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>
22 #include "print-tree.h"
23 #include "transaction.h"
25 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
26 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
27 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
29 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
30 btrfs_root *extent_root);
31 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
32 btrfs_root *extent_root);
34 static int cache_block_group(struct btrfs_root *root,
35 struct btrfs_block_group_cache *block_group)
37 struct btrfs_path *path;
40 struct extent_buffer *leaf;
41 struct extent_map_tree *free_space_cache;
48 root = root->fs_info->extent_root;
49 free_space_cache = &root->fs_info->free_space_cache;
51 if (block_group->cached)
54 path = btrfs_alloc_path();
59 first_free = block_group->key.objectid;
60 key.objectid = block_group->key.objectid;
63 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
64 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
69 if (ret && path->slots[0] > 0)
73 leaf = path->nodes[0];
74 slot = path->slots[0];
75 if (slot >= btrfs_header_nritems(leaf)) {
76 ret = btrfs_next_leaf(root, path);
86 btrfs_item_key_to_cpu(leaf, &key, slot);
87 if (key.objectid < block_group->key.objectid) {
88 if (key.objectid + key.offset > first_free)
89 first_free = key.objectid + key.offset;
93 if (key.objectid >= block_group->key.objectid +
94 block_group->key.offset) {
98 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
103 if (key.objectid > last) {
104 hole_size = key.objectid - last;
105 set_extent_dirty(free_space_cache, last,
106 last + hole_size - 1,
109 last = key.objectid + key.offset;
117 if (block_group->key.objectid +
118 block_group->key.offset > last) {
119 hole_size = block_group->key.objectid +
120 block_group->key.offset - last;
121 set_extent_dirty(free_space_cache, last,
122 last + hole_size - 1, GFP_NOFS);
124 block_group->cached = 1;
126 btrfs_free_path(path);
130 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
134 struct extent_map_tree *block_group_cache;
135 struct btrfs_block_group_cache *block_group = NULL;
141 block_group_cache = &info->block_group_cache;
142 ret = find_first_extent_bit(block_group_cache,
143 bytenr, &start, &end,
144 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA);
148 ret = get_state_private(block_group_cache, start, &ptr);
152 block_group = (struct btrfs_block_group_cache *)ptr;
155 if (block_group->key.objectid <= bytenr && bytenr <=
156 block_group->key.objectid + block_group->key.offset)
162 static u64 find_search_start(struct btrfs_root *root,
163 struct btrfs_block_group_cache **cache_ret,
164 u64 search_start, int num, int data)
167 struct btrfs_block_group_cache *cache = *cache_ret;
173 ret = cache_block_group(root, cache);
176 last = max(search_start, cache->key.objectid);
179 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
180 last, &start, &end, EXTENT_DIRTY);
185 start = max(last, start);
187 if (end + 1 - start < num)
189 if (start + num >= cache->key.objectid + cache->key.offset)
197 last = cache->key.objectid + cache->key.offset;
198 cache = btrfs_lookup_block_group(root->fs_info, last);
202 cache = btrfs_find_block_group(root, cache, last, data, 0);
207 static u64 div_factor(u64 num, int factor)
214 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
215 struct btrfs_block_group_cache
216 *hint, u64 search_start,
219 struct btrfs_block_group_cache *cache;
220 struct extent_map_tree *block_group_cache;
221 struct btrfs_block_group_cache *found_group = NULL;
222 struct btrfs_fs_info *info = root->fs_info;
236 block_group_cache = &info->block_group_cache;
242 bit = BLOCK_GROUP_DATA;
244 bit = BLOCK_GROUP_METADATA;
247 struct btrfs_block_group_cache *shint;
248 shint = btrfs_lookup_block_group(info, search_start);
249 if (shint && shint->data == data) {
