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