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 <math.h>
  23 #include "kerncompat.h"
  24 #include "radix-tree.h"
  25 #include "ctree.h"
  26 #include "disk-io.h"
  27 #include "print-tree.h"
  28 #include "transaction.h"
  29 #include "crc32c.h"
  30 #include "volumes.h"
  31 #include "free-space-cache.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 btrfs_fs_info *fs_info = root->fs_info;
  73         struct extent_io_tree *free_space_cache;
  74
  75         free_space_cache = &fs_info->free_space_cache;
  76         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
  77                 bytenr = btrfs_sb_offset(i);
  78                 ret = btrfs_rmap_block(fs_info, 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);
  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                         }
 154                         if (key.type == BTRFS_METADATA_ITEM_KEY)
 155                                 last = key.objectid + root->fs_info->nodesize;
 156                         else
 157                                 last = key.objectid + key.offset;
 158                 }
 159 next:
 160                 path->slots[0]++;
 161         }
 162
 163         if (block_group->key.objectid +
 164             block_group->key.offset > last) {
 165                 hole_size = block_group->key.objectid +
 166                         block_group->key.offset - last;
 167                 set_extent_dirty(free_space_cache, last, last + hole_size - 1);
 168         }
 169         remove_sb_from_cache(root, block_group);
 170         block_group->cached = 1;
 171 err:
 172         btrfs_free_path(path);
 173         return 0;
 174 }
 175
 176 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
 177                                                        btrfs_fs_info *info,
 178                                                        u64 bytenr)
 179 {
 180         struct extent_io_tree *block_group_cache;
 181         struct btrfs_block_group_cache *block_group = NULL;
 182         u64 ptr;
 183         u64 start;
 184         u64 end;
 185         int ret;
 186
 187         bytenr = max_t(u64, bytenr,
 188                        BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
 189         block_group_cache = &info->block_group_cache;
 190         ret = find_first_extent_bit(block_group_cache,
 191                                     bytenr, &start, &end,
 192                                     BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
 193                                     BLOCK_GROUP_SYSTEM);
 194         if (ret) {
 195                 return NULL;
 196         }
 197         ret = get_state_private(block_group_cache, start, &ptr);
 198         if (ret)
 199                 return NULL;
 200
 201         block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
 202         return block_group;
 203 }
 204
 205 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
 206                                                          btrfs_fs_info *info,
 207                                                          u64 bytenr)
 208 {
 209         struct extent_io_tree *block_group_cache;
 210         struct btrfs_block_group_cache *block_group = NULL;
 211         u64 ptr;
 212         u64 start;
 213         u64 end;
 214         int ret;
 215
 216         block_group_cache = &info->block_group_cache;
 217         ret = find_first_extent_bit(block_group_cache,
 218                                     bytenr, &start, &end,
 219                                     BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
 220                                     BLOCK_GROUP_SYSTEM);
 221         if (ret) {
 222                 return NULL;
 223         }
 224         ret = get_state_private(block_group_cache, start, &ptr);
 225         if (ret)
 226                 return NULL;
 227
 228         block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
 229         if (block_group->key.objectid <= bytenr && bytenr <
 230             block_group->key.objectid + block_group->key.offset)
 231                 return block_group;
 232         return NULL;
 233 }
 234
 235 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 236 {
 237         return (cache->flags & bits) == bits;
 238 }
 239
 240 static int noinline find_search_start(struct btrfs_root *root,
 241                               struct btrfs_block_group_cache **cache_ret,
 242                               u64 *start_ret, int num, int data)
 243 {
 244         int ret;
 245         struct btrfs_block_group_cache *cache = *cache_ret;
 246         u64 last = *start_ret;
 247         u64 start = 0;
 248         u64 end = 0;
 249         u64 search_start = *start_ret;
 250         int wrapped = 0;
 251
 252         if (!cache)
 253                 goto out;
 254 again:
 255         ret = cache_block_group(root, cache);
 256         if (ret)
 257                 goto out;
 258
 259         last = max(search_start, cache->key.objectid);
 260         if (cache->ro || !block_group_bits(cache, data))
 261                 goto new_group;
 262
 263         while(1) {
 264                 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
 265                                             last, &start, &end, EXTENT_DIRTY);
 266                 if (ret) {
 267                         goto new_group;
 268                 }
 269
 270                 start = max(last, start);
 271                 last = end + 1;
 272                 if (last - start < num) {
 273                         continue;
 274                 }
 275                 if (start + num > cache->key.objectid + cache->key.offset) {
 276                         goto new_group;
 277                 }
 278                 *start_ret = start;
 279                 return 0;
 280         }
 281 out:
 282         *start_ret = last;
 283         cache = btrfs_lookup_block_group(root->fs_info, search_start);
 284         if (!cache) {
 285                 printk("Unable to find block group for %llu\n",
 286                         (unsigned long long)search_start);
 287                 return -ENOENT;
 288         }
 289         return -ENOSPC;
 290
 291 new_group:
 292         last = cache->key.objectid + cache->key.offset;
 293 wrapped:
 294         cache = btrfs_lookup_first_block_group(root->fs_info, last);
 295         if (!cache) {
 296                 if (!wrapped) {
 297                         wrapped = 1;
 298                         last = search_start;
 299                         goto wrapped;
 300                 }
 301                 goto out;
 302         }
 303         *cache_ret = cache;
 304         goto again;
 305 }
 306
 307 static int block_group_state_bits(u64 flags)
 308 {
 309         int bits = 0;
 310         if (flags & BTRFS_BLOCK_GROUP_DATA)
 311                 bits |= BLOCK_GROUP_DATA;
 312         if (flags & BTRFS_BLOCK_GROUP_METADATA)
 313                 bits |= BLOCK_GROUP_METADATA;
 314         if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
 315                 bits |= BLOCK_GROUP_SYSTEM;
 316         return bits;
 317 }
 318
 319 static struct btrfs_block_group_cache *
 320 btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache
 321                        *hint, u64 search_start, int data, int owner)
 322 {
 323         struct btrfs_block_group_cache *cache;
 324         struct extent_io_tree *block_group_cache;
 325         struct btrfs_block_group_cache *found_group = NULL;
 326         struct btrfs_fs_info *info = root->fs_info;
 327         u64 used;
 328         u64 last = 0;
 329         u64 hint_last;
 330         u64 start;
 331         u64 end;
 332         u64 free_check;
 333         u64 ptr;
 334         int bit;
 335         int ret;
 336         int full_search = 0;
 337         int factor = 10;
 338
 339         block_group_cache = &info->block_group_cache;
 340
 341         if (!owner)
 342                 factor = 10;
 343
 344         bit = block_group_state_bits(data);
 345
 346         if (search_start) {
 347                 struct btrfs_block_group_cache *shint;
 348                 shint = btrfs_lookup_block_group(info, search_start);
 349                 if (shint && !shint->ro && block_group_bits(shint, data)) {
 350                         used = btrfs_block_group_used(&shint->item);
 351                         if (used + shint->pinned <
 352                             div_factor(shint->key.offset, factor)) {
 353                                 return shint;
 354                         }
 355                 }
 356         }
 357         if (hint && !hint->ro && block_group_bits(hint, data)) {
 358                 used = btrfs_block_group_used(&hint->item);
 359                 if (used + hint->pinned <
 360                     div_factor(hint->key.offset, factor)) {
 361                         return hint;
 362                 }
 363                 last = hint->key.objectid + hint->key.offset;
 364                 hint_last = last;
 365         } else {
 366                 if (hint)
 367                         hint_last = max(hint->key.objectid, search_start);
 368                 else
 369                         hint_last = search_start;
 370
 371                 last = hint_last;
 372         }
 373 again:
 374         while(1) {
 375                 ret = find_first_extent_bit(block_group_cache, last,
 376                                             &start, &end, bit);
 377                 if (ret)
 378                         break;
 379
 380                 ret = get_state_private(block_group_cache, start, &ptr);
 381                 if (ret)
 382                         break;
 383
 384                 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
 385                 last = cache->key.objectid + cache->key.offset;
 386                 used = btrfs_block_group_used(&cache->item);
 387
 388                 if (!cache->ro && block_group_bits(cache, data)) {
 389                         if (full_search)
 390                                 free_check = cache->key.offset;
 391                         else
 392                                 free_check = div_factor(cache->key.offset,
 393                                                         factor);
 394
 395                         if (used + cache->pinned < free_check) {
 396                                 found_group = cache;
 397                                 goto found;
 398                         }
 399                 }
 400                 cond_resched();
 401         }
 402         if (!full_search) {
 403                 last = search_start;
 404                 full_search = 1;
 405                 goto again;
 406         }
 407 found:
 408         return found_group;
 409 }
 410
 411 /*
 412  * Back reference rules.  Back refs have three main goals:
 413  *
 414  * 1) differentiate between all holders of references to an extent so that
 415  *    when a reference is dropped we can make sure it was a valid reference
 416  *    before freeing the extent.
 417  *
 418  * 2) Provide enough information to quickly find the holders of an extent
 419  *    if we notice a given block is corrupted or bad.
 420  *
 421  * 3) Make it easy to migrate blocks for FS shrinking or storage pool
 422  *    maintenance.  This is actually the same as #2, but with a slightly
 423  *    different use case.
 424  *
 425  * There are two kinds of back refs. The implicit back refs is optimized
 426  * for pointers in non-shared tree blocks. For a given pointer in a block,
 427  * back refs of this kind provide information about the block's owner tree
 428  * and the pointer's key. These information allow us to find the block by
 429  * b-tree searching. The full back refs is for pointers in tree blocks not
 430  * referenced by their owner trees. The location of tree block is recorded
 431  * in the back refs. Actually the full back refs is generic, and can be
 432  * used in all cases the implicit back refs is used. The major shortcoming
 433  * of the full back refs is its overhead. Every time a tree block gets
 434  * COWed, we have to update back refs entry for all pointers in it.
 435  *
 436  * For a newly allocated tree block, we use implicit back refs for
 437  * pointers in it. This means most tree related operations only involve
 438  * implicit back refs. For a tree block created in old transaction, the
 439  * only way to drop a reference to it is COW it. So we can detect the
 440  * event that tree block loses its owner tree's reference and do the
 441  * back refs conversion.
 442  *
 443  * When a tree block is COW'd through a tree, there are four cases:
 444  *
 445  * The reference count of the block is one and the tree is the block's
 446  * owner tree. Nothing to do in this case.
 447  *
 448  * The reference count of the block is one and the tree is not the
 449  * block's owner tree. In this case, full back refs is used for pointers
 450  * in the block. Remove these full back refs, add implicit back refs for
 451  * every pointers in the new block.
 452  *
 453  * The reference count of the block is greater than one and the tree is
 454  * the block's owner tree. In this case, implicit back refs is used for
 455  * pointers in the block. Add full back refs for every pointers in the
 456  * block, increase lower level extents' reference counts. The original
 457  * implicit back refs are entailed to the new block.
 458  *
 459  * The reference count of the block is greater than one and the tree is
 460  * not the block's owner tree. Add implicit back refs for every pointer in
 461  * the new block, increase lower level extents' reference count.
 462  *
 463  * Back Reference Key composing:
 464  *
 465  * The key objectid corresponds to the first byte in the extent,
 466  * The key type is used to differentiate between types of back refs.
 467  * There are different meanings of the key offset for different types
 468  * of back refs.
 469  *
 470  * File extents can be referenced by:
 471  *
 472  * - multiple snapshots, subvolumes, or different generations in one subvol
 473  * - different files inside a single subvolume
 474  * - different offsets inside a file (bookend extents in file.c)
 475  *
 476  * The extent ref structure for the implicit back refs has fields for:
 477  *
 478  * - Objectid of the subvolume root
 479  * - objectid of the file holding the reference
 480  * - original offset in the file
 481  * - how many bookend extents
 482  *
 483  * The key offset for the implicit back refs is hash of the first
 484  * three fields.
 485  *
 486  * The extent ref structure for the full back refs has field for:
 487  *
 488  * - number of pointers in the tree leaf
 489  *
 490  * The key offset for the implicit back refs is the first byte of
 491  * the tree leaf
 492  *
 493  * When a file extent is allocated, The implicit back refs is used.
 494  * the fields are filled in:
 495  *
 496  *     (root_key.objectid, inode objectid, offset in file, 1)
 497  *
 498  * When a file extent is removed file truncation, we find the
 499  * corresponding implicit back refs and check the following fields:
 500  *
 501  *     (btrfs_header_owner(leaf), inode objectid, offset in file)
 502  *
 503  * Btree extents can be referenced by:
 504  *
 505  * - Different subvolumes
 506  *
 507  * Both the implicit back refs and the full back refs for tree blocks
 508  * only consist of key. The key offset for the implicit back refs is
 509  * objectid of block's owner tree. The key offset for the full back refs
 510  * is the first byte of parent block.
 511  *
 512  * When implicit back refs is used, information about the lowest key and
 513  * level of the tree block are required. These information are stored in
 514  * tree block info structure.
