fs/btrfs/inode.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/bio.h>
   8 #include <linux/buffer_head.h>
   9 #include <linux/file.h>
  10 #include <linux/fs.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/highmem.h>
  13 #include <linux/time.h>
  14 #include <linux/init.h>
  15 #include <linux/string.h>
  16 #include <linux/backing-dev.h>
  17 #include <linux/mpage.h>
  18 #include <linux/swap.h>
  19 #include <linux/writeback.h>
  20 #include <linux/compat.h>
  21 #include <linux/bit_spinlock.h>
  22 #include <linux/xattr.h>
  23 #include <linux/posix_acl.h>
  24 #include <linux/falloc.h>
  25 #include <linux/slab.h>
  26 #include <linux/ratelimit.h>
  27 #include <linux/mount.h>
  28 #include <linux/btrfs.h>
  29 #include <linux/blkdev.h>
  30 #include <linux/posix_acl_xattr.h>
  31 #include <linux/uio.h>
  32 #include <linux/magic.h>
  33 #include <linux/iversion.h>
  34 #include <asm/unaligned.h>
  35 #include "ctree.h"
  36 #include "disk-io.h"
  37 #include "transaction.h"
  38 #include "btrfs_inode.h"
  39 #include "print-tree.h"
  40 #include "ordered-data.h"
  41 #include "xattr.h"
  42 #include "tree-log.h"
  43 #include "volumes.h"
  44 #include "compression.h"
  45 #include "locking.h"
  46 #include "free-space-cache.h"
  47 #include "inode-map.h"
  48 #include "backref.h"
  49 #include "props.h"
  50 #include "qgroup.h"
  51 #include "dedupe.h"
  52
  53 struct btrfs_iget_args {
  54         struct btrfs_key *location;
  55         struct btrfs_root *root;
  56 };
  57
  58 struct btrfs_dio_data {
  59         u64 reserve;
  60         u64 unsubmitted_oe_range_start;
  61         u64 unsubmitted_oe_range_end;
  62         int overwrite;
  63 };
  64
  65 static const struct inode_operations btrfs_dir_inode_operations;
  66 static const struct inode_operations btrfs_symlink_inode_operations;
  67 static const struct inode_operations btrfs_dir_ro_inode_operations;
  68 static const struct inode_operations btrfs_special_inode_operations;
  69 static const struct inode_operations btrfs_file_inode_operations;
  70 static const struct address_space_operations btrfs_aops;
  71 static const struct address_space_operations btrfs_symlink_aops;
  72 static const struct file_operations btrfs_dir_file_operations;
  73 static const struct extent_io_ops btrfs_extent_io_ops;
  74
  75 static struct kmem_cache *btrfs_inode_cachep;
  76 struct kmem_cache *btrfs_trans_handle_cachep;
  77 struct kmem_cache *btrfs_path_cachep;
  78 struct kmem_cache *btrfs_free_space_cachep;
  79
  80 #define S_SHIFT 12
  81 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
  82         [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
  83         [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
  84         [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
  85         [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
  86         [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
  87         [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
  88         [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
  89 };
  90
  91 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
  92 static int btrfs_truncate(struct inode *inode, bool skip_writeback);
  93 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
  94 static noinline int cow_file_range(struct inode *inode,
  95                                    struct page *locked_page,
  96                                    u64 start, u64 end, u64 delalloc_end,
  97                                    int *page_started, unsigned long *nr_written,
  98                                    int unlock, struct btrfs_dedupe_hash *hash);
  99 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
 100                                        u64 orig_start, u64 block_start,
 101                                        u64 block_len, u64 orig_block_len,
 102                                        u64 ram_bytes, int compress_type,
 103                                        int type);
 104
 105 static void __endio_write_update_ordered(struct inode *inode,
 106                                          const u64 offset, const u64 bytes,
 107                                          const bool uptodate);
 108
 109 /*
 110  * Cleanup all submitted ordered extents in specified range to handle errors
 111  * from the fill_dellaloc() callback.
 112  *
 113  * NOTE: caller must ensure that when an error happens, it can not call
 114  * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
 115  * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
 116  * to be released, which we want to happen only when finishing the ordered
 117  * extent (btrfs_finish_ordered_io()). Also note that the caller of the
 118  * fill_delalloc() callback already does proper cleanup for the first page of
 119  * the range, that is, it invokes the callback writepage_end_io_hook() for the
 120  * range of the first page.
 121  */
 122 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
 123                                                  const u64 offset,
 124                                                  const u64 bytes)
 125 {
 126         unsigned long index = offset >> PAGE_SHIFT;
 127         unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
 128         struct page *page;
 129
 130         while (index <= end_index) {
 131                 page = find_get_page(inode->i_mapping, index);
 132                 index++;
 133                 if (!page)
 134                         continue;
 135                 ClearPagePrivate2(page);
 136                 put_page(page);
 137         }
 138         return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
 139                                             bytes - PAGE_SIZE, false);
 140 }
 141
 142 static int btrfs_dirty_inode(struct inode *inode);
 143
 144 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 145 void btrfs_test_inode_set_ops(struct inode *inode)
 146 {
 147         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 148 }
 149 #endif
 150
 151 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
 152                                      struct inode *inode,  struct inode *dir,
 153                                      const struct qstr *qstr)
 154 {
 155         int err;
 156
 157         err = btrfs_init_acl(trans, inode, dir);
 158         if (!err)
 159                 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
 160         return err;
 161 }
 162
 163 /*
 164  * this does all the hard work for inserting an inline extent into
 165  * the btree.  The caller should have done a btrfs_drop_extents so that
 166  * no overlapping inline items exist in the btree
 167  */
 168 static int insert_inline_extent(struct btrfs_trans_handle *trans,
 169                                 struct btrfs_path *path, int extent_inserted,
 170                                 struct btrfs_root *root, struct inode *inode,
 171                                 u64 start, size_t size, size_t compressed_size,
 172                                 int compress_type,
 173                                 struct page **compressed_pages)
 174 {
 175         struct extent_buffer *leaf;
 176         struct page *page = NULL;
 177         char *kaddr;
 178         unsigned long ptr;
 179         struct btrfs_file_extent_item *ei;
 180         int ret;
 181         size_t cur_size = size;
 182         unsigned long offset;
 183
 184         if (compressed_size && compressed_pages)
 185                 cur_size = compressed_size;
 186
 187         inode_add_bytes(inode, size);
 188
 189         if (!extent_inserted) {
 190                 struct btrfs_key key;
 191                 size_t datasize;
 192
 193                 key.objectid = btrfs_ino(BTRFS_I(inode));
 194                 key.offset = start;
 195                 key.type = BTRFS_EXTENT_DATA_KEY;
 196
 197                 datasize = btrfs_file_extent_calc_inline_size(cur_size);
 198                 path->leave_spinning = 1;
 199                 ret = btrfs_insert_empty_item(trans, root, path, &key,
 200                                               datasize);
 201                 if (ret)
 202                         goto fail;
 203         }
 204         leaf = path->nodes[0];
 205         ei = btrfs_item_ptr(leaf, path->slots[0],
 206                             struct btrfs_file_extent_item);
 207         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
 208         btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
 209         btrfs_set_file_extent_encryption(leaf, ei, 0);
 210         btrfs_set_file_extent_other_encoding(leaf, ei, 0);
 211         btrfs_set_file_extent_ram_bytes(leaf, ei, size);
 212         ptr = btrfs_file_extent_inline_start(ei);
 213
 214         if (compress_type != BTRFS_COMPRESS_NONE) {
 215                 struct page *cpage;
 216                 int i = 0;
 217                 while (compressed_size > 0) {
 218                         cpage = compressed_pages[i];
 219                         cur_size = min_t(unsigned long, compressed_size,
 220                                        PAGE_SIZE);
 221
 222                         kaddr = kmap_atomic(cpage);
 223                         write_extent_buffer(leaf, kaddr, ptr, cur_size);
 224                         kunmap_atomic(kaddr);
 225
 226                         i++;
 227                         ptr += cur_size;
 228                         compressed_size -= cur_size;
 229                 }
 230                 btrfs_set_file_extent_compression(leaf, ei,
 231                                                   compress_type);
 232         } else {
 233                 page = find_get_page(inode->i_mapping,
 234                                      start >> PAGE_SHIFT);
 235                 btrfs_set_file_extent_compression(leaf, ei, 0);
 236                 kaddr = kmap_atomic(page);
 237                 offset = start & (PAGE_SIZE - 1);
 238                 write_extent_buffer(leaf, kaddr + offset, ptr, size);
 239                 kunmap_atomic(kaddr);
 240                 put_page(page);
 241         }
 242         btrfs_mark_buffer_dirty(leaf);
 243         btrfs_release_path(path);
 244
 245         /*
 246          * we're an inline extent, so nobody can
 247          * extend the file past i_size without locking
 248          * a page we already have locked.
 249          *
 250          * We must do any isize and inode updates
 251          * before we unlock the pages.  Otherwise we
 252          * could end up racing with unlink.
 253          */
 254         BTRFS_I(inode)->disk_i_size = inode->i_size;
 255         ret = btrfs_update_inode(trans, root, inode);
 256
 257 fail:
 258         return ret;
 259 }
 260
 261
 262 /*
 263  * conditionally insert an inline extent into the file.  This
 264  * does the checks required to make sure the data is small enough
 265  * to fit as an inline extent.
 266  */
 267 static noinline int cow_file_range_inline(struct inode *inode, u64 start,
 268                                           u64 end, size_t compressed_size,
 269                                           int compress_type,
 270                                           struct page **compressed_pages)
 271 {
 272         struct btrfs_root *root = BTRFS_I(inode)->root;
 273         struct btrfs_fs_info *fs_info = root->fs_info;
 274         struct btrfs_trans_handle *trans;
 275         u64 isize = i_size_read(inode);
 276         u64 actual_end = min(end + 1, isize);
 277         u64 inline_len = actual_end - start;
 278         u64 aligned_end = ALIGN(end, fs_info->sectorsize);
 279         u64 data_len = inline_len;
 280         int ret;
 281         struct btrfs_path *path;
 282         int extent_inserted = 0;
 283         u32 extent_item_size;
 284
 285         if (compressed_size)
 286                 data_len = compressed_size;
 287
 288         if (start > 0 ||
 289             actual_end > fs_info->sectorsize ||
 290             data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
 291             (!compressed_size &&
 292             (actual_end & (fs_info->sectorsize - 1)) == 0) ||
 293             end + 1 < isize ||
 294             data_len > fs_info->max_inline) {
 295                 return 1;
 296         }
 297
 298         path = btrfs_alloc_path();
 299         if (!path)
 300                 return -ENOMEM;
 301
 302         trans = btrfs_join_transaction(root);
 303         if (IS_ERR(trans)) {
 304                 btrfs_free_path(path);
 305                 return PTR_ERR(trans);
 306         }
 307         trans->block_rsv = &BTRFS_I(inode)->block_rsv;
 308
 309         if (compressed_size && compressed_pages)
 310                 extent_item_size = btrfs_file_extent_calc_inline_size(
 311                    compressed_size);
 312         else
 313                 extent_item_size = btrfs_file_extent_calc_inline_size(
 314                     inline_len);
 315
 316         ret = __btrfs_drop_extents(trans, root, inode, path,
 317                                    start, aligned_end, NULL,
 318                                    1, 1, extent_item_size, &extent_inserted);
 319         if (ret) {
 320                 btrfs_abort_transaction(trans, ret);
 321                 goto out;
 322         }
 323
 324         if (isize > actual_end)
 325                 inline_len = min_t(u64, isize, actual_end);
 326         ret = insert_inline_extent(trans, path, extent_inserted,
 327                                    root, inode, start,
 328                                    inline_len, compressed_size,
 329                                    compress_type, compressed_pages);
 330         if (ret && ret != -ENOSPC) {
 331                 btrfs_abort_transaction(trans, ret);
 332                 goto out;
 333         } else if (ret == -ENOSPC) {
 334                 ret = 1;
 335                 goto out;
 336         }
 337
 338         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
 339         btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
 340 out:
 341         /*
 342          * Don't forget to free the reserved space, as for inlined extent
 343          * it won't count as data extent, free them directly here.
 344          * And at reserve time, it's always aligned to page size, so
 345          * just free one page here.
 346          */
 347         btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
 348         btrfs_free_path(path);
 349         btrfs_end_transaction(trans);
 350         return ret;
 351 }
 352
 353 struct async_extent {
 354         u64 start;
 355         u64 ram_size;
 356         u64 compressed_size;
 357         struct page **pages;
 358         unsigned long nr_pages;
 359         int compress_type;
 360         struct list_head list;
 361 };
 362
 363 struct async_cow {
 364         struct inode *inode;
 365         struct btrfs_root *root;
 366         struct page *locked_page;
 367         u64 start;
 368         u64 end;
 369         unsigned int write_flags;
 370         struct list_head extents;
 371         struct btrfs_work work;
 372 };
 373
 374 static noinline int add_async_extent(struct async_cow *cow,
 375                                      u64 start, u64 ram_size,
 376                                      u64 compressed_size,
 377                                      struct page **pages,
 378                                      unsigned long nr_pages,
 379                                      int compress_type)
 380 {
 381         struct async_extent *async_extent;
 382
 383         async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
 384         BUG_ON(!async_extent); /* -ENOMEM */
 385         async_extent->start = start;
 386         async_extent->ram_size = ram_size;
 387         async_extent->compressed_size = compressed_size;
 388         async_extent->pages = pages;
 389         async_extent->nr_pages = nr_pages;
 390         async_extent->compress_type = compress_type;
 391         list_add_tail(&async_extent->list, &cow->extents);
 392         return 0;
 393 }
 394
 395 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
 396 {
 397         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 398
 399         /* force compress */
 400         if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
 401                 return 1;
 402         /* defrag ioctl */
 403         if (BTRFS_I(inode)->defrag_compress)
 404                 return 1;
 405         /* bad compression ratios */
 406         if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
 407                 return 0;
 408         if (btrfs_test_opt(fs_info, COMPRESS) ||
 409             BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
 410             BTRFS_I(inode)->prop_compress)
 411                 return btrfs_compress_heuristic(inode, start, end);
 412         return 0;
 413 }
 414
 415 static inline void inode_should_defrag(struct btrfs_inode *inode,
 416                 u64 start, u64 end, u64 num_bytes, u64 small_write)
 417 {
 418         /* If this is a small write inside eof, kick off a defrag */
 419         if (num_bytes < small_write &&
 420             (start > 0 || end + 1 < inode->disk_i_size))
 421                 btrfs_add_inode_defrag(NULL, inode);
 422 }
 423
 424 /*
 425  * we create compressed extents in two phases.  The first
 426  * phase compresses a range of pages that have already been
 427  * locked (both pages and state bits are locked).
 428  *
 429  * This is done inside an ordered work queue, and the compression
 430  * is spread across many cpus.  The actual IO submission is step
 431  * two, and the ordered work queue takes care of making sure that
 432  * happens in the same order things were put onto the queue by
 433  * writepages and friends.
 434  *
 435  * If this code finds it can't get good compression, it puts an
 436  * entry onto the work queue to write the uncompressed bytes.  This
 437  * makes sure that both compressed inodes and uncompressed inodes
 438  * are written in the same order that the flusher thread sent them
 439  * down.
 440  */
 441 static noinline void compress_file_range(struct inode *inode,
 442                                         struct page *locked_page,
 443                                         u64 start, u64 end,
 444                                         struct async_cow *async_cow,
 445                                         int *num_added)
 446 {
 447         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 448         u64 blocksize = fs_info->sectorsize;
 449         u64 actual_end;
 450         u64 isize = i_size_read(inode);
 451         int ret = 0;
 452         struct page **pages = NULL;
 453         unsigned long nr_pages;
 454         unsigned long total_compressed = 0;
 455         unsigned long total_in = 0;
 456         int i;
 457         int will_compress;
 458         int compress_type = fs_info->compress_type;
 459         int redirty = 0;
 460
 461         inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
 462                         SZ_16K);
 463
 464         actual_end = min_t(u64, isize, end + 1);
 465 again:
 466         will_compress = 0;
 467         nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
 468         BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
 469         nr_pages = min_t(unsigned long, nr_pages,
 470                         BTRFS_MAX_COMPRESSED / PAGE_SIZE);
 471
 472         /*
 473          * we don't want to send crud past the end of i_size through
 474          * compression, that's just a waste of CPU time.  So, if the
 475          * end of the file is before the start of our current
 476          * requested range of bytes, we bail out to the uncompressed
 477          * cleanup code that can deal with all of this.
 478          *
 479          * It isn't really the fastest way to fix things, but this is a
 480          * very uncommon corner.
 481          */
 482         if (actual_end <= start)
 483                 goto cleanup_and_bail_uncompressed;
 484
 485         total_compressed = actual_end - start;
 486
 487         /*
 488          * skip compression for a small file range(<=blocksize) that
 489          * isn't an inline extent, since it doesn't save disk space at all.
 490          */
 491         if (total_compressed <= blocksize &&
 492            (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
 493                 goto cleanup_and_bail_uncompressed;
 494
 495         total_compressed = min_t(unsigned long, total_compressed,
 496                         BTRFS_MAX_UNCOMPRESSED);
 497         total_in = 0;
 498         ret = 0;
 499
 500         /*
 501          * we do compression for mount -o compress and when the
 502          * inode has not been flagged as nocompress.  This flag can
 503          * change at any time if we discover bad compression ratios.
 504          */
 505         if (inode_need_compress(inode, start, end)) {
 506                 WARN_ON(pages);
 507                 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
 508                 if (!pages) {
 509                         /* just bail out to the uncompressed code */
 510                         goto cont;
 511                 }
 512
 513                 if (BTRFS_I(inode)->defrag_compress)
 514                         compress_type = BTRFS_I(inode)->defrag_compress;
 515                 else if (BTRFS_I(inode)->prop_compress)
 516                         compress_type = BTRFS_I(inode)->prop_compress;
 517
 518                 /*
 519                  * we need to call clear_page_dirty_for_io on each
 520                  * page in the range.  Otherwise applications with the file
 521                  * mmap'd can wander in and change the page contents while
 522                  * we are compressing them.
 523                  *
 524                  * If the compression fails for any reason, we set the pages
 525                  * dirty again later on.
 526                  *
 527                  * Note that the remaining part is redirtied, the start pointer
 528                  * has moved, the end is the original one.
 529                  */
 530                 if (!redirty) {
 531                         extent_range_clear_dirty_for_io(inode, start, end);
 532                         redirty = 1;
 533                 }
 534
 535                 /* Compression level is applied here and only here */
 536                 ret = btrfs_compress_pages(
 537                         compress_type | (fs_info->compress_level << 4),
 538                                            inode->i_mapping, start,
 539                                            pages,
 540                                            &nr_pages,
 541                                            &total_in,
 542                                            &total_compressed);
 543
 544                 if (!ret) {
 545                         unsigned long offset = total_compressed &
 546                                 (PAGE_SIZE - 1);
 547                         struct page *page = pages[nr_pages - 1];
 548                         char *kaddr;
 549
 550                         /* zero the tail end of the last page, we might be
 551                          * sending it down to disk
 552                          */
 553                         if (offset) {
 554                                 kaddr = kmap_atomic(page);
 555                                 memset(kaddr + offset, 0,
 556                                        PAGE_SIZE - offset);
 557                                 kunmap_atomic(kaddr);
 558                         }
 559                         will_compress = 1;
 560                 }
 561         }
 562 cont:
 563         if (start == 0) {
 564                 /* lets try to make an inline extent */
 565                 if (ret || total_in < actual_end) {
 566                         /* we didn't compress the entire range, try
 567                          * to make an uncompressed inline extent.
 568                          */
 569                         ret = cow_file_range_inline(inode, start, end, 0,
 570                                                     BTRFS_COMPRESS_NONE, NULL);
 571                 } else {
 572                         /* try making a compressed inline extent */
 573                         ret = cow_file_range_inline(inode, start, end,
 574                                                     total_compressed,
 575                                                     compress_type, pages);
 576                 }
 577                 if (ret <= 0) {
 578                         unsigned long clear_flags = EXTENT_DELALLOC |
 579                                 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
 580                                 EXTENT_DO_ACCOUNTING;
 581                         unsigned long page_error_op;
 582
 583                         page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
 584
 585                         /*
 586                          * inline extent creation worked or returned error,
 587                          * we don't need to create any more async work items.
 588                          * Unlock and free up our temp pages.
 589                          *
 590                          * We use DO_ACCOUNTING here because we need the
 591                          * delalloc_release_metadata to be done _after_ we drop
 592                          * our outstanding extent for clearing delalloc for this
 593                          * range.
 594                          */
 595                         extent_clear_unlock_delalloc(inode, start, end, end,
 596                                                      NULL, clear_flags,
 597                                                      PAGE_UNLOCK |
 598                                                      PAGE_CLEAR_DIRTY |
 599                                                      PAGE_SET_WRITEBACK |
 600                                                      page_error_op |
 601                                                      PAGE_END_WRITEBACK);
 602                         goto free_pages_out;
 603                 }
 604         }
 605
 606         if (will_compress) {
 607                 /*
 608                  * we aren't doing an inline extent round the compressed size
 609                  * up to a block size boundary so the allocator does sane
 610                  * things
 611                  */
 612                 total_compressed = ALIGN(total_compressed, blocksize);
 613
 614                 /*
 615                  * one last check to make sure the compression is really a
 616                  * win, compare the page count read with the blocks on disk,
 617                  * compression must free at least one sector size
 618                  */
 619                 total_in = ALIGN(total_in, PAGE_SIZE);
 620                 if (total_compressed + blocksize <= total_in) {
 621                         *num_added += 1;
 622
 623                         /*
 624                          * The async work queues will take care of doing actual
 625                          * allocation on disk for these compressed pages, and
 626                          * will submit them to the elevator.
 627                          */
 628                         add_async_extent(async_cow, start, total_in,
 629                                         total_compressed, pages, nr_pages,
 630                                         compress_type);
 631
 632                         if (start + total_in < end) {
 633                                 start += total_in;
 634                                 pages = NULL;
 635                                 cond_resched();
 636                                 goto again;
 637                         }
 638                         return;
 639                 }
 640         }
 641         if (pages) {
 642                 /*
 643                  * the compression code ran but failed to make things smaller,
 644                  * free any pages it allocated and our page pointer array
 645                  */
 646                 for (i = 0; i < nr_pages; i++) {
 647                         WARN_ON(pages[i]->mapping);
 648                         put_page(pages[i]);
 649                 }
 650                 kfree(pages);
 651                 pages = NULL;
 652                 total_compressed = 0;
 653                 nr_pages = 0;
 654
 655                 /* flag the file so we don't compress in the future */
 656                 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
 657                     !(BTRFS_I(inode)->prop_compress)) {
 658                         BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 659                 }
 660         }
 661 cleanup_and_bail_uncompressed:
 662         /*
 663          * No compression, but we still need to write the pages in the file
 664          * we've been given so far.  redirty the locked page if it corresponds
 665          * to our extent and set things up for the async work queue to run
 666          * cow_file_range to do the normal delalloc dance.
 667          */
 668         if (page_offset(locked_page) >= start &&
 669             page_offset(locked_page) <= end)
 670                 __set_page_dirty_nobuffers(locked_page);
 671                 /* unlocked later on in the async handlers */
 672
 673         if (redirty)
 674                 extent_range_redirty_for_io(inode, start, end);
 675         add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
 676                          BTRFS_COMPRESS_NONE);
 677         *num_added += 1;
 678
 679         return;
 680
 681 free_pages_out:
 682         for (i = 0; i < nr_pages; i++) {
 683                 WARN_ON(pages[i]->mapping);
 684                 put_page(pages[i]);
 685         }
 686         kfree(pages);
 687 }
 688
 689 static void free_async_extent_pages(struct async_extent *async_extent)
 690 {
 691         int i;
 692
 693         if (!async_extent->pages)
 694                 return;
 695
 696         for (i = 0; i < async_extent->nr_pages; i++) {
 697                 WARN_ON(async_extent->pages[i]->mapping);
 698                 put_page(async_extent->pages[i]);
 699         }
 700         kfree(async_extent->pages);
 701         async_extent->nr_pages = 0;
 702         async_extent->pages = NULL;
 703 }
 704
 705 /*
 706  * phase two of compressed writeback.  This is the ordered portion
 707  * of the code, which only gets called in the order the work was
 708  * queued.  We walk all the async extents created by compress_file_range
 709  * and send them down to the disk.
 710  */
 711 static noinline void submit_compressed_extents(struct inode *inode,
 712                                               struct async_cow *async_cow)
 713 {
 714         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 715         struct async_extent *async_extent;
 716         u64 alloc_hint = 0;
 717         struct btrfs_key ins;
 718         struct extent_map *em;
 719         struct btrfs_root *root = BTRFS_I(inode)->root;
 720         struct extent_io_tree *io_tree;
 721         int ret = 0;
 722
 723 again:
 724         while (!list_empty(&async_cow->extents)) {
 725                 async_extent = list_entry(async_cow->extents.next,
 726                                           struct async_extent, list);
 727                 list_del(&async_extent->list);
 728
 729                 io_tree = &BTRFS_I(inode)->io_tree;
 730
 731 retry:
 732                 /* did the compression code fall back to uncompressed IO? */
 733                 if (!async_extent->pages) {
 734                         int page_started = 0;
 735                         unsigned long nr_written = 0;
 736
 737                         lock_extent(io_tree, async_extent->start,
 738                                          async_extent->start +
 739                                          async_extent->ram_size - 1);
 740
 741                         /* allocate blocks */
 742                         ret = cow_file_range(inode, async_cow->locked_page,
 743                                              async_extent->start,
 744                                              async_extent->start +
 745                                              async_extent->ram_size - 1,
 746                                              async_extent->start +
 747                                              async_extent->ram_size - 1,
 748                                              &page_started, &nr_written, 0,
 749                                              NULL);
 750
 751                         /* JDM XXX */
 752
 753                         /*
 754                          * if page_started, cow_file_range inserted an
 755                          * inline extent and took care of all the unlocking
 756                          * and IO for us.  Otherwise, we need to submit
 757                          * all those pages down to the drive.
 758                          */
 759                         if (!page_started && !ret)
 760                                 extent_write_locked_range(inode,
 761                                                   async_extent->start,
 762                                                   async_extent->start +
 763                                                   async_extent->ram_size - 1,
 764                                                   WB_SYNC_ALL);
 765                         else if (ret)
 766                                 unlock_page(async_cow->locked_page);
 767                         kfree(async_extent);
 768                         cond_resched();
 769                         continue;
 770                 }
 771
 772                 lock_extent(io_tree, async_extent->start,
 773                             async_extent->start + async_extent->ram_size - 1);
 774
 775                 ret = btrfs_reserve_extent(root, async_extent->ram_size,
 776                                            async_extent->compressed_size,
 777                                            async_extent->compressed_size,
 778                                            0, alloc_hint, &ins, 1, 1);
 779                 if (ret) {
 780                         free_async_extent_pages(async_extent);
 781
 782                         if (ret == -ENOSPC) {
 783                                 unlock_extent(io_tree, async_extent->start,
 784                                               async_extent->start +
 785                                               async_extent->ram_size - 1);
 786
 787                                 /*
 788                                  * we need to redirty the pages if we decide to
 789                                  * fallback to uncompressed IO, otherwise we
 790                                  * will not submit these pages down to lower
 791                                  * layers.
 792                                  */
 793                                 extent_range_redirty_for_io(inode,
 794                                                 async_extent->start,
 795                                                 async_extent->start +
 796                                                 async_extent->ram_size - 1);
 797
 798                                 goto retry;
 799                         }
 800                         goto out_free;
 801                 }
 802                 /*
 803                  * here we're doing allocation and writeback of the
 804                  * compressed pages
 805                  */
 806                 em = create_io_em(inode, async_extent->start,
 807                                   async_extent->ram_size, /* len */
 808                                   async_extent->start, /* orig_start */
 809                                   ins.objectid, /* block_start */
 810                                   ins.offset, /* block_len */
 811                                   ins.offset, /* orig_block_len */
 812                                   async_extent->ram_size, /* ram_bytes */
 813                                   async_extent->compress_type,
 814                                   BTRFS_ORDERED_COMPRESSED);
 815                 if (IS_ERR(em))
 816                         /* ret value is not necessary due to void function */
 817                         goto out_free_reserve;
 818                 free_extent_map(em);
 819
 820                 ret = btrfs_add_ordered_extent_compress(inode,
 821                                                 async_extent->start,
 822                                                 ins.objectid,
 823                                                 async_extent->ram_size,
 824                                                 ins.offset,
 825                                                 BTRFS_ORDERED_COMPRESSED,
 826                                                 async_extent->compress_type);
 827                 if (ret) {
 828                         btrfs_drop_extent_cache(BTRFS_I(inode),
 829                                                 async_extent->start,
 830                                                 async_extent->start +
 831                                                 async_extent->ram_size - 1, 0);
 832                         goto out_free_reserve;
 833                 }
 834                 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
 835
 836                 /*
 837                  * clear dirty, set writeback and unlock the pages.
 838                  */
 839                 extent_clear_unlock_delalloc(inode, async_extent->start,
 840                                 async_extent->start +
 841                                 async_extent->ram_size - 1,
 842                                 async_extent->start +
 843                                 async_extent->ram_size - 1,
 844                                 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
 845                                 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
 846                                 PAGE_SET_WRITEBACK);
 847                 if (btrfs_submit_compressed_write(inode,
 848                                     async_extent->start,
 849                                     async_extent->ram_size,
 850                                     ins.objectid,
 851                                     ins.offset, async_extent->pages,
 852                                     async_extent->nr_pages,
 853                                     async_cow->write_flags)) {
 854                         struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 855                         struct page *p = async_extent->pages[0];
 856                         const u64 start = async_extent->start;
 857                         const u64 end = start + async_extent->ram_size - 1;
 858
 859                         p->mapping = inode->i_mapping;
 860                         tree->ops->writepage_end_io_hook(p, start, end,
 861                                                          NULL, 0);
 862                         p->mapping = NULL;
 863                         extent_clear_unlock_delalloc(inode, start, end, end,
 864                                                      NULL, 0,
 865                                                      PAGE_END_WRITEBACK |
 866                                                      PAGE_SET_ERROR);
 867                         free_async_extent_pages(async_extent);
 868                 }
 869                 alloc_hint = ins.objectid + ins.offset;
 870                 kfree(async_extent);
 871                 cond_resched();
 872         }
 873         return;
 874 out_free_reserve:
 875         btrfs_dec_block_group_reservations(fs_info, ins.objectid);
 876         btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
 877 out_free:
 878         extent_clear_unlock_delalloc(inode, async_extent->start,
 879                                      async_extent->start +
 880                                      async_extent->ram_size - 1,
 881                                      async_extent->start +
 882                                      async_extent->ram_size - 1,
 883                                      NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
 884                                      EXTENT_DELALLOC_NEW |
 885                                      EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
 886                                      PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
 887                                      PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
 888                                      PAGE_SET_ERROR);
 889         free_async_extent_pages(async_extent);
 890         kfree(async_extent);
 891         goto again;
 892 }
 893
 894 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
 895                                       u64 num_bytes)
 896 {
 897         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 898         struct extent_map *em;
 899         u64 alloc_hint = 0;
 900
 901         read_lock(&em_tree->lock);
 902         em = search_extent_mapping(em_tree, start, num_bytes);
 903         if (em) {
 904                 /*
 905                  * if block start isn't an actual block number then find the
 906                  * first block in this inode and use that as a hint.  If that
 907                  * block is also bogus then just don't worry about it.
 908                  */
 909                 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 910                         free_extent_map(em);
 911                         em = search_extent_mapping(em_tree, 0, 0);
 912                         if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
 913                                 alloc_hint = em->block_start;
 914                         if (em)
 915                                 free_extent_map(em);
 916                 } else {
 917                         alloc_hint = em->block_start;
 918                         free_extent_map(em);
 919                 }
 920         }
 921         read_unlock(&em_tree->lock);
 922
 923         return alloc_hint;
 924 }
 925
 926 /*
 927  * when extent_io.c finds a delayed allocation range in the file,
 928  * the call backs end up in this code.  The basic idea is to
 929  * allocate extents on disk for the range, and create ordered data structs
 930  * in ram to track those extents.
 931  *
 932  * locked_page is the page that writepage had locked already.  We use
 933  * it to make sure we don't do extra locks or unlocks.
 934  *
 935  * *page_started is set to one if we unlock locked_page and do everything
 936  * required to start IO on it.  It may be clean and already done with
 937  * IO when we return.
 938  */
 939 static noinline int cow_file_range(struct inode *inode,
 940                                    struct page *locked_page,
 941                                    u64 start, u64 end, u64 delalloc_end,
 942                                    int *page_started, unsigned long *nr_written,
 943                                    int unlock, struct btrfs_dedupe_hash *hash)
 944 {
 945         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 946         struct btrfs_root *root = BTRFS_I(inode)->root;
 947         u64 alloc_hint = 0;
 948         u64 num_bytes;
 949         unsigned long ram_size;
 950         u64 cur_alloc_size = 0;
 951         u64 blocksize = fs_info->sectorsize;
 952         struct btrfs_key ins;
 953         struct extent_map *em;
 954         unsigned clear_bits;
 955         unsigned long page_ops;
 956         bool extent_reserved = false;
 957         int ret = 0;
 958
 959         if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
 960                 WARN_ON_ONCE(1);
 961                 ret = -EINVAL;
 962                 goto out_unlock;
 963         }
 964
 965         num_bytes = ALIGN(end - start + 1, blocksize);
 966         num_bytes = max(blocksize,  num_bytes);
 967         ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
 968
 969         inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
 970
 971         if (start == 0) {
 972                 /* lets try to make an inline extent */
 973                 ret = cow_file_range_inline(inode, start, end, 0,
 974                                             BTRFS_COMPRESS_NONE, NULL);
 975                 if (ret == 0) {
 976                         /*
 977                          * We use DO_ACCOUNTING here because we need the
 978                          * delalloc_release_metadata to be run _after_ we drop
 979                          * our outstanding extent for clearing delalloc for this
 980                          * range.
 981                          */
 982                         extent_clear_unlock_delalloc(inode, start, end,
 983                                      delalloc_end, NULL,
 984                                      EXTENT_LOCKED | EXTENT_DELALLOC |
 985                                      EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
 986                                      EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
 987                                      PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
 988                                      PAGE_END_WRITEBACK);
 989                         *nr_written = *nr_written +
 990                              (end - start + PAGE_SIZE) / PAGE_SIZE;
 991                         *page_started = 1;
 992                         goto out;
 993                 } else if (ret < 0) {
 994                         goto out_unlock;
 995                 }
 996         }
 997
 998         alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
 999         btrfs_drop_extent_cache(BTRFS_I(inode), start,
1000                         start + num_bytes - 1, 0);
1001
1002         while (num_bytes > 0) {
1003                 cur_alloc_size = num_bytes;
1004                 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1005                                            fs_info->sectorsize, 0, alloc_hint,
1006                                            &ins, 1, 1);
1007                 if (ret < 0)
1008                         goto out_unlock;
1009                 cur_alloc_size = ins.offset;
1010                 extent_reserved = true;
1011
1012                 ram_size = ins.offset;
1013                 em = create_io_em(inode, start, ins.offset, /* len */
1014                                   start, /* orig_start */
1015                                   ins.objectid, /* block_start */
1016                                   ins.offset, /* block_len */
1017                                   ins.offset, /* orig_block_len */
1018                                   ram_size, /* ram_bytes */
1019                                   BTRFS_COMPRESS_NONE, /* compress_type */
1020                                   BTRFS_ORDERED_REGULAR /* type */);
1021                 if (IS_ERR(em))
1022                         goto out_reserve;
1023                 free_extent_map(em);
1024
1025                 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1026                                                ram_size, cur_alloc_size, 0);
1027                 if (ret)
1028                         goto out_drop_extent_cache;
1029
1030                 if (root->root_key.objectid ==
1031                     BTRFS_DATA_RELOC_TREE_OBJECTID) {
1032                         ret = btrfs_reloc_clone_csums(inode, start,
1033                                                       cur_alloc_size);
1034                         /*
1035                          * Only drop cache here, and process as normal.
1036                          *
1037                          * We must not allow extent_clear_unlock_delalloc()
1038                          * at out_unlock label to free meta of this ordered
1039                          * extent, as its meta should be freed by
1040                          * btrfs_finish_ordered_io().
1041                          *
1042                          * So we must continue until @start is increased to
1043                          * skip current ordered extent.
1044                          */
1045                         if (ret)
1046                                 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1047                                                 start + ram_size - 1, 0);
1048                 }
1049
1050                 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1051
1052                 /* we're not doing compressed IO, don't unlock the first
1053                  * page (which the caller expects to stay locked), don't
1054                  * clear any dirty bits and don't set any writeback bits
1055                  *
1056                  * Do set the Private2 bit so we know this page was properly
1057                  * setup for writepage
1058                  */
1059                 page_ops = unlock ? PAGE_UNLOCK : 0;
1060                 page_ops |= PAGE_SET_PRIVATE2;
1061
1062                 extent_clear_unlock_delalloc(inode, start,
1063                                              start + ram_size - 1,
1064                                              delalloc_end, locked_page,
1065                                              EXTENT_LOCKED | EXTENT_DELALLOC,
1066                                              page_ops);
1067                 if (num_bytes < cur_alloc_size)
1068                         num_bytes = 0;
1069                 else
1070                         num_bytes -= cur_alloc_size;
1071                 alloc_hint = ins.objectid + ins.offset;
1072                 start += cur_alloc_size;
1073                 extent_reserved = false;
1074
1075                 /*
1076                  * btrfs_reloc_clone_csums() error, since start is increased
1077                  * extent_clear_unlock_delalloc() at out_unlock label won't
1078                  * free metadata of current ordered extent, we're OK to exit.
1079                  */
1080                 if (ret)
1081                         goto out_unlock;
1082         }
1083 out:
1084         return ret;
1085
1086 out_drop_extent_cache:
1087         btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1088 out_reserve:
1089         btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1090         btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1091 out_unlock:
1092         clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1093                 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1094         page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1095                 PAGE_END_WRITEBACK;
1096         /*
1097          * If we reserved an extent for our delalloc range (or a subrange) and
1098          * failed to create the respective ordered extent, then it means that
1099          * when we reserved the extent we decremented the extent's size from
1100          * the data space_info's bytes_may_use counter and incremented the
1101          * space_info's bytes_reserved counter by the same amount. We must make
1102          * sure extent_clear_unlock_delalloc() does not try to decrement again
1103          * the data space_info's bytes_may_use counter, therefore we do not pass
1104          * it the flag EXTENT_CLEAR_DATA_RESV.
1105          */
1106         if (extent_reserved) {
1107                 extent_clear_unlock_delalloc(inode, start,
1108                                              start + cur_alloc_size,
1109                                              start + cur_alloc_size,
1110                                              locked_page,
1111                                              clear_bits,
1112                                              page_ops);
1113                 start += cur_alloc_size;
1114                 if (start >= end)
1115                         goto out;
1116         }
1117         extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1118                                      locked_page,
1119                                      clear_bits | EXTENT_CLEAR_DATA_RESV,
1120                                      page_ops);
1121         goto out;
1122 }
1123
1124 /*
1125  * work queue call back to started compression on a file and pages
1126  */
1127 static noinline void async_cow_start(struct btrfs_work *work)
1128 {
1129         struct async_cow *async_cow;
1130         int num_added = 0;
1131         async_cow = container_of(work, struct async_cow, work);
1132
1133         compress_file_range(async_cow->inode, async_cow->locked_page,
1134                             async_cow->start, async_cow->end, async_cow,
1135                             &num_added);
1136         if (num_added == 0) {
1137                 btrfs_add_delayed_iput(async_cow->inode);
1138                 async_cow->inode = NULL;
1139         }
1140 }
1141
1142 /*
1143  * work queue call back to submit previously compressed pages
1144  */
1145 static noinline void async_cow_submit(struct btrfs_work *work)
1146 {
1147         struct btrfs_fs_info *fs_info;
1148         struct async_cow *async_cow;
1149         struct btrfs_root *root;
1150         unsigned long nr_pages;
1151
1152         async_cow = container_of(work, struct async_cow, work);
1153
1154         root = async_cow->root;
1155         fs_info = root->fs_info;
1156         nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1157                 PAGE_SHIFT;
1158
1159         /*
1160          * atomic_sub_return implies a barrier for waitqueue_active
1161          */
1162         if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1163             5 * SZ_1M &&
1164             waitqueue_active(&fs_info->async_submit_wait))
1165                 wake_up(&fs_info->async_submit_wait);
1166
1167         if (async_cow->inode)
1168                 submit_compressed_extents(async_cow->inode, async_cow);
1169 }
1170
1171 static noinline void async_cow_free(struct btrfs_work *work)
1172 {
1173         struct async_cow *async_cow;
1174         async_cow = container_of(work, struct async_cow, work);
1175         if (async_cow->inode)
1176                 btrfs_add_delayed_iput(async_cow->inode);
1177         kfree(async_cow);
1178 }
1179
1180 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1181                                 u64 start, u64 end, int *page_started,
1182                                 unsigned long *nr_written,
1183                                 unsigned int write_flags)
1184 {
1185         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1186         struct async_cow *async_cow;
1187         struct btrfs_root *root = BTRFS_I(inode)->root;
1188         unsigned long nr_pages;
1189         u64 cur_end;
1190
1191         clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1192                          1, 0, NULL);
1193         while (start < end) {
1194                 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1195                 BUG_ON(!async_cow); /* -ENOMEM */
1196                 async_cow->inode = igrab(inode);
1197                 async_cow->root = root;
1198                 async_cow->locked_page = locked_page;
1199                 async_cow->start = start;
1200                 async_cow->write_flags = write_flags;
1201
1202                 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1203                     !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1204                         cur_end = end;
1205                 else
1206                         cur_end = min(end, start + SZ_512K - 1);
1207
1208                 async_cow->end = cur_end;
1209                 INIT_LIST_HEAD(&async_cow->extents);
1210
1211                 btrfs_init_work(&async_cow->work,
1212                                 btrfs_delalloc_helper,
1213                                 async_cow_start, async_cow_submit,
1214                                 async_cow_free);
1215
1216                 nr_pages = (cur_end - start + PAGE_SIZE) >>
1217                         PAGE_SHIFT;
1218                 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1219
1220                 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1221
1222                 *nr_written += nr_pages;
1223                 start = cur_end + 1;
1224         }
1225         *page_started = 1;
1226         return 0;
1227 }
1228
1229 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1230                                         u64 bytenr, u64 num_bytes)
1231 {
1232         int ret;
1233         struct btrfs_ordered_sum *sums;
1234         LIST_HEAD(list);
1235
1236         ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1237                                        bytenr + num_bytes - 1, &list, 0);
1238         if (ret == 0 && list_empty(&list))
1239                 return 0;
1240
1241         while (!list_empty(&list)) {
1242                 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1243                 list_del(&sums->list);
1244                 kfree(sums);
1245         }
1246         if (ret < 0)
1247                 return ret;
1248         return 1;
1249 }
1250
1251 /*
1252  * when nowcow writeback call back.  This checks for snapshots or COW copies
1253  * of the extents that exist in the file, and COWs the file as required.
