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
 387         if (btrfs_test_opt(root, NODATASUM) ||
 388             btrfs_test_flag(inode, NODATASUM))
 389                 return 0;
 390
 391         mutex_lock(&root->fs_info->fs_mutex);
 392         path = btrfs_alloc_path();
 393         item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
 394         if (IS_ERR(item)) {
 395                 ret = PTR_ERR(item);
 396                 /* a csum that isn't present is a preallocated region. */
 397                 if (ret == -ENOENT || ret == -EFBIG)
 398                         ret = 0;
 399                 csum = 0;
 400                 printk("no csum found for inode %lu start %Lu\n", inode->i_ino, start);
 401                 goto out;
 402         }
 403         read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
 404                            BTRFS_CRC32_SIZE);
 405         set_state_private(io_tree, start, csum);
 406 out:
 407         if (path)
 408                 btrfs_free_path(path);
 409         mutex_unlock(&root->fs_info->fs_mutex);
 410         return ret;
 411 }
 412
 413 struct io_failure_record {
 414         struct page *page;
 415         u64 start;
 416         u64 len;
 417         u64 logical;
 418         int last_mirror;
 419 };
 420
 421 int btrfs_readpage_io_failed_hook(struct bio *failed_bio,
 422                                   struct page *page, u64 start, u64 end,
 423                                   struct extent_state *state)
 424 {
 425         struct io_failure_record *failrec = NULL;
 426         u64 private;
 427         struct extent_map *em;
 428         struct inode *inode = page->mapping->host;
 429         struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
 430         struct bio *bio;
 431         int num_copies;
 432         int ret;
 433         u64 logical;
 434
 435         ret = get_state_private(failure_tree, start, &private);
 436         if (ret) {
 437                 size_t pg_offset = start - page_offset(page);
 438                 failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
 439                 if (!failrec)
 440                         return -ENOMEM;
 441                 failrec->start = start;
 442                 failrec->len = end - start + 1;
 443                 failrec->last_mirror = 0;
 444
 445                 em = btrfs_get_extent(inode, NULL, pg_offset, start,
 446                                       failrec->len, 0);
 447
 448                 if (!em || IS_ERR(em)) {
 449                         kfree(failrec);
 450                         return -EIO;
 451                 }
 452                 logical = start - em->start;
 453                 logical = em->block_start + logical;
 454                 failrec->logical = logical;
 455                 free_extent_map(em);
 456                 set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
 457                                 EXTENT_DIRTY, GFP_NOFS);
 458                 set_state_private(failure_tree, start,
 459                                  (u64)(unsigned long)failrec);
 460         } else {
 461                 failrec = (struct io_failure_record *)(unsigned long)private;
 462         }
 463         num_copies = btrfs_num_copies(
 464                               &BTRFS_I(inode)->root->fs_info->mapping_tree,
 465                               failrec->logical, failrec->len);
 466         failrec->last_mirror++;
 467         if (!state) {
 468                 spin_lock_irq(&BTRFS_I(inode)->io_tree.lock);
 469                 state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
 470                                                     failrec->start,
 471                                                     EXTENT_LOCKED);
 472                 if (state && state->start != failrec->start)
 473                         state = NULL;
 474                 spin_unlock_irq(&BTRFS_I(inode)->io_tree.lock);
 475         }
 476         if (!state || failrec->last_mirror > num_copies) {
 477                 set_state_private(failure_tree, failrec->start, 0);
 478                 clear_extent_bits(failure_tree, failrec->start,
 479                                   failrec->start + failrec->len - 1,
 480                                   EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
 481                 kfree(failrec);
 482                 return -EIO;
 483         }
 484         bio = bio_alloc(GFP_NOFS, 1);
 485         bio->bi_private = state;
 486         bio->bi_end_io = failed_bio->bi_end_io;
 487         bio->bi_sector = failrec->logical >> 9;
 488         bio->bi_bdev = failed_bio->bi_bdev;
 489         bio_add_page(bio, page, failrec->len, start - page_offset(page));
 490         btrfs_submit_bio_hook(inode, READ, bio, failrec->last_mirror);
 491         return 0;
 492 }
 493
 494 int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 495                                struct extent_state *state)
 496 {
 497         size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
 498         struct inode *inode = page->mapping->host;
 499         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 500         char *kaddr;
 501         u64 private = ~(u32)0;
 502         int ret;
 503         struct btrfs_root *root = BTRFS_I(inode)->root;
 504         u32 csum = ~(u32)0;
 505         unsigned long flags;
 506
 507         if (btrfs_test_opt(root, NODATASUM) ||
 508             btrfs_test_flag(inode, NODATASUM))
 509                 return 0;
 510         if (state && state->start == start) {
 511                 private = state->private;
 512                 ret = 0;
 513         } else {
 514                 ret = get_state_private(io_tree, start, &private);
 515         }
 516         local_irq_save(flags);
 517         kaddr = kmap_atomic(page, KM_IRQ0);
 518         if (ret) {
 519                 goto zeroit;
 520         }
 521         csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
 522         btrfs_csum_final(csum, (char *)&csum);
 523         if (csum != private) {
 524                 goto zeroit;
 525         }
 526         kunmap_atomic(kaddr, KM_IRQ0);
 527         local_irq_restore(flags);
 528
 529         /* if the io failure tree for this inode is non-empty,
 530          * check to see if we've recovered from a failed IO
 531          */
 532         private = 0;
 533         if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
 534                              (u64)-1, 1, EXTENT_DIRTY)) {
 535                 u64 private_failure;
 536                 struct io_failure_record *failure;
 537                 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
 538                                         start, &private_failure);
 539                 if (ret == 0) {
 540                         failure = (struct io_failure_record *)(unsigned long)
 541                                    private_failure;
 542                         set_state_private(&BTRFS_I(inode)->io_failure_tree,
 543                                           failure->start, 0);
 544                         clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
 545                                           failure->start,
 546                                           failure->start + failure->len - 1,
 547                                           EXTENT_DIRTY | EXTENT_LOCKED,
 548                                           GFP_NOFS);
 549                         kfree(failure);
 550                 }
 551         }
 552         return 0;
 553
 554 zeroit:
 555         printk("btrfs csum failed ino %lu off %llu csum %u private %Lu\n",
 556                page->mapping->host->i_ino, (unsigned long long)start, csum,
 557                private);
 558         memset(kaddr + offset, 1, end - start + 1);
 559         flush_dcache_page(page);
 560         kunmap_atomic(kaddr, KM_IRQ0);
 561         local_irq_restore(flags);
 562         return -EIO;
 563 }
 564
 565 void btrfs_read_locked_inode(struct inode *inode)
 566 {
 567         struct btrfs_path *path;
 568         struct extent_buffer *leaf;
 569         struct btrfs_inode_item *inode_item;
 570         struct btrfs_timespec *tspec;
 571         struct btrfs_root *root = BTRFS_I(inode)->root;
 572         struct btrfs_key location;
 573         u64 alloc_group_block;
 574         u32 rdev;
 575         int ret;
 576
 577         path = btrfs_alloc_path();
 578         BUG_ON(!path);
 579         mutex_lock(&root->fs_info->fs_mutex);
 580         memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
 581
 582         ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
 583         if (ret)
 584                 goto make_bad;
 585
 586         leaf = path->nodes[0];
 587         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 588                                     struct btrfs_inode_item);
 589
 590         inode->i_mode = btrfs_inode_mode(leaf, inode_item);
 591         inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
 592         inode->i_uid = btrfs_inode_uid(leaf, inode_item);
 593         inode->i_gid = btrfs_inode_gid(leaf, inode_item);
 594         inode->i_size = btrfs_inode_size(leaf, inode_item);
 595
 596         tspec = btrfs_inode_atime(inode_item);
 597         inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 598         inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 599
 600         tspec = btrfs_inode_mtime(inode_item);
 601         inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 602         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 603
 604         tspec = btrfs_inode_ctime(inode_item);
 605         inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
 606         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
 607
 608         inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
 609         inode->i_generation = btrfs_inode_generation(leaf, inode_item);
 610         inode->i_rdev = 0;
 611         rdev = btrfs_inode_rdev(leaf, inode_item);
 612
 613         alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
 614         BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
 615                                                        alloc_group_block);
 616         BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
 617         if (!BTRFS_I(inode)->block_group) {
 618                 BTRFS_I(inode)->block_group = btrfs_find_block_group(root,
 619                                                  NULL, 0,
 620                                                  BTRFS_BLOCK_GROUP_METADATA, 0);
 621         }
 622         btrfs_free_path(path);
 623         inode_item = NULL;
 624
 625         mutex_unlock(&root->fs_info->fs_mutex);
 626
 627         switch (inode->i_mode & S_IFMT) {
 628         case S_IFREG:
 629                 inode->i_mapping->a_ops = &btrfs_aops;
 630                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
 631                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 632                 inode->i_fop = &btrfs_file_operations;
 633                 inode->i_op = &btrfs_file_inode_operations;
 634                 break;
 635         case S_IFDIR:
 636                 inode->i_fop = &btrfs_dir_file_operations;
 637                 if (root == root->fs_info->tree_root)
 638                         inode->i_op = &btrfs_dir_ro_inode_operations;
 639                 else
 640                         inode->i_op = &btrfs_dir_inode_operations;
 641                 break;
 642         case S_IFLNK:
 643                 inode->i_op = &btrfs_symlink_inode_operations;
 644                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
 645                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
 646                 break;
 647         default:
 648                 init_special_inode(inode, inode->i_mode, rdev);
 649                 break;
 650         }
 651         return;
 652
 653 make_bad:
 654         btrfs_release_path(root, path);
 655         btrfs_free_path(path);
 656         mutex_unlock(&root->fs_info->fs_mutex);
 657         make_bad_inode(inode);
 658 }
 659
 660 static void fill_inode_item(struct extent_buffer *leaf,
 661                             struct btrfs_inode_item *item,
 662                             struct inode *inode)
 663 {
 664         btrfs_set_inode_uid(leaf, item, inode->i_uid);
 665         btrfs_set_inode_gid(leaf, item, inode->i_gid);
 666         btrfs_set_inode_size(leaf, item, inode->i_size);
 667         btrfs_set_inode_mode(leaf, item, inode->i_mode);
 668         btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
 669
 670         btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
 671                                inode->i_atime.tv_sec);
 672         btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
 673                                 inode->i_atime.tv_nsec);
 674
 675         btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
 676                                inode->i_mtime.tv_sec);
 677         btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
 678                                 inode->i_mtime.tv_nsec);
 679
 680         btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
 681                                inode->i_ctime.tv_sec);
 682         btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
 683                                 inode->i_ctime.tv_nsec);
 684
 685         btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
 686         btrfs_set_inode_generation(leaf, item, inode->i_generation);
 687         btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
 688         btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
 689         btrfs_set_inode_block_group(leaf, item,
 690                                     BTRFS_I(inode)->block_group->key.objectid);
 691 }
 692
 693 int btrfs_update_inode(struct btrfs_trans_handle *trans,
 694                               struct btrfs_root *root,
 695                               struct inode *inode)
 696 {
 697         struct btrfs_inode_item *inode_item;
 698         struct btrfs_path *path;
 699         struct extent_buffer *leaf;
 700         int ret;
 701
 702         path = btrfs_alloc_path();
 703         BUG_ON(!path);
 704         ret = btrfs_lookup_inode(trans, root, path,
 705                                  &BTRFS_I(inode)->location, 1);
 706         if (ret) {
 707                 if (ret > 0)
 708                         ret = -ENOENT;
 709                 goto failed;
 710         }
 711
 712         leaf = path->nodes[0];
 713         inode_item = btrfs_item_ptr(leaf, path->slots[0],
 714                                   struct btrfs_inode_item);
 715
 716         fill_inode_item(leaf, inode_item, inode);
 717         btrfs_mark_buffer_dirty(leaf);
 718         btrfs_set_inode_last_trans(trans, inode);
 719         ret = 0;
 720 failed:
 721         btrfs_release_path(root, path);
 722         btrfs_free_path(path);
 723         return ret;
 724 }
 725
 726
 727 static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
 728                               struct btrfs_root *root,
 729                               struct inode *dir,
 730                               struct dentry *dentry)
 731 {
 732         struct btrfs_path *path;
 733         const char *name = dentry->d_name.name;
 734         int name_len = dentry->d_name.len;
 735         int ret = 0;
 736         struct extent_buffer *leaf;
 737         struct btrfs_dir_item *di;
 738         struct btrfs_key key;
 739
 740         path = btrfs_alloc_path();
 741         if (!path) {
 742                 ret = -ENOMEM;
 743                 goto err;
 744         }
 745
 746         di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
 747                                     name, name_len, -1);
 748         if (IS_ERR(di)) {
 749                 ret = PTR_ERR(di);
 750                 goto err;
 751         }
 752         if (!di) {
 753                 ret = -ENOENT;
 754                 goto err;
 755         }
 756         leaf = path->nodes[0];
 757         btrfs_dir_item_key_to_cpu(leaf, di, &key);
 758         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 759         if (ret)
 760                 goto err;
 761         btrfs_release_path(root, path);
