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 int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
  76                            int for_del)
  77 {
  78         u64 total = btrfs_super_total_bytes(&root->fs_info->super_copy);
  79         u64 used = btrfs_super_bytes_used(&root->fs_info->super_copy);
  80         u64 thresh;
  81         int ret = 0;
  82
  83         if (for_del)
  84                 thresh = (total * 90) / 100;
  85         else
  86                 thresh = (total * 85) / 100;
  87
  88         spin_lock(&root->fs_info->delalloc_lock);
  89         if (used + root->fs_info->delalloc_bytes + num_required > thresh)
  90                 ret = -ENOSPC;
  91         spin_unlock(&root->fs_info->delalloc_lock);
  92         return ret;
  93 }
  94
  95 static int cow_file_range(struct inode *inode, u64 start, u64 end)
  96 {
  97         struct btrfs_root *root = BTRFS_I(inode)->root;
  98         struct btrfs_trans_handle *trans;
  99         u64 alloc_hint = 0;
 100         u64 num_bytes;
 101         u64 cur_alloc_size;
 102         u64 blocksize = root->sectorsize;
 103         struct btrfs_key ins;
 104         int ret;
 105
 106         trans = btrfs_start_transaction(root, 1);
 107         BUG_ON(!trans);
 108         btrfs_set_trans_block_group(trans, inode);
 109
 110         num_bytes = (end - start + blocksize) & ~(blocksize - 1);
 111         num_bytes = max(blocksize,  num_bytes);
 112         ret = btrfs_drop_extents(trans, root, inode,
 113                                  start, start + num_bytes, start, &alloc_hint);
 114
 115         if (alloc_hint == EXTENT_MAP_INLINE)
 116                 goto out;
 117
 118         while(num_bytes > 0) {
 119                 cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
 120                 ret = btrfs_alloc_extent(trans, root, cur_alloc_size,
 121                                          root->root_key.objectid,
 122                                          trans->transid,
 123                                          inode->i_ino, start, 0,
 124                                          alloc_hint, (u64)-1, &ins, 1);
 125                 if (ret) {
 126                         WARN_ON(1);
 127                         goto out;
 128                 }
 129                 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
 130                                                start, ins.objectid, ins.offset,
 131                                                ins.offset);
 132                 num_bytes -= cur_alloc_size;
 133                 alloc_hint = ins.objectid + ins.offset;
 134                 start += cur_alloc_size;
 135         }
 136 out:
 137         btrfs_end_transaction(trans, root);
 138         return ret;
 139 }
 140
 141 static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
 142 {
 143         u64 extent_start;
 144         u64 extent_end;
 145         u64 bytenr;
 146         u64 cow_end;
 147         u64 loops = 0;
 148         struct btrfs_root *root = BTRFS_I(inode)->root;
 149         struct extent_buffer *leaf;
 150         int found_type;
 151         struct btrfs_path *path;
 152         struct btrfs_file_extent_item *item;
 153         int ret;
 154         int err;
 155         struct btrfs_key found_key;
 156
 157         path = btrfs_alloc_path();
 158         BUG_ON(!path);
 159 again:
 160         ret = btrfs_lookup_file_extent(NULL, root, path,
 161                                        inode->i_ino, start, 0);
 162         if (ret < 0) {
 163                 btrfs_free_path(path);
 164                 return ret;
 165         }
 166
 167         cow_end = end;
 168         if (ret != 0) {
 169                 if (path->slots[0] == 0)
 170                         goto not_found;
 171                 path->slots[0]--;
 172         }
 173
 174         leaf = path->nodes[0];
 175         item = btrfs_item_ptr(leaf, path->slots[0],
 176                               struct btrfs_file_extent_item);
 177
 178         /* are we inside the extent that was found? */
 179         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 180         found_type = btrfs_key_type(&found_key);
 181         if (found_key.objectid != inode->i_ino ||
 182             found_type != BTRFS_EXTENT_DATA_KEY) {
 183                 goto not_found;
 184         }
 185
 186         found_type = btrfs_file_extent_type(leaf, item);
 187         extent_start = found_key.offset;
 188         if (found_type == BTRFS_FILE_EXTENT_REG) {
 189                 extent_end = extent_start +
 190                        btrfs_file_extent_num_bytes(leaf, item);
 191                 err = 0;
 192
 193                 if (loops && start != extent_start)
 194                         goto not_found;
 195
 196                 if (start < extent_start || start >= extent_end)
 197                         goto not_found;
 198
 199                 cow_end = min(end, extent_end - 1);
 200                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
 201                 if (bytenr == 0)
 202                         goto not_found;
 203
 204                 if (btrfs_count_snapshots_in_path(root, path, bytenr) != 1) {
 205                         goto not_found;
 206                 }
 207
 208                 start = extent_end;
 209         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 210                 goto not_found;
 211         }
 212 loop:
 213         if (start > end) {
 214                 btrfs_free_path(path);
 215                 return 0;
 216         }
 217         btrfs_release_path(root, path);
 218         loops++;
 219         goto again;
 220
 221 not_found:
 222         cow_file_range(inode, start, cow_end);
 223         start = cow_end + 1;
 224         goto loop;
 225 }
 226
 227 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
 228 {
 229         struct btrfs_root *root = BTRFS_I(inode)->root;
 230         u64 num_bytes;
 231         int ret;
 232
 233         mutex_lock(&root->fs_info->fs_mutex);
 234         if (btrfs_test_opt(root, NODATACOW))
 235                 ret = run_delalloc_nocow(inode, start, end);
 236         else
 237                 ret = cow_file_range(inode, start, end);
 238
 239         spin_lock(&root->fs_info->delalloc_lock);
 240         num_bytes = end + 1 - start;
 241         if (root->fs_info->delalloc_bytes < num_bytes) {
 242                 printk("delalloc accounting error total %llu sub %llu\n",
 243                        root->fs_info->delalloc_bytes, num_bytes);
 244         } else {
 245                 root->fs_info->delalloc_bytes -= num_bytes;
 246         }
 247         spin_unlock(&root->fs_info->delalloc_lock);
 248
 249         mutex_unlock(&root->fs_info->fs_mutex);
 250         return ret;
 251 }
 252
 253 int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
 254 {
 255         struct inode *inode = page->mapping->host;
 256         struct btrfs_root *root = BTRFS_I(inode)->root;
 257         struct btrfs_trans_handle *trans;
 258         char *kaddr;
 259         int ret = 0;
 260         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 261         size_t offset = start - page_start;
 262
 263         if (btrfs_test_opt(root, NODATASUM))
 264                 return 0;
 265
 266         mutex_lock(&root->fs_info->fs_mutex);
 267         trans = btrfs_start_transaction(root, 1);
 268         btrfs_set_trans_block_group(trans, inode);
 269         kaddr = kmap(page);
 270         btrfs_csum_file_block(trans, root, inode, inode->i_ino,
 271                               start, kaddr + offset, end - start + 1);
 272         kunmap(page);
 273         ret = btrfs_end_transaction(trans, root);
 274         BUG_ON(ret);
 275         mutex_unlock(&root->fs_info->fs_mutex);
 276         return ret;
 277 }
 278
 279 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
 280 {
 281         int ret = 0;
 282         struct inode *inode = page->mapping->host;
 283         struct btrfs_root *root = BTRFS_I(inode)->root;
 284         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 285         struct btrfs_csum_item *item;
 286         struct btrfs_path *path = NULL;
 287         u32 csum;
 288
 289         if (btrfs_test_opt(root, NODATASUM))
 290                 return 0;
 291
 292         mutex_lock(&root->fs_info->fs_mutex);
 293         path = btrfs_alloc_path();
 294         item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
 295         if (IS_ERR(item)) {
 296                 ret = PTR_ERR(item);
 297                 /* a csum that isn't present is a preallocated region. */
 298                 if (ret == -ENOENT || ret == -EFBIG)
 299                         ret = 0;
 300                 csum = 0;
 301                 goto out;
 302         }
 303         read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
 304                            BTRFS_CRC32_SIZE);
 305         set_state_private(em_tree, start, csum);
 306 out:
 307         if (path)
 308                 btrfs_free_path(path);
 309         mutex_unlock(&root->fs_info->fs_mutex);
 310         return ret;
 311 }
 312
 313 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
 314 {
 315         size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
 316         struct inode *inode = page->mapping->host;
 317         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 318         char *kaddr;
 319         u64 private;
 320         int ret;
 321         struct btrfs_root *root = BTRFS_I(inode)->root;
 322         u32 csum = ~(u32)0;
 323         unsigned long flags;
 324
 325         if (btrfs_test_opt(root, NODATASUM))
 326                 return 0;
 327
 328         ret = get_state_private(em_tree, start, &private);
 329         local_irq_save(flags);
 330         kaddr = kmap_atomic(page, KM_IRQ0);
 331         if (ret) {
 332                 goto zeroit;
 333         }
 334         csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
 335         btrfs_csum_final(csum, (char *)&csum);
 336         if (csum != private) {
 337                 goto zeroit;
 338         }
 339         kunmap_atomic(kaddr, KM_IRQ0);
 340         local_irq_restore(flags);
 341         return 0;
 342
 343 zeroit:
 344         printk("btrfs csum failed ino %lu off %llu\n",
 345                page->mapping->host->i_ino, (unsigned long long)start);
 346         memset(kaddr + offset, 1, end - start + 1);
 347         flush_dcache_page(page);
 348         kunmap_atomic(kaddr, KM_IRQ0);
 349         local_irq_restore(flags);
 350         return 0;
 351 }
 352
 353 void btrfs_read_locked_inode(struct inode *inode)
 354 {
 355         struct btrfs_path *path;
 356         struct extent_buffer *leaf;
 357         struct btrfs_inode_item *inode_item;
 358         struct btrfs_inode_timespec *tspec;
 359         struct btrfs_root *root = BTRFS_I(inode)->root;
 360         struct btrfs_key location;
 361         u64 alloc_group_block;
 362         u32 rdev;
 363         int ret;
 364
 365         path = btrfs_alloc_path();
 366         BUG_ON(!path);
 367         mutex_lock(&root->fs_info->fs_mutex);
 368
 369         memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
 370         ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
 371         if (ret)
 372                 goto make_bad;
 373
 374         leaf = path->nodes[0];
 375         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 376                                     struct btrfs_inode_item);
 377
 378         inode->i_mode = btrfs_inode_mode(leaf, inode_item);
 379         inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
 380         inode->i_uid = btrfs_inode_uid(leaf, inode_item);
 381         inode->i_gid = btrfs_inode_gid(leaf, inode_item);
 382         inode->i_size = btrfs_inode_size(leaf, inode_item);
 383
 384         tspec = btrfs_inode_atime(inode_item);
 385         inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 386         inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 387
 388         tspec = btrfs_inode_mtime(inode_item);
 389         inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 390         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 391
 392         tspec = btrfs_inode_ctime(inode_item);
 393         inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 394         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 395
 396         inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
 397         inode->i_generation = btrfs_inode_generation(leaf, inode_item);
 398         inode->i_rdev = 0;
 399         rdev = btrfs_inode_rdev(leaf, inode_item);
 400
 401         alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
 402         BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
 403                                                        alloc_group_block);
 404
 405         btrfs_free_path(path);
 406         inode_item = NULL;
 407
 408         mutex_unlock(&root->fs_info->fs_mutex);
 409
 410         switch (inode->i_mode & S_IFMT) {
 411         case S_IFREG:
 412                 inode->i_mapping->a_ops = &btrfs_aops;
 413                 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
 414                 inode->i_fop = &btrfs_file_operations;
 415                 inode->i_op = &btrfs_file_inode_operations;
 416                 break;
 417         case S_IFDIR:
 418                 inode->i_fop = &btrfs_dir_file_operations;
 419                 if (root == root->fs_info->tree_root)
 420                         inode->i_op = &btrfs_dir_ro_inode_operations;
 421                 else
 422                         inode->i_op = &btrfs_dir_inode_operations;
