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.
19 #include <linux/sched.h>
20 #include <linux/crc32c.h>
24 #include "print-tree.h"
25 #include "transaction.h"
27 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
28 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
29 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
31 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
32 btrfs_root *extent_root);
33 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
34 btrfs_root *extent_root);
36 static int cache_block_group(struct btrfs_root *root,
37 struct btrfs_block_group_cache *block_group)
39 struct btrfs_path *path;
42 struct extent_buffer *leaf;
43 struct extent_map_tree *free_space_cache;
53 root = root->fs_info->extent_root;
54 free_space_cache = &root->fs_info->free_space_cache;
56 if (block_group->cached)
59 path = btrfs_alloc_path();
64 first_free = block_group->key.objectid;
65 key.objectid = block_group->key.objectid;
68 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
69 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
74 if (ret && path->slots[0] > 0)
78 leaf = path->nodes[0];
79 slot = path->slots[0];
80 if (slot >= btrfs_header_nritems(leaf)) {
81 ret = btrfs_next_leaf(root, path);
91 btrfs_item_key_to_cpu(leaf, &key, slot);
92 if (key.objectid < block_group->key.objectid) {
93 if (btrfs_key_type(&key) != BTRFS_EXTENT_REF_KEY &&
94 key.objectid + key.offset > first_free)
95 first_free = key.objectid + key.offset;
99 if (key.objectid >= block_group->key.objectid +
100 block_group->key.offset) {
104 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
109 if (key.objectid > last) {
110 hole_size = key.objectid - last;
111 set_extent_dirty(free_space_cache, last,
112 last + hole_size - 1,
115 last = key.objectid + key.offset;
123 if (block_group->key.objectid +
124 block_group->key.offset > last) {
125 hole_size = block_group->key.objectid +
126 block_group->key.offset - last;
127 set_extent_dirty(free_space_cache, last,
128 last + hole_size - 1, GFP_NOFS);
130 block_group->cached = 1;
132 btrfs_free_path(path);
136 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
140 struct extent_map_tree *block_group_cache;
141 struct btrfs_block_group_cache *block_group = NULL;
147 block_group_cache = &info->block_group_cache;
148 ret = find_first_extent_bit(block_group_cache,
149 bytenr, &start, &end,
150 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA);
154 ret = get_state_private(block_group_cache, start, &ptr);
158 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
159 if (block_group->key.objectid <= bytenr && bytenr <
160 block_group->key.objectid + block_group->key.offset)
164 static u64 find_search_start(struct btrfs_root *root,
165 struct btrfs_block_group_cache **cache_ret,
166 u64 search_start, int num,
167 int data, int full_scan)
170 struct btrfs_block_group_cache *cache = *cache_ret;
181 ret = cache_block_group(root, cache);
185 last = max(search_start, cache->key.objectid);
188 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
189 last, &start, &end, EXTENT_DIRTY);
196 start = max(last, start);
198 if (last - start < num) {
199 if (last == cache->key.objectid + cache->key.offset)
203 if (data != BTRFS_BLOCK_GROUP_MIXED &&
204 start + num > cache->key.objectid + cache->key.offset)
209 cache = btrfs_lookup_block_group(root->fs_info, search_start);
211 printk("Unable to find block group for %Lu\n",
219 last = cache->key.objectid + cache->key.offset;
221 cache = btrfs_lookup_block_group(root->fs_info, last);
227 data = BTRFS_BLOCK_GROUP_MIXED;
232 if (cache_miss && !cache->cached) {
233 cache_block_group(root, cache);
235 cache = btrfs_lookup_block_group(root->fs_info, last);
237 cache = btrfs_find_block_group(root, cache, last, data, 0);
245 static u64 div_factor(u64 num, int factor)
254 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
255 struct btrfs_block_group_cache
256 *hint, u64 search_start,
259 struct btrfs_block_group_cache *cache;
260 struct extent_map_tree *block_group_cache;
261 struct btrfs_block_group_cache *found_group = NULL;
262 struct btrfs_fs_info *info = root->fs_info;
276 block_group_cache = &info->block_group_cache;
281 if (data == BTRFS_BLOCK_GROUP_MIXED) {
282 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
285 bit = BLOCK_GROUP_DATA;
287 bit = BLOCK_GROUP_METADATA;
290 struct btrfs_block_group_cache *shint;
291 shint = btrfs_lookup_block_group(info, search_start);
292 if (shint && (shint->data == data ||
293 shint->data == BTRFS_BLOCK_GROUP_MIXED)) {
294 used = btrfs_block_group_used(&shint->item);
295 if (used + shint->pinned <
296 div_factor(shint->key.offset, factor)) {
301 if (hint && (hint->data == data ||
302 hint->data == BTRFS_BLOCK_GROUP_MIXED)) {
303 used = btrfs_block_group_used(&hint->item);
304 if (used + hint->pinned <
305 div_factor(hint->key.offset, factor)) {
308 last = hint->key.objectid + hint->key.offset;
312 hint_last = max(hint->key.objectid, search_start);
314 hint_last = search_start;
320 ret = find_first_extent_bit(block_group_cache, last,
325 ret = get_state_private(block_group_cache, start, &ptr);
329 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
330 last = cache->key.objectid + cache->key.offset;
331 used = btrfs_block_group_used(&cache->item);
334 free_check = cache->key.offset;
336 free_check = div_factor(cache->key.offset, factor);
337 if (used + cache->pinned < free_check) {
350 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
358 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
359 u64 owner, u64 owner_offset)
361 u32 high_crc = ~(u32)0;
362 u32 low_crc = ~(u32)0;
365 lenum = cpu_to_le64(root_objectid);
