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/module.h>
22 #include "print-tree.h"
23 #include "transaction.h"
25 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
26 *orig_root, u64 num_blocks, u64 search_start,
27 u64 search_end, u64 hint_block,
28 struct btrfs_key *ins, int data);
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 void reada_extent_leaves(struct btrfs_root *root,
35 struct btrfs_path *path, u64 limit)
37 struct btrfs_node *node;
47 node = btrfs_buffer_node(path->nodes[1]);
48 slot = path->slots[1] + 1;
49 nritems = btrfs_header_nritems(&node->header);
50 for (i = slot; i < nritems && i < slot + 8; i++) {
51 item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
52 if (item_objectid > limit)
54 blocknr = btrfs_node_blockptr(node, i);
55 ret = readahead_tree_block(root, blocknr);
61 static int cache_block_group(struct btrfs_root *root,
62 struct btrfs_block_group_cache *block_group)
64 struct btrfs_path *path;
67 struct btrfs_leaf *leaf;
68 struct radix_tree_root *extent_radix;
76 root = root->fs_info->extent_root;
77 extent_radix = &root->fs_info->extent_map_radix;
79 if (block_group->cached)
81 if (block_group->data)
83 path = btrfs_alloc_path();
86 key.objectid = block_group->key.objectid;
89 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
90 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
93 if (ret && path->slots[0] > 0)
95 limit = block_group->key.objectid + block_group->key.offset;
96 reada_extent_leaves(root, path, limit);
98 leaf = btrfs_buffer_leaf(path->nodes[0]);
99 slot = path->slots[0];
100 if (slot >= btrfs_header_nritems(&leaf->header)) {
101 reada_extent_leaves(root, path, limit);
102 ret = btrfs_next_leaf(root, path);
107 hole_size = block_group->key.objectid +
108 block_group->key.offset - last;
110 last = block_group->key.objectid;
111 hole_size = block_group->key.offset;
113 for (i = 0; i < hole_size; i++) {
114 set_radix_bit(extent_radix,
120 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
121 if (key.objectid >= block_group->key.objectid +
122 block_group->key.offset) {
124 hole_size = block_group->key.objectid +
125 block_group->key.offset - last;
127 last = block_group->key.objectid;
128 hole_size = block_group->key.offset;
130 for (i = 0; i < hole_size; i++) {
131 set_radix_bit(extent_radix, last + i);
135 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
137 last = key.objectid + key.offset;
140 hole_size = key.objectid - last;
141 for (i = 0; i < hole_size; i++) {
142 set_radix_bit(extent_radix, last + i);
144 last = key.objectid + key.offset;
150 block_group->cached = 1;
151 btrfs_free_path(path);
155 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
159 struct btrfs_block_group_cache *block_group;
162 ret = radix_tree_gang_lookup(&info->block_group_radix,
163 (void **)&block_group,
166 if (block_group->key.objectid <= blocknr && blocknr <=
167 block_group->key.objectid + block_group->key.offset)
170 ret = radix_tree_gang_lookup(&info->block_group_data_radix,
171 (void **)&block_group,
174 if (block_group->key.objectid <= blocknr && blocknr <=
175 block_group->key.objectid + block_group->key.offset)
181 static u64 leaf_range(struct btrfs_root *root)
183 u64 size = BTRFS_LEAF_DATA_SIZE(root);
184 do_div(size, sizeof(struct btrfs_extent_item) +
185 sizeof(struct btrfs_item));
189 static u64 find_search_start(struct btrfs_root *root,
190 struct btrfs_block_group_cache **cache_ret,
191 u64 search_start, int num)
193 unsigned long gang[8];
