2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
21 #include "kerncompat.h"
22 #include "radix-tree.h"
25 #include "print-tree.h"
26 #include "transaction.h"
30 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
31 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
32 #define BLOCK_GROUP_SYSTEM EXTENT_NEW
34 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
36 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
37 btrfs_root *extent_root);
38 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
39 btrfs_root *extent_root);
41 static int cache_block_group(struct btrfs_root *root,
42 struct btrfs_block_group_cache *block_group)
44 struct btrfs_path *path;
47 struct extent_buffer *leaf;
48 struct extent_io_tree *free_space_cache;
58 root = root->fs_info->extent_root;
59 free_space_cache = &root->fs_info->free_space_cache;
61 if (block_group->cached)
64 path = btrfs_alloc_path();
69 first_free = block_group->key.objectid;
70 key.objectid = block_group->key.objectid;
72 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
73 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
76 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
80 leaf = path->nodes[0];
81 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
82 if (key.objectid + key.offset > first_free)
83 first_free = key.objectid + key.offset;
86 leaf = path->nodes[0];
87 slot = path->slots[0];
88 if (slot >= btrfs_header_nritems(leaf)) {
89 ret = btrfs_next_leaf(root, path);
98 btrfs_item_key_to_cpu(leaf, &key, slot);
99 if (key.objectid < block_group->key.objectid) {
102 if (key.objectid >= block_group->key.objectid +
103 block_group->key.offset) {
107 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
112 if (key.objectid > last) {
113 hole_size = key.objectid - last;
114 set_extent_dirty(free_space_cache, last,
115 last + hole_size - 1,
118 last = key.objectid + key.offset;
126 if (block_group->key.objectid +
127 block_group->key.offset > last) {
128 hole_size = block_group->key.objectid +
129 block_group->key.offset - last;
130 set_extent_dirty(free_space_cache, last,
131 last + hole_size - 1, GFP_NOFS);
133 block_group->cached = 1;
135 btrfs_free_path(path);
139 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
143 struct extent_io_tree *block_group_cache;
144 struct btrfs_block_group_cache *block_group = NULL;
150 block_group_cache = &info->block_group_cache;
151 ret = find_first_extent_bit(block_group_cache,
152 bytenr, &start, &end,
153 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
158 ret = get_state_private(block_group_cache, start, &ptr);
162 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
163 if (block_group->key.objectid <= bytenr && bytenr <
164 block_group->key.objectid + block_group->key.offset)
169 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
171 return (cache->flags & bits) == bits;
174 static int noinline find_search_start(struct btrfs_root *root,
175 struct btrfs_block_group_cache **cache_ret,
176 u64 *start_ret, int num, int data)
179 struct btrfs_block_group_cache *cache = *cache_ret;
184 u64 search_start = *start_ret;
191 ret = cache_block_group(root, cache);
195 last = max(search_start, cache->key.objectid);
196 if (!block_group_bits(cache, data)) {
201 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
202 last, &start, &end, EXTENT_DIRTY);
209 start = max(last, start);
211 if (last - start < num) {
212 if (last == cache->key.objectid + cache->key.offset)
216 if (start + num > cache->key.objectid + cache->key.offset)
222 cache = btrfs_lookup_block_group(root->fs_info, search_start);
224 printk("Unable to find block group for %llu\n",
225 (unsigned long long)search_start);
231 last = cache->key.objectid + cache->key.offset;
233 cache = btrfs_lookup_block_group(root->fs_info, last);
243 if (cache_miss && !cache->cached) {
244 cache_block_group(root, cache);
246 cache = btrfs_lookup_block_group(root->fs_info, last);
248 cache = btrfs_find_block_group(root, cache, last, data, 0);
256 static u64 div_factor(u64 num, int factor)
265 static int block_group_state_bits(u64 flags)
268 if (flags & BTRFS_BLOCK_GROUP_DATA)
269 bits |= BLOCK_GROUP_DATA;
270 if (flags & BTRFS_BLOCK_GROUP_METADATA)
271 bits |= BLOCK_GROUP_METADATA;
272 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
273 bits |= BLOCK_GROUP_SYSTEM;
277 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
278 struct btrfs_block_group_cache
279 *hint, u64 search_start,
282 struct btrfs_block_group_cache *cache;
283 struct extent_io_tree *block_group_cache;
284 struct btrfs_block_group_cache *found_group = NULL;
285 struct btrfs_fs_info *info = root->fs_info;
298 block_group_cache = &info->block_group_cache;
303 bit = block_group_state_bits(data);
306 struct btrfs_block_group_cache *shint;
307 shint = btrfs_lookup_block_group(info, search_start);
308 if (shint && block_group_bits(shint, data)) {
309 used = btrfs_block_group_used(&shint->item);
310 if (used + shint->pinned <
311 div_factor(shint->key.offset, factor)) {
316 if (hint && block_group_bits(hint, data)) {
317 used = btrfs_block_group_used(&hint->item);
318 if (used + hint->pinned <
319 div_factor(hint->key.offset, factor)) {
322 last = hint->key.objectid + hint->key.offset;
326 hint_last = max(hint->key.objectid, search_start);
328 hint_last = search_start;
334 ret = find_first_extent_bit(block_group_cache, last,
339 ret = get_state_private(block_group_cache, start, &ptr);
343 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
344 last = cache->key.objectid + cache->key.offset;
345 used = btrfs_block_group_used(&cache->item);
347 if (block_group_bits(cache, data)) {
349 free_check = cache->key.offset;
351 free_check = div_factor(cache->key.offset,
354 if (used + cache->pinned < free_check) {
370 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
371 u64 owner, u64 owner_offset)
373 u32 high_crc = ~(u32)0;
374 u32 low_crc = ~(u32)0;
377 lenum = cpu_to_le64(root_objectid);
378 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
379 lenum = cpu_to_le64(ref_generation);
380 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
381 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
382 lenum = cpu_to_le64(owner);
383 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
384 lenum = cpu_to_le64(owner_offset);
385 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
387 return ((u64)high_crc << 32) | (u64)low_crc;
390 static int match_extent_ref(struct extent_buffer *leaf,
391 struct btrfs_extent_ref *disk_ref,
392 struct btrfs_extent_ref *cpu_ref)
397 if (cpu_ref->objectid)
398 len = sizeof(*cpu_ref);
400 len = 2 * sizeof(u64);
401 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
406 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
407 struct btrfs_root *root,
408 struct btrfs_path *path, u64 bytenr,
410 u64 ref_generation, u64 owner,
411 u64 owner_offset, int del)
414 struct btrfs_key key;
415 struct btrfs_key found_key;
416 struct btrfs_extent_ref ref;
417 struct extent_buffer *leaf;
418 struct btrfs_extent_ref *disk_ref;
422 btrfs_set_stack_ref_root(&ref, root_objectid);
423 btrfs_set_stack_ref_generation(&ref, ref_generation);
424 btrfs_set_stack_ref_objectid(&ref, owner);
425 btrfs_set_stack_ref_offset(&ref, owner_offset);
427 hash = hash_extent_ref(root_objectid, ref_generation, owner,
430 key.objectid = bytenr;
431 key.type = BTRFS_EXTENT_REF_KEY;
434 ret = btrfs_search_slot(trans, root, &key, path,
438 leaf = path->nodes[0];
440 u32 nritems = btrfs_header_nritems(leaf);
441 if (path->slots[0] >= nritems) {
442 ret2 = btrfs_next_leaf(root, path);
445 leaf = path->nodes[0];
447 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
448 if (found_key.objectid != bytenr ||
449 found_key.type != BTRFS_EXTENT_REF_KEY)
451 key.offset = found_key.offset;
453 btrfs_release_path(root, path);
457 disk_ref = btrfs_item_ptr(path->nodes[0],
459 struct btrfs_extent_ref);
460 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
464 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
465 key.offset = found_key.offset + 1;
466 btrfs_release_path(root, path);
473 * Back reference rules. Back refs have three main goals:
475 * 1) differentiate between all holders of references to an extent so that
476 * when a reference is dropped we can make sure it was a valid reference
477 * before freeing the extent.
