extent-tree.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 <stdio.h>
  20 #include <stdlib.h>
  21 #include <stdint.h>
  22 #include "kerncompat.h"
  23 #include "radix-tree.h"
  24 #include "ctree.h"
  25 #include "disk-io.h"
  26 #include "print-tree.h"
  27 #include "transaction.h"
  28 #include "crc32c.h"
  29 #include "volumes.h"
  30 #include "free-space-cache.h"
  31 #include "math.h"
  32 #include "utils.h"
  33
  34 #define PENDING_EXTENT_INSERT 0
  35 #define PENDING_EXTENT_DELETE 1
  36 #define PENDING_BACKREF_UPDATE 2
  37
  38 struct pending_extent_op {
  39         int type;
  40         u64 bytenr;
  41         u64 num_bytes;
  42         u64 flags;
  43         struct btrfs_disk_key key;
  44         int level;
  45 };
  46
  47 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
  48                                      struct btrfs_root *root,
  49                                      u64 root_objectid, u64 generation,
  50                                      u64 flags, struct btrfs_disk_key *key,
  51                                      int level, struct btrfs_key *ins);
  52 static int __free_extent(struct btrfs_trans_handle *trans,
  53                          struct btrfs_root *root,
  54                          u64 bytenr, u64 num_bytes, u64 parent,
  55                          u64 root_objectid, u64 owner_objectid,
  56                          u64 owner_offset, int refs_to_drop);
  57 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
  58                                  btrfs_root *extent_root);
  59 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
  60                                btrfs_root *extent_root);
  61 static struct btrfs_block_group_cache *
  62 btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache
  63                        *hint, u64 search_start, int data, int owner);
  64
  65 static int remove_sb_from_cache(struct btrfs_root *root,
  66                                 struct btrfs_block_group_cache *cache)
  67 {
  68         u64 bytenr;
  69         u64 *logical;
  70         int stripe_len;
  71         int i, nr, ret;
  72         struct extent_io_tree *free_space_cache;
  73
  74         free_space_cache = &root->fs_info->free_space_cache;
  75         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
  76                 bytenr = btrfs_sb_offset(i);
  77                 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
  78                                        cache->key.objectid, bytenr, 0,
  79                                        &logical, &nr, &stripe_len);
  80                 BUG_ON(ret);
  81                 while (nr--) {
  82                         clear_extent_dirty(free_space_cache, logical[nr],
  83                                 logical[nr] + stripe_len - 1, GFP_NOFS);
  84                 }
  85                 kfree(logical);
  86         }
  87         return 0;
  88 }
  89
  90 static int cache_block_group(struct btrfs_root *root,
  91                              struct btrfs_block_group_cache *block_group)
  92 {
  93         struct btrfs_path *path;
  94         int ret;
  95         struct btrfs_key key;
  96         struct extent_buffer *leaf;
  97         struct extent_io_tree *free_space_cache;
  98         int slot;
  99         u64 last;
 100         u64 hole_size;
 101
 102         if (!block_group)
 103                 return 0;
 104
 105         root = root->fs_info->extent_root;
 106         free_space_cache = &root->fs_info->free_space_cache;
 107
 108         if (block_group->cached)
 109                 return 0;
 110
 111         path = btrfs_alloc_path();
 112         if (!path)
 113                 return -ENOMEM;
 114
 115         path->reada = 2;
 116         last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
 117         key.objectid = last;
 118         key.offset = 0;
 119         key.type = 0;
 120
 121         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 122         if (ret < 0)
 123                 goto err;
 124
 125         while(1) {
 126                 leaf = path->nodes[0];
 127                 slot = path->slots[0];
 128                 if (slot >= btrfs_header_nritems(leaf)) {
 129                         ret = btrfs_next_leaf(root, path);
 130                         if (ret < 0)
 131                                 goto err;
 132                         if (ret == 0) {
 133                                 continue;
 134                         } else {
 135                                 break;
 136                         }
 137                 }
 138                 btrfs_item_key_to_cpu(leaf, &key, slot);
 139                 if (key.objectid < block_group->key.objectid) {
 140                         goto next;
 141                 }
 142                 if (key.objectid >= block_group->key.objectid +
 143                     block_group->key.offset) {
 144                         break;
 145                 }
 146
 147                 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
 148                     key.type == BTRFS_METADATA_ITEM_KEY) {
 149                         if (key.objectid > last) {
 150                                 hole_size = key.objectid - last;
 151                                 set_extent_dirty(free_space_cache, last,
 152                                                  last + hole_size - 1,
 153                                                  GFP_NOFS);
 154                         }
 155                         if (key.type == BTRFS_METADATA_ITEM_KEY)
 156                                 last = key.objectid + root->leafsize;
 157                         else
 158                                 last = key.objectid + key.offset;
 159                 }
 160 next:
 161                 path->slots[0]++;
 162         }
 163
 164         if (block_group->key.objectid +
 165             block_group->key.offset > last) {
 166                 hole_size = block_group->key.objectid +
 167                         block_group->key.offset - last;
 168                 set_extent_dirty(free_space_cache, last,
 169                                  last + hole_size - 1, GFP_NOFS);
 170         }
 171         remove_sb_from_cache(root, block_group);
 172         block_group->cached = 1;
 173 err:
 174         btrfs_free_path(path);
 175         return 0;
 176 }
 177
 178 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
 179                                                        btrfs_fs_info *info,
 180                                                        u64 bytenr)
 181 {
 182         struct extent_io_tree *block_group_cache;
 183         struct btrfs_block_group_cache *block_group = NULL;
 184         u64 ptr;
 185         u64 start;
 186         u64 end;
 187         int ret;
 188
 189         bytenr = max_t(u64, bytenr,
 190                        BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
 191         block_group_cache = &info->block_group_cache;
 192         ret = find_first_extent_bit(block_group_cache,
 193                                     bytenr, &start, &end,
 194                                     BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
 195                                     BLOCK_GROUP_SYSTEM);
 196         if (ret) {
 197                 return NULL;
 198         }
 199         ret = get_state_private(block_group_cache, start, &ptr);
 200         if (ret)
 201                 return NULL;
 202
 203         block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
 204         return block_group;
 205 }
 206
 207 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
 208                                                          btrfs_fs_info *info,
 209                                                          u64 bytenr)
 210 {
 211         struct extent_io_tree *block_group_cache;
 212         struct btrfs_block_group_cache *block_group = NULL;
 213         u64 ptr;
 214         u64 start;
 215         u64 end;
 216         int ret;
 217
 218         block_group_cache = &info->block_group_cache;
 219         ret = find_first_extent_bit(block_group_cache,
 220                                     bytenr, &start, &end,
 221                                     BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
 222                                     BLOCK_GROUP_SYSTEM);
 223         if (ret) {
 224                 return NULL;
 225         }
 226         ret = get_state_private(block_group_cache, start, &ptr);
 227         if (ret)
 228                 return NULL;
 229
 230         block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
 231         if (block_group->key.objectid <= bytenr && bytenr <
 232             block_group->key.objectid + block_group->key.offset)
 233                 return block_group;
 234         return NULL;
 235 }
 236
 237 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 238 {
 239         return (cache->flags & bits) == bits;
 240 }
 241
 242 static int noinline find_search_start(struct btrfs_root *root,
 243                               struct btrfs_block_group_cache **cache_ret,
 244                               u64 *start_ret, int num, int data)
 245 {
 246         int ret;
 247         struct btrfs_block_group_cache *cache = *cache_ret;
 248         u64 last = *start_ret;
 249         u64 start = 0;
 250         u64 end = 0;
 251         u64 search_start = *start_ret;
 252         int wrapped = 0;
 253
 254         if (!cache)
 255                 goto out;
 256 again:
 257         ret = cache_block_group(root, cache);
 258         if (ret)
 259                 goto out;
 260
 261         last = max(search_start, cache->key.objectid);
 262         if (cache->ro || !block_group_bits(cache, data))
 263                 goto new_group;
 264
 265         while(1) {
 266                 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
 267                                             last, &start, &end, EXTENT_DIRTY);
 268                 if (ret) {
 269                         goto new_group;
 270                 }
 271
 272                 start = max(last, start);
 273                 last = end + 1;
 274                 if (last - start < num) {
 275                         continue;
 276                 }
 277                 if (start + num > cache->key.objectid + cache->key.offset) {
 278                         goto new_group;
 279                 }
 280                 *start_ret = start;
 281                 return 0;
 282         }
 283 out:
 284         *start_ret = last;
 285         cache = btrfs_lookup_block_group(root->fs_info, search_start);
 286         if (!cache) {
 287                 printk("Unable to find block group for %llu\n",
 288                         (unsigned long long)search_start);
 289                 WARN_ON(1);
 290         }
 291         return -ENOSPC;
 292
 293 new_group:
 294         last = cache->key.objectid + cache->key.offset;
 295 wrapped:
 296         cache = btrfs_lookup_first_block_group(root->fs_info, last);
 297         if (!cache) {
 298                 if (!wrapped) {
 299                         wrapped = 1;
 300                         last = search_start;
 301                         goto wrapped;
 302                 }
 303                 goto out;
 304         }
 305         *cache_ret = cache;
 306         goto again;
 307 }
 308
 309 static int block_group_state_bits(u64 flags)
 310 {
 311         int bits = 0;
 312         if (flags & BTRFS_BLOCK_GROUP_DATA)
 313                 bits |= BLOCK_GROUP_DATA;
 314         if (flags & BTRFS_BLOCK_GROUP_METADATA)
 315                 bits |= BLOCK_GROUP_METADATA;
 316         if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
 317                 bits |= BLOCK_GROUP_SYSTEM;
 318         return bits;
 319 }
 320
 321 static struct btrfs_block_group_cache *
 322 btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache
 323                        *hint, u64 search_start, int data, int owner)
 324 {
 325         struct btrfs_block_group_cache *cache;
 326         struct extent_io_tree *block_group_cache;
 327         struct btrfs_block_group_cache *found_group = NULL;
 328         struct btrfs_fs_info *info = root->fs_info;
 329         u64 used;
 330         u64 last = 0;
 331         u64 hint_last;
 332         u64 start;
 333         u64 end;
 334         u64 free_check;
 335         u64 ptr;
 336         int bit;
 337         int ret;
 338         int full_search = 0;
 339         int factor = 10;
 340
 341         block_group_cache = &info->block_group_cache;
 342
 343         if (!owner)
 344                 factor = 10;
 345
 346         bit = block_group_state_bits(data);
 347
 348         if (search_start) {
 349                 struct btrfs_block_group_cache *shint;
 350                 shint = btrfs_lookup_block_group(info, search_start);
 351                 if (shint && !shint->ro && block_group_bits(shint, data)) {
 352                         used = btrfs_block_group_used(&shint->item);
 353                         if (used + shint->pinned <
 354                             div_factor(shint->key.offset, factor)) {
 355                                 return shint;
 356                         }
 357                 }
 358         }
 359         if (hint && !hint->ro && block_group_bits(hint, data)) {
 360                 used = btrfs_block_group_used(&hint->item);
 361                 if (used + hint->pinned <
 362                     div_factor(hint->key.offset, factor)) {
 363                         return hint;
 364                 }
 365                 last = hint->key.objectid + hint->key.offset;
 366                 hint_last = last;
 367         } else {
 368                 if (hint)
 369                         hint_last = max(hint->key.objectid, search_start);
 370                 else
 371                         hint_last = search_start;
 372
 373                 last = hint_last;
 374         }
 375 again:
 376         while(1) {
 377                 ret = find_first_extent_bit(block_group_cache, last,
 378                                             &start, &end, bit);
 379                 if (ret)
 380                         break;
 381
 382                 ret = get_state_private(block_group_cache, start, &ptr);
 383                 if (ret)
 384                         break;
 385
 386                 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
 387                 last = cache->key.objectid + cache->key.offset;
 388                 used = btrfs_block_group_used(&cache->item);
 389
 390                 if (!cache->ro && block_group_bits(cache, data)) {
 391                         if (full_search)
 392                                 free_check = cache->key.offset;
 393                         else
 394                                 free_check = div_factor(cache->key.offset,
 395                                                         factor);
 396
 397                         if (used + cache->pinned < free_check) {
 398                                 found_group = cache;
 399                                 goto found;
 400                         }
 401                 }
 402                 cond_resched();
 403         }
 404         if (!full_search) {
 405                 last = search_start;
 406                 full_search = 1;
 407                 goto again;
 408         }
 409 found:
 410         return found_group;
 411 }
 412
 413 /*
 414  * Back reference rules.  Back refs have three main goals:
 415  *
 416  * 1) differentiate between all holders of references to an extent so that
 417  *    when a reference is dropped we can make sure it was a valid reference
 418  *    before freeing the extent.
 419  *
 420  * 2) Provide enough information to quickly find the holders of an extent
 421  *    if we notice a given block is corrupted or bad.
 422  *
 423  * 3) Make it easy to migrate blocks for FS shrinking or storage pool
 424  *    maintenance.  This is actually the same as #2, but with a slightly
 425  *    different use case.
 426  *
 427  * There are two kinds of back refs. The implicit back refs is optimized
 428  * for pointers in non-shared tree blocks. For a given pointer in a block,
 429  * back refs of this kind provide information about the block's owner tree
 430  * and the pointer's key. These information allow us to find the block by
 431  * b-tree searching. The full back refs is for pointers in tree blocks not
 432  * referenced by their owner trees. The location of tree block is recorded
 433  * in the back refs. Actually the full back refs is generic, and can be
 434  * used in all cases the implicit back refs is used. The major shortcoming
 435  * of the full back refs is its overhead. Every time a tree block gets
 436  * COWed, we have to update back refs entry for all pointers in it.
 437  *
 438  * For a newly allocated tree block, we use implicit back refs for
 439  * pointers in it. This means most tree related operations only involve
 440  * implicit back refs. For a tree block created in old transaction, the
 441  * only way to drop a reference to it is COW it. So we can detect the
 442  * event that tree block loses its owner tree's reference and do the
 443  * back refs conversion.
 444  *
 445  * When a tree block is COW'd through a tree, there are four cases:
 446  *
 447  * The reference count of the block is one and the tree is the block's
 448  * owner tree. Nothing to do in this case.
 449  *
 450  * The reference count of the block is one and the tree is not the
 451  * block's owner tree. In this case, full back refs is used for pointers
 452  * in the block. Remove these full back refs, add implicit back refs for
 453  * every pointers in the new block.
 454  *
 455  * The reference count of the block is greater than one and the tree is
 456  * the block's owner tree. In this case, implicit back refs is used for
 457  * pointers in the block. Add full back refs for every pointers in the
 458  * block, increase lower level extents' reference counts. The original
 459  * implicit back refs are entailed to the new block.
 460  *
 461  * The reference count of the block is greater than one and the tree is
 462  * not the block's owner tree. Add implicit back refs for every pointer in
 463  * the new block, increase lower level extents' reference count.
 464  *
 465  * Back Reference Key composing:
 466  *
 467  * The key objectid corresponds to the first byte in the extent,
 468  * The key type is used to differentiate between types of back refs.
 469  * There are different meanings of the key offset for different types
 470  * of back refs.
 471  *
 472  * File extents can be referenced by:
 473  *
 474  * - multiple snapshots, subvolumes, or different generations in one subvol
 475  * - different files inside a single subvolume
 476  * - different offsets inside a file (bookend extents in file.c)
 477  *
 478  * The extent ref structure for the implicit back refs has fields for:
 479  *
 480  * - Objectid of the subvolume root
 481  * - objectid of the file holding the reference
 482  * - original offset in the file
 483  * - how many bookend extents
 484  *
 485  * The key offset for the implicit back refs is hash of the first
 486  * three fields.
 487  *
 488  * The extent ref structure for the full back refs has field for:
 489  *
 490  * - number of pointers in the tree leaf
 491  *
 492  * The key offset for the implicit back refs is the first byte of
 493  * the tree leaf
 494  *
 495  * When a file extent is allocated, The implicit back refs is used.
 496  * the fields are filled in:
 497  *
 498  *     (root_key.objectid, inode objectid, offset in file, 1)
 499  *
 500  * When a file extent is removed file truncation, we find the
 501  * corresponding implicit back refs and check the following fields:
 502  *
 503  *     (btrfs_header_owner(leaf), inode objectid, offset in file)
 504  *
 505  * Btree extents can be referenced by:
 506  *
 507  * - Different subvolumes
 508  *
 509  * Both the implicit back refs and the full back refs for tree blocks
 510  * only consist of key. The key offset for the implicit back refs is
 511  * objectid of block's owner tree. The key offset for the full back refs
 512  * is the first byte of parent block.