195 struct btrfs_block_group_cache *cache = *cache_ret;
196 u64 last = max(search_start, cache->key.objectid);
201 last = max(last, cache->last_prealloc);
204 cache_block_group(root, cache);
206 ret = find_first_radix_bit(&root->fs_info->extent_map_radix,
207 gang, last, ARRAY_SIZE(gang));
210 last = gang[ret-1] + 1;
212 if (ret != ARRAY_SIZE(gang)) {
215 if (gang[ret-1] - gang[0] > leaf_range(root)) {
219 if (gang[0] >= cache->key.objectid + cache->key.offset) {
225 return max(cache->last_alloc, search_start);
228 cache = btrfs_lookup_block_group(root->fs_info,
229 last + cache->key.offset - 1);
231 return max((*cache_ret)->last_alloc, search_start);
233 cache = btrfs_find_block_group(root, cache,
234 last + cache->key.offset - 1, 0, 0);
239 static u64 div_factor(u64 num, int factor)
246 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
247 struct btrfs_block_group_cache
248 *hint, u64 search_start,
251 struct btrfs_block_group_cache *cache[8];
252 struct btrfs_block_group_cache *found_group = NULL;
253 struct btrfs_fs_info *info = root->fs_info;
254 struct radix_tree_root *radix;
255 struct radix_tree_root *swap_radix;
269 radix = &info->block_group_data_radix;
270 swap_radix = &info->block_group_radix;
272 radix = &info->block_group_radix;
273 swap_radix = &info->block_group_data_radix;
277 struct btrfs_block_group_cache *shint;
278 shint = btrfs_lookup_block_group(info, search_start);
279 if (shint->data == data) {
280 used = btrfs_block_group_used(&shint->item);
281 if (used + shint->pinned <
282 div_factor(shint->key.offset, factor)) {
287 if (hint && hint->data == data) {
288 used = btrfs_block_group_used(&hint->item);
289 if (used + hint->pinned <
290 div_factor(hint->key.offset, factor)) {
293 if (used >= div_factor(hint->key.offset, 8)) {
294 radix_tree_tag_clear(radix,
296 hint->key.offset - 1,
297 BTRFS_BLOCK_GROUP_AVAIL);
299 last = hint->key.offset * 3;
300 if (hint->key.objectid >= last)
301 last = max(search_start + hint->key.offset - 1,
302 hint->key.objectid - last);
304 last = hint->key.objectid + hint->key.offset;
308 hint_last = max(hint->key.objectid, search_start);
310 hint_last = search_start;
315 ret = radix_tree_gang_lookup_tag(radix, (void **)cache,
316 last, ARRAY_SIZE(cache),
317 BTRFS_BLOCK_GROUP_AVAIL);
320 for (i = 0; i < ret; i++) {
321 last = cache[i]->key.objectid +
322 cache[i]->key.offset;
323 used = btrfs_block_group_used(&cache[i]->item);
324 if (used + cache[i]->pinned <
325 div_factor(cache[i]->key.offset, factor)) {
326 found_group = cache[i];
329 if (used >= div_factor(cache[i]->key.offset, 8)) {
330 radix_tree_tag_clear(radix,
331 cache[i]->key.objectid +
332 cache[i]->key.offset - 1,
333 BTRFS_BLOCK_GROUP_AVAIL);
341 ret = radix_tree_gang_lookup(radix, (void **)cache,
342 last, ARRAY_SIZE(cache));
345 for (i = 0; i < ret; i++) {
346 last = cache[i]->key.objectid +
347 cache[i]->key.offset;
348 used = btrfs_block_group_used(&cache[i]->item);
349 if (used + cache[i]->pinned < cache[i]->key.offset) {
350 found_group = cache[i];
353 if (used >= cache[i]->key.offset) {
354 radix_tree_tag_clear(radix,
355 cache[i]->key.objectid +
356 cache[i]->key.offset - 1,
357 BTRFS_BLOCK_GROUP_AVAIL);
368 struct radix_tree_root *tmp = radix;
376 ret = radix_tree_gang_lookup(radix,
377 (void **)&found_group, 0, 1);
379 ret = radix_tree_gang_lookup(swap_radix,
380 (void **)&found_group,
389 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
390 struct btrfs_root *root,
391 u64 blocknr, u64 num_blocks)
393 struct btrfs_path *path;
