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/bio.h>
  20 #include <linux/buffer_head.h>
  21 #include <linux/fs.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/highmem.h>
  24 #include <linux/time.h>
  25 #include <linux/init.h>
  26 #include <linux/string.h>
  27 #include <linux/smp_lock.h>
  28 #include <linux/backing-dev.h>
  29 #include <linux/mpage.h>
  30 #include <linux/swap.h>
  31 #include <linux/writeback.h>
  32 #include <linux/statfs.h>
  33 #include <linux/compat.h>
  34 #include <linux/bit_spinlock.h>
  35 #include <linux/version.h>
  36 #include <linux/xattr.h>
  37 #include "ctree.h"
  38 #include "disk-io.h"
  39 #include "transaction.h"
  40 #include "btrfs_inode.h"
  41 #include "ioctl.h"
  42 #include "print-tree.h"
  43 #include "volumes.h"
  44
  45 struct btrfs_iget_args {
  46         u64 ino;
  47         struct btrfs_root *root;
  48 };
  49
  50 static struct inode_operations btrfs_dir_inode_operations;
  51 static struct inode_operations btrfs_symlink_inode_operations;
  52 static struct inode_operations btrfs_dir_ro_inode_operations;
  53 static struct inode_operations btrfs_special_inode_operations;
  54 static struct inode_operations btrfs_file_inode_operations;
  55 static struct address_space_operations btrfs_aops;
  56 static struct address_space_operations btrfs_symlink_aops;
  57 static struct file_operations btrfs_dir_file_operations;
  58 static struct extent_io_ops btrfs_extent_io_ops;
  59
  60 static struct kmem_cache *btrfs_inode_cachep;
  61 struct kmem_cache *btrfs_trans_handle_cachep;
  62 struct kmem_cache *btrfs_transaction_cachep;
  63 struct kmem_cache *btrfs_bit_radix_cachep;
  64 struct kmem_cache *btrfs_path_cachep;
  65
  66 #define S_SHIFT 12
  67 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
  68         [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
  69         [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
  70         [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
  71         [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
  72         [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
  73         [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
  74         [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
  75 };
  76
  77 int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
  78                            int for_del)
  79 {
  80         u64 total = btrfs_super_total_bytes(&root->fs_info->super_copy);
  81         u64 used = btrfs_super_bytes_used(&root->fs_info->super_copy);
  82         u64 thresh;
  83         int ret = 0;
  84
  85         if (for_del)
  86                 thresh = total * 90;
  87         else
  88                 thresh = total * 85;
  89
  90         do_div(thresh, 100);
  91
  92         spin_lock(&root->fs_info->delalloc_lock);
  93         if (used + root->fs_info->delalloc_bytes + num_required > thresh)
  94                 ret = -ENOSPC;
  95         spin_unlock(&root->fs_info->delalloc_lock);
  96         return ret;
  97 }
  98
  99 static int cow_file_range(struct inode *inode, u64 start, u64 end)
 100 {
 101         struct btrfs_root *root = BTRFS_I(inode)->root;
 102         struct btrfs_trans_handle *trans;
 103         u64 alloc_hint = 0;
 104         u64 num_bytes;
 105         u64 cur_alloc_size;
 106         u64 blocksize = root->sectorsize;
 107         u64 orig_start = start;
 108         u64 orig_num_bytes;
 109         struct btrfs_key ins;
 110         int ret;
 111
 112         trans = btrfs_start_transaction(root, 1);
 113         BUG_ON(!trans);
 114         btrfs_set_trans_block_group(trans, inode);
 115
 116         num_bytes = (end - start + blocksize) & ~(blocksize - 1);
 117         num_bytes = max(blocksize,  num_bytes);
 118         ret = btrfs_drop_extents(trans, root, inode,
 119                                  start, start + num_bytes, start, &alloc_hint);
 120         orig_num_bytes = num_bytes;
 121
 122         if (alloc_hint == EXTENT_MAP_INLINE)
 123                 goto out;
 124
 125         while(num_bytes > 0) {
 126                 cur_alloc_size = min(num_bytes, root->fs_info->max_extent);
 127                 ret = btrfs_alloc_extent(trans, root, cur_alloc_size,
 128                                          root->sectorsize,
 129                                          root->root_key.objectid,
 130                                          trans->transid,
 131                                          inode->i_ino, start, 0,
 132                                          alloc_hint, (u64)-1, &ins, 1);
 133                 if (ret) {
 134                         WARN_ON(1);
 135                         goto out;
 136                 }
 137                 cur_alloc_size = ins.offset;
 138                 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
 139                                                start, ins.objectid, ins.offset,
 140                                                ins.offset);
 141                 inode->i_blocks += ins.offset >> 9;
 142                 btrfs_check_file(root, inode);
 143                 num_bytes -= cur_alloc_size;
 144                 alloc_hint = ins.objectid + ins.offset;
 145                 start += cur_alloc_size;
 146         }
 147         btrfs_drop_extent_cache(inode, orig_start,
 148                                 orig_start + orig_num_bytes - 1);
 149         btrfs_add_ordered_inode(inode);
 150         btrfs_update_inode(trans, root, inode);
 151 out:
 152         btrfs_end_transaction(trans, root);
 153         return ret;
 154 }
 155
 156 static int run_delalloc_nocow(struct inode *inode, u64 start, u64 end)
 157 {
 158         u64 extent_start;
 159         u64 extent_end;
 160         u64 bytenr;
 161         u64 cow_end;
 162         u64 loops = 0;
 163         u64 total_fs_bytes;
 164         struct btrfs_root *root = BTRFS_I(inode)->root;
 165         struct extent_buffer *leaf;
 166         int found_type;
 167         struct btrfs_path *path;
 168         struct btrfs_file_extent_item *item;
 169         int ret;
 170         int err;
 171         struct btrfs_key found_key;
 172
 173         total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
 174         path = btrfs_alloc_path();
 175         BUG_ON(!path);
 176 again:
 177         ret = btrfs_lookup_file_extent(NULL, root, path,
 178                                        inode->i_ino, start, 0);
 179         if (ret < 0) {
 180                 btrfs_free_path(path);
 181                 return ret;
 182         }
 183
 184         cow_end = end;
 185         if (ret != 0) {
 186                 if (path->slots[0] == 0)
 187                         goto not_found;
 188                 path->slots[0]--;
 189         }
 190
 191         leaf = path->nodes[0];
 192         item = btrfs_item_ptr(leaf, path->slots[0],
 193                               struct btrfs_file_extent_item);
 194
 195         /* are we inside the extent that was found? */
 196         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 197         found_type = btrfs_key_type(&found_key);
 198         if (found_key.objectid != inode->i_ino ||
 199             found_type != BTRFS_EXTENT_DATA_KEY) {
 200                 goto not_found;
 201         }
 202
 203         found_type = btrfs_file_extent_type(leaf, item);
 204         extent_start = found_key.offset;
 205         if (found_type == BTRFS_FILE_EXTENT_REG) {
 206                 u64 extent_num_bytes;
 207
 208                 extent_num_bytes = btrfs_file_extent_num_bytes(leaf, item);
 209                 extent_end = extent_start + extent_num_bytes;
 210                 err = 0;
 211
 212                 if (loops && start != extent_start)
 213                         goto not_found;
 214
 215                 if (start < extent_start || start >= extent_end)
 216                         goto not_found;
 217
 218                 cow_end = min(end, extent_end - 1);
 219                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
 220                 if (bytenr == 0)
 221                         goto not_found;
 222
 223                 /*
 224                  * we may be called by the resizer, make sure we're inside
 225                  * the limits of the FS
 226                  */
 227                 if (bytenr + extent_num_bytes > total_fs_bytes)
 228                         goto not_found;
 229
 230                 if (btrfs_count_snapshots_in_path(root, path, bytenr) != 1) {
 231                         goto not_found;
 232                 }
 233
 234                 start = extent_end;
 235         } else {
 236                 goto not_found;
 237         }
 238 loop:
 239         if (start > end) {
 240                 btrfs_free_path(path);
 241                 return 0;
 242         }
 243         btrfs_release_path(root, path);
 244         loops++;
 245         goto again;
 246
 247 not_found:
 248         cow_file_range(inode, start, cow_end);
 249         start = cow_end + 1;
 250         goto loop;
 251 }
 252
 253 static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
 254 {
 255         struct btrfs_root *root = BTRFS_I(inode)->root;
 256         int ret;
 257         mutex_lock(&root->fs_info->fs_mutex);
 258         if (btrfs_test_opt(root, NODATACOW) ||
 259             btrfs_test_flag(inode, NODATACOW))
 260                 ret = run_delalloc_nocow(inode, start, end);
 261         else
 262                 ret = cow_file_range(inode, start, end);
 263
 264         mutex_unlock(&root->fs_info->fs_mutex);
 265         return ret;
 266 }
 267
 268 int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
 269                        unsigned long old, unsigned long bits)
 270 {
 271         if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
 272                 struct btrfs_root *root = BTRFS_I(inode)->root;
 273                 spin_lock(&root->fs_info->delalloc_lock);
 274                 BTRFS_I(inode)->delalloc_bytes += end - start + 1;
 275                 root->fs_info->delalloc_bytes += end - start + 1;
 276                 spin_unlock(&root->fs_info->delalloc_lock);
 277         }
 278         return 0;
 279 }
 280
 281 int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
 282                          unsigned long old, unsigned long bits)
 283 {
 284         if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
 285                 struct btrfs_root *root = BTRFS_I(inode)->root;
 286                 spin_lock(&root->fs_info->delalloc_lock);
 287                 if (end - start + 1 > root->fs_info->delalloc_bytes) {
 288                         printk("warning: delalloc account %Lu %Lu\n",
 289                                end - start + 1, root->fs_info->delalloc_bytes);
 290                         root->fs_info->delalloc_bytes = 0;
 291                         BTRFS_I(inode)->delalloc_bytes = 0;
 292                 } else {
 293                         root->fs_info->delalloc_bytes -= end - start + 1;
 294                         BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
 295                 }
 296                 spin_unlock(&root->fs_info->delalloc_lock);
 297         }
 298         return 0;
 299 }
 300
 301 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
 302                          size_t size, struct bio *bio)
 303 {
 304         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 305         struct btrfs_mapping_tree *map_tree;
 306         u64 logical = bio->bi_sector << 9;
 307         u64 length = 0;
 308         u64 map_length;
 309         struct bio_vec *bvec;
 310         int i;
 311         int ret;
 312
 313         bio_for_each_segment(bvec, bio, i) {
 314                 length += bvec->bv_len;
 315         }
 316         map_tree = &root->fs_info->mapping_tree;
 317         map_length = length;
 318         ret = btrfs_map_block(map_tree, READ, logical,
 319                               &map_length, NULL, 0);
 320
 321         if (map_length < length + size) {
 322                 return 1;
 323         }
 324         return 0;
 325 }
 326
 327 int __btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 328                           int mirror_num)
 329 {
 330         struct btrfs_root *root = BTRFS_I(inode)->root;
 331         struct btrfs_trans_handle *trans;
 332         int ret = 0;
 333         char *sums = NULL;
 334
 335         ret = btrfs_csum_one_bio(root, bio, &sums);
 336         BUG_ON(ret);
 337
 338         mutex_lock(&root->fs_info->fs_mutex);
 339         trans = btrfs_start_transaction(root, 1);
 340
 341         btrfs_set_trans_block_group(trans, inode);
 342         btrfs_csum_file_blocks(trans, root, inode, bio, sums);
 343
 344         ret = btrfs_end_transaction(trans, root);
 345         BUG_ON(ret);
 346         mutex_unlock(&root->fs_info->fs_mutex);
 347
 348         kfree(sums);
 349
 350         return btrfs_map_bio(root, rw, bio, mirror_num);
 351 }
 352
 353 int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 354                           int mirror_num)
 355 {
 356         struct btrfs_root *root = BTRFS_I(inode)->root;
 357         int ret = 0;
 358
 359         if (!(rw & (1 << BIO_RW))) {
 360                 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
 361                 BUG_ON(ret);
 362                 goto mapit;
 363         }
 364
 365         if (btrfs_test_opt(root, NODATASUM) ||
 366             btrfs_test_flag(inode, NODATASUM)) {
 367                 goto mapit;
 368         }
 369
 370         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 371                                    inode, rw, bio, mirror_num,
 372                                    __btrfs_submit_bio_hook);
 373 mapit:
 374         return btrfs_map_bio(root, rw, bio, mirror_num);
 375 }
 376
 377 int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
 378 {
 379         int ret = 0;
 380         struct inode *inode = page->mapping->host;
 381         struct btrfs_root *root = BTRFS_I(inode)->root;
 382         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 383         struct btrfs_csum_item *item;
 384         struct btrfs_path *path = NULL;
 385         u32 csum;
 386         if (btrfs_test_opt(root, NODATASUM) ||
 387             btrfs_test_flag(inode, NODATASUM))
 388                 return 0;
 389         mutex_lock(&root->fs_info->fs_mutex);
 390         path = btrfs_alloc_path();
 391         item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
 392         if (IS_ERR(item)) {
 393                 ret = PTR_ERR(item);
 394                 /* a csum that isn't present is a preallocated region. */
 395                 if (ret == -ENOENT || ret == -EFBIG)
 396                         ret = 0;
 397                 csum = 0;
 398                 printk("no csum found for inode %lu start %Lu\n", inode->i_ino, start);
 399                 goto out;
 400         }
 401         read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
 402                            BTRFS_CRC32_SIZE);
 403         set_state_private(io_tree, start, csum);
 404 out:
 405         if (path)
 406                 btrfs_free_path(path);
 407         mutex_unlock(&root->fs_info->fs_mutex);
 408         return ret;
 409 }
 410
 411 struct io_failure_record {
 412         struct page *page;
 413         u64 start;
 414         u64 len;
 415         u64 logical;
 416         int last_mirror;
 417 };
 418
 419 int btrfs_readpage_io_failed_hook(struct bio *failed_bio,
 420                                   struct page *page, u64 start, u64 end,
 421                                   struct extent_state *state)
 422 {
 423         struct io_failure_record *failrec = NULL;
 424         u64 private;
 425         struct extent_map *em;
 426         struct inode *inode = page->mapping->host;
 427         struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
 428         struct bio *bio;
 429         int num_copies;
 430         int ret;
 431         u64 logical;
 432
 433         ret = get_state_private(failure_tree, start, &private);
 434         if (ret) {
 435                 size_t pg_offset = start - page_offset(page);
 436                 failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
 437                 if (!failrec)
 438                         return -ENOMEM;
 439                 failrec->start = start;
 440                 failrec->len = end - start + 1;
 441                 failrec->last_mirror = 0;
 442
 443                 em = btrfs_get_extent(inode, NULL, pg_offset, start,
 444                                       failrec->len, 0);
 445
 446                 if (!em || IS_ERR(em)) {
 447                         kfree(failrec);
 448                         return -EIO;
 449                 }
 450                 logical = start - em->start;
 451                 logical = em->block_start + logical;
 452                 failrec->logical = logical;
 453                 free_extent_map(em);
 454                 set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
 455                                 EXTENT_DIRTY, GFP_NOFS);
 456                 set_state_private(failure_tree, start,
 457                                  (u64)(unsigned long)failrec);
 458         } else {
 459                 failrec = (struct io_failure_record *)(unsigned long)private;
 460         }