 423                 break;
 424         case S_IFLNK:
 425                 inode->i_op = &btrfs_symlink_inode_operations;
 426                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
 427                 break;
 428         default:
 429                 init_special_inode(inode, inode->i_mode, rdev);
 430                 break;
 431         }
 432         return;
 433
 434 make_bad:
 435         btrfs_release_path(root, path);
 436         btrfs_free_path(path);
 437         mutex_unlock(&root->fs_info->fs_mutex);
 438         make_bad_inode(inode);
 439 }
 440
 441 static void fill_inode_item(struct extent_buffer *leaf,
 442                             struct btrfs_inode_item *item,
 443                             struct inode *inode)
 444 {
 445         btrfs_set_inode_uid(leaf, item, inode->i_uid);
 446         btrfs_set_inode_gid(leaf, item, inode->i_gid);
 447         btrfs_set_inode_size(leaf, item, inode->i_size);
 448         btrfs_set_inode_mode(leaf, item, inode->i_mode);
 449         btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
 450
 451         btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
 452                                inode->i_atime.tv_sec);
 453         btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
 454                                 inode->i_atime.tv_nsec);
 455
 456         btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
 457                                inode->i_mtime.tv_sec);
 458         btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
 459                                 inode->i_mtime.tv_nsec);
 460
 461         btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
 462                                inode->i_ctime.tv_sec);
 463         btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
 464                                 inode->i_ctime.tv_nsec);
 465
 466         btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
 467         btrfs_set_inode_generation(leaf, item, inode->i_generation);
 468         btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
 469         btrfs_set_inode_block_group(leaf, item,
 470                                     BTRFS_I(inode)->block_group->key.objectid);
 471 }
 472
 473 int btrfs_update_inode(struct btrfs_trans_handle *trans,
 474                               struct btrfs_root *root,
 475                               struct inode *inode)
 476 {
 477         struct btrfs_inode_item *inode_item;
 478         struct btrfs_path *path;
 479         struct extent_buffer *leaf;
 480         int ret;
 481
 482         path = btrfs_alloc_path();
 483         BUG_ON(!path);
 484         ret = btrfs_lookup_inode(trans, root, path,
 485                                  &BTRFS_I(inode)->location, 1);
 486         if (ret) {
 487                 if (ret > 0)
 488                         ret = -ENOENT;
 489                 goto failed;
 490         }
 491
 492         leaf = path->nodes[0];
 493         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 494                                   struct btrfs_inode_item);
 495
 496         fill_inode_item(leaf, inode_item, inode);
 497         btrfs_mark_buffer_dirty(leaf);
 498         btrfs_set_inode_last_trans(trans, inode);
 499         ret = 0;
 500 failed:
 501         btrfs_release_path(root, path);
 502         btrfs_free_path(path);
 503         return ret;
 504 }
 505
 506
 507 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
 508                               struct btrfs_root *root,
 509                               struct inode *dir,
 510                               struct dentry *dentry)
 511 {
 512         struct btrfs_path *path;
 513         const char *name = dentry->d_name.name;
 514         int name_len = dentry->d_name.len;
 515         int ret = 0;
 516         struct extent_buffer *leaf;
 517         struct btrfs_dir_item *di;
 518         struct btrfs_key key;
 519
 520         path = btrfs_alloc_path();
 521         if (!path) {
 522                 ret = -ENOMEM;
 523                 goto err;
 524         }
 525
 526         di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
 527                                     name, name_len, -1);
 528         if (IS_ERR(di)) {
 529                 ret = PTR_ERR(di);
 530                 goto err;
 531         }
 532         if (!di) {
 533                 ret = -ENOENT;
 534                 goto err;
 535         }
 536         leaf = path->nodes[0];
 537         btrfs_dir_item_key_to_cpu(leaf, di, &key);
 538         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 539         if (ret)
 540                 goto err;
 541         btrfs_release_path(root, path);
 542
 543         di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
 544                                          key.objectid, name, name_len, -1);
 545         if (IS_ERR(di)) {
 546                 ret = PTR_ERR(di);
 547                 goto err;
 548         }
 549         if (!di) {
 550                 ret = -ENOENT;
 551                 goto err;
 552         }
 553         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 554
 555         dentry->d_inode->i_ctime = dir->i_ctime;
 556         ret = btrfs_del_inode_ref(trans, root, name, name_len,
 557                                   dentry->d_inode->i_ino,
 558                                   dentry->d_parent->d_inode->i_ino);
 559         if (ret) {
 560                 printk("failed to delete reference to %.*s, "
 561                        "inode %lu parent %lu\n", name_len, name,
 562                        dentry->d_inode->i_ino,
 563                        dentry->d_parent->d_inode->i_ino);
 564         }
 565 err:
 566         btrfs_free_path(path);
 567         if (!ret) {
 568                 dir->i_size -= name_len * 2;
 569                 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 570                 btrfs_update_inode(trans, root, dir);
 571 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 572                 dentry->d_inode->i_nlink--;
 573 #else
 574                 drop_nlink(dentry->d_inode);
 575 #endif
 576                 ret = btrfs_update_inode(trans, root, dentry->d_inode);
 577                 dir->i_sb->s_dirt = 1;
 578         }
 579         return ret;
 580 }
 581
 582 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 583 {
 584         struct btrfs_root *root;
 585         struct btrfs_trans_handle *trans;
 586         int ret;
 587         unsigned long nr = 0;
 588
 589         root = BTRFS_I(dir)->root;
 590         mutex_lock(&root->fs_info->fs_mutex);
 591
 592         ret = btrfs_check_free_space(root, 1, 1);
 593         if (ret)
 594                 goto fail;
 595
 596         trans = btrfs_start_transaction(root, 1);
 597
 598         btrfs_set_trans_block_group(trans, dir);
 599         ret = btrfs_unlink_trans(trans, root, dir, dentry);
 600         nr = trans->blocks_used;
 601
 602         btrfs_end_transaction(trans, root);
 603 fail:
 604         mutex_unlock(&root->fs_info->fs_mutex);
 605         btrfs_btree_balance_dirty(root, nr);
 606         return ret;
 607 }
 608
 609 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 610 {
 611         struct inode *inode = dentry->d_inode;
 612         int err = 0;
 613         int ret;
 614         struct btrfs_root *root = BTRFS_I(dir)->root;
 615         struct btrfs_trans_handle *trans;
 616         unsigned long nr = 0;
 617
 618         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
 619                 return -ENOTEMPTY;
 620
 621         mutex_lock(&root->fs_info->fs_mutex);
 622         ret = btrfs_check_free_space(root, 1, 1);
 623         if (ret)
 624                 goto fail;
 625
 626         trans = btrfs_start_transaction(root, 1);
 627         btrfs_set_trans_block_group(trans, dir);
 628
 629         /* now the directory is empty */
 630         err = btrfs_unlink_trans(trans, root, dir, dentry);
 631         if (!err) {
 632                 inode->i_size = 0;
 633         }
 634
 635         nr = trans->blocks_used;
 636         ret = btrfs_end_transaction(trans, root);
 637 fail:
 638         mutex_unlock(&root->fs_info->fs_mutex);
 639         btrfs_btree_balance_dirty(root, nr);
 640
 641         if (ret && !err)
 642                 err = ret;
 643         return err;
 644 }
 645
 646 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
 647                             struct btrfs_root *root,
 648                             struct inode *inode)
 649 {
 650         struct btrfs_path *path;
 651         int ret;
 652
 653         clear_inode(inode);
 654
 655         path = btrfs_alloc_path();
 656         BUG_ON(!path);
 657         ret = btrfs_lookup_inode(trans, root, path,
 658                                  &BTRFS_I(inode)->location, -1);
 659         if (ret > 0)
 660                 ret = -ENOENT;
 661         if (!ret)
 662                 ret = btrfs_del_item(trans, root, path);
 663         btrfs_free_path(path);
 664         return ret;
 665 }
 666
 667 /*
 668  * this can truncate away extent items, csum items and directory items.
 669  * It starts at a high offset and removes keys until it can't find
 670  * any higher than i_size.
 671  *
 672  * csum items that cross the new i_size are truncated to the new size
 673  * as well.
 674  */
 675 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
 676                                    struct btrfs_root *root,
 677                                    struct inode *inode)
 678 {
 679         int ret;
 680         struct btrfs_path *path;
 681         struct btrfs_key key;
 682         struct btrfs_key found_key;
 683         u32 found_type;
 684         struct extent_buffer *leaf;
 685         struct btrfs_file_extent_item *fi;
 686         u64 extent_start = 0;
 687         u64 extent_num_bytes = 0;
 688         u64 item_end = 0;
 689         u64 root_gen = 0;
 690         u64 root_owner = 0;
 691         int found_extent;
 692         int del_item;
 693         int extent_type = -1;
 694
 695         btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
 696         path = btrfs_alloc_path();
 697         path->reada = -1;
 698         BUG_ON(!path);
 699
 700         /* FIXME, add redo link to tree so we don't leak on crash */
 701         key.objectid = inode->i_ino;
 702         key.offset = (u64)-1;
 703         key.type = (u8)-1;
 704
 705         while(1) {
 706                 btrfs_init_path(path);
 707                 fi = NULL;
 708                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 709                 if (ret < 0) {
 710                         goto error;
 711                 }
 712                 if (ret > 0) {
 713                         BUG_ON(path->slots[0] == 0);
 714                         path->slots[0]--;
 715                 }
 716                 leaf = path->nodes[0];
 717                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 718                 found_type = btrfs_key_type(&found_key);
 719
 720                 if (found_key.objectid != inode->i_ino)
 721                         break;
 722
 723                 if (found_type != BTRFS_CSUM_ITEM_KEY &&
 724                     found_type != BTRFS_DIR_ITEM_KEY &&
 725                     found_type != BTRFS_DIR_INDEX_KEY &&
 726                     found_type != BTRFS_EXTENT_DATA_KEY)
 727                         break;
 728
 729                 item_end = found_key.offset;
 730                 if (found_type == BTRFS_EXTENT_DATA_KEY) {
 731                         fi = btrfs_item_ptr(leaf, path->slots[0],
 732                                             struct btrfs_file_extent_item);
 733                         extent_type = btrfs_file_extent_type(leaf, fi);
 734                         if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 735                                 item_end +=
 736                                     btrfs_file_extent_num_bytes(leaf, fi);
 737                         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 738                                 struct btrfs_item *item = btrfs_item_nr(leaf,
 739                                                                 path->slots[0]);
 740                                 item_end += btrfs_file_extent_inline_len(leaf,
 741                                                                          item);
 742                         }
 743                         item_end--;
 744                 }
 745                 if (found_type == BTRFS_CSUM_ITEM_KEY) {
 746                         ret = btrfs_csum_truncate(trans, root, path,
 747                                                   inode->i_size);
 748                         BUG_ON(ret);
 749                 }
 750                 if (item_end < inode->i_size) {
 751                         if (found_type == BTRFS_DIR_ITEM_KEY) {
 752                                 found_type = BTRFS_INODE_ITEM_KEY;
 753                         } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
 754                                 found_type = BTRFS_CSUM_ITEM_KEY;
 755                         } else if (found_type) {
 756                                 found_type--;
 757                         } else {
 758                                 break;
 759                         }
 760                         btrfs_set_key_type(&key, found_type);
 761                         btrfs_release_path(root, path);
 762                         continue;
 763                 }
 764                 if (found_key.offset >= inode->i_size)
 765                         del_item = 1;
 766                 else
