fs/btrfs/inode.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/buffer_head.h>
  20 #include <linux/fs.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/highmem.h>
  23 #include <linux/time.h>
  24 #include <linux/init.h>
  25 #include <linux/string.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/mpage.h>
  29 #include <linux/swap.h>
  30 #include <linux/writeback.h>
  31 #include <linux/statfs.h>
  32 #include <linux/compat.h>
  33 #include <linux/bit_spinlock.h>
  34 #include <linux/version.h>
  35 #include <linux/xattr.h>
  36 #include "ctree.h"
  37 #include "disk-io.h"
  38 #include "transaction.h"
  39 #include "btrfs_inode.h"
  40 #include "ioctl.h"
  41 #include "print-tree.h"
  42
  43 struct btrfs_iget_args {
  44         u64 ino;
  45         struct btrfs_root *root;
  46 };
  47
  48 static struct inode_operations btrfs_dir_inode_operations;
  49 static struct inode_operations btrfs_symlink_inode_operations;
  50 static struct inode_operations btrfs_dir_ro_inode_operations;
  51 static struct inode_operations btrfs_special_inode_operations;
  52 static struct inode_operations btrfs_file_inode_operations;
  53 static struct address_space_operations btrfs_aops;
  54 static struct address_space_operations btrfs_symlink_aops;
  55 static struct file_operations btrfs_dir_file_operations;
  56 static struct extent_map_ops btrfs_extent_map_ops;
  57
  58 static struct kmem_cache *btrfs_inode_cachep;
  59 struct kmem_cache *btrfs_trans_handle_cachep;
  60 struct kmem_cache *btrfs_transaction_cachep;
  61 struct kmem_cache *btrfs_bit_radix_cachep;
  62 struct kmem_cache *btrfs_path_cachep;
  63
  64 #define S_SHIFT 12
  65 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
  66         [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
  67         [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
  68         [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
  69         [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
  70         [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
  71         [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
  72         [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
  73 };
  74
  75 static int cow_file_range(struct inode *inode, u64 start, u64 end)
  76 {
  77         struct btrfs_root *root = BTRFS_I(inode)->root;
  78         struct btrfs_trans_handle *trans;
  79         u64 alloc_hint = 0;
  80         u64 num_bytes;
  81         u64 cur_alloc_size;
  82         u64 blocksize = root->sectorsize;
  83         struct btrfs_key ins;
  84         int ret;
  85
  86         trans = btrfs_start_transaction(root, 1);
  87         BUG_ON(!trans);
  88         btrfs_set_trans_block_group(trans, inode);
  89
  90         num_bytes = (end - start + blocksize) & ~(blocksize - 1);
  91         num_bytes = max(blocksize,  num_bytes);
  92         ret = btrfs_drop_extents(trans, root, inode,
  93                                  start, start + num_bytes, start, &alloc_hint);
  94
  95         if (alloc_hint == EXTENT_MAP_INLINE)
  96                 goto out;
  97
  98         while(num_bytes > 0) {
  99                 cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
 100                 ret = btrfs_alloc_extent(trans, root, cur_alloc_size,
 101                                          root->root_key.objectid,
 102                                          trans->transid,
 103                                          inode->i_ino, start, 0,
 104                                          alloc_hint, (u64)-1, &ins, 1);
 105                 if (ret) {
 106                         WARN_ON(1);
 107                         goto out;
 108                 }
 109                 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
 110                                                start, ins.objectid, ins.offset,
 111                                                ins.offset);
 112                 num_bytes -= cur_alloc_size;
 113                 alloc_hint = ins.objectid + ins.offset;
 114                 start += cur_alloc_size;
 115         }
 116 out:
 117         btrfs_end_transaction(trans, root);
 118         return ret;
 119 }
 120
 121 static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
 122 {
 123         u64 extent_start;
 124         u64 extent_end;
 125         u64 bytenr;
 126         u64 cow_end;
 127         struct btrfs_root *root = BTRFS_I(inode)->root;
 128         struct extent_buffer *leaf;
 129         int found_type;
 130         struct btrfs_path *path;
 131         struct btrfs_file_extent_item *item;
 132         int ret;
 133         int err;
 134         struct btrfs_key found_key;
 135
 136         path = btrfs_alloc_path();
 137         BUG_ON(!path);
 138 again:
 139         ret = btrfs_lookup_file_extent(NULL, root, path,
 140                                        inode->i_ino, start, 0);
 141         if (ret < 0) {
 142                 btrfs_free_path(path);
 143                 return ret;
 144         }
 145
 146         cow_end = end;
 147         if (ret != 0) {
 148                 if (path->slots[0] == 0)
 149                         goto not_found;
 150                 path->slots[0]--;
 151         }
 152
 153         leaf = path->nodes[0];
 154         item = btrfs_item_ptr(leaf, path->slots[0],
 155                               struct btrfs_file_extent_item);
 156
 157         /* are we inside the extent that was found? */
 158         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 159         found_type = btrfs_key_type(&found_key);
 160         if (found_key.objectid != inode->i_ino ||
 161             found_type != BTRFS_EXTENT_DATA_KEY) {
 162                 goto not_found;
 163         }
 164
 165         found_type = btrfs_file_extent_type(leaf, item);
 166         extent_start = found_key.offset;
 167         if (found_type == BTRFS_FILE_EXTENT_REG) {
 168                 extent_end = extent_start +
 169                        btrfs_file_extent_num_bytes(leaf, item);
 170                 err = 0;
 171
 172                 if (start < extent_start || start >= extent_end)
 173                         goto not_found;
 174
 175                 cow_end = min(end, extent_end - 1);
 176                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
 177                 if (bytenr == 0)
 178                         goto not_found;
 179
 180                 if (btrfs_count_snapshots_in_path(root, path, bytenr) != 1) {
 181                         goto not_found;
 182                 }
 183
 184                 start = extent_end;
 185         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 186                 goto not_found;
 187         }
 188 loop:
 189         if (start > end) {
 190                 btrfs_free_path(path);
 191                 return 0;
 192         }
 193         btrfs_release_path(root, path);
 194         goto again;
 195
 196 not_found:
 197         cow_file_range(inode, start, cow_end);
 198         start = cow_end + 1;
 199         goto loop;
 200 }
 201
 202 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
 203 {
 204         struct btrfs_root *root = BTRFS_I(inode)->root;
 205         int ret;
 206
 207         mutex_lock(&root->fs_info->fs_mutex);
 208         if (btrfs_test_opt(root, NODATACOW))
 209                 ret = run_delalloc_nocow(inode, start, end);
 210         else
 211                 ret = cow_file_range(inode, start, end);
 212         mutex_unlock(&root->fs_info->fs_mutex);
 213         return ret;
 214 }
 215
 216 int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
 217 {
 218         struct inode *inode = page->mapping->host;
 219         struct btrfs_root *root = BTRFS_I(inode)->root;
 220         struct btrfs_trans_handle *trans;
 221         char *kaddr;
 222         int ret = 0;
 223         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 224         size_t offset = start - page_start;
 225
 226         if (btrfs_test_opt(root, NODATASUM))
 227                 return 0;
 228
 229         mutex_lock(&root->fs_info->fs_mutex);
 230         trans = btrfs_start_transaction(root, 1);
 231         btrfs_set_trans_block_group(trans, inode);
 232         kaddr = kmap(page);
 233         btrfs_csum_file_block(trans, root, inode, inode->i_ino,
 234                               start, kaddr + offset, end - start + 1);
 235         kunmap(page);
 236         ret = btrfs_end_transaction(trans, root);
 237         BUG_ON(ret);
 238         mutex_unlock(&root->fs_info->fs_mutex);
 239         return ret;
 240 }
 241
 242 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
 243 {
 244         int ret = 0;
 245         struct inode *inode = page->mapping->host;
 246         struct btrfs_root *root = BTRFS_I(inode)->root;
 247         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 248         struct btrfs_csum_item *item;
 249         struct btrfs_path *path = NULL;
 250         u32 csum;
 251
 252         if (btrfs_test_opt(root, NODATASUM))
 253                 return 0;
 254
 255         mutex_lock(&root->fs_info->fs_mutex);
 256         path = btrfs_alloc_path();
 257         item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
 258         if (IS_ERR(item)) {
 259                 ret = PTR_ERR(item);
 260                 /* a csum that isn't present is a preallocated region. */
 261                 if (ret == -ENOENT || ret == -EFBIG)
 262                         ret = 0;
 263                 csum = 0;
 264                 goto out;
 265         }
 266         read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
 267                            BTRFS_CRC32_SIZE);
 268         set_state_private(em_tree, start, csum);
 269 out:
 270         if (path)
 271                 btrfs_free_path(path);
 272         mutex_unlock(&root->fs_info->fs_mutex);
 273         return ret;
 274 }
 275
 276 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
 277 {
 278         size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
 279         struct inode *inode = page->mapping->host;
 280         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 281         char *kaddr;
 282         u64 private;
 283         int ret;
 284         struct btrfs_root *root = BTRFS_I(inode)->root;
 285         u32 csum = ~(u32)0;
 286         unsigned long flags;
 287
 288         if (btrfs_test_opt(root, NODATASUM))
 289                 return 0;
 290
 291         ret = get_state_private(em_tree, start, &private);
 292         local_irq_save(flags);
 293         kaddr = kmap_atomic(page, KM_IRQ0);
 294         if (ret) {
 295                 goto zeroit;
 296         }
 297         csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
 298         btrfs_csum_final(csum, (char *)&csum);
 299         if (csum != private) {
 300                 goto zeroit;
 301         }
 302         kunmap_atomic(kaddr, KM_IRQ0);
 303         local_irq_restore(flags);
 304         return 0;
 305
 306 zeroit:
 307         printk("btrfs csum failed ino %lu off %llu\n",
 308                page->mapping->host->i_ino, (unsigned long long)start);
 309         memset(kaddr + offset, 1, end - start + 1);
 310         flush_dcache_page(page);
 311         kunmap_atomic(kaddr, KM_IRQ0);
 312         local_irq_restore(flags);
 313         return 0;
 314 }
 315
 316 void btrfs_read_locked_inode(struct inode *inode)
 317 {
 318         struct btrfs_path *path;
 319         struct extent_buffer *leaf;
 320         struct btrfs_inode_item *inode_item;
 321         struct btrfs_inode_timespec *tspec;
 322         struct btrfs_root *root = BTRFS_I(inode)->root;
 323         struct btrfs_key location;
 324         u64 alloc_group_block;
 325         u32 rdev;
 326         int ret;