366 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
367 lenum = cpu_to_le64(ref_generation);
368 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
371 lenum = cpu_to_le64(owner);
372 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
373 lenum = cpu_to_le64(owner_offset);
374 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
376 return ((u64)high_crc << 32) | (u64)low_crc;
379 static int match_extent_ref(struct extent_buffer *leaf,
380 struct btrfs_extent_ref *disk_ref,
381 struct btrfs_extent_ref *cpu_ref)
386 if (cpu_ref->objectid)
387 len = sizeof(*cpu_ref);
389 len = 2 * sizeof(u64);
390 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
395 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
396 struct btrfs_root *root,
397 struct btrfs_path *path, u64 bytenr,
398 u64 root_objectid, u64 ref_generation,
399 u64 owner, u64 owner_offset, int del)
402 struct btrfs_key key;
403 struct btrfs_key found_key;
404 struct btrfs_extent_ref ref;
405 struct extent_buffer *leaf;
406 struct btrfs_extent_ref *disk_ref;
410 btrfs_set_stack_ref_root(&ref, root_objectid);
411 btrfs_set_stack_ref_generation(&ref, ref_generation);
412 btrfs_set_stack_ref_objectid(&ref, owner);
413 btrfs_set_stack_ref_offset(&ref, owner_offset);
415 hash = hash_extent_ref(root_objectid, ref_generation, owner,
418 key.objectid = bytenr;
419 key.type = BTRFS_EXTENT_REF_KEY;
422 ret = btrfs_search_slot(trans, root, &key, path,
426 leaf = path->nodes[0];
428 u32 nritems = btrfs_header_nritems(leaf);
429 if (path->slots[0] >= nritems) {
430 ret2 = btrfs_next_leaf(root, path);
433 leaf = path->nodes[0];
435 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
436 if (found_key.objectid != bytenr ||
437 found_key.type != BTRFS_EXTENT_REF_KEY)
439 key.offset = found_key.offset;
441 btrfs_release_path(root, path);
445 disk_ref = btrfs_item_ptr(path->nodes[0],
447 struct btrfs_extent_ref);
448 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
452 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
453 key.offset = found_key.offset + 1;
454 btrfs_release_path(root, path);
461 * Back reference rules. Back refs have three main goals:
463 * 1) differentiate between all holders of references to an extent so that
464 * when a reference is dropped we can make sure it was a valid reference
465 * before freeing the extent.
467 * 2) Provide enough information to quickly find the holders of an extent
468 * if we notice a given block is corrupted or bad.
470 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
471 * maintenance. This is actually the same as #2, but with a slightly
472 * different use case.
474 * File extents can be referenced by:
476 * - multiple snapshots, subvolumes, or different generations in one subvol
477 * - different files inside a single subvolume (in theory, not implemented yet)
478 * - different offsets inside a file (bookend extents in file.c)
480 * The extent ref structure has fields for:
482 * - Objectid of the subvolume root
483 * - Generation number of the tree holding the reference
484 * - objectid of the file holding the reference
485 * - offset in the file corresponding to the key holding the reference
487 * When a file extent is allocated the fields are filled in:
488 * (root_key.objectid, trans->transid, inode objectid, offset in file)
490 * When a leaf is cow'd new references are added for every file extent found
491 * in the leaf. It looks the same as the create case, but trans->transid
492 * will be different when the block is cow'd.
494 * (root_key.objectid, trans->transid, inode objectid, offset in file)
496 * When a file extent is removed either during snapshot deletion or file
497 * truncation, the corresponding back reference is found
500 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
501 * inode objectid, offset in file)
503 * Btree extents can be referenced by:
505 * - Different subvolumes
506 * - Different generations of the same subvolume
508 * Storing sufficient information for a full reverse mapping of a btree
509 * block would require storing the lowest key of the block in the backref,
510 * and it would require updating that lowest key either before write out or
511 * every time it changed. Instead, the objectid of the lowest key is stored
512 * along with the level of the tree block. This provides a hint
513 * about where in the btree the block can be found. Searches through the
514 * btree only need to look for a pointer to that block, so they stop one
515 * level higher than the level recorded in the backref.
517 * Some btrees do not do reference counting on their extents. These
518 * include the extent tree and the tree of tree roots. Backrefs for these
519 * trees always have a generation of zero.
521 * When a tree block is created, back references are inserted:
523 * (root->root_key.objectid, trans->transid or zero, lowest_key_objectid, level)
525 * When a tree block is cow'd in a reference counted root,
526 * new back references are added for all the blocks it points to.
527 * These are of the form (trans->transid will have increased since creation):
529 * (root->root_key.objectid, trans->transid, lowest_key_objectid, level)
531 * Because the lowest_key_objectid and the level are just hints
532 * they are not used when backrefs are deleted. When a backref is deleted:
534 * if backref was for a tree root:
535 * root_objectid = root->root_key.objectid
537 * root_objectid = btrfs_header_owner(parent)
539 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
541 * Back Reference Key hashing:
543 * Back references have four fields, each 64 bits long. Unfortunately,
544 * This is hashed into a single 64 bit number and placed into the key offset.