479 * 2) Provide enough information to quickly find the holders of an extent
480 * if we notice a given block is corrupted or bad.
482 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
483 * maintenance. This is actually the same as #2, but with a slightly
484 * different use case.
486 * File extents can be referenced by:
488 * - multiple snapshots, subvolumes, or different generations in one subvol
489 * - different files inside a single subvolume (in theory, not implemented yet)
490 * - different offsets inside a file (bookend extents in file.c)
492 * The extent ref structure has fields for:
494 * - Objectid of the subvolume root
495 * - Generation number of the tree holding the reference
496 * - objectid of the file holding the reference
497 * - offset in the file corresponding to the key holding the reference
499 * When a file extent is allocated the fields are filled in:
500 * (root_key.objectid, trans->transid, inode objectid, offset in file)
502 * When a leaf is cow'd new references are added for every file extent found
503 * in the leaf. It looks the same as the create case, but trans->transid
504 * will be different when the block is cow'd.
506 * (root_key.objectid, trans->transid, inode objectid, offset in file)
508 * When a file extent is removed either during snapshot deletion or file
509 * truncation, the corresponding back reference is found
512 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
513 * inode objectid, offset in file)
515 * Btree extents can be referenced by:
517 * - Different subvolumes
518 * - Different generations of the same subvolume
520 * Storing sufficient information for a full reverse mapping of a btree
521 * block would require storing the lowest key of the block in the backref,
522 * and it would require updating that lowest key either before write out or
523 * every time it changed. Instead, the objectid of the lowest key is stored
524 * along with the level of the tree block. This provides a hint
525 * about where in the btree the block can be found. Searches through the
526 * btree only need to look for a pointer to that block, so they stop one
527 * level higher than the level recorded in the backref.
529 * Some btrees do not do reference counting on their extents. These
530 * include the extent tree and the tree of tree roots. Backrefs for these
531 * trees always have a generation of zero.
533 * When a tree block is created, back references are inserted:
535 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
537 * When a tree block is cow'd in a reference counted root,
538 * new back references are added for all the blocks it points to.
539 * These are of the form (trans->transid will have increased since creation):
541 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
543 * Because the lowest_key_objectid and the level are just hints
544 * they are not used when backrefs are deleted. When a backref is deleted:
546 * if backref was for a tree root:
547 * root_objectid = root->root_key.objectid
549 * root_objectid = btrfs_header_owner(parent)
551 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
553 * Back Reference Key hashing:
555 * Back references have four fields, each 64 bits long. Unfortunately,
556 * This is hashed into a single 64 bit number and placed into the key offset.
557 * The key objectid corresponds to the first byte in the extent, and the
558 * key type is set to BTRFS_EXTENT_REF_KEY
560 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
561 struct btrfs_root *root,
562 struct btrfs_path *path, u64 bytenr,
563 u64 root_objectid, u64 ref_generation,
564 u64 owner, u64 owner_offset)
567 struct btrfs_key key;
568 struct btrfs_extent_ref ref;
569 struct btrfs_extent_ref *disk_ref;
572 btrfs_set_stack_ref_root(&ref, root_objectid);
573 btrfs_set_stack_ref_generation(&ref, ref_generation);
574 btrfs_set_stack_ref_objectid(&ref, owner);
575 btrfs_set_stack_ref_offset(&ref, owner_offset);
577 hash = hash_extent_ref(root_objectid, ref_generation, owner,
580 key.objectid = bytenr;
581 key.type = BTRFS_EXTENT_REF_KEY;
583 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
584 while (ret == -EEXIST) {
585 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
586 struct btrfs_extent_ref);
587 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
590 btrfs_release_path(root, path);
591 ret = btrfs_insert_empty_item(trans, root, path, &key,
596 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
597 struct btrfs_extent_ref);
598 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
600 btrfs_mark_buffer_dirty(path->nodes[0]);
602 btrfs_release_path(root, path);
606 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
607 struct btrfs_root *root,
608 u64 bytenr, u64 num_bytes,
609 u64 root_objectid, u64 ref_generation,
610 u64 owner, u64 owner_offset)
612 struct btrfs_path *path;
614 struct btrfs_key key;
615 struct extent_buffer *l;
616 struct btrfs_extent_item *item;
619 WARN_ON(num_bytes < root->sectorsize);
620 path = btrfs_alloc_path();
624 key.objectid = bytenr;
625 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
626 key.offset = num_bytes;
627 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
636 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
637 refs = btrfs_extent_refs(l, item);
638 btrfs_set_extent_refs(l, item, refs + 1);
639 btrfs_mark_buffer_dirty(path->nodes[0]);
641 btrfs_release_path(root->fs_info->extent_root, path);
643 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
644 path, bytenr, root_objectid,
645 ref_generation, owner, owner_offset);
647 finish_current_insert(trans, root->fs_info->extent_root);
648 del_pending_extents(trans, root->fs_info->extent_root);
650 btrfs_free_path(path);
654 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
655 struct btrfs_root *root)
657 finish_current_insert(trans, root->fs_info->extent_root);
658 del_pending_extents(trans, root->fs_info->extent_root);
662 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
663 struct btrfs_root *root, u64 bytenr,
664 u64 num_bytes, u32 *refs)
666 struct btrfs_path *path;
668 struct btrfs_key key;
669 struct extent_buffer *l;
670 struct btrfs_extent_item *item;
672 WARN_ON(num_bytes < root->sectorsize);
673 path = btrfs_alloc_path();
674 key.objectid = bytenr;
675 key.offset = num_bytes;
676 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
677 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