 327
 328         path = btrfs_alloc_path();
 329         BUG_ON(!path);
 330         mutex_lock(&root->fs_info->fs_mutex);
 331
 332         memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
 333         ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
 334         if (ret)
 335                 goto make_bad;
 336
 337         leaf = path->nodes[0];
 338         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 339                                     struct btrfs_inode_item);
 340
 341         inode->i_mode = btrfs_inode_mode(leaf, inode_item);
 342         inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
 343         inode->i_uid = btrfs_inode_uid(leaf, inode_item);
 344         inode->i_gid = btrfs_inode_gid(leaf, inode_item);
 345         inode->i_size = btrfs_inode_size(leaf, inode_item);
 346
 347         tspec = btrfs_inode_atime(inode_item);
 348         inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 349         inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 350
 351         tspec = btrfs_inode_mtime(inode_item);
 352         inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 353         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 354
 355         tspec = btrfs_inode_ctime(inode_item);
 356         inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 357         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 358
 359         inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
 360         inode->i_generation = btrfs_inode_generation(leaf, inode_item);
 361         inode->i_rdev = 0;
 362         rdev = btrfs_inode_rdev(leaf, inode_item);
 363
 364         alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
 365         BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
 366                                                        alloc_group_block);
 367
 368         btrfs_free_path(path);
 369         inode_item = NULL;
 370
 371         mutex_unlock(&root->fs_info->fs_mutex);
 372
 373         switch (inode->i_mode & S_IFMT) {
 374         case S_IFREG:
 375                 inode->i_mapping->a_ops = &btrfs_aops;
 376                 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
 377                 inode->i_fop = &btrfs_file_operations;
 378                 inode->i_op = &btrfs_file_inode_operations;
 379                 break;
 380         case S_IFDIR:
 381                 inode->i_fop = &btrfs_dir_file_operations;
 382                 if (root == root->fs_info->tree_root)
 383                         inode->i_op = &btrfs_dir_ro_inode_operations;
 384                 else
 385                         inode->i_op = &btrfs_dir_inode_operations;
 386                 break;
 387         case S_IFLNK:
 388                 inode->i_op = &btrfs_symlink_inode_operations;
 389                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
 390                 break;
 391         default:
 392                 init_special_inode(inode, inode->i_mode, rdev);
 393                 break;
 394         }
 395         return;
 396
 397 make_bad:
 398         btrfs_release_path(root, path);
 399         btrfs_free_path(path);
 400         mutex_unlock(&root->fs_info->fs_mutex);
 401         make_bad_inode(inode);
 402 }
 403
 404 static void fill_inode_item(struct extent_buffer *leaf,
 405                             struct btrfs_inode_item *item,
 406                             struct inode *inode)
 407 {
 408         btrfs_set_inode_uid(leaf, item, inode->i_uid);
 409         btrfs_set_inode_gid(leaf, item, inode->i_gid);
 410         btrfs_set_inode_size(leaf, item, inode->i_size);
 411         btrfs_set_inode_mode(leaf, item, inode->i_mode);
 412         btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
 413
 414         btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
 415                                inode->i_atime.tv_sec);
 416         btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
 417                                 inode->i_atime.tv_nsec);
 418
 419         btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
 420                                inode->i_mtime.tv_sec);
 421         btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
 422                                 inode->i_mtime.tv_nsec);
 423
 424         btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
 425                                inode->i_ctime.tv_sec);
 426         btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
 427                                 inode->i_ctime.tv_nsec);
 428
 429         btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
 430         btrfs_set_inode_generation(leaf, item, inode->i_generation);
 431         btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
 432         btrfs_set_inode_block_group(leaf, item,
 433                                     BTRFS_I(inode)->block_group->key.objectid);
 434 }
 435
 436 int btrfs_update_inode(struct btrfs_trans_handle *trans,
 437                               struct btrfs_root *root,
 438                               struct inode *inode)
 439 {
 440         struct btrfs_inode_item *inode_item;
 441         struct btrfs_path *path;
 442         struct extent_buffer *leaf;
 443         int ret;
 444
 445         path = btrfs_alloc_path();
 446         BUG_ON(!path);
 447         ret = btrfs_lookup_inode(trans, root, path,
 448                                  &BTRFS_I(inode)->location, 1);
 449         if (ret) {
 450                 if (ret > 0)
 451                         ret = -ENOENT;
 452                 goto failed;
 453         }
 454
 455         leaf = path->nodes[0];
 456         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 457                                   struct btrfs_inode_item);
 458
 459         fill_inode_item(leaf, inode_item, inode);
 460         btrfs_mark_buffer_dirty(leaf);
 461         btrfs_set_inode_last_trans(trans, inode);
 462         ret = 0;
 463 failed:
 464         btrfs_release_path(root, path);
 465         btrfs_free_path(path);
 466         return ret;
 467 }
 468
 469
 470 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
 471                               struct btrfs_root *root,
 472                               struct inode *dir,
 473                               struct dentry *dentry)
 474 {
 475         struct btrfs_path *path;
 476         const char *name = dentry->d_name.name;
 477         int name_len = dentry->d_name.len;
 478         int ret = 0;
 479         struct extent_buffer *leaf;
 480         struct btrfs_dir_item *di;
 481         struct btrfs_key key;
 482
 483         path = btrfs_alloc_path();
 484         if (!path) {
 485                 ret = -ENOMEM;
 486                 goto err;
 487         }
 488
 489         di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
 490                                     name, name_len, -1);
 491         if (IS_ERR(di)) {
 492                 ret = PTR_ERR(di);
 493                 goto err;
 494         }
 495         if (!di) {
 496                 ret = -ENOENT;
 497                 goto err;
 498         }
 499         leaf = path->nodes[0];
 500         btrfs_dir_item_key_to_cpu(leaf, di, &key);
 501         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 502         if (ret)
 503                 goto err;
 504         btrfs_release_path(root, path);
 505
 506         di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
 507                                          key.objectid, name, name_len, -1);
 508         if (IS_ERR(di)) {
 509                 ret = PTR_ERR(di);
 510                 goto err;
 511         }
 512         if (!di) {
 513                 ret = -ENOENT;
 514                 goto err;
 515         }
 516         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 517
 518         dentry->d_inode->i_ctime = dir->i_ctime;
 519         ret = btrfs_del_inode_ref(trans, root, name, name_len,
 520                                   dentry->d_inode->i_ino,
 521                                   dentry->d_parent->d_inode->i_ino);
 522         if (ret) {
 523                 printk("failed to delete reference to %.*s, "
 524                        "inode %lu parent %lu\n", name_len, name,
 525                        dentry->d_inode->i_ino,
 526                        dentry->d_parent->d_inode->i_ino);
 527         }
 528 err:
 529         btrfs_free_path(path);
 530         if (!ret) {
 531                 dir->i_size -= name_len * 2;
 532                 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 533                 btrfs_update_inode(trans, root, dir);
 534 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 535                 dentry->d_inode->i_nlink--;
 536 #else
 537                 drop_nlink(dentry->d_inode);
 538 #endif
 539                 ret = btrfs_update_inode(trans, root, dentry->d_inode);
 540                 dir->i_sb->s_dirt = 1;
 541         }
 542         return ret;
 543 }
 544
 545 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 546 {
 547         struct btrfs_root *root;
 548         struct btrfs_trans_handle *trans;
 549         int ret;
 550         unsigned long nr;
 551
 552         root = BTRFS_I(dir)->root;
 553         mutex_lock(&root->fs_info->fs_mutex);
 554         trans = btrfs_start_transaction(root, 1);
 555
 556         btrfs_set_trans_block_group(trans, dir);
 557         ret = btrfs_unlink_trans(trans, root, dir, dentry);
 558         nr = trans->blocks_used;
 559
 560         btrfs_end_transaction(trans, root);
 561         mutex_unlock(&root->fs_info->fs_mutex);
 562         btrfs_btree_balance_dirty(root, nr);
 563
 564         return ret;
 565 }
 566
 567 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 568 {
 569         struct inode *inode = dentry->d_inode;
 570         int err;
 571         int ret;
 572         struct btrfs_root *root = BTRFS_I(dir)->root;
 573         struct btrfs_trans_handle *trans;
 574         unsigned long nr;
 575
 576         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
 577                 return -ENOTEMPTY;
 578
 579         mutex_lock(&root->fs_info->fs_mutex);
 580         trans = btrfs_start_transaction(root, 1);
 581         btrfs_set_trans_block_group(trans, dir);
 582
 583         /* now the directory is empty */
 584         err = btrfs_unlink_trans(trans, root, dir, dentry);
 585         if (!err) {
 586                 inode->i_size = 0;
 587         }
 588
 589         nr = trans->blocks_used;
 590         ret = btrfs_end_transaction(trans, root);
 591         mutex_unlock(&root->fs_info->fs_mutex);
 592         btrfs_btree_balance_dirty(root, nr);
 593
 594         if (ret && !err)
 595                 err = ret;
 596         return err;
 597 }
 598
 599 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
 600                             struct btrfs_root *root,
 601                             struct inode *inode)
 602 {
 603         struct btrfs_path *path;
 604         int ret;
 605
 606         clear_inode(inode);
 607
 608         path = btrfs_alloc_path();
 609         BUG_ON(!path);
 610         ret = btrfs_lookup_inode(trans, root, path,
 611                                  &BTRFS_I(inode)->location, -1);
 612         if (ret > 0)
 613                 ret = -ENOENT;
 614         if (!ret)
 615                 ret = btrfs_del_item(trans, root, path);
 616         btrfs_free_path(path);
 617         return ret;
 618 }
 619
 620 /*
 621  * this can truncate away extent items, csum items and directory items.
 622  * It starts at a high offset and removes keys until it can't find
 623  * any higher than i_size.
 624  *
 625  * csum items that cross the new i_size are truncated to the new size
 626  * as well.