545 * The key objectid corresponds to the first byte in the extent, and the
546 * key type is set to BTRFS_EXTENT_REF_KEY
548 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
549 struct btrfs_root *root,
550 struct btrfs_path *path, u64 bytenr,
551 u64 root_objectid, u64 ref_generation,
552 u64 owner, u64 owner_offset)
555 struct btrfs_key key;
556 struct btrfs_extent_ref ref;
557 struct btrfs_extent_ref *disk_ref;
560 btrfs_set_stack_ref_root(&ref, root_objectid);
561 btrfs_set_stack_ref_generation(&ref, ref_generation);
562 btrfs_set_stack_ref_objectid(&ref, owner);
563 btrfs_set_stack_ref_offset(&ref, owner_offset);
565 hash = hash_extent_ref(root_objectid, ref_generation, owner,
568 key.objectid = bytenr;
569 key.type = BTRFS_EXTENT_REF_KEY;
571 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
572 while (ret == -EEXIST) {
573 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
574 struct btrfs_extent_ref);
575 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
578 btrfs_release_path(root, path);
579 ret = btrfs_insert_empty_item(trans, root, path, &key,
584 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
585 struct btrfs_extent_ref);
586 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
588 btrfs_mark_buffer_dirty(path->nodes[0]);
590 btrfs_release_path(root, path);
594 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
595 struct btrfs_root *root,
596 u64 bytenr, u64 num_bytes,
597 u64 root_objectid, u64 ref_generation,
598 u64 owner, u64 owner_offset)
600 struct btrfs_path *path;
602 struct btrfs_key key;
603 struct extent_buffer *l;
604 struct btrfs_extent_item *item;
607 WARN_ON(num_bytes < root->sectorsize);
608 path = btrfs_alloc_path();
612 key.objectid = bytenr;
613 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
614 key.offset = num_bytes;
615 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
624 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
625 refs = btrfs_extent_refs(l, item);
626 btrfs_set_extent_refs(l, item, refs + 1);
627 btrfs_mark_buffer_dirty(path->nodes[0]);
629 btrfs_release_path(root->fs_info->extent_root, path);
631 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
632 path, bytenr, root_objectid,
633 ref_generation, owner, owner_offset);
635 finish_current_insert(trans, root->fs_info->extent_root);
636 del_pending_extents(trans, root->fs_info->extent_root);
638 btrfs_free_path(path);
642 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
643 struct btrfs_root *root)
645 finish_current_insert(trans, root->fs_info->extent_root);
646 del_pending_extents(trans, root->fs_info->extent_root);
650 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
651 struct btrfs_root *root, u64 bytenr,
652 u64 num_bytes, u32 *refs)
654 struct btrfs_path *path;
656 struct btrfs_key key;
657 struct extent_buffer *l;
658 struct btrfs_extent_item *item;
660 WARN_ON(num_bytes < root->sectorsize);
661 path = btrfs_alloc_path();
662 key.objectid = bytenr;
663 key.offset = num_bytes;
664 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
665 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
670 btrfs_print_leaf(root, path->nodes[0]);
671 printk("failed to find block number %Lu\n", bytenr);
675 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
676 *refs = btrfs_extent_refs(l, item);
678 btrfs_free_path(path);
682 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
683 struct btrfs_root *root, u64 owner_objectid)
689 struct btrfs_disk_key disk_key;
691 level = btrfs_header_level(root->node);
692 generation = trans->transid;
693 nritems = btrfs_header_nritems(root->node);
696 btrfs_item_key(root->node, &disk_key, 0);
698 btrfs_node_key(root->node, &disk_key, 0);
699 key_objectid = btrfs_disk_key_objectid(&disk_key);
703 return btrfs_inc_extent_ref(trans, root, root->node->start,
704 root->node->len, owner_objectid,
705 generation, key_objectid, level);
708 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
709 struct extent_buffer *buf)
713 struct btrfs_key key;
714 struct btrfs_file_extent_item *fi;
723 level = btrfs_header_level(buf);
724 nritems = btrfs_header_nritems(buf);
725 for (i = 0; i < nritems; i++) {
728 btrfs_item_key_to_cpu(buf, &key, i);
729 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
731 fi = btrfs_item_ptr(buf, i,
732 struct btrfs_file_extent_item);
733 if (btrfs_file_extent_type(buf, fi) ==
734 BTRFS_FILE_EXTENT_INLINE)
736 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
737 if (disk_bytenr == 0)
739 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
740 btrfs_file_extent_disk_num_bytes(buf, fi),
741 root->root_key.objectid, trans->transid,
742 key.objectid, key.offset);
748 bytenr = btrfs_node_blockptr(buf, i);
749 btrfs_node_key_to_cpu(buf, &key, i);
750 ret = btrfs_inc_extent_ref(trans, root, bytenr,
751 btrfs_level_size(root, level - 1),
752 root->root_key.objectid,
753 trans->transid, key.objectid,
765 for (i =0; i < faili; i++) {
768 btrfs_item_key_to_cpu(buf, &key, i);
769 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
771 fi = btrfs_item_ptr(buf, i,
772 struct btrfs_file_extent_item);
773 if (btrfs_file_extent_type(buf, fi) ==
774 BTRFS_FILE_EXTENT_INLINE)
776 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
777 if (disk_bytenr == 0)
779 err = btrfs_free_extent(trans, root, disk_bytenr,
780 btrfs_file_extent_disk_num_bytes(buf,
784 bytenr = btrfs_node_blockptr(buf, i);
785 err = btrfs_free_extent(trans, root, bytenr,
786 btrfs_level_size(root, level - 1), 0);
794 static int write_one_cache_group(struct btrfs_trans_handle *trans,
795 struct btrfs_root *root,
796 struct btrfs_path *path,
797 struct btrfs_block_group_cache *cache)
801 struct btrfs_root *extent_root = root->fs_info->extent_root;
803 struct extent_buffer *leaf;
805 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
810 leaf = path->nodes[0];
811 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
812 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
813 btrfs_mark_buffer_dirty(leaf);