1254  *
1255  * If no cow copies or snapshots exist, we write directly to the existing
1256  * blocks on disk
1257  */
1258 static noinline int run_delalloc_nocow(struct inode *inode,
1259                                        struct page *locked_page,
1260                               u64 start, u64 end, int *page_started, int force,
1261                               unsigned long *nr_written)
1262 {
1263         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1264         struct btrfs_root *root = BTRFS_I(inode)->root;
1265         struct extent_buffer *leaf;
1266         struct btrfs_path *path;
1267         struct btrfs_file_extent_item *fi;
1268         struct btrfs_key found_key;
1269         struct extent_map *em;
1270         u64 cow_start;
1271         u64 cur_offset;
1272         u64 extent_end;
1273         u64 extent_offset;
1274         u64 disk_bytenr;
1275         u64 num_bytes;
1276         u64 disk_num_bytes;
1277         u64 ram_bytes;
1278         int extent_type;
1279         int ret, err;
1280         int type;
1281         int nocow;
1282         int check_prev = 1;
1283         bool nolock;
1284         u64 ino = btrfs_ino(BTRFS_I(inode));
1285
1286         path = btrfs_alloc_path();
1287         if (!path) {
1288                 extent_clear_unlock_delalloc(inode, start, end, end,
1289                                              locked_page,
1290                                              EXTENT_LOCKED | EXTENT_DELALLOC |
1291                                              EXTENT_DO_ACCOUNTING |
1292                                              EXTENT_DEFRAG, PAGE_UNLOCK |
1293                                              PAGE_CLEAR_DIRTY |
1294                                              PAGE_SET_WRITEBACK |
1295                                              PAGE_END_WRITEBACK);
1296                 return -ENOMEM;
1297         }
1298
1299         nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1300
1301         cow_start = (u64)-1;
1302         cur_offset = start;
1303         while (1) {
1304                 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1305                                                cur_offset, 0);
1306                 if (ret < 0)
1307                         goto error;
1308                 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1309                         leaf = path->nodes[0];
1310                         btrfs_item_key_to_cpu(leaf, &found_key,
1311                                               path->slots[0] - 1);
1312                         if (found_key.objectid == ino &&
1313                             found_key.type == BTRFS_EXTENT_DATA_KEY)
1314                                 path->slots[0]--;
1315                 }
1316                 check_prev = 0;
1317 next_slot:
1318                 leaf = path->nodes[0];
1319                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1320                         ret = btrfs_next_leaf(root, path);
1321                         if (ret < 0) {
1322                                 if (cow_start != (u64)-1)
1323                                         cur_offset = cow_start;
1324                                 goto error;
1325                         }
1326                         if (ret > 0)
1327                                 break;
1328                         leaf = path->nodes[0];
1329                 }
1330
1331                 nocow = 0;
1332                 disk_bytenr = 0;
1333                 num_bytes = 0;
1334                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1335
1336                 if (found_key.objectid > ino)
1337                         break;
1338                 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1339                     found_key.type < BTRFS_EXTENT_DATA_KEY) {
1340                         path->slots[0]++;
1341                         goto next_slot;
1342                 }
1343                 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1344                     found_key.offset > end)
1345                         break;
1346
1347                 if (found_key.offset > cur_offset) {
1348                         extent_end = found_key.offset;
1349                         extent_type = 0;
1350                         goto out_check;
1351                 }
1352
1353                 fi = btrfs_item_ptr(leaf, path->slots[0],
1354                                     struct btrfs_file_extent_item);
1355                 extent_type = btrfs_file_extent_type(leaf, fi);
1356
1357                 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1358                 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1359                     extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1360                         disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1361                         extent_offset = btrfs_file_extent_offset(leaf, fi);
1362                         extent_end = found_key.offset +
1363                                 btrfs_file_extent_num_bytes(leaf, fi);
1364                         disk_num_bytes =
1365                                 btrfs_file_extent_disk_num_bytes(leaf, fi);
1366                         if (extent_end <= start) {
1367                                 path->slots[0]++;
1368                                 goto next_slot;
1369                         }
1370                         if (disk_bytenr == 0)
1371                                 goto out_check;
1372                         if (btrfs_file_extent_compression(leaf, fi) ||
1373                             btrfs_file_extent_encryption(leaf, fi) ||
1374                             btrfs_file_extent_other_encoding(leaf, fi))
1375                                 goto out_check;
1376                         if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1377                                 goto out_check;
1378                         if (btrfs_extent_readonly(fs_info, disk_bytenr))
1379                                 goto out_check;
1380                         ret = btrfs_cross_ref_exist(root, ino,
1381                                                     found_key.offset -
1382                                                     extent_offset, disk_bytenr);
1383                         if (ret) {
1384                                 /*
1385                                  * ret could be -EIO if the above fails to read
1386                                  * metadata.
1387                                  */
1388                                 if (ret < 0) {
1389                                         if (cow_start != (u64)-1)
1390                                                 cur_offset = cow_start;
1391                                         goto error;
1392                                 }
1393
1394                                 WARN_ON_ONCE(nolock);
1395                                 goto out_check;
1396                         }
1397                         disk_bytenr += extent_offset;
1398                         disk_bytenr += cur_offset - found_key.offset;
1399                         num_bytes = min(end + 1, extent_end) - cur_offset;
1400                         /*
1401                          * if there are pending snapshots for this root,
1402                          * we fall into common COW way.
1403                          */
1404                         if (!nolock) {
1405                                 err = btrfs_start_write_no_snapshotting(root);
1406                                 if (!err)
1407                                         goto out_check;
1408                         }
1409                         /*
1410                          * force cow if csum exists in the range.
1411                          * this ensure that csum for a given extent are
1412                          * either valid or do not exist.
1413                          */
1414                         ret = csum_exist_in_range(fs_info, disk_bytenr,
1415                                                   num_bytes);
1416                         if (ret) {
1417                                 if (!nolock)
1418                                         btrfs_end_write_no_snapshotting(root);
1419
1420                                 /*
1421                                  * ret could be -EIO if the above fails to read
1422                                  * metadata.
1423                                  */
1424                                 if (ret < 0) {
1425                                         if (cow_start != (u64)-1)
1426                                                 cur_offset = cow_start;
1427                                         goto error;
1428                                 }
1429                                 WARN_ON_ONCE(nolock);
1430                                 goto out_check;
1431                         }
1432                         if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1433                                 if (!nolock)
1434                                         btrfs_end_write_no_snapshotting(root);
1435                                 goto out_check;
1436                         }
1437                         nocow = 1;
1438                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1439                         extent_end = found_key.offset +
1440                                 btrfs_file_extent_inline_len(leaf,
1441                                                      path->slots[0], fi);
1442                         extent_end = ALIGN(extent_end,
1443                                            fs_info->sectorsize);
1444                 } else {
1445                         BUG_ON(1);
1446                 }
1447 out_check:
1448                 if (extent_end <= start) {
1449                         path->slots[0]++;
1450                         if (!nolock && nocow)
1451                                 btrfs_end_write_no_snapshotting(root);
1452                         if (nocow)
1453                                 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1454                         goto next_slot;
1455                 }
1456                 if (!nocow) {
1457                         if (cow_start == (u64)-1)
1458                                 cow_start = cur_offset;
1459                         cur_offset = extent_end;
1460                         if (cur_offset > end)
1461                                 break;
1462                         path->slots[0]++;
1463                         goto next_slot;
1464                 }
1465
1466                 btrfs_release_path(path);
1467                 if (cow_start != (u64)-1) {
1468                         ret = cow_file_range(inode, locked_page,
1469                                              cow_start, found_key.offset - 1,
1470                                              end, page_started, nr_written, 1,
1471                                              NULL);
1472                         if (ret) {
1473                                 if (!nolock && nocow)
1474                                         btrfs_end_write_no_snapshotting(root);
1475                                 if (nocow)
1476                                         btrfs_dec_nocow_writers(fs_info,
1477                                                                 disk_bytenr);
1478                                 goto error;
1479                         }
1480                         cow_start = (u64)-1;
1481                 }
1482
1483                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1484                         u64 orig_start = found_key.offset - extent_offset;
1485
1486                         em = create_io_em(inode, cur_offset, num_bytes,
1487                                           orig_start,
1488                                           disk_bytenr, /* block_start */
1489                                           num_bytes, /* block_len */
1490                                           disk_num_bytes, /* orig_block_len */
1491                                           ram_bytes, BTRFS_COMPRESS_NONE,
1492                                           BTRFS_ORDERED_PREALLOC);
1493                         if (IS_ERR(em)) {
1494                                 if (!nolock && nocow)
1495                                         btrfs_end_write_no_snapshotting(root);
1496                                 if (nocow)
1497                                         btrfs_dec_nocow_writers(fs_info,
1498                                                                 disk_bytenr);
1499                                 ret = PTR_ERR(em);
1500                                 goto error;
1501                         }
1502                         free_extent_map(em);
1503                 }
1504
1505                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1506                         type = BTRFS_ORDERED_PREALLOC;
1507                 } else {
1508                         type = BTRFS_ORDERED_NOCOW;
1509                 }
1510
1511                 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1512                                                num_bytes, num_bytes, type);
1513                 if (nocow)
1514                         btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1515                 BUG_ON(ret); /* -ENOMEM */
1516
1517                 if (root->root_key.objectid ==
1518                     BTRFS_DATA_RELOC_TREE_OBJECTID)
1519                         /*
1520                          * Error handled later, as we must prevent
1521                          * extent_clear_unlock_delalloc() in error handler
1522                          * from freeing metadata of created ordered extent.
1523                          */
1524                         ret = btrfs_reloc_clone_csums(inode, cur_offset,
1525                                                       num_bytes);
1526
1527                 extent_clear_unlock_delalloc(inode, cur_offset,
1528                                              cur_offset + num_bytes - 1, end,
1529                                              locked_page, EXTENT_LOCKED |
1530                                              EXTENT_DELALLOC |
1531                                              EXTENT_CLEAR_DATA_RESV,
1532                                              PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1533
1534                 if (!nolock && nocow)
1535                         btrfs_end_write_no_snapshotting(root);
1536                 cur_offset = extent_end;
1537
1538                 /*
1539                  * btrfs_reloc_clone_csums() error, now we're OK to call error
1540                  * handler, as metadata for created ordered extent will only
1541                  * be freed by btrfs_finish_ordered_io().
1542                  */
1543                 if (ret)
1544                         goto error;
1545                 if (cur_offset > end)
1546                         break;
1547         }
1548         btrfs_release_path(path);
1549
1550         if (cur_offset <= end && cow_start == (u64)-1) {
1551                 cow_start = cur_offset;
1552                 cur_offset = end;
1553         }
1554
1555         if (cow_start != (u64)-1) {
1556                 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1557                                      page_started, nr_written, 1, NULL);
1558                 if (ret)
1559                         goto error;
1560         }
1561
1562 error:
1563         if (ret && cur_offset < end)
1564                 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1565                                              locked_page, EXTENT_LOCKED |
1566                                              EXTENT_DELALLOC | EXTENT_DEFRAG |
1567                                              EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1568                                              PAGE_CLEAR_DIRTY |
1569                                              PAGE_SET_WRITEBACK |
1570                                              PAGE_END_WRITEBACK);
1571         btrfs_free_path(path);
1572         return ret;
1573 }
1574
1575 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1576 {
1577
1578         if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1579             !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1580                 return 0;
1581
1582         /*
1583          * @defrag_bytes is a hint value, no spinlock held here,
1584          * if is not zero, it means the file is defragging.
1585          * Force cow if given extent needs to be defragged.
1586          */
1587         if (BTRFS_I(inode)->defrag_bytes &&
1588             test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1589                            EXTENT_DEFRAG, 0, NULL))
1590                 return 1;
1591
1592         return 0;
1593 }
1594
1595 /*
1596  * extent_io.c call back to do delayed allocation processing
1597  */
1598 static int run_delalloc_range(void *private_data, struct page *locked_page,
1599                               u64 start, u64 end, int *page_started,
1600                               unsigned long *nr_written,
1601                               struct writeback_control *wbc)
1602 {
1603         struct inode *inode = private_data;
1604         int ret;
1605         int force_cow = need_force_cow(inode, start, end);
1606         unsigned int write_flags = wbc_to_write_flags(wbc);
1607
1608         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1609                 ret = run_delalloc_nocow(inode, locked_page, start, end,
1610                                          page_started, 1, nr_written);
1611         } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1612                 ret = run_delalloc_nocow(inode, locked_page, start, end,
1613                                          page_started, 0, nr_written);
1614         } else if (!inode_need_compress(inode, start, end)) {
1615                 ret = cow_file_range(inode, locked_page, start, end, end,
1616                                       page_started, nr_written, 1, NULL);
1617         } else {
1618                 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1619                         &BTRFS_I(inode)->runtime_flags);
1620                 ret = cow_file_range_async(inode, locked_page, start, end,
1621                                            page_started, nr_written,
1622                                            write_flags);
1623         }
1624         if (ret)
1625                 btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
1626         return ret;
1627 }
1628
1629 static void btrfs_split_extent_hook(void *private_data,
1630                                     struct extent_state *orig, u64 split)
1631 {
1632         struct inode *inode = private_data;
1633         u64 size;
1634
1635         /* not delalloc, ignore it */
1636         if (!(orig->state & EXTENT_DELALLOC))
1637                 return;
1638
1639         size = orig->end - orig->start + 1;
1640         if (size > BTRFS_MAX_EXTENT_SIZE) {
1641                 u32 num_extents;
1642                 u64 new_size;
1643
1644                 /*
1645                  * See the explanation in btrfs_merge_extent_hook, the same
1646                  * applies here, just in reverse.
1647                  */
1648                 new_size = orig->end - split + 1;
1649                 num_extents = count_max_extents(new_size);
1650                 new_size = split - orig->start;
1651                 num_extents += count_max_extents(new_size);
1652                 if (count_max_extents(size) >= num_extents)
1653                         return;
1654         }
1655
1656         spin_lock(&BTRFS_I(inode)->lock);
1657         btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1658         spin_unlock(&BTRFS_I(inode)->lock);
1659 }
1660
1661 /*
1662  * extent_io.c merge_extent_hook, used to track merged delayed allocation
1663  * extents so we can keep track of new extents that are just merged onto old
1664  * extents, such as when we are doing sequential writes, so we can properly
1665  * account for the metadata space we'll need.
1666  */
1667 static void btrfs_merge_extent_hook(void *private_data,
1668                                     struct extent_state *new,
1669                                     struct extent_state *other)
1670 {
1671         struct inode *inode = private_data;
1672         u64 new_size, old_size;
1673         u32 num_extents;
1674
1675         /* not delalloc, ignore it */
1676         if (!(other->state & EXTENT_DELALLOC))
1677                 return;
1678
1679         if (new->start > other->start)
1680                 new_size = new->end - other->start + 1;
1681         else
1682                 new_size = other->end - new->start + 1;
1683
1684         /* we're not bigger than the max, unreserve the space and go */
1685         if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1686                 spin_lock(&BTRFS_I(inode)->lock);
1687                 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1688                 spin_unlock(&BTRFS_I(inode)->lock);
1689                 return;
1690         }
1691
1692         /*
1693          * We have to add up either side to figure out how many extents were
1694          * accounted for before we merged into one big extent.  If the number of
1695          * extents we accounted for is <= the amount we need for the new range
1696          * then we can return, otherwise drop.  Think of it like this
1697          *
1698          * [ 4k][MAX_SIZE]
1699          *
1700          * So we've grown the extent by a MAX_SIZE extent, this would mean we
1701          * need 2 outstanding extents, on one side we have 1 and the other side
1702          * we have 1 so they are == and we can return.  But in this case
1703          *
1704          * [MAX_SIZE+4k][MAX_SIZE+4k]
1705          *
1706          * Each range on their own accounts for 2 extents, but merged together
1707          * they are only 3 extents worth of accounting, so we need to drop in
1708          * this case.
1709          */
1710         old_size = other->end - other->start + 1;
1711         num_extents = count_max_extents(old_size);
1712         old_size = new->end - new->start + 1;
1713         num_extents += count_max_extents(old_size);
1714         if (count_max_extents(new_size) >= num_extents)
1715                 return;
1716
1717         spin_lock(&BTRFS_I(inode)->lock);
1718         btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1719         spin_unlock(&BTRFS_I(inode)->lock);
1720 }
1721
1722 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1723                                       struct inode *inode)
1724 {
1725         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1726
1727         spin_lock(&root->delalloc_lock);
1728         if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1729                 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1730                               &root->delalloc_inodes);
1731                 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1732                         &BTRFS_I(inode)->runtime_flags);
1733                 root->nr_delalloc_inodes++;
1734                 if (root->nr_delalloc_inodes == 1) {
1735                         spin_lock(&fs_info->delalloc_root_lock);
1736                         BUG_ON(!list_empty(&root->delalloc_root));
1737                         list_add_tail(&root->delalloc_root,
1738                                       &fs_info->delalloc_roots);
1739                         spin_unlock(&fs_info->delalloc_root_lock);
1740                 }
1741         }
1742         spin_unlock(&root->delalloc_lock);
1743 }
1744
1745 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1746                                      struct btrfs_inode *inode)
1747 {
1748         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1749
1750         spin_lock(&root->delalloc_lock);
1751         if (!list_empty(&inode->delalloc_inodes)) {
1752                 list_del_init(&inode->delalloc_inodes);
1753                 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1754                           &inode->runtime_flags);
1755                 root->nr_delalloc_inodes--;
1756                 if (!root->nr_delalloc_inodes) {
1757                         spin_lock(&fs_info->delalloc_root_lock);
1758                         BUG_ON(list_empty(&root->delalloc_root));
1759                         list_del_init(&root->delalloc_root);
1760                         spin_unlock(&fs_info->delalloc_root_lock);
1761                 }
1762         }
1763         spin_unlock(&root->delalloc_lock);
1764 }
1765
1766 /*
1767  * extent_io.c set_bit_hook, used to track delayed allocation
1768  * bytes in this file, and to maintain the list of inodes that
1769  * have pending delalloc work to be done.
1770  */
1771 static void btrfs_set_bit_hook(void *private_data,
1772                                struct extent_state *state, unsigned *bits)
1773 {
1774         struct inode *inode = private_data;
1775
1776         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1777
1778         if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1779                 WARN_ON(1);
1780         /*
1781          * set_bit and clear bit hooks normally require _irqsave/restore
1782          * but in this case, we are only testing for the DELALLOC
1783          * bit, which is only set or cleared with irqs on
1784          */
1785         if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1786                 struct btrfs_root *root = BTRFS_I(inode)->root;
1787                 u64 len = state->end + 1 - state->start;
1788                 u32 num_extents = count_max_extents(len);
1789                 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1790
1791                 spin_lock(&BTRFS_I(inode)->lock);
1792                 btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
1793                 spin_unlock(&BTRFS_I(inode)->lock);
1794
1795                 /* For sanity tests */
1796                 if (btrfs_is_testing(fs_info))
1797                         return;
1798
1799                 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1800                                          fs_info->delalloc_batch);
1801                 spin_lock(&BTRFS_I(inode)->lock);
1802                 BTRFS_I(inode)->delalloc_bytes += len;
1803                 if (*bits & EXTENT_DEFRAG)
1804                         BTRFS_I(inode)->defrag_bytes += len;
1805                 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1806                                          &BTRFS_I(inode)->runtime_flags))
1807                         btrfs_add_delalloc_inodes(root, inode);
1808                 spin_unlock(&BTRFS_I(inode)->lock);
1809         }
1810
1811         if (!(state->state & EXTENT_DELALLOC_NEW) &&
1812             (*bits & EXTENT_DELALLOC_NEW)) {
1813                 spin_lock(&BTRFS_I(inode)->lock);
1814                 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1815                         state->start;
1816                 spin_unlock(&BTRFS_I(inode)->lock);
1817         }
1818 }
1819
1820 /*
1821  * extent_io.c clear_bit_hook, see set_bit_hook for why
1822  */
1823 static void btrfs_clear_bit_hook(void *private_data,
1824                                  struct extent_state *state,
1825                                  unsigned *bits)
1826 {
1827         struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
1828         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1829         u64 len = state->end + 1 - state->start;
1830         u32 num_extents = count_max_extents(len);
1831
1832         if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1833                 spin_lock(&inode->lock);
1834                 inode->defrag_bytes -= len;
1835                 spin_unlock(&inode->lock);
1836         }
1837
1838         /*
1839          * set_bit and clear bit hooks normally require _irqsave/restore
1840          * but in this case, we are only testing for the DELALLOC
1841          * bit, which is only set or cleared with irqs on
1842          */
1843         if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1844                 struct btrfs_root *root = inode->root;
1845                 bool do_list = !btrfs_is_free_space_inode(inode);
1846
1847                 spin_lock(&inode->lock);
1848                 btrfs_mod_outstanding_extents(inode, -num_extents);
1849                 spin_unlock(&inode->lock);
1850
1851                 /*
1852                  * We don't reserve metadata space for space cache inodes so we
1853                  * don't need to call dellalloc_release_metadata if there is an
1854                  * error.
1855                  */
1856                 if (*bits & EXTENT_CLEAR_META_RESV &&
1857                     root != fs_info->tree_root)
1858                         btrfs_delalloc_release_metadata(inode, len, false);
1859
1860                 /* For sanity tests. */
1861                 if (btrfs_is_testing(fs_info))
1862                         return;
1863
1864                 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1865                     do_list && !(state->state & EXTENT_NORESERVE) &&
1866                     (*bits & EXTENT_CLEAR_DATA_RESV))
1867                         btrfs_free_reserved_data_space_noquota(
1868                                         &inode->vfs_inode,
1869                                         state->start, len);
1870
1871                 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1872                                          fs_info->delalloc_batch);
1873                 spin_lock(&inode->lock);
1874                 inode->delalloc_bytes -= len;
1875                 if (do_list && inode->delalloc_bytes == 0 &&
1876                     test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1877                                         &inode->runtime_flags))
1878                         btrfs_del_delalloc_inode(root, inode);
1879                 spin_unlock(&inode->lock);
1880         }
1881
1882         if ((state->state & EXTENT_DELALLOC_NEW) &&
1883             (*bits & EXTENT_DELALLOC_NEW)) {
1884                 spin_lock(&inode->lock);
1885                 ASSERT(inode->new_delalloc_bytes >= len);
1886                 inode->new_delalloc_bytes -= len;
1887                 spin_unlock(&inode->lock);
1888         }
1889 }
1890
1891 /*
1892  * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1893  * we don't create bios that span stripes or chunks
1894  *
1895  * return 1 if page cannot be merged to bio
1896  * return 0 if page can be merged to bio
1897  * return error otherwise
1898  */
1899 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1900                          size_t size, struct bio *bio,
1901                          unsigned long bio_flags)
1902 {
1903         struct inode *inode = page->mapping->host;
1904         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1905         u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1906         u64 length = 0;
1907         u64 map_length;
1908         int ret;
1909
1910         if (bio_flags & EXTENT_BIO_COMPRESSED)
1911                 return 0;
1912
1913         length = bio->bi_iter.bi_size;
1914         map_length = length;
1915         ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1916                               NULL, 0);
1917         if (ret < 0)
1918                 return ret;
1919         if (map_length < length + size)
1920                 return 1;
1921         return 0;
1922 }
1923
1924 /*
1925  * in order to insert checksums into the metadata in large chunks,
1926  * we wait until bio submission time.   All the pages in the bio are
1927  * checksummed and sums are attached onto the ordered extent record.
1928  *
1929  * At IO completion time the cums attached on the ordered extent record
1930  * are inserted into the btree
1931  */
1932 static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
1933                                     u64 bio_offset)
1934 {
1935         struct inode *inode = private_data;
1936         blk_status_t ret = 0;
1937
1938         ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1939         BUG_ON(ret); /* -ENOMEM */
1940         return 0;
1941 }
1942
1943 /*
1944  * in order to insert checksums into the metadata in large chunks,
1945  * we wait until bio submission time.   All the pages in the bio are
1946  * checksummed and sums are attached onto the ordered extent record.
1947  *
1948  * At IO completion time the cums attached on the ordered extent record
1949  * are inserted into the btree
1950  */
1951 static blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
1952                           int mirror_num)
1953 {
1954         struct inode *inode = private_data;
1955         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1956         blk_status_t ret;
1957
1958         ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1959         if (ret) {
1960                 bio->bi_status = ret;
1961                 bio_endio(bio);
1962         }
1963         return ret;
1964 }
1965
1966 /*
1967  * extent_io.c submission hook. This does the right thing for csum calculation
1968  * on write, or reading the csums from the tree before a read.
1969  *
1970  * Rules about async/sync submit,
1971  * a) read:                             sync submit
1972  *
1973  * b) write without checksum:           sync submit
1974  *
1975  * c) write with checksum:
1976  *    c-1) if bio is issued by fsync:   sync submit
1977  *         (sync_writers != 0)
1978  *
1979  *    c-2) if root is reloc root:       sync submit
1980  *         (only in case of buffered IO)
1981  *
1982  *    c-3) otherwise:                   async submit
1983  */
1984 static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1985                                  int mirror_num, unsigned long bio_flags,
1986                                  u64 bio_offset)
1987 {
1988         struct inode *inode = private_data;
1989         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1990         struct btrfs_root *root = BTRFS_I(inode)->root;
1991         enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1992         blk_status_t ret = 0;
1993         int skip_sum;
1994         int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1995
1996         skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1997
1998         if (btrfs_is_free_space_inode(BTRFS_I(inode)))
1999                 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
2000
2001         if (bio_op(bio) != REQ_OP_WRITE) {
2002                 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
2003                 if (ret)
2004                         goto out;
2005
2006                 if (bio_flags & EXTENT_BIO_COMPRESSED) {
2007                         ret = btrfs_submit_compressed_read(inode, bio,
2008                                                            mirror_num,
2009                                                            bio_flags);
2010                         goto out;
2011                 } else if (!skip_sum) {
2012                         ret = btrfs_lookup_bio_sums(inode, bio, NULL);
2013                         if (ret)
2014                                 goto out;
2015                 }
2016                 goto mapit;
2017         } else if (async && !skip_sum) {
2018                 /* csum items have already been cloned */
2019                 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2020                         goto mapit;
2021                 /* we're doing a write, do the async checksumming */
2022                 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
2023                                           bio_offset, inode,
2024                                           btrfs_submit_bio_start,
2025                                           btrfs_submit_bio_done);
2026                 goto out;
2027         } else if (!skip_sum) {
2028                 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2029                 if (ret)
2030                         goto out;
2031         }
2032
2033 mapit:
2034         ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
2035
2036 out:
2037         if (ret) {
2038                 bio->bi_status = ret;
2039                 bio_endio(bio);
2040         }
2041         return ret;
2042 }
2043
2044 /*
2045  * given a list of ordered sums record them in the inode.  This happens
2046  * at IO completion time based on sums calculated at bio submission time.
2047  */
2048 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2049                              struct inode *inode, struct list_head *list)
2050 {
2051         struct btrfs_ordered_sum *sum;
2052         int ret;
2053
2054         list_for_each_entry(sum, list, list) {
2055                 trans->adding_csums = true;
2056                 ret = btrfs_csum_file_blocks(trans,
2057                        BTRFS_I(inode)->root->fs_info->csum_root, sum);
2058                 trans->adding_csums = false;
2059                 if (ret)
2060                         return ret;
2061         }
2062         return 0;
2063 }
2064
2065 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2066                               unsigned int extra_bits,
2067                               struct extent_state **cached_state, int dedupe)
2068 {
2069         WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2070         return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2071                                    extra_bits, cached_state);
2072 }
2073
2074 /* see btrfs_writepage_start_hook for details on why this is required */
2075 struct btrfs_writepage_fixup {
2076         struct page *page;
2077         struct btrfs_work work;
2078 };
2079
2080 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2081 {
2082         struct btrfs_writepage_fixup *fixup;
2083         struct btrfs_ordered_extent *ordered;
2084         struct extent_state *cached_state = NULL;
2085         struct extent_changeset *data_reserved = NULL;
2086         struct page *page;
2087         struct inode *inode;
2088         u64 page_start;
2089         u64 page_end;
2090         int ret;
2091
2092         fixup = container_of(work, struct btrfs_writepage_fixup, work);
2093         page = fixup->page;
2094 again:
2095         lock_page(page);
2096         if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2097                 ClearPageChecked(page);
2098                 goto out_page;
2099         }
2100
2101         inode = page->mapping->host;
2102         page_start = page_offset(page);
2103         page_end = page_offset(page) + PAGE_SIZE - 1;
2104
2105         lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2106                          &cached_state);
2107
2108         /* already ordered? We're done */
2109         if (PagePrivate2(page))
2110                 goto out;
2111
2112         ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2113                                         PAGE_SIZE);
2114         if (ordered) {
2115                 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2116                                      page_end, &cached_state);
2117                 unlock_page(page);
2118                 btrfs_start_ordered_extent(inode, ordered, 1);
2119                 btrfs_put_ordered_extent(ordered);
2120                 goto again;
2121         }
2122
2123         ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2124                                            PAGE_SIZE);
2125         if (ret) {
2126                 mapping_set_error(page->mapping, ret);
2127                 end_extent_writepage(page, ret, page_start, page_end);
2128                 ClearPageChecked(page);
2129                 goto out;
2130          }
2131
2132         ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
2133                                         &cached_state, 0);
2134         if (ret) {
2135                 mapping_set_error(page->mapping, ret);
2136                 end_extent_writepage(page, ret, page_start, page_end);
2137                 ClearPageChecked(page);
2138                 goto out;
2139         }
2140
2141         ClearPageChecked(page);
2142         set_page_dirty(page);
2143         btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, false);
2144 out:
2145         unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2146                              &cached_state);
2147 out_page:
2148         unlock_page(page);
2149         put_page(page);
2150         kfree(fixup);
2151         extent_changeset_free(data_reserved);
2152 }
2153
2154 /*
2155  * There are a few paths in the higher layers of the kernel that directly
2156  * set the page dirty bit without asking the filesystem if it is a
2157  * good idea.  This causes problems because we want to make sure COW
2158  * properly happens and the data=ordered rules are followed.
2159  *
2160  * In our case any range that doesn't have the ORDERED bit set
2161  * hasn't been properly setup for IO.  We kick off an async process
2162  * to fix it up.  The async helper will wait for ordered extents, set
2163  * the delalloc bit and make it safe to write the page.
2164  */
2165 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2166 {
2167         struct inode *inode = page->mapping->host;
2168         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2169         struct btrfs_writepage_fixup *fixup;
2170
2171         /* this page is properly in the ordered list */
2172         if (TestClearPagePrivate2(page))
2173                 return 0;
2174
2175         if (PageChecked(page))
2176                 return -EAGAIN;
2177
2178         fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2179         if (!fixup)
2180                 return -EAGAIN;
2181
2182         SetPageChecked(page);
2183         get_page(page);
2184         btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2185                         btrfs_writepage_fixup_worker, NULL, NULL);
2186         fixup->page = page;
2187         btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2188         return -EBUSY;
2189 }
2190
2191 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2192                                        struct inode *inode, u64 file_pos,
2193                                        u64 disk_bytenr, u64 disk_num_bytes,
2194                                        u64 num_bytes, u64 ram_bytes,
2195                                        u8 compression, u8 encryption,
2196                                        u16 other_encoding, int extent_type)
2197 {
2198         struct btrfs_root *root = BTRFS_I(inode)->root;
2199         struct btrfs_file_extent_item *fi;
2200         struct btrfs_path *path;
2201         struct extent_buffer *leaf;
2202         struct btrfs_key ins;
2203         u64 qg_released;
2204         int extent_inserted = 0;
2205         int ret;
2206
2207         path = btrfs_alloc_path();
2208         if (!path)
2209                 return -ENOMEM;
2210
2211         /*
2212          * we may be replacing one extent in the tree with another.
2213          * The new extent is pinned in the extent map, and we don't want
2214          * to drop it from the cache until it is completely in the btree.
2215          *
2216          * So, tell btrfs_drop_extents to leave this extent in the cache.
2217          * the caller is expected to unpin it and allow it to be merged
2218          * with the others.
2219          */
2220         ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2221                                    file_pos + num_bytes, NULL, 0,
2222                                    1, sizeof(*fi), &extent_inserted);
2223         if (ret)
2224                 goto out;
2225
2226         if (!extent_inserted) {
2227                 ins.objectid = btrfs_ino(BTRFS_I(inode));
2228                 ins.offset = file_pos;
2229                 ins.type = BTRFS_EXTENT_DATA_KEY;
2230
2231                 path->leave_spinning = 1;
2232                 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2233                                               sizeof(*fi));
2234                 if (ret)
2235                         goto out;
2236         }
2237         leaf = path->nodes[0];
2238         fi = btrfs_item_ptr(leaf, path->slots[0],
2239                             struct btrfs_file_extent_item);
2240         btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2241         btrfs_set_file_extent_type(leaf, fi, extent_type);
2242         btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2243         btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2244         btrfs_set_file_extent_offset(leaf, fi, 0);
2245         btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2246         btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2247         btrfs_set_file_extent_compression(leaf, fi, compression);
2248         btrfs_set_file_extent_encryption(leaf, fi, encryption);
2249         btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2250
2251         btrfs_mark_buffer_dirty(leaf);
2252         btrfs_release_path(path);
2253
2254         inode_add_bytes(inode, num_bytes);
2255
2256         ins.objectid = disk_bytenr;
2257         ins.offset = disk_num_bytes;
2258         ins.type = BTRFS_EXTENT_ITEM_KEY;
2259
2260         /*
2261          * Release the reserved range from inode dirty range map, as it is
2262          * already moved into delayed_ref_head
2263          */
2264         ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2265         if (ret < 0)
2266                 goto out;
2267         qg_released = ret;
2268         ret = btrfs_alloc_reserved_file_extent(trans, root,
2269                                                btrfs_ino(BTRFS_I(inode)),
2270                                                file_pos, qg_released, &ins);
2271 out:
2272         btrfs_free_path(path);
2273
2274         return ret;
2275 }
2276
2277 /* snapshot-aware defrag */
2278 struct sa_defrag_extent_backref {
2279         struct rb_node node;
2280         struct old_sa_defrag_extent *old;
2281         u64 root_id;
2282         u64 inum;
2283         u64 file_pos;
2284         u64 extent_offset;
2285         u64 num_bytes;
2286         u64 generation;
2287 };
2288
2289 struct old_sa_defrag_extent {
2290         struct list_head list;
2291         struct new_sa_defrag_extent *new;
2292
2293         u64 extent_offset;
2294         u64 bytenr;
2295         u64 offset;
2296         u64 len;
2297         int count;
2298 };
2299
2300 struct new_sa_defrag_extent {
2301         struct rb_root root;
2302         struct list_head head;
2303         struct btrfs_path *path;
2304         struct inode *inode;
2305         u64 file_pos;
2306         u64 len;
2307         u64 bytenr;
2308         u64 disk_len;
2309         u8 compress_type;
2310 };
2311
2312 static int backref_comp(struct sa_defrag_extent_backref *b1,
2313                         struct sa_defrag_extent_backref *b2)
2314 {
2315         if (b1->root_id < b2->root_id)
2316                 return -1;
2317         else if (b1->root_id > b2->root_id)
2318                 return 1;
2319
2320         if (b1->inum < b2->inum)
2321                 return -1;
2322         else if (b1->inum > b2->inum)
2323                 return 1;
2324
2325         if (b1->file_pos < b2->file_pos)
2326                 return -1;
2327         else if (b1->file_pos > b2->file_pos)
2328                 return 1;
2329
2330         /*
2331          * [------------------------------] ===> (a range of space)
2332          *     |<--->|   |<---->| =============> (fs/file tree A)
2333          * |<---------------------------->| ===> (fs/file tree B)
2334          *
2335          * A range of space can refer to two file extents in one tree while
2336          * refer to only one file extent in another tree.
2337          *
2338          * So we may process a disk offset more than one time(two extents in A)
2339          * and locate at the same extent(one extent in B), then insert two same
2340          * backrefs(both refer to the extent in B).
2341          */
2342         return 0;
2343 }
2344
2345 static void backref_insert(struct rb_root *root,
2346                            struct sa_defrag_extent_backref *backref)
2347 {
2348         struct rb_node **p = &root->rb_node;
2349         struct rb_node *parent = NULL;
2350         struct sa_defrag_extent_backref *entry;
2351         int ret;
2352
2353         while (*p) {
2354                 parent = *p;
2355                 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2356
2357                 ret = backref_comp(backref, entry);
2358                 if (ret < 0)
2359                         p = &(*p)->rb_left;
2360                 else
2361                         p = &(*p)->rb_right;
2362         }
2363
2364         rb_link_node(&backref->node, parent, p);
2365         rb_insert_color(&backref->node, root);
2366 }
2367
2368 /*
2369  * Note the backref might has changed, and in this case we just return 0.
2370  */
2371 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2372                                        void *ctx)
2373 {
2374         struct btrfs_file_extent_item *extent;
2375         struct old_sa_defrag_extent *old = ctx;
2376         struct new_sa_defrag_extent *new = old->new;
2377         struct btrfs_path *path = new->path;
2378         struct btrfs_key key;
2379         struct btrfs_root *root;
2380         struct sa_defrag_extent_backref *backref;
2381         struct extent_buffer *leaf;
2382         struct inode *inode = new->inode;
2383         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2384         int slot;
2385         int ret;
2386         u64 extent_offset;
2387         u64 num_bytes;
2388
2389         if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2390             inum == btrfs_ino(BTRFS_I(inode)))
2391                 return 0;
2392
2393         key.objectid = root_id;
2394         key.type = BTRFS_ROOT_ITEM_KEY;
2395         key.offset = (u64)-1;
2396
2397         root = btrfs_read_fs_root_no_name(fs_info, &key);
2398         if (IS_ERR(root)) {
2399                 if (PTR_ERR(root) == -ENOENT)
2400                         return 0;
2401                 WARN_ON(1);
2402                 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2403                          inum, offset, root_id);
2404                 return PTR_ERR(root);
2405         }
2406
2407         key.objectid = inum;
2408         key.type = BTRFS_EXTENT_DATA_KEY;
2409         if (offset > (u64)-1 << 32)
2410                 key.offset = 0;
2411         else
2412                 key.offset = offset;
2413
2414         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2415         if (WARN_ON(ret < 0))
2416                 return ret;
2417         ret = 0;
2418
2419         while (1) {
2420                 cond_resched();
2421
2422                 leaf = path->nodes[0];
2423                 slot = path->slots[0];
2424
2425                 if (slot >= btrfs_header_nritems(leaf)) {
2426                         ret = btrfs_next_leaf(root, path);
2427                         if (ret < 0) {
2428                                 goto out;
2429                         } else if (ret > 0) {
2430                                 ret = 0;
2431                                 goto out;
2432                         }
2433                         continue;
2434                 }
2435
2436                 path->slots[0]++;
2437
2438                 btrfs_item_key_to_cpu(leaf, &key, slot);
2439
2440                 if (key.objectid > inum)
2441                         goto out;
2442
2443                 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2444                         continue;
2445
2446                 extent = btrfs_item_ptr(leaf, slot,
2447                                         struct btrfs_file_extent_item);
2448
2449                 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2450                         continue;
2451
2452                 /*
2453                  * 'offset' refers to the exact key.offset,
2454                  * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2455                  * (key.offset - extent_offset).
2456                  */
2457                 if (key.offset != offset)
2458                         continue;
2459
2460                 extent_offset = btrfs_file_extent_offset(leaf, extent);
2461                 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2462
2463                 if (extent_offset >= old->extent_offset + old->offset +
2464                     old->len || extent_offset + num_bytes <=
2465                     old->extent_offset + old->offset)
2466                         continue;
2467                 break;
2468         }
2469
2470         backref = kmalloc(sizeof(*backref), GFP_NOFS);
2471         if (!backref) {
2472                 ret = -ENOENT;
2473                 goto out;
2474         }
2475
2476         backref->root_id = root_id;
2477         backref->inum = inum;
2478         backref->file_pos = offset;
2479         backref->num_bytes = num_bytes;
2480         backref->extent_offset = extent_offset;
2481         backref->generation = btrfs_file_extent_generation(leaf, extent);
2482         backref->old = old;
2483         backref_insert(&new->root, backref);
2484         old->count++;
2485 out:
2486         btrfs_release_path(path);
2487         WARN_ON(ret);
2488         return ret;
2489 }
2490
2491 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2492                                    struct new_sa_defrag_extent *new)
2493 {
2494         struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2495         struct old_sa_defrag_extent *old, *tmp;
2496         int ret;
2497
2498         new->path = path;
2499
2500         list_for_each_entry_safe(old, tmp, &new->head, list) {
2501                 ret = iterate_inodes_from_logical(old->bytenr +
2502                                                   old->extent_offset, fs_info,
2503                                                   path, record_one_backref,
2504                                                   old, false);
2505                 if (ret < 0 && ret != -ENOENT)
2506                         return false;
2507
2508                 /* no backref to be processed for this extent */
2509                 if (!old->count) {
2510                         list_del(&old->list);
2511                         kfree(old);
2512                 }
2513         }
2514
2515         if (list_empty(&new->head))
2516                 return false;
2517
2518         return true;
2519 }
2520
2521 static int relink_is_mergable(struct extent_buffer *leaf,
2522                               struct btrfs_file_extent_item *fi,
2523                               struct new_sa_defrag_extent *new)
2524 {
2525         if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2526                 return 0;
2527
2528         if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2529                 return 0;
2530
2531         if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2532                 return 0;
2533
2534         if (btrfs_file_extent_encryption(leaf, fi) ||
2535             btrfs_file_extent_other_encoding(leaf, fi))
2536                 return 0;
2537
2538         return 1;
2539 }
2540
2541 /*
2542  * Note the backref might has changed, and in this case we just return 0.