 461         num_copies = btrfs_num_copies(
 462                               &BTRFS_I(inode)->root->fs_info->mapping_tree,
 463                               failrec->logical, failrec->len);
 464         failrec->last_mirror++;
 465         if (!state) {
 466                 spin_lock_irq(&BTRFS_I(inode)->io_tree.lock);
 467                 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
 468                                                     failrec->start,
 469                                                     EXTENT_LOCKED);
 470                 if (state && state->start != failrec->start)
 471                         state = NULL;
 472                 spin_unlock_irq(&BTRFS_I(inode)->io_tree.lock);
 473         }
 474         if (!state || failrec->last_mirror > num_copies) {
 475                 set_state_private(failure_tree, failrec->start, 0);
 476                 clear_extent_bits(failure_tree, failrec->start,
 477                                   failrec->start + failrec->len - 1,
 478                                   EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
 479                 kfree(failrec);
 480                 return -EIO;
 481         }
 482         bio = bio_alloc(GFP_NOFS, 1);
 483         bio->bi_private = state;
 484         bio->bi_end_io = failed_bio->bi_end_io;
 485         bio->bi_sector = failrec->logical >> 9;
 486         bio->bi_bdev = failed_bio->bi_bdev;
 487         bio_add_page(bio, page, failrec->len, start - page_offset(page));
 488         btrfs_submit_bio_hook(inode, READ, bio, failrec->last_mirror);
 489         return 0;
 490 }
 491
 492 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 493                                struct extent_state *state)
 494 {
 495         size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
 496         struct inode *inode = page->mapping->host;
 497         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 498         char *kaddr;
 499         u64 private = ~(u32)0;
 500         int ret;
 501         struct btrfs_root *root = BTRFS_I(inode)->root;
 502         u32 csum = ~(u32)0;
 503         unsigned long flags;
 504
 505         if (btrfs_test_opt(root, NODATASUM) ||
 506             btrfs_test_flag(inode, NODATASUM))
 507                 return 0;
 508         if (state && state->start == start) {
 509                 private = state->private;
 510                 ret = 0;
 511         } else {
 512                 ret = get_state_private(io_tree, start, &private);
 513         }
 514         local_irq_save(flags);
 515         kaddr = kmap_atomic(page, KM_IRQ0);
 516         if (ret) {
 517                 goto zeroit;
 518         }
 519         csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
 520         btrfs_csum_final(csum, (char *)&csum);
 521         if (csum != private) {
 522                 goto zeroit;
 523         }
 524         kunmap_atomic(kaddr, KM_IRQ0);
 525         local_irq_restore(flags);
 526
 527         /* if the io failure tree for this inode is non-empty,
 528          * check to see if we've recovered from a failed IO
 529          */
 530         private = 0;
 531         if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
 532                              (u64)-1, 1, EXTENT_DIRTY)) {
 533                 u64 private_failure;
 534                 struct io_failure_record *failure;
 535                 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
 536                                         start, &private_failure);
 537                 if (ret == 0) {
 538                         failure = (struct io_failure_record *)(unsigned long)
 539                                    private_failure;
 540                         set_state_private(&BTRFS_I(inode)->io_failure_tree,
 541                                           failure->start, 0);
 542                         clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
 543                                           failure->start,
 544                                           failure->start + failure->len - 1,
 545                                           EXTENT_DIRTY | EXTENT_LOCKED,
 546                                           GFP_NOFS);
 547                         kfree(failure);
 548                 }
 549         }
 550         return 0;
 551
 552 zeroit:
 553         printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
 554                page->mapping->host->i_ino, (unsigned long long)start, csum,
 555                private);
 556         memset(kaddr + offset, 1, end - start + 1);
 557         flush_dcache_page(page);
 558         kunmap_atomic(kaddr, KM_IRQ0);
 559         local_irq_restore(flags);
 560         return -EIO;
 561 }
 562
 563 void btrfs_read_locked_inode(struct inode *inode)
 564 {
 565         struct btrfs_path *path;
 566         struct extent_buffer *leaf;
 567         struct btrfs_inode_item *inode_item;
 568         struct btrfs_timespec *tspec;
 569         struct btrfs_root *root = BTRFS_I(inode)->root;
 570         struct btrfs_key location;
 571         u64 alloc_group_block;
 572         u32 rdev;
 573         int ret;
 574
 575         path = btrfs_alloc_path();
 576         BUG_ON(!path);
 577         mutex_lock(&root->fs_info->fs_mutex);
 578         memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
 579
 580         ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
 581         if (ret)
 582                 goto make_bad;
 583
 584         leaf = path->nodes[0];
 585         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 586                                     struct btrfs_inode_item);
 587
 588         inode->i_mode = btrfs_inode_mode(leaf, inode_item);
 589         inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
 590         inode->i_uid = btrfs_inode_uid(leaf, inode_item);
 591         inode->i_gid = btrfs_inode_gid(leaf, inode_item);
 592         inode->i_size = btrfs_inode_size(leaf, inode_item);
 593
 594         tspec = btrfs_inode_atime(inode_item);
 595         inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 596         inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 597
 598         tspec = btrfs_inode_mtime(inode_item);
 599         inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 600         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 601
 602         tspec = btrfs_inode_ctime(inode_item);
 603         inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 604         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 605
 606         inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
 607         inode->i_generation = btrfs_inode_generation(leaf, inode_item);
 608         inode->i_rdev = 0;
 609         rdev = btrfs_inode_rdev(leaf, inode_item);
 610
 611         alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
 612         BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
 613                                                        alloc_group_block);
 614         BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
 615         if (!BTRFS_I(inode)->block_group) {
 616                 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
 617                                                  NULL, 0,
 618                                                  BTRFS_BLOCK_GROUP_METADATA, 0);
 619         }
 620         btrfs_free_path(path);
 621         inode_item = NULL;
 622
 623         mutex_unlock(&root->fs_info->fs_mutex);
 624
 625         switch (inode->i_mode & S_IFMT) {
 626         case S_IFREG:
 627                 inode->i_mapping->a_ops = &btrfs_aops;
 628                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
 629                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 630                 inode->i_fop = &btrfs_file_operations;
 631                 inode->i_op = &btrfs_file_inode_operations;
 632                 break;
 633         case S_IFDIR:
 634                 inode->i_fop = &btrfs_dir_file_operations;
 635                 if (root == root->fs_info->tree_root)
 636                         inode->i_op = &btrfs_dir_ro_inode_operations;
 637                 else
 638                         inode->i_op = &btrfs_dir_inode_operations;
 639                 break;
 640         case S_IFLNK:
 641                 inode->i_op = &btrfs_symlink_inode_operations;
 642                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
 643                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
 644                 break;
 645         default:
 646                 init_special_inode(inode, inode->i_mode, rdev);
 647                 break;
 648         }
 649         return;
 650
 651 make_bad:
 652         btrfs_release_path(root, path);
 653         btrfs_free_path(path);
 654         mutex_unlock(&root->fs_info->fs_mutex);
 655         make_bad_inode(inode);
 656 }
 657
 658 static void fill_inode_item(struct extent_buffer *leaf,
 659                             struct btrfs_inode_item *item,
 660                             struct inode *inode)
 661 {
 662         btrfs_set_inode_uid(leaf, item, inode->i_uid);
 663         btrfs_set_inode_gid(leaf, item, inode->i_gid);
 664         btrfs_set_inode_size(leaf, item, inode->i_size);
 665         btrfs_set_inode_mode(leaf, item, inode->i_mode);
 666         btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
 667
 668         btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
 669                                inode->i_atime.tv_sec);
 670         btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
 671                                 inode->i_atime.tv_nsec);
 672
 673         btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
 674                                inode->i_mtime.tv_sec);
 675         btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
 676                                 inode->i_mtime.tv_nsec);
 677
 678         btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
 679                                inode->i_ctime.tv_sec);
 680         btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
 681                                 inode->i_ctime.tv_nsec);
 682
 683         btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
 684         btrfs_set_inode_generation(leaf, item, inode->i_generation);
 685         btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
 686         btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
 687         btrfs_set_inode_block_group(leaf, item,
 688                                     BTRFS_I(inode)->block_group->key.objectid);
 689 }
 690
 691 int btrfs_update_inode(struct btrfs_trans_handle *trans,
 692                               struct btrfs_root *root,
 693                               struct inode *inode)
 694 {
 695         struct btrfs_inode_item *inode_item;
 696         struct btrfs_path *path;
 697         struct extent_buffer *leaf;
 698         int ret;
 699
 700         path = btrfs_alloc_path();
 701         BUG_ON(!path);
 702         ret = btrfs_lookup_inode(trans, root, path,
 703                                  &BTRFS_I(inode)->location, 1);
 704         if (ret) {
 705                 if (ret > 0)
 706                         ret = -ENOENT;
 707                 goto failed;
 708         }
 709
 710         leaf = path->nodes[0];
 711         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 712                                   struct btrfs_inode_item);
 713
 714         fill_inode_item(leaf, inode_item, inode);
 715         btrfs_mark_buffer_dirty(leaf);
 716         btrfs_set_inode_last_trans(trans, inode);
 717         ret = 0;
 718 failed:
 719         btrfs_release_path(root, path);
 720         btrfs_free_path(path);
 721         return ret;
 722 }
 723
 724
 725 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
 726                               struct btrfs_root *root,
 727                               struct inode *dir,
 728                               struct dentry *dentry)
 729 {
 730         struct btrfs_path *path;
 731         const char *name = dentry->d_name.name;
 732         int name_len = dentry->d_name.len;
 733         int ret = 0;
 734         struct extent_buffer *leaf;
 735         struct btrfs_dir_item *di;
 736         struct btrfs_key key;
 737
 738         path = btrfs_alloc_path();
 739         if (!path) {
 740                 ret = -ENOMEM;
 741                 goto err;
 742         }
 743
 744         di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
 745                                     name, name_len, -1);
 746         if (IS_ERR(di)) {
 747                 ret = PTR_ERR(di);
 748                 goto err;
 749         }
 750         if (!di) {
 751                 ret = -ENOENT;
 752                 goto err;
 753         }
 754         leaf = path->nodes[0];
 755         btrfs_dir_item_key_to_cpu(leaf, di, &key);
 756         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 757         if (ret)
 758                 goto err;
 759         btrfs_release_path(root, path);
 760
 761         di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
 762                                          key.objectid, name, name_len, -1);
 763         if (IS_ERR(di)) {
 764                 ret = PTR_ERR(di);
 765                 goto err;
 766         }
 767         if (!di) {
 768                 ret = -ENOENT;
 769                 goto err;
 770         }
 771         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 772
 773         dentry->d_inode->i_ctime = dir->i_ctime;
 774         ret = btrfs_del_inode_ref(trans, root, name, name_len,
 775                                   dentry->d_inode->i_ino,
 776                                   dentry->d_parent->d_inode->i_ino);
 777         if (ret) {
 778                 printk("failed to delete reference to %.*s, "
 779                        "inode %lu parent %lu\n", name_len, name,
 780                        dentry->d_inode->i_ino,
 781                        dentry->d_parent->d_inode->i_ino);
 782         }
 783 err:
 784         btrfs_free_path(path);
 785         if (!ret) {
 786                 dir->i_size -= name_len * 2;
 787                 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 788                 btrfs_update_inode(trans, root, dir);
 789 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 790                 dentry->d_inode->i_nlink--;
 791 #else
 792                 drop_nlink(dentry->d_inode);
 793 #endif
 794                 ret = btrfs_update_inode(trans, root, dentry->d_inode);
 795                 dir->i_sb->s_dirt = 1;
 796         }
 797         return ret;
 798 }
 799
 800 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 801 {
 802         struct btrfs_root *root;
 803         struct btrfs_trans_handle *trans;
 804         struct inode *inode = dentry->d_inode;
 805         int ret;
 806         unsigned long nr = 0;
 807
 808         root = BTRFS_I(dir)->root;
 809         mutex_lock(&root->fs_info->fs_mutex);
 810
 811         ret = btrfs_check_free_space(root, 1, 1);
 812         if (ret)
 813                 goto fail;
 814
 815         trans = btrfs_start_transaction(root, 1);
 816
 817         btrfs_set_trans_block_group(trans, dir);
 818         ret = btrfs_unlink_trans(trans, root, dir, dentry);
 819         nr = trans->blocks_used;
 820
 821         if (inode->i_nlink == 0) {
 822                 int found;
 823                 /* if the inode isn't linked anywhere,
 824                  * we don't need to worry about
 825                  * data=ordered
 826                  */
 827                 found = btrfs_del_ordered_inode(inode);
 828                 if (found == 1) {
 829                         atomic_dec(&inode->i_count);
 830                 }
 831         }
 832
 833         btrfs_end_transaction(trans, root);
 834 fail:
 835         mutex_unlock(&root->fs_info->fs_mutex);
 836         btrfs_btree_balance_dirty(root, nr);
 837         btrfs_throttle(root);
 838         return ret;
 839 }
 840
 841 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 842 {
 843         struct inode *inode = dentry->d_inode;
 844         int err = 0;
 845         int ret;
 846         struct btrfs_root *root = BTRFS_I(dir)->root;
 847         struct btrfs_trans_handle *trans;
 848         unsigned long nr = 0;
 849
 850         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
 851                 return -ENOTEMPTY;
 852
 853         mutex_lock(&root->fs_info->fs_mutex);
 854         ret = btrfs_check_free_space(root, 1, 1);
 855         if (ret)
 856                 goto fail;
 857
 858         trans = btrfs_start_transaction(root, 1);
 859         btrfs_set_trans_block_group(trans, dir);
 860
 861         /* now the directory is empty */
 862         err = btrfs_unlink_trans(trans, root, dir, dentry);
 863         if (!err) {
 864                 inode->i_size = 0;
 865         }
 866
 867         nr = trans->blocks_used;
 868         ret = btrfs_end_transaction(trans, root);
 869 fail:
 870         mutex_unlock(&root->fs_info->fs_mutex);
 871         btrfs_btree_balance_dirty(root, nr);
 872         btrfs_throttle(root);
 873
 874         if (ret && !err)
 875                 err = ret;
 876         return err;
 877 }
 878
 879 /*
 880  * this can truncate away extent items, csum items and directory items.
