_in, PAGE_SIZE);
 632                 if (total_compressed + blocksize <= total_in) {
 633                         *num_added += 1;
 634
 635                         /*
 636                          * The async work queues will take care of doing actual
 637                          * allocation on disk for these compressed pages, and
 638                          * will submit them to the elevator.
 639                          */
 640                         add_async_extent(async_cow, start, total_in,
 641                                         total_compressed, pages, nr_pages,
 642                                         compress_type);
 643
 644                         if (start + total_in < end) {
 645                                 start += total_in;
 646                                 pages = NULL;
 647                                 cond_resched();
 648                                 goto again;
 649                         }
 650                         return;
 651                 }
 652         }
 653         if (pages) {
 654                 /*
 655                  * the compression code ran but failed to make things smaller,
 656                  * free any pages it allocated and our page pointer array
 657                  */
 658                 for (i = 0; i < nr_pages; i++) {
 659                         WARN_ON(pages[i]->mapping);
 660                         put_page(pages[i]);
 661                 }
 662                 kfree(pages);
 663                 pages = NULL;
 664                 total_compressed = 0;
 665                 nr_pages = 0;
 666
 667                 /* flag the file so we don't compress in the future */
 668                 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
 669                     !(BTRFS_I(inode)->prop_compress)) {
 670                         BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 671                 }
 672         }
 673 cleanup_and_bail_uncompressed:
 674         /*
 675          * No compression, but we still need to write the pages in the file
 676          * we've been given so far.  redirty the locked page if it corresponds
 677          * to our extent and set things up for the async work queue to run
 678          * cow_file_range to do the normal delalloc dance.
 679          */
 680         if (page_offset(locked_page) >= start &&
 681             page_offset(locked_page) <= end)
 682                 __set_page_dirty_nobuffers(locked_page);
 683                 /* unlocked later on in the async handlers */
 684
 685         if (redirty)
 686                 extent_range_redirty_for_io(inode, start, end);
 687         add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
 688                          BTRFS_COMPRESS_NONE);
 689         *num_added += 1;
 690
 691         return;
 692
 693 free_pages_out:
 694         for (i = 0; i < nr_pages; i++) {
 695                 WARN_ON(pages[i]->mapping);
 696                 put_page(pages[i]);
 697         }
 698         kfree(pages);
 699 }
 700
 701 static void free_async_extent_pages(struct async_extent *async_extent)
 702 {
 703         int i;
 704
 705         if (!async_extent->pages)
 706                 return;
 707
 708         for (i = 0; i < async_extent->nr_pages; i++) {
 709                 WARN_ON(async_extent->pages[i]->mapping);
 710                 put_page(async_extent->pages[i]);
 711         }
 712         kfree(async_extent->pages);
 713         async_extent->nr_pages = 0;
 714         async_extent->pages = NULL;
 715 }
 716
 717 /*
 718  * phase two of compressed writeback.  This is the ordered portion
 719  * of the code, which only gets called in the order the work was
 720  * queued.  We walk all the async extents created by compress_file_range
 721  * and send them down to the disk.
 722  */
 723 static noinline void submit_compressed_extents(struct inode *inode,
 724                                               struct async_cow *async_cow)
 725 {
 726         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 727         struct async_extent *async_extent;
 728         u64 alloc_hint = 0;
 729         struct btrfs_key ins;
 730         struct extent_map *em;
 731         struct btrfs_root *root = BTRFS_I(inode)->root;
 732         struct extent_io_tree *io_tree;
 733         int ret = 0;
 734
 735 again:
 736         while (!list_empty(&async_cow->extents)) {
 737                 async_extent = list_entry(async_cow->extents.next,
 738                                           struct async_extent, list);
 739                 list_del(&async_extent->list);
 740
 741                 io_tree = &BTRFS_I(inode)->io_tree;
 742
 743 retry:
 744                 /* did the compression code fall back to uncompressed IO? */
 745                 if (!async_extent->pages) {
 746                         int page_started = 0;
 747                         unsigned long nr_written = 0;
 748
 749                         lock_extent(io_tree, async_extent->start,
 750                                          async_extent->start +
 751                                          async_extent->ram_size - 1);
 752
 753                         /* allocate blocks */
 754                         ret = cow_file_range(inode, async_cow->locked_page,
 755                                              async_extent->start,
 756                                              async_extent->start +
 757                                              async_extent->ram_size - 1,
 758                                              async_extent->start +
 759                                              async_extent->ram_size - 1,
 760                                              &page_started, &nr_written, 0,
 761                                              NULL);
 762
 763                         /* JDM XXX */
 764
 765                         /*
 766                          * if page_started, cow_file_range inserted an
 767                          * inline extent and took care of all the unlocking
 768                          * and IO for us.  Otherwise, we need to submit
 769                          * all those pages down to the drive.
 770                          */
 771                         if (!page_started && !ret)
 772                                 extent_write_locked_range(inode,
 773                                                   async_extent->start,
 774                                                   async_extent->start +
 775                                                   async_extent->ram_size - 1,
 776                                                   WB_SYNC_ALL);
 777                         else if (ret)
 778                                 unlock_page(async_cow->locked_page);
 779                         kfree(async_extent);
 780                         cond_resched();
 781                         continue;
 782                 }
 783
 784                 lock_extent(io_tree, async_extent->start,
 785                             async_extent->start + async_extent->ram_size - 1);
 786
 787                 ret = btrfs_reserve_extent(root, async_extent->ram_size,
 788                                            async_extent->compressed_size,
 789                                            async_extent->compressed_size,
 790                                            0, alloc_hint, &ins, 1, 1);
 791                 if (ret) {
 792                         free_async_extent_pages(async_extent);
 793
 794                         if (ret == -ENOSPC) {
 795                                 unlock_extent(io_tree, async_extent->start,
 796                                               async_extent->start +
 797                                               async_extent->ram_size - 1);
 798
 799                                 /*
 800                                  * we need to redirty the pages if we decide to
 801                                  * fallback to uncompressed IO, otherwise we
 802                                  * will not submit these pages down to lower
 803                                  * layers.
 804                                  */
 805                                 extent_range_redirty_for_io(inode,
 806                                                 async_extent->start,
 807                                                 async_extent->start +
 808                                                 async_extent->ram_size - 1);
 809
 810                                 goto retry;
 811                         }
 812                         goto out_free;
 813                 }
 814                 /*
 815                  * here we're doing allocation and writeback of the
 816                  * compressed pages
 817                  */
 818                 em = create_io_em(inode, async_extent->start,
 819                                   async_extent->ram_size, /* len */
 820                                   async_extent->start, /* orig_start */
 821                                   ins.objectid, /* block_start */
 822                                   ins.offset, /* block_len */
 823                                   ins.offset, /* orig_block_len */
 824                                   async_extent->ram_size, /* ram_bytes */
 825                                   async_extent->compress_type,
 826                                   BTRFS_ORDERED_COMPRESSED);
 827                 if (IS_ERR(em))
 828                         /* ret value is not necessary due to void function */
 829                         goto out_free_reserve;
 830                 free_extent_map(em);
 831
 832                 ret = btrfs_add_ordered_extent_compress(inode,
 833                                                 async_extent->start,
 834                                                 ins.objectid,
 835                                                 async_extent->ram_size,
 836                                                 ins.offset,
 837                                                 BTRFS_ORDERED_COMPRESSED,
 838                                                 async_extent->compress_type);
 839                 if (ret) {
 840                         btrfs_drop_extent_cache(BTRFS_I(inode),
 841                                                 async_extent->start,
 842                                                 async_extent->start +
 843                                                 async_extent->ram_size - 1, 0);
 844                         goto out_free_reserve;
 845                 }
 846                 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
 847
 848                 /*
 849                  * clear dirty, set writeback and unlock the pages.
 850                  */
 851                 extent_clear_unlock_delalloc(inode, async_extent->start,
 852                                 async_extent->start +
 853                                 async_extent->ram_size - 1,
 854                                 async_extent->start +
 855                                 async_extent->ram_size - 1,
 856                                 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
 857                                 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
 858                                 PAGE_SET_WRITEBACK);
 859                 if (btrfs_submit_compressed_write(inode,
 860                                     async_extent->start,
 861                                     async_extent->ram_size,
 862                                     ins.objectid,
 863                                     ins.offset, async_extent->pages,
 864                                     async_extent->nr_pages,
 865                                     async_cow->write_flags)) {
 866                         struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 867                         struct page *p = async_extent->pages[0];
 868                         const u64 start = async_extent->start;
 869                         const u64 end = start + async_extent->ram_size - 1;
 870
 871                         p->mapping = inode->i_mapping;
 872                         tree->ops->writepage_end_io_hook(p, start, end,
 873                                                          NULL, 0);
 874                         p->mapping = NULL;
 875                         extent_clear_unlock_delalloc(inode, start, end, end,
 876                                                      NULL, 0,
 877                                                      PAGE_END_WRITEBACK |
 878                                                      PAGE_SET_ERROR);
 879                         free_async_extent_pages(async_extent);
 880                 }
 881                 alloc_hint = ins.objectid + ins.offset;
 882                 kfree(async_extent);
 883                 cond_resched();
 884         }
 885         return;
 886 out_free_reserve:
 887         btrfs_dec_block_group_reservations(fs_info, ins.objectid);
 888         btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
 889 out_free:
 890         extent_clear_unlock_delalloc(inode, async_extent->start,
 891                                      async_extent->start +
 892                                      async_extent->ram_size - 1,
 893                                      async_extent->start +
 894                                      async_extent->ram_size - 1,
 895                                      NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
 896                                      EXTENT_DELALLOC_NEW |
 897                                      EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
 898                                      PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
 899                                      PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
 900                                      PAGE_SET_ERROR);
 901         free_async_extent_pages(async_extent);
 902         kfree(async_extent);
 903         goto again;
 904 }
 905
 906 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
 907                                       u64 num_bytes)
 908 {
 909         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 910         struct extent_map *em;
 911         u64 alloc_hint = 0;
 912
 913         read_lock(&em_tree->lock);
 914         em = search_extent_mapping(em_tree, start, num_bytes);
 915         if (em) {
 916                 /*
 917                  * if block start isn't an actual block number then find the
 918                  * first block in this inode and use that as a hint.  If that
 919                  * block is also bogus then just don't worry about it.
 920                  */
 921                 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 922                         free_extent_map(em);
 923                         em = search_extent_mapping(em_tree, 0, 0);
 924                         if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
 925                                 alloc_hint = em->block_start;
 926                         if (em)
 927                                 free_extent_map(em);
 928                 } else {
 929                         alloc_hint = em->block_start;
 930                         free_extent_map(em);
 931                 }
 932         }
 933         read_unlock(&em_tree->lock);
 934
 935         return alloc_hint;
 936 }
 937
 938 /*
 939  * when extent_io.c finds a delayed allocation range in the file,
 940  * the call backs end up in this code.  The basic idea is to
 941  * allocate extents on disk for the range, and create ordered data structs
 942  * in ram to track those extents.
 943  *
 944  * locked_page is the page that writepage had locked already.  We use
 945  * it to make sure we don't do extra locks or unlocks.
 946  *
 947  * *page_started is set to one if we unlock locked_page and do everything
 948  * required to start IO on it.  It may be clean and already done with
 949  * IO when we return.
 950  */
 951 static noinline int cow_file_range(struct inode *inode,
 952                                    struct page *locked_page,
 953                                    u64 start, u64 end, u64 delalloc_end,
 954                                    int *page_started, unsigned long *nr_written,
 955                                    int unlock, struct btrfs_dedupe_hash *hash)
 956 {
 957         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 958         struct btrfs_root *root = BTRFS_I(inode)->root;
 959         u64 alloc_hint = 0;
 960         u64 num_bytes;
 961         unsigned long ram_size;
 962         u64 cur_alloc_size = 0;
 963         u64 blocksize = fs_info->sectorsize;
 964         struct btrfs_key ins;
 965         struct extent_map *em;
 966         unsigned clear_bits;
 967         unsigned long page_ops;
 968         bool extent_reserved = false;
 969         int ret = 0;
 970
 971         if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
 972                 WARN_ON_ONCE(1);
 973                 ret = -EINVAL;
 974                 goto out_unlock;
 975         }
 976
 977         num_bytes = ALIGN(end - start + 1, blocksize);
 978         num_bytes = max(blocksize,  num_bytes);
 979         ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
 980
 981         inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
 982
 983         if (start == 0) {
 984                 /* lets try to make an inline extent */
 985                 ret = cow_file_range_inline(inode, start, end, 0,
 986                                             BTRFS_COMPRESS_NONE, NULL);
 987                 if (ret == 0) {
 988                         /*
 989                          * We use DO_ACCOUNTING here because we need the
 990                          * delalloc_release_metadata to be run _after_ we drop
 991                          * our outstanding extent for clearing delalloc for this
 992                          * range.
 993                          */
 994                         extent_clear_unlock_delalloc(inode, start, end,
 995                                      delalloc_end, NULL,
 996                                      EXTENT_LOCKED | EXTENT_DELALLOC |
 997                                      EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
 998                                      EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
 999                                      PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1000                                      PAGE_END_WRITEBACK);
1001                         *nr_written = *nr_written +
1002                              (end - start + PAGE_SIZE) / PAGE_SIZE;
1003                         *page_started = 1;
1004                         goto out;
1005                 } else if (ret < 0) {
1006                         goto out_unlock;
1007                 }
1008         }
1009
1010         alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
1011         btrfs_drop_extent_cache(BTRFS_I(inode), start,
1012                         start + num_bytes - 1, 0);
1013
1014         while (num_bytes > 0) {
1015                 cur_alloc_size = num_bytes;
1016                 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1017                                            fs_info->sectorsize, 0, alloc_hint,
1018                                            &ins, 1, 1);
1019                 if (ret < 0)
1020                         goto out_unlock;
1021                 cur_alloc_size = ins.offset;
1022                 extent_reserved = true;
1023
1024                 ram_size = ins.offset;
1025                 em = create_io_em(inode, start, ins.offset, /* len */
1026                                   start, /* orig_start */
1027                                   ins.objectid, /* block_start */
1028                                   ins.offset, /* block_len */
1029                                   ins.offset, /* orig_block_len */
1030                                   ram_size, /* ram_bytes */
1031                                   BTRFS_COMPRESS_NONE, /* compress_type */
1032                                   BTRFS_ORDERED_REGULAR /* type */);
1033                 if (IS_ERR(em))
1034                         goto out_reserve;
1035                 free_extent_map(em);
1036
1037                 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1038                                                ram_size, cur_alloc_size, 0);
1039                 if (ret)
1040                         goto out_drop_extent_cache;
1041
1042                 if (root->root_key.objectid ==
1043                     BTRFS_DATA_RELOC_TREE_OBJECTID) {
1044                         ret = btrfs_reloc_clone_csums(inode, start,
1045                                                       cur_alloc_size);
1046                         /*
1047                          * Only drop cache here, and process as normal.
1048                          *
1049                          * We must not allow extent_clear_unlock_delalloc()
1050                          * at out_unlock label to free meta of this ordered
1051                          * extent, as its meta should be freed by
1052                          * btrfs_finish_ordered_io().
1053                          *
1054                          * So we must continue until @start is increased to
1055                          * skip current ordered extent.
1056                          */
1057                         if (ret)
1058                                 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1059                                                 start + ram_size - 1, 0);
1060                 }
1061
1062                 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1063
1064                 /* we're not doing compressed IO, don't unlock the first
1065                  * page (which the caller expects to stay locked), don't
1066                  * clear any dirty bits and don't set any writeback bits
1067                  *
1068                  * Do set the Private2 bit so we know this page was properly
1069                  * setup for writepage
1070                  */
1071                 page_ops = unlock ? PAGE_UNLOCK : 0;
1072                 page_ops |= PAGE_SET_PRIVATE2;
1073
1074                 extent_clear_unlock_delalloc(inode, start,
1075                                              start + ram_size - 1,
1076                                              delalloc_end, locked_page,
1077                                              EXTENT_LOCKED | EXTENT_DELALLOC,
1078                                              page_ops);
1079                 if (num_bytes < cur_alloc_size)
1080                         num_bytes = 0;
1081                 else
1082                         num_bytes -= cur_alloc_size;
1083                 alloc_hint = ins.objectid + ins.offset;
1084                 start += cur_alloc_size;
1085                 extent_reserved = false;
1086
1087                 /*
1088                  * btrfs_reloc_clone_csums() error, since start is increased
1089                  * extent_clear_unlock_delalloc() at out_unlock label won't
1090                  * free metadata of current ordered extent, we're OK to exit.
1091                  */
1092                 if (ret)
1093                         goto out_unlock;
1094         }
1095 out:
1096         return ret;
1097
1098 out_drop_extent_cache:
1099         btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1100 out_reserve:
1101         btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1102         btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1103 out_unlock:
1104         clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1105                 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1106         page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1107                 PAGE_END_WRITEBACK;
1108         /*
1109          * If we reserved an extent for our delalloc range (or a subrange) and
1110          * failed to create the respective ordered extent, then it means that
1111          * when we reserved the extent we decremented the extent's size from
1112          * the data space_info's bytes_may_use counter and incremented the
1113          * space_info's bytes_reserved counter by the same amount. We must make
1114          * sure extent_clear_unlock_delalloc() does not try to decrement again
1115          * the data space_info's bytes_may_use counter, therefore we do not pass
1116          * it the flag EXTENT_CLEAR_DATA_RESV.
1117          */
1118         if (extent_reserved) {
1119                 extent_clear_unlock_delalloc(inode, start,
1120                                              start + cur_alloc_size,
1121                                              start + cur_alloc_size,
1122                                              locked_page,
1123                                              clear_bits,
1124                                              page_ops);
1125                 start += cur_alloc_size;
1126                 if (start >= end)
1127                         goto out;
1128         }
1129         extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1130                                      locked_page,
1131                                      clear_bits | EXTENT_CLEAR_DATA_RESV,
1132                                      page_ops);
1133         goto out;
1134 }
1135
1136 /*
1137  * work queue call back to started compression on a file and pages
1138  */
1139 static noinline void async_cow_start(struct btrfs_work *work)
1140 {
1141         struct async_cow *async_cow;
1142         int num_added = 0;
1143         async_cow = container_of(work, struct async_cow, work);
1144
1145         compress_file_range(async_cow->inode, async_cow->locked_page,
1146                             async_cow->start, async_cow->end, async_cow,
1147                             &num_added);
1148         if (num_added == 0) {
1149                 btrfs_add_delayed_iput(async_cow->inode);
1150                 async_cow->inode = NULL;
1151         }
1152 }
1153
1154 /*
1155  * work queue call back to submit previously compressed pages
1156  */
1157 static noinline void async_cow_submit(struct btrfs_work *work)
1158 {
1159         struct btrfs_fs_info *fs_info;
1160         struct async_cow *async_cow;
1161         struct btrfs_root *root;
1162         unsigned long nr_pages;
1163
1164         async_cow = container_of(work, struct async_cow, work);
1165
1166         root = async_cow->root;
1167         fs_info = root->fs_info;
1168         nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1169                 PAGE_SHIFT;
1170
1171         /*
1172          * atomic_sub_return implies a barrier for waitqueue_active
1173          */
1174         if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1175             5 * SZ_1M &&
1176             waitqueue_active(&fs_info->async_submit_wait))
1177                 wake_up(&fs_info->async_submit_wait);
1178
1179         if (async_cow->inode)
1180                 submit_compressed_extents(async_cow->inode, async_cow);
1181 }
1182
1183 static noinline void async_cow_free(struct btrfs_work *work)
1184 {
1185         struct async_cow *async_cow;
1186         async_cow = container_of(work, struct async_cow, work);
1187         if (async_cow->inode)
1188                 btrfs_add_delayed_iput(async_cow->inode);
1189         kfree(async_cow);
1190 }
1191
1192 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1193                                 u64 start, u64 end, int *page_started,
1194                                 unsigned long *nr_written,
1195                                 unsigned int write_flags)
1196 {
1197         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1198         struct async_cow *async_cow;
1199         struct btrfs_root *root = BTRFS_I(inode)->root;
1200         unsigned long nr_pages;
1201         u64 cur_end;
1202
1203         clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1204                          1, 0, NULL);
1205         while (start < end) {
1206                 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1207                 BUG_ON(!async_cow); /* -ENOMEM */
1208                 async_cow->inode = igrab(inode);
1209                 async_cow->root = root;
1210                 async_cow->locked_page = locked_page;
1211                 async_cow->start = start;
1212                 async_cow->write_flags = write_flags;
1213
1214                 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1215                     !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1216                         cur_end = end;
1217                 else
1218                         cur_end = min(end, start + SZ_512K - 1);
1219
1220                 async_cow->end = cur_end;
1221                 INIT_LIST_HEAD(&async_cow->extents);
1222
1223                 btrfs_init_work(&async_cow->work,
1224                                 btrfs_delalloc_helper,
1225                                 async_cow_start, async_cow_submit,
1226                                 async_cow_free);
1227
1228                 nr_pages = (cur_end - start + PAGE_SIZE) >>
1229                         PAGE_SHIFT;
1230                 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1231
1232                 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1233
1234                 *nr_written += nr_pages;
1235                 start = cur_end + 1;
1236         }
1237         *page_started = 1;
1238         return 0;
1239 }
1240
1241 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1242                                         u64 bytenr, u64 num_bytes)
1243 {
1244         int ret;
1245         struct btrfs_ordered_sum *sums;
1246         LIST_HEAD(list);
1247
1248         ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1249                                        bytenr + num_bytes - 1, &list, 0);
1250         if (ret == 0 && list_empty(&list))
1251                 return 0;
1252
1253         while (!list_empty(&list)) {
1254                 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1255                 list_del(&sums->list);
1256                 kfree(sums);
1257         }
1258         if (ret < 0)
1259                 return ret;
1260         return 1;
1261 }
1262
1263 /*
1264  * when nowcow writeback call back.  This checks for snapshots or COW copies
1265  * of the extents that exist in the file, and COWs the file as required.
1266  *
1267  * If no cow copies or snapshots exist, we write directly to the existing
1268  * blocks on disk
1269  */
1270 static noinline int run_delalloc_nocow(struct inode *inode,
1271                                        struct page *locked_page,
1272                               u64 start, u64 end, int *page_started, int force,
1273                               unsigned long *nr_written)
1274 {
1275         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1276         struct btrfs_root *root = BTRFS_I(inode)->root;
1277         struct extent_buffer *leaf;
1278         struct btrfs_path *path;
1279         struct btrfs_file_extent_item *fi;
1280         struct btrfs_key found_key;
1281         struct extent_map *em;
1282         u64 cow_start;
1283         u64 cur_offset;
1284         u64 extent_end;
1285         u64 extent_offset;
1286         u64 disk_bytenr;
1287         u64 num_bytes;
1288         u64 disk_num_bytes;
1289         u64 ram_bytes;
1290         int extent_type;
1291         int ret, err;
1292         int type;
1293         int nocow;
1294         int check_prev = 1;
1295         bool nolock;
1296         u64 ino = btrfs_ino(BTRFS_I(inode));
1297
1298         path = btrfs_alloc_path();
1299         if (!path) {
1300                 extent_clear_unlock_delalloc(inode, start, end, end,
1301                                              locked_page,
1302                                              EXTENT_LOCKED | EXTENT_DELALLOC |
1303                                              EXTENT_DO_ACCOUNTING |
1304                                              EXTENT_DEFRAG, PAGE_UNLOCK |
1305                                              PAGE_CLEAR_DIRTY |
1306                                              PAGE_SET_WRITEBACK |
1307                                              PAGE_END_WRITEBACK);
1308                 return -ENOMEM;
1309         }
1310
1311         nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1312
1313         cow_start = (u64)-1;
1314         cur_offset = start;
1315         while (1) {
1316                 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1317                                                cur_offset, 0);
1318                 if (ret < 0)
1319                         goto error;
1320                 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1321                         leaf = path->nodes[0];
1322                         btrfs_item_key_to_cpu(leaf, &found_key,
1323                                               path->slots[0] - 1);
1324                         if (found_key.objectid == ino &&
1325                             found_key.type == BTRFS_EXTENT_DATA_KEY)
1326                                 path->slots[0]--;
1327                 }
1328                 check_prev = 0;
1329 next_slot:
1330                 leaf = path->nodes[0];
1331                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1332                         ret = btrfs_next_leaf(root, path);
1333                         if (ret < 0) {
1334                                 if (cow_start != (u64)-1)
1335                                         cur_offset = cow_start;
1336                                 goto error;
1337                         }
1338                         if (ret > 0)
1339                                 break;
1340                         leaf = path->nodes[0];
1341                 }
1342
1343                 nocow = 0;
1344                 disk_bytenr = 0;
1345                 num_bytes = 0;
1346                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1347
1348                 if (found_key.objectid > ino)
1349                         break;
1350                 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1351                     found_key.type < BTRFS_EXTENT_DATA_KEY) {
1352                         path->slots[0]++;
1353                         goto next_slot;
1354                 }
1355                 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1356                     found_key.offset > end)
1357                         break;
1358
1359                 if (found_key.offset > cur_offset) {
1360                         extent_end = found_key.offset;
1361                         extent_type = 0;
1362                         goto out_check;
1363                 }
1364
1365                 fi = btrfs_item_ptr(leaf, path->slots[0],
1366                                     struct btrfs_file_extent_item);
1367                 extent_type = btrfs_file_extent_type(leaf, fi);
1368
1369                 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1370                 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1371                     extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1372                         disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1373                         extent_offset = btrfs_file_extent_offset(leaf, fi);
1374                         extent_end = found_key.offset +
1375                                 btrfs_file_extent_num_bytes(leaf, fi);
1376                         disk_num_bytes =
1377                                 btrfs_file_extent_disk_num_bytes(leaf, fi);
1378                         if (extent_end <= start) {
1379                                 path->slots[0]++;
1380                                 goto next_slot;
1381                         }
1382                         if (disk_bytenr == 0)
1383                                 goto out_check;
1384                         if (btrfs_file_extent_compression(leaf, fi) ||
1385                             btrfs_file_extent_encryption(leaf, fi) ||
1386                             btrfs_file_extent_other_encoding(leaf, fi))
1387                                 goto out_check;
1388                         if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1389                                 goto out_check;
1390                         if (btrfs_extent_readonly(fs_info, disk_bytenr))
1391                                 goto out_check;
1392                         ret = btrfs_cross_ref_exist(root, ino,
1393                                                     found_key.offset -
1394                                                     extent_offset, disk_bytenr);
1395                         if (ret) {
1396                                 /*
1397                                  * ret could be -EIO if the above fails to read
1398                                  * metadata.
1399                                  */
1400                                 if (ret < 0) {
1401                                         if (cow_start != (u64)-1)
1402                                                 cur_offset = cow_start;
1403                                         goto error;
1404                                 }
1405
1406                                 WARN_ON_ONCE(nolock);
1407                                 goto out_check;
1408                         }
1409                         disk_bytenr += extent_offset;
1410                         disk_bytenr += cur_offset - found_key.offset;
1411                         num_bytes = min(end + 1, extent_end) - cur_offset;
1412                         /*
1413                          * if there are pending snapshots for this root,
1414                          * we fall into common COW way.
1415                          */
1416                         if (!nolock) {
1417                                 err = btrfs_start_write_no_snapshotting(root);
1418                                 if (!err)
1419                                         goto out_check;
1420                         }
1421                         /*
1422                          * force cow if csum exists in the range.
1423                          * this ensure that csum for a given extent are
1424                          * either valid or do not exist.
1425                          */
1426                         ret = csum_exist_in_range(fs_info, disk_bytenr,
1427                                                   num_bytes);
1428                         if (ret) {
1429                                 if (!nolock)
1430                                         btrfs_end_write_no_snapshotting(root);
1431
1432                                 /*
1433                                  * ret could be -EIO if the above fails to read
1434                                  * metadata.
1435                                  */
1436                                 if (ret < 0) {
1437                                         if (cow_start != (u64)-1)
1438                                                 cur_offset = cow_start;
1439                                         goto error;
1440                                 }
1441                                 WARN_ON_ONCE(nolock);
1442                                 goto out_check;
1443                         }
1444                         if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1445                                 if (!nolock)
1446                                         btrfs_end_write_no_snapshotting(root);
1447                                 goto out_check;
1448                         }
1449                         nocow = 1;
1450                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1451                         extent_end = found_key.offset +
1452                                 btrfs_file_extent_inline_len(leaf,
1453                                                      path->slots[0], fi);
1454                         extent_end = ALIGN(extent_end,
1455                                            fs_info->sectorsize);
1456                 } else {
1457                         BUG_ON(1);
1458                 }
1459 out_check:
1460                 if (extent_end <= start) {
1461                         path->slots[0]++;
1462                         if (!nolock && nocow)
1463                                 btrfs_end_write_no_snapshotting(root);
1464                         if (nocow)
1465                                 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1466                         goto next_slot;
1467                 }
1468                 if (!nocow) {
1469                         if (cow_start == (u64)-1)
1470                                 cow_start = cur_offset;
1471                         cur_offset = extent_end;
1472                         if (cur_offset > end)
1473                                 break;
1474                         path->slots[0]++;
1475                         goto next_slot;
1476                 }
1477
1478                 btrfs_release_path(path);
1479                 if (cow_start != (u64)-1) {
1480                         ret = cow_file_range(inode, locked_page,
1481                                              cow_start, found_key.offset - 1,
1482                                              end, page_started, nr_written, 1,
1483                                              NULL);
1484                         if (ret) {
1485                                 if (!nolock && nocow)
1486                                         btrfs_end_write_no_snapshotting(root);
1487                                 if (nocow)
1488                                         btrfs_dec_nocow_writers(fs_info,
1489                                                                 disk_bytenr);
1490                                 goto error;
1491                         }
1492                         cow_start = (u64)-1;
1493                 }
1494
1495                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1496                         u64 orig_start = found_key.offset - extent_offset;
1497
1498                         em = create_io_em(inode, cur_offset, num_bytes,
1499                                           orig_start,
1500                                           disk_bytenr, /* block_start */
1501                                           num_bytes, /* block_len */
1502                                           disk_num_bytes, /* orig_block_len */
1503                                           ram_bytes, BTRFS_COMPRESS_NONE,
1504                                           BTRFS_ORDERED_PREALLOC);
1505                         if (IS_ERR(em)) {
1506                                 if (!nolock && nocow)
1507                                         btrfs_end_write_no_snapshotting(root);
1508                                 if (nocow)
1509                                         btrfs_dec_nocow_writers(fs_info,
1510                                                                 disk_bytenr);
1511                                 ret = PTR_ERR(em);
1512                                 goto error;
1513                         }
1514                         free_extent_map(em);
1515                 }
1516
1517                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1518                         type = BTRFS_ORDERED_PREALLOC;
1519                 } else {
1520                         type = BTRFS_ORDERED_NOCOW;
1521                 }
1522
1523                 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1524                                                num_bytes, num_bytes, type);
1525                 if (nocow)
1526                         btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1527                 BUG_ON(ret); /* -ENOMEM */
1528
1529                 if (root->root_key.objectid ==
1530                     BTRFS_DATA_RELOC_TREE_OBJECTID)
1531                         /*
1532                          * Error handled later, as we must prevent
1533                          * extent_clear_unlock_delalloc() in error handler
1534                          * from freeing metadata of created ordered extent.
1535                          */
1536                         ret = btrfs_reloc_clone_csums(inode, cur_offset,
1537                                                       num_bytes);
1538
1539                 extent_clear_unlock_delalloc(inode, cur_offset,
1540                                              cur_offset + num_bytes - 1, end,
1541                                              locked_page, EXTENT_LOCKED |
1542                                              EXTENT_DELALLOC |
1543                                              EXTENT_CLEAR_DATA_RESV,
1544                                              PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1545
1546                 if (!nolock && nocow)
1547                         btrfs_end_write_no_snapshotting(root);
1548                 cur_offset = extent_end;
1549
1550                 /*
1551                  * btrfs_reloc_clone_csums() error, now we're OK to call error
1552                  * handler, as metadata for created ordered extent will only
1553                  * be freed by btrfs_finish_ordered_io().
1554                  */
1555                 if (ret)
1556                         goto error;
1557                 if (cur_offset > end)
1558                         break;
1559         }
1560         btrfs_release_path(path);
1561
1562         if (cur_offset <= end && cow_start == (u64)-1) {
1563                 cow_start = cur_offset;
1564                 cur_offset = end;
1565         }
1566
1567         if (cow_start != (u64)-1) {
1568                 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1569                                      page_started, nr_written, 1, NULL);
1570                 if (ret)
1571                         goto error;
1572         }
1573
1574 error:
1575         if (ret && cur_offset < end)
1576                 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1577                                              locked_page, EXTENT_LOCKED |
1578                                              EXTENT_DELALLOC | EXTENT_DEFRAG |
1579                                              EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1580                                              PAGE_CLEAR_DIRTY |
1581                                              PAGE_SET_WRITEBACK |
1582                                              PAGE_END_WRITEBACK);
1583         btrfs_free_path(path);
1584         return ret;
1585 }
1586
1587 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1588 {
1589
1590         if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1591             !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1592                 return 0;
1593
1594         /*
1595          * @defrag_bytes is a hint value, no spinlock held here,
1596          * if is not zero, it means the file is defragging.
1597          * Force cow if given extent needs to be defragged.
1598          */
1599         if (BTRFS_I(inode)->defrag_bytes &&
1600             test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1601                            EXTENT_DEFRAG, 0, NULL))
1602                 return 1;
1603
1604         return 0;
1605 }
1606
1607 /*
1608  * extent_io.c call back to do delayed allocation processing
1609  */
1610 static int run_delalloc_range(void *private_data, struct page *locked_page,
1611                               u64 start, u64 end, int *page_started,
1612                               unsigned long *nr_written,
1613                               struct writeback_control *wbc)
1614 {
1615         struct inode *inode = private_data;
1616         int ret;
1617         int force_cow = need_force_cow(inode, start, end);
1618         unsigned int write_flags = wbc_to_write_flags(wbc);
1619
1620         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1621                 ret = run_delalloc_nocow(inode, locked_page, start, end,
1622                                          page_started, 1, nr_written);
1623         } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1624                 ret = run_delalloc_nocow(inode, locked_page, start, end,
1625                                          page_started, 0, nr_written);
1626         } else if (!inode_need_compress(inode, start, end)) {
1627                 ret = cow_file_range(inode, locked_page, start, end, end,
1628                                       page_started, nr_written, 1, NULL);
1629         } else {
1630                 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1631                         &BTRFS_I(inode)->runtime_flags);
1632                 ret = cow_file_range_async(inode, locked_page, start, end,
1633                                            page_started, nr_written,
1634                                            write_flags);
1635         }
1636         if (ret)
1637                 btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
1638         return ret;
1639 }
1640
1641 static void btrfs_split_extent_hook(void *private_data,
1642                                     struct extent_state *orig, u64 split)
1643 {
1644         struct inode *inode = private_data;
1645         u64 size;
1646
1647         /* not delalloc, ignore it */
1648         if (!(orig->state & EXTENT_DELALLOC))
1649                 return;
1650
1651         size = orig->end - orig->start + 1;
1652         if (size > BTRFS_MAX_EXTENT_SIZE) {
1653                 u32 num_extents;
1654                 u64 new_size;
1655
1656                 /*
1657                  * See the explanation in btrfs_merge_extent_hook, the same
1658                  * applies here, just in reverse.
1659                  */
1660                 new_size = orig->end - split + 1;
1661                 num_extents = count_max_extents(new_size);
1662                 new_size = split - orig->start;
1663                 num_extents += count_max_extents(new_size);
1664                 if (count_max_extents(size) >= num_extents)
1665                         return;
1666         }
1667
1668         spin_lock(&BTRFS_I(inode)->lock);
1669         btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1670         spin_unlock(&BTRFS_I(inode)->lock);
1671 }
1672
1673 /*
1674  * extent_io.c merge_extent_hook, used to track merged delayed allocation
1675  * extents so we can keep track of new extents that are just merged onto old
1676  * extents, such as when we are doing sequential writes, so we can properly
1677  * account for the metadata space we'll need.
1678  */
1679 static void btrfs_merge_extent_hook(void *private_data,
1680                                     struct extent_state *new,
1681                                     struct extent_state *other)
1682 {
1683         struct inode *inode = private_data;
1684         u64 new_size, old_size;
1685         u32 num_extents;
1686
1687         /* not delalloc, ignore it */
1688         if (!(other->state & EXTENT_DELALLOC))
1689                 return;
1690
1691         if (new->start > other->start)
1692                 new_size = new->end - other->start + 1;
1693         else
1694                 new_size = other->end - new->start + 1;
1695
1696         /* we're not bigger than the max, unreserve the space and go */
1697         if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1698                 spin_lock(&BTRFS_I(inode)->lock);
1699                 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1700                 spin_unlock(&BTRFS_I(inode)->lock);
1701                 return;
1702         }
1703
1704         /*
1705          * We have to add up either side to figure out how many extents were
1706          * accounted for before we merged into one big extent.  If the number of
1707          * extents we accounted for is <= the amount we need for the new range
1708          * then we can return, otherwise drop.  Think of it like this
1709          *
1710          * [ 4k][MAX_SIZE]
1711          *
1712          * So we've grown the extent by a MAX_SIZE extent, this would mean we
1713          * need 2 outstanding extents, on one side we have 1 and the other side
1714          * we have 1 so they are == and we can return.  But in this case
1715          *
1716          * [MAX_SIZE+4k][MAX_SIZE+4k]
1717          *
1718          * Each range on their own accounts for 2 extents, but merged together
1719          * they are only 3 extents worth of accounting, so we need to drop in
1720          * this case.
1721          */
1722         old_size = other->end - other->start + 1;
1723         num_extents = count_max_extents(old_size);
1724         old_size = new->end - new->start + 1;
1725         num_extents += count_max_extents(old_size);
1726         if (count_max_extents(new_size) >= num_extents)
1727                 return;
1728
1729         spin_lock(&BTRFS_I(inode)->lock);
1730         btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1731         spin_unlock(&BTRFS_I(inode)->lock);
1732 }
1733
1734 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1735                                       struct inode *inode)
1736 {
1737         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1738
1739         spin_lock(&root->delalloc_lock);
1740         if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1741                 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1742                               &root->delalloc_inodes);
1743                 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1744                         &BTRFS_I(inode)->runtime_flags);
1745                 root->nr_delalloc_inodes++;
1746                 if (root->nr_delalloc_inodes == 1) {
1747                         spin_lock(&fs_info->delalloc_root_lock);
1748                         BUG_ON(!list_empty(&root->delalloc_root));
1749                         list_add_tail(&root->delalloc_root,
1750                                       &fs_info->delalloc_roots);
1751                         spin_unlock(&fs_info->delalloc_root_lock);
1752                 }
1753         }
1754         spin_unlock(&root->delalloc_lock);
1755 }
1756
1757 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1758                                      struct btrfs_inode *inode)
1759 {
1760         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1761
1762         spin_lock(&root->delalloc_lock);
1763         if (!list_empty(&inode->delalloc_inodes)) {
1764                 list_del_init(&inode->delalloc_inodes);
1765                 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1766                           &inode->runtime_flags);
1767                 root->nr_delalloc_inodes--;
1768                 if (!root->nr_delalloc_inodes) {
1769                         spin_lock(&fs_info->delalloc_root_lock);
1770                         BUG_ON(list_empty(&root->delalloc_root));
1771                         list_del_init(&root->delalloc_root);
1772                         spin_unlock(&fs_info->delalloc_root_lock);
1773                 }
1774         }
1775         spin_unlock(&root->delalloc_lock);
1776 }
1777
1778 /*
1779  * extent_io.c set_bit_hook, used to track delayed allocation
1780  * bytes in this file, and to maintain the list of inodes that
1781  * have pending delalloc work to be done.