814 btrfs_release_path(extent_root, path);
816 finish_current_insert(trans, extent_root);
817 pending_ret = del_pending_extents(trans, extent_root);
826 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
827 struct btrfs_root *root)
829 struct extent_map_tree *block_group_cache;
830 struct btrfs_block_group_cache *cache;
834 struct btrfs_path *path;
840 block_group_cache = &root->fs_info->block_group_cache;
841 path = btrfs_alloc_path();
846 ret = find_first_extent_bit(block_group_cache, last,
847 &start, &end, BLOCK_GROUP_DIRTY);
852 ret = get_state_private(block_group_cache, start, &ptr);
856 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
857 err = write_one_cache_group(trans, root,
860 * if we fail to write the cache group, we want
861 * to keep it marked dirty in hopes that a later
868 clear_extent_bits(block_group_cache, start, end,
869 BLOCK_GROUP_DIRTY, GFP_NOFS);
871 btrfs_free_path(path);
875 static int update_block_group(struct btrfs_trans_handle *trans,
876 struct btrfs_root *root,
877 u64 bytenr, u64 num_bytes, int alloc,
878 int mark_free, int data)
880 struct btrfs_block_group_cache *cache;
881 struct btrfs_fs_info *info = root->fs_info;
882 u64 total = num_bytes;
889 cache = btrfs_lookup_block_group(info, bytenr);
893 byte_in_group = bytenr - cache->key.objectid;
894 WARN_ON(byte_in_group > cache->key.offset);
895 start = cache->key.objectid;
896 end = start + cache->key.offset - 1;
897 set_extent_bits(&info->block_group_cache, start, end,
898 BLOCK_GROUP_DIRTY, GFP_NOFS);
900 old_val = btrfs_block_group_used(&cache->item);
901 num_bytes = min(total, cache->key.offset - byte_in_group);
903 if (cache->data != data &&
904 old_val < (cache->key.offset >> 1)) {
909 bit_to_clear = BLOCK_GROUP_METADATA;
910 bit_to_set = BLOCK_GROUP_DATA;
912 ~BTRFS_BLOCK_GROUP_MIXED;
914 BTRFS_BLOCK_GROUP_DATA;
916 bit_to_clear = BLOCK_GROUP_DATA;
917 bit_to_set = BLOCK_GROUP_METADATA;
919 ~BTRFS_BLOCK_GROUP_MIXED;
921 ~BTRFS_BLOCK_GROUP_DATA;
923 clear_extent_bits(&info->block_group_cache,
924 start, end, bit_to_clear,
926 set_extent_bits(&info->block_group_cache,
927 start, end, bit_to_set,
929 } else if (cache->data != data &&
930 cache->data != BTRFS_BLOCK_GROUP_MIXED) {
931 cache->data = BTRFS_BLOCK_GROUP_MIXED;
932 set_extent_bits(&info->block_group_cache,
935 BLOCK_GROUP_METADATA,
938 old_val += num_bytes;
940 old_val -= num_bytes;
942 set_extent_dirty(&info->free_space_cache,
943 bytenr, bytenr + num_bytes - 1,
947 btrfs_set_block_group_used(&cache->item, old_val);
953 static int update_pinned_extents(struct btrfs_root *root,
954 u64 bytenr, u64 num, int pin)
957 struct btrfs_block_group_cache *cache;
958 struct btrfs_fs_info *fs_info = root->fs_info;
961 set_extent_dirty(&fs_info->pinned_extents,
962 bytenr, bytenr + num - 1, GFP_NOFS);
964 clear_extent_dirty(&fs_info->pinned_extents,
965 bytenr, bytenr + num - 1, GFP_NOFS);
968 cache = btrfs_lookup_block_group(fs_info, bytenr);
970 len = min(num, cache->key.offset -
971 (bytenr - cache->key.objectid));
973 cache->pinned += len;
974 fs_info->total_pinned += len;
976 cache->pinned -= len;
977 fs_info->total_pinned -= len;
985 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_map_tree *copy)
990 struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
994 ret = find_first_extent_bit(pinned_extents, last,
995 &start, &end, EXTENT_DIRTY);
998 set_extent_dirty(copy, start, end, GFP_NOFS);
1004 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1005 struct btrfs_root *root,
1006 struct extent_map_tree *unpin)
1011 struct extent_map_tree *free_space_cache;
1012 free_space_cache = &root->fs_info->free_space_cache;
1015 ret = find_first_extent_bit(unpin, 0, &start, &end,
1019 update_pinned_extents(root, start, end + 1 - start, 0);
1020 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1021 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1026 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
1027 btrfs_root *extent_root)
1031 struct btrfs_fs_info *info = extent_root->fs_info;
1032 struct extent_buffer *eb;
1033 struct btrfs_path *path;
1034 struct btrfs_key ins;
1035 struct btrfs_disk_key first;
1036 struct btrfs_extent_item extent_item;
1041 btrfs_set_stack_extent_refs(&extent_item, 1);
1042 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1043 path = btrfs_alloc_path();
1046 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1047 &end, EXTENT_LOCKED);
1051 ins.objectid = start;
1052 ins.offset = end + 1 - start;
1053 err = btrfs_insert_item(trans, extent_root, &ins,
1054 &extent_item, sizeof(extent_item));
1055 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1057 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1058 level = btrfs_header_level(eb);
1060 btrfs_item_key(eb, &first, 0);
1062 btrfs_node_key(eb, &first, 0);
1064 err = btrfs_insert_extent_backref(trans, extent_root, path,
1065 start, extent_root->root_key.objectid,
1066 0, btrfs_disk_key_objectid(&first),
1069 free_extent_buffer(eb);
1071 btrfs_free_path(path);
1075 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1079 struct extent_buffer *buf;
1082 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1084 if (btrfs_buffer_uptodate(buf)) {
1086 root->fs_info->running_transaction->transid;
1087 if (btrfs_header_generation(buf) == transid) {
1088 free_extent_buffer(buf);
1092 free_extent_buffer(buf);
1094 update_pinned_extents(root, bytenr, num_bytes, 1);
1096 set_extent_bits(&root->fs_info->pending_del,
1097 bytenr, bytenr + num_bytes - 1,
1098 EXTENT_LOCKED, GFP_NOFS);
1105 * remove an extent from the root, returns 0 on success
1107 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1108 *root, u64 bytenr, u64 num_bytes,
1109 u64 root_objectid, u64 ref_generation,
1110 u64 owner_objectid, u64 owner_offset, int pin,
1113 struct btrfs_path *path;
1114 struct btrfs_key key;
1115 struct btrfs_fs_info *info = root->fs_info;
1116 struct btrfs_root *extent_root = info->extent_root;
1117 struct extent_buffer *leaf;