 881  * It starts at a high offset and removes keys until it can't find
 882  * any higher than i_size.
 883  *
 884  * csum items that cross the new i_size are truncated to the new size
 885  * as well.
 886  */
 887 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
 888                                    struct btrfs_root *root,
 889                                    struct inode *inode,
 890                                    u32 min_type)
 891 {
 892         int ret;
 893         struct btrfs_path *path;
 894         struct btrfs_key key;
 895         struct btrfs_key found_key;
 896         u32 found_type;
 897         struct extent_buffer *leaf;
 898         struct btrfs_file_extent_item *fi;
 899         u64 extent_start = 0;
 900         u64 extent_num_bytes = 0;
 901         u64 item_end = 0;
 902         u64 root_gen = 0;
 903         u64 root_owner = 0;
 904         int found_extent;
 905         int del_item;
 906         int pending_del_nr = 0;
 907         int pending_del_slot = 0;
 908         int extent_type = -1;
 909
 910         btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
 911         path = btrfs_alloc_path();
 912         path->reada = -1;
 913         BUG_ON(!path);
 914
 915         /* FIXME, add redo link to tree so we don't leak on crash */
 916         key.objectid = inode->i_ino;
 917         key.offset = (u64)-1;
 918         key.type = (u8)-1;
 919
 920         btrfs_init_path(path);
 921 search_again:
 922         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 923         if (ret < 0) {
 924                 goto error;
 925         }
 926         if (ret > 0) {
 927                 BUG_ON(path->slots[0] == 0);
 928                 path->slots[0]--;
 929         }
 930
 931         while(1) {
 932                 fi = NULL;
 933                 leaf = path->nodes[0];
 934                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 935                 found_type = btrfs_key_type(&found_key);
 936
 937                 if (found_key.objectid != inode->i_ino)
 938                         break;
 939
 940                 if (found_type < min_type)
 941                         break;
 942
 943                 item_end = found_key.offset;
 944                 if (found_type == BTRFS_EXTENT_DATA_KEY) {
 945                         fi = btrfs_item_ptr(leaf, path->slots[0],
 946                                             struct btrfs_file_extent_item);
 947                         extent_type = btrfs_file_extent_type(leaf, fi);
 948                         if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 949                                 item_end +=
 950                                     btrfs_file_extent_num_bytes(leaf, fi);
 951                         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 952                                 struct btrfs_item *item = btrfs_item_nr(leaf,
 953                                                                 path->slots[0]);
 954                                 item_end += btrfs_file_extent_inline_len(leaf,
 955                                                                          item);
 956                         }
 957                         item_end--;
 958                 }
 959                 if (found_type == BTRFS_CSUM_ITEM_KEY) {
 960                         ret = btrfs_csum_truncate(trans, root, path,
 961                                                   inode->i_size);
 962                         BUG_ON(ret);
 963                 }
 964                 if (item_end < inode->i_size) {
 965                         if (found_type == BTRFS_DIR_ITEM_KEY) {
 966                                 found_type = BTRFS_INODE_ITEM_KEY;
 967                         } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
 968                                 found_type = BTRFS_CSUM_ITEM_KEY;
 969                         } else if (found_type == BTRFS_EXTENT_DATA_KEY) {
 970                                 found_type = BTRFS_XATTR_ITEM_KEY;
 971                         } else if (found_type == BTRFS_XATTR_ITEM_KEY) {
 972                                 found_type = BTRFS_INODE_REF_KEY;
 973                         } else if (found_type) {
 974                                 found_type--;
 975                         } else {
 976                                 break;
 977                         }
 978                         btrfs_set_key_type(&key, found_type);
 979                         goto next;
 980                 }
 981                 if (found_key.offset >= inode->i_size)
 982                         del_item = 1;
 983                 else
 984                         del_item = 0;
 985                 found_extent = 0;
 986
 987                 /* FIXME, shrink the extent if the ref count is only 1 */
 988                 if (found_type != BTRFS_EXTENT_DATA_KEY)
 989                         goto delete;
 990
 991                 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 992                         u64 num_dec;
 993                         extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
 994                         if (!del_item) {
 995                                 u64 orig_num_bytes =
 996                                         btrfs_file_extent_num_bytes(leaf, fi);
 997                                 extent_num_bytes = inode->i_size -
 998                                         found_key.offset + root->sectorsize - 1;
 999                                 extent_num_bytes = extent_num_bytes &
1000                                         ~((u64)root->sectorsize - 1);
1001                                 btrfs_set_file_extent_num_bytes(leaf, fi,
1002                                                          extent_num_bytes);
1003                                 num_dec = (orig_num_bytes -
1004                                            extent_num_bytes);
1005                                 if (extent_start != 0)
1006                                         dec_i_blocks(inode, num_dec);
1007                                 btrfs_mark_buffer_dirty(leaf);
1008                         } else {
1009                                 extent_num_bytes =
1010                                         btrfs_file_extent_disk_num_bytes(leaf,
1011                                                                          fi);
1012                                 /* FIXME blocksize != 4096 */
1013                                 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
1014                                 if (extent_start != 0) {
1015                                         found_extent = 1;
1016                                         dec_i_blocks(inode, num_dec);
1017                                 }
1018                                 root_gen = btrfs_header_generation(leaf);
1019                                 root_owner = btrfs_header_owner(leaf);
1020                         }
1021                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1022                         if (!del_item) {
1023                                 u32 newsize = inode->i_size - found_key.offset;
1024                                 dec_i_blocks(inode, item_end + 1 -
1025                                             found_key.offset - newsize);
1026                                 newsize =
1027                                     btrfs_file_extent_calc_inline_size(newsize);
1028                                 ret = btrfs_truncate_item(trans, root, path,
1029                                                           newsize, 1);
1030                                 BUG_ON(ret);
1031                         } else {
1032                                 dec_i_blocks(inode, item_end + 1 -
1033                                              found_key.offset);
1034                         }
1035                 }
1036 delete:
1037                 if (del_item) {
1038                         if (!pending_del_nr) {
1039                                 /* no pending yet, add ourselves */
1040                                 pending_del_slot = path->slots[0];
1041                                 pending_del_nr = 1;
1042                         } else if (pending_del_nr &&
1043                                    path->slots[0] + 1 == pending_del_slot) {
1044                                 /* hop on the pending chunk */
1045                                 pending_del_nr++;
1046                                 pending_del_slot = path->slots[0];
1047                         } else {
1048                                 printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
1049                         }
1050                 } else {
1051                         break;
1052                 }
1053                 if (found_extent) {
1054                         ret = btrfs_free_extent(trans, root, extent_start,
1055                                                 extent_num_bytes,
1056                                                 root_owner,
1057                                                 root_gen, inode->i_ino,
1058                                                 found_key.offset, 0);
1059                         BUG_ON(ret);
1060                 }
1061 next:
1062                 if (path->slots[0] == 0) {
1063                         if (pending_del_nr)
1064                                 goto del_pending;
1065                         btrfs_release_path(root, path);
1066                         goto search_again;
1067                 }
1068
1069                 path->slots[0]--;
1070                 if (pending_del_nr &&
1071                     path->slots[0] + 1 != pending_del_slot) {
1072                         struct btrfs_key debug;
1073 del_pending:
1074                         btrfs_item_key_to_cpu(path->nodes[0], &debug,
1075                                               pending_del_slot);
1076                         ret = btrfs_del_items(trans, root, path,
1077                                               pending_del_slot,
1078                                               pending_del_nr);
1079                         BUG_ON(ret);
1080                         pending_del_nr = 0;
1081                         btrfs_release_path(root, path);
1082                         goto search_again;
1083                 }
1084         }
1085         ret = 0;
1086 error:
1087         if (pending_del_nr) {
1088                 ret = btrfs_del_items(trans, root, path, pending_del_slot,
1089                                       pending_del_nr);
1090         }
1091         btrfs_release_path(root, path);
1092         btrfs_free_path(path);
1093         inode->i_sb->s_dirt = 1;
1094         return ret;
1095 }
1096
1097 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
1098                               size_t zero_start)
1099 {
1100         char *kaddr;
1101         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1102         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1103         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
1104         int ret = 0;
1105
1106         WARN_ON(!PageLocked(page));
1107         set_page_extent_mapped(page);
1108
1109         lock_extent(io_tree, page_start, page_end, GFP_NOFS);
1110         set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
1111                             page_end, GFP_NOFS);
1112
1113         if (zero_start != PAGE_CACHE_SIZE) {
1114                 kaddr = kmap(page);
1115                 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
1116                 flush_dcache_page(page);
1117                 kunmap(page);
1118         }
1119         set_page_dirty(page);
1120         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
1121
1122         return ret;
1123 }
1124
1125 /*
1126  * taken from block_truncate_page, but does cow as it zeros out
1127  * any bytes left in the last page in the file.
1128  */
1129 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
1130 {
1131         struct inode *inode = mapping->host;
1132         struct btrfs_root *root = BTRFS_I(inode)->root;
1133         u32 blocksize = root->sectorsize;
1134         pgoff_t index = from >> PAGE_CACHE_SHIFT;
1135         unsigned offset = from & (PAGE_CACHE_SIZE-1);
1136         struct page *page;
1137         int ret = 0;
1138         u64 page_start;
1139
1140         if ((offset & (blocksize - 1)) == 0)
1141                 goto out;
1142
1143         ret = -ENOMEM;
1144         page = grab_cache_page(mapping, index);
1145         if (!page)
1146                 goto out;
1147         if (!PageUptodate(page)) {
1148                 ret = btrfs_readpage(NULL, page);
1149                 lock_page(page);
1150                 if (!PageUptodate(page)) {
1151                         ret = -EIO;
1152                         goto out;
1153                 }
1154         }
1155         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1156
1157         ret = btrfs_cow_one_page(inode, page, offset);
1158
1159         unlock_page(page);
1160         page_cache_release(page);
1161 out:
1162         return ret;
1163 }
1164
1165 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
1166 {
1167         struct inode *inode = dentry->d_inode;
1168         int err;
1169
1170         err = inode_change_ok(inode, attr);
1171         if (err)
1172                 return err;
1173
1174         if (S_ISREG(inode->i_mode) &&
1175             attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
1176                 struct btrfs_trans_handle *trans;
1177                 struct btrfs_root *root = BTRFS_I(inode)->root;
1178                 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1179
1180                 u64 mask = root->sectorsize - 1;
1181                 u64 hole_start = (inode->i_size + mask) & ~mask;
1182                 u64 block_end = (attr->ia_size + mask) & ~mask;
1183                 u64 hole_size;
1184                 u64 alloc_hint = 0;
1185
1186                 if (attr->ia_size <= hole_start)
1187                         goto out;
1188
1189                 mutex_lock(&root->fs_info->fs_mutex);
1190                 err = btrfs_check_free_space(root, 1, 0);
1191                 mutex_unlock(&root->fs_info->fs_mutex);
1192                 if (err)
1193                         goto fail;
1194
1195                 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1196
1197                 lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1198                 hole_size = block_end - hole_start;
1199
1200                 mutex_lock(&root->fs_info->fs_mutex);
1201                 trans = btrfs_start_transaction(root, 1);
1202                 btrfs_set_trans_block_group(trans, inode);
1203                 err = btrfs_drop_extents(trans, root, inode,
1204                                          hole_start, block_end, hole_start,
1205                                          &alloc_hint);
1206
1207                 if (alloc_hint != EXTENT_MAP_INLINE) {
1208                         err = btrfs_insert_file_extent(trans, root,
1209                                                        inode->i_ino,
1210                                                        hole_start, 0, 0,
1211                                                        hole_size);
1212                         btrfs_drop_extent_cache(inode, hole_start,
1213                                                 hole_size - 1);
1214                         btrfs_check_file(root, inode);
1215                 }
1216                 btrfs_end_transaction(trans, root);
1217                 mutex_unlock(&root->fs_info->fs_mutex);
1218                 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1219                 if (err)
1220                         return err;
1221         }
1222 out:
1223         err = inode_setattr(inode, attr);
1224 fail:
1225         return err;
1226 }
1227
1228 void btrfs_put_inode(struct inode *inode)
1229 {
1230         int ret;
1231
1232         if (!BTRFS_I(inode)->ordered_trans) {
1233                 return;
1234         }
1235
1236         if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY) ||
1237             mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1238                 return;
1239
1240         ret = btrfs_del_ordered_inode(inode);
1241         if (ret == 1) {
1242                 atomic_dec(&inode->i_count);
1243         }
1244 }
1245
1246 void btrfs_delete_inode(struct inode *inode)
1247 {
1248         struct btrfs_trans_handle *trans;
1249         struct btrfs_root *root = BTRFS_I(inode)->root;
1250         unsigned long nr;
1251         int ret;
1252
1253         truncate_inode_pages(&inode->i_data, 0);
1254         if (is_bad_inode(inode)) {
1255                 goto no_delete;
1256         }
1257
1258         inode->i_size = 0;
1259         mutex_lock(&root->fs_info->fs_mutex);
1260         trans = btrfs_start_transaction(root, 1);
1261
1262         btrfs_set_trans_block_group(trans, inode);
1263         ret = btrfs_truncate_in_trans(trans, root, inode, 0);
1264         if (ret)
1265                 goto no_delete_lock;
1266
1267         nr = trans->blocks_used;
1268         clear_inode(inode);
1269
1270         btrfs_end_transaction(trans, root);
1271         mutex_unlock(&root->fs_info->fs_mutex);
1272         btrfs_btree_balance_dirty(root, nr);
1273         btrfs_throttle(root);
1274         return;
1275
1276 no_delete_lock:
1277         nr = trans->blocks_used;
1278         btrfs_end_transaction(trans, root);
1279         mutex_unlock(&root->fs_info->fs_mutex);
1280         btrfs_btree_balance_dirty(root, nr);
1281         btrfs_throttle(root);
1282 no_delete:
1283         clear_inode(inode);
1284 }
1285
1286 /*
1287  * this returns the key found in the dir entry in the location pointer.
