fs/btrfs/inode.c

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