 762
 763         di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
 764                                          key.objectid, name, name_len, -1);
 765         if (IS_ERR(di)) {
 766                 ret = PTR_ERR(di);
 767                 goto err;
 768         }
 769         if (!di) {
 770                 ret = -ENOENT;
 771                 goto err;
 772         }
 773         ret = btrfs_delete_one_dir_name(trans, root, path, di);
 774
 775         dentry->d_inode->i_ctime = dir->i_ctime;
 776         ret = btrfs_del_inode_ref(trans, root, name, name_len,
 777                                   dentry->d_inode->i_ino,
 778                                   dentry->d_parent->d_inode->i_ino);
 779         if (ret) {
 780                 printk("failed to delete reference to %.*s, "
 781                        "inode %lu parent %lu\n", name_len, name,
 782                        dentry->d_inode->i_ino,
 783                        dentry->d_parent->d_inode->i_ino);
 784         }
 785 err:
 786         btrfs_free_path(path);
 787         if (!ret) {
 788                 dir->i_size -= name_len * 2;
 789                 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 790                 btrfs_update_inode(trans, root, dir);
 791 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 792                 dentry->d_inode->i_nlink--;
 793 #else
 794                 drop_nlink(dentry->d_inode);
 795 #endif
 796                 ret = btrfs_update_inode(trans, root, dentry->d_inode);
 797                 dir->i_sb->s_dirt = 1;
 798         }
 799         return ret;
 800 }
 801
 802 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 803 {
 804         struct btrfs_root *root;
 805         struct btrfs_trans_handle *trans;
 806         struct inode *inode = dentry->d_inode;
 807         int ret;
 808         unsigned long nr = 0;
 809
 810         root = BTRFS_I(dir)->root;
 811         mutex_lock(&root->fs_info->fs_mutex);
 812
 813         ret = btrfs_check_free_space(root, 1, 1);
 814         if (ret)
 815                 goto fail;
 816
 817         trans = btrfs_start_transaction(root, 1);
 818
 819         btrfs_set_trans_block_group(trans, dir);
 820         ret = btrfs_unlink_trans(trans, root, dir, dentry);
 821         nr = trans->blocks_used;
 822
 823         if (inode->i_nlink == 0) {
 824                 int found;
 825                 /* if the inode isn't linked anywhere,
 826                  * we don't need to worry about
 827                  * data=ordered
 828                  */
 829                 found = btrfs_del_ordered_inode(inode);
 830                 if (found == 1) {
 831                         atomic_dec(&inode->i_count);
 832                 }
 833         }
 834
 835         btrfs_end_transaction(trans, root);
 836 fail:
 837         mutex_unlock(&root->fs_info->fs_mutex);
 838         btrfs_btree_balance_dirty(root, nr);
 839         btrfs_throttle(root);
 840         return ret;
 841 }
 842
 843 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 844 {
 845         struct inode *inode = dentry->d_inode;
 846         int err = 0;
 847         int ret;
 848         struct btrfs_root *root = BTRFS_I(dir)->root;
 849         struct btrfs_trans_handle *trans;
 850         unsigned long nr = 0;
 851
 852         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
 853                 return -ENOTEMPTY;
 854
 855         mutex_lock(&root->fs_info->fs_mutex);
 856         ret = btrfs_check_free_space(root, 1, 1);
 857         if (ret)
 858                 goto fail;
 859
 860         trans = btrfs_start_transaction(root, 1);
 861         btrfs_set_trans_block_group(trans, dir);
 862
 863         /* now the directory is empty */
 864         err = btrfs_unlink_trans(trans, root, dir, dentry);
 865         if (!err) {
 866                 inode->i_size = 0;
 867         }
 868
 869         nr = trans->blocks_used;
 870         ret = btrfs_end_transaction(trans, root);
 871 fail:
 872         mutex_unlock(&root->fs_info->fs_mutex);
 873         btrfs_btree_balance_dirty(root, nr);
 874         btrfs_throttle(root);
 875
 876         if (ret && !err)
 877                 err = ret;
 878         return err;
 879 }
 880
 881 /*
 882  * this can truncate away extent items, csum items and directory items.
 883  * It starts at a high offset and removes keys until it can't find
 884  * any higher than i_size.
 885  *
 886  * csum items that cross the new i_size are truncated to the new size
 887  * as well.
 888  */
 889 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
 890                                    struct btrfs_root *root,
 891                                    struct inode *inode,
 892                                    u32 min_type)
 893 {
 894         int ret;
 895         struct btrfs_path *path;
 896         struct btrfs_key key;
 897         struct btrfs_key found_key;
 898         u32 found_type;
 899         struct extent_buffer *leaf;
 900         struct btrfs_file_extent_item *fi;
 901         u64 extent_start = 0;
 902         u64 extent_num_bytes = 0;
 903         u64 item_end = 0;
 904         u64 root_gen = 0;
 905         u64 root_owner = 0;
 906         int found_extent;
 907         int del_item;
 908         int pending_del_nr = 0;
 909         int pending_del_slot = 0;
 910         int extent_type = -1;
 911
 912         btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
 913         path = btrfs_alloc_path();
 914         path->reada = -1;
 915         BUG_ON(!path);
 916
 917         /* FIXME, add redo link to tree so we don't leak on crash */
 918         key.objectid = inode->i_ino;
 919         key.offset = (u64)-1;
 920         key.type = (u8)-1;
 921
 922         btrfs_init_path(path);
 923 search_again:
 924         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 925         if (ret < 0) {
 926                 goto error;
 927         }
 928         if (ret > 0) {
 929                 BUG_ON(path->slots[0] == 0);
 930                 path->slots[0]--;
 931         }
 932
 933         while(1) {
 934                 fi = NULL;
 935                 leaf = path->nodes[0];
 936                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 937                 found_type = btrfs_key_type(&found_key);
 938
 939                 if (found_key.objectid != inode->i_ino)
 940                         break;
 941
 942                 if (found_type < min_type)
 943                         break;
 944
 945                 item_end = found_key.offset;
 946                 if (found_type == BTRFS_EXTENT_DATA_KEY) {
 947                         fi = btrfs_item_ptr(leaf, path->slots[0],
 948                                             struct btrfs_file_extent_item);
 949                         extent_type = btrfs_file_extent_type(leaf, fi);
 950                         if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 951                                 item_end +=
 952                                     btrfs_file_extent_num_bytes(leaf, fi);
 953                         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 954                                 struct btrfs_item *item = btrfs_item_nr(leaf,
 955                                                                 path->slots[0]);
 956                                 item_end += btrfs_file_extent_inline_len(leaf,
 957                                                                          item);
 958                         }
 959                         item_end--;
 960                 }
 961                 if (found_type == BTRFS_CSUM_ITEM_KEY) {
 962                         ret = btrfs_csum_truncate(trans, root, path,
 963                                                   inode->i_size);
 964                         BUG_ON(ret);
 965                 }
 966                 if (item_end < inode->i_size) {
 967                         if (found_type == BTRFS_DIR_ITEM_KEY) {
 968                                 found_type = BTRFS_INODE_ITEM_KEY;
 969                         } else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
 970                                 found_type = BTRFS_CSUM_ITEM_KEY;
 971                         } else if (found_type == BTRFS_EXTENT_DATA_KEY) {
 972                                 found_type = BTRFS_XATTR_ITEM_KEY;
 973                         } else if (found_type == BTRFS_XATTR_ITEM_KEY) {
 974                                 found_type = BTRFS_INODE_REF_KEY;
 975                         } else if (found_type) {
 976                                 found_type--;
 977                         } else {
 978                                 break;
 979                         }
 980                         btrfs_set_key_type(&key, found_type);
 981                         goto next;
 982                 }
 983                 if (found_key.offset >= inode->i_size)
 984                         del_item = 1;
 985                 else
 986                         del_item = 0;
 987                 found_extent = 0;
 988
 989                 /* FIXME, shrink the extent if the ref count is only 1 */
 990                 if (found_type != BTRFS_EXTENT_DATA_KEY)
 991                         goto delete;
 992
 993                 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
 994                         u64 num_dec;
 995                         extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
 996                         if (!del_item) {
 997                                 u64 orig_num_bytes =
 998                                         btrfs_file_extent_num_bytes(leaf, fi);
 999                                 extent_num_bytes = inode->i_size -
1000                                         found_key.offset + root->sectorsize - 1;
1001                                 extent_num_bytes = extent_num_bytes &
1002                                         ~((u64)root->sectorsize - 1);
1003                                 btrfs_set_file_extent_num_bytes(leaf, fi,
1004                                                          extent_num_bytes);
1005                                 num_dec = (orig_num_bytes -
1006                                            extent_num_bytes);
1007                                 if (extent_start != 0)
1008                                         dec_i_blocks(inode, num_dec);
1009                                 btrfs_mark_buffer_dirty(leaf);
1010                         } else {
1011                                 extent_num_bytes =
1012                                         btrfs_file_extent_disk_num_bytes(leaf,
1013                                                                          fi);
1014                                 /* FIXME blocksize != 4096 */
1015                                 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
1016                                 if (extent_start != 0) {
1017                                         found_extent = 1;
1018                                         dec_i_blocks(inode, num_dec);
1019                                 }
1020                                 root_gen = btrfs_header_generation(leaf);
1021                                 root_owner = btrfs_header_owner(leaf);
1022                         }
1023                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1024                         if (!del_item) {
1025                                 u32 newsize = inode->i_size - found_key.offset;
1026                                 dec_i_blocks(inode, item_end + 1 -
1027                                             found_key.offset - newsize);
1028                                 newsize =
1029                                     btrfs_file_extent_calc_inline_size(newsize);
1030                                 ret = btrfs_truncate_item(trans, root, path,
1031                                                           newsize, 1);
1032                                 BUG_ON(ret);
1033                         } else {
1034                                 dec_i_blocks(inode, item_end + 1 -
1035                                              found_key.offset);
1036                         }
1037                 }
1038 delete:
1039                 if (del_item) {
1040                         if (!pending_del_nr) {
1041                                 /* no pending yet, add ourselves */
1042                                 pending_del_slot = path->slots[0];
1043                                 pending_del_nr = 1;
1044                         } else if (pending_del_nr &&
1045                                    path->slots[0] + 1 == pending_del_slot) {
1046                                 /* hop on the pending chunk */
1047                                 pending_del_nr++;
1048                                 pending_del_slot = path->slots[0];
1049                         } else {
1050                                 printk("bad pending slot %d pending_del_nr %d pending_del_slot %d\n", path->slots[0], pending_del_nr, pending_del_slot);
1051                         }
1052                 } else {
1053                         break;
1054                 }
1055                 if (found_extent) {
1056                         ret = btrfs_free_extent(trans, root, extent_start,
1057                                                 extent_num_bytes,
1058                                                 root_owner,
1059                                                 root_gen, inode->i_ino,
1060                                                 found_key.offset, 0);
1061                         BUG_ON(ret);
1062                 }
1063 next:
1064                 if (path->slots[0] == 0) {
1065                         if (pending_del_nr)
1066                                 goto del_pending;
1067                         btrfs_release_path(root, path);
1068                         goto search_again;
1069                 }
1070
1071                 path->slots[0]--;
1072                 if (pending_del_nr &&
1073                     path->slots[0] + 1 != pending_del_slot) {
1074                         struct btrfs_key debug;
1075 del_pending:
1076                         btrfs_item_key_to_cpu(path->nodes[0], &debug,
1077                                               pending_del_slot);
1078                         ret = btrfs_del_items(trans, root, path,
1079                                               pending_del_slot,
1080                                               pending_del_nr);
1081                         BUG_ON(ret);
1082                         pending_del_nr = 0;
1083                         btrfs_release_path(root, path);
1084                         goto search_again;
1085                 }
1086         }
1087         ret = 0;
1088 error:
1089         if (pending_del_nr) {
1090                 ret = btrfs_del_items(trans, root, path, pending_del_slot,
1091                                       pending_del_nr);
1092         }
1093         btrfs_release_path(root, path);
1094         btrfs_free_path(path);
1095         inode->i_sb->s_dirt = 1;
1096         return ret;
1097 }
1098
1099 static int btrfs_cow_one_page(struct inode *inode, struct page *page,
1100                               size_t zero_start)
1101 {
1102         char *kaddr;
1103         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1104         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1105         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
1106         int ret = 0;
1107
1108         WARN_ON(!PageLocked(page));
1109         set_page_extent_mapped(page);
1110
1111         lock_extent(io_tree, page_start, page_end, GFP_NOFS);
1112         set_extent_delalloc(&BTRFS_I(inode)->io_tree, page_start,
1113                             page_end, GFP_NOFS);
1114
1115         if (zero_start != PAGE_CACHE_SIZE) {
1116                 kaddr = kmap(page);
1117                 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
1118                 flush_dcache_page(page);
1119                 kunmap(page);
1120         }
1121         set_page_dirty(page);
1122         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
1123
1124         return ret;
1125 }
1126
1127 /*
1128  * taken from block_truncate_page, but does cow as it zeros out
1129  * any bytes left in the last page in the file.