1782  */
1783 static void btrfs_set_bit_hook(void *private_data,
1784                                struct extent_state *state, unsigned *bits)
1785 {
1786         struct inode *inode = private_data;
1787
1788         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1789
1790         if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1791                 WARN_ON(1);
1792         /*
1793          * set_bit and clear bit hooks normally require _irqsave/restore
1794          * but in this case, we are only testing for the DELALLOC
1795          * bit, which is only set or cleared with irqs on
1796          */
1797         if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1798                 struct btrfs_root *root = BTRFS_I(inode)->root;
1799                 u64 len = state->end + 1 - state->start;
1800                 u32 num_extents = count_max_extents(len);
1801                 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1802
1803                 spin_lock(&BTRFS_I(inode)->lock);
1804                 btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
1805                 spin_unlock(&BTRFS_I(inode)->lock);
1806
1807                 /* For sanity tests */
1808                 if (btrfs_is_testing(fs_info))
1809                         return;
1810
1811                 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1812                                          fs_info->delalloc_batch);
1813                 spin_lock(&BTRFS_I(inode)->lock);
1814                 BTRFS_I(inode)->delalloc_bytes += len;
1815                 if (*bits & EXTENT_DEFRAG)
1816                         BTRFS_I(inode)->defrag_bytes += len;
1817                 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1818                                          &BTRFS_I(inode)->runtime_flags))
1819                         btrfs_add_delalloc_inodes(root, inode);
1820                 spin_unlock(&BTRFS_I(inode)->lock);
1821         }
1822
1823         if (!(state->state & EXTENT_DELALLOC_NEW) &&
1824             (*bits & EXTENT_DELALLOC_NEW)) {
1825                 spin_lock(&BTRFS_I(inode)->lock);
1826                 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1827                         state->start;
1828                 spin_unlock(&BTRFS_I(inode)->lock);
1829         }
1830 }
1831
1832 /*
1833  * extent_io.c clear_bit_hook, see set_bit_hook for why
1834  */
1835 static void btrfs_clear_bit_hook(void *private_data,
1836                                  struct extent_state *state,
1837                                  unsigned *bits)
1838 {
1839         struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
1840         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1841         u64 len = state->end + 1 - state->start;
1842         u32 num_extents = count_max_extents(len);
1843
1844         if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1845                 spin_lock(&inode->lock);
1846                 inode->defrag_bytes -= len;
1847                 spin_unlock(&inode->lock);
1848         }
1849
1850         /*
1851          * set_bit and clear bit hooks normally require _irqsave/restore
1852          * but in this case, we are only testing for the DELALLOC
1853          * bit, which is only set or cleared with irqs on
1854          */
1855         if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1856                 struct btrfs_root *root = inode->root;
1857                 bool do_list = !btrfs_is_free_space_inode(inode);
1858
1859                 spin_lock(&inode->lock);
1860                 btrfs_mod_outstanding_extents(inode, -num_extents);
1861                 spin_unlock(&inode->lock);
1862
1863                 /*
1864                  * We don't reserve metadata space for space cache inodes so we
1865                  * don't need to call dellalloc_release_metadata if there is an
1866                  * error.
1867                  */
1868                 if (*bits & EXTENT_CLEAR_META_RESV &&
1869                     root != fs_info->tree_root)
1870                         btrfs_delalloc_release_metadata(inode, len);
1871
1872                 /* For sanity tests. */
1873                 if (btrfs_is_testing(fs_info))
1874                         return;
1875
1876                 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1877                     do_list && !(state->state & EXTENT_NORESERVE) &&
1878                     (*bits & EXTENT_CLEAR_DATA_RESV))
1879                         btrfs_free_reserved_data_space_noquota(
1880                                         &inode->vfs_inode,
1881                                         state->start, len);
1882
1883                 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1884                                          fs_info->delalloc_batch);
1885                 spin_lock(&inode->lock);
1886                 inode->delalloc_bytes -= len;
1887                 if (do_list && inode->delalloc_bytes == 0 &&
1888                     test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1889                                         &inode->runtime_flags))
1890                         btrfs_del_delalloc_inode(root, inode);
1891                 spin_unlock(&inode->lock);
1892         }
1893
1894         if ((state->state & EXTENT_DELALLOC_NEW) &&
1895             (*bits & EXTENT_DELALLOC_NEW)) {
1896                 spin_lock(&inode->lock);
1897                 ASSERT(inode->new_delalloc_bytes >= len);
1898                 inode->new_delalloc_bytes -= len;
1899                 spin_unlock(&inode->lock);
1900         }
1901 }
1902
1903 /*
1904  * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1905  * we don't create bios that span stripes or chunks
1906  *
1907  * return 1 if page cannot be merged to bio
1908  * return 0 if page can be merged to bio
1909  * return error otherwise
1910  */
1911 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1912                          size_t size, struct bio *bio,
1913                          unsigned long bio_flags)
1914 {
1915         struct inode *inode = page->mapping->host;
1916         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1917         u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1918         u64 length = 0;
1919         u64 map_length;
1920         int ret;
1921
1922         if (bio_flags & EXTENT_BIO_COMPRESSED)
1923                 return 0;
1924
1925         length = bio->bi_iter.bi_size;
1926         map_length = length;
1927         ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1928                               NULL, 0);
1929         if (ret < 0)
1930                 return ret;
1931         if (map_length < length + size)
1932                 return 1;
1933         return 0;
1934 }
1935
1936 /*
1937  * in order to insert checksums into the metadata in large chunks,
1938  * we wait until bio submission time.   All the pages in the bio are
1939  * checksummed and sums are attached onto the ordered extent record.
1940  *
1941  * At IO completion time the cums attached on the ordered extent record
1942  * are inserted into the btree
1943  */
1944 static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
1945                                     u64 bio_offset)
1946 {
1947         struct inode *inode = private_data;
1948         blk_status_t ret = 0;
1949
1950         ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1951         BUG_ON(ret); /* -ENOMEM */
1952         return 0;
1953 }
1954
1955 /*
1956  * in order to insert checksums into the metadata in large chunks,
1957  * we wait until bio submission time.   All the pages in the bio are
1958  * checksummed and sums are attached onto the ordered extent record.
1959  *
1960  * At IO completion time the cums attached on the ordered extent record
1961  * are inserted into the btree
1962  */
1963 static blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
1964                           int mirror_num)
1965 {
1966         struct inode *inode = private_data;
1967         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1968         blk_status_t ret;
1969
1970         ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1971         if (ret) {
1972                 bio->bi_status = ret;
1973                 bio_endio(bio);
1974         }
1975         return ret;
1976 }
1977
1978 /*
1979  * extent_io.c submission hook. This does the right thing for csum calculation
1980  * on write, or reading the csums from the tree before a read.
1981  *
1982  * Rules about async/sync submit,
1983  * a) read:                             sync submit
1984  *
1985  * b) write without checksum:           sync submit
1986  *
1987  * c) write with checksum:
1988  *    c-1) if bio is issued by fsync:   sync submit
1989  *         (sync_writers != 0)
1990  *
1991  *    c-2) if root is reloc root:       sync submit
1992  *         (only in case of buffered IO)
1993  *
1994  *    c-3) otherwise:                   async submit
1995  */
1996 static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1997                                  int mirror_num, unsigned long bio_flags,
1998                                  u64 bio_offset)
1999 {
2000         struct inode *inode = private_data;
2001         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2002         struct btrfs_root *root = BTRFS_I(inode)->root;
2003         enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
2004         blk_status_t ret = 0;
2005         int skip_sum;
2006         int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
2007
2008         skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
2009
2010         if (btrfs_is_free_space_inode(BTRFS_I(inode)))
2011                 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
2012
2013         if (bio_op(bio) != REQ_OP_WRITE) {
2014                 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
2015                 if (ret)
2016                         goto out;
2017
2018                 if (bio_flags & EXTENT_BIO_COMPRESSED) {
2019                         ret = btrfs_submit_compressed_read(inode, bio,
2020                                                            mirror_num,
2021                                                            bio_flags);
2022                         goto out;
2023                 } else if (!skip_sum) {
2024                         ret = btrfs_lookup_bio_sums(inode, bio, NULL);
2025                         if (ret)
2026                                 goto out;
2027                 }
2028                 goto mapit;
2029         } else if (async && !skip_sum) {
2030                 /* csum items have already been cloned */
2031                 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2032                         goto mapit;
2033                 /* we're doing a write, do the async checksumming */
2034                 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
2035                                           bio_offset, inode,
2036                                           btrfs_submit_bio_start,
2037                                           btrfs_submit_bio_done);
2038                 goto out;
2039         } else if (!skip_sum) {
2040                 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2041                 if (ret)
2042                         goto out;
2043         }
2044
2045 mapit:
2046         ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
2047
2048 out:
2049         if (ret) {
2050                 bio->bi_status = ret;
2051                 bio_endio(bio);
2052         }
2053         return ret;
2054 }
2055
2056 /*
2057  * given a list of ordered sums record them in the inode.  This happens
2058  * at IO completion time based on sums calculated at bio submission time.
2059  */
2060 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2061                              struct inode *inode, struct list_head *list)
2062 {
2063         struct btrfs_ordered_sum *sum;
2064         int ret;
2065
2066         list_for_each_entry(sum, list, list) {
2067                 trans->adding_csums = true;
2068                 ret = btrfs_csum_file_blocks(trans,
2069                        BTRFS_I(inode)->root->fs_info->csum_root, sum);
2070                 trans->adding_csums = false;
2071                 if (ret)
2072                         return ret;
2073         }
2074         return 0;
2075 }
2076
2077 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2078                               unsigned int extra_bits,
2079                               struct extent_state **cached_state, int dedupe)
2080 {
2081         WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2082         return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2083                                    extra_bits, cached_state);
2084 }
2085
2086 /* see btrfs_writepage_start_hook for details on why this is required */
2087 struct btrfs_writepage_fixup {
2088         struct page *page;
2089         struct btrfs_work work;
2090 };
2091
2092 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2093 {
2094         struct btrfs_writepage_fixup *fixup;
2095         struct btrfs_ordered_extent *ordered;
2096         struct extent_state *cached_state = NULL;
2097         struct extent_changeset *data_reserved = NULL;
2098         struct page *page;
2099         struct inode *inode;
2100         u64 page_start;
2101         u64 page_end;
2102         int ret;
2103
2104         fixup = container_of(work, struct btrfs_writepage_fixup, work);
2105         page = fixup->page;
2106 again:
2107         lock_page(page);
2108         if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2109                 ClearPageChecked(page);
2110                 goto out_page;
2111         }
2112
2113         inode = page->mapping->host;
2114         page_start = page_offset(page);
2115         page_end = page_offset(page) + PAGE_SIZE - 1;
2116
2117         lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2118                          &cached_state);
2119
2120         /* already ordered? We're done */
2121         if (PagePrivate2(page))
2122                 goto out;
2123
2124         ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2125                                         PAGE_SIZE);
2126         if (ordered) {
2127                 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2128                                      page_end, &cached_state);
2129                 unlock_page(page);
2130                 btrfs_start_ordered_extent(inode, ordered, 1);
2131                 btrfs_put_ordered_extent(ordered);
2132                 goto again;
2133         }
2134
2135         ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2136                                            PAGE_SIZE);
2137         if (ret) {
2138                 mapping_set_error(page->mapping, ret);
2139                 end_extent_writepage(page, ret, page_start, page_end);
2140                 ClearPageChecked(page);
2141                 goto out;
2142          }
2143
2144         ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
2145                                         &cached_state, 0);
2146         if (ret) {
2147                 mapping_set_error(page->mapping, ret);
2148                 end_extent_writepage(page, ret, page_start, page_end);
2149                 ClearPageChecked(page);
2150                 goto out;
2151         }
2152
2153         ClearPageChecked(page);
2154         set_page_dirty(page);
2155         btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
2156 out:
2157         unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2158                              &cached_state);
2159 out_page:
2160         unlock_page(page);
2161         put_page(page);
2162         kfree(fixup);
2163         extent_changeset_free(data_reserved);
2164 }
2165
2166 /*
2167  * There are a few paths in the higher layers of the kernel that directly
2168  * set the page dirty bit without asking the filesystem if it is a
2169  * good idea.  This causes problems because we want to make sure COW
2170  * properly happens and the data=ordered rules are followed.
2171  *
2172  * In our case any range that doesn't have the ORDERED bit set
2173  * hasn't been properly setup for IO.  We kick off an async process
2174  * to fix it up.  The async helper will wait for ordered extents, set
2175  * the delalloc bit and make it safe to write the page.
2176  */
2177 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2178 {
2179         struct inode *inode = page->mapping->host;
2180         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2181         struct btrfs_writepage_fixup *fixup;
2182
2183         /* this page is properly in the ordered list */
2184         if (TestClearPagePrivate2(page))
2185                 return 0;
2186
2187         if (PageChecked(page))
2188                 return -EAGAIN;
2189
2190         fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2191         if (!fixup)
2192                 return -EAGAIN;
2193
2194         SetPageChecked(page);
2195         get_page(page);
2196         btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2197                         btrfs_writepage_fixup_worker, NULL, NULL);
2198         fixup->page = page;
2199         btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2200         return -EBUSY;
2201 }
2202
2203 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2204                                        struct inode *inode, u64 file_pos,
2205                                        u64 disk_bytenr, u64 disk_num_bytes,
2206                                        u64 num_bytes, u64 ram_bytes,
2207                                        u8 compression, u8 encryption,
2208                                        u16 other_encoding, int extent_type)
2209 {
2210         struct btrfs_root *root = BTRFS_I(inode)->root;
2211         struct btrfs_file_extent_item *fi;
2212         struct btrfs_path *path;
2213         struct extent_buffer *leaf;
2214         struct btrfs_key ins;
2215         u64 qg_released;
2216         int extent_inserted = 0;
2217         int ret;
2218
2219         path = btrfs_alloc_path();
2220         if (!path)
2221                 return -ENOMEM;
2222
2223         /*
2224          * we may be replacing one extent in the tree with another.
2225          * The new extent is pinned in the extent map, and we don't want
2226          * to drop it from the cache until it is completely in the btree.
2227          *
2228          * So, tell btrfs_drop_extents to leave this extent in the cache.
2229          * the caller is expected to unpin it and allow it to be merged
2230          * with the others.
2231          */
2232         ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2233                                    file_pos + num_bytes, NULL, 0,
2234                                    1, sizeof(*fi), &extent_inserted);
2235         if (ret)
2236                 goto out;
2237
2238         if (!extent_inserted) {
2239                 ins.objectid = btrfs_ino(BTRFS_I(inode));
2240                 ins.offset = file_pos;
2241                 ins.type = BTRFS_EXTENT_DATA_KEY;
2242
2243                 path->leave_spinning = 1;
2244                 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2245                                               sizeof(*fi));
2246                 if (ret)
2247                         goto out;
2248         }
2249         leaf = path->nodes[0];
2250         fi = btrfs_item_ptr(leaf, path->slots[0],
2251                             struct btrfs_file_extent_item);
2252         btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2253         btrfs_set_file_extent_type(leaf, fi, extent_type);
2254         btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2255         btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2256         btrfs_set_file_extent_offset(leaf, fi, 0);
2257         btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2258         btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2259         btrfs_set_file_extent_compression(leaf, fi, compression);
2260         btrfs_set_file_extent_encryption(leaf, fi, encryption);
2261         btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2262
2263         btrfs_mark_buffer_dirty(leaf);
2264         btrfs_release_path(path);
2265
2266         inode_add_bytes(inode, num_bytes);
2267
2268         ins.objectid = disk_bytenr;
2269         ins.offset = disk_num_bytes;
2270         ins.type = BTRFS_EXTENT_ITEM_KEY;
2271
2272         /*
2273          * Release the reserved range from inode dirty range map, as it is
2274          * already moved into delayed_ref_head
2275          */
2276         ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2277         if (ret < 0)
2278                 goto out;
2279         qg_released = ret;
2280         ret = btrfs_alloc_reserved_file_extent(trans, root,
2281                                                btrfs_ino(BTRFS_I(inode)),
2282                                                file_pos, qg_released, &ins);
2283 out:
2284         btrfs_free_path(path);
2285
2286         return ret;
2287 }
2288
2289 /* snapshot-aware defrag */
2290 struct sa_defrag_extent_backref {
2291         struct rb_node node;
2292         struct old_sa_defrag_extent *old;
2293         u64 root_id;
2294         u64 inum;
2295         u64 file_pos;
2296         u64 extent_offset;
2297         u64 num_bytes;
2298         u64 generation;
2299 };
2300
2301 struct old_sa_defrag_extent {
2302         struct list_head list;
2303         struct new_sa_defrag_extent *new;
2304
2305         u64 extent_offset;
2306         u64 bytenr;
2307         u64 offset;
2308         u64 len;
2309         int count;
2310 };
2311
2312 struct new_sa_defrag_extent {
2313         struct rb_root root;
2314         struct list_head head;
2315         struct btrfs_path *path;
2316         struct inode *inode;
2317         u64 file_pos;
2318         u64 len;
2319         u64 bytenr;
2320         u64 disk_len;
2321         u8 compress_type;
2322 };
2323
2324 static int backref_comp(struct sa_defrag_extent_backref *b1,
2325                         struct sa_defrag_extent_backref *b2)
2326 {
2327         if (b1->root_id < b2->root_id)
2328                 return -1;
2329         else if (b1->root_id > b2->root_id)
2330                 return 1;
2331
2332         if (b1->inum < b2->inum)
2333                 return -1;
2334         else if (b1->inum > b2->inum)
2335                 return 1;
2336
2337         if (b1->file_pos < b2->file_pos)
2338                 return -1;
2339         else if (b1->file_pos > b2->file_pos)
2340                 return 1;
2341
2342         /*
2343          * [------------------------------] ===> (a range of space)
2344          *     |<--->|   |<---->| =============> (fs/file tree A)
2345          * |<---------------------------->| ===> (fs/file tree B)
2346          *
2347          * A range of space can refer to two file extents in one tree while
2348          * refer to only one file extent in another tree.
2349          *
2350          * So we may process a disk offset more than one time(two extents in A)
2351          * and locate at the same extent(one extent in B), then insert two same
2352          * backrefs(both refer to the extent in B).
2353          */
2354         return 0;
2355 }
2356
2357 static void backref_insert(struct rb_root *root,
2358                            struct sa_defrag_extent_backref *backref)
2359 {
2360         struct rb_node **p = &root->rb_node;
2361         struct rb_node *parent = NULL;
2362         struct sa_defrag_extent_backref *entry;
2363         int ret;
2364
2365         while (*p) {
2366                 parent = *p;
2367                 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2368
2369                 ret = backref_comp(backref, entry);
2370                 if (ret < 0)
2371                         p = &(*p)->rb_left;
2372                 else
2373                         p = &(*p)->rb_right;
2374         }
2375
2376         rb_link_node(&backref->node, parent, p);
2377         rb_insert_color(&backref->node, root);
2378 }
2379
2380 /*
2381  * Note the backref might has changed, and in this case we just return 0.
2382  */
2383 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2384                                        void *ctx)
2385 {
2386         struct btrfs_file_extent_item *extent;
2387         struct old_sa_defrag_extent *old = ctx;
2388         struct new_sa_defrag_extent *new = old->new;
2389         struct btrfs_path *path = new->path;
2390         struct btrfs_key key;
2391         struct btrfs_root *root;
2392         struct sa_defrag_extent_backref *backref;
2393         struct extent_buffer *leaf;
2394         struct inode *inode = new->inode;
2395         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2396         int slot;
2397         int ret;
2398         u64 extent_offset;
2399         u64 num_bytes;
2400
2401         if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2402             inum == btrfs_ino(BTRFS_I(inode)))
2403                 return 0;
2404
2405         key.objectid = root_id;
2406         key.type = BTRFS_ROOT_ITEM_KEY;
2407         key.offset = (u64)-1;
2408
2409         root = btrfs_read_fs_root_no_name(fs_info, &key);
2410         if (IS_ERR(root)) {
2411                 if (PTR_ERR(root) == -ENOENT)
2412                         return 0;
2413                 WARN_ON(1);
2414                 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2415                          inum, offset, root_id);
2416                 return PTR_ERR(root);
2417         }
2418
2419         key.objectid = inum;
2420         key.type = BTRFS_EXTENT_DATA_KEY;
2421         if (offset > (u64)-1 << 32)
2422                 key.offset = 0;
2423         else
2424                 key.offset = offset;
2425
2426         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2427         if (WARN_ON(ret < 0))
2428                 return ret;
2429         ret = 0;
2430
2431         while (1) {
2432                 cond_resched();
2433
2434                 leaf = path->nodes[0];
2435                 slot = path->slots[0];
2436
2437                 if (slot >= btrfs_header_nritems(leaf)) {
2438                         ret = btrfs_next_leaf(root, path);
2439                         if (ret < 0) {
2440                                 goto out;
2441                         } else if (ret > 0) {
2442                                 ret = 0;
2443                                 goto out;
2444                         }
2445                         continue;
2446                 }
2447
2448                 path->slots[0]++;
2449
2450                 btrfs_item_key_to_cpu(leaf, &key, slot);
2451
2452                 if (key.objectid > inum)
2453                         goto out;
2454
2455                 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2456                         continue;
2457
2458                 extent = btrfs_item_ptr(leaf, slot,
2459                                         struct btrfs_file_extent_item);
2460
2461                 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2462                         continue;
2463
2464                 /*
2465                  * 'offset' refers to the exact key.offset,
2466                  * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2467                  * (key.offset - extent_offset).
2468                  */
2469                 if (key.offset != offset)
2470                         continue;
2471
2472                 extent_offset = btrfs_file_extent_offset(leaf, extent);
2473                 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2474
2475                 if (extent_offset >= old->extent_offset + old->offset +
2476                     old->len || extent_offset + num_bytes <=
2477                     old->extent_offset + old->offset)
2478                         continue;
2479                 break;
2480         }
2481
2482         backref = kmalloc(sizeof(*backref), GFP_NOFS);
2483         if (!backref) {
2484                 ret = -ENOENT;
2485                 goto out;
2486         }
2487
2488         backref->root_id = root_id;
2489         backref->inum = inum;
2490         backref->file_pos = offset;
2491         backref->num_bytes = num_bytes;
2492         backref->extent_offset = extent_offset;
2493         backref->generation = btrfs_file_extent_generation(leaf, extent);
2494         backref->old = old;
2495         backref_insert(&new->root, backref);
2496         old->count++;
2497 out:
2498         btrfs_release_path(path);
2499         WARN_ON(ret);
2500         return ret;
2501 }
2502
2503 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2504                                    struct new_sa_defrag_extent *new)
2505 {
2506         struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2507         struct old_sa_defrag_extent *old, *tmp;
2508         int ret;
2509
2510         new->path = path;
2511
2512         list_for_each_entry_safe(old, tmp, &new->head, list) {
2513                 ret = iterate_inodes_from_logical(old->bytenr +
2514                                                   old->extent_offset, fs_info,
2515                                                   path, record_one_backref,
2516                                                   old, false);
2517                 if (ret < 0 && ret != -ENOENT)
2518                         return false;
2519
2520                 /* no backref to be processed for this extent */
2521                 if (!old->count) {
2522                         list_del(&old->list);
2523                         kfree(old);
2524                 }
2525         }
2526
2527         if (list_empty(&new->head))
2528                 return false;
2529
2530         return true;
2531 }
2532
2533 static int relink_is_mergable(struct extent_buffer *leaf,
2534                               struct btrfs_file_extent_item *fi,
2535                               struct new_sa_defrag_extent *new)
2536 {
2537         if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2538                 return 0;
2539
2540         if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2541                 return 0;
2542
2543         if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2544                 return 0;
2545
2546         if (btrfs_file_extent_encryption(leaf, fi) ||
2547             btrfs_file_extent_other_encoding(leaf, fi))
2548                 return 0;
2549
2550         return 1;
2551 }
2552
2553 /*
2554  * Note the backref might has changed, and in this case we just return 0.
2555  */
2556 static noinline int relink_extent_backref(struct btrfs_path *path,
2557                                  struct sa_defrag_extent_backref *prev,
2558                                  struct sa_defrag_extent_backref *backref)
2559 {
2560         struct btrfs_file_extent_item *extent;
2561         struct btrfs_file_extent_item *item;
2562         struct btrfs_ordered_extent *ordered;
2563         struct btrfs_trans_handle *trans;
2564         struct btrfs_root *root;
2565         struct btrfs_key key;
2566         struct extent_buffer *leaf;
2567         struct old_sa_defrag_extent *old = backref->old;
2568         struct new_sa_defrag_extent *new = old->new;
2569         struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2570         struct inode *inode;
2571         struct extent_state *cached = NULL;
2572         int ret = 0;
2573         u64 start;
2574         u64 len;
2575         u64 lock_start;
2576         u64 lock_end;
2577         bool merge = false;
2578         int index;
2579
2580         if (prev && prev->root_id == backref->root_id &&
2581             prev->inum == backref->inum &&
2582             prev->file_pos + prev->num_bytes == backref->file_pos)
2583                 merge = true;
2584
2585         /* step 1: get root */
2586         key.objectid = backref->root_id;
2587         key.type = BTRFS_ROOT_ITEM_KEY;
2588         key.offset = (u64)-1;
2589
2590         index = srcu_read_lock(&fs_info->subvol_srcu);
2591
2592         root = btrfs_read_fs_root_no_name(fs_info, &key);
2593         if (IS_ERR(root)) {
2594                 srcu_read_unlock(&fs_info->subvol_srcu, index);
2595                 if (PTR_ERR(root) == -ENOENT)
2596                         return 0;
2597                 return PTR_ERR(root);
2598         }
2599
2600         if (btrfs_root_readonly(root)) {
2601                 srcu_read_unlock(&fs_info->subvol_srcu, index);
2602                 return 0;
2603         }
2604
2605         /* step 2: get inode */
2606         key.objectid = backref->inum;
2607         key.type = BTRFS_INODE_ITEM_KEY;
2608         key.offset = 0;
2609
2610         inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2611         if (IS_ERR(inode)) {
2612                 srcu_read_unlock(&fs_info->subvol_srcu, index);
2613                 return 0;
2614         }
2615
2616         srcu_read_unlock(&fs_info->subvol_srcu, index);
2617
2618         /* step 3: relink backref */
2619         lock_start = backref->file_pos;
2620         lock_end = backref->file_pos + backref->num_bytes - 1;
2621         lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2622                          &cached);
2623
2624         ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2625         if (ordered) {
2626                 btrfs_put_ordered_extent(ordered);
2627                 goto out_unlock;
2628         }
2629
2630         trans = btrfs_join_transaction(root);
2631         if (IS_ERR(trans)) {
2632                 ret = PTR_ERR(trans);
2633                 goto out_unlock;
2634         }
2635
2636         key.objectid = backref->inum;
2637         key.type = BTRFS_EXTENT_DATA_KEY;
2638         key.offset = backref->file_pos;
2639
2640         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2641         if (ret < 0) {
2642                 goto out_free_path;
2643         } else if (ret > 0) {
2644                 ret = 0;
2645                 goto out_free_path;
2646         }
2647
2648         extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2649                                 struct btrfs_file_extent_item);
2650
2651         if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2652             backref->generation)
2653                 goto out_free_path;
2654
2655         btrfs_release_path(path);
2656
2657         start = backref->file_pos;
2658         if (backref->extent_offset < old->extent_offset + old->offset)
2659                 start += old->extent_offset + old->offset -
2660                          backref->extent_offset;
2661
2662         len = min(backref->extent_offset + backref->num_bytes,
2663                   old->extent_offset + old->offset + old->len);
2664         len -= max(backref->extent_offset, old->extent_offset + old->offset);
2665
2666         ret = btrfs_drop_extents(trans, root, inode, start,
2667                                  start + len, 1);
2668         if (ret)
2669                 goto out_free_path;
2670 again:
2671         key.objectid = btrfs_ino(BTRFS_I(inode));
2672         key.type = BTRFS_EXTENT_DATA_KEY;
2673         key.offset = start;
2674
2675         path->leave_spinning = 1;
2676         if (merge) {
2677                 struct btrfs_file_extent_item *fi;
2678                 u64 extent_len;
2679                 struct btrfs_key found_key;
2680
2681                 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2682                 if (ret < 0)
2683                         goto out_free_path;
2684
2685                 path->slots[0]--;
2686                 leaf = path->nodes[0];
2687                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2688
2689                 fi = btrfs_item_ptr(leaf, path->slots[0],
2690                                     struct btrfs_file_extent_item);
2691                 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2692
2693                 if (extent_len + found_key.offset == start &&
2694                     relink_is_mergable(leaf, fi, new)) {
2695                         btrfs_set_file_extent_num_bytes(leaf, fi,
2696                                                         extent_len + len);
2697                         btrfs_mark_buffer_dirty(leaf);
2698                         inode_add_bytes(inode, len);
2699
2700                         ret = 1;
2701                         goto out_free_path;
2702                 } else {
2703                         merge = false;
2704                         btrfs_release_path(path);
2705                         goto again;
2706                 }
2707         }
2708
2709         ret = btrfs_insert_empty_item(trans, root, path, &key,
2710                                         sizeof(*extent));
2711         if (ret) {
2712                 btrfs_abort_transaction(trans, ret);
2713                 goto out_free_path;
2714         }
2715
2716         leaf = path->nodes[0];
2717         item = btrfs_item_ptr(leaf, path->slots[0],
2718                                 struct btrfs_file_extent_item);
2719         btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2720         btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2721         btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2722         btrfs_set_file_extent_num_bytes(leaf, item, len);
2723         btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2724         btrfs_set_file_extent_generation(leaf, item, trans->transid);
2725         btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2726         btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2727         btrfs_set_file_extent_encryption(leaf, item, 0);
2728         btrfs_set_file_extent_other_encoding(leaf, item, 0);
2729
2730         btrfs_mark_buffer_dirty(leaf);
2731         inode_add_bytes(inode, len);
2732         btrfs_release_path(path);
2733
2734         ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2735                         new->disk_len, 0,
2736                         backref->root_id, backref->inum,
2737                         new->file_pos); /* start - extent_offset */
2738         if (ret) {
2739                 btrfs_abort_transaction(trans, ret);
2740                 goto out_free_path;
2741         }
2742
2743         ret = 1;
2744 out_free_path:
2745         btrfs_release_path(path);
2746         path->leave_spinning = 0;
2747         btrfs_end_transaction(trans);
2748 out_unlock:
2749         unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2750                              &cached);
2751         iput(inode);
2752         return ret;
2753 }
2754
2755 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2756 {
2757         struct old_sa_defrag_extent *old, *tmp;
2758
2759         if (!new)
2760                 return;
2761
2762         list_for_each_entry_safe(old, tmp, &new->head, list) {
2763                 kfree(old);
2764         }
2765         kfree(new);
2766 }
2767
2768 static void relink_file_extents(struct new_sa_defrag_extent *new)
2769 {
2770         struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2771         struct btrfs_path *path;
2772         struct sa_defrag_extent_backref *backref;
2773         struct sa_defrag_extent_backref *prev = NULL;
2774         struct inode *inode;
2775         struct rb_node *node;
2776         int ret;
2777
2778         inode = new->inode;
2779
2780         path = btrfs_alloc_path();
2781         if (!path)
2782                 return;
2783
2784         if (!record_extent_backrefs(path, new)) {
2785                 btrfs_free_path(path);
2786                 goto out;
2787         }
2788         btrfs_release_path(path);
2789
2790         while (1) {
2791                 node = rb_first(&new->root);
2792                 if (!node)
2793                         break;
2794                 rb_erase(node, &new->root);
2795
2796                 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2797
2798                 ret = relink_extent_backref(path, prev, backref);
2799                 WARN_ON(ret < 0);
2800
2801                 kfree(prev);
2802
2803                 if (ret == 1)
2804                         prev = backref;
2805                 else
2806                         prev = NULL;
2807                 cond_resched();
2808         }
2809         kfree(prev);
2810
2811         btrfs_free_path(path);
2812 out:
2813         free_sa_defrag_extent(new);
2814
2815         atomic_dec(&fs_info->defrag_running);
2816         wake_up(&fs_info->transaction_wait);
2817 }
2818
2819 static struct new_sa_defrag_extent *
2820 record_old_file_extents(struct inode *inode,
2821                         struct btrfs_ordered_extent *ordered)
2822 {
2823         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2824         struct btrfs_root *root = BTRFS_I(inode)->root;
2825         struct btrfs_path *path;
2826         struct btrfs_key key;
2827         struct old_sa_defrag_extent *old;
2828         struct new_sa_defrag_extent *new;
2829         int ret;
2830
2831         new = kmalloc(sizeof(*new), GFP_NOFS);
2832         if (!new)
2833                 return NULL;
2834
2835         new->inode = inode;
2836         new->file_pos = ordered->file_offset;
2837         new->len = ordered->len;
2838         new->bytenr = ordered->start;
2839         new->disk_len = ordered->disk_len;
2840         new->compress_type = ordered->compress_type;
2841         new->root = RB_ROOT;
2842         INIT_LIST_HEAD(&new->head);
2843
2844         path = btrfs_alloc_path();
2845         if (!path)
2846                 goto out_kfree;
2847
2848         key.objectid = btrfs_ino(BTRFS_I(inode));
2849         key.type = BTRFS_EXTENT_DATA_KEY;
2850         key.offset = new->file_pos;
2851
2852         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2853         if (ret < 0)
2854                 goto out_free_path;
2855         if (ret > 0 && path->slots[0] > 0)
2856                 path->slots[0]--;
2857
2858         /* find out all the old extents for the file range */
2859         while (1) {
2860                 struct btrfs_file_extent_item *extent;
2861                 struct extent_buffer *l;
2862                 int slot;
2863                 u64 num_bytes;
2864                 u64 offset;
2865                 u64 end;
2866                 u64 disk_bytenr;
2867                 u64 extent_offset;
2868
2869                 l = path->nodes[0];
2870                 slot = path->slots[0];
2871
2872                 if (slot >= btrfs_header_nritems(l)) {
2873                         ret = btrfs_next_leaf(root, path);
2874                         if (ret < 0)
2875                                 goto out_free_path;
2876                         else if (ret > 0)
2877                                 break;
2878                         continue;
2879                 }
2880
2881                 btrfs_item_key_to_cpu(l, &key, slot);
2882
2883                 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2884                         break;
2885                 if (key.type != BTRFS_EXTENT_DATA_KEY)
2886                         break;
2887                 if (key.offset >= new->file_pos + new->len)
2888                         break;
2889
2890                 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2891
2892                 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2893                 if (key.offset + num_bytes < new->file_pos)
2894                         goto next;
2895
2896                 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2897                 if (!disk_bytenr)
2898                         goto next;
2899
2900                 extent_offset = btrfs_file_extent_offset(l, extent);
2901
2902                 old = kmalloc(sizeof(*old), GFP_NOFS);
2903                 if (!old)
2904                         goto out_free_path;
2905
2906                 offset = max(new->file_pos, key.offset);
2907                 end = min(new->file_pos + new->len, key.offset + num_bytes);
2908
2909                 old->bytenr = disk_bytenr;
2910                 old->extent_offset = extent_offset;
2911                 old->offset = offset - key.offset;
2912                 old->len = end - offset;
2913                 old->new = new;
2914                 old->count = 0;
2915                 list_add_tail(&old->list, &new->head);
2916 next:
2917                 path->slots[0]++;
2918                 cond_resched();
2919         }
2920
2921         btrfs_free_path(path);
2922         atomic_inc(&fs_info->defrag_running);
2923
2924         return new;
2925
2926 out_free_path:
2927         btrfs_free_path(path);
2928 out_kfree:
2929         free_sa_defrag_extent(new);
2930         return NULL;
2931 }
2932
2933 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2934                                          u64 start, u64 len)
2935 {
2936         struct btrfs_block_group_cache *cache;
2937
2938         cache = btrfs_lookup_block_group(fs_info, start);
2939         ASSERT(cache);
2940
2941         spin_lock(&cache->lock);
2942         cache->delalloc_bytes -= len;
2943         spin_unlock(&cache->lock);
2944
2945         btrfs_put_block_group(cache);
2946 }
2947
2948 /* as ordered data IO finishes, this gets called so we can finish
2949  * an ordered extent if the range of bytes in the file it covers are
2950  * fully written.
2951  */
2952 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2953 {
2954         struct inode *inode = ordered_extent->inode;
2955         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2956         struct btrfs_root *root = BTRFS_I(inode)->root;
2957         struct btrfs_trans_handle *trans = NULL;
2958         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2959         struct extent_state *cached_state = NULL;
2960         struct new_sa_defrag_extent *new = NULL;
2961         int compress_type = 0;
2962         int ret = 0;
2963         u64 logical_len = ordered_extent->len;
2964         bool nolock;
2965         bool truncated = false;
2966         bool range_locked = false;
2967         bool clear_new_delalloc_bytes = false;
2968
2969         if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2970             !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2971             !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2972                 clear_new_delalloc_bytes = true;
2973
2974         nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2975
2976         if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2977                 ret = -EIO;
2978                 goto out;
2979         }
2980
2981         btrfs_free_io_failure_record(BTRFS_I(inode),
2982                         ordered_extent->file_offset,
2983                         ordered_extent->file_offset +
2984                         ordered_extent->len - 1);
2985
2986         if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2987                 truncated = true;
2988                 logical_len = ordered_extent->truncated_len;
2989                 /* Truncated the entire extent, don't bother adding */
2990                 if (!logical_len)
2991                         goto out;
2992         }
2993
2994         if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2995                 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2996
2997                 /*
2998                  * For mwrite(mmap + memset to write) case, we still reserve
2999                  * space for NOCOW range.
3000                  * As NOCOW won't cause a new delayed ref, just free the space
3001                  */
3002                 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3003                                        ordered_extent->len);
3004                 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3005                 if (nolock)
3006                         trans = btrfs_join_transaction_nolock(root);
3007                 else
3008                         trans = btrfs_join_transaction(root);
3009                 if (IS_ERR(trans)) {
3010                         ret = PTR_ERR(trans);
3011                         trans = NULL;
3012                         goto out;
3013                 }
3014                 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3015                 ret = btrfs_update_inode_fallback(trans, root, inode);
3016                 if (ret) /* -ENOMEM or corruption */
3017                         btrfs_abort_transaction(trans, ret);
3018                 goto out;
3019         }
3020
3021         range_locked = true;
3022         lock_extent_bits(io_tree, ordered_extent->file_offset,
3023                          ordered_extent->file_offset + ordered_extent->len - 1,
3024                          &cached_state);
3025
3026         ret = test_range_bit(io_tree, ordered_extent->file_offset,
3027                         ordered_extent->file_offset + ordered_extent->len - 1,
3028                         EXTENT_DEFRAG, 0, cached_state);
3029         if (ret) {
3030                 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
3031                 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
3032                         /* the inode is shared */
3033                         new = record_old_file_extents(inode, ordered_extent);
3034
3035                 clear_extent_bit(io_tree, ordered_extent->file_offset,
3036                         ordered_extent->file_offset + ordered_extent->len - 1,
3037                         EXTENT_DEFRAG, 0, 0, &cached_state);
3038         }
3039
3040         if (nolock)
3041                 trans = btrfs_join_transaction_nolock(root);
3042         else
3043                 trans = btrfs_join_transaction(root);
3044         if (IS_ERR(trans)) {
3045                 ret = PTR_ERR(trans);
3046                 trans = NULL;
3047                 goto out;
3048         }
3049
3050         trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3051
3052         if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3053                 compress_type = ordered_extent->compress_type;
3054         if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3055                 BUG_ON(compress_type);
3056                 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3057                                        ordered_extent->len);
3058                 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
3059                                                 ordered_extent->file_offset,
3060                                                 ordered_extent->file_offset +
3061                                                 logical_len);
3062         } else {
3063                 BUG_ON(root == fs_info->tree_root);
3064                 ret = insert_reserved_file_extent(trans, inode,
3065                                                 ordered_extent->file_offset,
3066                                                 ordered_extent->start,
3067                                                 ordered_extent->disk_len,
3068                                                 logical_len, logical_len,
3069                                                 compress_type, 0, 0,
3070                                                 BTRFS_FILE_EXTENT_REG);
3071                 if (!ret)
3072                         btrfs_release_delalloc_bytes(fs_info,
3073                                                      ordered_extent->start,
3074                                                      ordered_extent->disk_len);
3075         }
3076         unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3077                            ordered_extent->file_offset, ordered_extent->len,
3078                            trans->transid);
3079         if (ret < 0) {
3080                 btrfs_abort_transaction(trans, ret);
3081                 goto out;
3082         }
3083
3084         ret = add_pending_csums(trans, inode, &ordered_extent->list);
3085         if (ret) {
3086                 btrfs_abort_transaction(trans, ret);
3087                 goto out;
3088         }
3089
3090         btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3091         ret = btrfs_update_inode_fallback(trans, root, inode);
3092         if (ret) { /* -ENOMEM or corruption */
3093                 btrfs_abort_transaction(trans, ret);
3094                 goto out;
3095         }
3096         ret = 0;
3097 out:
3098         if (range_locked || clear_new_delalloc_bytes) {
3099                 unsigned int clear_bits = 0;
3100
3101                 if (range_locked)
3102                         clear_bits |= EXTENT_LOCKED;
3103                 if (clear_new_delalloc_bytes)
3104                         clear_bits |= EXTENT_DELALLOC_NEW;
3105                 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3106                                  ordered_extent->file_offset,
3107                                  ordered_extent->file_offset +
3108                                  ordered_extent->len - 1,
3109                                  clear_bits,
3110                                  (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3111                                  0, &cached_state);
3112         }
3113
3114         if (trans)
3115                 btrfs_end_transaction(trans);
3116
3117         if (ret || truncated) {
3118                 u64 start, end;
3119
3120                 if (truncated)
3121                         start = ordered_extent->file_offset + logical_len;
3122                 else
3123                         start = ordered_extent->file_offset;
3124                 end = ordered_extent->file_offset + ordered_extent->len - 1;
3125                 clear_extent_uptodate(io_tree, start, end, NULL);
3126
3127                 /* Drop the cache for the part of the extent we didn't write. */
3128                 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3129
3130                 /*
3131                  * If the ordered extent had an IOERR or something else went
3132                  * wrong we need to return the space for this ordered extent
3133                  * back to the allocator.  We only free the extent in the
3134                  * truncated case if we didn't write out the extent at all.