2543  */
2544 static noinline int relink_extent_backref(struct btrfs_path *path,
2545                                  struct sa_defrag_extent_backref *prev,
2546                                  struct sa_defrag_extent_backref *backref)
2547 {
2548         struct btrfs_file_extent_item *extent;
2549         struct btrfs_file_extent_item *item;
2550         struct btrfs_ordered_extent *ordered;
2551         struct btrfs_trans_handle *trans;
2552         struct btrfs_root *root;
2553         struct btrfs_key key;
2554         struct extent_buffer *leaf;
2555         struct old_sa_defrag_extent *old = backref->old;
2556         struct new_sa_defrag_extent *new = old->new;
2557         struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2558         struct inode *inode;
2559         struct extent_state *cached = NULL;
2560         int ret = 0;
2561         u64 start;
2562         u64 len;
2563         u64 lock_start;
2564         u64 lock_end;
2565         bool merge = false;
2566         int index;
2567
2568         if (prev && prev->root_id == backref->root_id &&
2569             prev->inum == backref->inum &&
2570             prev->file_pos + prev->num_bytes == backref->file_pos)
2571                 merge = true;
2572
2573         /* step 1: get root */
2574         key.objectid = backref->root_id;
2575         key.type = BTRFS_ROOT_ITEM_KEY;
2576         key.offset = (u64)-1;
2577
2578         index = srcu_read_lock(&fs_info->subvol_srcu);
2579
2580         root = btrfs_read_fs_root_no_name(fs_info, &key);
2581         if (IS_ERR(root)) {
2582                 srcu_read_unlock(&fs_info->subvol_srcu, index);
2583                 if (PTR_ERR(root) == -ENOENT)
2584                         return 0;
2585                 return PTR_ERR(root);
2586         }
2587
2588         if (btrfs_root_readonly(root)) {
2589                 srcu_read_unlock(&fs_info->subvol_srcu, index);
2590                 return 0;
2591         }
2592
2593         /* step 2: get inode */
2594         key.objectid = backref->inum;
2595         key.type = BTRFS_INODE_ITEM_KEY;
2596         key.offset = 0;
2597
2598         inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2599         if (IS_ERR(inode)) {
2600                 srcu_read_unlock(&fs_info->subvol_srcu, index);
2601                 return 0;
2602         }
2603
2604         srcu_read_unlock(&fs_info->subvol_srcu, index);
2605
2606         /* step 3: relink backref */
2607         lock_start = backref->file_pos;
2608         lock_end = backref->file_pos + backref->num_bytes - 1;
2609         lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2610                          &cached);
2611
2612         ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2613         if (ordered) {
2614                 btrfs_put_ordered_extent(ordered);
2615                 goto out_unlock;
2616         }
2617
2618         trans = btrfs_join_transaction(root);
2619         if (IS_ERR(trans)) {
2620                 ret = PTR_ERR(trans);
2621                 goto out_unlock;
2622         }
2623
2624         key.objectid = backref->inum;
2625         key.type = BTRFS_EXTENT_DATA_KEY;
2626         key.offset = backref->file_pos;
2627
2628         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2629         if (ret < 0) {
2630                 goto out_free_path;
2631         } else if (ret > 0) {
2632                 ret = 0;
2633                 goto out_free_path;
2634         }
2635
2636         extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2637                                 struct btrfs_file_extent_item);
2638
2639         if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2640             backref->generation)
2641                 goto out_free_path;
2642
2643         btrfs_release_path(path);
2644
2645         start = backref->file_pos;
2646         if (backref->extent_offset < old->extent_offset + old->offset)
2647                 start += old->extent_offset + old->offset -
2648                          backref->extent_offset;
2649
2650         len = min(backref->extent_offset + backref->num_bytes,
2651                   old->extent_offset + old->offset + old->len);
2652         len -= max(backref->extent_offset, old->extent_offset + old->offset);
2653
2654         ret = btrfs_drop_extents(trans, root, inode, start,
2655                                  start + len, 1);
2656         if (ret)
2657                 goto out_free_path;
2658 again:
2659         key.objectid = btrfs_ino(BTRFS_I(inode));
2660         key.type = BTRFS_EXTENT_DATA_KEY;
2661         key.offset = start;
2662
2663         path->leave_spinning = 1;
2664         if (merge) {
2665                 struct btrfs_file_extent_item *fi;
2666                 u64 extent_len;
2667                 struct btrfs_key found_key;
2668
2669                 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2670                 if (ret < 0)
2671                         goto out_free_path;
2672
2673                 path->slots[0]--;
2674                 leaf = path->nodes[0];
2675                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2676
2677                 fi = btrfs_item_ptr(leaf, path->slots[0],
2678                                     struct btrfs_file_extent_item);
2679                 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2680
2681                 if (extent_len + found_key.offset == start &&
2682                     relink_is_mergable(leaf, fi, new)) {
2683                         btrfs_set_file_extent_num_bytes(leaf, fi,
2684                                                         extent_len + len);
2685                         btrfs_mark_buffer_dirty(leaf);
2686                         inode_add_bytes(inode, len);
2687
2688                         ret = 1;
2689                         goto out_free_path;
2690                 } else {
2691                         merge = false;
2692                         btrfs_release_path(path);
2693                         goto again;
2694                 }
2695         }
2696
2697         ret = btrfs_insert_empty_item(trans, root, path, &key,
2698                                         sizeof(*extent));
2699         if (ret) {
2700                 btrfs_abort_transaction(trans, ret);
2701                 goto out_free_path;
2702         }
2703
2704         leaf = path->nodes[0];
2705         item = btrfs_item_ptr(leaf, path->slots[0],
2706                                 struct btrfs_file_extent_item);
2707         btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2708         btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2709         btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2710         btrfs_set_file_extent_num_bytes(leaf, item, len);
2711         btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2712         btrfs_set_file_extent_generation(leaf, item, trans->transid);
2713         btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2714         btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2715         btrfs_set_file_extent_encryption(leaf, item, 0);
2716         btrfs_set_file_extent_other_encoding(leaf, item, 0);
2717
2718         btrfs_mark_buffer_dirty(leaf);
2719         inode_add_bytes(inode, len);
2720         btrfs_release_path(path);
2721
2722         ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2723                         new->disk_len, 0,
2724                         backref->root_id, backref->inum,
2725                         new->file_pos); /* start - extent_offset */
2726         if (ret) {
2727                 btrfs_abort_transaction(trans, ret);
2728                 goto out_free_path;
2729         }
2730
2731         ret = 1;
2732 out_free_path:
2733         btrfs_release_path(path);
2734         path->leave_spinning = 0;
2735         btrfs_end_transaction(trans);
2736 out_unlock:
2737         unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2738                              &cached);
2739         iput(inode);
2740         return ret;
2741 }
2742
2743 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2744 {
2745         struct old_sa_defrag_extent *old, *tmp;
2746
2747         if (!new)
2748                 return;
2749
2750         list_for_each_entry_safe(old, tmp, &new->head, list) {
2751                 kfree(old);
2752         }
2753         kfree(new);
2754 }
2755
2756 static void relink_file_extents(struct new_sa_defrag_extent *new)
2757 {
2758         struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2759         struct btrfs_path *path;
2760         struct sa_defrag_extent_backref *backref;
2761         struct sa_defrag_extent_backref *prev = NULL;
2762         struct inode *inode;
2763         struct rb_node *node;
2764         int ret;
2765
2766         inode = new->inode;
2767
2768         path = btrfs_alloc_path();
2769         if (!path)
2770                 return;
2771
2772         if (!record_extent_backrefs(path, new)) {
2773                 btrfs_free_path(path);
2774                 goto out;
2775         }
2776         btrfs_release_path(path);
2777
2778         while (1) {
2779                 node = rb_first(&new->root);
2780                 if (!node)
2781                         break;
2782                 rb_erase(node, &new->root);
2783
2784                 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2785
2786                 ret = relink_extent_backref(path, prev, backref);
2787                 WARN_ON(ret < 0);
2788
2789                 kfree(prev);
2790
2791                 if (ret == 1)
2792                         prev = backref;
2793                 else
2794                         prev = NULL;
2795                 cond_resched();
2796         }
2797         kfree(prev);
2798
2799         btrfs_free_path(path);
2800 out:
2801         free_sa_defrag_extent(new);
2802
2803         atomic_dec(&fs_info->defrag_running);
2804         wake_up(&fs_info->transaction_wait);
2805 }
2806
2807 static struct new_sa_defrag_extent *
2808 record_old_file_extents(struct inode *inode,
2809                         struct btrfs_ordered_extent *ordered)
2810 {
2811         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2812         struct btrfs_root *root = BTRFS_I(inode)->root;
2813         struct btrfs_path *path;
2814         struct btrfs_key key;
2815         struct old_sa_defrag_extent *old;
2816         struct new_sa_defrag_extent *new;
2817         int ret;
2818
2819         new = kmalloc(sizeof(*new), GFP_NOFS);
2820         if (!new)
2821                 return NULL;
2822
2823         new->inode = inode;
2824         new->file_pos = ordered->file_offset;
2825         new->len = ordered->len;
2826         new->bytenr = ordered->start;
2827         new->disk_len = ordered->disk_len;
2828         new->compress_type = ordered->compress_type;
2829         new->root = RB_ROOT;
2830         INIT_LIST_HEAD(&new->head);
2831
2832         path = btrfs_alloc_path();
2833         if (!path)
2834                 goto out_kfree;
2835
2836         key.objectid = btrfs_ino(BTRFS_I(inode));
2837         key.type = BTRFS_EXTENT_DATA_KEY;
2838         key.offset = new->file_pos;
2839
2840         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2841         if (ret < 0)
2842                 goto out_free_path;
2843         if (ret > 0 && path->slots[0] > 0)
2844                 path->slots[0]--;
2845
2846         /* find out all the old extents for the file range */
2847         while (1) {
2848                 struct btrfs_file_extent_item *extent;
2849                 struct extent_buffer *l;
2850                 int slot;
2851                 u64 num_bytes;
2852                 u64 offset;
2853                 u64 end;
2854                 u64 disk_bytenr;
2855                 u64 extent_offset;
2856
2857                 l = path->nodes[0];
2858                 slot = path->slots[0];
2859
2860                 if (slot >= btrfs_header_nritems(l)) {
2861                         ret = btrfs_next_leaf(root, path);
2862                         if (ret < 0)
2863                                 goto out_free_path;
2864                         else if (ret > 0)
2865                                 break;
2866                         continue;
2867                 }
2868
2869                 btrfs_item_key_to_cpu(l, &key, slot);
2870
2871                 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2872                         break;
2873                 if (key.type != BTRFS_EXTENT_DATA_KEY)
2874                         break;
2875                 if (key.offset >= new->file_pos + new->len)
2876                         break;
2877
2878                 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2879
2880                 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2881                 if (key.offset + num_bytes < new->file_pos)
2882                         goto next;
2883
2884                 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2885                 if (!disk_bytenr)
2886                         goto next;
2887
2888                 extent_offset = btrfs_file_extent_offset(l, extent);
2889
2890                 old = kmalloc(sizeof(*old), GFP_NOFS);
2891                 if (!old)
2892                         goto out_free_path;
2893
2894                 offset = max(new->file_pos, key.offset);
2895                 end = min(new->file_pos + new->len, key.offset + num_bytes);
2896
2897                 old->bytenr = disk_bytenr;
2898                 old->extent_offset = extent_offset;
2899                 old->offset = offset - key.offset;
2900                 old->len = end - offset;
2901                 old->new = new;
2902                 old->count = 0;
2903                 list_add_tail(&old->list, &new->head);
2904 next:
2905                 path->slots[0]++;
2906                 cond_resched();
2907         }
2908
2909         btrfs_free_path(path);
2910         atomic_inc(&fs_info->defrag_running);
2911
2912         return new;
2913
2914 out_free_path:
2915         btrfs_free_path(path);
2916 out_kfree:
2917         free_sa_defrag_extent(new);
2918         return NULL;
2919 }
2920
2921 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2922                                          u64 start, u64 len)
2923 {
2924         struct btrfs_block_group_cache *cache;
2925
2926         cache = btrfs_lookup_block_group(fs_info, start);
2927         ASSERT(cache);
2928
2929         spin_lock(&cache->lock);
2930         cache->delalloc_bytes -= len;
2931         spin_unlock(&cache->lock);
2932
2933         btrfs_put_block_group(cache);
2934 }
2935
2936 /* as ordered data IO finishes, this gets called so we can finish
2937  * an ordered extent if the range of bytes in the file it covers are
2938  * fully written.
2939  */
2940 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2941 {
2942         struct inode *inode = ordered_extent->inode;
2943         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2944         struct btrfs_root *root = BTRFS_I(inode)->root;
2945         struct btrfs_trans_handle *trans = NULL;
2946         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2947         struct extent_state *cached_state = NULL;
2948         struct new_sa_defrag_extent *new = NULL;
2949         int compress_type = 0;
2950         int ret = 0;
2951         u64 logical_len = ordered_extent->len;
2952         bool nolock;
2953         bool truncated = false;
2954         bool range_locked = false;
2955         bool clear_new_delalloc_bytes = false;
2956
2957         if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2958             !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2959             !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2960                 clear_new_delalloc_bytes = true;
2961
2962         nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2963
2964         if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2965                 ret = -EIO;
2966                 goto out;
2967         }
2968
2969         btrfs_free_io_failure_record(BTRFS_I(inode),
2970                         ordered_extent->file_offset,
2971                         ordered_extent->file_offset +
2972                         ordered_extent->len - 1);
2973
2974         if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2975                 truncated = true;
2976                 logical_len = ordered_extent->truncated_len;
2977                 /* Truncated the entire extent, don't bother adding */
2978                 if (!logical_len)
2979                         goto out;
2980         }
2981
2982         if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2983                 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2984
2985                 /*
2986                  * For mwrite(mmap + memset to write) case, we still reserve
2987                  * space for NOCOW range.
2988                  * As NOCOW won't cause a new delayed ref, just free the space
2989                  */
2990                 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
2991                                        ordered_extent->len);
2992                 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2993                 if (nolock)
2994                         trans = btrfs_join_transaction_nolock(root);
2995                 else
2996                         trans = btrfs_join_transaction(root);
2997                 if (IS_ERR(trans)) {
2998                         ret = PTR_ERR(trans);
2999                         trans = NULL;
3000                         goto out;
3001                 }
3002                 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3003                 ret = btrfs_update_inode_fallback(trans, root, inode);
3004                 if (ret) /* -ENOMEM or corruption */
3005                         btrfs_abort_transaction(trans, ret);
3006                 goto out;
3007         }
3008
3009         range_locked = true;
3010         lock_extent_bits(io_tree, ordered_extent->file_offset,
3011                          ordered_extent->file_offset + ordered_extent->len - 1,
3012                          &cached_state);
3013
3014         ret = test_range_bit(io_tree, ordered_extent->file_offset,
3015                         ordered_extent->file_offset + ordered_extent->len - 1,
3016                         EXTENT_DEFRAG, 0, cached_state);
3017         if (ret) {
3018                 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
3019                 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
3020                         /* the inode is shared */
3021                         new = record_old_file_extents(inode, ordered_extent);
3022
3023                 clear_extent_bit(io_tree, ordered_extent->file_offset,
3024                         ordered_extent->file_offset + ordered_extent->len - 1,
3025                         EXTENT_DEFRAG, 0, 0, &cached_state);
3026         }
3027
3028         if (nolock)
3029                 trans = btrfs_join_transaction_nolock(root);
3030         else
3031                 trans = btrfs_join_transaction(root);
3032         if (IS_ERR(trans)) {
3033                 ret = PTR_ERR(trans);
3034                 trans = NULL;
3035                 goto out;
3036         }
3037
3038         trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3039
3040         if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3041                 compress_type = ordered_extent->compress_type;
3042         if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3043                 BUG_ON(compress_type);
3044                 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3045                                        ordered_extent->len);
3046                 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
3047                                                 ordered_extent->file_offset,
3048                                                 ordered_extent->file_offset +
3049                                                 logical_len);
3050         } else {
3051                 BUG_ON(root == fs_info->tree_root);
3052                 ret = insert_reserved_file_extent(trans, inode,
3053                                                 ordered_extent->file_offset,
3054                                                 ordered_extent->start,
3055                                                 ordered_extent->disk_len,
3056                                                 logical_len, logical_len,
3057                                                 compress_type, 0, 0,
3058                                                 BTRFS_FILE_EXTENT_REG);
3059                 if (!ret)
3060                         btrfs_release_delalloc_bytes(fs_info,
3061                                                      ordered_extent->start,
3062                                                      ordered_extent->disk_len);
3063         }
3064         unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3065                            ordered_extent->file_offset, ordered_extent->len,
3066                            trans->transid);
3067         if (ret < 0) {
3068                 btrfs_abort_transaction(trans, ret);
3069                 goto out;
3070         }
3071
3072         ret = add_pending_csums(trans, inode, &ordered_extent->list);
3073         if (ret) {
3074                 btrfs_abort_transaction(trans, ret);
3075                 goto out;
3076         }
3077
3078         btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3079         ret = btrfs_update_inode_fallback(trans, root, inode);
3080         if (ret) { /* -ENOMEM or corruption */
3081                 btrfs_abort_transaction(trans, ret);
3082                 goto out;
3083         }
3084         ret = 0;
3085 out:
3086         if (range_locked || clear_new_delalloc_bytes) {
3087                 unsigned int clear_bits = 0;
3088
3089                 if (range_locked)
3090                         clear_bits |= EXTENT_LOCKED;
3091                 if (clear_new_delalloc_bytes)
3092                         clear_bits |= EXTENT_DELALLOC_NEW;
3093                 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3094                                  ordered_extent->file_offset,
3095                                  ordered_extent->file_offset +
3096                                  ordered_extent->len - 1,
3097                                  clear_bits,
3098                                  (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3099                                  0, &cached_state);
3100         }
3101
3102         if (trans)
3103                 btrfs_end_transaction(trans);
3104
3105         if (ret || truncated) {
3106                 u64 start, end;
3107
3108                 if (truncated)
3109                         start = ordered_extent->file_offset + logical_len;
3110                 else
3111                         start = ordered_extent->file_offset;
3112                 end = ordered_extent->file_offset + ordered_extent->len - 1;
3113                 clear_extent_uptodate(io_tree, start, end, NULL);
3114
3115                 /* Drop the cache for the part of the extent we didn't write. */
3116                 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3117
3118                 /*
3119                  * If the ordered extent had an IOERR or something else went
3120                  * wrong we need to return the space for this ordered extent
3121                  * back to the allocator.  We only free the extent in the
3122                  * truncated case if we didn't write out the extent at all.
3123                  */
3124                 if ((ret || !logical_len) &&
3125                     !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3126                     !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3127                         btrfs_free_reserved_extent(fs_info,
3128                                                    ordered_extent->start,
3129                                                    ordered_extent->disk_len, 1);
3130         }
3131
3132
3133         /*
3134          * This needs to be done to make sure anybody waiting knows we are done
3135          * updating everything for this ordered extent.
3136          */
3137         btrfs_remove_ordered_extent(inode, ordered_extent);
3138
3139         /* for snapshot-aware defrag */
3140         if (new) {
3141                 if (ret) {
3142                         free_sa_defrag_extent(new);
3143                         atomic_dec(&fs_info->defrag_running);
3144                 } else {
3145                         relink_file_extents(new);
3146                 }
3147         }
3148
3149         /* once for us */
3150         btrfs_put_ordered_extent(ordered_extent);
3151         /* once for the tree */
3152         btrfs_put_ordered_extent(ordered_extent);
3153
3154         return ret;
3155 }
3156
3157 static void finish_ordered_fn(struct btrfs_work *work)
3158 {
3159         struct btrfs_ordered_extent *ordered_extent;
3160         ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3161         btrfs_finish_ordered_io(ordered_extent);
3162 }
3163
3164 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3165                                 struct extent_state *state, int uptodate)
3166 {
3167         struct inode *inode = page->mapping->host;
3168         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3169         struct btrfs_ordered_extent *ordered_extent = NULL;
3170         struct btrfs_workqueue *wq;
3171         btrfs_work_func_t func;
3172
3173         trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3174
3175         ClearPagePrivate2(page);
3176         if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3177                                             end - start + 1, uptodate))
3178                 return;
3179
3180         if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3181                 wq = fs_info->endio_freespace_worker;
3182                 func = btrfs_freespace_write_helper;
3183         } else {
3184                 wq = fs_info->endio_write_workers;
3185                 func = btrfs_endio_write_helper;
3186         }
3187
3188         btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3189                         NULL);
3190         btrfs_queue_work(wq, &ordered_extent->work);
3191 }
3192
3193 static int __readpage_endio_check(struct inode *inode,
3194                                   struct btrfs_io_bio *io_bio,
3195                                   int icsum, struct page *page,
3196                                   int pgoff, u64 start, size_t len)
3197 {
3198         char *kaddr;
3199         u32 csum_expected;
3200         u32 csum = ~(u32)0;
3201
3202         csum_expected = *(((u32 *)io_bio->csum) + icsum);
3203
3204         kaddr = kmap_atomic(page);
3205         csum = btrfs_csum_data(kaddr + pgoff, csum,  len);
3206         btrfs_csum_final(csum, (u8 *)&csum);
3207         if (csum != csum_expected)
3208                 goto zeroit;
3209
3210         kunmap_atomic(kaddr);
3211         return 0;
3212 zeroit:
3213         btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3214                                     io_bio->mirror_num);
3215         memset(kaddr + pgoff, 1, len);
3216         flush_dcache_page(page);
3217         kunmap_atomic(kaddr);
3218         return -EIO;
3219 }
3220
3221 /*
3222  * when reads are done, we need to check csums to verify the data is correct
3223  * if there's a match, we allow the bio to finish.  If not, the code in
3224  * extent_io.c will try to find good copies for us.
3225  */
3226 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3227                                       u64 phy_offset, struct page *page,
3228                                       u64 start, u64 end, int mirror)
3229 {
3230         size_t offset = start - page_offset(page);
3231         struct inode *inode = page->mapping->host;
3232         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3233         struct btrfs_root *root = BTRFS_I(inode)->root;
3234
3235         if (PageChecked(page)) {
3236                 ClearPageChecked(page);
3237                 return 0;
3238         }
3239
3240         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3241                 return 0;
3242
3243         if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3244             test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3245                 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3246                 return 0;
3247         }
3248
3249         phy_offset >>= inode->i_sb->s_blocksize_bits;
3250         return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3251                                       start, (size_t)(end - start + 1));
3252 }
3253
3254 /*
3255  * btrfs_add_delayed_iput - perform a delayed iput on @inode
3256  *
3257  * @inode: The inode we want to perform iput on
3258  *
3259  * This function uses the generic vfs_inode::i_count to track whether we should
3260  * just decrement it (in case it's > 1) or if this is the last iput then link
3261  * the inode to the delayed iput machinery. Delayed iputs are processed at
3262  * transaction commit time/superblock commit/cleaner kthread.
3263  */
3264 void btrfs_add_delayed_iput(struct inode *inode)
3265 {
3266         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3267         struct btrfs_inode *binode = BTRFS_I(inode);
3268
3269         if (atomic_add_unless(&inode->i_count, -1, 1))
3270                 return;
3271
3272         spin_lock(&fs_info->delayed_iput_lock);
3273         ASSERT(list_empty(&binode->delayed_iput));
3274         list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3275         spin_unlock(&fs_info->delayed_iput_lock);
3276 }
3277
3278 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3279 {
3280
3281         spin_lock(&fs_info->delayed_iput_lock);
3282         while (!list_empty(&fs_info->delayed_iputs)) {
3283                 struct btrfs_inode *inode;
3284
3285                 inode = list_first_entry(&fs_info->delayed_iputs,
3286                                 struct btrfs_inode, delayed_iput);
3287                 list_del_init(&inode->delayed_iput);
3288                 spin_unlock(&fs_info->delayed_iput_lock);
3289                 iput(&inode->vfs_inode);
3290                 spin_lock(&fs_info->delayed_iput_lock);
3291         }
3292         spin_unlock(&fs_info->delayed_iput_lock);
3293 }
3294
3295 /*
3296  * This is called in transaction commit time. If there are no orphan
3297  * files in the subvolume, it removes orphan item and frees block_rsv
3298  * structure.
3299  */
3300 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3301                               struct btrfs_root *root)
3302 {
3303         struct btrfs_fs_info *fs_info = root->fs_info;
3304         struct btrfs_block_rsv *block_rsv;
3305         int ret;
3306
3307         if (atomic_read(&root->orphan_inodes) ||
3308             root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3309                 return;
3310
3311         spin_lock(&root->orphan_lock);
3312         if (atomic_read(&root->orphan_inodes)) {
3313                 spin_unlock(&root->orphan_lock);
3314                 return;
3315         }
3316
3317         if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3318                 spin_unlock(&root->orphan_lock);
3319                 return;
3320         }
3321
3322         block_rsv = root->orphan_block_rsv;
3323         root->orphan_block_rsv = NULL;
3324         spin_unlock(&root->orphan_lock);
3325
3326         if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3327             btrfs_root_refs(&root->root_item) > 0) {
3328                 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3329                                             root->root_key.objectid);
3330                 if (ret)
3331                         btrfs_abort_transaction(trans, ret);
3332                 else
3333                         clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3334                                   &root->state);
3335         }
3336
3337         if (block_rsv) {
3338                 WARN_ON(block_rsv->size > 0);
3339                 btrfs_free_block_rsv(fs_info, block_rsv);
3340         }
3341 }
3342
3343 /*
3344  * This creates an orphan entry for the given inode in case something goes
3345  * wrong in the middle of an unlink/truncate.
3346  *
3347  * NOTE: caller of this function should reserve 5 units of metadata for
3348  *       this function.
3349  */
3350 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3351                 struct btrfs_inode *inode)
3352 {
3353         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3354         struct btrfs_root *root = inode->root;
3355         struct btrfs_block_rsv *block_rsv = NULL;
3356         int reserve = 0;
3357         bool insert = false;
3358         int ret;
3359
3360         if (!root->orphan_block_rsv) {
3361                 block_rsv = btrfs_alloc_block_rsv(fs_info,
3362                                                   BTRFS_BLOCK_RSV_TEMP);
3363                 if (!block_rsv)
3364                         return -ENOMEM;
3365         }
3366
3367         if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3368                               &inode->runtime_flags))
3369                 insert = true;
3370
3371         if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3372                               &inode->runtime_flags))
3373                 reserve = 1;
3374
3375         spin_lock(&root->orphan_lock);
3376         /* If someone has created ->orphan_block_rsv, be happy to use it. */
3377         if (!root->orphan_block_rsv) {
3378                 root->orphan_block_rsv = block_rsv;
3379         } else if (block_rsv) {
3380                 btrfs_free_block_rsv(fs_info, block_rsv);
3381                 block_rsv = NULL;
3382         }
3383
3384         if (insert)
3385                 atomic_inc(&root->orphan_inodes);
3386         spin_unlock(&root->orphan_lock);
3387
3388         /* grab metadata reservation from transaction handle */
3389         if (reserve) {
3390                 ret = btrfs_orphan_reserve_metadata(trans, inode);
3391                 ASSERT(!ret);
3392                 if (ret) {
3393                         /*
3394                          * dec doesn't need spin_lock as ->orphan_block_rsv
3395                          * would be released only if ->orphan_inodes is
3396                          * zero.
3397                          */
3398                         atomic_dec(&root->orphan_inodes);
3399                         clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3400                                   &inode->runtime_flags);
3401                         if (insert)
3402                                 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3403                                           &inode->runtime_flags);
3404                         return ret;
3405                 }
3406         }
3407
3408         /* insert an orphan item to track this unlinked/truncated file */
3409         if (insert) {
3410                 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3411                 if (ret) {
3412                         if (reserve) {
3413                                 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3414                                           &inode->runtime_flags);
3415                                 btrfs_orphan_release_metadata(inode);
3416                         }
3417                         /*
3418                          * btrfs_orphan_commit_root may race with us and set
3419                          * ->orphan_block_rsv to zero, in order to avoid that,
3420                          * decrease ->orphan_inodes after everything is done.
3421                          */
3422                         atomic_dec(&root->orphan_inodes);
3423                         if (ret != -EEXIST) {
3424                                 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3425                                           &inode->runtime_flags);
3426                                 btrfs_abort_transaction(trans, ret);
3427                                 return ret;
3428                         }
3429                 }
3430                 ret = 0;
3431         }
3432
3433         return 0;
3434 }
3435
3436 /*
3437  * We have done the truncate/delete so we can go ahead and remove the orphan
3438  * item for this particular inode.
3439  */
3440 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3441                             struct btrfs_inode *inode)
3442 {
3443         struct btrfs_root *root = inode->root;
3444         int delete_item = 0;
3445         int ret = 0;
3446
3447         if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3448                                &inode->runtime_flags))
3449                 delete_item = 1;
3450
3451         if (delete_item && trans)
3452                 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3453
3454         if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3455                                &inode->runtime_flags))
3456                 btrfs_orphan_release_metadata(inode);
3457
3458         /*
3459          * btrfs_orphan_commit_root may race with us and set ->orphan_block_rsv
3460          * to zero, in order to avoid that, decrease ->orphan_inodes after
3461          * everything is done.
3462          */
3463         if (delete_item)
3464                 atomic_dec(&root->orphan_inodes);
3465
3466         return ret;
3467 }
3468
3469 /*
3470  * this cleans up any orphans that may be left on the list from the last use
3471  * of this root.
3472  */
3473 int btrfs_orphan_cleanup(struct btrfs_root *root)
3474 {
3475         struct btrfs_fs_info *fs_info = root->fs_info;
3476         struct btrfs_path *path;
3477         struct extent_buffer *leaf;
3478         struct btrfs_key key, found_key;
3479         struct btrfs_trans_handle *trans;
3480         struct inode *inode;
3481         u64 last_objectid = 0;
3482         int ret = 0, nr_unlink = 0, nr_truncate = 0;
3483
3484         if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3485                 return 0;
3486
3487         path = btrfs_alloc_path();
3488         if (!path) {
3489                 ret = -ENOMEM;
3490                 goto out;
3491         }
3492         path->reada = READA_BACK;
3493
3494         key.objectid = BTRFS_ORPHAN_OBJECTID;
3495         key.type = BTRFS_ORPHAN_ITEM_KEY;
3496         key.offset = (u64)-1;
3497
3498         while (1) {
3499                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3500                 if (ret < 0)
3501                         goto out;
3502
3503                 /*
3504                  * if ret == 0 means we found what we were searching for, which
3505                  * is weird, but possible, so only screw with path if we didn't
3506                  * find the key and see if we have stuff that matches
3507                  */
3508                 if (ret > 0) {
3509                         ret = 0;
3510                         if (path->slots[0] == 0)
3511                                 break;
3512                         path->slots[0]--;
3513                 }
3514
3515                 /* pull out the item */
3516                 leaf = path->nodes[0];
3517                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3518
3519                 /* make sure the item matches what we want */
3520                 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3521                         break;
3522                 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3523                         break;
3524
3525                 /* release the path since we're done with it */
3526                 btrfs_release_path(path);
3527
3528                 /*
3529                  * this is where we are basically btrfs_lookup, without the
3530                  * crossing root thing.  we store the inode number in the
3531                  * offset of the orphan item.
3532                  */
3533
3534                 if (found_key.offset == last_objectid) {
3535                         btrfs_err(fs_info,
3536                                   "Error removing orphan entry, stopping orphan cleanup");
3537                         ret = -EINVAL;
3538                         goto out;
3539                 }
3540
3541                 last_objectid = found_key.offset;
3542
3543                 found_key.objectid = found_key.offset;
3544                 found_key.type = BTRFS_INODE_ITEM_KEY;
3545                 found_key.offset = 0;
3546                 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3547                 ret = PTR_ERR_OR_ZERO(inode);
3548                 if (ret && ret != -ENOENT)
3549                         goto out;
3550
3551                 if (ret == -ENOENT && root == fs_info->tree_root) {
3552                         struct btrfs_root *dead_root;
3553                         struct btrfs_fs_info *fs_info = root->fs_info;
3554                         int is_dead_root = 0;
3555
3556                         /*
3557                          * this is an orphan in the tree root. Currently these
3558                          * could come from 2 sources:
3559                          *  a) a snapshot deletion in progress
3560                          *  b) a free space cache inode
3561                          * We need to distinguish those two, as the snapshot
3562                          * orphan must not get deleted.
3563                          * find_dead_roots already ran before us, so if this
3564                          * is a snapshot deletion, we should find the root
3565                          * in the dead_roots list
3566                          */
3567                         spin_lock(&fs_info->trans_lock);
3568                         list_for_each_entry(dead_root, &fs_info->dead_roots,
3569                                             root_list) {
3570                                 if (dead_root->root_key.objectid ==
3571                                     found_key.objectid) {
3572                                         is_dead_root = 1;
3573                                         break;
3574                                 }
3575                         }
3576                         spin_unlock(&fs_info->trans_lock);
3577                         if (is_dead_root) {
3578                                 /* prevent this orphan from being found again */
3579                                 key.offset = found_key.objectid - 1;
3580                                 continue;
3581                         }
3582                 }
3583                 /*
3584                  * Inode is already gone but the orphan item is still there,
3585                  * kill the orphan item.
3586                  */
3587                 if (ret == -ENOENT) {
3588                         trans = btrfs_start_transaction(root, 1);
3589                         if (IS_ERR(trans)) {
3590                                 ret = PTR_ERR(trans);
3591                                 goto out;
3592                         }
3593                         btrfs_debug(fs_info, "auto deleting %Lu",
3594                                     found_key.objectid);
3595                         ret = btrfs_del_orphan_item(trans, root,
3596                                                     found_key.objectid);
3597                         btrfs_end_transaction(trans);
3598                         if (ret)
3599                                 goto out;
3600                         continue;
3601                 }
3602
3603                 /*
3604                  * add this inode to the orphan list so btrfs_orphan_del does
3605                  * the proper thing when we hit it
3606                  */
3607                 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3608                         &BTRFS_I(inode)->runtime_flags);
3609                 atomic_inc(&root->orphan_inodes);
3610
3611                 /* if we have links, this was a truncate, lets do that */
3612                 if (inode->i_nlink) {
3613                         if (WARN_ON(!S_ISREG(inode->i_mode))) {
3614                                 iput(inode);
3615                                 continue;
3616                         }
3617                         nr_truncate++;
3618
3619                         /* 1 for the orphan item deletion. */
3620                         trans = btrfs_start_transaction(root, 1);
3621                         if (IS_ERR(trans)) {
3622                                 iput(inode);
3623                                 ret = PTR_ERR(trans);
3624                                 goto out;
3625                         }
3626                         ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3627                         btrfs_end_transaction(trans);
3628                         if (ret) {
3629                                 iput(inode);
3630                                 goto out;
3631                         }
3632
3633                         ret = btrfs_truncate(inode, false);
3634                         if (ret)
3635                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
3636                 } else {
3637                         nr_unlink++;
3638                 }
3639
3640                 /* this will do delete_inode and everything for us */
3641                 iput(inode);
3642                 if (ret)
3643                         goto out;
3644         }
3645         /* release the path since we're done with it */
3646         btrfs_release_path(path);
3647
3648         root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3649
3650         if (root->orphan_block_rsv)
3651                 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3652                                         (u64)-1);
3653
3654         if (root->orphan_block_rsv ||
3655             test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3656                 trans = btrfs_join_transaction(root);
3657                 if (!IS_ERR(trans))
3658                         btrfs_end_transaction(trans);
3659         }
3660
3661         if (nr_unlink)
3662                 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3663         if (nr_truncate)
3664                 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3665
3666 out:
3667         if (ret)
3668                 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3669         btrfs_free_path(path);
3670         return ret;
3671 }
3672
3673 /*
3674  * very simple check to peek ahead in the leaf looking for xattrs.  If we
3675  * don't find any xattrs, we know there can't be any acls.
3676  *
3677  * slot is the slot the inode is in, objectid is the objectid of the inode
3678  */
3679 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3680                                           int slot, u64 objectid,
3681                                           int *first_xattr_slot)
3682 {
3683         u32 nritems = btrfs_header_nritems(leaf);
3684         struct btrfs_key found_key;
3685         static u64 xattr_access = 0;
3686         static u64 xattr_default = 0;
3687         int scanned = 0;
3688
3689         if (!xattr_access) {
3690                 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3691                                         strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3692                 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3693                                         strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3694         }
3695
3696         slot++;
3697         *first_xattr_slot = -1;
3698         while (slot < nritems) {
3699                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3700
3701                 /* we found a different objectid, there must not be acls */
3702                 if (found_key.objectid != objectid)
3703                         return 0;
3704
3705                 /* we found an xattr, assume we've got an acl */
3706                 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3707                         if (*first_xattr_slot == -1)
3708                                 *first_xattr_slot = slot;
3709                         if (found_key.offset == xattr_access ||
3710                             found_key.offset == xattr_default)
3711                                 return 1;
3712                 }
3713
3714                 /*
3715                  * we found a key greater than an xattr key, there can't
3716                  * be any acls later on
3717                  */
3718                 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3719                         return 0;
3720
3721                 slot++;
3722                 scanned++;
3723
3724                 /*
3725                  * it goes inode, inode backrefs, xattrs, extents,
3726                  * so if there are a ton of hard links to an inode there can
3727                  * be a lot of backrefs.  Don't waste time searching too hard,
3728                  * this is just an optimization
3729                  */
3730                 if (scanned >= 8)
3731                         break;
3732         }
3733         /* we hit the end of the leaf before we found an xattr or
3734          * something larger than an xattr.  We have to assume the inode
3735          * has acls
3736          */
3737         if (*first_xattr_slot == -1)
3738                 *first_xattr_slot = slot;
3739         return 1;
3740 }
3741
3742 /*
3743  * read an inode from the btree into the in-memory inode
3744  */
3745 static int btrfs_read_locked_inode(struct inode *inode)
3746 {
3747         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3748         struct btrfs_path *path;
3749         struct extent_buffer *leaf;
3750         struct btrfs_inode_item *inode_item;
3751         struct btrfs_root *root = BTRFS_I(inode)->root;
3752         struct btrfs_key location;
3753         unsigned long ptr;
3754         int maybe_acls;
3755         u32 rdev;
3756         int ret;
3757         bool filled = false;
3758         int first_xattr_slot;
3759
3760         ret = btrfs_fill_inode(inode, &rdev);
3761         if (!ret)
3762                 filled = true;
3763
3764         path = btrfs_alloc_path();
3765         if (!path) {
3766                 ret = -ENOMEM;
3767                 goto make_bad;
3768         }
3769
3770         memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3771
3772         ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3773         if (ret) {
3774                 if (ret > 0)
3775                         ret = -ENOENT;
3776                 goto make_bad;
3777         }
3778
3779         leaf = path->nodes[0];
3780
3781         if (filled)
3782                 goto cache_index;
3783
3784         inode_item = btrfs_item_ptr(leaf, path->slots[0],
3785                                     struct btrfs_inode_item);
3786         inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3787         set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3788         i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3789         i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3790         btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3791
3792         inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3793         inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3794
3795         inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3796         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3797
3798         inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3799         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3800
3801         BTRFS_I(inode)->i_otime.tv_sec =
3802                 btrfs_timespec_sec(leaf, &inode_item->otime);
3803         BTRFS_I(inode)->i_otime.tv_nsec =
3804                 btrfs_timespec_nsec(leaf, &inode_item->otime);
3805
3806         inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3807         BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3808         BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3809
3810         inode_set_iversion_queried(inode,
3811                                    btrfs_inode_sequence(leaf, inode_item));
3812         inode->i_generation = BTRFS_I(inode)->generation;
3813         inode->i_rdev = 0;
3814         rdev = btrfs_inode_rdev(leaf, inode_item);
3815
3816         BTRFS_I(inode)->index_cnt = (u64)-1;
3817         BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3818
3819 cache_index:
3820         /*
3821          * If we were modified in the current generation and evicted from memory
3822          * and then re-read we need to do a full sync since we don't have any
3823          * idea about which extents were modified before we were evicted from
3824          * cache.
3825          *
3826          * This is required for both inode re-read from disk and delayed inode
3827          * in delayed_nodes_tree.
3828          */
3829         if (BTRFS_I(inode)->last_trans == fs_info->generation)
3830                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3831                         &BTRFS_I(inode)->runtime_flags);
3832
3833         /*
3834          * We don't persist the id of the transaction where an unlink operation
3835          * against the inode was last made. So here we assume the inode might
3836          * have been evicted, and therefore the exact value of last_unlink_trans
3837          * lost, and set it to last_trans to avoid metadata inconsistencies
3838          * between the inode and its parent if the inode is fsync'ed and the log
3839          * replayed. For example, in the scenario:
3840          *
3841          * touch mydir/foo
3842          * ln mydir/foo mydir/bar
3843          * sync
3844          * unlink mydir/bar
3845          * echo 2 > /proc/sys/vm/drop_caches   # evicts inode
3846          * xfs_io -c fsync mydir/foo
3847          * <power failure>
3848          * mount fs, triggers fsync log replay
3849          *
3850          * We must make sure that when we fsync our inode foo we also log its
3851          * parent inode, otherwise after log replay the parent still has the
3852          * dentry with the "bar" name but our inode foo has a link count of 1
3853          * and doesn't have an inode ref with the name "bar" anymore.
3854          *
3855          * Setting last_unlink_trans to last_trans is a pessimistic approach,
3856          * but it guarantees correctness at the expense of occasional full
3857          * transaction commits on fsync if our inode is a directory, or if our
3858          * inode is not a directory, logging its parent unnecessarily.
3859          */
3860         BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3861
3862         path->slots[0]++;
3863         if (inode->i_nlink != 1 ||
3864             path->slots[0] >= btrfs_header_nritems(leaf))
3865                 goto cache_acl;
3866
3867         btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3868         if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3869                 goto cache_acl;
3870
3871         ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3872         if (location.type == BTRFS_INODE_REF_KEY) {
3873                 struct btrfs_inode_ref *ref;
3874
3875                 ref = (struct btrfs_inode_ref *)ptr;
3876                 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3877         } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3878                 struct btrfs_inode_extref *extref;
3879
3880                 extref = (struct btrfs_inode_extref *)ptr;
3881                 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3882                                                                      extref);
3883         }
3884 cache_acl:
3885         /*
3886          * try to precache a NULL acl entry for files that don't have
3887          * any xattrs or acls
3888          */
3889         maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3890                         btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3891         if (first_xattr_slot != -1) {
3892                 path->slots[0] = first_xattr_slot;
3893                 ret = btrfs_load_inode_props(inode, path);
3894                 if (ret)
3895                         btrfs_err(fs_info,
3896                                   "error loading props for ino %llu (root %llu): %d",
3897                                   btrfs_ino(BTRFS_I(inode)),
3898                                   root->root_key.objectid, ret);
3899         }
3900         btrfs_free_path(path);
3901
3902         if (!maybe_acls)
3903                 cache_no_acl(inode);
3904
3905         switch (inode->i_mode & S_IFMT) {
3906         case S_IFREG:
3907                 inode->i_mapping->a_ops = &btrfs_aops;
3908                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3909                 inode->i_fop = &btrfs_file_operations;
3910                 inode->i_op = &btrfs_file_inode_operations;
3911                 break;
3912         case S_IFDIR:
3913                 inode->i_fop = &btrfs_dir_file_operations;
3914                 inode->i_op = &btrfs_dir_inode_operations;
3915                 break;
3916         case S_IFLNK:
3917                 inode->i_op = &btrfs_symlink_inode_operations;
3918                 inode_nohighmem(inode);
3919                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3920                 break;
3921         default:
3922                 inode->i_op = &btrfs_special_inode_operations;
3923                 init_special_inode(inode, inode->i_mode, rdev);
3924                 break;
3925         }
3926
3927         btrfs_update_iflags(inode);
3928         return 0;
3929
3930 make_bad:
3931         btrfs_free_path(path);
3932         make_bad_inode(inode);
3933         return ret;
3934 }
3935
3936 /*
3937  * given a leaf and an inode, copy the inode fields into the leaf
3938  */
3939 static void fill_inode_item(struct btrfs_trans_handle *trans,
3940                             struct extent_buffer *leaf,
3941                             struct btrfs_inode_item *item,
3942                             struct inode *inode)
3943 {
3944         struct btrfs_map_token token;
3945
3946         btrfs_init_map_token(&token);
3947
3948         btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3949         btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3950         btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3951                                    &token);
3952         btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3953         btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3954
3955         btrfs_set_token_timespec_sec(leaf, &item->atime,
3956                                      inode->i_atime.tv_sec, &token);
3957         btrfs_set_token_timespec_nsec(leaf, &item->atime,
3958                                       inode->i_atime.tv_nsec, &token);
3959
3960         btrfs_set_token_timespec_sec(leaf, &item->mtime,
3961                                      inode->i_mtime.tv_sec, &token);
3962         btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3963                                       inode->i_mtime.tv_nsec, &token);
3964
3965         btrfs_set_token_timespec_sec(leaf, &item->ctime,
3966                                      inode->i_ctime.tv_sec, &token);
3967         btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3968                                       inode->i_ctime.tv_nsec, &token);
3969
3970         btrfs_set_token_timespec_sec(leaf, &item->otime,
3971                                      BTRFS_I(inode)->i_otime.tv_sec, &token);
3972         btrfs_set_token_timespec_nsec(leaf, &item->otime,
3973                                       BTRFS_I(inode)->i_otime.tv_nsec, &token);
3974
3975         btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3976                                      &token);
3977         btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3978                                          &token);
3979         btrfs_set_token_inode_sequence(leaf, item, inode_peek_iversion(inode),
3980                                        &token);
3981         btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3982         btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3983         btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3984         btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3985 }
3986
3987 /*
3988  * copy everything in the in-memory inode into the btree.