1130  */
1131 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
1132 {
1133         struct inode *inode = mapping->host;
1134         struct btrfs_root *root = BTRFS_I(inode)->root;
1135         u32 blocksize = root->sectorsize;
1136         pgoff_t index = from >> PAGE_CACHE_SHIFT;
1137         unsigned offset = from & (PAGE_CACHE_SIZE-1);
1138         struct page *page;
1139         int ret = 0;
1140         u64 page_start;
1141
1142         if ((offset & (blocksize - 1)) == 0)
1143                 goto out;
1144
1145         ret = -ENOMEM;
1146         page = grab_cache_page(mapping, index);
1147         if (!page)
1148                 goto out;
1149         if (!PageUptodate(page)) {
1150                 ret = btrfs_readpage(NULL, page);
1151                 lock_page(page);
1152                 if (!PageUptodate(page)) {
1153                         ret = -EIO;
1154                         goto out;
1155                 }
1156         }
1157         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
1158
1159         ret = btrfs_cow_one_page(inode, page, offset);
1160
1161         unlock_page(page);
1162         page_cache_release(page);
1163 out:
1164         return ret;
1165 }
1166
1167 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
1168 {
1169         struct inode *inode = dentry->d_inode;
1170         int err;
1171
1172         err = inode_change_ok(inode, attr);
1173         if (err)
1174                 return err;
1175
1176         if (S_ISREG(inode->i_mode) &&
1177             attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
1178                 struct btrfs_trans_handle *trans;
1179                 struct btrfs_root *root = BTRFS_I(inode)->root;
1180                 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1181
1182                 u64 mask = root->sectorsize - 1;
1183                 u64 hole_start = (inode->i_size + mask) & ~mask;
1184                 u64 block_end = (attr->ia_size + mask) & ~mask;
1185                 u64 hole_size;
1186                 u64 alloc_hint = 0;
1187
1188                 if (attr->ia_size <= hole_start)
1189                         goto out;
1190
1191                 mutex_lock(&root->fs_info->fs_mutex);
1192                 err = btrfs_check_free_space(root, 1, 0);
1193                 mutex_unlock(&root->fs_info->fs_mutex);
1194                 if (err)
1195                         goto fail;
1196
1197                 btrfs_truncate_page(inode->i_mapping, inode->i_size);
1198
1199                 lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1200                 hole_size = block_end - hole_start;
1201
1202                 mutex_lock(&root->fs_info->fs_mutex);
1203                 trans = btrfs_start_transaction(root, 1);
1204                 btrfs_set_trans_block_group(trans, inode);
1205                 err = btrfs_drop_extents(trans, root, inode,
1206                                          hole_start, block_end, hole_start,
1207                                          &alloc_hint);
1208
1209                 if (alloc_hint != EXTENT_MAP_INLINE) {
1210                         err = btrfs_insert_file_extent(trans, root,
1211                                                        inode->i_ino,
1212                                                        hole_start, 0, 0,
1213                                                        hole_size);
1214                         btrfs_drop_extent_cache(inode, hole_start,
1215                                                 hole_size - 1);
1216                         btrfs_check_file(root, inode);
1217                 }
1218                 btrfs_end_transaction(trans, root);
1219                 mutex_unlock(&root->fs_info->fs_mutex);
1220                 unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
1221                 if (err)
1222                         return err;
1223         }
1224 out:
1225         err = inode_setattr(inode, attr);
1226 fail:
1227         return err;
1228 }
1229
1230 void btrfs_put_inode(struct inode *inode)
1231 {
1232         int ret;
1233
1234         if (!BTRFS_I(inode)->ordered_trans) {
1235                 return;
1236         }
1237
1238         if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY) ||
1239             mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1240                 return;
1241
1242         ret = btrfs_del_ordered_inode(inode);
1243         if (ret == 1) {
1244                 atomic_dec(&inode->i_count);
1245         }
1246 }
1247
1248 void btrfs_delete_inode(struct inode *inode)
1249 {
1250         struct btrfs_trans_handle *trans;
1251         struct btrfs_root *root = BTRFS_I(inode)->root;
1252         unsigned long nr;
1253         int ret;
1254
1255         truncate_inode_pages(&inode->i_data, 0);
1256         if (is_bad_inode(inode)) {
1257                 goto no_delete;
1258         }
1259
1260         inode->i_size = 0;
1261         mutex_lock(&root->fs_info->fs_mutex);
1262         trans = btrfs_start_transaction(root, 1);
1263
1264         btrfs_set_trans_block_group(trans, inode);
1265         ret = btrfs_truncate_in_trans(trans, root, inode, 0);
1266         if (ret)
1267                 goto no_delete_lock;
1268
1269         nr = trans->blocks_used;
1270         clear_inode(inode);
1271
1272         btrfs_end_transaction(trans, root);
1273         mutex_unlock(&root->fs_info->fs_mutex);
1274         btrfs_btree_balance_dirty(root, nr);
1275         btrfs_throttle(root);
1276         return;
1277
1278 no_delete_lock:
1279         nr = trans->blocks_used;
1280         btrfs_end_transaction(trans, root);
1281         mutex_unlock(&root->fs_info->fs_mutex);
1282         btrfs_btree_balance_dirty(root, nr);
1283         btrfs_throttle(root);
1284 no_delete:
1285         clear_inode(inode);
1286 }
1287
1288 /*
1289  * this returns the key found in the dir entry in the location pointer.
1290  * If no dir entries were found, location->objectid is 0.
1291  */
1292 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
1293                                struct btrfs_key *location)
1294 {
1295         const char *name = dentry->d_name.name;
1296         int namelen = dentry->d_name.len;
1297         struct btrfs_dir_item *di;
1298         struct btrfs_path *path;
1299         struct btrfs_root *root = BTRFS_I(dir)->root;
1300         int ret = 0;
1301
1302         if (namelen == 1 && strcmp(name, ".") == 0) {
1303                 location->objectid = dir->i_ino;
1304                 location->type = BTRFS_INODE_ITEM_KEY;
1305                 location->offset = 0;
1306                 return 0;
1307         }
1308         path = btrfs_alloc_path();
1309         BUG_ON(!path);
1310
1311         if (namelen == 2 && strcmp(name, "..") == 0) {
1312                 struct btrfs_key key;
1313                 struct extent_buffer *leaf;
1314                 u32 nritems;
1315                 int slot;
1316
1317                 key.objectid = dir->i_ino;
1318                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1319                 key.offset = 0;
1320                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1321                 BUG_ON(ret == 0);
1322                 ret = 0;
1323
1324                 leaf = path->nodes[0];
1325                 slot = path->slots[0];
1326                 nritems = btrfs_header_nritems(leaf);
1327                 if (slot >= nritems)
1328                         goto out_err;
1329
1330                 btrfs_item_key_to_cpu(leaf, &key, slot);
1331                 if (key.objectid != dir->i_ino ||
1332                     key.type != BTRFS_INODE_REF_KEY) {
1333                         goto out_err;
1334                 }
1335                 location->objectid = key.offset;
1336                 location->type = BTRFS_INODE_ITEM_KEY;
1337                 location->offset = 0;
1338                 goto out;
1339         }
1340
1341         di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
1342                                     namelen, 0);
1343         if (IS_ERR(di))
1344                 ret = PTR_ERR(di);
1345         if (!di || IS_ERR(di)) {
1346                 goto out_err;
1347         }
1348         btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
1349 out:
1350         btrfs_free_path(path);
1351         return ret;
1352 out_err:
1353         location->objectid = 0;
1354         goto out;
1355 }
1356
1357 /*
1358  * when we hit a tree root in a directory, the btrfs part of the inode
1359  * needs to be changed to reflect the root directory of the tree root.  This
1360  * is kind of like crossing a mount point.
1361  */
1362 static int fixup_tree_root_location(struct btrfs_root *root,
1363                              struct btrfs_key *location,
1364                              struct btrfs_root **sub_root,
1365                              struct dentry *dentry)
1366 {
1367         struct btrfs_path *path;
1368         struct btrfs_root_item *ri;
1369
1370         if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
1371                 return 0;
1372         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1373                 return 0;
1374
1375         path = btrfs_alloc_path();
1376         BUG_ON(!path);
1377         mutex_lock(&root->fs_info->fs_mutex);
1378
1379         *sub_root = btrfs_read_fs_root(root->fs_info, location,
1380                                         dentry->d_name.name,
1381                                         dentry->d_name.len);
1382         if (IS_ERR(*sub_root))
1383                 return PTR_ERR(*sub_root);
1384
1385         ri = &(*sub_root)->root_item;
1386         location->objectid = btrfs_root_dirid(ri);
1387         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1388         location->offset = 0;
1389
1390         btrfs_free_path(path);
1391         mutex_unlock(&root->fs_info->fs_mutex);
1392         return 0;
1393 }
1394
1395 static int btrfs_init_locked_inode(struct inode *inode, void *p)
1396 {
1397         struct btrfs_iget_args *args = p;
1398         inode->i_ino = args->ino;
1399         BTRFS_I(inode)->root = args->root;
1400         BTRFS_I(inode)->delalloc_bytes = 0;
1401         extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1402         extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1403                              inode->i_mapping, GFP_NOFS);
1404         extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1405                              inode->i_mapping, GFP_NOFS);
1406         return 0;
1407 }
1408
1409 static int btrfs_find_actor(struct inode *inode, void *opaque)
1410 {
1411         struct btrfs_iget_args *args = opaque;
1412         return (args->ino == inode->i_ino &&
1413                 args->root == BTRFS_I(inode)->root);
1414 }
1415
1416 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
1417                             u64 root_objectid)
1418 {
1419         struct btrfs_iget_args args;
1420         args.ino = objectid;
1421         args.root = btrfs_lookup_fs_root(btrfs_sb(s)->fs_info, root_objectid);
1422
1423         if (!args.root)
1424                 return NULL;
1425
1426         return ilookup5(s, objectid, btrfs_find_actor, (void *)&args);
1427 }
1428
1429 struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
1430                                 struct btrfs_root *root)
1431 {
1432         struct inode *inode;
1433         struct btrfs_iget_args args;
1434         args.ino = objectid;
1435         args.root = root;
1436
1437         inode = iget5_locked(s, objectid, btrfs_find_actor,
1438                              btrfs_init_locked_inode,
1439                              (void *)&args);
1440         return inode;
1441 }
1442
1443 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
1444                                    struct nameidata *nd)
1445 {
1446         struct inode * inode;
1447         struct btrfs_inode *bi = BTRFS_I(dir);
1448         struct btrfs_root *root = bi->root;
1449         struct btrfs_root *sub_root = root;
1450         struct btrfs_key location;
1451         int ret;
1452
1453         if (dentry->d_name.len > BTRFS_NAME_LEN)
1454                 return ERR_PTR(-ENAMETOOLONG);
1455
1456         mutex_lock(&root->fs_info->fs_mutex);
1457         ret = btrfs_inode_by_name(dir, dentry, &location);
1458         mutex_unlock(&root->fs_info->fs_mutex);
1459
1460         if (ret < 0)
1461                 return ERR_PTR(ret);
1462
1463         inode = NULL;
1464         if (location.objectid) {
1465                 ret = fixup_tree_root_location(root, &location, &sub_root,
1466                                                 dentry);
1467                 if (ret < 0)
1468                         return ERR_PTR(ret);
1469                 if (ret > 0)
1470                         return ERR_PTR(-ENOENT);
1471                 inode = btrfs_iget_locked(dir->i_sb, location.objectid,
1472                                           sub_root);
1473                 if (!inode)
1474                         return ERR_PTR(-EACCES);
1475                 if (inode->i_state & I_NEW) {
1476                         /* the inode and parent dir are two different roots */
1477                         if (sub_root != root) {
1478                                 igrab(inode);
1479                                 sub_root->inode = inode;
1480                         }
1481                         BTRFS_I(inode)->root = sub_root;
1482                         memcpy(&BTRFS_I(inode)->location, &location,
1483                                sizeof(location));
1484                         btrfs_read_locked_inode(inode);
1485                         unlock_new_inode(inode);
1486                 }
1487         }
1488         return d_splice_alias(inode, dentry);
1489 }
1490
1491 static unsigned char btrfs_filetype_table[] = {
1492         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
1493 };
1494
1495 static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
1496 {
1497         struct inode *inode = filp->f_dentry->d_inode;
1498         struct btrfs_root *root = BTRFS_I(inode)->root;
1499         struct btrfs_item *item;
1500         struct btrfs_dir_item *di;
1501         struct btrfs_key key;
1502         struct btrfs_key found_key;