3135                  */
3136                 if ((ret || !logical_len) &&
3137                     !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3138                     !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3139                         btrfs_free_reserved_extent(fs_info,
3140                                                    ordered_extent->start,
3141                                                    ordered_extent->disk_len, 1);
3142         }
3143
3144
3145         /*
3146          * This needs to be done to make sure anybody waiting knows we are done
3147          * updating everything for this ordered extent.
3148          */
3149         btrfs_remove_ordered_extent(inode, ordered_extent);
3150
3151         /* for snapshot-aware defrag */
3152         if (new) {
3153                 if (ret) {
3154                         free_sa_defrag_extent(new);
3155                         atomic_dec(&fs_info->defrag_running);
3156                 } else {
3157                         relink_file_extents(new);
3158                 }
3159         }
3160
3161         /* once for us */
3162         btrfs_put_ordered_extent(ordered_extent);
3163         /* once for the tree */
3164         btrfs_put_ordered_extent(ordered_extent);
3165
3166         return ret;
3167 }
3168
3169 static void finish_ordered_fn(struct btrfs_work *work)
3170 {
3171         struct btrfs_ordered_extent *ordered_extent;
3172         ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3173         btrfs_finish_ordered_io(ordered_extent);
3174 }
3175
3176 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3177                                 struct extent_state *state, int uptodate)
3178 {
3179         struct inode *inode = page->mapping->host;
3180         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3181         struct btrfs_ordered_extent *ordered_extent = NULL;
3182         struct btrfs_workqueue *wq;
3183         btrfs_work_func_t func;
3184
3185         trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3186
3187         ClearPagePrivate2(page);
3188         if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3189                                             end - start + 1, uptodate))
3190                 return;
3191
3192         if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3193                 wq = fs_info->endio_freespace_worker;
3194                 func = btrfs_freespace_write_helper;
3195         } else {
3196                 wq = fs_info->endio_write_workers;
3197                 func = btrfs_endio_write_helper;
3198         }
3199
3200         btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3201                         NULL);
3202         btrfs_queue_work(wq, &ordered_extent->work);
3203 }
3204
3205 static int __readpage_endio_check(struct inode *inode,
3206                                   struct btrfs_io_bio *io_bio,
3207                                   int icsum, struct page *page,
3208                                   int pgoff, u64 start, size_t len)
3209 {
3210         char *kaddr;
3211         u32 csum_expected;
3212         u32 csum = ~(u32)0;
3213
3214         csum_expected = *(((u32 *)io_bio->csum) + icsum);
3215
3216         kaddr = kmap_atomic(page);
3217         csum = btrfs_csum_data(kaddr + pgoff, csum,  len);
3218         btrfs_csum_final(csum, (u8 *)&csum);
3219         if (csum != csum_expected)
3220                 goto zeroit;
3221
3222         kunmap_atomic(kaddr);
3223         return 0;
3224 zeroit:
3225         btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3226                                     io_bio->mirror_num);
3227         memset(kaddr + pgoff, 1, len);
3228         flush_dcache_page(page);
3229         kunmap_atomic(kaddr);
3230         return -EIO;
3231 }
3232
3233 /*
3234  * when reads are done, we need to check csums to verify the data is correct
3235  * if there's a match, we allow the bio to finish.  If not, the code in
3236  * extent_io.c will try to find good copies for us.
3237  */
3238 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3239                                       u64 phy_offset, struct page *page,
3240                                       u64 start, u64 end, int mirror)
3241 {
3242         size_t offset = start - page_offset(page);
3243         struct inode *inode = page->mapping->host;
3244         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3245         struct btrfs_root *root = BTRFS_I(inode)->root;
3246
3247         if (PageChecked(page)) {
3248                 ClearPageChecked(page);
3249                 return 0;
3250         }
3251
3252         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3253                 return 0;
3254
3255         if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3256             test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3257                 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3258                 return 0;
3259         }
3260
3261         phy_offset >>= inode->i_sb->s_blocksize_bits;
3262         return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3263                                       start, (size_t)(end - start + 1));
3264 }
3265
3266 /*
3267  * btrfs_add_delayed_iput - perform a delayed iput on @inode
3268  *
3269  * @inode: The inode we want to perform iput on
3270  *
3271  * This function uses the generic vfs_inode::i_count to track whether we should
3272  * just decrement it (in case it's > 1) or if this is the last iput then link
3273  * the inode to the delayed iput machinery. Delayed iputs are processed at
3274  * transaction commit time/superblock commit/cleaner kthread.
3275  */
3276 void btrfs_add_delayed_iput(struct inode *inode)
3277 {
3278         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3279         struct btrfs_inode *binode = BTRFS_I(inode);
3280
3281         if (atomic_add_unless(&inode->i_count, -1, 1))
3282                 return;
3283
3284         spin_lock(&fs_info->delayed_iput_lock);
3285         ASSERT(list_empty(&binode->delayed_iput));
3286         list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3287         spin_unlock(&fs_info->delayed_iput_lock);
3288 }
3289
3290 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3291 {
3292
3293         spin_lock(&fs_info->delayed_iput_lock);
3294         while (!list_empty(&fs_info->delayed_iputs)) {
3295                 struct btrfs_inode *inode;
3296
3297                 inode = list_first_entry(&fs_info->delayed_iputs,
3298                                 struct btrfs_inode, delayed_iput);
3299                 list_del_init(&inode->delayed_iput);
3300                 spin_unlock(&fs_info->delayed_iput_lock);
3301                 iput(&inode->vfs_inode);
3302                 spin_lock(&fs_info->delayed_iput_lock);
3303         }
3304         spin_unlock(&fs_info->delayed_iput_lock);
3305 }
3306
3307 /*
3308  * This is called in transaction commit time. If there are no orphan
3309  * files in the subvolume, it removes orphan item and frees block_rsv
3310  * structure.
3311  */
3312 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3313                               struct btrfs_root *root)
3314 {
3315         struct btrfs_fs_info *fs_info = root->fs_info;
3316         struct btrfs_block_rsv *block_rsv;
3317         int ret;
3318
3319         if (atomic_read(&root->orphan_inodes) ||
3320             root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3321                 return;
3322
3323         spin_lock(&root->orphan_lock);
3324         if (atomic_read(&root->orphan_inodes)) {
3325                 spin_unlock(&root->orphan_lock);
3326                 return;
3327         }
3328
3329         if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3330                 spin_unlock(&root->orphan_lock);
3331                 return;
3332         }
3333
3334         block_rsv = root->orphan_block_rsv;
3335         root->orphan_block_rsv = NULL;
3336         spin_unlock(&root->orphan_lock);
3337
3338         if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3339             btrfs_root_refs(&root->root_item) > 0) {
3340                 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3341                                             root->root_key.objectid);
3342                 if (ret)
3343                         btrfs_abort_transaction(trans, ret);
3344                 else
3345                         clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3346                                   &root->state);
3347         }
3348
3349         if (block_rsv) {
3350                 WARN_ON(block_rsv->size > 0);
3351                 btrfs_free_block_rsv(fs_info, block_rsv);
3352         }
3353 }
3354
3355 /*
3356  * This creates an orphan entry for the given inode in case something goes
3357  * wrong in the middle of an unlink/truncate.
3358  *
3359  * NOTE: caller of this function should reserve 5 units of metadata for
3360  *       this function.
3361  */
3362 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3363                 struct btrfs_inode *inode)
3364 {
3365         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3366         struct btrfs_root *root = inode->root;
3367         struct btrfs_block_rsv *block_rsv = NULL;
3368         int reserve = 0;
3369         bool insert = false;
3370         int ret;
3371
3372         if (!root->orphan_block_rsv) {
3373                 block_rsv = btrfs_alloc_block_rsv(fs_info,
3374                                                   BTRFS_BLOCK_RSV_TEMP);
3375                 if (!block_rsv)
3376                         return -ENOMEM;
3377         }
3378
3379         if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3380                               &inode->runtime_flags))
3381                 insert = true;
3382
3383         if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3384                               &inode->runtime_flags))
3385                 reserve = 1;
3386
3387         spin_lock(&root->orphan_lock);
3388         /* If someone has created ->orphan_block_rsv, be happy to use it. */
3389         if (!root->orphan_block_rsv) {
3390                 root->orphan_block_rsv = block_rsv;
3391         } else if (block_rsv) {
3392                 btrfs_free_block_rsv(fs_info, block_rsv);
3393                 block_rsv = NULL;
3394         }
3395
3396         if (insert)
3397                 atomic_inc(&root->orphan_inodes);
3398         spin_unlock(&root->orphan_lock);
3399
3400         /* grab metadata reservation from transaction handle */
3401         if (reserve) {
3402                 ret = btrfs_orphan_reserve_metadata(trans, inode);
3403                 ASSERT(!ret);
3404                 if (ret) {
3405                         /*
3406                          * dec doesn't need spin_lock as ->orphan_block_rsv
3407                          * would be released only if ->orphan_inodes is
3408                          * zero.
3409                          */
3410                         atomic_dec(&root->orphan_inodes);
3411                         clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3412                                   &inode->runtime_flags);
3413                         if (insert)
3414                                 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3415                                           &inode->runtime_flags);
3416                         return ret;
3417                 }
3418         }
3419
3420         /* insert an orphan item to track this unlinked/truncated file */
3421         if (insert) {
3422                 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3423                 if (ret) {
3424                         if (reserve) {
3425                                 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3426                                           &inode->runtime_flags);
3427                                 btrfs_orphan_release_metadata(inode);
3428                         }
3429                         /*
3430                          * btrfs_orphan_commit_root may race with us and set
3431                          * ->orphan_block_rsv to zero, in order to avoid that,
3432                          * decrease ->orphan_inodes after everything is done.
3433                          */
3434                         atomic_dec(&root->orphan_inodes);
3435                         if (ret != -EEXIST) {
3436                                 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3437                                           &inode->runtime_flags);
3438                                 btrfs_abort_transaction(trans, ret);
3439                                 return ret;
3440                         }
3441                 }
3442                 ret = 0;
3443         }
3444
3445         return 0;
3446 }
3447
3448 /*
3449  * We have done the truncate/delete so we can go ahead and remove the orphan
3450  * item for this particular inode.
3451  */
3452 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3453                             struct btrfs_inode *inode)
3454 {
3455         struct btrfs_root *root = inode->root;
3456         int delete_item = 0;
3457         int ret = 0;
3458
3459         if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3460                                &inode->runtime_flags))
3461                 delete_item = 1;
3462
3463         if (delete_item && trans)
3464                 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3465
3466         if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3467                                &inode->runtime_flags))
3468                 btrfs_orphan_release_metadata(inode);
3469
3470         /*
3471          * btrfs_orphan_commit_root may race with us and set ->orphan_block_rsv
3472          * to zero, in order to avoid that, decrease ->orphan_inodes after
3473          * everything is done.
3474          */
3475         if (delete_item)
3476                 atomic_dec(&root->orphan_inodes);
3477
3478         return ret;
3479 }
3480
3481 /*
3482  * this cleans up any orphans that may be left on the list from the last use
3483  * of this root.
3484  */
3485 int btrfs_orphan_cleanup(struct btrfs_root *root)
3486 {
3487         struct btrfs_fs_info *fs_info = root->fs_info;
3488         struct btrfs_path *path;
3489         struct extent_buffer *leaf;
3490         struct btrfs_key key, found_key;
3491         struct btrfs_trans_handle *trans;
3492         struct inode *inode;
3493         u64 last_objectid = 0;
3494         int ret = 0, nr_unlink = 0, nr_truncate = 0;
3495
3496         if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3497                 return 0;
3498
3499         path = btrfs_alloc_path();
3500         if (!path) {
3501                 ret = -ENOMEM;
3502                 goto out;
3503         }
3504         path->reada = READA_BACK;
3505
3506         key.objectid = BTRFS_ORPHAN_OBJECTID;
3507         key.type = BTRFS_ORPHAN_ITEM_KEY;
3508         key.offset = (u64)-1;
3509
3510         while (1) {
3511                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3512                 if (ret < 0)
3513                         goto out;
3514
3515                 /*
3516                  * if ret == 0 means we found what we were searching for, which
3517                  * is weird, but possible, so only screw with path if we didn't
3518                  * find the key and see if we have stuff that matches
3519                  */
3520                 if (ret > 0) {
3521                         ret = 0;
3522                         if (path->slots[0] == 0)
3523                                 break;
3524                         path->slots[0]--;
3525                 }
3526
3527                 /* pull out the item */
3528                 leaf = path->nodes[0];
3529                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3530
3531                 /* make sure the item matches what we want */
3532                 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3533                         break;
3534                 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3535                         break;
3536
3537                 /* release the path since we're done with it */
3538                 btrfs_release_path(path);
3539
3540                 /*
3541                  * this is where we are basically btrfs_lookup, without the
3542                  * crossing root thing.  we store the inode number in the
3543                  * offset of the orphan item.
3544                  */
3545
3546                 if (found_key.offset == last_objectid) {
3547                         btrfs_err(fs_info,
3548                                   "Error removing orphan entry, stopping orphan cleanup");
3549                         ret = -EINVAL;
3550                         goto out;
3551                 }
3552
3553                 last_objectid = found_key.offset;
3554
3555                 found_key.objectid = found_key.offset;
3556                 found_key.type = BTRFS_INODE_ITEM_KEY;
3557                 found_key.offset = 0;
3558                 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3559                 ret = PTR_ERR_OR_ZERO(inode);
3560                 if (ret && ret != -ENOENT)
3561                         goto out;
3562
3563                 if (ret == -ENOENT && root == fs_info->tree_root) {
3564                         struct btrfs_root *dead_root;
3565                         struct btrfs_fs_info *fs_info = root->fs_info;
3566                         int is_dead_root = 0;
3567
3568                         /*
3569                          * this is an orphan in the tree root. Currently these
3570                          * could come from 2 sources:
3571                          *  a) a snapshot deletion in progress
3572                          *  b) a free space cache inode
3573                          * We need to distinguish those two, as the snapshot
3574                          * orphan must not get deleted.
3575                          * find_dead_roots already ran before us, so if this
3576                          * is a snapshot deletion, we should find the root
3577                          * in the dead_roots list
3578                          */
3579                         spin_lock(&fs_info->trans_lock);
3580                         list_for_each_entry(dead_root, &fs_info->dead_roots,
3581                                             root_list) {
3582                                 if (dead_root->root_key.objectid ==
3583                                     found_key.objectid) {
3584                                         is_dead_root = 1;
3585                                         break;
3586                                 }
3587                         }
3588                         spin_unlock(&fs_info->trans_lock);
3589                         if (is_dead_root) {
3590                                 /* prevent this orphan from being found again */
3591                                 key.offset = found_key.objectid - 1;
3592                                 continue;
3593                         }
3594                 }
3595                 /*
3596                  * Inode is already gone but the orphan item is still there,
3597                  * kill the orphan item.
3598                  */
3599                 if (ret == -ENOENT) {
3600                         trans = btrfs_start_transaction(root, 1);
3601                         if (IS_ERR(trans)) {
3602                                 ret = PTR_ERR(trans);
3603                                 goto out;
3604                         }
3605                         btrfs_debug(fs_info, "auto deleting %Lu",
3606                                     found_key.objectid);
3607                         ret = btrfs_del_orphan_item(trans, root,
3608                                                     found_key.objectid);
3609                         btrfs_end_transaction(trans);
3610                         if (ret)
3611                                 goto out;
3612                         continue;
3613                 }
3614
3615                 /*
3616                  * add this inode to the orphan list so btrfs_orphan_del does
3617                  * the proper thing when we hit it
3618                  */
3619                 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3620                         &BTRFS_I(inode)->runtime_flags);
3621                 atomic_inc(&root->orphan_inodes);
3622
3623                 /* if we have links, this was a truncate, lets do that */
3624                 if (inode->i_nlink) {
3625                         if (WARN_ON(!S_ISREG(inode->i_mode))) {
3626                                 iput(inode);
3627                                 continue;
3628                         }
3629                         nr_truncate++;
3630
3631                         /* 1 for the orphan item deletion. */
3632                         trans = btrfs_start_transaction(root, 1);
3633                         if (IS_ERR(trans)) {
3634                                 iput(inode);
3635                                 ret = PTR_ERR(trans);
3636                                 goto out;
3637                         }
3638                         ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3639                         btrfs_end_transaction(trans);
3640                         if (ret) {
3641                                 iput(inode);
3642                                 goto out;
3643                         }
3644
3645                         ret = btrfs_truncate(inode, false);
3646                         if (ret)
3647                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
3648                 } else {
3649                         nr_unlink++;
3650                 }
3651
3652                 /* this will do delete_inode and everything for us */
3653                 iput(inode);
3654                 if (ret)
3655                         goto out;
3656         }
3657         /* release the path since we're done with it */
3658         btrfs_release_path(path);
3659
3660         root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3661
3662         if (root->orphan_block_rsv)
3663                 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3664                                         (u64)-1);
3665
3666         if (root->orphan_block_rsv ||
3667             test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3668                 trans = btrfs_join_transaction(root);
3669                 if (!IS_ERR(trans))
3670                         btrfs_end_transaction(trans);
3671         }
3672
3673         if (nr_unlink)
3674                 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3675         if (nr_truncate)
3676                 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3677
3678 out:
3679         if (ret)
3680                 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3681         btrfs_free_path(path);
3682         return ret;
3683 }
3684
3685 /*
3686  * very simple check to peek ahead in the leaf looking for xattrs.  If we
3687  * don't find any xattrs, we know there can't be any acls.
3688  *
3689  * slot is the slot the inode is in, objectid is the objectid of the inode
3690  */
3691 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3692                                           int slot, u64 objectid,
3693                                           int *first_xattr_slot)
3694 {
3695         u32 nritems = btrfs_header_nritems(leaf);
3696         struct btrfs_key found_key;
3697         static u64 xattr_access = 0;
3698         static u64 xattr_default = 0;
3699         int scanned = 0;
3700
3701         if (!xattr_access) {
3702                 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3703                                         strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3704                 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3705                                         strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3706         }
3707
3708         slot++;
3709         *first_xattr_slot = -1;
3710         while (slot < nritems) {
3711                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3712
3713                 /* we found a different objectid, there must not be acls */
3714                 if (found_key.objectid != objectid)
3715                         return 0;
3716
3717                 /* we found an xattr, assume we've got an acl */
3718                 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3719                         if (*first_xattr_slot == -1)
3720                                 *first_xattr_slot = slot;
3721                         if (found_key.offset == xattr_access ||
3722                             found_key.offset == xattr_default)
3723                                 return 1;
3724                 }
3725
3726                 /*
3727                  * we found a key greater than an xattr key, there can't
3728                  * be any acls later on
3729                  */
3730                 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3731                         return 0;
3732
3733                 slot++;
3734                 scanned++;
3735
3736                 /*
3737                  * it goes inode, inode backrefs, xattrs, extents,
3738                  * so if there are a ton of hard links to an inode there can
3739                  * be a lot of backrefs.  Don't waste time searching too hard,
3740                  * this is just an optimization
3741                  */
3742                 if (scanned >= 8)
3743                         break;
3744         }
3745         /* we hit the end of the leaf before we found an xattr or
3746          * something larger than an xattr.  We have to assume the inode
3747          * has acls
3748          */
3749         if (*first_xattr_slot == -1)
3750                 *first_xattr_slot = slot;
3751         return 1;
3752 }
3753
3754 /*
3755  * read an inode from the btree into the in-memory inode
3756  */
3757 static int btrfs_read_locked_inode(struct inode *inode)
3758 {
3759         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3760         struct btrfs_path *path;
3761         struct extent_buffer *leaf;
3762         struct btrfs_inode_item *inode_item;
3763         struct btrfs_root *root = BTRFS_I(inode)->root;
3764         struct btrfs_key location;
3765         unsigned long ptr;
3766         int maybe_acls;
3767         u32 rdev;
3768         int ret;
3769         bool filled = false;
3770         int first_xattr_slot;
3771
3772         ret = btrfs_fill_inode(inode, &rdev);
3773         if (!ret)
3774                 filled = true;
3775
3776         path = btrfs_alloc_path();
3777         if (!path) {
3778                 ret = -ENOMEM;
3779                 goto make_bad;
3780         }
3781
3782         memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3783
3784         ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3785         if (ret) {
3786                 if (ret > 0)
3787                         ret = -ENOENT;
3788                 goto make_bad;
3789         }
3790
3791         leaf = path->nodes[0];
3792
3793         if (filled)
3794                 goto cache_index;
3795
3796         inode_item = btrfs_item_ptr(leaf, path->slots[0],
3797                                     struct btrfs_inode_item);
3798         inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3799         set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3800         i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3801         i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3802         btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3803
3804         inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3805         inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3806
3807         inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3808         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3809
3810         inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3811         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3812
3813         BTRFS_I(inode)->i_otime.tv_sec =
3814                 btrfs_timespec_sec(leaf, &inode_item->otime);
3815         BTRFS_I(inode)->i_otime.tv_nsec =
3816                 btrfs_timespec_nsec(leaf, &inode_item->otime);
3817
3818         inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3819         BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3820         BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3821
3822         inode_set_iversion_queried(inode,
3823                                    btrfs_inode_sequence(leaf, inode_item));
3824         inode->i_generation = BTRFS_I(inode)->generation;
3825         inode->i_rdev = 0;
3826         rdev = btrfs_inode_rdev(leaf, inode_item);
3827
3828         BTRFS_I(inode)->index_cnt = (u64)-1;
3829         BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3830
3831 cache_index:
3832         /*
3833          * If we were modified in the current generation and evicted from memory
3834          * and then re-read we need to do a full sync since we don't have any
3835          * idea about which extents were modified before we were evicted from
3836          * cache.
3837          *
3838          * This is required for both inode re-read from disk and delayed inode
3839          * in delayed_nodes_tree.
3840          */
3841         if (BTRFS_I(inode)->last_trans == fs_info->generation)
3842                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3843                         &BTRFS_I(inode)->runtime_flags);
3844
3845         /*
3846          * We don't persist the id of the transaction where an unlink operation
3847          * against the inode was last made. So here we assume the inode might
3848          * have been evicted, and therefore the exact value of last_unlink_trans
3849          * lost, and set it to last_trans to avoid metadata inconsistencies
3850          * between the inode and its parent if the inode is fsync'ed and the log
3851          * replayed. For example, in the scenario:
3852          *
3853          * touch mydir/foo
3854          * ln mydir/foo mydir/bar
3855          * sync
3856          * unlink mydir/bar
3857          * echo 2 > /proc/sys/vm/drop_caches   # evicts inode
3858          * xfs_io -c fsync mydir/foo
3859          * <power failure>
3860          * mount fs, triggers fsync log replay
3861          *
3862          * We must make sure that when we fsync our inode foo we also log its
3863          * parent inode, otherwise after log replay the parent still has the
3864          * dentry with the "bar" name but our inode foo has a link count of 1
3865          * and doesn't have an inode ref with the name "bar" anymore.
3866          *
3867          * Setting last_unlink_trans to last_trans is a pessimistic approach,
3868          * but it guarantees correctness at the expense of occasional full
3869          * transaction commits on fsync if our inode is a directory, or if our
3870          * inode is not a directory, logging its parent unnecessarily.
3871          */
3872         BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3873
3874         path->slots[0]++;
3875         if (inode->i_nlink != 1 ||
3876             path->slots[0] >= btrfs_header_nritems(leaf))
3877                 goto cache_acl;
3878
3879         btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3880         if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3881                 goto cache_acl;
3882
3883         ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3884         if (location.type == BTRFS_INODE_REF_KEY) {
3885                 struct btrfs_inode_ref *ref;
3886
3887                 ref = (struct btrfs_inode_ref *)ptr;
3888                 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3889         } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3890                 struct btrfs_inode_extref *extref;
3891
3892                 extref = (struct btrfs_inode_extref *)ptr;
3893                 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3894                                                                      extref);
3895         }
3896 cache_acl:
3897         /*
3898          * try to precache a NULL acl entry for files that don't have
3899          * any xattrs or acls
3900          */
3901         maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3902                         btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3903         if (first_xattr_slot != -1) {
3904                 path->slots[0] = first_xattr_slot;
3905                 ret = btrfs_load_inode_props(inode, path);
3906                 if (ret)
3907                         btrfs_err(fs_info,
3908                                   "error loading props for ino %llu (root %llu): %d",
3909                                   btrfs_ino(BTRFS_I(inode)),
3910                                   root->root_key.objectid, ret);
3911         }
3912         btrfs_free_path(path);
3913
3914         if (!maybe_acls)
3915                 cache_no_acl(inode);
3916
3917         switch (inode->i_mode & S_IFMT) {
3918         case S_IFREG:
3919                 inode->i_mapping->a_ops = &btrfs_aops;
3920                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3921                 inode->i_fop = &btrfs_file_operations;
3922                 inode->i_op = &btrfs_file_inode_operations;
3923                 break;
3924         case S_IFDIR:
3925                 inode->i_fop = &btrfs_dir_file_operations;
3926                 inode->i_op = &btrfs_dir_inode_operations;
3927                 break;
3928         case S_IFLNK:
3929                 inode->i_op = &btrfs_symlink_inode_operations;
3930                 inode_nohighmem(inode);
3931                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3932                 break;
3933         default:
3934                 inode->i_op = &btrfs_special_inode_operations;
3935                 init_special_inode(inode, inode->i_mode, rdev);
3936                 break;
3937         }
3938
3939         btrfs_update_iflags(inode);
3940         return 0;
3941
3942 make_bad:
3943         btrfs_free_path(path);
3944         make_bad_inode(inode);
3945         return ret;
3946 }
3947
3948 /*
3949  * given a leaf and an inode, copy the inode fields into the leaf
3950  */
3951 static void fill_inode_item(struct btrfs_trans_handle *trans,
3952                             struct extent_buffer *leaf,
3953                             struct btrfs_inode_item *item,
3954                             struct inode *inode)
3955 {
3956         struct btrfs_map_token token;
3957
3958         btrfs_init_map_token(&token);
3959
3960         btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3961         btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3962         btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3963                                    &token);
3964         btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3965         btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3966
3967         btrfs_set_token_timespec_sec(leaf, &item->atime,
3968                                      inode->i_atime.tv_sec, &token);
3969         btrfs_set_token_timespec_nsec(leaf, &item->atime,
3970                                       inode->i_atime.tv_nsec, &token);
3971
3972         btrfs_set_token_timespec_sec(leaf, &item->mtime,
3973                                      inode->i_mtime.tv_sec, &token);
3974         btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3975                                       inode->i_mtime.tv_nsec, &token);
3976
3977         btrfs_set_token_timespec_sec(leaf, &item->ctime,
3978                                      inode->i_ctime.tv_sec, &token);
3979         btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3980                                       inode->i_ctime.tv_nsec, &token);
3981
3982         btrfs_set_token_timespec_sec(leaf, &item->otime,
3983                                      BTRFS_I(inode)->i_otime.tv_sec, &token);
3984         btrfs_set_token_timespec_nsec(leaf, &item->otime,
3985                                       BTRFS_I(inode)->i_otime.tv_nsec, &token);
3986
3987         btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3988                                      &token);
3989         btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3990                                          &token);
3991         btrfs_set_token_inode_sequence(leaf, item, inode_peek_iversion(inode),
3992                                        &token);
3993         btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3994         btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3995         btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3996         btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3997 }
3998
3999 /*
4000  * copy everything in the in-memory inode into the btree.
4001  */
4002 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
4003                                 struct btrfs_root *root, struct inode *inode)
4004 {
4005         struct btrfs_inode_item *inode_item;
4006         struct btrfs_path *path;
4007         struct extent_buffer *leaf;
4008         int ret;
4009
4010         path = btrfs_alloc_path();
4011         if (!path)
4012                 return -ENOMEM;
4013
4014         path->leave_spinning = 1;
4015         ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
4016                                  1);
4017         if (ret) {
4018                 if (ret > 0)
4019                         ret = -ENOENT;
4020                 goto failed;
4021         }
4022
4023         leaf = path->nodes[0];
4024         inode_item = btrfs_item_ptr(leaf, path->slots[0],
4025                                     struct btrfs_inode_item);
4026
4027         fill_inode_item(trans, leaf, inode_item, inode);
4028         btrfs_mark_buffer_dirty(leaf);
4029         btrfs_set_inode_last_trans(trans, inode);
4030         ret = 0;
4031 failed:
4032         btrfs_free_path(path);
4033         return ret;
4034 }
4035
4036 /*
4037  * copy everything in the in-memory inode into the btree.
4038  */
4039 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
4040                                 struct btrfs_root *root, struct inode *inode)
4041 {
4042         struct btrfs_fs_info *fs_info = root->fs_info;
4043         int ret;
4044
4045         /*
4046          * If the inode is a free space inode, we can deadlock during commit
4047          * if we put it into the delayed code.
4048          *
4049          * The data relocation inode should also be directly updated
4050          * without delay
4051          */
4052         if (!btrfs_is_free_space_inode(BTRFS_I(inode))
4053             && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
4054             && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4055                 btrfs_update_root_times(trans, root);
4056
4057                 ret = btrfs_delayed_update_inode(trans, root, inode);
4058                 if (!ret)
4059                         btrfs_set_inode_last_trans(trans, inode);
4060                 return ret;
4061         }
4062
4063         return btrfs_update_inode_item(trans, root, inode);
4064 }
4065
4066 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4067                                          struct btrfs_root *root,
4068                                          struct inode *inode)
4069 {
4070         int ret;
4071
4072         ret = btrfs_update_inode(trans, root, inode);
4073         if (ret == -ENOSPC)
4074                 return btrfs_update_inode_item(trans, root, inode);
4075         return ret;
4076 }
4077
4078 /*
4079  * unlink helper that gets used here in inode.c and in the tree logging
4080  * recovery code.  It remove a link in a directory with a given name, and
4081  * also drops the back refs in the inode to the directory
4082  */
4083 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4084                                 struct btrfs_root *root,
4085                                 struct btrfs_inode *dir,
4086                                 struct btrfs_inode *inode,
4087                                 const char *name, int name_len)
4088 {
4089         struct btrfs_fs_info *fs_info = root->fs_info;
4090         struct btrfs_path *path;
4091         int ret = 0;
4092         struct extent_buffer *leaf;
4093         struct btrfs_dir_item *di;
4094         struct btrfs_key key;
4095         u64 index;
4096         u64 ino = btrfs_ino(inode);
4097         u64 dir_ino = btrfs_ino(dir);
4098
4099         path = btrfs_alloc_path();
4100         if (!path) {
4101                 ret = -ENOMEM;
4102                 goto out;
4103         }
4104
4105         path->leave_spinning = 1;
4106         di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4107                                     name, name_len, -1);
4108         if (IS_ERR(di)) {
4109                 ret = PTR_ERR(di);
4110                 goto err;
4111         }
4112         if (!di) {
4113                 ret = -ENOENT;
4114                 goto err;
4115         }
4116         leaf = path->nodes[0];
4117         btrfs_dir_item_key_to_cpu(leaf, di, &key);
4118         ret = btrfs_delete_one_dir_name(trans, root, path, di);
4119         if (ret)
4120                 goto err;
4121         btrfs_release_path(path);
4122
4123         /*
4124          * If we don't have dir index, we have to get it by looking up
4125          * the inode ref, since we get the inode ref, remove it directly,
4126          * it is unnecessary to do delayed deletion.
4127          *
4128          * But if we have dir index, needn't search inode ref to get it.
4129          * Since the inode ref is close to the inode item, it is better
4130          * that we delay to delete it, and just do this deletion when
4131          * we update the inode item.
4132          */
4133         if (inode->dir_index) {
4134                 ret = btrfs_delayed_delete_inode_ref(inode);
4135                 if (!ret) {
4136                         index = inode->dir_index;
4137                         goto skip_backref;
4138                 }
4139         }
4140
4141         ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4142                                   dir_ino, &index);
4143         if (ret) {
4144                 btrfs_info(fs_info,
4145                         "failed to delete reference to %.*s, inode %llu parent %llu",
4146                         name_len, name, ino, dir_ino);
4147                 btrfs_abort_transaction(trans, ret);
4148                 goto err;
4149         }
4150 skip_backref:
4151         ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4152         if (ret) {
4153                 btrfs_abort_transaction(trans, ret);
4154                 goto err;
4155         }
4156
4157         ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4158                         dir_ino);
4159         if (ret != 0 && ret != -ENOENT) {
4160                 btrfs_abort_transaction(trans, ret);
4161                 goto err;
4162         }
4163
4164         ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4165                         index);
4166         if (ret == -ENOENT)
4167                 ret = 0;
4168         else if (ret)
4169                 btrfs_abort_transaction(trans, ret);
4170 err:
4171         btrfs_free_path(path);
4172         if (ret)
4173                 goto out;
4174
4175         btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4176         inode_inc_iversion(&inode->vfs_inode);
4177         inode_inc_iversion(&dir->vfs_inode);
4178         inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4179                 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4180         ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4181 out:
4182         return ret;
4183 }
4184
4185 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4186                        struct btrfs_root *root,
4187                        struct btrfs_inode *dir, struct btrfs_inode *inode,
4188                        const char *name, int name_len)
4189 {
4190         int ret;
4191         ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4192         if (!ret) {
4193                 drop_nlink(&inode->vfs_inode);
4194                 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4195         }
4196         return ret;
4197 }
4198
4199 /*
4200  * helper to start transaction for unlink and rmdir.
4201  *
4202  * unlink and rmdir are special in btrfs, they do not always free space, so
4203  * if we cannot make our reservations the normal way try and see if there is
4204  * plenty of slack room in the global reserve to migrate, otherwise we cannot
4205  * allow the unlink to occur.
4206  */
4207 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4208 {
4209         struct btrfs_root *root = BTRFS_I(dir)->root;
4210
4211         /*
4212          * 1 for the possible orphan item
4213          * 1 for the dir item
4214          * 1 for the dir index
4215          * 1 for the inode ref
4216          * 1 for the inode
4217          */
4218         return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4219 }
4220
4221 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4222 {
4223         struct btrfs_root *root = BTRFS_I(dir)->root;
4224         struct btrfs_trans_handle *trans;
4225         struct inode *inode = d_inode(dentry);
4226         int ret;
4227
4228         trans = __unlink_start_trans(dir);
4229         if (IS_ERR(trans))
4230                 return PTR_ERR(trans);
4231
4232         btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4233                         0);
4234
4235         ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4236                         BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4237                         dentry->d_name.len);
4238         if (ret)
4239                 goto out;
4240
4241         if (inode->i_nlink == 0) {
4242                 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4243                 if (ret)
4244                         goto out;
4245         }
4246
4247 out:
4248         btrfs_end_transaction(trans);
4249         btrfs_btree_balance_dirty(root->fs_info);
4250         return ret;
4251 }
4252
4253 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4254                         struct btrfs_root *root,
4255                         struct inode *dir, u64 objectid,
4256                         const char *name, int name_len)
4257 {
4258         struct btrfs_fs_info *fs_info = root->fs_info;
4259         struct btrfs_path *path;
4260         struct extent_buffer *leaf;
4261         struct btrfs_dir_item *di;
4262         struct btrfs_key key;
4263         u64 index;
4264         int ret;
4265         u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4266
4267         path = btrfs_alloc_path();
4268         if (!path)
4269                 return -ENOMEM;
4270
4271         di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4272                                    name, name_len, -1);
4273         if (IS_ERR_OR_NULL(di)) {
4274                 if (!di)
4275                         ret = -ENOENT;
4276                 else
4277                         ret = PTR_ERR(di);
4278                 goto out;
4279         }
4280
4281         leaf = path->nodes[0];
4282         btrfs_dir_item_key_to_cpu(leaf, di, &key);
4283         WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4284         ret = btrfs_delete_one_dir_name(trans, root, path, di);
4285         if (ret) {
4286                 btrfs_abort_transaction(trans, ret);
4287                 goto out;
4288         }
4289         btrfs_release_path(path);
4290
4291         ret = btrfs_del_root_ref(trans, fs_info, objectid,
4292                                  root->root_key.objectid, dir_ino,
4293                                  &index, name, name_len);
4294         if (ret < 0) {
4295                 if (ret != -ENOENT) {
4296                         btrfs_abort_transaction(trans, ret);
4297                         goto out;
4298                 }
4299                 di = btrfs_search_dir_index_item(root, path, dir_ino,
4300                                                  name, name_len);
4301                 if (IS_ERR_OR_NULL(di)) {
4302                         if (!di)
4303                                 ret = -ENOENT;
4304                         else
4305                                 ret = PTR_ERR(di);
4306                         btrfs_abort_transaction(trans, ret);
4307                         goto out;
4308                 }
4309
4310                 leaf = path->nodes[0];
4311                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4312                 btrfs_release_path(path);
4313                 index = key.offset;
4314         }
4315         btrfs_release_path(path);
4316
4317         ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4318         if (ret) {
4319                 btrfs_abort_transaction(trans, ret);
4320                 goto out;
4321         }
4322
4323         btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4324         inode_inc_iversion(dir);
4325         dir->i_mtime = dir->i_ctime = current_time(dir);
4326         ret = btrfs_update_inode_fallback(trans, root, dir);
4327         if (ret)
4328                 btrfs_abort_transaction(trans, ret);
4329 out:
4330         btrfs_free_path(path);
4331         return ret;
4332 }
4333
4334 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4335 {
4336         struct inode *inode = d_inode(dentry);
4337         int err = 0;
4338         struct btrfs_root *root = BTRFS_I(dir)->root;
4339         struct btrfs_trans_handle *trans;
4340         u64 last_unlink_trans;
4341
4342         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4343                 return -ENOTEMPTY;
4344         if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4345                 return -EPERM;
4346
4347         trans = __unlink_start_trans(dir);
4348         if (IS_ERR(trans))
4349                 return PTR_ERR(trans);
4350
4351         if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4352                 err = btrfs_unlink_subvol(trans, root, dir,
4353                                           BTRFS_I(inode)->location.objectid,
4354                                           dentry->d_name.name,
4355                                           dentry->d_name.len);
4356                 goto out;
4357         }
4358
4359         err = btrfs_orphan_add(trans, BTRFS_I(inode));
4360         if (err)
4361                 goto out;
4362
4363         last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4364
4365         /* now the directory is empty */
4366         err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4367                         BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4368                         dentry->d_name.len);
4369         if (!err) {
4370                 btrfs_i_size_write(BTRFS_I(inode), 0);
4371                 /*
4372                  * Propagate the last_unlink_trans value of the deleted dir to
4373                  * its parent directory. This is to prevent an unrecoverable
4374                  * log tree in the case we do something like this:
4375                  * 1) create dir foo
4376                  * 2) create snapshot under dir foo
4377                  * 3) delete the snapshot
4378                  * 4) rmdir foo
4379                  * 5) mkdir foo
4380                  * 6) fsync foo or some file inside foo
4381                  */
4382                 if (last_unlink_trans >= trans->transid)
4383                         BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4384         }
4385 out:
4386         btrfs_end_transaction(trans);
4387         btrfs_btree_balance_dirty(root->fs_info);
4388
4389         return err;
4390 }
4391
4392 static int truncate_space_check(struct btrfs_trans_handle *trans,
4393                                 struct btrfs_root *root,
4394                                 u64 bytes_deleted)
4395 {
4396         struct btrfs_fs_info *fs_info = root->fs_info;
4397         int ret;
4398
4399         /*
4400          * This is only used to apply pressure to the enospc system, we don't
4401          * intend to use this reservation at all.
