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);
40 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root, u64 bytes_used,
42 u64 type, u64 chunk_tree, u64 chunk_objectid,
45 static int cache_block_group(struct btrfs_root *root,
46 struct btrfs_block_group_cache *block_group)
48 struct btrfs_path *path;
51 struct extent_buffer *leaf;
52 struct extent_io_tree *free_space_cache;
62 root = root->fs_info->extent_root;
63 free_space_cache = &root->fs_info->free_space_cache;
65 if (block_group->cached)
68 path = btrfs_alloc_path();
73 first_free = block_group->key.objectid;
74 key.objectid = block_group->key.objectid;
76 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
77 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
80 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
84 leaf = path->nodes[0];
85 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
86 if (key.objectid + key.offset > first_free)
87 first_free = key.objectid + key.offset;
90 leaf = path->nodes[0];
91 slot = path->slots[0];
92 if (slot >= btrfs_header_nritems(leaf)) {
93 ret = btrfs_next_leaf(root, path);
102 btrfs_item_key_to_cpu(leaf, &key, slot);
103 if (key.objectid < block_group->key.objectid) {
106 if (key.objectid >= block_group->key.objectid +
107 block_group->key.offset) {
111 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
116 if (key.objectid > last) {
117 hole_size = key.objectid - last;
118 set_extent_dirty(free_space_cache, last,
119 last + hole_size - 1,
122 last = key.objectid + key.offset;
130 if (block_group->key.objectid +
131 block_group->key.offset > last) {
132 hole_size = block_group->key.objectid +
133 block_group->key.offset - last;
134 set_extent_dirty(free_space_cache, last,
135 last + hole_size - 1, GFP_NOFS);
137 block_group->cached = 1;
139 btrfs_free_path(path);
143 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
147 struct extent_io_tree *block_group_cache;
148 struct btrfs_block_group_cache *block_group = NULL;
154 block_group_cache = &info->block_group_cache;
155 ret = find_first_extent_bit(block_group_cache,
156 bytenr, &start, &end,
157 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
162 ret = get_state_private(block_group_cache, start, &ptr);
166 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
167 if (block_group->key.objectid <= bytenr && bytenr <
168 block_group->key.objectid + block_group->key.offset)
173 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
175 return (cache->flags & bits);
178 static int noinline find_search_start(struct btrfs_root *root,
179 struct btrfs_block_group_cache **cache_ret,
180 u64 *start_ret, int num, int data)
183 struct btrfs_block_group_cache *cache = *cache_ret;
188 u64 search_start = *start_ret;
195 ret = cache_block_group(root, cache);
199 last = max(search_start, cache->key.objectid);
200 if (!block_group_bits(cache, data)) {
205 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
206 last, &start, &end, EXTENT_DIRTY);
213 start = max(last, start);
215 if (last - start < num) {
216 if (last == cache->key.objectid + cache->key.offset)
220 if (start + num > cache->key.objectid + cache->key.offset)
226 cache = btrfs_lookup_block_group(root->fs_info, search_start);
228 printk("Unable to find block group for %llu\n",
229 (unsigned long long)search_start);
235 last = cache->key.objectid + cache->key.offset;
237 cache = btrfs_lookup_block_group(root->fs_info, last);
247 if (cache_miss && !cache->cached) {
248 cache_block_group(root, cache);
250 cache = btrfs_lookup_block_group(root->fs_info, last);
252 cache = btrfs_find_block_group(root, cache, last, data, 0);
260 static u64 div_factor(u64 num, int factor)
269 static int block_group_state_bits(u64 flags)
272 if (flags & BTRFS_BLOCK_GROUP_DATA)
273 bits |= BLOCK_GROUP_DATA;
274 if (flags & BTRFS_BLOCK_GROUP_METADATA)
275 bits |= BLOCK_GROUP_METADATA;
276 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
277 bits |= BLOCK_GROUP_SYSTEM;
281 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
282 struct btrfs_block_group_cache
283 *hint, u64 search_start,
286 struct btrfs_block_group_cache *cache;
287 struct extent_io_tree *block_group_cache;
288 struct btrfs_block_group_cache *found_group = NULL;
289 struct btrfs_fs_info *info = root->fs_info;
302 block_group_cache = &info->block_group_cache;
307 bit = block_group_state_bits(data);
310 struct btrfs_block_group_cache *shint;
311 shint = btrfs_lookup_block_group(info, search_start);
312 if (shint && block_group_bits(shint, data)) {
313 used = btrfs_block_group_used(&shint->item);
314 if (used + shint->pinned <
315 div_factor(shint->key.offset, factor)) {
320 if (hint && block_group_bits(hint, data)) {
321 used = btrfs_block_group_used(&hint->item);
322 if (used + hint->pinned <
323 div_factor(hint->key.offset, factor)) {
326 last = hint->key.objectid + hint->key.offset;
330 hint_last = max(hint->key.objectid, search_start);
332 hint_last = search_start;
338 ret = find_first_extent_bit(block_group_cache, last,
343 ret = get_state_private(block_group_cache, start, &ptr);
347 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
348 last = cache->key.objectid + cache->key.offset;
349 used = btrfs_block_group_used(&cache->item);
352 free_check = cache->key.offset;
354 free_check = div_factor(cache->key.offset, factor);
356 if (used + cache->pinned < free_check) {
371 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
372 u64 owner, u64 owner_offset)
374 u32 high_crc = ~(u32)0;
375 u32 low_crc = ~(u32)0;
378 lenum = cpu_to_le64(root_objectid);
379 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
380 lenum = cpu_to_le64(ref_generation);
381 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
382 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
383 lenum = cpu_to_le64(owner);
384 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
385 lenum = cpu_to_le64(owner_offset);
386 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
388 return ((u64)high_crc << 32) | (u64)low_crc;
391 static int match_extent_ref(struct extent_buffer *leaf,
392 struct btrfs_extent_ref *disk_ref,
393 struct btrfs_extent_ref *cpu_ref)
398 if (cpu_ref->objectid)
399 len = sizeof(*cpu_ref);
401 len = 2 * sizeof(u64);
402 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
407 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
408 struct btrfs_root *root,
409 struct btrfs_path *path, u64 bytenr,
411 u64 ref_generation, u64 owner,
412 u64 owner_offset, int del)
415 struct btrfs_key key;
416 struct btrfs_key found_key;
417 struct btrfs_extent_ref ref;
418 struct extent_buffer *leaf;
419 struct btrfs_extent_ref *disk_ref;
423 btrfs_set_stack_ref_root(&ref, root_objectid);
424 btrfs_set_stack_ref_generation(&ref, ref_generation);
425 btrfs_set_stack_ref_objectid(&ref, owner);
426 btrfs_set_stack_ref_offset(&ref, owner_offset);
428 hash = hash_extent_ref(root_objectid, ref_generation, owner,
431 key.objectid = bytenr;
432 key.type = BTRFS_EXTENT_REF_KEY;
435 ret = btrfs_search_slot(trans, root, &key, path,
439 leaf = path->nodes[0];
441 u32 nritems = btrfs_header_nritems(leaf);
442 if (path->slots[0] >= nritems) {
443 ret2 = btrfs_next_leaf(root, path);
446 leaf = path->nodes[0];
448 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
449 if (found_key.objectid != bytenr ||
450 found_key.type != BTRFS_EXTENT_REF_KEY)
452 key.offset = found_key.offset;
454 btrfs_release_path(root, path);
458 disk_ref = btrfs_item_ptr(path->nodes[0],
460 struct btrfs_extent_ref);
461 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
465 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
466 key.offset = found_key.offset + 1;
467 btrfs_release_path(root, path);
474 * Back reference rules. Back refs have three main goals:
476 * 1) differentiate between all holders of references to an extent so that
477 * when a reference is dropped we can make sure it was a valid reference
478 * before freeing the extent.