 513  *
 514  * When implicit back refs is used, information about the lowest key and
 515  * level of the tree block are required. These information are stored in
 516  * tree block info structure.
 517  */
 518
 519 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 520 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
 521                                   struct btrfs_root *root,
 522                                   struct btrfs_path *path,
 523                                   u64 owner, u32 extra_size)
 524 {
 525         struct btrfs_extent_item *item;
 526         struct btrfs_extent_item_v0 *ei0;
 527         struct btrfs_extent_ref_v0 *ref0;
 528         struct btrfs_tree_block_info *bi;
 529         struct extent_buffer *leaf;
 530         struct btrfs_key key;
 531         struct btrfs_key found_key;
 532         u32 new_size = sizeof(*item);
 533         u64 refs;
 534         int ret;
 535
 536         leaf = path->nodes[0];
 537         BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
 538
 539         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 540         ei0 = btrfs_item_ptr(leaf, path->slots[0],
 541                              struct btrfs_extent_item_v0);
 542         refs = btrfs_extent_refs_v0(leaf, ei0);
 543
 544         if (owner == (u64)-1) {
 545                 while (1) {
 546                         if (path->slots[0] >= btrfs_header_nritems(leaf)) {
 547                                 ret = btrfs_next_leaf(root, path);
 548                                 if (ret < 0)
 549                                         return ret;
 550                                 BUG_ON(ret > 0);
 551                                 leaf = path->nodes[0];
 552                         }
 553                         btrfs_item_key_to_cpu(leaf, &found_key,
 554                                               path->slots[0]);
 555                         BUG_ON(key.objectid != found_key.objectid);
 556                         if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
 557                                 path->slots[0]++;
 558                                 continue;
 559                         }
 560                         ref0 = btrfs_item_ptr(leaf, path->slots[0],
 561                                               struct btrfs_extent_ref_v0);
 562                         owner = btrfs_ref_objectid_v0(leaf, ref0);
 563                         break;
 564                 }
 565         }
 566         btrfs_release_path(path);
 567
 568         if (owner < BTRFS_FIRST_FREE_OBJECTID)
 569                 new_size += sizeof(*bi);
 570
 571         new_size -= sizeof(*ei0);
 572         ret = btrfs_search_slot(trans, root, &key, path, new_size, 1);
 573         if (ret < 0)
 574                 return ret;
 575         BUG_ON(ret);
 576
 577         ret = btrfs_extend_item(trans, root, path, new_size);
 578         BUG_ON(ret);
 579
 580         leaf = path->nodes[0];
 581         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 582         btrfs_set_extent_refs(leaf, item, refs);
 583         /* FIXME: get real generation */
 584         btrfs_set_extent_generation(leaf, item, 0);
 585         if (owner < BTRFS_FIRST_FREE_OBJECTID) {
 586                 btrfs_set_extent_flags(leaf, item,
 587                                        BTRFS_EXTENT_FLAG_TREE_BLOCK |
 588                                        BTRFS_BLOCK_FLAG_FULL_BACKREF);
 589                 bi = (struct btrfs_tree_block_info *)(item + 1);
 590                 /* FIXME: get first key of the block */
 591                 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
 592                 btrfs_set_tree_block_level(leaf, bi, (int)owner);
 593         } else {
 594                 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
 595         }
 596         btrfs_mark_buffer_dirty(leaf);
 597         return 0;
 598 }
 599 #endif
 600
 601 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
 602 {
 603         u32 high_crc = ~(u32)0;
 604         u32 low_crc = ~(u32)0;
 605         __le64 lenum;
 606
 607         lenum = cpu_to_le64(root_objectid);
 608         high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
 609         lenum = cpu_to_le64(owner);
 610         low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
 611         lenum = cpu_to_le64(offset);
 612         low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
 613
 614         return ((u64)high_crc << 31) ^ (u64)low_crc;
 615 }
 616
 617 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
 618                                      struct btrfs_extent_data_ref *ref)
 619 {
 620         return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
 621                                     btrfs_extent_data_ref_objectid(leaf, ref),
 622                                     btrfs_extent_data_ref_offset(leaf, ref));
 623 }
 624
 625 static int match_extent_data_ref(struct extent_buffer *leaf,
 626                                  struct btrfs_extent_data_ref *ref,
 627                                  u64 root_objectid, u64 owner, u64 offset)
 628 {
 629         if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
 630             btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
 631             btrfs_extent_data_ref_offset(leaf, ref) != offset)
 632                 return 0;
 633         return 1;
 634 }
 635
 636 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
 637                                            struct btrfs_root *root,
 638                                            struct btrfs_path *path,
 639                                            u64 bytenr, u64 parent,
 640                                            u64 root_objectid,
 641                                            u64 owner, u64 offset)
 642 {
 643         struct btrfs_key key;
 644         struct btrfs_extent_data_ref *ref;
 645         struct extent_buffer *leaf;
 646         u32 nritems;
 647         int ret;
 648         int recow;
 649         int err = -ENOENT;
 650
 651         key.objectid = bytenr;
 652         if (parent) {
 653                 key.type = BTRFS_SHARED_DATA_REF_KEY;
 654                 key.offset = parent;
 655         } else {
 656                 key.type = BTRFS_EXTENT_DATA_REF_KEY;
 657                 key.offset = hash_extent_data_ref(root_objectid,
 658                                                   owner, offset);
 659         }
 660 again:
 661         recow = 0;
 662         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 663         if (ret < 0) {
 664                 err = ret;
 665                 goto fail;
 666         }
 667
 668         if (parent) {
 669                 if (!ret)
 670                         return 0;
 671 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 672                 key.type = BTRFS_EXTENT_REF_V0_KEY;
 673                 btrfs_release_path(path);
 674                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 675                 if (ret < 0) {
 676                         err = ret;
 677                         goto fail;
 678                 }
 679                 if (!ret)
 680                         return 0;
 681 #endif
 682                 goto fail;
 683         }
 684
 685         leaf = path->nodes[0];
 686         nritems = btrfs_header_nritems(leaf);
 687         while (1) {
 688                 if (path->slots[0] >= nritems) {
 689                         ret = btrfs_next_leaf(root, path);
 690                         if (ret < 0)
 691                                 err = ret;
 692                         if (ret)
 693                                 goto fail;
 694
 695                         leaf = path->nodes[0];
 696                         nritems = btrfs_header_nritems(leaf);
 697                         recow = 1;
 698                 }
 699
 700                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 701                 if (key.objectid != bytenr ||
 702                     key.type != BTRFS_EXTENT_DATA_REF_KEY)
 703                         goto fail;
 704
 705                 ref = btrfs_item_ptr(leaf, path->slots[0],
 706                                      struct btrfs_extent_data_ref);
 707
 708                 if (match_extent_data_ref(leaf, ref, root_objectid,
 709                                           owner, offset)) {
 710                         if (recow) {
 711                                 btrfs_release_path(path);
 712                                 goto again;
 713                         }
 714                         err = 0;
 715                         break;
 716                 }
 717                 path->slots[0]++;
 718         }
 719 fail:
 720         return err;
 721 }
 722
 723 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
 724                                            struct btrfs_root *root,
 725                                            struct btrfs_path *path,
 726                                            u64 bytenr, u64 parent,
 727                                            u64 root_objectid, u64 owner,
 728                                            u64 offset, int refs_to_add)
 729 {
 730         struct btrfs_key key;
 731         struct extent_buffer *leaf;
 732         u32 size;
 733         u32 num_refs;
 734         int ret;
 735
 736         key.objectid = bytenr;
 737         if (parent) {
 738                 key.type = BTRFS_SHARED_DATA_REF_KEY;
 739                 key.offset = parent;
 740                 size = sizeof(struct btrfs_shared_data_ref);
 741         } else {
 742                 key.type = BTRFS_EXTENT_DATA_REF_KEY;
 743                 key.offset = hash_extent_data_ref(root_objectid,
 744                                                   owner, offset);
 745                 size = sizeof(struct btrfs_extent_data_ref);
 746         }
 747
 748         ret = btrfs_insert_empty_item(trans, root, path, &key, size);
 749         if (ret && ret != -EEXIST)
 750                 goto fail;
 751
 752         leaf = path->nodes[0];
 753         if (parent) {
 754                 struct btrfs_shared_data_ref *ref;
 755                 ref = btrfs_item_ptr(leaf, path->slots[0],
 756                                      struct btrfs_shared_data_ref);
 757                 if (ret == 0) {
 758                         btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
 759                 } else {
 760                         num_refs = btrfs_shared_data_ref_count(leaf, ref);
 761                         num_refs += refs_to_add;
 762                         btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
 763                 }
 764         } else {
 765                 struct btrfs_extent_data_ref *ref;
 766                 while (ret == -EEXIST) {
 767                         ref = btrfs_item_ptr(leaf, path->slots[0],
 768                                              struct btrfs_extent_data_ref);
 769                         if (match_extent_data_ref(leaf, ref, root_objectid,
 770                                                   owner, offset))
 771                                 break;
 772                         btrfs_release_path(path);
 773
 774                         key.offset++;
 775                         ret = btrfs_insert_empty_item(trans, root, path, &key,
 776                                                       size);
 777                         if (ret && ret != -EEXIST)
 778                                 goto fail;
 779
 780                         leaf = path->nodes[0];
 781                 }
 782                 ref = btrfs_item_ptr(leaf, path->slots[0],
 783                                      struct btrfs_extent_data_ref);
 784                 if (ret == 0) {
 785                         btrfs_set_extent_data_ref_root(leaf, ref,
 786                                                        root_objectid);
 787                         btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
 788                         btrfs_set_extent_data_ref_offset(leaf, ref, offset);
 789                         btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
 790                 } else {
 791                         num_refs = btrfs_extent_data_ref_count(leaf, ref);
 792                         num_refs += refs_to_add;
 793                         btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
 794                 }
 795         }
 796         btrfs_mark_buffer_dirty(leaf);
 797         ret = 0;
 798 fail:
 799         btrfs_release_path(path);
 800         return ret;
 801 }
 802
 803 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
 804                                            struct btrfs_root *root,
 805                                            struct btrfs_path *path,
 806                                            int refs_to_drop)
 807 {
 808         struct btrfs_key key;
 809         struct btrfs_extent_data_ref *ref1 = NULL;
 810         struct btrfs_shared_data_ref *ref2 = NULL;
 811         struct extent_buffer *leaf;
 812         u32 num_refs = 0;
 813         int ret = 0;
 814
 815         leaf = path->nodes[0];
 816         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 817
 818         if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
 819                 ref1 = btrfs_item_ptr(leaf, path->slots[0],
 820                                       struct btrfs_extent_data_ref);
 821                 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
 822         } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
 823                 ref2 = btrfs_item_ptr(leaf, path->slots[0],
 824                                       struct btrfs_shared_data_ref);
 825                 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
 826 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 827         } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
 828                 struct btrfs_extent_ref_v0 *ref0;
 829                 ref0 = btrfs_item_ptr(leaf, path->slots[0],
 830                                       struct btrfs_extent_ref_v0);
 831                 num_refs = btrfs_ref_count_v0(leaf, ref0);
 832 #endif
 833         } else {
 834                 BUG();
 835         }
 836
 837         BUG_ON(num_refs < refs_to_drop);
 838         num_refs -= refs_to_drop;
 839
 840         if (num_refs == 0) {
 841                 ret = btrfs_del_item(trans, root, path);
 842         } else {
 843                 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
 844                         btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
 845                 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
 846                         btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
 847 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 848                 else {
 849                         struct btrfs_extent_ref_v0 *ref0;
 850                         ref0 = btrfs_item_ptr(leaf, path->slots[0],
 851                                         struct btrfs_extent_ref_v0);
 852                         btrfs_set_ref_count_v0(leaf, ref0, num_refs);
 853                 }
 854 #endif
 855                 btrfs_mark_buffer_dirty(leaf);
 856         }
 857         return ret;
 858 }
 859
 860 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
 861                                           struct btrfs_path *path,
 862                                           struct btrfs_extent_inline_ref *iref)
 863 {
 864         struct btrfs_key key;
 865         struct extent_buffer *leaf;
 866         struct btrfs_extent_data_ref *ref1;
 867         struct btrfs_shared_data_ref *ref2;
 868         u32 num_refs = 0;
 869
 870         leaf = path->nodes[0];
 871         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 872         if (iref) {
 873                 if (btrfs_extent_inline_ref_type(leaf, iref) ==
 874                     BTRFS_EXTENT_DATA_REF_KEY) {
 875                         ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
 876                         num_refs = btrfs_extent_data_ref_count(leaf, ref1);
 877                 } else {
 878                         ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
 879                         num_refs = btrfs_shared_data_ref_count(leaf, ref2);
 880                 }
 881         } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
 882                 ref1 = btrfs_item_ptr(leaf, path->slots[0],
 883                                       struct btrfs_extent_data_ref);
 884                 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
 885         } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
 886                 ref2 = btrfs_item_ptr(leaf, path->slots[0],
 887                                       struct btrfs_shared_data_ref);
 888                 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
 889 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 890         } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
 891                 struct btrfs_extent_ref_v0 *ref0;
 892                 ref0 = btrfs_item_ptr(leaf, path->slots[0],
 893                                       struct btrfs_extent_ref_v0);
 894                 num_refs = btrfs_ref_count_v0(leaf, ref0);
 895 #endif
 896         } else {
 897                 BUG();
 898         }
 899         return num_refs;
 900 }
 901
 902 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
 903                                           struct btrfs_root *root,
 904                                           struct btrfs_path *path,
 905                                           u64 bytenr, u64 parent,
 906                                           u64 root_objectid)
 907 {
 908         struct btrfs_key key;
 909         int ret;
 910
 911         key.objectid = bytenr;
 912         if (parent) {
 913                 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
 914                 key.offset = parent;
 915         } else {
 916                 key.type = BTRFS_TREE_BLOCK_REF_KEY;
 917                 key.offset = root_objectid;
 918         }
 919
 920         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 921         if (ret > 0)
 922                 ret = -ENOENT;
 923 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 924         if (ret == -ENOENT && parent) {
 925                 btrfs_release_path(path);
 926                 key.type = BTRFS_EXTENT_REF_V0_KEY;
 927                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 928                 if (ret > 0)
 929                         ret = -ENOENT;
 930         }
 931 #endif
 932         return ret;
 933 }
 934
 935 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
 936                                           struct btrfs_root *root,
 937                                           struct btrfs_path *path,
 938                                           u64 bytenr, u64 parent,
 939                                           u64 root_objectid)
 940 {
 941         struct btrfs_key key;
 942         int ret;
 943
 944         key.objectid = bytenr;
 945         if (parent) {
 946                 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
 947                 key.offset = parent;
 948         } else {
 949                 key.type = BTRFS_TREE_BLOCK_REF_KEY;
 950                 key.offset = root_objectid;
 951         }
 952
 953         ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
 954
 955         btrfs_release_path(path);
 956         return ret;
 957 }
 958
 959 static inline int extent_ref_type(u64 parent, u64 owner)
 960 {
 961         int type;
 962         if (owner < BTRFS_FIRST_FREE_OBJECTID) {
 963                 if (parent > 0)
 964                         type = BTRFS_SHARED_BLOCK_REF_KEY;
 965                 else
 966                         type = BTRFS_TREE_BLOCK_REF_KEY;
 967         } else {
 968                 if (parent > 0)
 969                         type = BTRFS_SHARED_DATA_REF_KEY;
 970                 else
 971                         type = BTRFS_EXTENT_DATA_REF_KEY;
 972         }
 973         return type;
 974 }
 975
 976 static int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
 977                                  struct btrfs_root *root,
 978                                  struct btrfs_path *path,
 979                                  struct btrfs_extent_inline_ref **ref_ret,
 980                                  u64 bytenr, u64 num_bytes,
 981                                  u64 parent, u64 root_objectid,
 982                                  u64 owner, u64 offset, int insert)
 983 {
 984         struct btrfs_key key;
 985         struct extent_buffer *leaf;
 986         struct btrfs_extent_item *ei;
 987         struct btrfs_extent_inline_ref *iref;
 988         u64 flags;
 989         u32 item_size;
 990         unsigned long ptr;
 991         unsigned long end;
 992         int extra_size;
 993         int type;
 994         int want;
 995         int ret;
 996         int err = 0;
 997         int skinny_metadata =
 998                 btrfs_fs_incompat(root->fs_info,
 999                                   BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
1000
1001         key.objectid = bytenr;
1002         key.type = BTRFS_EXTENT_ITEM_KEY;
1003         key.offset = num_bytes;
1004
1005         want = extent_ref_type(parent, owner);
1006         if (insert)
1007                 extra_size = btrfs_extent_inline_ref_size(want);
1008         else
1009                 extra_size = -1;
1010
1011         if (owner < BTRFS_FIRST_FREE_OBJECTID && skinny_metadata) {
1012                 skinny_metadata = 1;
1013                 key.type = BTRFS_METADATA_ITEM_KEY;
1014                 key.offset = owner;
1015         } else if (skinny_metadata) {
1016                 skinny_metadata = 0;
1017         }
1018
1019 again:
1020         ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1021         if (ret < 0) {
1022                 err = ret;
1023                 goto out;
1024         }
1025
1026         /*
1027          * We may be a newly converted file system which still has the old fat
1028          * extent entries for metadata, so try and see if we have one of those.