4402          */
4403         bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4404         bytes_deleted *= fs_info->nodesize;
4405         ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4406                                   bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4407         if (!ret) {
4408                 trace_btrfs_space_reservation(fs_info, "transaction",
4409                                               trans->transid,
4410                                               bytes_deleted, 1);
4411                 trans->bytes_reserved += bytes_deleted;
4412         }
4413         return ret;
4414
4415 }
4416
4417 /*
4418  * Return this if we need to call truncate_block for the last bit of the
4419  * truncate.
4420  */
4421 #define NEED_TRUNCATE_BLOCK 1
4422
4423 /*
4424  * this can truncate away extent items, csum items and directory items.
4425  * It starts at a high offset and removes keys until it can't find
4426  * any higher than new_size
4427  *
4428  * csum items that cross the new i_size are truncated to the new size
4429  * as well.
4430  *
4431  * min_type is the minimum key type to truncate down to.  If set to 0, this
4432  * will kill all the items on this inode, including the INODE_ITEM_KEY.
4433  */
4434 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4435                                struct btrfs_root *root,
4436                                struct inode *inode,
4437                                u64 new_size, u32 min_type)
4438 {
4439         struct btrfs_fs_info *fs_info = root->fs_info;
4440         struct btrfs_path *path;
4441         struct extent_buffer *leaf;
4442         struct btrfs_file_extent_item *fi;
4443         struct btrfs_key key;
4444         struct btrfs_key found_key;
4445         u64 extent_start = 0;
4446         u64 extent_num_bytes = 0;
4447         u64 extent_offset = 0;
4448         u64 item_end = 0;
4449         u64 last_size = new_size;
4450         u32 found_type = (u8)-1;
4451         int found_extent;
4452         int del_item;
4453         int pending_del_nr = 0;
4454         int pending_del_slot = 0;
4455         int extent_type = -1;
4456         int ret;
4457         int err = 0;
4458         u64 ino = btrfs_ino(BTRFS_I(inode));
4459         u64 bytes_deleted = 0;
4460         bool be_nice = false;
4461         bool should_throttle = false;
4462         bool should_end = false;
4463
4464         BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4465
4466         /*
4467          * for non-free space inodes and ref cows, we want to back off from
4468          * time to time
4469          */
4470         if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4471             test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4472                 be_nice = true;
4473
4474         path = btrfs_alloc_path();
4475         if (!path)
4476                 return -ENOMEM;
4477         path->reada = READA_BACK;
4478
4479         /*
4480          * We want to drop from the next block forward in case this new size is
4481          * not block aligned since we will be keeping the last block of the
4482          * extent just the way it is.
4483          */
4484         if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4485             root == fs_info->tree_root)
4486                 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4487                                         fs_info->sectorsize),
4488                                         (u64)-1, 0);
4489
4490         /*
4491          * This function is also used to drop the items in the log tree before
4492          * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4493          * it is used to drop the loged items. So we shouldn't kill the delayed
4494          * items.
4495          */
4496         if (min_type == 0 && root == BTRFS_I(inode)->root)
4497                 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4498
4499         key.objectid = ino;
4500         key.offset = (u64)-1;
4501         key.type = (u8)-1;
4502
4503 search_again:
4504         /*
4505          * with a 16K leaf size and 128MB extents, you can actually queue
4506          * up a huge file in a single leaf.  Most of the time that
4507          * bytes_deleted is > 0, it will be huge by the time we get here
4508          */
4509         if (be_nice && bytes_deleted > SZ_32M) {
4510                 if (btrfs_should_end_transaction(trans)) {
4511                         err = -EAGAIN;
4512                         goto error;
4513                 }
4514         }
4515
4516
4517         path->leave_spinning = 1;
4518         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4519         if (ret < 0) {
4520                 err = ret;
4521                 goto out;
4522         }
4523
4524         if (ret > 0) {
4525                 /* there are no items in the tree for us to truncate, we're
4526                  * done
4527                  */
4528                 if (path->slots[0] == 0)
4529                         goto out;
4530                 path->slots[0]--;
4531         }
4532
4533         while (1) {
4534                 fi = NULL;
4535                 leaf = path->nodes[0];
4536                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4537                 found_type = found_key.type;
4538
4539                 if (found_key.objectid != ino)
4540                         break;
4541
4542                 if (found_type < min_type)
4543                         break;
4544
4545                 item_end = found_key.offset;
4546                 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4547                         fi = btrfs_item_ptr(leaf, path->slots[0],
4548                                             struct btrfs_file_extent_item);
4549                         extent_type = btrfs_file_extent_type(leaf, fi);
4550                         if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4551                                 item_end +=
4552                                     btrfs_file_extent_num_bytes(leaf, fi);
4553
4554                                 trace_btrfs_truncate_show_fi_regular(
4555                                         BTRFS_I(inode), leaf, fi,
4556                                         found_key.offset);
4557                         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4558                                 item_end += btrfs_file_extent_inline_len(leaf,
4559                                                          path->slots[0], fi);
4560
4561                                 trace_btrfs_truncate_show_fi_inline(
4562                                         BTRFS_I(inode), leaf, fi, path->slots[0],
4563                                         found_key.offset);
4564                         }
4565                         item_end--;
4566                 }
4567                 if (found_type > min_type) {
4568                         del_item = 1;
4569                 } else {
4570                         if (item_end < new_size)
4571                                 break;
4572                         if (found_key.offset >= new_size)
4573                                 del_item = 1;
4574                         else
4575                                 del_item = 0;
4576                 }
4577                 found_extent = 0;
4578                 /* FIXME, shrink the extent if the ref count is only 1 */
4579                 if (found_type != BTRFS_EXTENT_DATA_KEY)
4580                         goto delete;
4581
4582                 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4583                         u64 num_dec;
4584                         extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4585                         if (!del_item) {
4586                                 u64 orig_num_bytes =
4587                                         btrfs_file_extent_num_bytes(leaf, fi);
4588                                 extent_num_bytes = ALIGN(new_size -
4589                                                 found_key.offset,
4590                                                 fs_info->sectorsize);
4591                                 btrfs_set_file_extent_num_bytes(leaf, fi,
4592                                                          extent_num_bytes);
4593                                 num_dec = (orig_num_bytes -
4594                                            extent_num_bytes);
4595                                 if (test_bit(BTRFS_ROOT_REF_COWS,
4596                                              &root->state) &&
4597                                     extent_start != 0)
4598                                         inode_sub_bytes(inode, num_dec);
4599                                 btrfs_mark_buffer_dirty(leaf);
4600                         } else {
4601                                 extent_num_bytes =
4602                                         btrfs_file_extent_disk_num_bytes(leaf,
4603                                                                          fi);
4604                                 extent_offset = found_key.offset -
4605                                         btrfs_file_extent_offset(leaf, fi);
4606
4607                                 /* FIXME blocksize != 4096 */
4608                                 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4609                                 if (extent_start != 0) {
4610                                         found_extent = 1;
4611                                         if (test_bit(BTRFS_ROOT_REF_COWS,
4612                                                      &root->state))
4613                                                 inode_sub_bytes(inode, num_dec);
4614                                 }
4615                         }
4616                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4617                         /*
4618                          * we can't truncate inline items that have had
4619                          * special encodings
4620                          */
4621                         if (!del_item &&
4622                             btrfs_file_extent_encryption(leaf, fi) == 0 &&
4623                             btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
4624                             btrfs_file_extent_compression(leaf, fi) == 0) {
4625                                 u32 size = (u32)(new_size - found_key.offset);
4626
4627                                 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4628                                 size = btrfs_file_extent_calc_inline_size(size);
4629                                 btrfs_truncate_item(root->fs_info, path, size, 1);
4630                         } else if (!del_item) {
4631                                 /*
4632                                  * We have to bail so the last_size is set to
4633                                  * just before this extent.
4634                                  */
4635                                 err = NEED_TRUNCATE_BLOCK;
4636                                 break;
4637                         }
4638
4639                         if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4640                                 inode_sub_bytes(inode, item_end + 1 - new_size);
4641                 }
4642 delete:
4643                 if (del_item)
4644                         last_size = found_key.offset;
4645                 else
4646                         last_size = new_size;
4647                 if (del_item) {
4648                         if (!pending_del_nr) {
4649                                 /* no pending yet, add ourselves */
4650                                 pending_del_slot = path->slots[0];
4651                                 pending_del_nr = 1;
4652                         } else if (pending_del_nr &&
4653                                    path->slots[0] + 1 == pending_del_slot) {
4654                                 /* hop on the pending chunk */
4655                                 pending_del_nr++;
4656                                 pending_del_slot = path->slots[0];
4657                         } else {
4658                                 BUG();
4659                         }
4660                 } else {
4661                         break;
4662                 }
4663                 should_throttle = false;
4664
4665                 if (found_extent &&
4666                     (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4667                      root == fs_info->tree_root)) {
4668                         btrfs_set_path_blocking(path);
4669                         bytes_deleted += extent_num_bytes;
4670                         ret = btrfs_free_extent(trans, root, extent_start,
4671                                                 extent_num_bytes, 0,
4672                                                 btrfs_header_owner(leaf),
4673                                                 ino, extent_offset);
4674                         BUG_ON(ret);
4675                         if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4676                                 btrfs_async_run_delayed_refs(fs_info,
4677                                         trans->delayed_ref_updates * 2,
4678                                         trans->transid, 0);
4679                         if (be_nice) {
4680                                 if (truncate_space_check(trans, root,
4681                                                          extent_num_bytes)) {
4682                                         should_end = true;
4683                                 }
4684                                 if (btrfs_should_throttle_delayed_refs(trans,
4685                                                                        fs_info))
4686                                         should_throttle = true;
4687                         }
4688                 }
4689
4690                 if (found_type == BTRFS_INODE_ITEM_KEY)
4691                         break;
4692
4693                 if (path->slots[0] == 0 ||
4694                     path->slots[0] != pending_del_slot ||
4695                     should_throttle || should_end) {
4696                         if (pending_del_nr) {
4697                                 ret = btrfs_del_items(trans, root, path,
4698                                                 pending_del_slot,
4699                                                 pending_del_nr);
4700                                 if (ret) {
4701                                         btrfs_abort_transaction(trans, ret);
4702                                         goto error;
4703                                 }
4704                                 pending_del_nr = 0;
4705                         }
4706                         btrfs_release_path(path);
4707                         if (should_throttle) {
4708                                 unsigned long updates = trans->delayed_ref_updates;
4709                                 if (updates) {
4710                                         trans->delayed_ref_updates = 0;
4711                                         ret = btrfs_run_delayed_refs(trans,
4712                                                                    updates * 2);
4713                                         if (ret && !err)
4714                                                 err = ret;
4715                                 }
4716                         }
4717                         /*
4718                          * if we failed to refill our space rsv, bail out
4719                          * and let the transaction restart
4720                          */
4721                         if (should_end) {
4722                                 err = -EAGAIN;
4723                                 goto error;
4724                         }
4725                         goto search_again;
4726                 } else {
4727                         path->slots[0]--;
4728                 }
4729         }
4730 out:
4731         if (pending_del_nr) {
4732                 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4733                                       pending_del_nr);
4734                 if (ret)
4735                         btrfs_abort_transaction(trans, ret);
4736         }
4737 error:
4738         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4739                 ASSERT(last_size >= new_size);
4740                 if (!err && last_size > new_size)
4741                         last_size = new_size;
4742                 btrfs_ordered_update_i_size(inode, last_size, NULL);
4743         }
4744
4745         btrfs_free_path(path);
4746
4747         if (be_nice && bytes_deleted > SZ_32M) {
4748                 unsigned long updates = trans->delayed_ref_updates;
4749                 if (updates) {
4750                         trans->delayed_ref_updates = 0;
4751                         ret = btrfs_run_delayed_refs(trans, updates * 2);
4752                         if (ret && !err)
4753                                 err = ret;
4754                 }
4755         }
4756         return err;
4757 }
4758
4759 /*
4760  * btrfs_truncate_block - read, zero a chunk and write a block
4761  * @inode - inode that we're zeroing
4762  * @from - the offset to start zeroing
4763  * @len - the length to zero, 0 to zero the entire range respective to the
4764  *      offset
4765  * @front - zero up to the offset instead of from the offset on
4766  *
4767  * This will find the block for the "from" offset and cow the block and zero the
4768  * part we want to zero.  This is used with truncate and hole punching.
4769  */
4770 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4771                         int front)
4772 {
4773         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4774         struct address_space *mapping = inode->i_mapping;
4775         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4776         struct btrfs_ordered_extent *ordered;
4777         struct extent_state *cached_state = NULL;
4778         struct extent_changeset *data_reserved = NULL;
4779         char *kaddr;
4780         u32 blocksize = fs_info->sectorsize;
4781         pgoff_t index = from >> PAGE_SHIFT;
4782         unsigned offset = from & (blocksize - 1);
4783         struct page *page;
4784         gfp_t mask = btrfs_alloc_write_mask(mapping);
4785         int ret = 0;
4786         u64 block_start;
4787         u64 block_end;
4788
4789         if (IS_ALIGNED(offset, blocksize) &&
4790             (!len || IS_ALIGNED(len, blocksize)))
4791                 goto out;
4792
4793         block_start = round_down(from, blocksize);
4794         block_end = block_start + blocksize - 1;
4795
4796         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
4797                                            block_start, blocksize);
4798         if (ret)
4799                 goto out;
4800
4801 again:
4802         page = find_or_create_page(mapping, index, mask);
4803         if (!page) {
4804                 btrfs_delalloc_release_space(inode, data_reserved,
4805                                              block_start, blocksize);
4806                 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
4807                 ret = -ENOMEM;
4808                 goto out;
4809         }
4810
4811         if (!PageUptodate(page)) {
4812                 ret = btrfs_readpage(NULL, page);
4813                 lock_page(page);
4814                 if (page->mapping != mapping) {
4815                         unlock_page(page);
4816                         put_page(page);
4817                         goto again;
4818                 }
4819                 if (!PageUptodate(page)) {
4820                         ret = -EIO;
4821                         goto out_unlock;
4822                 }
4823         }
4824         wait_on_page_writeback(page);
4825
4826         lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4827         set_page_extent_mapped(page);
4828
4829         ordered = btrfs_lookup_ordered_extent(inode, block_start);
4830         if (ordered) {
4831                 unlock_extent_cached(io_tree, block_start, block_end,
4832                                      &cached_state);
4833                 unlock_page(page);
4834                 put_page(page);
4835                 btrfs_start_ordered_extent(inode, ordered, 1);
4836                 btrfs_put_ordered_extent(ordered);
4837                 goto again;
4838         }
4839
4840         clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4841                           EXTENT_DIRTY | EXTENT_DELALLOC |
4842                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4843                           0, 0, &cached_state);
4844
4845         ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
4846                                         &cached_state, 0);
4847         if (ret) {
4848                 unlock_extent_cached(io_tree, block_start, block_end,
4849                                      &cached_state);
4850                 goto out_unlock;
4851         }
4852
4853         if (offset != blocksize) {
4854                 if (!len)
4855                         len = blocksize - offset;
4856                 kaddr = kmap(page);
4857                 if (front)
4858                         memset(kaddr + (block_start - page_offset(page)),
4859                                 0, offset);
4860                 else
4861                         memset(kaddr + (block_start - page_offset(page)) +  offset,
4862                                 0, len);
4863                 flush_dcache_page(page);
4864                 kunmap(page);
4865         }
4866         ClearPageChecked(page);
4867         set_page_dirty(page);
4868         unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
4869
4870 out_unlock:
4871         if (ret)
4872                 btrfs_delalloc_release_space(inode, data_reserved, block_start,
4873                                              blocksize);
4874         btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
4875         unlock_page(page);
4876         put_page(page);
4877 out:
4878         extent_changeset_free(data_reserved);
4879         return ret;
4880 }
4881
4882 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4883                              u64 offset, u64 len)
4884 {
4885         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4886         struct btrfs_trans_handle *trans;
4887         int ret;
4888
4889         /*
4890          * Still need to make sure the inode looks like it's been updated so
4891          * that any holes get logged if we fsync.
4892          */
4893         if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4894                 BTRFS_I(inode)->last_trans = fs_info->generation;
4895                 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4896                 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4897                 return 0;
4898         }
4899
4900         /*
4901          * 1 - for the one we're dropping
4902          * 1 - for the one we're adding
4903          * 1 - for updating the inode.
4904          */
4905         trans = btrfs_start_transaction(root, 3);
4906         if (IS_ERR(trans))
4907                 return PTR_ERR(trans);
4908
4909         ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4910         if (ret) {
4911                 btrfs_abort_transaction(trans, ret);
4912                 btrfs_end_transaction(trans);
4913                 return ret;
4914         }
4915
4916         ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4917                         offset, 0, 0, len, 0, len, 0, 0, 0);
4918         if (ret)
4919                 btrfs_abort_transaction(trans, ret);
4920         else
4921                 btrfs_update_inode(trans, root, inode);
4922         btrfs_end_transaction(trans);
4923         return ret;
4924 }
4925
4926 /*
4927  * This function puts in dummy file extents for the area we're creating a hole
4928  * for.  So if we are truncating this file to a larger size we need to insert
4929  * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4930  * the range between oldsize and size
4931  */
4932 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4933 {
4934         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4935         struct btrfs_root *root = BTRFS_I(inode)->root;
4936         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4937         struct extent_map *em = NULL;
4938         struct extent_state *cached_state = NULL;
4939         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4940         u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4941         u64 block_end = ALIGN(size, fs_info->sectorsize);
4942         u64 last_byte;
4943         u64 cur_offset;
4944         u64 hole_size;
4945         int err = 0;
4946
4947         /*
4948          * If our size started in the middle of a block we need to zero out the
4949          * rest of the block before we expand the i_size, otherwise we could
4950          * expose stale data.
4951          */
4952         err = btrfs_truncate_block(inode, oldsize, 0, 0);
4953         if (err)
4954                 return err;
4955
4956         if (size <= hole_start)
4957                 return 0;
4958
4959         while (1) {
4960                 struct btrfs_ordered_extent *ordered;
4961
4962                 lock_extent_bits(io_tree, hole_start, block_end - 1,
4963                                  &cached_state);
4964                 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4965                                                      block_end - hole_start);
4966                 if (!ordered)
4967                         break;
4968                 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4969                                      &cached_state);
4970                 btrfs_start_ordered_extent(inode, ordered, 1);
4971                 btrfs_put_ordered_extent(ordered);
4972         }
4973
4974         cur_offset = hole_start;
4975         while (1) {
4976                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4977                                 block_end - cur_offset, 0);
4978                 if (IS_ERR(em)) {
4979                         err = PTR_ERR(em);
4980                         em = NULL;
4981                         break;
4982                 }
4983                 last_byte = min(extent_map_end(em), block_end);
4984                 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4985                 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4986                         struct extent_map *hole_em;
4987                         hole_size = last_byte - cur_offset;
4988
4989                         err = maybe_insert_hole(root, inode, cur_offset,
4990                                                 hole_size);
4991                         if (err)
4992                                 break;
4993                         btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
4994                                                 cur_offset + hole_size - 1, 0);
4995                         hole_em = alloc_extent_map();
4996                         if (!hole_em) {
4997                                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4998                                         &BTRFS_I(inode)->runtime_flags);
4999                                 goto next;
5000                         }
5001                         hole_em->start = cur_offset;
5002                         hole_em->len = hole_size;
5003                         hole_em->orig_start = cur_offset;
5004
5005                         hole_em->block_start = EXTENT_MAP_HOLE;
5006                         hole_em->block_len = 0;
5007                         hole_em->orig_block_len = 0;
5008                         hole_em->ram_bytes = hole_size;
5009                         hole_em->bdev = fs_info->fs_devices->latest_bdev;
5010                         hole_em->compress_type = BTRFS_COMPRESS_NONE;
5011                         hole_em->generation = fs_info->generation;
5012
5013                         while (1) {
5014                                 write_lock(&em_tree->lock);
5015                                 err = add_extent_mapping(em_tree, hole_em, 1);
5016                                 write_unlock(&em_tree->lock);
5017                                 if (err != -EEXIST)
5018                                         break;
5019                                 btrfs_drop_extent_cache(BTRFS_I(inode),
5020                                                         cur_offset,
5021                                                         cur_offset +
5022                                                         hole_size - 1, 0);
5023                         }
5024                         free_extent_map(hole_em);
5025                 }
5026 next:
5027                 free_extent_map(em);
5028                 em = NULL;
5029                 cur_offset = last_byte;
5030                 if (cur_offset >= block_end)
5031                         break;
5032         }
5033         free_extent_map(em);
5034         unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
5035         return err;
5036 }
5037
5038 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5039 {
5040         struct btrfs_root *root = BTRFS_I(inode)->root;
5041         struct btrfs_trans_handle *trans;
5042         loff_t oldsize = i_size_read(inode);
5043         loff_t newsize = attr->ia_size;
5044         int mask = attr->ia_valid;
5045         int ret;
5046
5047         /*
5048          * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5049          * special case where we need to update the times despite not having
5050          * these flags set.  For all other operations the VFS set these flags
5051          * explicitly if it wants a timestamp update.
5052          */
5053         if (newsize != oldsize) {
5054                 inode_inc_iversion(inode);
5055                 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5056                         inode->i_ctime = inode->i_mtime =
5057                                 current_time(inode);
5058         }
5059
5060         if (newsize > oldsize) {
5061                 /*
5062                  * Don't do an expanding truncate while snapshotting is ongoing.
5063                  * This is to ensure the snapshot captures a fully consistent
5064                  * state of this file - if the snapshot captures this expanding
5065                  * truncation, it must capture all writes that happened before
5066                  * this truncation.
5067                  */
5068                 btrfs_wait_for_snapshot_creation(root);
5069                 ret = btrfs_cont_expand(inode, oldsize, newsize);
5070                 if (ret) {
5071                         btrfs_end_write_no_snapshotting(root);
5072                         return ret;
5073                 }
5074
5075                 trans = btrfs_start_transaction(root, 1);
5076                 if (IS_ERR(trans)) {
5077                         btrfs_end_write_no_snapshotting(root);
5078                         return PTR_ERR(trans);
5079                 }
5080
5081                 i_size_write(inode, newsize);
5082                 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5083                 pagecache_isize_extended(inode, oldsize, newsize);
5084                 ret = btrfs_update_inode(trans, root, inode);
5085                 btrfs_end_write_no_snapshotting(root);
5086                 btrfs_end_transaction(trans);
5087         } else {
5088
5089                 /*
5090                  * We're truncating a file that used to have good data down to
5091                  * zero. Make sure it gets into the ordered flush list so that
5092                  * any new writes get down to disk quickly.
5093                  */
5094                 if (newsize == 0)
5095                         set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5096                                 &BTRFS_I(inode)->runtime_flags);
5097
5098                 /*
5099                  * 1 for the orphan item we're going to add
5100                  * 1 for the orphan item deletion.
5101                  */
5102                 trans = btrfs_start_transaction(root, 2);
5103                 if (IS_ERR(trans))
5104                         return PTR_ERR(trans);
5105
5106                 /*
5107                  * We need to do this in case we fail at _any_ point during the
5108                  * actual truncate.  Once we do the truncate_setsize we could
5109                  * invalidate pages which forces any outstanding ordered io to
5110                  * be instantly completed which will give us extents that need
5111                  * to be truncated.  If we fail to get an orphan inode down we
5112                  * could have left over extents that were never meant to live,
5113                  * so we need to guarantee from this point on that everything
5114                  * will be consistent.
5115                  */
5116                 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
5117                 btrfs_end_transaction(trans);
5118                 if (ret)
5119                         return ret;
5120
5121                 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5122                 truncate_setsize(inode, newsize);
5123
5124                 /* Disable nonlocked read DIO to avoid the end less truncate */
5125                 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5126                 inode_dio_wait(inode);
5127                 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5128
5129                 ret = btrfs_truncate(inode, newsize == oldsize);
5130                 if (ret && inode->i_nlink) {
5131                         int err;
5132
5133                         /* To get a stable disk_i_size */
5134                         err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5135                         if (err) {
5136                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5137                                 return err;
5138                         }
5139
5140                         /*
5141                          * failed to truncate, disk_i_size is only adjusted down
5142                          * as we remove extents, so it should represent the true
5143                          * size of the inode, so reset the in memory size and
5144                          * delete our orphan entry.
5145                          */
5146                         trans = btrfs_join_transaction(root);
5147                         if (IS_ERR(trans)) {
5148                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5149                                 return ret;
5150                         }
5151                         i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5152                         err = btrfs_orphan_del(trans, BTRFS_I(inode));
5153                         if (err)
5154                                 btrfs_abort_transaction(trans, err);
5155                         btrfs_end_transaction(trans);
5156                 }
5157         }
5158
5159         return ret;
5160 }
5161
5162 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5163 {
5164         struct inode *inode = d_inode(dentry);
5165         struct btrfs_root *root = BTRFS_I(inode)->root;
5166         int err;
5167
5168         if (btrfs_root_readonly(root))
5169                 return -EROFS;
5170
5171         err = setattr_prepare(dentry, attr);
5172         if (err)
5173                 return err;
5174
5175         if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5176                 err = btrfs_setsize(inode, attr);
5177                 if (err)
5178                         return err;
5179         }
5180
5181         if (attr->ia_valid) {
5182                 setattr_copy(inode, attr);
5183                 inode_inc_iversion(inode);
5184                 err = btrfs_dirty_inode(inode);
5185
5186                 if (!err && attr->ia_valid & ATTR_MODE)
5187                         err = posix_acl_chmod(inode, inode->i_mode);
5188         }
5189
5190         return err;
5191 }
5192
5193 /*
5194  * While truncating the inode pages during eviction, we get the VFS calling
5195  * btrfs_invalidatepage() against each page of the inode. This is slow because
5196  * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5197  * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5198  * extent_state structures over and over, wasting lots of time.
5199  *
5200  * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5201  * those expensive operations on a per page basis and do only the ordered io
5202  * finishing, while we release here the extent_map and extent_state structures,
5203  * without the excessive merging and splitting.
5204  */
5205 static void evict_inode_truncate_pages(struct inode *inode)
5206 {
5207         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5208         struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5209         struct rb_node *node;
5210
5211         ASSERT(inode->i_state & I_FREEING);
5212         truncate_inode_pages_final(&inode->i_data);
5213
5214         write_lock(&map_tree->lock);
5215         while (!RB_EMPTY_ROOT(&map_tree->map)) {
5216                 struct extent_map *em;
5217
5218                 node = rb_first(&map_tree->map);
5219                 em = rb_entry(node, struct extent_map, rb_node);
5220                 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5221                 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5222                 remove_extent_mapping(map_tree, em);
5223                 free_extent_map(em);
5224                 if (need_resched()) {
5225                         write_unlock(&map_tree->lock);
5226                         cond_resched();
5227                         write_lock(&map_tree->lock);
5228                 }
5229         }
5230         write_unlock(&map_tree->lock);
5231
5232         /*
5233          * Keep looping until we have no more ranges in the io tree.
5234          * We can have ongoing bios started by readpages (called from readahead)
5235          * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5236          * still in progress (unlocked the pages in the bio but did not yet
5237          * unlocked the ranges in the io tree). Therefore this means some
5238          * ranges can still be locked and eviction started because before
5239          * submitting those bios, which are executed by a separate task (work
5240          * queue kthread), inode references (inode->i_count) were not taken
5241          * (which would be dropped in the end io callback of each bio).
5242          * Therefore here we effectively end up waiting for those bios and
5243          * anyone else holding locked ranges without having bumped the inode's
5244          * reference count - if we don't do it, when they access the inode's
5245          * io_tree to unlock a range it may be too late, leading to an
5246          * use-after-free issue.
5247          */
5248         spin_lock(&io_tree->lock);
5249         while (!RB_EMPTY_ROOT(&io_tree->state)) {
5250                 struct extent_state *state;
5251                 struct extent_state *cached_state = NULL;
5252                 u64 start;
5253                 u64 end;
5254
5255                 node = rb_first(&io_tree->state);
5256                 state = rb_entry(node, struct extent_state, rb_node);
5257                 start = state->start;
5258                 end = state->end;
5259                 spin_unlock(&io_tree->lock);
5260
5261                 lock_extent_bits(io_tree, start, end, &cached_state);
5262
5263                 /*
5264                  * If still has DELALLOC flag, the extent didn't reach disk,
5265                  * and its reserved space won't be freed by delayed_ref.
5266                  * So we need to free its reserved space here.
5267                  * (Refer to comment in btrfs_invalidatepage, case 2)
5268                  *
5269                  * Note, end is the bytenr of last byte, so we need + 1 here.
5270                  */
5271                 if (state->state & EXTENT_DELALLOC)
5272                         btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5273
5274                 clear_extent_bit(io_tree, start, end,
5275                                  EXTENT_LOCKED | EXTENT_DIRTY |
5276                                  EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5277                                  EXTENT_DEFRAG, 1, 1, &cached_state);
5278
5279                 cond_resched();
5280                 spin_lock(&io_tree->lock);
5281         }
5282         spin_unlock(&io_tree->lock);
5283 }
5284
5285 void btrfs_evict_inode(struct inode *inode)
5286 {
5287         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5288         struct btrfs_trans_handle *trans;
5289         struct btrfs_root *root = BTRFS_I(inode)->root;
5290         struct btrfs_block_rsv *rsv, *global_rsv;
5291         int steal_from_global = 0;
5292         u64 min_size;
5293         int ret;
5294
5295         trace_btrfs_inode_evict(inode);
5296
5297         if (!root) {
5298                 clear_inode(inode);
5299                 return;
5300         }
5301
5302         min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5303
5304         evict_inode_truncate_pages(inode);
5305
5306         if (inode->i_nlink &&
5307             ((btrfs_root_refs(&root->root_item) != 0 &&
5308               root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5309              btrfs_is_free_space_inode(BTRFS_I(inode))))
5310                 goto no_delete;
5311
5312         if (is_bad_inode(inode)) {
5313                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5314                 goto no_delete;
5315         }
5316         /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5317         if (!special_file(inode->i_mode))
5318                 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5319
5320         btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5321
5322         if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5323                 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5324                                  &BTRFS_I(inode)->runtime_flags));
5325                 goto no_delete;
5326         }
5327
5328         if (inode->i_nlink > 0) {
5329                 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5330                        root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5331                 goto no_delete;
5332         }
5333
5334         ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5335         if (ret) {
5336                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5337                 goto no_delete;
5338         }
5339
5340         rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5341         if (!rsv) {
5342                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5343                 goto no_delete;
5344         }
5345         rsv->size = min_size;
5346         rsv->failfast = 1;
5347         global_rsv = &fs_info->global_block_rsv;
5348
5349         btrfs_i_size_write(BTRFS_I(inode), 0);
5350
5351         /*
5352          * This is a bit simpler than btrfs_truncate since we've already
5353          * reserved our space for our orphan item in the unlink, so we just
5354          * need to reserve some slack space in case we add bytes and update
5355          * inode item when doing the truncate.
5356          */
5357         while (1) {
5358                 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5359                                              BTRFS_RESERVE_FLUSH_LIMIT);
5360
5361                 /*
5362                  * Try and steal from the global reserve since we will
5363                  * likely not use this space anyway, we want to try as
5364                  * hard as possible to get this to work.
5365                  */
5366                 if (ret)
5367                         steal_from_global++;
5368                 else
5369                         steal_from_global = 0;
5370                 ret = 0;
5371
5372                 /*
5373                  * steal_from_global == 0: we reserved stuff, hooray!
5374                  * steal_from_global == 1: we didn't reserve stuff, boo!
5375                  * steal_from_global == 2: we've committed, still not a lot of
5376                  * room but maybe we'll have room in the global reserve this
5377                  * time.
5378                  * steal_from_global == 3: abandon all hope!
5379                  */
5380                 if (steal_from_global > 2) {
5381                         btrfs_warn(fs_info,
5382                                    "Could not get space for a delete, will truncate on mount %d",
5383                                    ret);
5384                         btrfs_orphan_del(NULL, BTRFS_I(inode));
5385                         btrfs_free_block_rsv(fs_info, rsv);
5386                         goto no_delete;
5387                 }
5388
5389                 trans = btrfs_join_transaction(root);
5390                 if (IS_ERR(trans)) {
5391                         btrfs_orphan_del(NULL, BTRFS_I(inode));
5392                         btrfs_free_block_rsv(fs_info, rsv);
5393                         goto no_delete;
5394                 }
5395
5396                 /*
5397                  * We can't just steal from the global reserve, we need to make
5398                  * sure there is room to do it, if not we need to commit and try
5399                  * again.
5400                  */
5401                 if (steal_from_global) {
5402                         if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5403                                 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5404                                                               min_size, 0);
5405                         else
5406                                 ret = -ENOSPC;
5407                 }
5408
5409                 /*
5410                  * Couldn't steal from the global reserve, we have too much
5411                  * pending stuff built up, commit the transaction and try it
5412                  * again.
5413                  */
5414                 if (ret) {
5415                         ret = btrfs_commit_transaction(trans);
5416                         if (ret) {
5417                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5418                                 btrfs_free_block_rsv(fs_info, rsv);
5419                                 goto no_delete;
5420                         }
5421                         continue;
5422                 } else {
5423                         steal_from_global = 0;
5424                 }
5425
5426                 trans->block_rsv = rsv;
5427
5428                 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5429                 if (ret != -ENOSPC && ret != -EAGAIN)
5430                         break;
5431
5432                 trans->block_rsv = &fs_info->trans_block_rsv;
5433                 btrfs_end_transaction(trans);
5434                 trans = NULL;
5435                 btrfs_btree_balance_dirty(fs_info);
5436         }
5437
5438         btrfs_free_block_rsv(fs_info, rsv);
5439
5440         /*
5441          * Errors here aren't a big deal, it just means we leave orphan items
5442          * in the tree.  They will be cleaned up on the next mount.
5443          */
5444         if (ret == 0) {
5445                 trans->block_rsv = root->orphan_block_rsv;
5446                 btrfs_orphan_del(trans, BTRFS_I(inode));
5447         } else {
5448                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5449         }
5450
5451         trans->block_rsv = &fs_info->trans_block_rsv;
5452         if (!(root == fs_info->tree_root ||
5453               root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5454                 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5455
5456         btrfs_end_transaction(trans);
5457         btrfs_btree_balance_dirty(fs_info);
5458 no_delete:
5459         btrfs_remove_delayed_node(BTRFS_I(inode));
5460         clear_inode(inode);
5461 }
5462
5463 /*
5464  * this returns the key found in the dir entry in the location pointer.
5465  * If no dir entries were found, returns -ENOENT.
5466  * If found a corrupted location in dir entry, returns -EUCLEAN.
5467  */
5468 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5469                                struct btrfs_key *location)
5470 {
5471         const char *name = dentry->d_name.name;
5472         int namelen = dentry->d_name.len;
5473         struct btrfs_dir_item *di;
5474         struct btrfs_path *path;
5475         struct btrfs_root *root = BTRFS_I(dir)->root;
5476         int ret = 0;
5477
5478         path = btrfs_alloc_path();
5479         if (!path)
5480                 return -ENOMEM;
5481
5482         di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5483                         name, namelen, 0);
5484         if (!di) {
5485                 ret = -ENOENT;
5486                 goto out;
5487         }
5488         if (IS_ERR(di)) {
5489                 ret = PTR_ERR(di);
5490                 goto out;
5491         }
5492
5493         btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5494         if (location->type != BTRFS_INODE_ITEM_KEY &&
5495             location->type != BTRFS_ROOT_ITEM_KEY) {
5496                 ret = -EUCLEAN;
5497                 btrfs_warn(root->fs_info,
5498 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5499                            __func__, name, btrfs_ino(BTRFS_I(dir)),
5500                            location->objectid, location->type, location->offset);
5501         }
5502 out:
5503         btrfs_free_path(path);
5504         return ret;
5505 }
5506
5507 /*
5508  * when we hit a tree root in a directory, the btrfs part of the inode
5509  * needs to be changed to reflect the root directory of the tree root.  This
5510  * is kind of like crossing a mount point.
5511  */
5512 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5513                                     struct inode *dir,
5514                                     struct dentry *dentry,
5515                                     struct btrfs_key *location,
5516                                     struct btrfs_root **sub_root)
5517 {
5518         struct btrfs_path *path;
5519         struct btrfs_root *new_root;
5520         struct btrfs_root_ref *ref;
5521         struct extent_buffer *leaf;
5522         struct btrfs_key key;
5523         int ret;
5524         int err = 0;
5525
5526         path = btrfs_alloc_path();
5527         if (!path) {
5528                 err = -ENOMEM;
5529                 goto out;
5530         }
5531
5532         err = -ENOENT;
5533         key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5534         key.type = BTRFS_ROOT_REF_KEY;
5535         key.offset = location->objectid;
5536
5537         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5538         if (ret) {
5539                 if (ret < 0)
5540                         err = ret;
5541                 goto out;
5542         }
5543
5544         leaf = path->nodes[0];
5545         ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5546         if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5547             btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5548                 goto out;
5549
5550         ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5551                                    (unsigned long)(ref + 1),
5552                                    dentry->d_name.len);
5553         if (ret)
5554                 goto out;
5555
5556         btrfs_release_path(path);
5557
5558         new_root = btrfs_read_fs_root_no_name(fs_info, location);
5559         if (IS_ERR(new_root)) {
5560                 err = PTR_ERR(new_root);
5561                 goto out;
5562         }
5563
5564         *sub_root = new_root;
5565         location->objectid = btrfs_root_dirid(&new_root->root_item);
5566         location->type = BTRFS_INODE_ITEM_KEY;
5567         location->offset = 0;
5568         err = 0;
5569 out:
5570         btrfs_free_path(path);
5571         return err;
5572 }
5573
5574 static void inode_tree_add(struct inode *inode)
5575 {
5576         struct btrfs_root *root = BTRFS_I(inode)->root;
5577         struct btrfs_inode *entry;
5578         struct rb_node **p;
5579         struct rb_node *parent;
5580         struct rb_node *new = &BTRFS_I(inode)->rb_node;
5581         u64 ino = btrfs_ino(BTRFS_I(inode));
5582
5583         if (inode_unhashed(inode))
5584                 return;
5585         parent = NULL;
5586         spin_lock(&root->inode_lock);
5587         p = &root->inode_tree.rb_node;
5588         while (*p) {
5589                 parent = *p;
5590                 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5591
5592                 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5593                         p = &parent->rb_left;
5594                 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5595                         p = &parent->rb_right;
5596                 else {
5597                         WARN_ON(!(entry->vfs_inode.i_state &
5598                                   (I_WILL_FREE | I_FREEING)));
5599                         rb_replace_node(parent, new, &root->inode_tree);
5600                         RB_CLEAR_NODE(parent);
5601                         spin_unlock(&root->inode_lock);
5602                         return;
5603                 }
5604         }
5605         rb_link_node(new, parent, p);
5606         rb_insert_color(new, &root->inode_tree);
5607         spin_unlock(&root->inode_lock);
5608 }
5609
5610 static void inode_tree_del(struct inode *inode)
5611 {
5612         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5613         struct btrfs_root *root = BTRFS_I(inode)->root;
5614         int empty = 0;
5615
5616         spin_lock(&root->inode_lock);
5617         if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5618                 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5619                 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5620                 empty = RB_EMPTY_ROOT(&root->inode_tree);
5621         }
5622         spin_unlock(&root->inode_lock);
5623
5624         if (empty && btrfs_root_refs(&root->root_item) == 0) {
5625                 synchronize_srcu(&fs_info->subvol_srcu);
5626                 spin_lock(&root->inode_lock);
5627                 empty = RB_EMPTY_ROOT(&root->inode_tree);
5628                 spin_unlock(&root->inode_lock);
5629                 if (empty)
5630                         btrfs_add_dead_root(root);
5631         }
5632 }
5633
5634 void btrfs_invalidate_inodes(struct btrfs_root *root)
5635 {
5636         struct btrfs_fs_info *fs_info = root->fs_info;
5637         struct rb_node *node;
5638         struct rb_node *prev;
5639         struct btrfs_inode *entry;
5640         struct inode *inode;
5641         u64 objectid = 0;
5642
5643         if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5644                 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5645
5646         spin_lock(&root->inode_lock);
5647 again:
5648         node = root->inode_tree.rb_node;
5649         prev = NULL;
5650         while (node) {
5651                 prev = node;
5652                 entry = rb_entry(node, struct btrfs_inode, rb_node);
5653
5654                 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5655                         node = node->rb_left;
5656                 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5657                         node = node->rb_right;
5658                 else
5659                         break;
5660         }
5661         if (!node) {
5662                 while (prev) {
5663                         entry = rb_entry(prev, struct btrfs_inode, rb_node);
5664                         if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
5665                                 node = prev;
5666                                 break;
5667                         }
5668                         prev = rb_next(prev);
5669                 }
5670         }
5671         while (node) {
5672                 entry = rb_entry(node, struct btrfs_inode, rb_node);
5673                 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
5674                 inode = igrab(&entry->vfs_inode);
5675                 if (inode) {
5676                         spin_unlock(&root->inode_lock);
5677                         if (atomic_read(&inode->i_count) > 1)
5678                                 d_prune_aliases(inode);
5679                         /*
5680                          * btrfs_drop_inode will have it removed from
5681                          * the inode cache when its usage count
5682                          * hits zero.