 627  */
 628 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
 629                                    struct btrfs_root *root,
 630                                    struct inode *inode)
 631 {
 632         int ret;
 633         struct btrfs_path *path;
 634         struct btrfs_key key;
 635         struct btrfs_key found_key;
 636         u32 found_type;
 637         struct extent_buffer *leaf;
 638         struct btrfs_file_extent_item *fi;
 639         u64 extent_start = 0;
 640         u64 extent_num_bytes = 0;
 641         u64 item_end = 0;
 642         u64 root_gen = 0;
 643         u64 root_owner = 0;
 644         int found_extent;
 645         int del_item;
 646         int extent_type = -1;
 647
 648         btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
 649         path = btrfs_alloc_path();
 650         path->reada = -1;
 651         BUG_ON(!path);
 652
 653         /* FIXME, add redo link to tree so we don't leak on crash */
 654         key.objectid = inode->i_ino;
 655         key.offset = (u64)-1;
 656         key.type = (u8)-1;
 657
 658         while(1) {
 659                 btrfs_init_path(path);
 660                 fi = NULL;
 661                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 662                 if (ret < 0) {
 663                         goto error;
 664                 }
 665                 if (ret > 0) {
 666                         BUG_ON(path->slots[0] == 0);
 667                         path->slots[0]--;
 668                 }
 669                 leaf = path->nodes[0];
 670                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 671                 found_type = btrfs_key_type(&found_key);
 672
 673                 if (found_key.objectid != inode->i_ino)
 674                         break;
 675
 676                 if (found_type != BTRFS_CSUM_ITEM_KEY &&
 677                     found_type != BTRFS_DIR_ITEM_KEY &&
 678                     found_type != BTRFS_DIR_INDEX_KEY &&
 679                     found_type != BTRFS_EXTENT_DATA_KEY)
 680                         break;
 681
 682                 item_end = found_key.offset;
 683                 if (found_type == BTRFS_EXTENT_DATA_KEY) {
 684                         fi = btrfs_item_ptr(leaf, path->slots[0],
 685                                             struct btrfs_file_extent_item);
 686                         extent_type = btrfs_file_extent_type(leaf, fi);
 687                         if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 688                                 item_end +=
 689                                     btrfs_file_extent_num_bytes(leaf, fi);
 690                         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 691                                 struct btrfs_item *item = btrfs_item_nr(leaf,
 692                                                                 path->slots[0]);
 693                                 item_end += btrfs_file_extent_inline_len(leaf,
 694                                                                          item);
 695                         }
 696                         item_end--;
 697                 }
 698                 if (found_type == BTRFS_CSUM_ITEM_KEY) {
 699                         ret = btrfs_csum_truncate(trans, root, path,
 700                                                   inode->i_size);
 701                         BUG_ON(ret);
 702                 }
 703                 if (item_end < inode->i_size) {
 704                         if (found_type == BTRFS_DIR_ITEM_KEY) {
 705                                 found_type = BTRFS_INODE_ITEM_KEY;
 706                         } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
 707                                 found_type = BTRFS_CSUM_ITEM_KEY;
 708                         } else if (found_type) {
 709                                 found_type--;
 710                         } else {
 711                                 break;
 712                         }
 713                         btrfs_set_key_type(&key, found_type);
 714                         btrfs_release_path(root, path);
 715                         continue;
 716                 }
 717                 if (found_key.offset >= inode->i_size)
 718                         del_item = 1;
 719                 else
 720                         del_item = 0;
 721                 found_extent = 0;
 722
 723                 /* FIXME, shrink the extent if the ref count is only 1 */
 724                 if (found_type != BTRFS_EXTENT_DATA_KEY)
 725                         goto delete;
 726
 727                 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 728                         u64 num_dec;
 729                         extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
 730                         if (!del_item) {
 731                                 u64 orig_num_bytes =
 732                                         btrfs_file_extent_num_bytes(leaf, fi);
 733                                 extent_num_bytes = inode->i_size -
 734                                         found_key.offset + root->sectorsize - 1;
 735                                 btrfs_set_file_extent_num_bytes(leaf, fi,
 736                                                          extent_num_bytes);
 737                                 num_dec = (orig_num_bytes -
 738                                            extent_num_bytes) >> 9;
 739                                 if (extent_start != 0) {
 740                                         inode->i_blocks -= num_dec;
 741                                 }
 742                                 btrfs_mark_buffer_dirty(leaf);
 743                         } else {
 744                                 extent_num_bytes =
 745                                         btrfs_file_extent_disk_num_bytes(leaf,
 746                                                                          fi);
 747                                 /* FIXME blocksize != 4096 */
 748                                 num_dec = btrfs_file_extent_num_bytes(leaf,
 749                                                                        fi) >> 9;
 750                                 if (extent_start != 0) {
 751                                         found_extent = 1;
 752                                         inode->i_blocks -= num_dec;
 753                                 }
 754                                 root_gen = btrfs_header_generation(leaf);
 755                                 root_owner = btrfs_header_owner(leaf);
 756                         }
 757                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE &&
 758                            !del_item) {
 759                         u32 newsize = inode->i_size - found_key.offset;
 760                         newsize = btrfs_file_extent_calc_inline_size(newsize);
 761                         ret = btrfs_truncate_item(trans, root, path,
 762                                                   newsize, 1);
 763                         BUG_ON(ret);
 764                 }
 765 delete:
 766                 if (del_item) {
 767                         ret = btrfs_del_item(trans, root, path);
 768                         if (ret)
 769                                 goto error;
 770                 } else {
 771                         break;
 772                 }
 773                 btrfs_release_path(root, path);
 774                 if (found_extent) {
 775                         ret = btrfs_free_extent(trans, root, extent_start,
 776                                                 extent_num_bytes,
 777                                                 root_owner,
 778                                                 root_gen, inode->i_ino,
 779                                                 found_key.offset, 0);
 780                         BUG_ON(ret);
 781                 }
 782         }
 783         ret = 0;
 784 error:
 785         btrfs_release_path(root, path);
 786         btrfs_free_path(path);
 787         inode->i_sb->s_dirt = 1;
 788         return ret;
 789 }
 790
 791 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
 792                               size_t zero_start)
 793 {
 794         char *kaddr;
 795         int ret = 0;
 796         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 797         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 798         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
 799
 800         WARN_ON(!PageLocked(page));
 801         set_page_extent_mapped(page);
 802
 803         lock_extent(em_tree, page_start, page_end, GFP_NOFS);
 804         set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
 805                             page_end, GFP_NOFS);
 806         if (zero_start != PAGE_CACHE_SIZE) {
 807                 kaddr = kmap(page);
 808                 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
 809                 flush_dcache_page(page);
 810                 kunmap(page);
 811         }
 812         set_page_dirty(page);
 813         unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
 814
 815         return ret;
 816 }
 817
 818 /*
 819  * taken from block_truncate_page, but does cow as it zeros out
 820  * any bytes left in the last page in the file.
 821  */
 822 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
 823 {
 824         struct inode *inode = mapping->host;
 825         struct btrfs_root *root = BTRFS_I(inode)->root;
 826         u32 blocksize = root->sectorsize;
 827         pgoff_t index = from >> PAGE_CACHE_SHIFT;
 828         unsigned offset = from & (PAGE_CACHE_SIZE-1);
 829         struct page *page;
 830         int ret = 0;
 831         u64 page_start;
 832
 833         if ((offset & (blocksize - 1)) == 0)
 834                 goto out;
 835
 836         down_read(&root->snap_sem);
 837         ret = -ENOMEM;
 838         page = grab_cache_page(mapping, index);
 839         if (!page)
 840                 goto out;
 841         if (!PageUptodate(page)) {
 842                 ret = btrfs_readpage(NULL, page);
 843                 lock_page(page);
 844                 if (!PageUptodate(page)) {
 845                         ret = -EIO;
 846                         goto out;
 847                 }
 848         }
 849         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 850
 851         ret = btrfs_cow_one_page(inode, page, offset);
 852
 853         unlock_page(page);
 854         page_cache_release(page);
 855         up_read(&BTRFS_I(inode)->root->snap_sem);
 856 out:
 857         return ret;
 858 }
 859
 860 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
 861 {
 862         struct inode *inode = dentry->d_inode;
 863         int err;
 864
 865         err = inode_change_ok(inode, attr);
 866         if (err)
 867                 return err;
 868
 869         if (S_ISREG(inode->i_mode) &&
 870             attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
 871                 struct btrfs_trans_handle *trans;
 872                 struct btrfs_root *root = BTRFS_I(inode)->root;
 873                 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 874
 875                 u64 mask = root->sectorsize - 1;
 876                 u64 pos = (inode->i_size + mask) & ~mask;
 877                 u64 block_end = attr->ia_size | mask;
 878                 u64 hole_size;
 879                 u64 alloc_hint = 0;
 880
 881                 if (attr->ia_size <= pos)
 882                         goto out;
 883
 884                 btrfs_truncate_page(inode->i_mapping, inode->i_size);
 885
 886                 lock_extent(em_tree, pos, block_end, GFP_NOFS);
 887                 hole_size = (attr->ia_size - pos + mask) & ~mask;
 888
 889                 mutex_lock(&root->fs_info->fs_mutex);
 890                 trans = btrfs_start_transaction(root, 1);
 891                 btrfs_set_trans_block_group(trans, inode);
 892                 err = btrfs_drop_extents(trans, root, inode,
 893                                          pos, pos + hole_size, pos,
 894                                          &alloc_hint);
 895
 896                 if (alloc_hint != EXTENT_MAP_INLINE) {
 897                         err = btrfs_insert_file_extent(trans, root,
 898                                                        inode->i_ino,
 899                                                        pos, 0, 0, hole_size);
 900                 }
 901                 btrfs_end_transaction(trans, root);
 902                 mutex_unlock(&root->fs_info->fs_mutex);
 903                 unlock_extent(em_tree, pos, block_end, GFP_NOFS);
 904                 if (err)
 905                         return err;
 906         }
 907 out:
 908         err = inode_setattr(inode, attr);
 909
 910         return err;
 911 }
 912 void btrfs_delete_inode(struct inode *inode)
 913 {
 914         struct btrfs_trans_handle *trans;
 915         struct btrfs_root *root = BTRFS_I(inode)->root;
 916         unsigned long nr;
 917         int ret;
 918
 919         truncate_inode_pages(&inode->i_data, 0);
 920         if (is_bad_inode(inode)) {
 921                 goto no_delete;
 922         }
 923
 924         inode->i_size = 0;
 925         mutex_lock(&root->fs_info->fs_mutex);
 926         trans = btrfs_start_transaction(root, 1);
 927
 928         btrfs_set_trans_block_group(trans, inode);
 929         ret = btrfs_truncate_in_trans(trans, root, inode);
 930         if (ret)
 931                 goto no_delete_lock;
 932         ret = btrfs_delete_xattrs(trans, root, inode);
 933         if (ret)
 934                 goto no_delete_lock;
 935         ret = btrfs_free_inode(trans, root, inode);
 936         if (ret)
 937                 goto no_delete_lock;
 938         nr = trans->blocks_used;
 939
 940         btrfs_end_transaction(trans, root);
 941         mutex_unlock(&root->fs_info->fs_mutex);
 942         btrfs_btree_balance_dirty(root, nr);
 943         return;
 944
 945 no_delete_lock:
 946         nr = trans->blocks_used;
 947         btrfs_end_transaction(trans, root);
 948         mutex_unlock(&root->fs_info->fs_mutex);
 949         btrfs_btree_balance_dirty(root, nr);
 950 no_delete:
 951         clear_inode(inode);
 952 }
 953
 954 /*
 955  * this returns the key found in the dir entry in the location pointer.
 956  * If no dir entries were found, location->objectid is 0.
 957  */
 958 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
 959                                struct btrfs_key *location)
 960 {
 961         const char *name = dentry->d_name.name;
 962         int namelen = dentry->d_name.len;
 963         struct btrfs_dir_item *di;
 964         struct btrfs_path *path;
 965         struct btrfs_root *root = BTRFS_I(dir)->root;
 966         int ret = 0;
 967
 968         if (namelen == 1 && strcmp(name, ".") == 0) {
 969                 location->objectid = dir->i_ino;
 970                 location->type = BTRFS_INODE_ITEM_KEY;
 971                 location->offset = 0;
 972                 return 0;
 973         }
 974         path = btrfs_alloc_path();
 975         BUG_ON(!path);
 976
 977         if (namelen == 2 && strcmp(name, "..") == 0) {
 978                 struct btrfs_key key;
 979                 struct extent_buffer *leaf;
 980                 u32 nritems;
 981                 int slot;
 982
 983                 key.objectid = dir->i_ino;
 984                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
 985                 key.offset = 0;
 986                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 987                 BUG_ON(ret == 0);
 988                 ret = 0;
 989
 990                 leaf = path->nodes[0];
 991                 slot = path->slots[0];
 992                 nritems = btrfs_header_nritems(leaf);
 993                 if (slot >= nritems)
 994                         goto out_err;
 995
 996                 btrfs_item_key_to_cpu(leaf, &key, slot);
 997                 if (key.objectid != dir->i_ino ||
 998                     key.type != BTRFS_INODE_REF_KEY) {
 999                         goto out_err;
1000                 }
1001                 location->objectid = key.offset;
1002                 location->type = BTRFS_INODE_ITEM_KEY;
1003                 location->offset = 0;
1004                 goto out;
1005         }
1006
1007         di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1008                                     namelen, 0);
1009         if (IS_ERR(di))
1010                 ret = PTR_ERR(di);
1011         if (!di || IS_ERR(di)) {
1012                 goto out_err;
1013         }
1014         btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1015 out:
1016         btrfs_free_path(path);
1017         return ret;
1018 out_err:
1019         location->objectid = 0;
1020         goto out;
1021 }
1022
1023 /*
1024  * when we hit a tree root in a directory, the btrfs part of the inode
1025  * needs to be changed to reflect the root directory of the tree root.  This
1026  * is kind of like crossing a mount point.
