fs/btrfs/super.c

   1 #include <linux/module.h>
   2 #include <linux/buffer_head.h>
   3 #include <linux/fs.h>
   4 #include <linux/pagemap.h>
   5 #include <linux/highmem.h>
   6 #include <linux/time.h>
   7 #include <linux/init.h>
   8 #include <linux/string.h>
   9 #include <linux/smp_lock.h>
  10 #include <linux/backing-dev.h>
  11 #include <linux/mpage.h>
  12 #include <linux/swap.h>
  13 #include <linux/writeback.h>
  14 #include "ctree.h"
  15 #include "disk-io.h"
  16 #include "transaction.h"
  17 #include "btrfs_inode.h"
  18
  19 #define BTRFS_SUPER_MAGIC 0x9123682E
  20
  21 static struct inode_operations btrfs_dir_inode_operations;
  22 static struct super_operations btrfs_super_ops;
  23 static struct file_operations btrfs_dir_file_operations;
  24 static struct inode_operations btrfs_file_inode_operations;
  25 static struct address_space_operations btrfs_aops;
  26 static struct file_operations btrfs_file_operations;
  27
  28 static int check_inode(struct inode *inode)
  29 {
  30         struct btrfs_inode *ei = BTRFS_I(inode);
  31         WARN_ON(ei->magic != 0xDEADBEEF);
  32         WARN_ON(ei->magic2 != 0xDEADBEAF);
  33         return 0;
  34 }
  35
  36 static void btrfs_read_locked_inode(struct inode *inode)
  37 {
  38         struct btrfs_path path;
  39         struct btrfs_inode_item *inode_item;
  40         struct btrfs_root *root = btrfs_sb(inode->i_sb);
  41         int ret;
  42
  43         btrfs_init_path(&path);
  44         mutex_lock(&root->fs_info->fs_mutex);
  45
  46         check_inode(inode);
  47         ret = btrfs_lookup_inode(NULL, root, &path, inode->i_ino, 0);
  48         if (ret) {
  49                 btrfs_release_path(root, &path);
  50                 mutex_unlock(&root->fs_info->fs_mutex);
  51                 make_bad_inode(inode);
  52                 return;
  53         }
  54         check_inode(inode);
  55         inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
  56                                   path.slots[0],
  57                                   struct btrfs_inode_item);
  58
  59         inode->i_mode = btrfs_inode_mode(inode_item);
  60         inode->i_nlink = btrfs_inode_nlink(inode_item);
  61         inode->i_uid = btrfs_inode_uid(inode_item);
  62         inode->i_gid = btrfs_inode_gid(inode_item);
  63         inode->i_size = btrfs_inode_size(inode_item);
  64         inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
  65         inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
  66         inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
  67         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
  68         inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
  69         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
  70         inode->i_blocks = btrfs_inode_nblocks(inode_item);
  71         inode->i_generation = btrfs_inode_generation(inode_item);
  72         btrfs_release_path(root, &path);
  73         mutex_unlock(&root->fs_info->fs_mutex);
  74         check_inode(inode);
  75         switch (inode->i_mode & S_IFMT) {
  76 #if 0
  77         default:
  78                 init_special_inode(inode, inode->i_mode,
  79                                    btrfs_inode_rdev(inode_item));
  80                 break;
  81 #endif
  82         case S_IFREG:
  83                 inode->i_mapping->a_ops = &btrfs_aops;
  84                 inode->i_fop = &btrfs_file_operations;
  85                 inode->i_op = &btrfs_file_inode_operations;
  86                 break;
  87         case S_IFDIR:
  88                 inode->i_op = &btrfs_dir_inode_operations;
  89                 inode->i_fop = &btrfs_dir_file_operations;
  90                 break;
  91         case S_IFLNK:
  92                 // inode->i_op = &page_symlink_inode_operations;
  93                 break;
  94         }
  95         check_inode(inode);
  96         return;
  97 }
  98
  99 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
 100                               struct btrfs_root *root,
 101                               struct inode *dir,
 102                               struct dentry *dentry)
 103 {
 104         struct btrfs_path path;
 105         const char *name = dentry->d_name.name;
 106         int name_len = dentry->d_name.len;
 107         int ret;
 108         u64 objectid;
 109         struct btrfs_dir_item *di;
 110
 111         btrfs_init_path(&path);
 112         ret = btrfs_lookup_dir_item(trans, root, &path, dir->i_ino,
 113                                     name, name_len, -1);
 114         if (ret < 0)
 115                 goto err;
 116         if (ret > 0) {
 117                 ret = -ENOENT;
 118                 goto err;
 119         }
 120         di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
 121                             struct btrfs_dir_item);
 122         objectid = btrfs_dir_objectid(di);
 123
 124         ret = btrfs_del_item(trans, root, &path);
 125         BUG_ON(ret);
 126         dentry->d_inode->i_ctime = dir->i_ctime;
 127 err:
 128         btrfs_release_path(root, &path);
 129         if (ret == 0)
 130                 inode_dec_link_count(dentry->d_inode);
 131         return ret;
 132 }
 133
 134 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 135 {
 136         struct btrfs_root *root;
 137         struct btrfs_trans_handle *trans;
 138         int ret;
 139
 140         root = btrfs_sb(dir->i_sb);
 141         mutex_lock(&root->fs_info->fs_mutex);
 142         trans = btrfs_start_transaction(root, 1);
 143         ret = btrfs_unlink_trans(trans, root, dir, dentry);
 144         btrfs_end_transaction(trans, root);
 145         mutex_unlock(&root->fs_info->fs_mutex);
 146         return ret;
 147 }
 148
 149 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 150 {
 151         struct inode *inode = dentry->d_inode;
 152         int err;
 153         int ret;
 154         struct btrfs_root *root = btrfs_sb(dir->i_sb);
 155         struct btrfs_path path;
 156         struct btrfs_key key;
 157         struct btrfs_trans_handle *trans;
 158         struct btrfs_disk_key *found_key;
 159         struct btrfs_leaf *leaf;
 160
 161         btrfs_init_path(&path);
 162         mutex_lock(&root->fs_info->fs_mutex);
 163         trans = btrfs_start_transaction(root, 1);
 164         key.objectid = inode->i_ino;
 165         key.offset = (u64)-1;
 166         key.flags = 0;
 167         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 168         ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
 169         if (ret < 0) {
 170                 err = ret;
 171                 goto out;
 172         }
 173
 174         BUG_ON(ret == 0);
 175         BUG_ON(path.slots[0] == 0);
 176         path.slots[0]--;
 177         leaf = btrfs_buffer_leaf(path.nodes[0]);