 767                         del_item = 0;
 768                 found_extent = 0;
 769
 770                 /* FIXME, shrink the extent if the ref count is only 1 */
 771                 if (found_type != BTRFS_EXTENT_DATA_KEY)
 772                         goto delete;
 773
 774                 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 775                         u64 num_dec;
 776                         extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
 777                         if (!del_item) {
 778                                 u64 orig_num_bytes =
 779                                         btrfs_file_extent_num_bytes(leaf, fi);
 780                                 extent_num_bytes = inode->i_size -
 781                                         found_key.offset + root->sectorsize - 1;
 782                                 btrfs_set_file_extent_num_bytes(leaf, fi,
 783                                                          extent_num_bytes);
 784                                 num_dec = (orig_num_bytes -
 785                                            extent_num_bytes) >> 9;
 786                                 if (extent_start != 0) {
 787                                         inode->i_blocks -= num_dec;
 788                                 }
 789                                 btrfs_mark_buffer_dirty(leaf);
 790                         } else {
 791                                 extent_num_bytes =
 792                                         btrfs_file_extent_disk_num_bytes(leaf,
 793                                                                          fi);
 794                                 /* FIXME blocksize != 4096 */
 795                                 num_dec = btrfs_file_extent_num_bytes(leaf,
 796                                                                        fi) >> 9;
 797                                 if (extent_start != 0) {
 798                                         found_extent = 1;
 799                                         inode->i_blocks -= num_dec;
 800                                 }
 801                                 root_gen = btrfs_header_generation(leaf);
 802                                 root_owner = btrfs_header_owner(leaf);
 803                         }
 804                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE &&
 805                            !del_item) {
 806                         u32 newsize = inode->i_size - found_key.offset;
 807                         newsize = btrfs_file_extent_calc_inline_size(newsize);
 808                         ret = btrfs_truncate_item(trans, root, path,
 809                                                   newsize, 1);
 810                         BUG_ON(ret);
 811                 }
 812 delete:
 813                 if (del_item) {
 814                         ret = btrfs_del_item(trans, root, path);
 815                         if (ret)
 816                                 goto error;
 817                 } else {
 818                         break;
 819                 }
 820                 btrfs_release_path(root, path);
 821                 if (found_extent) {
 822                         ret = btrfs_free_extent(trans, root, extent_start,
 823                                                 extent_num_bytes,
 824                                                 root_owner,
 825                                                 root_gen, inode->i_ino,
 826                                                 found_key.offset, 0);
 827                         BUG_ON(ret);
 828                 }
 829         }
 830         ret = 0;
 831 error:
 832         btrfs_release_path(root, path);
 833         btrfs_free_path(path);
 834         inode->i_sb->s_dirt = 1;
 835         return ret;
 836 }
 837
 838 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
 839                               size_t zero_start)
 840 {
 841         char *kaddr;
 842         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 843         struct btrfs_root *root = BTRFS_I(inode)->root;
 844         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 845         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
 846         u64 existing_delalloc;
 847         u64 delalloc_start;
 848         int ret = 0;
 849
 850         WARN_ON(!PageLocked(page));
 851         set_page_extent_mapped(page);
 852
 853         lock_extent(em_tree, page_start, page_end, GFP_NOFS);
 854         delalloc_start = page_start;
 855         existing_delalloc = count_range_bits(&BTRFS_I(inode)->extent_tree,
 856                                              &delalloc_start, page_end,
 857                                              PAGE_CACHE_SIZE, EXTENT_DELALLOC);
 858         set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
 859                             page_end, GFP_NOFS);
 860
 861         spin_lock(&root->fs_info->delalloc_lock);
 862         root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE - existing_delalloc;
 863         spin_unlock(&root->fs_info->delalloc_lock);
 864
 865         if (zero_start != PAGE_CACHE_SIZE) {
 866                 kaddr = kmap(page);
 867                 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
 868                 flush_dcache_page(page);
 869                 kunmap(page);
 870         }
 871         set_page_dirty(page);
 872         unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
 873
 874         return ret;
 875 }
 876
 877 /*
 878  * taken from block_truncate_page, but does cow as it zeros out
 879  * any bytes left in the last page in the file.
 880  */
 881 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
 882 {
 883         struct inode *inode = mapping->host;
 884         struct btrfs_root *root = BTRFS_I(inode)->root;
 885         u32 blocksize = root->sectorsize;
 886         pgoff_t index = from >> PAGE_CACHE_SHIFT;
 887         unsigned offset = from & (PAGE_CACHE_SIZE-1);
 888         struct page *page;
 889         int ret = 0;
 890         u64 page_start;
 891
 892         if ((offset & (blocksize - 1)) == 0)
 893                 goto out;
 894
 895         down_read(&root->snap_sem);
 896         ret = -ENOMEM;
 897         page = grab_cache_page(mapping, index);
 898         if (!page)
 899                 goto out;
 900         if (!PageUptodate(page)) {
 901                 ret = btrfs_readpage(NULL, page);
 902                 lock_page(page);
 903                 if (!PageUptodate(page)) {
 904                         ret = -EIO;
 905                         goto out;
 906                 }
 907         }
 908         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 909
 910         ret = btrfs_cow_one_page(inode, page, offset);
 911
 912         unlock_page(page);
 913         page_cache_release(page);
 914         up_read(&BTRFS_I(inode)->root->snap_sem);
 915 out:
 916         return ret;
 917 }
 918
 919 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
 920 {
 921         struct inode *inode = dentry->d_inode;
 922         int err;
 923
 924         err = inode_change_ok(inode, attr);
 925         if (err)
 926                 return err;
 927
 928         if (S_ISREG(inode->i_mode) &&
 929             attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
 930                 struct btrfs_trans_handle *trans;
 931                 struct btrfs_root *root = BTRFS_I(inode)->root;
 932                 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 933
 934                 u64 mask = root->sectorsize - 1;
 935                 u64 pos = (inode->i_size + mask) & ~mask;
 936                 u64 block_end = attr->ia_size | mask;
 937                 u64 hole_size;
 938                 u64 alloc_hint = 0;
 939
 940                 if (attr->ia_size <= pos)
 941                         goto out;
 942
 943                 mutex_lock(&root->fs_info->fs_mutex);
 944                 err = btrfs_check_free_space(root, 1, 0);
 945                 mutex_unlock(&root->fs_info->fs_mutex);
 946                 if (err)
 947                         goto fail;
 948
 949                 btrfs_truncate_page(inode->i_mapping, inode->i_size);
 950
 951                 lock_extent(em_tree, pos, block_end, GFP_NOFS);
 952                 hole_size = (attr->ia_size - pos + mask) & ~mask;
 953
 954                 mutex_lock(&root->fs_info->fs_mutex);
 955                 trans = btrfs_start_transaction(root, 1);
 956                 btrfs_set_trans_block_group(trans, inode);
 957                 err = btrfs_drop_extents(trans, root, inode,
 958                                          pos, pos + hole_size, pos,
 959                                          &alloc_hint);
 960
 961                 if (alloc_hint != EXTENT_MAP_INLINE) {
 962                         err = btrfs_insert_file_extent(trans, root,
 963                                                        inode->i_ino,
 964                                                        pos, 0, 0, hole_size);
 965                 }
 966                 btrfs_end_transaction(trans, root);
 967                 mutex_unlock(&root->fs_info->fs_mutex);
 968                 unlock_extent(em_tree, pos, block_end, GFP_NOFS);
 969                 if (err)
 970                         return err;
 971         }
 972 out:
 973         err = inode_setattr(inode, attr);
 974 fail:
 975         return err;
 976 }
 977 void btrfs_delete_inode(struct inode *inode)
 978 {
 979         struct btrfs_trans_handle *trans;
 980         struct btrfs_root *root = BTRFS_I(inode)->root;
 981         unsigned long nr;
 982         int ret;
 983
 984         truncate_inode_pages(&inode->i_data, 0);
 985         if (is_bad_inode(inode)) {
 986                 goto no_delete;
 987         }
 988
 989         inode->i_size = 0;
 990         mutex_lock(&root->fs_info->fs_mutex);
 991         trans = btrfs_start_transaction(root, 1);
 992
 993         btrfs_set_trans_block_group(trans, inode);
 994         ret = btrfs_truncate_in_trans(trans, root, inode);
 995         if (ret)
 996                 goto no_delete_lock;
 997         ret = btrfs_delete_xattrs(trans, root, inode);
 998         if (ret)
 999                 goto no_delete_lock;
1000         ret = btrfs_free_inode(trans, root, inode);
1001         if (ret)
1002                 goto no_delete_lock;
1003         nr = trans->blocks_used;
1004
1005         btrfs_end_transaction(trans, root);
1006         mutex_unlock(&root->fs_info->fs_mutex);
1007         btrfs_btree_balance_dirty(root, nr);
1008         return;
1009
1010 no_delete_lock:
1011         nr = trans->blocks_used;
1012         btrfs_end_transaction(trans, root);
1013         mutex_unlock(&root->fs_info->fs_mutex);
1014         btrfs_btree_balance_dirty(root, nr);
1015 no_delete:
1016         clear_inode(inode);
1017 }
1018
1019 /*
1020  * this returns the key found in the dir entry in the location pointer.
1021  * If no dir entries were found, location->objectid is 0.
1022  */
1023 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1024                                struct btrfs_key *location)
1025 {
1026         const char *name = dentry->d_name.name;
1027         int namelen = dentry->d_name.len;
1028         struct btrfs_dir_item *di;
1029         struct btrfs_path *path;
1030         struct btrfs_root *root = BTRFS_I(dir)->root;
1031         int ret = 0;
1032
1033         if (namelen == 1 && strcmp(name, ".") == 0) {
1034                 location->objectid = dir->i_ino;
1035                 location->type = BTRFS_INODE_ITEM_KEY;
1036                 location->offset = 0;
1037                 return 0;
1038         }
1039         path = btrfs_alloc_path();
1040         BUG_ON(!path);
1041
1042         if (namelen == 2 && strcmp(name, "..") == 0) {
1043                 struct btrfs_key key;
1044                 struct extent_buffer *leaf;
1045                 u32 nritems;
1046                 int slot;
1047
1048                 key.objectid = dir->i_ino;
1049                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1050                 key.offset = 0;
1051                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1052                 BUG_ON(ret == 0);
1053                 ret = 0;
1054
1055                 leaf = path->nodes[0];
1056                 slot = path->slots[0];
1057                 nritems = btrfs_header_nritems(leaf);
1058                 if (slot >= nritems)
1059                         goto out_err;
1060
1061                 btrfs_item_key_to_cpu(leaf, &key, slot);
1062                 if (key.objectid != dir->i_ino ||
1063                     key.type != BTRFS_INODE_REF_KEY) {
1064                         goto out_err;
1065                 }
1066                 location->objectid = key.offset;
1067                 location->type = BTRFS_INODE_ITEM_KEY;
1068                 location->offset = 0;
1069                 goto out;
1070         }
1071
1072         di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1073                                     namelen, 0);
1074         if (IS_ERR(di))
1075                 ret = PTR_ERR(di);
1076         if (!di || IS_ERR(di)) {
1077                 goto out_err;
1078         }
1079         btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1080 out:
1081         btrfs_free_path(path);
1082         return ret;
1083 out_err:
1084         location->objectid = 0;
1085         goto out;
1086 }
1087
1088 /*
1089  * when we hit a tree root in a directory, the btrfs part of the inode
1090  * needs to be changed to reflect the root directory of the tree root.  This
1091  * is kind of like crossing a mount point.