1027  */
1028 static int fixup_tree_root_location(struct btrfs_root *root,
1029                              struct btrfs_key *location,
1030                              struct btrfs_root **sub_root,
1031                              struct dentry *dentry)
1032 {
1033         struct btrfs_path *path;
1034         struct btrfs_root_item *ri;
1035
1036         if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1037                 return 0;
1038         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1039                 return 0;
1040
1041         path = btrfs_alloc_path();
1042         BUG_ON(!path);
1043         mutex_lock(&root->fs_info->fs_mutex);
1044
1045         *sub_root = btrfs_read_fs_root(root->fs_info, location,
1046                                         dentry->d_name.name,
1047                                         dentry->d_name.len);
1048         if (IS_ERR(*sub_root))
1049                 return PTR_ERR(*sub_root);
1050
1051         ri = &(*sub_root)->root_item;
1052         location->objectid = btrfs_root_dirid(ri);
1053         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1054         location->offset = 0;
1055
1056         btrfs_free_path(path);
1057         mutex_unlock(&root->fs_info->fs_mutex);
1058         return 0;
1059 }
1060
1061 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1062 {
1063         struct btrfs_iget_args *args = p;
1064         inode->i_ino = args->ino;
1065         BTRFS_I(inode)->root = args->root;
1066         extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1067                              inode->i_mapping, GFP_NOFS);
1068         return 0;
1069 }
1070
1071 static int btrfs_find_actor(struct inode *inode, void *opaque)
1072 {
1073         struct btrfs_iget_args *args = opaque;
1074         return (args->ino == inode->i_ino &&
1075                 args->root == BTRFS_I(inode)->root);
1076 }
1077
1078 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1079                                 struct btrfs_root *root)
1080 {
1081         struct inode *inode;
1082         struct btrfs_iget_args args;
1083         args.ino = objectid;
1084         args.root = root;
1085
1086         inode = iget5_locked(s, objectid, btrfs_find_actor,
1087                              btrfs_init_locked_inode,
1088                              (void *)&args);
1089         return inode;
1090 }
1091
1092 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1093                                    struct nameidata *nd)
1094 {
1095         struct inode * inode;
1096         struct btrfs_inode *bi = BTRFS_I(dir);
1097         struct btrfs_root *root = bi->root;
1098         struct btrfs_root *sub_root = root;
1099         struct btrfs_key location;
1100         int ret;
1101
1102         if (dentry->d_name.len > BTRFS_NAME_LEN)
1103                 return ERR_PTR(-ENAMETOOLONG);
1104
1105         mutex_lock(&root->fs_info->fs_mutex);
1106         ret = btrfs_inode_by_name(dir, dentry, &location);
1107         mutex_unlock(&root->fs_info->fs_mutex);
1108
1109         if (ret < 0)
1110                 return ERR_PTR(ret);
1111
1112         inode = NULL;
1113         if (location.objectid) {
1114                 ret = fixup_tree_root_location(root, &location, &sub_root,
1115                                                 dentry);
1116                 if (ret < 0)
1117                         return ERR_PTR(ret);
1118                 if (ret > 0)
1119                         return ERR_PTR(-ENOENT);
1120                 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1121                                           sub_root);
1122                 if (!inode)
1123                         return ERR_PTR(-EACCES);
1124                 if (inode->i_state & I_NEW) {
1125                         /* the inode and parent dir are two different roots */
1126                         if (sub_root != root) {
1127                                 igrab(inode);
1128                                 sub_root->inode = inode;
1129                         }
1130                         BTRFS_I(inode)->root = sub_root;
1131                         memcpy(&BTRFS_I(inode)->location, &location,
1132                                sizeof(location));
1133                         btrfs_read_locked_inode(inode);
1134                         unlock_new_inode(inode);
1135                 }
1136         }
1137         return d_splice_alias(inode, dentry);
1138 }
1139
1140 static unsigned char btrfs_filetype_table[] = {
1141         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1142 };
1143
1144 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1145 {
1146         struct inode *inode = filp->f_dentry->d_inode;
1147         struct btrfs_root *root = BTRFS_I(inode)->root;
1148         struct btrfs_item *item;
1149         struct btrfs_dir_item *di;
1150         struct btrfs_key key;
1151         struct btrfs_key found_key;
1152         struct btrfs_path *path;
1153         int ret;
1154         u32 nritems;
1155         struct extent_buffer *leaf;
1156         int slot;
1157         int advance;
1158         unsigned char d_type;
1159         int over = 0;
1160         u32 di_cur;
1161         u32 di_total;
1162         u32 di_len;
1163         int key_type = BTRFS_DIR_INDEX_KEY;
1164         char tmp_name[32];
1165         char *name_ptr;
1166         int name_len;
1167
1168         /* FIXME, use a real flag for deciding about the key type */
1169         if (root->fs_info->tree_root == root)
1170                 key_type = BTRFS_DIR_ITEM_KEY;
1171
1172         /* special case for "." */
1173         if (filp->f_pos == 0) {
1174                 over = filldir(dirent, ".", 1,
1175                                1, inode->i_ino,
1176                                DT_DIR);
1177                 if (over)
1178                         return 0;
1179                 filp->f_pos = 1;
1180         }
1181
1182         mutex_lock(&root->fs_info->fs_mutex);
1183         key.objectid = inode->i_ino;
1184         path = btrfs_alloc_path();
1185         path->reada = 2;
1186
1187         /* special case for .., just use the back ref */
1188         if (filp->f_pos == 1) {
1189                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1190                 key.offset = 0;
1191                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1192                 BUG_ON(ret == 0);
1193                 leaf = path->nodes[0];
1194                 slot = path->slots[0];
1195                 nritems = btrfs_header_nritems(leaf);
1196                 if (slot >= nritems) {
1197                         btrfs_release_path(root, path);
1198                         goto read_dir_items;
1199                 }
1200                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1201                 btrfs_release_path(root, path);
1202                 if (found_key.objectid != key.objectid ||
1203                     found_key.type != BTRFS_INODE_REF_KEY)
1204                         goto read_dir_items;
1205                 over = filldir(dirent, "..", 2,
1206                                2, found_key.offset, DT_DIR);
1207                 if (over)
1208                         goto nopos;
1209                 filp->f_pos = 2;
1210         }
1211
1212 read_dir_items:
1213         btrfs_set_key_type(&key, key_type);
1214         key.offset = filp->f_pos;
1215
1216         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1217         if (ret < 0)
1218                 goto err;
1219         advance = 0;
1220         while(1) {
1221                 leaf = path->nodes[0];
1222                 nritems = btrfs_header_nritems(leaf);
1223                 slot = path->slots[0];
1224                 if (advance || slot >= nritems) {
1225                         if (slot >= nritems -1) {
1226                                 ret = btrfs_next_leaf(root, path);
1227                                 if (ret)
1228                                         break;
1229                                 leaf = path->nodes[0];
1230                                 nritems = btrfs_header_nritems(leaf);
1231                                 slot = path->slots[0];
1232                         } else {
1233                                 slot++;
1234                                 path->slots[0]++;
1235                         }
1236                 }
1237                 advance = 1;
1238                 item = btrfs_item_nr(leaf, slot);
1239                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1240
1241                 if (found_key.objectid != key.objectid)
1242                         break;
1243                 if (btrfs_key_type(&found_key) != key_type)
1244                         break;
1245                 if (found_key.offset < filp->f_pos)
1246                         continue;
1247
1248                 filp->f_pos = found_key.offset;
1249                 advance = 1;
1250                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1251                 di_cur = 0;
1252                 di_total = btrfs_item_size(leaf, item);
1253                 while(di_cur < di_total) {
1254                         struct btrfs_key location;
1255
1256                         name_len = btrfs_dir_name_len(leaf, di);
1257                         if (name_len < 32) {
1258                                 name_ptr = tmp_name;
1259                         } else {
1260                                 name_ptr = kmalloc(name_len, GFP_NOFS);
1261                                 BUG_ON(!name_ptr);
1262                         }
1263                         read_extent_buffer(leaf, name_ptr,
1264                                            (unsigned long)(di + 1), name_len);
1265
1266                         d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1267                         btrfs_dir_item_key_to_cpu(leaf, di, &location);
1268
1269                         over = filldir(dirent, name_ptr, name_len,
1270                                        found_key.offset,
1271                                        location.objectid,
1272                                        d_type);
1273
1274                         if (name_ptr != tmp_name)
1275                                 kfree(name_ptr);
1276
1277                         if (over)
1278                                 goto nopos;
1279                         di_len = btrfs_dir_name_len(leaf, di) +
1280                                 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1281                         di_cur += di_len;
1282                         di = (struct btrfs_dir_item *)((char *)di + di_len);
1283                 }
1284         }
1285         filp->f_pos++;
1286 nopos:
1287         ret = 0;
1288 err:
1289         btrfs_release_path(root, path);
1290         btrfs_free_path(path);
1291         mutex_unlock(&root->fs_info->fs_mutex);
1292         return ret;
1293 }
1294
1295 int btrfs_write_inode(struct inode *inode, int wait)
1296 {
1297         struct btrfs_root *root = BTRFS_I(inode)->root;
1298         struct btrfs_trans_handle *trans;
1299         int ret = 0;
1300
1301         if (wait) {
1302                 mutex_lock(&root->fs_info->fs_mutex);
1303                 trans = btrfs_start_transaction(root, 1);
1304                 btrfs_set_trans_block_group(trans, inode);
1305                 ret = btrfs_commit_transaction(trans, root);
1306                 mutex_unlock(&root->fs_info->fs_mutex);
1307         }
1308         return ret;
1309 }
1310
1311 /*
1312  * This is somewhat expensive, updating the tree every time the
1313  * inode changes.  But, it is most likely to find the inode in cache.
1314  * FIXME, needs more benchmarking...there are no reasons other than performance
1315  * to keep or drop this code.
