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,
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 ret = btrfs_inc_extent_ref(trans, root, bytenr,
750 btrfs_level_size(root, level - 1),
751 root->root_key.objectid,
752 trans->transid, 0, 0);
763 for (i =0; i < faili; i++) {
766 btrfs_item_key_to_cpu(buf, &key, i);
767 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
769 fi = btrfs_item_ptr(buf, i,
770 struct btrfs_file_extent_item);
771 if (btrfs_file_extent_type(buf, fi) ==
772 BTRFS_FILE_EXTENT_INLINE)
774 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
775 if (disk_bytenr == 0)
777 err = btrfs_free_extent(trans, root, disk_bytenr,
778 btrfs_file_extent_disk_num_bytes(buf,
782 bytenr = btrfs_node_blockptr(buf, i);
783 err = btrfs_free_extent(trans, root, bytenr,
784 btrfs_level_size(root, level - 1), 0);
792 static int write_one_cache_group(struct btrfs_trans_handle *trans,
793 struct btrfs_root *root,
794 struct btrfs_path *path,
795 struct btrfs_block_group_cache *cache)
799 struct btrfs_root *extent_root = root->fs_info->extent_root;
801 struct extent_buffer *leaf;
803 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
808 leaf = path->nodes[0];
809 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
810 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
811 btrfs_mark_buffer_dirty(leaf);
812 btrfs_release_path(extent_root, path);
814 finish_current_insert(trans, extent_root);
815 pending_ret = del_pending_extents(trans, extent_root);
824 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
825 struct btrfs_root *root)
827 struct extent_map_tree *block_group_cache;
828 struct btrfs_block_group_cache *cache;
832 struct btrfs_path *path;
838 block_group_cache = &root->fs_info->block_group_cache;
839 path = btrfs_alloc_path();
844 ret = find_first_extent_bit(block_group_cache, last,
845 &start, &end, BLOCK_GROUP_DIRTY);
850 ret = get_state_private(block_group_cache, start, &ptr);
854 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
855 err = write_one_cache_group(trans, root,
858 * if we fail to write the cache group, we want
859 * to keep it marked dirty in hopes that a later
866 clear_extent_bits(block_group_cache, start, end,
867 BLOCK_GROUP_DIRTY, GFP_NOFS);
869 btrfs_free_path(path);
873 static int update_block_group(struct btrfs_trans_handle *trans,
874 struct btrfs_root *root,
875 u64 bytenr, u64 num_bytes, int alloc,
876 int mark_free, int data)
878 struct btrfs_block_group_cache *cache;
879 struct btrfs_fs_info *info = root->fs_info;
880 u64 total = num_bytes;
887 cache = btrfs_lookup_block_group(info, bytenr);
891 byte_in_group = bytenr - cache->key.objectid;
892 WARN_ON(byte_in_group > cache->key.offset);
893 start = cache->key.objectid;
894 end = start + cache->key.offset - 1;
895 set_extent_bits(&info->block_group_cache, start, end,
896 BLOCK_GROUP_DIRTY, GFP_NOFS);
898 old_val = btrfs_block_group_used(&cache->item);
899 num_bytes = min(total, cache->key.offset - byte_in_group);
901 if (cache->data != data &&
902 old_val < (cache->key.offset >> 1)) {
907 bit_to_clear = BLOCK_GROUP_METADATA;
908 bit_to_set = BLOCK_GROUP_DATA;
910 ~BTRFS_BLOCK_GROUP_MIXED;
912 BTRFS_BLOCK_GROUP_DATA;
914 bit_to_clear = BLOCK_GROUP_DATA;
915 bit_to_set = BLOCK_GROUP_METADATA;
917 ~BTRFS_BLOCK_GROUP_MIXED;
919 ~BTRFS_BLOCK_GROUP_DATA;
921 clear_extent_bits(&info->block_group_cache,
922 start, end, bit_to_clear,
924 set_extent_bits(&info->block_group_cache,
925 start, end, bit_to_set,
927 } else if (cache->data != data &&
928 cache->data != BTRFS_BLOCK_GROUP_MIXED) {
929 cache->data = BTRFS_BLOCK_GROUP_MIXED;
930 set_extent_bits(&info->block_group_cache,
933 BLOCK_GROUP_METADATA,
936 old_val += num_bytes;
938 old_val -= num_bytes;
940 set_extent_dirty(&info->free_space_cache,
941 bytenr, bytenr + num_bytes - 1,
945 btrfs_set_block_group_used(&cache->item, old_val);
951 static int update_pinned_extents(struct btrfs_root *root,
952 u64 bytenr, u64 num, int pin)
955 struct btrfs_block_group_cache *cache;
956 struct btrfs_fs_info *fs_info = root->fs_info;
959 set_extent_dirty(&fs_info->pinned_extents,
960 bytenr, bytenr + num - 1, GFP_NOFS);
962 clear_extent_dirty(&fs_info->pinned_extents,
963 bytenr, bytenr + num - 1, GFP_NOFS);
966 cache = btrfs_lookup_block_group(fs_info, bytenr);
968 len = min(num, cache->key.offset -
969 (bytenr - cache->key.objectid));
971 cache->pinned += len;
972 fs_info->total_pinned += len;