 515  */
 516
 517 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 518 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
 519                                   struct btrfs_root *root,
 520                                   struct btrfs_path *path,
 521                                   u64 owner, u32 extra_size)
 522 {
 523         struct btrfs_extent_item *item;
 524         struct btrfs_extent_item_v0 *ei0;
 525         struct btrfs_extent_ref_v0 *ref0;
 526         struct btrfs_tree_block_info *bi;
 527         struct extent_buffer *leaf;
 528         struct btrfs_key key;
 529         struct btrfs_key found_key;
 530         u32 new_size = sizeof(*item);
 531         u64 refs;
 532         int ret;
 533
 534         leaf = path->nodes[0];
 535         BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
 536
 537         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 538         ei0 = btrfs_item_ptr(leaf, path->slots[0],
 539                              struct btrfs_extent_item_v0);
 540         refs = btrfs_extent_refs_v0(leaf, ei0);
 541
 542         if (owner == (u64)-1) {
 543                 while (1) {
 544                         if (path->slots[0] >= btrfs_header_nritems(leaf)) {
 545                                 ret = btrfs_next_leaf(root, path);
 546                                 if (ret < 0)
 547                                         return ret;
 548                                 BUG_ON(ret > 0);
 549                                 leaf = path->nodes[0];
 550                         }
 551                         btrfs_item_key_to_cpu(leaf, &found_key,
 552                                               path->slots[0]);
 553                         BUG_ON(key.objectid != found_key.objectid);
 554                         if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
 555                                 path->slots[0]++;
 556                                 continue;
 557                         }
 558                         ref0 = btrfs_item_ptr(leaf, path->slots[0],
 559                                               struct btrfs_extent_ref_v0);
 560                         owner = btrfs_ref_objectid_v0(leaf, ref0);
 561                         break;
 562                 }
 563         }
 564         btrfs_release_path(path);
 565
 566         if (owner < BTRFS_FIRST_FREE_OBJECTID)
 567                 new_size += sizeof(*bi);
 568
 569         new_size -= sizeof(*ei0);
 570         ret = btrfs_search_slot(trans, root, &key, path, new_size, 1);
 571         if (ret < 0)
 572                 return ret;
 573         BUG_ON(ret);
 574
 575         ret = btrfs_extend_item(root, path, new_size);
 576         BUG_ON(ret);
 577
 578         leaf = path->nodes[0];
 579         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 580         btrfs_set_extent_refs(leaf, item, refs);
 581         /* FIXME: get real generation */
 582         btrfs_set_extent_generation(leaf, item, 0);
 583         if (owner < BTRFS_FIRST_FREE_OBJECTID) {
 584                 btrfs_set_extent_flags(leaf, item,
 585                                        BTRFS_EXTENT_FLAG_TREE_BLOCK |
 586                                        BTRFS_BLOCK_FLAG_FULL_BACKREF);
 587                 bi = (struct btrfs_tree_block_info *)(item + 1);
 588                 /* FIXME: get first key of the block */
 589                 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
 590                 btrfs_set_tree_block_level(leaf, bi, (int)owner);
 591         } else {
 592                 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
 593         }
 594         btrfs_mark_buffer_dirty(leaf);
 595         return 0;
 596 }
 597 #endif
 598
 599 u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
 600 {
 601         u32 high_crc = ~(u32)0;
 602         u32 low_crc = ~(u32)0;
 603         __le64 lenum;
 604
 605         lenum = cpu_to_le64(root_objectid);
 606         high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
 607         lenum = cpu_to_le64(owner);
 608         low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
 609         lenum = cpu_to_le64(offset);
 610         low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
 611
 612         return ((u64)high_crc << 31) ^ (u64)low_crc;
 613 }
 614
 615 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
 616                                      struct btrfs_extent_data_ref *ref)
 617 {
 618         return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
 619                                     btrfs_extent_data_ref_objectid(leaf, ref),
 620                                     btrfs_extent_data_ref_offset(leaf, ref));
 621 }
 622
 623 static int match_extent_data_ref(struct extent_buffer *leaf,
 624                                  struct btrfs_extent_data_ref *ref,
 625                                  u64 root_objectid, u64 owner, u64 offset)
 626 {
 627         if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
 628             btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
 629             btrfs_extent_data_ref_offset(leaf, ref) != offset)
 630                 return 0;
 631         return 1;
 632 }
 633
 634 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
 635                                            struct btrfs_root *root,
 636                                            struct btrfs_path *path,
 637                                            u64 bytenr, u64 parent,
 638                                            u64 root_objectid,
 639                                            u64 owner, u64 offset)
 640 {
 641         struct btrfs_key key;
 642         struct btrfs_extent_data_ref *ref;
 643         struct extent_buffer *leaf;
 644         u32 nritems;
 645         int ret;
 646         int recow;
 647         int err = -ENOENT;
 648
 649         key.objectid = bytenr;
 650         if (parent) {
 651                 key.type = BTRFS_SHARED_DATA_REF_KEY;
 652                 key.offset = parent;
 653         } else {
 654                 key.type = BTRFS_EXTENT_DATA_REF_KEY;
 655                 key.offset = hash_extent_data_ref(root_objectid,
 656                                                   owner, offset);
 657         }
 658 again:
 659         recow = 0;
 660         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 661         if (ret < 0) {
 662                 err = ret;
 663                 goto fail;
 664         }
 665
 666         if (parent) {
 667                 if (!ret)
 668                         return 0;
 669 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 670                 key.type = BTRFS_EXTENT_REF_V0_KEY;
 671                 btrfs_release_path(path);
 672                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 673                 if (ret < 0) {
 674                         err = ret;
 675                         goto fail;
 676                 }
 677                 if (!ret)
 678                         return 0;
 679 #endif
 680                 goto fail;
 681         }
 682
 683         leaf = path->nodes[0];
 684         nritems = btrfs_header_nritems(leaf);
 685         while (1) {
 686                 if (path->slots[0] >= nritems) {
 687                         ret = btrfs_next_leaf(root, path);
 688                         if (ret < 0)
 689                                 err = ret;
 690                         if (ret)
 691                                 goto fail;
 692
 693                         leaf = path->nodes[0];
 694                         nritems = btrfs_header_nritems(leaf);
 695                         recow = 1;
 696                 }
 697
 698                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 699                 if (key.objectid != bytenr ||
 700                     key.type != BTRFS_EXTENT_DATA_REF_KEY)
 701                         goto fail;
 702
 703                 ref = btrfs_item_ptr(leaf, path->slots[0],
 704                                      struct btrfs_extent_data_ref);
 705
 706                 if (match_extent_data_ref(leaf, ref, root_objectid,
 707                                           owner, offset)) {
 708                         if (recow) {
 709                                 btrfs_release_path(path);
 710                                 goto again;
 711                         }
 712                         err = 0;
 713                         break;
 714                 }
 715                 path->slots[0]++;
 716         }
 717 fail:
 718         return err;
 719 }
 720
 721 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
 722                                            struct btrfs_root *root,
 723                                            struct btrfs_path *path,
 724                                            u64 bytenr, u64 parent,
 725                                            u64 root_objectid, u64 owner,
 726                                            u64 offset, int refs_to_add)
 727 {
 728         struct btrfs_key key;
 729         struct extent_buffer *leaf;
 730         u32 size;
 731         u32 num_refs;
 732         int ret;
 733
 734         key.objectid = bytenr;
 735         if (parent) {
 736                 key.type = BTRFS_SHARED_DATA_REF_KEY;
 737                 key.offset = parent;
 738                 size = sizeof(struct btrfs_shared_data_ref);
 739         } else {
 740                 key.type = BTRFS_EXTENT_DATA_REF_KEY;
 741                 key.offset = hash_extent_data_ref(root_objectid,
 742                                                   owner, offset);
 743                 size = sizeof(struct btrfs_extent_data_ref);
 744         }
 745
 746         ret = btrfs_insert_empty_item(trans, root, path, &key, size);
 747         if (ret && ret != -EEXIST)
 748                 goto fail;
 749
 750         leaf = path->nodes[0];
 751         if (parent) {
 752                 struct btrfs_shared_data_ref *ref;
 753                 ref = btrfs_item_ptr(leaf, path->slots[0],
 754                                      struct btrfs_shared_data_ref);
 755                 if (ret == 0) {
 756                         btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
 757                 } else {
 758                         num_refs = btrfs_shared_data_ref_count(leaf, ref);
 759                         num_refs += refs_to_add;
 760                         btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
 761                 }
 762         } else {
 763                 struct btrfs_extent_data_ref *ref;
 764                 while (ret == -EEXIST) {
 765                         ref = btrfs_item_ptr(leaf, path->slots[0],
 766                                              struct btrfs_extent_data_ref);
 767                         if (match_extent_data_ref(leaf, ref, root_objectid,
 768                                                   owner, offset))
 769                                 break;
 770                         btrfs_release_path(path);
 771
 772                         key.offset++;
 773                         ret = btrfs_insert_empty_item(trans, root, path, &key,
 774                                                       size);
 775                         if (ret && ret != -EEXIST)
 776                                 goto fail;
 777
 778                         leaf = path->nodes[0];
 779                 }
 780                 ref = btrfs_item_ptr(leaf, path->slots[0],
 781                                      struct btrfs_extent_data_ref);
 782                 if (ret == 0) {
 783                         btrfs_set_extent_data_ref_root(leaf, ref,
 784                                                        root_objectid);
 785                         btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
 786                         btrfs_set_extent_data_ref_offset(leaf, ref, offset);
 787                         btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
 788                 } else {
 789                         num_refs = btrfs_extent_data_ref_count(leaf, ref);
 790                         num_refs += refs_to_add;
 791                         btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
 792                 }
 793         }
 794         btrfs_mark_buffer_dirty(leaf);
 795         ret = 0;
 796 fail:
 797         btrfs_release_path(path);
 798         return ret;
 799 }
 800
 801 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
 802                                            struct btrfs_root *root,
 803                                            struct btrfs_path *path,
 804                                            int refs_to_drop)
 805 {
 806         struct btrfs_key key;
 807         struct btrfs_extent_data_ref *ref1 = NULL;
 808         struct btrfs_shared_data_ref *ref2 = NULL;
 809         struct extent_buffer *leaf;
 810         u32 num_refs = 0;
 811         int ret = 0;
 812
 813         leaf = path->nodes[0];
 814         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 815
 816         if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
 817                 ref1 = btrfs_item_ptr(leaf, path->slots[0],
 818                                       struct btrfs_extent_data_ref);
 819                 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
 820         } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
 821                 ref2 = btrfs_item_ptr(leaf, path->slots[0],
 822                                       struct btrfs_shared_data_ref);
 823                 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
 824 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 825         } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
 826                 struct btrfs_extent_ref_v0 *ref0;
 827                 ref0 = btrfs_item_ptr(leaf, path->slots[0],
 828                                       struct btrfs_extent_ref_v0);
 829                 num_refs = btrfs_ref_count_v0(leaf, ref0);
 830 #endif
 831         } else {
 832                 BUG();
 833         }
 834
 835         BUG_ON(num_refs < refs_to_drop);
 836         num_refs -= refs_to_drop;
 837
 838         if (num_refs == 0) {
 839                 ret = btrfs_del_item(trans, root, path);
 840         } else {
 841                 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
 842                         btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
 843                 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
 844                         btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
 845 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 846                 else {
 847                         struct btrfs_extent_ref_v0 *ref0;
 848                         ref0 = btrfs_item_ptr(leaf, path->slots[0],
 849                                         struct btrfs_extent_ref_v0);
 850                         btrfs_set_ref_count_v0(leaf, ref0, num_refs);
 851                 }
 852 #endif
 853                 btrfs_mark_buffer_dirty(leaf);
 854         }
 855         return ret;
 856 }
 857
 858 static noinline u32 extent_data_ref_count(struct btrfs_path *path,
 859                                           struct btrfs_extent_inline_ref *iref)
 860 {
 861         struct btrfs_key key;
 862         struct extent_buffer *leaf;
 863         struct btrfs_extent_data_ref *ref1;
 864         struct btrfs_shared_data_ref *ref2;
 865         u32 num_refs = 0;
 866
 867         leaf = path->nodes[0];
 868         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 869         if (iref) {
 870                 if (btrfs_extent_inline_ref_type(leaf, iref) ==
 871                     BTRFS_EXTENT_DATA_REF_KEY) {
 872                         ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
 873                         num_refs = btrfs_extent_data_ref_count(leaf, ref1);
 874                 } else {
 875                         ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
 876                         num_refs = btrfs_shared_data_ref_count(leaf, ref2);
 877                 }
 878         } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
 879                 ref1 = btrfs_item_ptr(leaf, path->slots[0],
 880                                       struct btrfs_extent_data_ref);
 881                 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
 882         } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
 883                 ref2 = btrfs_item_ptr(leaf, path->slots[0],
 884                                       struct btrfs_shared_data_ref);
 885                 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
 886 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 887         } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
 888                 struct btrfs_extent_ref_v0 *ref0;
 889                 ref0 = btrfs_item_ptr(leaf, path->slots[0],
 890                                       struct btrfs_extent_ref_v0);
 891                 num_refs = btrfs_ref_count_v0(leaf, ref0);
 892 #endif
 893         } else {
 894                 BUG();
 895         }
 896         return num_refs;
 897 }
 898
 899 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
 900                                           struct btrfs_root *root,
 901                                           struct btrfs_path *path,
 902                                           u64 bytenr, u64 parent,
 903                                           u64 root_objectid)
 904 {
 905         struct btrfs_key key;
 906         int ret;
 907
 908         key.objectid = bytenr;
 909         if (parent) {
 910                 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
 911                 key.offset = parent;
 912         } else {
 913                 key.type = BTRFS_TREE_BLOCK_REF_KEY;
 914                 key.offset = root_objectid;
 915         }
 916
 917         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 918         if (ret > 0)
 919                 ret = -ENOENT;
 920 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
 921         if (ret == -ENOENT && parent) {
 922                 btrfs_release_path(path);
 923                 key.type = BTRFS_EXTENT_REF_V0_KEY;
 924                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 925                 if (ret > 0)
 926                         ret = -ENOENT;
 927         }
 928 #endif
 929         return ret;
 930 }
 931
 932 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
 933                                           struct btrfs_root *root,
 934                                           struct btrfs_path *path,
 935                                           u64 bytenr, u64 parent,
 936                                           u64 root_objectid)
 937 {
 938         struct btrfs_key key;
 939         int ret;
 940
 941         key.objectid = bytenr;
 942         if (parent) {
 943                 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
 944                 key.offset = parent;
 945         } else {
 946                 key.type = BTRFS_TREE_BLOCK_REF_KEY;
 947                 key.offset = root_objectid;
 948         }
 949
 950         ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
 951
 952         btrfs_release_path(path);
 953         return ret;
 954 }
 955
 956 static inline int extent_ref_type(u64 parent, u64 owner)
 957 {
 958         int type;
 959         if (owner < BTRFS_FIRST_FREE_OBJECTID) {
 960                 if (parent > 0)
 961                         type = BTRFS_SHARED_BLOCK_REF_KEY;
 962                 else
 963                         type = BTRFS_TREE_BLOCK_REF_KEY;
 964         } else {
 965                 if (parent > 0)
 966                         type = BTRFS_SHARED_DATA_REF_KEY;
 967                 else
 968                         type = BTRFS_EXTENT_DATA_REF_KEY;
 969         }
 970         return type;
 971 }
 972
 973 static int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
 974                                  struct btrfs_root *root,
 975                                  struct btrfs_path *path,
 976                                  struct btrfs_extent_inline_ref **ref_ret,
 977                                  u64 bytenr, u64 num_bytes,
 978                                  u64 parent, u64 root_objectid,
 979                                  u64 owner, u64 offset, int insert)
 980 {
 981         struct btrfs_key key;
 982         struct extent_buffer *leaf;
 983         struct btrfs_extent_item *ei;
 984         struct btrfs_extent_inline_ref *iref;
 985         u64 flags;
 986         u32 item_size;
 987         unsigned long ptr;
 988         unsigned long end;
 989         int extra_size;
 990         int type;
 991         int want;
 992         int ret;
 993         int err = 0;
 994         int skinny_metadata =
 995                 btrfs_fs_incompat(root->fs_info, SKINNY_METADATA);
 996
 997         key.objectid = bytenr;
 998         key.type = BTRFS_EXTENT_ITEM_KEY;
 999         key.offset = num_bytes;
1000
1001         want = extent_ref_type(parent, owner);
1002         if (insert)
1003                 extra_size = btrfs_extent_inline_ref_size(want);
1004         else
1005                 extra_size = -1;
1006
1007         if (owner < BTRFS_FIRST_FREE_OBJECTID && skinny_metadata) {
1008                 key.type = BTRFS_METADATA_ITEM_KEY;
1009                 key.offset = owner;
1010         } else if (skinny_metadata) {
1011                 skinny_metadata = 0;
1012         }
1013
1014 again:
1015         ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1016         if (ret < 0) {
1017                 err = ret;
1018                 goto out;
1019         }
1020
1021         /*
1022          * We may be a newly converted file system which still has the old fat
1023          * extent entries for metadata, so try and see if we have one of those.