1503         struct btrfs_path *path;
1504         int ret;
1505         u32 nritems;
1506         struct extent_buffer *leaf;
1507         int slot;
1508         int advance;
1509         unsigned char d_type;
1510         int over = 0;
1511         u32 di_cur;
1512         u32 di_total;
1513         u32 di_len;
1514         int key_type = BTRFS_DIR_INDEX_KEY;
1515         char tmp_name[32];
1516         char *name_ptr;
1517         int name_len;
1518
1519         /* FIXME, use a real flag for deciding about the key type */
1520         if (root->fs_info->tree_root == root)
1521                 key_type = BTRFS_DIR_ITEM_KEY;
1522
1523         /* special case for "." */
1524         if (filp->f_pos == 0) {
1525                 over = filldir(dirent, ".", 1,
1526                                1, inode->i_ino,
1527                                DT_DIR);
1528                 if (over)
1529                         return 0;
1530                 filp->f_pos = 1;
1531         }
1532
1533         mutex_lock(&root->fs_info->fs_mutex);
1534         key.objectid = inode->i_ino;
1535         path = btrfs_alloc_path();
1536         path->reada = 2;
1537
1538         /* special case for .., just use the back ref */
1539         if (filp->f_pos == 1) {
1540                 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
1541                 key.offset = 0;
1542                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1543                 BUG_ON(ret == 0);
1544                 leaf = path->nodes[0];
1545                 slot = path->slots[0];
1546                 nritems = btrfs_header_nritems(leaf);
1547                 if (slot >= nritems) {
1548                         btrfs_release_path(root, path);
1549                         goto read_dir_items;
1550                 }
1551                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1552                 btrfs_release_path(root, path);
1553                 if (found_key.objectid != key.objectid ||
1554                     found_key.type != BTRFS_INODE_REF_KEY)
1555                         goto read_dir_items;
1556                 over = filldir(dirent, "..", 2,
1557                                2, found_key.offset, DT_DIR);
1558                 if (over)
1559                         goto nopos;
1560                 filp->f_pos = 2;
1561         }
1562
1563 read_dir_items:
1564         btrfs_set_key_type(&key, key_type);
1565         key.offset = filp->f_pos;
1566
1567         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1568         if (ret < 0)
1569                 goto err;
1570         advance = 0;
1571         while(1) {
1572                 leaf = path->nodes[0];
1573                 nritems = btrfs_header_nritems(leaf);
1574                 slot = path->slots[0];
1575                 if (advance || slot >= nritems) {
1576                         if (slot >= nritems -1) {
1577                                 ret = btrfs_next_leaf(root, path);
1578                                 if (ret)
1579                                         break;
1580                                 leaf = path->nodes[0];
1581                                 nritems = btrfs_header_nritems(leaf);
1582                                 slot = path->slots[0];
1583                         } else {
1584                                 slot++;
1585                                 path->slots[0]++;
1586                         }
1587                 }
1588                 advance = 1;
1589                 item = btrfs_item_nr(leaf, slot);
1590                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1591
1592                 if (found_key.objectid != key.objectid)
1593                         break;
1594                 if (btrfs_key_type(&found_key) != key_type)
1595                         break;
1596                 if (found_key.offset < filp->f_pos)
1597                         continue;
1598
1599                 filp->f_pos = found_key.offset;
1600                 advance = 1;
1601                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
1602                 di_cur = 0;
1603                 di_total = btrfs_item_size(leaf, item);
1604                 while(di_cur < di_total) {
1605                         struct btrfs_key location;
1606
1607                         name_len = btrfs_dir_name_len(leaf, di);
1608                         if (name_len < 32) {
1609                                 name_ptr = tmp_name;
1610                         } else {
1611                                 name_ptr = kmalloc(name_len, GFP_NOFS);
1612                                 BUG_ON(!name_ptr);
1613                         }
1614                         read_extent_buffer(leaf, name_ptr,
1615                                            (unsigned long)(di + 1), name_len);
1616
1617                         d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
1618                         btrfs_dir_item_key_to_cpu(leaf, di, &location);
1619                         over = filldir(dirent, name_ptr, name_len,
1620                                        found_key.offset,
1621                                        location.objectid,
1622                                        d_type);
1623
1624                         if (name_ptr != tmp_name)
1625                                 kfree(name_ptr);
1626
1627                         if (over)
1628                                 goto nopos;
1629                         di_len = btrfs_dir_name_len(leaf, di) +
1630                                 btrfs_dir_data_len(leaf, di) +sizeof(*di);
1631                         di_cur += di_len;
1632                         di = (struct btrfs_dir_item *)((char *)di + di_len);
1633                 }
1634         }
1635         if (key_type == BTRFS_DIR_INDEX_KEY)
1636                 filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
1637         else
1638                 filp->f_pos++;
1639 nopos:
1640         ret = 0;
1641 err:
1642         btrfs_release_path(root, path);
1643         btrfs_free_path(path);
1644         mutex_unlock(&root->fs_info->fs_mutex);
1645         return ret;
1646 }
1647
1648 int btrfs_write_inode(struct inode *inode, int wait)
1649 {
1650         struct btrfs_root *root = BTRFS_I(inode)->root;
1651         struct btrfs_trans_handle *trans;
1652         int ret = 0;
1653
1654         if (wait) {
1655                 mutex_lock(&root->fs_info->fs_mutex);
1656                 trans = btrfs_start_transaction(root, 1);
1657                 btrfs_set_trans_block_group(trans, inode);
1658                 ret = btrfs_commit_transaction(trans, root);
1659                 mutex_unlock(&root->fs_info->fs_mutex);
1660         }
1661         return ret;
1662 }
1663
1664 /*
1665  * This is somewhat expensive, updating the tree every time the
1666  * inode changes.  But, it is most likely to find the inode in cache.
1667  * FIXME, needs more benchmarking...there are no reasons other than performance
1668  * to keep or drop this code.
1669  */
1670 void btrfs_dirty_inode(struct inode *inode)
1671 {
1672         struct btrfs_root *root = BTRFS_I(inode)->root;
1673         struct btrfs_trans_handle *trans;
1674
1675         mutex_lock(&root->fs_info->fs_mutex);
1676         trans = btrfs_start_transaction(root, 1);
1677         btrfs_set_trans_block_group(trans, inode);
1678         btrfs_update_inode(trans, root, inode);
1679         btrfs_end_transaction(trans, root);
1680         mutex_unlock(&root->fs_info->fs_mutex);
1681 }
1682
1683 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
1684                                      struct btrfs_root *root,
1685                                      const char *name, int name_len,
1686                                      u64 ref_objectid,
1687                                      u64 objectid,
1688                                      struct btrfs_block_group_cache *group,
1689                                      int mode)
1690 {
1691         struct inode *inode;
1692         struct btrfs_inode_item *inode_item;
1693         struct btrfs_block_group_cache *new_inode_group;
1694         struct btrfs_key *location;
1695         struct btrfs_path *path;
1696         struct btrfs_inode_ref *ref;
1697         struct btrfs_key key[2];
1698         u32 sizes[2];
1699         unsigned long ptr;
1700         int ret;
1701         int owner;
1702
1703         path = btrfs_alloc_path();
1704         BUG_ON(!path);
1705
1706         inode = new_inode(root->fs_info->sb);
1707         if (!inode)
1708                 return ERR_PTR(-ENOMEM);
1709
1710         extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1711         extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1712                              inode->i_mapping, GFP_NOFS);
1713         extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1714                              inode->i_mapping, GFP_NOFS);
1715         BTRFS_I(inode)->delalloc_bytes = 0;
1716         BTRFS_I(inode)->root = root;
1717
1718         if (mode & S_IFDIR)
1719                 owner = 0;
1720         else
1721                 owner = 1;
1722         new_inode_group = btrfs_find_block_group(root, group, 0,
1723                                        BTRFS_BLOCK_GROUP_METADATA, owner);
1724         if (!new_inode_group) {
1725                 printk("find_block group failed\n");
1726                 new_inode_group = group;
1727         }
1728         BTRFS_I(inode)->block_group = new_inode_group;
1729         BTRFS_I(inode)->flags = 0;
1730
1731         key[0].objectid = objectid;
1732         btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
1733         key[0].offset = 0;
1734
1735         key[1].objectid = objectid;
1736         btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
1737         key[1].offset = ref_objectid;
1738
1739         sizes[0] = sizeof(struct btrfs_inode_item);
1740         sizes[1] = name_len + sizeof(*ref);
1741
1742         ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
1743         if (ret != 0)
1744                 goto fail;
1745
1746         if (objectid > root->highest_inode)
1747                 root->highest_inode = objectid;
1748
1749         inode->i_uid = current->fsuid;
1750         inode->i_gid = current->fsgid;
1751         inode->i_mode = mode;
1752         inode->i_ino = objectid;
1753         inode->i_blocks = 0;
1754         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1755         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1756                                   struct btrfs_inode_item);
1757         fill_inode_item(path->nodes[0], inode_item, inode);
1758
1759         ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1760                              struct btrfs_inode_ref);
1761         btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
1762         ptr = (unsigned long)(ref + 1);
1763         write_extent_buffer(path->nodes[0], name, ptr, name_len);
1764
1765         btrfs_mark_buffer_dirty(path->nodes[0]);
1766         btrfs_free_path(path);
1767
1768         location = &BTRFS_I(inode)->location;
1769         location->objectid = objectid;
1770         location->offset = 0;
1771         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
1772
1773         insert_inode_hash(inode);
1774         return inode;
1775 fail:
1776         btrfs_free_path(path);
1777         return ERR_PTR(ret);
1778 }
1779
1780 static inline u8 btrfs_inode_type(struct inode *inode)
1781 {
1782         return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
1783 }
1784
1785 static int btrfs_add_link(struct btrfs_trans_handle *trans,
1786                             struct dentry *dentry, struct inode *inode,
1787                             int add_backref)
1788 {
1789         int ret;
1790         struct btrfs_key key;
1791         struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
1792         struct inode *parent_inode;
1793
1794         key.objectid = inode->i_ino;
1795         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1796         key.offset = 0;
1797
1798         ret = btrfs_insert_dir_item(trans, root,
1799                                     dentry->d_name.name, dentry->d_name.len,
1800                                     dentry->d_parent->d_inode->i_ino,
1801                                     &key, btrfs_inode_type(inode));
1802         if (ret == 0) {
1803                 if (add_backref) {
1804                         ret = btrfs_insert_inode_ref(trans, root,
1805                                              dentry->d_name.name,
1806                                              dentry->d_name.len,
1807                                              inode->i_ino,
1808                                              dentry->d_parent->d_inode->i_ino);
1809                 }
1810                 parent_inode = dentry->d_parent->d_inode;
1811                 parent_inode->i_size += dentry->d_name.len * 2;
1812                 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1813                 ret = btrfs_update_inode(trans, root,
1814                                          dentry->d_parent->d_inode);
1815         }
1816         return ret;
1817 }
1818
1819 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
1820                             struct dentry *dentry, struct inode *inode,
1821                             int backref)
1822 {
1823         int err = btrfs_add_link(trans, dentry, inode, backref);
1824         if (!err) {
1825                 d_instantiate(dentry, inode);
1826                 return 0;
1827         }
1828         if (err > 0)
1829                 err = -EEXIST;
1830         return err;
1831 }
1832
1833 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
1834                         int mode, dev_t rdev)
1835 {
1836         struct btrfs_trans_handle *trans;
1837         struct btrfs_root *root = BTRFS_I(dir)->root;
1838         struct inode *inode = NULL;
1839         int err;
1840         int drop_inode = 0;
1841         u64 objectid;
1842         unsigned long nr = 0;
1843
1844         if (!new_valid_dev(rdev))
1845                 return -EINVAL;
1846
1847         mutex_lock(&root->fs_info->fs_mutex);
1848         err = btrfs_check_free_space(root, 1, 0);