1119 struct btrfs_extent_item *ei;
1122 key.objectid = bytenr;
1123 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1124 key.offset = num_bytes;
1126 path = btrfs_alloc_path();
1130 if (ref_generation && owner_objectid == 0 && root_objectid == 3) {
1131 //printk("drop backref root %Lu gen %Lu byte %Lu\n", root_objectid, ref_generation, bytenr );
1133 ret = lookup_extent_backref(trans, extent_root, path,
1134 bytenr, root_objectid,
1136 owner_objectid, owner_offset, 1);
1138 ret = btrfs_del_item(trans, extent_root, path);
1140 btrfs_print_leaf(extent_root, path->nodes[0]);
1142 printk("Unable to find ref byte nr %Lu root %Lu "
1143 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1144 root_objectid, ref_generation, owner_objectid,
1147 btrfs_release_path(extent_root, path);
1148 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1153 leaf = path->nodes[0];
1154 ei = btrfs_item_ptr(leaf, path->slots[0],
1155 struct btrfs_extent_item);
1156 refs = btrfs_extent_refs(leaf, ei);
1159 btrfs_set_extent_refs(leaf, ei, refs);
1160 btrfs_mark_buffer_dirty(leaf);
1167 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1173 /* block accounting for super block */
1174 super_used = btrfs_super_bytes_used(&info->super_copy);
1175 btrfs_set_super_bytes_used(&info->super_copy,
1176 super_used - num_bytes);
1178 /* block accounting for root item */
1179 root_used = btrfs_root_used(&root->root_item);
1180 btrfs_set_root_used(&root->root_item,
1181 root_used - num_bytes);
1183 ret = btrfs_del_item(trans, extent_root, path);
1187 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1191 btrfs_free_path(path);
1192 finish_current_insert(trans, extent_root);
1197 * find all the blocks marked as pending in the radix tree and remove
1198 * them from the extent map
1200 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1201 btrfs_root *extent_root)
1207 struct extent_map_tree *pending_del;
1208 struct extent_map_tree *pinned_extents;
1210 pending_del = &extent_root->fs_info->pending_del;
1211 pinned_extents = &extent_root->fs_info->pinned_extents;
1214 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1218 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1219 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1221 ret = __free_extent(trans, extent_root,
1222 start, end + 1 - start,
1223 extent_root->root_key.objectid,
1232 * remove an extent from the root, returns 0 on success
1234 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1235 *root, u64 bytenr, u64 num_bytes,
1236 u64 root_objectid, u64 ref_generation,
1237 u64 owner_objectid, u64 owner_offset, int pin)
1239 struct btrfs_root *extent_root = root->fs_info->extent_root;
1243 WARN_ON(num_bytes < root->sectorsize);
1244 if (!root->ref_cows)
1247 if (root == extent_root) {
1248 pin_down_bytes(root, bytenr, num_bytes, 1);
1251 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1252 ref_generation, owner_objectid, owner_offset,
1254 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1255 return ret ? ret : pending_ret;
1258 static u64 stripe_align(struct btrfs_root *root, u64 val)
1260 u64 mask = ((u64)root->stripesize - 1);
1261 u64 ret = (val + mask) & ~mask;
1266 * walks the btree of allocated extents and find a hole of a given size.
1267 * The key ins is changed to record the hole:
1268 * ins->objectid == block start
1269 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1270 * ins->offset == number of blocks
1271 * Any available blocks before search_start are skipped.
1273 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1274 *orig_root, u64 num_bytes, u64 empty_size,
1275 u64 search_start, u64 search_end, u64 hint_byte,
1276 struct btrfs_key *ins, u64 exclude_start,
1277 u64 exclude_nr, int data)
1279 struct btrfs_path *path;
1280 struct btrfs_key key;
1286 u64 orig_search_start = search_start;
1288 struct extent_buffer *l;
1289 struct btrfs_root * root = orig_root->fs_info->extent_root;
1290 struct btrfs_fs_info *info = root->fs_info;
1291 u64 total_needed = num_bytes;
1293 struct btrfs_block_group_cache *block_group;
1298 WARN_ON(num_bytes < root->sectorsize);
1299 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1301 level = btrfs_header_level(root->node);
1303 if (num_bytes >= 32 * 1024 * 1024 && hint_byte) {
1304 data = BTRFS_BLOCK_GROUP_MIXED;
1307 if (search_end == (u64)-1)
1308 search_end = btrfs_super_total_bytes(&info->super_copy);
1310 block_group = btrfs_lookup_block_group(info, hint_byte);
1312 hint_byte = search_start;
1313 block_group = btrfs_find_block_group(root, block_group,
1314 hint_byte, data, 1);
1316 block_group = btrfs_find_block_group(root,
1318 search_start, data, 1);
1321 total_needed += empty_size;
1322 path = btrfs_alloc_path();
1325 block_group = btrfs_lookup_block_group(info, search_start);
1327 block_group = btrfs_lookup_block_group(info,
1330 search_start = find_search_start(root, &block_group, search_start,
1331 total_needed, data, full_scan);
1332 search_start = stripe_align(root, search_start);
1333 cached_start = search_start;
1334 btrfs_init_path(path);
1335 ins->objectid = search_start;
1340 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
1344 if (path->slots[0] > 0) {
1349 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1352 * walk backwards to find the first extent item key
1354 while(btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
1355 if (path->slots[0] == 0) {
1356 ret = btrfs_prev_leaf(root, path);
1358 ret = btrfs_search_slot(trans, root, ins,
1362 if (path->slots[0] > 0)
1370 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1374 slot = path->slots[0];
1375 if (slot >= btrfs_header_nritems(l)) {
1376 ret = btrfs_next_leaf(root, path);
1382 search_start = max(search_start,
1383 block_group->key.objectid);
1385 aligned = stripe_align(root, search_start);
1386 ins->objectid = aligned;
1387 if (aligned >= search_end) {
1391 ins->offset = search_end - aligned;
1395 ins->objectid = stripe_align(root,
1396 last_byte > search_start ?