1024          */
1025         if (ret > 0 && skinny_metadata) {
1026                 skinny_metadata = 0;
1027                 if (path->slots[0]) {
1028                         path->slots[0]--;
1029                         btrfs_item_key_to_cpu(path->nodes[0], &key,
1030                                               path->slots[0]);
1031                         if (key.objectid == bytenr &&
1032                             key.type == BTRFS_EXTENT_ITEM_KEY &&
1033                             key.offset == num_bytes)
1034                                 ret = 0;
1035                 }
1036                 if (ret) {
1037                         key.type = BTRFS_EXTENT_ITEM_KEY;
1038                         key.offset = num_bytes;
1039                         btrfs_release_path(path);
1040                         goto again;
1041                 }
1042         }
1043
1044         if (ret) {
1045                 printf("Failed to find [%llu, %u, %llu]\n", key.objectid, key.type, key.offset);
1046                 return -ENOENT;
1047         }
1048
1049         BUG_ON(ret);
1050
1051         leaf = path->nodes[0];
1052         item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1053 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1054         if (item_size < sizeof(*ei)) {
1055                 if (!insert) {
1056                         err = -ENOENT;
1057                         goto out;
1058                 }
1059                 ret = convert_extent_item_v0(trans, root, path, owner,
1060                                              extra_size);
1061                 if (ret < 0) {
1062                         err = ret;
1063                         goto out;
1064                 }
1065                 leaf = path->nodes[0];
1066                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1067         }
1068 #endif
1069         if (item_size < sizeof(*ei)) {
1070                 printf("Size is %u, needs to be %u, slot %d\n",
1071                        (unsigned)item_size,
1072                        (unsigned)sizeof(*ei), path->slots[0]);
1073                 btrfs_print_leaf(leaf);
1074                 return -EINVAL;
1075         }
1076         BUG_ON(item_size < sizeof(*ei));
1077
1078         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1079         flags = btrfs_extent_flags(leaf, ei);
1080
1081         ptr = (unsigned long)(ei + 1);
1082         end = (unsigned long)ei + item_size;
1083
1084         if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1085                 ptr += sizeof(struct btrfs_tree_block_info);
1086                 BUG_ON(ptr > end);
1087         } else if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
1088                 if (!(flags & BTRFS_EXTENT_FLAG_DATA)) {
1089                         return -EIO;
1090                 }
1091         }
1092
1093         err = -ENOENT;
1094         while (1) {
1095                 if (ptr >= end) {
1096                         WARN_ON(ptr > end);
1097                         break;
1098                 }
1099                 iref = (struct btrfs_extent_inline_ref *)ptr;
1100                 type = btrfs_extent_inline_ref_type(leaf, iref);
1101                 if (want < type)
1102                         break;
1103                 if (want > type) {
1104                         ptr += btrfs_extent_inline_ref_size(type);
1105                         continue;
1106                 }
1107
1108                 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1109                         struct btrfs_extent_data_ref *dref;
1110                         dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1111                         if (match_extent_data_ref(leaf, dref, root_objectid,
1112                                                   owner, offset)) {
1113                                 err = 0;
1114                                 break;
1115                         }
1116                         if (hash_extent_data_ref_item(leaf, dref) <
1117                             hash_extent_data_ref(root_objectid, owner, offset))
1118                                 break;
1119                 } else {
1120                         u64 ref_offset;
1121                         ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1122                         if (parent > 0) {
1123                                 if (parent == ref_offset) {
1124                                         err = 0;
1125                                         break;
1126                                 }
1127                                 if (ref_offset < parent)
1128                                         break;
1129                         } else {
1130                                 if (root_objectid == ref_offset) {
1131                                         err = 0;
1132                                         break;
1133                                 }
1134                                 if (ref_offset < root_objectid)
1135                                         break;
1136                         }
1137                 }
1138                 ptr += btrfs_extent_inline_ref_size(type);
1139         }
1140         if (err == -ENOENT && insert) {
1141                 if (item_size + extra_size >=
1142                     BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1143                         err = -EAGAIN;
1144                         goto out;
1145                 }
1146                 /*
1147                  * To add new inline back ref, we have to make sure
1148                  * there is no corresponding back ref item.
1149                  * For simplicity, we just do not add new inline back
1150                  * ref if there is any back ref item.
1151                  */
1152                 if (find_next_key(path, &key) == 0 && key.objectid == bytenr &&
1153                     key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1154                         err = -EAGAIN;
1155                         goto out;
1156                 }
1157         }
1158         *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1159 out:
1160         return err;
1161 }
1162
1163 static int setup_inline_extent_backref(struct btrfs_root *root,
1164                                 struct btrfs_path *path,
1165                                 struct btrfs_extent_inline_ref *iref,
1166                                 u64 parent, u64 root_objectid,
1167                                 u64 owner, u64 offset, int refs_to_add)
1168 {
1169         struct extent_buffer *leaf;
1170         struct btrfs_extent_item *ei;
1171         unsigned long ptr;
1172         unsigned long end;
1173         unsigned long item_offset;
1174         u64 refs;
1175         int size;
1176         int type;
1177         int ret;
1178
1179         leaf = path->nodes[0];
1180         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1181         item_offset = (unsigned long)iref - (unsigned long)ei;
1182
1183         type = extent_ref_type(parent, owner);
1184         size = btrfs_extent_inline_ref_size(type);
1185
1186         ret = btrfs_extend_item(root, path, size);
1187         BUG_ON(ret);
1188
1189         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1190         refs = btrfs_extent_refs(leaf, ei);
1191         refs += refs_to_add;
1192         btrfs_set_extent_refs(leaf, ei, refs);
1193
1194         ptr = (unsigned long)ei + item_offset;
1195         end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1196         if (ptr < end - size)
1197                 memmove_extent_buffer(leaf, ptr + size, ptr,
1198                                       end - size - ptr);
1199
1200         iref = (struct btrfs_extent_inline_ref *)ptr;
1201         btrfs_set_extent_inline_ref_type(leaf, iref, type);
1202         if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1203                 struct btrfs_extent_data_ref *dref;
1204                 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1205                 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1206                 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1207                 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1208                 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1209         } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1210                 struct btrfs_shared_data_ref *sref;
1211                 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1212                 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1213                 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1214         } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1215                 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1216         } else {
1217                 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1218         }
1219         btrfs_mark_buffer_dirty(leaf);
1220         return 0;
1221 }
1222
1223 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1224                                  struct btrfs_root *root,
1225                                  struct btrfs_path *path,
1226                                  struct btrfs_extent_inline_ref **ref_ret,
1227                                  u64 bytenr, u64 num_bytes, u64 parent,
1228                                  u64 root_objectid, u64 owner, u64 offset)
1229 {
1230         int ret;
1231
1232         ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1233                                            bytenr, num_bytes, parent,
1234                                            root_objectid, owner, offset, 0);
1235         if (ret != -ENOENT)
1236                 return ret;
1237
1238         btrfs_release_path(path);
1239         *ref_ret = NULL;
1240
1241         if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1242                 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1243                                             root_objectid);
1244         } else {
1245                 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1246                                              root_objectid, owner, offset);
1247         }
1248         return ret;
1249 }
1250
1251 static int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1252                                  struct btrfs_root *root,
1253                                  struct btrfs_path *path,
1254                                  struct btrfs_extent_inline_ref *iref,
1255                                  int refs_to_mod)
1256 {
1257         struct extent_buffer *leaf;
1258         struct btrfs_extent_item *ei;
1259         struct btrfs_extent_data_ref *dref = NULL;
1260         struct btrfs_shared_data_ref *sref = NULL;
1261         unsigned long ptr;
1262         unsigned long end;
1263         u32 item_size;
1264         int size;
1265         int type;
1266         int ret;
1267         u64 refs;
1268
1269         leaf = path->nodes[0];
1270         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1271         refs = btrfs_extent_refs(leaf, ei);
1272         WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1273         refs += refs_to_mod;
1274         btrfs_set_extent_refs(leaf, ei, refs);
1275
1276         type = btrfs_extent_inline_ref_type(leaf, iref);
1277
1278         if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1279                 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1280                 refs = btrfs_extent_data_ref_count(leaf, dref);
1281         } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1282                 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1283                 refs = btrfs_shared_data_ref_count(leaf, sref);
1284         } else {
1285                 refs = 1;
1286                 BUG_ON(refs_to_mod != -1);
1287         }
1288
1289         BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1290         refs += refs_to_mod;
1291
1292         if (refs > 0) {
1293                 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1294                         btrfs_set_extent_data_ref_count(leaf, dref, refs);
1295                 else
1296                         btrfs_set_shared_data_ref_count(leaf, sref, refs);
1297         } else {
1298                 size =  btrfs_extent_inline_ref_size(type);
1299                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1300                 ptr = (unsigned long)iref;
1301                 end = (unsigned long)ei + item_size;
1302                 if (ptr + size < end)
1303                         memmove_extent_buffer(leaf, ptr, ptr + size,
1304                                               end - ptr - size);
1305                 item_size -= size;
1306                 ret = btrfs_truncate_item(root, path, item_size, 1);
1307                 BUG_ON(ret);
1308         }
1309         btrfs_mark_buffer_dirty(leaf);
1310         return 0;
1311 }
1312
1313 static int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1314                                  struct btrfs_root *root,
1315                                  struct btrfs_path *path,
1316                                  u64 bytenr, u64 num_bytes, u64 parent,
1317                                  u64 root_objectid, u64 owner,
1318                                  u64 offset, int refs_to_add)
1319 {
1320         struct btrfs_extent_inline_ref *iref;
1321         int ret;
1322
1323         ret = lookup_inline_extent_backref(trans, root, path, &iref,
1324                                            bytenr, num_bytes, parent,
1325                                            root_objectid, owner, offset, 1);
1326         if (ret == 0) {
1327                 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1328                 ret = update_inline_extent_backref(trans, root, path, iref,
1329                                                    refs_to_add);
1330         } else if (ret == -ENOENT) {
1331                 ret = setup_inline_extent_backref(root, path, iref,
1332                                                   parent, root_objectid,
1333                                                   owner, offset, refs_to_add);
1334         }
1335         return ret;
1336 }
1337
1338 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1339                                  struct btrfs_root *root,
1340                                  struct btrfs_path *path,
1341                                  u64 bytenr, u64 parent, u64 root_objectid,
1342                                  u64 owner, u64 offset, int refs_to_add)
1343 {
1344         int ret;
1345
1346         if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
1347                 ret = insert_extent_data_ref(trans, root, path, bytenr,
1348                                              parent, root_objectid,
1349                                              owner, offset, refs_to_add);
1350         } else {
1351                 BUG_ON(refs_to_add != 1);
1352                 ret = insert_tree_block_ref(trans, root, path, bytenr,
1353                                             parent, root_objectid);
1354         }
1355         return ret;
1356 }
1357
1358 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1359                                  struct btrfs_root *root,
1360                                  struct btrfs_path *path,
1361                                  struct btrfs_extent_inline_ref *iref,
1362                                  int refs_to_drop, int is_data)
1363 {
1364         int ret;
1365
1366         BUG_ON(!is_data && refs_to_drop != 1);
1367         if (iref) {
1368                 ret = update_inline_extent_backref(trans, root, path, iref,
1369                                                    -refs_to_drop);
1370         } else if (is_data) {
1371                 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1372         } else {
1373                 ret = btrfs_del_item(trans, root, path);
1374         }
1375         return ret;
1376 }
1377
1378 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1379                          struct btrfs_root *root,
1380                          u64 bytenr, u64 num_bytes, u64 parent,
1381                          u64 root_objectid, u64 owner, u64 offset)
1382 {
1383         struct btrfs_path *path;
1384         struct extent_buffer *leaf;
1385         struct btrfs_extent_item *item;
1386         u64 refs;
1387         int ret;
1388         int err = 0;
1389
1390         path = btrfs_alloc_path();
1391         if (!path)
1392                 return -ENOMEM;
1393
1394         path->reada = 1;
1395
1396         ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1397                                            path, bytenr, num_bytes, parent,
1398                                            root_objectid, owner, offset, 1);
1399         if (ret == 0)
1400                 goto out;
1401
1402         if (ret != -EAGAIN) {
1403                 err = ret;
1404                 goto out;
1405         }
1406
1407         leaf = path->nodes[0];
1408         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1409         refs = btrfs_extent_refs(leaf, item);
1410         btrfs_set_extent_refs(leaf, item, refs + 1);
1411
1412         btrfs_mark_buffer_dirty(leaf);
1413         btrfs_release_path(path);
1414
1415         path->reada = 1;
1416
1417         /* now insert the actual backref */
1418         ret = insert_extent_backref(trans, root->fs_info->extent_root,
1419                                     path, bytenr, parent, root_objectid,
1420                                     owner, offset, 1);
1421         if (ret)
1422                 err = ret;
1423 out:
1424         btrfs_free_path(path);
1425         finish_current_insert(trans, root->fs_info->extent_root);
1426         del_pending_extents(trans, root->fs_info->extent_root);
1427         BUG_ON(err);
1428         return err;
1429 }
1430
1431 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
1432                          struct btrfs_root *root)
1433 {
1434         finish_current_insert(trans, root->fs_info->extent_root);
1435         del_pending_extents(trans, root->fs_info->extent_root);
1436         return 0;
1437 }
1438
1439 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
1440                              struct btrfs_root *root, u64 bytenr,
1441                              u64 offset, int metadata, u64 *refs, u64 *flags)
1442 {
1443         struct btrfs_path *path;
1444         int ret;
1445         struct btrfs_key key;
1446         struct extent_buffer *l;
1447         struct btrfs_extent_item *item;
1448         u32 item_size;
1449         u64 num_refs;
1450         u64 extent_flags;
1451
1452         if (metadata &&
1453             !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
1454                 offset = root->fs_info->nodesize;
1455                 metadata = 0;
1456         }
1457
1458         path = btrfs_alloc_path();
1459         if (!path)
1460                 return -ENOMEM;
1461         path->reada = 1;
1462
1463         key.objectid = bytenr;
1464         key.offset = offset;
1465         if (metadata)
1466                 key.type = BTRFS_METADATA_ITEM_KEY;
1467         else
1468                 key.type = BTRFS_EXTENT_ITEM_KEY;
1469
1470 again:
1471         ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1472                                 0, 0);
1473         if (ret < 0)
1474                 goto out;
1475
1476         /*
1477          * Deal with the fact that we may have mixed SKINNY and normal refs.  If
1478          * we didn't find what we wanted check and see if we have a normal ref
1479          * right next to us, or re-search if we are on the edge of the leaf just
1480          * to make sure.