1288  * If no dir entries were found, location->objectid is 0.
1289  */
1290 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1291                                struct btrfs_key *location)
1292 {
1293         const char *name = dentry->d_name.name;
1294         int namelen = dentry->d_name.len;
1295         struct btrfs_dir_item *di;
1296         struct btrfs_path *path;
1297         struct btrfs_root *root = BTRFS_I(dir)->root;
1298         int ret = 0;
1299
1300         if (namelen == 1 && strcmp(name, ".") == 0) {
1301                 location->objectid = dir->i_ino;
1302                 location->type = BTRFS_INODE_ITEM_KEY;
1303                 location->offset = 0;
1304                 return 0;
1305         }
1306         path = btrfs_alloc_path();
1307         BUG_ON(!path);
1308
1309         if (namelen == 2 && strcmp(name, "..") == 0) {
1310                 struct btrfs_key key;
1311                 struct extent_buffer *leaf;
1312                 u32 nritems;
1313                 int slot;
1314
1315                 key.objectid = dir->i_ino;
1316                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1317                 key.offset = 0;
1318                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1319                 BUG_ON(ret == 0);
1320                 ret = 0;
1321
1322                 leaf = path->nodes[0];
1323                 slot = path->slots[0];
1324                 nritems = btrfs_header_nritems(leaf);
1325                 if (slot >= nritems)
1326                         goto out_err;
1327
1328                 btrfs_item_key_to_cpu(leaf, &key, slot);
1329                 if (key.objectid != dir->i_ino ||
1330                     key.type != BTRFS_INODE_REF_KEY) {
1331                         goto out_err;
1332                 }
1333                 location->objectid = key.offset;
1334                 location->type = BTRFS_INODE_ITEM_KEY;
1335                 location->offset = 0;
1336                 goto out;
1337         }
1338
1339         di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1340                                     namelen, 0);
1341         if (IS_ERR(di))
1342                 ret = PTR_ERR(di);
1343         if (!di || IS_ERR(di)) {
1344                 goto out_err;
1345         }
1346         btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1347 out:
1348         btrfs_free_path(path);
1349         return ret;
1350 out_err:
1351         location->objectid = 0;
1352         goto out;
1353 }
1354
1355 /*
1356  * when we hit a tree root in a directory, the btrfs part of the inode
1357  * needs to be changed to reflect the root directory of the tree root.  This
1358  * is kind of like crossing a mount point.
1359  */
1360 static int fixup_tree_root_location(struct btrfs_root *root,
1361                              struct btrfs_key *location,
1362                              struct btrfs_root **sub_root,
1363                              struct dentry *dentry)
1364 {
1365         struct btrfs_path *path;
1366         struct btrfs_root_item *ri;
1367
1368         if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1369                 return 0;
1370         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1371                 return 0;
1372
1373         path = btrfs_alloc_path();
1374         BUG_ON(!path);
1375         mutex_lock(&root->fs_info->fs_mutex);
1376
1377         *sub_root = btrfs_read_fs_root(root->fs_info, location,
1378                                         dentry->d_name.name,
1379                                         dentry->d_name.len);
1380         if (IS_ERR(*sub_root))
1381                 return PTR_ERR(*sub_root);
1382
1383         ri = &(*sub_root)->root_item;
1384         location->objectid = btrfs_root_dirid(ri);
1385         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1386         location->offset = 0;
1387
1388         btrfs_free_path(path);
1389         mutex_unlock(&root->fs_info->fs_mutex);
1390         return 0;
1391 }
1392
1393 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1394 {
1395         struct btrfs_iget_args *args = p;
1396         inode->i_ino = args->ino;
1397         BTRFS_I(inode)->root = args->root;
1398         BTRFS_I(inode)->delalloc_bytes = 0;
1399         extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1400         extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1401                              inode->i_mapping, GFP_NOFS);
1402         extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1403                              inode->i_mapping, GFP_NOFS);
1404         return 0;
1405 }
1406
1407 static int btrfs_find_actor(struct inode *inode, void *opaque)
1408 {
1409         struct btrfs_iget_args *args = opaque;
1410         return (args->ino == inode->i_ino &&
1411                 args->root == BTRFS_I(inode)->root);
1412 }
1413
1414 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1415                             u64 root_objectid)
1416 {
1417         struct btrfs_iget_args args;
1418         args.ino = objectid;
1419         args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1420
1421         if (!args.root)
1422                 return NULL;
1423
1424         return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1425 }
1426
1427 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1428                                 struct btrfs_root *root)
1429 {
1430         struct inode *inode;
1431         struct btrfs_iget_args args;
1432         args.ino = objectid;
1433         args.root = root;
1434
1435         inode = iget5_locked(s, objectid, btrfs_find_actor,
1436                              btrfs_init_locked_inode,
1437                              (void *)&args);
1438         return inode;
1439 }
1440
1441 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1442                                    struct nameidata *nd)
1443 {
1444         struct inode * inode;
1445         struct btrfs_inode *bi = BTRFS_I(dir);
1446         struct btrfs_root *root = bi->root;
1447         struct btrfs_root *sub_root = root;
1448         struct btrfs_key location;
1449         int ret;
1450
1451         if (dentry->d_name.len > BTRFS_NAME_LEN)
1452                 return ERR_PTR(-ENAMETOOLONG);
1453
1454         mutex_lock(&root->fs_info->fs_mutex);
1455         ret = btrfs_inode_by_name(dir, dentry, &location);
1456         mutex_unlock(&root->fs_info->fs_mutex);
1457
1458         if (ret < 0)
1459                 return ERR_PTR(ret);
1460
1461         inode = NULL;
1462         if (location.objectid) {
1463                 ret = fixup_tree_root_location(root, &location, &sub_root,
1464                                                 dentry);
1465                 if (ret < 0)
1466                         return ERR_PTR(ret);
1467                 if (ret > 0)
1468                         return ERR_PTR(-ENOENT);
1469                 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1470                                           sub_root);
1471                 if (!inode)
1472                         return ERR_PTR(-EACCES);
1473                 if (inode->i_state & I_NEW) {
1474                         /* the inode and parent dir are two different roots */
1475                         if (sub_root != root) {
1476                                 igrab(inode);
1477                                 sub_root->inode = inode;
1478                         }
1479                         BTRFS_I(inode)->root = sub_root;
1480                         memcpy(&BTRFS_I(inode)->location, &location,
1481                                sizeof(location));
1482                         btrfs_read_locked_inode(inode);
1483                         unlock_new_inode(inode);
1484                 }
1485         }
1486         return d_splice_alias(inode, dentry);
1487 }
1488
1489 static unsigned char btrfs_filetype_table[] = {
1490         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1491 };
1492
1493 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1494 {
1495         struct inode *inode = filp->f_dentry->d_inode;
1496         struct btrfs_root *root = BTRFS_I(inode)->root;
1497         struct btrfs_item *item;
1498         struct btrfs_dir_item *di;
1499         struct btrfs_key key;
1500         struct btrfs_key found_key;
1501         struct btrfs_path *path;
1502         int ret;
1503         u32 nritems;
1504         struct extent_buffer *leaf;
1505         int slot;
1506         int advance;
1507         unsigned char d_type;
1508         int over = 0;
1509         u32 di_cur;
1510         u32 di_total;
1511         u32 di_len;
1512         int key_type = BTRFS_DIR_INDEX_KEY;
1513         char tmp_name[32];
1514         char *name_ptr;
1515         int name_len;
1516
1517         /* FIXME, use a real flag for deciding about the key type */
1518         if (root->fs_info->tree_root == root)
1519                 key_type = BTRFS_DIR_ITEM_KEY;
1520
1521         /* special case for "." */
1522         if (filp->f_pos == 0) {
1523                 over = filldir(dirent, ".", 1,
1524                                1, inode->i_ino,
1525                                DT_DIR);
1526                 if (over)
1527                         return 0;
1528                 filp->f_pos = 1;
1529         }
1530
1531         mutex_lock(&root->fs_info->fs_mutex);
1532         key.objectid = inode->i_ino;
1533         path = btrfs_alloc_path();
1534         path->reada = 2;
1535
1536         /* special case for .., just use the back ref */
1537         if (filp->f_pos == 1) {
1538                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1539                 key.offset = 0;
1540                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1541                 BUG_ON(ret == 0);
1542                 leaf = path->nodes[0];
1543                 slot = path->slots[0];
1544                 nritems = btrfs_header_nritems(leaf);
1545                 if (slot >= nritems) {
1546                         btrfs_release_path(root, path);
1547                         goto read_dir_items;
1548                 }
1549                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1550                 btrfs_release_path(root, path);
1551                 if (found_key.objectid != key.objectid ||
1552                     found_key.type != BTRFS_INODE_REF_KEY)
1553                         goto read_dir_items;
1554                 over = filldir(dirent, "..", 2,
1555                                2, found_key.offset, DT_DIR);
1556                 if (over)
1557                         goto nopos;
1558                 filp->f_pos = 2;
1559         }
1560
1561 read_dir_items:
1562         btrfs_set_key_type(&key, key_type);
1563         key.offset = filp->f_pos;
1564
1565         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1566         if (ret < 0)
1567                 goto err;
1568         advance = 0;
1569         while(1) {
1570                 leaf = path->nodes[0];
1571                 nritems = btrfs_header_nritems(leaf);
1572                 slot = path->slots[0];
1573                 if (advance || slot >= nritems) {
1574                         if (slot >= nritems -1) {
1575                                 ret = btrfs_next_leaf(root, path);
1576                                 if (ret)
1577                                         break;
1578                                 leaf = path->nodes[0];
1579                                 nritems = btrfs_header_nritems(leaf);
1580                                 slot = path->slots[0];
1581                         } else {
1582                                 slot++;
1583                                 path->slots[0]++;
1584                         }
1585                 }
1586                 advance = 1;
1587                 item = btrfs_item_nr(leaf, slot);
1588                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1589
1590                 if (found_key.objectid != key.objectid)
1591                         break;
1592                 if (btrfs_key_type(&found_key) != key_type)
1593                         break;
1594                 if (found_key.offset < filp->f_pos)
1595                         continue;
1596
1597                 filp->f_pos = found_key.offset;
1598                 advance = 1;
1599                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1600                 di_cur = 0;
1601                 di_total = btrfs_item_size(leaf, item);
1602                 while(di_cur < di_total) {
1603                         struct btrfs_key location;
1604
1605                         name_len = btrfs_dir_name_len(leaf, di);
1606                         if (name_len < 32) {
1607                                 name_ptr = tmp_name;
1608                         } else {
1609                                 name_ptr = kmalloc(name_len, GFP_NOFS);
1610                                 BUG_ON(!name_ptr);
1611                         }
1612                         read_extent_buffer(leaf, name_ptr,
1613                                            (unsigned long)(di + 1), name_len);
1614
1615                         d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1616                         btrfs_dir_item_key_to_cpu(leaf, di, &location);
1617                         over = filldir(dirent, name_ptr, name_len,
1618                                        found_key.offset,
1619                                        location.objectid,
1620                                        d_type);
1621
1622                         if (name_ptr != tmp_name)
1623                                 kfree(name_ptr);
1624
1625                         if (over)
1626                                 goto nopos;
1627                         di_len = btrfs_dir_name_len(leaf, di) +
1628                                 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1629                         di_cur += di_len;
1630                         di = (struct btrfs_dir_item *)((char *)di + di_len);
1631                 }
1632         }
1633         if (key_type == BTRFS_DIR_INDEX_KEY)
1634                 filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
1635         else
1636                 filp->f_pos++;
1637 nopos:
1638         ret = 0;
1639 err:
1640         btrfs_release_path(root, path);
1641         btrfs_free_path(path);
1642         mutex_unlock(&root->fs_info->fs_mutex);
1643         return ret;
1644 }
1645
1646 int btrfs_write_inode(struct inode *inode, int wait)
1647 {
1648         struct btrfs_root *root = BTRFS_I(inode)->root;
1649         struct btrfs_trans_handle *trans;
1650         int ret = 0;
1651
1652         if (wait) {
1653                 mutex_lock(&root->fs_info->fs_mutex);
1654                 trans = btrfs_start_transaction(root, 1);
1655                 btrfs_set_trans_block_group(trans, inode);
1656                 ret = btrfs_commit_transaction(trans, root);
1657                 mutex_unlock(&root->fs_info->fs_mutex);
1658         }
1659         return ret;
1660 }
1661
1662 /*
1663  * This is somewhat expensive, updating the tree every time the
1664  * inode changes.  But, it is most likely to find the inode in cache.
1665  * FIXME, needs more benchmarking...there are no reasons other than performance
1666  * to keep or drop this code.