3989  */
3990 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3991                                 struct btrfs_root *root, struct inode *inode)
3992 {
3993         struct btrfs_inode_item *inode_item;
3994         struct btrfs_path *path;
3995         struct extent_buffer *leaf;
3996         int ret;
3997
3998         path = btrfs_alloc_path();
3999         if (!path)
4000                 return -ENOMEM;
4001
4002         path->leave_spinning = 1;
4003         ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
4004                                  1);
4005         if (ret) {
4006                 if (ret > 0)
4007                         ret = -ENOENT;
4008                 goto failed;
4009         }
4010
4011         leaf = path->nodes[0];
4012         inode_item = btrfs_item_ptr(leaf, path->slots[0],
4013                                     struct btrfs_inode_item);
4014
4015         fill_inode_item(trans, leaf, inode_item, inode);
4016         btrfs_mark_buffer_dirty(leaf);
4017         btrfs_set_inode_last_trans(trans, inode);
4018         ret = 0;
4019 failed:
4020         btrfs_free_path(path);
4021         return ret;
4022 }
4023
4024 /*
4025  * copy everything in the in-memory inode into the btree.
4026  */
4027 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
4028                                 struct btrfs_root *root, struct inode *inode)
4029 {
4030         struct btrfs_fs_info *fs_info = root->fs_info;
4031         int ret;
4032
4033         /*
4034          * If the inode is a free space inode, we can deadlock during commit
4035          * if we put it into the delayed code.
4036          *
4037          * The data relocation inode should also be directly updated
4038          * without delay
4039          */
4040         if (!btrfs_is_free_space_inode(BTRFS_I(inode))
4041             && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
4042             && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4043                 btrfs_update_root_times(trans, root);
4044
4045                 ret = btrfs_delayed_update_inode(trans, root, inode);
4046                 if (!ret)
4047                         btrfs_set_inode_last_trans(trans, inode);
4048                 return ret;
4049         }
4050
4051         return btrfs_update_inode_item(trans, root, inode);
4052 }
4053
4054 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4055                                          struct btrfs_root *root,
4056                                          struct inode *inode)
4057 {
4058         int ret;
4059
4060         ret = btrfs_update_inode(trans, root, inode);
4061         if (ret == -ENOSPC)
4062                 return btrfs_update_inode_item(trans, root, inode);
4063         return ret;
4064 }
4065
4066 /*
4067  * unlink helper that gets used here in inode.c and in the tree logging
4068  * recovery code.  It remove a link in a directory with a given name, and
4069  * also drops the back refs in the inode to the directory
4070  */
4071 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4072                                 struct btrfs_root *root,
4073                                 struct btrfs_inode *dir,
4074                                 struct btrfs_inode *inode,
4075                                 const char *name, int name_len)
4076 {
4077         struct btrfs_fs_info *fs_info = root->fs_info;
4078         struct btrfs_path *path;
4079         int ret = 0;
4080         struct extent_buffer *leaf;
4081         struct btrfs_dir_item *di;
4082         struct btrfs_key key;
4083         u64 index;
4084         u64 ino = btrfs_ino(inode);
4085         u64 dir_ino = btrfs_ino(dir);
4086
4087         path = btrfs_alloc_path();
4088         if (!path) {
4089                 ret = -ENOMEM;
4090                 goto out;
4091         }
4092
4093         path->leave_spinning = 1;
4094         di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4095                                     name, name_len, -1);
4096         if (IS_ERR(di)) {
4097                 ret = PTR_ERR(di);
4098                 goto err;
4099         }
4100         if (!di) {
4101                 ret = -ENOENT;
4102                 goto err;
4103         }
4104         leaf = path->nodes[0];
4105         btrfs_dir_item_key_to_cpu(leaf, di, &key);
4106         ret = btrfs_delete_one_dir_name(trans, root, path, di);
4107         if (ret)
4108                 goto err;
4109         btrfs_release_path(path);
4110
4111         /*
4112          * If we don't have dir index, we have to get it by looking up
4113          * the inode ref, since we get the inode ref, remove it directly,
4114          * it is unnecessary to do delayed deletion.
4115          *
4116          * But if we have dir index, needn't search inode ref to get it.
4117          * Since the inode ref is close to the inode item, it is better
4118          * that we delay to delete it, and just do this deletion when
4119          * we update the inode item.
4120          */
4121         if (inode->dir_index) {
4122                 ret = btrfs_delayed_delete_inode_ref(inode);
4123                 if (!ret) {
4124                         index = inode->dir_index;
4125                         goto skip_backref;
4126                 }
4127         }
4128
4129         ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4130                                   dir_ino, &index);
4131         if (ret) {
4132                 btrfs_info(fs_info,
4133                         "failed to delete reference to %.*s, inode %llu parent %llu",
4134                         name_len, name, ino, dir_ino);
4135                 btrfs_abort_transaction(trans, ret);
4136                 goto err;
4137         }
4138 skip_backref:
4139         ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4140         if (ret) {
4141                 btrfs_abort_transaction(trans, ret);
4142                 goto err;
4143         }
4144
4145         ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4146                         dir_ino);
4147         if (ret != 0 && ret != -ENOENT) {
4148                 btrfs_abort_transaction(trans, ret);
4149                 goto err;
4150         }
4151
4152         ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4153                         index);
4154         if (ret == -ENOENT)
4155                 ret = 0;
4156         else if (ret)
4157                 btrfs_abort_transaction(trans, ret);
4158 err:
4159         btrfs_free_path(path);
4160         if (ret)
4161                 goto out;
4162
4163         btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4164         inode_inc_iversion(&inode->vfs_inode);
4165         inode_inc_iversion(&dir->vfs_inode);
4166         inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4167                 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4168         ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4169 out:
4170         return ret;
4171 }
4172
4173 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4174                        struct btrfs_root *root,
4175                        struct btrfs_inode *dir, struct btrfs_inode *inode,
4176                        const char *name, int name_len)
4177 {
4178         int ret;
4179         ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4180         if (!ret) {
4181                 drop_nlink(&inode->vfs_inode);
4182                 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4183         }
4184         return ret;
4185 }
4186
4187 /*
4188  * helper to start transaction for unlink and rmdir.
4189  *
4190  * unlink and rmdir are special in btrfs, they do not always free space, so
4191  * if we cannot make our reservations the normal way try and see if there is
4192  * plenty of slack room in the global reserve to migrate, otherwise we cannot
4193  * allow the unlink to occur.
4194  */
4195 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4196 {
4197         struct btrfs_root *root = BTRFS_I(dir)->root;
4198
4199         /*
4200          * 1 for the possible orphan item
4201          * 1 for the dir item
4202          * 1 for the dir index
4203          * 1 for the inode ref
4204          * 1 for the inode
4205          */
4206         return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4207 }
4208
4209 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4210 {
4211         struct btrfs_root *root = BTRFS_I(dir)->root;
4212         struct btrfs_trans_handle *trans;
4213         struct inode *inode = d_inode(dentry);
4214         int ret;
4215
4216         trans = __unlink_start_trans(dir);
4217         if (IS_ERR(trans))
4218                 return PTR_ERR(trans);
4219
4220         btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4221                         0);
4222
4223         ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4224                         BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4225                         dentry->d_name.len);
4226         if (ret)
4227                 goto out;
4228
4229         if (inode->i_nlink == 0) {
4230                 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4231                 if (ret)
4232                         goto out;
4233         }
4234
4235 out:
4236         btrfs_end_transaction(trans);
4237         btrfs_btree_balance_dirty(root->fs_info);
4238         return ret;
4239 }
4240
4241 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4242                         struct btrfs_root *root,
4243                         struct inode *dir, u64 objectid,
4244                         const char *name, int name_len)
4245 {
4246         struct btrfs_fs_info *fs_info = root->fs_info;
4247         struct btrfs_path *path;
4248         struct extent_buffer *leaf;
4249         struct btrfs_dir_item *di;
4250         struct btrfs_key key;
4251         u64 index;
4252         int ret;
4253         u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4254
4255         path = btrfs_alloc_path();
4256         if (!path)
4257                 return -ENOMEM;
4258
4259         di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4260                                    name, name_len, -1);
4261         if (IS_ERR_OR_NULL(di)) {
4262                 if (!di)
4263                         ret = -ENOENT;
4264                 else
4265                         ret = PTR_ERR(di);
4266                 goto out;
4267         }
4268
4269         leaf = path->nodes[0];
4270         btrfs_dir_item_key_to_cpu(leaf, di, &key);
4271         WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4272         ret = btrfs_delete_one_dir_name(trans, root, path, di);
4273         if (ret) {
4274                 btrfs_abort_transaction(trans, ret);
4275                 goto out;
4276         }
4277         btrfs_release_path(path);
4278
4279         ret = btrfs_del_root_ref(trans, fs_info, objectid,
4280                                  root->root_key.objectid, dir_ino,
4281                                  &index, name, name_len);
4282         if (ret < 0) {
4283                 if (ret != -ENOENT) {
4284                         btrfs_abort_transaction(trans, ret);
4285                         goto out;
4286                 }
4287                 di = btrfs_search_dir_index_item(root, path, dir_ino,
4288                                                  name, name_len);
4289                 if (IS_ERR_OR_NULL(di)) {
4290                         if (!di)
4291                                 ret = -ENOENT;
4292                         else
4293                                 ret = PTR_ERR(di);
4294                         btrfs_abort_transaction(trans, ret);
4295                         goto out;
4296                 }
4297
4298                 leaf = path->nodes[0];
4299                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4300                 btrfs_release_path(path);
4301                 index = key.offset;
4302         }
4303         btrfs_release_path(path);
4304
4305         ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4306         if (ret) {
4307                 btrfs_abort_transaction(trans, ret);
4308                 goto out;
4309         }
4310
4311         btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4312         inode_inc_iversion(dir);
4313         dir->i_mtime = dir->i_ctime = current_time(dir);
4314         ret = btrfs_update_inode_fallback(trans, root, dir);
4315         if (ret)
4316                 btrfs_abort_transaction(trans, ret);
4317 out:
4318         btrfs_free_path(path);
4319         return ret;
4320 }
4321
4322 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4323 {
4324         struct inode *inode = d_inode(dentry);
4325         int err = 0;
4326         struct btrfs_root *root = BTRFS_I(dir)->root;
4327         struct btrfs_trans_handle *trans;
4328         u64 last_unlink_trans;
4329
4330         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4331                 return -ENOTEMPTY;
4332         if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4333                 return -EPERM;
4334
4335         trans = __unlink_start_trans(dir);
4336         if (IS_ERR(trans))
4337                 return PTR_ERR(trans);
4338
4339         if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4340                 err = btrfs_unlink_subvol(trans, root, dir,
4341                                           BTRFS_I(inode)->location.objectid,
4342                                           dentry->d_name.name,
4343                                           dentry->d_name.len);
4344                 goto out;
4345         }
4346
4347         err = btrfs_orphan_add(trans, BTRFS_I(inode));
4348         if (err)
4349                 goto out;
4350
4351         last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4352
4353         /* now the directory is empty */
4354         err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4355                         BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4356                         dentry->d_name.len);
4357         if (!err) {
4358                 btrfs_i_size_write(BTRFS_I(inode), 0);
4359                 /*
4360                  * Propagate the last_unlink_trans value of the deleted dir to
4361                  * its parent directory. This is to prevent an unrecoverable
4362                  * log tree in the case we do something like this:
4363                  * 1) create dir foo
4364                  * 2) create snapshot under dir foo
4365                  * 3) delete the snapshot
4366                  * 4) rmdir foo
4367                  * 5) mkdir foo
4368                  * 6) fsync foo or some file inside foo
4369                  */
4370                 if (last_unlink_trans >= trans->transid)
4371                         BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4372         }
4373 out:
4374         btrfs_end_transaction(trans);
4375         btrfs_btree_balance_dirty(root->fs_info);
4376
4377         return err;
4378 }
4379
4380 static int truncate_space_check(struct btrfs_trans_handle *trans,
4381                                 struct btrfs_root *root,
4382                                 u64 bytes_deleted)
4383 {
4384         struct btrfs_fs_info *fs_info = root->fs_info;
4385         int ret;
4386
4387         /*
4388          * This is only used to apply pressure to the enospc system, we don't
4389          * intend to use this reservation at all.
4390          */
4391         bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4392         bytes_deleted *= fs_info->nodesize;
4393         ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4394                                   bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4395         if (!ret) {
4396                 trace_btrfs_space_reservation(fs_info, "transaction",
4397                                               trans->transid,
4398                                               bytes_deleted, 1);
4399                 trans->bytes_reserved += bytes_deleted;
4400         }
4401         return ret;
4402
4403 }
4404
4405 /*
4406  * Return this if we need to call truncate_block for the last bit of the
4407  * truncate.
4408  */
4409 #define NEED_TRUNCATE_BLOCK 1
4410
4411 /*
4412  * this can truncate away extent items, csum items and directory items.
4413  * It starts at a high offset and removes keys until it can't find
4414  * any higher than new_size
4415  *
4416  * csum items that cross the new i_size are truncated to the new size
4417  * as well.
4418  *
4419  * min_type is the minimum key type to truncate down to.  If set to 0, this
4420  * will kill all the items on this inode, including the INODE_ITEM_KEY.
4421  */
4422 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4423                                struct btrfs_root *root,
4424                                struct inode *inode,
4425                                u64 new_size, u32 min_type)
4426 {
4427         struct btrfs_fs_info *fs_info = root->fs_info;
4428         struct btrfs_path *path;
4429         struct extent_buffer *leaf;
4430         struct btrfs_file_extent_item *fi;
4431         struct btrfs_key key;
4432         struct btrfs_key found_key;
4433         u64 extent_start = 0;
4434         u64 extent_num_bytes = 0;
4435         u64 extent_offset = 0;
4436         u64 item_end = 0;
4437         u64 last_size = new_size;
4438         u32 found_type = (u8)-1;
4439         int found_extent;
4440         int del_item;
4441         int pending_del_nr = 0;
4442         int pending_del_slot = 0;
4443         int extent_type = -1;
4444         int ret;
4445         int err = 0;
4446         u64 ino = btrfs_ino(BTRFS_I(inode));
4447         u64 bytes_deleted = 0;
4448         bool be_nice = false;
4449         bool should_throttle = false;
4450         bool should_end = false;
4451
4452         BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4453
4454         /*
4455          * for non-free space inodes and ref cows, we want to back off from
4456          * time to time
4457          */
4458         if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4459             test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4460                 be_nice = true;
4461
4462         path = btrfs_alloc_path();
4463         if (!path)
4464                 return -ENOMEM;
4465         path->reada = READA_BACK;
4466
4467         /*
4468          * We want to drop from the next block forward in case this new size is
4469          * not block aligned since we will be keeping the last block of the
4470          * extent just the way it is.
4471          */
4472         if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4473             root == fs_info->tree_root)
4474                 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4475                                         fs_info->sectorsize),
4476                                         (u64)-1, 0);
4477
4478         /*
4479          * This function is also used to drop the items in the log tree before
4480          * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4481          * it is used to drop the loged items. So we shouldn't kill the delayed
4482          * items.
4483          */
4484         if (min_type == 0 && root == BTRFS_I(inode)->root)
4485                 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4486
4487         key.objectid = ino;
4488         key.offset = (u64)-1;
4489         key.type = (u8)-1;
4490
4491 search_again:
4492         /*
4493          * with a 16K leaf size and 128MB extents, you can actually queue
4494          * up a huge file in a single leaf.  Most of the time that
4495          * bytes_deleted is > 0, it will be huge by the time we get here
4496          */
4497         if (be_nice && bytes_deleted > SZ_32M) {
4498                 if (btrfs_should_end_transaction(trans)) {
4499                         err = -EAGAIN;
4500                         goto error;
4501                 }
4502         }
4503
4504
4505         path->leave_spinning = 1;
4506         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4507         if (ret < 0) {
4508                 err = ret;
4509                 goto out;
4510         }
4511
4512         if (ret > 0) {
4513                 /* there are no items in the tree for us to truncate, we're
4514                  * done
4515                  */
4516                 if (path->slots[0] == 0)
4517                         goto out;
4518                 path->slots[0]--;
4519         }
4520
4521         while (1) {
4522                 fi = NULL;
4523                 leaf = path->nodes[0];
4524                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4525                 found_type = found_key.type;
4526
4527                 if (found_key.objectid != ino)
4528                         break;
4529
4530                 if (found_type < min_type)
4531                         break;
4532
4533                 item_end = found_key.offset;
4534                 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4535                         fi = btrfs_item_ptr(leaf, path->slots[0],
4536                                             struct btrfs_file_extent_item);
4537                         extent_type = btrfs_file_extent_type(leaf, fi);
4538                         if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4539                                 item_end +=
4540                                     btrfs_file_extent_num_bytes(leaf, fi);
4541
4542                                 trace_btrfs_truncate_show_fi_regular(
4543                                         BTRFS_I(inode), leaf, fi,
4544                                         found_key.offset);
4545                         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4546                                 item_end += btrfs_file_extent_inline_len(leaf,
4547                                                          path->slots[0], fi);
4548
4549                                 trace_btrfs_truncate_show_fi_inline(
4550                                         BTRFS_I(inode), leaf, fi, path->slots[0],
4551                                         found_key.offset);
4552                         }
4553                         item_end--;
4554                 }
4555                 if (found_type > min_type) {
4556                         del_item = 1;
4557                 } else {
4558                         if (item_end < new_size)
4559                                 break;
4560                         if (found_key.offset >= new_size)
4561                                 del_item = 1;
4562                         else
4563                                 del_item = 0;
4564                 }
4565                 found_extent = 0;
4566                 /* FIXME, shrink the extent if the ref count is only 1 */
4567                 if (found_type != BTRFS_EXTENT_DATA_KEY)
4568                         goto delete;
4569
4570                 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4571                         u64 num_dec;
4572                         extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4573                         if (!del_item) {
4574                                 u64 orig_num_bytes =
4575                                         btrfs_file_extent_num_bytes(leaf, fi);
4576                                 extent_num_bytes = ALIGN(new_size -
4577                                                 found_key.offset,
4578                                                 fs_info->sectorsize);
4579                                 btrfs_set_file_extent_num_bytes(leaf, fi,
4580                                                          extent_num_bytes);
4581                                 num_dec = (orig_num_bytes -
4582                                            extent_num_bytes);
4583                                 if (test_bit(BTRFS_ROOT_REF_COWS,
4584                                              &root->state) &&
4585                                     extent_start != 0)
4586                                         inode_sub_bytes(inode, num_dec);
4587                                 btrfs_mark_buffer_dirty(leaf);
4588                         } else {
4589                                 extent_num_bytes =
4590                                         btrfs_file_extent_disk_num_bytes(leaf,
4591                                                                          fi);
4592                                 extent_offset = found_key.offset -
4593                                         btrfs_file_extent_offset(leaf, fi);
4594
4595                                 /* FIXME blocksize != 4096 */
4596                                 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4597                                 if (extent_start != 0) {
4598                                         found_extent = 1;
4599                                         if (test_bit(BTRFS_ROOT_REF_COWS,
4600                                                      &root->state))
4601                                                 inode_sub_bytes(inode, num_dec);
4602                                 }
4603                         }
4604                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4605                         /*
4606                          * we can't truncate inline items that have had
4607                          * special encodings
4608                          */
4609                         if (!del_item &&
4610                             btrfs_file_extent_encryption(leaf, fi) == 0 &&
4611                             btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
4612                             btrfs_file_extent_compression(leaf, fi) == 0) {
4613                                 u32 size = (u32)(new_size - found_key.offset);
4614
4615                                 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4616                                 size = btrfs_file_extent_calc_inline_size(size);
4617                                 btrfs_truncate_item(root->fs_info, path, size, 1);
4618                         } else if (!del_item) {
4619                                 /*
4620                                  * We have to bail so the last_size is set to
4621                                  * just before this extent.
4622                                  */
4623                                 err = NEED_TRUNCATE_BLOCK;
4624                                 break;
4625                         }
4626
4627                         if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4628                                 inode_sub_bytes(inode, item_end + 1 - new_size);
4629                 }
4630 delete:
4631                 if (del_item)
4632                         last_size = found_key.offset;
4633                 else
4634                         last_size = new_size;
4635                 if (del_item) {
4636                         if (!pending_del_nr) {
4637                                 /* no pending yet, add ourselves */
4638                                 pending_del_slot = path->slots[0];
4639                                 pending_del_nr = 1;
4640                         } else if (pending_del_nr &&
4641                                    path->slots[0] + 1 == pending_del_slot) {
4642                                 /* hop on the pending chunk */
4643                                 pending_del_nr++;
4644                                 pending_del_slot = path->slots[0];
4645                         } else {
4646                                 BUG();
4647                         }
4648                 } else {
4649                         break;
4650                 }
4651                 should_throttle = false;
4652
4653                 if (found_extent &&
4654                     (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4655                      root == fs_info->tree_root)) {
4656                         btrfs_set_path_blocking(path);
4657                         bytes_deleted += extent_num_bytes;
4658                         ret = btrfs_free_extent(trans, root, extent_start,
4659                                                 extent_num_bytes, 0,
4660                                                 btrfs_header_owner(leaf),
4661                                                 ino, extent_offset);
4662                         BUG_ON(ret);
4663                         if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4664                                 btrfs_async_run_delayed_refs(fs_info,
4665                                         trans->delayed_ref_updates * 2,
4666                                         trans->transid, 0);
4667                         if (be_nice) {
4668                                 if (truncate_space_check(trans, root,
4669                                                          extent_num_bytes)) {
4670                                         should_end = true;
4671                                 }
4672                                 if (btrfs_should_throttle_delayed_refs(trans,
4673                                                                        fs_info))
4674                                         should_throttle = true;
4675                         }
4676                 }
4677
4678                 if (found_type == BTRFS_INODE_ITEM_KEY)
4679                         break;
4680
4681                 if (path->slots[0] == 0 ||
4682                     path->slots[0] != pending_del_slot ||
4683                     should_throttle || should_end) {
4684                         if (pending_del_nr) {
4685                                 ret = btrfs_del_items(trans, root, path,
4686                                                 pending_del_slot,
4687                                                 pending_del_nr);
4688                                 if (ret) {
4689                                         btrfs_abort_transaction(trans, ret);
4690                                         goto error;
4691                                 }
4692                                 pending_del_nr = 0;
4693                         }
4694                         btrfs_release_path(path);
4695                         if (should_throttle) {
4696                                 unsigned long updates = trans->delayed_ref_updates;
4697                                 if (updates) {
4698                                         trans->delayed_ref_updates = 0;
4699                                         ret = btrfs_run_delayed_refs(trans,
4700                                                                    updates * 2);
4701                                         if (ret && !err)
4702                                                 err = ret;
4703                                 }
4704                         }
4705                         /*
4706                          * if we failed to refill our space rsv, bail out
4707                          * and let the transaction restart
4708                          */
4709                         if (should_end) {
4710                                 err = -EAGAIN;
4711                                 goto error;
4712                         }
4713                         goto search_again;
4714                 } else {
4715                         path->slots[0]--;
4716                 }
4717         }
4718 out:
4719         if (pending_del_nr) {
4720                 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4721                                       pending_del_nr);
4722                 if (ret)
4723                         btrfs_abort_transaction(trans, ret);
4724         }
4725 error:
4726         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4727                 ASSERT(last_size >= new_size);
4728                 if (!err && last_size > new_size)
4729                         last_size = new_size;
4730                 btrfs_ordered_update_i_size(inode, last_size, NULL);
4731         }
4732
4733         btrfs_free_path(path);
4734
4735         if (be_nice && bytes_deleted > SZ_32M) {
4736                 unsigned long updates = trans->delayed_ref_updates;
4737                 if (updates) {
4738                         trans->delayed_ref_updates = 0;
4739                         ret = btrfs_run_delayed_refs(trans, updates * 2);
4740                         if (ret && !err)
4741                                 err = ret;
4742                 }
4743         }
4744         return err;
4745 }
4746
4747 /*
4748  * btrfs_truncate_block - read, zero a chunk and write a block
4749  * @inode - inode that we're zeroing
4750  * @from - the offset to start zeroing
4751  * @len - the length to zero, 0 to zero the entire range respective to the
4752  *      offset
4753  * @front - zero up to the offset instead of from the offset on
4754  *
4755  * This will find the block for the "from" offset and cow the block and zero the
4756  * part we want to zero.  This is used with truncate and hole punching.
4757  */
4758 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4759                         int front)
4760 {
4761         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4762         struct address_space *mapping = inode->i_mapping;
4763         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4764         struct btrfs_ordered_extent *ordered;
4765         struct extent_state *cached_state = NULL;
4766         struct extent_changeset *data_reserved = NULL;
4767         char *kaddr;
4768         u32 blocksize = fs_info->sectorsize;
4769         pgoff_t index = from >> PAGE_SHIFT;
4770         unsigned offset = from & (blocksize - 1);
4771         struct page *page;
4772         gfp_t mask = btrfs_alloc_write_mask(mapping);
4773         int ret = 0;
4774         u64 block_start;
4775         u64 block_end;
4776
4777         if (IS_ALIGNED(offset, blocksize) &&
4778             (!len || IS_ALIGNED(len, blocksize)))
4779                 goto out;
4780
4781         block_start = round_down(from, blocksize);
4782         block_end = block_start + blocksize - 1;
4783
4784         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
4785                                            block_start, blocksize);
4786         if (ret)
4787                 goto out;
4788
4789 again:
4790         page = find_or_create_page(mapping, index, mask);
4791         if (!page) {
4792                 btrfs_delalloc_release_space(inode, data_reserved,
4793                                              block_start, blocksize, true);
4794                 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, true);
4795                 ret = -ENOMEM;
4796                 goto out;
4797         }
4798
4799         if (!PageUptodate(page)) {
4800                 ret = btrfs_readpage(NULL, page);
4801                 lock_page(page);
4802                 if (page->mapping != mapping) {
4803                         unlock_page(page);
4804                         put_page(page);
4805                         goto again;
4806                 }
4807                 if (!PageUptodate(page)) {
4808                         ret = -EIO;
4809                         goto out_unlock;
4810                 }
4811         }
4812         wait_on_page_writeback(page);
4813
4814         lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4815         set_page_extent_mapped(page);
4816
4817         ordered = btrfs_lookup_ordered_extent(inode, block_start);
4818         if (ordered) {
4819                 unlock_extent_cached(io_tree, block_start, block_end,
4820                                      &cached_state);
4821                 unlock_page(page);
4822                 put_page(page);
4823                 btrfs_start_ordered_extent(inode, ordered, 1);
4824                 btrfs_put_ordered_extent(ordered);
4825                 goto again;
4826         }
4827
4828         clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4829                           EXTENT_DIRTY | EXTENT_DELALLOC |
4830                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4831                           0, 0, &cached_state);
4832
4833         ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
4834                                         &cached_state, 0);
4835         if (ret) {
4836                 unlock_extent_cached(io_tree, block_start, block_end,
4837                                      &cached_state);
4838                 goto out_unlock;
4839         }
4840
4841         if (offset != blocksize) {
4842                 if (!len)
4843                         len = blocksize - offset;
4844                 kaddr = kmap(page);
4845                 if (front)
4846                         memset(kaddr + (block_start - page_offset(page)),
4847                                 0, offset);
4848                 else
4849                         memset(kaddr + (block_start - page_offset(page)) +  offset,
4850                                 0, len);
4851                 flush_dcache_page(page);
4852                 kunmap(page);
4853         }
4854         ClearPageChecked(page);
4855         set_page_dirty(page);
4856         unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
4857
4858 out_unlock:
4859         if (ret)
4860                 btrfs_delalloc_release_space(inode, data_reserved, block_start,
4861                                              blocksize, true);
4862         btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, (ret != 0));
4863         unlock_page(page);
4864         put_page(page);
4865 out:
4866         extent_changeset_free(data_reserved);
4867         return ret;
4868 }
4869
4870 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4871                              u64 offset, u64 len)
4872 {
4873         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4874         struct btrfs_trans_handle *trans;
4875         int ret;
4876
4877         /*
4878          * Still need to make sure the inode looks like it's been updated so
4879          * that any holes get logged if we fsync.
4880          */
4881         if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4882                 BTRFS_I(inode)->last_trans = fs_info->generation;
4883                 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4884                 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4885                 return 0;
4886         }
4887
4888         /*
4889          * 1 - for the one we're dropping
4890          * 1 - for the one we're adding
4891          * 1 - for updating the inode.
4892          */
4893         trans = btrfs_start_transaction(root, 3);
4894         if (IS_ERR(trans))
4895                 return PTR_ERR(trans);
4896
4897         ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4898         if (ret) {
4899                 btrfs_abort_transaction(trans, ret);
4900                 btrfs_end_transaction(trans);
4901                 return ret;
4902         }
4903
4904         ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4905                         offset, 0, 0, len, 0, len, 0, 0, 0);
4906         if (ret)
4907                 btrfs_abort_transaction(trans, ret);
4908         else
4909                 btrfs_update_inode(trans, root, inode);
4910         btrfs_end_transaction(trans);
4911         return ret;
4912 }
4913
4914 /*
4915  * This function puts in dummy file extents for the area we're creating a hole
4916  * for.  So if we are truncating this file to a larger size we need to insert
4917  * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4918  * the range between oldsize and size
4919  */
4920 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4921 {
4922         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4923         struct btrfs_root *root = BTRFS_I(inode)->root;
4924         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4925         struct extent_map *em = NULL;
4926         struct extent_state *cached_state = NULL;
4927         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4928         u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4929         u64 block_end = ALIGN(size, fs_info->sectorsize);
4930         u64 last_byte;
4931         u64 cur_offset;
4932         u64 hole_size;
4933         int err = 0;
4934
4935         /*
4936          * If our size started in the middle of a block we need to zero out the
4937          * rest of the block before we expand the i_size, otherwise we could
4938          * expose stale data.
4939          */
4940         err = btrfs_truncate_block(inode, oldsize, 0, 0);
4941         if (err)
4942                 return err;
4943
4944         if (size <= hole_start)
4945                 return 0;
4946
4947         while (1) {
4948                 struct btrfs_ordered_extent *ordered;
4949
4950                 lock_extent_bits(io_tree, hole_start, block_end - 1,
4951                                  &cached_state);
4952                 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4953                                                      block_end - hole_start);
4954                 if (!ordered)
4955                         break;
4956                 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4957                                      &cached_state);
4958                 btrfs_start_ordered_extent(inode, ordered, 1);
4959                 btrfs_put_ordered_extent(ordered);
4960         }
4961
4962         cur_offset = hole_start;
4963         while (1) {
4964                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4965                                 block_end - cur_offset, 0);
4966                 if (IS_ERR(em)) {
4967                         err = PTR_ERR(em);
4968                         em = NULL;
4969                         break;
4970                 }
4971                 last_byte = min(extent_map_end(em), block_end);
4972                 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4973                 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4974                         struct extent_map *hole_em;
4975                         hole_size = last_byte - cur_offset;
4976
4977                         err = maybe_insert_hole(root, inode, cur_offset,
4978                                                 hole_size);
4979                         if (err)
4980                                 break;
4981                         btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
4982                                                 cur_offset + hole_size - 1, 0);
4983                         hole_em = alloc_extent_map();
4984                         if (!hole_em) {
4985                                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4986                                         &BTRFS_I(inode)->runtime_flags);
4987                                 goto next;
4988                         }
4989                         hole_em->start = cur_offset;
4990                         hole_em->len = hole_size;
4991                         hole_em->orig_start = cur_offset;
4992
4993                         hole_em->block_start = EXTENT_MAP_HOLE;
4994                         hole_em->block_len = 0;
4995                         hole_em->orig_block_len = 0;
4996                         hole_em->ram_bytes = hole_size;
4997                         hole_em->bdev = fs_info->fs_devices->latest_bdev;
4998                         hole_em->compress_type = BTRFS_COMPRESS_NONE;
4999                         hole_em->generation = fs_info->generation;
5000
5001                         while (1) {
5002                                 write_lock(&em_tree->lock);
5003                                 err = add_extent_mapping(em_tree, hole_em, 1);
5004                                 write_unlock(&em_tree->lock);
5005                                 if (err != -EEXIST)
5006                                         break;
5007                                 btrfs_drop_extent_cache(BTRFS_I(inode),
5008                                                         cur_offset,
5009                                                         cur_offset +
5010                                                         hole_size - 1, 0);
5011                         }
5012                         free_extent_map(hole_em);
5013                 }
5014 next:
5015                 free_extent_map(em);
5016                 em = NULL;
5017                 cur_offset = last_byte;
5018                 if (cur_offset >= block_end)
5019                         break;
5020         }
5021         free_extent_map(em);
5022         unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
5023         return err;
5024 }
5025
5026 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5027 {
5028         struct btrfs_root *root = BTRFS_I(inode)->root;
5029         struct btrfs_trans_handle *trans;
5030         loff_t oldsize = i_size_read(inode);
5031         loff_t newsize = attr->ia_size;
5032         int mask = attr->ia_valid;
5033         int ret;
5034
5035         /*
5036          * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5037          * special case where we need to update the times despite not having
5038          * these flags set.  For all other operations the VFS set these flags
5039          * explicitly if it wants a timestamp update.
5040          */
5041         if (newsize != oldsize) {
5042                 inode_inc_iversion(inode);
5043                 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5044                         inode->i_ctime = inode->i_mtime =
5045                                 current_time(inode);
5046         }
5047
5048         if (newsize > oldsize) {
5049                 /*
5050                  * Don't do an expanding truncate while snapshotting is ongoing.
5051                  * This is to ensure the snapshot captures a fully consistent
5052                  * state of this file - if the snapshot captures this expanding
5053                  * truncation, it must capture all writes that happened before
5054                  * this truncation.
5055                  */
5056                 btrfs_wait_for_snapshot_creation(root);
5057                 ret = btrfs_cont_expand(inode, oldsize, newsize);
5058                 if (ret) {
5059                         btrfs_end_write_no_snapshotting(root);
5060                         return ret;
5061                 }
5062
5063                 trans = btrfs_start_transaction(root, 1);
5064                 if (IS_ERR(trans)) {
5065                         btrfs_end_write_no_snapshotting(root);
5066                         return PTR_ERR(trans);
5067                 }
5068
5069                 i_size_write(inode, newsize);
5070                 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5071                 pagecache_isize_extended(inode, oldsize, newsize);
5072                 ret = btrfs_update_inode(trans, root, inode);
5073                 btrfs_end_write_no_snapshotting(root);
5074                 btrfs_end_transaction(trans);
5075         } else {
5076
5077                 /*
5078                  * We're truncating a file that used to have good data down to
5079                  * zero. Make sure it gets into the ordered flush list so that
5080                  * any new writes get down to disk quickly.
5081                  */
5082                 if (newsize == 0)
5083                         set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5084                                 &BTRFS_I(inode)->runtime_flags);
5085
5086                 /*
5087                  * 1 for the orphan item we're going to add
5088                  * 1 for the orphan item deletion.
5089                  */
5090                 trans = btrfs_start_transaction(root, 2);
5091                 if (IS_ERR(trans))
5092                         return PTR_ERR(trans);
5093
5094                 /*
5095                  * We need to do this in case we fail at _any_ point during the
5096                  * actual truncate.  Once we do the truncate_setsize we could
5097                  * invalidate pages which forces any outstanding ordered io to
5098                  * be instantly completed which will give us extents that need
5099                  * to be truncated.  If we fail to get an orphan inode down we
5100                  * could have left over extents that were never meant to live,
5101                  * so we need to guarantee from this point on that everything
5102                  * will be consistent.
5103                  */
5104                 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
5105                 btrfs_end_transaction(trans);
5106                 if (ret)
5107                         return ret;
5108
5109                 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5110                 truncate_setsize(inode, newsize);
5111
5112                 /* Disable nonlocked read DIO to avoid the end less truncate */
5113                 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5114                 inode_dio_wait(inode);
5115                 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5116
5117                 ret = btrfs_truncate(inode, newsize == oldsize);
5118                 if (ret && inode->i_nlink) {
5119                         int err;
5120
5121                         /* To get a stable disk_i_size */
5122                         err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5123                         if (err) {
5124                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5125                                 return err;
5126                         }
5127
5128                         /*
5129                          * failed to truncate, disk_i_size is only adjusted down
5130                          * as we remove extents, so it should represent the true
5131                          * size of the inode, so reset the in memory size and
5132                          * delete our orphan entry.
5133                          */
5134                         trans = btrfs_join_transaction(root);
5135                         if (IS_ERR(trans)) {
5136                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5137                                 return ret;
5138                         }
5139                         i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5140                         err = btrfs_orphan_del(trans, BTRFS_I(inode));
5141                         if (err)
5142                                 btrfs_abort_transaction(trans, err);
5143                         btrfs_end_transaction(trans);
5144                 }
5145         }
5146
5147         return ret;
5148 }
5149
5150 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5151 {
5152         struct inode *inode = d_inode(dentry);
5153         struct btrfs_root *root = BTRFS_I(inode)->root;
5154         int err;
5155
5156         if (btrfs_root_readonly(root))
5157                 return -EROFS;
5158
5159         err = setattr_prepare(dentry, attr);
5160         if (err)
5161                 return err;
5162
5163         if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5164                 err = btrfs_setsize(inode, attr);
5165                 if (err)
5166                         return err;
5167         }
5168
5169         if (attr->ia_valid) {
5170                 setattr_copy(inode, attr);
5171                 inode_inc_iversion(inode);
5172                 err = btrfs_dirty_inode(inode);
5173
5174                 if (!err && attr->ia_valid & ATTR_MODE)
5175                         err = posix_acl_chmod(inode, inode->i_mode);
5176         }
5177
5178         return err;
5179 }
5180
5181 /*
5182  * While truncating the inode pages during eviction, we get the VFS calling
5183  * btrfs_invalidatepage() against each page of the inode. This is slow because
5184  * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5185  * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5186  * extent_state structures over and over, wasting lots of time.
5187  *
5188  * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5189  * those expensive operations on a per page basis and do only the ordered io
5190  * finishing, while we release here the extent_map and extent_state structures,
5191  * without the excessive merging and splitting.
5192  */
5193 static void evict_inode_truncate_pages(struct inode *inode)
5194 {
5195         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5196         struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5197         struct rb_node *node;
5198
5199         ASSERT(inode->i_state & I_FREEING);
5200         truncate_inode_pages_final(&inode->i_data);
5201
5202         write_lock(&map_tree->lock);
5203         while (!RB_EMPTY_ROOT(&map_tree->map)) {
5204                 struct extent_map *em;
5205
5206                 node = rb_first(&map_tree->map);
5207                 em = rb_entry(node, struct extent_map, rb_node);
5208                 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5209                 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5210                 remove_extent_mapping(map_tree, em);
5211                 free_extent_map(em);
5212                 if (need_resched()) {
5213                         write_unlock(&map_tree->lock);
5214                         cond_resched();
5215                         write_lock(&map_tree->lock);
5216                 }
5217         }
5218         write_unlock(&map_tree->lock);
5219
5220         /*
5221          * Keep looping until we have no more ranges in the io tree.
5222          * We can have ongoing bios started by readpages (called from readahead)
5223          * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5224          * still in progress (unlocked the pages in the bio but did not yet
5225          * unlocked the ranges in the io tree). Therefore this means some
5226          * ranges can still be locked and eviction started because before
5227          * submitting those bios, which are executed by a separate task (work
5228          * queue kthread), inode references (inode->i_count) were not taken
5229          * (which would be dropped in the end io callback of each bio).
5230          * Therefore here we effectively end up waiting for those bios and
5231          * anyone else holding locked ranges without having bumped the inode's
5232          * reference count - if we don't do it, when they access the inode's
5233          * io_tree to unlock a range it may be too late, leading to an
5234          * use-after-free issue.
5235          */
5236         spin_lock(&io_tree->lock);
5237         while (!RB_EMPTY_ROOT(&io_tree->state)) {
5238                 struct extent_state *state;
5239                 struct extent_state *cached_state = NULL;
5240                 u64 start;
5241                 u64 end;
5242
5243                 node = rb_first(&io_tree->state);
5244                 state = rb_entry(node, struct extent_state, rb_node);
5245                 start = state->start;
5246                 end = state->end;
5247                 spin_unlock(&io_tree->lock);
5248
5249                 lock_extent_bits(io_tree, start, end, &cached_state);
5250
5251                 /*
5252                  * If still has DELALLOC flag, the extent didn't reach disk,
5253                  * and its reserved space won't be freed by delayed_ref.
5254                  * So we need to free its reserved space here.
5255                  * (Refer to comment in btrfs_invalidatepage, case 2)
5256                  *
5257                  * Note, end is the bytenr of last byte, so we need + 1 here.
5258                  */
5259                 if (state->state & EXTENT_DELALLOC)
5260                         btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5261
5262                 clear_extent_bit(io_tree, start, end,
5263                                  EXTENT_LOCKED | EXTENT_DIRTY |
5264                                  EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5265                                  EXTENT_DEFRAG, 1, 1, &cached_state);
5266
5267                 cond_resched();
5268                 spin_lock(&io_tree->lock);
5269         }
5270         spin_unlock(&io_tree->lock);
5271 }
5272
5273 void btrfs_evict_inode(struct inode *inode)
5274 {
5275         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5276         struct btrfs_trans_handle *trans;
5277         struct btrfs_root *root = BTRFS_I(inode)->root;
5278         struct btrfs_block_rsv *rsv, *global_rsv;
5279         int steal_from_global = 0;
5280         u64 min_size;
5281         int ret;
5282
5283         trace_btrfs_inode_evict(inode);
5284
5285         if (!root) {
5286                 clear_inode(inode);
5287                 return;
5288         }
5289
5290         min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5291
5292         evict_inode_truncate_pages(inode);
5293
5294         if (inode->i_nlink &&
5295             ((btrfs_root_refs(&root->root_item) != 0 &&
5296               root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5297              btrfs_is_free_space_inode(BTRFS_I(inode))))
5298                 goto no_delete;
5299
5300         if (is_bad_inode(inode)) {
5301                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5302                 goto no_delete;
5303         }
5304         /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5305         if (!special_file(inode->i_mode))
5306                 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5307
5308         btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5309
5310         if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5311                 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5312                                  &BTRFS_I(inode)->runtime_flags));
5313                 goto no_delete;
5314         }
5315
5316         if (inode->i_nlink > 0) {
5317                 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5318                        root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5319                 goto no_delete;
5320         }
5321
5322         ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5323         if (ret) {
5324                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5325                 goto no_delete;
5326         }
5327
5328         rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5329         if (!rsv) {
5330                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5331                 goto no_delete;
5332         }
5333         rsv->size = min_size;
5334         rsv->failfast = 1;
5335         global_rsv = &fs_info->global_block_rsv;
5336
5337         btrfs_i_size_write(BTRFS_I(inode), 0);
5338
5339         /*
5340          * This is a bit simpler than btrfs_truncate since we've already
5341          * reserved our space for our orphan item in the unlink, so we just
5342          * need to reserve some slack space in case we add bytes and update
5343          * inode item when doing the truncate.