1481          */
1482         if (ret > 0 && metadata) {
1483                 if (path->slots[0]) {
1484                         path->slots[0]--;
1485                         btrfs_item_key_to_cpu(path->nodes[0], &key,
1486                                               path->slots[0]);
1487                         if (key.objectid == bytenr &&
1488                             key.type == BTRFS_EXTENT_ITEM_KEY &&
1489                             key.offset == root->fs_info->nodesize)
1490                                 ret = 0;
1491                 }
1492
1493                 if (ret) {
1494                         btrfs_release_path(path);
1495                         key.type = BTRFS_EXTENT_ITEM_KEY;
1496                         key.offset = root->fs_info->nodesize;
1497                         metadata = 0;
1498                         goto again;
1499                 }
1500         }
1501
1502         if (ret != 0) {
1503                 ret = -EIO;
1504                 goto out;
1505         }
1506
1507         l = path->nodes[0];
1508         item_size = btrfs_item_size_nr(l, path->slots[0]);
1509         if (item_size >= sizeof(*item)) {
1510                 item = btrfs_item_ptr(l, path->slots[0],
1511                                       struct btrfs_extent_item);
1512                 num_refs = btrfs_extent_refs(l, item);
1513                 extent_flags = btrfs_extent_flags(l, item);
1514         } else {
1515 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1516                         struct btrfs_extent_item_v0 *ei0;
1517                         BUG_ON(item_size != sizeof(*ei0));
1518                         ei0 = btrfs_item_ptr(l, path->slots[0],
1519                                              struct btrfs_extent_item_v0);
1520                         num_refs = btrfs_extent_refs_v0(l, ei0);
1521                         /* FIXME: this isn't correct for data */
1522                         extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
1523 #else
1524                         BUG();
1525 #endif
1526         }
1527         item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1528         if (refs)
1529                 *refs = num_refs;
1530         if (flags)
1531                 *flags = extent_flags;
1532 out:
1533         btrfs_free_path(path);
1534         return ret;
1535 }
1536
1537 int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
1538                           struct btrfs_root *root,
1539                           u64 bytenr, int level, u64 flags)
1540 {
1541         struct btrfs_path *path;
1542         int ret;
1543         struct btrfs_key key;
1544         struct extent_buffer *l;
1545         struct btrfs_extent_item *item;
1546         u32 item_size;
1547         int skinny_metadata =
1548                 btrfs_fs_incompat(root->fs_info, SKINNY_METADATA);
1549
1550         path = btrfs_alloc_path();
1551         if (!path)
1552                 return -ENOMEM;
1553         path->reada = 1;
1554
1555         key.objectid = bytenr;
1556         if (skinny_metadata) {
1557                 key.offset = level;
1558                 key.type = BTRFS_METADATA_ITEM_KEY;
1559         } else {
1560                 key.offset = root->fs_info->nodesize;
1561                 key.type = BTRFS_EXTENT_ITEM_KEY;
1562         }
1563
1564 again:
1565         ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1566                                 0, 0);
1567         if (ret < 0)
1568                 goto out;
1569
1570         if (ret > 0 && skinny_metadata) {
1571                 skinny_metadata = 0;
1572                 if (path->slots[0]) {
1573                         path->slots[0]--;
1574                         btrfs_item_key_to_cpu(path->nodes[0], &key,
1575                                               path->slots[0]);
1576                         if (key.objectid == bytenr &&
1577                             key.offset == root->fs_info->nodesize &&
1578                             key.type == BTRFS_EXTENT_ITEM_KEY)
1579                                 ret = 0;
1580                 }
1581                 if (ret) {
1582                         btrfs_release_path(path);
1583                         key.offset = root->fs_info->nodesize;
1584                         key.type = BTRFS_EXTENT_ITEM_KEY;
1585                         goto again;
1586                 }
1587         }
1588
1589         if (ret != 0) {
1590                 btrfs_print_leaf(path->nodes[0]);
1591                 printk("failed to find block number %Lu\n",
1592                         (unsigned long long)bytenr);
1593                 BUG();
1594         }
1595         l = path->nodes[0];
1596         item_size = btrfs_item_size_nr(l, path->slots[0]);
1597 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1598         if (item_size < sizeof(*item)) {
1599                 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1600                                              path, (u64)-1, 0);
1601                 if (ret < 0)
1602                         goto out;
1603
1604                 l = path->nodes[0];
1605                 item_size = btrfs_item_size_nr(l, path->slots[0]);
1606         }
1607 #endif
1608         BUG_ON(item_size < sizeof(*item));
1609         item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1610         flags |= btrfs_extent_flags(l, item);
1611         btrfs_set_extent_flags(l, item, flags);
1612 out:
1613         btrfs_free_path(path);
1614         finish_current_insert(trans, root->fs_info->extent_root);
1615         del_pending_extents(trans, root->fs_info->extent_root);
1616         return ret;
1617 }
1618
1619 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
1620                            struct btrfs_root *root,
1621                            struct extent_buffer *buf,
1622                            int record_parent, int inc)
1623 {
1624         u64 bytenr;
1625         u64 num_bytes;
1626         u64 parent;
1627         u64 ref_root;
1628         u32 nritems;
1629         struct btrfs_key key;
1630         struct btrfs_file_extent_item *fi;
1631         int i;
1632         int level;
1633         int ret = 0;
1634         int (*process_func)(struct btrfs_trans_handle *trans,
1635                             struct btrfs_root *root,
1636                             u64, u64, u64, u64, u64, u64);
1637
1638         ref_root = btrfs_header_owner(buf);
1639         nritems = btrfs_header_nritems(buf);
1640         level = btrfs_header_level(buf);
1641
1642         if (!root->ref_cows && level == 0)
1643                 return 0;
1644
1645         if (inc)
1646                 process_func = btrfs_inc_extent_ref;
1647         else
1648                 process_func = btrfs_free_extent;
1649
1650         if (record_parent)
1651                 parent = buf->start;
1652         else
1653                 parent = 0;
1654
1655         for (i = 0; i < nritems; i++) {
1656                 cond_resched();
1657                 if (level == 0) {
1658                         btrfs_item_key_to_cpu(buf, &key, i);
1659                         if (key.type != BTRFS_EXTENT_DATA_KEY)
1660                                 continue;
1661                         fi = btrfs_item_ptr(buf, i,
1662                                             struct btrfs_file_extent_item);
1663                         if (btrfs_file_extent_type(buf, fi) ==
1664                             BTRFS_FILE_EXTENT_INLINE)
1665                                 continue;
1666                         bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1667                         if (bytenr == 0)
1668                                 continue;
1669
1670                         num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
1671                         key.offset -= btrfs_file_extent_offset(buf, fi);
1672                         ret = process_func(trans, root, bytenr, num_bytes,
1673                                            parent, ref_root, key.objectid,
1674                                            key.offset);
1675                         if (ret) {
1676                                 WARN_ON(1);
1677                                 goto fail;
1678                         }
1679                 } else {
1680                         bytenr = btrfs_node_blockptr(buf, i);
1681                         num_bytes = root->fs_info->nodesize;
1682                         ret = process_func(trans, root, bytenr, num_bytes,
1683                                            parent, ref_root, level - 1, 0);
1684                         if (ret) {
1685                                 WARN_ON(1);
1686                                 goto fail;
1687                         }
1688                 }
1689         }
1690         return 0;
1691 fail:
1692         WARN_ON(1);
1693         return ret;
1694 }
1695
1696 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1697                   struct extent_buffer *buf, int record_parent)
1698 {
1699         return __btrfs_mod_ref(trans, root, buf, record_parent, 1);
1700 }
1701
1702 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1703                   struct extent_buffer *buf, int record_parent)
1704 {
1705         return __btrfs_mod_ref(trans, root, buf, record_parent, 0);
1706 }
1707
1708 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1709                                  struct btrfs_root *root,
1710                                  struct btrfs_path *path,
1711                                  struct btrfs_block_group_cache *cache)
1712 {
1713         int ret;
1714         int pending_ret;
1715         struct btrfs_root *extent_root = root->fs_info->extent_root;
1716         unsigned long bi;
1717         struct extent_buffer *leaf;
1718
1719         ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1720         if (ret < 0)
1721                 goto fail;
1722         BUG_ON(ret);
1723
1724         leaf = path->nodes[0];
1725         bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1726         write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1727         btrfs_mark_buffer_dirty(leaf);
1728         btrfs_release_path(path);
1729 fail:
1730         finish_current_insert(trans, extent_root);
1731         pending_ret = del_pending_extents(trans, extent_root);
1732         if (ret)
1733                 return ret;
1734         if (pending_ret)
1735                 return pending_ret;
1736         return 0;
1737
1738 }
1739
1740 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1741                                    struct btrfs_root *root)
1742 {
1743         struct extent_io_tree *block_group_cache;
1744         struct btrfs_block_group_cache *cache;
1745         int ret;
1746         struct btrfs_path *path;
1747         u64 last = 0;
1748         u64 start;
1749         u64 end;
1750         u64 ptr;
1751
1752         block_group_cache = &root->fs_info->block_group_cache;
1753         path = btrfs_alloc_path();
1754         if (!path)
1755                 return -ENOMEM;
1756
1757         while(1) {
1758                 ret = find_first_extent_bit(block_group_cache, last,
1759                                             &start, &end, BLOCK_GROUP_DIRTY);
1760                 if (ret) {
1761                         if (last == 0)
1762                                 break;
1763                         last = 0;
1764                         continue;
1765                 }
1766
1767                 last = end + 1;
1768                 ret = get_state_private(block_group_cache, start, &ptr);
1769                 BUG_ON(ret);
1770
1771                 clear_extent_bits(block_group_cache, start, end,
1772                                   BLOCK_GROUP_DIRTY);
1773
1774                 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
1775                 ret = write_one_cache_group(trans, root, path, cache);
1776         }
1777         btrfs_free_path(path);
1778         return 0;
1779 }
1780
1781 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1782                                                   u64 flags)
1783 {
1784         struct btrfs_space_info *found;
1785
1786         flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
1787
1788         list_for_each_entry(found, &info->space_info, list) {
1789                 if (found->flags & flags)
1790                         return found;
1791         }
1792         return NULL;
1793
1794 }
1795
1796 static int free_space_info(struct btrfs_fs_info *fs_info, u64 flags,
1797                           u64 total_bytes, u64 bytes_used,
1798                           struct btrfs_space_info **space_info)
1799 {
1800         struct btrfs_space_info *found;
1801
1802         /* only support free block group which is empty */
1803         if (bytes_used)
1804                 return -ENOTEMPTY;
1805
1806         found = __find_space_info(fs_info, flags);
1807         if (!found)
1808                 return -ENOENT;
1809         if (found->total_bytes < total_bytes) {
1810                 fprintf(stderr,
1811                         "WARNING: bad space info to free %llu only have %llu\n",
1812                         total_bytes, found->total_bytes);
1813                 return -EINVAL;
1814         }
1815         found->total_bytes -= total_bytes;
1816         if (space_info)
1817                 *space_info = found;
1818         return 0;
1819 }
1820
1821 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1822                              u64 total_bytes, u64 bytes_used,
1823                              struct btrfs_space_info **space_info)
1824 {
1825         struct btrfs_space_info *found;
1826
1827         found = __find_space_info(info, flags);
1828         if (found) {
1829                 found->total_bytes += total_bytes;
1830                 found->bytes_used += bytes_used;
1831                 if (found->total_bytes < found->bytes_used) {
1832                         fprintf(stderr, "warning, bad space info total_bytes "
1833                                 "%llu used %llu\n",
1834                                (unsigned long long)found->total_bytes,
1835                                (unsigned long long)found->bytes_used);
1836                 }
1837                 *space_info = found;
1838                 return 0;
1839         }
1840         found = kmalloc(sizeof(*found), GFP_NOFS);
1841         if (!found)
1842                 return -ENOMEM;
1843
1844         list_add(&found->list, &info->space_info);
1845         found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
1846         found->total_bytes = total_bytes;
1847         found->bytes_used = bytes_used;
1848         found->bytes_pinned = 0;
1849         found->full = 0;
1850         *space_info = found;
1851         return 0;
1852 }
1853
1854
1855 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1856 {
1857         u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1858                                    BTRFS_BLOCK_GROUP_RAID1 |
1859                                    BTRFS_BLOCK_GROUP_RAID10 |
1860                                    BTRFS_BLOCK_GROUP_RAID5 |
1861                                    BTRFS_BLOCK_GROUP_RAID6 |
1862                                    BTRFS_BLOCK_GROUP_DUP);
1863         if (extra_flags) {
1864                 if (flags & BTRFS_BLOCK_GROUP_DATA)
1865                         fs_info->avail_data_alloc_bits |= extra_flags;
1866                 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1867                         fs_info->avail_metadata_alloc_bits |= extra_flags;
1868                 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1869                         fs_info->avail_system_alloc_bits |= extra_flags;
1870         }
1871 }
1872
1873 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1874                           struct btrfs_fs_info *fs_info, u64 alloc_bytes,
1875                           u64 flags)
1876 {
1877         struct btrfs_space_info *space_info;
1878         u64 thresh;
1879         u64 start;
1880         u64 num_bytes;
1881         int ret;
1882
1883         space_info = __find_space_info(fs_info, flags);
1884         if (!space_info) {
1885                 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
1886                 BUG_ON(ret);
1887         }
1888         BUG_ON(!space_info);
1889
1890         if (space_info->full)
1891                 return 0;
1892
1893         thresh = div_factor(space_info->total_bytes, 7);
1894         if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1895             thresh)
1896                 return 0;
1897
1898         /*
1899          * Avoid allocating given chunk type
1900          */
1901         if (fs_info->avoid_meta_chunk_alloc &&
1902             (flags & BTRFS_BLOCK_GROUP_METADATA))
1903                 return 0;
1904         if (fs_info->avoid_sys_chunk_alloc &&
1905             (flags & BTRFS_BLOCK_GROUP_SYSTEM))
1906                 return 0;
1907
1908         ret = btrfs_alloc_chunk(trans, fs_info, &start, &num_bytes,
1909                                 space_info->flags);
1910         if (ret == -ENOSPC) {
1911                 space_info->full = 1;
1912                 return 0;
1913         }
1914
1915         BUG_ON(ret);
1916
1917         ret = btrfs_make_block_group(trans, fs_info, 0, space_info->flags,
1918                                      start, num_bytes);
1919         BUG_ON(ret);
1920         return 0;
1921 }
1922
1923 static int update_block_group(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);
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                         }
1976                 }
1977                 btrfs_set_block_group_used(&cache->item, old_val);
1978                 total -= num_bytes;
1979                 bytenr += num_bytes;
1980         }
1981         return 0;
1982 }
1983
1984 static int update_pinned_extents(struct btrfs_root *root,
1985                                 u64 bytenr, u64 num, int pin)
1986 {
1987         u64 len;
1988         struct btrfs_block_group_cache *cache;
1989         struct btrfs_fs_info *fs_info = root->fs_info;
1990
1991         if (pin) {
1992                 set_extent_dirty(&fs_info->pinned_extents,
1993                                 bytenr, bytenr + num - 1);
1994         } else {
1995                 clear_extent_dirty(&fs_info->pinned_extents,
1996                                 bytenr, bytenr + num - 1);
1997         }
1998         while (num > 0) {
1999                 cache = btrfs_lookup_block_group(fs_info, bytenr);
2000                 if (!cache) {
2001                         len = min((u64)fs_info->sectorsize, num);
2002                         goto next;
2003                 }
2004                 WARN_ON(!cache);
2005                 len = min(num, cache->key.offset -
2006                           (bytenr - cache->key.objectid));
2007                 if (pin) {
2008                         cache->pinned += len;
2009                         cache->space_info->bytes_pinned += len;
2010                         fs_info->total_pinned += len;
2011                 } else {
2012                         cache->pinned -= len;
2013                         cache->space_info->bytes_pinned -= len;
2014                         fs_info->total_pinned -= len;
2015                 }
2016 next:
2017                 bytenr += len;
2018                 num -= len;
2019         }
2020         return 0;
2021 }
2022
2023 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
2024                                struct btrfs_root *root,
2025                                struct extent_io_tree *unpin)
2026 {
2027         u64 start;
2028         u64 end;
2029         int ret;
2030         struct extent_io_tree *free_space_cache;
2031         free_space_cache = &root->fs_info->free_space_cache;
2032
2033         while(1) {
2034                 ret = find_first_extent_bit(unpin, 0, &start, &end,
2035                                             EXTENT_DIRTY);
2036                 if (ret)
2037                         break;
2038                 update_pinned_extents(root, start, end + 1 - start, 0);
2039                 clear_extent_dirty(unpin, start, end);
2040                 set_extent_dirty(free_space_cache, start, end);
2041         }
2042         return 0;
2043 }
2044
2045 static int extent_root_pending_ops(struct btrfs_fs_info *info)
2046 {
2047         u64 start;
2048         u64 end;
2049         int ret;
2050
2051         ret = find_first_extent_bit(&info->extent_ins, 0, &start,
2052                                     &end, EXTENT_LOCKED);
2053         if (!ret) {
2054                 ret = find_first_extent_bit(&info->pending_del, 0, &start, &end,
2055                                             EXTENT_LOCKED);
2056         }
2057         return ret == 0;
2058
2059 }
2060 static int finish_current_insert(struct btrfs_trans_handle *trans,
2061                                  struct btrfs_root *extent_root)
2062 {
2063         u64 start;
2064         u64 end;
2065         u64 priv;
2066         struct btrfs_fs_info *info = extent_root->fs_info;
2067         struct pending_extent_op *extent_op;
2068         struct btrfs_key key;
2069         int ret;
2070         int skinny_metadata =
2071                 btrfs_fs_incompat(extent_root->fs_info, SKINNY_METADATA);
2072
2073         while(1) {
2074                 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
2075                                             &end, EXTENT_LOCKED);
2076                 if (ret)
2077                         break;
2078
2079                 ret = get_state_private(&info->extent_ins, start, &priv);
2080                 BUG_ON(ret);
2081                 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2082
2083                 if (extent_op->type == PENDING_EXTENT_INSERT) {
2084                         key.objectid = start;
2085                         if (skinny_metadata) {
2086                                 key.offset = extent_op->level;
2087                                 key.type = BTRFS_METADATA_ITEM_KEY;
2088                         } else {
2089                                 key.offset = extent_op->num_bytes;
2090                                 key.type = BTRFS_EXTENT_ITEM_KEY;
2091                         }
2092                         ret = alloc_reserved_tree_block(trans, extent_root,
2093                                                 extent_root->root_key.objectid,
2094                                                 trans->transid,
2095                                                 extent_op->flags,
2096                                                 &extent_op->key,
2097                                                 extent_op->level, &key);
2098                         BUG_ON(ret);
2099                 } else {
2100                         BUG_ON(1);
2101                 }
2102
2103                 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED);
2104                 kfree(extent_op);
2105         }
2106         return 0;
2107 }
2108
2109 static int pin_down_bytes(struct btrfs_trans_handle *trans,
2110                           struct btrfs_root *root,
2111                           u64 bytenr, u64 num_bytes, int is_data)
2112 {
2113         int err = 0;
2114         struct extent_buffer *buf;
2115
2116         if (is_data)
2117                 goto pinit;
2118
2119         buf = btrfs_find_tree_block(root->fs_info, bytenr, num_bytes);
2120         if (!buf)
2121                 goto pinit;
2122
2123         /* we can reuse a block if it hasn't been written
2124          * and it is from this transaction.  We can't
2125          * reuse anything from the tree log root because
2126          * it has tiny sub-transactions.