1029          */
1030         if (ret > 0 && skinny_metadata) {
1031                 skinny_metadata = 0;
1032                 if (path->slots[0]) {
1033                         path->slots[0]--;
1034                         btrfs_item_key_to_cpu(path->nodes[0], &key,
1035                                               path->slots[0]);
1036                         if (key.objectid == bytenr &&
1037                             key.type == BTRFS_EXTENT_ITEM_KEY &&
1038                             key.offset == num_bytes)
1039                                 ret = 0;
1040                 }
1041                 if (ret) {
1042                         key.type = BTRFS_EXTENT_ITEM_KEY;
1043                         key.offset = num_bytes;
1044                         btrfs_release_path(path);
1045                         goto again;
1046                 }
1047         }
1048
1049         if (ret) {
1050                 printf("Failed to find [%llu, %u, %llu]\n", key.objectid, key.type, key.offset);
1051                 return -ENOENT;
1052         }
1053
1054         BUG_ON(ret);
1055
1056         leaf = path->nodes[0];
1057         item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1058 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1059         if (item_size < sizeof(*ei)) {
1060                 if (!insert) {
1061                         err = -ENOENT;
1062                         goto out;
1063                 }
1064                 ret = convert_extent_item_v0(trans, root, path, owner,
1065                                              extra_size);
1066                 if (ret < 0) {
1067                         err = ret;
1068                         goto out;
1069                 }
1070                 leaf = path->nodes[0];
1071                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1072         }
1073 #endif
1074         if (item_size < sizeof(*ei)) {
1075                 printf("Size is %u, needs to be %u, slot %d\n",
1076                        (unsigned)item_size,
1077                        (unsigned)sizeof(*ei), path->slots[0]);
1078                 btrfs_print_leaf(root, leaf);
1079                 return -EINVAL;
1080         }
1081         BUG_ON(item_size < sizeof(*ei));
1082
1083         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1084         flags = btrfs_extent_flags(leaf, ei);
1085
1086         ptr = (unsigned long)(ei + 1);
1087         end = (unsigned long)ei + item_size;
1088
1089         if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1090                 ptr += sizeof(struct btrfs_tree_block_info);
1091                 BUG_ON(ptr > end);
1092         } else if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
1093                 if (!(flags & BTRFS_EXTENT_FLAG_DATA)) {
1094                         return -EIO;
1095                 }
1096         }
1097
1098         err = -ENOENT;
1099         while (1) {
1100                 if (ptr >= end) {
1101                         WARN_ON(ptr > end);
1102                         break;
1103                 }
1104                 iref = (struct btrfs_extent_inline_ref *)ptr;
1105                 type = btrfs_extent_inline_ref_type(leaf, iref);
1106                 if (want < type)
1107                         break;
1108                 if (want > type) {
1109                         ptr += btrfs_extent_inline_ref_size(type);
1110                         continue;
1111                 }
1112
1113                 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1114                         struct btrfs_extent_data_ref *dref;
1115                         dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1116                         if (match_extent_data_ref(leaf, dref, root_objectid,
1117                                                   owner, offset)) {
1118                                 err = 0;
1119                                 break;
1120                         }
1121                         if (hash_extent_data_ref_item(leaf, dref) <
1122                             hash_extent_data_ref(root_objectid, owner, offset))
1123                                 break;
1124                 } else {
1125                         u64 ref_offset;
1126                         ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1127                         if (parent > 0) {
1128                                 if (parent == ref_offset) {
1129                                         err = 0;
1130                                         break;
1131                                 }
1132                                 if (ref_offset < parent)
1133                                         break;
1134                         } else {
1135                                 if (root_objectid == ref_offset) {
1136                                         err = 0;
1137                                         break;
1138                                 }
1139                                 if (ref_offset < root_objectid)
1140                                         break;
1141                         }
1142                 }
1143                 ptr += btrfs_extent_inline_ref_size(type);
1144         }
1145         if (err == -ENOENT && insert) {
1146                 if (item_size + extra_size >=
1147                     BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1148                         err = -EAGAIN;
1149                         goto out;
1150                 }
1151                 /*
1152                  * To add new inline back ref, we have to make sure
1153                  * there is no corresponding back ref item.
1154                  * For simplicity, we just do not add new inline back
1155                  * ref if there is any back ref item.
1156                  */
1157                 if (find_next_key(path, &key) == 0 && key.objectid == bytenr &&
1158                     key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1159                         err = -EAGAIN;
1160                         goto out;
1161                 }
1162         }
1163         *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1164 out:
1165         return err;
1166 }
1167
1168 static int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1169                                 struct btrfs_root *root,
1170                                 struct btrfs_path *path,
1171                                 struct btrfs_extent_inline_ref *iref,
1172                                 u64 parent, u64 root_objectid,
1173                                 u64 owner, u64 offset, int refs_to_add)
1174 {
1175         struct extent_buffer *leaf;
1176         struct btrfs_extent_item *ei;
1177         unsigned long ptr;
1178         unsigned long end;
1179         unsigned long item_offset;
1180         u64 refs;
1181         int size;
1182         int type;
1183         int ret;
1184
1185         leaf = path->nodes[0];
1186         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1187         item_offset = (unsigned long)iref - (unsigned long)ei;
1188
1189         type = extent_ref_type(parent, owner);
1190         size = btrfs_extent_inline_ref_size(type);
1191
1192         ret = btrfs_extend_item(trans, root, path, size);
1193         BUG_ON(ret);
1194
1195         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1196         refs = btrfs_extent_refs(leaf, ei);
1197         refs += refs_to_add;
1198         btrfs_set_extent_refs(leaf, ei, refs);
1199
1200         ptr = (unsigned long)ei + item_offset;
1201         end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1202         if (ptr < end - size)
1203                 memmove_extent_buffer(leaf, ptr + size, ptr,
1204                                       end - size - ptr);
1205
1206         iref = (struct btrfs_extent_inline_ref *)ptr;
1207         btrfs_set_extent_inline_ref_type(leaf, iref, type);
1208         if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1209                 struct btrfs_extent_data_ref *dref;
1210                 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1211                 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1212                 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1213                 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1214                 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1215         } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1216                 struct btrfs_shared_data_ref *sref;
1217                 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1218                 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1219                 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1220         } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1221                 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1222         } else {
1223                 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1224         }
1225         btrfs_mark_buffer_dirty(leaf);
1226         return 0;
1227 }
1228
1229 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1230                                  struct btrfs_root *root,
1231                                  struct btrfs_path *path,
1232                                  struct btrfs_extent_inline_ref **ref_ret,
1233                                  u64 bytenr, u64 num_bytes, u64 parent,
1234                                  u64 root_objectid, u64 owner, u64 offset)
1235 {
1236         int ret;
1237
1238         ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1239                                            bytenr, num_bytes, parent,
1240                                            root_objectid, owner, offset, 0);
1241         if (ret != -ENOENT)
1242                 return ret;
1243
1244         btrfs_release_path(path);
1245         *ref_ret = NULL;
1246
1247         if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1248                 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1249                                             root_objectid);
1250         } else {
1251                 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1252                                              root_objectid, owner, offset);
1253         }
1254         return ret;
1255 }
1256
1257 static int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1258                                  struct btrfs_root *root,
1259                                  struct btrfs_path *path,
1260                                  struct btrfs_extent_inline_ref *iref,
1261                                  int refs_to_mod)
1262 {
1263         struct extent_buffer *leaf;
1264         struct btrfs_extent_item *ei;
1265         struct btrfs_extent_data_ref *dref = NULL;
1266         struct btrfs_shared_data_ref *sref = NULL;
1267         unsigned long ptr;
1268         unsigned long end;
1269         u32 item_size;
1270         int size;
1271         int type;
1272         int ret;
1273         u64 refs;
1274
1275         leaf = path->nodes[0];
1276         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1277         refs = btrfs_extent_refs(leaf, ei);
1278         WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1279         refs += refs_to_mod;
1280         btrfs_set_extent_refs(leaf, ei, refs);
1281
1282         type = btrfs_extent_inline_ref_type(leaf, iref);
1283
1284         if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1285                 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1286                 refs = btrfs_extent_data_ref_count(leaf, dref);
1287         } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1288                 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1289                 refs = btrfs_shared_data_ref_count(leaf, sref);
1290         } else {
1291                 refs = 1;
1292                 BUG_ON(refs_to_mod != -1);
1293         }
1294
1295         BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1296         refs += refs_to_mod;
1297
1298         if (refs > 0) {
1299                 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1300                         btrfs_set_extent_data_ref_count(leaf, dref, refs);
1301                 else
1302                         btrfs_set_shared_data_ref_count(leaf, sref, refs);
1303         } else {
1304                 size =  btrfs_extent_inline_ref_size(type);
1305                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1306                 ptr = (unsigned long)iref;
1307                 end = (unsigned long)ei + item_size;
1308                 if (ptr + size < end)
1309                         memmove_extent_buffer(leaf, ptr, ptr + size,
1310                                               end - ptr - size);
1311                 item_size -= size;
1312                 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1313                 BUG_ON(ret);
1314         }
1315         btrfs_mark_buffer_dirty(leaf);
1316         return 0;
1317 }
1318
1319 static int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1320                                  struct btrfs_root *root,
1321                                  struct btrfs_path *path,
1322                                  u64 bytenr, u64 num_bytes, u64 parent,
1323                                  u64 root_objectid, u64 owner,
1324                                  u64 offset, int refs_to_add)
1325 {
1326         struct btrfs_extent_inline_ref *iref;
1327         int ret;
1328
1329         ret = lookup_inline_extent_backref(trans, root, path, &iref,
1330                                            bytenr, num_bytes, parent,
1331                                            root_objectid, owner, offset, 1);
1332         if (ret == 0) {
1333                 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1334                 ret = update_inline_extent_backref(trans, root, path, iref,
1335                                                    refs_to_add);
1336         } else if (ret == -ENOENT) {
1337                 ret = setup_inline_extent_backref(trans, root, path, iref,
1338                                                   parent, root_objectid,
1339                                                   owner, offset, refs_to_add);
1340         }
1341         return ret;
1342 }
1343
1344 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1345                                  struct btrfs_root *root,
1346                                  struct btrfs_path *path,
1347                                  u64 bytenr, u64 parent, u64 root_objectid,
1348                                  u64 owner, u64 offset, int refs_to_add)
1349 {
1350         int ret;
1351
1352         if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
1353                 ret = insert_extent_data_ref(trans, root, path, bytenr,
1354                                              parent, root_objectid,
1355                                              owner, offset, refs_to_add);
1356         } else {
1357                 BUG_ON(refs_to_add != 1);
1358                 ret = insert_tree_block_ref(trans, root, path, bytenr,
1359                                             parent, root_objectid);
1360         }
1361         return ret;
1362 }
1363
1364 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1365                                  struct btrfs_root *root,
1366                                  struct btrfs_path *path,
1367                                  struct btrfs_extent_inline_ref *iref,
1368                                  int refs_to_drop, int is_data)
1369 {
1370         int ret;
1371
1372         BUG_ON(!is_data && refs_to_drop != 1);
1373         if (iref) {
1374                 ret = update_inline_extent_backref(trans, root, path, iref,
1375                                                    -refs_to_drop);
1376         } else if (is_data) {
1377                 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1378         } else {
1379                 ret = btrfs_del_item(trans, root, path);
1380         }
1381         return ret;
1382 }
1383
1384 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1385                          struct btrfs_root *root,
1386                          u64 bytenr, u64 num_bytes, u64 parent,
1387                          u64 root_objectid, u64 owner, u64 offset)
1388 {
1389         struct btrfs_path *path;
1390         struct extent_buffer *leaf;
1391         struct btrfs_extent_item *item;
1392         u64 refs;
1393         int ret;
1394         int err = 0;
1395
1396         path = btrfs_alloc_path();
1397         if (!path)
1398                 return -ENOMEM;
1399
1400         path->reada = 1;
1401
1402         ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1403                                            path, bytenr, num_bytes, parent,
1404                                            root_objectid, owner, offset, 1);
1405         if (ret == 0)
1406                 goto out;
1407
1408         if (ret != -EAGAIN) {
1409                 err = ret;
1410                 goto out;
1411         }
1412
1413         leaf = path->nodes[0];
1414         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1415         refs = btrfs_extent_refs(leaf, item);
1416         btrfs_set_extent_refs(leaf, item, refs + 1);
1417
1418         btrfs_mark_buffer_dirty(leaf);
1419         btrfs_release_path(path);
1420
1421         path->reada = 1;
1422
1423         /* now insert the actual backref */
1424         ret = insert_extent_backref(trans, root->fs_info->extent_root,
1425                                     path, bytenr, parent, root_objectid,
1426                                     owner, offset, 1);
1427         if (ret)
1428                 err = ret;
1429 out:
1430         btrfs_free_path(path);
1431         finish_current_insert(trans, root->fs_info->extent_root);
1432         del_pending_extents(trans, root->fs_info->extent_root);
1433         BUG_ON(err);
1434         return err;
1435 }
1436
1437 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
1438                          struct btrfs_root *root)
1439 {
1440         finish_current_insert(trans, root->fs_info->extent_root);
1441         del_pending_extents(trans, root->fs_info->extent_root);
1442         return 0;
1443 }
1444
1445 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
1446                              struct btrfs_root *root, u64 bytenr,
1447                              u64 offset, int metadata, u64 *refs, u64 *flags)
1448 {
1449         struct btrfs_path *path;
1450         int ret;
1451         struct btrfs_key key;
1452         struct extent_buffer *l;
1453         struct btrfs_extent_item *item;
1454         u32 item_size;
1455         u64 num_refs;
1456         u64 extent_flags;
1457
1458         if (metadata &&
1459             !btrfs_fs_incompat(root->fs_info,
1460                                BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)) {
1461                 offset = root->leafsize;
1462                 metadata = 0;
1463         }
1464
1465         path = btrfs_alloc_path();
1466         if (!path)
1467                 return -ENOMEM;
1468         path->reada = 1;
1469
1470         key.objectid = bytenr;
1471         key.offset = offset;
1472         if (metadata)
1473                 key.type = BTRFS_METADATA_ITEM_KEY;
1474         else
1475                 key.type = BTRFS_EXTENT_ITEM_KEY;
1476
1477 again:
1478         ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1479                                 0, 0);
1480         if (ret < 0)
1481                 goto out;
1482
1483         /*
1484          * Deal with the fact that we may have mixed SKINNY and normal refs.  If
1485          * we didn't find what we wanted check and see if we have a normal ref
1486          * right next to us, or re-search if we are on the edge of the leaf just
1487          * to make sure.