5683                          */
5684                         iput(inode);
5685                         cond_resched();
5686                         spin_lock(&root->inode_lock);
5687                         goto again;
5688                 }
5689
5690                 if (cond_resched_lock(&root->inode_lock))
5691                         goto again;
5692
5693                 node = rb_next(node);
5694         }
5695         spin_unlock(&root->inode_lock);
5696 }
5697
5698 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5699 {
5700         struct btrfs_iget_args *args = p;
5701         inode->i_ino = args->location->objectid;
5702         memcpy(&BTRFS_I(inode)->location, args->location,
5703                sizeof(*args->location));
5704         BTRFS_I(inode)->root = args->root;
5705         return 0;
5706 }
5707
5708 static int btrfs_find_actor(struct inode *inode, void *opaque)
5709 {
5710         struct btrfs_iget_args *args = opaque;
5711         return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5712                 args->root == BTRFS_I(inode)->root;
5713 }
5714
5715 static struct inode *btrfs_iget_locked(struct super_block *s,
5716                                        struct btrfs_key *location,
5717                                        struct btrfs_root *root)
5718 {
5719         struct inode *inode;
5720         struct btrfs_iget_args args;
5721         unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5722
5723         args.location = location;
5724         args.root = root;
5725
5726         inode = iget5_locked(s, hashval, btrfs_find_actor,
5727                              btrfs_init_locked_inode,
5728                              (void *)&args);
5729         return inode;
5730 }
5731
5732 /* Get an inode object given its location and corresponding root.
5733  * Returns in *is_new if the inode was read from disk
5734  */
5735 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5736                          struct btrfs_root *root, int *new)
5737 {
5738         struct inode *inode;
5739
5740         inode = btrfs_iget_locked(s, location, root);
5741         if (!inode)
5742                 return ERR_PTR(-ENOMEM);
5743
5744         if (inode->i_state & I_NEW) {
5745                 int ret;
5746
5747                 ret = btrfs_read_locked_inode(inode);
5748                 if (!is_bad_inode(inode)) {
5749                         inode_tree_add(inode);
5750                         unlock_new_inode(inode);
5751                         if (new)
5752                                 *new = 1;
5753                 } else {
5754                         unlock_new_inode(inode);
5755                         iput(inode);
5756                         ASSERT(ret < 0);
5757                         inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5758                 }
5759         }
5760
5761         return inode;
5762 }
5763
5764 static struct inode *new_simple_dir(struct super_block *s,
5765                                     struct btrfs_key *key,
5766                                     struct btrfs_root *root)
5767 {
5768         struct inode *inode = new_inode(s);
5769
5770         if (!inode)
5771                 return ERR_PTR(-ENOMEM);
5772
5773         BTRFS_I(inode)->root = root;
5774         memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5775         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5776
5777         inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5778         inode->i_op = &btrfs_dir_ro_inode_operations;
5779         inode->i_opflags &= ~IOP_XATTR;
5780         inode->i_fop = &simple_dir_operations;
5781         inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5782         inode->i_mtime = current_time(inode);
5783         inode->i_atime = inode->i_mtime;
5784         inode->i_ctime = inode->i_mtime;
5785         BTRFS_I(inode)->i_otime = inode->i_mtime;
5786
5787         return inode;
5788 }
5789
5790 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5791 {
5792         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5793         struct inode *inode;
5794         struct btrfs_root *root = BTRFS_I(dir)->root;
5795         struct btrfs_root *sub_root = root;
5796         struct btrfs_key location;
5797         int index;
5798         int ret = 0;
5799
5800         if (dentry->d_name.len > BTRFS_NAME_LEN)
5801                 return ERR_PTR(-ENAMETOOLONG);
5802
5803         ret = btrfs_inode_by_name(dir, dentry, &location);
5804         if (ret < 0)
5805                 return ERR_PTR(ret);
5806
5807         if (location.type == BTRFS_INODE_ITEM_KEY) {
5808                 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5809                 return inode;
5810         }
5811
5812         index = srcu_read_lock(&fs_info->subvol_srcu);
5813         ret = fixup_tree_root_location(fs_info, dir, dentry,
5814                                        &location, &sub_root);
5815         if (ret < 0) {
5816                 if (ret != -ENOENT)
5817                         inode = ERR_PTR(ret);
5818                 else
5819                         inode = new_simple_dir(dir->i_sb, &location, sub_root);
5820         } else {
5821                 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5822         }
5823         srcu_read_unlock(&fs_info->subvol_srcu, index);
5824
5825         if (!IS_ERR(inode) && root != sub_root) {
5826                 down_read(&fs_info->cleanup_work_sem);
5827                 if (!sb_rdonly(inode->i_sb))
5828                         ret = btrfs_orphan_cleanup(sub_root);
5829                 up_read(&fs_info->cleanup_work_sem);
5830                 if (ret) {
5831                         iput(inode);
5832                         inode = ERR_PTR(ret);
5833                 }
5834         }
5835
5836         return inode;
5837 }
5838
5839 static int btrfs_dentry_delete(const struct dentry *dentry)
5840 {
5841         struct btrfs_root *root;
5842         struct inode *inode = d_inode(dentry);
5843
5844         if (!inode && !IS_ROOT(dentry))
5845                 inode = d_inode(dentry->d_parent);
5846
5847         if (inode) {
5848                 root = BTRFS_I(inode)->root;
5849                 if (btrfs_root_refs(&root->root_item) == 0)
5850                         return 1;
5851
5852                 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5853                         return 1;
5854         }
5855         return 0;
5856 }
5857
5858 static void btrfs_dentry_release(struct dentry *dentry)
5859 {
5860         kfree(dentry->d_fsdata);
5861 }
5862
5863 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5864                                    unsigned int flags)
5865 {
5866         struct inode *inode;
5867
5868         inode = btrfs_lookup_dentry(dir, dentry);
5869         if (IS_ERR(inode)) {
5870                 if (PTR_ERR(inode) == -ENOENT)
5871                         inode = NULL;
5872                 else
5873                         return ERR_CAST(inode);
5874         }
5875
5876         return d_splice_alias(inode, dentry);
5877 }
5878
5879 unsigned char btrfs_filetype_table[] = {
5880         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5881 };
5882
5883 /*
5884  * All this infrastructure exists because dir_emit can fault, and we are holding
5885  * the tree lock when doing readdir.  For now just allocate a buffer and copy
5886  * our information into that, and then dir_emit from the buffer.  This is
5887  * similar to what NFS does, only we don't keep the buffer around in pagecache
5888  * because I'm afraid I'll mess that up.  Long term we need to make filldir do
5889  * copy_to_user_inatomic so we don't have to worry about page faulting under the
5890  * tree lock.
5891  */
5892 static int btrfs_opendir(struct inode *inode, struct file *file)
5893 {
5894         struct btrfs_file_private *private;
5895
5896         private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
5897         if (!private)
5898                 return -ENOMEM;
5899         private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
5900         if (!private->filldir_buf) {
5901                 kfree(private);
5902                 return -ENOMEM;
5903         }
5904         file->private_data = private;
5905         return 0;
5906 }
5907
5908 struct dir_entry {
5909         u64 ino;
5910         u64 offset;
5911         unsigned type;
5912         int name_len;
5913 };
5914
5915 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
5916 {
5917         while (entries--) {
5918                 struct dir_entry *entry = addr;
5919                 char *name = (char *)(entry + 1);
5920
5921                 ctx->pos = entry->offset;
5922                 if (!dir_emit(ctx, name, entry->name_len, entry->ino,
5923                               entry->type))
5924                         return 1;
5925                 addr += sizeof(struct dir_entry) + entry->name_len;
5926                 ctx->pos++;
5927         }
5928         return 0;
5929 }
5930
5931 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5932 {
5933         struct inode *inode = file_inode(file);
5934         struct btrfs_root *root = BTRFS_I(inode)->root;
5935         struct btrfs_file_private *private = file->private_data;
5936         struct btrfs_dir_item *di;
5937         struct btrfs_key key;
5938         struct btrfs_key found_key;
5939         struct btrfs_path *path;
5940         void *addr;
5941         struct list_head ins_list;
5942         struct list_head del_list;
5943         int ret;
5944         struct extent_buffer *leaf;
5945         int slot;
5946         char *name_ptr;
5947         int name_len;
5948         int entries = 0;
5949         int total_len = 0;
5950         bool put = false;
5951         struct btrfs_key location;
5952
5953         if (!dir_emit_dots(file, ctx))
5954                 return 0;
5955
5956         path = btrfs_alloc_path();
5957         if (!path)
5958                 return -ENOMEM;
5959
5960         addr = private->filldir_buf;
5961         path->reada = READA_FORWARD;
5962
5963         INIT_LIST_HEAD(&ins_list);
5964         INIT_LIST_HEAD(&del_list);
5965         put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5966
5967 again:
5968         key.type = BTRFS_DIR_INDEX_KEY;
5969         key.offset = ctx->pos;
5970         key.objectid = btrfs_ino(BTRFS_I(inode));
5971
5972         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5973         if (ret < 0)
5974                 goto err;
5975
5976         while (1) {
5977                 struct dir_entry *entry;
5978
5979                 leaf = path->nodes[0];
5980                 slot = path->slots[0];
5981                 if (slot >= btrfs_header_nritems(leaf)) {
5982                         ret = btrfs_next_leaf(root, path);
5983                         if (ret < 0)
5984                                 goto err;
5985                         else if (ret > 0)
5986                                 break;
5987                         continue;
5988                 }
5989
5990                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5991
5992                 if (found_key.objectid != key.objectid)
5993                         break;
5994                 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5995                         break;
5996                 if (found_key.offset < ctx->pos)
5997                         goto next;
5998                 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5999                         goto next;
6000                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
6001                 name_len = btrfs_dir_name_len(leaf, di);
6002                 if ((total_len + sizeof(struct dir_entry) + name_len) >=
6003                     PAGE_SIZE) {
6004                         btrfs_release_path(path);
6005                         ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6006                         if (ret)
6007                                 goto nopos;
6008                         addr = private->filldir_buf;
6009                         entries = 0;
6010                         total_len = 0;
6011                         goto again;
6012                 }
6013
6014                 entry = addr;
6015                 entry->name_len = name_len;
6016                 name_ptr = (char *)(entry + 1);
6017                 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
6018                                    name_len);
6019                 entry->type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
6020                 btrfs_dir_item_key_to_cpu(leaf, di, &location);
6021                 entry->ino = location.objectid;
6022                 entry->offset = found_key.offset;
6023                 entries++;
6024                 addr += sizeof(struct dir_entry) + name_len;
6025                 total_len += sizeof(struct dir_entry) + name_len;
6026 next:
6027                 path->slots[0]++;
6028         }
6029         btrfs_release_path(path);
6030
6031         ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6032         if (ret)
6033                 goto nopos;
6034
6035         ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6036         if (ret)
6037                 goto nopos;
6038
6039         /*
6040          * Stop new entries from being returned after we return the last
6041          * entry.
6042          *
6043          * New directory entries are assigned a strictly increasing
6044          * offset.  This means that new entries created during readdir
6045          * are *guaranteed* to be seen in the future by that readdir.
6046          * This has broken buggy programs which operate on names as
6047          * they're returned by readdir.  Until we re-use freed offsets
6048          * we have this hack to stop new entries from being returned
6049          * under the assumption that they'll never reach this huge
6050          * offset.
6051          *
6052          * This is being careful not to overflow 32bit loff_t unless the
6053          * last entry requires it because doing so has broken 32bit apps
6054          * in the past.
6055          */
6056         if (ctx->pos >= INT_MAX)
6057                 ctx->pos = LLONG_MAX;
6058         else
6059                 ctx->pos = INT_MAX;
6060 nopos:
6061         ret = 0;
6062 err:
6063         if (put)
6064                 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6065         btrfs_free_path(path);
6066         return ret;
6067 }
6068
6069 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
6070 {
6071         struct btrfs_root *root = BTRFS_I(inode)->root;
6072         struct btrfs_trans_handle *trans;
6073         int ret = 0;
6074         bool nolock = false;
6075
6076         if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6077                 return 0;
6078
6079         if (btrfs_fs_closing(root->fs_info) &&
6080                         btrfs_is_free_space_inode(BTRFS_I(inode)))
6081                 nolock = true;
6082
6083         if (wbc->sync_mode == WB_SYNC_ALL) {
6084                 if (nolock)
6085                         trans = btrfs_join_transaction_nolock(root);
6086                 else
6087                         trans = btrfs_join_transaction(root);
6088                 if (IS_ERR(trans))
6089                         return PTR_ERR(trans);
6090                 ret = btrfs_commit_transaction(trans);
6091         }
6092         return ret;
6093 }
6094
6095 /*
6096  * This is somewhat expensive, updating the tree every time the
6097  * inode changes.  But, it is most likely to find the inode in cache.
6098  * FIXME, needs more benchmarking...there are no reasons other than performance
6099  * to keep or drop this code.
6100  */
6101 static int btrfs_dirty_inode(struct inode *inode)
6102 {
6103         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6104         struct btrfs_root *root = BTRFS_I(inode)->root;
6105         struct btrfs_trans_handle *trans;
6106         int ret;
6107
6108         if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6109                 return 0;
6110
6111         trans = btrfs_join_transaction(root);
6112         if (IS_ERR(trans))
6113                 return PTR_ERR(trans);
6114
6115         ret = btrfs_update_inode(trans, root, inode);
6116         if (ret && ret == -ENOSPC) {
6117                 /* whoops, lets try again with the full transaction */
6118                 btrfs_end_transaction(trans);
6119                 trans = btrfs_start_transaction(root, 1);
6120                 if (IS_ERR(trans))
6121                         return PTR_ERR(trans);
6122
6123                 ret = btrfs_update_inode(trans, root, inode);
6124         }
6125         btrfs_end_transaction(trans);
6126         if (BTRFS_I(inode)->delayed_node)
6127                 btrfs_balance_delayed_items(fs_info);
6128
6129         return ret;
6130 }
6131
6132 /*
6133  * This is a copy of file_update_time.  We need this so we can return error on
6134  * ENOSPC for updating the inode in the case of file write and mmap writes.
6135  */
6136 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6137                              int flags)
6138 {
6139         struct btrfs_root *root = BTRFS_I(inode)->root;
6140         bool dirty = flags & ~S_VERSION;
6141
6142         if (btrfs_root_readonly(root))
6143                 return -EROFS;
6144
6145         if (flags & S_VERSION)
6146                 dirty |= inode_maybe_inc_iversion(inode, dirty);
6147         if (flags & S_CTIME)
6148                 inode->i_ctime = *now;
6149         if (flags & S_MTIME)
6150                 inode->i_mtime = *now;
6151         if (flags & S_ATIME)
6152                 inode->i_atime = *now;
6153         return dirty ? btrfs_dirty_inode(inode) : 0;
6154 }
6155
6156 /*
6157  * find the highest existing sequence number in a directory
6158  * and then set the in-memory index_cnt variable to reflect
6159  * free sequence numbers
6160  */
6161 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6162 {
6163         struct btrfs_root *root = inode->root;
6164         struct btrfs_key key, found_key;
6165         struct btrfs_path *path;
6166         struct extent_buffer *leaf;
6167         int ret;
6168
6169         key.objectid = btrfs_ino(inode);
6170         key.type = BTRFS_DIR_INDEX_KEY;
6171         key.offset = (u64)-1;
6172
6173         path = btrfs_alloc_path();
6174         if (!path)
6175                 return -ENOMEM;
6176
6177         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6178         if (ret < 0)
6179                 goto out;
6180         /* FIXME: we should be able to handle this */
6181         if (ret == 0)
6182                 goto out;
6183         ret = 0;
6184
6185         /*
6186          * MAGIC NUMBER EXPLANATION:
6187          * since we search a directory based on f_pos we have to start at 2
6188          * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6189          * else has to start at 2
6190          */
6191         if (path->slots[0] == 0) {
6192                 inode->index_cnt = 2;
6193                 goto out;
6194         }
6195
6196         path->slots[0]--;
6197
6198         leaf = path->nodes[0];
6199         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6200
6201         if (found_key.objectid != btrfs_ino(inode) ||
6202             found_key.type != BTRFS_DIR_INDEX_KEY) {
6203                 inode->index_cnt = 2;
6204                 goto out;
6205         }
6206
6207         inode->index_cnt = found_key.offset + 1;
6208 out:
6209         btrfs_free_path(path);
6210         return ret;
6211 }
6212
6213 /*
6214  * helper to find a free sequence number in a given directory.  This current
6215  * code is very simple, later versions will do smarter things in the btree
6216  */
6217 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6218 {
6219         int ret = 0;
6220
6221         if (dir->index_cnt == (u64)-1) {
6222                 ret = btrfs_inode_delayed_dir_index_count(dir);
6223                 if (ret) {
6224                         ret = btrfs_set_inode_index_count(dir);
6225                         if (ret)
6226                                 return ret;
6227                 }
6228         }
6229
6230         *index = dir->index_cnt;
6231         dir->index_cnt++;
6232
6233         return ret;
6234 }
6235
6236 static int btrfs_insert_inode_locked(struct inode *inode)
6237 {
6238         struct btrfs_iget_args args;
6239         args.location = &BTRFS_I(inode)->location;
6240         args.root = BTRFS_I(inode)->root;
6241
6242         return insert_inode_locked4(inode,
6243                    btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6244                    btrfs_find_actor, &args);
6245 }
6246
6247 /*
6248  * Inherit flags from the parent inode.
6249  *
6250  * Currently only the compression flags and the cow flags are inherited.
6251  */
6252 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6253 {
6254         unsigned int flags;
6255
6256         if (!dir)
6257                 return;
6258
6259         flags = BTRFS_I(dir)->flags;
6260
6261         if (flags & BTRFS_INODE_NOCOMPRESS) {
6262                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6263                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6264         } else if (flags & BTRFS_INODE_COMPRESS) {
6265                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6266                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6267         }
6268
6269         if (flags & BTRFS_INODE_NODATACOW) {
6270                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6271                 if (S_ISREG(inode->i_mode))
6272                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6273         }
6274
6275         btrfs_update_iflags(inode);
6276 }
6277
6278 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6279                                      struct btrfs_root *root,
6280                                      struct inode *dir,
6281                                      const char *name, int name_len,
6282                                      u64 ref_objectid, u64 objectid,
6283                                      umode_t mode, u64 *index)
6284 {
6285         struct btrfs_fs_info *fs_info = root->fs_info;
6286         struct inode *inode;
6287         struct btrfs_inode_item *inode_item;
6288         struct btrfs_key *location;
6289         struct btrfs_path *path;
6290         struct btrfs_inode_ref *ref;
6291         struct btrfs_key key[2];
6292         u32 sizes[2];
6293         int nitems = name ? 2 : 1;
6294         unsigned long ptr;
6295         int ret;
6296
6297         path = btrfs_alloc_path();
6298         if (!path)
6299                 return ERR_PTR(-ENOMEM);
6300
6301         inode = new_inode(fs_info->sb);
6302         if (!inode) {
6303                 btrfs_free_path(path);
6304                 return ERR_PTR(-ENOMEM);
6305         }
6306
6307         /*
6308          * O_TMPFILE, set link count to 0, so that after this point,
6309          * we fill in an inode item with the correct link count.
6310          */
6311         if (!name)
6312                 set_nlink(inode, 0);
6313
6314         /*
6315          * we have to initialize this early, so we can reclaim the inode
6316          * number if we fail afterwards in this function.
6317          */
6318         inode->i_ino = objectid;
6319
6320         if (dir && name) {
6321                 trace_btrfs_inode_request(dir);
6322
6323                 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6324                 if (ret) {
6325                         btrfs_free_path(path);
6326                         iput(inode);
6327                         return ERR_PTR(ret);
6328                 }
6329         } else if (dir) {
6330                 *index = 0;
6331         }
6332         /*
6333          * index_cnt is ignored for everything but a dir,
6334          * btrfs_set_inode_index_count has an explanation for the magic
6335          * number
6336          */
6337         BTRFS_I(inode)->index_cnt = 2;
6338         BTRFS_I(inode)->dir_index = *index;
6339         BTRFS_I(inode)->root = root;
6340         BTRFS_I(inode)->generation = trans->transid;
6341         inode->i_generation = BTRFS_I(inode)->generation;
6342
6343         /*
6344          * We could have gotten an inode number from somebody who was fsynced
6345          * and then removed in this same transaction, so let's just set full
6346          * sync since it will be a full sync anyway and this will blow away the
6347          * old info in the log.
6348          */
6349         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6350
6351         key[0].objectid = objectid;
6352         key[0].type = BTRFS_INODE_ITEM_KEY;
6353         key[0].offset = 0;
6354
6355         sizes[0] = sizeof(struct btrfs_inode_item);
6356
6357         if (name) {
6358                 /*
6359                  * Start new inodes with an inode_ref. This is slightly more
6360                  * efficient for small numbers of hard links since they will
6361                  * be packed into one item. Extended refs will kick in if we
6362                  * add more hard links than can fit in the ref item.
6363                  */
6364                 key[1].objectid = objectid;
6365                 key[1].type = BTRFS_INODE_REF_KEY;
6366                 key[1].offset = ref_objectid;
6367
6368                 sizes[1] = name_len + sizeof(*ref);
6369         }
6370
6371         location = &BTRFS_I(inode)->location;
6372         location->objectid = objectid;
6373         location->offset = 0;
6374         location->type = BTRFS_INODE_ITEM_KEY;
6375
6376         ret = btrfs_insert_inode_locked(inode);
6377         if (ret < 0)
6378                 goto fail;
6379
6380         path->leave_spinning = 1;
6381         ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6382         if (ret != 0)
6383                 goto fail_unlock;
6384
6385         inode_init_owner(inode, dir, mode);
6386         inode_set_bytes(inode, 0);
6387
6388         inode->i_mtime = current_time(inode);
6389         inode->i_atime = inode->i_mtime;
6390         inode->i_ctime = inode->i_mtime;
6391         BTRFS_I(inode)->i_otime = inode->i_mtime;
6392
6393         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6394                                   struct btrfs_inode_item);
6395         memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6396                              sizeof(*inode_item));
6397         fill_inode_item(trans, path->nodes[0], inode_item, inode);
6398
6399         if (name) {
6400                 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6401                                      struct btrfs_inode_ref);
6402                 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6403                 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6404                 ptr = (unsigned long)(ref + 1);
6405                 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6406         }
6407
6408         btrfs_mark_buffer_dirty(path->nodes[0]);
6409         btrfs_free_path(path);
6410
6411         btrfs_inherit_iflags(inode, dir);
6412
6413         if (S_ISREG(mode)) {
6414                 if (btrfs_test_opt(fs_info, NODATASUM))
6415                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6416                 if (btrfs_test_opt(fs_info, NODATACOW))
6417                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6418                                 BTRFS_INODE_NODATASUM;
6419         }
6420
6421         inode_tree_add(inode);
6422
6423         trace_btrfs_inode_new(inode);
6424         btrfs_set_inode_last_trans(trans, inode);
6425
6426         btrfs_update_root_times(trans, root);
6427
6428         ret = btrfs_inode_inherit_props(trans, inode, dir);
6429         if (ret)
6430                 btrfs_err(fs_info,
6431                           "error inheriting props for ino %llu (root %llu): %d",
6432                         btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6433
6434         return inode;
6435
6436 fail_unlock:
6437         unlock_new_inode(inode);
6438 fail:
6439         if (dir && name)
6440                 BTRFS_I(dir)->index_cnt--;
6441         btrfs_free_path(path);
6442         iput(inode);
6443         return ERR_PTR(ret);
6444 }
6445
6446 static inline u8 btrfs_inode_type(struct inode *inode)
6447 {
6448         return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6449 }
6450
6451 /*
6452  * utility function to add 'inode' into 'parent_inode' with
6453  * a give name and a given sequence number.
6454  * if 'add_backref' is true, also insert a backref from the
6455  * inode to the parent directory.
6456  */
6457 int btrfs_add_link(struct btrfs_trans_handle *trans,
6458                    struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6459                    const char *name, int name_len, int add_backref, u64 index)
6460 {
6461         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6462         int ret = 0;
6463         struct btrfs_key key;
6464         struct btrfs_root *root = parent_inode->root;
6465         u64 ino = btrfs_ino(inode);
6466         u64 parent_ino = btrfs_ino(parent_inode);
6467
6468         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6469                 memcpy(&key, &inode->root->root_key, sizeof(key));
6470         } else {
6471                 key.objectid = ino;
6472                 key.type = BTRFS_INODE_ITEM_KEY;
6473                 key.offset = 0;
6474         }
6475
6476         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6477                 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6478                                          root->root_key.objectid, parent_ino,
6479                                          index, name, name_len);
6480         } else if (add_backref) {
6481                 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6482                                              parent_ino, index);
6483         }
6484
6485         /* Nothing to clean up yet */
6486         if (ret)
6487                 return ret;
6488
6489         ret = btrfs_insert_dir_item(trans, root, name, name_len,
6490                                     parent_inode, &key,
6491                                     btrfs_inode_type(&inode->vfs_inode), index);
6492         if (ret == -EEXIST || ret == -EOVERFLOW)
6493                 goto fail_dir_item;
6494         else if (ret) {
6495                 btrfs_abort_transaction(trans, ret);
6496                 return ret;
6497         }
6498
6499         btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6500                            name_len * 2);
6501         inode_inc_iversion(&parent_inode->vfs_inode);
6502         parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6503                 current_time(&parent_inode->vfs_inode);
6504         ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6505         if (ret)
6506                 btrfs_abort_transaction(trans, ret);
6507         return ret;
6508
6509 fail_dir_item:
6510         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6511                 u64 local_index;
6512                 int err;
6513                 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6514                                          root->root_key.objectid, parent_ino,
6515                                          &local_index, name, name_len);
6516
6517         } else if (add_backref) {
6518                 u64 local_index;
6519                 int err;
6520
6521                 err = btrfs_del_inode_ref(trans, root, name, name_len,
6522                                           ino, parent_ino, &local_index);
6523         }
6524         return ret;
6525 }
6526
6527 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6528                             struct btrfs_inode *dir, struct dentry *dentry,
6529                             struct btrfs_inode *inode, int backref, u64 index)
6530 {
6531         int err = btrfs_add_link(trans, dir, inode,
6532                                  dentry->d_name.name, dentry->d_name.len,
6533                                  backref, index);
6534         if (err > 0)
6535                 err = -EEXIST;
6536         return err;
6537 }
6538
6539 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6540                         umode_t mode, dev_t rdev)
6541 {
6542         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6543         struct btrfs_trans_handle *trans;
6544         struct btrfs_root *root = BTRFS_I(dir)->root;
6545         struct inode *inode = NULL;
6546         int err;
6547         int drop_inode = 0;
6548         u64 objectid;
6549         u64 index = 0;
6550
6551         /*
6552          * 2 for inode item and ref
6553          * 2 for dir items
6554          * 1 for xattr if selinux is on
6555          */
6556         trans = btrfs_start_transaction(root, 5);
6557         if (IS_ERR(trans))
6558                 return PTR_ERR(trans);
6559
6560         err = btrfs_find_free_ino(root, &objectid);
6561         if (err)
6562                 goto out_unlock;
6563
6564         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6565                         dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6566                         mode, &index);
6567         if (IS_ERR(inode)) {
6568                 err = PTR_ERR(inode);
6569                 goto out_unlock;
6570         }
6571
6572         /*
6573         * If the active LSM wants to access the inode during
6574         * d_instantiate it needs these. Smack checks to see
6575         * if the filesystem supports xattrs by looking at the
6576         * ops vector.
6577         */
6578         inode->i_op = &btrfs_special_inode_operations;
6579         init_special_inode(inode, inode->i_mode, rdev);
6580
6581         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6582         if (err)
6583                 goto out_unlock_inode;
6584
6585         err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6586                         0, index);
6587         if (err) {
6588                 goto out_unlock_inode;
6589         } else {
6590                 btrfs_update_inode(trans, root, inode);
6591                 unlock_new_inode(inode);
6592                 d_instantiate(dentry, inode);
6593         }
6594
6595 out_unlock:
6596         btrfs_end_transaction(trans);
6597         btrfs_btree_balance_dirty(fs_info);
6598         if (drop_inode) {
6599                 inode_dec_link_count(inode);
6600                 iput(inode);
6601         }
6602         return err;
6603
6604 out_unlock_inode:
6605         drop_inode = 1;
6606         unlock_new_inode(inode);
6607         goto out_unlock;
6608
6609 }
6610
6611 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6612                         umode_t mode, bool excl)
6613 {
6614         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6615         struct btrfs_trans_handle *trans;
6616         struct btrfs_root *root = BTRFS_I(dir)->root;
6617         struct inode *inode = NULL;
6618         int drop_inode_on_err = 0;
6619         int err;
6620         u64 objectid;
6621         u64 index = 0;
6622
6623         /*
6624          * 2 for inode item and ref
6625          * 2 for dir items
6626          * 1 for xattr if selinux is on
6627          */
6628         trans = btrfs_start_transaction(root, 5);
6629         if (IS_ERR(trans))
6630                 return PTR_ERR(trans);
6631
6632         err = btrfs_find_free_ino(root, &objectid);
6633         if (err)
6634                 goto out_unlock;
6635
6636         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6637                         dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6638                         mode, &index);
6639         if (IS_ERR(inode)) {
6640                 err = PTR_ERR(inode);
6641                 goto out_unlock;
6642         }
6643         drop_inode_on_err = 1;
6644         /*
6645         * If the active LSM wants to access the inode during
6646         * d_instantiate it needs these. Smack checks to see
6647         * if the filesystem supports xattrs by looking at the
6648         * ops vector.
6649         */
6650         inode->i_fop = &btrfs_file_operations;
6651         inode->i_op = &btrfs_file_inode_operations;
6652         inode->i_mapping->a_ops = &btrfs_aops;
6653
6654         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6655         if (err)
6656                 goto out_unlock_inode;
6657
6658         err = btrfs_update_inode(trans, root, inode);
6659         if (err)
6660                 goto out_unlock_inode;
6661
6662         err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6663                         0, index);
6664         if (err)
6665                 goto out_unlock_inode;
6666
6667         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6668         unlock_new_inode(inode);
6669         d_instantiate(dentry, inode);
6670
6671 out_unlock:
6672         btrfs_end_transaction(trans);
6673         if (err && drop_inode_on_err) {
6674                 inode_dec_link_count(inode);
6675                 iput(inode);
6676         }
6677         btrfs_btree_balance_dirty(fs_info);
6678         return err;
6679
6680 out_unlock_inode:
6681         unlock_new_inode(inode);
6682         goto out_unlock;
6683
6684 }
6685
6686 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6687                       struct dentry *dentry)
6688 {
6689         struct btrfs_trans_handle *trans = NULL;
6690         struct btrfs_root *root = BTRFS_I(dir)->root;
6691         struct inode *inode = d_inode(old_dentry);
6692         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6693         u64 index;
6694         int err;
6695         int drop_inode = 0;
6696
6697         /* do not allow sys_link's with other subvols of the same device */
6698         if (root->objectid != BTRFS_I(inode)->root->objectid)
6699                 return -EXDEV;
6700
6701         if (inode->i_nlink >= BTRFS_LINK_MAX)
6702                 return -EMLINK;
6703
6704         err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6705         if (err)
6706                 goto fail;
6707
6708         /*
6709          * 2 items for inode and inode ref
6710          * 2 items for dir items
6711          * 1 item for parent inode
6712          */
6713         trans = btrfs_start_transaction(root, 5);
6714         if (IS_ERR(trans)) {
6715                 err = PTR_ERR(trans);
6716                 trans = NULL;
6717                 goto fail;
6718         }
6719
6720         /* There are several dir indexes for this inode, clear the cache. */
6721         BTRFS_I(inode)->dir_index = 0ULL;
6722         inc_nlink(inode);
6723         inode_inc_iversion(inode);
6724         inode->i_ctime = current_time(inode);
6725         ihold(inode);
6726         set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6727
6728         err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6729                         1, index);
6730
6731         if (err) {
6732                 drop_inode = 1;
6733         } else {
6734                 struct dentry *parent = dentry->d_parent;
6735                 err = btrfs_update_inode(trans, root, inode);
6736                 if (err)
6737                         goto fail;
6738                 if (inode->i_nlink == 1) {
6739                         /*
6740                          * If new hard link count is 1, it's a file created
6741                          * with open(2) O_TMPFILE flag.
6742                          */
6743                         err = btrfs_orphan_del(trans, BTRFS_I(inode));
6744                         if (err)
6745                                 goto fail;
6746                 }
6747                 d_instantiate(dentry, inode);
6748                 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6749         }
6750
6751 fail:
6752         if (trans)
6753                 btrfs_end_transaction(trans);
6754         if (drop_inode) {
6755                 inode_dec_link_count(inode);
6756                 iput(inode);
6757         }
6758         btrfs_btree_balance_dirty(fs_info);
6759         return err;
6760 }
6761
6762 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6763 {
6764         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6765         struct inode *inode = NULL;
6766         struct btrfs_trans_handle *trans;
6767         struct btrfs_root *root = BTRFS_I(dir)->root;
6768         int err = 0;
6769         int drop_on_err = 0;
6770         u64 objectid = 0;
6771         u64 index = 0;
6772
6773         /*
6774          * 2 items for inode and ref
6775          * 2 items for dir items
6776          * 1 for xattr if selinux is on
6777          */
6778         trans = btrfs_start_transaction(root, 5);
6779         if (IS_ERR(trans))
6780                 return PTR_ERR(trans);
6781
6782         err = btrfs_find_free_ino(root, &objectid);
6783         if (err)
6784                 goto out_fail;
6785
6786         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6787                         dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6788                         S_IFDIR | mode, &index);
6789         if (IS_ERR(inode)) {
6790                 err = PTR_ERR(inode);
6791                 goto out_fail;
6792         }
6793
6794         drop_on_err = 1;
6795         /* these must be set before we unlock the inode */
6796         inode->i_op = &btrfs_dir_inode_operations;
6797         inode->i_fop = &btrfs_dir_file_operations;
6798
6799         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6800         if (err)
6801                 goto out_fail_inode;
6802
6803         btrfs_i_size_write(BTRFS_I(inode), 0);
6804         err = btrfs_update_inode(trans, root, inode);
6805         if (err)
6806                 goto out_fail_inode;
6807
6808         err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6809                         dentry->d_name.name,
6810                         dentry->d_name.len, 0, index);
6811         if (err)
6812                 goto out_fail_inode;
6813
6814         d_instantiate(dentry, inode);
6815         /*
6816          * mkdir is special.  We're unlocking after we call d_instantiate
6817          * to avoid a race with nfsd calling d_instantiate.
6818          */
6819         unlock_new_inode(inode);
6820         drop_on_err = 0;
6821
6822 out_fail:
6823         btrfs_end_transaction(trans);
6824         if (drop_on_err) {
6825                 inode_dec_link_count(inode);
6826                 iput(inode);
6827         }
6828         btrfs_btree_balance_dirty(fs_info);
6829         return err;
6830
6831 out_fail_inode:
6832         unlock_new_inode(inode);
6833         goto out_fail;
6834 }
6835
6836 static noinline int uncompress_inline(struct btrfs_path *path,
6837                                       struct page *page,
6838                                       size_t pg_offset, u64 extent_offset,
6839                                       struct btrfs_file_extent_item *item)
6840 {
6841         int ret;
6842         struct extent_buffer *leaf = path->nodes[0];
6843         char *tmp;
6844         size_t max_size;
6845         unsigned long inline_size;
6846         unsigned long ptr;
6847         int compress_type;
6848
6849         WARN_ON(pg_offset != 0);
6850         compress_type = btrfs_file_extent_compression(leaf, item);
6851         max_size = btrfs_file_extent_ram_bytes(leaf, item);
6852         inline_size = btrfs_file_extent_inline_item_len(leaf,
6853                                         btrfs_item_nr(path->slots[0]));
6854         tmp = kmalloc(inline_size, GFP_NOFS);
6855         if (!tmp)
6856                 return -ENOMEM;
6857         ptr = btrfs_file_extent_inline_start(item);
6858
6859         read_extent_buffer(leaf, tmp, ptr, inline_size);
6860
6861         max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6862         ret = btrfs_decompress(compress_type, tmp, page,
6863                                extent_offset, inline_size, max_size);
6864
6865         /*
6866          * decompression code contains a memset to fill in any space between the end
6867          * of the uncompressed data and the end of max_size in case the decompressed
6868          * data ends up shorter than ram_bytes.  That doesn't cover the hole between
6869          * the end of an inline extent and the beginning of the next block, so we
6870          * cover that region here.
6871          */
6872
6873         if (max_size + pg_offset < PAGE_SIZE) {
6874                 char *map = kmap(page);
6875                 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6876                 kunmap(page);
6877         }
6878         kfree(tmp);
6879         return ret;
6880 }
6881
6882 /*
6883  * a bit scary, this does extent mapping from logical file offset to the disk.
6884  * the ugly parts come from merging extents from the disk with the in-ram
6885  * representation.  This gets more complex because of the data=ordered code,
6886  * where the in-ram extents might be locked pending data=ordered completion.
6887  *
6888  * This also copies inline extents directly into the page.
6889  */
6890 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6891                 struct page *page,
6892             size_t pg_offset, u64 start, u64 len,
6893                 int create)
6894 {
6895         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6896         int ret;
6897         int err = 0;
6898         u64 extent_start = 0;
6899         u64 extent_end = 0;
6900         u64 objectid = btrfs_ino(inode);
6901         u32 found_type;
6902         struct btrfs_path *path = NULL;
6903         struct btrfs_root *root = inode->root;
6904         struct btrfs_file_extent_item *item;
6905         struct extent_buffer *leaf;
6906         struct btrfs_key found_key;
6907         struct extent_map *em = NULL;
6908         struct extent_map_tree *em_tree = &inode->extent_tree;
6909         struct extent_io_tree *io_tree = &inode->io_tree;
6910         const bool new_inline = !page || create;
6911
6912         read_lock(&em_tree->lock);
6913         em = lookup_extent_mapping(em_tree, start, len);
6914         if (em)
6915                 em->bdev = fs_info->fs_devices->latest_bdev;
6916         read_unlock(&em_tree->lock);
6917
6918         if (em) {
6919                 if (em->start > start || em->start + em->len <= start)
6920                         free_extent_map(em);
6921                 else if (em->block_start == EXTENT_MAP_INLINE && page)
6922                         free_extent_map(em);
6923                 else
6924                         goto out;
6925         }
6926         em = alloc_extent_map();
6927         if (!em) {
6928                 err = -ENOMEM;
6929                 goto out;
6930         }
6931         em->bdev = fs_info->fs_devices->latest_bdev;
6932         em->start = EXTENT_MAP_HOLE;
6933         em->orig_start = EXTENT_MAP_HOLE;
6934         em->len = (u64)-1;
6935         em->block_len = (u64)-1;
6936
6937         if (!path) {
6938                 path = btrfs_alloc_path();
6939                 if (!path) {
6940                         err = -ENOMEM;
6941                         goto out;
6942                 }
6943                 /*
6944                  * Chances are we'll be called again, so go ahead and do
6945                  * readahead
6946                  */
6947                 path->reada = READA_FORWARD;
6948         }
6949
6950         ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
6951         if (ret < 0) {
6952                 err = ret;
6953                 goto out;
6954         }
6955
6956         if (ret != 0) {
6957                 if (path->slots[0] == 0)
6958                         goto not_found;
6959                 path->slots[0]--;
6960         }
6961
6962         leaf = path->nodes[0];
6963         item = btrfs_item_ptr(leaf, path->slots[0],
6964                               struct btrfs_file_extent_item);
6965         /* are we inside the extent that was found? */
6966         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6967         found_type = found_key.type;
6968         if (found_key.objectid != objectid ||
6969             found_type != BTRFS_EXTENT_DATA_KEY) {
6970                 /*
6971                  * If we backup past the first extent we want to move forward
6972                  * and see if there is an extent in front of us, otherwise we'll
6973                  * say there is a hole for our whole search range which can
6974                  * cause problems.