682 btrfs_print_leaf(root, path->nodes[0]);
683 printk("failed to find block number %llu\n",
684 (unsigned long long)bytenr);
688 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
689 *refs = btrfs_extent_refs(l, item);
691 btrfs_free_path(path);
695 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
696 struct btrfs_path *count_path,
699 struct btrfs_root *extent_root = root->fs_info->extent_root;
700 struct btrfs_path *path;
703 u64 root_objectid = root->root_key.objectid;
709 struct btrfs_key key;
710 struct btrfs_key found_key;
711 struct extent_buffer *l;
712 struct btrfs_extent_item *item;
713 struct btrfs_extent_ref *ref_item;
716 path = btrfs_alloc_path();
719 bytenr = first_extent;
721 bytenr = count_path->nodes[level]->start;
724 key.objectid = bytenr;
727 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
728 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
734 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
736 if (found_key.objectid != bytenr ||
737 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
741 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
742 refs = btrfs_extent_refs(l, item);
744 nritems = btrfs_header_nritems(l);
745 if (path->slots[0] >= nritems) {
746 ret = btrfs_next_leaf(extent_root, path);
751 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
752 if (found_key.objectid != bytenr)
754 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
760 ref_item = btrfs_item_ptr(l, path->slots[0],
761 struct btrfs_extent_ref);
762 found_objectid = btrfs_ref_root(l, ref_item);
764 if (found_objectid != root_objectid) {
771 if (cur_count == 0) {
775 if (level >= 0 && root->node == count_path->nodes[level])
778 btrfs_release_path(root, path);
782 btrfs_free_path(path);
785 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
786 struct btrfs_root *root, u64 owner_objectid)
792 struct btrfs_disk_key disk_key;
794 level = btrfs_header_level(root->node);
795 generation = trans->transid;
796 nritems = btrfs_header_nritems(root->node);
799 btrfs_item_key(root->node, &disk_key, 0);
801 btrfs_node_key(root->node, &disk_key, 0);
802 key_objectid = btrfs_disk_key_objectid(&disk_key);
806 return btrfs_inc_extent_ref(trans, root, root->node->start,
807 root->node->len, owner_objectid,
808 generation, level, key_objectid);
811 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
812 struct extent_buffer *buf)
816 struct btrfs_key key;
817 struct btrfs_file_extent_item *fi;
826 level = btrfs_header_level(buf);
827 nritems = btrfs_header_nritems(buf);
828 for (i = 0; i < nritems; i++) {
831 btrfs_item_key_to_cpu(buf, &key, i);
832 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
834 fi = btrfs_item_ptr(buf, i,
835 struct btrfs_file_extent_item);
836 if (btrfs_file_extent_type(buf, fi) ==
837 BTRFS_FILE_EXTENT_INLINE)
839 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
840 if (disk_bytenr == 0)
842 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
843 btrfs_file_extent_disk_num_bytes(buf, fi),
844 root->root_key.objectid, trans->transid,
845 key.objectid, key.offset);
851 bytenr = btrfs_node_blockptr(buf, i);
852 btrfs_node_key_to_cpu(buf, &key, i);
853 ret = btrfs_inc_extent_ref(trans, root, bytenr,
854 btrfs_level_size(root, level - 1),
855 root->root_key.objectid,
857 level - 1, key.objectid);
868 for (i =0; i < faili; i++) {
871 btrfs_item_key_to_cpu(buf, &key, i);
872 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
874 fi = btrfs_item_ptr(buf, i,
875 struct btrfs_file_extent_item);
876 if (btrfs_file_extent_type(buf, fi) ==
877 BTRFS_FILE_EXTENT_INLINE)
879 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
880 if (disk_bytenr == 0)
882 err = btrfs_free_extent(trans, root, disk_bytenr,
883 btrfs_file_extent_disk_num_bytes(buf,
887 bytenr = btrfs_node_blockptr(buf, i);
888 err = btrfs_free_extent(trans, root, bytenr,
889 btrfs_level_size(root, level - 1), 0);
897 static int write_one_cache_group(struct btrfs_trans_handle *trans,
898 struct btrfs_root *root,
899 struct btrfs_path *path,
900 struct btrfs_block_group_cache *cache)
904 struct btrfs_root *extent_root = root->fs_info->extent_root;
906 struct extent_buffer *leaf;
908 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
913 leaf = path->nodes[0];
914 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
915 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
916 btrfs_mark_buffer_dirty(leaf);
917 btrfs_release_path(extent_root, path);
919 finish_current_insert(trans, extent_root);
920 pending_ret = del_pending_extents(trans, extent_root);
929 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
930 struct btrfs_root *root)
932 struct extent_io_tree *block_group_cache;
933 struct btrfs_block_group_cache *cache;
937 struct btrfs_path *path;
943 block_group_cache = &root->fs_info->block_group_cache;
944 path = btrfs_alloc_path();
949 ret = find_first_extent_bit(block_group_cache, last,
950 &start, &end, BLOCK_GROUP_DIRTY);
955 ret = get_state_private(block_group_cache, start, &ptr);
958 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
959 err = write_one_cache_group(trans, root,
962 * if we fail to write the cache group, we want
963 * to keep it marked dirty in hopes that a later
970 clear_extent_bits(block_group_cache, start, end,
971 BLOCK_GROUP_DIRTY, GFP_NOFS);
973 btrfs_free_path(path);
977 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
980 struct list_head *head = &info->space_info;
981 struct list_head *cur;
982 struct btrfs_space_info *found;
983 list_for_each(cur, head) {
984 found = list_entry(cur, struct btrfs_space_info, list);
985 if (found->flags == flags)
992 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
993 u64 total_bytes, u64 bytes_used,
994 struct btrfs_space_info **space_info)
996 struct btrfs_space_info *found;
998 found = __find_space_info(info, flags);
1000 found->total_bytes += total_bytes;
1001 found->bytes_used += bytes_used;
1002 WARN_ON(found->total_bytes < found->bytes_used);
1003 *space_info = found;
1006 found = kmalloc(sizeof(*found), GFP_NOFS);
1010 list_add(&found->list, &info->space_info);
1011 found->flags = flags;
1012 found->total_bytes = total_bytes;
1013 found->bytes_used = bytes_used;
1014 found->bytes_pinned = 0;
1016 *space_info = found;
1021 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1023 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1024 BTRFS_BLOCK_GROUP_RAID1 |
1025 BTRFS_BLOCK_GROUP_DUP);