1849         if (err)
1850                 goto fail;
1851
1852         trans = btrfs_start_transaction(root, 1);
1853         btrfs_set_trans_block_group(trans, dir);
1854
1855         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1856         if (err) {
1857                 err = -ENOSPC;
1858                 goto out_unlock;
1859         }
1860
1861         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1862                                 dentry->d_name.len,
1863                                 dentry->d_parent->d_inode->i_ino, objectid,
1864                                 BTRFS_I(dir)->block_group, mode);
1865         err = PTR_ERR(inode);
1866         if (IS_ERR(inode))
1867                 goto out_unlock;
1868
1869         btrfs_set_trans_block_group(trans, inode);
1870         err = btrfs_add_nondir(trans, dentry, inode, 0);
1871         if (err)
1872                 drop_inode = 1;
1873         else {
1874                 inode->i_op = &btrfs_special_inode_operations;
1875                 init_special_inode(inode, inode->i_mode, rdev);
1876                 btrfs_update_inode(trans, root, inode);
1877         }
1878         dir->i_sb->s_dirt = 1;
1879         btrfs_update_inode_block_group(trans, inode);
1880         btrfs_update_inode_block_group(trans, dir);
1881 out_unlock:
1882         nr = trans->blocks_used;
1883         btrfs_end_transaction(trans, root);
1884 fail:
1885         mutex_unlock(&root->fs_info->fs_mutex);
1886
1887         if (drop_inode) {
1888                 inode_dec_link_count(inode);
1889                 iput(inode);
1890         }
1891         btrfs_btree_balance_dirty(root, nr);
1892         btrfs_throttle(root);
1893         return err;
1894 }
1895
1896 static int btrfs_create(struct inode *dir, struct dentry *dentry,
1897                         int mode, struct nameidata *nd)
1898 {
1899         struct btrfs_trans_handle *trans;
1900         struct btrfs_root *root = BTRFS_I(dir)->root;
1901         struct inode *inode = NULL;
1902         int err;
1903         int drop_inode = 0;
1904         unsigned long nr = 0;
1905         u64 objectid;
1906
1907         mutex_lock(&root->fs_info->fs_mutex);
1908         err = btrfs_check_free_space(root, 1, 0);
1909         if (err)
1910                 goto fail;
1911         trans = btrfs_start_transaction(root, 1);
1912         btrfs_set_trans_block_group(trans, dir);
1913
1914         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
1915         if (err) {
1916                 err = -ENOSPC;
1917                 goto out_unlock;
1918         }
1919
1920         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
1921                                 dentry->d_name.len,
1922                                 dentry->d_parent->d_inode->i_ino,
1923                                 objectid, BTRFS_I(dir)->block_group, mode);
1924         err = PTR_ERR(inode);
1925         if (IS_ERR(inode))
1926                 goto out_unlock;
1927
1928         btrfs_set_trans_block_group(trans, inode);
1929         err = btrfs_add_nondir(trans, dentry, inode, 0);
1930         if (err)
1931                 drop_inode = 1;
1932         else {
1933                 inode->i_mapping->a_ops = &btrfs_aops;
1934                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
1935                 inode->i_fop = &btrfs_file_operations;
1936                 inode->i_op = &btrfs_file_inode_operations;
1937                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
1938                 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
1939                                      inode->i_mapping, GFP_NOFS);
1940                 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
1941                                      inode->i_mapping, GFP_NOFS);
1942                 BTRFS_I(inode)->delalloc_bytes = 0;
1943                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
1944         }
1945         dir->i_sb->s_dirt = 1;
1946         btrfs_update_inode_block_group(trans, inode);
1947         btrfs_update_inode_block_group(trans, dir);
1948 out_unlock:
1949         nr = trans->blocks_used;
1950         btrfs_end_transaction(trans, root);
1951 fail:
1952         mutex_unlock(&root->fs_info->fs_mutex);
1953
1954         if (drop_inode) {
1955                 inode_dec_link_count(inode);
1956                 iput(inode);
1957         }
1958         btrfs_btree_balance_dirty(root, nr);
1959         btrfs_throttle(root);
1960         return err;
1961 }
1962
1963 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
1964                       struct dentry *dentry)
1965 {
1966         struct btrfs_trans_handle *trans;
1967         struct btrfs_root *root = BTRFS_I(dir)->root;
1968         struct inode *inode = old_dentry->d_inode;
1969         unsigned long nr = 0;
1970         int err;
1971         int drop_inode = 0;
1972
1973         if (inode->i_nlink == 0)
1974                 return -ENOENT;
1975
1976 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1977         inode->i_nlink++;
1978 #else
1979         inc_nlink(inode);
1980 #endif
1981         mutex_lock(&root->fs_info->fs_mutex);
1982         err = btrfs_check_free_space(root, 1, 0);
1983         if (err)
1984                 goto fail;
1985         trans = btrfs_start_transaction(root, 1);
1986
1987         btrfs_set_trans_block_group(trans, dir);
1988         atomic_inc(&inode->i_count);
1989         err = btrfs_add_nondir(trans, dentry, inode, 1);
1990
1991         if (err)
1992                 drop_inode = 1;
1993
1994         dir->i_sb->s_dirt = 1;
1995         btrfs_update_inode_block_group(trans, dir);
1996         err = btrfs_update_inode(trans, root, inode);
1997
1998         if (err)
1999                 drop_inode = 1;
2000
2001         nr = trans->blocks_used;
2002         btrfs_end_transaction(trans, root);
2003 fail:
2004         mutex_unlock(&root->fs_info->fs_mutex);
2005
2006         if (drop_inode) {
2007                 inode_dec_link_count(inode);
2008                 iput(inode);
2009         }
2010         btrfs_btree_balance_dirty(root, nr);
2011         btrfs_throttle(root);
2012         return err;
2013 }
2014
2015 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
2016 {
2017         struct inode *inode;
2018         struct btrfs_trans_handle *trans;
2019         struct btrfs_root *root = BTRFS_I(dir)->root;
2020         int err = 0;
2021         int drop_on_err = 0;
2022         u64 objectid;
2023         unsigned long nr = 1;
2024
2025         mutex_lock(&root->fs_info->fs_mutex);
2026         err = btrfs_check_free_space(root, 1, 0);
2027         if (err)
2028                 goto out_unlock;
2029
2030         trans = btrfs_start_transaction(root, 1);
2031         btrfs_set_trans_block_group(trans, dir);
2032
2033         if (IS_ERR(trans)) {
2034                 err = PTR_ERR(trans);
2035                 goto out_unlock;
2036         }
2037
2038         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
2039         if (err) {
2040                 err = -ENOSPC;
2041                 goto out_unlock;
2042         }
2043
2044         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
2045                                 dentry->d_name.len,
2046                                 dentry->d_parent->d_inode->i_ino, objectid,
2047                                 BTRFS_I(dir)->block_group, S_IFDIR | mode);
2048         if (IS_ERR(inode)) {
2049                 err = PTR_ERR(inode);
2050                 goto out_fail;
2051         }
2052
2053         drop_on_err = 1;
2054         inode->i_op = &btrfs_dir_inode_operations;
2055         inode->i_fop = &btrfs_dir_file_operations;
2056         btrfs_set_trans_block_group(trans, inode);
2057
2058         inode->i_size = 0;
2059         err = btrfs_update_inode(trans, root, inode);
2060         if (err)
2061                 goto out_fail;
2062
2063         err = btrfs_add_link(trans, dentry, inode, 0);
2064         if (err)
2065                 goto out_fail;
2066
2067         d_instantiate(dentry, inode);
2068         drop_on_err = 0;
2069         dir->i_sb->s_dirt = 1;
2070         btrfs_update_inode_block_group(trans, inode);
2071         btrfs_update_inode_block_group(trans, dir);
2072
2073 out_fail:
2074         nr = trans->blocks_used;
2075         btrfs_end_transaction(trans, root);
2076
2077 out_unlock:
2078         mutex_unlock(&root->fs_info->fs_mutex);
2079         if (drop_on_err)
2080                 iput(inode);
2081         btrfs_btree_balance_dirty(root, nr);
2082         btrfs_throttle(root);
2083         return err;
2084 }
2085
2086 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
2087                                     size_t pg_offset, u64 start, u64 len,
2088                                     int create)
2089 {
2090         int ret;
2091         int err = 0;
2092         u64 bytenr;
2093         u64 extent_start = 0;
2094         u64 extent_end = 0;
2095         u64 objectid = inode->i_ino;
2096         u32 found_type;
2097         struct btrfs_path *path;
2098         struct btrfs_root *root = BTRFS_I(inode)->root;
2099         struct btrfs_file_extent_item *item;
2100         struct extent_buffer *leaf;
2101         struct btrfs_key found_key;
2102         struct extent_map *em = NULL;
2103         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2104         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2105         struct btrfs_trans_handle *trans = NULL;
2106
2107         path = btrfs_alloc_path();
2108         BUG_ON(!path);
2109         mutex_lock(&root->fs_info->fs_mutex);
2110
2111 again:
2112         spin_lock(&em_tree->lock);
2113         em = lookup_extent_mapping(em_tree, start, len);
2114         spin_unlock(&em_tree->lock);
2115
2116         if (em) {
2117                 if (em->start > start) {
2118                         printk("get_extent lookup [%Lu %Lu] em [%Lu %Lu]\n",
2119                                start, len, em->start, em->len);
2120                         WARN_ON(1);
2121                 }
2122                 if (em->block_start == EXTENT_MAP_INLINE && page)
2123                         free_extent_map(em);
2124                 else
2125                         goto out;
2126         }
2127         em = alloc_extent_map(GFP_NOFS);
2128         if (!em) {
2129                 err = -ENOMEM;
2130                 goto out;
2131         }
2132
2133         em->start = EXTENT_MAP_HOLE;
2134         em->len = (u64)-1;
2135         em->bdev = inode->i_sb->s_bdev;
2136         ret = btrfs_lookup_file_extent(trans, root, path,
2137                                        objectid, start, trans != NULL);
2138         if (ret < 0) {
2139                 err = ret;
2140                 goto out;
2141         }
2142
2143         if (ret != 0) {
2144                 if (path->slots[0] == 0)
2145                         goto not_found;
2146                 path->slots[0]--;
2147         }
2148
2149         leaf = path->nodes[0];
2150         item = btrfs_item_ptr(leaf, path->slots[0],
2151                               struct btrfs_file_extent_item);
2152         /* are we inside the extent that was found? */
2153         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2154         found_type = btrfs_key_type(&found_key);
2155         if (found_key.objectid != objectid ||
2156             found_type != BTRFS_EXTENT_DATA_KEY) {
2157                 goto not_found;
2158         }
2159
2160         found_type = btrfs_file_extent_type(leaf, item);
2161         extent_start = found_key.offset;
2162         if (found_type == BTRFS_FILE_EXTENT_REG) {
2163                 extent_end = extent_start +
2164                        btrfs_file_extent_num_bytes(leaf, item);
2165                 err = 0;
2166                 if (start < extent_start || start >= extent_end) {
2167                         em->start = start;
2168                         if (start < extent_start) {
2169                                 if (start + len <= extent_start)
2170                                         goto not_found;
2171                                 em->len = extent_end - extent_start;
2172                         } else {
2173                                 em->len = len;
2174                         }
2175                         goto not_found_em;
2176                 }
2177                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
2178                 if (bytenr == 0) {
2179                         em->start = extent_start;
2180                         em->len = extent_end - extent_start;
2181                         em->block_start = EXTENT_MAP_HOLE;
2182                         goto insert;
2183                 }
2184                 bytenr += btrfs_file_extent_offset(leaf, item);
2185                 em->block_start = bytenr;
2186                 em->start = extent_start;
2187                 em->len = extent_end - extent_start;
2188                 goto insert;
2189         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
2190                 u64 page_start;
2191                 unsigned long ptr;
2192                 char *map;
2193                 size_t size;
2194                 size_t extent_offset;
2195                 size_t copy_size;
2196
2197                 size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
2198                                                     path->slots[0]));
2199                 extent_end = (extent_start + size + root->sectorsize - 1) &
2200                         ~((u64)root->sectorsize - 1);
2201                 if (start < extent_start || start >= extent_end) {
2202                         em->start = start;
2203                         if (start < extent_start) {
2204                                 if (start + len <= extent_start)
2205                                         goto not_found;
2206                                 em->len = extent_end - extent_start;
2207                         } else {
2208                                 em->len = len;
2209                         }
2210                         goto not_found_em;
2211                 }
2212                 em->block_start = EXTENT_MAP_INLINE;
2213
2214                 if (!page) {
2215                         em->start = extent_start;