480 * 2) Provide enough information to quickly find the holders of an extent
481 * if we notice a given block is corrupted or bad.
483 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
484 * maintenance. This is actually the same as #2, but with a slightly
485 * different use case.
487 * File extents can be referenced by:
489 * - multiple snapshots, subvolumes, or different generations in one subvol
490 * - different files inside a single subvolume (in theory, not implemented yet)
491 * - different offsets inside a file (bookend extents in file.c)
493 * The extent ref structure has fields for:
495 * - Objectid of the subvolume root
496 * - Generation number of the tree holding the reference
497 * - objectid of the file holding the reference
498 * - offset in the file corresponding to the key holding the reference
500 * When a file extent is allocated the fields are filled in:
501 * (root_key.objectid, trans->transid, inode objectid, offset in file)
503 * When a leaf is cow'd new references are added for every file extent found
504 * in the leaf. It looks the same as the create case, but trans->transid
505 * will be different when the block is cow'd.
507 * (root_key.objectid, trans->transid, inode objectid, offset in file)
509 * When a file extent is removed either during snapshot deletion or file
510 * truncation, the corresponding back reference is found
513 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
514 * inode objectid, offset in file)
516 * Btree extents can be referenced by:
518 * - Different subvolumes
519 * - Different generations of the same subvolume
521 * Storing sufficient information for a full reverse mapping of a btree
522 * block would require storing the lowest key of the block in the backref,
523 * and it would require updating that lowest key either before write out or
524 * every time it changed. Instead, the objectid of the lowest key is stored
525 * along with the level of the tree block. This provides a hint
526 * about where in the btree the block can be found. Searches through the
527 * btree only need to look for a pointer to that block, so they stop one
528 * level higher than the level recorded in the backref.
530 * Some btrees do not do reference counting on their extents. These
531 * include the extent tree and the tree of tree roots. Backrefs for these
532 * trees always have a generation of zero.
534 * When a tree block is created, back references are inserted:
536 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
538 * When a tree block is cow'd in a reference counted root,
539 * new back references are added for all the blocks it points to.
540 * These are of the form (trans->transid will have increased since creation):
542 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
544 * Because the lowest_key_objectid and the level are just hints
545 * they are not used when backrefs are deleted. When a backref is deleted:
547 * if backref was for a tree root:
548 * root_objectid = root->root_key.objectid
550 * root_objectid = btrfs_header_owner(parent)
552 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
554 * Back Reference Key hashing:
556 * Back references have four fields, each 64 bits long. Unfortunately,
557 * This is hashed into a single 64 bit number and placed into the key offset.