 178         found_key = &leaf->items[path.slots[0]].key;
 179         if (btrfs_disk_key_objectid(found_key) != inode->i_ino) {
 180                 err = -ENOENT;
 181                 goto out;
 182         }
 183         if (btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
 184             btrfs_disk_key_offset(found_key) != 2) {
 185                 err = -ENOTEMPTY;
 186                 goto out;
 187         }
 188         ret = btrfs_del_item(trans, root, &path);
 189         BUG_ON(ret);
 190         btrfs_release_path(root, &path);
 191         key.offset = 1;
 192         ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
 193         if (ret < 0) {
 194                 err = ret;
 195                 goto out;
 196         }
 197         if (ret > 0) {
 198                 err = -ENOTEMPTY;
 199                 goto out;
 200         }
 201         ret = btrfs_del_item(trans, root, &path);
 202         if (ret) {
 203                 err = ret;
 204                 goto out;
 205         }
 206         btrfs_release_path(root, &path);
 207
 208         /* now the directory is empty */
 209         err = btrfs_unlink_trans(trans, root, dir, dentry);
 210         if (!err) {
 211                 inode->i_size = 0;
 212         }
 213 out:
 214         mutex_unlock(&root->fs_info->fs_mutex);
 215         ret = btrfs_end_transaction(trans, root);
 216         if (ret && !err)
 217                 err = ret;
 218         return err;
 219 }
 220
 221 static int btrfs_free_inode(struct btrfs_trans_handle *trans,
 222                             struct btrfs_root *root,
 223                             struct inode *inode)
 224 {
 225         u64 objectid = inode->i_ino;
 226         struct btrfs_path path;
 227         struct btrfs_inode_map_item *map;
 228         struct btrfs_key stat_data_key;
 229         int ret;
 230         clear_inode(inode);
 231         btrfs_init_path(&path);
 232         ret = btrfs_lookup_inode_map(trans, root, &path, objectid, -1);
 233         if (ret) {
 234                 if (ret > 0)
 235                         ret = -ENOENT;
 236                 btrfs_release_path(root, &path);
 237                 goto error;
 238         }
 239         map = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
 240                             struct btrfs_inode_map_item);
 241         btrfs_disk_key_to_cpu(&stat_data_key, &map->key);
 242         ret = btrfs_del_item(trans, root->fs_info->inode_root, &path);
 243         BUG_ON(ret);
 244         btrfs_release_path(root, &path);
 245         btrfs_init_path(&path);
 246
 247         ret = btrfs_lookup_inode(trans, root, &path, objectid, -1);
 248         BUG_ON(ret);
 249         ret = btrfs_del_item(trans, root, &path);
 250         BUG_ON(ret);
 251         btrfs_release_path(root, &path);
 252 error:
 253         return ret;
 254 }
 255
 256 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
 257                                    struct btrfs_root *root,
 258                                    struct inode *inode)
 259 {
 260         int ret;
 261         struct btrfs_path path;
 262         struct btrfs_key key;
 263         struct btrfs_disk_key *found_key;
 264         struct btrfs_leaf *leaf;
 265         struct btrfs_file_extent_item *fi = NULL;
 266         u64 extent_start = 0;
 267         u64 extent_num_blocks = 0;
 268         int found_extent;
 269
 270         /* FIXME, add redo link to tree so we don't leak on crash */
 271         key.objectid = inode->i_ino;
 272         key.offset = (u64)-1;
 273         key.flags = 0;
 274         btrfs_set_key_type(&key, BTRFS_CSUM_ITEM_KEY);
 275         while(1) {
 276                 btrfs_init_path(&path);
 277                 ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
 278                 if (ret < 0) {
 279                         btrfs_release_path(root, &path);
 280                         goto error;
 281                 }
 282                 if (ret > 0) {
 283                         BUG_ON(path.slots[0] == 0);
 284                         path.slots[0]--;
 285                 }
 286                 leaf = btrfs_buffer_leaf(path.nodes[0]);
 287                 found_key = &leaf->items[path.slots[0]].key;
 288                 if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
 289                         break;
 290                 if (btrfs_disk_key_type(found_key) != BTRFS_CSUM_ITEM_KEY &&
 291                     btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
 292                         break;
 293                 if (btrfs_disk_key_offset(found_key) < inode->i_size)
 294                         break;
 295                 if (btrfs_disk_key_type(found_key) == BTRFS_EXTENT_DATA_KEY) {
 296                         fi = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
 297                                             path.slots[0],
 298                                             struct btrfs_file_extent_item);
 299                         extent_start = btrfs_file_extent_disk_blocknr(fi);
 300                         extent_num_blocks =
 301                                 btrfs_file_extent_disk_num_blocks(fi);
 302                         inode->i_blocks -=
 303                                 btrfs_file_extent_num_blocks(fi) >> 9;
 304                         found_extent = 1;
 305                 } else {
 306                         found_extent = 0;
 307                 }
 308                 ret = btrfs_del_item(trans, root, &path);
 309                 BUG_ON(ret);
 310                 btrfs_release_path(root, &path);
 311                 if (found_extent) {
 312                         ret = btrfs_free_extent(trans, root, extent_start,
 313                                                 extent_num_blocks, 0);
 314                         BUG_ON(ret);
 315                 }
 316         }
 317         btrfs_release_path(root, &path);
 318         ret = 0;
 319 error:
 320         return ret;
 321 }
 322
 323 static void btrfs_delete_inode(struct inode *inode)
 324 {
 325         struct btrfs_trans_handle *trans;
 326         struct btrfs_root *root = btrfs_sb(inode->i_sb);
 327         int ret;
 328
 329         truncate_inode_pages(&inode->i_data, 0);
 330         if (is_bad_inode(inode)) {
 331                 goto no_delete;
 332         }
 333         inode->i_size = 0;
 334         mutex_lock(&root->fs_info->fs_mutex);
 335         trans = btrfs_start_transaction(root, 1);
 336         if (S_ISREG(inode->i_mode)) {
 337                 ret = btrfs_truncate_in_trans(trans, root, inode);
 338                 BUG_ON(ret);
 339         }
 340         btrfs_free_inode(trans, root, inode);
 341         btrfs_end_transaction(trans, root);
 342         mutex_unlock(&root->fs_info->fs_mutex);