2216                         em->len = size;
2217                         goto out;
2218                 }
2219
2220                 page_start = page_offset(page) + pg_offset;
2221                 extent_offset = page_start - extent_start;
2222                 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
2223                                 size - extent_offset);
2224                 em->start = extent_start + extent_offset;
2225                 em->len = (copy_size + root->sectorsize - 1) &
2226                         ~((u64)root->sectorsize - 1);
2227                 map = kmap(page);
2228                 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
2229                 if (create == 0 && !PageUptodate(page)) {
2230                         read_extent_buffer(leaf, map + pg_offset, ptr,
2231                                            copy_size);
2232                         flush_dcache_page(page);
2233                 } else if (create && PageUptodate(page)) {
2234                         if (!trans) {
2235                                 kunmap(page);
2236                                 free_extent_map(em);
2237                                 em = NULL;
2238                                 btrfs_release_path(root, path);
2239                                 trans = btrfs_start_transaction(root, 1);
2240                                 goto again;
2241                         }
2242                         write_extent_buffer(leaf, map + pg_offset, ptr,
2243                                             copy_size);
2244                         btrfs_mark_buffer_dirty(leaf);
2245                 }
2246                 kunmap(page);
2247                 set_extent_uptodate(io_tree, em->start,
2248                                     extent_map_end(em) - 1, GFP_NOFS);
2249                 goto insert;
2250         } else {
2251                 printk("unkknown found_type %d\n", found_type);
2252                 WARN_ON(1);
2253         }
2254 not_found:
2255         em->start = start;
2256         em->len = len;
2257 not_found_em:
2258         em->block_start = EXTENT_MAP_HOLE;
2259 insert:
2260         btrfs_release_path(root, path);
2261         if (em->start > start || extent_map_end(em) <= start) {
2262                 printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->len, start, len);
2263                 err = -EIO;
2264                 goto out;
2265         }
2266
2267         err = 0;
2268         spin_lock(&em_tree->lock);
2269         ret = add_extent_mapping(em_tree, em);
2270         if (ret == -EEXIST) {
2271                 free_extent_map(em);
2272                 em = lookup_extent_mapping(em_tree, start, len);
2273                 if (!em) {
2274                         err = -EIO;
2275                         printk("failing to insert %Lu %Lu\n", start, len);
2276                 }
2277         }
2278         spin_unlock(&em_tree->lock);
2279 out:
2280         btrfs_free_path(path);
2281         if (trans) {
2282                 ret = btrfs_end_transaction(trans, root);
2283                 if (!err)
2284                         err = ret;
2285         }
2286         mutex_unlock(&root->fs_info->fs_mutex);
2287         if (err) {
2288                 free_extent_map(em);
2289                 WARN_ON(1);
2290                 return ERR_PTR(err);
2291         }
2292         return em;
2293 }
2294
2295 static int btrfs_get_block(struct inode *inode, sector_t iblock,
2296                         struct buffer_head *bh_result, int create)
2297 {
2298         struct extent_map *em;
2299         u64 start = (u64)iblock << inode->i_blkbits;
2300         struct btrfs_multi_bio *multi = NULL;
2301         struct btrfs_root *root = BTRFS_I(inode)->root;
2302         u64 len;
2303         u64 logical;
2304         u64 map_length;
2305         int ret = 0;
2306
2307         em = btrfs_get_extent(inode, NULL, 0, start, bh_result->b_size, 0);
2308
2309         if (!em || IS_ERR(em))
2310                 goto out;
2311
2312         if (em->start > start || em->start + em->len <= start)
2313             goto out;
2314
2315         if (em->block_start == EXTENT_MAP_INLINE) {
2316                 ret = -EINVAL;
2317                 goto out;
2318         }
2319
2320         if (em->block_start == EXTENT_MAP_HOLE ||
2321             em->block_start == EXTENT_MAP_DELALLOC) {
2322                 goto out;
2323         }
2324
2325         len = em->start + em->len - start;
2326         len = min_t(u64, len, INT_LIMIT(typeof(bh_result->b_size)));
2327
2328         logical = start - em->start;
2329         logical = em->block_start + logical;
2330
2331         map_length = len;
2332         ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
2333                               logical, &map_length, &multi, 0);
2334         BUG_ON(ret);
2335         bh_result->b_blocknr = multi->stripes[0].physical >> inode->i_blkbits;
2336         bh_result->b_size = min(map_length, len);
2337         bh_result->b_bdev = multi->stripes[0].dev->bdev;
2338         set_buffer_mapped(bh_result);
2339         kfree(multi);
2340 out:
2341         free_extent_map(em);
2342         return ret;
2343 }
2344
2345 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
2346                         const struct iovec *iov, loff_t offset,
2347                         unsigned long nr_segs)
2348 {
2349         struct file *file = iocb->ki_filp;
2350         struct inode *inode = file->f_mapping->host;
2351
2352         if (rw == WRITE)
2353                 return -EINVAL;
2354
2355         return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
2356                                   offset, nr_segs, btrfs_get_block, NULL);
2357 }
2358
2359 static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
2360 {
2361         return extent_bmap(mapping, iblock, btrfs_get_extent);
2362 }
2363
2364 int btrfs_readpage(struct file *file, struct page *page)
2365 {
2366         struct extent_io_tree *tree;
2367         tree = &BTRFS_I(page->mapping->host)->io_tree;
2368         return extent_read_full_page(tree, page, btrfs_get_extent);
2369 }
2370
2371 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
2372 {
2373         struct extent_io_tree *tree;
2374
2375
2376         if (current->flags & PF_MEMALLOC) {
2377                 redirty_page_for_writepage(wbc, page);
2378                 unlock_page(page);
2379                 return 0;
2380         }
2381         tree = &BTRFS_I(page->mapping->host)->io_tree;
2382         return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
2383 }
2384
2385 static int btrfs_writepages(struct address_space *mapping,
2386                             struct writeback_control *wbc)
2387 {
2388         struct extent_io_tree *tree;
2389         tree = &BTRFS_I(mapping->host)->io_tree;
2390         return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
2391 }
2392
2393 static int
2394 btrfs_readpages(struct file *file, struct address_space *mapping,
2395                 struct list_head *pages, unsigned nr_pages)
2396 {
2397         struct extent_io_tree *tree;
2398         tree = &BTRFS_I(mapping->host)->io_tree;
2399         return extent_readpages(tree, mapping, pages, nr_pages,
2400                                 btrfs_get_extent);
2401 }
2402
2403 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
2404 {
2405         struct extent_io_tree *tree;
2406         struct extent_map_tree *map;
2407         int ret;
2408
2409         tree = &BTRFS_I(page->mapping->host)->io_tree;
2410         map = &BTRFS_I(page->mapping->host)->extent_tree;
2411         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
2412         if (ret == 1) {
2413                 ClearPagePrivate(page);
2414                 set_page_private(page, 0);
2415                 page_cache_release(page);
2416         }
2417         return ret;
2418 }
2419
2420 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
2421 {
2422         struct extent_io_tree *tree;
2423
2424         tree = &BTRFS_I(page->mapping->host)->io_tree;
2425         extent_invalidatepage(tree, page, offset);
2426         btrfs_releasepage(page, GFP_NOFS);
2427 }
2428
2429 /*
2430  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
2431  * called from a page fault handler when a page is first dirtied. Hence we must
2432  * be careful to check for EOF conditions here. We set the page up correctly
2433  * for a written page which means we get ENOSPC checking when writing into
2434  * holes and correct delalloc and unwritten extent mapping on filesystems that
2435  * support these features.
2436  *
2437  * We are not allowed to take the i_mutex here so we have to play games to
2438  * protect against truncate races as the page could now be beyond EOF.  Because
2439  * vmtruncate() writes the inode size before removing pages, once we have the
2440  * page lock we can determine safely if the page is beyond EOF. If it is not
2441  * beyond EOF, then the page is guaranteed safe against truncation until we
2442  * unlock the page.
2443  */
2444 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
2445 {
2446         struct inode *inode = fdentry(vma->vm_file)->d_inode;
2447         struct btrfs_root *root = BTRFS_I(inode)->root;
2448         unsigned long end;
2449         loff_t size;
2450         int ret;
2451         u64 page_start;
2452
2453         mutex_lock(&root->fs_info->fs_mutex);
2454         ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
2455         mutex_unlock(&root->fs_info->fs_mutex);
2456         if (ret)
2457                 goto out;
2458
2459         ret = -EINVAL;
2460
2461         lock_page(page);
2462         wait_on_page_writeback(page);
2463         size = i_size_read(inode);
2464         page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2465
2466         if ((page->mapping != inode->i_mapping) ||
2467             (page_start > size)) {
2468                 /* page got truncated out from underneath us */
2469                 goto out_unlock;
2470         }
2471
2472         /* page is wholly or partially inside EOF */
2473         if (page_start + PAGE_CACHE_SIZE > size)
2474                 end = size & ~PAGE_CACHE_MASK;
2475         else
2476                 end = PAGE_CACHE_SIZE;
2477
2478         ret = btrfs_cow_one_page(inode, page, end);
2479
2480 out_unlock:
2481         unlock_page(page);
2482 out:
2483         return ret;
2484 }
2485
2486 static void btrfs_truncate(struct inode *inode)
2487 {
2488         struct btrfs_root *root = BTRFS_I(inode)->root;
2489         int ret;
2490         struct btrfs_trans_handle *trans;
2491         unsigned long nr;
2492
2493         if (!S_ISREG(inode->i_mode))
2494                 return;
2495         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2496                 return;
2497
2498         btrfs_truncate_page(inode->i_mapping, inode->i_size);
2499
2500         mutex_lock(&root->fs_info->fs_mutex);
2501         trans = btrfs_start_transaction(root, 1);
2502         btrfs_set_trans_block_group(trans, inode);
2503
2504         /* FIXME, add redo link to tree so we don't leak on crash */
2505         ret = btrfs_truncate_in_trans(trans, root, inode,
2506                                       BTRFS_EXTENT_DATA_KEY);
2507         btrfs_update_inode(trans, root, inode);
2508         nr = trans->blocks_used;
2509
2510         ret = btrfs_end_transaction(trans, root);
2511         BUG_ON(ret);
2512         mutex_unlock(&root->fs_info->fs_mutex);
2513         btrfs_btree_balance_dirty(root, nr);
2514         btrfs_throttle(root);
2515 }
2516
2517 static int noinline create_subvol(struct btrfs_root *root, char *name,
2518                                   int namelen)
2519 {
2520         struct btrfs_trans_handle *trans;
2521         struct btrfs_key key;
2522         struct btrfs_root_item root_item;
2523         struct btrfs_inode_item *inode_item;
2524         struct extent_buffer *leaf;
2525         struct btrfs_root *new_root = root;
2526         struct inode *inode;
2527         struct inode *dir;
2528         int ret;
2529         int err;
2530         u64 objectid;
2531         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
2532         unsigned long nr = 1;
2533
2534         mutex_lock(&root->fs_info->fs_mutex);
2535         ret = btrfs_check_free_space(root, 1, 0);
2536         if (ret)
2537                 goto fail_commit;
2538
2539         trans = btrfs_start_transaction(root, 1);
2540         BUG_ON(!trans);
2541
2542         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
2543                                        0, &objectid);
2544         if (ret)
2545                 goto fail;
2546
2547         leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
2548                                         objectid, trans->transid, 0, 0,
2549                                         0, 0);
2550         if (IS_ERR(leaf))
2551                 return PTR_ERR(leaf);
2552
2553         btrfs_set_header_nritems(leaf, 0);
2554         btrfs_set_header_level(leaf, 0);
2555         btrfs_set_header_bytenr(leaf, leaf->start);
2556         btrfs_set_header_generation(leaf, trans->transid);
2557         btrfs_set_header_owner(leaf, objectid);
2558
2559         write_extent_buffer(leaf, root->fs_info->fsid,
2560                             (unsigned long)btrfs_header_fsid(leaf),
2561                             BTRFS_FSID_SIZE);
2562         btrfs_mark_buffer_dirty(leaf);
2563
2564         inode_item = &root_item.inode;
2565         memset(inode_item, 0, sizeof(*inode_item));
2566         inode_item->generation = cpu_to_le64(1);
2567         inode_item->size = cpu_to_le64(3);
2568         inode_item->nlink = cpu_to_le32(1);
2569         inode_item->nblocks = cpu_to_le64(1);
2570         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
2571
2572         btrfs_set_root_bytenr(&root_item, leaf->start);
2573         btrfs_set_root_level(&root_item, 0);
2574         btrfs_set_root_refs(&root_item, 1);
2575         btrfs_set_root_used(&root_item, 0);
2576
2577         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
2578         root_item.drop_level = 0;
2579
2580         free_extent_buffer(leaf);
2581         leaf = NULL;
2582