558 * The key objectid corresponds to the first byte in the extent, and the
559 * key type is set to BTRFS_EXTENT_REF_KEY
561 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
562 struct btrfs_root *root,
563 struct btrfs_path *path, u64 bytenr,
564 u64 root_objectid, u64 ref_generation,
565 u64 owner, u64 owner_offset)
568 struct btrfs_key key;
569 struct btrfs_extent_ref ref;
570 struct btrfs_extent_ref *disk_ref;
573 btrfs_set_stack_ref_root(&ref, root_objectid);
574 btrfs_set_stack_ref_generation(&ref, ref_generation);
575 btrfs_set_stack_ref_objectid(&ref, owner);
576 btrfs_set_stack_ref_offset(&ref, owner_offset);
578 hash = hash_extent_ref(root_objectid, ref_generation, owner,
581 key.objectid = bytenr;
582 key.type = BTRFS_EXTENT_REF_KEY;
584 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
585 while (ret == -EEXIST) {
586 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
587 struct btrfs_extent_ref);
588 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
591 btrfs_release_path(root, path);
592 ret = btrfs_insert_empty_item(trans, root, path, &key,
597 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
598 struct btrfs_extent_ref);
599 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
601 btrfs_mark_buffer_dirty(path->nodes[0]);
603 btrfs_release_path(root, path);
607 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
608 struct btrfs_root *root,
609 u64 bytenr, u64 num_bytes,
610 u64 root_objectid, u64 ref_generation,
611 u64 owner, u64 owner_offset)
613 struct btrfs_path *path;
615 struct btrfs_key key;
616 struct extent_buffer *l;
617 struct btrfs_extent_item *item;
620 WARN_ON(num_bytes < root->sectorsize);
621 path = btrfs_alloc_path();
625 key.objectid = bytenr;
626 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
627 key.offset = num_bytes;
628 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
637 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
638 refs = btrfs_extent_refs(l, item);
639 btrfs_set_extent_refs(l, item, refs + 1);
640 btrfs_mark_buffer_dirty(path->nodes[0]);
642 btrfs_release_path(root->fs_info->extent_root, path);
644 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
645 path, bytenr, root_objectid,
646 ref_generation, owner, owner_offset);
648 finish_current_insert(trans, root->fs_info->extent_root);
649 del_pending_extents(trans, root->fs_info->extent_root);
651 btrfs_free_path(path);
655 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
656 struct btrfs_root *root)
658 finish_current_insert(trans, root->fs_info->extent_root);
659 del_pending_extents(trans, root->fs_info->extent_root);
663 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
664 struct btrfs_root *root, u64 bytenr,
665 u64 num_bytes, u32 *refs)
667 struct btrfs_path *path;
669 struct btrfs_key key;
670 struct extent_buffer *l;
671 struct btrfs_extent_item *item;
673 WARN_ON(num_bytes < root->sectorsize);
674 path = btrfs_alloc_path();
675 key.objectid = bytenr;
676 key.offset = num_bytes;
677 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
678 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
683 btrfs_print_leaf(root, path->nodes[0]);
684 printk("failed to find block number %llu\n",
685 (unsigned long long)bytenr);
689 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
690 *refs = btrfs_extent_refs(l, item);
692 btrfs_free_path(path);
696 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
697 struct btrfs_path *count_path,
700 struct btrfs_root *extent_root = root->fs_info->extent_root;
701 struct btrfs_path *path;
704 u64 root_objectid = root->root_key.objectid;
710 struct btrfs_key key;
711 struct btrfs_key found_key;
712 struct extent_buffer *l;
713 struct btrfs_extent_item *item;
714 struct btrfs_extent_ref *ref_item;
717 path = btrfs_alloc_path();
720 bytenr = first_extent;
722 bytenr = count_path->nodes[level]->start;
725 key.objectid = bytenr;
728 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
729 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
735 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
737 if (found_key.objectid != bytenr ||
738 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
742 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
743 refs = btrfs_extent_refs(l, item);
745 nritems = btrfs_header_nritems(l);
746 if (path->slots[0] >= nritems) {
747 ret = btrfs_next_leaf(extent_root, path);
752 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
753 if (found_key.objectid != bytenr)
755 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
761 ref_item = btrfs_item_ptr(l, path->slots[0],
762 struct btrfs_extent_ref);
763 found_objectid = btrfs_ref_root(l, ref_item);
765 if (found_objectid != root_objectid) {
772 if (cur_count == 0) {
776 if (level >= 0 && root->node == count_path->nodes[level])
779 btrfs_release_path(root, path);
783 btrfs_free_path(path);
786 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
787 struct btrfs_root *root, u64 owner_objectid)
793 struct btrfs_disk_key disk_key;
795 level = btrfs_header_level(root->node);
796 generation = trans->transid;
797 nritems = btrfs_header_nritems(root->node);
800 btrfs_item_key(root->node, &disk_key, 0);
802 btrfs_node_key(root->node, &disk_key, 0);
803 key_objectid = btrfs_disk_key_objectid(&disk_key);
807 return btrfs_inc_extent_ref(trans, root, root->node->start,
808 root->node->len, owner_objectid,
809 generation, level, key_objectid);
812 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
813 struct extent_buffer *buf)
817 struct btrfs_key key;
818 struct btrfs_file_extent_item *fi;
827 level = btrfs_header_level(buf);
828 nritems = btrfs_header_nritems(buf);
829 for (i = 0; i < nritems; i++) {
832 btrfs_item_key_to_cpu(buf, &key, i);
833 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
835 fi = btrfs_item_ptr(buf, i,
836 struct btrfs_file_extent_item);
837 if (btrfs_file_extent_type(buf, fi) ==
838 BTRFS_FILE_EXTENT_INLINE)
840 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
841 if (disk_bytenr == 0)
843 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
844 btrfs_file_extent_disk_num_bytes(buf, fi),
845 root->root_key.objectid, trans->transid,
846 key.objectid, key.offset);
852 bytenr = btrfs_node_blockptr(buf, i);
853 btrfs_node_key_to_cpu(buf, &key, i);
854 ret = btrfs_inc_extent_ref(trans, root, bytenr,
855 btrfs_level_size(root, level - 1),
856 root->root_key.objectid,
858 level - 1, key.objectid);