 343         return;
 344 no_delete:
 345         clear_inode(inode);
 346 }
 347
 348 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
 349                               ino_t *ino)
 350 {
 351         const char *name = dentry->d_name.name;
 352         int namelen = dentry->d_name.len;
 353         struct btrfs_dir_item *di;
 354         struct btrfs_path path;
 355         struct btrfs_root *root = btrfs_sb(dir->i_sb);
 356         int ret;
 357
 358         btrfs_init_path(&path);
 359         ret = btrfs_lookup_dir_item(NULL, root, &path, dir->i_ino, name,
 360                                     namelen, 0);
 361         if (ret || !btrfs_match_dir_item_name(root, &path, name, namelen)) {
 362                 *ino = 0;
 363                 ret = 0;
 364                 goto out;
 365         }
 366         di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
 367                             struct btrfs_dir_item);
 368         *ino = btrfs_dir_objectid(di);
 369 out:
 370         btrfs_release_path(root, &path);
 371         check_inode(dir);
 372         return ret;
 373 }
 374
 375 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
 376                                    struct nameidata *nd)
 377 {
 378         struct inode * inode;
 379         struct btrfs_root *root = btrfs_sb(dir->i_sb);
 380         ino_t ino;
 381         int ret;
 382
 383         if (dentry->d_name.len > BTRFS_NAME_LEN)
 384                 return ERR_PTR(-ENAMETOOLONG);
 385         mutex_lock(&root->fs_info->fs_mutex);
 386         ret = btrfs_inode_by_name(dir, dentry, &ino);
 387         mutex_unlock(&root->fs_info->fs_mutex);
 388         if (ret < 0)
 389                 return ERR_PTR(ret);
 390         inode = NULL;
 391         if (ino) {
 392                 inode = iget(dir->i_sb, ino);
 393                 if (!inode)
 394                         return ERR_PTR(-EACCES);
 395                 check_inode(inode);
 396         }
 397         check_inode(dir);
 398         return d_splice_alias(inode, dentry);
 399 }
 400
 401 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 402 {
 403         struct inode *inode = filp->f_path.dentry->d_inode;
 404         struct btrfs_root *root = btrfs_sb(inode->i_sb);
 405         struct btrfs_item *item;
 406         struct btrfs_dir_item *di;
 407         struct btrfs_key key;
 408         struct btrfs_path path;
 409         int ret;
 410         u32 nritems;
 411         struct btrfs_leaf *leaf;
 412         int slot;
 413         int advance;
 414         unsigned char d_type = DT_UNKNOWN;
 415         int over = 0;
 416
 417         mutex_lock(&root->fs_info->fs_mutex);
 418         key.objectid = inode->i_ino;
 419         key.flags = 0;
 420         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 421         key.offset = filp->f_pos;
 422         btrfs_init_path(&path);
 423         ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
 424         if (ret < 0) {
 425                 goto err;
 426         }
 427         advance = 0;
 428         while(1) {
 429                 leaf = btrfs_buffer_leaf(path.nodes[0]);
 430                 nritems = btrfs_header_nritems(&leaf->header);
 431                 slot = path.slots[0];
 432                 if (advance || slot >= nritems) {
 433                         if (slot >= nritems -1) {
 434                                 ret = btrfs_next_leaf(root, &path);
 435                                 if (ret)
 436                                         break;
 437                                 leaf = btrfs_buffer_leaf(path.nodes[0]);
 438                                 nritems = btrfs_header_nritems(&leaf->header);
 439                                 slot = path.slots[0];
 440                         } else {
 441                                 slot++;
 442                                 path.slots[0]++;
 443                         }
 444                 }
 445                 advance = 1;
 446                 item = leaf->items + slot;
 447                 if (btrfs_disk_key_objectid(&item->key) != key.objectid)
 448                         break;
 449                 if (btrfs_disk_key_type(&item->key) != BTRFS_DIR_ITEM_KEY)
 450                         continue;
 451                 if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
 452                         continue;
 453
 454                 advance = 1;
 455                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
 456                 over = filldir(dirent, (const char *)(di + 1),
 457                                btrfs_dir_name_len(di),
 458                                btrfs_disk_key_offset(&item->key),
 459                                btrfs_dir_objectid(di), d_type);
 460                 if (over) {
 461                         filp->f_pos = btrfs_disk_key_offset(&item->key);
 462                         break;
 463                 }
 464                 filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
 465         }
 466         ret = 0;
 467 err:
 468         btrfs_release_path(root, &path);
 469         mutex_unlock(&root->fs_info->fs_mutex);
 470         return ret;
 471 }
 472
 473 static void btrfs_put_super (struct super_block * sb)
 474 {
 475         struct btrfs_root *root = btrfs_sb(sb);
 476         int ret;
 477
 478         ret = close_ctree(root);
 479         if (ret) {
 480                 printk("close ctree returns %d\n", ret);
 481         }
 482         sb->s_fs_info = NULL;
 483 }
 484
 485 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
 486 {
 487         struct inode * inode;
 488         struct dentry * root_dentry;
 489         struct btrfs_super_block *disk_super;
 490         struct btrfs_root *root;
 491
 492         sb->s_maxbytes = MAX_LFS_FILESIZE;
 493         sb->s_magic = BTRFS_SUPER_MAGIC;
 494         sb->s_op = &btrfs_super_ops;
 495         sb->s_time_gran = 1;
 496
 497         root = open_ctree(sb);
 498
 499         if (!root) {
 500                 printk("btrfs: open_ctree failed\n");
 501                 return -EIO;
 502         }
 503         sb->s_fs_info = root;
 504         disk_super = root->fs_info->disk_super;
 505         printk("read in super total blocks %Lu root %Lu\n",
 506                btrfs_super_total_blocks(disk_super),
 507                btrfs_super_root_dir(disk_super));
 508
 509         inode = iget_locked(sb, btrfs_super_root_dir(disk_super));
 510         if (!inode)
 511                 return -ENOMEM;
 512         if (inode->i_state & I_NEW) {
 513                 btrfs_read_locked_inode(inode);
 514                 unlock_new_inode(inode);
 515         }
 516
 517         root_dentry = d_alloc_root(inode);
 518         if (!root_dentry) {
 519                 iput(inode);
 520                 return -ENOMEM;