1488          */
1489         if (ret > 0 && metadata) {
1490                 if (path->slots[0]) {
1491                         path->slots[0]--;
1492                         btrfs_item_key_to_cpu(path->nodes[0], &key,
1493                                               path->slots[0]);
1494                         if (key.objectid == bytenr &&
1495                             key.type == BTRFS_EXTENT_ITEM_KEY &&
1496                             key.offset == root->leafsize)
1497                                 ret = 0;
1498                 }
1499
1500                 if (ret) {
1501                         btrfs_release_path(path);
1502                         key.type = BTRFS_EXTENT_ITEM_KEY;
1503                         key.offset = root->leafsize;
1504                         metadata = 0;
1505                         goto again;
1506                 }
1507         }
1508
1509         if (ret != 0) {
1510                 ret = -EIO;
1511                 goto out;
1512         }
1513
1514         l = path->nodes[0];
1515         item_size = btrfs_item_size_nr(l, path->slots[0]);
1516         if (item_size >= sizeof(*item)) {
1517                 item = btrfs_item_ptr(l, path->slots[0],
1518                                       struct btrfs_extent_item);
1519                 num_refs = btrfs_extent_refs(l, item);
1520                 extent_flags = btrfs_extent_flags(l, item);
1521         } else {
1522 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1523                         struct btrfs_extent_item_v0 *ei0;
1524                         BUG_ON(item_size != sizeof(*ei0));
1525                         ei0 = btrfs_item_ptr(l, path->slots[0],
1526                                              struct btrfs_extent_item_v0);
1527                         num_refs = btrfs_extent_refs_v0(l, ei0);
1528                         /* FIXME: this isn't correct for data */
1529                         extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
1530 #else
1531                         BUG();
1532 #endif
1533         }
1534         item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1535         if (refs)
1536                 *refs = num_refs;
1537         if (flags)
1538                 *flags = extent_flags;
1539 out:
1540         btrfs_free_path(path);
1541         return ret;
1542 }
1543
1544 int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
1545                           struct btrfs_root *root,
1546                           u64 bytenr, int level, u64 flags)
1547 {
1548         struct btrfs_path *path;
1549         int ret;
1550         struct btrfs_key key;
1551         struct extent_buffer *l;
1552         struct btrfs_extent_item *item;
1553         u32 item_size;
1554         int skinny_metadata =
1555                 btrfs_fs_incompat(root->fs_info,
1556                                   BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
1557
1558         path = btrfs_alloc_path();
1559         if (!path)
1560                 return -ENOMEM;
1561         path->reada = 1;
1562
1563         key.objectid = bytenr;
1564         if (skinny_metadata) {
1565                 key.offset = level;
1566                 key.type = BTRFS_METADATA_ITEM_KEY;
1567         } else {
1568                 key.offset = root->leafsize;
1569                 key.type = BTRFS_EXTENT_ITEM_KEY;
1570         }
1571
1572 again:
1573         ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1574                                 0, 0);
1575         if (ret < 0)
1576                 goto out;
1577
1578         if (ret > 0 && skinny_metadata) {
1579                 skinny_metadata = 0;
1580                 if (path->slots[0]) {
1581                         path->slots[0]--;
1582                         btrfs_item_key_to_cpu(path->nodes[0], &key,
1583                                               path->slots[0]);
1584                         if (key.objectid == bytenr &&
1585                             key.offset == root->leafsize &&
1586                             key.type == BTRFS_EXTENT_ITEM_KEY)
1587                                 ret = 0;
1588                 }
1589                 if (ret) {
1590                         btrfs_release_path(path);
1591                         key.offset = root->leafsize;
1592                         key.type = BTRFS_EXTENT_ITEM_KEY;
1593                         goto again;
1594                 }
1595         }
1596
1597         if (ret != 0) {
1598                 btrfs_print_leaf(root, path->nodes[0]);
1599                 printk("failed to find block number %Lu\n",
1600                         (unsigned long long)bytenr);
1601                 BUG();
1602         }
1603         l = path->nodes[0];
1604         item_size = btrfs_item_size_nr(l, path->slots[0]);
1605 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1606         if (item_size < sizeof(*item)) {
1607                 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1608                                              path, (u64)-1, 0);
1609                 if (ret < 0)
1610                         goto out;
1611
1612                 l = path->nodes[0];
1613                 item_size = btrfs_item_size_nr(l, path->slots[0]);
1614         }
1615 #endif
1616         BUG_ON(item_size < sizeof(*item));
1617         item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1618         flags |= btrfs_extent_flags(l, item);
1619         btrfs_set_extent_flags(l, item, flags);
1620 out:
1621         btrfs_free_path(path);
1622         finish_current_insert(trans, root->fs_info->extent_root);
1623         del_pending_extents(trans, root->fs_info->extent_root);
1624         return ret;
1625 }
1626
1627 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
1628                            struct btrfs_root *root,
1629                            struct extent_buffer *buf,
1630                            int record_parent, int inc)
1631 {
1632         u64 bytenr;
1633         u64 num_bytes;
1634         u64 parent;
1635         u64 ref_root;
1636         u32 nritems;
1637         struct btrfs_key key;
1638         struct btrfs_file_extent_item *fi;
1639         int i;
1640         int level;
1641         int ret = 0;
1642         int (*process_func)(struct btrfs_trans_handle *trans,
1643                             struct btrfs_root *root,
1644                             u64, u64, u64, u64, u64, u64);
1645
1646         ref_root = btrfs_header_owner(buf);
1647         nritems = btrfs_header_nritems(buf);
1648         level = btrfs_header_level(buf);
1649
1650         if (!root->ref_cows && level == 0)
1651                 return 0;
1652
1653         if (inc)
1654                 process_func = btrfs_inc_extent_ref;
1655         else
1656                 process_func = btrfs_free_extent;
1657
1658         if (record_parent)
1659                 parent = buf->start;
1660         else
1661                 parent = 0;
1662
1663         for (i = 0; i < nritems; i++) {
1664                 cond_resched();
1665                 if (level == 0) {
1666                         btrfs_item_key_to_cpu(buf, &key, i);
1667                         if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1668                                 continue;
1669                         fi = btrfs_item_ptr(buf, i,
1670                                             struct btrfs_file_extent_item);
1671                         if (btrfs_file_extent_type(buf, fi) ==
1672                             BTRFS_FILE_EXTENT_INLINE)
1673                                 continue;
1674                         bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1675                         if (bytenr == 0)
1676                                 continue;
1677
1678                         num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
1679                         key.offset -= btrfs_file_extent_offset(buf, fi);
1680                         ret = process_func(trans, root, bytenr, num_bytes,
1681                                            parent, ref_root, key.objectid,
1682                                            key.offset);
1683                         if (ret) {
1684                                 WARN_ON(1);
1685                                 goto fail;
1686                         }
1687                 } else {
1688                         bytenr = btrfs_node_blockptr(buf, i);
1689                         num_bytes = btrfs_level_size(root, level - 1);
1690                         ret = process_func(trans, root, bytenr, num_bytes,
1691                                            parent, ref_root, level - 1, 0);
1692                         if (ret) {
1693                                 WARN_ON(1);
1694                                 goto fail;
1695                         }
1696                 }
1697         }
1698         return 0;
1699 fail:
1700         WARN_ON(1);
1701         return ret;
1702 }
1703
1704 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1705                   struct extent_buffer *buf, int record_parent)
1706 {
1707         return __btrfs_mod_ref(trans, root, buf, record_parent, 1);
1708 }
1709
1710 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1711                   struct extent_buffer *buf, int record_parent)
1712 {
1713         return __btrfs_mod_ref(trans, root, buf, record_parent, 0);
1714 }
1715
1716 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1717                                  struct btrfs_root *root,
1718                                  struct btrfs_path *path,
1719                                  struct btrfs_block_group_cache *cache)
1720 {
1721         int ret;
1722         int pending_ret;
1723         struct btrfs_root *extent_root = root->fs_info->extent_root;
1724         unsigned long bi;
1725         struct extent_buffer *leaf;
1726
1727         ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1728         if (ret < 0)
1729                 goto fail;
1730         BUG_ON(ret);
1731
1732         leaf = path->nodes[0];
1733         bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1734         write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1735         btrfs_mark_buffer_dirty(leaf);
1736         btrfs_release_path(path);
1737 fail:
1738         finish_current_insert(trans, extent_root);
1739         pending_ret = del_pending_extents(trans, extent_root);
1740         if (ret)
1741                 return ret;
1742         if (pending_ret)
1743                 return pending_ret;
1744         return 0;
1745
1746 }
1747
1748 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1749                                    struct btrfs_root *root)
1750 {
1751         struct extent_io_tree *block_group_cache;
1752         struct btrfs_block_group_cache *cache;
1753         int ret;
1754         struct btrfs_path *path;
1755         u64 last = 0;
1756         u64 start;
1757         u64 end;
1758         u64 ptr;
1759
1760         block_group_cache = &root->fs_info->block_group_cache;
1761         path = btrfs_alloc_path();
1762         if (!path)
1763                 return -ENOMEM;
1764
1765         while(1) {
1766                 ret = find_first_extent_bit(block_group_cache, last,
1767                                             &start, &end, BLOCK_GROUP_DIRTY);
1768                 if (ret) {
1769                         if (last == 0)
1770                                 break;
1771                         last = 0;
1772                         continue;
1773                 }
1774
1775                 last = end + 1;
1776                 ret = get_state_private(block_group_cache, start, &ptr);
1777                 BUG_ON(ret);
1778
1779                 clear_extent_bits(block_group_cache, start, end,
1780                                   BLOCK_GROUP_DIRTY, GFP_NOFS);
1781
1782                 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
1783                 ret = write_one_cache_group(trans, root, path, cache);
1784         }
1785         btrfs_free_path(path);
1786         return 0;
1787 }
1788
1789 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1790                                                   u64 flags)
1791 {
1792         struct btrfs_space_info *found;
1793
1794         flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
1795
1796         list_for_each_entry(found, &info->space_info, list) {
1797                 if (found->flags & flags)
1798                         return found;
1799         }
1800         return NULL;
1801
1802 }
1803
1804 static int free_space_info(struct btrfs_fs_info *fs_info, u64 flags,
1805                           u64 total_bytes, u64 bytes_used,
1806                           struct btrfs_space_info **space_info)
1807 {
1808         struct btrfs_space_info *found;
1809
1810         /* only support free block group which is empty */
1811         if (bytes_used)
1812                 return -ENOTEMPTY;
1813
1814         found = __find_space_info(fs_info, flags);
1815         if (!found)
1816                 return -ENOENT;
1817         if (found->total_bytes < total_bytes) {
1818                 fprintf(stderr,
1819                         "WARNING: bad space info to free %llu only have %llu\n",
1820                         total_bytes, found->total_bytes);
1821                 return -EINVAL;
1822         }
1823         found->total_bytes -= total_bytes;
1824         if (space_info)
1825                 *space_info = found;
1826         return 0;
1827 }
1828
1829 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1830                              u64 total_bytes, u64 bytes_used,
1831                              struct btrfs_space_info **space_info)
1832 {
1833         struct btrfs_space_info *found;
1834
1835         found = __find_space_info(info, flags);
1836         if (found) {
1837                 found->total_bytes += total_bytes;
1838                 found->bytes_used += bytes_used;
1839                 if (found->total_bytes < found->bytes_used) {
1840                         fprintf(stderr, "warning, bad space info total_bytes "
1841                                 "%llu used %llu\n",
1842                                (unsigned long long)found->total_bytes,
1843                                (unsigned long long)found->bytes_used);
1844                 }
1845                 *space_info = found;
1846                 return 0;
1847         }
1848         found = kmalloc(sizeof(*found), GFP_NOFS);
1849         if (!found)
1850                 return -ENOMEM;
1851
1852         list_add(&found->list, &info->space_info);
1853         found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
1854         found->total_bytes = total_bytes;
1855         found->bytes_used = bytes_used;
1856         found->bytes_pinned = 0;
1857         found->full = 0;
1858         *space_info = found;
1859         return 0;
1860 }
1861
1862
1863 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1864 {
1865         u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1866                                    BTRFS_BLOCK_GROUP_RAID1 |
1867                                    BTRFS_BLOCK_GROUP_RAID10 |
1868                                    BTRFS_BLOCK_GROUP_RAID5 |
1869                                    BTRFS_BLOCK_GROUP_RAID6 |
1870                                    BTRFS_BLOCK_GROUP_DUP);
1871         if (extra_flags) {
1872                 if (flags & BTRFS_BLOCK_GROUP_DATA)
1873                         fs_info->avail_data_alloc_bits |= extra_flags;
1874                 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1875                         fs_info->avail_metadata_alloc_bits |= extra_flags;
1876                 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1877                         fs_info->avail_system_alloc_bits |= extra_flags;
1878         }
1879 }
1880
1881 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1882                           struct btrfs_root *extent_root, u64 alloc_bytes,
1883                           u64 flags)
1884 {
1885         struct btrfs_space_info *space_info;
1886         u64 thresh;
1887         u64 start;
1888         u64 num_bytes;
1889         int ret;
1890
1891         space_info = __find_space_info(extent_root->fs_info, flags);
1892         if (!space_info) {
1893                 ret = update_space_info(extent_root->fs_info, flags,
1894                                         0, 0, &space_info);
1895                 BUG_ON(ret);
1896         }
1897         BUG_ON(!space_info);
1898
1899         if (space_info->full)
1900                 return 0;
1901
1902         thresh = div_factor(space_info->total_bytes, 7);
1903         if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1904             thresh)
1905                 return 0;
1906
1907         ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes,
1908                                 space_info->flags);
1909         if (ret == -ENOSPC) {
1910                 space_info->full = 1;
1911                 return 0;
1912         }
1913
1914         BUG_ON(ret);
1915
1916         ret = btrfs_make_block_group(trans, extent_root, 0, space_info->flags,
1917                      BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1918         BUG_ON(ret);
1919         return 0;
1920 }
1921
1922 static int update_block_group(struct btrfs_trans_handle *trans,
1923                               struct btrfs_root *root,
1924                               u64 bytenr, u64 num_bytes, int alloc,
1925                               int mark_free)
1926 {
1927         struct btrfs_block_group_cache *cache;
1928         struct btrfs_fs_info *info = root->fs_info;
1929         u64 total = num_bytes;
1930         u64 old_val;
1931         u64 byte_in_group;
1932         u64 start;
1933         u64 end;
1934
1935         /* block accounting for super block */
1936         old_val = btrfs_super_bytes_used(info->super_copy);
1937         if (alloc)
1938                 old_val += num_bytes;
1939         else
1940                 old_val -= num_bytes;
1941         btrfs_set_super_bytes_used(info->super_copy, old_val);
1942
1943         /* block accounting for root item */
1944         old_val = btrfs_root_used(&root->root_item);
1945         if (alloc)
1946                 old_val += num_bytes;
1947         else
1948                 old_val -= num_bytes;
1949         btrfs_set_root_used(&root->root_item, old_val);
1950
1951         while(total) {
1952                 cache = btrfs_lookup_block_group(info, bytenr);
1953                 if (!cache) {
1954                         return -1;
1955                 }
1956                 byte_in_group = bytenr - cache->key.objectid;
1957                 WARN_ON(byte_in_group > cache->key.offset);
1958                 start = cache->key.objectid;
1959                 end = start + cache->key.offset - 1;
1960                 set_extent_bits(&info->block_group_cache, start, end,
1961                                 BLOCK_GROUP_DIRTY, GFP_NOFS);
1962
1963                 old_val = btrfs_block_group_used(&cache->item);
1964                 num_bytes = min(total, cache->key.offset - byte_in_group);
1965
1966                 if (alloc) {
1967                         old_val += num_bytes;
1968                         cache->space_info->bytes_used += num_bytes;
1969                 } else {
1970                         old_val -= num_bytes;
1971                         cache->space_info->bytes_used -= num_bytes;
1972                         if (mark_free) {
1973                                 set_extent_dirty(&info->free_space_cache,
1974                                                  bytenr, bytenr + num_bytes - 1,
1975                                                  GFP_NOFS);
1976                         }
1977                 }
1978                 btrfs_set_block_group_used(&cache->item, old_val);
1979                 total -= num_bytes;
1980                 bytenr += num_bytes;
1981         }
1982         return 0;
1983 }
1984
1985 static int update_pinned_extents(struct btrfs_root *root,
1986                                 u64 bytenr, u64 num, int pin)
1987 {
1988         u64 len;
1989         struct btrfs_block_group_cache *cache;
1990         struct btrfs_fs_info *fs_info = root->fs_info;
1991
1992         if (pin) {
1993                 set_extent_dirty(&fs_info->pinned_extents,
1994                                 bytenr, bytenr + num - 1, GFP_NOFS);
1995         } else {
1996                 clear_extent_dirty(&fs_info->pinned_extents,
1997                                 bytenr, bytenr + num - 1, GFP_NOFS);
1998         }
1999         while (num > 0) {
2000                 cache = btrfs_lookup_block_group(fs_info, bytenr);
2001                 if (!cache) {
2002                         len = min((u64)root->sectorsize, num);
2003                         goto next;
2004                 }
2005                 WARN_ON(!cache);
2006                 len = min(num, cache->key.offset -
2007                           (bytenr - cache->key.objectid));
2008                 if (pin) {
2009                         cache->pinned += len;
2010                         cache->space_info->bytes_pinned += len;
2011                         fs_info->total_pinned += len;
2012                 } else {
2013                         cache->pinned -= len;
2014                         cache->space_info->bytes_pinned -= len;
2015                         fs_info->total_pinned -= len;
2016                 }
2017 next:
2018                 bytenr += len;
2019                 num -= len;
2020         }
2021         return 0;
2022 }
2023
2024 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
2025                                struct btrfs_root *root,
2026                                struct extent_io_tree *unpin)
2027 {
2028         u64 start;
2029         u64 end;
2030         int ret;
2031         struct extent_io_tree *free_space_cache;
2032         free_space_cache = &root->fs_info->free_space_cache;
2033
2034         while(1) {
2035                 ret = find_first_extent_bit(unpin, 0, &start, &end,
2036                                             EXTENT_DIRTY);
2037                 if (ret)
2038                         break;
2039                 update_pinned_extents(root, start, end + 1 - start, 0);
2040                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2041                 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
2042         }
2043         return 0;
2044 }
2045
2046 static int extent_root_pending_ops(struct btrfs_fs_info *info)
2047 {
2048         u64 start;
2049         u64 end;
2050         int ret;
2051
2052         ret = find_first_extent_bit(&info->extent_ins, 0, &start,
2053                                     &end, EXTENT_LOCKED);
2054         if (!ret) {
2055                 ret = find_first_extent_bit(&info->pending_del, 0, &start, &end,
2056                                             EXTENT_LOCKED);
2057         }
2058         return ret == 0;
2059
2060 }
2061 static int finish_current_insert(struct btrfs_trans_handle *trans,
2062                                  struct btrfs_root *extent_root)
2063 {
2064         u64 start;
2065         u64 end;
2066         u64 priv;
2067         struct btrfs_fs_info *info = extent_root->fs_info;
2068         struct pending_extent_op *extent_op;
2069         struct btrfs_key key;
2070         int ret;
2071         int skinny_metadata =
2072                 btrfs_fs_incompat(extent_root->fs_info,
2073                                   BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
2074
2075         while(1) {
2076                 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
2077                                             &end, EXTENT_LOCKED);
2078                 if (ret)
2079                         break;
2080
2081                 ret = get_state_private(&info->extent_ins, start, &priv);
2082                 BUG_ON(ret);
2083                 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2084
2085                 if (extent_op->type == PENDING_EXTENT_INSERT) {
2086                         key.objectid = start;
2087                         if (skinny_metadata) {
2088                                 key.offset = extent_op->level;
2089                                 key.type = BTRFS_METADATA_ITEM_KEY;
2090                         } else {
2091                                 key.offset = extent_op->num_bytes;
2092                                 key.type = BTRFS_EXTENT_ITEM_KEY;
2093                         }
2094                         ret = alloc_reserved_tree_block(trans, extent_root,
2095                                                 extent_root->root_key.objectid,
2096                                                 trans->transid,
2097                                                 extent_op->flags,
2098                                                 &extent_op->key,
2099                                                 extent_op->level, &key);
2100                         BUG_ON(ret);
2101                 } else {
2102                         BUG_ON(1);
2103                 }
2104
2105                 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
2106                                   GFP_NOFS);
2107                 kfree(extent_op);
2108         }
2109         return 0;
2110 }
2111
2112 static int pin_down_bytes(struct btrfs_trans_handle *trans,
2113                           struct btrfs_root *root,
2114                           u64 bytenr, u64 num_bytes, int is_data)
2115 {
2116         int err = 0;
2117         struct extent_buffer *buf;
2118
2119         if (is_data)
2120                 goto pinit;
2121
2122         buf = btrfs_find_tree_block(root, bytenr, num_bytes);
2123         if (!buf)
2124                 goto pinit;
2125
2126         /* we can reuse a block if it hasn't been written
2127          * and it is from this transaction.  We can't
2128          * reuse anything from the tree log root because
2129          * it has tiny sub-transactions.
