fs/btrfs/inode.c

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