2583         btrfs_set_root_dirid(&root_item, new_dirid);
2584
2585         key.objectid = objectid;
2586         key.offset = 1;
2587         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2588         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
2589                                 &root_item);
2590         if (ret)
2591                 goto fail;
2592
2593         /*
2594          * insert the directory item
2595          */
2596         key.offset = (u64)-1;
2597         dir = root->fs_info->sb->s_root->d_inode;
2598         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
2599                                     name, namelen, dir->i_ino, &key,
2600                                     BTRFS_FT_DIR);
2601         if (ret)
2602                 goto fail;
2603
2604         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
2605                              name, namelen, objectid,
2606                              root->fs_info->sb->s_root->d_inode->i_ino);
2607         if (ret)
2608                 goto fail;
2609
2610         ret = btrfs_commit_transaction(trans, root);
2611         if (ret)
2612                 goto fail_commit;
2613
2614         new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
2615         BUG_ON(!new_root);
2616
2617         trans = btrfs_start_transaction(new_root, 1);
2618         BUG_ON(!trans);
2619
2620         inode = btrfs_new_inode(trans, new_root, "..", 2, new_dirid,
2621                                 new_dirid,
2622                                 BTRFS_I(dir)->block_group, S_IFDIR | 0700);
2623         if (IS_ERR(inode))
2624                 goto fail;
2625         inode->i_op = &btrfs_dir_inode_operations;
2626         inode->i_fop = &btrfs_dir_file_operations;
2627         new_root->inode = inode;
2628
2629         ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
2630                                      new_dirid);
2631         inode->i_nlink = 1;
2632         inode->i_size = 0;
2633         ret = btrfs_update_inode(trans, new_root, inode);
2634         if (ret)
2635                 goto fail;
2636 fail:
2637         nr = trans->blocks_used;
2638         err = btrfs_commit_transaction(trans, new_root);
2639         if (err && !ret)
2640                 ret = err;
2641 fail_commit:
2642         mutex_unlock(&root->fs_info->fs_mutex);
2643         btrfs_btree_balance_dirty(root, nr);
2644         btrfs_throttle(root);
2645         return ret;
2646 }
2647
2648 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
2649 {
2650         struct btrfs_pending_snapshot *pending_snapshot;
2651         struct btrfs_trans_handle *trans;
2652         int ret;
2653         int err;
2654         unsigned long nr = 0;
2655
2656         if (!root->ref_cows)
2657                 return -EINVAL;
2658
2659         mutex_lock(&root->fs_info->fs_mutex);
2660         ret = btrfs_check_free_space(root, 1, 0);
2661         if (ret)
2662                 goto fail_unlock;
2663
2664         pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
2665         if (!pending_snapshot) {
2666                 ret = -ENOMEM;
2667                 goto fail_unlock;
2668         }
2669         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
2670         if (!pending_snapshot->name) {
2671                 ret = -ENOMEM;
2672                 kfree(pending_snapshot);
2673                 goto fail_unlock;
2674         }
2675         memcpy(pending_snapshot->name, name, namelen);
2676         pending_snapshot->name[namelen] = '\0';
2677         trans = btrfs_start_transaction(root, 1);
2678         BUG_ON(!trans);
2679         pending_snapshot->root = root;
2680         list_add(&pending_snapshot->list,
2681                  &trans->transaction->pending_snapshots);
2682         ret = btrfs_update_inode(trans, root, root->inode);
2683         err = btrfs_commit_transaction(trans, root);
2684
2685 fail_unlock:
2686         mutex_unlock(&root->fs_info->fs_mutex);
2687         btrfs_btree_balance_dirty(root, nr);
2688         btrfs_throttle(root);
2689         return ret;
2690 }
2691
2692 unsigned long btrfs_force_ra(struct address_space *mapping,
2693                               struct file_ra_state *ra, struct file *file,
2694                               pgoff_t offset, pgoff_t last_index)
2695 {
2696         pgoff_t req_size;
2697
2698 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
2699         req_size = last_index - offset + 1;
2700         offset = page_cache_readahead(mapping, ra, file, offset, req_size);
2701         return offset;
2702 #else
2703         req_size = min(last_index - offset + 1, (pgoff_t)128);
2704         page_cache_sync_readahead(mapping, ra, file, offset, req_size);
2705         return offset + req_size;
2706 #endif
2707 }
2708
2709 int btrfs_defrag_file(struct file *file) {
2710         struct inode *inode = fdentry(file)->d_inode;
2711         struct btrfs_root *root = BTRFS_I(inode)->root;
2712         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2713         struct page *page;
2714         unsigned long last_index;
2715         unsigned long ra_index = 0;
2716         u64 page_start;
2717         u64 page_end;
2718         unsigned long i;
2719         int ret;
2720
2721         mutex_lock(&root->fs_info->fs_mutex);
2722         ret = btrfs_check_free_space(root, inode->i_size, 0);
2723         mutex_unlock(&root->fs_info->fs_mutex);
2724         if (ret)
2725                 return -ENOSPC;
2726
2727         mutex_lock(&inode->i_mutex);
2728         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
2729         for (i = 0; i <= last_index; i++) {
2730                 if (i == ra_index) {
2731                         ra_index = btrfs_force_ra(inode->i_mapping,
2732                                                   &file->f_ra,
2733                                                   file, ra_index, last_index);
2734                 }
2735                 page = grab_cache_page(inode->i_mapping, i);
2736                 if (!page)
2737                         goto out_unlock;
2738                 if (!PageUptodate(page)) {
2739                         btrfs_readpage(NULL, page);
2740                         lock_page(page);
2741                         if (!PageUptodate(page)) {
2742                                 unlock_page(page);
2743                                 page_cache_release(page);
2744                                 goto out_unlock;
2745                         }
2746                 }
2747                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2748                 page_end = page_start + PAGE_CACHE_SIZE - 1;
2749
2750                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2751                 set_extent_delalloc(io_tree, page_start,
2752                                     page_end, GFP_NOFS);
2753
2754                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2755                 set_page_dirty(page);
2756                 unlock_page(page);
2757                 page_cache_release(page);
2758                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
2759         }
2760
2761 out_unlock:
2762         mutex_unlock(&inode->i_mutex);
2763         return 0;
2764 }
2765
2766 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
2767 {
2768         u64 new_size;
2769         u64 old_size;
2770         struct btrfs_ioctl_vol_args *vol_args;
2771         struct btrfs_trans_handle *trans;
2772         char *sizestr;
2773         int ret = 0;
2774         int namelen;
2775         int mod = 0;
2776
2777         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2778
2779         if (!vol_args)
2780                 return -ENOMEM;
2781
2782         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2783                 ret = -EFAULT;
2784                 goto out;
2785         }
2786         namelen = strlen(vol_args->name);
2787         if (namelen > BTRFS_VOL_NAME_MAX) {
2788                 ret = -EINVAL;
2789                 goto out;
2790         }
2791
2792         sizestr = vol_args->name;
2793         if (!strcmp(sizestr, "max"))
2794                 new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
2795         else {
2796                 if (sizestr[0] == '-') {
2797                         mod = -1;
2798                         sizestr++;
2799                 } else if (sizestr[0] == '+') {
2800                         mod = 1;
2801                         sizestr++;
2802                 }
2803                 new_size = btrfs_parse_size(sizestr);
2804                 if (new_size == 0) {
2805                         ret = -EINVAL;
2806                         goto out;
2807                 }
2808         }
2809
2810         mutex_lock(&root->fs_info->fs_mutex);
2811         old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
2812
2813         if (mod < 0) {
2814                 if (new_size > old_size) {
2815                         ret = -EINVAL;
2816                         goto out_unlock;
2817                 }
2818                 new_size = old_size - new_size;
2819         } else if (mod > 0) {
2820                 new_size = old_size + new_size;
2821         }
2822
2823         if (new_size < 256 * 1024 * 1024) {
2824                 ret = -EINVAL;
2825                 goto out_unlock;
2826         }
2827         if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
2828                 ret = -EFBIG;
2829                 goto out_unlock;
2830         }
2831
2832         do_div(new_size, root->sectorsize);
2833         new_size *= root->sectorsize;
2834
2835 printk("new size is %Lu\n", new_size);
2836         if (new_size > old_size) {
2837                 trans = btrfs_start_transaction(root, 1);
2838                 ret = btrfs_grow_extent_tree(trans, root, new_size);
2839                 btrfs_commit_transaction(trans, root);
2840         } else {
2841                 ret = btrfs_shrink_extent_tree(root, new_size);
2842         }
2843
2844 out_unlock:
2845         mutex_unlock(&root->fs_info->fs_mutex);
2846 out:
2847         kfree(vol_args);
2848         return ret;
2849 }
2850
2851 static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
2852                                             void __user *arg)
2853 {
2854         struct btrfs_ioctl_vol_args *vol_args;
2855         struct btrfs_dir_item *di;
2856         struct btrfs_path *path;
2857         u64 root_dirid;
2858         int namelen;
2859         int ret;
2860
2861         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
2862
2863         if (!vol_args)
2864                 return -ENOMEM;
2865
2866         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
2867                 ret = -EFAULT;
2868                 goto out;
2869         }
2870
2871         namelen = strlen(vol_args->name);
2872         if (namelen > BTRFS_VOL_NAME_MAX) {
2873                 ret = -EINVAL;
2874                 goto out;
2875         }
2876         if (strchr(vol_args->name, '/')) {
2877                 ret = -EINVAL;
2878                 goto out;
2879         }
2880
2881         path = btrfs_alloc_path();
2882         if (!path) {
2883                 ret = -ENOMEM;
2884                 goto out;
2885         }
2886
2887         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
2888         mutex_lock(&root->fs_info->fs_mutex);
2889         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
2890                             path, root_dirid,
2891                             vol_args->name, namelen, 0);
2892         mutex_unlock(&root->fs_info->fs_mutex);
2893         btrfs_free_path(path);
2894
2895         if (di && !IS_ERR(di)) {
2896                 ret = -EEXIST;
2897                 goto out;
2898         }
2899
2900         if (IS_ERR(di)) {
2901                 ret = PTR_ERR(di);
2902                 goto out;
2903         }
2904
2905         if (root == root->fs_info->tree_root)
2906                 ret = create_subvol(root, vol_args->name, namelen);
2907         else
2908                 ret = create_snapshot(root, vol_args->name, namelen);
2909 out:
2910         kfree(vol_args);
2911         return ret;
2912 }
2913
2914 static int btrfs_ioctl_defrag(struct file *file)
2915 {
2916         struct inode *inode = fdentry(file)->d_inode;
2917         struct btrfs_root *root = BTRFS_I(inode)->root;
2918
2919         switch (inode->i_mode & S_IFMT) {
2920         case S_IFDIR:
2921                 mutex_lock(&root->fs_info->fs_mutex);
2922                 btrfs_defrag_root(root, 0);
2923                 btrfs_defrag_root(root->fs_info->extent_root, 0);
2924                 mutex_unlock(&root->fs_info->fs_mutex);
2925                 break;
2926         case S_IFREG:
2927                 btrfs_defrag_file(file);
2928                 break;
2929         }
2930
2931         return 0;
2932 }
2933
2934 long btrfs_ioctl(struct file *file, unsigned int
2935                 cmd, unsigned long arg)
2936 {
2937         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2938
2939         switch (cmd) {
2940         case BTRFS_IOC_SNAP_CREATE:
2941                 return btrfs_ioctl_snap_create(root, (void __user *)arg);
2942         case BTRFS_IOC_DEFRAG:
2943                 return btrfs_ioctl_defrag(file);
2944         case BTRFS_IOC_RESIZE:
2945                 return btrfs_ioctl_resize(root, (void __user *)arg);
2946         }
2947
2948         return -ENOTTY;
2949 }
2950
2951 /*
2952  * Called inside transaction, so use GFP_NOFS
2953  */
2954 struct inode *btrfs_alloc_inode(struct super_block *sb)
2955 {
2956         struct btrfs_inode *ei;
2957
2958         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
2959         if (!ei)
2960                 return NULL;
2961         ei->last_trans = 0;
2962         ei->ordered_trans = 0;
2963         return &ei->vfs_inode;
2964 }
2965
2966 void btrfs_destroy_inode(struct inode *inode)
2967 {
2968         WARN_ON(!list_empty(&inode->i_dentry));
2969         WARN_ON(inode->i_data.nrpages);
2970
2971         btrfs_drop_extent_cache(inode, 0, (u64)-1);
2972         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
2973 }
2974
2975 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
2976 static void init_once(struct kmem_cache * cachep, void *foo)