974 cache->pinned -= len;
975 fs_info->total_pinned -= len;
983 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_map_tree *copy)
988 struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
992 ret = find_first_extent_bit(pinned_extents, last,
993 &start, &end, EXTENT_DIRTY);
996 set_extent_dirty(copy, start, end, GFP_NOFS);
1002 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1003 struct btrfs_root *root,
1004 struct extent_map_tree *unpin)
1009 struct extent_map_tree *free_space_cache;
1010 free_space_cache = &root->fs_info->free_space_cache;
1013 ret = find_first_extent_bit(unpin, 0, &start, &end,
1017 update_pinned_extents(root, start, end + 1 - start, 0);
1018 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1019 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1024 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
1025 btrfs_root *extent_root)
1029 struct btrfs_fs_info *info = extent_root->fs_info;
1030 struct extent_buffer *eb;
1031 struct btrfs_path *path;
1032 struct btrfs_key ins;
1033 struct btrfs_disk_key first;
1034 struct btrfs_extent_item extent_item;
1039 btrfs_set_stack_extent_refs(&extent_item, 1);
1040 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1041 path = btrfs_alloc_path();
1044 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1045 &end, EXTENT_LOCKED);
1049 ins.objectid = start;
1050 ins.offset = end + 1 - start;
1051 err = btrfs_insert_item(trans, extent_root, &ins,
1052 &extent_item, sizeof(extent_item));
1053 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1055 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1056 level = btrfs_header_level(eb);
1058 btrfs_item_key(eb, &first, 0);
1060 btrfs_node_key(eb, &first, 0);
1062 err = btrfs_insert_extent_backref(trans, extent_root, path,
1063 start, extent_root->root_key.objectid,
1064 0, btrfs_disk_key_objectid(&first),
1067 free_extent_buffer(eb);
1069 btrfs_free_path(path);
1073 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1077 struct extent_buffer *buf;
1080 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1082 if (btrfs_buffer_uptodate(buf)) {
1084 root->fs_info->running_transaction->transid;
1085 if (btrfs_header_generation(buf) == transid) {
1086 free_extent_buffer(buf);
1090 free_extent_buffer(buf);
1092 update_pinned_extents(root, bytenr, num_bytes, 1);
1094 set_extent_bits(&root->fs_info->pending_del,
1095 bytenr, bytenr + num_bytes - 1,
1096 EXTENT_LOCKED, GFP_NOFS);
1103 * remove an extent from the root, returns 0 on success
1105 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1106 *root, u64 bytenr, u64 num_bytes,
1107 u64 root_objectid, u64 ref_generation,
1108 u64 owner_objectid, u64 owner_offset, int pin,
1111 struct btrfs_path *path;
1112 struct btrfs_key key;
1113 struct btrfs_fs_info *info = root->fs_info;
1114 struct btrfs_root *extent_root = info->extent_root;
1115 struct extent_buffer *leaf;
1117 struct btrfs_extent_item *ei;
1120 key.objectid = bytenr;
1121 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1122 key.offset = num_bytes;
1124 path = btrfs_alloc_path();
1128 if (ref_generation && owner_objectid == 0 && root_objectid == 3) {
1129 //printk("drop backref root %Lu gen %Lu byte %Lu\n", root_objectid, ref_generation, bytenr );
1131 ret = lookup_extent_backref(trans, extent_root, path,
1132 bytenr, root_objectid,
1134 owner_objectid, owner_offset, 1);
1136 ret = btrfs_del_item(trans, extent_root, path);
1138 btrfs_print_leaf(extent_root, path->nodes[0]);
1140 printk("Unable to find ref byte nr %Lu root %Lu "
1141 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1142 root_objectid, ref_generation, owner_objectid,
1145 btrfs_release_path(extent_root, path);
1146 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1151 leaf = path->nodes[0];
1152 ei = btrfs_item_ptr(leaf, path->slots[0],
1153 struct btrfs_extent_item);
1154 refs = btrfs_extent_refs(leaf, ei);
1157 btrfs_set_extent_refs(leaf, ei, refs);
1158 btrfs_mark_buffer_dirty(leaf);
1165 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1171 /* block accounting for super block */
1172 super_used = btrfs_super_bytes_used(&info->super_copy);
1173 btrfs_set_super_bytes_used(&info->super_copy,
1174 super_used - num_bytes);
1176 /* block accounting for root item */
1177 root_used = btrfs_root_used(&root->root_item);
1178 btrfs_set_root_used(&root->root_item,
1179 root_used - num_bytes);
1181 ret = btrfs_del_item(trans, extent_root, path);