250 used = btrfs_block_group_used(&shint->item);
251 if (used < div_factor(shint->key.offset, factor)) {
256 if (hint && hint->data == data) {
257 used = btrfs_block_group_used(&hint->item);
258 if (used < div_factor(hint->key.offset, factor)) {
261 last = hint->key.objectid + hint->key.offset;
265 hint_last = max(hint->key.objectid, search_start);
267 hint_last = search_start;
273 ret = find_first_extent_bit(block_group_cache, last,
278 ret = get_state_private(block_group_cache, start, &ptr);
282 cache = (struct btrfs_block_group_cache *)ptr;
283 last = cache->key.objectid + cache->key.offset;
284 used = btrfs_block_group_used(&cache->item);
287 free_check = cache->key.offset;
289 free_check = div_factor(cache->key.offset, factor);
291 if (used < free_check) {
304 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
312 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
313 struct btrfs_root *root,
314 u64 bytenr, u64 num_bytes)
316 struct btrfs_path *path;
318 struct btrfs_key key;
319 struct extent_buffer *l;
320 struct btrfs_extent_item *item;
323 WARN_ON(num_bytes < root->sectorsize);
324 path = btrfs_alloc_path();
328 key.objectid = bytenr;
329 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
330 key.offset = num_bytes;
331 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
340 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
341 refs = btrfs_extent_refs(l, item);
342 btrfs_set_extent_refs(l, item, refs + 1);
343 btrfs_mark_buffer_dirty(path->nodes[0]);
345 btrfs_release_path(root->fs_info->extent_root, path);
346 btrfs_free_path(path);
347 finish_current_insert(trans, root->fs_info->extent_root);
348 del_pending_extents(trans, root->fs_info->extent_root);
352 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
353 struct btrfs_root *root)
355 finish_current_insert(trans, root->fs_info->extent_root);
356 del_pending_extents(trans, root->fs_info->extent_root);
360 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
361 struct btrfs_root *root, u64 bytenr,
362 u64 num_bytes, u32 *refs)
364 struct btrfs_path *path;
366 struct btrfs_key key;
367 struct extent_buffer *l;
368 struct btrfs_extent_item *item;
370 WARN_ON(num_bytes < root->sectorsize);
371 path = btrfs_alloc_path();
372 key.objectid = bytenr;
373 key.offset = num_bytes;
374 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
375 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
380 btrfs_print_leaf(root, path->nodes[0]);
381 printk("failed to find block number %Lu\n", bytenr);
385 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
386 *refs = btrfs_extent_refs(l, item);
388 btrfs_free_path(path);
392 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
393 struct btrfs_root *root)
395 return btrfs_inc_extent_ref(trans, root, root->node->start,
399 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
400 struct extent_buffer *buf)
404 struct btrfs_key key;
405 struct btrfs_file_extent_item *fi;
415 level = btrfs_header_level(buf);
416 nritems = btrfs_header_nritems(buf);
417 for (i = 0; i < nritems; i++) {
420 btrfs_item_key_to_cpu(buf, &key, i);
421 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
423 fi = btrfs_item_ptr(buf, i,
424 struct btrfs_file_extent_item);
425 if (btrfs_file_extent_type(buf, fi) ==
426 BTRFS_FILE_EXTENT_INLINE)
428 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
429 if (disk_bytenr == 0)
431 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
432 btrfs_file_extent_disk_num_bytes(buf, fi));
438 bytenr = btrfs_node_blockptr(buf, i);
439 ret = btrfs_inc_extent_ref(trans, root, bytenr,
440 btrfs_level_size(root, level - 1));
450 for (i =0; i < faili; i++) {
453 btrfs_item_key_to_cpu(buf, &key, i);
454 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
456 fi = btrfs_item_ptr(buf, i,
457 struct btrfs_file_extent_item);
458 if (btrfs_file_extent_type(buf, fi) ==
459 BTRFS_FILE_EXTENT_INLINE)