6975                  */
6976                 extent_end = start;
6977                 goto next;
6978         }
6979
6980         found_type = btrfs_file_extent_type(leaf, item);
6981         extent_start = found_key.offset;
6982         if (found_type == BTRFS_FILE_EXTENT_REG ||
6983             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6984                 extent_end = extent_start +
6985                        btrfs_file_extent_num_bytes(leaf, item);
6986
6987                 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
6988                                                        extent_start);
6989         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6990                 size_t size;
6991                 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6992                 extent_end = ALIGN(extent_start + size,
6993                                    fs_info->sectorsize);
6994
6995                 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
6996                                                       path->slots[0],
6997                                                       extent_start);
6998         }
6999 next:
7000         if (start >= extent_end) {
7001                 path->slots[0]++;
7002                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
7003                         ret = btrfs_next_leaf(root, path);
7004                         if (ret < 0) {
7005                                 err = ret;
7006                                 goto out;
7007                         }
7008                         if (ret > 0)
7009                                 goto not_found;
7010                         leaf = path->nodes[0];
7011                 }
7012                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7013                 if (found_key.objectid != objectid ||
7014                     found_key.type != BTRFS_EXTENT_DATA_KEY)
7015                         goto not_found;
7016                 if (start + len <= found_key.offset)
7017                         goto not_found;
7018                 if (start > found_key.offset)
7019                         goto next;
7020                 em->start = start;
7021                 em->orig_start = start;
7022                 em->len = found_key.offset - start;
7023                 goto not_found_em;
7024         }
7025
7026         btrfs_extent_item_to_extent_map(inode, path, item,
7027                         new_inline, em);
7028
7029         if (found_type == BTRFS_FILE_EXTENT_REG ||
7030             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7031                 goto insert;
7032         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7033                 unsigned long ptr;
7034                 char *map;
7035                 size_t size;
7036                 size_t extent_offset;
7037                 size_t copy_size;
7038
7039                 if (new_inline)
7040                         goto out;
7041
7042                 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7043                 extent_offset = page_offset(page) + pg_offset - extent_start;
7044                 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7045                                   size - extent_offset);
7046                 em->start = extent_start + extent_offset;
7047                 em->len = ALIGN(copy_size, fs_info->sectorsize);
7048                 em->orig_block_len = em->len;
7049                 em->orig_start = em->start;
7050                 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7051                 if (!PageUptodate(page)) {
7052                         if (btrfs_file_extent_compression(leaf, item) !=
7053                             BTRFS_COMPRESS_NONE) {
7054                                 ret = uncompress_inline(path, page, pg_offset,
7055                                                         extent_offset, item);
7056                                 if (ret) {
7057                                         err = ret;
7058                                         goto out;
7059                                 }
7060                         } else {
7061                                 map = kmap(page);
7062                                 read_extent_buffer(leaf, map + pg_offset, ptr,
7063                                                    copy_size);
7064                                 if (pg_offset + copy_size < PAGE_SIZE) {
7065                                         memset(map + pg_offset + copy_size, 0,
7066                                                PAGE_SIZE - pg_offset -
7067                                                copy_size);
7068                                 }
7069                                 kunmap(page);
7070                         }
7071                         flush_dcache_page(page);
7072                 }
7073                 set_extent_uptodate(io_tree, em->start,
7074                                     extent_map_end(em) - 1, NULL, GFP_NOFS);
7075                 goto insert;
7076         }
7077 not_found:
7078         em->start = start;
7079         em->orig_start = start;
7080         em->len = len;
7081 not_found_em:
7082         em->block_start = EXTENT_MAP_HOLE;
7083 insert:
7084         btrfs_release_path(path);
7085         if (em->start > start || extent_map_end(em) <= start) {
7086                 btrfs_err(fs_info,
7087                           "bad extent! em: [%llu %llu] passed [%llu %llu]",
7088                           em->start, em->len, start, len);
7089                 err = -EIO;
7090                 goto out;
7091         }
7092
7093         err = 0;
7094         write_lock(&em_tree->lock);
7095         err = btrfs_add_extent_mapping(em_tree, &em, start, len);
7096         write_unlock(&em_tree->lock);
7097 out:
7098
7099         trace_btrfs_get_extent(root, inode, em);
7100
7101         btrfs_free_path(path);
7102         if (err) {
7103                 free_extent_map(em);
7104                 return ERR_PTR(err);
7105         }
7106         BUG_ON(!em); /* Error is always set */
7107         return em;
7108 }
7109
7110 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7111                 struct page *page,
7112                 size_t pg_offset, u64 start, u64 len,
7113                 int create)
7114 {
7115         struct extent_map *em;
7116         struct extent_map *hole_em = NULL;
7117         u64 range_start = start;
7118         u64 end;
7119         u64 found;
7120         u64 found_end;
7121         int err = 0;
7122
7123         em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7124         if (IS_ERR(em))
7125                 return em;
7126         /*
7127          * If our em maps to:
7128          * - a hole or
7129          * - a pre-alloc extent,
7130          * there might actually be delalloc bytes behind it.
7131          */
7132         if (em->block_start != EXTENT_MAP_HOLE &&
7133             !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7134                 return em;
7135         else
7136                 hole_em = em;
7137
7138         /* check to see if we've wrapped (len == -1 or similar) */
7139         end = start + len;
7140         if (end < start)
7141                 end = (u64)-1;
7142         else
7143                 end -= 1;
7144
7145         em = NULL;
7146
7147         /* ok, we didn't find anything, lets look for delalloc */
7148         found = count_range_bits(&inode->io_tree, &range_start,
7149                                  end, len, EXTENT_DELALLOC, 1);
7150         found_end = range_start + found;
7151         if (found_end < range_start)
7152                 found_end = (u64)-1;
7153
7154         /*
7155          * we didn't find anything useful, return
7156          * the original results from get_extent()
7157          */
7158         if (range_start > end || found_end <= start) {
7159                 em = hole_em;
7160                 hole_em = NULL;
7161                 goto out;
7162         }
7163
7164         /* adjust the range_start to make sure it doesn't
7165          * go backwards from the start they passed in
7166          */
7167         range_start = max(start, range_start);
7168         found = found_end - range_start;
7169
7170         if (found > 0) {
7171                 u64 hole_start = start;
7172                 u64 hole_len = len;
7173
7174                 em = alloc_extent_map();
7175                 if (!em) {
7176                         err = -ENOMEM;
7177                         goto out;
7178                 }
7179                 /*
7180                  * when btrfs_get_extent can't find anything it
7181                  * returns one huge hole
7182                  *
7183                  * make sure what it found really fits our range, and
7184                  * adjust to make sure it is based on the start from
7185                  * the caller
7186                  */
7187                 if (hole_em) {
7188                         u64 calc_end = extent_map_end(hole_em);
7189
7190                         if (calc_end <= start || (hole_em->start > end)) {
7191                                 free_extent_map(hole_em);
7192                                 hole_em = NULL;
7193                         } else {
7194                                 hole_start = max(hole_em->start, start);
7195                                 hole_len = calc_end - hole_start;
7196                         }
7197                 }
7198                 em->bdev = NULL;
7199                 if (hole_em && range_start > hole_start) {
7200                         /* our hole starts before our delalloc, so we
7201                          * have to return just the parts of the hole
7202                          * that go until  the delalloc starts
7203                          */
7204                         em->len = min(hole_len,
7205                                       range_start - hole_start);
7206                         em->start = hole_start;
7207                         em->orig_start = hole_start;
7208                         /*
7209                          * don't adjust block start at all,
7210                          * it is fixed at EXTENT_MAP_HOLE
7211                          */
7212                         em->block_start = hole_em->block_start;
7213                         em->block_len = hole_len;
7214                         if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7215                                 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7216                 } else {
7217                         em->start = range_start;
7218                         em->len = found;
7219                         em->orig_start = range_start;
7220                         em->block_start = EXTENT_MAP_DELALLOC;
7221                         em->block_len = found;
7222                 }
7223         } else {
7224                 return hole_em;
7225         }
7226 out:
7227
7228         free_extent_map(hole_em);
7229         if (err) {
7230                 free_extent_map(em);
7231                 return ERR_PTR(err);
7232         }
7233         return em;
7234 }
7235
7236 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7237                                                   const u64 start,
7238                                                   const u64 len,
7239                                                   const u64 orig_start,
7240                                                   const u64 block_start,
7241                                                   const u64 block_len,
7242                                                   const u64 orig_block_len,
7243                                                   const u64 ram_bytes,
7244                                                   const int type)
7245 {
7246         struct extent_map *em = NULL;
7247         int ret;
7248
7249         if (type != BTRFS_ORDERED_NOCOW) {
7250                 em = create_io_em(inode, start, len, orig_start,
7251                                   block_start, block_len, orig_block_len,
7252                                   ram_bytes,
7253                                   BTRFS_COMPRESS_NONE, /* compress_type */
7254                                   type);
7255                 if (IS_ERR(em))
7256                         goto out;
7257         }
7258         ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7259                                            len, block_len, type);
7260         if (ret) {
7261                 if (em) {
7262                         free_extent_map(em);
7263                         btrfs_drop_extent_cache(BTRFS_I(inode), start,
7264                                                 start + len - 1, 0);
7265                 }
7266                 em = ERR_PTR(ret);
7267         }
7268  out:
7269
7270         return em;
7271 }
7272
7273 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7274                                                   u64 start, u64 len)
7275 {
7276         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7277         struct btrfs_root *root = BTRFS_I(inode)->root;
7278         struct extent_map *em;
7279         struct btrfs_key ins;
7280         u64 alloc_hint;
7281         int ret;
7282
7283         alloc_hint = get_extent_allocation_hint(inode, start, len);
7284         ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7285                                    0, alloc_hint, &ins, 1, 1);
7286         if (ret)
7287                 return ERR_PTR(ret);
7288
7289         em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7290                                      ins.objectid, ins.offset, ins.offset,
7291                                      ins.offset, BTRFS_ORDERED_REGULAR);
7292         btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7293         if (IS_ERR(em))
7294                 btrfs_free_reserved_extent(fs_info, ins.objectid,
7295                                            ins.offset, 1);
7296
7297         return em;
7298 }
7299
7300 /*
7301  * returns 1 when the nocow is safe, < 1 on error, 0 if the
7302  * block must be cow'd
7303  */
7304 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7305                               u64 *orig_start, u64 *orig_block_len,
7306                               u64 *ram_bytes)
7307 {
7308         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7309         struct btrfs_path *path;
7310         int ret;
7311         struct extent_buffer *leaf;
7312         struct btrfs_root *root = BTRFS_I(inode)->root;
7313         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7314         struct btrfs_file_extent_item *fi;
7315         struct btrfs_key key;
7316         u64 disk_bytenr;
7317         u64 backref_offset;
7318         u64 extent_end;
7319         u64 num_bytes;
7320         int slot;
7321         int found_type;
7322         bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7323
7324         path = btrfs_alloc_path();
7325         if (!path)
7326                 return -ENOMEM;
7327
7328         ret = btrfs_lookup_file_extent(NULL, root, path,
7329                         btrfs_ino(BTRFS_I(inode)), offset, 0);
7330         if (ret < 0)
7331                 goto out;
7332
7333         slot = path->slots[0];
7334         if (ret == 1) {
7335                 if (slot == 0) {
7336                         /* can't find the item, must cow */
7337                         ret = 0;
7338                         goto out;
7339                 }
7340                 slot--;
7341         }
7342         ret = 0;
7343         leaf = path->nodes[0];
7344         btrfs_item_key_to_cpu(leaf, &key, slot);
7345         if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7346             key.type != BTRFS_EXTENT_DATA_KEY) {
7347                 /* not our file or wrong item type, must cow */
7348                 goto out;
7349         }
7350
7351         if (key.offset > offset) {
7352                 /* Wrong offset, must cow */
7353                 goto out;
7354         }
7355
7356         fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7357         found_type = btrfs_file_extent_type(leaf, fi);
7358         if (found_type != BTRFS_FILE_EXTENT_REG &&
7359             found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7360                 /* not a regular extent, must cow */
7361                 goto out;
7362         }
7363
7364         if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7365                 goto out;
7366
7367         extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7368         if (extent_end <= offset)
7369                 goto out;
7370
7371         disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7372         if (disk_bytenr == 0)
7373                 goto out;
7374
7375         if (btrfs_file_extent_compression(leaf, fi) ||
7376             btrfs_file_extent_encryption(leaf, fi) ||
7377             btrfs_file_extent_other_encoding(leaf, fi))
7378                 goto out;
7379
7380         backref_offset = btrfs_file_extent_offset(leaf, fi);
7381
7382         if (orig_start) {
7383                 *orig_start = key.offset - backref_offset;
7384                 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7385                 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7386         }
7387
7388         if (btrfs_extent_readonly(fs_info, disk_bytenr))
7389                 goto out;
7390
7391         num_bytes = min(offset + *len, extent_end) - offset;
7392         if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7393                 u64 range_end;
7394
7395                 range_end = round_up(offset + num_bytes,
7396                                      root->fs_info->sectorsize) - 1;
7397                 ret = test_range_bit(io_tree, offset, range_end,
7398                                      EXTENT_DELALLOC, 0, NULL);
7399                 if (ret) {
7400                         ret = -EAGAIN;
7401                         goto out;
7402                 }
7403         }
7404
7405         btrfs_release_path(path);
7406
7407         /*
7408          * look for other files referencing this extent, if we
7409          * find any we must cow
7410          */
7411
7412         ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7413                                     key.offset - backref_offset, disk_bytenr);
7414         if (ret) {
7415                 ret = 0;
7416                 goto out;
7417         }
7418
7419         /*
7420          * adjust disk_bytenr and num_bytes to cover just the bytes
7421          * in this extent we are about to write.  If there
7422          * are any csums in that range we have to cow in order
7423          * to keep the csums correct
7424          */
7425         disk_bytenr += backref_offset;
7426         disk_bytenr += offset - key.offset;
7427         if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7428                 goto out;
7429         /*
7430          * all of the above have passed, it is safe to overwrite this extent
7431          * without cow
7432          */
7433         *len = num_bytes;
7434         ret = 1;
7435 out:
7436         btrfs_free_path(path);
7437         return ret;
7438 }
7439
7440 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7441                               struct extent_state **cached_state, int writing)
7442 {
7443         struct btrfs_ordered_extent *ordered;
7444         int ret = 0;
7445
7446         while (1) {
7447                 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7448                                  cached_state);
7449                 /*
7450                  * We're concerned with the entire range that we're going to be
7451                  * doing DIO to, so we need to make sure there's no ordered
7452                  * extents in this range.
7453                  */
7454                 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7455                                                      lockend - lockstart + 1);
7456
7457                 /*
7458                  * We need to make sure there are no buffered pages in this
7459                  * range either, we could have raced between the invalidate in
7460                  * generic_file_direct_write and locking the extent.  The
7461                  * invalidate needs to happen so that reads after a write do not
7462                  * get stale data.
7463                  */
7464                 if (!ordered &&
7465                     (!writing || !filemap_range_has_page(inode->i_mapping,
7466                                                          lockstart, lockend)))
7467                         break;
7468
7469                 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7470                                      cached_state);
7471
7472                 if (ordered) {
7473                         /*
7474                          * If we are doing a DIO read and the ordered extent we
7475                          * found is for a buffered write, we can not wait for it
7476                          * to complete and retry, because if we do so we can
7477                          * deadlock with concurrent buffered writes on page
7478                          * locks. This happens only if our DIO read covers more
7479                          * than one extent map, if at this point has already
7480                          * created an ordered extent for a previous extent map
7481                          * and locked its range in the inode's io tree, and a
7482                          * concurrent write against that previous extent map's
7483                          * range and this range started (we unlock the ranges
7484                          * in the io tree only when the bios complete and
7485                          * buffered writes always lock pages before attempting
7486                          * to lock range in the io tree).
7487                          */
7488                         if (writing ||
7489                             test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7490                                 btrfs_start_ordered_extent(inode, ordered, 1);
7491                         else
7492                                 ret = -ENOTBLK;
7493                         btrfs_put_ordered_extent(ordered);
7494                 } else {
7495                         /*
7496                          * We could trigger writeback for this range (and wait
7497                          * for it to complete) and then invalidate the pages for
7498                          * this range (through invalidate_inode_pages2_range()),
7499                          * but that can lead us to a deadlock with a concurrent
7500                          * call to readpages() (a buffered read or a defrag call
7501                          * triggered a readahead) on a page lock due to an
7502                          * ordered dio extent we created before but did not have
7503                          * yet a corresponding bio submitted (whence it can not
7504                          * complete), which makes readpages() wait for that
7505                          * ordered extent to complete while holding a lock on
7506                          * that page.
7507                          */
7508                         ret = -ENOTBLK;
7509                 }
7510
7511                 if (ret)
7512                         break;
7513
7514                 cond_resched();
7515         }
7516
7517         return ret;
7518 }
7519
7520 /* The callers of this must take lock_extent() */
7521 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7522                                        u64 orig_start, u64 block_start,
7523                                        u64 block_len, u64 orig_block_len,
7524                                        u64 ram_bytes, int compress_type,
7525                                        int type)
7526 {
7527         struct extent_map_tree *em_tree;
7528         struct extent_map *em;
7529         struct btrfs_root *root = BTRFS_I(inode)->root;
7530         int ret;
7531
7532         ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7533                type == BTRFS_ORDERED_COMPRESSED ||
7534                type == BTRFS_ORDERED_NOCOW ||
7535                type == BTRFS_ORDERED_REGULAR);
7536
7537         em_tree = &BTRFS_I(inode)->extent_tree;
7538         em = alloc_extent_map();
7539         if (!em)
7540                 return ERR_PTR(-ENOMEM);
7541
7542         em->start = start;
7543         em->orig_start = orig_start;
7544         em->len = len;
7545         em->block_len = block_len;
7546         em->block_start = block_start;
7547         em->bdev = root->fs_info->fs_devices->latest_bdev;
7548         em->orig_block_len = orig_block_len;
7549         em->ram_bytes = ram_bytes;
7550         em->generation = -1;
7551         set_bit(EXTENT_FLAG_PINNED, &em->flags);
7552         if (type == BTRFS_ORDERED_PREALLOC) {
7553                 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7554         } else if (type == BTRFS_ORDERED_COMPRESSED) {
7555                 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7556                 em->compress_type = compress_type;
7557         }
7558
7559         do {
7560                 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7561                                 em->start + em->len - 1, 0);
7562                 write_lock(&em_tree->lock);
7563                 ret = add_extent_mapping(em_tree, em, 1);
7564                 write_unlock(&em_tree->lock);
7565                 /*
7566                  * The caller has taken lock_extent(), who could race with us
7567                  * to add em?
7568                  */
7569         } while (ret == -EEXIST);
7570
7571         if (ret) {
7572                 free_extent_map(em);
7573                 return ERR_PTR(ret);
7574         }
7575
7576         /* em got 2 refs now, callers needs to do free_extent_map once. */
7577         return em;
7578 }
7579
7580 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7581                                    struct buffer_head *bh_result, int create)
7582 {
7583         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7584         struct extent_map *em;
7585         struct extent_state *cached_state = NULL;
7586         struct btrfs_dio_data *dio_data = NULL;
7587         u64 start = iblock << inode->i_blkbits;
7588         u64 lockstart, lockend;
7589         u64 len = bh_result->b_size;
7590         int unlock_bits = EXTENT_LOCKED;
7591         int ret = 0;
7592
7593         if (create)
7594                 unlock_bits |= EXTENT_DIRTY;
7595         else
7596                 len = min_t(u64, len, fs_info->sectorsize);
7597
7598         lockstart = start;
7599         lockend = start + len - 1;
7600
7601         if (current->journal_info) {
7602                 /*
7603                  * Need to pull our outstanding extents and set journal_info to NULL so
7604                  * that anything that needs to check if there's a transaction doesn't get
7605                  * confused.
7606                  */
7607                 dio_data = current->journal_info;
7608                 current->journal_info = NULL;
7609         }
7610
7611         /*
7612          * If this errors out it's because we couldn't invalidate pagecache for
7613          * this range and we need to fallback to buffered.
7614          */
7615         if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7616                                create)) {
7617                 ret = -ENOTBLK;
7618                 goto err;
7619         }
7620
7621         em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7622         if (IS_ERR(em)) {
7623                 ret = PTR_ERR(em);
7624                 goto unlock_err;
7625         }
7626
7627         /*
7628          * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7629          * io.  INLINE is special, and we could probably kludge it in here, but
7630          * it's still buffered so for safety lets just fall back to the generic
7631          * buffered path.
7632          *
7633          * For COMPRESSED we _have_ to read the entire extent in so we can
7634          * decompress it, so there will be buffering required no matter what we
7635          * do, so go ahead and fallback to buffered.
7636          *
7637          * We return -ENOTBLK because that's what makes DIO go ahead and go back
7638          * to buffered IO.  Don't blame me, this is the price we pay for using
7639          * the generic code.
7640          */
7641         if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7642             em->block_start == EXTENT_MAP_INLINE) {
7643                 free_extent_map(em);
7644                 ret = -ENOTBLK;
7645                 goto unlock_err;
7646         }
7647
7648         /* Just a good old fashioned hole, return */
7649         if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7650                         test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7651                 free_extent_map(em);
7652                 goto unlock_err;
7653         }
7654
7655         /*
7656          * We don't allocate a new extent in the following cases
7657          *
7658          * 1) The inode is marked as NODATACOW.  In this case we'll just use the
7659          * existing extent.
7660          * 2) The extent is marked as PREALLOC.  We're good to go here and can
7661          * just use the extent.
7662          *
7663          */
7664         if (!create) {
7665                 len = min(len, em->len - (start - em->start));
7666                 lockstart = start + len;
7667                 goto unlock;
7668         }
7669
7670         if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7671             ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7672              em->block_start != EXTENT_MAP_HOLE)) {
7673                 int type;
7674                 u64 block_start, orig_start, orig_block_len, ram_bytes;
7675
7676                 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7677                         type = BTRFS_ORDERED_PREALLOC;
7678                 else
7679                         type = BTRFS_ORDERED_NOCOW;
7680                 len = min(len, em->len - (start - em->start));
7681                 block_start = em->block_start + (start - em->start);
7682
7683                 if (can_nocow_extent(inode, start, &len, &orig_start,
7684                                      &orig_block_len, &ram_bytes) == 1 &&
7685                     btrfs_inc_nocow_writers(fs_info, block_start)) {
7686                         struct extent_map *em2;
7687
7688                         em2 = btrfs_create_dio_extent(inode, start, len,
7689                                                       orig_start, block_start,
7690                                                       len, orig_block_len,
7691                                                       ram_bytes, type);
7692                         btrfs_dec_nocow_writers(fs_info, block_start);
7693                         if (type == BTRFS_ORDERED_PREALLOC) {
7694                                 free_extent_map(em);
7695                                 em = em2;
7696                         }
7697                         if (em2 && IS_ERR(em2)) {
7698                                 ret = PTR_ERR(em2);
7699                                 goto unlock_err;
7700                         }
7701                         /*
7702                          * For inode marked NODATACOW or extent marked PREALLOC,
7703                          * use the existing or preallocated extent, so does not
7704                          * need to adjust btrfs_space_info's bytes_may_use.
7705                          */
7706                         btrfs_free_reserved_data_space_noquota(inode,
7707                                         start, len);
7708                         goto unlock;
7709                 }
7710         }
7711
7712         /*
7713          * this will cow the extent, reset the len in case we changed
7714          * it above
7715          */
7716         len = bh_result->b_size;
7717         free_extent_map(em);
7718         em = btrfs_new_extent_direct(inode, start, len);
7719         if (IS_ERR(em)) {
7720                 ret = PTR_ERR(em);
7721                 goto unlock_err;
7722         }
7723         len = min(len, em->len - (start - em->start));
7724 unlock:
7725         bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7726                 inode->i_blkbits;
7727         bh_result->b_size = len;
7728         bh_result->b_bdev = em->bdev;
7729         set_buffer_mapped(bh_result);
7730         if (create) {
7731                 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7732                         set_buffer_new(bh_result);
7733
7734                 /*
7735                  * Need to update the i_size under the extent lock so buffered
7736                  * readers will get the updated i_size when we unlock.
7737                  */
7738                 if (!dio_data->overwrite && start + len > i_size_read(inode))
7739                         i_size_write(inode, start + len);
7740
7741                 WARN_ON(dio_data->reserve < len);
7742                 dio_data->reserve -= len;
7743                 dio_data->unsubmitted_oe_range_end = start + len;
7744                 current->journal_info = dio_data;
7745         }
7746
7747         /*
7748          * In the case of write we need to clear and unlock the entire range,
7749          * in the case of read we need to unlock only the end area that we
7750          * aren't using if there is any left over space.
7751          */
7752         if (lockstart < lockend) {
7753                 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7754                                  lockend, unlock_bits, 1, 0,
7755                                  &cached_state);
7756         } else {
7757                 free_extent_state(cached_state);
7758         }
7759
7760         free_extent_map(em);
7761
7762         return 0;
7763
7764 unlock_err:
7765         clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7766                          unlock_bits, 1, 0, &cached_state);
7767 err:
7768         if (dio_data)
7769                 current->journal_info = dio_data;
7770         return ret;
7771 }
7772
7773 static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
7774                                                  struct bio *bio,
7775                                                  int mirror_num)
7776 {
7777         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7778         blk_status_t ret;
7779
7780         BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7781
7782         ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7783         if (ret)
7784                 return ret;
7785
7786         ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7787
7788         return ret;
7789 }
7790
7791 static int btrfs_check_dio_repairable(struct inode *inode,
7792                                       struct bio *failed_bio,
7793                                       struct io_failure_record *failrec,
7794                                       int failed_mirror)
7795 {
7796         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7797         int num_copies;
7798
7799         num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7800         if (num_copies == 1) {
7801                 /*
7802                  * we only have a single copy of the data, so don't bother with
7803                  * all the retry and error correction code that follows. no
7804                  * matter what the error is, it is very likely to persist.
7805                  */
7806                 btrfs_debug(fs_info,
7807                         "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7808                         num_copies, failrec->this_mirror, failed_mirror);
7809                 return 0;
7810         }
7811
7812         failrec->failed_mirror = failed_mirror;
7813         failrec->this_mirror++;
7814         if (failrec->this_mirror == failed_mirror)
7815                 failrec->this_mirror++;
7816
7817         if (failrec->this_mirror > num_copies) {
7818                 btrfs_debug(fs_info,
7819                         "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7820                         num_copies, failrec->this_mirror, failed_mirror);
7821                 return 0;
7822         }
7823
7824         return 1;
7825 }
7826
7827 static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
7828                                    struct page *page, unsigned int pgoff,
7829                                    u64 start, u64 end, int failed_mirror,
7830                                    bio_end_io_t *repair_endio, void *repair_arg)
7831 {
7832         struct io_failure_record *failrec;
7833         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7834         struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
7835         struct bio *bio;
7836         int isector;
7837         unsigned int read_mode = 0;
7838         int segs;
7839         int ret;
7840         blk_status_t status;
7841         struct bio_vec bvec;
7842
7843         BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7844
7845         ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7846         if (ret)
7847                 return errno_to_blk_status(ret);
7848
7849         ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7850                                          failed_mirror);
7851         if (!ret) {
7852                 free_io_failure(failure_tree, io_tree, failrec);
7853                 return BLK_STS_IOERR;
7854         }
7855
7856         segs = bio_segments(failed_bio);
7857         bio_get_first_bvec(failed_bio, &bvec);
7858         if (segs > 1 ||
7859             (bvec.bv_len > btrfs_inode_sectorsize(inode)))
7860                 read_mode |= REQ_FAILFAST_DEV;
7861
7862         isector = start - btrfs_io_bio(failed_bio)->logical;
7863         isector >>= inode->i_sb->s_blocksize_bits;
7864         bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7865                                 pgoff, isector, repair_endio, repair_arg);
7866         bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7867
7868         btrfs_debug(BTRFS_I(inode)->root->fs_info,
7869                     "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
7870                     read_mode, failrec->this_mirror, failrec->in_validation);
7871
7872         status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7873         if (status) {
7874                 free_io_failure(failure_tree, io_tree, failrec);
7875                 bio_put(bio);
7876         }
7877
7878         return status;
7879 }
7880
7881 struct btrfs_retry_complete {
7882         struct completion done;
7883         struct inode *inode;
7884         u64 start;
7885         int uptodate;
7886 };
7887
7888 static void btrfs_retry_endio_nocsum(struct bio *bio)
7889 {
7890         struct btrfs_retry_complete *done = bio->bi_private;
7891         struct inode *inode = done->inode;
7892         struct bio_vec *bvec;
7893         struct extent_io_tree *io_tree, *failure_tree;
7894         int i;
7895
7896         if (bio->bi_status)
7897                 goto end;
7898
7899         ASSERT(bio->bi_vcnt == 1);
7900         io_tree = &BTRFS_I(inode)->io_tree;
7901         failure_tree = &BTRFS_I(inode)->io_failure_tree;
7902         ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
7903
7904         done->uptodate = 1;
7905         ASSERT(!bio_flagged(bio, BIO_CLONED));
7906         bio_for_each_segment_all(bvec, bio, i)
7907                 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
7908                                  io_tree, done->start, bvec->bv_page,
7909                                  btrfs_ino(BTRFS_I(inode)), 0);
7910 end:
7911         complete(&done->done);
7912         bio_put(bio);
7913 }
7914
7915 static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
7916                                                 struct btrfs_io_bio *io_bio)
7917 {
7918         struct btrfs_fs_info *fs_info;
7919         struct bio_vec bvec;
7920         struct bvec_iter iter;
7921         struct btrfs_retry_complete done;
7922         u64 start;
7923         unsigned int pgoff;
7924         u32 sectorsize;
7925         int nr_sectors;
7926         blk_status_t ret;
7927         blk_status_t err = BLK_STS_OK;
7928
7929         fs_info = BTRFS_I(inode)->root->fs_info;
7930         sectorsize = fs_info->sectorsize;
7931
7932         start = io_bio->logical;
7933         done.inode = inode;
7934         io_bio->bio.bi_iter = io_bio->iter;
7935
7936         bio_for_each_segment(bvec, &io_bio->bio, iter) {
7937                 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
7938                 pgoff = bvec.bv_offset;
7939
7940 next_block_or_try_again:
7941                 done.uptodate = 0;
7942                 done.start = start;
7943                 init_completion(&done.done);
7944
7945                 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
7946                                 pgoff, start, start + sectorsize - 1,
7947                                 io_bio->mirror_num,
7948                                 btrfs_retry_endio_nocsum, &done);
7949                 if (ret) {
7950                         err = ret;
7951                         goto next;
7952                 }
7953
7954                 wait_for_completion_io(&done.done);
7955
7956                 if (!done.uptodate) {
7957                         /* We might have another mirror, so try again */
7958                         goto next_block_or_try_again;
7959                 }
7960
7961 next:
7962                 start += sectorsize;
7963
7964                 nr_sectors--;
7965                 if (nr_sectors) {
7966                         pgoff += sectorsize;
7967                         ASSERT(pgoff < PAGE_SIZE);
7968                         goto next_block_or_try_again;
7969                 }
7970         }
7971
7972         return err;
7973 }
7974
7975 static void btrfs_retry_endio(struct bio *bio)
7976 {
7977         struct btrfs_retry_complete *done = bio->bi_private;
7978         struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7979         struct extent_io_tree *io_tree, *failure_tree;
7980         struct inode *inode = done->inode;
7981         struct bio_vec *bvec;
7982         int uptodate;
7983         int ret;
7984         int i;
7985
7986         if (bio->bi_status)
7987                 goto end;
7988
7989         uptodate = 1;
7990
7991         ASSERT(bio->bi_vcnt == 1);
7992         ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
7993
7994         io_tree = &BTRFS_I(inode)->io_tree;
7995         failure_tree = &BTRFS_I(inode)->io_failure_tree;
7996
7997         ASSERT(!bio_flagged(bio, BIO_CLONED));
7998         bio_for_each_segment_all(bvec, bio, i) {
7999                 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
8000                                              bvec->bv_offset, done->start,
8001                                              bvec->bv_len);
8002                 if (!ret)
8003                         clean_io_failure(BTRFS_I(inode)->root->fs_info,
8004                                          failure_tree, io_tree, done->start,
8005                                          bvec->bv_page,
8006                                          btrfs_ino(BTRFS_I(inode)),
8007                                          bvec->bv_offset);
8008                 else
8009                         uptodate = 0;
8010         }
8011
8012         done->uptodate = uptodate;
8013 end:
8014         complete(&done->done);
8015         bio_put(bio);
8016 }
8017
8018 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8019                 struct btrfs_io_bio *io_bio, blk_status_t err)
8020 {
8021         struct btrfs_fs_info *fs_info;
8022         struct bio_vec bvec;
8023         struct bvec_iter iter;
8024         struct btrfs_retry_complete done;
8025         u64 start;
8026         u64 offset = 0;
8027         u32 sectorsize;
8028         int nr_sectors;
8029         unsigned int pgoff;
8030         int csum_pos;
8031         bool uptodate = (err == 0);
8032         int ret;
8033         blk_status_t status;
8034
8035         fs_info = BTRFS_I(inode)->root->fs_info;
8036         sectorsize = fs_info->sectorsize;
8037
8038         err = BLK_STS_OK;
8039         start = io_bio->logical;
8040         done.inode = inode;
8041         io_bio->bio.bi_iter = io_bio->iter;
8042
8043         bio_for_each_segment(bvec, &io_bio->bio, iter) {
8044                 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8045
8046                 pgoff = bvec.bv_offset;
8047 next_block:
8048                 if (uptodate) {
8049                         csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8050                         ret = __readpage_endio_check(inode, io_bio, csum_pos,
8051                                         bvec.bv_page, pgoff, start, sectorsize);
8052                         if (likely(!ret))
8053                                 goto next;
8054                 }
8055 try_again:
8056                 done.uptodate = 0;
8057                 done.start = start;
8058                 init_completion(&done.done);
8059
8060                 status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8061                                         pgoff, start, start + sectorsize - 1,
8062                                         io_bio->mirror_num, btrfs_retry_endio,
8063                                         &done);
8064                 if (status) {
8065                         err = status;
8066                         goto next;
8067                 }
8068
8069                 wait_for_completion_io(&done.done);
8070
8071                 if (!done.uptodate) {
8072                         /* We might have another mirror, so try again */
8073                         goto try_again;
8074                 }
8075 next:
8076                 offset += sectorsize;
8077                 start += sectorsize;
8078
8079                 ASSERT(nr_sectors);
8080
8081                 nr_sectors--;
8082                 if (nr_sectors) {
8083                         pgoff += sectorsize;
8084                         ASSERT(pgoff < PAGE_SIZE);
8085                         goto next_block;
8086                 }
8087         }
8088
8089         return err;
8090 }
8091
8092 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8093                 struct btrfs_io_bio *io_bio, blk_status_t err)
8094 {
8095         bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8096
8097         if (skip_csum) {
8098                 if (unlikely(err))
8099                         return __btrfs_correct_data_nocsum(inode, io_bio);
8100                 else
8101                         return BLK_STS_OK;
8102         } else {
8103                 return __btrfs_subio_endio_read(inode, io_bio, err);
8104         }
8105 }
8106
8107 static void btrfs_endio_direct_read(struct bio *bio)
8108 {
8109         struct btrfs_dio_private *dip = bio->bi_private;
8110         struct inode *inode = dip->inode;
8111         struct bio *dio_bio;
8112         struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8113         blk_status_t err = bio->bi_status;
8114
8115         if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8116                 err = btrfs_subio_endio_read(inode, io_bio, err);
8117
8118         unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8119                       dip->logical_offset + dip->bytes - 1);
8120         dio_bio = dip->dio_bio;
8121
8122         kfree(dip);
8123
8124         dio_bio->bi_status = err;
8125         dio_end_io(dio_bio);
8126
8127         if (io_bio->end_io)
8128                 io_bio->end_io(io_bio, blk_status_to_errno(err));
8129         bio_put(bio);
8130 }
8131
8132 static void __endio_write_update_ordered(struct inode *inode,
8133                                          const u64 offset, const u64 bytes,
8134                                          const bool uptodate)
8135 {
8136         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8137         struct btrfs_ordered_extent *ordered = NULL;
8138         struct btrfs_workqueue *wq;
8139         btrfs_work_func_t func;
8140         u64 ordered_offset = offset;
8141         u64 ordered_bytes = bytes;
8142         u64 last_offset;
8143         int ret;
8144
8145         if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8146                 wq = fs_info->endio_freespace_worker;
8147                 func = btrfs_freespace_write_helper;
8148         } else {
8149                 wq = fs_info->endio_write_workers;
8150                 func = btrfs_endio_write_helper;
8151         }
8152
8153 again:
8154         last_offset = ordered_offset;
8155         ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8156                                                    &ordered_offset,
8157                                                    ordered_bytes,
8158                                                    uptodate);
8159         if (!ret)
8160                 goto out_test;
8161
8162         btrfs_init_work(&ordered->work, func, finish_ordered_fn, NULL, NULL);
8163         btrfs_queue_work(wq, &ordered->work);
8164 out_test:
8165         /*
8166          * If btrfs_dec_test_ordered_pending does not find any ordered extent
8167          * in the range, we can exit.
8168          */
8169         if (ordered_offset == last_offset)
8170                 return;
8171         /*
8172          * our bio might span multiple ordered extents.  If we haven't
8173          * completed the accounting for the whole dio, go back and try again
8174          */
8175         if (ordered_offset < offset + bytes) {
8176                 ordered_bytes = offset + bytes - ordered_offset;
8177                 ordered = NULL;
8178                 goto again;
8179         }
8180 }
8181
8182 static void btrfs_endio_direct_write(struct bio *bio)
8183 {
8184         struct btrfs_dio_private *dip = bio->bi_private;
8185         struct bio *dio_bio = dip->dio_bio;
8186
8187         __endio_write_update_ordered(dip->inode, dip->logical_offset,
8188                                      dip->bytes, !bio->bi_status);
8189
8190         kfree(dip);
8191
8192         dio_bio->bi_status = bio->bi_status;
8193         dio_end_io(dio_bio);
8194         bio_put(bio);
8195 }
8196
8197 static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
8198                                     struct bio *bio, u64 offset)
8199 {
8200         struct inode *inode = private_data;
8201         blk_status_t ret;
8202         ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8203         BUG_ON(ret); /* -ENOMEM */
8204         return 0;
8205 }
8206
8207 static void btrfs_end_dio_bio(struct bio *bio)
8208 {
8209         struct btrfs_dio_private *dip = bio->bi_private;
8210         blk_status_t err = bio->bi_status;
8211
8212         if (err)
8213                 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8214                            "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8215                            btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8216                            bio->bi_opf,
8217                            (unsigned long long)bio->bi_iter.bi_sector,
8218                            bio->bi_iter.bi_size, err);
8219
8220         if (dip->subio_endio)
8221                 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8222
8223         if (err) {
8224                 /*
8225                  * We want to perceive the errors flag being set before
8226                  * decrementing the reference count. We don't need a barrier
8227                  * since atomic operations with a return value are fully
8228                  * ordered as per atomic_t.txt
8229                  */
8230                 dip->errors = 1;
8231         }
8232
8233         /* if there are more bios still pending for this dio, just exit */
8234         if (!atomic_dec_and_test(&dip->pending_bios))
8235                 goto out;
8236
8237         if (dip->errors) {
8238                 bio_io_error(dip->orig_bio);
8239         } else {
8240                 dip->dio_bio->bi_status = BLK_STS_OK;
8241                 bio_endio(dip->orig_bio);
8242         }
8243 out:
8244         bio_put(bio);
8245 }
8246
8247 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8248                                                  struct btrfs_dio_private *dip,
8249                                                  struct bio *bio,
8250                                                  u64 file_offset)
8251 {
8252         struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8253         struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8254         blk_status_t ret;
8255
8256         /*
8257          * We load all the csum data we need when we submit
8258          * the first bio to reduce the csum tree search and
8259          * contention.
