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