395 struct btrfs_key key;
396 struct btrfs_leaf *l;
397 struct btrfs_extent_item *item;
398 struct btrfs_key ins;
401 find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1, 0,
403 path = btrfs_alloc_path();
405 key.objectid = blocknr;
407 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
408 key.offset = num_blocks;
409 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
415 l = btrfs_buffer_leaf(path->nodes[0]);
416 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
417 refs = btrfs_extent_refs(item);
418 btrfs_set_extent_refs(item, refs + 1);
419 btrfs_mark_buffer_dirty(path->nodes[0]);
421 btrfs_release_path(root->fs_info->extent_root, path);
422 btrfs_free_path(path);
423 finish_current_insert(trans, root->fs_info->extent_root);
424 del_pending_extents(trans, root->fs_info->extent_root);
428 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
429 struct btrfs_root *root, u64 blocknr,
430 u64 num_blocks, u32 *refs)
432 struct btrfs_path *path;
434 struct btrfs_key key;
435 struct btrfs_leaf *l;
436 struct btrfs_extent_item *item;
438 path = btrfs_alloc_path();
439 key.objectid = blocknr;
440 key.offset = num_blocks;
442 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
443 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
447 l = btrfs_buffer_leaf(path->nodes[0]);
448 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
449 *refs = btrfs_extent_refs(item);
450 btrfs_release_path(root->fs_info->extent_root, path);
451 btrfs_free_path(path);
455 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
456 struct btrfs_root *root)
458 return btrfs_inc_extent_ref(trans, root, bh_blocknr(root->node), 1);
461 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
462 struct buffer_head *buf)
465 struct btrfs_node *buf_node;
466 struct btrfs_leaf *buf_leaf;
467 struct btrfs_disk_key *key;
468 struct btrfs_file_extent_item *fi;
475 buf_node = btrfs_buffer_node(buf);
476 leaf = btrfs_is_leaf(buf_node);
477 buf_leaf = btrfs_buffer_leaf(buf);
478 for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) {
481 key = &buf_leaf->items[i].key;
482 if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
484 fi = btrfs_item_ptr(buf_leaf, i,
485 struct btrfs_file_extent_item);
486 if (btrfs_file_extent_type(fi) ==
487 BTRFS_FILE_EXTENT_INLINE)
489 disk_blocknr = btrfs_file_extent_disk_blocknr(fi);
490 if (disk_blocknr == 0)
492 ret = btrfs_inc_extent_ref(trans, root, disk_blocknr,
493 btrfs_file_extent_disk_num_blocks(fi));
496 blocknr = btrfs_node_blockptr(buf_node, i);
497 ret = btrfs_inc_extent_ref(trans, root, blocknr, 1);
504 static int write_one_cache_group(struct btrfs_trans_handle *trans,
505 struct btrfs_root *root,
506 struct btrfs_path *path,
507 struct btrfs_block_group_cache *cache)
511 struct btrfs_root *extent_root = root->fs_info->extent_root;
512 struct btrfs_block_group_item *bi;
513 struct btrfs_key ins;
515 find_free_extent(trans, extent_root, 0, 0, (u64)-1, 0, &ins, 0);
516 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
518 bi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
519 struct btrfs_block_group_item);
520 memcpy(bi, &cache->item, sizeof(*bi));
521 mark_buffer_dirty(path->nodes[0]);
522 btrfs_release_path(extent_root, path);
524 finish_current_insert(trans, extent_root);
525 pending_ret = del_pending_extents(trans, extent_root);
531 cache->last_alloc = cache->first_free;
536 static int write_dirty_block_radix(struct btrfs_trans_handle *trans,
537 struct btrfs_root *root,
538 struct radix_tree_root *radix)