5344          */
5345         while (1) {
5346                 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5347                                              BTRFS_RESERVE_FLUSH_LIMIT);
5348
5349                 /*
5350                  * Try and steal from the global reserve since we will
5351                  * likely not use this space anyway, we want to try as
5352                  * hard as possible to get this to work.
5353                  */
5354                 if (ret)
5355                         steal_from_global++;
5356                 else
5357                         steal_from_global = 0;
5358                 ret = 0;
5359
5360                 /*
5361                  * steal_from_global == 0: we reserved stuff, hooray!
5362                  * steal_from_global == 1: we didn't reserve stuff, boo!
5363                  * steal_from_global == 2: we've committed, still not a lot of
5364                  * room but maybe we'll have room in the global reserve this
5365                  * time.
5366                  * steal_from_global == 3: abandon all hope!
5367                  */
5368                 if (steal_from_global > 2) {
5369                         btrfs_warn(fs_info,
5370                                    "Could not get space for a delete, will truncate on mount %d",
5371                                    ret);
5372                         btrfs_orphan_del(NULL, BTRFS_I(inode));
5373                         btrfs_free_block_rsv(fs_info, rsv);
5374                         goto no_delete;
5375                 }
5376
5377                 trans = btrfs_join_transaction(root);
5378                 if (IS_ERR(trans)) {
5379                         btrfs_orphan_del(NULL, BTRFS_I(inode));
5380                         btrfs_free_block_rsv(fs_info, rsv);
5381                         goto no_delete;
5382                 }
5383
5384                 /*
5385                  * We can't just steal from the global reserve, we need to make
5386                  * sure there is room to do it, if not we need to commit and try
5387                  * again.
5388                  */
5389                 if (steal_from_global) {
5390                         if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5391                                 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5392                                                               min_size, 0);
5393                         else
5394                                 ret = -ENOSPC;
5395                 }
5396
5397                 /*
5398                  * Couldn't steal from the global reserve, we have too much
5399                  * pending stuff built up, commit the transaction and try it
5400                  * again.
5401                  */
5402                 if (ret) {
5403                         ret = btrfs_commit_transaction(trans);
5404                         if (ret) {
5405                                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5406                                 btrfs_free_block_rsv(fs_info, rsv);
5407                                 goto no_delete;
5408                         }
5409                         continue;
5410                 } else {
5411                         steal_from_global = 0;
5412                 }
5413
5414                 trans->block_rsv = rsv;
5415
5416                 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5417                 if (ret != -ENOSPC && ret != -EAGAIN)
5418                         break;
5419
5420                 trans->block_rsv = &fs_info->trans_block_rsv;
5421                 btrfs_end_transaction(trans);
5422                 trans = NULL;
5423                 btrfs_btree_balance_dirty(fs_info);
5424         }
5425
5426         btrfs_free_block_rsv(fs_info, rsv);
5427
5428         /*
5429          * Errors here aren't a big deal, it just means we leave orphan items
5430          * in the tree.  They will be cleaned up on the next mount.
5431          */
5432         if (ret == 0) {
5433                 trans->block_rsv = root->orphan_block_rsv;
5434                 btrfs_orphan_del(trans, BTRFS_I(inode));
5435         } else {
5436                 btrfs_orphan_del(NULL, BTRFS_I(inode));
5437         }
5438
5439         trans->block_rsv = &fs_info->trans_block_rsv;
5440         if (!(root == fs_info->tree_root ||
5441               root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5442                 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5443
5444         btrfs_end_transaction(trans);
5445         btrfs_btree_balance_dirty(fs_info);
5446 no_delete:
5447         btrfs_remove_delayed_node(BTRFS_I(inode));
5448         clear_inode(inode);
5449 }
5450
5451 /*
5452  * this returns the key found in the dir entry in the location pointer.
5453  * If no dir entries were found, returns -ENOENT.
5454  * If found a corrupted location in dir entry, returns -EUCLEAN.
5455  */
5456 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5457                                struct btrfs_key *location)
5458 {
5459         const char *name = dentry->d_name.name;
5460         int namelen = dentry->d_name.len;
5461         struct btrfs_dir_item *di;
5462         struct btrfs_path *path;
5463         struct btrfs_root *root = BTRFS_I(dir)->root;
5464         int ret = 0;
5465
5466         path = btrfs_alloc_path();
5467         if (!path)
5468                 return -ENOMEM;
5469
5470         di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5471                         name, namelen, 0);
5472         if (!di) {
5473                 ret = -ENOENT;
5474                 goto out;
5475         }
5476         if (IS_ERR(di)) {
5477                 ret = PTR_ERR(di);
5478                 goto out;
5479         }
5480
5481         btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5482         if (location->type != BTRFS_INODE_ITEM_KEY &&
5483             location->type != BTRFS_ROOT_ITEM_KEY) {
5484                 ret = -EUCLEAN;
5485                 btrfs_warn(root->fs_info,
5486 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5487                            __func__, name, btrfs_ino(BTRFS_I(dir)),
5488                            location->objectid, location->type, location->offset);
5489         }
5490 out:
5491         btrfs_free_path(path);
5492         return ret;
5493 }
5494
5495 /*
5496  * when we hit a tree root in a directory, the btrfs part of the inode
5497  * needs to be changed to reflect the root directory of the tree root.  This
5498  * is kind of like crossing a mount point.
5499  */
5500 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5501                                     struct inode *dir,
5502                                     struct dentry *dentry,
5503                                     struct btrfs_key *location,
5504                                     struct btrfs_root **sub_root)
5505 {
5506         struct btrfs_path *path;
5507         struct btrfs_root *new_root;
5508         struct btrfs_root_ref *ref;
5509         struct extent_buffer *leaf;
5510         struct btrfs_key key;
5511         int ret;
5512         int err = 0;
5513
5514         path = btrfs_alloc_path();
5515         if (!path) {
5516                 err = -ENOMEM;
5517                 goto out;
5518         }
5519
5520         err = -ENOENT;
5521         key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5522         key.type = BTRFS_ROOT_REF_KEY;
5523         key.offset = location->objectid;
5524
5525         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5526         if (ret) {
5527                 if (ret < 0)
5528                         err = ret;
5529                 goto out;
5530         }
5531
5532         leaf = path->nodes[0];
5533         ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5534         if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5535             btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5536                 goto out;
5537
5538         ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5539                                    (unsigned long)(ref + 1),
5540                                    dentry->d_name.len);
5541         if (ret)
5542                 goto out;
5543
5544         btrfs_release_path(path);
5545
5546         new_root = btrfs_read_fs_root_no_name(fs_info, location);
5547         if (IS_ERR(new_root)) {
5548                 err = PTR_ERR(new_root);
5549                 goto out;
5550         }
5551
5552         *sub_root = new_root;
5553         location->objectid = btrfs_root_dirid(&new_root->root_item);
5554         location->type = BTRFS_INODE_ITEM_KEY;
5555         location->offset = 0;
5556         err = 0;
5557 out:
5558         btrfs_free_path(path);
5559         return err;
5560 }
5561
5562 static void inode_tree_add(struct inode *inode)
5563 {
5564         struct btrfs_root *root = BTRFS_I(inode)->root;
5565         struct btrfs_inode *entry;
5566         struct rb_node **p;
5567         struct rb_node *parent;
5568         struct rb_node *new = &BTRFS_I(inode)->rb_node;
5569         u64 ino = btrfs_ino(BTRFS_I(inode));
5570
5571         if (inode_unhashed(inode))
5572                 return;
5573         parent = NULL;
5574         spin_lock(&root->inode_lock);
5575         p = &root->inode_tree.rb_node;
5576         while (*p) {
5577                 parent = *p;
5578                 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5579
5580                 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5581                         p = &parent->rb_left;
5582                 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5583                         p = &parent->rb_right;
5584                 else {
5585                         WARN_ON(!(entry->vfs_inode.i_state &
5586                                   (I_WILL_FREE | I_FREEING)));
5587                         rb_replace_node(parent, new, &root->inode_tree);
5588                         RB_CLEAR_NODE(parent);
5589                         spin_unlock(&root->inode_lock);
5590                         return;
5591                 }
5592         }
5593         rb_link_node(new, parent, p);
5594         rb_insert_color(new, &root->inode_tree);
5595         spin_unlock(&root->inode_lock);
5596 }
5597
5598 static void inode_tree_del(struct inode *inode)
5599 {
5600         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5601         struct btrfs_root *root = BTRFS_I(inode)->root;
5602         int empty = 0;
5603
5604         spin_lock(&root->inode_lock);
5605         if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5606                 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5607                 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5608                 empty = RB_EMPTY_ROOT(&root->inode_tree);
5609         }
5610         spin_unlock(&root->inode_lock);
5611
5612         if (empty && btrfs_root_refs(&root->root_item) == 0) {
5613                 synchronize_srcu(&fs_info->subvol_srcu);
5614                 spin_lock(&root->inode_lock);
5615                 empty = RB_EMPTY_ROOT(&root->inode_tree);
5616                 spin_unlock(&root->inode_lock);
5617                 if (empty)
5618                         btrfs_add_dead_root(root);
5619         }
5620 }
5621
5622 void btrfs_invalidate_inodes(struct btrfs_root *root)
5623 {
5624         struct btrfs_fs_info *fs_info = root->fs_info;
5625         struct rb_node *node;
5626         struct rb_node *prev;
5627         struct btrfs_inode *entry;
5628         struct inode *inode;
5629         u64 objectid = 0;
5630
5631         if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5632                 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5633
5634         spin_lock(&root->inode_lock);
5635 again:
5636         node = root->inode_tree.rb_node;
5637         prev = NULL;
5638         while (node) {
5639                 prev = node;
5640                 entry = rb_entry(node, struct btrfs_inode, rb_node);
5641
5642                 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5643                         node = node->rb_left;
5644                 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5645                         node = node->rb_right;
5646                 else
5647                         break;
5648         }
5649         if (!node) {
5650                 while (prev) {
5651                         entry = rb_entry(prev, struct btrfs_inode, rb_node);
5652                         if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
5653                                 node = prev;
5654                                 break;
5655                         }
5656                         prev = rb_next(prev);
5657                 }
5658         }
5659         while (node) {
5660                 entry = rb_entry(node, struct btrfs_inode, rb_node);
5661                 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
5662                 inode = igrab(&entry->vfs_inode);
5663                 if (inode) {
5664                         spin_unlock(&root->inode_lock);
5665                         if (atomic_read(&inode->i_count) > 1)
5666                                 d_prune_aliases(inode);
5667                         /*
5668                          * btrfs_drop_inode will have it removed from
5669                          * the inode cache when its usage count
5670                          * hits zero.
5671                          */
5672                         iput(inode);
5673                         cond_resched();
5674                         spin_lock(&root->inode_lock);
5675                         goto again;
5676                 }
5677
5678                 if (cond_resched_lock(&root->inode_lock))
5679                         goto again;
5680
5681                 node = rb_next(node);
5682         }
5683         spin_unlock(&root->inode_lock);
5684 }
5685
5686 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5687 {
5688         struct btrfs_iget_args *args = p;
5689         inode->i_ino = args->location->objectid;
5690         memcpy(&BTRFS_I(inode)->location, args->location,
5691                sizeof(*args->location));
5692         BTRFS_I(inode)->root = args->root;
5693         return 0;
5694 }
5695
5696 static int btrfs_find_actor(struct inode *inode, void *opaque)
5697 {
5698         struct btrfs_iget_args *args = opaque;
5699         return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5700                 args->root == BTRFS_I(inode)->root;
5701 }
5702
5703 static struct inode *btrfs_iget_locked(struct super_block *s,
5704                                        struct btrfs_key *location,
5705                                        struct btrfs_root *root)
5706 {
5707         struct inode *inode;
5708         struct btrfs_iget_args args;
5709         unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5710
5711         args.location = location;
5712         args.root = root;
5713
5714         inode = iget5_locked(s, hashval, btrfs_find_actor,
5715                              btrfs_init_locked_inode,
5716                              (void *)&args);
5717         return inode;
5718 }
5719
5720 /* Get an inode object given its location and corresponding root.
5721  * Returns in *is_new if the inode was read from disk
5722  */
5723 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5724                          struct btrfs_root *root, int *new)
5725 {
5726         struct inode *inode;
5727
5728         inode = btrfs_iget_locked(s, location, root);
5729         if (!inode)
5730                 return ERR_PTR(-ENOMEM);
5731
5732         if (inode->i_state & I_NEW) {
5733                 int ret;
5734
5735                 ret = btrfs_read_locked_inode(inode);
5736                 if (!is_bad_inode(inode)) {
5737                         inode_tree_add(inode);
5738                         unlock_new_inode(inode);
5739                         if (new)
5740                                 *new = 1;
5741                 } else {
5742                         unlock_new_inode(inode);
5743                         iput(inode);
5744                         ASSERT(ret < 0);
5745                         inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5746                 }
5747         }
5748
5749         return inode;
5750 }
5751
5752 static struct inode *new_simple_dir(struct super_block *s,
5753                                     struct btrfs_key *key,
5754                                     struct btrfs_root *root)
5755 {
5756         struct inode *inode = new_inode(s);
5757
5758         if (!inode)
5759                 return ERR_PTR(-ENOMEM);
5760
5761         BTRFS_I(inode)->root = root;
5762         memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5763         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5764
5765         inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5766         inode->i_op = &btrfs_dir_ro_inode_operations;
5767         inode->i_opflags &= ~IOP_XATTR;
5768         inode->i_fop = &simple_dir_operations;
5769         inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5770         inode->i_mtime = current_time(inode);
5771         inode->i_atime = inode->i_mtime;
5772         inode->i_ctime = inode->i_mtime;
5773         BTRFS_I(inode)->i_otime = inode->i_mtime;
5774
5775         return inode;
5776 }
5777
5778 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5779 {
5780         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5781         struct inode *inode;
5782         struct btrfs_root *root = BTRFS_I(dir)->root;
5783         struct btrfs_root *sub_root = root;
5784         struct btrfs_key location;
5785         int index;
5786         int ret = 0;
5787
5788         if (dentry->d_name.len > BTRFS_NAME_LEN)
5789                 return ERR_PTR(-ENAMETOOLONG);
5790
5791         ret = btrfs_inode_by_name(dir, dentry, &location);
5792         if (ret < 0)
5793                 return ERR_PTR(ret);
5794
5795         if (location.type == BTRFS_INODE_ITEM_KEY) {
5796                 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5797                 return inode;
5798         }
5799
5800         index = srcu_read_lock(&fs_info->subvol_srcu);
5801         ret = fixup_tree_root_location(fs_info, dir, dentry,
5802                                        &location, &sub_root);
5803         if (ret < 0) {
5804                 if (ret != -ENOENT)
5805                         inode = ERR_PTR(ret);
5806                 else
5807                         inode = new_simple_dir(dir->i_sb, &location, sub_root);
5808         } else {
5809                 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5810         }
5811         srcu_read_unlock(&fs_info->subvol_srcu, index);
5812
5813         if (!IS_ERR(inode) && root != sub_root) {
5814                 down_read(&fs_info->cleanup_work_sem);
5815                 if (!sb_rdonly(inode->i_sb))
5816                         ret = btrfs_orphan_cleanup(sub_root);
5817                 up_read(&fs_info->cleanup_work_sem);
5818                 if (ret) {
5819                         iput(inode);
5820                         inode = ERR_PTR(ret);
5821                 }
5822         }
5823
5824         return inode;
5825 }
5826
5827 static int btrfs_dentry_delete(const struct dentry *dentry)
5828 {
5829         struct btrfs_root *root;
5830         struct inode *inode = d_inode(dentry);
5831
5832         if (!inode && !IS_ROOT(dentry))
5833                 inode = d_inode(dentry->d_parent);
5834
5835         if (inode) {
5836                 root = BTRFS_I(inode)->root;
5837                 if (btrfs_root_refs(&root->root_item) == 0)
5838                         return 1;
5839
5840                 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5841                         return 1;
5842         }
5843         return 0;
5844 }
5845
5846 static void btrfs_dentry_release(struct dentry *dentry)
5847 {
5848         kfree(dentry->d_fsdata);
5849 }
5850
5851 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5852                                    unsigned int flags)
5853 {
5854         struct inode *inode;
5855
5856         inode = btrfs_lookup_dentry(dir, dentry);
5857         if (IS_ERR(inode)) {
5858                 if (PTR_ERR(inode) == -ENOENT)
5859                         inode = NULL;
5860                 else
5861                         return ERR_CAST(inode);
5862         }
5863
5864         return d_splice_alias(inode, dentry);
5865 }
5866
5867 unsigned char btrfs_filetype_table[] = {
5868         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5869 };
5870
5871 /*
5872  * All this infrastructure exists because dir_emit can fault, and we are holding
5873  * the tree lock when doing readdir.  For now just allocate a buffer and copy
5874  * our information into that, and then dir_emit from the buffer.  This is
5875  * similar to what NFS does, only we don't keep the buffer around in pagecache
5876  * because I'm afraid I'll mess that up.  Long term we need to make filldir do
5877  * copy_to_user_inatomic so we don't have to worry about page faulting under the
5878  * tree lock.
5879  */
5880 static int btrfs_opendir(struct inode *inode, struct file *file)
5881 {
5882         struct btrfs_file_private *private;
5883
5884         private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
5885         if (!private)
5886                 return -ENOMEM;
5887         private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
5888         if (!private->filldir_buf) {
5889                 kfree(private);
5890                 return -ENOMEM;
5891         }
5892         file->private_data = private;
5893         return 0;
5894 }
5895
5896 struct dir_entry {
5897         u64 ino;
5898         u64 offset;
5899         unsigned type;
5900         int name_len;
5901 };
5902
5903 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
5904 {
5905         while (entries--) {
5906                 struct dir_entry *entry = addr;
5907                 char *name = (char *)(entry + 1);
5908
5909                 ctx->pos = get_unaligned(&entry->offset);
5910                 if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
5911                                          get_unaligned(&entry->ino),
5912                                          get_unaligned(&entry->type)))
5913                         return 1;
5914                 addr += sizeof(struct dir_entry) +
5915                         get_unaligned(&entry->name_len);
5916                 ctx->pos++;
5917         }
5918         return 0;
5919 }
5920
5921 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5922 {
5923         struct inode *inode = file_inode(file);
5924         struct btrfs_root *root = BTRFS_I(inode)->root;
5925         struct btrfs_file_private *private = file->private_data;
5926         struct btrfs_dir_item *di;
5927         struct btrfs_key key;
5928         struct btrfs_key found_key;
5929         struct btrfs_path *path;
5930         void *addr;
5931         struct list_head ins_list;
5932         struct list_head del_list;
5933         int ret;
5934         struct extent_buffer *leaf;
5935         int slot;
5936         char *name_ptr;
5937         int name_len;
5938         int entries = 0;
5939         int total_len = 0;
5940         bool put = false;
5941         struct btrfs_key location;
5942
5943         if (!dir_emit_dots(file, ctx))
5944                 return 0;
5945
5946         path = btrfs_alloc_path();
5947         if (!path)
5948                 return -ENOMEM;
5949
5950         addr = private->filldir_buf;
5951         path->reada = READA_FORWARD;
5952
5953         INIT_LIST_HEAD(&ins_list);
5954         INIT_LIST_HEAD(&del_list);
5955         put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5956
5957 again:
5958         key.type = BTRFS_DIR_INDEX_KEY;
5959         key.offset = ctx->pos;
5960         key.objectid = btrfs_ino(BTRFS_I(inode));
5961
5962         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5963         if (ret < 0)
5964                 goto err;
5965
5966         while (1) {
5967                 struct dir_entry *entry;
5968
5969                 leaf = path->nodes[0];
5970                 slot = path->slots[0];
5971                 if (slot >= btrfs_header_nritems(leaf)) {
5972                         ret = btrfs_next_leaf(root, path);
5973                         if (ret < 0)
5974                                 goto err;
5975                         else if (ret > 0)
5976                                 break;
5977                         continue;
5978                 }
5979
5980                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5981
5982                 if (found_key.objectid != key.objectid)
5983                         break;
5984                 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5985                         break;
5986                 if (found_key.offset < ctx->pos)
5987                         goto next;
5988                 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5989                         goto next;
5990                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5991                 name_len = btrfs_dir_name_len(leaf, di);
5992                 if ((total_len + sizeof(struct dir_entry) + name_len) >=
5993                     PAGE_SIZE) {
5994                         btrfs_release_path(path);
5995                         ret = btrfs_filldir(private->filldir_buf, entries, ctx);
5996                         if (ret)
5997                                 goto nopos;
5998                         addr = private->filldir_buf;
5999                         entries = 0;
6000                         total_len = 0;
6001                         goto again;
6002                 }
6003
6004                 entry = addr;
6005                 put_unaligned(name_len, &entry->name_len);
6006                 name_ptr = (char *)(entry + 1);
6007                 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
6008                                    name_len);
6009                 put_unaligned(btrfs_filetype_table[btrfs_dir_type(leaf, di)],
6010                                 &entry->type);
6011                 btrfs_dir_item_key_to_cpu(leaf, di, &location);
6012                 put_unaligned(location.objectid, &entry->ino);
6013                 put_unaligned(found_key.offset, &entry->offset);
6014                 entries++;
6015                 addr += sizeof(struct dir_entry) + name_len;
6016                 total_len += sizeof(struct dir_entry) + name_len;
6017 next:
6018                 path->slots[0]++;
6019         }
6020         btrfs_release_path(path);
6021
6022         ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6023         if (ret)
6024                 goto nopos;
6025
6026         ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6027         if (ret)
6028                 goto nopos;
6029
6030         /*
6031          * Stop new entries from being returned after we return the last
6032          * entry.
6033          *
6034          * New directory entries are assigned a strictly increasing
6035          * offset.  This means that new entries created during readdir
6036          * are *guaranteed* to be seen in the future by that readdir.
6037          * This has broken buggy programs which operate on names as
6038          * they're returned by readdir.  Until we re-use freed offsets
6039          * we have this hack to stop new entries from being returned
6040          * under the assumption that they'll never reach this huge
6041          * offset.
6042          *
6043          * This is being careful not to overflow 32bit loff_t unless the
6044          * last entry requires it because doing so has broken 32bit apps
6045          * in the past.
6046          */
6047         if (ctx->pos >= INT_MAX)
6048                 ctx->pos = LLONG_MAX;
6049         else
6050                 ctx->pos = INT_MAX;
6051 nopos:
6052         ret = 0;
6053 err:
6054         if (put)
6055                 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6056         btrfs_free_path(path);
6057         return ret;
6058 }
6059
6060 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
6061 {
6062         struct btrfs_root *root = BTRFS_I(inode)->root;
6063         struct btrfs_trans_handle *trans;
6064         int ret = 0;
6065         bool nolock = false;
6066
6067         if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6068                 return 0;
6069
6070         if (btrfs_fs_closing(root->fs_info) &&
6071                         btrfs_is_free_space_inode(BTRFS_I(inode)))
6072                 nolock = true;
6073
6074         if (wbc->sync_mode == WB_SYNC_ALL) {
6075                 if (nolock)
6076                         trans = btrfs_join_transaction_nolock(root);
6077                 else
6078                         trans = btrfs_join_transaction(root);
6079                 if (IS_ERR(trans))
6080                         return PTR_ERR(trans);
6081                 ret = btrfs_commit_transaction(trans);
6082         }
6083         return ret;
6084 }
6085
6086 /*
6087  * This is somewhat expensive, updating the tree every time the
6088  * inode changes.  But, it is most likely to find the inode in cache.
6089  * FIXME, needs more benchmarking...there are no reasons other than performance
6090  * to keep or drop this code.
6091  */
6092 static int btrfs_dirty_inode(struct inode *inode)
6093 {
6094         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6095         struct btrfs_root *root = BTRFS_I(inode)->root;
6096         struct btrfs_trans_handle *trans;
6097         int ret;
6098
6099         if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6100                 return 0;
6101
6102         trans = btrfs_join_transaction(root);
6103         if (IS_ERR(trans))
6104                 return PTR_ERR(trans);
6105
6106         ret = btrfs_update_inode(trans, root, inode);
6107         if (ret && ret == -ENOSPC) {
6108                 /* whoops, lets try again with the full transaction */
6109                 btrfs_end_transaction(trans);
6110                 trans = btrfs_start_transaction(root, 1);
6111                 if (IS_ERR(trans))
6112                         return PTR_ERR(trans);
6113
6114                 ret = btrfs_update_inode(trans, root, inode);
6115         }
6116         btrfs_end_transaction(trans);
6117         if (BTRFS_I(inode)->delayed_node)
6118                 btrfs_balance_delayed_items(fs_info);
6119
6120         return ret;
6121 }
6122
6123 /*
6124  * This is a copy of file_update_time.  We need this so we can return error on
6125  * ENOSPC for updating the inode in the case of file write and mmap writes.
6126  */
6127 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6128                              int flags)
6129 {
6130         struct btrfs_root *root = BTRFS_I(inode)->root;
6131         bool dirty = flags & ~S_VERSION;
6132
6133         if (btrfs_root_readonly(root))
6134                 return -EROFS;
6135
6136         if (flags & S_VERSION)
6137                 dirty |= inode_maybe_inc_iversion(inode, dirty);
6138         if (flags & S_CTIME)
6139                 inode->i_ctime = *now;
6140         if (flags & S_MTIME)
6141                 inode->i_mtime = *now;
6142         if (flags & S_ATIME)
6143                 inode->i_atime = *now;
6144         return dirty ? btrfs_dirty_inode(inode) : 0;
6145 }
6146
6147 /*
6148  * find the highest existing sequence number in a directory
6149  * and then set the in-memory index_cnt variable to reflect
6150  * free sequence numbers
6151  */
6152 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6153 {
6154         struct btrfs_root *root = inode->root;
6155         struct btrfs_key key, found_key;
6156         struct btrfs_path *path;
6157         struct extent_buffer *leaf;
6158         int ret;
6159
6160         key.objectid = btrfs_ino(inode);
6161         key.type = BTRFS_DIR_INDEX_KEY;
6162         key.offset = (u64)-1;
6163
6164         path = btrfs_alloc_path();
6165         if (!path)
6166                 return -ENOMEM;
6167
6168         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6169         if (ret < 0)
6170                 goto out;
6171         /* FIXME: we should be able to handle this */
6172         if (ret == 0)
6173                 goto out;
6174         ret = 0;
6175
6176         /*
6177          * MAGIC NUMBER EXPLANATION:
6178          * since we search a directory based on f_pos we have to start at 2
6179          * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6180          * else has to start at 2
6181          */
6182         if (path->slots[0] == 0) {
6183                 inode->index_cnt = 2;
6184                 goto out;
6185         }
6186
6187         path->slots[0]--;
6188
6189         leaf = path->nodes[0];
6190         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6191
6192         if (found_key.objectid != btrfs_ino(inode) ||
6193             found_key.type != BTRFS_DIR_INDEX_KEY) {
6194                 inode->index_cnt = 2;
6195                 goto out;
6196         }
6197
6198         inode->index_cnt = found_key.offset + 1;
6199 out:
6200         btrfs_free_path(path);
6201         return ret;
6202 }
6203
6204 /*
6205  * helper to find a free sequence number in a given directory.  This current
6206  * code is very simple, later versions will do smarter things in the btree
6207  */
6208 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6209 {
6210         int ret = 0;
6211
6212         if (dir->index_cnt == (u64)-1) {
6213                 ret = btrfs_inode_delayed_dir_index_count(dir);
6214                 if (ret) {
6215                         ret = btrfs_set_inode_index_count(dir);
6216                         if (ret)
6217                                 return ret;
6218                 }
6219         }
6220
6221         *index = dir->index_cnt;
6222         dir->index_cnt++;
6223
6224         return ret;
6225 }
6226
6227 static int btrfs_insert_inode_locked(struct inode *inode)
6228 {
6229         struct btrfs_iget_args args;
6230         args.location = &BTRFS_I(inode)->location;
6231         args.root = BTRFS_I(inode)->root;
6232
6233         return insert_inode_locked4(inode,
6234                    btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6235                    btrfs_find_actor, &args);
6236 }
6237
6238 /*
6239  * Inherit flags from the parent inode.
6240  *
6241  * Currently only the compression flags and the cow flags are inherited.
6242  */
6243 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6244 {
6245         unsigned int flags;
6246
6247         if (!dir)
6248                 return;
6249
6250         flags = BTRFS_I(dir)->flags;
6251
6252         if (flags & BTRFS_INODE_NOCOMPRESS) {
6253                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6254                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6255         } else if (flags & BTRFS_INODE_COMPRESS) {
6256                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6257                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6258         }
6259
6260         if (flags & BTRFS_INODE_NODATACOW) {
6261                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6262                 if (S_ISREG(inode->i_mode))
6263                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6264         }
6265
6266         btrfs_update_iflags(inode);
6267 }
6268
6269 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6270                                      struct btrfs_root *root,
6271                                      struct inode *dir,
6272                                      const char *name, int name_len,
6273                                      u64 ref_objectid, u64 objectid,
6274                                      umode_t mode, u64 *index)
6275 {
6276         struct btrfs_fs_info *fs_info = root->fs_info;
6277         struct inode *inode;
6278         struct btrfs_inode_item *inode_item;
6279         struct btrfs_key *location;
6280         struct btrfs_path *path;
6281         struct btrfs_inode_ref *ref;
6282         struct btrfs_key key[2];
6283         u32 sizes[2];
6284         int nitems = name ? 2 : 1;
6285         unsigned long ptr;
6286         int ret;
6287
6288         path = btrfs_alloc_path();
6289         if (!path)
6290                 return ERR_PTR(-ENOMEM);
6291
6292         inode = new_inode(fs_info->sb);
6293         if (!inode) {
6294                 btrfs_free_path(path);
6295                 return ERR_PTR(-ENOMEM);
6296         }
6297
6298         /*
6299          * O_TMPFILE, set link count to 0, so that after this point,
6300          * we fill in an inode item with the correct link count.
6301          */
6302         if (!name)
6303                 set_nlink(inode, 0);
6304
6305         /*
6306          * we have to initialize this early, so we can reclaim the inode
6307          * number if we fail afterwards in this function.
6308          */
6309         inode->i_ino = objectid;
6310
6311         if (dir && name) {
6312                 trace_btrfs_inode_request(dir);
6313
6314                 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6315                 if (ret) {
6316                         btrfs_free_path(path);
6317                         iput(inode);
6318                         return ERR_PTR(ret);
6319                 }
6320         } else if (dir) {
6321                 *index = 0;
6322         }
6323         /*
6324          * index_cnt is ignored for everything but a dir,
6325          * btrfs_set_inode_index_count has an explanation for the magic
6326          * number
6327          */
6328         BTRFS_I(inode)->index_cnt = 2;
6329         BTRFS_I(inode)->dir_index = *index;
6330         BTRFS_I(inode)->root = root;
6331         BTRFS_I(inode)->generation = trans->transid;
6332         inode->i_generation = BTRFS_I(inode)->generation;
6333
6334         /*
6335          * We could have gotten an inode number from somebody who was fsynced
6336          * and then removed in this same transaction, so let's just set full
6337          * sync since it will be a full sync anyway and this will blow away the
6338          * old info in the log.
6339          */
6340         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6341
6342         key[0].objectid = objectid;
6343         key[0].type = BTRFS_INODE_ITEM_KEY;
6344         key[0].offset = 0;
6345
6346         sizes[0] = sizeof(struct btrfs_inode_item);
6347
6348         if (name) {
6349                 /*
6350                  * Start new inodes with an inode_ref. This is slightly more
6351                  * efficient for small numbers of hard links since they will
6352                  * be packed into one item. Extended refs will kick in if we
6353                  * add more hard links than can fit in the ref item.
6354                  */
6355                 key[1].objectid = objectid;
6356                 key[1].type = BTRFS_INODE_REF_KEY;
6357                 key[1].offset = ref_objectid;
6358
6359                 sizes[1] = name_len + sizeof(*ref);
6360         }
6361
6362         location = &BTRFS_I(inode)->location;
6363         location->objectid = objectid;
6364         location->offset = 0;
6365         location->type = BTRFS_INODE_ITEM_KEY;
6366
6367         ret = btrfs_insert_inode_locked(inode);
6368         if (ret < 0)
6369                 goto fail;
6370
6371         path->leave_spinning = 1;
6372         ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6373         if (ret != 0)
6374                 goto fail_unlock;
6375
6376         inode_init_owner(inode, dir, mode);
6377         inode_set_bytes(inode, 0);
6378
6379         inode->i_mtime = current_time(inode);
6380         inode->i_atime = inode->i_mtime;
6381         inode->i_ctime = inode->i_mtime;
6382         BTRFS_I(inode)->i_otime = inode->i_mtime;
6383
6384         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6385                                   struct btrfs_inode_item);
6386         memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6387                              sizeof(*inode_item));
6388         fill_inode_item(trans, path->nodes[0], inode_item, inode);
6389
6390         if (name) {
6391                 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6392                                      struct btrfs_inode_ref);
6393                 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6394                 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6395                 ptr = (unsigned long)(ref + 1);
6396                 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6397         }
6398
6399         btrfs_mark_buffer_dirty(path->nodes[0]);
6400         btrfs_free_path(path);
6401
6402         btrfs_inherit_iflags(inode, dir);
6403
6404         if (S_ISREG(mode)) {
6405                 if (btrfs_test_opt(fs_info, NODATASUM))
6406                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6407                 if (btrfs_test_opt(fs_info, NODATACOW))
6408                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6409                                 BTRFS_INODE_NODATASUM;
6410         }
6411
6412         inode_tree_add(inode);
6413
6414         trace_btrfs_inode_new(inode);
6415         btrfs_set_inode_last_trans(trans, inode);
6416
6417         btrfs_update_root_times(trans, root);
6418
6419         ret = btrfs_inode_inherit_props(trans, inode, dir);
6420         if (ret)
6421                 btrfs_err(fs_info,
6422                           "error inheriting props for ino %llu (root %llu): %d",
6423                         btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6424
6425         return inode;
6426
6427 fail_unlock:
6428         unlock_new_inode(inode);
6429 fail:
6430         if (dir && name)
6431                 BTRFS_I(dir)->index_cnt--;
6432         btrfs_free_path(path);
6433         iput(inode);
6434         return ERR_PTR(ret);
6435 }
6436
6437 static inline u8 btrfs_inode_type(struct inode *inode)
6438 {
6439         return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6440 }
6441
6442 /*
6443  * utility function to add 'inode' into 'parent_inode' with
6444  * a give name and a given sequence number.
6445  * if 'add_backref' is true, also insert a backref from the
6446  * inode to the parent directory.
6447  */
6448 int btrfs_add_link(struct btrfs_trans_handle *trans,
6449                    struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6450                    const char *name, int name_len, int add_backref, u64 index)
6451 {
6452         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6453         int ret = 0;
6454         struct btrfs_key key;
6455         struct btrfs_root *root = parent_inode->root;
6456         u64 ino = btrfs_ino(inode);
6457         u64 parent_ino = btrfs_ino(parent_inode);
6458
6459         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6460                 memcpy(&key, &inode->root->root_key, sizeof(key));
6461         } else {
6462                 key.objectid = ino;
6463                 key.type = BTRFS_INODE_ITEM_KEY;
6464                 key.offset = 0;
6465         }
6466
6467         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6468                 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6469                                          root->root_key.objectid, parent_ino,
6470                                          index, name, name_len);
6471         } else if (add_backref) {
6472                 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6473                                              parent_ino, index);
6474         }
6475
6476         /* Nothing to clean up yet */
6477         if (ret)
6478                 return ret;
6479
6480         ret = btrfs_insert_dir_item(trans, root, name, name_len,
6481                                     parent_inode, &key,
6482                                     btrfs_inode_type(&inode->vfs_inode), index);
6483         if (ret == -EEXIST || ret == -EOVERFLOW)
6484                 goto fail_dir_item;
6485         else if (ret) {
6486                 btrfs_abort_transaction(trans, ret);
6487                 return ret;
6488         }
6489
6490         btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6491                            name_len * 2);
6492         inode_inc_iversion(&parent_inode->vfs_inode);
6493         parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6494                 current_time(&parent_inode->vfs_inode);
6495         ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6496         if (ret)
6497                 btrfs_abort_transaction(trans, ret);
6498         return ret;
6499
6500 fail_dir_item:
6501         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6502                 u64 local_index;
6503                 int err;
6504                 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6505                                          root->root_key.objectid, parent_ino,
6506                                          &local_index, name, name_len);
6507
6508         } else if (add_backref) {
6509                 u64 local_index;
6510                 int err;
6511
6512                 err = btrfs_del_inode_ref(trans, root, name, name_len,
6513                                           ino, parent_ino, &local_index);
6514         }
6515         return ret;
6516 }
6517
6518 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6519                             struct btrfs_inode *dir, struct dentry *dentry,
6520                             struct btrfs_inode *inode, int backref, u64 index)
6521 {
6522         int err = btrfs_add_link(trans, dir, inode,
6523                                  dentry->d_name.name, dentry->d_name.len,
6524                                  backref, index);
6525         if (err > 0)
6526                 err = -EEXIST;
6527         return err;
6528 }
6529
6530 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6531                         umode_t mode, dev_t rdev)
6532 {
6533         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6534         struct btrfs_trans_handle *trans;
6535         struct btrfs_root *root = BTRFS_I(dir)->root;
6536         struct inode *inode = NULL;
6537         int err;
6538         int drop_inode = 0;
6539         u64 objectid;
6540         u64 index = 0;
6541
6542         /*
6543          * 2 for inode item and ref
6544          * 2 for dir items
6545          * 1 for xattr if selinux is on
6546          */
6547         trans = btrfs_start_transaction(root, 5);
6548         if (IS_ERR(trans))
6549                 return PTR_ERR(trans);
6550
6551         err = btrfs_find_free_ino(root, &objectid);
6552         if (err)
6553                 goto out_unlock;
6554
6555         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6556                         dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6557                         mode, &index);
6558         if (IS_ERR(inode)) {
6559                 err = PTR_ERR(inode);
6560                 goto out_unlock;
6561         }
6562
6563         /*
6564         * If the active LSM wants to access the inode during
6565         * d_instantiate it needs these. Smack checks to see
6566         * if the filesystem supports xattrs by looking at the
6567         * ops vector.
6568         */
6569         inode->i_op = &btrfs_special_inode_operations;
6570         init_special_inode(inode, inode->i_mode, rdev);
6571
6572         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6573         if (err)
6574                 goto out_unlock_inode;
6575
6576         err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6577                         0, index);
6578         if (err) {
6579                 goto out_unlock_inode;
6580         } else {
6581                 btrfs_update_inode(trans, root, inode);
6582                 unlock_new_inode(inode);
6583                 d_instantiate(dentry, inode);
6584         }
6585
6586 out_unlock:
6587         btrfs_end_transaction(trans);
6588         btrfs_btree_balance_dirty(fs_info);
6589         if (drop_inode) {
6590                 inode_dec_link_count(inode);
6591                 iput(inode);
6592         }
6593         return err;
6594
6595 out_unlock_inode:
6596         drop_inode = 1;
6597         unlock_new_inode(inode);
6598         goto out_unlock;
6599
6600 }
6601
6602 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6603                         umode_t mode, bool excl)
6604 {
6605         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6606         struct btrfs_trans_handle *trans;
6607         struct btrfs_root *root = BTRFS_I(dir)->root;
6608         struct inode *inode = NULL;
6609         int drop_inode_on_err = 0;
6610         int err;
6611         u64 objectid;
6612         u64 index = 0;
6613
6614         /*
6615          * 2 for inode item and ref
6616          * 2 for dir items
6617          * 1 for xattr if selinux is on
6618          */
6619         trans = btrfs_start_transaction(root, 5);
6620         if (IS_ERR(trans))
6621                 return PTR_ERR(trans);
6622
6623         err = btrfs_find_free_ino(root, &objectid);
6624         if (err)
6625                 goto out_unlock;
6626
6627         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6628                         dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6629                         mode, &index);
6630         if (IS_ERR(inode)) {
6631                 err = PTR_ERR(inode);
6632                 goto out_unlock;
6633         }
6634         drop_inode_on_err = 1;
6635         /*
6636         * If the active LSM wants to access the inode during
6637         * d_instantiate it needs these. Smack checks to see
6638         * if the filesystem supports xattrs by looking at the
6639         * ops vector.
6640         */
6641         inode->i_fop = &btrfs_file_operations;
6642         inode->i_op = &btrfs_file_inode_operations;
6643         inode->i_mapping->a_ops = &btrfs_aops;
6644
6645         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6646         if (err)
6647                 goto out_unlock_inode;
6648
6649         err = btrfs_update_inode(trans, root, inode);
6650         if (err)
6651                 goto out_unlock_inode;
6652
6653         err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6654                         0, index);
6655         if (err)
6656                 goto out_unlock_inode;
6657
6658         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6659         unlock_new_inode(inode);
6660         d_instantiate(dentry, inode);
6661
6662 out_unlock:
6663         btrfs_end_transaction(trans);
6664         if (err && drop_inode_on_err) {
6665                 inode_dec_link_count(inode);
6666                 iput(inode);
6667         }
6668         btrfs_btree_balance_dirty(fs_info);
6669         return err;
6670
6671 out_unlock_inode:
6672         unlock_new_inode(inode);
6673         goto out_unlock;
6674
6675 }
6676
6677 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6678                       struct dentry *dentry)
6679 {
6680         struct btrfs_trans_handle *trans = NULL;
6681         struct btrfs_root *root = BTRFS_I(dir)->root;
6682         struct inode *inode = d_inode(old_dentry);
6683         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6684         u64 index;
6685         int err;
6686         int drop_inode = 0;
6687
6688         /* do not allow sys_link's with other subvols of the same device */
6689         if (root->objectid != BTRFS_I(inode)->root->objectid)
6690                 return -EXDEV;
6691
6692         if (inode->i_nlink >= BTRFS_LINK_MAX)
6693                 return -EMLINK;
6694
6695         err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6696         if (err)
6697                 goto fail;
6698
6699         /*
6700          * 2 items for inode and inode ref
6701          * 2 items for dir items
6702          * 1 item for parent inode
6703          */
6704         trans = btrfs_start_transaction(root, 5);
6705         if (IS_ERR(trans)) {
6706                 err = PTR_ERR(trans);
6707                 trans = NULL;
6708                 goto fail;
6709         }
6710
6711         /* There are several dir indexes for this inode, clear the cache. */
6712         BTRFS_I(inode)->dir_index = 0ULL;
6713         inc_nlink(inode);
6714         inode_inc_iversion(inode);
6715         inode->i_ctime = current_time(inode);
6716         ihold(inode);
6717         set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6718
6719         err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6720                         1, index);
6721
6722         if (err) {
6723                 drop_inode = 1;
6724         } else {
6725                 struct dentry *parent = dentry->d_parent;
6726                 err = btrfs_update_inode(trans, root, inode);
6727                 if (err)
6728                         goto fail;
6729                 if (inode->i_nlink == 1) {
6730                         /*
6731                          * If new hard link count is 1, it's a file created
6732                          * with open(2) O_TMPFILE flag.