 521         }
 522         sb->s_root = root_dentry;
 523
 524         return 0;
 525 }
 526
 527 static void fill_inode_item(struct btrfs_inode_item *item,
 528                             struct inode *inode)
 529 {
 530         btrfs_set_inode_uid(item, inode->i_uid);
 531         btrfs_set_inode_gid(item, inode->i_gid);
 532         btrfs_set_inode_size(item, inode->i_size);
 533         btrfs_set_inode_mode(item, inode->i_mode);
 534         btrfs_set_inode_nlink(item, inode->i_nlink);
 535         btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
 536         btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
 537         btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
 538         btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
 539         btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
 540         btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
 541         btrfs_set_inode_nblocks(item, inode->i_blocks);
 542         btrfs_set_inode_generation(item, inode->i_generation);
 543         check_inode(inode);
 544 }
 545
 546 static int btrfs_update_inode(struct btrfs_trans_handle *trans,
 547                               struct btrfs_root *root,
 548                               struct inode *inode)
 549 {
 550         struct btrfs_inode_item *inode_item;
 551         struct btrfs_path path;
 552         int ret;
 553
 554         btrfs_init_path(&path);
 555
 556         ret = btrfs_lookup_inode(trans, root, &path, inode->i_ino, 1);
 557         if (ret) {
 558                 if (ret > 0)
 559                         ret = -ENOENT;
 560                 goto failed;
 561         }
 562
 563         inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
 564                                   path.slots[0],
 565                                   struct btrfs_inode_item);
 566
 567         fill_inode_item(inode_item, inode);
 568         btrfs_mark_buffer_dirty(path.nodes[0]);
 569 failed:
 570         btrfs_release_path(root, &path);
 571         check_inode(inode);
 572         return 0;
 573 }
 574
 575 static int btrfs_write_inode(struct inode *inode, int wait)
 576 {
 577         struct btrfs_root *root = btrfs_sb(inode->i_sb);
 578         struct btrfs_trans_handle *trans;
 579         int ret;
 580
 581         mutex_lock(&root->fs_info->fs_mutex);
 582         trans = btrfs_start_transaction(root, 1);
 583         ret = btrfs_update_inode(trans, root, inode);
 584         if (wait)
 585                 btrfs_commit_transaction(trans, root);
 586         else
 587                 btrfs_end_transaction(trans, root);
 588         mutex_unlock(&root->fs_info->fs_mutex);
 589         check_inode(inode);
 590         return ret;
 591 }
 592
 593 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 594                                      struct inode *dir, int mode)
 595 {
 596         struct inode *inode;
 597         struct btrfs_inode_item inode_item;
 598         struct btrfs_root *root = btrfs_sb(dir->i_sb);
 599         struct btrfs_key key;
 600         int ret;
 601         u64 objectid;
 602
 603         inode = new_inode(dir->i_sb);
 604         if (!inode)
 605                 return ERR_PTR(-ENOMEM);
 606
 607         check_inode(inode);
 608         ret = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
 609         BUG_ON(ret);
 610
 611         inode->i_uid = current->fsuid;
 612         inode->i_gid = current->fsgid;
 613         inode->i_mode = mode;
 614         inode->i_ino = objectid;
 615         inode->i_blocks = 0;
 616         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 617         fill_inode_item(&inode_item, inode);
 618
 619         key.objectid = objectid;
 620         key.flags = 0;
 621         key.offset = 0;
 622         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
 623         ret = btrfs_insert_inode_map(trans, root, objectid, &key);
 624         BUG_ON(ret);
 625
 626         ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
 627         BUG_ON(ret);
 628
 629         insert_inode_hash(inode);
 630         check_inode(inode);
 631         check_inode(dir);
 632         return inode;
 633 }
 634
 635 static int btrfs_add_link(struct btrfs_trans_handle *trans,
 636                             struct dentry *dentry, struct inode *inode)
 637 {
 638         int ret;
 639         ret = btrfs_insert_dir_item(trans, btrfs_sb(inode->i_sb),
 640                                     dentry->d_name.name, dentry->d_name.len,
 641                                     dentry->d_parent->d_inode->i_ino,
 642                                     inode->i_ino, 0);
 643         if (ret == 0) {
 644                 dentry->d_parent->d_inode->i_size += dentry->d_name.len;
 645                 ret = btrfs_update_inode(trans, btrfs_sb(inode->i_sb),
 646                                          dentry->d_parent->d_inode);
 647         }
 648         check_inode(inode);
 649         check_inode(dentry->d_parent->d_inode);
 650         return ret;
 651 }
 652
 653 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
 654                             struct dentry *dentry, struct inode *inode)
 655 {
 656         int err = btrfs_add_link(trans, dentry, inode);
 657         if (!err) {
 658                 d_instantiate(dentry, inode);
 659                 return 0;
 660         }
 661         if (err > 0)
 662                 err = -EEXIST;
 663         check_inode(inode);
 664         return err;
 665 }
 666
 667 static int btrfs_create(struct inode *dir, struct dentry *dentry,
 668                         int mode, struct nameidata *nd)
 669 {
 670         struct btrfs_trans_handle *trans;
 671         struct btrfs_root *root = btrfs_sb(dir->i_sb);
 672         struct inode *inode;
 673         int err;
 674         int drop_inode = 0;
 675
 676         mutex_lock(&root->fs_info->fs_mutex);
 677         trans = btrfs_start_transaction(root, 1);
 678         inode = btrfs_new_inode(trans, dir, mode);
 679         err = PTR_ERR(inode);
 680         if (IS_ERR(inode))
 681                 goto out_unlock;
 682         // FIXME mark the inode dirty
 683         err = btrfs_add_nondir(trans, dentry, inode);
 684         if (err)
 685                 drop_inode = 1;
 686         else {
 687                 inode->i_mapping->a_ops = &btrfs_aops;
 688                 inode->i_fop = &btrfs_file_operations;
 689                 inode->i_op = &btrfs_file_inode_operations;
 690         }
 691         dir->i_sb->s_dirt = 1;
 692 out_unlock:
 693         btrfs_end_transaction(trans, root);
 694         mutex_unlock(&root->fs_info->fs_mutex);
 695         check_inode(inode);
 696         check_inode(dir);
 697
 698         if (drop_inode) {
 699                 inode_dec_link_count(inode);
 700                 iput(inode);
