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