2130          */
2131         if (btrfs_buffer_uptodate(buf, 0)) {
2132                 u64 header_owner = btrfs_header_owner(buf);
2133                 u64 header_transid = btrfs_header_generation(buf);
2134                 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
2135                     header_transid == trans->transid &&
2136                     !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
2137                         clean_tree_block(NULL, root, buf);
2138                         free_extent_buffer(buf);
2139                         return 1;
2140                 }
2141         }
2142         free_extent_buffer(buf);
2143 pinit:
2144         update_pinned_extents(root, bytenr, num_bytes, 1);
2145
2146         BUG_ON(err < 0);
2147         return 0;
2148 }
2149
2150 void btrfs_pin_extent(struct btrfs_fs_info *fs_info,
2151                        u64 bytenr, u64 num_bytes)
2152 {
2153         update_pinned_extents(fs_info->extent_root, bytenr, num_bytes, 1);
2154 }
2155
2156 void btrfs_unpin_extent(struct btrfs_fs_info *fs_info,
2157                         u64 bytenr, u64 num_bytes)
2158 {
2159         update_pinned_extents(fs_info->extent_root, bytenr, num_bytes, 0);
2160 }
2161
2162 /*
2163  * remove an extent from the root, returns 0 on success
2164  */
2165 static int __free_extent(struct btrfs_trans_handle *trans,
2166                          struct btrfs_root *root,
2167                          u64 bytenr, u64 num_bytes, u64 parent,
2168                          u64 root_objectid, u64 owner_objectid,
2169                          u64 owner_offset, int refs_to_drop)
2170 {
2171
2172         struct btrfs_key key;
2173         struct btrfs_path *path;
2174         struct btrfs_extent_ops *ops = root->fs_info->extent_ops;
2175         struct btrfs_root *extent_root = root->fs_info->extent_root;
2176         struct extent_buffer *leaf;
2177         struct btrfs_extent_item *ei;
2178         struct btrfs_extent_inline_ref *iref;
2179         int ret;
2180         int is_data;
2181         int extent_slot = 0;
2182         int found_extent = 0;
2183         int num_to_del = 1;
2184         u32 item_size;
2185         u64 refs;
2186         int skinny_metadata =
2187                 btrfs_fs_incompat(extent_root->fs_info,
2188                                   BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
2189
2190         if (root->fs_info->free_extent_hook) {
2191                 root->fs_info->free_extent_hook(trans, root, bytenr, num_bytes,
2192                                                 parent, root_objectid, owner_objectid,
2193                                                 owner_offset, refs_to_drop);
2194
2195         }
2196         path = btrfs_alloc_path();
2197         if (!path)
2198                 return -ENOMEM;
2199
2200         path->reada = 1;
2201
2202         is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
2203         if (is_data)
2204                 skinny_metadata = 0;
2205         BUG_ON(!is_data && refs_to_drop != 1);
2206
2207         ret = lookup_extent_backref(trans, extent_root, path, &iref,
2208                                     bytenr, num_bytes, parent,
2209                                     root_objectid, owner_objectid,
2210                                     owner_offset);
2211         if (ret == 0) {
2212                 extent_slot = path->slots[0];
2213                 while (extent_slot >= 0) {
2214                         btrfs_item_key_to_cpu(path->nodes[0], &key,
2215                                               extent_slot);
2216                         if (key.objectid != bytenr)
2217                                 break;
2218                         if (key.type == BTRFS_EXTENT_ITEM_KEY &&
2219                             key.offset == num_bytes) {
2220                                 found_extent = 1;
2221                                 break;
2222                         }
2223                         if (key.type == BTRFS_METADATA_ITEM_KEY &&
2224                             key.offset == owner_objectid) {
2225                                 found_extent = 1;
2226                                 break;
2227                         }
2228                         if (path->slots[0] - extent_slot > 5)
2229                                 break;
2230                         extent_slot--;
2231                 }
2232 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2233                 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
2234                 if (found_extent && item_size < sizeof(*ei))
2235                         found_extent = 0;
2236 #endif
2237                 if (!found_extent) {
2238                         BUG_ON(iref);
2239                         ret = remove_extent_backref(trans, extent_root, path,
2240                                                     NULL, refs_to_drop,
2241                                                     is_data);
2242                         BUG_ON(ret);
2243                         btrfs_release_path(path);
2244
2245                         key.objectid = bytenr;
2246
2247                         if (skinny_metadata) {
2248                                 key.type = BTRFS_METADATA_ITEM_KEY;
2249                                 key.offset = owner_objectid;
2250                         } else {
2251                                 key.type = BTRFS_EXTENT_ITEM_KEY;
2252                                 key.offset = num_bytes;
2253                         }
2254
2255                         ret = btrfs_search_slot(trans, extent_root,
2256                                                 &key, path, -1, 1);
2257                         if (ret > 0 && skinny_metadata && path->slots[0]) {
2258                                 path->slots[0]--;
2259                                 btrfs_item_key_to_cpu(path->nodes[0],
2260                                                       &key,
2261                                                       path->slots[0]);
2262                                 if (key.objectid == bytenr &&
2263                                     key.type == BTRFS_EXTENT_ITEM_KEY &&
2264                                     key.offset == num_bytes)
2265                                         ret = 0;
2266                         }
2267
2268                         if (ret > 0 && skinny_metadata) {
2269                                 skinny_metadata = 0;
2270                                 btrfs_release_path(path);
2271                                 key.type = BTRFS_EXTENT_ITEM_KEY;
2272                                 key.offset = num_bytes;
2273                                 ret = btrfs_search_slot(trans, extent_root,
2274                                                         &key, path, -1, 1);
2275                         }
2276
2277                         if (ret) {
2278                                 printk(KERN_ERR "umm, got %d back from search"
2279                                        ", was looking for %llu\n", ret,
2280                                        (unsigned long long)bytenr);
2281                                 btrfs_print_leaf(extent_root, path->nodes[0]);
2282                         }
2283                         BUG_ON(ret);
2284                         extent_slot = path->slots[0];
2285                 }
2286         } else {
2287                 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
2288                        "parent %llu root %llu  owner %llu offset %llu\n",
2289                        (unsigned long long)bytenr,
2290                        (unsigned long long)parent,
2291                        (unsigned long long)root_objectid,
2292                        (unsigned long long)owner_objectid,
2293                        (unsigned long long)owner_offset);
2294                 ret = -EIO;
2295                 goto fail;
2296         }
2297
2298         leaf = path->nodes[0];
2299         item_size = btrfs_item_size_nr(leaf, extent_slot);
2300 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2301         if (item_size < sizeof(*ei)) {
2302                 BUG_ON(found_extent || extent_slot != path->slots[0]);
2303                 ret = convert_extent_item_v0(trans, extent_root, path,
2304                                              owner_objectid, 0);
2305                 BUG_ON(ret < 0);
2306
2307                 btrfs_release_path(path);
2308
2309                 key.objectid = bytenr;
2310                 key.type = BTRFS_EXTENT_ITEM_KEY;
2311                 key.offset = num_bytes;
2312
2313                 ret = btrfs_search_slot(trans, extent_root, &key, path,
2314                                         -1, 1);
2315                 if (ret) {
2316                         printk(KERN_ERR "umm, got %d back from search"
2317                                ", was looking for %llu\n", ret,
2318                                (unsigned long long)bytenr);
2319                         btrfs_print_leaf(extent_root, path->nodes[0]);
2320                 }
2321                 BUG_ON(ret);
2322                 extent_slot = path->slots[0];
2323                 leaf = path->nodes[0];
2324                 item_size = btrfs_item_size_nr(leaf, extent_slot);
2325         }
2326 #endif
2327         BUG_ON(item_size < sizeof(*ei));
2328         ei = btrfs_item_ptr(leaf, extent_slot,
2329                             struct btrfs_extent_item);
2330         if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
2331             key.type == BTRFS_EXTENT_ITEM_KEY) {
2332                 struct btrfs_tree_block_info *bi;
2333                 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
2334                 bi = (struct btrfs_tree_block_info *)(ei + 1);
2335                 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
2336         }
2337
2338         refs = btrfs_extent_refs(leaf, ei);
2339         BUG_ON(refs < refs_to_drop);
2340         refs -= refs_to_drop;
2341
2342         if (refs > 0) {
2343                 /*
2344                  * In the case of inline back ref, reference count will
2345                  * be updated by remove_extent_backref
2346                  */
2347                 if (iref) {
2348                         BUG_ON(!found_extent);
2349                 } else {
2350                         btrfs_set_extent_refs(leaf, ei, refs);
2351                         btrfs_mark_buffer_dirty(leaf);
2352                 }
2353                 if (found_extent) {
2354                         ret = remove_extent_backref(trans, extent_root, path,
2355                                                     iref, refs_to_drop,
2356                                                     is_data);
2357                         BUG_ON(ret);
2358                 }
2359         } else {
2360                 int mark_free = 0;
2361                 int pin = 1;
2362
2363                 if (found_extent) {
2364                         BUG_ON(is_data && refs_to_drop !=
2365                                extent_data_ref_count(root, path, iref));
2366                         if (iref) {
2367                                 BUG_ON(path->slots[0] != extent_slot);
2368                         } else {
2369                                 BUG_ON(path->slots[0] != extent_slot + 1);
2370                                 path->slots[0] = extent_slot;
2371                                 num_to_del = 2;
2372                         }
2373                 }
2374
2375                 if (ops && ops->free_extent) {
2376                         ret = ops->free_extent(root, bytenr, num_bytes);
2377                         if (ret > 0) {
2378                                 pin = 0;
2379                                 mark_free = 0;
2380                         }
2381                 }
2382
2383                 if (pin) {
2384                         ret = pin_down_bytes(trans, root, bytenr, num_bytes,
2385                                              is_data);
2386                         if (ret > 0)
2387                                 mark_free = 1;
2388                         BUG_ON(ret < 0);
2389                 }
2390
2391                 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2392                                       num_to_del);
2393                 BUG_ON(ret);
2394                 btrfs_release_path(path);
2395
2396                 if (is_data) {
2397                         ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
2398                         BUG_ON(ret);
2399                 }
2400
2401                 update_block_group(trans, root, bytenr, num_bytes, 0, mark_free);
2402         }
2403 fail:
2404         btrfs_free_path(path);
2405         finish_current_insert(trans, extent_root);
2406         return ret;
2407 }
2408
2409 /*
2410  * find all the blocks marked as pending in the radix tree and remove
2411  * them from the extent map
2412  */
2413 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2414                                btrfs_root *extent_root)
2415 {
2416         int ret;
2417         int err = 0;
2418         u64 start;
2419         u64 end;
2420         u64 priv;
2421         struct extent_io_tree *pending_del;
2422         struct extent_io_tree *extent_ins;
2423         struct pending_extent_op *extent_op;
2424
2425         extent_ins = &extent_root->fs_info->extent_ins;
2426         pending_del = &extent_root->fs_info->pending_del;
2427
2428         while(1) {
2429                 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2430                                             EXTENT_LOCKED);
2431                 if (ret)
2432                         break;
2433
2434                 ret = get_state_private(pending_del, start, &priv);
2435                 BUG_ON(ret);
2436                 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2437
2438                 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
2439                                   GFP_NOFS);
2440
2441                 if (!test_range_bit(extent_ins, start, end,
2442                                     EXTENT_LOCKED, 0)) {
2443                         ret = __free_extent(trans, extent_root,
2444                                             start, end + 1 - start, 0,
2445                                             extent_root->root_key.objectid,
2446                                             extent_op->level, 0, 1);
2447                         kfree(extent_op);
2448                 } else {
2449                         kfree(extent_op);
2450                         ret = get_state_private(extent_ins, start, &priv);
2451                         BUG_ON(ret);
2452                         extent_op = (struct pending_extent_op *)
2453                                                         (unsigned long)priv;
2454
2455                         clear_extent_bits(extent_ins, start, end,
2456                                           EXTENT_LOCKED, GFP_NOFS);
2457
2458                         if (extent_op->type == PENDING_BACKREF_UPDATE)
2459                                 BUG_ON(1);
2460
2461                         kfree(extent_op);
2462                 }
2463                 if (ret)
2464                         err = ret;
2465         }
2466         return err;
2467 }
2468
2469 /*
2470  * remove an extent from the root, returns 0 on success
2471  */
2472
2473 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2474                       struct btrfs_root *root,
2475                       u64 bytenr, u64 num_bytes, u64 parent,
2476                       u64 root_objectid, u64 owner, u64 offset)
2477 {
2478         struct btrfs_root *extent_root = root->fs_info->extent_root;
2479         int pending_ret;
2480         int ret;
2481
2482         WARN_ON(num_bytes < root->sectorsize);
2483         if (root == extent_root) {
2484                 struct pending_extent_op *extent_op;
2485
2486                 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2487                 BUG_ON(!extent_op);
2488
2489                 extent_op->type = PENDING_EXTENT_DELETE;
2490                 extent_op->bytenr = bytenr;
2491                 extent_op->num_bytes = num_bytes;
2492                 extent_op->level = (int)owner;
2493
2494                 set_extent_bits(&root->fs_info->pending_del,
2495                                 bytenr, bytenr + num_bytes - 1,
2496                                 EXTENT_LOCKED, GFP_NOFS);
2497                 set_state_private(&root->fs_info->pending_del,
2498                                   bytenr, (unsigned long)extent_op);
2499                 return 0;
2500         }
2501         ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2502                             root_objectid, owner, offset, 1);
2503         pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2504         return ret ? ret : pending_ret;
2505 }
2506
2507 static u64 stripe_align(struct btrfs_root *root, u64 val)
2508 {
2509         u64 mask = ((u64)root->stripesize - 1);
2510         u64 ret = (val + mask) & ~mask;
2511         return ret;
2512 }
2513
2514 /*
2515  * walks the btree of allocated extents and find a hole of a given size.