869 for (i =0; i < faili; i++) {
872 btrfs_item_key_to_cpu(buf, &key, i);
873 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
875 fi = btrfs_item_ptr(buf, i,
876 struct btrfs_file_extent_item);
877 if (btrfs_file_extent_type(buf, fi) ==
878 BTRFS_FILE_EXTENT_INLINE)
880 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
881 if (disk_bytenr == 0)
883 err = btrfs_free_extent(trans, root, disk_bytenr,
884 btrfs_file_extent_disk_num_bytes(buf,
888 bytenr = btrfs_node_blockptr(buf, i);
889 err = btrfs_free_extent(trans, root, bytenr,
890 btrfs_level_size(root, level - 1), 0);
898 static int write_one_cache_group(struct btrfs_trans_handle *trans,
899 struct btrfs_root *root,
900 struct btrfs_path *path,
901 struct btrfs_block_group_cache *cache)
905 struct btrfs_root *extent_root = root->fs_info->extent_root;
907 struct extent_buffer *leaf;
909 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
914 leaf = path->nodes[0];
915 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
916 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
917 btrfs_mark_buffer_dirty(leaf);
918 btrfs_release_path(extent_root, path);
920 finish_current_insert(trans, extent_root);
921 pending_ret = del_pending_extents(trans, extent_root);
930 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
931 struct btrfs_root *root)
933 struct extent_io_tree *block_group_cache;
934 struct btrfs_block_group_cache *cache;
938 struct btrfs_path *path;
944 block_group_cache = &root->fs_info->block_group_cache;
945 path = btrfs_alloc_path();
950 ret = find_first_extent_bit(block_group_cache, last,
951 &start, &end, BLOCK_GROUP_DIRTY);
956 ret = get_state_private(block_group_cache, start, &ptr);
960 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
961 err = write_one_cache_group(trans, root,
964 * if we fail to write the cache group, we want
965 * to keep it marked dirty in hopes that a later
972 clear_extent_bits(block_group_cache, start, end,
973 BLOCK_GROUP_DIRTY, GFP_NOFS);
975 btrfs_free_path(path);
979 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
982 struct list_head *head = &info->space_info;
983 struct list_head *cur;
984 struct btrfs_space_info *found;
985 list_for_each(cur, head) {
986 found = list_entry(cur, struct btrfs_space_info, list);
987 if (found->flags == flags)
994 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
995 u64 total_bytes, u64 bytes_used,
996 struct btrfs_space_info **space_info)
998 struct btrfs_space_info *found;
1000 found = __find_space_info(info, flags);
1002 found->total_bytes += total_bytes;
1003 found->bytes_used += bytes_used;
1004 WARN_ON(found->total_bytes < found->bytes_used);
1005 *space_info = found;
1008 found = kmalloc(sizeof(*found), GFP_NOFS);
1012 list_add(&found->list, &info->space_info);
1013 found->flags = flags;
1014 found->total_bytes = total_bytes;
1015 found->bytes_used = bytes_used;
1016 found->bytes_pinned = 0;
1018 *space_info = found;
1023 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1024 struct btrfs_root *extent_root, u64 alloc_bytes,
1027 struct btrfs_space_info *space_info;
1033 space_info = __find_space_info(extent_root->fs_info, flags);
1035 ret = update_space_info(extent_root->fs_info, flags,
1039 BUG_ON(!space_info);
1041 if (space_info->full)
1044 thresh = div_factor(space_info->total_bytes, 7);
1045 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1049 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1050 if (ret == -ENOSPC) {
1051 printk("space info full %llu\n", (unsigned long long)flags);
1052 space_info->full = 1;
1058 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1059 extent_root->fs_info->chunk_root->root_key.objectid,
1065 static int update_block_group(struct btrfs_trans_handle *trans,
1066 struct btrfs_root *root,
1067 u64 bytenr, u64 num_bytes, int alloc,
1070 struct btrfs_block_group_cache *cache;
1071 struct btrfs_fs_info *info = root->fs_info;
1072 u64 total = num_bytes;
1079 cache = btrfs_lookup_block_group(info, bytenr);
1083 byte_in_group = bytenr - cache->key.objectid;
1084 WARN_ON(byte_in_group > cache->key.offset);
1085 start = cache->key.objectid;
1086 end = start + cache->key.offset - 1;
1087 set_extent_bits(&info->block_group_cache, start, end,
1088 BLOCK_GROUP_DIRTY, GFP_NOFS);
1090 old_val = btrfs_block_group_used(&cache->item);
1091 num_bytes = min(total, cache->key.offset - byte_in_group);
1093 old_val += num_bytes;
1094 cache->space_info->bytes_used += num_bytes;
1096 old_val -= num_bytes;
1097 cache->space_info->bytes_used -= num_bytes;
1099 set_extent_dirty(&info->free_space_cache,
1100 bytenr, bytenr + num_bytes - 1,
1104 btrfs_set_block_group_used(&cache->item, old_val);
1106 bytenr += num_bytes;
1111 static int update_pinned_extents(struct btrfs_root *root,
1112 u64 bytenr, u64 num, int pin)
1115 struct btrfs_block_group_cache *cache;
1116 struct btrfs_fs_info *fs_info = root->fs_info;
1119 set_extent_dirty(&fs_info->pinned_extents,
1120 bytenr, bytenr + num - 1, GFP_NOFS);
1122 clear_extent_dirty(&fs_info->pinned_extents,
1123 bytenr, bytenr + num - 1, GFP_NOFS);
1126 cache = btrfs_lookup_block_group(fs_info, bytenr);
1128 len = min(num, cache->key.offset -
1129 (bytenr - cache->key.objectid));
1131 cache->pinned += len;
1132 cache->space_info->bytes_pinned += len;
1133 fs_info->total_pinned += len;
1135 cache->pinned -= len;
1136 cache->space_info->bytes_pinned -= len;
1137 fs_info->total_pinned -= len;
1145 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1150 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1154 ret = find_first_extent_bit(pinned_extents, last,
1155 &start, &end, EXTENT_DIRTY);
1158 set_extent_dirty(copy, start, end, GFP_NOFS);
1164 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1165 struct btrfs_root *root,
1166 struct extent_io_tree *unpin)
1171 struct extent_io_tree *free_space_cache;
1172 free_space_cache = &root->fs_info->free_space_cache;
1175 ret = find_first_extent_bit(unpin, 0, &start, &end,
1179 update_pinned_extents(root, start, end + 1 - start, 0);
1180 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1181 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1186 static int finish_current_insert(struct btrfs_trans_handle *trans,
1187 struct btrfs_root *extent_root)
1191 struct btrfs_fs_info *info = extent_root->fs_info;
1192 struct extent_buffer *eb;
1193 struct btrfs_path *path;
1194 struct btrfs_key ins;