1092  */
1093 static int fixup_tree_root_location(struct btrfs_root *root,
1094                              struct btrfs_key *location,
1095                              struct btrfs_root **sub_root,
1096                              struct dentry *dentry)
1097 {
1098         struct btrfs_path *path;
1099         struct btrfs_root_item *ri;
1100
1101         if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1102                 return 0;
1103         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1104                 return 0;
1105
1106         path = btrfs_alloc_path();
1107         BUG_ON(!path);
1108         mutex_lock(&root->fs_info->fs_mutex);
1109
1110         *sub_root = btrfs_read_fs_root(root->fs_info, location,
1111                                         dentry->d_name.name,
1112                                         dentry->d_name.len);
1113         if (IS_ERR(*sub_root))
1114                 return PTR_ERR(*sub_root);
1115
1116         ri = &(*sub_root)->root_item;
1117         location->objectid = btrfs_root_dirid(ri);
1118         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1119         location->offset = 0;
1120
1121         btrfs_free_path(path);
1122         mutex_unlock(&root->fs_info->fs_mutex);
1123         return 0;
1124 }
1125
1126 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1127 {
1128         struct btrfs_iget_args *args = p;
1129         inode->i_ino = args->ino;
1130         BTRFS_I(inode)->root = args->root;
1131         extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1132                              inode->i_mapping, GFP_NOFS);
1133         return 0;
1134 }
1135
1136 static int btrfs_find_actor(struct inode *inode, void *opaque)
1137 {
1138         struct btrfs_iget_args *args = opaque;
1139         return (args->ino == inode->i_ino &&
1140                 args->root == BTRFS_I(inode)->root);
1141 }
1142
1143 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1144                                 struct btrfs_root *root)
1145 {
1146         struct inode *inode;
1147         struct btrfs_iget_args args;
1148         args.ino = objectid;
1149         args.root = root;
1150
1151         inode = iget5_locked(s, objectid, btrfs_find_actor,
1152                              btrfs_init_locked_inode,
1153                              (void *)&args);
1154         return inode;
1155 }
1156
1157 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1158                                    struct nameidata *nd)
1159 {
1160         struct inode * inode;
1161         struct btrfs_inode *bi = BTRFS_I(dir);
1162         struct btrfs_root *root = bi->root;
1163         struct btrfs_root *sub_root = root;
1164         struct btrfs_key location;
1165         int ret;
1166
1167         if (dentry->d_name.len > BTRFS_NAME_LEN)
1168                 return ERR_PTR(-ENAMETOOLONG);
1169
1170         mutex_lock(&root->fs_info->fs_mutex);
1171         ret = btrfs_inode_by_name(dir, dentry, &location);
1172         mutex_unlock(&root->fs_info->fs_mutex);
1173
1174         if (ret < 0)
1175                 return ERR_PTR(ret);
1176
1177         inode = NULL;
1178         if (location.objectid) {
1179                 ret = fixup_tree_root_location(root, &location, &sub_root,
1180                                                 dentry);
1181                 if (ret < 0)
1182                         return ERR_PTR(ret);
1183                 if (ret > 0)
1184                         return ERR_PTR(-ENOENT);
1185                 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1186                                           sub_root);
1187                 if (!inode)
1188                         return ERR_PTR(-EACCES);
1189                 if (inode->i_state & I_NEW) {
1190                         /* the inode and parent dir are two different roots */
1191                         if (sub_root != root) {
1192                                 igrab(inode);
1193                                 sub_root->inode = inode;
1194                         }
1195                         BTRFS_I(inode)->root = sub_root;
1196                         memcpy(&BTRFS_I(inode)->location, &location,
1197                                sizeof(location));
1198                         btrfs_read_locked_inode(inode);
1199                         unlock_new_inode(inode);
1200                 }
1201         }
1202         return d_splice_alias(inode, dentry);
1203 }
1204
1205 static unsigned char btrfs_filetype_table[] = {
1206         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1207 };
1208
1209 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1210 {
1211         struct inode *inode = filp->f_dentry->d_inode;
1212         struct btrfs_root *root = BTRFS_I(inode)->root;
1213         struct btrfs_item *item;
1214         struct btrfs_dir_item *di;
1215         struct btrfs_key key;
1216         struct btrfs_key found_key;
1217         struct btrfs_path *path;
1218         int ret;
1219         u32 nritems;
1220         struct extent_buffer *leaf;
1221         int slot;
1222         int advance;
1223         unsigned char d_type;
1224         int over = 0;
1225         u32 di_cur;
1226         u32 di_total;
1227         u32 di_len;
1228         int key_type = BTRFS_DIR_INDEX_KEY;
1229         char tmp_name[32];
1230         char *name_ptr;
1231         int name_len;
1232
1233         /* FIXME, use a real flag for deciding about the key type */
1234         if (root->fs_info->tree_root == root)
1235                 key_type = BTRFS_DIR_ITEM_KEY;
1236
1237         /* special case for "." */
1238         if (filp->f_pos == 0) {
1239                 over = filldir(dirent, ".", 1,
1240                                1, inode->i_ino,
1241                                DT_DIR);
1242                 if (over)
1243                         return 0;
1244                 filp->f_pos = 1;
1245         }
1246
1247         mutex_lock(&root->fs_info->fs_mutex);
1248         key.objectid = inode->i_ino;
1249         path = btrfs_alloc_path();
1250         path->reada = 2;
1251
1252         /* special case for .., just use the back ref */
1253         if (filp->f_pos == 1) {
1254                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1255                 key.offset = 0;
1256                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1257                 BUG_ON(ret == 0);
1258                 leaf = path->nodes[0];
1259                 slot = path->slots[0];
1260                 nritems = btrfs_header_nritems(leaf);
1261                 if (slot >= nritems) {
1262                         btrfs_release_path(root, path);
1263                         goto read_dir_items;
1264                 }
1265                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1266                 btrfs_release_path(root, path);
1267                 if (found_key.objectid != key.objectid ||
1268                     found_key.type != BTRFS_INODE_REF_KEY)
1269                         goto read_dir_items;
1270                 over = filldir(dirent, "..", 2,
1271                                2, found_key.offset, DT_DIR);
1272                 if (over)
1273                         goto nopos;
1274                 filp->f_pos = 2;
1275         }
1276
1277 read_dir_items:
1278         btrfs_set_key_type(&key, key_type);
1279         key.offset = filp->f_pos;
1280
1281         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1282         if (ret < 0)
1283                 goto err;
1284         advance = 0;
1285         while(1) {
1286                 leaf = path->nodes[0];
1287                 nritems = btrfs_header_nritems(leaf);
1288                 slot = path->slots[0];
1289                 if (advance || slot >= nritems) {
1290                         if (slot >= nritems -1) {
1291                                 ret = btrfs_next_leaf(root, path);
1292                                 if (ret)
1293                                         break;
1294                                 leaf = path->nodes[0];
1295                                 nritems = btrfs_header_nritems(leaf);
1296                                 slot = path->slots[0];
1297                         } else {
1298                                 slot++;
1299                                 path->slots[0]++;
1300                         }
1301                 }
1302                 advance = 1;
1303                 item = btrfs_item_nr(leaf, slot);
1304                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1305
1306                 if (found_key.objectid != key.objectid)
1307                         break;
1308                 if (btrfs_key_type(&found_key) != key_type)
1309                         break;
1310                 if (found_key.offset < filp->f_pos)
1311                         continue;
1312
1313                 filp->f_pos = found_key.offset;
1314                 advance = 1;
1315                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1316                 di_cur = 0;
1317                 di_total = btrfs_item_size(leaf, item);
1318                 while(di_cur < di_total) {
1319                         struct btrfs_key location;
1320
1321                         name_len = btrfs_dir_name_len(leaf, di);
1322                         if (name_len < 32) {
1323                                 name_ptr = tmp_name;
1324                         } else {
1325                                 name_ptr = kmalloc(name_len, GFP_NOFS);
1326                                 BUG_ON(!name_ptr);
1327                         }
1328                         read_extent_buffer(leaf, name_ptr,
1329                                            (unsigned long)(di + 1), name_len);
1330
1331                         d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1332                         btrfs_dir_item_key_to_cpu(leaf, di, &location);
1333
1334                         over = filldir(dirent, name_ptr, name_len,
1335                                        found_key.offset,
1336                                        location.objectid,
1337                                        d_type);
1338
1339                         if (name_ptr != tmp_name)
1340                                 kfree(name_ptr);
1341
1342                         if (over)
1343                                 goto nopos;
1344                         di_len = btrfs_dir_name_len(leaf, di) +
1345                                 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1346                         di_cur += di_len;
1347                         di = (struct btrfs_dir_item *)((char *)di + di_len);
1348                 }
1349         }
1350         filp->f_pos++;
1351 nopos:
1352         ret = 0;
1353 err:
1354         btrfs_release_path(root, path);
1355         btrfs_free_path(path);
1356         mutex_unlock(&root->fs_info->fs_mutex);
1357         return ret;
1358 }
1359
1360 int btrfs_write_inode(struct inode *inode, int wait)
1361 {
1362         struct btrfs_root *root = BTRFS_I(inode)->root;
1363         struct btrfs_trans_handle *trans;
1364         int ret = 0;
1365
1366         if (wait) {
1367                 mutex_lock(&root->fs_info->fs_mutex);
1368                 trans = btrfs_start_transaction(root, 1);
1369                 btrfs_set_trans_block_group(trans, inode);
1370                 ret = btrfs_commit_transaction(trans, root);
1371                 mutex_unlock(&root->fs_info->fs_mutex);
1372         }
1373         return ret;
1374 }
1375
1376 /*
1377  * This is somewhat expensive, updating the tree every time the
1378  * inode changes.  But, it is most likely to find the inode in cache.
1379  * FIXME, needs more benchmarking...there are no reasons other than performance
1380  * to keep or drop this code.