461 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
462 if (disk_bytenr == 0)
464 err = btrfs_free_extent(trans, root, disk_bytenr,
465 btrfs_file_extent_disk_num_bytes(buf,
469 bytenr = btrfs_node_blockptr(buf, i);
470 err = btrfs_free_extent(trans, root, bytenr,
471 btrfs_level_size(root, level - 1), 0);
478 static int write_one_cache_group(struct btrfs_trans_handle *trans,
479 struct btrfs_root *root,
480 struct btrfs_path *path,
481 struct btrfs_block_group_cache *cache)
485 struct btrfs_root *extent_root = root->fs_info->extent_root;
487 struct extent_buffer *leaf;
489 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
494 leaf = path->nodes[0];
495 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
496 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
497 btrfs_mark_buffer_dirty(leaf);
498 btrfs_release_path(extent_root, path);
500 finish_current_insert(trans, extent_root);
501 pending_ret = del_pending_extents(trans, extent_root);
510 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
511 struct btrfs_root *root)
513 struct extent_map_tree *block_group_cache;
514 struct btrfs_block_group_cache *cache;
518 struct btrfs_path *path;
524 block_group_cache = &root->fs_info->block_group_cache;
525 path = btrfs_alloc_path();
530 ret = find_first_extent_bit(block_group_cache, last,
531 &start, &end, BLOCK_GROUP_DIRTY);
536 ret = get_state_private(block_group_cache, start, &ptr);
540 cache = (struct btrfs_block_group_cache *)ptr;
541 err = write_one_cache_group(trans, root,
544 * if we fail to write the cache group, we want
545 * to keep it marked dirty in hopes that a later
552 clear_extent_bits(block_group_cache, start, end,
553 BLOCK_GROUP_DIRTY, GFP_NOFS);
555 btrfs_free_path(path);
559 static int update_block_group(struct btrfs_trans_handle *trans,
560 struct btrfs_root *root,
561 u64 bytenr, u64 num_bytes, int alloc,
562 int mark_free, int data)
564 struct btrfs_block_group_cache *cache;
565 struct btrfs_fs_info *info = root->fs_info;
566 u64 total = num_bytes;
573 cache = btrfs_lookup_block_group(info, bytenr);
577 byte_in_group = bytenr - cache->key.objectid;
578 WARN_ON(byte_in_group > cache->key.offset);
579 start = cache->key.objectid;
580 end = start + cache->key.offset - 1;
581 set_extent_bits(&info->block_group_cache, start, end,
582 BLOCK_GROUP_DIRTY, GFP_NOFS);
584 old_val = btrfs_block_group_used(&cache->item);
585 num_bytes = min(total, cache->key.offset - byte_in_group);
587 if (cache->data != data &&
588 old_val < (cache->key.offset >> 1)) {
594 bit_to_clear = BLOCK_GROUP_DATA;
595 bit_to_set = BLOCK_GROUP_METADATA;
597 BTRFS_BLOCK_GROUP_DATA;
599 bit_to_clear = BLOCK_GROUP_METADATA;
600 bit_to_set = BLOCK_GROUP_DATA;
602 ~BTRFS_BLOCK_GROUP_DATA;
604 clear_extent_bits(&info->block_group_cache,
605 start, end, bit_to_clear,
607 set_extent_bits(&info->block_group_cache,
608 start, end, bit_to_set,
611 old_val += num_bytes;
613 old_val -= num_bytes;
615 set_extent_dirty(&info->free_space_cache,
616 bytenr, bytenr + num_bytes - 1,
620 btrfs_set_block_group_used(&cache->item, old_val);
627 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_map_tree *copy)
632 struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
636 ret = find_first_extent_bit(pinned_extents, last,
637 &start, &end, EXTENT_DIRTY);
640 set_extent_dirty(copy, start, end, GFP_NOFS);
646 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
647 struct btrfs_root *root,
648 struct extent_map_tree *unpin)
653 struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
654 struct extent_map_tree *free_space_cache;
656 free_space_cache = &root->fs_info->free_space_cache;
659 ret = find_first_extent_bit(unpin, 0, &start, &end,
664 clear_extent_dirty(pinned_extents, start, end,
666 clear_extent_dirty(unpin, start, end, GFP_NOFS);
667 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