8260          */
8261         if (dip->logical_offset == file_offset) {
8262                 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8263                                                 file_offset);
8264                 if (ret)
8265                         return ret;
8266         }
8267
8268         if (bio == dip->orig_bio)
8269                 return 0;
8270
8271         file_offset -= dip->logical_offset;
8272         file_offset >>= inode->i_sb->s_blocksize_bits;
8273         io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8274
8275         return 0;
8276 }
8277
8278 static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
8279                 struct inode *inode, u64 file_offset, int async_submit)
8280 {
8281         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8282         struct btrfs_dio_private *dip = bio->bi_private;
8283         bool write = bio_op(bio) == REQ_OP_WRITE;
8284         blk_status_t ret;
8285
8286         /* Check btrfs_submit_bio_hook() for rules about async submit. */
8287         if (async_submit)
8288                 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8289
8290         if (!write) {
8291                 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8292                 if (ret)
8293                         goto err;
8294         }
8295
8296         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8297                 goto map;
8298
8299         if (write && async_submit) {
8300                 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8301                                           file_offset, inode,
8302                                           btrfs_submit_bio_start_direct_io,
8303                                           btrfs_submit_bio_done);
8304                 goto err;
8305         } else if (write) {
8306                 /*
8307                  * If we aren't doing async submit, calculate the csum of the
8308                  * bio now.
8309                  */
8310                 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8311                 if (ret)
8312                         goto err;
8313         } else {
8314                 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8315                                                      file_offset);
8316                 if (ret)
8317                         goto err;
8318         }
8319 map:
8320         ret = btrfs_map_bio(fs_info, bio, 0, 0);
8321 err:
8322         return ret;
8323 }
8324
8325 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8326 {
8327         struct inode *inode = dip->inode;
8328         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8329         struct bio *bio;
8330         struct bio *orig_bio = dip->orig_bio;
8331         u64 start_sector = orig_bio->bi_iter.bi_sector;
8332         u64 file_offset = dip->logical_offset;
8333         u64 map_length;
8334         int async_submit = 0;
8335         u64 submit_len;
8336         int clone_offset = 0;
8337         int clone_len;
8338         int ret;
8339         blk_status_t status;
8340
8341         map_length = orig_bio->bi_iter.bi_size;
8342         submit_len = map_length;
8343         ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8344                               &map_length, NULL, 0);
8345         if (ret)
8346                 return -EIO;
8347
8348         if (map_length >= submit_len) {
8349                 bio = orig_bio;
8350                 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8351                 goto submit;
8352         }
8353
8354         /* async crcs make it difficult to collect full stripe writes. */
8355         if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8356                 async_submit = 0;
8357         else
8358                 async_submit = 1;
8359
8360         /* bio split */
8361         ASSERT(map_length <= INT_MAX);
8362         atomic_inc(&dip->pending_bios);
8363         do {
8364                 clone_len = min_t(int, submit_len, map_length);
8365
8366                 /*
8367                  * This will never fail as it's passing GPF_NOFS and
8368                  * the allocation is backed by btrfs_bioset.
8369                  */
8370                 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8371                                               clone_len);
8372                 bio->bi_private = dip;
8373                 bio->bi_end_io = btrfs_end_dio_bio;
8374                 btrfs_io_bio(bio)->logical = file_offset;
8375
8376                 ASSERT(submit_len >= clone_len);
8377                 submit_len -= clone_len;
8378                 if (submit_len == 0)
8379                         break;
8380
8381                 /*
8382                  * Increase the count before we submit the bio so we know
8383                  * the end IO handler won't happen before we increase the
8384                  * count. Otherwise, the dip might get freed before we're
8385                  * done setting it up.
8386                  */
8387                 atomic_inc(&dip->pending_bios);
8388
8389                 status = btrfs_submit_dio_bio(bio, inode, file_offset,
8390                                                 async_submit);
8391                 if (status) {
8392                         bio_put(bio);
8393                         atomic_dec(&dip->pending_bios);
8394                         goto out_err;
8395                 }
8396
8397                 clone_offset += clone_len;
8398                 start_sector += clone_len >> 9;
8399                 file_offset += clone_len;
8400
8401                 map_length = submit_len;
8402                 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8403                                       start_sector << 9, &map_length, NULL, 0);
8404                 if (ret)
8405                         goto out_err;
8406         } while (submit_len > 0);
8407
8408 submit:
8409         status = btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8410         if (!status)
8411                 return 0;
8412
8413         bio_put(bio);
8414 out_err:
8415         dip->errors = 1;
8416         /*
8417          * Before atomic variable goto zero, we must  make sure dip->errors is
8418          * perceived to be set. This ordering is ensured by the fact that an
8419          * atomic operations with a return value are fully ordered as per
8420          * atomic_t.txt
8421          */
8422         if (atomic_dec_and_test(&dip->pending_bios))
8423                 bio_io_error(dip->orig_bio);
8424
8425         /* bio_end_io() will handle error, so we needn't return it */
8426         return 0;
8427 }
8428
8429 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8430                                 loff_t file_offset)
8431 {
8432         struct btrfs_dio_private *dip = NULL;
8433         struct bio *bio = NULL;
8434         struct btrfs_io_bio *io_bio;
8435         bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8436         int ret = 0;
8437
8438         bio = btrfs_bio_clone(dio_bio);
8439
8440         dip = kzalloc(sizeof(*dip), GFP_NOFS);
8441         if (!dip) {
8442                 ret = -ENOMEM;
8443                 goto free_ordered;
8444         }
8445
8446         dip->private = dio_bio->bi_private;
8447         dip->inode = inode;
8448         dip->logical_offset = file_offset;
8449         dip->bytes = dio_bio->bi_iter.bi_size;
8450         dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8451         bio->bi_private = dip;
8452         dip->orig_bio = bio;
8453         dip->dio_bio = dio_bio;
8454         atomic_set(&dip->pending_bios, 0);
8455         io_bio = btrfs_io_bio(bio);
8456         io_bio->logical = file_offset;
8457
8458         if (write) {
8459                 bio->bi_end_io = btrfs_endio_direct_write;
8460         } else {
8461                 bio->bi_end_io = btrfs_endio_direct_read;
8462                 dip->subio_endio = btrfs_subio_endio_read;
8463         }
8464
8465         /*
8466          * Reset the range for unsubmitted ordered extents (to a 0 length range)
8467          * even if we fail to submit a bio, because in such case we do the
8468          * corresponding error handling below and it must not be done a second
8469          * time by btrfs_direct_IO().
8470          */
8471         if (write) {
8472                 struct btrfs_dio_data *dio_data = current->journal_info;
8473
8474                 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8475                         dip->bytes;
8476                 dio_data->unsubmitted_oe_range_start =
8477                         dio_data->unsubmitted_oe_range_end;
8478         }
8479
8480         ret = btrfs_submit_direct_hook(dip);
8481         if (!ret)
8482                 return;
8483
8484         if (io_bio->end_io)
8485                 io_bio->end_io(io_bio, ret);
8486
8487 free_ordered:
8488         /*
8489          * If we arrived here it means either we failed to submit the dip
8490          * or we either failed to clone the dio_bio or failed to allocate the
8491          * dip. If we cloned the dio_bio and allocated the dip, we can just
8492          * call bio_endio against our io_bio so that we get proper resource
8493          * cleanup if we fail to submit the dip, otherwise, we must do the
8494          * same as btrfs_endio_direct_[write|read] because we can't call these
8495          * callbacks - they require an allocated dip and a clone of dio_bio.
8496          */
8497         if (bio && dip) {
8498                 bio_io_error(bio);
8499                 /*
8500                  * The end io callbacks free our dip, do the final put on bio
8501                  * and all the cleanup and final put for dio_bio (through
8502                  * dio_end_io()).
8503                  */
8504                 dip = NULL;
8505                 bio = NULL;
8506         } else {
8507                 if (write)
8508                         __endio_write_update_ordered(inode,
8509                                                 file_offset,
8510                                                 dio_bio->bi_iter.bi_size,
8511                                                 false);
8512                 else
8513                         unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8514                               file_offset + dio_bio->bi_iter.bi_size - 1);
8515
8516                 dio_bio->bi_status = BLK_STS_IOERR;
8517                 /*
8518                  * Releases and cleans up our dio_bio, no need to bio_put()
8519                  * nor bio_endio()/bio_io_error() against dio_bio.
8520                  */
8521                 dio_end_io(dio_bio);
8522         }
8523         if (bio)
8524                 bio_put(bio);
8525         kfree(dip);
8526 }
8527
8528 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8529                                const struct iov_iter *iter, loff_t offset)
8530 {
8531         int seg;
8532         int i;
8533         unsigned int blocksize_mask = fs_info->sectorsize - 1;
8534         ssize_t retval = -EINVAL;
8535
8536         if (offset & blocksize_mask)
8537                 goto out;
8538
8539         if (iov_iter_alignment(iter) & blocksize_mask)
8540                 goto out;
8541
8542         /* If this is a write we don't need to check anymore */
8543         if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8544                 return 0;
8545         /*
8546          * Check to make sure we don't have duplicate iov_base's in this
8547          * iovec, if so return EINVAL, otherwise we'll get csum errors
8548          * when reading back.
8549          */
8550         for (seg = 0; seg < iter->nr_segs; seg++) {
8551                 for (i = seg + 1; i < iter->nr_segs; i++) {
8552                         if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8553                                 goto out;
8554                 }
8555         }
8556         retval = 0;
8557 out:
8558         return retval;
8559 }
8560
8561 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8562 {
8563         struct file *file = iocb->ki_filp;
8564         struct inode *inode = file->f_mapping->host;
8565         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8566         struct btrfs_dio_data dio_data = { 0 };
8567         struct extent_changeset *data_reserved = NULL;
8568         loff_t offset = iocb->ki_pos;
8569         size_t count = 0;
8570         int flags = 0;
8571         bool wakeup = true;
8572         bool relock = false;
8573         ssize_t ret;
8574
8575         if (check_direct_IO(fs_info, iter, offset))
8576                 return 0;
8577
8578         inode_dio_begin(inode);
8579
8580         /*
8581          * The generic stuff only does filemap_write_and_wait_range, which
8582          * isn't enough if we've written compressed pages to this area, so
8583          * we need to flush the dirty pages again to make absolutely sure
8584          * that any outstanding dirty pages are on disk.
8585          */
8586         count = iov_iter_count(iter);
8587         if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8588                      &BTRFS_I(inode)->runtime_flags))
8589                 filemap_fdatawrite_range(inode->i_mapping, offset,
8590                                          offset + count - 1);
8591
8592         if (iov_iter_rw(iter) == WRITE) {
8593                 /*
8594                  * If the write DIO is beyond the EOF, we need update
8595                  * the isize, but it is protected by i_mutex. So we can
8596                  * not unlock the i_mutex at this case.
8597                  */
8598                 if (offset + count <= inode->i_size) {
8599                         dio_data.overwrite = 1;
8600                         inode_unlock(inode);
8601                         relock = true;
8602                 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8603                         ret = -EAGAIN;
8604                         goto out;
8605                 }
8606                 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8607                                                    offset, count);
8608                 if (ret)
8609                         goto out;
8610
8611                 /*
8612                  * We need to know how many extents we reserved so that we can
8613                  * do the accounting properly if we go over the number we
8614                  * originally calculated.  Abuse current->journal_info for this.
8615                  */
8616                 dio_data.reserve = round_up(count,
8617                                             fs_info->sectorsize);
8618                 dio_data.unsubmitted_oe_range_start = (u64)offset;
8619                 dio_data.unsubmitted_oe_range_end = (u64)offset;
8620                 current->journal_info = &dio_data;
8621                 down_read(&BTRFS_I(inode)->dio_sem);
8622         } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8623                                      &BTRFS_I(inode)->runtime_flags)) {
8624                 inode_dio_end(inode);
8625                 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8626                 wakeup = false;
8627         }
8628
8629         ret = __blockdev_direct_IO(iocb, inode,
8630                                    fs_info->fs_devices->latest_bdev,
8631                                    iter, btrfs_get_blocks_direct, NULL,
8632                                    btrfs_submit_direct, flags);
8633         if (iov_iter_rw(iter) == WRITE) {
8634                 up_read(&BTRFS_I(inode)->dio_sem);
8635                 current->journal_info = NULL;
8636                 if (ret < 0 && ret != -EIOCBQUEUED) {
8637                         if (dio_data.reserve)
8638                                 btrfs_delalloc_release_space(inode, data_reserved,
8639                                         offset, dio_data.reserve);
8640                         /*
8641                          * On error we might have left some ordered extents
8642                          * without submitting corresponding bios for them, so
8643                          * cleanup them up to avoid other tasks getting them
8644                          * and waiting for them to complete forever.
8645                          */
8646                         if (dio_data.unsubmitted_oe_range_start <
8647                             dio_data.unsubmitted_oe_range_end)
8648                                 __endio_write_update_ordered(inode,
8649                                         dio_data.unsubmitted_oe_range_start,
8650                                         dio_data.unsubmitted_oe_range_end -
8651                                         dio_data.unsubmitted_oe_range_start,
8652                                         false);
8653                 } else if (ret >= 0 && (size_t)ret < count)
8654                         btrfs_delalloc_release_space(inode, data_reserved,
8655                                         offset, count - (size_t)ret);
8656                 btrfs_delalloc_release_extents(BTRFS_I(inode), count);
8657         }
8658 out:
8659         if (wakeup)
8660                 inode_dio_end(inode);
8661         if (relock)
8662                 inode_lock(inode);
8663
8664         extent_changeset_free(data_reserved);
8665         return ret;
8666 }
8667
8668 #define BTRFS_FIEMAP_FLAGS      (FIEMAP_FLAG_SYNC)
8669
8670 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8671                 __u64 start, __u64 len)
8672 {
8673         int     ret;
8674
8675         ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8676         if (ret)
8677                 return ret;
8678
8679         return extent_fiemap(inode, fieinfo, start, len);
8680 }
8681
8682 int btrfs_readpage(struct file *file, struct page *page)
8683 {
8684         struct extent_io_tree *tree;
8685         tree = &BTRFS_I(page->mapping->host)->io_tree;
8686         return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8687 }
8688
8689 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8690 {
8691         struct inode *inode = page->mapping->host;
8692         int ret;
8693
8694         if (current->flags & PF_MEMALLOC) {
8695                 redirty_page_for_writepage(wbc, page);
8696                 unlock_page(page);
8697                 return 0;
8698         }
8699
8700         /*
8701          * If we are under memory pressure we will call this directly from the
8702          * VM, we need to make sure we have the inode referenced for the ordered
8703          * extent.  If not just return like we didn't do anything.
8704          */
8705         if (!igrab(inode)) {
8706                 redirty_page_for_writepage(wbc, page);
8707                 return AOP_WRITEPAGE_ACTIVATE;
8708         }
8709         ret = extent_write_full_page(page, wbc);
8710         btrfs_add_delayed_iput(inode);
8711         return ret;
8712 }
8713
8714 static int btrfs_writepages(struct address_space *mapping,
8715                             struct writeback_control *wbc)
8716 {
8717         struct extent_io_tree *tree;
8718
8719         tree = &BTRFS_I(mapping->host)->io_tree;
8720         return extent_writepages(tree, mapping, wbc);
8721 }
8722
8723 static int
8724 btrfs_readpages(struct file *file, struct address_space *mapping,
8725                 struct list_head *pages, unsigned nr_pages)
8726 {
8727         struct extent_io_tree *tree;
8728         tree = &BTRFS_I(mapping->host)->io_tree;
8729         return extent_readpages(tree, mapping, pages, nr_pages);
8730 }
8731 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8732 {
8733         struct extent_io_tree *tree;
8734         struct extent_map_tree *map;
8735         int ret;
8736
8737         tree = &BTRFS_I(page->mapping->host)->io_tree;
8738         map = &BTRFS_I(page->mapping->host)->extent_tree;
8739         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8740         if (ret == 1) {
8741                 ClearPagePrivate(page);
8742                 set_page_private(page, 0);
8743                 put_page(page);
8744         }
8745         return ret;
8746 }
8747
8748 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8749 {
8750         if (PageWriteback(page) || PageDirty(page))
8751                 return 0;
8752         return __btrfs_releasepage(page, gfp_flags);
8753 }
8754
8755 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8756                                  unsigned int length)
8757 {
8758         struct inode *inode = page->mapping->host;
8759         struct extent_io_tree *tree;
8760         struct btrfs_ordered_extent *ordered;
8761         struct extent_state *cached_state = NULL;
8762         u64 page_start = page_offset(page);
8763         u64 page_end = page_start + PAGE_SIZE - 1;
8764         u64 start;
8765         u64 end;
8766         int inode_evicting = inode->i_state & I_FREEING;
8767
8768         /*
8769          * we have the page locked, so new writeback can't start,
8770          * and the dirty bit won't be cleared while we are here.
8771          *
8772          * Wait for IO on this page so that we can safely clear
8773          * the PagePrivate2 bit and do ordered accounting
8774          */
8775         wait_on_page_writeback(page);
8776
8777         tree = &BTRFS_I(inode)->io_tree;
8778         if (offset) {
8779                 btrfs_releasepage(page, GFP_NOFS);
8780                 return;
8781         }
8782
8783         if (!inode_evicting)
8784                 lock_extent_bits(tree, page_start, page_end, &cached_state);
8785 again:
8786         start = page_start;
8787         ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8788                                         page_end - start + 1);
8789         if (ordered) {
8790                 end = min(page_end, ordered->file_offset + ordered->len - 1);
8791                 /*
8792                  * IO on this page will never be started, so we need
8793                  * to account for any ordered extents now
8794                  */
8795                 if (!inode_evicting)
8796                         clear_extent_bit(tree, start, end,
8797                                          EXTENT_DIRTY | EXTENT_DELALLOC |
8798                                          EXTENT_DELALLOC_NEW |
8799                                          EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8800                                          EXTENT_DEFRAG, 1, 0, &cached_state);
8801                 /*
8802                  * whoever cleared the private bit is responsible
8803                  * for the finish_ordered_io
8804                  */
8805                 if (TestClearPagePrivate2(page)) {
8806                         struct btrfs_ordered_inode_tree *tree;
8807                         u64 new_len;
8808
8809                         tree = &BTRFS_I(inode)->ordered_tree;
8810
8811                         spin_lock_irq(&tree->lock);
8812                         set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8813                         new_len = start - ordered->file_offset;
8814                         if (new_len < ordered->truncated_len)
8815                                 ordered->truncated_len = new_len;
8816                         spin_unlock_irq(&tree->lock);
8817
8818                         if (btrfs_dec_test_ordered_pending(inode, &ordered,
8819                                                            start,
8820                                                            end - start + 1, 1))
8821                                 btrfs_finish_ordered_io(ordered);
8822                 }
8823                 btrfs_put_ordered_extent(ordered);
8824                 if (!inode_evicting) {
8825                         cached_state = NULL;
8826                         lock_extent_bits(tree, start, end,
8827                                          &cached_state);
8828                 }
8829
8830                 start = end + 1;
8831                 if (start < page_end)
8832                         goto again;
8833         }
8834
8835         /*
8836          * Qgroup reserved space handler
8837          * Page here will be either
8838          * 1) Already written to disk
8839          *    In this case, its reserved space is released from data rsv map
8840          *    and will be freed by delayed_ref handler finally.
8841          *    So even we call qgroup_free_data(), it won't decrease reserved
8842          *    space.
8843          * 2) Not written to disk
8844          *    This means the reserved space should be freed here. However,
8845          *    if a truncate invalidates the page (by clearing PageDirty)
8846          *    and the page is accounted for while allocating extent
8847          *    in btrfs_check_data_free_space() we let delayed_ref to
8848          *    free the entire extent.
8849          */
8850         if (PageDirty(page))
8851                 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
8852         if (!inode_evicting) {
8853                 clear_extent_bit(tree, page_start, page_end,
8854                                  EXTENT_LOCKED | EXTENT_DIRTY |
8855                                  EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
8856                                  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
8857                                  &cached_state);
8858
8859                 __btrfs_releasepage(page, GFP_NOFS);
8860         }
8861
8862         ClearPageChecked(page);
8863         if (PagePrivate(page)) {
8864                 ClearPagePrivate(page);
8865                 set_page_private(page, 0);
8866                 put_page(page);
8867         }
8868 }
8869
8870 /*
8871  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8872  * called from a page fault handler when a page is first dirtied. Hence we must
8873  * be careful to check for EOF conditions here. We set the page up correctly
8874  * for a written page which means we get ENOSPC checking when writing into
8875  * holes and correct delalloc and unwritten extent mapping on filesystems that
8876  * support these features.
8877  *
8878  * We are not allowed to take the i_mutex here so we have to play games to
8879  * protect against truncate races as the page could now be beyond EOF.  Because
8880  * vmtruncate() writes the inode size before removing pages, once we have the
8881  * page lock we can determine safely if the page is beyond EOF. If it is not
8882  * beyond EOF, then the page is guaranteed safe against truncation until we
8883  * unlock the page.
8884  */
8885 int btrfs_page_mkwrite(struct vm_fault *vmf)
8886 {
8887         struct page *page = vmf->page;
8888         struct inode *inode = file_inode(vmf->vma->vm_file);
8889         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8890         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8891         struct btrfs_ordered_extent *ordered;
8892         struct extent_state *cached_state = NULL;
8893         struct extent_changeset *data_reserved = NULL;
8894         char *kaddr;
8895         unsigned long zero_start;
8896         loff_t size;
8897         int ret;
8898         int reserved = 0;
8899         u64 reserved_space;
8900         u64 page_start;
8901         u64 page_end;
8902         u64 end;
8903
8904         reserved_space = PAGE_SIZE;
8905
8906         sb_start_pagefault(inode->i_sb);
8907         page_start = page_offset(page);
8908         page_end = page_start + PAGE_SIZE - 1;
8909         end = page_end;
8910
8911         /*
8912          * Reserving delalloc space after obtaining the page lock can lead to
8913          * deadlock. For example, if a dirty page is locked by this function
8914          * and the call to btrfs_delalloc_reserve_space() ends up triggering
8915          * dirty page write out, then the btrfs_writepage() function could
8916          * end up waiting indefinitely to get a lock on the page currently
8917          * being processed by btrfs_page_mkwrite() function.
8918          */
8919         ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
8920                                            reserved_space);
8921         if (!ret) {
8922                 ret = file_update_time(vmf->vma->vm_file);
8923                 reserved = 1;
8924         }
8925         if (ret) {
8926                 if (ret == -ENOMEM)
8927                         ret = VM_FAULT_OOM;
8928                 else /* -ENOSPC, -EIO, etc */
8929                         ret = VM_FAULT_SIGBUS;
8930                 if (reserved)
8931                         goto out;
8932                 goto out_noreserve;
8933         }
8934
8935         ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8936 again:
8937         lock_page(page);
8938         size = i_size_read(inode);
8939
8940         if ((page->mapping != inode->i_mapping) ||
8941             (page_start >= size)) {
8942                 /* page got truncated out from underneath us */
8943                 goto out_unlock;
8944         }
8945         wait_on_page_writeback(page);
8946
8947         lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8948         set_page_extent_mapped(page);
8949
8950         /*
8951          * we can't set the delalloc bits if there are pending ordered
8952          * extents.  Drop our locks and wait for them to finish
8953          */
8954         ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
8955                         PAGE_SIZE);
8956         if (ordered) {
8957                 unlock_extent_cached(io_tree, page_start, page_end,
8958                                      &cached_state);
8959                 unlock_page(page);
8960                 btrfs_start_ordered_extent(inode, ordered, 1);
8961                 btrfs_put_ordered_extent(ordered);
8962                 goto again;
8963         }
8964
8965         if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8966                 reserved_space = round_up(size - page_start,
8967                                           fs_info->sectorsize);
8968                 if (reserved_space < PAGE_SIZE) {
8969                         end = page_start + reserved_space - 1;
8970                         btrfs_delalloc_release_space(inode, data_reserved,
8971                                         page_start, PAGE_SIZE - reserved_space);
8972                 }
8973         }
8974
8975         /*
8976          * page_mkwrite gets called when the page is firstly dirtied after it's
8977          * faulted in, but write(2) could also dirty a page and set delalloc
8978          * bits, thus in this case for space account reason, we still need to
8979          * clear any delalloc bits within this page range since we have to
8980          * reserve data&meta space before lock_page() (see above comments).
8981          */
8982         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
8983                           EXTENT_DIRTY | EXTENT_DELALLOC |
8984                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8985                           0, 0, &cached_state);
8986
8987         ret = btrfs_set_extent_delalloc(inode, page_start, end, 0,
8988                                         &cached_state, 0);
8989         if (ret) {
8990                 unlock_extent_cached(io_tree, page_start, page_end,
8991                                      &cached_state);
8992                 ret = VM_FAULT_SIGBUS;
8993                 goto out_unlock;
8994         }
8995         ret = 0;
8996
8997         /* page is wholly or partially inside EOF */
8998         if (page_start + PAGE_SIZE > size)
8999                 zero_start = size & ~PAGE_MASK;
9000         else
9001                 zero_start = PAGE_SIZE;
9002
9003         if (zero_start != PAGE_SIZE) {
9004                 kaddr = kmap(page);
9005                 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9006                 flush_dcache_page(page);
9007                 kunmap(page);
9008         }
9009         ClearPageChecked(page);
9010         set_page_dirty(page);
9011         SetPageUptodate(page);
9012
9013         BTRFS_I(inode)->last_trans = fs_info->generation;
9014         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9015         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9016
9017         unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
9018
9019 out_unlock:
9020         if (!ret) {
9021                 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9022                 sb_end_pagefault(inode->i_sb);
9023                 extent_changeset_free(data_reserved);
9024                 return VM_FAULT_LOCKED;
9025         }
9026         unlock_page(page);
9027 out:
9028         btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9029         btrfs_delalloc_release_space(inode, data_reserved, page_start,
9030                                      reserved_space);
9031 out_noreserve:
9032         sb_end_pagefault(inode->i_sb);
9033         extent_changeset_free(data_reserved);
9034         return ret;
9035 }
9036
9037 static int btrfs_truncate(struct inode *inode, bool skip_writeback)
9038 {
9039         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9040         struct btrfs_root *root = BTRFS_I(inode)->root;
9041         struct btrfs_block_rsv *rsv;
9042         int ret = 0;
9043         int err = 0;
9044         struct btrfs_trans_handle *trans;
9045         u64 mask = fs_info->sectorsize - 1;
9046         u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9047
9048         if (!skip_writeback) {
9049                 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9050                                                (u64)-1);
9051                 if (ret)
9052                         return ret;
9053         }
9054
9055         /*
9056          * Yes ladies and gentlemen, this is indeed ugly.  The fact is we have
9057          * 3 things going on here
9058          *
9059          * 1) We need to reserve space for our orphan item and the space to
9060          * delete our orphan item.  Lord knows we don't want to have a dangling
9061          * orphan item because we didn't reserve space to remove it.
9062          *
9063          * 2) We need to reserve space to update our inode.
9064          *
9065          * 3) We need to have something to cache all the space that is going to
9066          * be free'd up by the truncate operation, but also have some slack
9067          * space reserved in case it uses space during the truncate (thank you
9068          * very much snapshotting).
9069          *
9070          * And we need these to all be separate.  The fact is we can use a lot of
9071          * space doing the truncate, and we have no earthly idea how much space
9072          * we will use, so we need the truncate reservation to be separate so it
9073          * doesn't end up using space reserved for updating the inode or
9074          * removing the orphan item.  We also need to be able to stop the
9075          * transaction and start a new one, which means we need to be able to
9076          * update the inode several times, and we have no idea of knowing how
9077          * many times that will be, so we can't just reserve 1 item for the
9078          * entirety of the operation, so that has to be done separately as well.
9079          * Then there is the orphan item, which does indeed need to be held on
9080          * to for the whole operation, and we need nobody to touch this reserved
9081          * space except the orphan code.
9082          *
9083          * So that leaves us with
9084          *
9085          * 1) root->orphan_block_rsv - for the orphan deletion.
9086          * 2) rsv - for the truncate reservation, which we will steal from the
9087          * transaction reservation.
9088          * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9089          * updating the inode.
9090          */
9091         rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9092         if (!rsv)
9093                 return -ENOMEM;
9094         rsv->size = min_size;
9095         rsv->failfast = 1;
9096
9097         /*
9098          * 1 for the truncate slack space
9099          * 1 for updating the inode.
9100          */
9101         trans = btrfs_start_transaction(root, 2);
9102         if (IS_ERR(trans)) {
9103                 err = PTR_ERR(trans);
9104                 goto out;
9105         }
9106
9107         /* Migrate the slack space for the truncate to our reserve */
9108         ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9109                                       min_size, 0);
9110         BUG_ON(ret);
9111
9112         /*
9113          * So if we truncate and then write and fsync we normally would just
9114          * write the extents that changed, which is a problem if we need to
9115          * first truncate that entire inode.  So set this flag so we write out
9116          * all of the extents in the inode to the sync log so we're completely
9117          * safe.
9118          */
9119         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9120         trans->block_rsv = rsv;
9121
9122         while (1) {
9123                 ret = btrfs_truncate_inode_items(trans, root, inode,
9124                                                  inode->i_size,
9125                                                  BTRFS_EXTENT_DATA_KEY);
9126                 trans->block_rsv = &fs_info->trans_block_rsv;
9127                 if (ret != -ENOSPC && ret != -EAGAIN) {
9128                         err = ret;
9129                         break;
9130                 }
9131
9132                 ret = btrfs_update_inode(trans, root, inode);
9133                 if (ret) {
9134                         err = ret;
9135                         break;
9136                 }
9137
9138                 btrfs_end_transaction(trans);
9139                 btrfs_btree_balance_dirty(fs_info);
9140
9141                 trans = btrfs_start_transaction(root, 2);
9142                 if (IS_ERR(trans)) {
9143                         ret = err = PTR_ERR(trans);
9144                         trans = NULL;
9145                         break;
9146                 }
9147
9148                 btrfs_block_rsv_release(fs_info, rsv, -1);
9149                 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9150                                               rsv, min_size, 0);
9151                 BUG_ON(ret);    /* shouldn't happen */
9152                 trans->block_rsv = rsv;
9153         }
9154
9155         /*
9156          * We can't call btrfs_truncate_block inside a trans handle as we could
9157          * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
9158          * we've truncated everything except the last little bit, and can do
9159          * btrfs_truncate_block and then update the disk_i_size.
9160          */
9161         if (ret == NEED_TRUNCATE_BLOCK) {
9162                 btrfs_end_transaction(trans);
9163                 btrfs_btree_balance_dirty(fs_info);
9164
9165                 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
9166                 if (ret)
9167                         goto out;
9168                 trans = btrfs_start_transaction(root, 1);
9169                 if (IS_ERR(trans)) {
9170                         ret = PTR_ERR(trans);
9171                         goto out;
9172                 }
9173                 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
9174         }
9175
9176         if (ret == 0 && inode->i_nlink > 0) {
9177                 trans->block_rsv = root->orphan_block_rsv;
9178                 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9179                 if (ret)
9180                         err = ret;
9181         }
9182
9183         if (trans) {
9184                 trans->block_rsv = &fs_info->trans_block_rsv;
9185                 ret = btrfs_update_inode(trans, root, inode);
9186                 if (ret && !err)
9187                         err = ret;
9188
9189                 ret = btrfs_end_transaction(trans);
9190                 btrfs_btree_balance_dirty(fs_info);
9191         }
9192 out:
9193         btrfs_free_block_rsv(fs_info, rsv);
9194
9195         if (ret && !err)
9196                 err = ret;
9197
9198         return err;
9199 }
9200
9201 /*
9202  * create a new subvolume directory/inode (helper for the ioctl).
9203  */
9204 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9205                              struct btrfs_root *new_root,
9206                              struct btrfs_root *parent_root,
9207                              u64 new_dirid)
9208 {
9209         struct inode *inode;
9210         int err;
9211         u64 index = 0;
9212
9213         inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9214                                 new_dirid, new_dirid,
9215                                 S_IFDIR | (~current_umask() & S_IRWXUGO),
9216                                 &index);
9217         if (IS_ERR(inode))
9218                 return PTR_ERR(inode);
9219         inode->i_op = &btrfs_dir_inode_operations;
9220         inode->i_fop = &btrfs_dir_file_operations;
9221
9222         set_nlink(inode, 1);
9223         btrfs_i_size_write(BTRFS_I(inode), 0);
9224         unlock_new_inode(inode);
9225
9226         err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9227         if (err)
9228                 btrfs_err(new_root->fs_info,
9229                           "error inheriting subvolume %llu properties: %d",
9230                           new_root->root_key.objectid, err);
9231
9232         err = btrfs_update_inode(trans, new_root, inode);
9233
9234         iput(inode);
9235         return err;
9236 }
9237
9238 struct inode *btrfs_alloc_inode(struct super_block *sb)
9239 {
9240         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
9241         struct btrfs_inode *ei;
9242         struct inode *inode;
9243
9244         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
9245         if (!ei)
9246                 return NULL;
9247
9248         ei->root = NULL;
9249         ei->generation = 0;
9250         ei->last_trans = 0;
9251         ei->last_sub_trans = 0;
9252         ei->logged_trans = 0;
9253         ei->delalloc_bytes = 0;
9254         ei->new_delalloc_bytes = 0;
9255         ei->defrag_bytes = 0;
9256         ei->disk_i_size = 0;
9257         ei->flags = 0;
9258         ei->csum_bytes = 0;
9259         ei->index_cnt = (u64)-1;
9260         ei->dir_index = 0;
9261         ei->last_unlink_trans = 0;
9262         ei->last_log_commit = 0;
9263
9264         spin_lock_init(&ei->lock);
9265         ei->outstanding_extents = 0;
9266         if (sb->s_magic != BTRFS_TEST_MAGIC)
9267                 btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
9268                                               BTRFS_BLOCK_RSV_DELALLOC);
9269         ei->runtime_flags = 0;
9270         ei->prop_compress = BTRFS_COMPRESS_NONE;
9271         ei->defrag_compress = BTRFS_COMPRESS_NONE;
9272
9273         ei->delayed_node = NULL;
9274
9275         ei->i_otime.tv_sec = 0;
9276         ei->i_otime.tv_nsec = 0;
9277
9278         inode = &ei->vfs_inode;
9279         extent_map_tree_init(&ei->extent_tree);
9280         extent_io_tree_init(&ei->io_tree, inode);
9281         extent_io_tree_init(&ei->io_failure_tree, inode);
9282         ei->io_tree.track_uptodate = 1;
9283         ei->io_failure_tree.track_uptodate = 1;
9284         atomic_set(&ei->sync_writers, 0);
9285         mutex_init(&ei->log_mutex);
9286         mutex_init(&ei->delalloc_mutex);
9287         btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9288         INIT_LIST_HEAD(&ei->delalloc_inodes);
9289         INIT_LIST_HEAD(&ei->delayed_iput);
9290         RB_CLEAR_NODE(&ei->rb_node);
9291         init_rwsem(&ei->dio_sem);
9292
9293         return inode;
9294 }
9295
9296 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9297 void btrfs_test_destroy_inode(struct inode *inode)
9298 {
9299         btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9300         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9301 }
9302 #endif
9303
9304 static void btrfs_i_callback(struct rcu_head *head)
9305 {
9306         struct inode *inode = container_of(head, struct inode, i_rcu);
9307         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9308 }
9309
9310 void btrfs_destroy_inode(struct inode *inode)
9311 {
9312         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9313         struct btrfs_ordered_extent *ordered;
9314         struct btrfs_root *root = BTRFS_I(inode)->root;
9315
9316         WARN_ON(!hlist_empty(&inode->i_dentry));
9317         WARN_ON(inode->i_data.nrpages);
9318         WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
9319         WARN_ON(BTRFS_I(inode)->block_rsv.size);
9320         WARN_ON(BTRFS_I(inode)->outstanding_extents);
9321         WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9322         WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9323         WARN_ON(BTRFS_I(inode)->csum_bytes);
9324         WARN_ON(BTRFS_I(inode)->defrag_bytes);
9325
9326         /*
9327          * This can happen where we create an inode, but somebody else also
9328          * created the same inode and we need to destroy the one we already
9329          * created.
9330          */
9331         if (!root)
9332                 goto free;
9333
9334         if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9335                      &BTRFS_I(inode)->runtime_flags)) {
9336                 btrfs_info(fs_info, "inode %llu still on the orphan list",
9337                            btrfs_ino(BTRFS_I(inode)));
9338                 atomic_dec(&root->orphan_inodes);
9339         }
9340
9341         while (1) {
9342                 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9343                 if (!ordered)
9344                         break;
9345                 else {
9346                         btrfs_err(fs_info,
9347                                   "found ordered extent %llu %llu on inode cleanup",
9348                                   ordered->file_offset, ordered->len);
9349                         btrfs_remove_ordered_extent(inode, ordered);
9350                         btrfs_put_ordered_extent(ordered);
9351                         btrfs_put_ordered_extent(ordered);
9352                 }
9353         }
9354         btrfs_qgroup_check_reserved_leak(inode);
9355         inode_tree_del(inode);
9356         btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9357 free:
9358         call_rcu(&inode->i_rcu, btrfs_i_callback);
9359 }
9360
9361 int btrfs_drop_inode(struct inode *inode)
9362 {
9363         struct btrfs_root *root = BTRFS_I(inode)->root;
9364
9365         if (root == NULL)
9366                 return 1;
9367
9368         /* the snap/subvol tree is on deleting */
9369         if (btrfs_root_refs(&root->root_item) == 0)
9370                 return 1;
9371         else
9372                 return generic_drop_inode(inode);
9373 }
9374
9375 static void init_once(void *foo)
9376 {
9377         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9378
9379         inode_init_once(&ei->vfs_inode);
9380 }
9381
9382 void __cold btrfs_destroy_cachep(void)
9383 {
9384         /*
9385          * Make sure all delayed rcu free inodes are flushed before we
9386          * destroy cache.
9387          */
9388         rcu_barrier();
9389         kmem_cache_destroy(btrfs_inode_cachep);
9390         kmem_cache_destroy(btrfs_trans_handle_cachep);
9391         kmem_cache_destroy(btrfs_path_cachep);
9392         kmem_cache_destroy(btrfs_free_space_cachep);
9393 }
9394
9395 int __init btrfs_init_cachep(void)
9396 {
9397         btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9398                         sizeof(struct btrfs_inode), 0,
9399                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9400                         init_once);
9401         if (!btrfs_inode_cachep)
9402                 goto fail;
9403
9404         btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9405                         sizeof(struct btrfs_trans_handle), 0,
9406                         SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9407         if (!btrfs_trans_handle_cachep)
9408                 goto fail;
9409
9410         btrfs_path_cachep = kmem_cache_create("btrfs_path",
9411                         sizeof(struct btrfs_path), 0,
9412                         SLAB_MEM_SPREAD, NULL);
9413         if (!btrfs_path_cachep)
9414                 goto fail;
9415
9416         btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9417                         sizeof(struct btrfs_free_space), 0,
9418                         SLAB_MEM_SPREAD, NULL);
9419         if (!btrfs_free_space_cachep)
9420                 goto fail;
9421
9422         return 0;
9423 fail:
9424         btrfs_destroy_cachep();
9425         return -ENOMEM;
9426 }
9427
9428 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9429                          u32 request_mask, unsigned int flags)
9430 {
9431         u64 delalloc_bytes;
9432         struct inode *inode = d_inode(path->dentry);
9433         u32 blocksize = inode->i_sb->s_blocksize;
9434         u32 bi_flags = BTRFS_I(inode)->flags;
9435
9436         stat->result_mask |= STATX_BTIME;
9437         stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9438         stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9439         if (bi_flags & BTRFS_INODE_APPEND)
9440                 stat->attributes |= STATX_ATTR_APPEND;
9441         if (bi_flags & BTRFS_INODE_COMPRESS)
9442                 stat->attributes |= STATX_ATTR_COMPRESSED;
9443         if (bi_flags & BTRFS_INODE_IMMUTABLE)
9444                 stat->attributes |= STATX_ATTR_IMMUTABLE;
9445         if (bi_flags & BTRFS_INODE_NODUMP)
9446                 stat->attributes |= STATX_ATTR_NODUMP;
9447
9448         stat->attributes_mask |= (STATX_ATTR_APPEND |
9449                                   STATX_ATTR_COMPRESSED |
9450                                   STATX_ATTR_IMMUTABLE |
9451                                   STATX_ATTR_NODUMP);
9452
9453         generic_fillattr(inode, stat);
9454         stat->dev = BTRFS_I(inode)->root->anon_dev;
9455
9456         spin_lock(&BTRFS_I(inode)->lock);
9457         delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9458         spin_unlock(&BTRFS_I(inode)->lock);
9459         stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9460                         ALIGN(delalloc_bytes, blocksize)) >> 9;
9461         return 0;
9462 }
9463
9464 static int btrfs_rename_exchange(struct inode *old_dir,
9465                               struct dentry *old_dentry,
9466                               struct inode *new_dir,
9467                               struct dentry *new_dentry)
9468 {
9469         struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9470         struct btrfs_trans_handle *trans;
9471         struct btrfs_root *root = BTRFS_I(old_dir)->root;
9472         struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9473         struct inode *new_inode = new_dentry->d_inode;
9474         struct inode *old_inode = old_dentry->d_inode;
9475         struct timespec ctime = current_time(old_inode);
9476         struct dentry *parent;
9477         u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9478         u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9479         u64 old_idx = 0;
9480         u64 new_idx = 0;
9481         u64 root_objectid;
9482         int ret;
9483         bool root_log_pinned = false;
9484         bool dest_log_pinned = false;
9485
9486         /* we only allow rename subvolume link between subvolumes */
9487         if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9488                 return -EXDEV;
9489
9490         /* close the race window with snapshot create/destroy ioctl */
9491         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9492                 down_read(&fs_info->subvol_sem);
9493         if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9494                 down_read(&fs_info->subvol_sem);
9495
9496         /*
9497          * We want to reserve the absolute worst case amount of items.  So if
9498          * both inodes are subvols and we need to unlink them then that would
9499          * require 4 item modifications, but if they are both normal inodes it
9500          * would require 5 item modifications, so we'll assume their normal
9501          * inodes.  So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9502          * should cover the worst case number of items we'll modify.