1381  */
1382 void btrfs_dirty_inode(struct inode *inode)
1383 {
1384         struct btrfs_root *root = BTRFS_I(inode)->root;
1385         struct btrfs_trans_handle *trans;
1386
1387         mutex_lock(&root->fs_info->fs_mutex);
1388         trans = btrfs_start_transaction(root, 1);
1389         btrfs_set_trans_block_group(trans, inode);
1390         btrfs_update_inode(trans, root, inode);
1391         btrfs_end_transaction(trans, root);
1392         mutex_unlock(&root->fs_info->fs_mutex);
1393 }
1394
1395 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1396                                      struct btrfs_root *root,
1397                                      u64 objectid,
1398                                      struct btrfs_block_group_cache *group,
1399                                      int mode)
1400 {
1401         struct inode *inode;
1402         struct btrfs_inode_item *inode_item;
1403         struct btrfs_key *location;
1404         struct btrfs_path *path;
1405         int ret;
1406         int owner;
1407
1408         path = btrfs_alloc_path();
1409         BUG_ON(!path);
1410
1411         inode = new_inode(root->fs_info->sb);
1412         if (!inode)
1413                 return ERR_PTR(-ENOMEM);
1414
1415         extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1416                              inode->i_mapping, GFP_NOFS);
1417         BTRFS_I(inode)->root = root;
1418
1419         if (mode & S_IFDIR)
1420                 owner = 0;
1421         else
1422                 owner = 1;
1423         group = btrfs_find_block_group(root, group, 0, 0, owner);
1424         BTRFS_I(inode)->block_group = group;
1425
1426         ret = btrfs_insert_empty_inode(trans, root, path, objectid);
1427         if (ret)
1428                 goto fail;
1429
1430         inode->i_uid = current->fsuid;
1431         inode->i_gid = current->fsgid;
1432         inode->i_mode = mode;
1433         inode->i_ino = objectid;
1434         inode->i_blocks = 0;
1435         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1436         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1437                                   struct btrfs_inode_item);
1438         fill_inode_item(path->nodes[0], inode_item, inode);
1439         btrfs_mark_buffer_dirty(path->nodes[0]);
1440         btrfs_free_path(path);
1441
1442         location = &BTRFS_I(inode)->location;
1443         location->objectid = objectid;
1444         location->offset = 0;
1445         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1446
1447         insert_inode_hash(inode);
1448         return inode;
1449 fail:
1450         btrfs_free_path(path);
1451         return ERR_PTR(ret);
1452 }
1453
1454 static inline u8 btrfs_inode_type(struct inode *inode)
1455 {
1456         return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1457 }
1458
1459 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1460                             struct dentry *dentry, struct inode *inode)
1461 {
1462         int ret;
1463         struct btrfs_key key;
1464         struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1465         struct inode *parent_inode;
1466
1467         key.objectid = inode->i_ino;
1468         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1469         key.offset = 0;
1470
1471         ret = btrfs_insert_dir_item(trans, root,
1472                                     dentry->d_name.name, dentry->d_name.len,
1473                                     dentry->d_parent->d_inode->i_ino,
1474                                     &key, btrfs_inode_type(inode));
1475         if (ret == 0) {
1476                 ret = btrfs_insert_inode_ref(trans, root,
1477                                      dentry->d_name.name,
1478                                      dentry->d_name.len,
1479                                      inode->i_ino,
1480                                      dentry->d_parent->d_inode->i_ino);
1481                 parent_inode = dentry->d_parent->d_inode;
1482                 parent_inode->i_size += dentry->d_name.len * 2;
1483                 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1484                 ret = btrfs_update_inode(trans, root,
1485                                          dentry->d_parent->d_inode);
1486         }
1487         return ret;
1488 }
1489
1490 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1491                             struct dentry *dentry, struct inode *inode)
1492 {
1493         int err = btrfs_add_link(trans, dentry, inode);
1494         if (!err) {
1495                 d_instantiate(dentry, inode);
1496                 return 0;
1497         }
1498         if (err > 0)
1499                 err = -EEXIST;
1500         return err;
1501 }
1502
1503 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1504                         int mode, dev_t rdev)
1505 {
1506         struct btrfs_trans_handle *trans;
1507         struct btrfs_root *root = BTRFS_I(dir)->root;
1508         struct inode *inode = NULL;
1509         int err;
1510         int drop_inode = 0;
1511         u64 objectid;
1512         unsigned long nr = 0;
1513
1514         if (!new_valid_dev(rdev))
1515                 return -EINVAL;
1516
1517         mutex_lock(&root->fs_info->fs_mutex);
1518         err = btrfs_check_free_space(root, 1, 0);
1519         if (err)
1520                 goto fail;
1521
1522         trans = btrfs_start_transaction(root, 1);
1523         btrfs_set_trans_block_group(trans, dir);
1524
1525         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1526         if (err) {
1527                 err = -ENOSPC;
1528                 goto out_unlock;
1529         }
1530
1531         inode = btrfs_new_inode(trans, root, objectid,
1532                                 BTRFS_I(dir)->block_group, mode);
1533         err = PTR_ERR(inode);
1534         if (IS_ERR(inode))
1535                 goto out_unlock;
1536
1537         btrfs_set_trans_block_group(trans, inode);
1538         err = btrfs_add_nondir(trans, dentry, inode);
1539         if (err)
1540                 drop_inode = 1;
1541         else {
1542                 inode->i_op = &btrfs_special_inode_operations;
1543                 init_special_inode(inode, inode->i_mode, rdev);
1544                 btrfs_update_inode(trans, root, inode);
1545         }
1546         dir->i_sb->s_dirt = 1;
1547         btrfs_update_inode_block_group(trans, inode);
1548         btrfs_update_inode_block_group(trans, dir);
1549 out_unlock:
1550         nr = trans->blocks_used;
1551         btrfs_end_transaction(trans, root);
1552 fail:
1553         mutex_unlock(&root->fs_info->fs_mutex);
1554
1555         if (drop_inode) {
1556                 inode_dec_link_count(inode);
1557                 iput(inode);
1558         }
1559         btrfs_btree_balance_dirty(root, nr);
1560         return err;
1561 }
1562
1563 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1564                         int mode, struct nameidata *nd)
1565 {
1566         struct btrfs_trans_handle *trans;
1567         struct btrfs_root *root = BTRFS_I(dir)->root;
1568         struct inode *inode = NULL;
1569         int err;
1570         int drop_inode = 0;
1571         unsigned long nr = 0;
1572         u64 objectid;
1573
1574         mutex_lock(&root->fs_info->fs_mutex);
1575         err = btrfs_check_free_space(root, 1, 0);
1576         if (err)
1577                 goto fail;
1578         trans = btrfs_start_transaction(root, 1);
1579         btrfs_set_trans_block_group(trans, dir);
1580
1581         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1582         if (err) {
1583                 err = -ENOSPC;
1584                 goto out_unlock;
1585         }
1586
1587         inode = btrfs_new_inode(trans, root, objectid,
1588                                 BTRFS_I(dir)->block_group, mode);
1589         err = PTR_ERR(inode);
1590         if (IS_ERR(inode))
1591                 goto out_unlock;
1592
1593         btrfs_set_trans_block_group(trans, inode);
1594         err = btrfs_add_nondir(trans, dentry, inode);
1595         if (err)
1596                 drop_inode = 1;
1597         else {
1598                 inode->i_mapping->a_ops = &btrfs_aops;
1599                 inode->i_fop = &btrfs_file_operations;
1600                 inode->i_op = &btrfs_file_inode_operations;
1601                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
1602                                      inode->i_mapping, GFP_NOFS);
1603                 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
1604         }
1605         dir->i_sb->s_dirt = 1;
1606         btrfs_update_inode_block_group(trans, inode);
1607         btrfs_update_inode_block_group(trans, dir);
1608 out_unlock:
1609         nr = trans->blocks_used;
1610         btrfs_end_transaction(trans, root);
1611 fail:
1612         mutex_unlock(&root->fs_info->fs_mutex);
1613
1614         if (drop_inode) {
1615                 inode_dec_link_count(inode);
1616                 iput(inode);
1617         }
1618         btrfs_btree_balance_dirty(root, nr);
1619         return err;
1620 }
1621
1622 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1623                       struct dentry *dentry)
1624 {
1625         struct btrfs_trans_handle *trans;
1626         struct btrfs_root *root = BTRFS_I(dir)->root;
1627         struct inode *inode = old_dentry->d_inode;
1628         unsigned long nr = 0;
1629         int err;
1630         int drop_inode = 0;
1631
1632         if (inode->i_nlink == 0)
1633                 return -ENOENT;
1634
1635 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1636         inode->i_nlink++;
1637 #else
1638         inc_nlink(inode);
1639 #endif
1640         mutex_lock(&root->fs_info->fs_mutex);
1641         err = btrfs_check_free_space(root, 1, 0);
1642         if (err)
1643                 goto fail;
1644         trans = btrfs_start_transaction(root, 1);
1645
1646         btrfs_set_trans_block_group(trans, dir);
1647         atomic_inc(&inode->i_count);
1648         err = btrfs_add_nondir(trans, dentry, inode);
1649
1650         if (err)
1651                 drop_inode = 1;
1652
1653         dir->i_sb->s_dirt = 1;
1654         btrfs_update_inode_block_group(trans, dir);
1655         err = btrfs_update_inode(trans, root, inode);
1656
1657         if (err)
1658                 drop_inode = 1;
1659
1660         nr = trans->blocks_used;
1661         btrfs_end_transaction(trans, root);
1662 fail:
1663         mutex_unlock(&root->fs_info->fs_mutex);
1664
1665         if (drop_inode) {
1666                 inode_dec_link_count(inode);
1667                 iput(inode);
1668         }
1669         btrfs_btree_balance_dirty(root, nr);
1670         return err;
1671 }
1672
1673 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1674 {
1675         struct inode *inode;
1676         struct btrfs_trans_handle *trans;
1677         struct btrfs_root *root = BTRFS_I(dir)->root;
1678         int err = 0;
1679         int drop_on_err = 0;
1680         u64 objectid;
1681         unsigned long nr = 1;
1682
1683         mutex_lock(&root->fs_info->fs_mutex);
1684         err = btrfs_check_free_space(root, 1, 0);
1685         if (err)
1686                 goto out_unlock;
1687
1688         trans = btrfs_start_transaction(root, 1);
1689         btrfs_set_trans_block_group(trans, dir);
1690
1691         if (IS_ERR(trans)) {
1692                 err = PTR_ERR(trans);
1693                 goto out_unlock;
1694         }
1695
1696         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1697         if (err) {
1698                 err = -ENOSPC;
1699                 goto out_unlock;
1700         }
1701
1702         inode = btrfs_new_inode(trans, root, objectid,
1703                                 BTRFS_I(dir)->block_group, S_IFDIR | mode);
1704         if (IS_ERR(inode)) {
1705                 err = PTR_ERR(inode);
1706                 goto out_fail;
1707         }
1708
1709         drop_on_err = 1;
1710         inode->i_op = &btrfs_dir_inode_operations;
1711         inode->i_fop = &btrfs_dir_file_operations;
1712         btrfs_set_trans_block_group(trans, inode);
1713
1714         inode->i_size = 0;
1715         err = btrfs_update_inode(trans, root, inode);
1716         if (err)
1717                 goto out_fail;
1718
1719         err = btrfs_add_link(trans, dentry, inode);
1720         if (err)
1721                 goto out_fail;
1722
1723         d_instantiate(dentry, inode);
1724         drop_on_err = 0;
1725         dir->i_sb->s_dirt = 1;
1726         btrfs_update_inode_block_group(trans, inode);
1727         btrfs_update_inode_block_group(trans, dir);
1728
1729 out_fail:
1730         nr = trans->blocks_used;
1731         btrfs_end_transaction(trans, root);
1732
1733 out_unlock:
1734         mutex_unlock(&root->fs_info->fs_mutex);
1735         if (drop_on_err)
1736                 iput(inode);
1737         btrfs_btree_balance_dirty(root, nr);
1738         return err;
1739 }
1740
1741 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
1742                                     size_t page_offset, u64 start, u64 end,
1743                                     int create)
1744 {
1745         int ret;
1746         int err = 0;
1747         u64 bytenr;
1748         u64 extent_start = 0;
1749         u64 extent_end = 0;
1750         u64 objectid = inode->i_ino;
1751         u32 found_type;
1752         int failed_insert = 0;
1753         struct btrfs_path *path;
1754         struct btrfs_root *root = BTRFS_I(inode)->root;
1755         struct btrfs_file_extent_item *item;
1756         struct extent_buffer *leaf;
1757         struct btrfs_key found_key;
1758         struct extent_map *em = NULL;
1759         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1760         struct btrfs_trans_handle *trans = NULL;
1761
1762         path = btrfs_alloc_path();
1763         BUG_ON(!path);
1764         mutex_lock(&root->fs_info->fs_mutex);
1765
1766 again:
1767         em = lookup_extent_mapping(em_tree, start, end);
1768         if (em) {
1769                 goto out;
1770         }
1771         if (!em) {
1772                 em = alloc_extent_map(GFP_NOFS);