1316  */
1317 void btrfs_dirty_inode(struct inode *inode)
1318 {
1319         struct btrfs_root *root = BTRFS_I(inode)->root;
1320         struct btrfs_trans_handle *trans;
1321
1322         mutex_lock(&root->fs_info->fs_mutex);
1323         trans = btrfs_start_transaction(root, 1);
1324         btrfs_set_trans_block_group(trans, inode);
1325         btrfs_update_inode(trans, root, inode);
1326         btrfs_end_transaction(trans, root);
1327         mutex_unlock(&root->fs_info->fs_mutex);
1328 }
1329
1330 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1331                                      struct btrfs_root *root,
1332                                      u64 objectid,
1333                                      struct btrfs_block_group_cache *group,
1334                                      int mode)
1335 {
1336         struct inode *inode;
1337         struct btrfs_inode_item *inode_item;
1338         struct btrfs_key *location;
1339         struct btrfs_path *path;
1340         int ret;
1341         int owner;
1342
1343         path = btrfs_alloc_path();
1344         BUG_ON(!path);
1345
1346         inode = new_inode(root->fs_info->sb);
1347         if (!inode)
1348                 return ERR_PTR(-ENOMEM);
1349
1350         extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1351                              inode->i_mapping, GFP_NOFS);
1352         BTRFS_I(inode)->root = root;
1353
1354         if (mode & S_IFDIR)
1355                 owner = 0;
1356         else
1357                 owner = 1;
1358         group = btrfs_find_block_group(root, group, 0, 0, owner);
1359         BTRFS_I(inode)->block_group = group;
1360
1361         ret = btrfs_insert_empty_inode(trans, root, path, objectid);
1362         if (ret)
1363                 goto fail;
1364
1365         inode->i_uid = current->fsuid;
1366         inode->i_gid = current->fsgid;
1367         inode->i_mode = mode;
1368         inode->i_ino = objectid;
1369         inode->i_blocks = 0;
1370         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1371         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1372                                   struct btrfs_inode_item);
1373         fill_inode_item(path->nodes[0], inode_item, inode);
1374         btrfs_mark_buffer_dirty(path->nodes[0]);
1375         btrfs_free_path(path);
1376
1377         location = &BTRFS_I(inode)->location;
1378         location->objectid = objectid;
1379         location->offset = 0;
1380         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1381
1382         insert_inode_hash(inode);
1383         return inode;
1384 fail:
1385         btrfs_free_path(path);
1386         return ERR_PTR(ret);
1387 }
1388
1389 static inline u8 btrfs_inode_type(struct inode *inode)
1390 {
1391         return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1392 }
1393
1394 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1395                             struct dentry *dentry, struct inode *inode)
1396 {
1397         int ret;
1398         struct btrfs_key key;
1399         struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1400         struct inode *parent_inode;
1401
1402         key.objectid = inode->i_ino;
1403         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1404         key.offset = 0;
1405
1406         ret = btrfs_insert_dir_item(trans, root,
1407                                     dentry->d_name.name, dentry->d_name.len,
1408                                     dentry->d_parent->d_inode->i_ino,
1409                                     &key, btrfs_inode_type(inode));
1410         if (ret == 0) {
1411                 ret = btrfs_insert_inode_ref(trans, root,
1412                                      dentry->d_name.name,
1413                                      dentry->d_name.len,
1414                                      inode->i_ino,
1415                                      dentry->d_parent->d_inode->i_ino);
1416                 parent_inode = dentry->d_parent->d_inode;
1417                 parent_inode->i_size += dentry->d_name.len * 2;
1418                 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1419                 ret = btrfs_update_inode(trans, root,
1420                                          dentry->d_parent->d_inode);
1421         }
1422         return ret;
1423 }
1424
1425 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1426                             struct dentry *dentry, struct inode *inode)
1427 {
1428         int err = btrfs_add_link(trans, dentry, inode);
1429         if (!err) {
1430                 d_instantiate(dentry, inode);
1431                 return 0;
1432         }
1433         if (err > 0)
1434                 err = -EEXIST;
1435         return err;
1436 }
1437
1438 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1439                         int mode, dev_t rdev)
1440 {
1441         struct btrfs_trans_handle *trans;
1442         struct btrfs_root *root = BTRFS_I(dir)->root;
1443         struct inode *inode;
1444         int err;
1445         int drop_inode = 0;
1446         u64 objectid;
1447         unsigned long nr;
1448
1449         if (!new_valid_dev(rdev))
1450                 return -EINVAL;
1451
1452         mutex_lock(&root->fs_info->fs_mutex);
1453         trans = btrfs_start_transaction(root, 1);
1454         btrfs_set_trans_block_group(trans, dir);
1455
1456         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1457         if (err) {
1458                 err = -ENOSPC;
1459                 goto out_unlock;
1460         }
1461
1462         inode = btrfs_new_inode(trans, root, objectid,
1463                                 BTRFS_I(dir)->block_group, mode);
1464         err = PTR_ERR(inode);
1465         if (IS_ERR(inode))
1466                 goto out_unlock;
1467
1468         btrfs_set_trans_block_group(trans, inode);
1469         err = btrfs_add_nondir(trans, dentry, inode);
1470         if (err)
1471                 drop_inode = 1;
1472         else {
1473                 inode->i_op = &btrfs_special_inode_operations;
1474                 init_special_inode(inode, inode->i_mode, rdev);
1475                 btrfs_update_inode(trans, root, inode);
1476         }
1477         dir->i_sb->s_dirt = 1;
1478         btrfs_update_inode_block_group(trans, inode);
1479         btrfs_update_inode_block_group(trans, dir);
1480 out_unlock:
1481         nr = trans->blocks_used;
1482         btrfs_end_transaction(trans, root);
1483         mutex_unlock(&root->fs_info->fs_mutex);
1484
1485         if (drop_inode) {
1486                 inode_dec_link_count(inode);
1487                 iput(inode);
1488         }
1489         btrfs_btree_balance_dirty(root, nr);
1490         return err;
1491 }
1492
1493 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1494                         int mode, struct nameidata *nd)
1495 {
1496         struct btrfs_trans_handle *trans;
1497         struct btrfs_root *root = BTRFS_I(dir)->root;
1498         struct inode *inode;
1499         int err;
1500         int drop_inode = 0;
1501         unsigned long nr;
1502         u64 objectid;
1503
1504         mutex_lock(&root->fs_info->fs_mutex);
1505         trans = btrfs_start_transaction(root, 1);
1506         btrfs_set_trans_block_group(trans, dir);
1507
1508         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1509         if (err) {
1510                 err = -ENOSPC;
1511                 goto out_unlock;
1512         }
1513
1514         inode = btrfs_new_inode(trans, root, objectid,
1515                                 BTRFS_I(dir)->block_group, mode);
1516         err = PTR_ERR(inode);
1517         if (IS_ERR(inode))
1518                 goto out_unlock;
1519
1520         btrfs_set_trans_block_group(trans, inode);
1521         err = btrfs_add_nondir(trans, dentry, inode);
1522         if (err)
1523                 drop_inode = 1;
1524         else {
1525                 inode->i_mapping->a_ops = &btrfs_aops;
1526                 inode->i_fop = &btrfs_file_operations;
1527                 inode->i_op = &btrfs_file_inode_operations;
1528                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1529                                      inode->i_mapping, GFP_NOFS);
1530                 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
1531         }
1532         dir->i_sb->s_dirt = 1;
1533         btrfs_update_inode_block_group(trans, inode);
1534         btrfs_update_inode_block_group(trans, dir);
1535 out_unlock:
1536         nr = trans->blocks_used;
1537         btrfs_end_transaction(trans, root);
1538         mutex_unlock(&root->fs_info->fs_mutex);
1539
1540         if (drop_inode) {
1541                 inode_dec_link_count(inode);
1542                 iput(inode);
1543         }
1544         btrfs_btree_balance_dirty(root, nr);
1545         return err;
1546 }
1547
1548 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1549                       struct dentry *dentry)
1550 {
1551         struct btrfs_trans_handle *trans;
1552         struct btrfs_root *root = BTRFS_I(dir)->root;
1553         struct inode *inode = old_dentry->d_inode;
1554         unsigned long nr;
1555         int err;
1556         int drop_inode = 0;
1557
1558         if (inode->i_nlink == 0)
1559                 return -ENOENT;
1560
1561 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1562         inode->i_nlink++;
1563 #else
1564         inc_nlink(inode);
1565 #endif
1566         mutex_lock(&root->fs_info->fs_mutex);
1567         trans = btrfs_start_transaction(root, 1);
1568
1569         btrfs_set_trans_block_group(trans, dir);
1570         atomic_inc(&inode->i_count);
1571         err = btrfs_add_nondir(trans, dentry, inode);
1572
1573         if (err)
1574                 drop_inode = 1;
1575
1576         dir->i_sb->s_dirt = 1;
1577         btrfs_update_inode_block_group(trans, dir);
1578         err = btrfs_update_inode(trans, root, inode);
1579
1580         if (err)
1581                 drop_inode = 1;
1582
1583         nr = trans->blocks_used;
1584         btrfs_end_transaction(trans, root);
1585         mutex_unlock(&root->fs_info->fs_mutex);
1586
1587         if (drop_inode) {
1588                 inode_dec_link_count(inode);
1589                 iput(inode);
1590         }
1591         btrfs_btree_balance_dirty(root, nr);
1592         return err;
1593 }
1594
1595 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1596 {
1597         struct inode *inode;
1598         struct btrfs_trans_handle *trans;
1599         struct btrfs_root *root = BTRFS_I(dir)->root;
1600         int err = 0;
1601         int drop_on_err = 0;
1602         u64 objectid;
1603         unsigned long nr = 1;
1604
1605         mutex_lock(&root->fs_info->fs_mutex);
1606         trans = btrfs_start_transaction(root, 1);
1607         btrfs_set_trans_block_group(trans, dir);
1608
1609         if (IS_ERR(trans)) {
1610                 err = PTR_ERR(trans);
1611                 goto out_unlock;
1612         }
1613
1614         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1615         if (err) {
1616                 err = -ENOSPC;
1617                 goto out_unlock;
1618         }
1619
1620         inode = btrfs_new_inode(trans, root, objectid,
1621                                 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1622         if (IS_ERR(inode)) {
1623                 err = PTR_ERR(inode);
1624                 goto out_fail;
1625         }
1626
1627         drop_on_err = 1;
1628         inode->i_op = &btrfs_dir_inode_operations;
1629         inode->i_fop = &btrfs_dir_file_operations;
1630         btrfs_set_trans_block_group(trans, inode);
1631
1632         inode->i_size = 0;
1633         err = btrfs_update_inode(trans, root, inode);
1634         if (err)
1635                 goto out_fail;
1636
1637         err = btrfs_add_link(trans, dentry, inode);
1638         if (err)
1639                 goto out_fail;
1640
1641         d_instantiate(dentry, inode);
1642         drop_on_err = 0;
1643         dir->i_sb->s_dirt = 1;
1644         btrfs_update_inode_block_group(trans, inode);
1645         btrfs_update_inode_block_group(trans, dir);
1646
1647 out_fail:
1648         nr = trans->blocks_used;
1649         btrfs_end_transaction(trans, root);
1650
1651 out_unlock:
1652         mutex_unlock(&root->fs_info->fs_mutex);
1653         if (drop_on_err)
1654                 iput(inode);
1655         btrfs_btree_balance_dirty(root, nr);
1656         return err;