2516  * The key ins is changed to record the hole:
2517  * ins->objectid == block start
2518  * ins->flags = BTRFS_EXTENT_ITEM_KEY
2519  * ins->offset == number of blocks
2520  * Any available blocks before search_start are skipped.
2521  */
2522 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2523                                      struct btrfs_root *orig_root,
2524                                      u64 num_bytes, u64 empty_size,
2525                                      u64 search_start, u64 search_end,
2526                                      u64 hint_byte, struct btrfs_key *ins,
2527                                      u64 exclude_start, u64 exclude_nr,
2528                                      int data)
2529 {
2530         int ret;
2531         u64 orig_search_start = search_start;
2532         struct btrfs_root * root = orig_root->fs_info->extent_root;
2533         struct btrfs_fs_info *info = root->fs_info;
2534         u64 total_needed = num_bytes;
2535         struct btrfs_block_group_cache *block_group;
2536         int full_scan = 0;
2537         int wrapped = 0;
2538
2539         WARN_ON(num_bytes < root->sectorsize);
2540         btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2541
2542         search_start = stripe_align(root, search_start);
2543
2544         if (hint_byte) {
2545                 block_group = btrfs_lookup_first_block_group(info, hint_byte);
2546                 if (!block_group)
2547                         hint_byte = search_start;
2548                 block_group = btrfs_find_block_group(root, block_group,
2549                                                      hint_byte, data, 1);
2550         } else {
2551                 block_group = btrfs_find_block_group(root,
2552                                                      trans->block_group,
2553                                                      search_start, data, 1);
2554         }
2555
2556         total_needed += empty_size;
2557
2558 check_failed:
2559         search_start = stripe_align(root, search_start);
2560         if (!block_group) {
2561                 block_group = btrfs_lookup_first_block_group(info,
2562                                                              search_start);
2563                 if (!block_group)
2564                         block_group = btrfs_lookup_first_block_group(info,
2565                                                        orig_search_start);
2566         }
2567         ret = find_search_start(root, &block_group, &search_start,
2568                                 total_needed, data);
2569         if (ret)
2570                 goto new_group;
2571
2572         ins->objectid = search_start;
2573         ins->offset = num_bytes;
2574
2575         if (ins->objectid + num_bytes >
2576             block_group->key.objectid + block_group->key.offset) {
2577                 search_start = block_group->key.objectid +
2578                         block_group->key.offset;
2579                 goto new_group;
2580         }
2581
2582         if (test_range_bit(&info->extent_ins, ins->objectid,
2583                            ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
2584                 search_start = ins->objectid + num_bytes;
2585                 goto new_group;
2586         }
2587
2588         if (test_range_bit(&info->pinned_extents, ins->objectid,
2589                            ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2590                 search_start = ins->objectid + num_bytes;
2591                 goto new_group;
2592         }
2593
2594         if (info->excluded_extents &&
2595             test_range_bit(info->excluded_extents, ins->objectid,
2596                            ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2597                 search_start = ins->objectid + num_bytes;
2598                 goto new_group;
2599         }
2600
2601         if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2602             ins->objectid < exclude_start + exclude_nr)) {
2603                 search_start = exclude_start + exclude_nr;
2604                 goto new_group;
2605         }
2606
2607         if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
2608                 block_group = btrfs_lookup_block_group(info, ins->objectid);
2609                 if (block_group)
2610                         trans->block_group = block_group;
2611         }
2612         ins->offset = num_bytes;
2613         return 0;
2614
2615 new_group:
2616         block_group = btrfs_lookup_first_block_group(info, search_start);
2617         if (!block_group) {
2618                 search_start = orig_search_start;
2619                 if (full_scan) {
2620                         ret = -ENOSPC;
2621                         goto error;
2622                 }
2623                 if (wrapped) {
2624                         if (!full_scan)
2625                                 total_needed -= empty_size;
2626                         full_scan = 1;
2627                 } else
2628                         wrapped = 1;
2629         }
2630         cond_resched();
2631         block_group = btrfs_find_block_group(root, block_group,
2632                                              search_start, data, 0);
2633         goto check_failed;
2634
2635 error:
2636         return ret;
2637 }
2638
2639 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2640                          struct btrfs_root *root,
2641                          u64 num_bytes, u64 empty_size,
2642                          u64 hint_byte, u64 search_end,
2643                          struct btrfs_key *ins, int data)
2644 {
2645         int ret;
2646         u64 search_start = 0;
2647         u64 alloc_profile;
2648         struct btrfs_fs_info *info = root->fs_info;
2649
2650         if (info->extent_ops) {
2651                 struct btrfs_extent_ops *ops = info->extent_ops;
2652                 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
2653                 BUG_ON(ret);
2654                 goto found;
2655         }
2656
2657         if (data) {
2658                 alloc_profile = info->avail_data_alloc_bits &
2659                                 info->data_alloc_profile;
2660                 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2661         } else if ((info->system_allocs > 0 || root == info->chunk_root) &&
2662                    info->system_allocs >= 0) {
2663                 alloc_profile = info->avail_system_alloc_bits &
2664                                 info->system_alloc_profile;
2665                 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2666         } else {
2667                 alloc_profile = info->avail_metadata_alloc_bits &
2668                                 info->metadata_alloc_profile;
2669                 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2670         }
2671
2672         if (root->ref_cows) {
2673                 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2674                         ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2675                                              num_bytes,
2676                                              BTRFS_BLOCK_GROUP_METADATA);
2677                         BUG_ON(ret);
2678                 }
2679                 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2680                                      num_bytes + 2 * 1024 * 1024, data);
2681                 BUG_ON(ret);
2682         }
2683
2684         WARN_ON(num_bytes < root->sectorsize);
2685         ret = find_free_extent(trans, root, num_bytes, empty_size,
2686                                search_start, search_end, hint_byte, ins,
2687                                trans->alloc_exclude_start,
2688                                trans->alloc_exclude_nr, data);
2689         BUG_ON(ret);
2690 found:
2691         clear_extent_dirty(&root->fs_info->free_space_cache,
2692                            ins->objectid, ins->objectid + ins->offset - 1,
2693                            GFP_NOFS);
2694         return ret;
2695 }
2696
2697 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
2698                                      struct btrfs_root *root,
2699                                      u64 root_objectid, u64 generation,
2700                                      u64 flags, struct btrfs_disk_key *key,
2701                                      int level, struct btrfs_key *ins)
2702 {
2703         int ret;
2704         struct btrfs_fs_info *fs_info = root->fs_info;
2705         struct btrfs_extent_item *extent_item;
2706         struct btrfs_tree_block_info *block_info;
2707         struct btrfs_extent_inline_ref *iref;
2708         struct btrfs_path *path;
2709         struct extent_buffer *leaf;
2710         u32 size = sizeof(*extent_item) + sizeof(*iref);
2711         int skinny_metadata =
2712                 btrfs_fs_incompat(fs_info,
2713                                   BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
2714
2715         if (!skinny_metadata)
2716                 size += sizeof(*block_info);
2717
2718         path = btrfs_alloc_path();
2719         BUG_ON(!path);
2720
2721         ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
2722                                       ins, size);
2723         BUG_ON(ret);
2724
2725         leaf = path->nodes[0];
2726         extent_item = btrfs_item_ptr(leaf, path->slots[0],
2727                                      struct btrfs_extent_item);
2728         btrfs_set_extent_refs(leaf, extent_item, 1);
2729         btrfs_set_extent_generation(leaf, extent_item, generation);
2730         btrfs_set_extent_flags(leaf, extent_item,
2731                                flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
2732
2733         if (skinny_metadata) {
2734                 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
2735         } else {
2736                 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
2737                 btrfs_set_tree_block_key(leaf, block_info, key);
2738                 btrfs_set_tree_block_level(leaf, block_info, level);
2739                 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
2740         }
2741
2742         btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_TREE_BLOCK_REF_KEY);
2743         btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
2744
2745         btrfs_mark_buffer_dirty(leaf);
2746         btrfs_free_path(path);
2747
2748         ret = update_block_group(trans, root, ins->objectid, root->leafsize,
2749                                  1, 0);
2750         return ret;
2751 }
2752
2753 static int alloc_tree_block(struct btrfs_trans_handle *trans,
2754                             struct btrfs_root *root, u64 num_bytes,
2755                             u64 root_objectid, u64 generation,
2756                             u64 flags, struct btrfs_disk_key *key,
2757                             int level, u64 empty_size, u64 hint_byte,
2758                             u64 search_end, struct btrfs_key *ins)
2759 {
2760         int ret;
2761         ret = btrfs_reserve_extent(trans, root, num_bytes, empty_size,
2762                                    hint_byte, search_end, ins, 0);
2763         BUG_ON(ret);
2764
2765         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) {
2766                 struct pending_extent_op *extent_op;
2767
2768                 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2769                 BUG_ON(!extent_op);
2770
2771                 extent_op->type = PENDING_EXTENT_INSERT;
2772                 extent_op->bytenr = ins->objectid;
2773                 extent_op->num_bytes = ins->offset;
2774                 extent_op->level = level;
2775                 extent_op->flags = flags;
2776                 memcpy(&extent_op->key, key, sizeof(*key));
2777
2778                 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2779                                 ins->objectid + ins->offset - 1,
2780                                 EXTENT_LOCKED, GFP_NOFS);
2781                 set_state_private(&root->fs_info->extent_ins,
2782                                   ins->objectid, (unsigned long)extent_op);
2783         } else {
2784                 if (btrfs_fs_incompat(root->fs_info,
2785                                 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)) {
2786                         ins->offset = level;
2787                         ins->type = BTRFS_METADATA_ITEM_KEY;
2788                 }
2789                 ret = alloc_reserved_tree_block(trans, root, root_objectid,
2790                                                 generation, flags,
2791                                                 key, level, ins);
2792                 finish_current_insert(trans, root->fs_info->extent_root);
2793                 del_pending_extents(trans, root->fs_info->extent_root);
2794         }
2795         return ret;
2796 }
2797
2798 /*
2799  * helper function to allocate a block for a given tree
2800  * returns the tree buffer or NULL.
2801  */
2802 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2803                                         struct btrfs_root *root,
2804                                         u32 blocksize, u64 root_objectid,
2805                                         struct btrfs_disk_key *key, int level,
2806                                         u64 hint, u64 empty_size)
2807 {
2808         struct btrfs_key ins;
2809         int ret;
2810         struct extent_buffer *buf;
2811
2812         ret = alloc_tree_block(trans, root, blocksize, root_objectid,
2813                                trans->transid, 0, key, level,
2814                                empty_size, hint, (u64)-1, &ins);
2815         if (ret) {
2816                 BUG_ON(ret > 0);
2817                 return ERR_PTR(ret);
2818         }
2819
2820         buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
2821         if (!buf) {
2822                 btrfs_free_extent(trans, root, ins.objectid, ins.offset,
2823                                   0, root->root_key.objectid, level, 0);
2824                 BUG_ON(1);
2825                 return ERR_PTR(-ENOMEM);
2826         }
2827         btrfs_set_buffer_uptodate(buf);
2828         trans->blocks_used++;
2829
2830         return buf;
2831 }
2832
2833 #if 0
2834
2835 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
2836                                   struct btrfs_root *root,
2837                                   struct extent_buffer *leaf)
2838 {
2839         u64 leaf_owner;
2840         u64 leaf_generation;
2841         struct btrfs_key key;
2842         struct btrfs_file_extent_item *fi;
2843         int i;
2844         int nritems;
2845         int ret;
2846
2847         BUG_ON(!btrfs_is_leaf(leaf));
2848         nritems = btrfs_header_nritems(leaf);
2849         leaf_owner = btrfs_header_owner(leaf);
2850         leaf_generation = btrfs_header_generation(leaf);
2851
2852         for (i = 0; i < nritems; i++) {
2853                 u64 disk_bytenr;
2854
2855                 btrfs_item_key_to_cpu(leaf, &key, i);
2856                 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2857                         continue;
2858                 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2859                 if (btrfs_file_extent_type(leaf, fi) ==
2860                     BTRFS_FILE_EXTENT_INLINE)
2861                         continue;
2862                 /*
2863                  * FIXME make sure to insert a trans record that
2864                  * repeats the snapshot del on crash
2865                  */
2866                 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2867                 if (disk_bytenr == 0)
2868                         continue;
2869                 ret = btrfs_free_extent(trans, root, disk_bytenr,
2870                                 btrfs_file_extent_disk_num_bytes(leaf, fi),
2871                                 leaf->start, leaf_owner, leaf_generation,
2872                                 key.objectid, 0);
2873                 BUG_ON(ret);
2874         }
2875         return 0;
2876 }
2877
2878 static void noinline reada_walk_down(struct btrfs_root *root,
2879                                      struct extent_buffer *node,
2880                                      int slot)
2881 {
2882         u64 bytenr;
2883         u64 last = 0;
2884         u32 nritems;
2885         u32 refs;
2886         u32 blocksize;
2887         int ret;
2888         int i;
2889         int level;
2890         int skipped = 0;
2891
2892         nritems = btrfs_header_nritems(node);
2893         level = btrfs_header_level(node);
2894         if (level)
2895                 return;
2896
2897         for (i = slot; i < nritems && skipped < 32; i++) {
2898                 bytenr = btrfs_node_blockptr(node, i);
2899                 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
2900                              (last > bytenr && last - bytenr > 32 * 1024))) {
2901                         skipped++;
2902                         continue;
2903                 }
2904                 blocksize = btrfs_level_size(root, level - 1);
2905                 if (i != slot) {
2906                         ret = btrfs_lookup_extent_ref(NULL, root, bytenr,
2907                                                       blocksize, &refs);
2908                         BUG_ON(ret);
2909                         if (refs != 1) {
2910                                 skipped++;
2911                                 continue;
2912                         }
2913                 }
2914                 mutex_unlock(&root->fs_info->fs_mutex);
2915                 ret = readahead_tree_block(root, bytenr, blocksize,
2916                                            btrfs_node_ptr_generation(node, i));
2917                 last = bytenr + blocksize;
2918                 cond_resched();
2919                 mutex_lock(&root->fs_info->fs_mutex);
2920                 if (ret)
2921                         break;
2922         }
2923 }
2924
2925 /*
2926  * helper function for drop_snapshot, this walks down the tree dropping ref
2927  * counts as it goes.