1773                 if (!em) {
1774                         err = -ENOMEM;
1775                         goto out;
1776                 }
1777                 em->start = EXTENT_MAP_HOLE;
1778                 em->end = EXTENT_MAP_HOLE;
1779         }
1780         em->bdev = inode->i_sb->s_bdev;
1781         ret = btrfs_lookup_file_extent(trans, root, path,
1782                                        objectid, start, trans != NULL);
1783         if (ret < 0) {
1784                 err = ret;
1785                 goto out;
1786         }
1787
1788         if (ret != 0) {
1789                 if (path->slots[0] == 0)
1790                         goto not_found;
1791                 path->slots[0]--;
1792         }
1793
1794         leaf = path->nodes[0];
1795         item = btrfs_item_ptr(leaf, path->slots[0],
1796                               struct btrfs_file_extent_item);
1797         /* are we inside the extent that was found? */
1798         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1799         found_type = btrfs_key_type(&found_key);
1800         if (found_key.objectid != objectid ||
1801             found_type != BTRFS_EXTENT_DATA_KEY) {
1802                 goto not_found;
1803         }
1804
1805         found_type = btrfs_file_extent_type(leaf, item);
1806         extent_start = found_key.offset;
1807         if (found_type == BTRFS_FILE_EXTENT_REG) {
1808                 extent_end = extent_start +
1809                        btrfs_file_extent_num_bytes(leaf, item);
1810                 err = 0;
1811                 if (start < extent_start || start >= extent_end) {
1812                         em->start = start;
1813                         if (start < extent_start) {
1814                                 if (end < extent_start)
1815                                         goto not_found;
1816                                 em->end = extent_end - 1;
1817                         } else {
1818                                 em->end = end;
1819                         }
1820                         goto not_found_em;
1821                 }
1822                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
1823                 if (bytenr == 0) {
1824                         em->start = extent_start;
1825                         em->end = extent_end - 1;
1826                         em->block_start = EXTENT_MAP_HOLE;
1827                         em->block_end = EXTENT_MAP_HOLE;
1828                         goto insert;
1829                 }
1830                 bytenr += btrfs_file_extent_offset(leaf, item);
1831                 em->block_start = bytenr;
1832                 em->block_end = em->block_start +
1833                         btrfs_file_extent_num_bytes(leaf, item) - 1;
1834                 em->start = extent_start;
1835                 em->end = extent_end - 1;
1836                 goto insert;
1837         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
1838                 unsigned long ptr;
1839                 char *map;
1840                 size_t size;
1841                 size_t extent_offset;
1842                 size_t copy_size;
1843
1844                 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
1845                                                     path->slots[0]));
1846                 extent_end = (extent_start + size - 1) |
1847                         ((u64)root->sectorsize - 1);
1848                 if (start < extent_start || start >= extent_end) {
1849                         em->start = start;
1850                         if (start < extent_start) {
1851                                 if (end < extent_start)
1852                                         goto not_found;
1853                                 em->end = extent_end;
1854                         } else {
1855                                 em->end = end;
1856                         }
1857                         goto not_found_em;
1858                 }
1859                 em->block_start = EXTENT_MAP_INLINE;
1860                 em->block_end = EXTENT_MAP_INLINE;
1861
1862                 if (!page) {
1863                         em->start = extent_start;
1864                         em->end = extent_start + size - 1;
1865                         goto out;
1866                 }
1867
1868                 extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
1869                         extent_start + page_offset;
1870                 copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
1871                                 size - extent_offset);
1872                 em->start = extent_start + extent_offset;
1873                 em->end = (em->start + copy_size -1) |
1874                         ((u64)root->sectorsize -1);
1875                 map = kmap(page);
1876                 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
1877                 if (create == 0 && !PageUptodate(page)) {
1878                         read_extent_buffer(leaf, map + page_offset, ptr,
1879                                            copy_size);
1880                         flush_dcache_page(page);
1881                 } else if (create && PageUptodate(page)) {
1882                         if (!trans) {
1883                                 kunmap(page);
1884                                 free_extent_map(em);
1885                                 em = NULL;
1886                                 btrfs_release_path(root, path);
1887                                 trans = btrfs_start_transaction(root, 1);
1888                                 goto again;
1889                         }
1890                         write_extent_buffer(leaf, map + page_offset, ptr,
1891                                             copy_size);
1892                         btrfs_mark_buffer_dirty(leaf);
1893                 }
1894                 kunmap(page);
1895                 set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
1896                 goto insert;
1897         } else {
1898                 printk("unkknown found_type %d\n", found_type);
1899                 WARN_ON(1);
1900         }
1901 not_found:
1902         em->start = start;
1903         em->end = end;
1904 not_found_em:
1905         em->block_start = EXTENT_MAP_HOLE;
1906         em->block_end = EXTENT_MAP_HOLE;
1907 insert:
1908         btrfs_release_path(root, path);
1909         if (em->start > start || em->end < start) {
1910                 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
1911                 err = -EIO;
1912                 goto out;
1913         }
1914         ret = add_extent_mapping(em_tree, em);
1915         if (ret == -EEXIST) {
1916                 free_extent_map(em);
1917                 em = NULL;
1918                 if (0 && failed_insert == 1) {
1919                         btrfs_drop_extent_cache(inode, start, end);
1920                 }
1921                 failed_insert++;
1922                 if (failed_insert > 5) {
1923                         printk("failing to insert %Lu %Lu\n", start, end);
1924                         err = -EIO;
1925                         goto out;
1926                 }
1927                 goto again;
1928         }
1929         err = 0;
1930 out:
1931         btrfs_free_path(path);
1932         if (trans) {
1933                 ret = btrfs_end_transaction(trans, root);
1934                 if (!err)
1935                         err = ret;
1936         }
1937         mutex_unlock(&root->fs_info->fs_mutex);
1938         if (err) {
1939                 free_extent_map(em);
1940                 WARN_ON(1);
1941                 return ERR_PTR(err);
1942         }
1943         return em;
1944 }
1945
1946 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
1947 {
1948         return extent_bmap(mapping, iblock, btrfs_get_extent);
1949 }
1950
1951 static int btrfs_prepare_write(struct file *file, struct page *page,
1952                                unsigned from, unsigned to)
1953 {
1954         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1955         int err;
1956
1957         mutex_lock(&root->fs_info->fs_mutex);
1958         err = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
1959         mutex_lock(&root->fs_info->fs_mutex);
1960         if (err)
1961                 return -ENOSPC;
1962
1963         return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
1964                                     page->mapping->host, page, from, to,
1965                                     btrfs_get_extent);
1966 }
1967
1968 int btrfs_readpage(struct file *file, struct page *page)
1969 {
1970         struct extent_map_tree *tree;
1971         tree = &BTRFS_I(page->mapping->host)->extent_tree;
1972         return extent_read_full_page(tree, page, btrfs_get_extent);
1973 }
1974
1975 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
1976 {
1977         struct extent_map_tree *tree;
1978
1979
1980         if (current->flags & PF_MEMALLOC) {
1981                 redirty_page_for_writepage(wbc, page);
1982                 unlock_page(page);
1983                 return 0;
1984         }
1985         tree = &BTRFS_I(page->mapping->host)->extent_tree;
1986         return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
1987 }
1988
1989 static int btrfs_writepages(struct address_space *mapping,
1990                             struct writeback_control *wbc)
1991 {
1992         struct extent_map_tree *tree;
1993         tree = &BTRFS_I(mapping->host)->extent_tree;
1994         return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
1995 }
1996
1997 static int
1998 btrfs_readpages(struct file *file, struct address_space *mapping,
1999                 struct list_head *pages, unsigned nr_pages)
2000 {
2001         struct extent_map_tree *tree;
2002         tree = &BTRFS_I(mapping->host)->extent_tree;
2003         return extent_readpages(tree, mapping, pages, nr_pages,
2004                                 btrfs_get_extent);
2005 }
2006
2007 static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
2008 {
2009         struct extent_map_tree *tree;
2010         int ret;
2011
2012         tree = &BTRFS_I(page->mapping->host)->extent_tree;
2013         ret = try_release_extent_mapping(tree, page);
2014         if (ret == 1) {
2015                 ClearPagePrivate(page);
2016                 set_page_private(page, 0);
2017                 page_cache_release(page);
2018         }
2019         return ret;
2020 }
2021
2022 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2023 {
2024         struct extent_map_tree *tree;
2025
2026         tree = &BTRFS_I(page->mapping->host)->extent_tree;
2027         extent_invalidatepage(tree, page, offset);
2028         btrfs_releasepage(page, GFP_NOFS);
2029 }
2030
2031 /*
2032  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2033  * called from a page fault handler when a page is first dirtied. Hence we must
2034  * be careful to check for EOF conditions here. We set the page up correctly
2035  * for a written page which means we get ENOSPC checking when writing into
2036  * holes and correct delalloc and unwritten extent mapping on filesystems that
2037  * support these features.
2038  *
2039  * We are not allowed to take the i_mutex here so we have to play games to
2040  * protect against truncate races as the page could now be beyond EOF.  Because
2041  * vmtruncate() writes the inode size before removing pages, once we have the
2042  * page lock we can determine safely if the page is beyond EOF. If it is not
2043  * beyond EOF, then the page is guaranteed safe against truncation until we
2044  * unlock the page.
2045  */
2046 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2047 {
2048         struct inode *inode = fdentry(vma->vm_file)->d_inode;
2049         struct btrfs_root *root = BTRFS_I(inode)->root;
2050         unsigned long end;
2051         loff_t size;
2052         int ret;
2053         u64 page_start;
2054
2055         mutex_lock(&root->fs_info->fs_mutex);
2056         ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2057         mutex_lock(&root->fs_info->fs_mutex);
2058         if (ret)
2059                 goto out;
2060
2061         ret = -EINVAL;
2062
2063         down_read(&BTRFS_I(inode)->root->snap_sem);
2064         lock_page(page);
2065         wait_on_page_writeback(page);
2066         size = i_size_read(inode);
2067         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2068
2069         if ((page->mapping != inode->i_mapping) ||
2070             (page_start > size)) {
2071                 /* page got truncated out from underneath us */
2072                 goto out_unlock;
2073         }
2074
2075         /* page is wholly or partially inside EOF */
2076         if (page_start + PAGE_CACHE_SIZE > size)
2077                 end = size & ~PAGE_CACHE_MASK;
2078         else
2079                 end = PAGE_CACHE_SIZE;
2080
2081         ret = btrfs_cow_one_page(inode, page, end);
2082
2083 out_unlock:
2084         up_read(&BTRFS_I(inode)->root->snap_sem);
2085         unlock_page(page);
2086 out:
2087         return ret;
2088 }
2089
2090 static void btrfs_truncate(struct inode *inode)
2091 {
2092         struct btrfs_root *root = BTRFS_I(inode)->root;
2093         int ret;
2094         struct btrfs_trans_handle *trans;
2095         unsigned long nr;
2096
2097         if (!S_ISREG(inode->i_mode))
2098                 return;
2099         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2100                 return;
2101
2102         btrfs_truncate_page(inode->i_mapping, inode->i_size);
2103
2104         mutex_lock(&root->fs_info->fs_mutex);
2105         trans = btrfs_start_transaction(root, 1);
2106         btrfs_set_trans_block_group(trans, inode);
2107
2108         /* FIXME, add redo link to tree so we don't leak on crash */
2109         ret = btrfs_truncate_in_trans(trans, root, inode);
2110         btrfs_update_inode(trans, root, inode);
2111         nr = trans->blocks_used;
2112
2113         ret = btrfs_end_transaction(trans, root);
2114         BUG_ON(ret);
2115         mutex_unlock(&root->fs_info->fs_mutex);
2116         btrfs_btree_balance_dirty(root, nr);
2117 }