1657 }
1658
1659 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1660                                     size_t page_offset, u64 start, u64 end,
1661                                     int create)
1662 {
1663         int ret;
1664         int err = 0;
1665         u64 bytenr;
1666         u64 extent_start = 0;
1667         u64 extent_end = 0;
1668         u64 objectid = inode->i_ino;
1669         u32 found_type;
1670         int failed_insert = 0;
1671         struct btrfs_path *path;
1672         struct btrfs_root *root = BTRFS_I(inode)->root;
1673         struct btrfs_file_extent_item *item;
1674         struct extent_buffer *leaf;
1675         struct btrfs_key found_key;
1676         struct extent_map *em = NULL;
1677         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1678         struct btrfs_trans_handle *trans = NULL;
1679
1680         path = btrfs_alloc_path();
1681         BUG_ON(!path);
1682         mutex_lock(&root->fs_info->fs_mutex);
1683
1684 again:
1685         em = lookup_extent_mapping(em_tree, start, end);
1686         if (em) {
1687                 goto out;
1688         }
1689         if (!em) {
1690                 em = alloc_extent_map(GFP_NOFS);
1691                 if (!em) {
1692                         err = -ENOMEM;
1693                         goto out;
1694                 }
1695                 em->start = EXTENT_MAP_HOLE;
1696                 em->end = EXTENT_MAP_HOLE;
1697         }
1698         em->bdev = inode->i_sb->s_bdev;
1699         ret = btrfs_lookup_file_extent(trans, root, path,
1700                                        objectid, start, trans != NULL);
1701         if (ret < 0) {
1702                 err = ret;
1703                 goto out;
1704         }
1705
1706         if (ret != 0) {
1707                 if (path->slots[0] == 0)
1708                         goto not_found;
1709                 path->slots[0]--;
1710         }
1711
1712         leaf = path->nodes[0];
1713         item = btrfs_item_ptr(leaf, path->slots[0],
1714                               struct btrfs_file_extent_item);
1715         /* are we inside the extent that was found? */
1716         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1717         found_type = btrfs_key_type(&found_key);
1718         if (found_key.objectid != objectid ||
1719             found_type != BTRFS_EXTENT_DATA_KEY) {
1720                 goto not_found;
1721         }
1722
1723         found_type = btrfs_file_extent_type(leaf, item);
1724         extent_start = found_key.offset;
1725         if (found_type == BTRFS_FILE_EXTENT_REG) {
1726                 extent_end = extent_start +
1727                        btrfs_file_extent_num_bytes(leaf, item);
1728                 err = 0;
1729                 if (start < extent_start || start >= extent_end) {
1730                         em->start = start;
1731                         if (start < extent_start) {
1732                                 if (end < extent_start)
1733                                         goto not_found;
1734                                 em->end = extent_end - 1;
1735                         } else {
1736                                 em->end = end;
1737                         }
1738                         goto not_found_em;
1739                 }
1740                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
1741                 if (bytenr == 0) {
1742                         em->start = extent_start;
1743                         em->end = extent_end - 1;
1744                         em->block_start = EXTENT_MAP_HOLE;
1745                         em->block_end = EXTENT_MAP_HOLE;
1746                         goto insert;
1747                 }
1748                 bytenr += btrfs_file_extent_offset(leaf, item);
1749                 em->block_start = bytenr;
1750                 em->block_end = em->block_start +
1751                         btrfs_file_extent_num_bytes(leaf, item) - 1;
1752                 em->start = extent_start;
1753                 em->end = extent_end - 1;
1754                 goto insert;
1755         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1756                 unsigned long ptr;
1757                 char *map;
1758                 size_t size;
1759                 size_t extent_offset;
1760                 size_t copy_size;
1761
1762                 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
1763                                                     path->slots[0]));
1764                 extent_end = (extent_start + size - 1) |
1765                         ((u64)root->sectorsize - 1);
1766                 if (start < extent_start || start >= extent_end) {
1767                         em->start = start;
1768                         if (start < extent_start) {
1769                                 if (end < extent_start)
1770                                         goto not_found;
1771                                 em->end = extent_end;
1772                         } else {
1773                                 em->end = end;
1774                         }
1775                         goto not_found_em;
1776                 }
1777                 em->block_start = EXTENT_MAP_INLINE;
1778                 em->block_end = EXTENT_MAP_INLINE;
1779
1780                 if (!page) {
1781                         em->start = extent_start;
1782                         em->end = extent_start + size - 1;
1783                         goto out;
1784                 }
1785
1786                 extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
1787                         extent_start + page_offset;
1788                 copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1789                                 size - extent_offset);
1790                 em->start = extent_start + extent_offset;
1791                 em->end = (em->start + copy_size -1) |
1792                         ((u64)root->sectorsize -1);
1793                 map = kmap(page);
1794                 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1795                 if (create == 0 && !PageUptodate(page)) {
1796                         read_extent_buffer(leaf, map + page_offset, ptr,
1797                                            copy_size);
1798                         flush_dcache_page(page);
1799                 } else if (create && PageUptodate(page)) {
1800                         if (!trans) {
1801                                 kunmap(page);
1802                                 free_extent_map(em);
1803                                 em = NULL;
1804                                 btrfs_release_path(root, path);
1805                                 trans = btrfs_start_transaction(root, 1);
1806                                 goto again;
1807                         }
1808                         write_extent_buffer(leaf, map + page_offset, ptr,
1809                                             copy_size);
1810                         btrfs_mark_buffer_dirty(leaf);
1811                 }
1812                 kunmap(page);
1813                 set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1814                 goto insert;
1815         } else {
1816                 printk("unkknown found_type %d\n", found_type);
1817                 WARN_ON(1);
1818         }
1819 not_found:
1820         em->start = start;
1821         em->end = end;
1822 not_found_em:
1823         em->block_start = EXTENT_MAP_HOLE;
1824         em->block_end = EXTENT_MAP_HOLE;
1825 insert:
1826         btrfs_release_path(root, path);
1827         if (em->start > start || em->end < start) {
1828                 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1829                 err = -EIO;
1830                 goto out;
1831         }
1832         ret = add_extent_mapping(em_tree, em);
1833         if (ret == -EEXIST) {
1834                 free_extent_map(em);
1835                 em = NULL;
1836                 if (0 && failed_insert == 1) {
1837                         btrfs_drop_extent_cache(inode, start, end);
1838                 }
1839                 failed_insert++;
1840                 if (failed_insert > 5) {
1841                         printk("failing to insert %Lu %Lu\n", start, end);
1842                         err = -EIO;
1843                         goto out;
1844                 }
1845                 goto again;
1846         }
1847         err = 0;
1848 out:
1849         btrfs_free_path(path);
1850         if (trans) {
1851                 ret = btrfs_end_transaction(trans, root);
1852                 if (!err)
1853                         err = ret;
1854         }
1855         mutex_unlock(&root->fs_info->fs_mutex);
1856         if (err) {
1857                 free_extent_map(em);
1858                 WARN_ON(1);
1859                 return ERR_PTR(err);
1860         }
1861         return em;
1862 }
1863
1864 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
1865 {
1866         return extent_bmap(mapping, iblock, btrfs_get_extent);
1867 }
1868
1869 static int btrfs_prepare_write(struct file *file, struct page *page,
1870                                unsigned from, unsigned to)
1871 {
1872         return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
1873                                     page->mapping->host, page, from, to,
1874                                     btrfs_get_extent);
1875 }
1876
1877 int btrfs_readpage(struct file *file, struct page *page)
1878 {
1879         struct extent_map_tree *tree;
1880         tree = &BTRFS_I(page->mapping->host)->extent_tree;
1881         return extent_read_full_page(tree, page, btrfs_get_extent);
1882 }
1883 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1884 {
1885         struct extent_map_tree *tree;
1886
1887
1888         if (current->flags & PF_MEMALLOC) {
1889                 redirty_page_for_writepage(wbc, page);
1890                 unlock_page(page);
1891                 return 0;
1892         }
1893         tree = &BTRFS_I(page->mapping->host)->extent_tree;
1894         return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
1895 }
1896
1897 static int btrfs_writepages(struct address_space *mapping,
1898                             struct writeback_control *wbc)
1899 {
1900         struct extent_map_tree *tree;
1901         tree = &BTRFS_I(mapping->host)->extent_tree;
1902         return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
1903 }
1904
1905 static int
1906 btrfs_readpages(struct file *file, struct address_space *mapping,
1907                 struct list_head *pages, unsigned nr_pages)
1908 {
1909         struct extent_map_tree *tree;
1910         tree = &BTRFS_I(mapping->host)->extent_tree;
1911         return extent_readpages(tree, mapping, pages, nr_pages,
1912                                 btrfs_get_extent);
1913 }
1914
1915 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
1916 {
1917         struct extent_map_tree *tree;
1918         int ret;
1919
1920         tree = &BTRFS_I(page->mapping->host)->extent_tree;
1921         ret = try_release_extent_mapping(tree, page);
1922         if (ret == 1) {
1923                 ClearPagePrivate(page);
1924                 set_page_private(page, 0);
1925                 page_cache_release(page);
1926         }
1927         return ret;
1928 }
1929
1930 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
1931 {
1932         struct extent_map_tree *tree;
1933
1934         tree = &BTRFS_I(page->mapping->host)->extent_tree;
1935         extent_invalidatepage(tree, page, offset);
1936         btrfs_releasepage(page, GFP_NOFS);
1937 }
1938
1939 /*
1940  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
1941  * called from a page fault handler when a page is first dirtied. Hence we must
1942  * be careful to check for EOF conditions here. We set the page up correctly
1943  * for a written page which means we get ENOSPC checking when writing into
1944  * holes and correct delalloc and unwritten extent mapping on filesystems that
1945  * support these features.
1946  *
1947  * We are not allowed to take the i_mutex here so we have to play games to
1948  * protect against truncate races as the page could now be beyond EOF.  Because
1949  * vmtruncate() writes the inode size before removing pages, once we have the
1950  * page lock we can determine safely if the page is beyond EOF. If it is not
1951  * beyond EOF, then the page is guaranteed safe against truncation until we
1952  * unlock the page.