1185 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1189 btrfs_free_path(path);
1190 finish_current_insert(trans, extent_root);
1195 * find all the blocks marked as pending in the radix tree and remove
1196 * them from the extent map
1198 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1199 btrfs_root *extent_root)
1205 struct extent_map_tree *pending_del;
1206 struct extent_map_tree *pinned_extents;
1208 pending_del = &extent_root->fs_info->pending_del;
1209 pinned_extents = &extent_root->fs_info->pinned_extents;
1212 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1216 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1217 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1219 ret = __free_extent(trans, extent_root,
1220 start, end + 1 - start,
1221 extent_root->root_key.objectid,
1230 * remove an extent from the root, returns 0 on success
1232 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1233 *root, u64 bytenr, u64 num_bytes,
1234 u64 root_objectid, u64 ref_generation,
1235 u64 owner_objectid, u64 owner_offset, int pin)
1237 struct btrfs_root *extent_root = root->fs_info->extent_root;
1241 WARN_ON(num_bytes < root->sectorsize);
1242 if (!root->ref_cows)
1245 if (root == extent_root) {
1246 pin_down_bytes(root, bytenr, num_bytes, 1);
1249 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1250 ref_generation, owner_objectid, owner_offset,
1252 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1253 return ret ? ret : pending_ret;
1256 static u64 stripe_align(struct btrfs_root *root, u64 val)
1258 u64 mask = ((u64)root->stripesize - 1);
1259 u64 ret = (val + mask) & ~mask;
1264 * walks the btree of allocated extents and find a hole of a given size.
1265 * The key ins is changed to record the hole:
1266 * ins->objectid == block start
1267 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1268 * ins->offset == number of blocks
1269 * Any available blocks before search_start are skipped.
1271 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1272 *orig_root, u64 num_bytes, u64 empty_size,
1273 u64 search_start, u64 search_end, u64 hint_byte,
1274 struct btrfs_key *ins, u64 exclude_start,
1275 u64 exclude_nr, int data)
1277 struct btrfs_path *path;
1278 struct btrfs_key key;
1284 u64 orig_search_start = search_start;
1286 struct extent_buffer *l;
1287 struct btrfs_root * root = orig_root->fs_info->extent_root;
1288 struct btrfs_fs_info *info = root->fs_info;
1289 u64 total_needed = num_bytes;
1291 struct btrfs_block_group_cache *block_group;
1296 WARN_ON(num_bytes < root->sectorsize);
1297 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1299 level = btrfs_header_level(root->node);
1301 if (num_bytes >= 32 * 1024 * 1024 && hint_byte) {
1302 data = BTRFS_BLOCK_GROUP_MIXED;
1305 if (search_end == (u64)-1)
1306 search_end = btrfs_super_total_bytes(&info->super_copy);
1308 block_group = btrfs_lookup_block_group(info, hint_byte);
1310 hint_byte = search_start;
1311 block_group = btrfs_find_block_group(root, block_group,
1312 hint_byte, data, 1);
1314 block_group = btrfs_find_block_group(root,
1316 search_start, data, 1);
1319 total_needed += empty_size;
1320 path = btrfs_alloc_path();
1323 block_group = btrfs_lookup_block_group(info, search_start);
1325 block_group = btrfs_lookup_block_group(info,
1328 search_start = find_search_start(root, &block_group, search_start,
1329 total_needed, data, full_scan);
1330 search_start = stripe_align(root, search_start);
1331 cached_start = search_start;
1332 btrfs_init_path(path);
1333 ins->objectid = search_start;
1338 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
1342 if (path->slots[0] > 0) {
1347 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1350 * walk backwards to find the first extent item key
1352 while(btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
1353 if (path->slots[0] == 0) {
1354 ret = btrfs_prev_leaf(root, path);
1356 ret = btrfs_search_slot(trans, root, ins,
1360 if (path->slots[0] > 0)
1368 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1372 slot = path->slots[0];
1373 if (slot >= btrfs_header_nritems(l)) {
1374 ret = btrfs_next_leaf(root, path);
1380 search_start = max(search_start,
1381 block_group->key.objectid);
1383 aligned = stripe_align(root, search_start);
1384 ins->objectid = aligned;
1385 if (aligned >= search_end) {
1389 ins->offset = search_end - aligned;
1393 ins->objectid = stripe_align(root,
1394 last_byte > search_start ?