1027 if (flags & BTRFS_BLOCK_GROUP_DATA)
1028 fs_info->avail_data_alloc_bits |= extra_flags;
1029 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1030 fs_info->avail_metadata_alloc_bits |= extra_flags;
1031 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1032 fs_info->avail_system_alloc_bits |= extra_flags;
1036 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1037 struct btrfs_root *extent_root, u64 alloc_bytes,
1040 struct btrfs_space_info *space_info;
1046 space_info = __find_space_info(extent_root->fs_info, flags);
1048 ret = update_space_info(extent_root->fs_info, flags,
1052 BUG_ON(!space_info);
1054 if (space_info->full)
1057 thresh = div_factor(space_info->total_bytes, 7);
1058 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1062 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1063 if (ret == -ENOSPC) {
1064 space_info->full = 1;
1070 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1071 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1076 static int update_block_group(struct btrfs_trans_handle *trans,
1077 struct btrfs_root *root,
1078 u64 bytenr, u64 num_bytes, int alloc,
1081 struct btrfs_block_group_cache *cache;
1082 struct btrfs_fs_info *info = root->fs_info;
1083 u64 total = num_bytes;
1090 cache = btrfs_lookup_block_group(info, bytenr);
1094 byte_in_group = bytenr - cache->key.objectid;
1095 WARN_ON(byte_in_group > cache->key.offset);
1096 start = cache->key.objectid;
1097 end = start + cache->key.offset - 1;
1098 set_extent_bits(&info->block_group_cache, start, end,
1099 BLOCK_GROUP_DIRTY, GFP_NOFS);
1101 old_val = btrfs_block_group_used(&cache->item);
1102 num_bytes = min(total, cache->key.offset - byte_in_group);
1104 old_val += num_bytes;
1105 cache->space_info->bytes_used += num_bytes;
1107 old_val -= num_bytes;
1108 cache->space_info->bytes_used -= num_bytes;
1110 set_extent_dirty(&info->free_space_cache,
1111 bytenr, bytenr + num_bytes - 1,
1115 btrfs_set_block_group_used(&cache->item, old_val);
1117 bytenr += num_bytes;
1122 static int update_pinned_extents(struct btrfs_root *root,
1123 u64 bytenr, u64 num, int pin)
1126 struct btrfs_block_group_cache *cache;
1127 struct btrfs_fs_info *fs_info = root->fs_info;
1130 set_extent_dirty(&fs_info->pinned_extents,
1131 bytenr, bytenr + num - 1, GFP_NOFS);
1133 clear_extent_dirty(&fs_info->pinned_extents,
1134 bytenr, bytenr + num - 1, GFP_NOFS);
1137 cache = btrfs_lookup_block_group(fs_info, bytenr);
1139 len = min(num, cache->key.offset -
1140 (bytenr - cache->key.objectid));
1142 cache->pinned += len;
1143 cache->space_info->bytes_pinned += len;
1144 fs_info->total_pinned += len;
1146 cache->pinned -= len;
1147 cache->space_info->bytes_pinned -= len;
1148 fs_info->total_pinned -= len;
1156 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1161 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1165 ret = find_first_extent_bit(pinned_extents, last,
1166 &start, &end, EXTENT_DIRTY);
1169 set_extent_dirty(copy, start, end, GFP_NOFS);
1175 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1176 struct btrfs_root *root,
1177 struct extent_io_tree *unpin)
1182 struct extent_io_tree *free_space_cache;
1183 free_space_cache = &root->fs_info->free_space_cache;
1186 ret = find_first_extent_bit(unpin, 0, &start, &end,
1190 update_pinned_extents(root, start, end + 1 - start, 0);
1191 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1192 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1197 static int finish_current_insert(struct btrfs_trans_handle *trans,
1198 struct btrfs_root *extent_root)
1202 struct btrfs_fs_info *info = extent_root->fs_info;
1203 struct extent_buffer *eb;
1204 struct btrfs_path *path;
1205 struct btrfs_key ins;
1206 struct btrfs_disk_key first;
1207 struct btrfs_extent_item extent_item;
1212 btrfs_set_stack_extent_refs(&extent_item, 1);
1213 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1214 path = btrfs_alloc_path();
1217 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1218 &end, EXTENT_LOCKED);
1222 ins.objectid = start;
1223 ins.offset = end + 1 - start;
1224 err = btrfs_insert_item(trans, extent_root, &ins,
1225 &extent_item, sizeof(extent_item));
1226 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1228 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1229 level = btrfs_header_level(eb);
1231 btrfs_item_key(eb, &first, 0);
1233 btrfs_node_key(eb, &first, 0);
1235 err = btrfs_insert_extent_backref(trans, extent_root, path,
1236 start, extent_root->root_key.objectid,
1238 btrfs_disk_key_objectid(&first));
1240 free_extent_buffer(eb);
1242 btrfs_free_path(path);
1246 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1250 struct extent_buffer *buf;
1253 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1255 if (btrfs_buffer_uptodate(buf)) {
1257 root->fs_info->running_transaction->transid;
1258 if (btrfs_header_generation(buf) ==
1259 transid && !btrfs_header_flag(buf,
1260 BTRFS_HEADER_FLAG_WRITTEN)) {
1261 free_extent_buffer(buf);
1265 free_extent_buffer(buf);
1267 update_pinned_extents(root, bytenr, num_bytes, 1);
1269 set_extent_bits(&root->fs_info->pending_del,
1270 bytenr, bytenr + num_bytes - 1,
1271 EXTENT_LOCKED, GFP_NOFS);
1278 * remove an extent from the root, returns 0 on success
1280 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1281 *root, u64 bytenr, u64 num_bytes,
1282 u64 root_objectid, u64 ref_generation,
1283 u64 owner_objectid, u64 owner_offset, int pin,
1286 struct btrfs_path *path;
1287 struct btrfs_key key;
1288 struct btrfs_fs_info *info = root->fs_info;
1289 struct btrfs_extent_ops *ops = info->extent_ops;
1290 struct btrfs_root *extent_root = info->extent_root;
1291 struct extent_buffer *leaf;
1293 int extent_slot = 0;
1294 int found_extent = 0;
1296 struct btrfs_extent_item *ei;
1299 key.objectid = bytenr;
1300 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1301 key.offset = num_bytes;
1303 path = btrfs_alloc_path();
1307 ret = lookup_extent_backref(trans, extent_root, path,
1308 bytenr, root_objectid,
1310 owner_objectid, owner_offset, 1);
1312 struct btrfs_key found_key;
1313 extent_slot = path->slots[0];
1314 while(extent_slot > 0) {
1316 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1318 if (found_key.objectid != bytenr)
1320 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1321 found_key.offset == num_bytes) {
1325 if (path->slots[0] - extent_slot > 5)
1329 ret = btrfs_del_item(trans, extent_root, path);