1195 struct btrfs_disk_key first;
1196 struct btrfs_extent_item extent_item;
1201 btrfs_set_stack_extent_refs(&extent_item, 1);
1202 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1203 path = btrfs_alloc_path();
1206 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1207 &end, EXTENT_LOCKED);
1211 ins.objectid = start;
1212 ins.offset = end + 1 - start;
1213 err = btrfs_insert_item(trans, extent_root, &ins,
1214 &extent_item, sizeof(extent_item));
1215 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1217 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1218 level = btrfs_header_level(eb);
1220 btrfs_item_key(eb, &first, 0);
1222 btrfs_node_key(eb, &first, 0);
1224 err = btrfs_insert_extent_backref(trans, extent_root, path,
1225 start, extent_root->root_key.objectid,
1227 btrfs_disk_key_objectid(&first));
1229 free_extent_buffer(eb);
1231 btrfs_free_path(path);
1235 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1239 struct extent_buffer *buf;
1242 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1244 if (btrfs_buffer_uptodate(buf)) {
1246 root->fs_info->running_transaction->transid;
1247 if (btrfs_header_generation(buf) == transid) {
1248 free_extent_buffer(buf);
1252 free_extent_buffer(buf);
1254 update_pinned_extents(root, bytenr, num_bytes, 1);
1256 set_extent_bits(&root->fs_info->pending_del,
1257 bytenr, bytenr + num_bytes - 1,
1258 EXTENT_LOCKED, GFP_NOFS);
1265 * remove an extent from the root, returns 0 on success
1267 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1268 *root, u64 bytenr, u64 num_bytes,
1269 u64 root_objectid, u64 ref_generation,
1270 u64 owner_objectid, u64 owner_offset, int pin,
1273 struct btrfs_path *path;
1274 struct btrfs_key key;
1275 struct btrfs_fs_info *info = root->fs_info;
1276 struct btrfs_extent_ops *ops = info->extent_ops;
1277 struct btrfs_root *extent_root = info->extent_root;
1278 struct extent_buffer *leaf;
1280 int extent_slot = 0;
1281 int found_extent = 0;
1283 struct btrfs_extent_item *ei;
1286 key.objectid = bytenr;
1287 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1288 key.offset = num_bytes;
1290 path = btrfs_alloc_path();
1294 ret = lookup_extent_backref(trans, extent_root, path,
1295 bytenr, root_objectid,
1297 owner_objectid, owner_offset, 1);
1299 struct btrfs_key found_key;
1300 extent_slot = path->slots[0];
1301 while(extent_slot > 0) {
1303 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1305 if (found_key.objectid != bytenr)
1307 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1308 found_key.offset == num_bytes) {
1312 if (path->slots[0] - extent_slot > 5)
1316 ret = btrfs_del_item(trans, extent_root, path);
1318 btrfs_print_leaf(extent_root, path->nodes[0]);
1320 printk("Unable to find ref byte nr %llu root %llu "
1321 " gen %llu owner %llu offset %llu\n",
1322 (unsigned long long)bytenr,
1323 (unsigned long long)root_objectid,
1324 (unsigned long long)ref_generation,
1325 (unsigned long long)owner_objectid,
1326 (unsigned long long)owner_offset);
1328 if (!found_extent) {
1329 btrfs_release_path(extent_root, path);
1330 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1334 extent_slot = path->slots[0];
1337 leaf = path->nodes[0];
1338 ei = btrfs_item_ptr(leaf, extent_slot,
1339 struct btrfs_extent_item);
1340 refs = btrfs_extent_refs(leaf, ei);
1343 btrfs_set_extent_refs(leaf, ei, refs);
1345 btrfs_mark_buffer_dirty(leaf);
1347 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1348 /* if the back ref and the extent are next to each other
1349 * they get deleted below in one shot
1351 path->slots[0] = extent_slot;
1353 } else if (found_extent) {
1354 /* otherwise delete the extent back ref */
1355 ret = btrfs_del_item(trans, extent_root, path);
1357 /* if refs are 0, we need to setup the path for deletion */
1359 btrfs_release_path(extent_root, path);
1360 ret = btrfs_search_slot(trans, extent_root, &key, path,
1373 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1379 /* block accounting for super block */
1380 super_used = btrfs_super_bytes_used(&info->super_copy);
1381 btrfs_set_super_bytes_used(&info->super_copy,
1382 super_used - num_bytes);
1384 /* block accounting for root item */
1385 root_used = btrfs_root_used(&root->root_item);
1386 btrfs_set_root_used(&root->root_item,
1387 root_used - num_bytes);
1388 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1393 if (ops && ops->free_extent)
1394 ops->free_extent(root, bytenr, num_bytes);
1396 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1400 btrfs_free_path(path);
1401 finish_current_insert(trans, extent_root);
1406 * find all the blocks marked as pending in the radix tree and remove
1407 * them from the extent map
1409 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1410 btrfs_root *extent_root)
1416 struct extent_io_tree *pending_del;
1417 struct extent_io_tree *pinned_extents;
1419 pending_del = &extent_root->fs_info->pending_del;
1420 pinned_extents = &extent_root->fs_info->pinned_extents;
1423 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1427 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1428 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1430 ret = __free_extent(trans, extent_root,
1431 start, end + 1 - start,
1432 extent_root->root_key.objectid,
1441 * remove an extent from the root, returns 0 on success
1443 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1444 *root, u64 bytenr, u64 num_bytes,
1445 u64 root_objectid, u64 ref_generation,
1446 u64 owner_objectid, u64 owner_offset, int pin)
1448 struct btrfs_root *extent_root = root->fs_info->extent_root;
1452 WARN_ON(num_bytes < root->sectorsize);
1453 if (!root->ref_cows)
1456 if (root == extent_root) {
1457 pin_down_bytes(root, bytenr, num_bytes, 1);
1460 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1461 ref_generation, owner_objectid, owner_offset,
1463 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1464 return ret ? ret : pending_ret;
1467 static u64 stripe_align(struct btrfs_root *root, u64 val)
1469 u64 mask = ((u64)root->stripesize - 1);
1470 u64 ret = (val + mask) & ~mask;
1475 * walks the btree of allocated extents and find a hole of a given size.
1476 * The key ins is changed to record the hole:
1477 * ins->objectid == block start
1478 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1479 * ins->offset == number of blocks
1480 * Any available blocks before search_start are skipped.