1395 last_byte : search_start);
1396 if (search_end <= ins->objectid) {
1400 ins->offset = search_end - ins->objectid;
1401 BUG_ON(ins->objectid >= search_end);
1404 btrfs_item_key_to_cpu(l, &key, slot);
1406 if (key.objectid >= search_start && key.objectid > last_byte &&
1408 if (last_byte < search_start)
1409 last_byte = search_start;
1410 aligned = stripe_align(root, last_byte);
1411 hole_size = key.objectid - aligned;
1412 if (key.objectid > aligned && hole_size >= num_bytes) {
1413 ins->objectid = aligned;
1414 ins->offset = hole_size;
1418 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
1419 if (!start_found && btrfs_key_type(&key) ==
1420 BTRFS_BLOCK_GROUP_ITEM_KEY) {
1421 last_byte = key.objectid;
1429 last_byte = key.objectid + key.offset;
1431 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1432 last_byte >= block_group->key.objectid +
1433 block_group->key.offset) {
1434 btrfs_release_path(root, path);
1435 search_start = block_group->key.objectid +
1436 block_group->key.offset;
1444 /* we have to make sure we didn't find an extent that has already
1445 * been allocated by the map tree or the original allocation
1447 btrfs_release_path(root, path);
1448 BUG_ON(ins->objectid < search_start);
1450 if (ins->objectid + num_bytes >= search_end)
1452 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1453 ins->objectid + num_bytes > block_group->
1454 key.objectid + block_group->key.offset) {
1455 search_start = block_group->key.objectid +
1456 block_group->key.offset;
1459 if (test_range_bit(&info->extent_ins, ins->objectid,
1460 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1461 search_start = ins->objectid + num_bytes;
1464 if (test_range_bit(&info->pinned_extents, ins->objectid,
1465 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1466 search_start = ins->objectid + num_bytes;
1469 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1470 ins->objectid < exclude_start + exclude_nr)) {
1471 search_start = exclude_start + exclude_nr;
1475 block_group = btrfs_lookup_block_group(info, ins->objectid);
1477 trans->block_group = block_group;
1479 ins->offset = num_bytes;
1480 btrfs_free_path(path);
1484 if (search_start + num_bytes >= search_end) {
1486 search_start = orig_search_start;
1493 total_needed -= empty_size;
1495 data = BTRFS_BLOCK_GROUP_MIXED;
1499 block_group = btrfs_lookup_block_group(info, search_start);
1501 block_group = btrfs_find_block_group(root, block_group,
1502 search_start, data, 0);
1506 btrfs_release_path(root, path);
1507 btrfs_free_path(path);
1511 * finds a free extent and does all the dirty work required for allocation
1512 * returns the key for the extent through ins, and a tree buffer for
1513 * the first block of the extent through buf.
1515 * returns 0 if everything worked, non-zero otherwise.