1331 btrfs_print_leaf(extent_root, path->nodes[0]);
1333 printk("Unable to find ref byte nr %llu root %llu "
1334 " gen %llu owner %llu offset %llu\n",
1335 (unsigned long long)bytenr,
1336 (unsigned long long)root_objectid,
1337 (unsigned long long)ref_generation,
1338 (unsigned long long)owner_objectid,
1339 (unsigned long long)owner_offset);
1341 if (!found_extent) {
1342 btrfs_release_path(extent_root, path);
1343 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1347 extent_slot = path->slots[0];
1350 leaf = path->nodes[0];
1351 ei = btrfs_item_ptr(leaf, extent_slot,
1352 struct btrfs_extent_item);
1353 refs = btrfs_extent_refs(leaf, ei);
1356 btrfs_set_extent_refs(leaf, ei, refs);
1358 btrfs_mark_buffer_dirty(leaf);
1360 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1361 /* if the back ref and the extent are next to each other
1362 * they get deleted below in one shot
1364 path->slots[0] = extent_slot;
1366 } else if (found_extent) {
1367 /* otherwise delete the extent back ref */
1368 ret = btrfs_del_item(trans, extent_root, path);
1370 /* if refs are 0, we need to setup the path for deletion */
1372 btrfs_release_path(extent_root, path);
1373 ret = btrfs_search_slot(trans, extent_root, &key, path,
1386 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1392 /* block accounting for super block */
1393 super_used = btrfs_super_bytes_used(&info->super_copy);
1394 btrfs_set_super_bytes_used(&info->super_copy,
1395 super_used - num_bytes);
1397 /* block accounting for root item */
1398 root_used = btrfs_root_used(&root->root_item);
1399 btrfs_set_root_used(&root->root_item,
1400 root_used - num_bytes);
1401 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1406 if (ops && ops->free_extent)
1407 ops->free_extent(root, bytenr, num_bytes);
1409 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1413 btrfs_free_path(path);
1414 finish_current_insert(trans, extent_root);
1419 * find all the blocks marked as pending in the radix tree and remove
1420 * them from the extent map
1422 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1423 btrfs_root *extent_root)
1429 struct extent_io_tree *pending_del;
1430 struct extent_io_tree *pinned_extents;
1432 pending_del = &extent_root->fs_info->pending_del;
1433 pinned_extents = &extent_root->fs_info->pinned_extents;
1436 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1440 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1441 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1443 ret = __free_extent(trans, extent_root,
1444 start, end + 1 - start,
1445 extent_root->root_key.objectid,
1454 * remove an extent from the root, returns 0 on success
1456 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1457 *root, u64 bytenr, u64 num_bytes,
1458 u64 root_objectid, u64 ref_generation,
1459 u64 owner_objectid, u64 owner_offset, int pin)
1461 struct btrfs_root *extent_root = root->fs_info->extent_root;
1465 WARN_ON(num_bytes < root->sectorsize);
1466 if (!root->ref_cows)
1469 if (root == extent_root) {
1470 pin_down_bytes(root, bytenr, num_bytes, 1);
1473 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1474 ref_generation, owner_objectid, owner_offset,
1476 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1477 return ret ? ret : pending_ret;
1480 static u64 stripe_align(struct btrfs_root *root, u64 val)
1482 u64 mask = ((u64)root->stripesize - 1);
1483 u64 ret = (val + mask) & ~mask;
1488 * walks the btree of allocated extents and find a hole of a given size.
1489 * The key ins is changed to record the hole:
1490 * ins->objectid == block start
1491 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1492 * ins->offset == number of blocks
1493 * Any available blocks before search_start are skipped.
1495 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1496 struct btrfs_root *orig_root,
1497 u64 num_bytes, u64 empty_size,
1498 u64 search_start, u64 search_end,
1499 u64 hint_byte, struct btrfs_key *ins,
1500 u64 exclude_start, u64 exclude_nr,
1504 u64 orig_search_start = search_start;
1505 struct btrfs_root * root = orig_root->fs_info->extent_root;
1506 struct btrfs_fs_info *info = root->fs_info;
1507 u64 total_needed = num_bytes;
1508 struct btrfs_block_group_cache *block_group;
1512 WARN_ON(num_bytes < root->sectorsize);
1513 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1515 if (search_end == (u64)-1)
1516 search_end = btrfs_super_total_bytes(&info->super_copy);
1519 block_group = btrfs_lookup_block_group(info, hint_byte);
1521 hint_byte = search_start;
1522 block_group = btrfs_find_block_group(root, block_group,
1523 hint_byte, data, 1);
1525 block_group = btrfs_find_block_group(root,
1527 search_start, data, 1);
1530 total_needed += empty_size;
1534 block_group = btrfs_lookup_block_group(info, search_start);
1536 block_group = btrfs_lookup_block_group(info,
1539 ret = find_search_start(root, &block_group, &search_start,
1540 total_needed, data);
1544 search_start = stripe_align(root, search_start);
1545 ins->objectid = search_start;
1546 ins->offset = num_bytes;
1548 if (ins->objectid + num_bytes >= search_end)
1551 if (ins->objectid + num_bytes >
1552 block_group->key.objectid + block_group->key.offset) {
1553 search_start = block_group->key.objectid +
1554 block_group->key.offset;
1558 if (test_range_bit(&info->extent_ins, ins->objectid,
1559 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1560 search_start = ins->objectid + num_bytes;
1564 if (test_range_bit(&info->pinned_extents, ins->objectid,
1565 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1566 search_start = ins->objectid + num_bytes;
1570 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1571 ins->objectid < exclude_start + exclude_nr)) {
1572 search_start = exclude_start + exclude_nr;
1576 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1577 block_group = btrfs_lookup_block_group(info, ins->objectid);
1579 trans->block_group = block_group;
1581 ins->offset = num_bytes;
1585 if (search_start + num_bytes >= search_end) {
1587 search_start = orig_search_start;
1594 total_needed -= empty_size;
1599 block_group = btrfs_lookup_block_group(info, search_start);
1601 block_group = btrfs_find_block_group(root, block_group,
1602 search_start, data, 0);
1609 * finds a free extent and does all the dirty work required for allocation
1610 * returns the key for the extent through ins, and a tree buffer for
1611 * the first block of the extent through buf.