1953  */
1954 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
1955 {
1956         struct inode *inode = fdentry(vma->vm_file)->d_inode;
1957         unsigned long end;
1958         loff_t size;
1959         int ret = -EINVAL;
1960         u64 page_start;
1961
1962         down_read(&BTRFS_I(inode)->root->snap_sem);
1963         lock_page(page);
1964         wait_on_page_writeback(page);
1965         size = i_size_read(inode);
1966         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1967
1968         if ((page->mapping != inode->i_mapping) ||
1969             (page_start > size)) {
1970                 /* page got truncated out from underneath us */
1971                 goto out_unlock;
1972         }
1973
1974         /* page is wholly or partially inside EOF */
1975         if (page_start + PAGE_CACHE_SIZE > size)
1976                 end = size & ~PAGE_CACHE_MASK;
1977         else
1978                 end = PAGE_CACHE_SIZE;
1979
1980         ret = btrfs_cow_one_page(inode, page, end);
1981
1982 out_unlock:
1983         up_read(&BTRFS_I(inode)->root->snap_sem);
1984         unlock_page(page);
1985         return ret;
1986 }
1987
1988 static void btrfs_truncate(struct inode *inode)
1989 {
1990         struct btrfs_root *root = BTRFS_I(inode)->root;
1991         int ret;
1992         struct btrfs_trans_handle *trans;
1993         unsigned long nr;
1994
1995         if (!S_ISREG(inode->i_mode))
1996                 return;
1997         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1998                 return;
1999
2000         btrfs_truncate_page(inode->i_mapping, inode->i_size);
2001
2002         mutex_lock(&root->fs_info->fs_mutex);
2003         trans = btrfs_start_transaction(root, 1);
2004         btrfs_set_trans_block_group(trans, inode);
2005
2006         /* FIXME, add redo link to tree so we don't leak on crash */
2007         ret = btrfs_truncate_in_trans(trans, root, inode);
2008         btrfs_update_inode(trans, root, inode);
2009         nr = trans->blocks_used;
2010
2011         ret = btrfs_end_transaction(trans, root);
2012         BUG_ON(ret);
2013         mutex_unlock(&root->fs_info->fs_mutex);
2014         btrfs_btree_balance_dirty(root, nr);
2015 }
2016
2017 int btrfs_commit_write(struct file *file, struct page *page,
2018                        unsigned from, unsigned to)
2019 {
2020         loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2021         struct inode *inode = page->mapping->host;
2022
2023         btrfs_cow_one_page(inode, page, PAGE_CACHE_SIZE);
2024
2025         if (pos > inode->i_size) {
2026                 i_size_write(inode, pos);
2027                 mark_inode_dirty(inode);
2028         }
2029         return 0;
2030 }
2031
2032 static int create_subvol(struct btrfs_root *root, char *name, int namelen)
2033 {
2034         struct btrfs_trans_handle *trans;
2035         struct btrfs_key key;
2036         struct btrfs_root_item root_item;
2037         struct btrfs_inode_item *inode_item;
2038         struct extent_buffer *leaf;
2039         struct btrfs_root *new_root;
2040         struct inode *inode;
2041         struct inode *dir;
2042         int ret;
2043         int err;
2044         u64 objectid;
2045         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2046         unsigned long nr = 1;
2047
2048         mutex_lock(&root->fs_info->fs_mutex);
2049         trans = btrfs_start_transaction(root, 1);
2050         BUG_ON(!trans);
2051
2052         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2053                                        0, &objectid);
2054         if (ret)
2055                 goto fail;
2056
2057         leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2058                                         objectid, trans->transid, 0, 0,
2059                                         0, 0);
2060         if (IS_ERR(leaf))
2061                 return PTR_ERR(leaf);
2062
2063         btrfs_set_header_nritems(leaf, 0);
2064         btrfs_set_header_level(leaf, 0);
2065         btrfs_set_header_bytenr(leaf, leaf->start);
2066         btrfs_set_header_generation(leaf, trans->transid);
2067         btrfs_set_header_owner(leaf, objectid);
2068
2069         write_extent_buffer(leaf, root->fs_info->fsid,
2070                             (unsigned long)btrfs_header_fsid(leaf),
2071                             BTRFS_FSID_SIZE);
2072         btrfs_mark_buffer_dirty(leaf);
2073
2074         inode_item = &root_item.inode;
2075         memset(inode_item, 0, sizeof(*inode_item));
2076         inode_item->generation = cpu_to_le64(1);
2077         inode_item->size = cpu_to_le64(3);
2078         inode_item->nlink = cpu_to_le32(1);
2079         inode_item->nblocks = cpu_to_le64(1);
2080         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2081
2082         btrfs_set_root_bytenr(&root_item, leaf->start);
2083         btrfs_set_root_level(&root_item, 0);
2084         btrfs_set_root_refs(&root_item, 1);
2085         btrfs_set_root_used(&root_item, 0);
2086
2087         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2088         root_item.drop_level = 0;
2089
2090         free_extent_buffer(leaf);
2091         leaf = NULL;
2092
2093         btrfs_set_root_dirid(&root_item, new_dirid);
2094
2095         key.objectid = objectid;
2096         key.offset = 1;
2097         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2098         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2099                                 &root_item);
2100         if (ret)
2101                 goto fail;
2102
2103         /*
2104          * insert the directory item
2105          */
2106         key.offset = (u64)-1;
2107         dir = root->fs_info->sb->s_root->d_inode;
2108         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2109                                     name, namelen, dir->i_ino, &key,
2110                                     BTRFS_FT_DIR);
2111         if (ret)
2112                 goto fail;
2113
2114         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2115                              name, namelen, objectid,
2116                              root->fs_info->sb->s_root->d_inode->i_ino);
2117         if (ret)
2118                 goto fail;
2119
2120         ret = btrfs_commit_transaction(trans, root);
2121         if (ret)
2122                 goto fail_commit;
2123
2124         new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2125         BUG_ON(!new_root);
2126
2127         trans = btrfs_start_transaction(new_root, 1);
2128         BUG_ON(!trans);
2129
2130         inode = btrfs_new_inode(trans, new_root, new_dirid,
2131                                 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2132         if (IS_ERR(inode))
2133                 goto fail;
2134         inode->i_op = &btrfs_dir_inode_operations;
2135         inode->i_fop = &btrfs_dir_file_operations;
2136         new_root->inode = inode;
2137
2138         ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2139                                      new_dirid);
2140         inode->i_nlink = 1;
2141         inode->i_size = 0;
2142         ret = btrfs_update_inode(trans, new_root, inode);
2143         if (ret)
2144                 goto fail;
2145 fail:
2146         nr = trans->blocks_used;
2147         err = btrfs_commit_transaction(trans, root);
2148         if (err && !ret)
2149                 ret = err;
2150 fail_commit:
2151         mutex_unlock(&root->fs_info->fs_mutex);
2152         btrfs_btree_balance_dirty(root, nr);
2153         return ret;
2154 }
2155
2156 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2157 {
2158         struct btrfs_trans_handle *trans;
2159         struct btrfs_key key;
2160         struct btrfs_root_item new_root_item;
2161         struct extent_buffer *tmp;
2162         int ret;
2163         int err;
2164         u64 objectid;
2165         unsigned long nr;
2166
2167         if (!root->ref_cows)
2168                 return -EINVAL;
2169
2170         down_write(&root->snap_sem);
2171         freeze_bdev(root->fs_info->sb->s_bdev);
2172         thaw_bdev(root->fs_info->sb->s_bdev, root->fs_info->sb);
2173
2174         mutex_lock(&root->fs_info->fs_mutex);
2175         trans = btrfs_start_transaction(root, 1);
2176         BUG_ON(!trans);
2177
2178         ret = btrfs_update_inode(trans, root, root->inode);
2179         if (ret)
2180                 goto fail;
2181
2182         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2183                                        0, &objectid);
2184         if (ret)
2185                 goto fail;
2186
2187         memcpy(&new_root_item, &root->root_item,
2188                sizeof(new_root_item));
2189
2190         key.objectid = objectid;
2191         key.offset = 1;
2192         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2193
2194         extent_buffer_get(root->node);
2195         btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
2196         free_extent_buffer(tmp);
2197
2198         btrfs_copy_root(trans, root, root->node, &tmp, objectid);
2199
2200         btrfs_set_root_bytenr(&new_root_item, tmp->start);
2201         btrfs_set_root_level(&new_root_item, btrfs_header_level(tmp));
2202         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2203                                 &new_root_item);
2204         free_extent_buffer(tmp);
2205         if (ret)
2206                 goto fail;
2207
2208         /*
2209          * insert the directory item
2210          */
2211         key.offset = (u64)-1;
2212         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2213                                     name, namelen,
2214                                     root->fs_info->sb->s_root->d_inode->i_ino,
2215                                     &key, BTRFS_FT_DIR);
2216
2217         if (ret)
2218                 goto fail;
2219
2220         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2221                              name, namelen, objectid,
2222                              root->fs_info->sb->s_root->d_inode->i_ino);
2223
2224         if (ret)
2225                 goto fail;
2226 fail:
2227         nr = trans->blocks_used;
2228         err = btrfs_commit_transaction(trans, root);
2229
2230         if (err && !ret)
2231                 ret = err;
2232
2233         mutex_unlock(&root->fs_info->fs_mutex);
2234         up_write(&root->snap_sem);
2235         btrfs_btree_balance_dirty(root, nr);
2236         return ret;
2237 }
2238
2239 static unsigned long force_ra(struct address_space *mapping,
2240                               struct file_ra_state *ra, struct file *file,
2241                               pgoff_t offset, pgoff_t last_index)
2242 {
2243         pgoff_t req_size;
2244
2245 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2246         req_size = last_index - offset + 1;
2247         offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2248         return offset;
2249 #else
2250         req_size = min(last_index - offset + 1, (pgoff_t)128);
2251         page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2252         return offset + req_size;
2253 #endif
2254 }
2255
2256 int btrfs_defrag_file(struct file *file) {
2257         struct inode *inode = fdentry(file)->d_inode;
2258         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2259         struct page *page;
2260         unsigned long last_index;
2261         unsigned long ra_index = 0;
2262         u64 page_start;
2263         u64 page_end;
2264         unsigned long i;
2265
2266         mutex_lock(&inode->i_mutex);
2267         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2268         for (i = 0; i <= last_index; i++) {
2269                 if (i == ra_index) {
2270                         ra_index = force_ra(inode->i_mapping, &file->f_ra,
2271                                             file, ra_index, last_index);
2272                 }
2273                 page = grab_cache_page(inode->i_mapping, i);
2274                 if (!page)
2275                         goto out_unlock;
2276                 if (!PageUptodate(page)) {
2277                         btrfs_readpage(NULL, page);
2278                         lock_page(page);
2279                         if (!PageUptodate(page)) {
2280                                 unlock_page(page);
2281                                 page_cache_release(page);
2282                                 goto out_unlock;
2283                         }
2284                 }
2285                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2286                 page_end = page_start + PAGE_CACHE_SIZE - 1;
2287
2288                 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2289                 set_extent_delalloc(em_tree, page_start,
2290                                     page_end, GFP_NOFS);
2291                 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2292                 set_page_dirty(page);
2293                 unlock_page(page);
2294                 page_cache_release(page);
2295                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2296         }
2297
2298 out_unlock:
2299         mutex_unlock(&inode->i_mutex);
2300         return 0;
2301 }
2302
2303 static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
2304 {
2305         struct btrfs_ioctl_vol_args *vol_args;
2306         struct btrfs_dir_item *di;
2307         struct btrfs_path *path;
2308         u64 root_dirid;
2309         int namelen;
2310         int ret;
2311
2312         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2313
2314         if (!vol_args)
2315                 return -ENOMEM;
2316
2317         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2318                 ret = -EFAULT;
2319                 goto out;
2320         }
2321
2322         namelen = strlen(vol_args->name);
2323         if (namelen > BTRFS_VOL_NAME_MAX) {
2324                 ret = -EINVAL;
2325                 goto out;
2326         }
2327         if (strchr(vol_args->name, '/')) {
2328                 ret = -EINVAL;
2329                 goto out;
2330         }
2331
2332         path = btrfs_alloc_path();
2333         if (!path) {
2334                 ret = -ENOMEM;
2335                 goto out;
2336         }
2337
2338         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2339         mutex_lock(&root->fs_info->fs_mutex);
2340         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2341                             path, root_dirid,
2342                             vol_args->name, namelen, 0);
2343         mutex_unlock(&root->fs_info->fs_mutex);
2344         btrfs_free_path(path);
2345
2346         if (di && !IS_ERR(di)) {
2347                 ret = -EEXIST;
2348                 goto out;
2349         }
2350
2351         if (IS_ERR(di)) {