2127          */
2128         if (btrfs_buffer_uptodate(buf, 0)) {
2129                 u64 header_owner = btrfs_header_owner(buf);
2130                 u64 header_transid = btrfs_header_generation(buf);
2131                 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
2132                     header_transid == trans->transid &&
2133                     !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
2134                         clean_tree_block(NULL, root, buf);
2135                         free_extent_buffer(buf);
2136                         return 1;
2137                 }
2138         }
2139         free_extent_buffer(buf);
2140 pinit:
2141         update_pinned_extents(root, bytenr, num_bytes, 1);
2142
2143         BUG_ON(err < 0);
2144         return 0;
2145 }
2146
2147 void btrfs_pin_extent(struct btrfs_fs_info *fs_info,
2148                        u64 bytenr, u64 num_bytes)
2149 {
2150         update_pinned_extents(fs_info->extent_root, bytenr, num_bytes, 1);
2151 }
2152
2153 void btrfs_unpin_extent(struct btrfs_fs_info *fs_info,
2154                         u64 bytenr, u64 num_bytes)
2155 {
2156         update_pinned_extents(fs_info->extent_root, bytenr, num_bytes, 0);
2157 }
2158
2159 /*
2160  * remove an extent from the root, returns 0 on success
2161  */
2162 static int __free_extent(struct btrfs_trans_handle *trans,
2163                          struct btrfs_root *root,
2164                          u64 bytenr, u64 num_bytes, u64 parent,
2165                          u64 root_objectid, u64 owner_objectid,
2166                          u64 owner_offset, int refs_to_drop)
2167 {
2168
2169         struct btrfs_key key;
2170         struct btrfs_path *path;
2171         struct btrfs_root *extent_root = root->fs_info->extent_root;
2172         struct extent_buffer *leaf;
2173         struct btrfs_extent_item *ei;
2174         struct btrfs_extent_inline_ref *iref;
2175         int ret;
2176         int is_data;
2177         int extent_slot = 0;
2178         int found_extent = 0;
2179         int num_to_del = 1;
2180         u32 item_size;
2181         u64 refs;
2182         int skinny_metadata =
2183                 btrfs_fs_incompat(extent_root->fs_info, SKINNY_METADATA);
2184
2185         if (root->fs_info->free_extent_hook) {
2186                 root->fs_info->free_extent_hook(trans, root, bytenr, num_bytes,
2187                                                 parent, root_objectid, owner_objectid,
2188                                                 owner_offset, refs_to_drop);
2189
2190         }
2191         path = btrfs_alloc_path();
2192         if (!path)
2193                 return -ENOMEM;
2194
2195         path->reada = 1;
2196
2197         is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
2198         if (is_data)
2199                 skinny_metadata = 0;
2200         BUG_ON(!is_data && refs_to_drop != 1);
2201
2202         ret = lookup_extent_backref(trans, extent_root, path, &iref,
2203                                     bytenr, num_bytes, parent,
2204                                     root_objectid, owner_objectid,
2205                                     owner_offset);
2206         if (ret == 0) {
2207                 extent_slot = path->slots[0];
2208                 while (extent_slot >= 0) {
2209                         btrfs_item_key_to_cpu(path->nodes[0], &key,
2210                                               extent_slot);
2211                         if (key.objectid != bytenr)
2212                                 break;
2213                         if (key.type == BTRFS_EXTENT_ITEM_KEY &&
2214                             key.offset == num_bytes) {
2215                                 found_extent = 1;
2216                                 break;
2217                         }
2218                         if (key.type == BTRFS_METADATA_ITEM_KEY &&
2219                             key.offset == owner_objectid) {
2220                                 found_extent = 1;
2221                                 break;
2222                         }
2223                         if (path->slots[0] - extent_slot > 5)
2224                                 break;
2225                         extent_slot--;
2226                 }
2227 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2228                 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
2229                 if (found_extent && item_size < sizeof(*ei))
2230                         found_extent = 0;
2231 #endif
2232                 if (!found_extent) {
2233                         BUG_ON(iref);
2234                         ret = remove_extent_backref(trans, extent_root, path,
2235                                                     NULL, refs_to_drop,
2236                                                     is_data);
2237                         BUG_ON(ret);
2238                         btrfs_release_path(path);
2239
2240                         key.objectid = bytenr;
2241
2242                         if (skinny_metadata) {
2243                                 key.type = BTRFS_METADATA_ITEM_KEY;
2244                                 key.offset = owner_objectid;
2245                         } else {
2246                                 key.type = BTRFS_EXTENT_ITEM_KEY;
2247                                 key.offset = num_bytes;
2248                         }
2249
2250                         ret = btrfs_search_slot(trans, extent_root,
2251                                                 &key, path, -1, 1);
2252                         if (ret > 0 && skinny_metadata && path->slots[0]) {
2253                                 path->slots[0]--;
2254                                 btrfs_item_key_to_cpu(path->nodes[0],
2255                                                       &key,
2256                                                       path->slots[0]);
2257                                 if (key.objectid == bytenr &&
2258                                     key.type == BTRFS_EXTENT_ITEM_KEY &&
2259                                     key.offset == num_bytes)
2260                                         ret = 0;
2261                         }
2262
2263                         if (ret > 0 && skinny_metadata) {
2264                                 skinny_metadata = 0;
2265                                 btrfs_release_path(path);
2266                                 key.type = BTRFS_EXTENT_ITEM_KEY;
2267                                 key.offset = num_bytes;
2268                                 ret = btrfs_search_slot(trans, extent_root,
2269                                                         &key, path, -1, 1);
2270                         }
2271
2272                         if (ret) {
2273                                 printk(KERN_ERR "umm, got %d back from search"
2274                                        ", was looking for %llu\n", ret,
2275                                        (unsigned long long)bytenr);
2276                                 btrfs_print_leaf(path->nodes[0]);
2277                         }
2278                         BUG_ON(ret);
2279                         extent_slot = path->slots[0];
2280                 }
2281         } else {
2282                 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
2283                        "parent %llu root %llu  owner %llu offset %llu\n",
2284                        (unsigned long long)bytenr,
2285                        (unsigned long long)parent,
2286                        (unsigned long long)root_objectid,
2287                        (unsigned long long)owner_objectid,
2288                        (unsigned long long)owner_offset);
2289                 ret = -EIO;
2290                 goto fail;
2291         }
2292
2293         leaf = path->nodes[0];
2294         item_size = btrfs_item_size_nr(leaf, extent_slot);
2295 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2296         if (item_size < sizeof(*ei)) {
2297                 BUG_ON(found_extent || extent_slot != path->slots[0]);
2298                 ret = convert_extent_item_v0(trans, extent_root, path,
2299                                              owner_objectid, 0);
2300                 BUG_ON(ret < 0);
2301
2302                 btrfs_release_path(path);
2303
2304                 key.objectid = bytenr;
2305                 key.type = BTRFS_EXTENT_ITEM_KEY;
2306                 key.offset = num_bytes;
2307
2308                 ret = btrfs_search_slot(trans, extent_root, &key, path,
2309                                         -1, 1);
2310                 if (ret) {
2311                         printk(KERN_ERR "umm, got %d back from search"
2312                                ", was looking for %llu\n", ret,
2313                                (unsigned long long)bytenr);
2314                         btrfs_print_leaf(path->nodes[0]);
2315                 }
2316                 BUG_ON(ret);
2317                 extent_slot = path->slots[0];
2318                 leaf = path->nodes[0];
2319                 item_size = btrfs_item_size_nr(leaf, extent_slot);
2320         }
2321 #endif
2322         BUG_ON(item_size < sizeof(*ei));
2323         ei = btrfs_item_ptr(leaf, extent_slot,
2324                             struct btrfs_extent_item);
2325         if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
2326             key.type == BTRFS_EXTENT_ITEM_KEY) {
2327                 struct btrfs_tree_block_info *bi;
2328                 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
2329                 bi = (struct btrfs_tree_block_info *)(ei + 1);
2330                 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
2331         }
2332
2333         refs = btrfs_extent_refs(leaf, ei);
2334         BUG_ON(refs < refs_to_drop);
2335         refs -= refs_to_drop;
2336
2337         if (refs > 0) {
2338                 /*
2339                  * In the case of inline back ref, reference count will
2340                  * be updated by remove_extent_backref
2341                  */
2342                 if (iref) {
2343                         BUG_ON(!found_extent);
2344                 } else {
2345                         btrfs_set_extent_refs(leaf, ei, refs);
2346                         btrfs_mark_buffer_dirty(leaf);
2347                 }
2348                 if (found_extent) {
2349                         ret = remove_extent_backref(trans, extent_root, path,
2350                                                     iref, refs_to_drop,
2351                                                     is_data);
2352                         BUG_ON(ret);
2353                 }
2354         } else {
2355                 int mark_free = 0;
2356                 int pin = 1;
2357
2358                 if (found_extent) {
2359                         BUG_ON(is_data && refs_to_drop !=
2360                                extent_data_ref_count(path, iref));
2361                         if (iref) {
2362                                 BUG_ON(path->slots[0] != extent_slot);
2363                         } else {
2364                                 BUG_ON(path->slots[0] != extent_slot + 1);
2365                                 path->slots[0] = extent_slot;
2366                                 num_to_del = 2;
2367                         }
2368                 }
2369
2370                 if (pin) {
2371                         ret = pin_down_bytes(trans, root, bytenr, num_bytes,
2372                                              is_data);
2373                         if (ret > 0)
2374                                 mark_free = 1;
2375                         BUG_ON(ret < 0);
2376                 }
2377
2378                 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2379                                       num_to_del);
2380                 BUG_ON(ret);
2381                 btrfs_release_path(path);
2382
2383                 if (is_data) {
2384                         ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
2385                         BUG_ON(ret);
2386                 }
2387
2388                 update_block_group(root, bytenr, num_bytes, 0, mark_free);
2389         }
2390 fail:
2391         btrfs_free_path(path);
2392         finish_current_insert(trans, extent_root);
2393         return ret;
2394 }
2395
2396 /*
2397  * find all the blocks marked as pending in the radix tree and remove
2398  * them from the extent map
2399  */
2400 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2401                                btrfs_root *extent_root)
2402 {
2403         int ret;
2404         int err = 0;
2405         u64 start;
2406         u64 end;
2407         u64 priv;
2408         struct extent_io_tree *pending_del;
2409         struct extent_io_tree *extent_ins;
2410         struct pending_extent_op *extent_op;
2411
2412         extent_ins = &extent_root->fs_info->extent_ins;
2413         pending_del = &extent_root->fs_info->pending_del;
2414
2415         while(1) {
2416                 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2417                                             EXTENT_LOCKED);
2418                 if (ret)
2419                         break;
2420
2421                 ret = get_state_private(pending_del, start, &priv);
2422                 BUG_ON(ret);
2423                 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2424
2425                 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED);
2426
2427                 if (!test_range_bit(extent_ins, start, end,
2428                                     EXTENT_LOCKED, 0)) {
2429                         ret = __free_extent(trans, extent_root,
2430                                             start, end + 1 - start, 0,
2431                                             extent_root->root_key.objectid,
2432                                             extent_op->level, 0, 1);
2433                         kfree(extent_op);
2434                 } else {
2435                         kfree(extent_op);
2436                         ret = get_state_private(extent_ins, start, &priv);
2437                         BUG_ON(ret);
2438                         extent_op = (struct pending_extent_op *)
2439                                                         (unsigned long)priv;
2440
2441                         clear_extent_bits(extent_ins, start, end,
2442                                           EXTENT_LOCKED);
2443
2444                         if (extent_op->type == PENDING_BACKREF_UPDATE)
2445                                 BUG_ON(1);
2446
2447                         kfree(extent_op);
2448                 }
2449                 if (ret)
2450                         err = ret;
2451         }
2452         return err;
2453 }
2454
2455
2456 int btrfs_free_tree_block(struct btrfs_trans_handle *trans,
2457                           struct btrfs_root *root,
2458                           struct extent_buffer *buf,
2459                           u64 parent, int last_ref)
2460 {
2461         return btrfs_free_extent(trans, root, buf->start, buf->len, parent,
2462                                  root->root_key.objectid,
2463                                  btrfs_header_level(buf), 0);
2464 }
2465
2466 /*
2467  * remove an extent from the root, returns 0 on success
2468  */
2469
2470 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2471                       struct btrfs_root *root,
2472                       u64 bytenr, u64 num_bytes, u64 parent,
2473                       u64 root_objectid, u64 owner, u64 offset)
2474 {
2475         struct btrfs_root *extent_root = root->fs_info->extent_root;
2476         int pending_ret;
2477         int ret;
2478
2479         WARN_ON(num_bytes < root->fs_info->sectorsize);
2480         if (root == extent_root) {
2481                 struct pending_extent_op *extent_op;
2482
2483                 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2484                 BUG_ON(!extent_op);
2485
2486                 extent_op->type = PENDING_EXTENT_DELETE;
2487                 extent_op->bytenr = bytenr;
2488                 extent_op->num_bytes = num_bytes;
2489                 extent_op->level = (int)owner;
2490
2491                 set_extent_bits(&root->fs_info->pending_del,
2492                                 bytenr, bytenr + num_bytes - 1,
2493                                 EXTENT_LOCKED);
2494                 set_state_private(&root->fs_info->pending_del,
2495                                   bytenr, (unsigned long)extent_op);
2496                 return 0;
2497         }
2498         ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2499                             root_objectid, owner, offset, 1);
2500         pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2501         return ret ? ret : pending_ret;
2502 }
2503
2504 static u64 stripe_align(struct btrfs_root *root, u64 val)
2505 {
2506         return round_up(val, (u64)root->fs_info->stripesize);
2507 }
2508
2509 /*
2510  * walks the btree of allocated extents and find a hole of a given size.
2511  * The key ins is changed to record the hole:
2512  * ins->objectid == block start
2513  * ins->flags = BTRFS_EXTENT_ITEM_KEY
2514  * ins->offset == number of blocks
2515  * Any available blocks before search_start are skipped.