1613 * returns 0 if everything worked, non-zero otherwise.
1615 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1616 struct btrfs_root *root,
1617 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1618 u64 owner, u64 owner_offset,
1619 u64 empty_size, u64 hint_byte,
1620 u64 search_end, struct btrfs_key *ins, int data)
1624 u64 super_used, root_used;
1625 u64 search_start = 0;
1628 struct btrfs_fs_info *info = root->fs_info;
1629 struct btrfs_root *extent_root = info->extent_root;
1630 struct btrfs_path *path;
1631 struct btrfs_extent_item *extent_item;
1632 struct btrfs_extent_ref *ref;
1633 struct btrfs_key keys[2];
1635 if (info->extent_ops) {
1636 struct btrfs_extent_ops *ops = info->extent_ops;
1637 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
1643 alloc_profile = info->avail_data_alloc_bits &
1644 info->data_alloc_profile;
1645 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1646 } else if ((info->system_allocs > 0 || root == info->chunk_root) &&
1647 info->system_allocs >= 0) {
1648 alloc_profile = info->avail_system_alloc_bits &
1649 info->system_alloc_profile;
1650 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1652 alloc_profile = info->avail_metadata_alloc_bits &
1653 info->metadata_alloc_profile;
1654 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1657 if (root->ref_cows) {
1658 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1659 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1661 BTRFS_BLOCK_GROUP_METADATA);
1664 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1665 num_bytes + 2 * 1024 * 1024, data);
1669 WARN_ON(num_bytes < root->sectorsize);
1670 ret = find_free_extent(trans, root, num_bytes, empty_size,
1671 search_start, search_end, hint_byte, ins,
1672 trans->alloc_exclude_start,
1673 trans->alloc_exclude_nr, data);
1679 /* block accounting for super block */
1680 super_used = btrfs_super_bytes_used(&info->super_copy);
1681 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1683 /* block accounting for root item */
1684 root_used = btrfs_root_used(&root->root_item);
1685 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1687 clear_extent_dirty(&root->fs_info->free_space_cache,
1688 ins->objectid, ins->objectid + ins->offset - 1,
1691 if (root == extent_root) {
1692 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1693 ins->objectid + ins->offset - 1,
1694 EXTENT_LOCKED, GFP_NOFS);
1698 WARN_ON(trans->alloc_exclude_nr);
1699 trans->alloc_exclude_start = ins->objectid;
1700 trans->alloc_exclude_nr = ins->offset;
1702 memcpy(&keys[0], ins, sizeof(*ins));
1703 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1704 owner, owner_offset);
1705 keys[1].objectid = ins->objectid;
1706 keys[1].type = BTRFS_EXTENT_REF_KEY;
1707 sizes[0] = sizeof(*extent_item);
1708 sizes[1] = sizeof(*ref);
1710 path = btrfs_alloc_path();
1713 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1717 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1718 struct btrfs_extent_item);
1719 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1720 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1721 struct btrfs_extent_ref);
1723 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1724 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1725 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1726 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1728 btrfs_mark_buffer_dirty(path->nodes[0]);
1730 trans->alloc_exclude_start = 0;
1731 trans->alloc_exclude_nr = 0;
1732 btrfs_free_path(path);
1733 finish_current_insert(trans, extent_root);
1734 pending_ret = del_pending_extents(trans, extent_root);
1744 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1746 printk("update block group failed for %llu %llu\n",
1747 (unsigned long long)ins->objectid,
1748 (unsigned long long)ins->offset);
1755 * helper function to allocate a block for a given tree
1756 * returns the tree buffer or NULL.
1758 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1759 struct btrfs_root *root,
1761 u64 root_objectid, u64 hint,
1767 ref_generation = trans->transid;
1772 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1773 ref_generation, 0, 0, hint, empty_size);
1777 * helper function to allocate a block for a given tree
1778 * returns the tree buffer or NULL.
1780 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1781 struct btrfs_root *root,
1790 struct btrfs_key ins;
1792 struct extent_buffer *buf;
1794 ret = btrfs_alloc_extent(trans, root, blocksize,
1795 root_objectid, ref_generation,
1796 level, first_objectid, empty_size, hint,
1800 return ERR_PTR(ret);
1802 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1804 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1805 root->root_key.objectid, ref_generation,
1808 return ERR_PTR(-ENOMEM);
1810 btrfs_set_buffer_uptodate(buf);
1811 trans->blocks_used++;
1815 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1816 struct btrfs_root *root,
1817 struct extent_buffer *leaf)
1820 u64 leaf_generation;
1821 struct btrfs_key key;
1822 struct btrfs_file_extent_item *fi;
1827 BUG_ON(!btrfs_is_leaf(leaf));
1828 nritems = btrfs_header_nritems(leaf);
1829 leaf_owner = btrfs_header_owner(leaf);
1830 leaf_generation = btrfs_header_generation(leaf);
1832 for (i = 0; i < nritems; i++) {
1835 btrfs_item_key_to_cpu(leaf, &key, i);
1836 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1838 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1839 if (btrfs_file_extent_type(leaf, fi) ==
1840 BTRFS_FILE_EXTENT_INLINE)
1843 * FIXME make sure to insert a trans record that
1844 * repeats the snapshot del on crash
1846 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1847 if (disk_bytenr == 0)
1849 ret = btrfs_free_extent(trans, root, disk_bytenr,
1850 btrfs_file_extent_disk_num_bytes(leaf, fi),
1851 leaf_owner, leaf_generation,
1852 key.objectid, key.offset, 0);
1858 static void noinline reada_walk_down(struct btrfs_root *root,
1859 struct extent_buffer *node,
1872 nritems = btrfs_header_nritems(node);
1873 level = btrfs_header_level(node);
1877 for (i = slot; i < nritems && skipped < 32; i++) {
1878 bytenr = btrfs_node_blockptr(node, i);
1879 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1880 (last > bytenr && last - bytenr > 32 * 1024))) {
1884 blocksize = btrfs_level_size(root, level - 1);
1886 ret = lookup_extent_ref(NULL, root, bytenr,
1894 mutex_unlock(&root->fs_info->fs_mutex);
1895 ret = readahead_tree_block(root, bytenr, blocksize);
1896 last = bytenr + blocksize;
1898 mutex_lock(&root->fs_info->fs_mutex);
1905 * helper function for drop_snapshot, this walks down the tree dropping ref
1906 * counts as it goes.