1397 last_byte : search_start);
1398 if (search_end <= ins->objectid) {
1402 ins->offset = search_end - ins->objectid;
1403 BUG_ON(ins->objectid >= search_end);
1406 btrfs_item_key_to_cpu(l, &key, slot);
1408 if (key.objectid >= search_start && key.objectid > last_byte &&
1410 if (last_byte < search_start)
1411 last_byte = search_start;
1412 aligned = stripe_align(root, last_byte);
1413 hole_size = key.objectid - aligned;
1414 if (key.objectid > aligned && hole_size >= num_bytes) {
1415 ins->objectid = aligned;
1416 ins->offset = hole_size;
1420 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
1421 if (!start_found && btrfs_key_type(&key) ==
1422 BTRFS_BLOCK_GROUP_ITEM_KEY) {
1423 last_byte = key.objectid;
1431 last_byte = key.objectid + key.offset;
1433 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1434 last_byte >= block_group->key.objectid +
1435 block_group->key.offset) {
1436 btrfs_release_path(root, path);
1437 search_start = block_group->key.objectid +
1438 block_group->key.offset;
1446 /* we have to make sure we didn't find an extent that has already
1447 * been allocated by the map tree or the original allocation
1449 btrfs_release_path(root, path);
1450 BUG_ON(ins->objectid < search_start);
1452 if (ins->objectid + num_bytes >= search_end)
1454 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1455 ins->objectid + num_bytes > block_group->
1456 key.objectid + block_group->key.offset) {
1457 search_start = block_group->key.objectid +
1458 block_group->key.offset;
1461 if (test_range_bit(&info->extent_ins, ins->objectid,
1462 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1463 search_start = ins->objectid + num_bytes;
1466 if (test_range_bit(&info->pinned_extents, ins->objectid,
1467 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1468 search_start = ins->objectid + num_bytes;
1471 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1472 ins->objectid < exclude_start + exclude_nr)) {
1473 search_start = exclude_start + exclude_nr;
1477 block_group = btrfs_lookup_block_group(info, ins->objectid);
1479 trans->block_group = block_group;
1481 ins->offset = num_bytes;
1482 btrfs_free_path(path);
1486 if (search_start + num_bytes >= search_end) {
1488 search_start = orig_search_start;
1495 total_needed -= empty_size;
1497 data = BTRFS_BLOCK_GROUP_MIXED;
1501 block_group = btrfs_lookup_block_group(info, search_start);
1503 block_group = btrfs_find_block_group(root, block_group,
1504 search_start, data, 0);
1508 btrfs_release_path(root, path);
1509 btrfs_free_path(path);
1513 * finds a free extent and does all the dirty work required for allocation
1514 * returns the key for the extent through ins, and a tree buffer for
1515 * the first block of the extent through buf.
1517 * returns 0 if everything worked, non-zero otherwise.
1519 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1520 struct btrfs_root *root,
1521 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1522 u64 owner, u64 owner_offset,
1523 u64 empty_size, u64 hint_byte,
1524 u64 search_end, struct btrfs_key *ins, int data)
1528 u64 super_used, root_used;
1529 u64 search_start = 0;
1530 struct btrfs_fs_info *info = root->fs_info;
1531 struct btrfs_root *extent_root = info->extent_root;
1532 struct btrfs_extent_item extent_item;
1533 struct btrfs_path *path;
1535 btrfs_set_stack_extent_refs(&extent_item, 1);
1537 WARN_ON(num_bytes < root->sectorsize);
1538 ret = find_free_extent(trans, root, num_bytes, empty_size,
1539 search_start, search_end, hint_byte, ins,
1540 trans->alloc_exclude_start,
1541 trans->alloc_exclude_nr, data);
1546 /* block accounting for super block */
1547 super_used = btrfs_super_bytes_used(&info->super_copy);
1548 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1550 /* block accounting for root item */
1551 root_used = btrfs_root_used(&root->root_item);
1552 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1554 clear_extent_dirty(&root->fs_info->free_space_cache,
1555 ins->objectid, ins->objectid + ins->offset - 1,
1558 if (root == extent_root) {
1559 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1560 ins->objectid + ins->offset - 1,
1561 EXTENT_LOCKED, GFP_NOFS);
1566 WARN_ON(trans->alloc_exclude_nr);
1567 trans->alloc_exclude_start = ins->objectid;
1568 trans->alloc_exclude_nr = ins->offset;
1569 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
1570 sizeof(extent_item));
1572 trans->alloc_exclude_start = 0;
1573 trans->alloc_exclude_nr = 0;
1576 path = btrfs_alloc_path();
1578 ret = btrfs_insert_extent_backref(trans, extent_root, path,
1579 ins->objectid, root_objectid,
1580 ref_generation, owner, owner_offset);
1583 btrfs_free_path(path);
1584 finish_current_insert(trans, extent_root);
1585 pending_ret = del_pending_extents(trans, extent_root);
1595 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
1602 * helper function to allocate a block for a given tree
1603 * returns the tree buffer or NULL.