2516  */
2517 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2518                                      struct btrfs_root *orig_root,
2519                                      u64 num_bytes, u64 empty_size,
2520                                      u64 search_start, u64 search_end,
2521                                      u64 hint_byte, struct btrfs_key *ins,
2522                                      u64 exclude_start, u64 exclude_nr,
2523                                      int data)
2524 {
2525         int ret;
2526         u64 orig_search_start = search_start;
2527         struct btrfs_root * root = orig_root->fs_info->extent_root;
2528         struct btrfs_fs_info *info = root->fs_info;
2529         u64 total_needed = num_bytes;
2530         struct btrfs_block_group_cache *block_group;
2531         int full_scan = 0;
2532         int wrapped = 0;
2533
2534         WARN_ON(num_bytes < info->sectorsize);
2535         ins->type = BTRFS_EXTENT_ITEM_KEY;
2536
2537         search_start = stripe_align(root, search_start);
2538
2539         if (hint_byte) {
2540                 block_group = btrfs_lookup_first_block_group(info, hint_byte);
2541                 if (!block_group)
2542                         hint_byte = search_start;
2543                 block_group = btrfs_find_block_group(root, block_group,
2544                                                      hint_byte, data, 1);
2545         } else {
2546                 block_group = btrfs_find_block_group(root,
2547                                                      trans->block_group,
2548                                                      search_start, data, 1);
2549         }
2550
2551         total_needed += empty_size;
2552
2553 check_failed:
2554         search_start = stripe_align(root, search_start);
2555         if (!block_group) {
2556                 block_group = btrfs_lookup_first_block_group(info,
2557                                                              search_start);
2558                 if (!block_group)
2559                         block_group = btrfs_lookup_first_block_group(info,
2560                                                        orig_search_start);
2561         }
2562         ret = find_search_start(root, &block_group, &search_start,
2563                                 total_needed, data);
2564         if (ret)
2565                 goto new_group;
2566
2567         ins->objectid = search_start;
2568         ins->offset = num_bytes;
2569
2570         if (ins->objectid + num_bytes >
2571             block_group->key.objectid + block_group->key.offset) {
2572                 search_start = block_group->key.objectid +
2573                         block_group->key.offset;
2574                 goto new_group;
2575         }
2576
2577         if (test_range_bit(&info->extent_ins, ins->objectid,
2578                            ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
2579                 search_start = ins->objectid + num_bytes;
2580                 goto new_group;
2581         }
2582
2583         if (test_range_bit(&info->pinned_extents, ins->objectid,
2584                            ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2585                 search_start = ins->objectid + num_bytes;
2586                 goto new_group;
2587         }
2588
2589         if (info->excluded_extents &&
2590             test_range_bit(info->excluded_extents, ins->objectid,
2591                            ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2592                 search_start = ins->objectid + num_bytes;
2593                 goto new_group;
2594         }
2595
2596         if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2597             ins->objectid < exclude_start + exclude_nr)) {
2598                 search_start = exclude_start + exclude_nr;
2599                 goto new_group;
2600         }
2601
2602         if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
2603                 if (check_crossing_stripes(info, ins->objectid, num_bytes)) {
2604                         struct btrfs_block_group_cache *bg_cache;
2605                         u64 bg_offset;
2606
2607                         bg_cache = btrfs_lookup_block_group(info, ins->objectid);
2608                         if (!bg_cache)
2609                                 goto no_bg_cache;
2610                         bg_offset = ins->objectid - bg_cache->key.objectid;
2611
2612                         search_start = round_up(
2613                                 bg_offset + num_bytes, BTRFS_STRIPE_LEN) +
2614                                 bg_cache->key.objectid;
2615                         goto new_group;
2616                 }
2617 no_bg_cache:
2618                 block_group = btrfs_lookup_block_group(info, ins->objectid);
2619                 if (block_group)
2620                         trans->block_group = block_group;
2621         }
2622         ins->offset = num_bytes;
2623         return 0;
2624
2625 new_group:
2626         block_group = btrfs_lookup_first_block_group(info, search_start);
2627         if (!block_group) {
2628                 search_start = orig_search_start;
2629                 if (full_scan) {
2630                         ret = -ENOSPC;
2631                         goto error;
2632                 }
2633                 if (wrapped) {
2634                         if (!full_scan)
2635                                 total_needed -= empty_size;
2636                         full_scan = 1;
2637                 } else
2638                         wrapped = 1;
2639         }
2640         cond_resched();
2641         block_group = btrfs_find_block_group(root, block_group,
2642                                              search_start, data, 0);
2643         goto check_failed;
2644
2645 error:
2646         return ret;
2647 }
2648
2649 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2650                          struct btrfs_root *root,
2651                          u64 num_bytes, u64 empty_size,
2652                          u64 hint_byte, u64 search_end,
2653                          struct btrfs_key *ins, bool is_data)
2654 {
2655         int ret;
2656         u64 search_start = 0;
2657         u64 alloc_profile;
2658         u64 profile;
2659         struct btrfs_fs_info *info = root->fs_info;
2660
2661         if (is_data) {
2662                 alloc_profile = info->avail_data_alloc_bits &
2663                                 info->data_alloc_profile;
2664                 profile = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2665         } else if (info->system_allocs == 1 || root == info->chunk_root) {
2666                 alloc_profile = info->avail_system_alloc_bits &
2667                                 info->system_alloc_profile;
2668                 profile = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2669         } else {
2670                 alloc_profile = info->avail_metadata_alloc_bits &
2671                                 info->metadata_alloc_profile;
2672                 profile = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2673         }
2674
2675         if (root->ref_cows) {
2676                 if (!(profile & BTRFS_BLOCK_GROUP_METADATA)) {
2677                         ret = do_chunk_alloc(trans, info,
2678                                              num_bytes,
2679                                              BTRFS_BLOCK_GROUP_METADATA);
2680                         BUG_ON(ret);
2681                 }
2682                 ret = do_chunk_alloc(trans, info,
2683                                      num_bytes + SZ_2M, profile);
2684                 BUG_ON(ret);
2685         }
2686
2687         WARN_ON(num_bytes < info->sectorsize);
2688         ret = find_free_extent(trans, root, num_bytes, empty_size,
2689                                search_start, search_end, hint_byte, ins,
2690                                trans->alloc_exclude_start,
2691                                trans->alloc_exclude_nr, profile);
2692         if (ret < 0)
2693                 return ret;
2694         clear_extent_dirty(&info->free_space_cache,
2695                            ins->objectid, ins->objectid + ins->offset - 1);
2696         return ret;
2697 }
2698
2699 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
2700                                      struct btrfs_root *root,
2701                                      u64 root_objectid, u64 generation,
2702                                      u64 flags, struct btrfs_disk_key *key,
2703                                      int level, struct btrfs_key *ins)
2704 {
2705         int ret;
2706         struct btrfs_fs_info *fs_info = root->fs_info;
2707         struct btrfs_extent_item *extent_item;
2708         struct btrfs_tree_block_info *block_info;
2709         struct btrfs_extent_inline_ref *iref;
2710         struct btrfs_path *path;
2711         struct extent_buffer *leaf;
2712         u32 size = sizeof(*extent_item) + sizeof(*iref);
2713         int skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
2714
2715         if (!skinny_metadata)
2716                 size += sizeof(*block_info);
2717
2718         path = btrfs_alloc_path();
2719         if (!path)
2720                 return -ENOMEM;
2721
2722         ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
2723                                       ins, size);
2724         BUG_ON(ret);
2725
2726         leaf = path->nodes[0];
2727         extent_item = btrfs_item_ptr(leaf, path->slots[0],
2728                                      struct btrfs_extent_item);
2729         btrfs_set_extent_refs(leaf, extent_item, 1);
2730         btrfs_set_extent_generation(leaf, extent_item, generation);
2731         btrfs_set_extent_flags(leaf, extent_item,
2732                                flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
2733
2734         if (skinny_metadata) {
2735                 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
2736         } else {
2737                 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
2738                 btrfs_set_tree_block_key(leaf, block_info, key);
2739                 btrfs_set_tree_block_level(leaf, block_info, level);
2740                 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
2741         }
2742
2743         btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_TREE_BLOCK_REF_KEY);
2744         btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
2745
2746         btrfs_mark_buffer_dirty(leaf);
2747         btrfs_free_path(path);
2748
2749         ret = update_block_group(root, ins->objectid, fs_info->nodesize,
2750                                  1, 0);
2751         return ret;
2752 }
2753
2754 static int alloc_tree_block(struct btrfs_trans_handle *trans,
2755                             struct btrfs_root *root, u64 num_bytes,
2756                             u64 root_objectid, u64 generation,
2757                             u64 flags, struct btrfs_disk_key *key,
2758                             int level, u64 empty_size, u64 hint_byte,
2759                             u64 search_end, struct btrfs_key *ins)
2760 {
2761         int ret;
2762         ret = btrfs_reserve_extent(trans, root, num_bytes, empty_size,
2763                                    hint_byte, search_end, ins, 0);
2764         BUG_ON(ret);
2765
2766         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) {
2767                 struct pending_extent_op *extent_op;
2768
2769                 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2770                 BUG_ON(!extent_op);
2771
2772                 extent_op->type = PENDING_EXTENT_INSERT;
2773                 extent_op->bytenr = ins->objectid;
2774                 extent_op->num_bytes = ins->offset;
2775                 extent_op->level = level;
2776                 extent_op->flags = flags;
2777                 memcpy(&extent_op->key, key, sizeof(*key));
2778
2779                 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2780                                 ins->objectid + ins->offset - 1,
2781                                 EXTENT_LOCKED);
2782                 set_state_private(&root->fs_info->extent_ins,
2783                                   ins->objectid, (unsigned long)extent_op);
2784         } else {
2785                 if (btrfs_fs_incompat(root->fs_info, 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->fs_info, ins.objectid);
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 > SZ_32K) ||
2900                              (last > bytenr && last - bytenr > SZ_32K))) {
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);
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, end);
3122         }
3123
3124         while (!list_empty(&info->space_info)) {
3125                 sinfo = list_entry(info->space_info.next,
3126                                    struct btrfs_space_info, list);
3127                 list_del_init(&sinfo->list);
3128                 kfree(sinfo);
3129         }
3130         return 0;
3131 }
3132
3133 static int find_first_block_group(struct btrfs_root *root,
3134                 struct btrfs_path *path, struct btrfs_key *key)
3135 {
3136         int ret;
3137         struct btrfs_key found_key;
3138         struct extent_buffer *leaf;
3139         int slot;
3140
3141         ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
3142         if (ret < 0)
3143                 return ret;
3144         while(1) {
3145                 slot = path->slots[0];
3146                 leaf = path->nodes[0];
3147                 if (slot >= btrfs_header_nritems(leaf)) {
3148                         ret = btrfs_next_leaf(root, path);
3149                         if (ret == 0)
3150                                 continue;
3151                         if (ret < 0)
3152                                 goto error;
3153                         break;
3154                 }
3155                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3156
3157                 if (found_key.objectid >= key->objectid &&
3158                     found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
3159                         return 0;
3160                 path->slots[0]++;
3161         }
3162         ret = -ENOENT;
3163 error:
3164         return ret;
3165 }
3166
3167 static void account_super_bytes(struct btrfs_fs_info *fs_info,
3168                                 struct btrfs_block_group_cache *cache)
3169 {
3170         u64 bytenr;
3171         u64 *logical;
3172         int stripe_len;
3173         int i, nr, ret;
3174
3175         if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
3176                 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
3177                 cache->bytes_super += stripe_len;
3178         }
3179
3180         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3181                 bytenr = btrfs_sb_offset(i);
3182                 ret = btrfs_rmap_block(fs_info,
3183                                        cache->key.objectid, bytenr,
3184                                        0, &logical, &nr, &stripe_len);
3185                 if (ret)
3186                         return;
3187
3188                 while (nr--) {
3189                         u64 start, len;
3190
3191                         if (logical[nr] > cache->key.objectid +
3192                             cache->key.offset)
3193                                 continue;
3194
3195                         if (logical[nr] + stripe_len <= cache->key.objectid)
3196                                 continue;
3197
3198                         start = logical[nr];
3199                         if (start < cache->key.objectid) {
3200                                 start = cache->key.objectid;
3201                                 len = (logical[nr] + stripe_len) - start;
3202                         } else {
3203                                 len = min_t(u64, stripe_len,
3204                                             cache->key.objectid +
3205                                             cache->key.offset - start);
3206                         }
3207
3208                         cache->bytes_super += len;
3209                 }
3210
3211                 kfree(logical);
3212         }
3213 }
3214
3215 int btrfs_read_block_groups(struct btrfs_root *root)
3216 {
3217         struct btrfs_path *path;
3218         int ret;
3219         int bit;
3220         struct btrfs_block_group_cache *cache;
3221         struct btrfs_fs_info *info = root->fs_info;
3222         struct btrfs_space_info *space_info;
3223         struct extent_io_tree *block_group_cache;
3224         struct btrfs_key key;
3225         struct btrfs_key found_key;
3226         struct extent_buffer *leaf;
3227
3228         block_group_cache = &info->block_group_cache;
3229
3230         root = info->extent_root;
3231         key.objectid = 0;
3232         key.offset = 0;
3233         key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3234         path = btrfs_alloc_path();
3235         if (!path)
3236                 return -ENOMEM;
3237
3238         while(1) {
3239                 ret = find_first_block_group(root, path, &key);
3240                 if (ret > 0) {
3241                         ret = 0;
3242                         goto error;
3243                 }
3244                 if (ret != 0) {
3245                         goto error;
3246                 }
3247                 leaf = path->nodes[0];
3248                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3249
3250                 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3251                 if (!cache) {
3252                         ret = -ENOMEM;
3253                         goto error;
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                 if (found_key.offset == 0)
3264                         key.objectid++;
3265                 btrfs_release_path(path);
3266
3267                 /*
3268                  * Skip 0 sized block group, don't insert them into block
3269                  * group cache tree, as its length is 0, it won't get
3270                  * freed at close_ctree() time.
3271                  */
3272                 if (found_key.offset == 0) {
3273                         free(cache);
3274                         continue;
3275                 }
3276
3277                 cache->flags = btrfs_block_group_flags(&cache->item);
3278                 bit = 0;
3279                 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
3280                         bit = BLOCK_GROUP_DATA;
3281                 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
3282                         bit = BLOCK_GROUP_SYSTEM;
3283                 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
3284                         bit = BLOCK_GROUP_METADATA;
3285                 }
3286                 set_avail_alloc_bits(info, cache->flags);
3287                 if (btrfs_chunk_readonly(info, cache->key.objectid))
3288                         cache->ro = 1;
3289
3290                 account_super_bytes(info, cache);
3291
3292                 ret = update_space_info(info, cache->flags, found_key.offset,
3293                                         btrfs_block_group_used(&cache->item),
3294                                         &space_info);
3295                 BUG_ON(ret);
3296                 cache->space_info = space_info;
3297
3298                 /* use EXTENT_LOCKED to prevent merging */
3299                 set_extent_bits(block_group_cache, found_key.objectid,
3300                                 found_key.objectid + found_key.offset - 1,
3301                                 bit | EXTENT_LOCKED);
3302                 set_state_private(block_group_cache, found_key.objectid,
3303                                   (unsigned long)cache);
3304         }
3305         ret = 0;
3306 error:
3307         btrfs_free_path(path);
3308         return ret;
3309 }
3310
3311 struct btrfs_block_group_cache *
3312 btrfs_add_block_group(struct btrfs_fs_info *fs_info, u64 bytes_used, u64 type,
3313                       u64 chunk_offset, u64 size)
3314 {
3315         int ret;
3316         int bit = 0;
3317         struct btrfs_block_group_cache *cache;
3318         struct extent_io_tree *block_group_cache;
3319
3320         block_group_cache = &fs_info->block_group_cache;
3321
3322         cache = kzalloc(sizeof(*cache), GFP_NOFS);
3323         BUG_ON(!cache);
3324         cache->key.objectid = chunk_offset;
3325         cache->key.offset = size;
3326
3327         cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3328         btrfs_set_block_group_used(&cache->item, bytes_used);
3329         btrfs_set_block_group_chunk_objectid(&cache->item,
3330                                              BTRFS_FIRST_CHUNK_TREE_OBJECTID);
3331         cache->flags = type;
3332         btrfs_set_block_group_flags(&cache->item, type);
3333
3334         account_super_bytes(fs_info, cache);
3335         ret = update_space_info(fs_info, cache->flags, size, bytes_used,
3336                                 &cache->space_info);
3337         BUG_ON(ret);
3338
3339         bit = block_group_state_bits(type);
3340         ret = set_extent_bits(block_group_cache, chunk_offset,
3341                               chunk_offset + size - 1,
3342                               bit | EXTENT_LOCKED);
3343         BUG_ON(ret);
3344
3345         ret = set_state_private(block_group_cache, chunk_offset,
3346                                 (unsigned long)cache);
3347         BUG_ON(ret);
3348         set_avail_alloc_bits(fs_info, type);
3349
3350         return cache;
3351 }
3352
3353 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
3354                            struct btrfs_fs_info *fs_info, u64 bytes_used,
3355                            u64 type, u64 chunk_offset, u64 size)
3356 {
3357         int ret;
3358         struct btrfs_root *extent_root = fs_info->extent_root;
3359         struct btrfs_block_group_cache *cache;
3360
3361         cache = btrfs_add_block_group(fs_info, bytes_used, type, chunk_offset,
3362                                       size);
3363         ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3364                                 sizeof(cache->item));
3365         BUG_ON(ret);
3366
3367         ret = finish_current_insert(trans, extent_root);
3368         BUG_ON(ret);
3369         ret = del_pending_extents(trans, extent_root);
3370         BUG_ON(ret);
3371
3372         return 0;
3373 }
3374
3375 /*
3376  * This is for converter use only.