1908 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
1909 struct btrfs_root *root,
1910 struct btrfs_path *path, int *level)
1915 struct extent_buffer *next;
1916 struct extent_buffer *cur;
1917 struct extent_buffer *parent;
1922 WARN_ON(*level < 0);
1923 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1924 ret = lookup_extent_ref(trans, root,
1925 path->nodes[*level]->start,
1926 path->nodes[*level]->len, &refs);
1932 * walk down to the last node level and free all the leaves
1934 while(*level >= 0) {
1935 WARN_ON(*level < 0);
1936 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1937 cur = path->nodes[*level];
1939 if (btrfs_header_level(cur) != *level)
1942 if (path->slots[*level] >=
1943 btrfs_header_nritems(cur))
1946 ret = drop_leaf_ref(trans, root, cur);
1950 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1951 blocksize = btrfs_level_size(root, *level - 1);
1952 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1955 parent = path->nodes[*level];
1956 root_owner = btrfs_header_owner(parent);
1957 root_gen = btrfs_header_generation(parent);
1958 path->slots[*level]++;
1959 ret = btrfs_free_extent(trans, root, bytenr,
1960 blocksize, root_owner,
1965 next = btrfs_find_tree_block(root, bytenr, blocksize);
1966 if (!next || !btrfs_buffer_uptodate(next)) {
1967 free_extent_buffer(next);
1968 reada_walk_down(root, cur, path->slots[*level]);
1969 mutex_unlock(&root->fs_info->fs_mutex);
1970 next = read_tree_block(root, bytenr, blocksize);
1971 mutex_lock(&root->fs_info->fs_mutex);
1973 /* we dropped the lock, check one more time */
1974 ret = lookup_extent_ref(trans, root, bytenr,
1978 parent = path->nodes[*level];
1979 root_owner = btrfs_header_owner(parent);
1980 root_gen = btrfs_header_generation(parent);
1982 path->slots[*level]++;
1983 free_extent_buffer(next);
1984 ret = btrfs_free_extent(trans, root, bytenr,
1992 WARN_ON(*level <= 0);
1993 if (path->nodes[*level-1])
1994 free_extent_buffer(path->nodes[*level-1]);
1995 path->nodes[*level-1] = next;
1996 *level = btrfs_header_level(next);
1997 path->slots[*level] = 0;
2000 WARN_ON(*level < 0);
2001 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2003 if (path->nodes[*level] == root->node) {
2004 root_owner = root->root_key.objectid;
2005 parent = path->nodes[*level];
2007 parent = path->nodes[*level + 1];
2008 root_owner = btrfs_header_owner(parent);
2011 root_gen = btrfs_header_generation(parent);
2012 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
2013 path->nodes[*level]->len,
2014 root_owner, root_gen, 0, 0, 1);
2015 free_extent_buffer(path->nodes[*level]);
2016 path->nodes[*level] = NULL;
2023 * helper for dropping snapshots. This walks back up the tree in the path
2024 * to find the first node higher up where we haven't yet gone through
2027 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2028 struct btrfs_root *root,
2029 struct btrfs_path *path, int *level)
2033 struct btrfs_root_item *root_item = &root->root_item;
2038 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2039 slot = path->slots[i];
2040 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2041 struct extent_buffer *node;
2042 struct btrfs_disk_key disk_key;
2043 node = path->nodes[i];
2046 WARN_ON(*level == 0);
2047 btrfs_node_key(node, &disk_key, path->slots[i]);
2048 memcpy(&root_item->drop_progress,
2049 &disk_key, sizeof(disk_key));
2050 root_item->drop_level = i;
2053 if (path->nodes[*level] == root->node) {
2054 root_owner = root->root_key.objectid;
2056 btrfs_header_generation(path->nodes[*level]);
2058 struct extent_buffer *node;
2059 node = path->nodes[*level + 1];
2060 root_owner = btrfs_header_owner(node);
2061 root_gen = btrfs_header_generation(node);
2063 ret = btrfs_free_extent(trans, root,
2064 path->nodes[*level]->start,
2065 path->nodes[*level]->len,
2066 root_owner, root_gen, 0, 0, 1);
2068 free_extent_buffer(path->nodes[*level]);
2069 path->nodes[*level] = NULL;
2077 * drop the reference count on the tree rooted at 'snap'. This traverses
2078 * the tree freeing any blocks that have a ref count of zero after being
2081 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2087 struct btrfs_path *path;
2090 struct btrfs_root_item *root_item = &root->root_item;
2092 path = btrfs_alloc_path();
2095 level = btrfs_header_level(root->node);
2097 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2098 path->nodes[level] = root->node;
2099 extent_buffer_get(root->node);
2100 path->slots[level] = 0;
2102 struct btrfs_key key;
2103 struct btrfs_disk_key found_key;
2104 struct extent_buffer *node;
2106 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2107 level = root_item->drop_level;
2108 path->lowest_level = level;
2109 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2114 node = path->nodes[level];
2115 btrfs_node_key(node, &found_key, path->slots[level]);
2116 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2117 sizeof(found_key)));
2120 wret = walk_down_tree(trans, root, path, &level);
2126 wret = walk_up_tree(trans, root, path, &level);
2136 for (i = 0; i <= orig_level; i++) {
2137 if (path->nodes[i]) {
2138 free_extent_buffer(path->nodes[i]);
2139 path->nodes[i] = NULL;
2143 btrfs_free_path(path);
2147 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2154 ret = find_first_extent_bit(&info->block_group_cache, 0,
2155 &start, &end, (unsigned int)-1);
2158 ret = get_state_private(&info->block_group_cache, start, &ptr);
2160 kfree((void *)(unsigned long)ptr);
2161 clear_extent_bits(&info->block_group_cache, start,
2162 end, (unsigned int)-1, GFP_NOFS);
2165 ret = find_first_extent_bit(&info->free_space_cache, 0,
2166 &start, &end, EXTENT_DIRTY);
2169 clear_extent_dirty(&info->free_space_cache, start,
2175 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2176 struct btrfs_key *key)
2179 struct btrfs_key found_key;
2180 struct extent_buffer *leaf;
2183 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2187 slot = path->slots[0];
2188 leaf = path->nodes[0];
2189 if (slot >= btrfs_header_nritems(leaf)) {
2190 ret = btrfs_next_leaf(root, path);