2928  */
2929 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2930                                    struct btrfs_root *root,
2931                                    struct btrfs_path *path, int *level)
2932 {
2933         u64 root_owner;
2934         u64 root_gen;
2935         u64 bytenr;
2936         u64 ptr_gen;
2937         struct extent_buffer *next;
2938         struct extent_buffer *cur;
2939         struct extent_buffer *parent;
2940         u32 blocksize;
2941         int ret;
2942         u32 refs;
2943
2944         WARN_ON(*level < 0);
2945         WARN_ON(*level >= BTRFS_MAX_LEVEL);
2946         ret = btrfs_lookup_extent_ref(trans, root,
2947                                       path->nodes[*level]->start,
2948                                       path->nodes[*level]->len, &refs);
2949         BUG_ON(ret);
2950         if (refs > 1)
2951                 goto out;
2952
2953         /*
2954          * walk down to the last node level and free all the leaves
2955          */
2956         while(*level >= 0) {
2957                 WARN_ON(*level < 0);
2958                 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2959                 cur = path->nodes[*level];
2960
2961                 if (btrfs_header_level(cur) != *level)
2962                         WARN_ON(1);
2963
2964                 if (path->slots[*level] >=
2965                     btrfs_header_nritems(cur))
2966                         break;
2967                 if (*level == 0) {
2968                         ret = drop_leaf_ref(trans, root, cur);
2969                         BUG_ON(ret);
2970                         break;
2971                 }
2972                 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2973                 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2974                 blocksize = btrfs_level_size(root, *level - 1);
2975                 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
2976                                               &refs);
2977                 BUG_ON(ret);
2978                 if (refs != 1) {
2979                         parent = path->nodes[*level];
2980                         root_owner = btrfs_header_owner(parent);
2981                         root_gen = btrfs_header_generation(parent);
2982                         path->slots[*level]++;
2983                         ret = btrfs_free_extent(trans, root, bytenr, blocksize,
2984                                                 parent->start, root_owner,
2985                                                 root_gen, *level - 1, 1);
2986                         BUG_ON(ret);
2987                         continue;
2988                 }
2989                 next = btrfs_find_tree_block(root, bytenr, blocksize);
2990                 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2991                         free_extent_buffer(next);
2992                         reada_walk_down(root, cur, path->slots[*level]);
2993                         mutex_unlock(&root->fs_info->fs_mutex);
2994                         next = read_tree_block(root, bytenr, blocksize,
2995                                                ptr_gen);
2996                         mutex_lock(&root->fs_info->fs_mutex);
2997                         if (!extent_buffer_uptodate(next)) {
2998                                 if (IS_ERR(next))
2999                                         ret = PTR_ERR(next);
3000                                 else
3001                                         ret = -EIO;
3002                                 break;
3003                         }
3004                 }
3005                 WARN_ON(*level <= 0);
3006                 if (path->nodes[*level-1])
3007                         free_extent_buffer(path->nodes[*level-1]);
3008                 path->nodes[*level-1] = next;
3009                 *level = btrfs_header_level(next);
3010                 path->slots[*level] = 0;
3011         }
3012 out:
3013         WARN_ON(*level < 0);
3014         WARN_ON(*level >= BTRFS_MAX_LEVEL);
3015
3016         if (path->nodes[*level] == root->node) {
3017                 root_owner = root->root_key.objectid;
3018                 parent = path->nodes[*level];
3019         } else {
3020                 parent = path->nodes[*level + 1];
3021                 root_owner = btrfs_header_owner(parent);
3022         }
3023
3024         root_gen = btrfs_header_generation(parent);
3025         ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
3026                                 path->nodes[*level]->len, parent->start,
3027                                 root_owner, root_gen, *level, 1);
3028         free_extent_buffer(path->nodes[*level]);
3029         path->nodes[*level] = NULL;
3030         *level += 1;
3031         BUG_ON(ret);
3032         return 0;
3033 }
3034
3035 /*
3036  * helper for dropping snapshots.  This walks back up the tree in the path
3037  * to find the first node higher up where we haven't yet gone through
3038  * all the slots
3039  */
3040 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3041                                  struct btrfs_root *root,
3042                                  struct btrfs_path *path, int *level)
3043 {
3044         u64 root_owner;
3045         u64 root_gen;
3046         struct btrfs_root_item *root_item = &root->root_item;
3047         int i;
3048         int slot;
3049         int ret;
3050
3051         for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
3052                 slot = path->slots[i];
3053                 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3054                         struct extent_buffer *node;
3055                         struct btrfs_disk_key disk_key;
3056                         node = path->nodes[i];
3057                         path->slots[i]++;
3058                         *level = i;
3059                         WARN_ON(*level == 0);
3060                         btrfs_node_key(node, &disk_key, path->slots[i]);
3061                         memcpy(&root_item->drop_progress,
3062                                &disk_key, sizeof(disk_key));
3063                         root_item->drop_level = i;
3064                         return 0;
3065                 } else {
3066                         struct extent_buffer *parent;
3067                         if (path->nodes[*level] == root->node)
3068                                 parent = path->nodes[*level];
3069                         else
3070                                 parent = path->nodes[*level + 1];
3071
3072                         root_owner = btrfs_header_owner(parent);
3073                         root_gen = btrfs_header_generation(parent);
3074                         ret = btrfs_free_extent(trans, root,
3075                                                 path->nodes[*level]->start,
3076                                                 path->nodes[*level]->len,
3077                                                 parent->start, root_owner,
3078                                                 root_gen, *level, 1);
3079                         BUG_ON(ret);
3080                         free_extent_buffer(path->nodes[*level]);
3081                         path->nodes[*level] = NULL;
3082                         *level = i + 1;
3083                 }
3084         }
3085         return 1;
3086 }
3087
3088 #endif
3089
3090 int btrfs_free_block_groups(struct btrfs_fs_info *info)
3091 {
3092         struct btrfs_space_info *sinfo;
3093         struct btrfs_block_group_cache *cache;
3094         u64 start;
3095         u64 end;
3096         u64 ptr;
3097         int ret;
3098
3099         while(1) {
3100                 ret = find_first_extent_bit(&info->block_group_cache, 0,
3101                                             &start, &end, (unsigned int)-1);
3102                 if (ret)
3103                         break;
3104                 ret = get_state_private(&info->block_group_cache, start, &ptr);
3105                 if (!ret) {
3106                         cache = u64_to_ptr(ptr);
3107                         if (cache->free_space_ctl) {
3108                                 btrfs_remove_free_space_cache(cache);
3109                                 kfree(cache->free_space_ctl);
3110                         }
3111                         kfree(cache);
3112                 }
3113                 clear_extent_bits(&info->block_group_cache, start,
3114                                   end, (unsigned int)-1, GFP_NOFS);
3115         }
3116         while(1) {
3117                 ret = find_first_extent_bit(&info->free_space_cache, 0,
3118                                             &start, &end, EXTENT_DIRTY);
3119                 if (ret)
3120                         break;
3121                 clear_extent_dirty(&info->free_space_cache, start,
3122                                    end, GFP_NOFS);
3123         }
3124
3125         while (!list_empty(&info->space_info)) {
3126                 sinfo = list_entry(info->space_info.next,
3127                                    struct btrfs_space_info, list);
3128                 list_del_init(&sinfo->list);
3129                 kfree(sinfo);
3130         }
3131         return 0;
3132 }
3133
3134 static int find_first_block_group(struct btrfs_root *root,
3135                 struct btrfs_path *path, struct btrfs_key *key)
3136 {
3137         int ret;
3138         struct btrfs_key found_key;
3139         struct extent_buffer *leaf;
3140         int slot;
3141
3142         ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
3143         if (ret < 0)
3144                 return ret;
3145         while(1) {
3146                 slot = path->slots[0];
3147                 leaf = path->nodes[0];
3148                 if (slot >= btrfs_header_nritems(leaf)) {
3149                         ret = btrfs_next_leaf(root, path);
3150                         if (ret == 0)
3151                                 continue;
3152                         if (ret < 0)
3153                                 goto error;
3154                         break;
3155                 }
3156                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3157
3158                 if (found_key.objectid >= key->objectid &&
3159                     found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
3160                         return 0;
3161                 path->slots[0]++;
3162         }
3163         ret = -ENOENT;
3164 error:
3165         return ret;
3166 }
3167
3168 static void account_super_bytes(struct btrfs_fs_info *fs_info,
3169                                 struct btrfs_block_group_cache *cache)
3170 {
3171         u64 bytenr;
3172         u64 *logical;
3173         int stripe_len;
3174         int i, nr, ret;
3175
3176         if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
3177                 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
3178                 cache->bytes_super += stripe_len;
3179         }
3180
3181         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3182                 bytenr = btrfs_sb_offset(i);
3183                 ret = btrfs_rmap_block(&fs_info->mapping_tree,
3184                                        cache->key.objectid, bytenr,
3185                                        0, &logical, &nr, &stripe_len);
3186                 if (ret)
3187                         return;
3188
3189                 while (nr--) {
3190                         u64 start, len;
3191
3192                         if (logical[nr] > cache->key.objectid +
3193                             cache->key.offset)
3194                                 continue;
3195
3196                         if (logical[nr] + stripe_len <= cache->key.objectid)
3197                                 continue;
3198
3199                         start = logical[nr];
3200                         if (start < cache->key.objectid) {
3201                                 start = cache->key.objectid;
3202                                 len = (logical[nr] + stripe_len) - start;
3203                         } else {
3204                                 len = min_t(u64, stripe_len,
3205                                             cache->key.objectid +
3206                                             cache->key.offset - start);
3207                         }
3208
3209                         cache->bytes_super += len;
3210                 }
3211
3212                 kfree(logical);
3213         }
3214 }
3215
3216 int btrfs_read_block_groups(struct btrfs_root *root)
3217 {
3218         struct btrfs_path *path;
3219         int ret;
3220         int bit;
3221         struct btrfs_block_group_cache *cache;
3222         struct btrfs_fs_info *info = root->fs_info;
3223         struct btrfs_space_info *space_info;
3224         struct extent_io_tree *block_group_cache;
3225         struct btrfs_key key;
3226         struct btrfs_key found_key;
3227         struct extent_buffer *leaf;
3228
3229         block_group_cache = &info->block_group_cache;
3230
3231         root = info->extent_root;
3232         key.objectid = 0;
3233         key.offset = 0;
3234         btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3235         path = btrfs_alloc_path();
3236         if (!path)
3237                 return -ENOMEM;
3238
3239         while(1) {
3240                 ret = find_first_block_group(root, path, &key);
3241                 if (ret > 0) {
3242                         ret = 0;
3243                         goto error;
3244                 }
3245                 if (ret != 0) {
3246                         goto error;
3247                 }
3248                 leaf = path->nodes[0];
3249                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3250                 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3251                 if (!cache) {
3252                         ret = -ENOMEM;
3253                         break;
3254                 }
3255
3256                 read_extent_buffer(leaf, &cache->item,
3257                                    btrfs_item_ptr_offset(leaf, path->slots[0]),
3258                                    sizeof(cache->item));
3259                 memcpy(&cache->key, &found_key, sizeof(found_key));
3260                 cache->cached = 0;
3261                 cache->pinned = 0;
3262                 key.objectid = found_key.objectid + found_key.offset;
3263                 btrfs_release_path(path);
3264                 cache->flags = btrfs_block_group_flags(&cache->item);
3265                 bit = 0;
3266                 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
3267                         bit = BLOCK_GROUP_DATA;
3268                 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
3269                         bit = BLOCK_GROUP_SYSTEM;
3270                 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
3271                         bit = BLOCK_GROUP_METADATA;
3272                 }
3273                 set_avail_alloc_bits(info, cache->flags);
3274                 if (btrfs_chunk_readonly(root, cache->key.objectid))
3275                         cache->ro = 1;
3276
3277                 account_super_bytes(info, cache);
3278
3279                 ret = update_space_info(info, cache->flags, found_key.offset,
3280                                         btrfs_block_group_used(&cache->item),
3281                                         &space_info);
3282                 BUG_ON(ret);
3283                 cache->space_info = space_info;
3284
3285                 /* use EXTENT_LOCKED to prevent merging */
3286                 set_extent_bits(block_group_cache, found_key.objectid,
3287                                 found_key.objectid + found_key.offset - 1,
3288                                 bit | EXTENT_LOCKED, GFP_NOFS);
3289                 set_state_private(block_group_cache, found_key.objectid,
3290                                   (unsigned long)cache);
3291         }
3292         ret = 0;
3293 error:
3294         btrfs_free_path(path);
3295         return ret;
3296 }
3297
3298 struct btrfs_block_group_cache *
3299 btrfs_add_block_group(struct btrfs_fs_info *fs_info, u64 bytes_used, u64 type,
3300                       u64 chunk_objectid, u64 chunk_offset, u64 size)
3301 {
3302         int ret;
3303         int bit = 0;
3304         struct btrfs_block_group_cache *cache;
3305         struct extent_io_tree *block_group_cache;
3306
3307         block_group_cache = &fs_info->block_group_cache;
3308
3309         cache = kzalloc(sizeof(*cache), GFP_NOFS);
3310         BUG_ON(!cache);
3311         cache->key.objectid = chunk_offset;
3312         cache->key.offset = size;
3313
3314         btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3315         btrfs_set_block_group_used(&cache->item, bytes_used);
3316         btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
3317         cache->flags = type;
3318         btrfs_set_block_group_flags(&cache->item, type);
3319
3320         account_super_bytes(fs_info, cache);
3321         ret = update_space_info(fs_info, cache->flags, size, bytes_used,
3322                                 &cache->space_info);
3323         BUG_ON(ret);
3324
3325         bit = block_group_state_bits(type);
3326         ret = set_extent_bits(block_group_cache, chunk_offset,
3327                               chunk_offset + size - 1,
3328                               bit | EXTENT_LOCKED, GFP_NOFS);
3329         BUG_ON(ret);
3330
3331         ret = set_state_private(block_group_cache, chunk_offset,
3332                                 (unsigned long)cache);
3333         BUG_ON(ret);
3334         set_avail_alloc_bits(fs_info, type);
3335
3336         return cache;
3337 }
3338
3339 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
3340                            struct btrfs_root *root, u64 bytes_used,
3341                            u64 type, u64 chunk_objectid, u64 chunk_offset,
3342                            u64 size)
3343 {
3344         int ret;
3345         struct btrfs_root *extent_root;
3346         struct btrfs_block_group_cache *cache;
3347
3348         cache = btrfs_add_block_group(root->fs_info, bytes_used, type,
3349                                       chunk_objectid, chunk_offset, size);
3350         extent_root = root->fs_info->extent_root;
3351         ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3352                                 sizeof(cache->item));
3353         BUG_ON(ret);
3354
3355         ret = finish_current_insert(trans, extent_root);
3356         BUG_ON(ret);
3357         ret = del_pending_extents(trans, extent_root);
3358         BUG_ON(ret);
3359
3360         return 0;
3361 }
3362
3363 /*
3364  * This is for converter use only.
3365  *
3366  * In that case, we don't know where are free blocks located.
3367  * Therefore all block group cache entries must be setup properly
3368  * before doing any block allocation.
3369  */
3370 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
3371                             struct btrfs_root *root)
3372 {
3373         u64 total_bytes;
3374         u64 cur_start;
3375         u64 group_type;
3376         u64 group_size;
3377         u64 group_align;
3378         u64 total_data = 0;
3379         u64 total_metadata = 0;
3380         u64 chunk_objectid;
3381         int ret;
3382         int bit;
3383         struct btrfs_root *extent_root;
3384         struct btrfs_block_group_cache *cache;
3385         struct extent_io_tree *block_group_cache;
3386
3387         extent_root = root->fs_info->extent_root;
3388         block_group_cache = &root->fs_info->block_group_cache;
3389         chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3390         total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
3391         group_align = 64 * root->sectorsize;
3392
3393         cur_start = 0;
3394         while (cur_start < total_bytes) {
3395                 group_size = total_bytes / 12;
3396                 group_size = min_t(u64, group_size, total_bytes - cur_start);
3397                 if (cur_start == 0) {
3398                         bit = BLOCK_GROUP_SYSTEM;
3399                         group_type = BTRFS_BLOCK_GROUP_SYSTEM;
3400                         group_size /= 4;
3401                         group_size &= ~(group_align - 1);
3402                         group_size = max_t(u64, group_size, 8 * 1024 * 1024);
3403                         group_size = min_t(u64, group_size, 32 * 1024 * 1024);
3404                 } else {
3405                         group_size &= ~(group_align - 1);
3406                         if (total_data >= total_metadata * 2) {
3407                                 group_type = BTRFS_BLOCK_GROUP_METADATA;
3408                                 group_size = min_t(u64, group_size,
3409                                                    1ULL * 1024 * 1024 * 1024);
3410                                 total_metadata += group_size;
3411                         } else {
3412                                 group_type = BTRFS_BLOCK_GROUP_DATA;
3413                                 group_size = min_t(u64, group_size,
3414                                                    5ULL * 1024 * 1024 * 1024);
3415                                 total_data += group_size;
3416                         }
3417                         if ((total_bytes - cur_start) * 4 < group_size * 5)
3418                                 group_size = total_bytes - cur_start;
3419                 }
3420
3421                 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3422                 BUG_ON(!cache);
3423
3424                 cache->key.objectid = cur_start;
3425                 cache->key.offset = group_size;
3426                 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3427
3428                 btrfs_set_block_group_used(&cache->item, 0);
3429                 btrfs_set_block_group_chunk_objectid(&cache->item,
3430                                                      chunk_objectid);
3431                 btrfs_set_block_group_flags(&cache->item, group_type);
3432
3433                 cache->flags = group_type;
3434
3435                 ret = update_space_info(root->fs_info, group_type, group_size,
3436                                         0, &cache->space_info);
3437                 BUG_ON(ret);
3438                 set_avail_alloc_bits(extent_root->fs_info, group_type);
3439
3440                 set_extent_bits(block_group_cache, cur_start,
3441                                 cur_start + group_size - 1,
3442                                 bit | EXTENT_LOCKED, GFP_NOFS);
3443                 set_state_private(block_group_cache, cur_start,
3444                                   (unsigned long)cache);
3445                 cur_start += group_size;
3446         }
3447         /* then insert all the items */
3448         cur_start = 0;
3449         while(cur_start < total_bytes) {
3450                 cache = btrfs_lookup_block_group(root->fs_info, cur_start);
3451                 BUG_ON(!cache);
3452
3453                 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3454                                         sizeof(cache->item));
3455                 BUG_ON(ret);
3456
3457                 finish_current_insert(trans, extent_root);
3458                 ret = del_pending_extents(trans, extent_root);
3459                 BUG_ON(ret);
3460
3461                 cur_start = cache->key.objectid + cache->key.offset;
3462         }
3463         return 0;
3464 }
3465
3466 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
3467                              struct btrfs_root *root,
3468                              u64 bytenr, u64 num_bytes, int alloc,
3469                              int mark_free)
3470 {
3471         return update_block_group(trans, root, bytenr, num_bytes,
3472                                   alloc, mark_free);
3473 }
3474
3475 /*
3476  * Just remove a block group item in extent tree
3477  * Caller should ensure the block group is empty and all space is pinned.