672 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
673 btrfs_root *extent_root)
675 struct btrfs_key ins;
676 struct btrfs_extent_item extent_item;
681 struct btrfs_fs_info *info = extent_root->fs_info;
683 btrfs_set_stack_extent_refs(&extent_item, 1);
684 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
685 btrfs_set_stack_extent_owner(&extent_item,
686 extent_root->root_key.objectid);
689 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
690 &end, EXTENT_LOCKED);
694 ins.objectid = start;
695 ins.offset = end + 1 - start;
696 err = btrfs_insert_item(trans, extent_root, &ins,
697 &extent_item, sizeof(extent_item));
698 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
704 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
708 struct extent_buffer *buf;
711 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
713 if (btrfs_buffer_uptodate(buf)) {
715 root->fs_info->running_transaction->transid;
716 if (btrfs_header_generation(buf) == transid) {
717 free_extent_buffer(buf);
721 free_extent_buffer(buf);
723 set_extent_dirty(&root->fs_info->pinned_extents,
724 bytenr, bytenr + num_bytes - 1, GFP_NOFS);
726 set_extent_bits(&root->fs_info->pending_del,
727 bytenr, bytenr + num_bytes - 1,
728 EXTENT_LOCKED, GFP_NOFS);
735 * remove an extent from the root, returns 0 on success
737 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
738 *root, u64 bytenr, u64 num_bytes, int pin,
741 struct btrfs_path *path;
742 struct btrfs_key key;
743 struct btrfs_fs_info *info = root->fs_info;
744 struct btrfs_root *extent_root = info->extent_root;
745 struct extent_buffer *leaf;
747 struct btrfs_extent_item *ei;
750 key.objectid = bytenr;
751 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
752 key.offset = num_bytes;
754 path = btrfs_alloc_path();
758 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
763 leaf = path->nodes[0];
764 ei = btrfs_item_ptr(leaf, path->slots[0],
765 struct btrfs_extent_item);
766 refs = btrfs_extent_refs(leaf, ei);
769 btrfs_set_extent_refs(leaf, ei, refs);
770 btrfs_mark_buffer_dirty(leaf);
777 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
781 /* block accounting for super block */
782 super_used = btrfs_super_bytes_used(&info->super_copy);
783 btrfs_set_super_bytes_used(&info->super_copy,
784 super_used - num_bytes);
786 /* block accounting for root item */
787 root_used = btrfs_root_used(&root->root_item);
788 btrfs_set_root_used(&root->root_item,
789 root_used - num_bytes);
791 ret = btrfs_del_item(trans, extent_root, path);
795 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
799 btrfs_free_path(path);
800 finish_current_insert(trans, extent_root);
805 * find all the blocks marked as pending in the radix tree and remove
806 * them from the extent map
808 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
809 btrfs_root *extent_root)
815 struct extent_map_tree *pending_del;
816 struct extent_map_tree *pinned_extents;
818 pending_del = &extent_root->fs_info->pending_del;
819 pinned_extents = &extent_root->fs_info->pinned_extents;
822 ret = find_first_extent_bit(pending_del, 0, &start, &end,
827 set_extent_dirty(pinned_extents, start, end, GFP_NOFS);
828 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
830 ret = __free_extent(trans, extent_root,
831 start, end + 1 - start, 0, 0);
839 * remove an extent from the root, returns 0 on success
841 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
842 *root, u64 bytenr, u64 num_bytes, int pin)
844 struct btrfs_root *extent_root = root->fs_info->extent_root;
848 WARN_ON(num_bytes < root->sectorsize);
849 if (root == extent_root) {
850 pin_down_bytes(root, bytenr, num_bytes, 1);
853 ret = __free_extent(trans, root, bytenr, num_bytes, pin, pin == 0);
854 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
855 return ret ? ret : pending_ret;
859 * walks the btree of allocated extents and find a hole of a given size.