1517 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1518 struct btrfs_root *root,
1519 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1520 u64 owner, u64 owner_offset,
1521 u64 empty_size, u64 hint_byte,
1522 u64 search_end, struct btrfs_key *ins, int data)
1526 u64 super_used, root_used;
1527 u64 search_start = 0;
1528 struct btrfs_fs_info *info = root->fs_info;
1529 struct btrfs_root *extent_root = info->extent_root;
1530 struct btrfs_extent_item extent_item;
1531 struct btrfs_path *path;
1533 btrfs_set_stack_extent_refs(&extent_item, 1);
1535 WARN_ON(num_bytes < root->sectorsize);
1536 ret = find_free_extent(trans, root, num_bytes, empty_size,
1537 search_start, search_end, hint_byte, ins,
1538 trans->alloc_exclude_start,
1539 trans->alloc_exclude_nr, data);
1544 /* block accounting for super block */
1545 super_used = btrfs_super_bytes_used(&info->super_copy);
1546 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1548 /* block accounting for root item */
1549 root_used = btrfs_root_used(&root->root_item);
1550 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1552 clear_extent_dirty(&root->fs_info->free_space_cache,
1553 ins->objectid, ins->objectid + ins->offset - 1,
1556 if (root == extent_root) {
1557 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1558 ins->objectid + ins->offset - 1,
1559 EXTENT_LOCKED, GFP_NOFS);
1564 WARN_ON(trans->alloc_exclude_nr);
1565 trans->alloc_exclude_start = ins->objectid;
1566 trans->alloc_exclude_nr = ins->offset;
1567 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
1568 sizeof(extent_item));
1570 trans->alloc_exclude_start = 0;
1571 trans->alloc_exclude_nr = 0;
1574 path = btrfs_alloc_path();
1576 ret = btrfs_insert_extent_backref(trans, extent_root, path,
1577 ins->objectid, root_objectid,
1578 ref_generation, owner, owner_offset);
1581 btrfs_free_path(path);
1582 finish_current_insert(trans, extent_root);
1583 pending_ret = del_pending_extents(trans, extent_root);
1593 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
1600 * helper function to allocate a block for a given tree
1601 * returns the tree buffer or NULL.
1603 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1604 struct btrfs_root *root,
1606 u64 root_objectid, u64 hint,
1612 ref_generation = trans->transid;
1617 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1618 ref_generation, 0, 0, hint, empty_size);
1622 * helper function to allocate a block for a given tree
1623 * returns the tree buffer or NULL.
1625 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1626 struct btrfs_root *root,
1635 struct btrfs_key ins;
1637 struct extent_buffer *buf;
1639 ret = btrfs_alloc_extent(trans, root, blocksize,
1640 root_objectid, ref_generation,
1641 first_objectid, level, empty_size, hint,
1645 return ERR_PTR(ret);
1647 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1649 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1650 root->root_key.objectid, ref_generation,
1652 return ERR_PTR(-ENOMEM);
1654 btrfs_set_buffer_uptodate(buf);
1655 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1656 buf->start + buf->len - 1, GFP_NOFS);
1657 set_extent_bits(&BTRFS_I(root->fs_info->btree_inode)->extent_tree,
1658 buf->start, buf->start + buf->len - 1,
1659 EXTENT_CSUM, GFP_NOFS);
1660 buf->flags |= EXTENT_CSUM;
1661 btrfs_set_buffer_defrag(buf);
1662 trans->blocks_used++;
1666 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
1667 struct btrfs_root *root, struct extent_buffer *leaf)
1670 u64 leaf_generation;
1671 struct btrfs_key key;
1672 struct btrfs_file_extent_item *fi;
1677 BUG_ON(!btrfs_is_leaf(leaf));
1678 nritems = btrfs_header_nritems(leaf);
1679 leaf_owner = btrfs_header_owner(leaf);
1680 leaf_generation = btrfs_header_generation(leaf);
1682 for (i = 0; i < nritems; i++) {
1685 btrfs_item_key_to_cpu(leaf, &key, i);
1686 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1688 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1689 if (btrfs_file_extent_type(leaf, fi) ==
1690 BTRFS_FILE_EXTENT_INLINE)
1693 * FIXME make sure to insert a trans record that
1694 * repeats the snapshot del on crash
1696 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1697 if (disk_bytenr == 0)
1699 ret = btrfs_free_extent(trans, root, disk_bytenr,
1700 btrfs_file_extent_disk_num_bytes(leaf, fi),
1701 leaf_owner, leaf_generation,
1702 key.objectid, key.offset, 0);
1708 static void reada_walk_down(struct btrfs_root *root,
1709 struct extent_buffer *node)
1719 nritems = btrfs_header_nritems(node);
1720 level = btrfs_header_level(node);
1721 for (i = 0; i < nritems; i++) {
1722 bytenr = btrfs_node_blockptr(node, i);
1723 blocksize = btrfs_level_size(root, level - 1);
1724 ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs);
1728 mutex_unlock(&root->fs_info->fs_mutex);
1729 ret = readahead_tree_block(root, bytenr, blocksize);
1731 mutex_lock(&root->fs_info->fs_mutex);
1738 * helper function for drop_snapshot, this walks down the tree dropping ref
1739 * counts as it goes.