9503          */
9504         trans = btrfs_start_transaction(root, 12);
9505         if (IS_ERR(trans)) {
9506                 ret = PTR_ERR(trans);
9507                 goto out_notrans;
9508         }
9509
9510         /*
9511          * We need to find a free sequence number both in the source and
9512          * in the destination directory for the exchange.
9513          */
9514         ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9515         if (ret)
9516                 goto out_fail;
9517         ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9518         if (ret)
9519                 goto out_fail;
9520
9521         BTRFS_I(old_inode)->dir_index = 0ULL;
9522         BTRFS_I(new_inode)->dir_index = 0ULL;
9523
9524         /* Reference for the source. */
9525         if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9526                 /* force full log commit if subvolume involved. */
9527                 btrfs_set_log_full_commit(fs_info, trans);
9528         } else {
9529                 btrfs_pin_log_trans(root);
9530                 root_log_pinned = true;
9531                 ret = btrfs_insert_inode_ref(trans, dest,
9532                                              new_dentry->d_name.name,
9533                                              new_dentry->d_name.len,
9534                                              old_ino,
9535                                              btrfs_ino(BTRFS_I(new_dir)),
9536                                              old_idx);
9537                 if (ret)
9538                         goto out_fail;
9539         }
9540
9541         /* And now for the dest. */
9542         if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9543                 /* force full log commit if subvolume involved. */
9544                 btrfs_set_log_full_commit(fs_info, trans);
9545         } else {
9546                 btrfs_pin_log_trans(dest);
9547                 dest_log_pinned = true;
9548                 ret = btrfs_insert_inode_ref(trans, root,
9549                                              old_dentry->d_name.name,
9550                                              old_dentry->d_name.len,
9551                                              new_ino,
9552                                              btrfs_ino(BTRFS_I(old_dir)),
9553                                              new_idx);
9554                 if (ret)
9555                         goto out_fail;
9556         }
9557
9558         /* Update inode version and ctime/mtime. */
9559         inode_inc_iversion(old_dir);
9560         inode_inc_iversion(new_dir);
9561         inode_inc_iversion(old_inode);
9562         inode_inc_iversion(new_inode);
9563         old_dir->i_ctime = old_dir->i_mtime = ctime;
9564         new_dir->i_ctime = new_dir->i_mtime = ctime;
9565         old_inode->i_ctime = ctime;
9566         new_inode->i_ctime = ctime;
9567
9568         if (old_dentry->d_parent != new_dentry->d_parent) {
9569                 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9570                                 BTRFS_I(old_inode), 1);
9571                 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9572                                 BTRFS_I(new_inode), 1);
9573         }
9574
9575         /* src is a subvolume */
9576         if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9577                 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9578                 ret = btrfs_unlink_subvol(trans, root, old_dir,
9579                                           root_objectid,
9580                                           old_dentry->d_name.name,
9581                                           old_dentry->d_name.len);
9582         } else { /* src is an inode */
9583                 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9584                                            BTRFS_I(old_dentry->d_inode),
9585                                            old_dentry->d_name.name,
9586                                            old_dentry->d_name.len);
9587                 if (!ret)
9588                         ret = btrfs_update_inode(trans, root, old_inode);
9589         }
9590         if (ret) {
9591                 btrfs_abort_transaction(trans, ret);
9592                 goto out_fail;
9593         }
9594
9595         /* dest is a subvolume */
9596         if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9597                 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9598                 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9599                                           root_objectid,
9600                                           new_dentry->d_name.name,
9601                                           new_dentry->d_name.len);
9602         } else { /* dest is an inode */
9603                 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9604                                            BTRFS_I(new_dentry->d_inode),
9605                                            new_dentry->d_name.name,
9606                                            new_dentry->d_name.len);
9607                 if (!ret)
9608                         ret = btrfs_update_inode(trans, dest, new_inode);
9609         }
9610         if (ret) {
9611                 btrfs_abort_transaction(trans, ret);
9612                 goto out_fail;
9613         }
9614
9615         ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9616                              new_dentry->d_name.name,
9617                              new_dentry->d_name.len, 0, old_idx);
9618         if (ret) {
9619                 btrfs_abort_transaction(trans, ret);
9620                 goto out_fail;
9621         }
9622
9623         ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9624                              old_dentry->d_name.name,
9625                              old_dentry->d_name.len, 0, new_idx);
9626         if (ret) {
9627                 btrfs_abort_transaction(trans, ret);
9628                 goto out_fail;
9629         }
9630
9631         if (old_inode->i_nlink == 1)
9632                 BTRFS_I(old_inode)->dir_index = old_idx;
9633         if (new_inode->i_nlink == 1)
9634                 BTRFS_I(new_inode)->dir_index = new_idx;
9635
9636         if (root_log_pinned) {
9637                 parent = new_dentry->d_parent;
9638                 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9639                                 parent);
9640                 btrfs_end_log_trans(root);
9641                 root_log_pinned = false;
9642         }
9643         if (dest_log_pinned) {
9644                 parent = old_dentry->d_parent;
9645                 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9646                                 parent);
9647                 btrfs_end_log_trans(dest);
9648                 dest_log_pinned = false;
9649         }
9650 out_fail:
9651         /*
9652          * If we have pinned a log and an error happened, we unpin tasks
9653          * trying to sync the log and force them to fallback to a transaction
9654          * commit if the log currently contains any of the inodes involved in
9655          * this rename operation (to ensure we do not persist a log with an
9656          * inconsistent state for any of these inodes or leading to any
9657          * inconsistencies when replayed). If the transaction was aborted, the
9658          * abortion reason is propagated to userspace when attempting to commit
9659          * the transaction. If the log does not contain any of these inodes, we
9660          * allow the tasks to sync it.
9661          */
9662         if (ret && (root_log_pinned || dest_log_pinned)) {
9663                 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9664                     btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9665                     btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9666                     (new_inode &&
9667                      btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9668                         btrfs_set_log_full_commit(fs_info, trans);
9669
9670                 if (root_log_pinned) {
9671                         btrfs_end_log_trans(root);
9672                         root_log_pinned = false;
9673                 }
9674                 if (dest_log_pinned) {
9675                         btrfs_end_log_trans(dest);
9676                         dest_log_pinned = false;
9677                 }
9678         }
9679         ret = btrfs_end_transaction(trans);
9680 out_notrans:
9681         if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9682                 up_read(&fs_info->subvol_sem);
9683         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9684                 up_read(&fs_info->subvol_sem);
9685
9686         return ret;
9687 }
9688
9689 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9690                                      struct btrfs_root *root,
9691                                      struct inode *dir,
9692                                      struct dentry *dentry)
9693 {
9694         int ret;
9695         struct inode *inode;
9696         u64 objectid;
9697         u64 index;
9698
9699         ret = btrfs_find_free_ino(root, &objectid);
9700         if (ret)
9701                 return ret;
9702
9703         inode = btrfs_new_inode(trans, root, dir,
9704                                 dentry->d_name.name,
9705                                 dentry->d_name.len,
9706                                 btrfs_ino(BTRFS_I(dir)),
9707                                 objectid,
9708                                 S_IFCHR | WHITEOUT_MODE,
9709                                 &index);
9710
9711         if (IS_ERR(inode)) {
9712                 ret = PTR_ERR(inode);
9713                 return ret;
9714         }
9715
9716         inode->i_op = &btrfs_special_inode_operations;
9717         init_special_inode(inode, inode->i_mode,
9718                 WHITEOUT_DEV);
9719
9720         ret = btrfs_init_inode_security(trans, inode, dir,
9721                                 &dentry->d_name);
9722         if (ret)
9723                 goto out;
9724
9725         ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9726                                 BTRFS_I(inode), 0, index);
9727         if (ret)
9728                 goto out;
9729
9730         ret = btrfs_update_inode(trans, root, inode);
9731 out:
9732         unlock_new_inode(inode);
9733         if (ret)
9734                 inode_dec_link_count(inode);
9735         iput(inode);
9736
9737         return ret;
9738 }
9739
9740 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9741                            struct inode *new_dir, struct dentry *new_dentry,
9742                            unsigned int flags)
9743 {
9744         struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9745         struct btrfs_trans_handle *trans;
9746         unsigned int trans_num_items;
9747         struct btrfs_root *root = BTRFS_I(old_dir)->root;
9748         struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9749         struct inode *new_inode = d_inode(new_dentry);
9750         struct inode *old_inode = d_inode(old_dentry);
9751         u64 index = 0;
9752         u64 root_objectid;
9753         int ret;
9754         u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9755         bool log_pinned = false;
9756
9757         if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9758                 return -EPERM;
9759
9760         /* we only allow rename subvolume link between subvolumes */
9761         if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9762                 return -EXDEV;
9763
9764         if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9765             (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9766                 return -ENOTEMPTY;
9767
9768         if (S_ISDIR(old_inode->i_mode) && new_inode &&
9769             new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9770                 return -ENOTEMPTY;
9771
9772
9773         /* check for collisions, even if the  name isn't there */
9774         ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9775                              new_dentry->d_name.name,
9776                              new_dentry->d_name.len);
9777
9778         if (ret) {
9779                 if (ret == -EEXIST) {
9780                         /* we shouldn't get
9781                          * eexist without a new_inode */
9782                         if (WARN_ON(!new_inode)) {
9783                                 return ret;
9784                         }
9785                 } else {
9786                         /* maybe -EOVERFLOW */
9787                         return ret;
9788                 }
9789         }
9790         ret = 0;
9791
9792         /*
9793          * we're using rename to replace one file with another.  Start IO on it
9794          * now so  we don't add too much work to the end of the transaction
9795          */
9796         if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9797                 filemap_flush(old_inode->i_mapping);
9798
9799         /* close the racy window with snapshot create/destroy ioctl */
9800         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9801                 down_read(&fs_info->subvol_sem);
9802         /*
9803          * We want to reserve the absolute worst case amount of items.  So if
9804          * both inodes are subvols and we need to unlink them then that would
9805          * require 4 item modifications, but if they are both normal inodes it
9806          * would require 5 item modifications, so we'll assume they are normal
9807          * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9808          * should cover the worst case number of items we'll modify.
9809          * If our rename has the whiteout flag, we need more 5 units for the
9810          * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9811          * when selinux is enabled).
9812          */
9813         trans_num_items = 11;
9814         if (flags & RENAME_WHITEOUT)
9815                 trans_num_items += 5;
9816         trans = btrfs_start_transaction(root, trans_num_items);
9817         if (IS_ERR(trans)) {
9818                 ret = PTR_ERR(trans);
9819                 goto out_notrans;
9820         }
9821
9822         if (dest != root)
9823                 btrfs_record_root_in_trans(trans, dest);
9824
9825         ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9826         if (ret)
9827                 goto out_fail;
9828
9829         BTRFS_I(old_inode)->dir_index = 0ULL;
9830         if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9831                 /* force full log commit if subvolume involved. */
9832                 btrfs_set_log_full_commit(fs_info, trans);
9833         } else {
9834                 btrfs_pin_log_trans(root);
9835                 log_pinned = true;
9836                 ret = btrfs_insert_inode_ref(trans, dest,
9837                                              new_dentry->d_name.name,
9838                                              new_dentry->d_name.len,
9839                                              old_ino,
9840                                              btrfs_ino(BTRFS_I(new_dir)), index);
9841                 if (ret)
9842                         goto out_fail;
9843         }
9844
9845         inode_inc_iversion(old_dir);
9846         inode_inc_iversion(new_dir);
9847         inode_inc_iversion(old_inode);
9848         old_dir->i_ctime = old_dir->i_mtime =
9849         new_dir->i_ctime = new_dir->i_mtime =
9850         old_inode->i_ctime = current_time(old_dir);
9851
9852         if (old_dentry->d_parent != new_dentry->d_parent)
9853                 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9854                                 BTRFS_I(old_inode), 1);
9855
9856         if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9857                 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9858                 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9859                                         old_dentry->d_name.name,
9860                                         old_dentry->d_name.len);
9861         } else {
9862                 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9863                                         BTRFS_I(d_inode(old_dentry)),
9864                                         old_dentry->d_name.name,
9865                                         old_dentry->d_name.len);
9866                 if (!ret)
9867                         ret = btrfs_update_inode(trans, root, old_inode);
9868         }
9869         if (ret) {
9870                 btrfs_abort_transaction(trans, ret);
9871                 goto out_fail;
9872         }
9873
9874         if (new_inode) {
9875                 inode_inc_iversion(new_inode);
9876                 new_inode->i_ctime = current_time(new_inode);
9877                 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
9878                              BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9879                         root_objectid = BTRFS_I(new_inode)->location.objectid;
9880                         ret = btrfs_unlink_subvol(trans, dest, new_dir,
9881                                                 root_objectid,
9882                                                 new_dentry->d_name.name,
9883                                                 new_dentry->d_name.len);
9884                         BUG_ON(new_inode->i_nlink == 0);
9885                 } else {
9886                         ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9887                                                  BTRFS_I(d_inode(new_dentry)),
9888                                                  new_dentry->d_name.name,
9889                                                  new_dentry->d_name.len);
9890                 }
9891                 if (!ret && new_inode->i_nlink == 0)
9892                         ret = btrfs_orphan_add(trans,
9893                                         BTRFS_I(d_inode(new_dentry)));
9894                 if (ret) {
9895                         btrfs_abort_transaction(trans, ret);
9896                         goto out_fail;
9897                 }
9898         }
9899
9900         ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9901                              new_dentry->d_name.name,
9902                              new_dentry->d_name.len, 0, index);
9903         if (ret) {
9904                 btrfs_abort_transaction(trans, ret);
9905                 goto out_fail;
9906         }
9907
9908         if (old_inode->i_nlink == 1)
9909                 BTRFS_I(old_inode)->dir_index = index;
9910
9911         if (log_pinned) {
9912                 struct dentry *parent = new_dentry->d_parent;
9913
9914                 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9915                                 parent);
9916                 btrfs_end_log_trans(root);
9917                 log_pinned = false;
9918         }
9919
9920         if (flags & RENAME_WHITEOUT) {
9921                 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9922                                                 old_dentry);
9923
9924                 if (ret) {
9925                         btrfs_abort_transaction(trans, ret);
9926                         goto out_fail;
9927                 }
9928         }
9929 out_fail:
9930         /*
9931          * If we have pinned the log and an error happened, we unpin tasks
9932          * trying to sync the log and force them to fallback to a transaction
9933          * commit if the log currently contains any of the inodes involved in
9934          * this rename operation (to ensure we do not persist a log with an
9935          * inconsistent state for any of these inodes or leading to any
9936          * inconsistencies when replayed). If the transaction was aborted, the
9937          * abortion reason is propagated to userspace when attempting to commit
9938          * the transaction. If the log does not contain any of these inodes, we
9939          * allow the tasks to sync it.
9940          */
9941         if (ret && log_pinned) {
9942                 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9943                     btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9944                     btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9945                     (new_inode &&
9946                      btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9947                         btrfs_set_log_full_commit(fs_info, trans);
9948
9949                 btrfs_end_log_trans(root);
9950                 log_pinned = false;
9951         }
9952         btrfs_end_transaction(trans);
9953 out_notrans:
9954         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9955                 up_read(&fs_info->subvol_sem);
9956
9957         return ret;
9958 }
9959
9960 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9961                          struct inode *new_dir, struct dentry *new_dentry,
9962                          unsigned int flags)
9963 {
9964         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9965                 return -EINVAL;
9966
9967         if (flags & RENAME_EXCHANGE)
9968                 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9969                                           new_dentry);
9970
9971         return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9972 }
9973
9974 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9975 {
9976         struct btrfs_delalloc_work *delalloc_work;
9977         struct inode *inode;
9978
9979         delalloc_work = container_of(work, struct btrfs_delalloc_work,
9980                                      work);
9981         inode = delalloc_work->inode;
9982         filemap_flush(inode->i_mapping);
9983         if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9984                                 &BTRFS_I(inode)->runtime_flags))
9985                 filemap_flush(inode->i_mapping);
9986
9987         if (delalloc_work->delay_iput)
9988                 btrfs_add_delayed_iput(inode);
9989         else
9990                 iput(inode);
9991         complete(&delalloc_work->completion);
9992 }
9993
9994 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9995                                                     int delay_iput)
9996 {
9997         struct btrfs_delalloc_work *work;
9998
9999         work = kmalloc(sizeof(*work), GFP_NOFS);
10000         if (!work)
10001                 return NULL;
10002
10003         init_completion(&work->completion);
10004         INIT_LIST_HEAD(&work->list);
10005         work->inode = inode;
10006         work->delay_iput = delay_iput;
10007         WARN_ON_ONCE(!inode);
10008         btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10009                         btrfs_run_delalloc_work, NULL, NULL);
10010
10011         return work;
10012 }
10013
10014 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10015 {
10016         wait_for_completion(&work->completion);
10017         kfree(work);
10018 }
10019
10020 /*
10021  * some fairly slow code that needs optimization. This walks the list
10022  * of all the inodes with pending delalloc and forces them to disk.
10023  */
10024 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10025                                    int nr)
10026 {
10027         struct btrfs_inode *binode;
10028         struct inode *inode;
10029         struct btrfs_delalloc_work *work, *next;
10030         struct list_head works;
10031         struct list_head splice;
10032         int ret = 0;
10033
10034         INIT_LIST_HEAD(&works);
10035         INIT_LIST_HEAD(&splice);
10036
10037         mutex_lock(&root->delalloc_mutex);
10038         spin_lock(&root->delalloc_lock);
10039         list_splice_init(&root->delalloc_inodes, &splice);
10040         while (!list_empty(&splice)) {
10041                 binode = list_entry(splice.next, struct btrfs_inode,
10042                                     delalloc_inodes);
10043
10044                 list_move_tail(&binode->delalloc_inodes,
10045                                &root->delalloc_inodes);
10046                 inode = igrab(&binode->vfs_inode);
10047                 if (!inode) {
10048                         cond_resched_lock(&root->delalloc_lock);
10049                         continue;
10050                 }
10051                 spin_unlock(&root->delalloc_lock);
10052
10053                 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10054                 if (!work) {
10055                         if (delay_iput)
10056                                 btrfs_add_delayed_iput(inode);
10057                         else
10058                                 iput(inode);
10059                         ret = -ENOMEM;
10060                         goto out;
10061                 }
10062                 list_add_tail(&work->list, &works);
10063                 btrfs_queue_work(root->fs_info->flush_workers,
10064                                  &work->work);
10065                 ret++;
10066                 if (nr != -1 && ret >= nr)
10067                         goto out;
10068                 cond_resched();
10069                 spin_lock(&root->delalloc_lock);
10070         }
10071         spin_unlock(&root->delalloc_lock);
10072
10073 out:
10074         list_for_each_entry_safe(work, next, &works, list) {
10075                 list_del_init(&work->list);
10076                 btrfs_wait_and_free_delalloc_work(work);
10077         }
10078
10079         if (!list_empty_careful(&splice)) {
10080                 spin_lock(&root->delalloc_lock);
10081                 list_splice_tail(&splice, &root->delalloc_inodes);
10082                 spin_unlock(&root->delalloc_lock);
10083         }
10084         mutex_unlock(&root->delalloc_mutex);
10085         return ret;
10086 }
10087
10088 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10089 {
10090         struct btrfs_fs_info *fs_info = root->fs_info;
10091         int ret;
10092
10093         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10094                 return -EROFS;
10095
10096         ret = __start_delalloc_inodes(root, delay_iput, -1);
10097         if (ret > 0)
10098                 ret = 0;
10099         return ret;
10100 }
10101
10102 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10103                                int nr)
10104 {
10105         struct btrfs_root *root;
10106         struct list_head splice;
10107         int ret;
10108
10109         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10110                 return -EROFS;
10111
10112         INIT_LIST_HEAD(&splice);
10113
10114         mutex_lock(&fs_info->delalloc_root_mutex);
10115         spin_lock(&fs_info->delalloc_root_lock);
10116         list_splice_init(&fs_info->delalloc_roots, &splice);
10117         while (!list_empty(&splice) && nr) {
10118                 root = list_first_entry(&splice, struct btrfs_root,
10119                                         delalloc_root);
10120                 root = btrfs_grab_fs_root(root);
10121                 BUG_ON(!root);
10122                 list_move_tail(&root->delalloc_root,
10123                                &fs_info->delalloc_roots);
10124                 spin_unlock(&fs_info->delalloc_root_lock);
10125
10126                 ret = __start_delalloc_inodes(root, delay_iput, nr);
10127                 btrfs_put_fs_root(root);
10128                 if (ret < 0)
10129                         goto out;
10130
10131                 if (nr != -1) {
10132                         nr -= ret;
10133                         WARN_ON(nr < 0);
10134                 }
10135                 spin_lock(&fs_info->delalloc_root_lock);
10136         }
10137         spin_unlock(&fs_info->delalloc_root_lock);
10138
10139         ret = 0;
10140 out:
10141         if (!list_empty_careful(&splice)) {
10142                 spin_lock(&fs_info->delalloc_root_lock);
10143                 list_splice_tail(&splice, &fs_info->delalloc_roots);
10144                 spin_unlock(&fs_info->delalloc_root_lock);
10145         }
10146         mutex_unlock(&fs_info->delalloc_root_mutex);
10147         return ret;
10148 }
10149
10150 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10151                          const char *symname)
10152 {
10153         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10154         struct btrfs_trans_handle *trans;
10155         struct btrfs_root *root = BTRFS_I(dir)->root;
10156         struct btrfs_path *path;
10157         struct btrfs_key key;
10158         struct inode *inode = NULL;
10159         int err;
10160         int drop_inode = 0;
10161         u64 objectid;
10162         u64 index = 0;
10163         int name_len;
10164         int datasize;
10165         unsigned long ptr;
10166         struct btrfs_file_extent_item *ei;
10167         struct extent_buffer *leaf;
10168
10169         name_len = strlen(symname);
10170         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10171                 return -ENAMETOOLONG;
10172
10173         /*
10174          * 2 items for inode item and ref
10175          * 2 items for dir items
10176          * 1 item for updating parent inode item
10177          * 1 item for the inline extent item
10178          * 1 item for xattr if selinux is on
10179          */
10180         trans = btrfs_start_transaction(root, 7);
10181         if (IS_ERR(trans))
10182                 return PTR_ERR(trans);
10183
10184         err = btrfs_find_free_ino(root, &objectid);
10185         if (err)
10186                 goto out_unlock;
10187
10188         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10189                                 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10190                                 objectid, S_IFLNK|S_IRWXUGO, &index);
10191         if (IS_ERR(inode)) {
10192                 err = PTR_ERR(inode);
10193                 goto out_unlock;
10194         }
10195
10196         /*
10197         * If the active LSM wants to access the inode during
10198         * d_instantiate it needs these. Smack checks to see
10199         * if the filesystem supports xattrs by looking at the
10200         * ops vector.
10201         */
10202         inode->i_fop = &btrfs_file_operations;
10203         inode->i_op = &btrfs_file_inode_operations;
10204         inode->i_mapping->a_ops = &btrfs_aops;
10205         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10206
10207         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10208         if (err)
10209                 goto out_unlock_inode;
10210
10211         path = btrfs_alloc_path();
10212         if (!path) {
10213                 err = -ENOMEM;
10214                 goto out_unlock_inode;
10215         }
10216         key.objectid = btrfs_ino(BTRFS_I(inode));
10217         key.offset = 0;
10218         key.type = BTRFS_EXTENT_DATA_KEY;
10219         datasize = btrfs_file_extent_calc_inline_size(name_len);
10220         err = btrfs_insert_empty_item(trans, root, path, &key,
10221                                       datasize);
10222         if (err) {
10223                 btrfs_free_path(path);
10224                 goto out_unlock_inode;
10225         }
10226         leaf = path->nodes[0];
10227         ei = btrfs_item_ptr(leaf, path->slots[0],
10228                             struct btrfs_file_extent_item);
10229         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10230         btrfs_set_file_extent_type(leaf, ei,
10231                                    BTRFS_FILE_EXTENT_INLINE);
10232         btrfs_set_file_extent_encryption(leaf, ei, 0);
10233         btrfs_set_file_extent_compression(leaf, ei, 0);
10234         btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10235         btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10236
10237         ptr = btrfs_file_extent_inline_start(ei);
10238         write_extent_buffer(leaf, symname, ptr, name_len);
10239         btrfs_mark_buffer_dirty(leaf);
10240         btrfs_free_path(path);
10241
10242         inode->i_op = &btrfs_symlink_inode_operations;
10243         inode_nohighmem(inode);
10244         inode->i_mapping->a_ops = &btrfs_symlink_aops;
10245         inode_set_bytes(inode, name_len);
10246         btrfs_i_size_write(BTRFS_I(inode), name_len);
10247         err = btrfs_update_inode(trans, root, inode);
10248         /*
10249          * Last step, add directory indexes for our symlink inode. This is the
10250          * last step to avoid extra cleanup of these indexes if an error happens
10251          * elsewhere above.
10252          */
10253         if (!err)
10254                 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10255                                 BTRFS_I(inode), 0, index);
10256         if (err) {
10257                 drop_inode = 1;
10258                 goto out_unlock_inode;
10259         }
10260
10261         unlock_new_inode(inode);
10262         d_instantiate(dentry, inode);
10263
10264 out_unlock:
10265         btrfs_end_transaction(trans);
10266         if (drop_inode) {
10267                 inode_dec_link_count(inode);
10268                 iput(inode);
10269         }
10270         btrfs_btree_balance_dirty(fs_info);
10271         return err;
10272
10273 out_unlock_inode:
10274         drop_inode = 1;
10275         unlock_new_inode(inode);
10276         goto out_unlock;
10277 }
10278
10279 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10280                                        u64 start, u64 num_bytes, u64 min_size,
10281                                        loff_t actual_len, u64 *alloc_hint,
10282                                        struct btrfs_trans_handle *trans)
10283 {
10284         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10285         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10286         struct extent_map *em;
10287         struct btrfs_root *root = BTRFS_I(inode)->root;
10288         struct btrfs_key ins;
10289         u64 cur_offset = start;
10290         u64 i_size;
10291         u64 cur_bytes;
10292         u64 last_alloc = (u64)-1;
10293         int ret = 0;
10294         bool own_trans = true;
10295         u64 end = start + num_bytes - 1;
10296
10297         if (trans)
10298                 own_trans = false;
10299         while (num_bytes > 0) {
10300                 if (own_trans) {
10301                         trans = btrfs_start_transaction(root, 3);
10302                         if (IS_ERR(trans)) {
10303                                 ret = PTR_ERR(trans);
10304                                 break;
10305                         }
10306                 }
10307
10308                 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10309                 cur_bytes = max(cur_bytes, min_size);
10310                 /*
10311                  * If we are severely fragmented we could end up with really
10312                  * small allocations, so if the allocator is returning small
10313                  * chunks lets make its job easier by only searching for those
10314                  * sized chunks.
10315                  */
10316                 cur_bytes = min(cur_bytes, last_alloc);
10317                 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10318                                 min_size, 0, *alloc_hint, &ins, 1, 0);
10319                 if (ret) {
10320                         if (own_trans)
10321                                 btrfs_end_transaction(trans);
10322                         break;
10323                 }
10324                 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10325
10326                 last_alloc = ins.offset;
10327                 ret = insert_reserved_file_extent(trans, inode,
10328                                                   cur_offset, ins.objectid,
10329                                                   ins.offset, ins.offset,
10330                                                   ins.offset, 0, 0, 0,
10331                                                   BTRFS_FILE_EXTENT_PREALLOC);
10332                 if (ret) {
10333                         btrfs_free_reserved_extent(fs_info, ins.objectid,
10334                                                    ins.offset, 0);
10335                         btrfs_abort_transaction(trans, ret);
10336                         if (own_trans)
10337                                 btrfs_end_transaction(trans);
10338                         break;
10339                 }
10340
10341                 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10342                                         cur_offset + ins.offset -1, 0);
10343
10344                 em = alloc_extent_map();
10345                 if (!em) {
10346                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10347                                 &BTRFS_I(inode)->runtime_flags);
10348                         goto next;
10349                 }
10350
10351                 em->start = cur_offset;
10352                 em->orig_start = cur_offset;
10353                 em->len = ins.offset;
10354                 em->block_start = ins.objectid;
10355                 em->block_len = ins.offset;
10356                 em->orig_block_len = ins.offset;
10357                 em->ram_bytes = ins.offset;
10358                 em->bdev = fs_info->fs_devices->latest_bdev;
10359                 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10360                 em->generation = trans->transid;
10361
10362                 while (1) {
10363                         write_lock(&em_tree->lock);
10364                         ret = add_extent_mapping(em_tree, em, 1);
10365                         write_unlock(&em_tree->lock);
10366                         if (ret != -EEXIST)
10367                                 break;
10368                         btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10369                                                 cur_offset + ins.offset - 1,
10370                                                 0);
10371                 }
10372                 free_extent_map(em);
10373 next:
10374                 num_bytes -= ins.offset;
10375                 cur_offset += ins.offset;
10376                 *alloc_hint = ins.objectid + ins.offset;
10377
10378                 inode_inc_iversion(inode);
10379                 inode->i_ctime = current_time(inode);
10380                 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10381                 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10382                     (actual_len > inode->i_size) &&
10383                     (cur_offset > inode->i_size)) {
10384                         if (cur_offset > actual_len)
10385                                 i_size = actual_len;
10386                         else
10387                                 i_size = cur_offset;
10388                         i_size_write(inode, i_size);
10389                         btrfs_ordered_update_i_size(inode, i_size, NULL);
10390                 }
10391
10392                 ret = btrfs_update_inode(trans, root, inode);
10393
10394                 if (ret) {
10395                         btrfs_abort_transaction(trans, ret);
10396                         if (own_trans)
10397                                 btrfs_end_transaction(trans);
10398                         break;
10399                 }
10400
10401                 if (own_trans)
10402                         btrfs_end_transaction(trans);
10403         }
10404         if (cur_offset < end)
10405                 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10406                         end - cur_offset + 1);
10407         return ret;
10408 }
10409
10410 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10411                               u64 start, u64 num_bytes, u64 min_size,
10412                               loff_t actual_len, u64 *alloc_hint)
10413 {
10414         return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10415                                            min_size, actual_len, alloc_hint,
10416                                            NULL);
10417 }
10418
10419 int btrfs_prealloc_file_range_trans(struct inode *inode,
10420                                     struct btrfs_trans_handle *trans, int mode,
10421                                     u64 start, u64 num_bytes, u64 min_size,
10422                                     loff_t actual_len, u64 *alloc_hint)
10423 {
10424         return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10425                                            min_size, actual_len, alloc_hint, trans);
10426 }
10427
10428 static int btrfs_set_page_dirty(struct page *page)
10429 {
10430         return __set_page_dirty_nobuffers(page);
10431 }
10432
10433 static int btrfs_permission(struct inode *inode, int mask)
10434 {
10435         struct btrfs_root *root = BTRFS_I(inode)->root;
10436         umode_t mode = inode->i_mode;
10437
10438         if (mask & MAY_WRITE &&
10439             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10440                 if (btrfs_root_readonly(root))
10441                         return -EROFS;
10442                 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10443                         return -EACCES;
10444         }
10445         return generic_permission(inode, mask);
10446 }
10447
10448 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10449 {
10450         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10451         struct btrfs_trans_handle *trans;
10452         struct btrfs_root *root = BTRFS_I(dir)->root;
10453         struct inode *inode = NULL;
10454         u64 objectid;
10455         u64 index;
10456         int ret = 0;
10457
10458         /*
10459          * 5 units required for adding orphan entry
10460          */
10461         trans = btrfs_start_transaction(root, 5);
10462         if (IS_ERR(trans))
10463                 return PTR_ERR(trans);
10464
10465         ret = btrfs_find_free_ino(root, &objectid);
10466         if (ret)
10467                 goto out;
10468
10469         inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10470                         btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10471         if (IS_ERR(inode)) {
10472                 ret = PTR_ERR(inode);
10473                 inode = NULL;
10474                 goto out;
10475         }
10476
10477         inode->i_fop = &btrfs_file_operations;
10478         inode->i_op = &btrfs_file_inode_operations;
10479
10480         inode->i_mapping->a_ops = &btrfs_aops;
10481         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10482
10483         ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10484         if (ret)
10485                 goto out_inode;
10486
10487         ret = btrfs_update_inode(trans, root, inode);
10488         if (ret)
10489                 goto out_inode;
10490         ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10491         if (ret)
10492                 goto out_inode;
10493
10494         /*
10495          * We set number of links to 0 in btrfs_new_inode(), and here we set
10496          * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10497          * through:
10498          *
10499          *    d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10500          */
10501         set_nlink(inode, 1);
10502         unlock_new_inode(inode);
10503         d_tmpfile(dentry, inode);
10504         mark_inode_dirty(inode);
10505
10506 out:
10507         btrfs_end_transaction(trans);
10508         if (ret)
10509                 iput(inode);
10510         btrfs_btree_balance_dirty(fs_info);
10511         return ret;
10512
10513 out_inode:
10514         unlock_new_inode(inode);
10515         goto out;
10516
10517 }
10518
10519 __attribute__((const))
10520 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10521 {
10522         return -EAGAIN;
10523 }
10524
10525 static struct btrfs_fs_info *iotree_fs_info(void *private_data)
10526 {
10527         struct inode *inode = private_data;
10528         return btrfs_sb(inode->i_sb);
10529 }
10530
10531 static void btrfs_check_extent_io_range(void *private_data, const char *caller,
10532                                         u64 start, u64 end)
10533 {
10534         struct inode *inode = private_data;
10535         u64 isize;
10536
10537         isize = i_size_read(inode);
10538         if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
10539                 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
10540                     "%s: ino %llu isize %llu odd range [%llu,%llu]",
10541                         caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
10542         }
10543 }
10544
10545 void btrfs_set_range_writeback(void *private_data, u64 start, u64 end)
10546 {
10547         struct inode *inode = private_data;
10548         unsigned long index = start >> PAGE_SHIFT;
10549         unsigned long end_index = end >> PAGE_SHIFT;
10550         struct page *page;
10551
10552         while (index <= end_index) {
10553                 page = find_get_page(inode->i_mapping, index);
10554                 ASSERT(page); /* Pages should be in the extent_io_tree */
10555                 set_page_writeback(page);
10556                 put_page(page);
10557                 index++;
10558         }
10559 }
10560
10561 static const struct inode_operations btrfs_dir_inode_operations = {
10562         .getattr        = btrfs_getattr,
10563         .lookup         = btrfs_lookup,
10564         .create         = btrfs_create,
10565         .unlink         = btrfs_unlink,
10566         .link           = btrfs_link,
10567         .mkdir          = btrfs_mkdir,
10568         .rmdir          = btrfs_rmdir,
10569         .rename         = btrfs_rename2,
10570         .symlink        = btrfs_symlink,
10571         .setattr        = btrfs_setattr,
10572         .mknod          = btrfs_mknod,
10573         .listxattr      = btrfs_listxattr,
10574         .permission     = btrfs_permission,
10575         .get_acl        = btrfs_get_acl,
10576         .set_acl        = btrfs_set_acl,
10577         .update_time    = btrfs_update_time,
10578         .tmpfile        = btrfs_tmpfile,
10579 };
10580 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10581         .lookup         = btrfs_lookup,
10582         .permission     = btrfs_permission,
10583         .update_time    = btrfs_update_time,
10584 };
10585
10586 static const struct file_operations btrfs_dir_file_operations = {
10587         .llseek         = generic_file_llseek,
10588         .read           = generic_read_dir,
10589         .iterate_shared = btrfs_real_readdir,
10590         .open           = btrfs_opendir,
10591         .unlocked_ioctl = btrfs_ioctl,
10592 #ifdef CONFIG_COMPAT
10593         .compat_ioctl   = btrfs_compat_ioctl,
10594 #endif
10595         .release        = btrfs_release_file,
10596         .fsync          = btrfs_sync_file,
10597 };
10598
10599 static const struct extent_io_ops btrfs_extent_io_ops = {
10600         /* mandatory callbacks */
10601         .submit_bio_hook = btrfs_submit_bio_hook,
10602         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10603         .merge_bio_hook = btrfs_merge_bio_hook,
10604         .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10605         .tree_fs_info = iotree_fs_info,
10606         .set_range_writeback = btrfs_set_range_writeback,
10607
10608         /* optional callbacks */
10609         .fill_delalloc = run_delalloc_range,
10610         .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10611         .writepage_start_hook = btrfs_writepage_start_hook,
10612         .set_bit_hook = btrfs_set_bit_hook,
10613         .clear_bit_hook = btrfs_clear_bit_hook,
10614         .merge_extent_hook = btrfs_merge_extent_hook,
10615         .split_extent_hook = btrfs_split_extent_hook,
10616         .check_extent_io_range = btrfs_check_extent_io_range,
10617 };
10618
10619 /*
10620  * btrfs doesn't support the bmap operation because swapfiles
10621  * use bmap to make a mapping of extents in the file.  They assume
10622  * these extents won't change over the life of the file and they
10623  * use the bmap result to do IO directly to the drive.
10624  *
10625  * the btrfs bmap call would return logical addresses that aren't
10626  * suitable for IO and they also will change frequently as COW
10627  * operations happen.  So, swapfile + btrfs == corruption.
10628  *
10629  * For now we're avoiding this by dropping bmap.
10630  */
10631 static const struct address_space_operations btrfs_aops = {
10632         .readpage       = btrfs_readpage,
10633         .writepage      = btrfs_writepage,
10634         .writepages     = btrfs_writepages,
10635         .readpages      = btrfs_readpages,
10636         .direct_IO      = btrfs_direct_IO,
10637         .invalidatepage = btrfs_invalidatepage,
10638         .releasepage    = btrfs_releasepage,
10639         .set_page_dirty = btrfs_set_page_dirty,
10640         .error_remove_page = generic_error_remove_page,
10641 };
10642
10643 static const struct address_space_operations btrfs_symlink_aops = {
10644         .readpage       = btrfs_readpage,
10645         .writepage      = btrfs_writepage,
10646         .invalidatepage = btrfs_invalidatepage,
10647         .releasepage    = btrfs_releasepage,
10648 };
10649
10650 static const struct inode_operations btrfs_file_inode_operations = {
10651         .getattr        = btrfs_getattr,
10652         .setattr        = btrfs_setattr,
10653         .listxattr      = btrfs_listxattr,
10654         .permission     = btrfs_permission,
10655         .fiemap         = btrfs_fiemap,
10656         .get_acl        = btrfs_get_acl,
10657         .set_acl        = btrfs_set_acl,
10658         .update_time    = btrfs_update_time,
10659 };
10660 static const struct inode_operations btrfs_special_inode_operations = {
10661         .getattr        = btrfs_getattr,
10662         .setattr        = btrfs_setattr,
10663         .permission     = btrfs_permission,
10664         .listxattr      = btrfs_listxattr,
10665         .get_acl        = btrfs_get_acl,
10666         .set_acl        = btrfs_set_acl,
10667         .update_time    = btrfs_update_time,
10668 };
10669 static const struct inode_operations btrfs_symlink_inode_operations = {
10670         .get_link       = page_get_link,
10671         .getattr        = btrfs_getattr,
10672         .setattr        = btrfs_setattr,
10673         .permission     = btrfs_permission,
10674         .listxattr      = btrfs_listxattr,
10675         .update_time    = btrfs_update_time,
10676 };
10677
10678 const struct dentry_operations btrfs_dentry_operations = {
10679         .d_delete       = btrfs_dentry_delete,
10680         .d_release      = btrfs_dentry_release,
10681 };