860 * The key ins is changed to record the hole:
861 * ins->objectid == block start
862 * ins->flags = BTRFS_EXTENT_ITEM_KEY
863 * ins->offset == number of blocks
864 * Any available blocks before search_start are skipped.
866 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
867 *orig_root, u64 num_bytes, u64 empty_size,
868 u64 search_start, u64 search_end, u64 hint_byte,
869 struct btrfs_key *ins, u64 exclude_start,
870 u64 exclude_nr, int data)
872 struct btrfs_path *path;
873 struct btrfs_key key;
878 u64 orig_search_start = search_start;
880 struct extent_buffer *l;
881 struct btrfs_root * root = orig_root->fs_info->extent_root;
882 struct btrfs_fs_info *info = root->fs_info;
883 u64 total_needed = num_bytes;
885 struct btrfs_block_group_cache *block_group;
889 WARN_ON(num_bytes < root->sectorsize);
890 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
892 level = btrfs_header_level(root->node);
894 if (search_end == (u64)-1)
895 search_end = btrfs_super_total_bytes(&info->super_copy);
897 block_group = btrfs_lookup_block_group(info, hint_byte);
898 block_group = btrfs_find_block_group(root, block_group,
901 block_group = btrfs_find_block_group(root,
902 trans->block_group, 0,
906 total_needed += empty_size;
907 path = btrfs_alloc_path();
910 search_start = find_search_start(root, &block_group,
911 search_start, total_needed, data);
912 btrfs_init_path(path);
913 ins->objectid = search_start;
918 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
922 if (path->slots[0] > 0) {
927 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
930 * a rare case, go back one key if we hit a block group item
931 * instead of an extent item
933 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY &&
934 key.objectid + key.offset >= search_start) {
935 ins->objectid = key.objectid;
936 ins->offset = key.offset - 1;
937 btrfs_release_path(root, path);
938 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
942 if (path->slots[0] > 0) {
949 slot = path->slots[0];
950 if (slot >= btrfs_header_nritems(l)) {
951 ret = btrfs_next_leaf(root, path);
957 search_start = max(search_start,
958 block_group->key.objectid);
960 ins->objectid = search_start;
961 ins->offset = search_end - search_start;
965 ins->objectid = last_byte > search_start ?
966 last_byte : search_start;
967 ins->offset = search_end - ins->objectid;
968 BUG_ON(ins->objectid >= search_end);
971 btrfs_item_key_to_cpu(l, &key, slot);
973 if (key.objectid >= search_start && key.objectid > last_byte &&
975 if (last_byte < search_start)
976 last_byte = search_start;
977 hole_size = key.objectid - last_byte;
978 if (hole_size >= num_bytes) {
979 ins->objectid = last_byte;
980 ins->offset = hole_size;
984 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
986 last_byte = key.objectid;
994 last_byte = key.objectid + key.offset;
996 if (!full_scan && last_byte >= block_group->key.objectid +
997 block_group->key.offset) {
998 btrfs_release_path(root, path);
999 search_start = block_group->key.objectid +
1000 block_group->key.offset;
1008 /* we have to make sure we didn't find an extent that has already
1009 * been allocated by the map tree or the original allocation
1011 btrfs_release_path(root, path);
1012 BUG_ON(ins->objectid < search_start);
1014 if (ins->objectid + num_bytes >= search_end)
1017 if (!full_scan && ins->objectid + num_bytes >= block_group->
1018 key.objectid + block_group->key.offset) {
1019 search_start = block_group->key.objectid +
1020 block_group->key.offset;
1023 if (test_range_bit(&info->extent_ins, ins->objectid,
1024 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1025 search_start = ins->objectid + num_bytes;
1028 if (test_range_bit(&info->pinned_extents, ins->objectid,
1029 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1030 search_start = ins->objectid + num_bytes;
1033 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1034 ins->objectid < exclude_start + exclude_nr)) {
1035 search_start = exclude_start + exclude_nr;
1039 block_group = btrfs_lookup_block_group(info, ins->objectid);
1041 trans->block_group = block_group;
1043 ins->offset = num_bytes;
1044 btrfs_free_path(path);
1048 if (search_start + num_bytes >= search_end) {
1050 search_start = orig_search_start;
1057 total_needed -= empty_size;
1062 block_group = btrfs_lookup_block_group(info, search_start);
1065 block_group = btrfs_find_block_group(root, block_group,
1066 search_start, data, 0);
1070 btrfs_release_path(root, path);
1071 btrfs_free_path(path);
1075 * finds a free extent and does all the dirty work required for allocation
1076 * returns the key for the extent through ins, and a tree buffer for
1077 * the first block of the extent through buf.
