git.oblomov.eu Git - linux-2.6/blob - fs/btrfs/inode.c

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