2197 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2199 if (found_key.objectid >= key->objectid &&
2200 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2209 int btrfs_read_block_groups(struct btrfs_root *root)
2211 struct btrfs_path *path;
2214 struct btrfs_block_group_cache *cache;
2215 struct btrfs_fs_info *info = root->fs_info;
2216 struct btrfs_space_info *space_info;
2217 struct extent_io_tree *block_group_cache;
2218 struct btrfs_key key;
2219 struct btrfs_key found_key;
2220 struct extent_buffer *leaf;
2222 block_group_cache = &info->block_group_cache;
2224 root = info->extent_root;
2227 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2228 path = btrfs_alloc_path();
2233 ret = find_first_block_group(root, path, &key);
2241 leaf = path->nodes[0];
2242 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2243 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2249 read_extent_buffer(leaf, &cache->item,
2250 btrfs_item_ptr_offset(leaf, path->slots[0]),
2251 sizeof(cache->item));
2252 memcpy(&cache->key, &found_key, sizeof(found_key));
2255 key.objectid = found_key.objectid + found_key.offset;
2256 btrfs_release_path(root, path);
2257 cache->flags = btrfs_block_group_flags(&cache->item);
2259 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2260 bit = BLOCK_GROUP_DATA;
2261 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2262 bit = BLOCK_GROUP_SYSTEM;
2263 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2264 bit = BLOCK_GROUP_METADATA;
2266 set_avail_alloc_bits(info, cache->flags);
2268 ret = update_space_info(info, cache->flags, found_key.offset,
2269 btrfs_block_group_used(&cache->item),
2272 cache->space_info = space_info;
2274 /* use EXTENT_LOCKED to prevent merging */
2275 set_extent_bits(block_group_cache, found_key.objectid,
2276 found_key.objectid + found_key.offset - 1,
2277 bit | EXTENT_LOCKED, GFP_NOFS);
2278 set_state_private(block_group_cache, found_key.objectid,
2279 (unsigned long)cache);
2282 btrfs_super_total_bytes(&info->super_copy))
2287 btrfs_free_path(path);
2291 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2292 struct btrfs_root *root, u64 bytes_used,
2293 u64 type, u64 chunk_objectid, u64 chunk_offset,
2298 struct btrfs_root *extent_root;
2299 struct btrfs_block_group_cache *cache;
2300 struct extent_io_tree *block_group_cache;
2302 extent_root = root->fs_info->extent_root;
2303 block_group_cache = &root->fs_info->block_group_cache;
2305 cache = kzalloc(sizeof(*cache), GFP_NOFS);
2307 cache->key.objectid = chunk_offset;
2308 cache->key.offset = size;
2310 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2311 btrfs_set_block_group_used(&cache->item, bytes_used);
2312 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2313 cache->flags = type;
2314 btrfs_set_block_group_flags(&cache->item, type);
2316 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2317 &cache->space_info);
2320 bit = block_group_state_bits(type);
2321 set_extent_bits(block_group_cache, chunk_offset,
2322 chunk_offset + size - 1,
2323 bit | EXTENT_LOCKED, GFP_NOFS);
2325 set_state_private(block_group_cache, chunk_offset,
2326 (unsigned long)cache);
2327 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2328 sizeof(cache->item));
2331 finish_current_insert(trans, extent_root);
2332 ret = del_pending_extents(trans, extent_root);
2334 set_avail_alloc_bits(extent_root->fs_info, type);
2339 * This is for converter use only.
2341 * In that case, we don't know where are free blocks located.
2342 * Therefore all block group cache entries must be setup properly
2343 * before doing any block allocation.
2345 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
2346 struct btrfs_root *root)
2356 struct btrfs_root *extent_root;
2357 struct btrfs_block_group_cache *cache;
2358 struct extent_io_tree *block_group_cache;
2360 extent_root = root->fs_info->extent_root;
2361 block_group_cache = &root->fs_info->block_group_cache;
2362 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2363 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
2366 while (cur_start < total_bytes) {
2367 if (group_nr == 0) {
2368 bit = BLOCK_GROUP_SYSTEM;
2369 group_type = BTRFS_BLOCK_GROUP_SYSTEM;
2370 } else if (group_nr % 3 == 1) {
2371 bit = BLOCK_GROUP_DATA;
2372 group_type = BTRFS_BLOCK_GROUP_METADATA;
2374 bit = BLOCK_GROUP_METADATA;
2375 group_type = BTRFS_BLOCK_GROUP_DATA;
2379 if (group_type == BTRFS_BLOCK_GROUP_SYSTEM) {
2380 group_size = 32 * 1024 * 1024;
2382 group_size = 256 * 1024 * 1024;
2383 if (total_bytes - cur_start < group_size * 5 / 4)
2384 group_size = total_bytes - cur_start;
2387 cache = kzalloc(sizeof(*cache), GFP_NOFS);
2390 cache->key.objectid = cur_start;
2391 cache->key.offset = group_size;
2392 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2394 btrfs_set_block_group_used(&cache->item, 0);
2395 btrfs_set_block_group_chunk_objectid(&cache->item,
2397 btrfs_set_block_group_flags(&cache->item, group_type);
2399 cache->flags = group_type;
2401 ret = update_space_info(root->fs_info, group_type, group_size,
2402 0, &cache->space_info);
2404 set_avail_alloc_bits(extent_root->fs_info, group_type);
2406 set_extent_bits(block_group_cache, cur_start,
2407 cur_start + group_size - 1,
2408 bit | EXTENT_LOCKED, GFP_NOFS);
2409 set_state_private(block_group_cache, cur_start,
2410 (unsigned long)cache);
2411 cur_start += group_size;
2413 /* then insert all the items */
2415 while(cur_start < total_bytes) {
2416 cache = btrfs_lookup_block_group(root->fs_info, cur_start);
2419 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2420 sizeof(cache->item));
2423 finish_current_insert(trans, extent_root);
2424 ret = del_pending_extents(trans, extent_root);
2427 cur_start = cache->key.objectid + cache->key.offset;
2432 u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
2433 u64 owner, u64 owner_offset)
2435 return hash_extent_ref(root_objectid, ref_generation,
2436 owner, owner_offset);
2439 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
2440 struct btrfs_root *root,
2441 u64 bytenr, u64 num_bytes, int alloc,
2444 return update_block_group(trans, root, bytenr, num_bytes,