2977 #else
2978 static void init_once(void * foo, struct kmem_cache * cachep,
2979                       unsigned long flags)
2980 #endif
2981 {
2982         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
2983
2984         inode_init_once(&ei->vfs_inode);
2985 }
2986
2987 void btrfs_destroy_cachep(void)
2988 {
2989         if (btrfs_inode_cachep)
2990                 kmem_cache_destroy(btrfs_inode_cachep);
2991         if (btrfs_trans_handle_cachep)
2992                 kmem_cache_destroy(btrfs_trans_handle_cachep);
2993         if (btrfs_transaction_cachep)
2994                 kmem_cache_destroy(btrfs_transaction_cachep);
2995         if (btrfs_bit_radix_cachep)
2996                 kmem_cache_destroy(btrfs_bit_radix_cachep);
2997         if (btrfs_path_cachep)
2998                 kmem_cache_destroy(btrfs_path_cachep);
2999 }
3000
3001 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
3002                                        unsigned long extra_flags,
3003 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
3004                                        void (*ctor)(struct kmem_cache *, void *)
3005 #else
3006                                        void (*ctor)(void *, struct kmem_cache *,
3007                                                     unsigned long)
3008 #endif
3009                                      )
3010 {
3011         return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
3012                                  SLAB_MEM_SPREAD | extra_flags), ctor
3013 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
3014                                  ,NULL
3015 #endif
3016                                 );
3017 }
3018
3019 int btrfs_init_cachep(void)
3020 {
3021         btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
3022                                           sizeof(struct btrfs_inode),
3023                                           0, init_once);
3024         if (!btrfs_inode_cachep)
3025                 goto fail;
3026         btrfs_trans_handle_cachep =
3027                         btrfs_cache_create("btrfs_trans_handle_cache",
3028                                            sizeof(struct btrfs_trans_handle),
3029                                            0, NULL);
3030         if (!btrfs_trans_handle_cachep)
3031                 goto fail;
3032         btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
3033                                              sizeof(struct btrfs_transaction),
3034                                              0, NULL);
3035         if (!btrfs_transaction_cachep)
3036                 goto fail;
3037         btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
3038                                          sizeof(struct btrfs_path),
3039                                          0, NULL);
3040         if (!btrfs_path_cachep)
3041                 goto fail;
3042         btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
3043                                               SLAB_DESTROY_BY_RCU, NULL);
3044         if (!btrfs_bit_radix_cachep)
3045                 goto fail;
3046         return 0;
3047 fail:
3048         btrfs_destroy_cachep();
3049         return -ENOMEM;
3050 }
3051
3052 static int btrfs_getattr(struct vfsmount *mnt,
3053                          struct dentry *dentry, struct kstat *stat)
3054 {
3055         struct inode *inode = dentry->d_inode;
3056         generic_fillattr(inode, stat);
3057         stat->blksize = PAGE_CACHE_SIZE;
3058         stat->blocks = inode->i_blocks + (BTRFS_I(inode)->delalloc_bytes >> 9);
3059         return 0;
3060 }
3061
3062 static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
3063                            struct inode * new_dir,struct dentry *new_dentry)
3064 {
3065         struct btrfs_trans_handle *trans;
3066         struct btrfs_root *root = BTRFS_I(old_dir)->root;
3067         struct inode *new_inode = new_dentry->d_inode;
3068         struct inode *old_inode = old_dentry->d_inode;
3069         struct timespec ctime = CURRENT_TIME;
3070         struct btrfs_path *path;
3071         int ret;
3072
3073         if (S_ISDIR(old_inode->i_mode) && new_inode &&
3074             new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
3075                 return -ENOTEMPTY;
3076         }
3077
3078         mutex_lock(&root->fs_info->fs_mutex);
3079         ret = btrfs_check_free_space(root, 1, 0);
3080         if (ret)
3081                 goto out_unlock;
3082
3083         trans = btrfs_start_transaction(root, 1);
3084
3085         btrfs_set_trans_block_group(trans, new_dir);
3086         path = btrfs_alloc_path();
3087         if (!path) {
3088                 ret = -ENOMEM;
3089                 goto out_fail;
3090         }
3091
3092         old_dentry->d_inode->i_nlink++;
3093         old_dir->i_ctime = old_dir->i_mtime = ctime;
3094         new_dir->i_ctime = new_dir->i_mtime = ctime;
3095         old_inode->i_ctime = ctime;
3096
3097         ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
3098         if (ret)
3099                 goto out_fail;
3100
3101         if (new_inode) {
3102                 new_inode->i_ctime = CURRENT_TIME;
3103                 ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
3104                 if (ret)
3105                         goto out_fail;
3106         }
3107         ret = btrfs_add_link(trans, new_dentry, old_inode, 1);
3108         if (ret)
3109                 goto out_fail;
3110
3111 out_fail:
3112         btrfs_free_path(path);
3113         btrfs_end_transaction(trans, root);
3114 out_unlock:
3115         mutex_unlock(&root->fs_info->fs_mutex);
3116         return ret;
3117 }
3118
3119 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
3120                          const char *symname)
3121 {
3122         struct btrfs_trans_handle *trans;
3123         struct btrfs_root *root = BTRFS_I(dir)->root;
3124         struct btrfs_path *path;
3125         struct btrfs_key key;
3126         struct inode *inode = NULL;
3127         int err;
3128         int drop_inode = 0;
3129         u64 objectid;
3130         int name_len;
3131         int datasize;
3132         unsigned long ptr;
3133         struct btrfs_file_extent_item *ei;
3134         struct extent_buffer *leaf;
3135         unsigned long nr = 0;
3136
3137         name_len = strlen(symname) + 1;
3138         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
3139                 return -ENAMETOOLONG;
3140
3141         mutex_lock(&root->fs_info->fs_mutex);
3142         err = btrfs_check_free_space(root, 1, 0);
3143         if (err)
3144                 goto out_fail;
3145
3146         trans = btrfs_start_transaction(root, 1);
3147         btrfs_set_trans_block_group(trans, dir);
3148
3149         err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
3150         if (err) {
3151                 err = -ENOSPC;
3152                 goto out_unlock;
3153         }
3154
3155         inode = btrfs_new_inode(trans, root, dentry->d_name.name,
3156                                 dentry->d_name.len,
3157                                 dentry->d_parent->d_inode->i_ino, objectid,
3158                                 BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
3159         err = PTR_ERR(inode);
3160         if (IS_ERR(inode))
3161                 goto out_unlock;
3162
3163         btrfs_set_trans_block_group(trans, inode);
3164         err = btrfs_add_nondir(trans, dentry, inode, 0);
3165         if (err)
3166                 drop_inode = 1;
3167         else {
3168                 inode->i_mapping->a_ops = &btrfs_aops;
3169                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3170                 inode->i_fop = &btrfs_file_operations;
3171                 inode->i_op = &btrfs_file_inode_operations;
3172                 extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
3173                 extent_io_tree_init(&BTRFS_I(inode)->io_tree,
3174                                      inode->i_mapping, GFP_NOFS);
3175                 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
3176                                      inode->i_mapping, GFP_NOFS);
3177                 BTRFS_I(inode)->delalloc_bytes = 0;
3178                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3179         }
3180         dir->i_sb->s_dirt = 1;
3181         btrfs_update_inode_block_group(trans, inode);
3182         btrfs_update_inode_block_group(trans, dir);
3183         if (drop_inode)
3184                 goto out_unlock;
3185
3186         path = btrfs_alloc_path();
3187         BUG_ON(!path);
3188         key.objectid = inode->i_ino;
3189         key.offset = 0;
3190         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
3191         datasize = btrfs_file_extent_calc_inline_size(name_len);
3192         err = btrfs_insert_empty_item(trans, root, path, &key,
3193                                       datasize);
3194         if (err) {
3195                 drop_inode = 1;
3196                 goto out_unlock;
3197         }
3198         leaf = path->nodes[0];
3199         ei = btrfs_item_ptr(leaf, path->slots[0],
3200                             struct btrfs_file_extent_item);
3201         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
3202         btrfs_set_file_extent_type(leaf, ei,
3203                                    BTRFS_FILE_EXTENT_INLINE);
3204         ptr = btrfs_file_extent_inline_start(ei);
3205         write_extent_buffer(leaf, symname, ptr, name_len);
3206         btrfs_mark_buffer_dirty(leaf);
3207         btrfs_free_path(path);
3208
3209         inode->i_op = &btrfs_symlink_inode_operations;
3210         inode->i_mapping->a_ops = &btrfs_symlink_aops;
3211         inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3212         inode->i_size = name_len - 1;
3213         err = btrfs_update_inode(trans, root, inode);
3214         if (err)
3215                 drop_inode = 1;
3216
3217 out_unlock:
3218         nr = trans->blocks_used;
3219         btrfs_end_transaction(trans, root);
3220 out_fail:
3221         mutex_unlock(&root->fs_info->fs_mutex);
3222         if (drop_inode) {
3223                 inode_dec_link_count(inode);
3224                 iput(inode);
3225         }
3226         btrfs_btree_balance_dirty(root, nr);
3227         btrfs_throttle(root);
3228         return err;
3229 }
3230
3231 static int btrfs_permission(struct inode *inode, int mask,
3232                             struct nameidata *nd)
3233 {
3234         if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
3235                 return -EACCES;
3236         return generic_permission(inode, mask, NULL);
3237 }
3238
3239 static struct inode_operations btrfs_dir_inode_operations = {
3240         .lookup         = btrfs_lookup,
3241         .create         = btrfs_create,
3242         .unlink         = btrfs_unlink,
3243         .link           = btrfs_link,
3244         .mkdir          = btrfs_mkdir,
3245         .rmdir          = btrfs_rmdir,
3246         .rename         = btrfs_rename,
3247         .symlink        = btrfs_symlink,
3248         .setattr        = btrfs_setattr,
3249         .mknod          = btrfs_mknod,
3250         .setxattr       = generic_setxattr,
3251         .getxattr       = generic_getxattr,
3252         .listxattr      = btrfs_listxattr,
3253         .removexattr    = generic_removexattr,
3254         .permission     = btrfs_permission,
3255 };
3256 static struct inode_operations btrfs_dir_ro_inode_operations = {
3257         .lookup         = btrfs_lookup,
3258         .permission     = btrfs_permission,
3259 };
3260 static struct file_operations btrfs_dir_file_operations = {
3261         .llseek         = generic_file_llseek,
3262         .read           = generic_read_dir,
3263         .readdir        = btrfs_readdir,
3264         .unlocked_ioctl = btrfs_ioctl,
3265 #ifdef CONFIG_COMPAT
3266         .compat_ioctl   = btrfs_ioctl,
3267 #endif
3268 };
3269
3270 static struct extent_io_ops btrfs_extent_io_ops = {
3271         .fill_delalloc = run_delalloc_range,
3272         .submit_bio_hook = btrfs_submit_bio_hook,
3273         .merge_bio_hook = btrfs_merge_bio_hook,
3274         .readpage_io_hook = btrfs_readpage_io_hook,
3275         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
3276         .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
3277         .set_bit_hook = btrfs_set_bit_hook,
3278         .clear_bit_hook = btrfs_clear_bit_hook,
3279 };
3280
3281 static struct address_space_operations btrfs_aops = {
3282         .readpage       = btrfs_readpage,
3283         .writepage      = btrfs_writepage,
3284         .writepages     = btrfs_writepages,
3285         .readpages      = btrfs_readpages,
3286         .sync_page      = block_sync_page,
3287         .bmap           = btrfs_bmap,
3288         .direct_IO      = btrfs_direct_IO,
3289         .invalidatepage = btrfs_invalidatepage,
3290         .releasepage    = btrfs_releasepage,
3291         .set_page_dirty = __set_page_dirty_nobuffers,
3292 };
3293
3294 static struct address_space_operations btrfs_symlink_aops = {
3295         .readpage       = btrfs_readpage,
3296         .writepage      = btrfs_writepage,
3297         .invalidatepage = btrfs_invalidatepage,
3298         .releasepage    = btrfs_releasepage,
3299 };
3300
3301 static struct inode_operations btrfs_file_inode_operations = {
3302         .truncate       = btrfs_truncate,
3303         .getattr        = btrfs_getattr,
3304         .setattr        = btrfs_setattr,
3305         .setxattr       = generic_setxattr,
3306         .getxattr       = generic_getxattr,
3307         .listxattr      = btrfs_listxattr,
3308         .removexattr    = generic_removexattr,
3309         .permission     = btrfs_permission,
3310 };
3311 static struct inode_operations btrfs_special_inode_operations = {
3312         .getattr        = btrfs_getattr,
3313         .setattr        = btrfs_setattr,
3314         .permission     = btrfs_permission,
3315 };
3316 static struct inode_operations btrfs_symlink_inode_operations = {
3317         .readlink       = generic_readlink,
3318         .follow_link    = page_follow_link_light,
3319         .put_link       = page_put_link,
3320         .permission     = btrfs_permission,
3321 };