1482 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1483 struct btrfs_root *orig_root,
1484 u64 num_bytes, u64 empty_size,
1485 u64 search_start, u64 search_end,
1486 u64 hint_byte, struct btrfs_key *ins,
1487 u64 exclude_start, u64 exclude_nr,
1491 u64 orig_search_start = search_start;
1492 struct btrfs_root * root = orig_root->fs_info->extent_root;
1493 struct btrfs_fs_info *info = root->fs_info;
1494 u64 total_needed = num_bytes;
1495 struct btrfs_block_group_cache *block_group;
1499 WARN_ON(num_bytes < root->sectorsize);
1500 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1502 if (search_end == (u64)-1)
1503 search_end = btrfs_super_total_bytes(&info->super_copy);
1506 block_group = btrfs_lookup_block_group(info, hint_byte);
1508 hint_byte = search_start;
1509 block_group = btrfs_find_block_group(root, block_group,
1510 hint_byte, data, 1);
1512 block_group = btrfs_find_block_group(root,
1514 search_start, data, 1);
1517 total_needed += empty_size;
1521 block_group = btrfs_lookup_block_group(info, search_start);
1523 block_group = btrfs_lookup_block_group(info,
1526 ret = find_search_start(root, &block_group, &search_start,
1527 total_needed, data);
1531 search_start = stripe_align(root, search_start);
1532 ins->objectid = search_start;
1533 ins->offset = num_bytes;
1535 if (ins->objectid + num_bytes >= search_end)
1538 if (ins->objectid + num_bytes >
1539 block_group->key.objectid + block_group->key.offset) {
1540 search_start = block_group->key.objectid +
1541 block_group->key.offset;
1545 if (test_range_bit(&info->extent_ins, ins->objectid,
1546 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1547 search_start = ins->objectid + num_bytes;
1551 if (test_range_bit(&info->pinned_extents, ins->objectid,
1552 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1553 search_start = ins->objectid + num_bytes;
1557 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1558 ins->objectid < exclude_start + exclude_nr)) {
1559 search_start = exclude_start + exclude_nr;
1563 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1564 block_group = btrfs_lookup_block_group(info, ins->objectid);
1566 trans->block_group = block_group;
1568 ins->offset = num_bytes;
1572 if (search_start + num_bytes >= search_end) {
1574 search_start = orig_search_start;
1581 total_needed -= empty_size;
1586 block_group = btrfs_lookup_block_group(info, search_start);
1588 block_group = btrfs_find_block_group(root, block_group,
1589 search_start, data, 0);
1596 * finds a free extent and does all the dirty work required for allocation
1597 * returns the key for the extent through ins, and a tree buffer for
1598 * the first block of the extent through buf.
1600 * returns 0 if everything worked, non-zero otherwise.
1602 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1603 struct btrfs_root *root,
1604 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1605 u64 owner, u64 owner_offset,
1606 u64 empty_size, u64 hint_byte,
1607 u64 search_end, struct btrfs_key *ins, int data)
1611 u64 super_used, root_used;
1612 u64 search_start = 0;
1613 struct btrfs_fs_info *info = root->fs_info;
1614 struct btrfs_extent_ops *ops = info->extent_ops;
1616 struct btrfs_root *extent_root = info->extent_root;
1617 struct btrfs_path *path;
1618 struct btrfs_extent_item *extent_item;
1619 struct btrfs_extent_ref *ref;
1620 struct btrfs_key keys[2];
1623 data = BTRFS_BLOCK_GROUP_DATA;
1624 } else if (root == root->fs_info->chunk_root ||
1625 info->force_system_allocs) {
1626 data = BTRFS_BLOCK_GROUP_SYSTEM;
1628 data = BTRFS_BLOCK_GROUP_METADATA;
1631 if (root->ref_cows) {
1632 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1633 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1635 BTRFS_BLOCK_GROUP_METADATA);
1638 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1639 num_bytes + 2 * 1024 * 1024, data);
1643 WARN_ON(num_bytes < root->sectorsize);
1644 if (ops && ops->alloc_extent) {
1645 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
1647 ret = find_free_extent(trans, root, num_bytes, empty_size,
1648 search_start, search_end, hint_byte,
1649 ins, trans->alloc_exclude_start,
1650 trans->alloc_exclude_nr, data);
1656 /* block accounting for super block */
1657 super_used = btrfs_super_bytes_used(&info->super_copy);
1658 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1660 /* block accounting for root item */
1661 root_used = btrfs_root_used(&root->root_item);
1662 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1664 clear_extent_dirty(&root->fs_info->free_space_cache,
1665 ins->objectid, ins->objectid + ins->offset - 1,
1668 if (root == extent_root) {
1669 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1670 ins->objectid + ins->offset - 1,
1671 EXTENT_LOCKED, GFP_NOFS);
1675 WARN_ON(trans->alloc_exclude_nr);
1676 trans->alloc_exclude_start = ins->objectid;
1677 trans->alloc_exclude_nr = ins->offset;
1679 memcpy(&keys[0], ins, sizeof(*ins));
1680 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1681 owner, owner_offset);
1682 keys[1].objectid = ins->objectid;
1683 keys[1].type = BTRFS_EXTENT_REF_KEY;
1684 sizes[0] = sizeof(*extent_item);
1685 sizes[1] = sizeof(*ref);
1687 path = btrfs_alloc_path();
1690 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1694 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1695 struct btrfs_extent_item);
1696 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1697 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1698 struct btrfs_extent_ref);
1700 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1701 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1702 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1703 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1705 btrfs_mark_buffer_dirty(path->nodes[0]);
1707 trans->alloc_exclude_start = 0;
1708 trans->alloc_exclude_nr = 0;
1709 btrfs_free_path(path);
1710 finish_current_insert(trans, extent_root);
1711 pending_ret = del_pending_extents(trans, extent_root);
1721 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1723 printk("update block group failed for %llu %llu\n",
1724 (unsigned long long)ins->objectid,
1725 (unsigned long long)ins->offset);
1732 * helper function to allocate a block for a given tree
1733 * returns the tree buffer or NULL.
1735 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1736 struct btrfs_root *root,
1738 u64 root_objectid, u64 hint,
1744 ref_generation = trans->transid;
1749 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1750 ref_generation, 0, 0, hint, empty_size);
1754 * helper function to allocate a block for a given tree
1755 * returns the tree buffer or NULL.