6733                          */
6734                         err = btrfs_orphan_del(trans, BTRFS_I(inode));
6735                         if (err)
6736                                 goto fail;
6737                 }
6738                 d_instantiate(dentry, inode);
6739                 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6740         }
6741
6742 fail:
6743         if (trans)
6744                 btrfs_end_transaction(trans);
6745         if (drop_inode) {
6746                 inode_dec_link_count(inode);
6747                 iput(inode);
6748         }
6749         btrfs_btree_balance_dirty(fs_info);
6750         return err;
6751 }
6752
6753 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6754 {
6755         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6756         struct inode *inode = NULL;
6757         struct btrfs_trans_handle *trans;
6758         struct btrfs_root *root = BTRFS_I(dir)->root;
6759         int err = 0;
6760         int drop_on_err = 0;
6761         u64 objectid = 0;
6762         u64 index = 0;
6763
6764         /*
6765          * 2 items for inode and ref
6766          * 2 items for dir items
6767          * 1 for xattr if selinux is on
6768          */
6769         trans = btrfs_start_transaction(root, 5);
6770         if (IS_ERR(trans))
6771                 return PTR_ERR(trans);
6772
6773         err = btrfs_find_free_ino(root, &objectid);
6774         if (err)
6775                 goto out_fail;
6776
6777         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6778                         dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6779                         S_IFDIR | mode, &index);
6780         if (IS_ERR(inode)) {
6781                 err = PTR_ERR(inode);
6782                 goto out_fail;
6783         }
6784
6785         drop_on_err = 1;
6786         /* these must be set before we unlock the inode */
6787         inode->i_op = &btrfs_dir_inode_operations;
6788         inode->i_fop = &btrfs_dir_file_operations;
6789
6790         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6791         if (err)
6792                 goto out_fail_inode;
6793
6794         btrfs_i_size_write(BTRFS_I(inode), 0);
6795         err = btrfs_update_inode(trans, root, inode);
6796         if (err)
6797                 goto out_fail_inode;
6798
6799         err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6800                         dentry->d_name.name,
6801                         dentry->d_name.len, 0, index);
6802         if (err)
6803                 goto out_fail_inode;
6804
6805         d_instantiate(dentry, inode);
6806         /*
6807          * mkdir is special.  We're unlocking after we call d_instantiate
6808          * to avoid a race with nfsd calling d_instantiate.
6809          */
6810         unlock_new_inode(inode);
6811         drop_on_err = 0;
6812
6813 out_fail:
6814         btrfs_end_transaction(trans);
6815         if (drop_on_err) {
6816                 inode_dec_link_count(inode);
6817                 iput(inode);
6818         }
6819         btrfs_btree_balance_dirty(fs_info);
6820         return err;
6821
6822 out_fail_inode:
6823         unlock_new_inode(inode);
6824         goto out_fail;
6825 }
6826
6827 static noinline int uncompress_inline(struct btrfs_path *path,
6828                                       struct page *page,
6829                                       size_t pg_offset, u64 extent_offset,
6830                                       struct btrfs_file_extent_item *item)
6831 {
6832         int ret;
6833         struct extent_buffer *leaf = path->nodes[0];
6834         char *tmp;
6835         size_t max_size;
6836         unsigned long inline_size;
6837         unsigned long ptr;
6838         int compress_type;
6839
6840         WARN_ON(pg_offset != 0);
6841         compress_type = btrfs_file_extent_compression(leaf, item);
6842         max_size = btrfs_file_extent_ram_bytes(leaf, item);
6843         inline_size = btrfs_file_extent_inline_item_len(leaf,
6844                                         btrfs_item_nr(path->slots[0]));
6845         tmp = kmalloc(inline_size, GFP_NOFS);
6846         if (!tmp)
6847                 return -ENOMEM;
6848         ptr = btrfs_file_extent_inline_start(item);
6849
6850         read_extent_buffer(leaf, tmp, ptr, inline_size);
6851
6852         max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6853         ret = btrfs_decompress(compress_type, tmp, page,
6854                                extent_offset, inline_size, max_size);
6855
6856         /*
6857          * decompression code contains a memset to fill in any space between the end
6858          * of the uncompressed data and the end of max_size in case the decompressed
6859          * data ends up shorter than ram_bytes.  That doesn't cover the hole between
6860          * the end of an inline extent and the beginning of the next block, so we
6861          * cover that region here.
6862          */
6863
6864         if (max_size + pg_offset < PAGE_SIZE) {
6865                 char *map = kmap(page);
6866                 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6867                 kunmap(page);
6868         }
6869         kfree(tmp);
6870         return ret;
6871 }
6872
6873 /*
6874  * a bit scary, this does extent mapping from logical file offset to the disk.
6875  * the ugly parts come from merging extents from the disk with the in-ram
6876  * representation.  This gets more complex because of the data=ordered code,
6877  * where the in-ram extents might be locked pending data=ordered completion.
6878  *
6879  * This also copies inline extents directly into the page.
6880  */
6881 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6882                 struct page *page,
6883             size_t pg_offset, u64 start, u64 len,
6884                 int create)
6885 {
6886         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6887         int ret;
6888         int err = 0;
6889         u64 extent_start = 0;
6890         u64 extent_end = 0;
6891         u64 objectid = btrfs_ino(inode);
6892         u32 found_type;
6893         struct btrfs_path *path = NULL;
6894         struct btrfs_root *root = inode->root;
6895         struct btrfs_file_extent_item *item;
6896         struct extent_buffer *leaf;
6897         struct btrfs_key found_key;
6898         struct extent_map *em = NULL;
6899         struct extent_map_tree *em_tree = &inode->extent_tree;
6900         struct extent_io_tree *io_tree = &inode->io_tree;
6901         const bool new_inline = !page || create;
6902
6903         read_lock(&em_tree->lock);
6904         em = lookup_extent_mapping(em_tree, start, len);
6905         if (em)
6906                 em->bdev = fs_info->fs_devices->latest_bdev;
6907         read_unlock(&em_tree->lock);
6908
6909         if (em) {
6910                 if (em->start > start || em->start + em->len <= start)
6911                         free_extent_map(em);
6912                 else if (em->block_start == EXTENT_MAP_INLINE && page)
6913                         free_extent_map(em);
6914                 else
6915                         goto out;
6916         }
6917         em = alloc_extent_map();
6918         if (!em) {
6919                 err = -ENOMEM;
6920                 goto out;
6921         }
6922         em->bdev = fs_info->fs_devices->latest_bdev;
6923         em->start = EXTENT_MAP_HOLE;
6924         em->orig_start = EXTENT_MAP_HOLE;
6925         em->len = (u64)-1;
6926         em->block_len = (u64)-1;
6927
6928         if (!path) {
6929                 path = btrfs_alloc_path();
6930                 if (!path) {
6931                         err = -ENOMEM;
6932                         goto out;
6933                 }
6934                 /*
6935                  * Chances are we'll be called again, so go ahead and do
6936                  * readahead
6937                  */
6938                 path->reada = READA_FORWARD;
6939         }
6940
6941         ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
6942         if (ret < 0) {
6943                 err = ret;
6944                 goto out;
6945         }
6946
6947         if (ret != 0) {
6948                 if (path->slots[0] == 0)
6949                         goto not_found;
6950                 path->slots[0]--;
6951         }
6952
6953         leaf = path->nodes[0];
6954         item = btrfs_item_ptr(leaf, path->slots[0],
6955                               struct btrfs_file_extent_item);
6956         /* are we inside the extent that was found? */
6957         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6958         found_type = found_key.type;
6959         if (found_key.objectid != objectid ||
6960             found_type != BTRFS_EXTENT_DATA_KEY) {
6961                 /*
6962                  * If we backup past the first extent we want to move forward
6963                  * and see if there is an extent in front of us, otherwise we'll
6964                  * say there is a hole for our whole search range which can
6965                  * cause problems.
6966                  */
6967                 extent_end = start;
6968                 goto next;
6969         }
6970
6971         found_type = btrfs_file_extent_type(leaf, item);
6972         extent_start = found_key.offset;
6973         if (found_type == BTRFS_FILE_EXTENT_REG ||
6974             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6975                 extent_end = extent_start +
6976                        btrfs_file_extent_num_bytes(leaf, item);
6977
6978                 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
6979                                                        extent_start);
6980         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6981                 size_t size;
6982                 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6983                 extent_end = ALIGN(extent_start + size,
6984                                    fs_info->sectorsize);
6985
6986                 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
6987                                                       path->slots[0],
6988                                                       extent_start);
6989         }
6990 next:
6991         if (start >= extent_end) {
6992                 path->slots[0]++;
6993                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6994                         ret = btrfs_next_leaf(root, path);
6995                         if (ret < 0) {
6996                                 err = ret;
6997                                 goto out;
6998                         }
6999                         if (ret > 0)
7000                                 goto not_found;
7001                         leaf = path->nodes[0];
7002                 }
7003                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7004                 if (found_key.objectid != objectid ||
7005                     found_key.type != BTRFS_EXTENT_DATA_KEY)
7006                         goto not_found;
7007                 if (start + len <= found_key.offset)
7008                         goto not_found;
7009                 if (start > found_key.offset)
7010                         goto next;
7011                 em->start = start;
7012                 em->orig_start = start;
7013                 em->len = found_key.offset - start;
7014                 goto not_found_em;
7015         }
7016
7017         btrfs_extent_item_to_extent_map(inode, path, item,
7018                         new_inline, em);
7019
7020         if (found_type == BTRFS_FILE_EXTENT_REG ||
7021             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7022                 goto insert;
7023         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7024                 unsigned long ptr;
7025                 char *map;
7026                 size_t size;
7027                 size_t extent_offset;
7028                 size_t copy_size;
7029
7030                 if (new_inline)
7031                         goto out;
7032
7033                 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7034                 extent_offset = page_offset(page) + pg_offset - extent_start;
7035                 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7036                                   size - extent_offset);
7037                 em->start = extent_start + extent_offset;
7038                 em->len = ALIGN(copy_size, fs_info->sectorsize);
7039                 em->orig_block_len = em->len;
7040                 em->orig_start = em->start;
7041                 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7042                 if (!PageUptodate(page)) {
7043                         if (btrfs_file_extent_compression(leaf, item) !=
7044                             BTRFS_COMPRESS_NONE) {
7045                                 ret = uncompress_inline(path, page, pg_offset,
7046                                                         extent_offset, item);
7047                                 if (ret) {
7048                                         err = ret;
7049                                         goto out;
7050                                 }
7051                         } else {
7052                                 map = kmap(page);
7053                                 read_extent_buffer(leaf, map + pg_offset, ptr,
7054                                                    copy_size);
7055                                 if (pg_offset + copy_size < PAGE_SIZE) {
7056                                         memset(map + pg_offset + copy_size, 0,
7057                                                PAGE_SIZE - pg_offset -
7058                                                copy_size);
7059                                 }
7060                                 kunmap(page);
7061                         }
7062                         flush_dcache_page(page);
7063                 }
7064                 set_extent_uptodate(io_tree, em->start,
7065                                     extent_map_end(em) - 1, NULL, GFP_NOFS);
7066                 goto insert;
7067         }
7068 not_found:
7069         em->start = start;
7070         em->orig_start = start;
7071         em->len = len;
7072 not_found_em:
7073         em->block_start = EXTENT_MAP_HOLE;
7074 insert:
7075         btrfs_release_path(path);
7076         if (em->start > start || extent_map_end(em) <= start) {
7077                 btrfs_err(fs_info,
7078                           "bad extent! em: [%llu %llu] passed [%llu %llu]",
7079                           em->start, em->len, start, len);
7080                 err = -EIO;
7081                 goto out;
7082         }
7083
7084         err = 0;
7085         write_lock(&em_tree->lock);
7086         err = btrfs_add_extent_mapping(em_tree, &em, start, len);
7087         write_unlock(&em_tree->lock);
7088 out:
7089
7090         trace_btrfs_get_extent(root, inode, em);
7091
7092         btrfs_free_path(path);
7093         if (err) {
7094                 free_extent_map(em);
7095                 return ERR_PTR(err);
7096         }
7097         BUG_ON(!em); /* Error is always set */
7098         return em;
7099 }
7100
7101 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7102                 struct page *page,
7103                 size_t pg_offset, u64 start, u64 len,
7104                 int create)
7105 {
7106         struct extent_map *em;
7107         struct extent_map *hole_em = NULL;
7108         u64 range_start = start;
7109         u64 end;
7110         u64 found;
7111         u64 found_end;
7112         int err = 0;
7113
7114         em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7115         if (IS_ERR(em))
7116                 return em;
7117         /*
7118          * If our em maps to:
7119          * - a hole or
7120          * - a pre-alloc extent,
7121          * there might actually be delalloc bytes behind it.
7122          */
7123         if (em->block_start != EXTENT_MAP_HOLE &&
7124             !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7125                 return em;
7126         else
7127                 hole_em = em;
7128
7129         /* check to see if we've wrapped (len == -1 or similar) */
7130         end = start + len;
7131         if (end < start)
7132                 end = (u64)-1;
7133         else
7134                 end -= 1;
7135
7136         em = NULL;
7137
7138         /* ok, we didn't find anything, lets look for delalloc */
7139         found = count_range_bits(&inode->io_tree, &range_start,
7140                                  end, len, EXTENT_DELALLOC, 1);
7141         found_end = range_start + found;
7142         if (found_end < range_start)
7143                 found_end = (u64)-1;
7144
7145         /*
7146          * we didn't find anything useful, return
7147          * the original results from get_extent()
7148          */
7149         if (range_start > end || found_end <= start) {
7150                 em = hole_em;
7151                 hole_em = NULL;
7152                 goto out;
7153         }
7154
7155         /* adjust the range_start to make sure it doesn't
7156          * go backwards from the start they passed in
7157          */
7158         range_start = max(start, range_start);
7159         found = found_end - range_start;
7160
7161         if (found > 0) {
7162                 u64 hole_start = start;
7163                 u64 hole_len = len;
7164
7165                 em = alloc_extent_map();
7166                 if (!em) {
7167                         err = -ENOMEM;
7168                         goto out;
7169                 }
7170                 /*
7171                  * when btrfs_get_extent can't find anything it
7172                  * returns one huge hole
7173                  *
7174                  * make sure what it found really fits our range, and
7175                  * adjust to make sure it is based on the start from
7176                  * the caller
7177                  */
7178                 if (hole_em) {
7179                         u64 calc_end = extent_map_end(hole_em);
7180
7181                         if (calc_end <= start || (hole_em->start > end)) {
7182                                 free_extent_map(hole_em);
7183                                 hole_em = NULL;
7184                         } else {
7185                                 hole_start = max(hole_em->start, start);
7186                                 hole_len = calc_end - hole_start;
7187                         }
7188                 }
7189                 em->bdev = NULL;
7190                 if (hole_em && range_start > hole_start) {
7191                         /* our hole starts before our delalloc, so we
7192                          * have to return just the parts of the hole
7193                          * that go until  the delalloc starts
7194                          */
7195                         em->len = min(hole_len,
7196                                       range_start - hole_start);
7197                         em->start = hole_start;
7198                         em->orig_start = hole_start;
7199                         /*
7200                          * don't adjust block start at all,
7201                          * it is fixed at EXTENT_MAP_HOLE
7202                          */
7203                         em->block_start = hole_em->block_start;
7204                         em->block_len = hole_len;
7205                         if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7206                                 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7207                 } else {
7208                         em->start = range_start;
7209                         em->len = found;
7210                         em->orig_start = range_start;
7211                         em->block_start = EXTENT_MAP_DELALLOC;
7212                         em->block_len = found;
7213                 }
7214         } else {
7215                 return hole_em;
7216         }
7217 out:
7218
7219         free_extent_map(hole_em);
7220         if (err) {
7221                 free_extent_map(em);
7222                 return ERR_PTR(err);
7223         }
7224         return em;
7225 }
7226
7227 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7228                                                   const u64 start,
7229                                                   const u64 len,
7230                                                   const u64 orig_start,
7231                                                   const u64 block_start,
7232                                                   const u64 block_len,
7233                                                   const u64 orig_block_len,
7234                                                   const u64 ram_bytes,
7235                                                   const int type)
7236 {
7237         struct extent_map *em = NULL;
7238         int ret;
7239
7240         if (type != BTRFS_ORDERED_NOCOW) {
7241                 em = create_io_em(inode, start, len, orig_start,
7242                                   block_start, block_len, orig_block_len,
7243                                   ram_bytes,
7244                                   BTRFS_COMPRESS_NONE, /* compress_type */
7245                                   type);
7246                 if (IS_ERR(em))
7247                         goto out;
7248         }
7249         ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7250                                            len, block_len, type);
7251         if (ret) {
7252                 if (em) {
7253                         free_extent_map(em);
7254                         btrfs_drop_extent_cache(BTRFS_I(inode), start,
7255                                                 start + len - 1, 0);
7256                 }
7257                 em = ERR_PTR(ret);
7258         }
7259  out:
7260
7261         return em;
7262 }
7263
7264 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7265                                                   u64 start, u64 len)
7266 {
7267         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7268         struct btrfs_root *root = BTRFS_I(inode)->root;
7269         struct extent_map *em;
7270         struct btrfs_key ins;
7271         u64 alloc_hint;
7272         int ret;
7273
7274         alloc_hint = get_extent_allocation_hint(inode, start, len);
7275         ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7276                                    0, alloc_hint, &ins, 1, 1);
7277         if (ret)
7278                 return ERR_PTR(ret);
7279
7280         em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7281                                      ins.objectid, ins.offset, ins.offset,
7282                                      ins.offset, BTRFS_ORDERED_REGULAR);
7283         btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7284         if (IS_ERR(em))
7285                 btrfs_free_reserved_extent(fs_info, ins.objectid,
7286                                            ins.offset, 1);
7287
7288         return em;
7289 }
7290
7291 /*
7292  * returns 1 when the nocow is safe, < 1 on error, 0 if the
7293  * block must be cow'd
7294  */
7295 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7296                               u64 *orig_start, u64 *orig_block_len,
7297                               u64 *ram_bytes)
7298 {
7299         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7300         struct btrfs_path *path;
7301         int ret;
7302         struct extent_buffer *leaf;
7303         struct btrfs_root *root = BTRFS_I(inode)->root;
7304         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7305         struct btrfs_file_extent_item *fi;
7306         struct btrfs_key key;
7307         u64 disk_bytenr;
7308         u64 backref_offset;
7309         u64 extent_end;
7310         u64 num_bytes;
7311         int slot;
7312         int found_type;
7313         bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7314
7315         path = btrfs_alloc_path();
7316         if (!path)
7317                 return -ENOMEM;
7318
7319         ret = btrfs_lookup_file_extent(NULL, root, path,
7320                         btrfs_ino(BTRFS_I(inode)), offset, 0);
7321         if (ret < 0)
7322                 goto out;
7323
7324         slot = path->slots[0];
7325         if (ret == 1) {
7326                 if (slot == 0) {
7327                         /* can't find the item, must cow */
7328                         ret = 0;
7329                         goto out;
7330                 }
7331                 slot--;
7332         }
7333         ret = 0;
7334         leaf = path->nodes[0];
7335         btrfs_item_key_to_cpu(leaf, &key, slot);
7336         if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7337             key.type != BTRFS_EXTENT_DATA_KEY) {
7338                 /* not our file or wrong item type, must cow */
7339                 goto out;
7340         }
7341
7342         if (key.offset > offset) {
7343                 /* Wrong offset, must cow */
7344                 goto out;
7345         }
7346
7347         fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7348         found_type = btrfs_file_extent_type(leaf, fi);
7349         if (found_type != BTRFS_FILE_EXTENT_REG &&
7350             found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7351                 /* not a regular extent, must cow */
7352                 goto out;
7353         }
7354
7355         if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7356                 goto out;
7357
7358         extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7359         if (extent_end <= offset)
7360                 goto out;
7361
7362         disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7363         if (disk_bytenr == 0)
7364                 goto out;
7365
7366         if (btrfs_file_extent_compression(leaf, fi) ||
7367             btrfs_file_extent_encryption(leaf, fi) ||
7368             btrfs_file_extent_other_encoding(leaf, fi))
7369                 goto out;
7370
7371         backref_offset = btrfs_file_extent_offset(leaf, fi);
7372
7373         if (orig_start) {
7374                 *orig_start = key.offset - backref_offset;
7375                 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7376                 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7377         }
7378
7379         if (btrfs_extent_readonly(fs_info, disk_bytenr))
7380                 goto out;
7381
7382         num_bytes = min(offset + *len, extent_end) - offset;
7383         if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7384                 u64 range_end;
7385
7386                 range_end = round_up(offset + num_bytes,
7387                                      root->fs_info->sectorsize) - 1;
7388                 ret = test_range_bit(io_tree, offset, range_end,
7389                                      EXTENT_DELALLOC, 0, NULL);
7390                 if (ret) {
7391                         ret = -EAGAIN;
7392                         goto out;
7393                 }
7394         }
7395
7396         btrfs_release_path(path);
7397
7398         /*
7399          * look for other files referencing this extent, if we
7400          * find any we must cow
7401          */
7402
7403         ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7404                                     key.offset - backref_offset, disk_bytenr);
7405         if (ret) {
7406                 ret = 0;
7407                 goto out;
7408         }
7409
7410         /*
7411          * adjust disk_bytenr and num_bytes to cover just the bytes
7412          * in this extent we are about to write.  If there
7413          * are any csums in that range we have to cow in order
7414          * to keep the csums correct
7415          */
7416         disk_bytenr += backref_offset;
7417         disk_bytenr += offset - key.offset;
7418         if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7419                 goto out;
7420         /*
7421          * all of the above have passed, it is safe to overwrite this extent
7422          * without cow
7423          */
7424         *len = num_bytes;
7425         ret = 1;
7426 out:
7427         btrfs_free_path(path);
7428         return ret;
7429 }
7430
7431 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7432                               struct extent_state **cached_state, int writing)
7433 {
7434         struct btrfs_ordered_extent *ordered;
7435         int ret = 0;
7436
7437         while (1) {
7438                 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7439                                  cached_state);
7440                 /*
7441                  * We're concerned with the entire range that we're going to be
7442                  * doing DIO to, so we need to make sure there's no ordered
7443                  * extents in this range.
7444                  */
7445                 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7446                                                      lockend - lockstart + 1);
7447
7448                 /*
7449                  * We need to make sure there are no buffered pages in this
7450                  * range either, we could have raced between the invalidate in
7451                  * generic_file_direct_write and locking the extent.  The
7452                  * invalidate needs to happen so that reads after a write do not
7453                  * get stale data.
7454                  */
7455                 if (!ordered &&
7456                     (!writing || !filemap_range_has_page(inode->i_mapping,
7457                                                          lockstart, lockend)))
7458                         break;
7459
7460                 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7461                                      cached_state);
7462
7463                 if (ordered) {
7464                         /*
7465                          * If we are doing a DIO read and the ordered extent we
7466                          * found is for a buffered write, we can not wait for it
7467                          * to complete and retry, because if we do so we can
7468                          * deadlock with concurrent buffered writes on page
7469                          * locks. This happens only if our DIO read covers more
7470                          * than one extent map, if at this point has already
7471                          * created an ordered extent for a previous extent map
7472                          * and locked its range in the inode's io tree, and a
7473                          * concurrent write against that previous extent map's
7474                          * range and this range started (we unlock the ranges
7475                          * in the io tree only when the bios complete and
7476                          * buffered writes always lock pages before attempting
7477                          * to lock range in the io tree).
7478                          */
7479                         if (writing ||
7480                             test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7481                                 btrfs_start_ordered_extent(inode, ordered, 1);
7482                         else
7483                                 ret = -ENOTBLK;
7484                         btrfs_put_ordered_extent(ordered);
7485                 } else {
7486                         /*
7487                          * We could trigger writeback for this range (and wait
7488                          * for it to complete) and then invalidate the pages for
7489                          * this range (through invalidate_inode_pages2_range()),
7490                          * but that can lead us to a deadlock with a concurrent
7491                          * call to readpages() (a buffered read or a defrag call
7492                          * triggered a readahead) on a page lock due to an
7493                          * ordered dio extent we created before but did not have
7494                          * yet a corresponding bio submitted (whence it can not
7495                          * complete), which makes readpages() wait for that
7496                          * ordered extent to complete while holding a lock on
7497                          * that page.
7498                          */
7499                         ret = -ENOTBLK;
7500                 }
7501
7502                 if (ret)
7503                         break;
7504
7505                 cond_resched();
7506         }
7507
7508         return ret;
7509 }
7510
7511 /* The callers of this must take lock_extent() */
7512 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7513                                        u64 orig_start, u64 block_start,
7514                                        u64 block_len, u64 orig_block_len,
7515                                        u64 ram_bytes, int compress_type,
7516                                        int type)
7517 {
7518         struct extent_map_tree *em_tree;
7519         struct extent_map *em;
7520         struct btrfs_root *root = BTRFS_I(inode)->root;
7521         int ret;
7522
7523         ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7524                type == BTRFS_ORDERED_COMPRESSED ||
7525                type == BTRFS_ORDERED_NOCOW ||
7526                type == BTRFS_ORDERED_REGULAR);
7527
7528         em_tree = &BTRFS_I(inode)->extent_tree;
7529         em = alloc_extent_map();
7530         if (!em)
7531                 return ERR_PTR(-ENOMEM);
7532
7533         em->start = start;
7534         em->orig_start = orig_start;
7535         em->len = len;
7536         em->block_len = block_len;
7537         em->block_start = block_start;
7538         em->bdev = root->fs_info->fs_devices->latest_bdev;
7539         em->orig_block_len = orig_block_len;
7540         em->ram_bytes = ram_bytes;
7541         em->generation = -1;
7542         set_bit(EXTENT_FLAG_PINNED, &em->flags);
7543         if (type == BTRFS_ORDERED_PREALLOC) {
7544                 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7545         } else if (type == BTRFS_ORDERED_COMPRESSED) {
7546                 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7547                 em->compress_type = compress_type;
7548         }
7549
7550         do {
7551                 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7552                                 em->start + em->len - 1, 0);
7553                 write_lock(&em_tree->lock);
7554                 ret = add_extent_mapping(em_tree, em, 1);
7555                 write_unlock(&em_tree->lock);
7556                 /*
7557                  * The caller has taken lock_extent(), who could race with us
7558                  * to add em?
7559                  */
7560         } while (ret == -EEXIST);
7561
7562         if (ret) {
7563                 free_extent_map(em);
7564                 return ERR_PTR(ret);
7565         }
7566
7567         /* em got 2 refs now, callers needs to do free_extent_map once. */
7568         return em;
7569 }
7570
7571 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7572                                    struct buffer_head *bh_result, int create)
7573 {
7574         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7575         struct extent_map *em;
7576         struct extent_state *cached_state = NULL;
7577         struct btrfs_dio_data *dio_data = NULL;
7578         u64 start = iblock << inode->i_blkbits;
7579         u64 lockstart, lockend;
7580         u64 len = bh_result->b_size;
7581         int unlock_bits = EXTENT_LOCKED;
7582         int ret = 0;
7583
7584         if (create)
7585                 unlock_bits |= EXTENT_DIRTY;
7586         else
7587                 len = min_t(u64, len, fs_info->sectorsize);
7588
7589         lockstart = start;
7590         lockend = start + len - 1;
7591
7592         if (current->journal_info) {
7593                 /*
7594                  * Need to pull our outstanding extents and set journal_info to NULL so
7595                  * that anything that needs to check if there's a transaction doesn't get
7596                  * confused.
7597                  */
7598                 dio_data = current->journal_info;
7599                 current->journal_info = NULL;
7600         }
7601
7602         /*
7603          * If this errors out it's because we couldn't invalidate pagecache for
7604          * this range and we need to fallback to buffered.
7605          */
7606         if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7607                                create)) {
7608                 ret = -ENOTBLK;
7609                 goto err;
7610         }
7611
7612         em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7613         if (IS_ERR(em)) {
7614                 ret = PTR_ERR(em);
7615                 goto unlock_err;
7616         }
7617
7618         /*
7619          * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7620          * io.  INLINE is special, and we could probably kludge it in here, but
7621          * it's still buffered so for safety lets just fall back to the generic
7622          * buffered path.
7623          *
7624          * For COMPRESSED we _have_ to read the entire extent in so we can
7625          * decompress it, so there will be buffering required no matter what we
7626          * do, so go ahead and fallback to buffered.
7627          *
7628          * We return -ENOTBLK because that's what makes DIO go ahead and go back
7629          * to buffered IO.  Don't blame me, this is the price we pay for using
7630          * the generic code.
7631          */
7632         if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7633             em->block_start == EXTENT_MAP_INLINE) {
7634                 free_extent_map(em);
7635                 ret = -ENOTBLK;
7636                 goto unlock_err;
7637         }
7638
7639         /* Just a good old fashioned hole, return */
7640         if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7641                         test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7642                 free_extent_map(em);
7643                 goto unlock_err;
7644         }
7645
7646         /*
7647          * We don't allocate a new extent in the following cases
7648          *
7649          * 1) The inode is marked as NODATACOW.  In this case we'll just use the
7650          * existing extent.
7651          * 2) The extent is marked as PREALLOC.  We're good to go here and can
7652          * just use the extent.
7653          *
7654          */
7655         if (!create) {
7656                 len = min(len, em->len - (start - em->start));
7657                 lockstart = start + len;
7658                 goto unlock;
7659         }
7660
7661         if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7662             ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7663              em->block_start != EXTENT_MAP_HOLE)) {
7664                 int type;
7665                 u64 block_start, orig_start, orig_block_len, ram_bytes;
7666
7667                 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7668                         type = BTRFS_ORDERED_PREALLOC;
7669                 else
7670                         type = BTRFS_ORDERED_NOCOW;
7671                 len = min(len, em->len - (start - em->start));
7672                 block_start = em->block_start + (start - em->start);
7673
7674                 if (can_nocow_extent(inode, start, &len, &orig_start,
7675                                      &orig_block_len, &ram_bytes) == 1 &&
7676                     btrfs_inc_nocow_writers(fs_info, block_start)) {
7677                         struct extent_map *em2;
7678
7679                         em2 = btrfs_create_dio_extent(inode, start, len,
7680                                                       orig_start, block_start,
7681                                                       len, orig_block_len,
7682                                                       ram_bytes, type);
7683                         btrfs_dec_nocow_writers(fs_info, block_start);
7684                         if (type == BTRFS_ORDERED_PREALLOC) {
7685                                 free_extent_map(em);
7686                                 em = em2;
7687                         }
7688                         if (em2 && IS_ERR(em2)) {
7689                                 ret = PTR_ERR(em2);
7690                                 goto unlock_err;
7691                         }
7692                         /*
7693                          * For inode marked NODATACOW or extent marked PREALLOC,
7694                          * use the existing or preallocated extent, so does not
7695                          * need to adjust btrfs_space_info's bytes_may_use.
7696                          */
7697                         btrfs_free_reserved_data_space_noquota(inode,
7698                                         start, len);
7699                         goto unlock;
7700                 }
7701         }
7702
7703         /*
7704          * this will cow the extent, reset the len in case we changed
7705          * it above
7706          */
7707         len = bh_result->b_size;
7708         free_extent_map(em);
7709         em = btrfs_new_extent_direct(inode, start, len);
7710         if (IS_ERR(em)) {
7711                 ret = PTR_ERR(em);
7712                 goto unlock_err;
7713         }
7714         len = min(len, em->len - (start - em->start));
7715 unlock:
7716         bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7717                 inode->i_blkbits;
7718         bh_result->b_size = len;
7719         bh_result->b_bdev = em->bdev;
7720         set_buffer_mapped(bh_result);
7721         if (create) {
7722                 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7723                         set_buffer_new(bh_result);
7724
7725                 /*
7726                  * Need to update the i_size under the extent lock so buffered
7727                  * readers will get the updated i_size when we unlock.
7728                  */
7729                 if (!dio_data->overwrite && start + len > i_size_read(inode))
7730                         i_size_write(inode, start + len);
7731
7732                 WARN_ON(dio_data->reserve < len);
7733                 dio_data->reserve -= len;
7734                 dio_data->unsubmitted_oe_range_end = start + len;
7735                 current->journal_info = dio_data;
7736         }
7737
7738         /*
7739          * In the case of write we need to clear and unlock the entire range,
7740          * in the case of read we need to unlock only the end area that we
7741          * aren't using if there is any left over space.
7742          */
7743         if (lockstart < lockend) {
7744                 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7745                                  lockend, unlock_bits, 1, 0,
7746                                  &cached_state);
7747         } else {
7748                 free_extent_state(cached_state);
7749         }
7750
7751         free_extent_map(em);
7752
7753         return 0;
7754
7755 unlock_err:
7756         clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7757                          unlock_bits, 1, 0, &cached_state);
7758 err:
7759         if (dio_data)
7760                 current->journal_info = dio_data;
7761         return ret;
7762 }
7763
7764 static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
7765                                                  struct bio *bio,
7766                                                  int mirror_num)
7767 {
7768         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7769         blk_status_t ret;
7770
7771         BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7772
7773         ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7774         if (ret)
7775                 return ret;
7776
7777         ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7778
7779         return ret;
7780 }
7781
7782 static int btrfs_check_dio_repairable(struct inode *inode,
7783                                       struct bio *failed_bio,
7784                                       struct io_failure_record *failrec,
7785                                       int failed_mirror)
7786 {
7787         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7788         int num_copies;
7789
7790         num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7791         if (num_copies == 1) {
7792                 /*
7793                  * we only have a single copy of the data, so don't bother with
7794                  * all the retry and error correction code that follows. no
7795                  * matter what the error is, it is very likely to persist.
7796                  */
7797                 btrfs_debug(fs_info,
7798                         "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7799                         num_copies, failrec->this_mirror, failed_mirror);
7800                 return 0;
7801         }
7802
7803         failrec->failed_mirror = failed_mirror;
7804         failrec->this_mirror++;
7805         if (failrec->this_mirror == failed_mirror)
7806                 failrec->this_mirror++;
7807
7808         if (failrec->this_mirror > num_copies) {
7809                 btrfs_debug(fs_info,
7810                         "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7811                         num_copies, failrec->this_mirror, failed_mirror);
7812                 return 0;
7813         }
7814
7815         return 1;
7816 }
7817
7818 static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
7819                                    struct page *page, unsigned int pgoff,
7820                                    u64 start, u64 end, int failed_mirror,
7821                                    bio_end_io_t *repair_endio, void *repair_arg)
7822 {
7823         struct io_failure_record *failrec;
7824         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7825         struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
7826         struct bio *bio;
7827         int isector;
7828         unsigned int read_mode = 0;
7829         int segs;
7830         int ret;
7831         blk_status_t status;
7832         struct bio_vec bvec;
7833
7834         BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7835
7836         ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7837         if (ret)
7838                 return errno_to_blk_status(ret);
7839
7840         ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7841                                          failed_mirror);
7842         if (!ret) {
7843                 free_io_failure(failure_tree, io_tree, failrec);
7844                 return BLK_STS_IOERR;
7845         }
7846
7847         segs = bio_segments(failed_bio);
7848         bio_get_first_bvec(failed_bio, &bvec);
7849         if (segs > 1 ||
7850             (bvec.bv_len > btrfs_inode_sectorsize(inode)))
7851                 read_mode |= REQ_FAILFAST_DEV;
7852
7853         isector = start - btrfs_io_bio(failed_bio)->logical;
7854         isector >>= inode->i_sb->s_blocksize_bits;
7855         bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7856                                 pgoff, isector, repair_endio, repair_arg);
7857         bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7858
7859         btrfs_debug(BTRFS_I(inode)->root->fs_info,
7860                     "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
7861                     read_mode, failrec->this_mirror, failrec->in_validation);
7862
7863         status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7864         if (status) {
7865                 free_io_failure(failure_tree, io_tree, failrec);
7866                 bio_put(bio);
7867         }
7868
7869         return status;
7870 }
7871
7872 struct btrfs_retry_complete {
7873         struct completion done;
7874         struct inode *inode;
7875         u64 start;
7876         int uptodate;
7877 };
7878
7879 static void btrfs_retry_endio_nocsum(struct bio *bio)
7880 {
7881         struct btrfs_retry_complete *done = bio->bi_private;
7882         struct inode *inode = done->inode;
7883         struct bio_vec *bvec;
7884         struct extent_io_tree *io_tree, *failure_tree;
7885         int i;
7886
7887         if (bio->bi_status)
7888                 goto end;
7889
7890         ASSERT(bio->bi_vcnt == 1);
7891         io_tree = &BTRFS_I(inode)->io_tree;
7892         failure_tree = &BTRFS_I(inode)->io_failure_tree;
7893         ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
7894
7895         done->uptodate = 1;
7896         ASSERT(!bio_flagged(bio, BIO_CLONED));
7897         bio_for_each_segment_all(bvec, bio, i)
7898                 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
7899                                  io_tree, done->start, bvec->bv_page,
7900                                  btrfs_ino(BTRFS_I(inode)), 0);
7901 end:
7902         complete(&done->done);
7903         bio_put(bio);
7904 }
7905
7906 static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
7907                                                 struct btrfs_io_bio *io_bio)
7908 {
7909         struct btrfs_fs_info *fs_info;
7910         struct bio_vec bvec;
7911         struct bvec_iter iter;
7912         struct btrfs_retry_complete done;
7913         u64 start;
7914         unsigned int pgoff;
7915         u32 sectorsize;
7916         int nr_sectors;
7917         blk_status_t ret;
7918         blk_status_t err = BLK_STS_OK;
7919
7920         fs_info = BTRFS_I(inode)->root->fs_info;
7921         sectorsize = fs_info->sectorsize;
7922
7923         start = io_bio->logical;
7924         done.inode = inode;
7925         io_bio->bio.bi_iter = io_bio->iter;
7926
7927         bio_for_each_segment(bvec, &io_bio->bio, iter) {
7928                 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
7929                 pgoff = bvec.bv_offset;
7930
7931 next_block_or_try_again:
7932                 done.uptodate = 0;
7933                 done.start = start;
7934                 init_completion(&done.done);
7935
7936                 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
7937                                 pgoff, start, start + sectorsize - 1,
7938                                 io_bio->mirror_num,
7939                                 btrfs_retry_endio_nocsum, &done);
7940                 if (ret) {
7941                         err = ret;
7942                         goto next;
7943                 }
7944
7945                 wait_for_completion_io(&done.done);
7946
7947                 if (!done.uptodate) {
7948                         /* We might have another mirror, so try again */
7949                         goto next_block_or_try_again;
7950                 }
7951
7952 next:
7953                 start += sectorsize;
7954
7955                 nr_sectors--;
7956                 if (nr_sectors) {
7957                         pgoff += sectorsize;
7958                         ASSERT(pgoff < PAGE_SIZE);
7959                         goto next_block_or_try_again;
7960                 }
7961         }
7962
7963         return err;
7964 }
7965
7966 static void btrfs_retry_endio(struct bio *bio)
7967 {
7968         struct btrfs_retry_complete *done = bio->bi_private;
7969         struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7970         struct extent_io_tree *io_tree, *failure_tree;
7971         struct inode *inode = done->inode;
7972         struct bio_vec *bvec;
7973         int uptodate;
7974         int ret;
7975         int i;
7976
7977         if (bio->bi_status)
7978                 goto end;
7979
7980         uptodate = 1;
7981
7982         ASSERT(bio->bi_vcnt == 1);
7983         ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
7984
7985         io_tree = &BTRFS_I(inode)->io_tree;
7986         failure_tree = &BTRFS_I(inode)->io_failure_tree;
7987
7988         ASSERT(!bio_flagged(bio, BIO_CLONED));
7989         bio_for_each_segment_all(bvec, bio, i) {
7990                 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7991                                              bvec->bv_offset, done->start,
7992                                              bvec->bv_len);
7993                 if (!ret)
7994                         clean_io_failure(BTRFS_I(inode)->root->fs_info,
7995                                          failure_tree, io_tree, done->start,
7996                                          bvec->bv_page,
7997                                          btrfs_ino(BTRFS_I(inode)),
7998                                          bvec->bv_offset);
7999                 else
8000                         uptodate = 0;
8001         }
8002
8003         done->uptodate = uptodate;
8004 end:
8005         complete(&done->done);
8006         bio_put(bio);
8007 }
8008
8009 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8010                 struct btrfs_io_bio *io_bio, blk_status_t err)
8011 {
8012         struct btrfs_fs_info *fs_info;
8013         struct bio_vec bvec;
8014         struct bvec_iter iter;
8015         struct btrfs_retry_complete done;
8016         u64 start;
8017         u64 offset = 0;
8018         u32 sectorsize;
8019         int nr_sectors;
8020         unsigned int pgoff;
8021         int csum_pos;
8022         bool uptodate = (err == 0);
8023         int ret;
8024         blk_status_t status;
8025
8026         fs_info = BTRFS_I(inode)->root->fs_info;
8027         sectorsize = fs_info->sectorsize;
8028
8029         err = BLK_STS_OK;
8030         start = io_bio->logical;
8031         done.inode = inode;
8032         io_bio->bio.bi_iter = io_bio->iter;
8033
8034         bio_for_each_segment(bvec, &io_bio->bio, iter) {
8035                 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8036
8037                 pgoff = bvec.bv_offset;
8038 next_block:
8039                 if (uptodate) {
8040                         csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8041                         ret = __readpage_endio_check(inode, io_bio, csum_pos,
8042                                         bvec.bv_page, pgoff, start, sectorsize);
8043                         if (likely(!ret))
8044                                 goto next;
8045                 }
8046 try_again:
8047                 done.uptodate = 0;
8048                 done.start = start;
8049                 init_completion(&done.done);
8050
8051                 status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8052                                         pgoff, start, start + sectorsize - 1,
8053                                         io_bio->mirror_num, btrfs_retry_endio,
8054                                         &done);
8055                 if (status) {
8056                         err = status;
8057                         goto next;
8058                 }
8059
8060                 wait_for_completion_io(&done.done);
8061
8062                 if (!done.uptodate) {
8063                         /* We might have another mirror, so try again */
8064                         goto try_again;
8065                 }
8066 next:
8067                 offset += sectorsize;
8068                 start += sectorsize;
8069
8070                 ASSERT(nr_sectors);
8071
8072                 nr_sectors--;
8073                 if (nr_sectors) {
8074                         pgoff += sectorsize;
8075                         ASSERT(pgoff < PAGE_SIZE);
8076                         goto next_block;
8077                 }
8078         }
8079
8080         return err;
8081 }
8082
8083 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8084                 struct btrfs_io_bio *io_bio, blk_status_t err)
8085 {
8086         bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8087
8088         if (skip_csum) {
8089                 if (unlikely(err))
8090                         return __btrfs_correct_data_nocsum(inode, io_bio);
8091                 else
8092                         return BLK_STS_OK;
8093         } else {
8094                 return __btrfs_subio_endio_read(inode, io_bio, err);
8095         }
8096 }
8097
8098 static void btrfs_endio_direct_read(struct bio *bio)
8099 {
8100         struct btrfs_dio_private *dip = bio->bi_private;
8101         struct inode *inode = dip->inode;
8102         struct bio *dio_bio;
8103         struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8104         blk_status_t err = bio->bi_status;
8105
8106         if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8107                 err = btrfs_subio_endio_read(inode, io_bio, err);
8108
8109         unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8110                       dip->logical_offset + dip->bytes - 1);
8111         dio_bio = dip->dio_bio;
8112
8113         kfree(dip);
8114
8115         dio_bio->bi_status = err;
8116         dio_end_io(dio_bio);
8117
8118         if (io_bio->end_io)
8119                 io_bio->end_io(io_bio, blk_status_to_errno(err));
8120         bio_put(bio);
8121 }
8122
8123 static void __endio_write_update_ordered(struct inode *inode,
8124                                          const u64 offset, const u64 bytes,
8125                                          const bool uptodate)
8126 {
8127         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8128         struct btrfs_ordered_extent *ordered = NULL;
8129         struct btrfs_workqueue *wq;
8130         btrfs_work_func_t func;
8131         u64 ordered_offset = offset;
8132         u64 ordered_bytes = bytes;
8133         u64 last_offset;
8134         int ret;
8135
8136         if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8137                 wq = fs_info->endio_freespace_worker;
8138                 func = btrfs_freespace_write_helper;
8139         } else {
8140                 wq = fs_info->endio_write_workers;
8141                 func = btrfs_endio_write_helper;
8142         }
8143
8144 again:
8145         last_offset = ordered_offset;
8146         ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8147                                                    &ordered_offset,
8148                                                    ordered_bytes,
8149                                                    uptodate);
8150         if (!ret)
8151                 goto out_test;
8152
8153         btrfs_init_work(&ordered->work, func, finish_ordered_fn, NULL, NULL);
8154         btrfs_queue_work(wq, &ordered->work);
8155 out_test:
8156         /*
8157          * If btrfs_dec_test_ordered_pending does not find any ordered extent
8158          * in the range, we can exit.