1741 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1742 *root, struct btrfs_path *path, int *level)
1747 struct extent_buffer *next;
1748 struct extent_buffer *cur;
1749 struct extent_buffer *parent;
1754 WARN_ON(*level < 0);
1755 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1756 ret = lookup_extent_ref(trans, root,
1757 path->nodes[*level]->start,
1758 path->nodes[*level]->len, &refs);
1764 * walk down to the last node level and free all the leaves
1766 while(*level >= 0) {
1767 WARN_ON(*level < 0);
1768 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1769 cur = path->nodes[*level];
1771 if (*level > 0 && path->slots[*level] == 0)
1772 reada_walk_down(root, cur);
1774 if (btrfs_header_level(cur) != *level)
1777 if (path->slots[*level] >=
1778 btrfs_header_nritems(cur))
1781 ret = drop_leaf_ref(trans, root, cur);
1785 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1786 blocksize = btrfs_level_size(root, *level - 1);
1787 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1790 parent = path->nodes[*level];
1791 root_owner = btrfs_header_owner(parent);
1792 root_gen = btrfs_header_generation(parent);
1793 path->slots[*level]++;
1794 ret = btrfs_free_extent(trans, root, bytenr,
1795 blocksize, root_owner,
1800 next = btrfs_find_tree_block(root, bytenr, blocksize);
1801 if (!next || !btrfs_buffer_uptodate(next)) {
1802 free_extent_buffer(next);
1803 mutex_unlock(&root->fs_info->fs_mutex);
1804 next = read_tree_block(root, bytenr, blocksize);
1805 mutex_lock(&root->fs_info->fs_mutex);
1807 /* we dropped the lock, check one more time */
1808 ret = lookup_extent_ref(trans, root, bytenr,
1812 parent = path->nodes[*level];
1813 root_owner = btrfs_header_owner(parent);
1814 root_gen = btrfs_header_generation(parent);
1816 path->slots[*level]++;
1817 free_extent_buffer(next);
1818 ret = btrfs_free_extent(trans, root, bytenr,
1826 WARN_ON(*level <= 0);
1827 if (path->nodes[*level-1])
1828 free_extent_buffer(path->nodes[*level-1]);
1829 path->nodes[*level-1] = next;
1830 *level = btrfs_header_level(next);
1831 path->slots[*level] = 0;
1834 WARN_ON(*level < 0);
1835 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1837 if (path->nodes[*level] == root->node) {
1838 root_owner = root->root_key.objectid;
1839 parent = path->nodes[*level];
1841 parent = path->nodes[*level + 1];
1842 root_owner = btrfs_header_owner(parent);
1845 root_gen = btrfs_header_generation(parent);
1846 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1847 path->nodes[*level]->len,
1848 root_owner, root_gen, 0, 0, 1);
1849 free_extent_buffer(path->nodes[*level]);
1850 path->nodes[*level] = NULL;
1857 * helper for dropping snapshots. This walks back up the tree in the path
1858 * to find the first node higher up where we haven't yet gone through
1861 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1862 *root, struct btrfs_path *path, int *level)
1866 struct btrfs_root_item *root_item = &root->root_item;
1871 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1872 slot = path->slots[i];
1873 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1874 struct extent_buffer *node;
1875 struct btrfs_disk_key disk_key;
1876 node = path->nodes[i];
1879 WARN_ON(*level == 0);
1880 btrfs_node_key(node, &disk_key, path->slots[i]);
1881 memcpy(&root_item->drop_progress,
1882 &disk_key, sizeof(disk_key));
1883 root_item->drop_level = i;
1886 if (path->nodes[*level] == root->node) {
1887 root_owner = root->root_key.objectid;
1889 btrfs_header_generation(path->nodes[*level]);
1891 struct extent_buffer *node;
1892 node = path->nodes[*level + 1];
1893 root_owner = btrfs_header_owner(node);
1894 root_gen = btrfs_header_generation(node);