3377  *
3378  * In that case, we don't know where are free blocks located.
3379  * Therefore all block group cache entries must be setup properly
3380  * before doing any block allocation.
3381  */
3382 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
3383                             struct btrfs_fs_info *fs_info)
3384 {
3385         u64 total_bytes;
3386         u64 cur_start;
3387         u64 group_type;
3388         u64 group_size;
3389         u64 group_align;
3390         u64 total_data = 0;
3391         u64 total_metadata = 0;
3392         u64 chunk_objectid;
3393         int ret;
3394         int bit;
3395         struct btrfs_root *extent_root = fs_info->extent_root;
3396         struct btrfs_block_group_cache *cache;
3397         struct extent_io_tree *block_group_cache;
3398
3399         block_group_cache = &fs_info->block_group_cache;
3400         chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3401         total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
3402         group_align = 64 * fs_info->sectorsize;
3403
3404         cur_start = 0;
3405         while (cur_start < total_bytes) {
3406                 group_size = total_bytes / 12;
3407                 group_size = min_t(u64, group_size, total_bytes - cur_start);
3408                 if (cur_start == 0) {
3409                         bit = BLOCK_GROUP_SYSTEM;
3410                         group_type = BTRFS_BLOCK_GROUP_SYSTEM;
3411                         group_size /= 4;
3412                         group_size &= ~(group_align - 1);
3413                         group_size = max_t(u64, group_size, SZ_8M);
3414                         group_size = min_t(u64, group_size, SZ_32M);
3415                 } else {
3416                         group_size &= ~(group_align - 1);
3417                         if (total_data >= total_metadata * 2) {
3418                                 group_type = BTRFS_BLOCK_GROUP_METADATA;
3419                                 group_size = min_t(u64, group_size, SZ_1G);
3420                                 total_metadata += group_size;
3421                         } else {
3422                                 group_type = BTRFS_BLOCK_GROUP_DATA;
3423                                 group_size = min_t(u64, group_size,
3424                                                    5ULL * SZ_1G);
3425                                 total_data += group_size;
3426                         }
3427                         if ((total_bytes - cur_start) * 4 < group_size * 5)
3428                                 group_size = total_bytes - cur_start;
3429                 }
3430
3431                 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3432                 BUG_ON(!cache);
3433
3434                 cache->key.objectid = cur_start;
3435                 cache->key.offset = group_size;
3436                 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3437
3438                 btrfs_set_block_group_used(&cache->item, 0);
3439                 btrfs_set_block_group_chunk_objectid(&cache->item,
3440                                                      chunk_objectid);
3441                 btrfs_set_block_group_flags(&cache->item, group_type);
3442
3443                 cache->flags = group_type;
3444
3445                 ret = update_space_info(fs_info, group_type, group_size,
3446                                         0, &cache->space_info);
3447                 BUG_ON(ret);
3448                 set_avail_alloc_bits(fs_info, group_type);
3449
3450                 set_extent_bits(block_group_cache, cur_start,
3451                                 cur_start + group_size - 1,
3452                                 bit | EXTENT_LOCKED);
3453                 set_state_private(block_group_cache, cur_start,
3454                                   (unsigned long)cache);
3455                 cur_start += group_size;
3456         }
3457         /* then insert all the items */
3458         cur_start = 0;
3459         while(cur_start < total_bytes) {
3460                 cache = btrfs_lookup_block_group(fs_info, cur_start);
3461                 BUG_ON(!cache);
3462
3463                 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3464                                         sizeof(cache->item));
3465                 BUG_ON(ret);
3466
3467                 finish_current_insert(trans, extent_root);
3468                 ret = del_pending_extents(trans, extent_root);
3469                 BUG_ON(ret);
3470
3471                 cur_start = cache->key.objectid + cache->key.offset;
3472         }
3473         return 0;
3474 }
3475
3476 int btrfs_update_block_group(struct btrfs_root *root,
3477                              u64 bytenr, u64 num_bytes, int alloc,
3478                              int mark_free)
3479 {
3480         return update_block_group(root, bytenr, num_bytes,
3481                                   alloc, mark_free);
3482 }
3483
3484 /*
3485  * Just remove a block group item in extent tree
3486  * Caller should ensure the block group is empty and all space is pinned.
3487  * Or new tree block/data may be allocated into it.
3488  */
3489 static int free_block_group_item(struct btrfs_trans_handle *trans,
3490                                  struct btrfs_fs_info *fs_info,
3491                                  u64 bytenr, u64 len)
3492 {
3493         struct btrfs_path *path;
3494         struct btrfs_key key;
3495         struct btrfs_root *root = fs_info->extent_root;
3496         int ret = 0;
3497
3498         key.objectid = bytenr;
3499         key.offset = len;
3500         key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3501
3502         path = btrfs_alloc_path();
3503         if (!path)
3504                 return -ENOMEM;
3505
3506         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3507         if (ret > 0) {
3508                 ret = -ENOENT;
3509                 goto out;
3510         }
3511         if (ret < 0)
3512                 goto out;
3513
3514         ret = btrfs_del_item(trans, root, path);
3515 out:
3516         btrfs_free_path(path);
3517         return ret;
3518 }
3519
3520 static int free_dev_extent_item(struct btrfs_trans_handle *trans,
3521                                 struct btrfs_fs_info *fs_info,
3522                                 u64 devid, u64 dev_offset)
3523 {
3524         struct btrfs_root *root = fs_info->dev_root;
3525         struct btrfs_path *path;
3526         struct btrfs_key key;
3527         int ret;
3528
3529         path = btrfs_alloc_path();
3530         if (!path)
3531                 return -ENOMEM;
3532
3533         key.objectid = devid;
3534         key.type = BTRFS_DEV_EXTENT_KEY;
3535         key.offset = dev_offset;
3536
3537         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3538         if (ret < 0)
3539                 goto out;
3540         if (ret > 0) {
3541                 ret = -ENOENT;
3542                 goto out;
3543         }
3544
3545         ret = btrfs_del_item(trans, root, path);
3546 out:
3547         btrfs_free_path(path);
3548         return ret;
3549 }
3550
3551 static int free_chunk_dev_extent_items(struct btrfs_trans_handle *trans,
3552                                        struct btrfs_fs_info *fs_info,
3553                                        u64 chunk_offset)
3554 {
3555         struct btrfs_chunk *chunk = NULL;
3556         struct btrfs_root *root= fs_info->chunk_root;
3557         struct btrfs_path *path;
3558         struct btrfs_key key;
3559         u16 num_stripes;
3560         int i;
3561         int ret;
3562
3563         path = btrfs_alloc_path();
3564         if (!path)
3565                 return -ENOMEM;
3566
3567         key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3568         key.type = BTRFS_CHUNK_ITEM_KEY;
3569         key.offset = chunk_offset;
3570
3571         ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
3572         if (ret < 0)
3573                 goto out;
3574         if (ret > 0) {
3575                 ret = -ENOENT;
3576                 goto out;
3577         }
3578         chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
3579                                struct btrfs_chunk);
3580         num_stripes = btrfs_chunk_num_stripes(path->nodes[0], chunk);
3581         for (i = 0; i < num_stripes; i++) {
3582                 ret = free_dev_extent_item(trans, fs_info,
3583                         btrfs_stripe_devid_nr(path->nodes[0], chunk, i),
3584                         btrfs_stripe_offset_nr(path->nodes[0], chunk, i));
3585                 if (ret < 0)
3586                         goto out;
3587         }
3588 out:
3589         btrfs_free_path(path);
3590         return ret;
3591 }
3592
3593 static int free_system_chunk_item(struct btrfs_super_block *super,
3594                                   struct btrfs_key *key)
3595 {
3596         struct btrfs_disk_key *disk_key;
3597         struct btrfs_key cpu_key;
3598         u32 array_size = btrfs_super_sys_array_size(super);
3599         char *ptr = (char *)super->sys_chunk_array;
3600         int cur = 0;
3601         int ret = -ENOENT;
3602
3603         while (cur < btrfs_super_sys_array_size(super)) {
3604                 struct btrfs_chunk *chunk;
3605                 u32 num_stripes;
3606                 u32 chunk_len;
3607
3608                 disk_key = (struct btrfs_disk_key *)(ptr + cur);
3609                 btrfs_disk_key_to_cpu(&cpu_key, disk_key);
3610                 if (cpu_key.type != BTRFS_CHUNK_ITEM_KEY) {
3611                         /* just in case */
3612                         ret = -EIO;
3613                         goto out;
3614                 }
3615
3616                 chunk = (struct btrfs_chunk *)(ptr + cur + sizeof(*disk_key));
3617                 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
3618                 chunk_len = btrfs_chunk_item_size(num_stripes) +
3619                             sizeof(*disk_key);
3620
3621                 if (key->objectid == cpu_key.objectid &&
3622                     key->offset == cpu_key.offset &&
3623                     key->type == cpu_key.type) {
3624                         memmove(ptr + cur, ptr + cur + chunk_len,
3625                                 array_size - cur - chunk_len);
3626                         array_size -= chunk_len;
3627                         btrfs_set_super_sys_array_size(super, array_size);
3628                         ret = 0;
3629                         goto out;
3630                 }
3631
3632                 cur += chunk_len;
3633         }
3634 out:
3635         return ret;
3636 }
3637
3638 static int free_chunk_item(struct btrfs_trans_handle *trans,
3639                            struct btrfs_fs_info *fs_info,
3640                            u64 bytenr)
3641 {
3642         struct btrfs_path *path;
3643         struct btrfs_key key;
3644         struct btrfs_root *root = fs_info->chunk_root;
3645         struct btrfs_chunk *chunk;
3646         u64 chunk_type;
3647         int ret;
3648
3649         key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3650         key.offset = bytenr;
3651         key.type = BTRFS_CHUNK_ITEM_KEY;
3652
3653         path = btrfs_alloc_path();
3654         if (!path)
3655                 return -ENOMEM;
3656
3657         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3658         if (ret > 0) {
3659                 ret = -ENOENT;
3660                 goto out;
3661         }
3662         if (ret < 0)
3663                 goto out;
3664         chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
3665                                struct btrfs_chunk);
3666         chunk_type = btrfs_chunk_type(path->nodes[0], chunk);
3667
3668         ret = btrfs_del_item(trans, root, path);
3669         if (ret < 0)
3670                 goto out;
3671
3672         if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
3673                 ret = free_system_chunk_item(fs_info->super_copy, &key);
3674 out:
3675         btrfs_free_path(path);
3676         return ret;
3677 }
3678
3679 static u64 get_dev_extent_len(struct map_lookup *map)
3680 {
3681         int div;
3682
3683         switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3684         case 0: /* Single */
3685         case BTRFS_BLOCK_GROUP_DUP:
3686         case BTRFS_BLOCK_GROUP_RAID1:
3687                 div = 1;
3688                 break;
3689         case BTRFS_BLOCK_GROUP_RAID5:
3690                 div = (map->num_stripes - 1);
3691                 break;
3692         case BTRFS_BLOCK_GROUP_RAID6:
3693                 div = (map->num_stripes - 2);
3694                 break;
3695         case BTRFS_BLOCK_GROUP_RAID10:
3696                 div = (map->num_stripes / map->sub_stripes);
3697                 break;
3698         default:
3699                 /* normally, read chunk security hook should handled it */
3700                 BUG_ON(1);
3701         }
3702         return map->ce.size / div;
3703 }
3704
3705 /* free block group/chunk related caches */
3706 static int free_block_group_cache(struct btrfs_trans_handle *trans,
3707                                   struct btrfs_fs_info *fs_info,
3708                                   u64 bytenr, u64 len)
3709 {
3710         struct btrfs_block_group_cache *cache;
3711         struct cache_extent *ce;
3712         struct map_lookup *map;
3713         int ret;
3714         int i;
3715         u64 flags;
3716
3717         /* Free block group cache first */
3718         cache = btrfs_lookup_block_group(fs_info, bytenr);
3719         if (!cache)
3720                 return -ENOENT;
3721         flags = cache->flags;
3722         if (cache->free_space_ctl) {
3723                 btrfs_remove_free_space_cache(cache);
3724                 kfree(cache->free_space_ctl);
3725         }
3726         clear_extent_bits(&fs_info->block_group_cache, bytenr, bytenr + len - 1,
3727                           (unsigned int)-1);
3728         ret = free_space_info(fs_info, flags, len, 0, NULL);
3729         if (ret < 0)
3730                 goto out;
3731         kfree(cache);
3732
3733         /* Then free mapping info and dev usage info */
3734         ce = search_cache_extent(&fs_info->mapping_tree.cache_tree, bytenr);
3735         if (!ce || ce->start != bytenr) {
3736                 ret = -ENOENT;
3737                 goto out;
3738         }
3739         map = container_of(ce, struct map_lookup, ce);
3740         for (i = 0; i < map->num_stripes; i++) {
3741                 struct btrfs_device *device;
3742
3743                 device = map->stripes[i].dev;
3744                 device->bytes_used -= get_dev_extent_len(map);
3745                 ret = btrfs_update_device(trans, device);
3746                 if (ret < 0)
3747                         goto out;
3748         }
3749         remove_cache_extent(&fs_info->mapping_tree.cache_tree, ce);
3750         free(map);
3751 out:
3752         return ret;
3753 }
3754
3755 int btrfs_free_block_group(struct btrfs_trans_handle *trans,
3756                            struct btrfs_fs_info *fs_info, u64 bytenr, u64 len)
3757 {
3758         struct btrfs_root *extent_root = fs_info->extent_root;
3759         struct btrfs_path *path;
3760         struct btrfs_block_group_item *bgi;
3761         struct btrfs_key key;
3762         int ret = 0;
3763
3764         path = btrfs_alloc_path();
3765         if (!path)
3766                 return -ENOMEM;
3767
3768         key.objectid = bytenr;
3769         key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3770         key.offset = len;
3771
3772         /* Double check the block group to ensure it's empty */
3773         ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3774         if (ret > 0) {
3775                 ret = -ENONET;
3776                 goto out;
3777         }
3778         if (ret < 0)
3779                 goto out;
3780
3781         bgi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3782                              struct btrfs_block_group_item);
3783         if (btrfs_disk_block_group_used(path->nodes[0], bgi)) {
3784                 fprintf(stderr,
3785                         "WARNING: block group [%llu,%llu) is not empty\n",
3786                         bytenr, bytenr + len);
3787                 ret = -EINVAL;
3788                 goto out;
3789         }
3790         btrfs_release_path(path);
3791
3792         /*
3793          * Now pin all space in the block group, to prevent further transaction
3794          * allocate space from it.
3795          * Every operation needs a transaction must be in the range.
3796          */
3797         btrfs_pin_extent(fs_info, bytenr, len);
3798
3799         /* delete block group item and chunk item */
3800         ret = free_block_group_item(trans, fs_info, bytenr, len);
3801         if (ret < 0) {
3802                 fprintf(stderr,
3803                         "failed to free block group item for [%llu,%llu)\n",
3804                         bytenr, bytenr + len);
3805                 btrfs_unpin_extent(fs_info, bytenr, len);
3806                 goto out;
3807         }
3808
3809         ret = free_chunk_dev_extent_items(trans, fs_info, bytenr);
3810         if (ret < 0) {
3811                 fprintf(stderr,
3812                         "failed to dev extents belongs to [%llu,%llu)\n",
3813                         bytenr, bytenr + len);
3814                 btrfs_unpin_extent(fs_info, bytenr, len);
3815                 goto out;
3816         }
3817         ret = free_chunk_item(trans, fs_info, bytenr);
3818         if (ret < 0) {
3819                 fprintf(stderr,
3820                         "failed to free chunk for [%llu,%llu)\n",
3821                         bytenr, bytenr + len);
3822                 btrfs_unpin_extent(fs_info, bytenr, len);
3823                 goto out;
3824         }
3825
3826         /* Now release the block_group_cache */
3827         ret = free_block_group_cache(trans, fs_info, bytenr, len);
3828         btrfs_unpin_extent(fs_info, bytenr, len);
3829
3830 out:
3831         btrfs_free_path(path);
3832         return ret;
3833 }
3834
3835 /*
3836  * Fixup block accounting. The initial block accounting created by
3837  * make_block_groups isn't accuracy in this case.