2118
2119 int btrfs_commit_write(struct file *file, struct page *page,
2120                        unsigned from, unsigned to)
2121 {
2122         loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
2123         struct inode *inode = page->mapping->host;
2124
2125         btrfs_cow_one_page(inode, page, PAGE_CACHE_SIZE);
2126
2127         if (pos > inode->i_size) {
2128                 i_size_write(inode, pos);
2129                 mark_inode_dirty(inode);
2130         }
2131         return 0;
2132 }
2133
2134 static int create_subvol(struct btrfs_root *root, char *name, int namelen)
2135 {
2136         struct btrfs_trans_handle *trans;
2137         struct btrfs_key key;
2138         struct btrfs_root_item root_item;
2139         struct btrfs_inode_item *inode_item;
2140         struct extent_buffer *leaf;
2141         struct btrfs_root *new_root;
2142         struct inode *inode;
2143         struct inode *dir;
2144         int ret;
2145         int err;
2146         u64 objectid;
2147         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2148         unsigned long nr = 1;
2149
2150         mutex_lock(&root->fs_info->fs_mutex);
2151         ret = btrfs_check_free_space(root, 1, 0);
2152         if (ret)
2153                 goto fail_commit;
2154
2155         trans = btrfs_start_transaction(root, 1);
2156         BUG_ON(!trans);
2157
2158         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2159                                        0, &objectid);
2160         if (ret)
2161                 goto fail;
2162
2163         leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2164                                         objectid, trans->transid, 0, 0,
2165                                         0, 0);
2166         if (IS_ERR(leaf))
2167                 return PTR_ERR(leaf);
2168
2169         btrfs_set_header_nritems(leaf, 0);
2170         btrfs_set_header_level(leaf, 0);
2171         btrfs_set_header_bytenr(leaf, leaf->start);
2172         btrfs_set_header_generation(leaf, trans->transid);
2173         btrfs_set_header_owner(leaf, objectid);
2174
2175         write_extent_buffer(leaf, root->fs_info->fsid,
2176                             (unsigned long)btrfs_header_fsid(leaf),
2177                             BTRFS_FSID_SIZE);
2178         btrfs_mark_buffer_dirty(leaf);
2179
2180         inode_item = &root_item.inode;
2181         memset(inode_item, 0, sizeof(*inode_item));
2182         inode_item->generation = cpu_to_le64(1);
2183         inode_item->size = cpu_to_le64(3);
2184         inode_item->nlink = cpu_to_le32(1);
2185         inode_item->nblocks = cpu_to_le64(1);
2186         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2187
2188         btrfs_set_root_bytenr(&root_item, leaf->start);
2189         btrfs_set_root_level(&root_item, 0);
2190         btrfs_set_root_refs(&root_item, 1);
2191         btrfs_set_root_used(&root_item, 0);
2192
2193         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2194         root_item.drop_level = 0;
2195
2196         free_extent_buffer(leaf);
2197         leaf = NULL;
2198
2199         btrfs_set_root_dirid(&root_item, new_dirid);
2200
2201         key.objectid = objectid;
2202         key.offset = 1;
2203         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2204         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2205                                 &root_item);
2206         if (ret)
2207                 goto fail;
2208
2209         /*
2210          * insert the directory item
2211          */
2212         key.offset = (u64)-1;
2213         dir = root->fs_info->sb->s_root->d_inode;
2214         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2215                                     name, namelen, dir->i_ino, &key,
2216                                     BTRFS_FT_DIR);
2217         if (ret)
2218                 goto fail;
2219
2220         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2221                              name, namelen, objectid,
2222                              root->fs_info->sb->s_root->d_inode->i_ino);
2223         if (ret)
2224                 goto fail;
2225
2226         ret = btrfs_commit_transaction(trans, root);
2227         if (ret)
2228                 goto fail_commit;
2229
2230         new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2231         BUG_ON(!new_root);
2232
2233         trans = btrfs_start_transaction(new_root, 1);
2234         BUG_ON(!trans);
2235
2236         inode = btrfs_new_inode(trans, new_root, new_dirid,
2237                                 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2238         if (IS_ERR(inode))
2239                 goto fail;
2240         inode->i_op = &btrfs_dir_inode_operations;
2241         inode->i_fop = &btrfs_dir_file_operations;
2242         new_root->inode = inode;
2243
2244         ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2245                                      new_dirid);
2246         inode->i_nlink = 1;
2247         inode->i_size = 0;
2248         ret = btrfs_update_inode(trans, new_root, inode);
2249         if (ret)
2250                 goto fail;
2251 fail:
2252         nr = trans->blocks_used;
2253         err = btrfs_commit_transaction(trans, root);
2254         if (err && !ret)
2255                 ret = err;
2256 fail_commit:
2257         mutex_unlock(&root->fs_info->fs_mutex);
2258         btrfs_btree_balance_dirty(root, nr);
2259         return ret;
2260 }
2261
2262 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2263 {
2264         struct btrfs_trans_handle *trans;
2265         struct btrfs_key key;
2266         struct btrfs_root_item new_root_item;
2267         struct extent_buffer *tmp;
2268         int ret;
2269         int err;
2270         u64 objectid;
2271         unsigned long nr = 0;
2272
2273         if (!root->ref_cows)
2274                 return -EINVAL;
2275
2276         down_write(&root->snap_sem);
2277         freeze_bdev(root->fs_info->sb->s_bdev);
2278         thaw_bdev(root->fs_info->sb->s_bdev, root->fs_info->sb);
2279
2280         mutex_lock(&root->fs_info->fs_mutex);
2281         ret = btrfs_check_free_space(root, 1, 0);
2282         if (ret)
2283                 goto fail_unlock;
2284
2285         trans = btrfs_start_transaction(root, 1);
2286         BUG_ON(!trans);
2287
2288         ret = btrfs_update_inode(trans, root, root->inode);
2289         if (ret)
2290                 goto fail;
2291
2292         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2293                                        0, &objectid);
2294         if (ret)
2295                 goto fail;
2296
2297         memcpy(&new_root_item, &root->root_item,
2298                sizeof(new_root_item));
2299
2300         key.objectid = objectid;
2301         key.offset = 1;
2302         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2303
2304         extent_buffer_get(root->node);
2305         btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
2306         free_extent_buffer(tmp);
2307
2308         btrfs_copy_root(trans, root, root->node, &tmp, objectid);
2309
2310         btrfs_set_root_bytenr(&new_root_item, tmp->start);
2311         btrfs_set_root_level(&new_root_item, btrfs_header_level(tmp));
2312         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2313                                 &new_root_item);
2314         free_extent_buffer(tmp);
2315         if (ret)
2316                 goto fail;
2317
2318         /*
2319          * insert the directory item
2320          */
2321         key.offset = (u64)-1;
2322         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2323                                     name, namelen,
2324                                     root->fs_info->sb->s_root->d_inode->i_ino,
2325                                     &key, BTRFS_FT_DIR);
2326
2327         if (ret)
2328                 goto fail;
2329
2330         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2331                              name, namelen, objectid,
2332                              root->fs_info->sb->s_root->d_inode->i_ino);
2333
2334         if (ret)
2335                 goto fail;
2336 fail:
2337         nr = trans->blocks_used;
2338         err = btrfs_commit_transaction(trans, root);
2339
2340         if (err && !ret)
2341                 ret = err;
2342 fail_unlock:
2343         mutex_unlock(&root->fs_info->fs_mutex);
2344         up_write(&root->snap_sem);
2345         btrfs_btree_balance_dirty(root, nr);
2346         return ret;
2347 }
2348
2349 static unsigned long force_ra(struct address_space *mapping,
2350                               struct file_ra_state *ra, struct file *file,
2351                               pgoff_t offset, pgoff_t last_index)
2352 {
2353         pgoff_t req_size;
2354
2355 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2356         req_size = last_index - offset + 1;
2357         offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2358         return offset;
2359 #else
2360         req_size = min(last_index - offset + 1, (pgoff_t)128);
2361         page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2362         return offset + req_size;
2363 #endif
2364 }
2365
2366 int btrfs_defrag_file(struct file *file) {
2367         struct inode *inode = fdentry(file)->d_inode;
2368         struct btrfs_root *root = BTRFS_I(inode)->root;
2369         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2370         struct page *page;
2371         unsigned long last_index;
2372         unsigned long ra_index = 0;
2373         u64 page_start;
2374         u64 page_end;
2375         unsigned long i;
2376         int ret;
2377
2378         mutex_lock(&root->fs_info->fs_mutex);
2379         ret = btrfs_check_free_space(root, inode->i_size, 0);
2380         mutex_unlock(&root->fs_info->fs_mutex);
2381         if (ret)
2382                 return -ENOSPC;
2383
2384         mutex_lock(&inode->i_mutex);
2385         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2386         for (i = 0; i <= last_index; i++) {
2387                 if (i == ra_index) {
2388                         ra_index = force_ra(inode->i_mapping, &file->f_ra,
2389                                             file, ra_index, last_index);
2390                 }
2391                 page = grab_cache_page(inode->i_mapping, i);
2392                 if (!page)
2393                         goto out_unlock;
2394                 if (!PageUptodate(page)) {
2395                         btrfs_readpage(NULL, page);
2396                         lock_page(page);
2397                         if (!PageUptodate(page)) {
2398                                 unlock_page(page);
2399                                 page_cache_release(page);
2400                                 goto out_unlock;
2401                         }
2402                 }
2403                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2404                 page_end = page_start + PAGE_CACHE_SIZE - 1;
2405
2406                 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2407                 set_extent_delalloc(em_tree, page_start,
2408                                     page_end, GFP_NOFS);
2409                 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2410                 set_page_dirty(page);
2411                 unlock_page(page);
2412                 page_cache_release(page);
2413                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2414         }
2415
2416 out_unlock:
2417         mutex_unlock(&inode->i_mutex);
2418         return 0;
2419 }
2420
2421 static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
2422 {
2423         struct btrfs_ioctl_vol_args *vol_args;
2424         struct btrfs_dir_item *di;
2425         struct btrfs_path *path;
2426         u64 root_dirid;
2427         int namelen;
2428         int ret;
2429
2430         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2431
2432         if (!vol_args)
2433                 return -ENOMEM;
2434
2435         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2436                 ret = -EFAULT;
2437                 goto out;
2438         }
2439
2440         namelen = strlen(vol_args->name);
2441         if (namelen > BTRFS_VOL_NAME_MAX) {
2442                 ret = -EINVAL;
2443                 goto out;
2444         }
2445         if (strchr(vol_args->name, '/')) {
2446                 ret = -EINVAL;
2447                 goto out;
2448         }
2449
2450         path = btrfs_alloc_path();
2451         if (!path) {
2452                 ret = -ENOMEM;
2453                 goto out;
2454         }
2455
2456         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2457         mutex_lock(&root->fs_info->fs_mutex);
2458         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2459                             path, root_dirid,
2460                             vol_args->name, namelen, 0);
2461         mutex_unlock(&root->fs_info->fs_mutex);
2462         btrfs_free_path(path);
2463
2464         if (di && !IS_ERR(di)) {
2465                 ret = -EEXIST;
2466                 goto out;
2467         }
2468
2469         if (IS_ERR(di)) {
2470                 ret = PTR_ERR(di);
2471                 goto out;
2472         }
2473
2474         if (root == root->fs_info->tree_root)
2475                 ret = create_subvol(root, vol_args->name, namelen);
2476         else
2477                 ret = create_snapshot(root, vol_args->name, namelen);
2478 out:
2479         kfree(vol_args);
2480         return ret;
2481 }
2482
2483 static int btrfs_ioctl_defrag(struct file *file)
2484 {
2485         struct inode *inode = fdentry(file)->d_inode;
2486         struct btrfs_root *root = BTRFS_I(inode)->root;
2487
2488         switch (inode->i_mode & S_IFMT) {
2489         case S_IFDIR:
2490                 mutex_lock(&root->fs_info->fs_mutex);
2491                 btrfs_defrag_root(root, 0);
2492                 btrfs_defrag_root(root->fs_info->extent_root, 0);
2493                 mutex_unlock(&root->fs_info->fs_mutex);
2494                 break;
2495         case S_IFREG:
2496                 btrfs_defrag_file(file);