1896 ret = btrfs_free_extent(trans, root,
1897 path->nodes[*level]->start,
1898 path->nodes[*level]->len,
1899 root_owner, root_gen, 0, 0, 1);
1901 free_extent_buffer(path->nodes[*level]);
1902 path->nodes[*level] = NULL;
1910 * drop the reference count on the tree rooted at 'snap'. This traverses
1911 * the tree freeing any blocks that have a ref count of zero after being
1914 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
1920 struct btrfs_path *path;
1923 struct btrfs_root_item *root_item = &root->root_item;
1925 path = btrfs_alloc_path();
1928 level = btrfs_header_level(root->node);
1930 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
1931 path->nodes[level] = root->node;
1932 extent_buffer_get(root->node);
1933 path->slots[level] = 0;
1935 struct btrfs_key key;
1936 struct btrfs_disk_key found_key;
1937 struct extent_buffer *node;
1939 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
1940 level = root_item->drop_level;
1941 path->lowest_level = level;
1942 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1947 node = path->nodes[level];
1948 btrfs_node_key(node, &found_key, path->slots[level]);
1949 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
1950 sizeof(found_key)));
1953 wret = walk_down_tree(trans, root, path, &level);
1959 wret = walk_up_tree(trans, root, path, &level);
1967 for (i = 0; i <= orig_level; i++) {
1968 if (path->nodes[i]) {
1969 free_extent_buffer(path->nodes[i]);
1970 path->nodes[i] = NULL;
1974 btrfs_free_path(path);
1978 int btrfs_free_block_groups(struct btrfs_fs_info *info)
1985 ret = find_first_extent_bit(&info->block_group_cache, 0,
1986 &start, &end, (unsigned int)-1);
1989 ret = get_state_private(&info->block_group_cache, start, &ptr);
1991 kfree((void *)(unsigned long)ptr);
1992 clear_extent_bits(&info->block_group_cache, start,
1993 end, (unsigned int)-1, GFP_NOFS);
1996 ret = find_first_extent_bit(&info->free_space_cache, 0,
1997 &start, &end, EXTENT_DIRTY);
2000 clear_extent_dirty(&info->free_space_cache, start,
2006 int btrfs_read_block_groups(struct btrfs_root *root)
2008 struct btrfs_path *path;
2012 struct btrfs_block_group_cache *cache;
2013 struct btrfs_fs_info *info = root->fs_info;
2014 struct extent_map_tree *block_group_cache;
2015 struct btrfs_key key;
2016 struct btrfs_key found_key;
2017 struct extent_buffer *leaf;
2019 block_group_cache = &info->block_group_cache;
2021 root = info->extent_root;
2023 key.offset = BTRFS_BLOCK_GROUP_SIZE;
2024 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2026 path = btrfs_alloc_path();
2031 ret = btrfs_search_slot(NULL, info->extent_root,
2037 leaf = path->nodes[0];
2038 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2039 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2045 read_extent_buffer(leaf, &cache->item,
2046 btrfs_item_ptr_offset(leaf, path->slots[0]),
2047 sizeof(cache->item));
2048 memcpy(&cache->key, &found_key, sizeof(found_key));
2051 key.objectid = found_key.objectid + found_key.offset;
2052 btrfs_release_path(root, path);
2054 if (cache->item.flags & BTRFS_BLOCK_GROUP_MIXED) {
2055 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
2056 cache->data = BTRFS_BLOCK_GROUP_MIXED;
2057 } else if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
2058 bit = BLOCK_GROUP_DATA;
2059 cache->data = BTRFS_BLOCK_GROUP_DATA;
2061 bit = BLOCK_GROUP_METADATA;
2065 /* use EXTENT_LOCKED to prevent merging */
2066 set_extent_bits(block_group_cache, found_key.objectid,
2067 found_key.objectid + found_key.offset - 1,
2068 bit | EXTENT_LOCKED, GFP_NOFS);
2069 set_state_private(block_group_cache, found_key.objectid,
2070 (unsigned long)cache);
2073 btrfs_super_total_bytes(&info->super_copy))
2077 btrfs_free_path(path);