 701         }
 702         return err;
 703 }
 704
 705 static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
 706                                 struct inode *inode, struct inode *dir)
 707 {
 708         struct btrfs_root *root = btrfs_sb(inode->i_sb);
 709         int ret;
 710         char buf[2];
 711         buf[0] = '.';
 712         buf[1] = '.';
 713
 714         ret = btrfs_insert_dir_item(trans, root, buf, 1, inode->i_ino,
 715                                     inode->i_ino, 1);
 716         if (ret)
 717                 goto error;
 718         ret = btrfs_insert_dir_item(trans, root, buf, 2, inode->i_ino,
 719                                     dir->i_ino, 1);
 720         if (ret)
 721                 goto error;
 722         inode->i_size = 3;
 723         ret = btrfs_update_inode(trans, root, inode);
 724 error:
 725         return ret;
 726 }
 727
 728 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 729 {
 730         struct inode *inode;
 731         struct btrfs_trans_handle *trans;
 732         struct btrfs_root *root = btrfs_sb(dir->i_sb);
 733         int err = 0;
 734         int drop_on_err = 0;
 735
 736         mutex_lock(&root->fs_info->fs_mutex);
 737         trans = btrfs_start_transaction(root, 1);
 738         if (IS_ERR(trans)) {
 739                 err = PTR_ERR(trans);
 740                 goto out_unlock;
 741         }
 742         inode = btrfs_new_inode(trans, dir, S_IFDIR | mode);
 743         if (IS_ERR(inode)) {
 744                 err = PTR_ERR(inode);
 745                 goto out_fail;
 746         }
 747         drop_on_err = 1;
 748         inode->i_op = &btrfs_dir_inode_operations;
 749         inode->i_fop = &btrfs_dir_file_operations;
 750
 751         err = btrfs_make_empty_dir(trans, inode, dir);
 752         if (err)
 753                 goto out_fail;
 754         err = btrfs_add_link(trans, dentry, inode);
 755         if (err)
 756                 goto out_fail;
 757         d_instantiate(dentry, inode);
 758         drop_on_err = 0;
 759
 760 out_fail:
 761         btrfs_end_transaction(trans, root);
 762 out_unlock:
 763         mutex_unlock(&root->fs_info->fs_mutex);
 764         if (drop_on_err)
 765                 iput(inode);
 766         return err;
 767 }
 768
 769 static int btrfs_sync_fs(struct super_block *sb, int wait)
 770 {
 771         struct btrfs_trans_handle *trans;
 772         struct btrfs_root *root;
 773         int ret;
 774         root = btrfs_sb(sb);
 775
 776         sb->s_dirt = 0;
 777         if (!wait) {
 778                 // filemap_flush(root->fs_info->btree_inode->i_mapping);
 779                 filemap_flush(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
 780                 return 0;
 781         }
 782         filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
 783         mutex_lock(&root->fs_info->fs_mutex);
 784         trans = btrfs_start_transaction(root, 1);
 785         ret = btrfs_commit_transaction(trans, root);
 786         sb->s_dirt = 0;
 787         BUG_ON(ret);
 788 printk("btrfs sync_fs\n");
 789         mutex_unlock(&root->fs_info->fs_mutex);
 790         return 0;
 791 }
 792
 793 static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
 794                            struct buffer_head *result, int create)
 795 {
 796         int ret;
 797         int err = 0;
 798         u64 blocknr;
 799         u64 extent_start = 0;
 800         u64 extent_end = 0;
 801         u64 objectid = inode->i_ino;
 802         struct btrfs_path path;
 803         struct btrfs_root *root = btrfs_sb(inode->i_sb);
 804         struct btrfs_trans_handle *trans = NULL;
 805         struct btrfs_file_extent_item *item;
 806         struct btrfs_leaf *leaf;
 807         struct btrfs_disk_key *found_key;
 808
 809         btrfs_init_path(&path);
 810         if (create)
 811                 trans = btrfs_start_transaction(root, 1);
 812
 813
 814         ret = btrfs_lookup_file_extent(trans, root, &path,
 815                                        inode->i_ino,
 816                                        iblock << inode->i_blkbits, 0);
 817         if (ret < 0) {
 818                 btrfs_release_path(root, &path);
 819                 err = ret;
 820                 goto out;
 821         }
 822
 823         if (ret != 0) {
 824                 if (path.slots[0] == 0) {
 825                         btrfs_release_path(root, &path);
 826                         goto allocate;
 827                 }
 828                 path.slots[0]--;
 829         }
 830
 831         item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
 832                               struct btrfs_file_extent_item);
 833         leaf = btrfs_buffer_leaf(path.nodes[0]);
 834         blocknr = btrfs_file_extent_disk_blocknr(item);
 835         blocknr += btrfs_file_extent_offset(item);
 836
 837         /* exact match found, use it */
 838         if (ret == 0) {
 839                 err = 0;
 840                 map_bh(result, inode->i_sb, blocknr);
 841                 btrfs_release_path(root, &path);
 842                 goto out;
 843         }
 844
 845         /* are we inside the extent that was found? */
 846         found_key = &leaf->items[path.slots[0]].key;
 847         if (btrfs_disk_key_objectid(found_key) != objectid ||
 848             btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) {
 849                 extent_end = 0;
 850                 extent_start = 0;
 851                 btrfs_release_path(root, &path);
 852                 goto allocate;
 853         }
 854
 855         extent_start = btrfs_disk_key_offset(&leaf->items[path.slots[0]].key);
 856         extent_start = extent_start >> inode->i_blkbits;
 857         extent_start += btrfs_file_extent_offset(item);
 858         extent_end = extent_start + btrfs_file_extent_num_blocks(item);
 859         btrfs_release_path(root, &path);
 860         if (iblock >= extent_start && iblock < extent_end) {
 861                 err = 0;
 862                 map_bh(result, inode->i_sb, blocknr + iblock - extent_start);
 863                 goto out;
 864         }
 865 allocate:
 866         /* ok, create a new extent */
 867         if (!create) {
 868                 err = 0;
 869                 goto out;
 870         }
 871         ret = btrfs_alloc_file_extent(trans, root, objectid,
 872                                       iblock << inode->i_blkbits,
 873                                       1, extent_end, &blocknr);
 874         if (ret) {
 875                 err = ret;
 876                 goto out;
 877         }
 878         inode->i_blocks += inode->i_sb->s_blocksize >> 9;
 879         set_buffer_new(result);
 880         map_bh(result, inode->i_sb, blocknr);
 881
 882 out:
 883         if (trans)
 884                 btrfs_end_transaction(trans, root);