3838  */
3839 int btrfs_fix_block_accounting(struct btrfs_trans_handle *trans,
3840                                struct btrfs_root *root)
3841 {
3842         int ret = 0;
3843         int slot;
3844         u64 start = 0;
3845         u64 bytes_used = 0;
3846         struct btrfs_path path;
3847         struct btrfs_key key;
3848         struct extent_buffer *leaf;
3849         struct btrfs_block_group_cache *cache;
3850         struct btrfs_fs_info *fs_info = root->fs_info;
3851
3852         root = root->fs_info->extent_root;
3853
3854         while(extent_root_pending_ops(fs_info)) {
3855                 ret = finish_current_insert(trans, root);
3856                 if (ret)
3857                         return ret;
3858                 ret = del_pending_extents(trans, root);
3859                 if (ret)
3860                         return ret;
3861         }
3862
3863         while(1) {
3864                 cache = btrfs_lookup_first_block_group(fs_info, start);
3865                 if (!cache)
3866                         break;
3867                 start = cache->key.objectid + cache->key.offset;
3868                 btrfs_set_block_group_used(&cache->item, 0);
3869                 cache->space_info->bytes_used = 0;
3870                 set_extent_bits(&root->fs_info->block_group_cache,
3871                                 cache->key.objectid,
3872                                 cache->key.objectid + cache->key.offset -1,
3873                                 BLOCK_GROUP_DIRTY);
3874         }
3875
3876         btrfs_init_path(&path);
3877         key.offset = 0;
3878         key.objectid = 0;
3879         key.type = BTRFS_EXTENT_ITEM_KEY;
3880         ret = btrfs_search_slot(trans, root->fs_info->extent_root,
3881                                 &key, &path, 0, 0);
3882         if (ret < 0)
3883                 return ret;
3884         while(1) {
3885                 leaf = path.nodes[0];
3886                 slot = path.slots[0];
3887                 if (slot >= btrfs_header_nritems(leaf)) {
3888                         ret = btrfs_next_leaf(root, &path);
3889                         if (ret < 0)
3890                                 return ret;
3891                         if (ret > 0)
3892                                 break;
3893                         leaf = path.nodes[0];
3894                         slot = path.slots[0];
3895                 }
3896                 btrfs_item_key_to_cpu(leaf, &key, slot);
3897                 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
3898                         bytes_used += key.offset;
3899                         ret = btrfs_update_block_group(root,
3900                                   key.objectid, key.offset, 1, 0);
3901                         BUG_ON(ret);
3902                 } else if (key.type == BTRFS_METADATA_ITEM_KEY) {
3903                         bytes_used += fs_info->nodesize;
3904                         ret = btrfs_update_block_group(root,
3905                                   key.objectid, fs_info->nodesize, 1, 0);
3906                         if (ret)
3907                                 goto out;
3908                 }
3909                 path.slots[0]++;
3910         }
3911         btrfs_set_super_bytes_used(root->fs_info->super_copy, bytes_used);
3912         ret = 0;
3913 out:
3914         btrfs_release_path(&path);
3915         return ret;
3916 }
3917
3918 static void __get_extent_size(struct btrfs_root *root, struct btrfs_path *path,
3919                               u64 *start, u64 *len)
3920 {
3921         struct btrfs_key key;
3922
3923         btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3924         BUG_ON(!(key.type == BTRFS_EXTENT_ITEM_KEY ||
3925                  key.type == BTRFS_METADATA_ITEM_KEY));
3926         *start = key.objectid;
3927         if (key.type == BTRFS_EXTENT_ITEM_KEY)
3928                 *len = key.offset;
3929         else
3930                 *len = root->fs_info->nodesize;
3931 }
3932
3933 /*
3934  * Find first overlap extent for range [bytenr, bytenr + len)
3935  * Return 0 for found and point path to it.
3936  * Return >0 for not found.
3937  * Return <0 for err
3938  */
3939 int btrfs_search_overlap_extent(struct btrfs_root *root,
3940                                 struct btrfs_path *path, u64 bytenr, u64 len)
3941 {
3942         struct btrfs_key key;
3943         u64 cur_start;
3944         u64 cur_len;
3945         int ret;
3946
3947         key.objectid = bytenr;
3948         key.type = BTRFS_EXTENT_DATA_KEY;
3949         key.offset = (u64)-1;
3950
3951         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3952         if (ret < 0)
3953                 return ret;
3954         BUG_ON(ret == 0);
3955
3956         ret = btrfs_previous_extent_item(root, path, 0);
3957         if (ret < 0)
3958                 return ret;
3959         /* no previous, check next extent */
3960         if (ret > 0)
3961                 goto next;
3962         __get_extent_size(root, path, &cur_start, &cur_len);
3963         /* Tail overlap */
3964         if (cur_start + cur_len > bytenr)
3965                 return 1;
3966
3967 next:
3968         ret = btrfs_next_extent_item(root, path, bytenr + len);
3969         if (ret < 0)
3970                 return ret;
3971         /* No next, prev already checked, no overlap */
3972         if (ret > 0)
3973                 return 0;
3974         __get_extent_size(root, path, &cur_start, &cur_len);
3975         /* head overlap*/
3976         if (cur_start < bytenr + len)
3977                 return 1;
3978         return 0;
3979 }
3980
3981 static int __btrfs_record_file_extent(struct btrfs_trans_handle *trans,
3982                                       struct btrfs_root *root, u64 objectid,
3983                                       struct btrfs_inode_item *inode,
3984                                       u64 file_pos, u64 disk_bytenr,
3985                                       u64 *ret_num_bytes)
3986 {
3987         int ret;
3988         struct btrfs_fs_info *info = root->fs_info;
3989         struct btrfs_root *extent_root = info->extent_root;
3990         struct extent_buffer *leaf;
3991         struct btrfs_file_extent_item *fi;
3992         struct btrfs_key ins_key;
3993         struct btrfs_path *path;
3994         struct btrfs_extent_item *ei;
3995         u64 nbytes;
3996         u64 extent_num_bytes;
3997         u64 extent_bytenr;
3998         u64 extent_offset;
3999         u64 num_bytes = *ret_num_bytes;
4000
4001         /*
4002          * All supported file system should not use its 0 extent.
4003          * As it's for hole
4004          *
4005          * And hole extent has no size limit, no need to loop.
4006          */
4007         if (disk_bytenr == 0) {
4008                 ret = btrfs_insert_file_extent(trans, root, objectid,
4009                                                 file_pos, disk_bytenr,
4010                                                 num_bytes, num_bytes);
4011                 return ret;
4012         }
4013         num_bytes = min_t(u64, num_bytes, BTRFS_MAX_EXTENT_SIZE);
4014
4015         path = btrfs_alloc_path();
4016         if (!path)
4017                 return -ENOMEM;
4018
4019         /* First to check extent overlap */
4020         ret = btrfs_search_overlap_extent(extent_root, path, disk_bytenr,
4021                                           num_bytes);
4022         if (ret < 0)
4023                 goto fail;
4024         if (ret > 0) {
4025                 /* Found overlap */
4026                 u64 cur_start;
4027                 u64 cur_len;
4028
4029                 __get_extent_size(extent_root, path, &cur_start, &cur_len);
4030                 /*
4031                  * For convert case, this extent should be a subset of
4032                  * existing one.
4033                  */
4034                 BUG_ON(disk_bytenr < cur_start);
4035
4036                 extent_bytenr = cur_start;
4037                 extent_num_bytes = cur_len;
4038                 extent_offset = disk_bytenr - extent_bytenr;
4039         } else {
4040                 /* No overlap, create new extent */
4041                 btrfs_release_path(path);
4042                 ins_key.objectid = disk_bytenr;
4043                 ins_key.offset = num_bytes;
4044                 ins_key.type = BTRFS_EXTENT_ITEM_KEY;
4045
4046                 ret = btrfs_insert_empty_item(trans, extent_root, path,
4047                                               &ins_key, sizeof(*ei));
4048                 if (ret == 0) {
4049                         leaf = path->nodes[0];
4050                         ei = btrfs_item_ptr(leaf, path->slots[0],
4051                                             struct btrfs_extent_item);
4052
4053                         btrfs_set_extent_refs(leaf, ei, 0);
4054                         btrfs_set_extent_generation(leaf, ei, 0);
4055                         btrfs_set_extent_flags(leaf, ei,
4056                                                BTRFS_EXTENT_FLAG_DATA);
4057                         btrfs_mark_buffer_dirty(leaf);
4058
4059                         ret = btrfs_update_block_group(root, disk_bytenr,
4060                                                        num_bytes, 1, 0);
4061                         if (ret)
4062                                 goto fail;
4063                 } else if (ret != -EEXIST) {
4064                         goto fail;
4065                 }
4066                 btrfs_extent_post_op(trans, extent_root);
4067                 extent_bytenr = disk_bytenr;
4068                 extent_num_bytes = num_bytes;
4069                 extent_offset = 0;
4070         }
4071         btrfs_release_path(path);
4072         ins_key.objectid = objectid;
4073         ins_key.offset = file_pos;
4074         ins_key.type = BTRFS_EXTENT_DATA_KEY;
4075         ret = btrfs_insert_empty_item(trans, root, path, &ins_key,
4076                                       sizeof(*fi));
4077         if (ret)
4078                 goto fail;
4079         leaf = path->nodes[0];
4080         fi = btrfs_item_ptr(leaf, path->slots[0],
4081                             struct btrfs_file_extent_item);
4082         btrfs_set_file_extent_generation(leaf, fi, trans->transid);
4083         btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
4084         btrfs_set_file_extent_disk_bytenr(leaf, fi, extent_bytenr);
4085         btrfs_set_file_extent_disk_num_bytes(leaf, fi, extent_num_bytes);
4086         btrfs_set_file_extent_offset(leaf, fi, extent_offset);
4087         btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
4088         btrfs_set_file_extent_ram_bytes(leaf, fi, extent_num_bytes);
4089         btrfs_set_file_extent_compression(leaf, fi, 0);
4090         btrfs_set_file_extent_encryption(leaf, fi, 0);
4091         btrfs_set_file_extent_other_encoding(leaf, fi, 0);
4092         btrfs_mark_buffer_dirty(leaf);
4093
4094         nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
4095         btrfs_set_stack_inode_nbytes(inode, nbytes);
4096         btrfs_release_path(path);
4097
4098         ret = btrfs_inc_extent_ref(trans, root, extent_bytenr, extent_num_bytes,
4099                                    0, root->root_key.objectid, objectid,
4100                                    file_pos - extent_offset);
4101         if (ret)
4102                 goto fail;
4103         ret = 0;
4104         *ret_num_bytes = min(extent_num_bytes - extent_offset, num_bytes);
4105 fail:
4106         btrfs_free_path(path);
4107         return ret;
4108 }
4109
4110 /*
4111  * Record a file extent. Do all the required works, such as inserting
4112  * file extent item, inserting extent item and backref item into extent
4113  * tree and updating block accounting.
4114  */
4115 int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
4116                               struct btrfs_root *root, u64 objectid,
4117                               struct btrfs_inode_item *inode,
4118                               u64 file_pos, u64 disk_bytenr,
4119                               u64 num_bytes)
4120 {
4121         u64 cur_disk_bytenr = disk_bytenr;
4122         u64 cur_file_pos = file_pos;
4123         u64 cur_num_bytes = num_bytes;
4124         int ret = 0;
4125
4126         while (num_bytes > 0) {
4127                 ret = __btrfs_record_file_extent(trans, root, objectid,
4128                                                  inode, cur_file_pos,
4129                                                  cur_disk_bytenr,
4130                                                  &cur_num_bytes);
4131                 if (ret < 0)
4132                         break;
4133                 cur_disk_bytenr += cur_num_bytes;
4134                 cur_file_pos += cur_num_bytes;
4135                 num_bytes -= cur_num_bytes;
4136         }
4137         return ret;
4138 }
4139
4140
4141 static int add_excluded_extent(struct btrfs_root *root,
4142                                u64 start, u64 num_bytes)
4143 {
4144         u64 end = start + num_bytes - 1;
4145         set_extent_bits(&root->fs_info->pinned_extents,
4146                         start, end, EXTENT_UPTODATE);
4147         return 0;
4148 }
4149
4150 void free_excluded_extents(struct btrfs_root *root,
4151                            struct btrfs_block_group_cache *cache)
4152 {
4153         u64 start, end;
4154
4155         start = cache->key.objectid;
4156         end = start + cache->key.offset - 1;
4157
4158         clear_extent_bits(&root->fs_info->pinned_extents,
4159                           start, end, EXTENT_UPTODATE);
4160 }
4161
4162 int exclude_super_stripes(struct btrfs_root *root,
4163                           struct btrfs_block_group_cache *cache)
4164 {
4165         u64 bytenr;
4166         u64 *logical;
4167         int stripe_len;
4168         int i, nr, ret;
4169
4170         if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
4171                 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
4172                 cache->bytes_super += stripe_len;
4173                 ret = add_excluded_extent(root, cache->key.objectid,
4174                                           stripe_len);
4175                 if (ret)
4176                         return ret;
4177         }
4178
4179         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
4180                 bytenr = btrfs_sb_offset(i);
4181                 ret = btrfs_rmap_block(root->fs_info,
4182                                        cache->key.objectid, bytenr,
4183                                        0, &logical, &nr, &stripe_len);
4184                 if (ret)
4185                         return ret;
4186
4187                 while (nr--) {
4188                         u64 start, len;
4189
4190                         if (logical[nr] > cache->key.objectid +
4191                             cache->key.offset)
4192                                 continue;
4193
4194                         if (logical[nr] + stripe_len <= cache->key.objectid)
4195                                 continue;
4196
4197                         start = logical[nr];
4198                         if (start < cache->key.objectid) {
4199                                 start = cache->key.objectid;
4200                                 len = (logical[nr] + stripe_len) - start;
4201                         } else {
4202                                 len = min_t(u64, stripe_len,
4203                                             cache->key.objectid +
4204                                             cache->key.offset - start);
4205                         }
4206
4207                         cache->bytes_super += len;
4208                         ret = add_excluded_extent(root, start, len);
4209                         if (ret) {
4210                                 kfree(logical);
4211                                 return ret;
4212                         }
4213                 }
4214
4215                 kfree(logical);
4216         }
4217         return 0;
4218 }
4219
4220 u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
4221                        struct btrfs_fs_info *info, u64 start, u64 end)
4222 {
4223         u64 extent_start, extent_end, size, total_added = 0;
4224         int ret;
4225
4226         while (start < end) {
4227                 ret = find_first_extent_bit(&info->pinned_extents, start,
4228                                             &extent_start, &extent_end,
4229                                             EXTENT_DIRTY | EXTENT_UPTODATE);
4230                 if (ret)
4231                         break;
4232
4233                 if (extent_start <= start) {
4234                         start = extent_end + 1;
4235                 } else if (extent_start > start && extent_start < end) {
4236                         size = extent_start - start;
4237                         total_added += size;
4238                         ret = btrfs_add_free_space(block_group->free_space_ctl,
4239                                                    start, size);
4240                         BUG_ON(ret); /* -ENOMEM or logic error */
4241                         start = extent_end + 1;
4242                 } else {
4243                         break;
4244                 }
4245         }
4246
4247         if (start < end) {
4248                 size = end - start;
4249                 total_added += size;
4250                 ret = btrfs_add_free_space(block_group->free_space_ctl, start,
4251                                            size);
4252                 BUG_ON(ret); /* -ENOMEM or logic error */
4253         }
4254
4255         return total_added;
4256 }