1605 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1606 struct btrfs_root *root,
1608 u64 root_objectid, u64 hint,
1614 ref_generation = trans->transid;
1619 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1620 ref_generation, 0, 0, hint, empty_size);
1624 * helper function to allocate a block for a given tree
1625 * returns the tree buffer or NULL.
1627 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1628 struct btrfs_root *root,
1637 struct btrfs_key ins;
1639 struct extent_buffer *buf;
1641 ret = btrfs_alloc_extent(trans, root, blocksize,
1642 root_objectid, ref_generation,
1643 first_objectid, level, empty_size, hint,
1647 return ERR_PTR(ret);
1649 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1651 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1652 root->root_key.objectid, ref_generation,
1654 return ERR_PTR(-ENOMEM);
1656 btrfs_set_buffer_uptodate(buf);
1657 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1658 buf->start + buf->len - 1, GFP_NOFS);
1659 set_extent_bits(&BTRFS_I(root->fs_info->btree_inode)->extent_tree,
1660 buf->start, buf->start + buf->len - 1,
1661 EXTENT_CSUM, GFP_NOFS);
1662 buf->flags |= EXTENT_CSUM;
1663 btrfs_set_buffer_defrag(buf);
1664 trans->blocks_used++;
1668 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
1669 struct btrfs_root *root, struct extent_buffer *leaf)
1672 u64 leaf_generation;
1673 struct btrfs_key key;
1674 struct btrfs_file_extent_item *fi;
1679 BUG_ON(!btrfs_is_leaf(leaf));
1680 nritems = btrfs_header_nritems(leaf);
1681 leaf_owner = btrfs_header_owner(leaf);
1682 leaf_generation = btrfs_header_generation(leaf);
1684 for (i = 0; i < nritems; i++) {
1687 btrfs_item_key_to_cpu(leaf, &key, i);
1688 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1690 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1691 if (btrfs_file_extent_type(leaf, fi) ==
1692 BTRFS_FILE_EXTENT_INLINE)
1695 * FIXME make sure to insert a trans record that
1696 * repeats the snapshot del on crash
1698 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1699 if (disk_bytenr == 0)
1701 ret = btrfs_free_extent(trans, root, disk_bytenr,
1702 btrfs_file_extent_disk_num_bytes(leaf, fi),
1703 leaf_owner, leaf_generation,
1704 key.objectid, key.offset, 0);
1710 static void reada_walk_down(struct btrfs_root *root,
1711 struct extent_buffer *node)
1721 nritems = btrfs_header_nritems(node);
1722 level = btrfs_header_level(node);
1723 for (i = 0; i < nritems; i++) {
1724 bytenr = btrfs_node_blockptr(node, i);
1725 blocksize = btrfs_level_size(root, level - 1);
1726 ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs);
1730 mutex_unlock(&root->fs_info->fs_mutex);
1731 ret = readahead_tree_block(root, bytenr, blocksize);
1733 mutex_lock(&root->fs_info->fs_mutex);
1740 * helper function for drop_snapshot, this walks down the tree dropping ref
1741 * counts as it goes.
1743 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1744 *root, struct btrfs_path *path, int *level)
1749 struct extent_buffer *next;
1750 struct extent_buffer *cur;
1751 struct extent_buffer *parent;
1756 WARN_ON(*level < 0);
1757 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1758 ret = lookup_extent_ref(trans, root,
1759 path->nodes[*level]->start,
1760 path->nodes[*level]->len, &refs);
1766 * walk down to the last node level and free all the leaves
1768 while(*level >= 0) {
1769 WARN_ON(*level < 0);
1770 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1771 cur = path->nodes[*level];
1773 if (*level > 0 && path->slots[*level] == 0)
1774 reada_walk_down(root, cur);
1776 if (btrfs_header_level(cur) != *level)
1779 if (path->slots[*level] >=
1780 btrfs_header_nritems(cur))
1783 ret = drop_leaf_ref(trans, root, cur);
1787 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1788 blocksize = btrfs_level_size(root, *level - 1);
1789 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1792 parent = path->nodes[*level];
1793 root_owner = btrfs_header_owner(parent);
1794 root_gen = btrfs_header_generation(parent);
1795 path->slots[*level]++;
1796 ret = btrfs_free_extent(trans, root, bytenr,
1797 blocksize, root_owner,
1802 next = btrfs_find_tree_block(root, bytenr, blocksize);
1803 if (!next || !btrfs_buffer_uptodate(next)) {
1804 free_extent_buffer(next);
1805 mutex_unlock(&root->fs_info->fs_mutex);
1806 next = read_tree_block(root, bytenr, blocksize);
1807 mutex_lock(&root->fs_info->fs_mutex);
1809 /* we dropped the lock, check one more time */
1810 ret = lookup_extent_ref(trans, root, bytenr,
1814 parent = path->nodes[*level];
1815 root_owner = btrfs_header_owner(parent);
1816 root_gen = btrfs_header_generation(parent);
1818 path->slots[*level]++;
1819 free_extent_buffer(next);
1820 ret = btrfs_free_extent(trans, root, bytenr,
1828 WARN_ON(*level <= 0);
1829 if (path->nodes[*level-1])
1830 free_extent_buffer(path->nodes[*level-1]);
1831 path->nodes[*level-1] = next;
1832 *level = btrfs_header_level(next);
1833 path->slots[*level] = 0;
1836 WARN_ON(*level < 0);
1837 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1839 if (path->nodes[*level] == root->node) {
1840 root_owner = root->root_key.objectid;