 885         return err;
 886 }
 887
 888 static int btrfs_get_block(struct inode *inode, sector_t iblock,
 889                            struct buffer_head *result, int create)
 890 {
 891         int err;
 892         struct btrfs_root *root = btrfs_sb(inode->i_sb);
 893         mutex_lock(&root->fs_info->fs_mutex);
 894         err = btrfs_get_block_lock(inode, iblock, result, create);
 895         mutex_unlock(&root->fs_info->fs_mutex);
 896         return err;
 897 }
 898
 899 static int btrfs_prepare_write(struct file *file, struct page *page,
 900                                unsigned from, unsigned to)
 901 {
 902         WARN_ON(1);
 903         return nobh_prepare_write(page, from, to, btrfs_get_block);
 904 }
 905 static int btrfs_commit_write(struct file *file, struct page *page,
 906                                unsigned from, unsigned to)
 907 {
 908         WARN_ON(1);
 909         return nobh_commit_write(file, page, from, to);
 910 }
 911
 912 static void btrfs_write_super(struct super_block *sb)
 913 {
 914         btrfs_sync_fs(sb, 1);
 915 }
 916
 917 static int btrfs_readpage(struct file *file, struct page *page)
 918 {
 919         return mpage_readpage(page, btrfs_get_block);
 920 }
 921
 922 static int btrfs_readpages(struct file *file, struct address_space *mapping,
 923                            struct list_head *pages, unsigned nr_pages)
 924 {
 925         return mpage_readpages(mapping, pages, nr_pages, btrfs_get_block);
 926 }
 927
 928 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
 929 {
 930         return nobh_writepage(page, btrfs_get_block, wbc);
 931 }
 932
 933 static void btrfs_truncate(struct inode *inode)
 934 {
 935         struct btrfs_root *root = btrfs_sb(inode->i_sb);
 936         int ret;
 937         struct btrfs_trans_handle *trans;
 938
 939         if (!S_ISREG(inode->i_mode))
 940                 return;
 941         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 942                 return;
 943
 944         nobh_truncate_page(inode->i_mapping, inode->i_size);
 945
 946         /* FIXME, add redo link to tree so we don't leak on crash */
 947         mutex_lock(&root->fs_info->fs_mutex);
 948         trans = btrfs_start_transaction(root, 1);
 949         ret = btrfs_truncate_in_trans(trans, root, inode);
 950         BUG_ON(ret);
 951         ret = btrfs_end_transaction(trans, root);
 952         BUG_ON(ret);
 953         mutex_unlock(&root->fs_info->fs_mutex);
 954         mark_inode_dirty(inode);
 955 }
 956
 957 static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
 958                                 struct page **prepared_pages,
 959                                 const char __user * buf)
 960 {
 961         long page_fault = 0;
 962         int i;
 963         int offset = pos & (PAGE_CACHE_SIZE - 1);
 964
 965         for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
 966                 size_t count = min_t(size_t,
 967                                      PAGE_CACHE_SIZE - offset, write_bytes);
 968                 struct page *page = prepared_pages[i];
 969                 fault_in_pages_readable(buf, count);
 970
 971                 /* Copy data from userspace to the current page */
 972                 kmap(page);
 973                 page_fault = __copy_from_user(page_address(page) + offset,
 974                                               buf, count);
 975                 /* Flush processor's dcache for this page */
 976                 flush_dcache_page(page);
 977                 kunmap(page);
 978                 buf += count;
 979                 write_bytes -= count;
 980
 981                 if (page_fault)
 982                         break;
 983         }
 984         return page_fault ? -EFAULT : 0;
 985 }
 986
 987 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
 988 {
 989         size_t i;
 990         for (i = 0; i < num_pages; i++) {
 991                 if (!pages[i])
 992                         break;
 993                 unlock_page(pages[i]);
 994                 mark_page_accessed(pages[i]);
 995                 page_cache_release(pages[i]);
 996         }
 997 }
 998 static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
 999                                    struct btrfs_root *root,
1000                                    struct file *file,
1001                                    struct page **pages,
1002                                    size_t num_pages,
1003                                    loff_t pos,
1004                                    size_t write_bytes)
1005 {
1006         int i;
1007         int offset;
1008         int err = 0;
1009         int ret;
1010         int this_write;
1011         struct inode *inode = file->f_path.dentry->d_inode;
1012
1013         for (i = 0; i < num_pages; i++) {
1014                 offset = pos & (PAGE_CACHE_SIZE -1);
1015                 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
1016                 /* FIXME, one block at a time */
1017
1018                 mutex_lock(&root->fs_info->fs_mutex);
1019                 trans = btrfs_start_transaction(root, 1);
1020                 btrfs_csum_file_block(trans, root, inode->i_ino,
1021                                       pages[i]->index << PAGE_CACHE_SHIFT,
1022                                       kmap(pages[i]), PAGE_CACHE_SIZE);
1023                 kunmap(pages[i]);
1024                 SetPageChecked(pages[i]);
1025                 ret = btrfs_end_transaction(trans, root);
1026                 BUG_ON(ret);
1027                 mutex_unlock(&root->fs_info->fs_mutex);
1028
1029                 ret = nobh_commit_write(file, pages[i], offset,
1030                                          offset + this_write);
1031                 pos += this_write;
1032                 if (ret) {
1033                         err = ret;
1034                         goto failed;
1035                 }
1036                 WARN_ON(this_write > write_bytes);
1037                 write_bytes -= this_write;
1038         }
1039 failed:
1040         return err;
1041 }
1042
1043 static int prepare_pages(struct btrfs_trans_handle *trans,
1044                          struct btrfs_root *root,
1045                          struct file *file,
1046                          struct page **pages,
1047                          size_t num_pages,
1048                          loff_t pos,
1049                          size_t write_bytes)
1050 {
1051         int i;
1052         unsigned long index = pos >> PAGE_CACHE_SHIFT;
1053         struct inode *inode = file->f_path.dentry->d_inode;
1054         int offset;
1055         int err = 0;
1056         int ret;
1057         int this_write;
1058         loff_t isize = i_size_read(inode);
1059