2352                 ret = PTR_ERR(di);
2353                 goto out;
2354         }
2355
2356         if (root == root->fs_info->tree_root)
2357                 ret = create_subvol(root, vol_args->name, namelen);
2358         else
2359                 ret = create_snapshot(root, vol_args->name, namelen);
2360 out:
2361         kfree(vol_args);
2362         return ret;
2363 }
2364
2365 static int btrfs_ioctl_defrag(struct file *file)
2366 {
2367         struct inode *inode = fdentry(file)->d_inode;
2368         struct btrfs_root *root = BTRFS_I(inode)->root;
2369
2370         switch (inode->i_mode & S_IFMT) {
2371         case S_IFDIR:
2372                 mutex_lock(&root->fs_info->fs_mutex);
2373                 btrfs_defrag_root(root, 0);
2374                 btrfs_defrag_root(root->fs_info->extent_root, 0);
2375                 mutex_unlock(&root->fs_info->fs_mutex);
2376                 break;
2377         case S_IFREG:
2378                 btrfs_defrag_file(file);
2379                 break;
2380         }
2381
2382         return 0;
2383 }
2384
2385 long btrfs_ioctl(struct file *file, unsigned int
2386                 cmd, unsigned long arg)
2387 {
2388         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2389
2390         switch (cmd) {
2391         case BTRFS_IOC_SNAP_CREATE:
2392                 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2393         case BTRFS_IOC_DEFRAG:
2394                 return btrfs_ioctl_defrag(file);
2395         }
2396
2397         return -ENOTTY;
2398 }
2399
2400 /*
2401  * Called inside transaction, so use GFP_NOFS
2402  */
2403 struct inode *btrfs_alloc_inode(struct super_block *sb)
2404 {
2405         struct btrfs_inode *ei;
2406
2407         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2408         if (!ei)
2409                 return NULL;
2410         ei->last_trans = 0;
2411         return &ei->vfs_inode;
2412 }
2413
2414 void btrfs_destroy_inode(struct inode *inode)
2415 {
2416         WARN_ON(!list_empty(&inode->i_dentry));
2417         WARN_ON(inode->i_data.nrpages);
2418
2419         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2420 }
2421
2422 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2423 static void init_once(struct kmem_cache * cachep, void *foo)
2424 #else
2425 static void init_once(void * foo, struct kmem_cache * cachep,
2426                       unsigned long flags)
2427 #endif
2428 {
2429         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2430
2431         inode_init_once(&ei->vfs_inode);
2432 }
2433
2434 void btrfs_destroy_cachep(void)
2435 {
2436         if (btrfs_inode_cachep)
2437                 kmem_cache_destroy(btrfs_inode_cachep);
2438         if (btrfs_trans_handle_cachep)
2439                 kmem_cache_destroy(btrfs_trans_handle_cachep);
2440         if (btrfs_transaction_cachep)
2441                 kmem_cache_destroy(btrfs_transaction_cachep);
2442         if (btrfs_bit_radix_cachep)
2443                 kmem_cache_destroy(btrfs_bit_radix_cachep);
2444         if (btrfs_path_cachep)
2445                 kmem_cache_destroy(btrfs_path_cachep);
2446 }
2447
2448 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2449                                        unsigned long extra_flags,
2450 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2451                                        void (*ctor)(struct kmem_cache *, void *)
2452 #else
2453                                        void (*ctor)(void *, struct kmem_cache *,
2454                                                     unsigned long)
2455 #endif
2456                                      )
2457 {
2458         return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2459                                  SLAB_MEM_SPREAD | extra_flags), ctor
2460 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2461                                  ,NULL
2462 #endif
2463                                 );
2464 }
2465
2466 int btrfs_init_cachep(void)
2467 {
2468         btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2469                                           sizeof(struct btrfs_inode),
2470                                           0, init_once);
2471         if (!btrfs_inode_cachep)
2472                 goto fail;
2473         btrfs_trans_handle_cachep =
2474                         btrfs_cache_create("btrfs_trans_handle_cache",
2475                                            sizeof(struct btrfs_trans_handle),
2476                                            0, NULL);
2477         if (!btrfs_trans_handle_cachep)
2478                 goto fail;
2479         btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2480                                              sizeof(struct btrfs_transaction),
2481                                              0, NULL);
2482         if (!btrfs_transaction_cachep)
2483                 goto fail;
2484         btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2485                                          sizeof(struct btrfs_path),
2486                                          0, NULL);
2487         if (!btrfs_path_cachep)
2488                 goto fail;
2489         btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2490                                               SLAB_DESTROY_BY_RCU, NULL);
2491         if (!btrfs_bit_radix_cachep)
2492                 goto fail;
2493         return 0;
2494 fail:
2495         btrfs_destroy_cachep();
2496         return -ENOMEM;
2497 }
2498
2499 static int btrfs_getattr(struct vfsmount *mnt,
2500                          struct dentry *dentry, struct kstat *stat)
2501 {
2502         struct inode *inode = dentry->d_inode;
2503         generic_fillattr(inode, stat);
2504         stat->blksize = 256 * 1024;
2505         return 0;
2506 }
2507
2508 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2509                            struct inode * new_dir,struct dentry *new_dentry)
2510 {
2511         struct btrfs_trans_handle *trans;
2512         struct btrfs_root *root = BTRFS_I(old_dir)->root;
2513         struct inode *new_inode = new_dentry->d_inode;
2514         struct inode *old_inode = old_dentry->d_inode;
2515         struct timespec ctime = CURRENT_TIME;
2516         struct btrfs_path *path;
2517         int ret;
2518
2519         if (S_ISDIR(old_inode->i_mode) && new_inode &&
2520             new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2521                 return -ENOTEMPTY;
2522         }
2523
2524         mutex_lock(&root->fs_info->fs_mutex);
2525         trans = btrfs_start_transaction(root, 1);
2526
2527         btrfs_set_trans_block_group(trans, new_dir);
2528         path = btrfs_alloc_path();
2529         if (!path) {
2530                 ret = -ENOMEM;
2531                 goto out_fail;
2532         }
2533
2534         old_dentry->d_inode->i_nlink++;
2535         old_dir->i_ctime = old_dir->i_mtime = ctime;
2536         new_dir->i_ctime = new_dir->i_mtime = ctime;
2537         old_inode->i_ctime = ctime;
2538
2539         ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2540         if (ret)
2541                 goto out_fail;
2542
2543         if (new_inode) {
2544                 new_inode->i_ctime = CURRENT_TIME;
2545                 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2546                 if (ret)
2547                         goto out_fail;
2548         }
2549         ret = btrfs_add_link(trans, new_dentry, old_inode);
2550         if (ret)
2551                 goto out_fail;
2552
2553 out_fail:
2554         btrfs_free_path(path);
2555         btrfs_end_transaction(trans, root);
2556         mutex_unlock(&root->fs_info->fs_mutex);
2557         return ret;
2558 }
2559
2560 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2561                          const char *symname)
2562 {
2563         struct btrfs_trans_handle *trans;
2564         struct btrfs_root *root = BTRFS_I(dir)->root;
2565         struct btrfs_path *path;
2566         struct btrfs_key key;
2567         struct inode *inode;
2568         int err;
2569         int drop_inode = 0;
2570         u64 objectid;
2571         int name_len;
2572         int datasize;
2573         unsigned long ptr;
2574         struct btrfs_file_extent_item *ei;
2575         struct extent_buffer *leaf;
2576         unsigned long nr;
2577
2578         name_len = strlen(symname) + 1;
2579         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2580                 return -ENAMETOOLONG;
2581         mutex_lock(&root->fs_info->fs_mutex);
2582         trans = btrfs_start_transaction(root, 1);
2583         btrfs_set_trans_block_group(trans, dir);
2584
2585         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2586         if (err) {
2587                 err = -ENOSPC;
2588                 goto out_unlock;
2589         }
2590
2591         inode = btrfs_new_inode(trans, root, objectid,
2592                                 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2593         err = PTR_ERR(inode);
2594         if (IS_ERR(inode))
2595                 goto out_unlock;
2596
2597         btrfs_set_trans_block_group(trans, inode);
2598         err = btrfs_add_nondir(trans, dentry, inode);
2599         if (err)
2600                 drop_inode = 1;
2601         else {
2602                 inode->i_mapping->a_ops = &btrfs_aops;
2603                 inode->i_fop = &btrfs_file_operations;
2604                 inode->i_op = &btrfs_file_inode_operations;
2605                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2606                                      inode->i_mapping, GFP_NOFS);
2607                 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
2608         }
2609         dir->i_sb->s_dirt = 1;
2610         btrfs_update_inode_block_group(trans, inode);
2611         btrfs_update_inode_block_group(trans, dir);
2612         if (drop_inode)
2613                 goto out_unlock;
2614
2615         path = btrfs_alloc_path();
2616         BUG_ON(!path);
2617         key.objectid = inode->i_ino;
2618         key.offset = 0;
2619         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2620         datasize = btrfs_file_extent_calc_inline_size(name_len);
2621         err = btrfs_insert_empty_item(trans, root, path, &key,
2622                                       datasize);
2623         if (err) {
2624                 drop_inode = 1;
2625                 goto out_unlock;
2626         }
2627         leaf = path->nodes[0];
2628         ei = btrfs_item_ptr(leaf, path->slots[0],
2629                             struct btrfs_file_extent_item);
2630         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2631         btrfs_set_file_extent_type(leaf, ei,
2632                                    BTRFS_FILE_EXTENT_INLINE);
2633         ptr = btrfs_file_extent_inline_start(ei);
2634         write_extent_buffer(leaf, symname, ptr, name_len);
2635         btrfs_mark_buffer_dirty(leaf);
2636         btrfs_free_path(path);
2637
2638         inode->i_op = &btrfs_symlink_inode_operations;
2639         inode->i_mapping->a_ops = &btrfs_symlink_aops;
2640         inode->i_size = name_len - 1;
2641         err = btrfs_update_inode(trans, root, inode);
2642         if (err)
2643                 drop_inode = 1;
2644
2645 out_unlock:
2646         nr = trans->blocks_used;
2647         btrfs_end_transaction(trans, root);
2648         mutex_unlock(&root->fs_info->fs_mutex);
2649         if (drop_inode) {
2650                 inode_dec_link_count(inode);
2651                 iput(inode);
2652         }
2653         btrfs_btree_balance_dirty(root, nr);
2654         return err;
2655 }
2656
2657 static struct inode_operations btrfs_dir_inode_operations = {
2658         .lookup         = btrfs_lookup,
2659         .create         = btrfs_create,
2660         .unlink         = btrfs_unlink,
2661         .link           = btrfs_link,
2662         .mkdir          = btrfs_mkdir,
2663         .rmdir          = btrfs_rmdir,
2664         .rename         = btrfs_rename,
2665         .symlink        = btrfs_symlink,
2666         .setattr        = btrfs_setattr,
2667         .mknod          = btrfs_mknod,
2668         .setxattr       = generic_setxattr,
2669         .getxattr       = generic_getxattr,
2670         .listxattr      = btrfs_listxattr,
2671         .removexattr    = generic_removexattr,
2672 };
2673
2674 static struct inode_operations btrfs_dir_ro_inode_operations = {
2675         .lookup         = btrfs_lookup,
2676 };
2677
2678 static struct file_operations btrfs_dir_file_operations = {
2679         .llseek         = generic_file_llseek,
2680         .read           = generic_read_dir,
2681         .readdir        = btrfs_readdir,
2682         .unlocked_ioctl = btrfs_ioctl,
2683 #ifdef CONFIG_COMPAT
2684         .compat_ioctl   = btrfs_ioctl,
2685 #endif
2686 };
2687
2688 static struct extent_map_ops btrfs_extent_map_ops = {
2689         .fill_delalloc = run_delalloc_range,
2690         .writepage_io_hook = btrfs_writepage_io_hook,
2691         .readpage_io_hook = btrfs_readpage_io_hook,
2692         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
2693 };
2694
2695 static struct address_space_operations btrfs_aops = {
2696         .readpage       = btrfs_readpage,
2697         .writepage      = btrfs_writepage,
2698         .writepages     = btrfs_writepages,
2699         .readpages      = btrfs_readpages,
2700         .sync_page      = block_sync_page,
2701         .prepare_write  = btrfs_prepare_write,
2702         .commit_write   = btrfs_commit_write,
2703         .bmap           = btrfs_bmap,
2704         .invalidatepage = btrfs_invalidatepage,
2705         .releasepage    = btrfs_releasepage,
2706         .set_page_dirty = __set_page_dirty_nobuffers,
2707 };
2708
2709 static struct address_space_operations btrfs_symlink_aops = {
2710         .readpage       = btrfs_readpage,
2711         .writepage      = btrfs_writepage,
2712         .invalidatepage = btrfs_invalidatepage,
2713         .releasepage    = btrfs_releasepage,
2714 };
2715
2716 static struct inode_operations btrfs_file_inode_operations = {
2717         .truncate       = btrfs_truncate,
2718         .getattr        = btrfs_getattr,
2719         .setattr        = btrfs_setattr,
2720         .setxattr       = generic_setxattr,
2721         .getxattr       = generic_getxattr,
2722         .listxattr      = btrfs_listxattr,
2723         .removexattr    = generic_removexattr,
2724 };
2725
2726 static struct inode_operations btrfs_special_inode_operations = {
2727         .getattr        = btrfs_getattr,
2728         .setattr        = btrfs_setattr,
2729 };
2730
2731 static struct inode_operations btrfs_symlink_inode_operations = {
2732         .readlink       = generic_readlink,
2733         .follow_link    = page_follow_link_light,
2734         .put_link       = page_put_link,
2735 };