1757 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1758 struct btrfs_root *root,
1767 struct btrfs_key ins;
1769 struct extent_buffer *buf;
1771 ret = btrfs_alloc_extent(trans, root, blocksize,
1772 root_objectid, ref_generation,
1773 level, first_objectid, empty_size, hint,
1777 return ERR_PTR(ret);
1779 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1781 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1782 root->root_key.objectid, ref_generation,
1785 return ERR_PTR(-ENOMEM);
1787 btrfs_set_buffer_uptodate(buf);
1788 trans->blocks_used++;
1792 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1793 struct btrfs_root *root,
1794 struct extent_buffer *leaf)
1797 u64 leaf_generation;
1798 struct btrfs_key key;
1799 struct btrfs_file_extent_item *fi;
1804 BUG_ON(!btrfs_is_leaf(leaf));
1805 nritems = btrfs_header_nritems(leaf);
1806 leaf_owner = btrfs_header_owner(leaf);
1807 leaf_generation = btrfs_header_generation(leaf);
1809 for (i = 0; i < nritems; i++) {
1812 btrfs_item_key_to_cpu(leaf, &key, i);
1813 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1815 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1816 if (btrfs_file_extent_type(leaf, fi) ==
1817 BTRFS_FILE_EXTENT_INLINE)
1820 * FIXME make sure to insert a trans record that
1821 * repeats the snapshot del on crash
1823 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1824 if (disk_bytenr == 0)
1826 ret = btrfs_free_extent(trans, root, disk_bytenr,
1827 btrfs_file_extent_disk_num_bytes(leaf, fi),
1828 leaf_owner, leaf_generation,
1829 key.objectid, key.offset, 0);
1835 static void noinline reada_walk_down(struct btrfs_root *root,
1836 struct extent_buffer *node,
1849 nritems = btrfs_header_nritems(node);
1850 level = btrfs_header_level(node);
1854 for (i = slot; i < nritems && skipped < 32; i++) {
1855 bytenr = btrfs_node_blockptr(node, i);
1856 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1857 (last > bytenr && last - bytenr > 32 * 1024))) {
1861 blocksize = btrfs_level_size(root, level - 1);
1863 ret = lookup_extent_ref(NULL, root, bytenr,
1871 mutex_unlock(&root->fs_info->fs_mutex);
1872 ret = readahead_tree_block(root, bytenr, blocksize);
1873 last = bytenr + blocksize;
1875 mutex_lock(&root->fs_info->fs_mutex);
1882 * helper function for drop_snapshot, this walks down the tree dropping ref
1883 * counts as it goes.
1885 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
1886 struct btrfs_root *root,
1887 struct btrfs_path *path, int *level)
1892 struct extent_buffer *next;
1893 struct extent_buffer *cur;
1894 struct extent_buffer *parent;
1899 WARN_ON(*level < 0);
1900 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1901 ret = lookup_extent_ref(trans, root,
1902 path->nodes[*level]->start,
1903 path->nodes[*level]->len, &refs);
1909 * walk down to the last node level and free all the leaves
1911 while(*level >= 0) {
1912 WARN_ON(*level < 0);
1913 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1914 cur = path->nodes[*level];
1916 if (btrfs_header_level(cur) != *level)
1919 if (path->slots[*level] >=
1920 btrfs_header_nritems(cur))
1923 ret = drop_leaf_ref(trans, root, cur);
1927 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1928 blocksize = btrfs_level_size(root, *level - 1);
1929 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1932 parent = path->nodes[*level];
1933 root_owner = btrfs_header_owner(parent);
1934 root_gen = btrfs_header_generation(parent);
1935 path->slots[*level]++;
1936 ret = btrfs_free_extent(trans, root, bytenr,
1937 blocksize, root_owner,
1942 next = btrfs_find_tree_block(root, bytenr, blocksize);
1943 if (!next || !btrfs_buffer_uptodate(next)) {
1944 free_extent_buffer(next);
1945 reada_walk_down(root, cur, path->slots[*level]);
1946 mutex_unlock(&root->fs_info->fs_mutex);
1947 next = read_tree_block(root, bytenr, blocksize);
1948 mutex_lock(&root->fs_info->fs_mutex);
1950 /* we dropped the lock, check one more time */
1951 ret = lookup_extent_ref(trans, root, bytenr,
1955 parent = path->nodes[*level];
1956 root_owner = btrfs_header_owner(parent);
1957 root_gen = btrfs_header_generation(parent);
1959 path->slots[*level]++;
1960 free_extent_buffer(next);
1961 ret = btrfs_free_extent(trans, root, bytenr,
1969 WARN_ON(*level <= 0);
1970 if (path->nodes[*level-1])
1971 free_extent_buffer(path->nodes[*level-1]);
1972 path->nodes[*level-1] = next;
1973 *level = btrfs_header_level(next);
1974 path->slots[*level] = 0;
1977 WARN_ON(*level < 0);
1978 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1980 if (path->nodes[*level] == root->node) {
1981 root_owner = root->root_key.objectid;
1982 parent = path->nodes[*level];
1984 parent = path->nodes[*level + 1];
1985 root_owner = btrfs_header_owner(parent);
1988 root_gen = btrfs_header_generation(parent);
1989 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1990 path->nodes[*level]->len,
1991 root_owner, root_gen, 0, 0, 1);
1992 free_extent_buffer(path->nodes[*level]);
1993 path->nodes[*level] = NULL;
2000 * helper for dropping snapshots. This walks back up the tree in the path
2001 * to find the first node higher up where we haven't yet gone through
2004 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2005 struct btrfs_root *root,
2006 struct btrfs_path *path, int *level)
2010 struct btrfs_root_item *root_item = &root->root_item;
2015 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2016 slot = path->slots[i];
2017 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2018 struct extent_buffer *node;
2019 struct btrfs_disk_key disk_key;
2020 node = path->nodes[i];
2023 WARN_ON(*level == 0);
2024 btrfs_node_key(node, &disk_key, path->slots[i]);
2025 memcpy(&root_item->drop_progress,
2026 &disk_key, sizeof(disk_key));
2027 root_item->drop_level = i;
2030 if (path->nodes[*level] == root->node) {
2031 root_owner = root->root_key.objectid;
2033 btrfs_header_generation(path->nodes[*level]);
2035 struct extent_buffer *node;
2036 node = path->nodes[*level + 1];
2037 root_owner = btrfs_header_owner(node);
2038 root_gen = btrfs_header_generation(node);
2040 ret = btrfs_free_extent(trans, root,
2041 path->nodes[*level]->start,
2042 path->nodes[*level]->len,
2043 root_owner, root_gen, 0, 0, 1);