1079 * returns 0 if everything worked, non-zero otherwise.
1081 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1082 struct btrfs_root *root, u64 owner,
1083 u64 num_bytes, u64 empty_size, u64 hint_byte,
1084 u64 search_end, struct btrfs_key *ins, int data)
1088 u64 super_used, root_used;
1089 u64 search_start = 0;
1090 struct btrfs_fs_info *info = root->fs_info;
1091 struct btrfs_root *extent_root = info->extent_root;
1092 struct btrfs_extent_item extent_item;
1094 btrfs_set_stack_extent_refs(&extent_item, 1);
1095 btrfs_set_stack_extent_owner(&extent_item, owner);
1097 WARN_ON(num_bytes < root->sectorsize);
1098 ret = find_free_extent(trans, root, num_bytes, empty_size,
1099 search_start, search_end, hint_byte, ins,
1100 trans->alloc_exclude_start,
1101 trans->alloc_exclude_nr, data);
1106 /* block accounting for super block */
1107 super_used = btrfs_super_bytes_used(&info->super_copy);
1108 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1110 /* block accounting for root item */
1111 root_used = btrfs_root_used(&root->root_item);
1112 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1114 clear_extent_dirty(&root->fs_info->free_space_cache,
1115 ins->objectid, ins->objectid + ins->offset - 1,
1118 if (root == extent_root) {
1119 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1120 ins->objectid + ins->offset - 1,
1121 EXTENT_LOCKED, GFP_NOFS);
1126 WARN_ON(trans->alloc_exclude_nr);
1127 trans->alloc_exclude_start = ins->objectid;
1128 trans->alloc_exclude_nr = ins->offset;
1129 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
1130 sizeof(extent_item));
1132 trans->alloc_exclude_start = 0;
1133 trans->alloc_exclude_nr = 0;
1136 finish_current_insert(trans, extent_root);
1137 pending_ret = del_pending_extents(trans, extent_root);
1147 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
1154 * helper function to allocate a block for a given tree
1155 * returns the tree buffer or NULL.