1667  */
1668 void btrfs_dirty_inode(struct inode *inode)
1669 {
1670         struct btrfs_root *root = BTRFS_I(inode)->root;
1671         struct btrfs_trans_handle *trans;
1672
1673         mutex_lock(&root->fs_info->fs_mutex);
1674         trans = btrfs_start_transaction(root, 1);
1675         btrfs_set_trans_block_group(trans, inode);
1676         btrfs_update_inode(trans, root, inode);
1677         btrfs_end_transaction(trans, root);
1678         mutex_unlock(&root->fs_info->fs_mutex);
1679 }
1680
1681 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1682                                      struct btrfs_root *root,
1683                                      const char *name, int name_len,
1684                                      u64 ref_objectid,
1685                                      u64 objectid,
1686                                      struct btrfs_block_group_cache *group,
1687                                      int mode)
1688 {
1689         struct inode *inode;
1690         struct btrfs_inode_item *inode_item;
1691         struct btrfs_block_group_cache *new_inode_group;
1692         struct btrfs_key *location;
1693         struct btrfs_path *path;
1694         struct btrfs_inode_ref *ref;
1695         struct btrfs_key key[2];
1696         u32 sizes[2];
1697         unsigned long ptr;
1698         int ret;
1699         int owner;
1700
1701         path = btrfs_alloc_path();
1702         BUG_ON(!path);
1703
1704         inode = new_inode(root->fs_info->sb);
1705         if (!inode)
1706                 return ERR_PTR(-ENOMEM);
1707
1708         extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1709         extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1710                              inode->i_mapping, GFP_NOFS);
1711         extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1712                              inode->i_mapping, GFP_NOFS);
1713         BTRFS_I(inode)->delalloc_bytes = 0;
1714         BTRFS_I(inode)->root = root;
1715
1716         if (mode & S_IFDIR)
1717                 owner = 0;
1718         else
1719                 owner = 1;
1720         new_inode_group = btrfs_find_block_group(root, group, 0,
1721                                        BTRFS_BLOCK_GROUP_METADATA, owner);
1722         if (!new_inode_group) {
1723                 printk("find_block group failed\n");
1724                 new_inode_group = group;
1725         }
1726         BTRFS_I(inode)->block_group = new_inode_group;
1727         BTRFS_I(inode)->flags = 0;
1728
1729         key[0].objectid = objectid;
1730         btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
1731         key[0].offset = 0;
1732
1733         key[1].objectid = objectid;
1734         btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
1735         key[1].offset = ref_objectid;
1736
1737         sizes[0] = sizeof(struct btrfs_inode_item);
1738         sizes[1] = name_len + sizeof(*ref);
1739
1740         ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
1741         if (ret != 0)
1742                 goto fail;
1743
1744         if (objectid > root->highest_inode)
1745                 root->highest_inode = objectid;
1746
1747         inode->i_uid = current->fsuid;
1748         inode->i_gid = current->fsgid;
1749         inode->i_mode = mode;
1750         inode->i_ino = objectid;
1751         inode->i_blocks = 0;
1752         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1753         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1754                                   struct btrfs_inode_item);
1755         fill_inode_item(path->nodes[0], inode_item, inode);
1756
1757         ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1758                              struct btrfs_inode_ref);
1759         btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
1760         ptr = (unsigned long)(ref + 1);
1761         write_extent_buffer(path->nodes[0], name, ptr, name_len);
1762
1763         btrfs_mark_buffer_dirty(path->nodes[0]);
1764         btrfs_free_path(path);
1765
1766         location = &BTRFS_I(inode)->location;
1767         location->objectid = objectid;
1768         location->offset = 0;
1769         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1770
1771         insert_inode_hash(inode);
1772         return inode;
1773 fail:
1774         btrfs_free_path(path);
1775         return ERR_PTR(ret);
1776 }
1777
1778 static inline u8 btrfs_inode_type(struct inode *inode)
1779 {
1780         return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1781 }
1782
1783 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1784                             struct dentry *dentry, struct inode *inode,
1785                             int add_backref)
1786 {
1787         int ret;
1788         struct btrfs_key key;
1789         struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1790         struct inode *parent_inode;
1791
1792         key.objectid = inode->i_ino;
1793         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1794         key.offset = 0;
1795
1796         ret = btrfs_insert_dir_item(trans, root,
1797                                     dentry->d_name.name, dentry->d_name.len,
1798                                     dentry->d_parent->d_inode->i_ino,
1799                                     &key, btrfs_inode_type(inode));
1800         if (ret == 0) {
1801                 if (add_backref) {
1802                         ret = btrfs_insert_inode_ref(trans, root,
1803                                              dentry->d_name.name,
1804                                              dentry->d_name.len,
1805                                              inode->i_ino,
1806                                              dentry->d_parent->d_inode->i_ino);
1807                 }
1808                 parent_inode = dentry->d_parent->d_inode;
1809                 parent_inode->i_size += dentry->d_name.len * 2;
1810                 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1811                 ret = btrfs_update_inode(trans, root,
1812                                          dentry->d_parent->d_inode);
1813         }
1814         return ret;
1815 }
1816
1817 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1818                             struct dentry *dentry, struct inode *inode,
1819                             int backref)
1820 {
1821         int err = btrfs_add_link(trans, dentry, inode, backref);
1822         if (!err) {
1823                 d_instantiate(dentry, inode);
1824                 return 0;
1825         }
1826         if (err > 0)
1827                 err = -EEXIST;
1828         return err;
1829 }
1830
1831 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1832                         int mode, dev_t rdev)
1833 {
1834         struct btrfs_trans_handle *trans;
1835         struct btrfs_root *root = BTRFS_I(dir)->root;
1836         struct inode *inode = NULL;
1837         int err;
1838         int drop_inode = 0;
1839         u64 objectid;
1840         unsigned long nr = 0;
1841
1842         if (!new_valid_dev(rdev))
1843                 return -EINVAL;
1844
1845         mutex_lock(&root->fs_info->fs_mutex);
1846         err = btrfs_check_free_space(root, 1, 0);
1847         if (err)
1848                 goto fail;
1849
1850         trans = btrfs_start_transaction(root, 1);
1851         btrfs_set_trans_block_group(trans, dir);
1852
1853         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1854         if (err) {
1855                 err = -ENOSPC;
1856                 goto out_unlock;
1857         }
1858
1859         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1860                                 dentry->d_name.len,
1861                                 dentry->d_parent->d_inode->i_ino, objectid,
1862                                 BTRFS_I(dir)->block_group, mode);
1863         err = PTR_ERR(inode);
1864         if (IS_ERR(inode))
1865                 goto out_unlock;
1866
1867         btrfs_set_trans_block_group(trans, inode);
1868         err = btrfs_add_nondir(trans, dentry, inode, 0);
1869         if (err)
1870                 drop_inode = 1;
1871         else {
1872                 inode->i_op = &btrfs_special_inode_operations;
1873                 init_special_inode(inode, inode->i_mode, rdev);
1874                 btrfs_update_inode(trans, root, inode);
1875         }
1876         dir->i_sb->s_dirt = 1;
1877         btrfs_update_inode_block_group(trans, inode);
1878         btrfs_update_inode_block_group(trans, dir);
1879 out_unlock:
1880         nr = trans->blocks_used;
1881         btrfs_end_transaction(trans, root);
1882 fail:
1883         mutex_unlock(&root->fs_info->fs_mutex);
1884
1885         if (drop_inode) {
1886                 inode_dec_link_count(inode);
1887                 iput(inode);
1888         }
1889         btrfs_btree_balance_dirty(root, nr);
1890         btrfs_throttle(root);
1891         return err;
1892 }
1893
1894 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1895                         int mode, struct nameidata *nd)
1896 {
1897         struct btrfs_trans_handle *trans;
1898         struct btrfs_root *root = BTRFS_I(dir)->root;
1899         struct inode *inode = NULL;
1900         int err;
1901         int drop_inode = 0;
1902         unsigned long nr = 0;
1903         u64 objectid;
1904
1905         mutex_lock(&root->fs_info->fs_mutex);
1906         err = btrfs_check_free_space(root, 1, 0);
1907         if (err)
1908                 goto fail;
1909         trans = btrfs_start_transaction(root, 1);
1910         btrfs_set_trans_block_group(trans, dir);
1911
1912         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1913         if (err) {
1914                 err = -ENOSPC;
1915                 goto out_unlock;
1916         }
1917
1918         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1919                                 dentry->d_name.len,
1920                                 dentry->d_parent->d_inode->i_ino,
1921                                 objectid, BTRFS_I(dir)->block_group, mode);
1922         err = PTR_ERR(inode);
1923         if (IS_ERR(inode))
1924                 goto out_unlock;
1925
1926         btrfs_set_trans_block_group(trans, inode);
1927         err = btrfs_add_nondir(trans, dentry, inode, 0);
1928         if (err)
1929                 drop_inode = 1;
1930         else {
1931                 inode->i_mapping->a_ops = &btrfs_aops;
1932                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
1933                 inode->i_fop = &btrfs_file_operations;
1934                 inode->i_op = &btrfs_file_inode_operations;
1935                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1936                 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1937                                      inode->i_mapping, GFP_NOFS);
1938                 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1939                                      inode->i_mapping, GFP_NOFS);
1940                 BTRFS_I(inode)->delalloc_bytes = 0;
1941                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
1942         }
1943         dir->i_sb->s_dirt = 1;
1944         btrfs_update_inode_block_group(trans, inode);
1945         btrfs_update_inode_block_group(trans, dir);
1946 out_unlock:
1947         nr = trans->blocks_used;
1948         btrfs_end_transaction(trans, root);
1949 fail:
1950         mutex_unlock(&root->fs_info->fs_mutex);
1951
1952         if (drop_inode) {
1953                 inode_dec_link_count(inode);
1954                 iput(inode);
1955         }
1956         btrfs_btree_balance_dirty(root, nr);
1957         btrfs_throttle(root);
1958         return err;
1959 }
1960
1961 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1962                       struct dentry *dentry)
1963 {
1964         struct btrfs_trans_handle *trans;
1965         struct btrfs_root *root = BTRFS_I(dir)->root;
1966         struct inode *inode = old_dentry->d_inode;
1967         unsigned long nr = 0;
1968         int err;
1969         int drop_inode = 0;
1970
1971         if (inode->i_nlink == 0)
1972                 return -ENOENT;
1973
1974 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1975         inode->i_nlink++;
1976 #else
1977         inc_nlink(inode);
1978 #endif
1979         mutex_lock(&root->fs_info->fs_mutex);
1980         err = btrfs_check_free_space(root, 1, 0);
1981         if (err)
1982                 goto fail;
1983         trans = btrfs_start_transaction(root, 1);
1984
1985         btrfs_set_trans_block_group(trans, dir);
1986         atomic_inc(&inode->i_count);
1987         err = btrfs_add_nondir(trans, dentry, inode, 1);
1988
1989         if (err)
1990                 drop_inode = 1;
1991
1992         dir->i_sb->s_dirt = 1;
1993         btrfs_update_inode_block_group(trans, dir);
1994         err = btrfs_update_inode(trans, root, inode);
1995
1996         if (err)
1997                 drop_inode = 1;
1998
1999         nr = trans->blocks_used;
2000         btrfs_end_transaction(trans, root);
2001 fail:
2002         mutex_unlock(&root->fs_info->fs_mutex);
2003
2004         if (drop_inode) {
2005                 inode_dec_link_count(inode);
2006                 iput(inode);
2007         }
2008         btrfs_btree_balance_dirty(root, nr);
2009         btrfs_throttle(root);
2010         return err;
2011 }
2012
2013 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
2014 {
2015         struct inode *inode;
2016         struct btrfs_trans_handle *trans;
2017         struct btrfs_root *root = BTRFS_I(dir)->root;
2018         int err = 0;
2019         int drop_on_err = 0;
2020         u64 objectid;
2021         unsigned long nr = 1;
2022
2023         mutex_lock(&root->fs_info->fs_mutex);
2024         err = btrfs_check_free_space(root, 1, 0);
2025         if (err)
2026                 goto out_unlock;
2027
2028         trans = btrfs_start_transaction(root, 1);
2029         btrfs_set_trans_block_group(trans, dir);
2030
2031         if (IS_ERR(trans)) {
2032                 err = PTR_ERR(trans);
2033                 goto out_unlock;
2034         }
2035
2036         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2037         if (err) {
2038                 err = -ENOSPC;
2039                 goto out_unlock;
2040         }
2041
2042         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2043                                 dentry->d_name.len,
2044                                 dentry->d_parent->d_inode->i_ino, objectid,
2045                                 BTRFS_I(dir)->block_group, S_IFDIR | mode);
2046         if (IS_ERR(inode)) {
2047                 err = PTR_ERR(inode);
2048                 goto out_fail;
2049         }
2050
2051         drop_on_err = 1;
2052         inode->i_op = &btrfs_dir_inode_operations;
2053         inode->i_fop = &btrfs_dir_file_operations;
2054         btrfs_set_trans_block_group(trans, inode);
2055
2056         inode->i_size = 0;
2057         err = btrfs_update_inode(trans, root, inode);
2058         if (err)
2059                 goto out_fail;
2060
2061         err = btrfs_add_link(trans, dentry, inode, 0);
2062         if (err)
2063                 goto out_fail;
2064