1060         memset(pages, 0, num_pages * sizeof(struct page *));
1061
1062         for (i = 0; i < num_pages; i++) {
1063                 pages[i] = grab_cache_page(inode->i_mapping, index + i);
1064                 if (!pages[i]) {
1065                         err = -ENOMEM;
1066                         goto failed_release;
1067                 }
1068                 offset = pos & (PAGE_CACHE_SIZE -1);
1069                 this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
1070                 ret = nobh_prepare_write(pages[i], offset,
1071                                          offset + this_write,
1072                                          btrfs_get_block);
1073                 pos += this_write;
1074                 if (ret) {
1075                         err = ret;
1076                         goto failed_truncate;
1077                 }
1078                 WARN_ON(this_write > write_bytes);
1079                 write_bytes -= this_write;
1080         }
1081         return 0;
1082
1083 failed_release:
1084         btrfs_drop_pages(pages, num_pages);
1085         return err;
1086
1087 failed_truncate:
1088         btrfs_drop_pages(pages, num_pages);
1089         if (pos > isize)
1090                 vmtruncate(inode, isize);
1091         return err;
1092 }
1093
1094 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
1095                                 size_t count, loff_t *ppos)
1096 {
1097         loff_t pos;
1098         size_t num_written = 0;
1099         int err = 0;
1100         int ret = 0;
1101         struct inode *inode = file->f_path.dentry->d_inode;
1102         struct btrfs_root *root = btrfs_sb(inode->i_sb);
1103         struct page *pages[1];
1104
1105         if (file->f_flags & O_DIRECT)
1106                 return -EINVAL;
1107         pos = *ppos;
1108
1109         vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1110         current->backing_dev_info = inode->i_mapping->backing_dev_info;
1111         err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1112         if (err)
1113                 goto out;
1114         if (count == 0)
1115                 goto out;
1116         err = remove_suid(file->f_path.dentry);
1117         if (err)
1118                 goto out;
1119         file_update_time(file);
1120         mutex_lock(&inode->i_mutex);
1121         while(count > 0) {
1122                 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1123                 size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
1124                 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
1125                                         PAGE_CACHE_SHIFT;
1126                 ret = prepare_pages(NULL, root, file, pages, num_pages,
1127                                     pos, write_bytes);
1128                 BUG_ON(ret);
1129                 ret = btrfs_copy_from_user(pos, num_pages,
1130                                            write_bytes, pages, buf);
1131                 BUG_ON(ret);
1132
1133                 ret = dirty_and_release_pages(NULL, root, file, pages,
1134                                               num_pages, pos, write_bytes);
1135                 BUG_ON(ret);
1136                 btrfs_drop_pages(pages, num_pages);
1137
1138                 buf += write_bytes;
1139                 count -= write_bytes;
1140                 pos += write_bytes;
1141                 num_written += write_bytes;
1142
1143                 balance_dirty_pages_ratelimited(inode->i_mapping);
1144                 cond_resched();
1145         }
1146         mutex_unlock(&inode->i_mutex);
1147 out:
1148         *ppos = pos;
1149         current->backing_dev_info = NULL;
1150         return num_written ? num_written : err;
1151 }
1152
1153 static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
1154                         unsigned long offset, unsigned long size)
1155 {
1156         char *kaddr;
1157         unsigned long left, count = desc->count;
1158
1159         if (size > count)
1160                 size = count;
1161
1162         if (!PageChecked(page)) {
1163                 /* FIXME, do it per block */
1164                 struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
1165                 int ret = btrfs_csum_verify_file_block(root,
1166                                           page->mapping->host->i_ino,
1167                                           page->index << PAGE_CACHE_SHIFT,
1168                                           kmap(page), PAGE_CACHE_SIZE);
1169                 if (ret) {
1170                         printk("failed to verify ino %lu page %lu\n",
1171                                page->mapping->host->i_ino,
1172                                page->index);
1173                         memset(page_address(page), 0, PAGE_CACHE_SIZE);
1174                 }
1175                 SetPageChecked(page);
1176                 kunmap(page);
1177         }
1178         /*
1179          * Faults on the destination of a read are common, so do it before
1180          * taking the kmap.
1181          */
1182         if (!fault_in_pages_writeable(desc->arg.buf, size)) {
1183                 kaddr = kmap_atomic(page, KM_USER0);
1184                 left = __copy_to_user_inatomic(desc->arg.buf,
1185                                                 kaddr + offset, size);
1186                 kunmap_atomic(kaddr, KM_USER0);
1187                 if (left == 0)
1188                         goto success;
1189         }
1190
1191         /* Do it the slow way */
1192         kaddr = kmap(page);
1193         left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
1194         kunmap(page);
1195
1196         if (left) {
1197                 size -= left;
1198                 desc->error = -EFAULT;
1199         }
1200 success:
1201         desc->count = count - size;
1202         desc->written += size;
1203         desc->arg.buf += size;
1204         return size;
1205 }
1206
1207 /**
1208  * btrfs_file_aio_read - filesystem read routine
1209  * @iocb:       kernel I/O control block
1210  * @iov:        io vector request
1211  * @nr_segs:    number of segments in the iovec
1212  * @pos:        current file position
1213  */
1214 static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
1215                                    unsigned long nr_segs, loff_t pos)
1216 {
1217         struct file *filp = iocb->ki_filp;
1218         ssize_t retval;
1219         unsigned long seg;
1220         size_t count;
1221         loff_t *ppos = &iocb->ki_pos;
1222
1223         count = 0;
1224         for (seg = 0; seg < nr_segs; seg++) {
1225                 const struct iovec *iv = &iov[seg];
1226
1227                 /*
1228                  * If any segment has a negative length, or the cumulative
1229                  * length ever wraps negative then return -EINVAL.