2045 free_extent_buffer(path->nodes[*level]);
2046 path->nodes[*level] = NULL;
2054 * drop the reference count on the tree rooted at 'snap'. This traverses
2055 * the tree freeing any blocks that have a ref count of zero after being
2058 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2064 struct btrfs_path *path;
2067 struct btrfs_root_item *root_item = &root->root_item;
2069 path = btrfs_alloc_path();
2072 level = btrfs_header_level(root->node);
2074 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2075 path->nodes[level] = root->node;
2076 extent_buffer_get(root->node);
2077 path->slots[level] = 0;
2079 struct btrfs_key key;
2080 struct btrfs_disk_key found_key;
2081 struct extent_buffer *node;
2083 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2084 level = root_item->drop_level;
2085 path->lowest_level = level;
2086 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2091 node = path->nodes[level];
2092 btrfs_node_key(node, &found_key, path->slots[level]);
2093 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2094 sizeof(found_key)));
2097 wret = walk_down_tree(trans, root, path, &level);
2103 wret = walk_up_tree(trans, root, path, &level);
2113 for (i = 0; i <= orig_level; i++) {
2114 if (path->nodes[i]) {
2115 free_extent_buffer(path->nodes[i]);
2116 path->nodes[i] = NULL;
2120 btrfs_free_path(path);
2124 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2131 ret = find_first_extent_bit(&info->block_group_cache, 0,
2132 &start, &end, (unsigned int)-1);
2135 ret = get_state_private(&info->block_group_cache, start, &ptr);
2137 kfree((void *)(unsigned long)ptr);
2138 clear_extent_bits(&info->block_group_cache, start,
2139 end, (unsigned int)-1, GFP_NOFS);
2142 ret = find_first_extent_bit(&info->free_space_cache, 0,
2143 &start, &end, EXTENT_DIRTY);
2146 clear_extent_dirty(&info->free_space_cache, start,
2152 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2153 struct btrfs_key *key)
2156 struct btrfs_key found_key;
2157 struct extent_buffer *leaf;
2160 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2164 slot = path->slots[0];
2165 leaf = path->nodes[0];
2166 if (slot >= btrfs_header_nritems(leaf)) {
2167 ret = btrfs_next_leaf(root, path);
2174 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2176 if (found_key.objectid >= key->objectid &&
2177 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2186 int btrfs_read_block_groups(struct btrfs_root *root)
2188 struct btrfs_path *path;
2191 struct btrfs_block_group_cache *cache;
2192 struct btrfs_fs_info *info = root->fs_info;
2193 struct btrfs_space_info *space_info;
2194 struct extent_io_tree *block_group_cache;
2195 struct btrfs_key key;
2196 struct btrfs_key found_key;
2197 struct extent_buffer *leaf;
2199 block_group_cache = &info->block_group_cache;
2201 root = info->extent_root;
2204 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2205 path = btrfs_alloc_path();
2210 ret = find_first_block_group(root, path, &key);
2218 leaf = path->nodes[0];
2219 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2220 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2226 read_extent_buffer(leaf, &cache->item,
2227 btrfs_item_ptr_offset(leaf, path->slots[0]),
2228 sizeof(cache->item));
2229 memcpy(&cache->key, &found_key, sizeof(found_key));
2232 key.objectid = found_key.objectid + found_key.offset;
2233 btrfs_release_path(root, path);
2234 cache->flags = btrfs_block_group_flags(&cache->item);
2236 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2237 bit = BLOCK_GROUP_DATA;
2238 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2239 bit = BLOCK_GROUP_SYSTEM;
2240 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2241 bit = BLOCK_GROUP_METADATA;
2244 ret = update_space_info(info, cache->flags, found_key.offset,
2245 btrfs_block_group_used(&cache->item),
2248 cache->space_info = space_info;
2250 /* use EXTENT_LOCKED to prevent merging */
2251 set_extent_bits(block_group_cache, found_key.objectid,
2252 found_key.objectid + found_key.offset - 1,
2253 bit | EXTENT_LOCKED, GFP_NOFS);
2254 set_state_private(block_group_cache, found_key.objectid,
2255 (unsigned long)cache);
2258 btrfs_super_total_bytes(&info->super_copy))
2263 btrfs_free_path(path);
2267 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2268 struct btrfs_root *root, u64 bytes_used,
2269 u64 type, u64 chunk_tree, u64 chunk_objectid,
2274 struct btrfs_root *extent_root;
2275 struct btrfs_block_group_cache *cache;
2276 struct extent_io_tree *block_group_cache;
2278 extent_root = root->fs_info->extent_root;
2279 block_group_cache = &root->fs_info->block_group_cache;
2281 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2283 cache->key.objectid = chunk_objectid;
2284 cache->key.offset = size;
2286 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2287 memset(&cache->item, 0, sizeof(cache->item));
2288 btrfs_set_block_group_used(&cache->item, bytes_used);
2289 btrfs_set_block_group_chunk_tree(&cache->item, chunk_tree);
2290 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2291 cache->flags = type;
2292 btrfs_set_block_group_flags(&cache->item, type);
2294 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2295 &cache->space_info);
2298 if (type & BTRFS_BLOCK_GROUP_DATA) {
2299 bit = BLOCK_GROUP_DATA;
2300 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2301 bit = BLOCK_GROUP_SYSTEM;
2302 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2303 bit = BLOCK_GROUP_METADATA;
2305 set_extent_bits(block_group_cache, chunk_objectid,
2306 chunk_objectid + size - 1,
2307 bit | EXTENT_LOCKED, GFP_NOFS);
2308 set_state_private(block_group_cache, chunk_objectid,
2309 (unsigned long)cache);
2311 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2312 sizeof(cache->item));
2315 finish_current_insert(trans, extent_root);
2316 ret = del_pending_extents(trans, extent_root);
2321 u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
2322 u64 owner, u64 owner_offset)
2324 return hash_extent_ref(root_objectid, ref_generation,
2325 owner, owner_offset);
2328 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
2329 struct btrfs_root *root,
2330 u64 bytenr, u64 num_bytes, int alloc,
2333 return update_block_group(trans, root, bytenr, num_bytes,