1157 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1158 struct btrfs_root *root,
1159 u32 blocksize, u64 hint,
1162 struct btrfs_key ins;
1164 struct extent_buffer *buf;
1166 ret = btrfs_alloc_extent(trans, root, root->root_key.objectid,
1167 blocksize, empty_size, hint,
1171 return ERR_PTR(ret);
1173 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1175 btrfs_free_extent(trans, root, ins.objectid, blocksize, 0);
1176 return ERR_PTR(-ENOMEM);
1178 btrfs_set_buffer_uptodate(buf);
1179 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1180 buf->start + buf->len - 1, GFP_NOFS);
1181 btrfs_set_buffer_defrag(buf);
1182 trans->blocks_used++;
1186 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
1187 struct btrfs_root *root, struct extent_buffer *leaf)
1189 struct btrfs_key key;
1190 struct btrfs_file_extent_item *fi;
1195 BUG_ON(!btrfs_is_leaf(leaf));
1196 nritems = btrfs_header_nritems(leaf);
1197 for (i = 0; i < nritems; i++) {
1200 btrfs_item_key_to_cpu(leaf, &key, i);
1201 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1203 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1204 if (btrfs_file_extent_type(leaf, fi) ==
1205 BTRFS_FILE_EXTENT_INLINE)
1208 * FIXME make sure to insert a trans record that
1209 * repeats the snapshot del on crash
1211 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1212 if (disk_bytenr == 0)
1214 ret = btrfs_free_extent(trans, root, disk_bytenr,
1215 btrfs_file_extent_disk_num_bytes(leaf, fi), 0);
1221 static void reada_walk_down(struct btrfs_root *root,
1222 struct extent_buffer *node)
1232 nritems = btrfs_header_nritems(node);
1233 level = btrfs_header_level(node);
1234 for (i = 0; i < nritems; i++) {
1235 bytenr = btrfs_node_blockptr(node, i);
1236 blocksize = btrfs_level_size(root, level - 1);
1237 ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs);
1241 mutex_unlock(&root->fs_info->fs_mutex);
1242 ret = readahead_tree_block(root, bytenr, blocksize);
1244 mutex_lock(&root->fs_info->fs_mutex);
1251 * helper function for drop_snapshot, this walks down the tree dropping ref
1252 * counts as it goes.
1254 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1255 *root, struct btrfs_path *path, int *level)
1257 struct extent_buffer *next;
1258 struct extent_buffer *cur;
1264 WARN_ON(*level < 0);
1265 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1266 ret = lookup_extent_ref(trans, root,
1267 path->nodes[*level]->start,
1268 path->nodes[*level]->len, &refs);
1274 * walk down to the last node level and free all the leaves
1276 while(*level >= 0) {
1277 WARN_ON(*level < 0);
1278 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1279 cur = path->nodes[*level];
1281 if (*level > 0 && path->slots[*level] == 0)
1282 reada_walk_down(root, cur);
1284 if (btrfs_header_level(cur) != *level)
1287 if (path->slots[*level] >=
1288 btrfs_header_nritems(cur))
1291 ret = drop_leaf_ref(trans, root, cur);
1295 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1296 blocksize = btrfs_level_size(root, *level - 1);
1297 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1300 path->slots[*level]++;
1301 ret = btrfs_free_extent(trans, root, bytenr,
1306 next = btrfs_find_tree_block(root, bytenr, blocksize);
1307 if (!next || !btrfs_buffer_uptodate(next)) {
1308 free_extent_buffer(next);
1309 mutex_unlock(&root->fs_info->fs_mutex);
1310 next = read_tree_block(root, bytenr, blocksize);
1311 mutex_lock(&root->fs_info->fs_mutex);
1313 /* we dropped the lock, check one more time */
1314 ret = lookup_extent_ref(trans, root, bytenr,
1318 path->slots[*level]++;
1319 free_extent_buffer(next);
1320 ret = btrfs_free_extent(trans, root,
1321 bytenr, blocksize, 1);
1326 WARN_ON(*level <= 0);
1327 if (path->nodes[*level-1])
1328 free_extent_buffer(path->nodes[*level-1]);
1329 path->nodes[*level-1] = next;
1330 *level = btrfs_header_level(next);
1331 path->slots[*level] = 0;
1334 WARN_ON(*level < 0);
1335 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1336 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1337 path->nodes[*level]->len, 1);
1338 free_extent_buffer(path->nodes[*level]);