1230                  */
1231                 count += iv->iov_len;
1232                 if (unlikely((ssize_t)(count|iv->iov_len) < 0))
1233                         return -EINVAL;
1234                 if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
1235                         continue;
1236                 if (seg == 0)
1237                         return -EFAULT;
1238                 nr_segs = seg;
1239                 count -= iv->iov_len;   /* This segment is no good */
1240                 break;
1241         }
1242         retval = 0;
1243         if (count) {
1244                 for (seg = 0; seg < nr_segs; seg++) {
1245                         read_descriptor_t desc;
1246
1247                         desc.written = 0;
1248                         desc.arg.buf = iov[seg].iov_base;
1249                         desc.count = iov[seg].iov_len;
1250                         if (desc.count == 0)
1251                                 continue;
1252                         desc.error = 0;
1253                         do_generic_file_read(filp, ppos, &desc,
1254                                              btrfs_read_actor);
1255                         retval += desc.written;
1256                         if (desc.error) {
1257                                 retval = retval ?: desc.error;
1258                                 break;
1259                         }
1260                 }
1261         }
1262         return retval;
1263 }
1264
1265 static struct kmem_cache *btrfs_inode_cachep;
1266 struct kmem_cache *btrfs_trans_handle_cachep;
1267 struct kmem_cache *btrfs_transaction_cachep;
1268 struct kmem_cache *btrfs_bit_radix_cachep;
1269 struct kmem_cache *btrfs_path_cachep;
1270
1271 /*
1272  * Called inside transaction, so use GFP_NOFS
1273  */
1274 static struct inode *btrfs_alloc_inode(struct super_block *sb)
1275 {
1276         struct btrfs_inode *ei;
1277
1278         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
1279         if (!ei)
1280                 return NULL;
1281         ei->magic = 0xDEADBEEF;
1282         ei->magic2 = 0xDEADBEAF;
1283         return &ei->vfs_inode;
1284 }
1285
1286 static void btrfs_destroy_inode(struct inode *inode)
1287 {
1288         struct btrfs_inode *ei = BTRFS_I(inode);
1289         WARN_ON(ei->magic != 0xDEADBEEF);
1290         WARN_ON(ei->magic2 != 0xDEADBEAF);
1291         WARN_ON(!list_empty(&inode->i_dentry));
1292         WARN_ON(inode->i_ino == 1);
1293         WARN_ON(inode->i_data.nrpages);
1294
1295         ei->magic = 0;
1296         ei->magic2 = 0;
1297         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
1298 }
1299
1300 static void init_once(void * foo, struct kmem_cache * cachep,
1301                       unsigned long flags)
1302 {
1303         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
1304
1305         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
1306             SLAB_CTOR_CONSTRUCTOR) {
1307                 inode_init_once(&ei->vfs_inode);
1308         }
1309 }
1310
1311 static int init_inodecache(void)
1312 {
1313         btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
1314                                              sizeof(struct btrfs_inode),
1315                                              0, (SLAB_RECLAIM_ACCOUNT|
1316                                                 SLAB_MEM_SPREAD),
1317                                              init_once, NULL);
1318         btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
1319                                              sizeof(struct btrfs_trans_handle),
1320                                              0, (SLAB_RECLAIM_ACCOUNT|
1321                                                 SLAB_MEM_SPREAD),
1322                                              NULL, NULL);
1323         btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
1324                                              sizeof(struct btrfs_transaction),
1325                                              0, (SLAB_RECLAIM_ACCOUNT|
1326                                                 SLAB_MEM_SPREAD),
1327                                              NULL, NULL);
1328         btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
1329                                              sizeof(struct btrfs_transaction),
1330                                              0, (SLAB_RECLAIM_ACCOUNT|
1331                                                 SLAB_MEM_SPREAD),
1332                                              NULL, NULL);
1333         btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
1334                                              256,
1335                                              0, (SLAB_RECLAIM_ACCOUNT|
1336                                                 SLAB_MEM_SPREAD |
1337                                                 SLAB_DESTROY_BY_RCU),
1338                                              NULL, NULL);
1339         if (btrfs_inode_cachep == NULL || btrfs_trans_handle_cachep == NULL ||
1340             btrfs_transaction_cachep == NULL || btrfs_bit_radix_cachep == NULL)
1341                 return -ENOMEM;
1342         return 0;
1343 }
1344
1345 static void destroy_inodecache(void)
1346 {
1347         kmem_cache_destroy(btrfs_inode_cachep);
1348         kmem_cache_destroy(btrfs_trans_handle_cachep);
1349         kmem_cache_destroy(btrfs_transaction_cachep);
1350         kmem_cache_destroy(btrfs_bit_radix_cachep);
1351         kmem_cache_destroy(btrfs_path_cachep);
1352 }
1353
1354 static int btrfs_get_sb(struct file_system_type *fs_type,
1355         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1356 {
1357         return get_sb_bdev(fs_type, flags, dev_name, data,
1358                            btrfs_fill_super, mnt);
1359 }
1360
1361 static struct file_system_type btrfs_fs_type = {
1362         .owner          = THIS_MODULE,
1363         .name           = "btrfs",
1364         .get_sb         = btrfs_get_sb,
1365         .kill_sb        = kill_block_super,
1366         .fs_flags       = FS_REQUIRES_DEV,
1367 };
1368
1369 static struct super_operations btrfs_super_ops = {
1370         .statfs         = simple_statfs,
1371         .delete_inode   = btrfs_delete_inode,
1372         .put_super      = btrfs_put_super,
1373         .read_inode     = btrfs_read_locked_inode,
1374         .write_super    = btrfs_write_super,
1375         .sync_fs        = btrfs_sync_fs,
1376         .write_inode    = btrfs_write_inode,
1377         .alloc_inode    = btrfs_alloc_inode,
1378         .destroy_inode  = btrfs_destroy_inode,
1379 };
1380
1381 static struct inode_operations btrfs_dir_inode_operations = {
1382         .lookup         = btrfs_lookup,
1383         .create         = btrfs_create,
1384         .unlink         = btrfs_unlink,
1385         .mkdir          = btrfs_mkdir,
1386         .rmdir          = btrfs_rmdir,
1387 };
1388
1389 static struct file_operations btrfs_dir_file_operations = {
1390         .llseek         = generic_file_llseek,
1391         .read           = generic_read_dir,
1392         .readdir        = btrfs_readdir,
1393 };
1394
1395 static struct address_space_operations btrfs_aops = {
1396         .readpage       = btrfs_readpage,
1397         .readpages      = btrfs_readpages,
1398         .writepage      = btrfs_writepage,
1399         .sync_page      = block_sync_page,
1400         .prepare_write  = btrfs_prepare_write,
1401         .commit_write   = btrfs_commit_write,
1402 };
1403
1404 static struct inode_operations btrfs_file_inode_operations = {
1405         .truncate       = btrfs_truncate,
1406 };
1407
1408 static struct file_operations btrfs_file_operations = {
1409         .llseek         = generic_file_llseek,
1410         .read           = do_sync_read,
1411         .aio_read       = btrfs_file_aio_read,
1412         .write          = btrfs_file_write,
1413         .mmap           = generic_file_mmap,
1414         .open           = generic_file_open,
1415 };
1416
1417 static int __init init_btrfs_fs(void)
1418 {
1419         int err;
1420         printk("btrfs loaded!\n");
1421         err = init_inodecache();
1422         if (err)
1423                 return err;
1424         return register_filesystem(&btrfs_fs_type);
1425 }
1426
1427 static void __exit exit_btrfs_fs(void)
1428 {
1429         destroy_inodecache();
1430         unregister_filesystem(&btrfs_fs_type);
1431         printk("btrfs unloaded\n");
1432 }
1433
1434 module_init(init_btrfs_fs)
1435 module_exit(exit_btrfs_fs)
1436
1437 MODULE_LICENSE("GPL");