1841 parent = path->nodes[*level];
1843 parent = path->nodes[*level + 1];
1844 root_owner = btrfs_header_owner(parent);
1847 root_gen = btrfs_header_generation(parent);
1848 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1849 path->nodes[*level]->len,
1850 root_owner, root_gen, 0, 0, 1);
1851 free_extent_buffer(path->nodes[*level]);
1852 path->nodes[*level] = NULL;
1859 * helper for dropping snapshots. This walks back up the tree in the path
1860 * to find the first node higher up where we haven't yet gone through
1863 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1864 *root, struct btrfs_path *path, int *level)
1868 struct btrfs_root_item *root_item = &root->root_item;
1873 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1874 slot = path->slots[i];
1875 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1876 struct extent_buffer *node;
1877 struct btrfs_disk_key disk_key;
1878 node = path->nodes[i];
1881 WARN_ON(*level == 0);
1882 btrfs_node_key(node, &disk_key, path->slots[i]);
1883 memcpy(&root_item->drop_progress,
1884 &disk_key, sizeof(disk_key));
1885 root_item->drop_level = i;
1888 if (path->nodes[*level] == root->node) {
1889 root_owner = root->root_key.objectid;
1891 btrfs_header_generation(path->nodes[*level]);
1893 struct extent_buffer *node;
1894 node = path->nodes[*level + 1];
1895 root_owner = btrfs_header_owner(node);
1896 root_gen = btrfs_header_generation(node);
1898 ret = btrfs_free_extent(trans, root,
1899 path->nodes[*level]->start,
1900 path->nodes[*level]->len,
1901 root_owner, root_gen, 0, 0, 1);
1903 free_extent_buffer(path->nodes[*level]);
1904 path->nodes[*level] = NULL;
1912 * drop the reference count on the tree rooted at 'snap'. This traverses
1913 * the tree freeing any blocks that have a ref count of zero after being
1916 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
1922 struct btrfs_path *path;
1925 struct btrfs_root_item *root_item = &root->root_item;
1927 path = btrfs_alloc_path();
1930 level = btrfs_header_level(root->node);
1932 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
1933 path->nodes[level] = root->node;
1934 extent_buffer_get(root->node);
1935 path->slots[level] = 0;
1937 struct btrfs_key key;
1938 struct btrfs_disk_key found_key;
1939 struct extent_buffer *node;
1941 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
1942 level = root_item->drop_level;
1943 path->lowest_level = level;
1944 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1949 node = path->nodes[level];
1950 btrfs_node_key(node, &found_key, path->slots[level]);
1951 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
1952 sizeof(found_key)));
1955 wret = walk_down_tree(trans, root, path, &level);
1961 wret = walk_up_tree(trans, root, path, &level);
1969 for (i = 0; i <= orig_level; i++) {
1970 if (path->nodes[i]) {
1971 free_extent_buffer(path->nodes[i]);
1972 path->nodes[i] = NULL;
1976 btrfs_free_path(path);
1980 int btrfs_free_block_groups(struct btrfs_fs_info *info)
1987 ret = find_first_extent_bit(&info->block_group_cache, 0,
1988 &start, &end, (unsigned int)-1);
1991 ret = get_state_private(&info->block_group_cache, start, &ptr);
1993 kfree((void *)(unsigned long)ptr);
1994 clear_extent_bits(&info->block_group_cache, start,
1995 end, (unsigned int)-1, GFP_NOFS);
1998 ret = find_first_extent_bit(&info->free_space_cache, 0,
1999 &start, &end, EXTENT_DIRTY);
2002 clear_extent_dirty(&info->free_space_cache, start,
2008 int btrfs_read_block_groups(struct btrfs_root *root)
2010 struct btrfs_path *path;
2014 struct btrfs_block_group_cache *cache;
2015 struct btrfs_fs_info *info = root->fs_info;
2016 struct extent_map_tree *block_group_cache;
2017 struct btrfs_key key;
2018 struct btrfs_key found_key;
2019 struct extent_buffer *leaf;
2021 block_group_cache = &info->block_group_cache;
2023 root = info->extent_root;
2025 key.offset = BTRFS_BLOCK_GROUP_SIZE;
2026 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2028 path = btrfs_alloc_path();
2033 ret = btrfs_search_slot(NULL, info->extent_root,
2039 leaf = path->nodes[0];
2040 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2041 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2047 read_extent_buffer(leaf, &cache->item,
2048 btrfs_item_ptr_offset(leaf, path->slots[0]),
2049 sizeof(cache->item));
2050 memcpy(&cache->key, &found_key, sizeof(found_key));
2053 key.objectid = found_key.objectid + found_key.offset;
2054 btrfs_release_path(root, path);
2056 if (cache->item.flags & BTRFS_BLOCK_GROUP_MIXED) {
2057 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
2058 cache->data = BTRFS_BLOCK_GROUP_MIXED;
2059 } else if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
2060 bit = BLOCK_GROUP_DATA;
2061 cache->data = BTRFS_BLOCK_GROUP_DATA;
2063 bit = BLOCK_GROUP_METADATA;
2067 /* use EXTENT_LOCKED to prevent merging */
2068 set_extent_bits(block_group_cache, found_key.objectid,
2069 found_key.objectid + found_key.offset - 1,
2070 bit | EXTENT_LOCKED, GFP_NOFS);
2071 set_state_private(block_group_cache, found_key.objectid,
2072 (unsigned long)cache);
2075 btrfs_super_total_bytes(&info->super_copy))
2079 btrfs_free_path(path);