2065         d_instantiate(dentry, inode);
2066         drop_on_err = 0;
2067         dir->i_sb->s_dirt = 1;
2068         btrfs_update_inode_block_group(trans, inode);
2069         btrfs_update_inode_block_group(trans, dir);
2070
2071 out_fail:
2072         nr = trans->blocks_used;
2073         btrfs_end_transaction(trans, root);
2074
2075 out_unlock:
2076         mutex_unlock(&root->fs_info->fs_mutex);
2077         if (drop_on_err)
2078                 iput(inode);
2079         btrfs_btree_balance_dirty(root, nr);
2080         btrfs_throttle(root);
2081         return err;
2082 }
2083
2084 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
2085                                     size_t pg_offset, u64 start, u64 len,
2086                                     int create)
2087 {
2088         int ret;
2089         int err = 0;
2090         u64 bytenr;
2091         u64 extent_start = 0;
2092         u64 extent_end = 0;
2093         u64 objectid = inode->i_ino;
2094         u32 found_type;
2095         struct btrfs_path *path;
2096         struct btrfs_root *root = BTRFS_I(inode)->root;
2097         struct btrfs_file_extent_item *item;
2098         struct extent_buffer *leaf;
2099         struct btrfs_key found_key;
2100         struct extent_map *em = NULL;
2101         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2102         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2103         struct btrfs_trans_handle *trans = NULL;
2104
2105         path = btrfs_alloc_path();
2106         BUG_ON(!path);
2107         mutex_lock(&root->fs_info->fs_mutex);
2108
2109 again:
2110         spin_lock(&em_tree->lock);
2111         em = lookup_extent_mapping(em_tree, start, len);
2112         spin_unlock(&em_tree->lock);
2113
2114         if (em) {
2115                 if (em->start > start) {
2116                         printk("get_extent lookup [%Lu %Lu] em [%Lu %Lu]\n",
2117                                start, len, em->start, em->len);
2118                         WARN_ON(1);
2119                 }
2120                 if (em->block_start == EXTENT_MAP_INLINE && page)
2121                         free_extent_map(em);
2122                 else
2123                         goto out;
2124         }
2125         em = alloc_extent_map(GFP_NOFS);
2126         if (!em) {
2127                 err = -ENOMEM;
2128                 goto out;
2129         }
2130
2131         em->start = EXTENT_MAP_HOLE;
2132         em->len = (u64)-1;
2133         em->bdev = inode->i_sb->s_bdev;
2134         ret = btrfs_lookup_file_extent(trans, root, path,
2135                                        objectid, start, trans != NULL);
2136         if (ret < 0) {
2137                 err = ret;
2138                 goto out;
2139         }
2140
2141         if (ret != 0) {
2142                 if (path->slots[0] == 0)
2143                         goto not_found;
2144                 path->slots[0]--;
2145         }
2146
2147         leaf = path->nodes[0];
2148         item = btrfs_item_ptr(leaf, path->slots[0],
2149                               struct btrfs_file_extent_item);
2150         /* are we inside the extent that was found? */
2151         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2152         found_type = btrfs_key_type(&found_key);
2153         if (found_key.objectid != objectid ||
2154             found_type != BTRFS_EXTENT_DATA_KEY) {
2155                 goto not_found;
2156         }
2157
2158         found_type = btrfs_file_extent_type(leaf, item);
2159         extent_start = found_key.offset;
2160         if (found_type == BTRFS_FILE_EXTENT_REG) {
2161                 extent_end = extent_start +
2162                        btrfs_file_extent_num_bytes(leaf, item);
2163                 err = 0;
2164                 if (start < extent_start || start >= extent_end) {
2165                         em->start = start;
2166                         if (start < extent_start) {
2167                                 if (start + len <= extent_start)
2168                                         goto not_found;
2169                                 em->len = extent_end - extent_start;
2170                         } else {
2171                                 em->len = len;
2172                         }
2173                         goto not_found_em;
2174                 }
2175                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
2176                 if (bytenr == 0) {
2177                         em->start = extent_start;
2178                         em->len = extent_end - extent_start;
2179                         em->block_start = EXTENT_MAP_HOLE;
2180                         goto insert;
2181                 }
2182                 bytenr += btrfs_file_extent_offset(leaf, item);
2183                 em->block_start = bytenr;
2184                 em->start = extent_start;
2185                 em->len = extent_end - extent_start;
2186                 goto insert;
2187         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
2188                 u64 page_start;
2189                 unsigned long ptr;
2190                 char *map;
2191                 size_t size;
2192                 size_t extent_offset;
2193                 size_t copy_size;
2194
2195                 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
2196                                                     path->slots[0]));
2197                 extent_end = (extent_start + size + root->sectorsize - 1) &
2198                         ~((u64)root->sectorsize - 1);
2199                 if (start < extent_start || start >= extent_end) {
2200                         em->start = start;
2201                         if (start < extent_start) {
2202                                 if (start + len <= extent_start)
2203                                         goto not_found;
2204                                 em->len = extent_end - extent_start;
2205                         } else {
2206                                 em->len = len;
2207                         }
2208                         goto not_found_em;
2209                 }
2210                 em->block_start = EXTENT_MAP_INLINE;
2211
2212                 if (!page) {
2213                         em->start = extent_start;
2214                         em->len = size;
2215                         goto out;
2216                 }
2217
2218                 page_start = page_offset(page) + pg_offset;
2219                 extent_offset = page_start - extent_start;
2220                 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
2221                                 size - extent_offset);
2222                 em->start = extent_start + extent_offset;
2223                 em->len = (copy_size + root->sectorsize - 1) &
2224                         ~((u64)root->sectorsize - 1);
2225                 map = kmap(page);
2226                 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
2227                 if (create == 0 && !PageUptodate(page)) {
2228                         read_extent_buffer(leaf, map + pg_offset, ptr,
2229                                            copy_size);
2230                         flush_dcache_page(page);
2231                 } else if (create && PageUptodate(page)) {
2232                         if (!trans) {
2233                                 kunmap(page);
2234                                 free_extent_map(em);
2235                                 em = NULL;
2236                                 btrfs_release_path(root, path);
2237                                 trans = btrfs_start_transaction(root, 1);
2238                                 goto again;
2239                         }
2240                         write_extent_buffer(leaf, map + pg_offset, ptr,
2241                                             copy_size);
2242                         btrfs_mark_buffer_dirty(leaf);
2243                 }
2244                 kunmap(page);
2245                 set_extent_uptodate(io_tree, em->start,
2246                                     extent_map_end(em) - 1, GFP_NOFS);
2247                 goto insert;
2248         } else {
2249                 printk("unkknown found_type %d\n", found_type);
2250                 WARN_ON(1);
2251         }
2252 not_found:
2253         em->start = start;
2254         em->len = len;
2255 not_found_em:
2256         em->block_start = EXTENT_MAP_HOLE;
2257 insert:
2258         btrfs_release_path(root, path);
2259         if (em->start > start || extent_map_end(em) <= start) {
2260                 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
2261                 err = -EIO;
2262                 goto out;
2263         }
2264
2265         err = 0;
2266         spin_lock(&em_tree->lock);
2267         ret = add_extent_mapping(em_tree, em);
2268         if (ret == -EEXIST) {
2269                 free_extent_map(em);
2270                 em = lookup_extent_mapping(em_tree, start, len);
2271                 if (!em) {
2272                         err = -EIO;
2273                         printk("failing to insert %Lu %Lu\n", start, len);
2274                 }
2275         }
2276         spin_unlock(&em_tree->lock);
2277 out:
2278         btrfs_free_path(path);
2279         if (trans) {
2280                 ret = btrfs_end_transaction(trans, root);
2281                 if (!err)
2282                         err = ret;
2283         }
2284         mutex_unlock(&root->fs_info->fs_mutex);
2285         if (err) {
2286                 free_extent_map(em);
2287                 WARN_ON(1);
2288                 return ERR_PTR(err);
2289         }
2290         return em;
2291 }
2292
2293 static int btrfs_get_block(struct inode *inode, sector_t iblock,
2294                         struct buffer_head *bh_result, int create)
2295 {
2296         struct extent_map *em;
2297         u64 start = (u64)iblock << inode->i_blkbits;
2298         struct btrfs_multi_bio *multi = NULL;
2299         struct btrfs_root *root = BTRFS_I(inode)->root;
2300         u64 len;
2301         u64 logical;
2302         u64 map_length;
2303         int ret = 0;
2304
2305         em = btrfs_get_extent(inode, NULL, 0, start, bh_result->b_size, 0);
2306
2307         if (!em || IS_ERR(em))
2308                 goto out;
2309
2310         if (em->start > start || em->start + em->len <= start)
2311             goto out;
2312
2313         if (em->block_start == EXTENT_MAP_INLINE) {
2314                 ret = -EINVAL;
2315                 goto out;
2316         }
2317
2318         if (em->block_start == EXTENT_MAP_HOLE ||
2319             em->block_start == EXTENT_MAP_DELALLOC) {
2320                 goto out;
2321         }
2322
2323         len = em->start + em->len - start;
2324         len = min_t(u64, len, INT_LIMIT(typeof(bh_result->b_size)));
2325
2326         logical = start - em->start;
2327         logical = em->block_start + logical;
2328
2329         map_length = len;
2330         ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
2331                               logical, &map_length, &multi, 0);
2332         BUG_ON(ret);
2333         bh_result->b_blocknr = multi->stripes[0].physical >> inode->i_blkbits;
2334         bh_result->b_size = min(map_length, len);
2335         bh_result->b_bdev = multi->stripes[0].dev->bdev;
2336         set_buffer_mapped(bh_result);
2337         kfree(multi);
2338 out:
2339         free_extent_map(em);
2340         return ret;
2341 }
2342
2343 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
2344                         const struct iovec *iov, loff_t offset,
2345                         unsigned long nr_segs)
2346 {
2347         struct file *file = iocb->ki_filp;
2348         struct inode *inode = file->f_mapping->host;
2349
2350         if (rw == WRITE)
2351                 return -EINVAL;
2352
2353         return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
2354                                   offset, nr_segs, btrfs_get_block, NULL);
2355 }
2356
2357 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2358 {
2359         return extent_bmap(mapping, iblock, btrfs_get_extent);
2360 }
2361
2362 int btrfs_readpage(struct file *file, struct page *page)
2363 {
2364         struct extent_io_tree *tree;
2365         tree = &BTRFS_I(page->mapping->host)->io_tree;
2366         return extent_read_full_page(tree, page, btrfs_get_extent);
2367 }
2368
2369 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2370 {
2371         struct extent_io_tree *tree;
2372
2373
2374         if (current->flags & PF_MEMALLOC) {
2375                 redirty_page_for_writepage(wbc, page);
2376                 unlock_page(page);
2377                 return 0;
2378         }
2379         tree = &BTRFS_I(page->mapping->host)->io_tree;
2380         return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2381 }
2382
2383 static int btrfs_writepages(struct address_space *mapping,
2384                             struct writeback_control *wbc)
2385 {
2386         struct extent_io_tree *tree;
2387         tree = &BTRFS_I(mapping->host)->io_tree;
2388         return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2389 }
2390
2391 static int
2392 btrfs_readpages(struct file *file, struct address_space *mapping,
2393                 struct list_head *pages, unsigned nr_pages)
2394 {
2395         struct extent_io_tree *tree;
2396         tree = &BTRFS_I(mapping->host)->io_tree;
2397         return extent_readpages(tree, mapping, pages, nr_pages,
2398                                 btrfs_get_extent);
2399 }
2400
2401 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
2402 {
2403         struct extent_io_tree *tree;
2404         struct extent_map_tree *map;
2405         int ret;
2406
2407         tree = &BTRFS_I(page->mapping->host)->io_tree;
2408         map = &BTRFS_I(page->mapping->host)->extent_tree;
2409         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
2410         if (ret == 1) {
2411                 ClearPagePrivate(page);
2412                 set_page_private(page, 0);
2413                 page_cache_release(page);
2414         }
2415         return ret;
2416 }
2417
2418 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2419 {
2420         struct extent_io_tree *tree;
2421
2422         tree = &BTRFS_I(page->mapping->host)->io_tree;
2423         extent_invalidatepage(tree, page, offset);
2424         btrfs_releasepage(page, GFP_NOFS);
2425 }
2426
2427 /*
2428  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2429  * called from a page fault handler when a page is first dirtied. Hence we must
2430  * be careful to check for EOF conditions here. We set the page up correctly
2431  * for a written page which means we get ENOSPC checking when writing into
2432  * holes and correct delalloc and unwritten extent mapping on filesystems that
2433  * support these features.
2434  *
2435  * We are not allowed to take the i_mutex here so we have to play games to
2436  * protect against truncate races as the page could now be beyond EOF.  Because
2437  * vmtruncate() writes the inode size before removing pages, once we have the
2438  * page lock we can determine safely if the page is beyond EOF. If it is not
2439  * beyond EOF, then the page is guaranteed safe against truncation until we
2440  * unlock the page.
