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