1339 path->nodes[*level] = NULL;
1346 * helper for dropping snapshots. This walks back up the tree in the path
1347 * to find the first node higher up where we haven't yet gone through
1350 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1351 *root, struct btrfs_path *path, int *level)
1356 struct btrfs_root_item *root_item = &root->root_item;
1358 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1359 slot = path->slots[i];
1360 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1361 struct extent_buffer *node;
1362 struct btrfs_disk_key disk_key;
1363 node = path->nodes[i];
1366 WARN_ON(*level == 0);
1367 btrfs_node_key(node, &disk_key, path->slots[i]);
1368 memcpy(&root_item->drop_progress,
1369 &disk_key, sizeof(disk_key));
1370 root_item->drop_level = i;
1373 ret = btrfs_free_extent(trans, root,
1374 path->nodes[*level]->start,
1375 path->nodes[*level]->len, 1);
1377 free_extent_buffer(path->nodes[*level]);
1378 path->nodes[*level] = NULL;
1386 * drop the reference count on the tree rooted at 'snap'. This traverses
1387 * the tree freeing any blocks that have a ref count of zero after being
1390 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
1396 struct btrfs_path *path;
1399 struct btrfs_root_item *root_item = &root->root_item;
1401 path = btrfs_alloc_path();
1404 level = btrfs_header_level(root->node);
1406 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
1407 path->nodes[level] = root->node;
1408 extent_buffer_get(root->node);
1409 path->slots[level] = 0;
1411 struct btrfs_key key;
1412 struct btrfs_disk_key found_key;
1413 struct extent_buffer *node;
1415 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
1416 level = root_item->drop_level;
1417 path->lowest_level = level;
1418 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1423 node = path->nodes[level];
1424 btrfs_node_key(node, &found_key, path->slots[level]);
1425 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
1426 sizeof(found_key)));
1429 wret = walk_down_tree(trans, root, path, &level);
1435 wret = walk_up_tree(trans, root, path, &level);
1443 for (i = 0; i <= orig_level; i++) {
1444 if (path->nodes[i]) {
1445 free_extent_buffer(path->nodes[i]);
1450 btrfs_free_path(path);
1454 int btrfs_free_block_groups(struct btrfs_fs_info *info)
1461 ret = find_first_extent_bit(&info->block_group_cache, 0,
1462 &start, &end, (unsigned int)-1);
1465 clear_extent_bits(&info->block_group_cache, start,
1466 end, (unsigned int)-1, GFP_NOFS);
1469 ret = find_first_extent_bit(&info->free_space_cache, 0,
1470 &start, &end, EXTENT_DIRTY);
1473 clear_extent_dirty(&info->free_space_cache, start,
1479 int btrfs_read_block_groups(struct btrfs_root *root)
1481 struct btrfs_path *path;
1485 struct btrfs_block_group_cache *cache;
1486 struct btrfs_fs_info *info = root->fs_info;
1487 struct extent_map_tree *block_group_cache;
1488 struct btrfs_key key;
1489 struct btrfs_key found_key;
1490 struct extent_buffer *leaf;
1492 block_group_cache = &info->block_group_cache;
1494 root = info->extent_root;
1496 key.offset = BTRFS_BLOCK_GROUP_SIZE;
1497 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
1499 path = btrfs_alloc_path();
1504 ret = btrfs_search_slot(NULL, info->extent_root,
1510 leaf = path->nodes[0];
1511 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1512 cache = kmalloc(sizeof(*cache), GFP_NOFS);
1518 read_extent_buffer(leaf, &cache->item,
1519 btrfs_item_ptr_offset(leaf, path->slots[0]),
1520 sizeof(cache->item));
1521 memcpy(&cache->key, &found_key, sizeof(found_key));
1524 key.objectid = found_key.objectid + found_key.offset;
1525 btrfs_release_path(root, path);
1527 if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
1528 bit = BLOCK_GROUP_DATA;
1531 bit = BLOCK_GROUP_METADATA;
1535 /* use EXTENT_LOCKED to prevent merging */
1536 set_extent_bits(block_group_cache, found_key.objectid,
1537 found_key.objectid + found_key.offset - 1,
1538 bit | EXTENT_LOCKED, GFP_NOFS);
1539 set_state_private(block_group_cache, found_key.objectid,
1543 btrfs_super_total_bytes(&info->super_copy))
1547 btrfs_free_path(path);