2441  */
2442 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2443 {
2444         struct inode *inode = fdentry(vma->vm_file)->d_inode;
2445         struct btrfs_root *root = BTRFS_I(inode)->root;
2446         unsigned long end;
2447         loff_t size;
2448         int ret;
2449         u64 page_start;
2450
2451         mutex_lock(&root->fs_info->fs_mutex);
2452         ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2453         mutex_unlock(&root->fs_info->fs_mutex);
2454         if (ret)
2455                 goto out;
2456
2457         ret = -EINVAL;
2458
2459         lock_page(page);
2460         wait_on_page_writeback(page);
2461         size = i_size_read(inode);
2462         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2463
2464         if ((page->mapping != inode->i_mapping) ||
2465             (page_start > size)) {
2466                 /* page got truncated out from underneath us */
2467                 goto out_unlock;
2468         }
2469
2470         /* page is wholly or partially inside EOF */
2471         if (page_start + PAGE_CACHE_SIZE > size)
2472                 end = size & ~PAGE_CACHE_MASK;
2473         else
2474                 end = PAGE_CACHE_SIZE;
2475
2476         ret = btrfs_cow_one_page(inode, page, end);
2477
2478 out_unlock:
2479         unlock_page(page);
2480 out:
2481         return ret;
2482 }
2483
2484 static void btrfs_truncate(struct inode *inode)
2485 {
2486         struct btrfs_root *root = BTRFS_I(inode)->root;
2487         int ret;
2488         struct btrfs_trans_handle *trans;
2489         unsigned long nr;
2490
2491         if (!S_ISREG(inode->i_mode))
2492                 return;
2493         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2494                 return;
2495
2496         btrfs_truncate_page(inode->i_mapping, inode->i_size);
2497
2498         mutex_lock(&root->fs_info->fs_mutex);
2499         trans = btrfs_start_transaction(root, 1);
2500         btrfs_set_trans_block_group(trans, inode);
2501
2502         /* FIXME, add redo link to tree so we don't leak on crash */
2503         ret = btrfs_truncate_in_trans(trans, root, inode,
2504                                       BTRFS_EXTENT_DATA_KEY);
2505         btrfs_update_inode(trans, root, inode);
2506         nr = trans->blocks_used;
2507
2508         ret = btrfs_end_transaction(trans, root);
2509         BUG_ON(ret);
2510         mutex_unlock(&root->fs_info->fs_mutex);
2511         btrfs_btree_balance_dirty(root, nr);
2512         btrfs_throttle(root);
2513 }
2514
2515 static int noinline create_subvol(struct btrfs_root *root, char *name,
2516                                   int namelen)
2517 {
2518         struct btrfs_trans_handle *trans;
2519         struct btrfs_key key;
2520         struct btrfs_root_item root_item;
2521         struct btrfs_inode_item *inode_item;
2522         struct extent_buffer *leaf;
2523         struct btrfs_root *new_root = root;
2524         struct inode *inode;
2525         struct inode *dir;
2526         int ret;
2527         int err;
2528         u64 objectid;
2529         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2530         unsigned long nr = 1;
2531
2532         mutex_lock(&root->fs_info->fs_mutex);
2533         ret = btrfs_check_free_space(root, 1, 0);
2534         if (ret)
2535                 goto fail_commit;
2536
2537         trans = btrfs_start_transaction(root, 1);
2538         BUG_ON(!trans);
2539
2540         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2541                                        0, &objectid);
2542         if (ret)
2543                 goto fail;
2544
2545         leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2546                                         objectid, trans->transid, 0, 0,
2547                                         0, 0);
2548         if (IS_ERR(leaf))
2549                 return PTR_ERR(leaf);
2550
2551         btrfs_set_header_nritems(leaf, 0);
2552         btrfs_set_header_level(leaf, 0);
2553         btrfs_set_header_bytenr(leaf, leaf->start);
2554         btrfs_set_header_generation(leaf, trans->transid);
2555         btrfs_set_header_owner(leaf, objectid);
2556
2557         write_extent_buffer(leaf, root->fs_info->fsid,
2558                             (unsigned long)btrfs_header_fsid(leaf),
2559                             BTRFS_FSID_SIZE);
2560         btrfs_mark_buffer_dirty(leaf);
2561
2562         inode_item = &root_item.inode;
2563         memset(inode_item, 0, sizeof(*inode_item));
2564         inode_item->generation = cpu_to_le64(1);
2565         inode_item->size = cpu_to_le64(3);
2566         inode_item->nlink = cpu_to_le32(1);
2567         inode_item->nblocks = cpu_to_le64(1);
2568         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2569
2570         btrfs_set_root_bytenr(&root_item, leaf->start);
2571         btrfs_set_root_level(&root_item, 0);
2572         btrfs_set_root_refs(&root_item, 1);
2573         btrfs_set_root_used(&root_item, 0);
2574
2575         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2576         root_item.drop_level = 0;
2577
2578         free_extent_buffer(leaf);
2579         leaf = NULL;
2580
2581         btrfs_set_root_dirid(&root_item, new_dirid);
2582
2583         key.objectid = objectid;
2584         key.offset = 1;
2585         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2586         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2587                                 &root_item);
2588         if (ret)
2589                 goto fail;
2590
2591         /*
2592          * insert the directory item
2593          */
2594         key.offset = (u64)-1;
2595         dir = root->fs_info->sb->s_root->d_inode;
2596         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2597                                     name, namelen, dir->i_ino, &key,
2598                                     BTRFS_FT_DIR);
2599         if (ret)
2600                 goto fail;
2601
2602         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2603                              name, namelen, objectid,
2604                              root->fs_info->sb->s_root->d_inode->i_ino);
2605         if (ret)
2606                 goto fail;
2607
2608         ret = btrfs_commit_transaction(trans, root);
2609         if (ret)
2610                 goto fail_commit;
2611
2612         new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2613         BUG_ON(!new_root);
2614
2615         trans = btrfs_start_transaction(new_root, 1);
2616         BUG_ON(!trans);
2617
2618         inode = btrfs_new_inode(trans, new_root, "..", 2, new_dirid,
2619                                 new_dirid,
2620                                 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2621         if (IS_ERR(inode))
2622                 goto fail;
2623         inode->i_op = &btrfs_dir_inode_operations;
2624         inode->i_fop = &btrfs_dir_file_operations;
2625         new_root->inode = inode;
2626
2627         ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2628                                      new_dirid);
2629         inode->i_nlink = 1;
2630         inode->i_size = 0;
2631         ret = btrfs_update_inode(trans, new_root, inode);
2632         if (ret)
2633                 goto fail;
2634 fail:
2635         nr = trans->blocks_used;
2636         err = btrfs_commit_transaction(trans, new_root);
2637         if (err && !ret)
2638                 ret = err;
2639 fail_commit:
2640         mutex_unlock(&root->fs_info->fs_mutex);
2641         btrfs_btree_balance_dirty(root, nr);
2642         btrfs_throttle(root);
2643         return ret;
2644 }
2645
2646 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2647 {
2648         struct btrfs_pending_snapshot *pending_snapshot;
2649         struct btrfs_trans_handle *trans;
2650         int ret;
2651         int err;
2652         unsigned long nr = 0;
2653
2654         if (!root->ref_cows)
2655                 return -EINVAL;
2656
2657         mutex_lock(&root->fs_info->fs_mutex);
2658         ret = btrfs_check_free_space(root, 1, 0);
2659         if (ret)
2660                 goto fail_unlock;
2661
2662         pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2663         if (!pending_snapshot) {
2664                 ret = -ENOMEM;
2665                 goto fail_unlock;
2666         }
2667         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
2668         if (!pending_snapshot->name) {
2669                 ret = -ENOMEM;
2670                 kfree(pending_snapshot);
2671                 goto fail_unlock;
2672         }
2673         memcpy(pending_snapshot->name, name, namelen);
2674         pending_snapshot->name[namelen] = '\0';
2675         trans = btrfs_start_transaction(root, 1);
2676         BUG_ON(!trans);
2677         pending_snapshot->root = root;
2678         list_add(&pending_snapshot->list,
2679                  &trans->transaction->pending_snapshots);
2680         ret = btrfs_update_inode(trans, root, root->inode);
2681         err = btrfs_commit_transaction(trans, root);
2682
2683 fail_unlock:
2684         mutex_unlock(&root->fs_info->fs_mutex);
2685         btrfs_btree_balance_dirty(root, nr);
2686         btrfs_throttle(root);
2687         return ret;
2688 }
2689
2690 unsigned long btrfs_force_ra(struct address_space *mapping,
2691                               struct file_ra_state *ra, struct file *file,
2692                               pgoff_t offset, pgoff_t last_index)
2693 {
2694         pgoff_t req_size;
2695
2696 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2697         req_size = last_index - offset + 1;
2698         offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2699         return offset;
2700 #else
2701         req_size = min(last_index - offset + 1, (pgoff_t)128);
2702         page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2703         return offset + req_size;
2704 #endif
2705 }
2706
2707 int btrfs_defrag_file(struct file *file) {
2708         struct inode *inode = fdentry(file)->d_inode;
2709         struct btrfs_root *root = BTRFS_I(inode)->root;
2710         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2711         struct page *page;
2712         unsigned long last_index;
2713         unsigned long ra_index = 0;
2714         u64 page_start;
2715         u64 page_end;
2716         unsigned long i;
2717         int ret;
2718
2719         mutex_lock(&root->fs_info->fs_mutex);
2720         ret = btrfs_check_free_space(root, inode->i_size, 0);
2721         mutex_unlock(&root->fs_info->fs_mutex);
2722         if (ret)
2723                 return -ENOSPC;
2724
2725         mutex_lock(&inode->i_mutex);
2726         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2727         for (i = 0; i <= last_index; i++) {
2728                 if (i == ra_index) {
2729                         ra_index = btrfs_force_ra(inode->i_mapping,
2730                                                   &file->f_ra,
2731                                                   file, ra_index, last_index);
2732                 }
2733                 page = grab_cache_page(inode->i_mapping, i);
2734                 if (!page)
2735                         goto out_unlock;
2736                 if (!PageUptodate(page)) {
2737                         btrfs_readpage(NULL, page);
2738                         lock_page(page);
2739                         if (!PageUptodate(page)) {
2740                                 unlock_page(page);
2741                                 page_cache_release(page);
2742                                 goto out_unlock;
2743                         }
2744                 }
2745                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2746                 page_end = page_start + PAGE_CACHE_SIZE - 1;
2747
2748                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2749                 set_extent_delalloc(io_tree, page_start,
2750                                     page_end, GFP_NOFS);
2751
2752                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2753                 set_page_dirty(page);
2754                 unlock_page(page);
2755                 page_cache_release(page);
2756                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2757         }
2758
2759 out_unlock:
2760         mutex_unlock(&inode->i_mutex);
2761         return 0;
2762 }
2763
2764 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2765 {
2766         u64 new_size;
2767         u64 old_size;
2768         struct btrfs_ioctl_vol_args *vol_args;
2769         struct btrfs_trans_handle *trans;
2770         char *sizestr;
2771         int ret = 0;
2772         int namelen;
2773         int mod = 0;
2774
2775         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2776
2777         if (!vol_args)
2778                 return -ENOMEM;
2779
2780         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2781                 ret = -EFAULT;
2782                 goto out;
2783         }
2784         namelen = strlen(vol_args->name);
2785         if (namelen > BTRFS_VOL_NAME_MAX) {
2786                 ret = -EINVAL;
2787                 goto out;
2788         }
2789
2790         sizestr = vol_args->name;
2791         if (!strcmp(sizestr, "max"))
2792                 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2793         else {
2794                 if (sizestr[0] == '-') {
2795                         mod = -1;
2796                         sizestr++;
2797                 } else if (sizestr[0] == '+') {
2798                         mod = 1;
2799                         sizestr++;
2800                 }
2801                 new_size = btrfs_parse_size(sizestr);
2802                 if (new_size == 0) {
2803                         ret = -EINVAL;
2804                         goto out;
2805                 }
2806         }
2807
2808         mutex_lock(&root->fs_info->fs_mutex);
2809         old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2810
2811         if (mod < 0) {
2812                 if (new_size > old_size) {
2813                         ret = -EINVAL;
2814                         goto out_unlock;
2815                 }
2816                 new_size = old_size - new_size;
2817         } else if (mod > 0) {
2818                 new_size = old_size + new_size;
2819         }
2820
2821         if (new_size < 256 * 1024 * 1024) {
2822                 ret = -EINVAL;
2823                 goto out_unlock;
2824         }
2825         if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2826                 ret = -EFBIG;
2827                 goto out_unlock;
2828         }
2829
2830         do_div(new_size, root->sectorsize);
2831         new_size *= root->sectorsize;
2832
2833 printk("new size is %Lu\n", new_size);
2834         if (new_size > old_size) {
2835                 trans = btrfs_start_transaction(root, 1);
2836                 ret = btrfs_grow_extent_tree(trans, root, new_size);
2837                 btrfs_commit_transaction(trans, root);
2838         } else {
2839                 ret = btrfs_shrink_extent_tree(root, new_size);
2840         }
2841
2842 out_unlock:
2843         mutex_unlock(&root->fs_info->fs_mutex);
2844 out:
2845         kfree(vol_args);
2846         return ret;
2847 }
2848
2849 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2850                                             void __user *arg)
2851 {
2852         struct btrfs_ioctl_vol_args *vol_args;
2853         struct btrfs_dir_item *di;
2854         struct btrfs_path *path;
2855         u64 root_dirid;
2856         int namelen;
2857         int ret;
2858
2859         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2860
2861         if (!vol_args)
2862                 return -ENOMEM;
2863
2864         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2865                 ret = -EFAULT;
2866                 goto out;
2867         }
2868
2869         namelen = strlen(vol_args->name);
2870         if (namelen > BTRFS_VOL_NAME_MAX) {
2871                 ret = -EINVAL;
2872                 goto out;
2873         }
2874         if (strchr(vol_args->name, '/')) {
2875                 ret = -EINVAL;
2876                 goto out;
2877         }
2878
2879         path = btrfs_alloc_path();
2880         if (!path) {
2881                 ret = -ENOMEM;
2882                 goto out;
2883         }
2884
2885         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2886         mutex_lock(&root->fs_info->fs_mutex);
2887         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2888                             path, root_dirid,
2889                             vol_args->name, namelen, 0);
2890         mutex_unlock(&root->fs_info->fs_mutex);
2891         btrfs_free_path(path);
2892
2893         if (di && !IS_ERR(di)) {
2894                 ret = -EEXIST;