8159          */
8160         if (ordered_offset == last_offset)
8161                 return;
8162         /*
8163          * our bio might span multiple ordered extents.  If we haven't
8164          * completed the accounting for the whole dio, go back and try again
8165          */
8166         if (ordered_offset < offset + bytes) {
8167                 ordered_bytes = offset + bytes - ordered_offset;
8168                 ordered = NULL;
8169                 goto again;
8170         }
8171 }
8172
8173 static void btrfs_endio_direct_write(struct bio *bio)
8174 {
8175         struct btrfs_dio_private *dip = bio->bi_private;
8176         struct bio *dio_bio = dip->dio_bio;
8177
8178         __endio_write_update_ordered(dip->inode, dip->logical_offset,
8179                                      dip->bytes, !bio->bi_status);
8180
8181         kfree(dip);
8182
8183         dio_bio->bi_status = bio->bi_status;
8184         dio_end_io(dio_bio);
8185         bio_put(bio);
8186 }
8187
8188 static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
8189                                     struct bio *bio, u64 offset)
8190 {
8191         struct inode *inode = private_data;
8192         blk_status_t ret;
8193         ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8194         BUG_ON(ret); /* -ENOMEM */
8195         return 0;
8196 }
8197
8198 static void btrfs_end_dio_bio(struct bio *bio)
8199 {
8200         struct btrfs_dio_private *dip = bio->bi_private;
8201         blk_status_t err = bio->bi_status;
8202
8203         if (err)
8204                 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8205                            "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8206                            btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8207                            bio->bi_opf,
8208                            (unsigned long long)bio->bi_iter.bi_sector,
8209                            bio->bi_iter.bi_size, err);
8210
8211         if (dip->subio_endio)
8212                 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8213
8214         if (err) {
8215                 /*
8216                  * We want to perceive the errors flag being set before
8217                  * decrementing the reference count. We don't need a barrier
8218                  * since atomic operations with a return value are fully
8219                  * ordered as per atomic_t.txt
8220                  */
8221                 dip->errors = 1;
8222         }
8223
8224         /* if there are more bios still pending for this dio, just exit */
8225         if (!atomic_dec_and_test(&dip->pending_bios))
8226                 goto out;
8227
8228         if (dip->errors) {
8229                 bio_io_error(dip->orig_bio);
8230         } else {
8231                 dip->dio_bio->bi_status = BLK_STS_OK;
8232                 bio_endio(dip->orig_bio);
8233         }
8234 out:
8235         bio_put(bio);
8236 }
8237
8238 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8239                                                  struct btrfs_dio_private *dip,
8240                                                  struct bio *bio,
8241                                                  u64 file_offset)
8242 {
8243         struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8244         struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8245         blk_status_t ret;
8246
8247         /*
8248          * We load all the csum data we need when we submit
8249          * the first bio to reduce the csum tree search and
8250          * contention.
8251          */
8252         if (dip->logical_offset == file_offset) {
8253                 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8254                                                 file_offset);
8255                 if (ret)
8256                         return ret;
8257         }
8258
8259         if (bio == dip->orig_bio)
8260                 return 0;
8261
8262         file_offset -= dip->logical_offset;
8263         file_offset >>= inode->i_sb->s_blocksize_bits;
8264         io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8265
8266         return 0;
8267 }
8268
8269 static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
8270                 struct inode *inode, u64 file_offset, int async_submit)
8271 {
8272         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8273         struct btrfs_dio_private *dip = bio->bi_private;
8274         bool write = bio_op(bio) == REQ_OP_WRITE;
8275         blk_status_t ret;
8276
8277         /* Check btrfs_submit_bio_hook() for rules about async submit. */
8278         if (async_submit)
8279                 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8280
8281         if (!write) {
8282                 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8283                 if (ret)
8284                         goto err;
8285         }
8286
8287         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8288                 goto map;
8289
8290         if (write && async_submit) {
8291                 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8292                                           file_offset, inode,
8293                                           btrfs_submit_bio_start_direct_io,
8294                                           btrfs_submit_bio_done);
8295                 goto err;
8296         } else if (write) {
8297                 /*
8298                  * If we aren't doing async submit, calculate the csum of the
8299                  * bio now.
8300                  */
8301                 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8302                 if (ret)
8303                         goto err;
8304         } else {
8305                 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8306                                                      file_offset);
8307                 if (ret)
8308                         goto err;
8309         }
8310 map:
8311         ret = btrfs_map_bio(fs_info, bio, 0, 0);
8312 err:
8313         return ret;
8314 }
8315
8316 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8317 {
8318         struct inode *inode = dip->inode;
8319         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8320         struct bio *bio;
8321         struct bio *orig_bio = dip->orig_bio;
8322         u64 start_sector = orig_bio->bi_iter.bi_sector;
8323         u64 file_offset = dip->logical_offset;
8324         u64 map_length;
8325         int async_submit = 0;
8326         u64 submit_len;
8327         int clone_offset = 0;
8328         int clone_len;
8329         int ret;
8330         blk_status_t status;
8331
8332         map_length = orig_bio->bi_iter.bi_size;
8333         submit_len = map_length;
8334         ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8335                               &map_length, NULL, 0);
8336         if (ret)
8337                 return -EIO;
8338
8339         if (map_length >= submit_len) {
8340                 bio = orig_bio;
8341                 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8342                 goto submit;
8343         }
8344
8345         /* async crcs make it difficult to collect full stripe writes. */
8346         if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8347                 async_submit = 0;
8348         else
8349                 async_submit = 1;
8350
8351         /* bio split */
8352         ASSERT(map_length <= INT_MAX);
8353         atomic_inc(&dip->pending_bios);
8354         do {
8355                 clone_len = min_t(int, submit_len, map_length);
8356
8357                 /*
8358                  * This will never fail as it's passing GPF_NOFS and
8359                  * the allocation is backed by btrfs_bioset.
8360                  */
8361                 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8362                                               clone_len);
8363                 bio->bi_private = dip;
8364                 bio->bi_end_io = btrfs_end_dio_bio;
8365                 btrfs_io_bio(bio)->logical = file_offset;
8366
8367                 ASSERT(submit_len >= clone_len);
8368                 submit_len -= clone_len;
8369                 if (submit_len == 0)
8370                         break;
8371
8372                 /*
8373                  * Increase the count before we submit the bio so we know
8374                  * the end IO handler won't happen before we increase the
8375                  * count. Otherwise, the dip might get freed before we're
8376                  * done setting it up.
8377                  */
8378                 atomic_inc(&dip->pending_bios);
8379
8380                 status = btrfs_submit_dio_bio(bio, inode, file_offset,
8381                                                 async_submit);
8382                 if (status) {
8383                         bio_put(bio);
8384                         atomic_dec(&dip->pending_bios);
8385                         goto out_err;
8386                 }
8387
8388                 clone_offset += clone_len;
8389                 start_sector += clone_len >> 9;
8390                 file_offset += clone_len;
8391
8392                 map_length = submit_len;
8393                 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8394                                       start_sector << 9, &map_length, NULL, 0);
8395                 if (ret)
8396                         goto out_err;
8397         } while (submit_len > 0);
8398
8399 submit:
8400         status = btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8401         if (!status)
8402                 return 0;
8403
8404         bio_put(bio);
8405 out_err:
8406         dip->errors = 1;
8407         /*
8408          * Before atomic variable goto zero, we must  make sure dip->errors is
8409          * perceived to be set. This ordering is ensured by the fact that an
8410          * atomic operations with a return value are fully ordered as per
8411          * atomic_t.txt
8412          */
8413         if (atomic_dec_and_test(&dip->pending_bios))
8414                 bio_io_error(dip->orig_bio);
8415
8416         /* bio_end_io() will handle error, so we needn't return it */
8417         return 0;
8418 }
8419
8420 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8421                                 loff_t file_offset)
8422 {
8423         struct btrfs_dio_private *dip = NULL;
8424         struct bio *bio = NULL;
8425         struct btrfs_io_bio *io_bio;
8426         bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8427         int ret = 0;
8428
8429         bio = btrfs_bio_clone(dio_bio);
8430
8431         dip = kzalloc(sizeof(*dip), GFP_NOFS);
8432         if (!dip) {
8433                 ret = -ENOMEM;
8434                 goto free_ordered;
8435         }
8436
8437         dip->private = dio_bio->bi_private;
8438         dip->inode = inode;
8439         dip->logical_offset = file_offset;
8440         dip->bytes = dio_bio->bi_iter.bi_size;
8441         dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8442         bio->bi_private = dip;
8443         dip->orig_bio = bio;
8444         dip->dio_bio = dio_bio;
8445         atomic_set(&dip->pending_bios, 0);
8446         io_bio = btrfs_io_bio(bio);
8447         io_bio->logical = file_offset;
8448
8449         if (write) {
8450                 bio->bi_end_io = btrfs_endio_direct_write;
8451         } else {
8452                 bio->bi_end_io = btrfs_endio_direct_read;
8453                 dip->subio_endio = btrfs_subio_endio_read;
8454         }
8455
8456         /*
8457          * Reset the range for unsubmitted ordered extents (to a 0 length range)
8458          * even if we fail to submit a bio, because in such case we do the
8459          * corresponding error handling below and it must not be done a second
8460          * time by btrfs_direct_IO().
8461          */
8462         if (write) {
8463                 struct btrfs_dio_data *dio_data = current->journal_info;
8464
8465                 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8466                         dip->bytes;
8467                 dio_data->unsubmitted_oe_range_start =
8468                         dio_data->unsubmitted_oe_range_end;
8469         }
8470
8471         ret = btrfs_submit_direct_hook(dip);
8472         if (!ret)
8473                 return;
8474
8475         if (io_bio->end_io)
8476                 io_bio->end_io(io_bio, ret);
8477
8478 free_ordered:
8479         /*
8480          * If we arrived here it means either we failed to submit the dip
8481          * or we either failed to clone the dio_bio or failed to allocate the
8482          * dip. If we cloned the dio_bio and allocated the dip, we can just
8483          * call bio_endio against our io_bio so that we get proper resource
8484          * cleanup if we fail to submit the dip, otherwise, we must do the
8485          * same as btrfs_endio_direct_[write|read] because we can't call these
8486          * callbacks - they require an allocated dip and a clone of dio_bio.
8487          */
8488         if (bio && dip) {
8489                 bio_io_error(bio);
8490                 /*
8491                  * The end io callbacks free our dip, do the final put on bio
8492                  * and all the cleanup and final put for dio_bio (through
8493                  * dio_end_io()).
8494                  */
8495                 dip = NULL;
8496                 bio = NULL;
8497         } else {
8498                 if (write)
8499                         __endio_write_update_ordered(inode,
8500                                                 file_offset,
8501                                                 dio_bio->bi_iter.bi_size,
8502                                                 false);
8503                 else
8504                         unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8505                               file_offset + dio_bio->bi_iter.bi_size - 1);
8506
8507                 dio_bio->bi_status = BLK_STS_IOERR;
8508                 /*
8509                  * Releases and cleans up our dio_bio, no need to bio_put()
8510                  * nor bio_endio()/bio_io_error() against dio_bio.
8511                  */
8512                 dio_end_io(dio_bio);
8513         }
8514         if (bio)
8515                 bio_put(bio);
8516         kfree(dip);
8517 }
8518
8519 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8520                                const struct iov_iter *iter, loff_t offset)
8521 {
8522         int seg;
8523         int i;
8524         unsigned int blocksize_mask = fs_info->sectorsize - 1;
8525         ssize_t retval = -EINVAL;
8526
8527         if (offset & blocksize_mask)
8528                 goto out;
8529
8530         if (iov_iter_alignment(iter) & blocksize_mask)
8531                 goto out;
8532
8533         /* If this is a write we don't need to check anymore */
8534         if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8535                 return 0;
8536         /*
8537          * Check to make sure we don't have duplicate iov_base's in this
8538          * iovec, if so return EINVAL, otherwise we'll get csum errors
8539          * when reading back.
8540          */
8541         for (seg = 0; seg < iter->nr_segs; seg++) {
8542                 for (i = seg + 1; i < iter->nr_segs; i++) {
8543                         if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8544                                 goto out;
8545                 }
8546         }
8547         retval = 0;
8548 out:
8549         return retval;
8550 }
8551
8552 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8553 {
8554         struct file *file = iocb->ki_filp;
8555         struct inode *inode = file->f_mapping->host;
8556         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8557         struct btrfs_dio_data dio_data = { 0 };
8558         struct extent_changeset *data_reserved = NULL;
8559         loff_t offset = iocb->ki_pos;
8560         size_t count = 0;
8561         int flags = 0;
8562         bool wakeup = true;
8563         bool relock = false;
8564         ssize_t ret;
8565
8566         if (check_direct_IO(fs_info, iter, offset))
8567                 return 0;
8568
8569         inode_dio_begin(inode);
8570
8571         /*
8572          * The generic stuff only does filemap_write_and_wait_range, which
8573          * isn't enough if we've written compressed pages to this area, so
8574          * we need to flush the dirty pages again to make absolutely sure
8575          * that any outstanding dirty pages are on disk.
8576          */
8577         count = iov_iter_count(iter);
8578         if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8579                      &BTRFS_I(inode)->runtime_flags))
8580                 filemap_fdatawrite_range(inode->i_mapping, offset,
8581                                          offset + count - 1);
8582
8583         if (iov_iter_rw(iter) == WRITE) {
8584                 /*
8585                  * If the write DIO is beyond the EOF, we need update
8586                  * the isize, but it is protected by i_mutex. So we can
8587                  * not unlock the i_mutex at this case.
8588                  */
8589                 if (offset + count <= inode->i_size) {
8590                         dio_data.overwrite = 1;
8591                         inode_unlock(inode);
8592                         relock = true;
8593                 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8594                         ret = -EAGAIN;
8595                         goto out;
8596                 }
8597                 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8598                                                    offset, count);
8599                 if (ret)
8600                         goto out;
8601
8602                 /*
8603                  * We need to know how many extents we reserved so that we can
8604                  * do the accounting properly if we go over the number we
8605                  * originally calculated.  Abuse current->journal_info for this.
8606                  */
8607                 dio_data.reserve = round_up(count,
8608                                             fs_info->sectorsize);
8609                 dio_data.unsubmitted_oe_range_start = (u64)offset;
8610                 dio_data.unsubmitted_oe_range_end = (u64)offset;
8611                 current->journal_info = &dio_data;
8612                 down_read(&BTRFS_I(inode)->dio_sem);
8613         } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8614                                      &BTRFS_I(inode)->runtime_flags)) {
8615                 inode_dio_end(inode);
8616                 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8617                 wakeup = false;
8618         }
8619
8620         ret = __blockdev_direct_IO(iocb, inode,
8621                                    fs_info->fs_devices->latest_bdev,
8622                                    iter, btrfs_get_blocks_direct, NULL,
8623                                    btrfs_submit_direct, flags);
8624         if (iov_iter_rw(iter) == WRITE) {
8625                 up_read(&BTRFS_I(inode)->dio_sem);
8626                 current->journal_info = NULL;
8627                 if (ret < 0 && ret != -EIOCBQUEUED) {
8628                         if (dio_data.reserve)
8629                                 btrfs_delalloc_release_space(inode, data_reserved,
8630                                         offset, dio_data.reserve, true);
8631                         /*
8632                          * On error we might have left some ordered extents
8633                          * without submitting corresponding bios for them, so
8634                          * cleanup them up to avoid other tasks getting them
8635                          * and waiting for them to complete forever.
8636                          */
8637                         if (dio_data.unsubmitted_oe_range_start <
8638                             dio_data.unsubmitted_oe_range_end)
8639                                 __endio_write_update_ordered(inode,
8640                                         dio_data.unsubmitted_oe_range_start,
8641                                         dio_data.unsubmitted_oe_range_end -
8642                                         dio_data.unsubmitted_oe_range_start,
8643                                         false);
8644                 } else if (ret >= 0 && (size_t)ret < count)
8645                         btrfs_delalloc_release_space(inode, data_reserved,
8646                                         offset, count - (size_t)ret, true);
8647                 btrfs_delalloc_release_extents(BTRFS_I(inode), count, false);
8648         }
8649 out:
8650         if (wakeup)
8651                 inode_dio_end(inode);
8652         if (relock)
8653                 inode_lock(inode);
8654
8655         extent_changeset_free(data_reserved);
8656         return ret;
8657 }
8658
8659 #define BTRFS_FIEMAP_FLAGS      (FIEMAP_FLAG_SYNC)
8660
8661 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8662                 __u64 start, __u64 len)
8663 {
8664         int     ret;
8665
8666         ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8667         if (ret)
8668                 return ret;
8669
8670         return extent_fiemap(inode, fieinfo, start, len);
8671 }
8672
8673 int btrfs_readpage(struct file *file, struct page *page)
8674 {
8675         struct extent_io_tree *tree;
8676         tree = &BTRFS_I(page->mapping->host)->io_tree;
8677         return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8678 }
8679
8680 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8681 {
8682         struct inode *inode = page->mapping->host;
8683         int ret;
8684
8685         if (current->flags & PF_MEMALLOC) {
8686                 redirty_page_for_writepage(wbc, page);
8687                 unlock_page(page);
8688                 return 0;
8689         }
8690
8691         /*
8692          * If we are under memory pressure we will call this directly from the
8693          * VM, we need to make sure we have the inode referenced for the ordered
8694          * extent.  If not just return like we didn't do anything.
8695          */
8696         if (!igrab(inode)) {
8697                 redirty_page_for_writepage(wbc, page);
8698                 return AOP_WRITEPAGE_ACTIVATE;
8699         }
8700         ret = extent_write_full_page(page, wbc);
8701         btrfs_add_delayed_iput(inode);
8702         return ret;
8703 }
8704
8705 static int btrfs_writepages(struct address_space *mapping,
8706                             struct writeback_control *wbc)
8707 {
8708         struct extent_io_tree *tree;
8709
8710         tree = &BTRFS_I(mapping->host)->io_tree;
8711         return extent_writepages(tree, mapping, wbc);
8712 }
8713
8714 static int
8715 btrfs_readpages(struct file *file, struct address_space *mapping,
8716                 struct list_head *pages, unsigned nr_pages)
8717 {
8718         struct extent_io_tree *tree;
8719         tree = &BTRFS_I(mapping->host)->io_tree;
8720         return extent_readpages(tree, mapping, pages, nr_pages);
8721 }
8722 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8723 {
8724         struct extent_io_tree *tree;
8725         struct extent_map_tree *map;
8726         int ret;
8727
8728         tree = &BTRFS_I(page->mapping->host)->io_tree;
8729         map = &BTRFS_I(page->mapping->host)->extent_tree;
8730         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8731         if (ret == 1) {
8732                 ClearPagePrivate(page);
8733                 set_page_private(page, 0);
8734                 put_page(page);
8735         }
8736         return ret;
8737 }
8738
8739 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8740 {
8741         if (PageWriteback(page) || PageDirty(page))
8742                 return 0;
8743         return __btrfs_releasepage(page, gfp_flags);
8744 }
8745
8746 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8747                                  unsigned int length)
8748 {
8749         struct inode *inode = page->mapping->host;
8750         struct extent_io_tree *tree;
8751         struct btrfs_ordered_extent *ordered;
8752         struct extent_state *cached_state = NULL;
8753         u64 page_start = page_offset(page);
8754         u64 page_end = page_start + PAGE_SIZE - 1;
8755         u64 start;
8756         u64 end;
8757         int inode_evicting = inode->i_state & I_FREEING;
8758
8759         /*
8760          * we have the page locked, so new writeback can't start,
8761          * and the dirty bit won't be cleared while we are here.
8762          *
8763          * Wait for IO on this page so that we can safely clear
8764          * the PagePrivate2 bit and do ordered accounting
8765          */
8766         wait_on_page_writeback(page);
8767
8768         tree = &BTRFS_I(inode)->io_tree;
8769         if (offset) {
8770                 btrfs_releasepage(page, GFP_NOFS);
8771                 return;
8772         }
8773
8774         if (!inode_evicting)
8775                 lock_extent_bits(tree, page_start, page_end, &cached_state);
8776 again:
8777         start = page_start;
8778         ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8779                                         page_end - start + 1);
8780         if (ordered) {
8781                 end = min(page_end, ordered->file_offset + ordered->len - 1);
8782                 /*
8783                  * IO on this page will never be started, so we need
8784                  * to account for any ordered extents now
8785                  */
8786                 if (!inode_evicting)
8787                         clear_extent_bit(tree, start, end,
8788                                          EXTENT_DIRTY | EXTENT_DELALLOC |
8789                                          EXTENT_DELALLOC_NEW |
8790                                          EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8791                                          EXTENT_DEFRAG, 1, 0, &cached_state);
8792                 /*
8793                  * whoever cleared the private bit is responsible
8794                  * for the finish_ordered_io
8795                  */
8796                 if (TestClearPagePrivate2(page)) {
8797                         struct btrfs_ordered_inode_tree *tree;
8798                         u64 new_len;
8799
8800                         tree = &BTRFS_I(inode)->ordered_tree;
8801
8802                         spin_lock_irq(&tree->lock);
8803                         set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8804                         new_len = start - ordered->file_offset;
8805                         if (new_len < ordered->truncated_len)
8806                                 ordered->truncated_len = new_len;
8807                         spin_unlock_irq(&tree->lock);
8808
8809                         if (btrfs_dec_test_ordered_pending(inode, &ordered,
8810                                                            start,
8811                                                            end - start + 1, 1))
8812                                 btrfs_finish_ordered_io(ordered);
8813                 }
8814                 btrfs_put_ordered_extent(ordered);
8815                 if (!inode_evicting) {
8816                         cached_state = NULL;
8817                         lock_extent_bits(tree, start, end,
8818                                          &cached_state);
8819                 }
8820
8821                 start = end + 1;
8822                 if (start < page_end)
8823                         goto again;
8824         }
8825
8826         /*
8827          * Qgroup reserved space handler
8828          * Page here will be either
8829          * 1) Already written to disk
8830          *    In this case, its reserved space is released from data rsv map
8831          *    and will be freed by delayed_ref handler finally.
8832          *    So even we call qgroup_free_data(), it won't decrease reserved
8833          *    space.
8834          * 2) Not written to disk
8835          *    This means the reserved space should be freed here. However,
8836          *    if a truncate invalidates the page (by clearing PageDirty)
8837          *    and the page is accounted for while allocating extent
8838          *    in btrfs_check_data_free_space() we let delayed_ref to
8839          *    free the entire extent.
8840          */
8841         if (PageDirty(page))
8842                 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
8843         if (!inode_evicting) {
8844                 clear_extent_bit(tree, page_start, page_end,
8845                                  EXTENT_LOCKED | EXTENT_DIRTY |
8846                                  EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
8847                                  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
8848                                  &cached_state);
8849
8850                 __btrfs_releasepage(page, GFP_NOFS);
8851         }
8852
8853         ClearPageChecked(page);
8854         if (PagePrivate(page)) {
8855                 ClearPagePrivate(page);
8856                 set_page_private(page, 0);
8857                 put_page(page);
8858         }
8859 }
8860
8861 /*
8862  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8863  * called from a page fault handler when a page is first dirtied. Hence we must
8864  * be careful to check for EOF conditions here. We set the page up correctly
8865  * for a written page which means we get ENOSPC checking when writing into
8866  * holes and correct delalloc and unwritten extent mapping on filesystems that
8867  * support these features.
8868  *
8869  * We are not allowed to take the i_mutex here so we have to play games to
8870  * protect against truncate races as the page could now be beyond EOF.  Because
8871  * vmtruncate() writes the inode size before removing pages, once we have the
8872  * page lock we can determine safely if the page is beyond EOF. If it is not
8873  * beyond EOF, then the page is guaranteed safe against truncation until we
8874  * unlock the page.
8875  */
8876 int btrfs_page_mkwrite(struct vm_fault *vmf)
8877 {
8878         struct page *page = vmf->page;
8879         struct inode *inode = file_inode(vmf->vma->vm_file);
8880         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8881         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8882         struct btrfs_ordered_extent *ordered;
8883         struct extent_state *cached_state = NULL;
8884         struct extent_changeset *data_reserved = NULL;
8885         char *kaddr;
8886         unsigned long zero_start;
8887         loff_t size;
8888         int ret;
8889         int reserved = 0;
8890         u64 reserved_space;
8891         u64 page_start;
8892         u64 page_end;
8893         u64 end;
8894
8895         reserved_space = PAGE_SIZE;
8896
8897         sb_start_pagefault(inode->i_sb);
8898         page_start = page_offset(page);
8899         page_end = page_start + PAGE_SIZE - 1;
8900         end = page_end;
8901
8902         /*
8903          * Reserving delalloc space after obtaining the page lock can lead to
8904          * deadlock. For example, if a dirty page is locked by this function
8905          * and the call to btrfs_delalloc_reserve_space() ends up triggering
8906          * dirty page write out, then the btrfs_writepage() function could
8907          * end up waiting indefinitely to get a lock on the page currently
8908          * being processed by btrfs_page_mkwrite() function.
8909          */
8910         ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
8911                                            reserved_space);
8912         if (!ret) {
8913                 ret = file_update_time(vmf->vma->vm_file);
8914                 reserved = 1;
8915         }
8916         if (ret) {
8917                 if (ret == -ENOMEM)
8918                         ret = VM_FAULT_OOM;
8919                 else /* -ENOSPC, -EIO, etc */
8920                         ret = VM_FAULT_SIGBUS;
8921                 if (reserved)
8922                         goto out;
8923                 goto out_noreserve;
8924         }
8925
8926         ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8927 again:
8928         lock_page(page);
8929         size = i_size_read(inode);
8930
8931         if ((page->mapping != inode->i_mapping) ||
8932             (page_start >= size)) {
8933                 /* page got truncated out from underneath us */
8934                 goto out_unlock;
8935         }
8936         wait_on_page_writeback(page);
8937
8938         lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8939         set_page_extent_mapped(page);
8940
8941         /*
8942          * we can't set the delalloc bits if there are pending ordered
8943          * extents.  Drop our locks and wait for them to finish
8944          */
8945         ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
8946                         PAGE_SIZE);
8947         if (ordered) {
8948                 unlock_extent_cached(io_tree, page_start, page_end,
8949                                      &cached_state);
8950                 unlock_page(page);
8951                 btrfs_start_ordered_extent(inode, ordered, 1);
8952                 btrfs_put_ordered_extent(ordered);
8953                 goto again;
8954         }
8955
8956         if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8957                 reserved_space = round_up(size - page_start,
8958                                           fs_info->sectorsize);
8959                 if (reserved_space < PAGE_SIZE) {
8960                         end = page_start + reserved_space - 1;
8961                         btrfs_delalloc_release_space(inode, data_reserved,
8962                                         page_start, PAGE_SIZE - reserved_space,
8963                                         true);
8964                 }
8965         }
8966
8967         /*
8968          * page_mkwrite gets called when the page is firstly dirtied after it's
8969          * faulted in, but write(2) could also dirty a page and set delalloc
8970          * bits, thus in this case for space account reason, we still need to
8971          * clear any delalloc bits within this page range since we have to
8972          * reserve data&meta space before lock_page() (see above comments).
8973          */
8974         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
8975                           EXTENT_DIRTY | EXTENT_DELALLOC |
8976                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8977                           0, 0, &cached_state);
8978
8979         ret = btrfs_set_extent_delalloc(inode, page_start, end, 0,
8980                                         &cached_state, 0);
8981         if (ret) {
8982                 unlock_extent_cached(io_tree, page_start, page_end,
8983                                      &cached_state);
8984                 ret = VM_FAULT_SIGBUS;
8985                 goto out_unlock;
8986         }
8987         ret = 0;
8988
8989         /* page is wholly or partially inside EOF */
8990         if (page_start + PAGE_SIZE > size)
8991                 zero_start = size & ~PAGE_MASK;
8992         else
8993                 zero_start = PAGE_SIZE;
8994
8995         if (zero_start != PAGE_SIZE) {
8996                 kaddr = kmap(page);
8997                 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
8998                 flush_dcache_page(page);
8999                 kunmap(page);
9000         }
9001         ClearPageChecked(page);
9002         set_page_dirty(page);
9003         SetPageUptodate(page);
9004
9005         BTRFS_I(inode)->last_trans = fs_info->generation;
9006         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9007         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9008
9009         unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
9010
9011 out_unlock:
9012         if (!ret) {
9013                 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true);
9014                 sb_end_pagefault(inode->i_sb);
9015                 extent_changeset_free(data_reserved);
9016                 return VM_FAULT_LOCKED;
9017         }
9018         unlock_page(page);
9019 out:
9020         btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, (ret != 0));
9021         btrfs_delalloc_release_space(inode, data_reserved, page_start,
9022                                      reserved_space, (ret != 0));
9023 out_noreserve:
9024         sb_end_pagefault(inode->i_sb);
9025         extent_changeset_free(data_reserved);
9026         return ret;
9027 }
9028
9029 static int btrfs_truncate(struct inode *inode, bool skip_writeback)
9030 {
9031         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9032         struct btrfs_root *root = BTRFS_I(inode)->root;
9033         struct btrfs_block_rsv *rsv;
9034         int ret = 0;
9035         int err = 0;
9036         struct btrfs_trans_handle *trans;
9037         u64 mask = fs_info->sectorsize - 1;
9038         u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9039
9040         if (!skip_writeback) {
9041                 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9042                                                (u64)-1);
9043                 if (ret)
9044                         return ret;
9045         }
9046
9047         /*
9048          * Yes ladies and gentlemen, this is indeed ugly.  The fact is we have
9049          * 3 things going on here
9050          *
9051          * 1) We need to reserve space for our orphan item and the space to
9052          * delete our orphan item.  Lord knows we don't want to have a dangling
9053          * orphan item because we didn't reserve space to remove it.
9054          *
9055          * 2) We need to reserve space to update our inode.
9056          *
9057          * 3) We need to have something to cache all the space that is going to
9058          * be free'd up by the truncate operation, but also have some slack
9059          * space reserved in case it uses space during the truncate (thank you
9060          * very much snapshotting).
9061          *
9062          * And we need these to all be separate.  The fact is we can use a lot of
9063          * space doing the truncate, and we have no earthly idea how much space
9064          * we will use, so we need the truncate reservation to be separate so it
9065          * doesn't end up using space reserved for updating the inode or
9066          * removing the orphan item.  We also need to be able to stop the
9067          * transaction and start a new one, which means we need to be able to
9068          * update the inode several times, and we have no idea of knowing how
9069          * many times that will be, so we can't just reserve 1 item for the
9070          * entirety of the operation, so that has to be done separately as well.
9071          * Then there is the orphan item, which does indeed need to be held on
9072          * to for the whole operation, and we need nobody to touch this reserved
9073          * space except the orphan code.
9074          *
9075          * So that leaves us with
9076          *
9077          * 1) root->orphan_block_rsv - for the orphan deletion.
9078          * 2) rsv - for the truncate reservation, which we will steal from the
9079          * transaction reservation.
9080          * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9081          * updating the inode.
9082          */
9083         rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9084         if (!rsv)
9085                 return -ENOMEM;
9086         rsv->size = min_size;
9087         rsv->failfast = 1;
9088
9089         /*
9090          * 1 for the truncate slack space
9091          * 1 for updating the inode.
9092          */
9093         trans = btrfs_start_transaction(root, 2);
9094         if (IS_ERR(trans)) {
9095                 err = PTR_ERR(trans);
9096                 goto out;
9097         }
9098
9099         /* Migrate the slack space for the truncate to our reserve */
9100         ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9101                                       min_size, 0);
9102         BUG_ON(ret);
9103
9104         /*
9105          * So if we truncate and then write and fsync we normally would just
9106          * write the extents that changed, which is a problem if we need to
9107          * first truncate that entire inode.  So set this flag so we write out
9108          * all of the extents in the inode to the sync log so we're completely
9109          * safe.
9110          */
9111         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9112         trans->block_rsv = rsv;
9113
9114         while (1) {
9115                 ret = btrfs_truncate_inode_items(trans, root, inode,
9116                                                  inode->i_size,
9117                                                  BTRFS_EXTENT_DATA_KEY);
9118                 trans->block_rsv = &fs_info->trans_block_rsv;
9119                 if (ret != -ENOSPC && ret != -EAGAIN) {
9120                         err = ret;
9121                         break;
9122                 }
9123
9124                 ret = btrfs_update_inode(trans, root, inode);
9125                 if (ret) {
9126                         err = ret;
9127                         break;
9128                 }
9129
9130                 btrfs_end_transaction(trans);
9131                 btrfs_btree_balance_dirty(fs_info);
9132
9133                 trans = btrfs_start_transaction(root, 2);
9134                 if (IS_ERR(trans)) {
9135                         ret = err = PTR_ERR(trans);
9136                         trans = NULL;
9137                         break;
9138                 }
9139
9140                 btrfs_block_rsv_release(fs_info, rsv, -1);
9141                 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9142                                               rsv, min_size, 0);
9143                 BUG_ON(ret);    /* shouldn't happen */
9144                 trans->block_rsv = rsv;
9145         }
9146
9147         /*
9148          * We can't call btrfs_truncate_block inside a trans handle as we could
9149          * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
9150          * we've truncated everything except the last little bit, and can do
9151          * btrfs_truncate_block and then update the disk_i_size.
9152          */
9153         if (ret == NEED_TRUNCATE_BLOCK) {
9154                 btrfs_end_transaction(trans);
9155                 btrfs_btree_balance_dirty(fs_info);
9156
9157                 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
9158                 if (ret)
9159                         goto out;
9160                 trans = btrfs_start_transaction(root, 1);
9161                 if (IS_ERR(trans)) {
9162                         ret = PTR_ERR(trans);
9163                         goto out;
9164                 }
9165                 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
9166         }
9167
9168         if (ret == 0 && inode->i_nlink > 0) {
9169                 trans->block_rsv = root->orphan_block_rsv;
9170                 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9171                 if (ret)
9172                         err = ret;
9173         }
9174
9175         if (trans) {
9176                 trans->block_rsv = &fs_info->trans_block_rsv;
9177                 ret = btrfs_update_inode(trans, root, inode);
9178                 if (ret && !err)
9179                         err = ret;
9180
9181                 ret = btrfs_end_transaction(trans);
9182                 btrfs_btree_balance_dirty(fs_info);
9183         }
9184 out:
9185         btrfs_free_block_rsv(fs_info, rsv);
9186
9187         if (ret && !err)
9188                 err = ret;
9189
9190         return err;
9191 }
9192
9193 /*
9194  * create a new subvolume directory/inode (helper for the ioctl).
9195  */
9196 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9197                              struct btrfs_root *new_root,
9198                              struct btrfs_root *parent_root,
9199                              u64 new_dirid)
9200 {
9201         struct inode *inode;
9202         int err;
9203         u64 index = 0;
9204
9205         inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9206                                 new_dirid, new_dirid,
9207                                 S_IFDIR | (~current_umask() & S_IRWXUGO),
9208                                 &index);
9209         if (IS_ERR(inode))
9210                 return PTR_ERR(inode);
9211         inode->i_op = &btrfs_dir_inode_operations;
9212         inode->i_fop = &btrfs_dir_file_operations;
9213
9214         set_nlink(inode, 1);
9215         btrfs_i_size_write(BTRFS_I(inode), 0);
9216         unlock_new_inode(inode);
9217
9218         err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9219         if (err)
9220                 btrfs_err(new_root->fs_info,
9221                           "error inheriting subvolume %llu properties: %d",
9222                           new_root->root_key.objectid, err);
9223
9224         err = btrfs_update_inode(trans, new_root, inode);
9225
9226         iput(inode);
9227         return err;
9228 }
9229
9230 struct inode *btrfs_alloc_inode(struct super_block *sb)
9231 {
9232         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
9233         struct btrfs_inode *ei;
9234         struct inode *inode;
9235
9236         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
9237         if (!ei)
9238                 return NULL;
9239
9240         ei->root = NULL;
9241         ei->generation = 0;
9242         ei->last_trans = 0;
9243         ei->last_sub_trans = 0;
9244         ei->logged_trans = 0;
9245         ei->delalloc_bytes = 0;
9246         ei->new_delalloc_bytes = 0;
9247         ei->defrag_bytes = 0;
9248         ei->disk_i_size = 0;
9249         ei->flags = 0;
9250         ei->csum_bytes = 0;
9251         ei->index_cnt = (u64)-1;
9252         ei->dir_index = 0;
9253         ei->last_unlink_trans = 0;
9254         ei->last_log_commit = 0;
9255
9256         spin_lock_init(&ei->lock);
9257         ei->outstanding_extents = 0;
9258         if (sb->s_magic != BTRFS_TEST_MAGIC)
9259                 btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
9260                                               BTRFS_BLOCK_RSV_DELALLOC);
9261         ei->runtime_flags = 0;
9262         ei->prop_compress = BTRFS_COMPRESS_NONE;
9263         ei->defrag_compress = BTRFS_COMPRESS_NONE;
9264
9265         ei->delayed_node = NULL;
9266
9267         ei->i_otime.tv_sec = 0;
9268         ei->i_otime.tv_nsec = 0;
9269
9270         inode = &ei->vfs_inode;
9271         extent_map_tree_init(&ei->extent_tree);
9272         extent_io_tree_init(&ei->io_tree, inode);
9273         extent_io_tree_init(&ei->io_failure_tree, inode);
9274         ei->io_tree.track_uptodate = 1;
9275         ei->io_failure_tree.track_uptodate = 1;
9276         atomic_set(&ei->sync_writers, 0);
9277         mutex_init(&ei->log_mutex);
9278         mutex_init(&ei->delalloc_mutex);
9279         btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9280         INIT_LIST_HEAD(&ei->delalloc_inodes);
9281         INIT_LIST_HEAD(&ei->delayed_iput);
9282         RB_CLEAR_NODE(&ei->rb_node);
9283         init_rwsem(&ei->dio_sem);
9284
9285         return inode;
9286 }
9287
9288 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9289 void btrfs_test_destroy_inode(struct inode *inode)
9290 {
9291         btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9292         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9293 }
9294 #endif
9295
9296 static void btrfs_i_callback(struct rcu_head *head)
9297 {
9298         struct inode *inode = container_of(head, struct inode, i_rcu);
9299         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9300 }
9301
9302 void btrfs_destroy_inode(struct inode *inode)
9303 {
9304         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9305         struct btrfs_ordered_extent *ordered;
9306         struct btrfs_root *root = BTRFS_I(inode)->root;
9307
9308         WARN_ON(!hlist_empty(&inode->i_dentry));
9309         WARN_ON(inode->i_data.nrpages);
9310         WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
9311         WARN_ON(BTRFS_I(inode)->block_rsv.size);
9312         WARN_ON(BTRFS_I(inode)->outstanding_extents);
9313         WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9314         WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9315         WARN_ON(BTRFS_I(inode)->csum_bytes);
9316         WARN_ON(BTRFS_I(inode)->defrag_bytes);
9317
9318         /*
9319          * This can happen where we create an inode, but somebody else also
9320          * created the same inode and we need to destroy the one we already
9321          * created.
9322          */
9323         if (!root)
9324                 goto free;
9325
9326         if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9327                      &BTRFS_I(inode)->runtime_flags)) {
9328                 btrfs_info(fs_info, "inode %llu still on the orphan list",
9329                            btrfs_ino(BTRFS_I(inode)));
9330                 atomic_dec(&root->orphan_inodes);
9331         }
9332
9333         while (1) {
9334                 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9335                 if (!ordered)
9336                         break;
9337                 else {
9338                         btrfs_err(fs_info,
9339                                   "found ordered extent %llu %llu on inode cleanup",
9340                                   ordered->file_offset, ordered->len);
9341                         btrfs_remove_ordered_extent(inode, ordered);
9342                         btrfs_put_ordered_extent(ordered);
9343                         btrfs_put_ordered_extent(ordered);
9344                 }
9345         }
9346         btrfs_qgroup_check_reserved_leak(inode);
9347         inode_tree_del(inode);
9348         btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9349 free:
9350         call_rcu(&inode->i_rcu, btrfs_i_callback);
9351 }
9352
9353 int btrfs_drop_inode(struct inode *inode)
9354 {
9355         struct btrfs_root *root = BTRFS_I(inode)->root;
9356
9357         if (root == NULL)
9358                 return 1;
9359
9360         /* the snap/subvol tree is on deleting */
9361         if (btrfs_root_refs(&root->root_item) == 0)
9362                 return 1;
9363         else
9364                 return generic_drop_inode(inode);
9365 }
9366
9367 static void init_once(void *foo)
9368 {
9369         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9370
9371         inode_init_once(&ei->vfs_inode);
9372 }
9373
9374 void __cold btrfs_destroy_cachep(void)
9375 {
9376         /*
9377          * Make sure all delayed rcu free inodes are flushed before we
9378          * destroy cache.