2497                 break;
2498         }
2499
2500         return 0;
2501 }
2502
2503 long btrfs_ioctl(struct file *file, unsigned int
2504                 cmd, unsigned long arg)
2505 {
2506         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2507
2508         switch (cmd) {
2509         case BTRFS_IOC_SNAP_CREATE:
2510                 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2511         case BTRFS_IOC_DEFRAG:
2512                 return btrfs_ioctl_defrag(file);
2513         }
2514
2515         return -ENOTTY;
2516 }
2517
2518 /*
2519  * Called inside transaction, so use GFP_NOFS
2520  */
2521 struct inode *btrfs_alloc_inode(struct super_block *sb)
2522 {
2523         struct btrfs_inode *ei;
2524
2525         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2526         if (!ei)
2527                 return NULL;
2528         ei->last_trans = 0;
2529         return &ei->vfs_inode;
2530 }
2531
2532 void btrfs_destroy_inode(struct inode *inode)
2533 {
2534         WARN_ON(!list_empty(&inode->i_dentry));
2535         WARN_ON(inode->i_data.nrpages);
2536
2537         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2538 }
2539
2540 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2541 static void init_once(struct kmem_cache * cachep, void *foo)
2542 #else
2543 static void init_once(void * foo, struct kmem_cache * cachep,
2544                       unsigned long flags)
2545 #endif
2546 {
2547         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2548
2549         inode_init_once(&ei->vfs_inode);
2550 }
2551
2552 void btrfs_destroy_cachep(void)
2553 {
2554         if (btrfs_inode_cachep)
2555                 kmem_cache_destroy(btrfs_inode_cachep);
2556         if (btrfs_trans_handle_cachep)
2557                 kmem_cache_destroy(btrfs_trans_handle_cachep);
2558         if (btrfs_transaction_cachep)
2559                 kmem_cache_destroy(btrfs_transaction_cachep);
2560         if (btrfs_bit_radix_cachep)
2561                 kmem_cache_destroy(btrfs_bit_radix_cachep);
2562         if (btrfs_path_cachep)
2563                 kmem_cache_destroy(btrfs_path_cachep);
2564 }
2565
2566 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
2567                                        unsigned long extra_flags,
2568 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2569                                        void (*ctor)(struct kmem_cache *, void *)
2570 #else
2571                                        void (*ctor)(void *, struct kmem_cache *,
2572                                                     unsigned long)
2573 #endif
2574                                      )
2575 {
2576         return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
2577                                  SLAB_MEM_SPREAD | extra_flags), ctor
2578 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2579                                  ,NULL
2580 #endif
2581                                 );
2582 }
2583
2584 int btrfs_init_cachep(void)
2585 {
2586         btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
2587                                           sizeof(struct btrfs_inode),
2588                                           0, init_once);
2589         if (!btrfs_inode_cachep)
2590                 goto fail;
2591         btrfs_trans_handle_cachep =
2592                         btrfs_cache_create("btrfs_trans_handle_cache",
2593                                            sizeof(struct btrfs_trans_handle),
2594                                            0, NULL);
2595         if (!btrfs_trans_handle_cachep)
2596                 goto fail;
2597         btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
2598                                              sizeof(struct btrfs_transaction),
2599                                              0, NULL);
2600         if (!btrfs_transaction_cachep)
2601                 goto fail;
2602         btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
2603                                          sizeof(struct btrfs_path),
2604                                          0, NULL);
2605         if (!btrfs_path_cachep)
2606                 goto fail;
2607         btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
2608                                               SLAB_DESTROY_BY_RCU, NULL);
2609         if (!btrfs_bit_radix_cachep)
2610                 goto fail;
2611         return 0;
2612 fail:
2613         btrfs_destroy_cachep();
2614         return -ENOMEM;
2615 }
2616
2617 static int btrfs_getattr(struct vfsmount *mnt,
2618                          struct dentry *dentry, struct kstat *stat)
2619 {
2620         struct inode *inode = dentry->d_inode;
2621         generic_fillattr(inode, stat);
2622         stat->blksize = 256 * 1024;
2623         return 0;
2624 }
2625
2626 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
2627                            struct inode * new_dir,struct dentry *new_dentry)
2628 {
2629         struct btrfs_trans_handle *trans;
2630         struct btrfs_root *root = BTRFS_I(old_dir)->root;
2631         struct inode *new_inode = new_dentry->d_inode;
2632         struct inode *old_inode = old_dentry->d_inode;
2633         struct timespec ctime = CURRENT_TIME;
2634         struct btrfs_path *path;
2635         int ret;
2636
2637         if (S_ISDIR(old_inode->i_mode) && new_inode &&
2638             new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
2639                 return -ENOTEMPTY;
2640         }
2641
2642         mutex_lock(&root->fs_info->fs_mutex);
2643         ret = btrfs_check_free_space(root, 1, 0);
2644         if (ret)
2645                 goto out_unlock;
2646
2647         trans = btrfs_start_transaction(root, 1);
2648
2649         btrfs_set_trans_block_group(trans, new_dir);
2650         path = btrfs_alloc_path();
2651         if (!path) {
2652                 ret = -ENOMEM;
2653                 goto out_fail;
2654         }
2655
2656         old_dentry->d_inode->i_nlink++;
2657         old_dir->i_ctime = old_dir->i_mtime = ctime;
2658         new_dir->i_ctime = new_dir->i_mtime = ctime;
2659         old_inode->i_ctime = ctime;
2660
2661         ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
2662         if (ret)
2663                 goto out_fail;
2664
2665         if (new_inode) {
2666                 new_inode->i_ctime = CURRENT_TIME;
2667                 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
2668                 if (ret)
2669                         goto out_fail;
2670         }
2671         ret = btrfs_add_link(trans, new_dentry, old_inode);
2672         if (ret)
2673                 goto out_fail;
2674
2675 out_fail:
2676         btrfs_free_path(path);
2677         btrfs_end_transaction(trans, root);
2678 out_unlock:
2679         mutex_unlock(&root->fs_info->fs_mutex);
2680         return ret;
2681 }
2682
2683 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
2684                          const char *symname)
2685 {
2686         struct btrfs_trans_handle *trans;
2687         struct btrfs_root *root = BTRFS_I(dir)->root;
2688         struct btrfs_path *path;
2689         struct btrfs_key key;
2690         struct inode *inode = NULL;
2691         int err;
2692         int drop_inode = 0;
2693         u64 objectid;
2694         int name_len;
2695         int datasize;
2696         unsigned long ptr;
2697         struct btrfs_file_extent_item *ei;
2698         struct extent_buffer *leaf;
2699         unsigned long nr = 0;
2700
2701         name_len = strlen(symname) + 1;
2702         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
2703                 return -ENAMETOOLONG;
2704
2705         mutex_lock(&root->fs_info->fs_mutex);
2706         err = btrfs_check_free_space(root, 1, 0);
2707         if (err)
2708                 goto out_fail;
2709
2710         trans = btrfs_start_transaction(root, 1);
2711         btrfs_set_trans_block_group(trans, dir);
2712
2713         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2714         if (err) {
2715                 err = -ENOSPC;
2716                 goto out_unlock;
2717         }
2718
2719         inode = btrfs_new_inode(trans, root, objectid,
2720                                 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
2721         err = PTR_ERR(inode);
2722         if (IS_ERR(inode))
2723                 goto out_unlock;
2724
2725         btrfs_set_trans_block_group(trans, inode);
2726         err = btrfs_add_nondir(trans, dentry, inode);
2727         if (err)
2728                 drop_inode = 1;
2729         else {
2730                 inode->i_mapping->a_ops = &btrfs_aops;
2731                 inode->i_fop = &btrfs_file_operations;
2732                 inode->i_op = &btrfs_file_inode_operations;
2733                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
2734                                      inode->i_mapping, GFP_NOFS);
2735                 BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
2736         }
2737         dir->i_sb->s_dirt = 1;
2738         btrfs_update_inode_block_group(trans, inode);
2739         btrfs_update_inode_block_group(trans, dir);
2740         if (drop_inode)
2741                 goto out_unlock;
2742
2743         path = btrfs_alloc_path();
2744         BUG_ON(!path);
2745         key.objectid = inode->i_ino;
2746         key.offset = 0;
2747         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2748         datasize = btrfs_file_extent_calc_inline_size(name_len);
2749         err = btrfs_insert_empty_item(trans, root, path, &key,
2750                                       datasize);
2751         if (err) {
2752                 drop_inode = 1;
2753                 goto out_unlock;
2754         }
2755         leaf = path->nodes[0];
2756         ei = btrfs_item_ptr(leaf, path->slots[0],
2757                             struct btrfs_file_extent_item);
2758         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
2759         btrfs_set_file_extent_type(leaf, ei,
2760                                    BTRFS_FILE_EXTENT_INLINE);
2761         ptr = btrfs_file_extent_inline_start(ei);
2762         write_extent_buffer(leaf, symname, ptr, name_len);
2763         btrfs_mark_buffer_dirty(leaf);
2764         btrfs_free_path(path);
2765
2766         inode->i_op = &btrfs_symlink_inode_operations;
2767         inode->i_mapping->a_ops = &btrfs_symlink_aops;
2768         inode->i_size = name_len - 1;
2769         err = btrfs_update_inode(trans, root, inode);
2770         if (err)
2771                 drop_inode = 1;
2772
2773 out_unlock:
2774         nr = trans->blocks_used;
2775         btrfs_end_transaction(trans, root);
2776 out_fail:
2777         mutex_unlock(&root->fs_info->fs_mutex);
2778         if (drop_inode) {
2779                 inode_dec_link_count(inode);
2780                 iput(inode);
2781         }
2782         btrfs_btree_balance_dirty(root, nr);
2783         return err;
2784 }
2785
2786 static struct inode_operations btrfs_dir_inode_operations = {
2787         .lookup         = btrfs_lookup,
2788         .create         = btrfs_create,
2789         .unlink         = btrfs_unlink,
2790         .link           = btrfs_link,
2791         .mkdir          = btrfs_mkdir,
2792         .rmdir          = btrfs_rmdir,
2793         .rename         = btrfs_rename,
2794         .symlink        = btrfs_symlink,
2795         .setattr        = btrfs_setattr,
2796         .mknod          = btrfs_mknod,
2797         .setxattr       = generic_setxattr,
2798         .getxattr       = generic_getxattr,
2799         .listxattr      = btrfs_listxattr,
2800         .removexattr    = generic_removexattr,
2801 };
2802
2803 static struct inode_operations btrfs_dir_ro_inode_operations = {
2804         .lookup         = btrfs_lookup,
2805 };
2806
2807 static struct file_operations btrfs_dir_file_operations = {
2808         .llseek         = generic_file_llseek,
2809         .read           = generic_read_dir,
2810         .readdir        = btrfs_readdir,
2811         .unlocked_ioctl = btrfs_ioctl,
2812 #ifdef CONFIG_COMPAT
2813         .compat_ioctl   = btrfs_ioctl,
2814 #endif
2815 };
2816
2817 static struct extent_map_ops btrfs_extent_map_ops = {
2818         .fill_delalloc = run_delalloc_range,
2819         .writepage_io_hook = btrfs_writepage_io_hook,
2820         .readpage_io_hook = btrfs_readpage_io_hook,
2821         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
2822 };
2823
2824 static struct address_space_operations btrfs_aops = {
2825         .readpage       = btrfs_readpage,
2826         .writepage      = btrfs_writepage,
2827         .writepages     = btrfs_writepages,
2828         .readpages      = btrfs_readpages,
2829         .sync_page      = block_sync_page,
2830         .prepare_write  = btrfs_prepare_write,
2831         .commit_write   = btrfs_commit_write,
2832         .bmap           = btrfs_bmap,
2833         .invalidatepage = btrfs_invalidatepage,
2834         .releasepage    = btrfs_releasepage,
2835         .set_page_dirty = __set_page_dirty_nobuffers,
2836 };
2837
2838 static struct address_space_operations btrfs_symlink_aops = {
2839         .readpage       = btrfs_readpage,
2840         .writepage      = btrfs_writepage,
2841         .invalidatepage = btrfs_invalidatepage,
2842         .releasepage    = btrfs_releasepage,
2843 };
2844
2845 static struct inode_operations btrfs_file_inode_operations = {
2846         .truncate       = btrfs_truncate,
2847         .getattr        = btrfs_getattr,
2848         .setattr        = btrfs_setattr,
2849         .setxattr       = generic_setxattr,
2850         .getxattr       = generic_getxattr,
2851         .listxattr      = btrfs_listxattr,
2852         .removexattr    = generic_removexattr,
2853 };
2854
2855 static struct inode_operations btrfs_special_inode_operations = {
2856         .getattr        = btrfs_getattr,
2857         .setattr        = btrfs_setattr,
2858 };
2859
2860 static struct inode_operations btrfs_symlink_inode_operations = {
2861         .readlink       = generic_readlink,
2862         .follow_link    = page_follow_link_light,
2863         .put_link       = page_put_link,
2864 };