2895                 goto out;
2896         }
2897
2898         if (IS_ERR(di)) {
2899                 ret = PTR_ERR(di);
2900                 goto out;
2901         }
2902
2903         if (root == root->fs_info->tree_root)
2904                 ret = create_subvol(root, vol_args->name, namelen);
2905         else
2906                 ret = create_snapshot(root, vol_args->name, namelen);
2907 out:
2908         kfree(vol_args);
2909         return ret;
2910 }
2911
2912 static int btrfs_ioctl_defrag(struct file *file)
2913 {
2914         struct inode *inode = fdentry(file)->d_inode;
2915         struct btrfs_root *root = BTRFS_I(inode)->root;
2916
2917         switch (inode->i_mode & S_IFMT) {
2918         case S_IFDIR:
2919                 mutex_lock(&root->fs_info->fs_mutex);
2920                 btrfs_defrag_root(root, 0);
2921                 btrfs_defrag_root(root->fs_info->extent_root, 0);
2922                 mutex_unlock(&root->fs_info->fs_mutex);
2923                 break;
2924         case S_IFREG:
2925                 btrfs_defrag_file(file);
2926                 break;
2927         }
2928
2929         return 0;
2930 }
2931
2932 long btrfs_ioctl(struct file *file, unsigned int
2933                 cmd, unsigned long arg)
2934 {
2935         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2936
2937         switch (cmd) {
2938         case BTRFS_IOC_SNAP_CREATE:
2939                 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2940         case BTRFS_IOC_DEFRAG:
2941                 return btrfs_ioctl_defrag(file);
2942         case BTRFS_IOC_RESIZE:
2943                 return btrfs_ioctl_resize(root, (void __user *)arg);
2944         }
2945
2946         return -ENOTTY;
2947 }
2948
2949 /*
2950  * Called inside transaction, so use GFP_NOFS
2951  */
2952 struct inode *btrfs_alloc_inode(struct super_block *sb)
2953 {
2954         struct btrfs_inode *ei;
2955
2956         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2957         if (!ei)
2958                 return NULL;
2959         ei->last_trans = 0;
2960         ei->ordered_trans = 0;
2961         return &ei->vfs_inode;
2962 }
2963
2964 void btrfs_destroy_inode(struct inode *inode)
2965 {
2966         WARN_ON(!list_empty(&inode->i_dentry));
2967         WARN_ON(inode->i_data.nrpages);
2968
2969         btrfs_drop_extent_cache(inode, 0, (u64)-1);
2970         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2971 }
2972
2973 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2974 static void init_once(struct kmem_cache * cachep, void *foo)
2975 #else
2976 static void init_once(void * foo, struct kmem_cache * cachep,
2977                       unsigned long flags)
2978 #endif
2979 {
2980         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2981
2982         inode_init_once(&ei->vfs_inode);
2983 }
2984
2985 void btrfs_destroy_cachep(void)
2986 {
2987         if (btrfs_inode_cachep)
2988                 kmem_cache_destroy(btrfs_inode_cachep);
2989         if (btrfs_trans_handle_cachep)
2990                 kmem_cache_destroy(btrfs_trans_handle_cachep);
2991         if (btrfs_transaction_cachep)
2992                 kmem_cache_destroy(btrfs_transaction_cachep);
2993         if (btrfs_bit_radix_cachep)
2994                 kmem_cache_destroy(btrfs_bit_radix_cachep);
2995         if (btrfs_path_cachep)
2996                 kmem_cache_destroy(btrfs_path_cachep);
2997 }
2998
2999 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
3000                                        unsigned long extra_flags,
3001 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
3002                                        void (*ctor)(struct kmem_cache *, void *)
3003 #else
3004                                        void (*ctor)(void *, struct kmem_cache *,
3005                                                     unsigned long)
3006 #endif
3007                                      )
3008 {
3009         return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
3010                                  SLAB_MEM_SPREAD | extra_flags), ctor
3011 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
3012                                  ,NULL
3013 #endif
3014                                 );
3015 }
3016
3017 int btrfs_init_cachep(void)
3018 {
3019         btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
3020                                           sizeof(struct btrfs_inode),
3021                                           0, init_once);
3022         if (!btrfs_inode_cachep)
3023                 goto fail;
3024         btrfs_trans_handle_cachep =
3025                         btrfs_cache_create("btrfs_trans_handle_cache",
3026                                            sizeof(struct btrfs_trans_handle),
3027                                            0, NULL);
3028         if (!btrfs_trans_handle_cachep)
3029                 goto fail;
3030         btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
3031                                              sizeof(struct btrfs_transaction),
3032                                              0, NULL);
3033         if (!btrfs_transaction_cachep)
3034                 goto fail;
3035         btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
3036                                          sizeof(struct btrfs_path),
3037                                          0, NULL);
3038         if (!btrfs_path_cachep)
3039                 goto fail;
3040         btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
3041                                               SLAB_DESTROY_BY_RCU, NULL);
3042         if (!btrfs_bit_radix_cachep)
3043                 goto fail;
3044         return 0;
3045 fail:
3046         btrfs_destroy_cachep();
3047         return -ENOMEM;
3048 }
3049
3050 static int btrfs_getattr(struct vfsmount *mnt,
3051                          struct dentry *dentry, struct kstat *stat)
3052 {
3053         struct inode *inode = dentry->d_inode;
3054         generic_fillattr(inode, stat);
3055         stat->blksize = PAGE_CACHE_SIZE;
3056         stat->blocks = inode->i_blocks + (BTRFS_I(inode)->delalloc_bytes >> 9);
3057         return 0;
3058 }
3059
3060 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
3061                            struct inode * new_dir,struct dentry *new_dentry)
3062 {
3063         struct btrfs_trans_handle *trans;
3064         struct btrfs_root *root = BTRFS_I(old_dir)->root;
3065         struct inode *new_inode = new_dentry->d_inode;
3066         struct inode *old_inode = old_dentry->d_inode;
3067         struct timespec ctime = CURRENT_TIME;
3068         struct btrfs_path *path;
3069         int ret;
3070
3071         if (S_ISDIR(old_inode->i_mode) && new_inode &&
3072             new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
3073                 return -ENOTEMPTY;
3074         }
3075
3076         mutex_lock(&root->fs_info->fs_mutex);
3077         ret = btrfs_check_free_space(root, 1, 0);
3078         if (ret)
3079                 goto out_unlock;
3080
3081         trans = btrfs_start_transaction(root, 1);
3082
3083         btrfs_set_trans_block_group(trans, new_dir);
3084         path = btrfs_alloc_path();
3085         if (!path) {
3086                 ret = -ENOMEM;
3087                 goto out_fail;
3088         }
3089
3090         old_dentry->d_inode->i_nlink++;
3091         old_dir->i_ctime = old_dir->i_mtime = ctime;
3092         new_dir->i_ctime = new_dir->i_mtime = ctime;
3093         old_inode->i_ctime = ctime;
3094
3095         ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
3096         if (ret)
3097                 goto out_fail;
3098
3099         if (new_inode) {
3100                 new_inode->i_ctime = CURRENT_TIME;
3101                 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
3102                 if (ret)
3103                         goto out_fail;
3104         }
3105         ret = btrfs_add_link(trans, new_dentry, old_inode, 1);
3106         if (ret)
3107                 goto out_fail;
3108
3109 out_fail:
3110         btrfs_free_path(path);
3111         btrfs_end_transaction(trans, root);
3112 out_unlock:
3113         mutex_unlock(&root->fs_info->fs_mutex);
3114         return ret;
3115 }
3116
3117 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
3118                          const char *symname)
3119 {
3120         struct btrfs_trans_handle *trans;
3121         struct btrfs_root *root = BTRFS_I(dir)->root;
3122         struct btrfs_path *path;
3123         struct btrfs_key key;
3124         struct inode *inode = NULL;
3125         int err;
3126         int drop_inode = 0;
3127         u64 objectid;
3128         int name_len;
3129         int datasize;
3130         unsigned long ptr;
3131         struct btrfs_file_extent_item *ei;
3132         struct extent_buffer *leaf;
3133         unsigned long nr = 0;
3134
3135         name_len = strlen(symname) + 1;
3136         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
3137                 return -ENAMETOOLONG;
3138
3139         mutex_lock(&root->fs_info->fs_mutex);
3140         err = btrfs_check_free_space(root, 1, 0);
3141         if (err)
3142                 goto out_fail;
3143
3144         trans = btrfs_start_transaction(root, 1);
3145         btrfs_set_trans_block_group(trans, dir);
3146
3147         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
3148         if (err) {
3149                 err = -ENOSPC;
3150                 goto out_unlock;
3151         }
3152
3153         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
3154                                 dentry->d_name.len,
3155                                 dentry->d_parent->d_inode->i_ino, objectid,
3156                                 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
3157         err = PTR_ERR(inode);
3158         if (IS_ERR(inode))
3159                 goto out_unlock;
3160
3161         btrfs_set_trans_block_group(trans, inode);
3162         err = btrfs_add_nondir(trans, dentry, inode, 0);
3163         if (err)
3164                 drop_inode = 1;
3165         else {
3166                 inode->i_mapping->a_ops = &btrfs_aops;
3167                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3168                 inode->i_fop = &btrfs_file_operations;
3169                 inode->i_op = &btrfs_file_inode_operations;
3170                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
3171                 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
3172                                      inode->i_mapping, GFP_NOFS);
3173                 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
3174                                      inode->i_mapping, GFP_NOFS);
3175                 BTRFS_I(inode)->delalloc_bytes = 0;
3176                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3177         }
3178         dir->i_sb->s_dirt = 1;
3179         btrfs_update_inode_block_group(trans, inode);
3180         btrfs_update_inode_block_group(trans, dir);
3181         if (drop_inode)
3182                 goto out_unlock;
3183
3184         path = btrfs_alloc_path();
3185         BUG_ON(!path);
3186         key.objectid = inode->i_ino;
3187         key.offset = 0;
3188         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
3189         datasize = btrfs_file_extent_calc_inline_size(name_len);
3190         err = btrfs_insert_empty_item(trans, root, path, &key,
3191                                       datasize);
3192         if (err) {
3193                 drop_inode = 1;
3194                 goto out_unlock;
3195         }
3196         leaf = path->nodes[0];
3197         ei = btrfs_item_ptr(leaf, path->slots[0],
3198                             struct btrfs_file_extent_item);
3199         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
3200         btrfs_set_file_extent_type(leaf, ei,
3201                                    BTRFS_FILE_EXTENT_INLINE);
3202         ptr = btrfs_file_extent_inline_start(ei);
3203         write_extent_buffer(leaf, symname, ptr, name_len);
3204         btrfs_mark_buffer_dirty(leaf);
3205         btrfs_free_path(path);
3206
3207         inode->i_op = &btrfs_symlink_inode_operations;
3208         inode->i_mapping->a_ops = &btrfs_symlink_aops;
3209         inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3210         inode->i_size = name_len - 1;
3211         err = btrfs_update_inode(trans, root, inode);
3212         if (err)
3213                 drop_inode = 1;
3214
3215 out_unlock:
3216         nr = trans->blocks_used;
3217         btrfs_end_transaction(trans, root);
3218 out_fail:
3219         mutex_unlock(&root->fs_info->fs_mutex);
3220         if (drop_inode) {
3221                 inode_dec_link_count(inode);
3222                 iput(inode);
3223         }
3224         btrfs_btree_balance_dirty(root, nr);
3225         btrfs_throttle(root);
3226         return err;
3227 }
3228
3229 static int btrfs_permission(struct inode *inode, int mask,
3230                             struct nameidata *nd)
3231 {
3232         if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
3233                 return -EACCES;
3234         return generic_permission(inode, mask, NULL);
3235 }
3236
3237 static struct inode_operations btrfs_dir_inode_operations = {
3238         .lookup         = btrfs_lookup,
3239         .create         = btrfs_create,
3240         .unlink         = btrfs_unlink,
3241         .link           = btrfs_link,
3242         .mkdir          = btrfs_mkdir,
3243         .rmdir          = btrfs_rmdir,
3244         .rename         = btrfs_rename,
3245         .symlink        = btrfs_symlink,
3246         .setattr        = btrfs_setattr,
3247         .mknod          = btrfs_mknod,
3248         .setxattr       = generic_setxattr,
3249         .getxattr       = generic_getxattr,
3250         .listxattr      = btrfs_listxattr,
3251         .removexattr    = generic_removexattr,
3252         .permission     = btrfs_permission,
3253 };
3254 static struct inode_operations btrfs_dir_ro_inode_operations = {
3255         .lookup         = btrfs_lookup,
3256         .permission     = btrfs_permission,
3257 };
3258 static struct file_operations btrfs_dir_file_operations = {
3259         .llseek         = generic_file_llseek,
3260         .read           = generic_read_dir,
3261         .readdir        = btrfs_readdir,
3262         .unlocked_ioctl = btrfs_ioctl,
3263 #ifdef CONFIG_COMPAT
3264         .compat_ioctl   = btrfs_ioctl,
3265 #endif
3266 };
3267
3268 static struct extent_io_ops btrfs_extent_io_ops = {
3269         .fill_delalloc = run_delalloc_range,
3270         .submit_bio_hook = btrfs_submit_bio_hook,
3271         .merge_bio_hook = btrfs_merge_bio_hook,
3272         .readpage_io_hook = btrfs_readpage_io_hook,
3273         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
3274         .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
3275         .set_bit_hook = btrfs_set_bit_hook,
3276         .clear_bit_hook = btrfs_clear_bit_hook,
3277 };
3278
3279 static struct address_space_operations btrfs_aops = {
3280         .readpage       = btrfs_readpage,
3281         .writepage      = btrfs_writepage,
3282         .writepages     = btrfs_writepages,
3283         .readpages      = btrfs_readpages,
3284         .sync_page      = block_sync_page,
3285         .bmap           = btrfs_bmap,
3286         .direct_IO      = btrfs_direct_IO,
3287         .invalidatepage = btrfs_invalidatepage,
3288         .releasepage    = btrfs_releasepage,
3289         .set_page_dirty = __set_page_dirty_nobuffers,
3290 };
3291
3292 static struct address_space_operations btrfs_symlink_aops = {
3293         .readpage       = btrfs_readpage,
3294         .writepage      = btrfs_writepage,
3295         .invalidatepage = btrfs_invalidatepage,
3296         .releasepage    = btrfs_releasepage,
3297 };
3298
3299 static struct inode_operations btrfs_file_inode_operations = {
3300         .truncate       = btrfs_truncate,
3301         .getattr        = btrfs_getattr,
3302         .setattr        = btrfs_setattr,
3303         .setxattr       = generic_setxattr,
3304         .getxattr       = generic_getxattr,
3305         .listxattr      = btrfs_listxattr,
3306         .removexattr    = generic_removexattr,
3307         .permission     = btrfs_permission,
3308 };
3309 static struct inode_operations btrfs_special_inode_operations = {
3310         .getattr        = btrfs_getattr,
3311         .setattr        = btrfs_setattr,
3312         .permission     = btrfs_permission,
3313 };
3314 static struct inode_operations btrfs_symlink_inode_operations = {
3315         .readlink       = generic_readlink,
3316         .follow_link    = page_follow_link_light,
3317         .put_link       = page_put_link,
3318         .permission     = btrfs_permission,
3319 };