3478  * Or new tree block/data may be allocated into it.
3479  */
3480 static int free_block_group_item(struct btrfs_trans_handle *trans,
3481                                  struct btrfs_fs_info *fs_info,
3482                                  u64 bytenr, u64 len)
3483 {
3484         struct btrfs_path *path;
3485         struct btrfs_key key;
3486         struct btrfs_root *root = fs_info->extent_root;
3487         int ret = 0;
3488
3489         key.objectid = bytenr;
3490         key.offset = len;
3491         key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3492
3493         path = btrfs_alloc_path();
3494         if (!path)
3495                 return -ENOMEM;
3496
3497         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3498         if (ret > 0) {
3499                 ret = -ENOENT;
3500                 goto out;
3501         }
3502         if (ret < 0)
3503                 goto out;
3504
3505         ret = btrfs_del_item(trans, root, path);
3506 out:
3507         btrfs_free_path(path);
3508         return ret;
3509 }
3510
3511 static int free_dev_extent_item(struct btrfs_trans_handle *trans,
3512                                 struct btrfs_fs_info *fs_info,
3513                                 u64 devid, u64 dev_offset)
3514 {
3515         struct btrfs_root *root = fs_info->dev_root;
3516         struct btrfs_path *path;
3517         struct btrfs_key key;
3518         int ret;
3519
3520         path = btrfs_alloc_path();
3521         if (!path)
3522                 return -ENOMEM;
3523
3524         key.objectid = devid;
3525         key.type = BTRFS_DEV_EXTENT_KEY;
3526         key.offset = dev_offset;
3527
3528         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3529         if (ret < 0)
3530                 goto out;
3531         if (ret > 0) {
3532                 ret = -ENOENT;
3533                 goto out;
3534         }
3535
3536         ret = btrfs_del_item(trans, root, path);
3537 out:
3538         btrfs_free_path(path);
3539         return ret;
3540 }
3541
3542 static int free_chunk_dev_extent_items(struct btrfs_trans_handle *trans,
3543                                        struct btrfs_fs_info *fs_info,
3544                                        u64 chunk_offset)
3545 {
3546         struct btrfs_chunk *chunk = NULL;
3547         struct btrfs_root *root= fs_info->chunk_root;
3548         struct btrfs_path *path;
3549         struct btrfs_key key;
3550         u16 num_stripes;
3551         int i;
3552         int ret;
3553
3554         path = btrfs_alloc_path();
3555         if (!path)
3556                 return -ENOMEM;
3557
3558         key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3559         key.type = BTRFS_CHUNK_ITEM_KEY;
3560         key.offset = chunk_offset;
3561
3562         ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
3563         if (ret < 0)
3564                 goto out;
3565         if (ret > 0) {
3566                 ret = -ENOENT;
3567                 goto out;
3568         }
3569         chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
3570                                struct btrfs_chunk);
3571         num_stripes = btrfs_chunk_num_stripes(path->nodes[0], chunk);
3572         for (i = 0; i < num_stripes; i++) {
3573                 ret = free_dev_extent_item(trans, fs_info,
3574                         btrfs_stripe_devid_nr(path->nodes[0], chunk, i),
3575                         btrfs_stripe_offset_nr(path->nodes[0], chunk, i));
3576                 if (ret < 0)
3577                         goto out;
3578         }
3579 out:
3580         btrfs_free_path(path);
3581         return ret;
3582 }
3583
3584 static int free_system_chunk_item(struct btrfs_super_block *super,
3585                                   struct btrfs_key *key)
3586 {
3587         struct btrfs_disk_key *disk_key;
3588         struct btrfs_key cpu_key;
3589         u32 array_size = btrfs_super_sys_array_size(super);
3590         char *ptr = (char *)super->sys_chunk_array;
3591         int cur = 0;
3592         int ret = -ENOENT;
3593
3594         while (cur < btrfs_super_sys_array_size(super)) {
3595                 struct btrfs_chunk *chunk;
3596                 u32 num_stripes;
3597                 u32 chunk_len;
3598
3599                 disk_key = (struct btrfs_disk_key *)(ptr + cur);
3600                 btrfs_disk_key_to_cpu(&cpu_key, disk_key);
3601                 if (cpu_key.type != BTRFS_CHUNK_ITEM_KEY) {
3602                         /* just in case */
3603                         ret = -EIO;
3604                         goto out;
3605                 }
3606
3607                 chunk = (struct btrfs_chunk *)(ptr + cur + sizeof(*disk_key));
3608                 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
3609                 chunk_len = btrfs_chunk_item_size(num_stripes) +
3610                             sizeof(*disk_key);
3611
3612                 if (key->objectid == cpu_key.objectid &&
3613                     key->offset == cpu_key.offset &&
3614                     key->type == cpu_key.type) {
3615                         memmove(ptr + cur, ptr + cur + chunk_len,
3616                                 array_size - cur - chunk_len);
3617                         array_size -= chunk_len;
3618                         btrfs_set_super_sys_array_size(super, array_size);
3619                         ret = 0;
3620                         goto out;
3621                 }
3622
3623                 cur += chunk_len;
3624         }
3625 out:
3626         return ret;
3627 }
3628
3629 static int free_chunk_item(struct btrfs_trans_handle *trans,
3630                            struct btrfs_fs_info *fs_info,
3631                            u64 bytenr, u64 len)
3632 {
3633         struct btrfs_path *path;
3634         struct btrfs_key key;
3635         struct btrfs_root *root = fs_info->chunk_root;
3636         struct btrfs_chunk *chunk;
3637         u64 chunk_type;
3638         int ret;
3639
3640         key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3641         key.offset = bytenr;
3642         key.type = BTRFS_CHUNK_ITEM_KEY;
3643
3644         path = btrfs_alloc_path();
3645         if (!path)
3646                 return -ENOMEM;
3647
3648         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3649         if (ret > 0) {
3650                 ret = -ENOENT;
3651                 goto out;
3652         }
3653         if (ret < 0)
3654                 goto out;
3655         chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
3656                                struct btrfs_chunk);
3657         chunk_type = btrfs_chunk_type(path->nodes[0], chunk);
3658
3659         ret = btrfs_del_item(trans, root, path);
3660         if (ret < 0)
3661                 goto out;
3662
3663         if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
3664                 ret = free_system_chunk_item(fs_info->super_copy, &key);
3665 out:
3666         btrfs_free_path(path);
3667         return ret;
3668 }
3669
3670 static u64 get_dev_extent_len(struct map_lookup *map)
3671 {
3672         int div;
3673
3674         switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3675         case 0: /* Single */
3676         case BTRFS_BLOCK_GROUP_DUP:
3677         case BTRFS_BLOCK_GROUP_RAID1:
3678                 div = 1;
3679                 break;
3680         case BTRFS_BLOCK_GROUP_RAID5:
3681                 div = (map->num_stripes - 1);
3682                 break;
3683         case BTRFS_BLOCK_GROUP_RAID6:
3684                 div = (map->num_stripes - 2);
3685                 break;
3686         case BTRFS_BLOCK_GROUP_RAID10:
3687                 div = (map->num_stripes / map->sub_stripes);
3688                 break;
3689         default:
3690                 /* normally, read chunk security hook should handled it */
3691                 BUG_ON(1);
3692         }
3693         return map->ce.size / div;
3694 }
3695
3696 /* free block group/chunk related caches */
3697 static int free_block_group_cache(struct btrfs_trans_handle *trans,
3698                                   struct btrfs_fs_info *fs_info,
3699                                   u64 bytenr, u64 len)
3700 {
3701         struct btrfs_block_group_cache *cache;
3702         struct cache_extent *ce;
3703         struct map_lookup *map;
3704         int ret;
3705         int i;
3706         u64 flags;
3707
3708         /* Free block group cache first */
3709         cache = btrfs_lookup_block_group(fs_info, bytenr);
3710         if (!cache)
3711                 return -ENOENT;
3712         flags = cache->flags;
3713         if (cache->free_space_ctl) {
3714                 btrfs_remove_free_space_cache(cache);
3715                 kfree(cache->free_space_ctl);
3716         }
3717         clear_extent_bits(&fs_info->block_group_cache, bytenr, bytenr + len,
3718                           (unsigned int)-1, GFP_NOFS);
3719         ret = free_space_info(fs_info, flags, len, 0, NULL);
3720         if (ret < 0)
3721                 goto out;
3722         kfree(cache);
3723
3724         /* Then free mapping info and dev usage info */
3725         ce = search_cache_extent(&fs_info->mapping_tree.cache_tree, bytenr);
3726         if (!ce || ce->start != bytenr) {
3727                 ret = -ENOENT;
3728                 goto out;
3729         }
3730         map = container_of(ce, struct map_lookup, ce);
3731         for (i = 0; i < map->num_stripes; i++) {
3732                 struct btrfs_device *device;
3733
3734                 device = map->stripes[i].dev;
3735                 device->bytes_used -= get_dev_extent_len(map);
3736                 ret = btrfs_update_device(trans, device);
3737                 if (ret < 0)
3738                         goto out;
3739         }
3740         remove_cache_extent(&fs_info->mapping_tree.cache_tree, ce);
3741         free(map);
3742 out:
3743         return ret;
3744 }
3745
3746 /*
3747  * Fixup block accounting. The initial block accounting created by
3748  * make_block_groups isn't accuracy in this case.
3749  */
3750 int btrfs_fix_block_accounting(struct btrfs_trans_handle *trans,
3751                                struct btrfs_root *root)
3752 {
3753         int ret;
3754         int slot;
3755         u64 start = 0;
3756         u64 bytes_used = 0;
3757         struct btrfs_path path;
3758         struct btrfs_key key;
3759         struct extent_buffer *leaf;
3760         struct btrfs_block_group_cache *cache;
3761         struct btrfs_fs_info *fs_info = root->fs_info;
3762
3763         root = root->fs_info->extent_root;
3764
3765         while(extent_root_pending_ops(fs_info)) {
3766                 ret = finish_current_insert(trans, root);
3767                 if (ret)
3768                         return ret;
3769                 ret = del_pending_extents(trans, root);
3770                 if (ret)
3771                         return ret;
3772         }
3773
3774         while(1) {
3775                 cache = btrfs_lookup_first_block_group(fs_info, start);
3776                 if (!cache)
3777                         break;
3778                 start = cache->key.objectid + cache->key.offset;
3779                 btrfs_set_block_group_used(&cache->item, 0);
3780                 cache->space_info->bytes_used = 0;
3781                 set_extent_bits(&root->fs_info->block_group_cache,
3782                                 cache->key.objectid,
3783                                 cache->key.objectid + cache->key.offset -1,
3784                                 BLOCK_GROUP_DIRTY, GFP_NOFS);
3785         }
3786
3787         btrfs_init_path(&path);
3788         key.offset = 0;
3789         key.objectid = 0;
3790         btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
3791         ret = btrfs_search_slot(trans, root->fs_info->extent_root,
3792                                 &key, &path, 0, 0);
3793         if (ret < 0)
3794                 return ret;
3795         while(1) {
3796                 leaf = path.nodes[0];
3797                 slot = path.slots[0];
3798                 if (slot >= btrfs_header_nritems(leaf)) {
3799                         ret = btrfs_next_leaf(root, &path);
3800                         if (ret < 0)
3801                                 return ret;
3802                         if (ret > 0)
3803                                 break;
3804                         leaf = path.nodes[0];
3805                         slot = path.slots[0];
3806                 }
3807                 btrfs_item_key_to_cpu(leaf, &key, slot);
3808                 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
3809                         bytes_used += key.offset;
3810                         ret = btrfs_update_block_group(trans, root,
3811                                   key.objectid, key.offset, 1, 0);
3812                         BUG_ON(ret);
3813                 } else if (key.type == BTRFS_METADATA_ITEM_KEY) {
3814                         bytes_used += root->leafsize;
3815                         ret = btrfs_update_block_group(trans, root,
3816                                   key.objectid, root->leafsize, 1, 0);
3817                         BUG_ON(ret);
3818                 }
3819                 path.slots[0]++;
3820         }
3821         btrfs_set_super_bytes_used(root->fs_info->super_copy, bytes_used);
3822         btrfs_release_path(&path);
3823         return 0;
3824 }
3825
3826 /*
3827  * Record a file extent. Do all the required works, such as inserting
3828  * file extent item, inserting extent item and backref item into extent
3829  * tree and updating block accounting.
3830  */
3831 int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
3832                               struct btrfs_root *root, u64 objectid,
3833                               struct btrfs_inode_item *inode,
3834                               u64 file_pos, u64 disk_bytenr,
3835                               u64 num_bytes)
3836 {
3837         int ret;
3838         struct btrfs_fs_info *info = root->fs_info;
3839         struct btrfs_root *extent_root = info->extent_root;
3840         struct extent_buffer *leaf;
3841         struct btrfs_file_extent_item *fi;
3842         struct btrfs_key ins_key;
3843         struct btrfs_path path;
3844         struct btrfs_extent_item *ei;
3845         u64 nbytes;
3846
3847         if (disk_bytenr == 0) {
3848                 ret = btrfs_insert_file_extent(trans, root, objectid,
3849                                                 file_pos, disk_bytenr,
3850                                                 num_bytes, num_bytes);
3851                 return ret;
3852         }
3853
3854         btrfs_init_path(&path);
3855
3856         ins_key.objectid = objectid;
3857         ins_key.offset = file_pos;
3858         btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
3859         ret = btrfs_insert_empty_item(trans, root, &path, &ins_key,
3860                                       sizeof(*fi));
3861         if (ret)
3862                 goto fail;
3863         leaf = path.nodes[0];
3864         fi = btrfs_item_ptr(leaf, path.slots[0],
3865                             struct btrfs_file_extent_item);
3866         btrfs_set_file_extent_generation(leaf, fi, trans->transid);
3867         btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
3868         btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
3869         btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
3870         btrfs_set_file_extent_offset(leaf, fi, 0);
3871         btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
3872         btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
3873         btrfs_set_file_extent_compression(leaf, fi, 0);
3874         btrfs_set_file_extent_encryption(leaf, fi, 0);
3875         btrfs_set_file_extent_other_encoding(leaf, fi, 0);
3876         btrfs_mark_buffer_dirty(leaf);
3877
3878         nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
3879         btrfs_set_stack_inode_nbytes(inode, nbytes);
3880
3881         btrfs_release_path(&path);
3882
3883         ins_key.objectid = disk_bytenr;
3884         ins_key.offset = num_bytes;
3885         ins_key.type = BTRFS_EXTENT_ITEM_KEY;
3886
3887         ret = btrfs_insert_empty_item(trans, extent_root, &path,
3888                                       &ins_key, sizeof(*ei));
3889         if (ret == 0) {
3890                 leaf = path.nodes[0];
3891                 ei = btrfs_item_ptr(leaf, path.slots[0],
3892                                     struct btrfs_extent_item);
3893
3894                 btrfs_set_extent_refs(leaf, ei, 0);
3895                 btrfs_set_extent_generation(leaf, ei, 0);
3896                 btrfs_set_extent_flags(leaf, ei, BTRFS_EXTENT_FLAG_DATA);
3897
3898                 btrfs_mark_buffer_dirty(leaf);
3899
3900                 ret = btrfs_update_block_group(trans, root, disk_bytenr,
3901                                                num_bytes, 1, 0);
3902                 if (ret)
3903                         goto fail;
3904         } else if (ret != -EEXIST) {
3905                 goto fail;
3906         }
3907         btrfs_extent_post_op(trans, extent_root);
3908
3909         ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, num_bytes, 0,
3910                                    root->root_key.objectid,
3911                                    objectid, file_pos);
3912         if (ret)
3913                 goto fail;
3914         ret = 0;
3915 fail:
3916         btrfs_release_path(&path);
3917         return ret;
3918 }