9379          */
9380         rcu_barrier();
9381         kmem_cache_destroy(btrfs_inode_cachep);
9382         kmem_cache_destroy(btrfs_trans_handle_cachep);
9383         kmem_cache_destroy(btrfs_path_cachep);
9384         kmem_cache_destroy(btrfs_free_space_cachep);
9385 }
9386
9387 int __init btrfs_init_cachep(void)
9388 {
9389         btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9390                         sizeof(struct btrfs_inode), 0,
9391                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9392                         init_once);
9393         if (!btrfs_inode_cachep)
9394                 goto fail;
9395
9396         btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9397                         sizeof(struct btrfs_trans_handle), 0,
9398                         SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9399         if (!btrfs_trans_handle_cachep)
9400                 goto fail;
9401
9402         btrfs_path_cachep = kmem_cache_create("btrfs_path",
9403                         sizeof(struct btrfs_path), 0,
9404                         SLAB_MEM_SPREAD, NULL);
9405         if (!btrfs_path_cachep)
9406                 goto fail;
9407
9408         btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9409                         sizeof(struct btrfs_free_space), 0,
9410                         SLAB_MEM_SPREAD, NULL);
9411         if (!btrfs_free_space_cachep)
9412                 goto fail;
9413
9414         return 0;
9415 fail:
9416         btrfs_destroy_cachep();
9417         return -ENOMEM;
9418 }
9419
9420 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9421                          u32 request_mask, unsigned int flags)
9422 {
9423         u64 delalloc_bytes;
9424         struct inode *inode = d_inode(path->dentry);
9425         u32 blocksize = inode->i_sb->s_blocksize;
9426         u32 bi_flags = BTRFS_I(inode)->flags;
9427
9428         stat->result_mask |= STATX_BTIME;
9429         stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9430         stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9431         if (bi_flags & BTRFS_INODE_APPEND)
9432                 stat->attributes |= STATX_ATTR_APPEND;
9433         if (bi_flags & BTRFS_INODE_COMPRESS)
9434                 stat->attributes |= STATX_ATTR_COMPRESSED;
9435         if (bi_flags & BTRFS_INODE_IMMUTABLE)
9436                 stat->attributes |= STATX_ATTR_IMMUTABLE;
9437         if (bi_flags & BTRFS_INODE_NODUMP)
9438                 stat->attributes |= STATX_ATTR_NODUMP;
9439
9440         stat->attributes_mask |= (STATX_ATTR_APPEND |
9441                                   STATX_ATTR_COMPRESSED |
9442                                   STATX_ATTR_IMMUTABLE |
9443                                   STATX_ATTR_NODUMP);
9444
9445         generic_fillattr(inode, stat);
9446         stat->dev = BTRFS_I(inode)->root->anon_dev;
9447
9448         spin_lock(&BTRFS_I(inode)->lock);
9449         delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9450         spin_unlock(&BTRFS_I(inode)->lock);
9451         stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9452                         ALIGN(delalloc_bytes, blocksize)) >> 9;
9453         return 0;
9454 }
9455
9456 static int btrfs_rename_exchange(struct inode *old_dir,
9457                               struct dentry *old_dentry,
9458                               struct inode *new_dir,
9459                               struct dentry *new_dentry)
9460 {
9461         struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9462         struct btrfs_trans_handle *trans;
9463         struct btrfs_root *root = BTRFS_I(old_dir)->root;
9464         struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9465         struct inode *new_inode = new_dentry->d_inode;
9466         struct inode *old_inode = old_dentry->d_inode;
9467         struct timespec ctime = current_time(old_inode);
9468         struct dentry *parent;
9469         u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9470         u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9471         u64 old_idx = 0;
9472         u64 new_idx = 0;
9473         u64 root_objectid;
9474         int ret;
9475         bool root_log_pinned = false;
9476         bool dest_log_pinned = false;
9477
9478         /* we only allow rename subvolume link between subvolumes */
9479         if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9480                 return -EXDEV;
9481
9482         /* close the race window with snapshot create/destroy ioctl */
9483         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9484                 down_read(&fs_info->subvol_sem);
9485         if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9486                 down_read(&fs_info->subvol_sem);
9487
9488         /*
9489          * We want to reserve the absolute worst case amount of items.  So if
9490          * both inodes are subvols and we need to unlink them then that would
9491          * require 4 item modifications, but if they are both normal inodes it
9492          * would require 5 item modifications, so we'll assume their normal
9493          * inodes.  So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9494          * should cover the worst case number of items we'll modify.
9495          */
9496         trans = btrfs_start_transaction(root, 12);
9497         if (IS_ERR(trans)) {
9498                 ret = PTR_ERR(trans);
9499                 goto out_notrans;
9500         }
9501
9502         /*
9503          * We need to find a free sequence number both in the source and
9504          * in the destination directory for the exchange.
9505          */
9506         ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9507         if (ret)
9508                 goto out_fail;
9509         ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9510         if (ret)
9511                 goto out_fail;
9512
9513         BTRFS_I(old_inode)->dir_index = 0ULL;
9514         BTRFS_I(new_inode)->dir_index = 0ULL;
9515
9516         /* Reference for the source. */
9517         if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9518                 /* force full log commit if subvolume involved. */
9519                 btrfs_set_log_full_commit(fs_info, trans);
9520         } else {
9521                 btrfs_pin_log_trans(root);
9522                 root_log_pinned = true;
9523                 ret = btrfs_insert_inode_ref(trans, dest,
9524                                              new_dentry->d_name.name,
9525                                              new_dentry->d_name.len,
9526                                              old_ino,
9527                                              btrfs_ino(BTRFS_I(new_dir)),
9528                                              old_idx);
9529                 if (ret)
9530                         goto out_fail;
9531         }
9532
9533         /* And now for the dest. */
9534         if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9535                 /* force full log commit if subvolume involved. */
9536                 btrfs_set_log_full_commit(fs_info, trans);
9537         } else {
9538                 btrfs_pin_log_trans(dest);
9539                 dest_log_pinned = true;
9540                 ret = btrfs_insert_inode_ref(trans, root,
9541                                              old_dentry->d_name.name,
9542                                              old_dentry->d_name.len,
9543                                              new_ino,
9544                                              btrfs_ino(BTRFS_I(old_dir)),
9545                                              new_idx);
9546                 if (ret)
9547                         goto out_fail;
9548         }
9549
9550         /* Update inode version and ctime/mtime. */
9551         inode_inc_iversion(old_dir);
9552         inode_inc_iversion(new_dir);
9553         inode_inc_iversion(old_inode);
9554         inode_inc_iversion(new_inode);
9555         old_dir->i_ctime = old_dir->i_mtime = ctime;
9556         new_dir->i_ctime = new_dir->i_mtime = ctime;
9557         old_inode->i_ctime = ctime;
9558         new_inode->i_ctime = ctime;
9559
9560         if (old_dentry->d_parent != new_dentry->d_parent) {
9561                 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9562                                 BTRFS_I(old_inode), 1);
9563                 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9564                                 BTRFS_I(new_inode), 1);
9565         }
9566
9567         /* src is a subvolume */
9568         if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9569                 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9570                 ret = btrfs_unlink_subvol(trans, root, old_dir,
9571                                           root_objectid,
9572                                           old_dentry->d_name.name,
9573                                           old_dentry->d_name.len);
9574         } else { /* src is an inode */
9575                 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9576                                            BTRFS_I(old_dentry->d_inode),
9577                                            old_dentry->d_name.name,
9578                                            old_dentry->d_name.len);
9579                 if (!ret)
9580                         ret = btrfs_update_inode(trans, root, old_inode);
9581         }
9582         if (ret) {
9583                 btrfs_abort_transaction(trans, ret);
9584                 goto out_fail;
9585         }
9586
9587         /* dest is a subvolume */
9588         if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9589                 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9590                 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9591                                           root_objectid,
9592                                           new_dentry->d_name.name,
9593                                           new_dentry->d_name.len);
9594         } else { /* dest is an inode */
9595                 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9596                                            BTRFS_I(new_dentry->d_inode),
9597                                            new_dentry->d_name.name,
9598                                            new_dentry->d_name.len);
9599                 if (!ret)
9600                         ret = btrfs_update_inode(trans, dest, new_inode);
9601         }
9602         if (ret) {
9603                 btrfs_abort_transaction(trans, ret);
9604                 goto out_fail;
9605         }
9606
9607         ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9608                              new_dentry->d_name.name,
9609                              new_dentry->d_name.len, 0, old_idx);
9610         if (ret) {
9611                 btrfs_abort_transaction(trans, ret);
9612                 goto out_fail;
9613         }
9614
9615         ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9616                              old_dentry->d_name.name,
9617                              old_dentry->d_name.len, 0, new_idx);
9618         if (ret) {
9619                 btrfs_abort_transaction(trans, ret);
9620                 goto out_fail;
9621         }
9622
9623         if (old_inode->i_nlink == 1)
9624                 BTRFS_I(old_inode)->dir_index = old_idx;
9625         if (new_inode->i_nlink == 1)
9626                 BTRFS_I(new_inode)->dir_index = new_idx;
9627
9628         if (root_log_pinned) {
9629                 parent = new_dentry->d_parent;
9630                 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9631                                 parent);
9632                 btrfs_end_log_trans(root);
9633                 root_log_pinned = false;
9634         }
9635         if (dest_log_pinned) {
9636                 parent = old_dentry->d_parent;
9637                 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9638                                 parent);
9639                 btrfs_end_log_trans(dest);
9640                 dest_log_pinned = false;
9641         }
9642 out_fail:
9643         /*
9644          * If we have pinned a log and an error happened, we unpin tasks
9645          * trying to sync the log and force them to fallback to a transaction
9646          * commit if the log currently contains any of the inodes involved in
9647          * this rename operation (to ensure we do not persist a log with an
9648          * inconsistent state for any of these inodes or leading to any
9649          * inconsistencies when replayed). If the transaction was aborted, the
9650          * abortion reason is propagated to userspace when attempting to commit
9651          * the transaction. If the log does not contain any of these inodes, we
9652          * allow the tasks to sync it.
9653          */
9654         if (ret && (root_log_pinned || dest_log_pinned)) {
9655                 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9656                     btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9657                     btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9658                     (new_inode &&
9659                      btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9660                         btrfs_set_log_full_commit(fs_info, trans);
9661
9662                 if (root_log_pinned) {
9663                         btrfs_end_log_trans(root);
9664                         root_log_pinned = false;
9665                 }
9666                 if (dest_log_pinned) {
9667                         btrfs_end_log_trans(dest);
9668                         dest_log_pinned = false;
9669                 }
9670         }
9671         ret = btrfs_end_transaction(trans);
9672 out_notrans:
9673         if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9674                 up_read(&fs_info->subvol_sem);
9675         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9676                 up_read(&fs_info->subvol_sem);
9677
9678         return ret;
9679 }
9680
9681 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9682                                      struct btrfs_root *root,
9683                                      struct inode *dir,
9684                                      struct dentry *dentry)
9685 {
9686         int ret;
9687         struct inode *inode;
9688         u64 objectid;
9689         u64 index;
9690
9691         ret = btrfs_find_free_ino(root, &objectid);
9692         if (ret)
9693                 return ret;
9694
9695         inode = btrfs_new_inode(trans, root, dir,
9696                                 dentry->d_name.name,
9697                                 dentry->d_name.len,
9698                                 btrfs_ino(BTRFS_I(dir)),
9699                                 objectid,
9700                                 S_IFCHR | WHITEOUT_MODE,
9701                                 &index);
9702
9703         if (IS_ERR(inode)) {
9704                 ret = PTR_ERR(inode);
9705                 return ret;
9706         }
9707
9708         inode->i_op = &btrfs_special_inode_operations;
9709         init_special_inode(inode, inode->i_mode,
9710                 WHITEOUT_DEV);
9711
9712         ret = btrfs_init_inode_security(trans, inode, dir,
9713                                 &dentry->d_name);
9714         if (ret)
9715                 goto out;
9716
9717         ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9718                                 BTRFS_I(inode), 0, index);
9719         if (ret)
9720                 goto out;
9721
9722         ret = btrfs_update_inode(trans, root, inode);
9723 out:
9724         unlock_new_inode(inode);
9725         if (ret)
9726                 inode_dec_link_count(inode);
9727         iput(inode);
9728
9729         return ret;
9730 }
9731
9732 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9733                            struct inode *new_dir, struct dentry *new_dentry,
9734                            unsigned int flags)
9735 {
9736         struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9737         struct btrfs_trans_handle *trans;
9738         unsigned int trans_num_items;
9739         struct btrfs_root *root = BTRFS_I(old_dir)->root;
9740         struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9741         struct inode *new_inode = d_inode(new_dentry);
9742         struct inode *old_inode = d_inode(old_dentry);
9743         u64 index = 0;
9744         u64 root_objectid;
9745         int ret;
9746         u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9747         bool log_pinned = false;
9748
9749         if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9750                 return -EPERM;
9751
9752         /* we only allow rename subvolume link between subvolumes */
9753         if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9754                 return -EXDEV;
9755
9756         if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9757             (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9758                 return -ENOTEMPTY;
9759
9760         if (S_ISDIR(old_inode->i_mode) && new_inode &&
9761             new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9762                 return -ENOTEMPTY;
9763
9764
9765         /* check for collisions, even if the  name isn't there */
9766         ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9767                              new_dentry->d_name.name,
9768                              new_dentry->d_name.len);
9769
9770         if (ret) {
9771                 if (ret == -EEXIST) {
9772                         /* we shouldn't get
9773                          * eexist without a new_inode */
9774                         if (WARN_ON(!new_inode)) {
9775                                 return ret;
9776                         }
9777                 } else {
9778                         /* maybe -EOVERFLOW */
9779                         return ret;
9780                 }
9781         }
9782         ret = 0;
9783
9784         /*
9785          * we're using rename to replace one file with another.  Start IO on it
9786          * now so  we don't add too much work to the end of the transaction
9787          */
9788         if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9789                 filemap_flush(old_inode->i_mapping);
9790
9791         /* close the racy window with snapshot create/destroy ioctl */
9792         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9793                 down_read(&fs_info->subvol_sem);
9794         /*
9795          * We want to reserve the absolute worst case amount of items.  So if
9796          * both inodes are subvols and we need to unlink them then that would
9797          * require 4 item modifications, but if they are both normal inodes it
9798          * would require 5 item modifications, so we'll assume they are normal
9799          * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9800          * should cover the worst case number of items we'll modify.
9801          * If our rename has the whiteout flag, we need more 5 units for the
9802          * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9803          * when selinux is enabled).
9804          */
9805         trans_num_items = 11;
9806         if (flags & RENAME_WHITEOUT)
9807                 trans_num_items += 5;
9808         trans = btrfs_start_transaction(root, trans_num_items);
9809         if (IS_ERR(trans)) {
9810                 ret = PTR_ERR(trans);
9811                 goto out_notrans;
9812         }
9813
9814         if (dest != root)
9815                 btrfs_record_root_in_trans(trans, dest);
9816
9817         ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9818         if (ret)
9819                 goto out_fail;
9820
9821         BTRFS_I(old_inode)->dir_index = 0ULL;
9822         if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9823                 /* force full log commit if subvolume involved. */
9824                 btrfs_set_log_full_commit(fs_info, trans);
9825         } else {
9826                 btrfs_pin_log_trans(root);
9827                 log_pinned = true;
9828                 ret = btrfs_insert_inode_ref(trans, dest,
9829                                              new_dentry->d_name.name,
9830                                              new_dentry->d_name.len,
9831                                              old_ino,
9832                                              btrfs_ino(BTRFS_I(new_dir)), index);
9833                 if (ret)
9834                         goto out_fail;
9835         }
9836
9837         inode_inc_iversion(old_dir);
9838         inode_inc_iversion(new_dir);
9839         inode_inc_iversion(old_inode);
9840         old_dir->i_ctime = old_dir->i_mtime =
9841         new_dir->i_ctime = new_dir->i_mtime =
9842         old_inode->i_ctime = current_time(old_dir);
9843
9844         if (old_dentry->d_parent != new_dentry->d_parent)
9845                 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9846                                 BTRFS_I(old_inode), 1);
9847
9848         if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9849                 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9850                 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9851                                         old_dentry->d_name.name,
9852                                         old_dentry->d_name.len);
9853         } else {
9854                 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9855                                         BTRFS_I(d_inode(old_dentry)),
9856                                         old_dentry->d_name.name,
9857                                         old_dentry->d_name.len);
9858                 if (!ret)
9859                         ret = btrfs_update_inode(trans, root, old_inode);
9860         }
9861         if (ret) {
9862                 btrfs_abort_transaction(trans, ret);
9863                 goto out_fail;
9864         }
9865
9866         if (new_inode) {
9867                 inode_inc_iversion(new_inode);
9868                 new_inode->i_ctime = current_time(new_inode);
9869                 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
9870                              BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9871                         root_objectid = BTRFS_I(new_inode)->location.objectid;
9872                         ret = btrfs_unlink_subvol(trans, dest, new_dir,
9873                                                 root_objectid,
9874                                                 new_dentry->d_name.name,
9875                                                 new_dentry->d_name.len);
9876                         BUG_ON(new_inode->i_nlink == 0);
9877                 } else {
9878                         ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9879                                                  BTRFS_I(d_inode(new_dentry)),
9880                                                  new_dentry->d_name.name,
9881                                                  new_dentry->d_name.len);
9882                 }
9883                 if (!ret && new_inode->i_nlink == 0)
9884                         ret = btrfs_orphan_add(trans,
9885                                         BTRFS_I(d_inode(new_dentry)));
9886                 if (ret) {
9887                         btrfs_abort_transaction(trans, ret);
9888                         goto out_fail;
9889                 }
9890         }
9891
9892         ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9893                              new_dentry->d_name.name,
9894                              new_dentry->d_name.len, 0, index);
9895         if (ret) {
9896                 btrfs_abort_transaction(trans, ret);
9897                 goto out_fail;
9898         }
9899
9900         if (old_inode->i_nlink == 1)
9901                 BTRFS_I(old_inode)->dir_index = index;
9902
9903         if (log_pinned) {
9904                 struct dentry *parent = new_dentry->d_parent;
9905
9906                 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9907                                 parent);
9908                 btrfs_end_log_trans(root);
9909                 log_pinned = false;
9910         }
9911
9912         if (flags & RENAME_WHITEOUT) {
9913                 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9914                                                 old_dentry);
9915
9916                 if (ret) {
9917                         btrfs_abort_transaction(trans, ret);
9918                         goto out_fail;
9919                 }
9920         }
9921 out_fail:
9922         /*
9923          * If we have pinned the log and an error happened, we unpin tasks
9924          * trying to sync the log and force them to fallback to a transaction
9925          * commit if the log currently contains any of the inodes involved in
9926          * this rename operation (to ensure we do not persist a log with an
9927          * inconsistent state for any of these inodes or leading to any
9928          * inconsistencies when replayed). If the transaction was aborted, the
9929          * abortion reason is propagated to userspace when attempting to commit
9930          * the transaction. If the log does not contain any of these inodes, we
9931          * allow the tasks to sync it.
9932          */
9933         if (ret && log_pinned) {
9934                 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9935                     btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9936                     btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9937                     (new_inode &&
9938                      btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9939                         btrfs_set_log_full_commit(fs_info, trans);
9940
9941                 btrfs_end_log_trans(root);
9942                 log_pinned = false;
9943         }
9944         btrfs_end_transaction(trans);
9945 out_notrans:
9946         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9947                 up_read(&fs_info->subvol_sem);
9948
9949         return ret;
9950 }
9951
9952 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9953                          struct inode *new_dir, struct dentry *new_dentry,
9954                          unsigned int flags)
9955 {
9956         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9957                 return -EINVAL;
9958
9959         if (flags & RENAME_EXCHANGE)
9960                 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9961                                           new_dentry);
9962
9963         return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9964 }
9965
9966 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9967 {
9968         struct btrfs_delalloc_work *delalloc_work;
9969         struct inode *inode;
9970
9971         delalloc_work = container_of(work, struct btrfs_delalloc_work,
9972                                      work);
9973         inode = delalloc_work->inode;
9974         filemap_flush(inode->i_mapping);
9975         if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9976                                 &BTRFS_I(inode)->runtime_flags))
9977                 filemap_flush(inode->i_mapping);
9978
9979         if (delalloc_work->delay_iput)
9980                 btrfs_add_delayed_iput(inode);
9981         else
9982                 iput(inode);
9983         complete(&delalloc_work->completion);
9984 }
9985
9986 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9987                                                     int delay_iput)
9988 {
9989         struct btrfs_delalloc_work *work;
9990
9991         work = kmalloc(sizeof(*work), GFP_NOFS);
9992         if (!work)
9993                 return NULL;
9994
9995         init_completion(&work->completion);
9996         INIT_LIST_HEAD(&work->list);
9997         work->inode = inode;
9998         work->delay_iput = delay_iput;
9999         WARN_ON_ONCE(!inode);
10000         btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10001                         btrfs_run_delalloc_work, NULL, NULL);
10002
10003         return work;
10004 }
10005
10006 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10007 {
10008         wait_for_completion(&work->completion);
10009         kfree(work);
10010 }
10011
10012 /*
10013  * some fairly slow code that needs optimization. This walks the list
10014  * of all the inodes with pending delalloc and forces them to disk.
10015  */
10016 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10017                                    int nr)
10018 {
10019         struct btrfs_inode *binode;
10020         struct inode *inode;
10021         struct btrfs_delalloc_work *work, *next;
10022         struct list_head works;
10023         struct list_head splice;
10024         int ret = 0;
10025
10026         INIT_LIST_HEAD(&works);
10027         INIT_LIST_HEAD(&splice);
10028
10029         mutex_lock(&root->delalloc_mutex);
10030         spin_lock(&root->delalloc_lock);
10031         list_splice_init(&root->delalloc_inodes, &splice);
10032         while (!list_empty(&splice)) {
10033                 binode = list_entry(splice.next, struct btrfs_inode,
10034                                     delalloc_inodes);
10035
10036                 list_move_tail(&binode->delalloc_inodes,
10037                                &root->delalloc_inodes);
10038                 inode = igrab(&binode->vfs_inode);
10039                 if (!inode) {
10040                         cond_resched_lock(&root->delalloc_lock);
10041                         continue;
10042                 }
10043                 spin_unlock(&root->delalloc_lock);
10044
10045                 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10046                 if (!work) {
10047                         if (delay_iput)
10048                                 btrfs_add_delayed_iput(inode);
10049                         else
10050                                 iput(inode);
10051                         ret = -ENOMEM;
10052                         goto out;
10053                 }
10054                 list_add_tail(&work->list, &works);
10055                 btrfs_queue_work(root->fs_info->flush_workers,
10056                                  &work->work);
10057                 ret++;
10058                 if (nr != -1 && ret >= nr)
10059                         goto out;
10060                 cond_resched();
10061                 spin_lock(&root->delalloc_lock);
10062         }
10063         spin_unlock(&root->delalloc_lock);
10064
10065 out:
10066         list_for_each_entry_safe(work, next, &works, list) {
10067                 list_del_init(&work->list);
10068                 btrfs_wait_and_free_delalloc_work(work);
10069         }
10070
10071         if (!list_empty_careful(&splice)) {
10072                 spin_lock(&root->delalloc_lock);
10073                 list_splice_tail(&splice, &root->delalloc_inodes);
10074                 spin_unlock(&root->delalloc_lock);
10075         }
10076         mutex_unlock(&root->delalloc_mutex);
10077         return ret;
10078 }
10079
10080 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10081 {
10082         struct btrfs_fs_info *fs_info = root->fs_info;
10083         int ret;
10084
10085         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10086                 return -EROFS;
10087
10088         ret = __start_delalloc_inodes(root, delay_iput, -1);
10089         if (ret > 0)
10090                 ret = 0;
10091         return ret;
10092 }
10093
10094 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10095                                int nr)
10096 {
10097         struct btrfs_root *root;
10098         struct list_head splice;
10099         int ret;
10100
10101         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10102                 return -EROFS;
10103
10104         INIT_LIST_HEAD(&splice);
10105
10106         mutex_lock(&fs_info->delalloc_root_mutex);
10107         spin_lock(&fs_info->delalloc_root_lock);
10108         list_splice_init(&fs_info->delalloc_roots, &splice);
10109         while (!list_empty(&splice) && nr) {
10110                 root = list_first_entry(&splice, struct btrfs_root,
10111                                         delalloc_root);
10112                 root = btrfs_grab_fs_root(root);
10113                 BUG_ON(!root);
10114                 list_move_tail(&root->delalloc_root,
10115                                &fs_info->delalloc_roots);
10116                 spin_unlock(&fs_info->delalloc_root_lock);
10117
10118                 ret = __start_delalloc_inodes(root, delay_iput, nr);
10119                 btrfs_put_fs_root(root);
10120                 if (ret < 0)
10121                         goto out;
10122
10123                 if (nr != -1) {
10124                         nr -= ret;
10125                         WARN_ON(nr < 0);
10126                 }
10127                 spin_lock(&fs_info->delalloc_root_lock);
10128         }
10129         spin_unlock(&fs_info->delalloc_root_lock);
10130
10131         ret = 0;
10132 out:
10133         if (!list_empty_careful(&splice)) {
10134                 spin_lock(&fs_info->delalloc_root_lock);
10135                 list_splice_tail(&splice, &fs_info->delalloc_roots);
10136                 spin_unlock(&fs_info->delalloc_root_lock);
10137         }
10138         mutex_unlock(&fs_info->delalloc_root_mutex);
10139         return ret;
10140 }
10141
10142 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10143                          const char *symname)
10144 {
10145         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10146         struct btrfs_trans_handle *trans;
10147         struct btrfs_root *root = BTRFS_I(dir)->root;
10148         struct btrfs_path *path;
10149         struct btrfs_key key;
10150         struct inode *inode = NULL;
10151         int err;
10152         int drop_inode = 0;
10153         u64 objectid;
10154         u64 index = 0;
10155         int name_len;
10156         int datasize;
10157         unsigned long ptr;
10158         struct btrfs_file_extent_item *ei;
10159         struct extent_buffer *leaf;
10160
10161         name_len = strlen(symname);
10162         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10163                 return -ENAMETOOLONG;
10164
10165         /*
10166          * 2 items for inode item and ref
10167          * 2 items for dir items
10168          * 1 item for updating parent inode item
10169          * 1 item for the inline extent item
10170          * 1 item for xattr if selinux is on
10171          */
10172         trans = btrfs_start_transaction(root, 7);
10173         if (IS_ERR(trans))
10174                 return PTR_ERR(trans);
10175
10176         err = btrfs_find_free_ino(root, &objectid);
10177         if (err)
10178                 goto out_unlock;
10179
10180         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10181                                 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10182                                 objectid, S_IFLNK|S_IRWXUGO, &index);
10183         if (IS_ERR(inode)) {
10184                 err = PTR_ERR(inode);
10185                 goto out_unlock;
10186         }
10187
10188         /*
10189         * If the active LSM wants to access the inode during
10190         * d_instantiate it needs these. Smack checks to see
10191         * if the filesystem supports xattrs by looking at the
10192         * ops vector.
10193         */
10194         inode->i_fop = &btrfs_file_operations;
10195         inode->i_op = &btrfs_file_inode_operations;
10196         inode->i_mapping->a_ops = &btrfs_aops;
10197         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10198
10199         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10200         if (err)
10201                 goto out_unlock_inode;
10202
10203         path = btrfs_alloc_path();
10204         if (!path) {
10205                 err = -ENOMEM;
10206                 goto out_unlock_inode;
10207         }
10208         key.objectid = btrfs_ino(BTRFS_I(inode));
10209         key.offset = 0;
10210         key.type = BTRFS_EXTENT_DATA_KEY;
10211         datasize = btrfs_file_extent_calc_inline_size(name_len);
10212         err = btrfs_insert_empty_item(trans, root, path, &key,
10213                                       datasize);
10214         if (err) {
10215                 btrfs_free_path(path);
10216                 goto out_unlock_inode;
10217         }
10218         leaf = path->nodes[0];
10219         ei = btrfs_item_ptr(leaf, path->slots[0],
10220                             struct btrfs_file_extent_item);
10221         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10222         btrfs_set_file_extent_type(leaf, ei,
10223                                    BTRFS_FILE_EXTENT_INLINE);
10224         btrfs_set_file_extent_encryption(leaf, ei, 0);
10225         btrfs_set_file_extent_compression(leaf, ei, 0);
10226         btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10227         btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10228
10229         ptr = btrfs_file_extent_inline_start(ei);
10230         write_extent_buffer(leaf, symname, ptr, name_len);
10231         btrfs_mark_buffer_dirty(leaf);
10232         btrfs_free_path(path);
10233
10234         inode->i_op = &btrfs_symlink_inode_operations;
10235         inode_nohighmem(inode);
10236         inode->i_mapping->a_ops = &btrfs_symlink_aops;
10237         inode_set_bytes(inode, name_len);
10238         btrfs_i_size_write(BTRFS_I(inode), name_len);
10239         err = btrfs_update_inode(trans, root, inode);
10240         /*
10241          * Last step, add directory indexes for our symlink inode. This is the
10242          * last step to avoid extra cleanup of these indexes if an error happens
10243          * elsewhere above.
10244          */
10245         if (!err)
10246                 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10247                                 BTRFS_I(inode), 0, index);
10248         if (err) {
10249                 drop_inode = 1;
10250                 goto out_unlock_inode;
10251         }
10252
10253         unlock_new_inode(inode);
10254         d_instantiate(dentry, inode);
10255
10256 out_unlock:
10257         btrfs_end_transaction(trans);
10258         if (drop_inode) {
10259                 inode_dec_link_count(inode);
10260                 iput(inode);
10261         }
10262         btrfs_btree_balance_dirty(fs_info);
10263         return err;
10264
10265 out_unlock_inode:
10266         drop_inode = 1;
10267         unlock_new_inode(inode);
10268         goto out_unlock;
10269 }
10270
10271 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10272                                        u64 start, u64 num_bytes, u64 min_size,
10273                                        loff_t actual_len, u64 *alloc_hint,
10274                                        struct btrfs_trans_handle *trans)
10275 {
10276         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10277         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10278         struct extent_map *em;
10279         struct btrfs_root *root = BTRFS_I(inode)->root;
10280         struct btrfs_key ins;
10281         u64 cur_offset = start;
10282         u64 i_size;
10283         u64 cur_bytes;
10284         u64 last_alloc = (u64)-1;
10285         int ret = 0;
10286         bool own_trans = true;
10287         u64 end = start + num_bytes - 1;
10288
10289         if (trans)
10290                 own_trans = false;
10291         while (num_bytes > 0) {
10292                 if (own_trans) {
10293                         trans = btrfs_start_transaction(root, 3);
10294                         if (IS_ERR(trans)) {
10295                                 ret = PTR_ERR(trans);
10296                                 break;
10297                         }
10298                 }
10299
10300                 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10301                 cur_bytes = max(cur_bytes, min_size);
10302                 /*
10303                  * If we are severely fragmented we could end up with really
10304                  * small allocations, so if the allocator is returning small
10305                  * chunks lets make its job easier by only searching for those
10306                  * sized chunks.
10307                  */
10308                 cur_bytes = min(cur_bytes, last_alloc);
10309                 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10310                                 min_size, 0, *alloc_hint, &ins, 1, 0);
10311                 if (ret) {
10312                         if (own_trans)
10313                                 btrfs_end_transaction(trans);
10314                         break;
10315                 }
10316                 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10317
10318                 last_alloc = ins.offset;
10319                 ret = insert_reserved_file_extent(trans, inode,
10320                                                   cur_offset, ins.objectid,
10321                                                   ins.offset, ins.offset,
10322                                                   ins.offset, 0, 0, 0,
10323                                                   BTRFS_FILE_EXTENT_PREALLOC);
10324                 if (ret) {
10325                         btrfs_free_reserved_extent(fs_info, ins.objectid,
10326                                                    ins.offset, 0);
10327                         btrfs_abort_transaction(trans, ret);
10328                         if (own_trans)
10329                                 btrfs_end_transaction(trans);
10330                         break;
10331                 }
10332
10333                 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10334                                         cur_offset + ins.offset -1, 0);
10335
10336                 em = alloc_extent_map();
10337                 if (!em) {
10338                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10339                                 &BTRFS_I(inode)->runtime_flags);
10340                         goto next;
10341                 }
10342
10343                 em->start = cur_offset;
10344                 em->orig_start = cur_offset;
10345                 em->len = ins.offset;
10346                 em->block_start = ins.objectid;
10347                 em->block_len = ins.offset;
10348                 em->orig_block_len = ins.offset;
10349                 em->ram_bytes = ins.offset;
10350                 em->bdev = fs_info->fs_devices->latest_bdev;
10351                 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10352                 em->generation = trans->transid;
10353
10354                 while (1) {
10355                         write_lock(&em_tree->lock);
10356                         ret = add_extent_mapping(em_tree, em, 1);
10357                         write_unlock(&em_tree->lock);
10358                         if (ret != -EEXIST)
10359                                 break;
10360                         btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10361                                                 cur_offset + ins.offset - 1,
10362                                                 0);
10363                 }
10364                 free_extent_map(em);
10365 next:
10366                 num_bytes -= ins.offset;
10367                 cur_offset += ins.offset;
10368                 *alloc_hint = ins.objectid + ins.offset;
10369
10370                 inode_inc_iversion(inode);
10371                 inode->i_ctime = current_time(inode);
10372                 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10373                 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10374                     (actual_len > inode->i_size) &&
10375                     (cur_offset > inode->i_size)) {
10376                         if (cur_offset > actual_len)
10377                                 i_size = actual_len;
10378                         else
10379                                 i_size = cur_offset;
10380                         i_size_write(inode, i_size);
10381                         btrfs_ordered_update_i_size(inode, i_size, NULL);
10382                 }
10383
10384                 ret = btrfs_update_inode(trans, root, inode);
10385
10386                 if (ret) {
10387                         btrfs_abort_transaction(trans, ret);
10388                         if (own_trans)
10389                                 btrfs_end_transaction(trans);
10390                         break;
10391                 }
10392
10393                 if (own_trans)
10394                         btrfs_end_transaction(trans);
10395         }
10396         if (cur_offset < end)
10397                 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10398                         end - cur_offset + 1);
10399         return ret;
10400 }
10401
10402 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10403                               u64 start, u64 num_bytes, u64 min_size,
10404                               loff_t actual_len, u64 *alloc_hint)
10405 {
10406         return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10407                                            min_size, actual_len, alloc_hint,
10408                                            NULL);
10409 }
10410
10411 int btrfs_prealloc_file_range_trans(struct inode *inode,
10412                                     struct btrfs_trans_handle *trans, int mode,
10413                                     u64 start, u64 num_bytes, u64 min_size,
10414                                     loff_t actual_len, u64 *alloc_hint)
10415 {
10416         return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10417                                            min_size, actual_len, alloc_hint, trans);
10418 }
10419
10420 static int btrfs_set_page_dirty(struct page *page)
10421 {
10422         return __set_page_dirty_nobuffers(page);
10423 }
10424
10425 static int btrfs_permission(struct inode *inode, int mask)
10426 {
10427         struct btrfs_root *root = BTRFS_I(inode)->root;
10428         umode_t mode = inode->i_mode;
10429
10430         if (mask & MAY_WRITE &&
10431             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10432                 if (btrfs_root_readonly(root))
10433                         return -EROFS;
10434                 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10435                         return -EACCES;
10436         }
10437         return generic_permission(inode, mask);
10438 }
10439
10440 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10441 {
10442         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10443         struct btrfs_trans_handle *trans;
10444         struct btrfs_root *root = BTRFS_I(dir)->root;
10445         struct inode *inode = NULL;
10446         u64 objectid;
10447         u64 index;
10448         int ret = 0;
10449
10450         /*
10451          * 5 units required for adding orphan entry
10452          */
10453         trans = btrfs_start_transaction(root, 5);
10454         if (IS_ERR(trans))
10455                 return PTR_ERR(trans);
10456
10457         ret = btrfs_find_free_ino(root, &objectid);
10458         if (ret)
10459                 goto out;
10460
10461         inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10462                         btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10463         if (IS_ERR(inode)) {
10464                 ret = PTR_ERR(inode);
10465                 inode = NULL;
10466                 goto out;
10467         }
10468
10469         inode->i_fop = &btrfs_file_operations;
10470         inode->i_op = &btrfs_file_inode_operations;
10471
10472         inode->i_mapping->a_ops = &btrfs_aops;
10473         BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10474
10475         ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10476         if (ret)
10477                 goto out_inode;
10478
10479         ret = btrfs_update_inode(trans, root, inode);
10480         if (ret)
10481                 goto out_inode;
10482         ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10483         if (ret)
10484                 goto out_inode;
10485
10486         /*
10487          * We set number of links to 0 in btrfs_new_inode(), and here we set
10488          * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10489          * through:
10490          *
10491          *    d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10492          */
10493         set_nlink(inode, 1);
10494         unlock_new_inode(inode);
10495         d_tmpfile(dentry, inode);
10496         mark_inode_dirty(inode);
10497
10498 out:
10499         btrfs_end_transaction(trans);
10500         if (ret)
10501                 iput(inode);
10502         btrfs_btree_balance_dirty(fs_info);
10503         return ret;
10504
10505 out_inode:
10506         unlock_new_inode(inode);
10507         goto out;
10508
10509 }
10510
10511 __attribute__((const))
10512 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10513 {
10514         return -EAGAIN;
10515 }
10516
10517 static struct btrfs_fs_info *iotree_fs_info(void *private_data)
10518 {
10519         struct inode *inode = private_data;
10520         return btrfs_sb(inode->i_sb);
10521 }
10522
10523 static void btrfs_check_extent_io_range(void *private_data, const char *caller,
10524                                         u64 start, u64 end)
10525 {
10526         struct inode *inode = private_data;
10527         u64 isize;
10528
10529         isize = i_size_read(inode);
10530         if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
10531                 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
10532                     "%s: ino %llu isize %llu odd range [%llu,%llu]",
10533                         caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
10534         }
10535 }
10536
10537 void btrfs_set_range_writeback(void *private_data, u64 start, u64 end)
10538 {
10539         struct inode *inode = private_data;
10540         unsigned long index = start >> PAGE_SHIFT;
10541         unsigned long end_index = end >> PAGE_SHIFT;
10542         struct page *page;
10543
10544         while (index <= end_index) {
10545                 page = find_get_page(inode->i_mapping, index);
10546                 ASSERT(page); /* Pages should be in the extent_io_tree */
10547                 set_page_writeback(page);
10548                 put_page(page);
10549                 index++;
10550         }
10551 }
10552
10553 static const struct inode_operations btrfs_dir_inode_operations = {
10554         .getattr        = btrfs_getattr,
10555         .lookup         = btrfs_lookup,
10556         .create         = btrfs_create,
10557         .unlink         = btrfs_unlink,
10558         .link           = btrfs_link,
10559         .mkdir          = btrfs_mkdir,
10560         .rmdir          = btrfs_rmdir,
10561         .rename         = btrfs_rename2,
10562         .symlink        = btrfs_symlink,
10563         .setattr        = btrfs_setattr,
10564         .mknod          = btrfs_mknod,
10565         .listxattr      = btrfs_listxattr,
10566         .permission     = btrfs_permission,
10567         .get_acl        = btrfs_get_acl,
10568         .set_acl        = btrfs_set_acl,
10569         .update_time    = btrfs_update_time,
10570         .tmpfile        = btrfs_tmpfile,
10571 };
10572 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10573         .lookup         = btrfs_lookup,
10574         .permission     = btrfs_permission,
10575         .update_time    = btrfs_update_time,
10576 };
10577
10578 static const struct file_operations btrfs_dir_file_operations = {
10579         .llseek         = generic_file_llseek,
10580         .read           = generic_read_dir,
10581         .iterate_shared = btrfs_real_readdir,
10582         .open           = btrfs_opendir,
10583         .unlocked_ioctl = btrfs_ioctl,
10584 #ifdef CONFIG_COMPAT
10585         .compat_ioctl   = btrfs_compat_ioctl,
10586 #endif
10587         .release        = btrfs_release_file,
10588         .fsync          = btrfs_sync_file,
10589 };
10590
10591 static const struct extent_io_ops btrfs_extent_io_ops = {
10592         /* mandatory callbacks */
10593         .submit_bio_hook = btrfs_submit_bio_hook,
10594         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10595         .merge_bio_hook = btrfs_merge_bio_hook,
10596         .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10597         .tree_fs_info = iotree_fs_info,
10598         .set_range_writeback = btrfs_set_range_writeback,
10599
10600         /* optional callbacks */
10601         .fill_delalloc = run_delalloc_range,
10602         .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10603         .writepage_start_hook = btrfs_writepage_start_hook,
10604         .set_bit_hook = btrfs_set_bit_hook,
10605         .clear_bit_hook = btrfs_clear_bit_hook,
10606         .merge_extent_hook = btrfs_merge_extent_hook,
10607         .split_extent_hook = btrfs_split_extent_hook,
10608         .check_extent_io_range = btrfs_check_extent_io_range,
10609 };
10610
10611 /*
10612  * btrfs doesn't support the bmap operation because swapfiles
10613  * use bmap to make a mapping of extents in the file.  They assume
10614  * these extents won't change over the life of the file and they
10615  * use the bmap result to do IO directly to the drive.
10616  *
10617  * the btrfs bmap call would return logical addresses that aren't
10618  * suitable for IO and they also will change frequently as COW
10619  * operations happen.  So, swapfile + btrfs == corruption.
10620  *
10621  * For now we're avoiding this by dropping bmap.
10622  */
10623 static const struct address_space_operations btrfs_aops = {
10624         .readpage       = btrfs_readpage,
10625         .writepage      = btrfs_writepage,
10626         .writepages     = btrfs_writepages,
10627         .readpages      = btrfs_readpages,
10628         .direct_IO      = btrfs_direct_IO,
10629         .invalidatepage = btrfs_invalidatepage,
10630         .releasepage    = btrfs_releasepage,
10631         .set_page_dirty = btrfs_set_page_dirty,
10632         .error_remove_page = generic_error_remove_page,
10633 };
10634
10635 static const struct address_space_operations btrfs_symlink_aops = {
10636         .readpage       = btrfs_readpage,
10637         .writepage      = btrfs_writepage,
10638         .invalidatepage = btrfs_invalidatepage,
10639         .releasepage    = btrfs_releasepage,
10640 };
10641
10642 static const struct inode_operations btrfs_file_inode_operations = {
10643         .getattr        = btrfs_getattr,
10644         .setattr        = btrfs_setattr,
10645         .listxattr      = btrfs_listxattr,
10646         .permission     = btrfs_permission,
10647         .fiemap         = btrfs_fiemap,
10648         .get_acl        = btrfs_get_acl,
10649         .set_acl        = btrfs_set_acl,
10650         .update_time    = btrfs_update_time,
10651 };
10652 static const struct inode_operations btrfs_special_inode_operations = {
10653         .getattr        = btrfs_getattr,
10654         .setattr        = btrfs_setattr,
10655         .permission     = btrfs_permission,
10656         .listxattr      = btrfs_listxattr,
10657         .get_acl        = btrfs_get_acl,
10658         .set_acl        = btrfs_set_acl,
10659         .update_time    = btrfs_update_time,
10660 };
10661 static const struct inode_operations btrfs_symlink_inode_operations = {
10662         .get_link       = page_get_link,
10663         .getattr        = btrfs_getattr,
10664         .setattr        = btrfs_setattr,
10665         .permission     = btrfs_permission,
10666         .listxattr      = btrfs_listxattr,
10667         .update_time    = btrfs_update_time,
10668 };
10669
10670 const struct dentry_operations btrfs_dentry_operations = {
10671         .d_delete       = btrfs_dentry_delete,
10672         .d_release      = btrfs_dentry_release,
10673 };