540 struct btrfs_block_group_cache *cache[8];
545 struct btrfs_path *path;
547 path = btrfs_alloc_path();
552 ret = radix_tree_gang_lookup_tag(radix, (void **)cache,
553 0, ARRAY_SIZE(cache),
554 BTRFS_BLOCK_GROUP_DIRTY);
557 for (i = 0; i < ret; i++) {
558 radix_tree_tag_clear(radix, cache[i]->key.objectid +
559 cache[i]->key.offset - 1,
560 BTRFS_BLOCK_GROUP_DIRTY);
561 err = write_one_cache_group(trans, root,
567 btrfs_free_path(path);
571 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
572 struct btrfs_root *root)
576 ret = write_dirty_block_radix(trans, root,
577 &root->fs_info->block_group_radix);
578 ret2 = write_dirty_block_radix(trans, root,
579 &root->fs_info->block_group_data_radix);
587 static int update_block_group(struct btrfs_trans_handle *trans,
588 struct btrfs_root *root,
589 u64 blocknr, u64 num, int alloc, int mark_free,
592 struct btrfs_block_group_cache *cache;
593 struct btrfs_fs_info *info = root->fs_info;
601 cache = btrfs_lookup_block_group(info, blocknr);
605 block_in_group = blocknr - cache->key.objectid;
606 WARN_ON(block_in_group > cache->key.offset);
607 radix_tree_tag_set(cache->radix, cache->key.objectid +
608 cache->key.offset - 1,
609 BTRFS_BLOCK_GROUP_DIRTY);
611 old_val = btrfs_block_group_used(&cache->item);
612 num = min(total, cache->key.offset - block_in_group);
614 if (blocknr > cache->last_alloc)
615 cache->last_alloc = blocknr;
617 for (i = 0; i < num; i++) {
618 clear_radix_bit(&info->extent_map_radix,
622 if (cache->data != data &&
623 old_val < (cache->key.offset >> 1)) {
625 radix_tree_delete(cache->radix,
626 cache->key.objectid +
627 cache->key.offset - 1);
631 &info->block_group_data_radix;
633 BTRFS_BLOCK_GROUP_DATA;
635 cache->radix = &info->block_group_radix;
637 ~BTRFS_BLOCK_GROUP_DATA;
639 ret = radix_tree_insert(cache->radix,
640 cache->key.objectid +
641 cache->key.offset - 1,
647 if (blocknr < cache->first_free)
648 cache->first_free = blocknr;
649 if (!cache->data && mark_free) {
650 for (i = 0; i < num; i++) {
651 set_radix_bit(&info->extent_map_radix,
655 if (old_val < (cache->key.offset >> 1) &&
656 old_val + num >= (cache->key.offset >> 1)) {
657 radix_tree_tag_set(cache->radix,
658 cache->key.objectid +
659 cache->key.offset - 1,
660 BTRFS_BLOCK_GROUP_AVAIL);
663 btrfs_set_block_group_used(&cache->item, old_val);
670 static int try_remove_page(struct address_space *mapping, unsigned long index)
673 ret = invalidate_mapping_pages(mapping, index, index);
677 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
680 unsigned long gang[8];
681 struct inode *btree_inode = root->fs_info->btree_inode;
682 struct btrfs_block_group_cache *block_group;
686 struct radix_tree_root *pinned_radix = &root->fs_info->pinned_radix;
687 struct radix_tree_root *extent_radix = &root->fs_info->extent_map_radix;
690 ret = find_first_radix_bit(pinned_radix, gang, 0,
696 for (i = 0; i < ret; i++) {
697 clear_radix_bit(pinned_radix, gang[i]);
698 block_group = btrfs_lookup_block_group(root->fs_info,
701 WARN_ON(block_group->pinned == 0);
702 block_group->pinned--;
703 if (gang[i] < block_group->last_alloc)
704 block_group->last_alloc = gang[i];
705 if (gang[i] < block_group->last_prealloc)
706 block_group->last_prealloc = gang[i];
707 if (!block_group->data)
708 set_radix_bit(extent_radix, gang[i]);
710 try_remove_page(btree_inode->i_mapping,
711 gang[i] << (PAGE_CACHE_SHIFT -
712 btree_inode->i_blkbits));
718 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
719 btrfs_root *extent_root)
721 struct btrfs_key ins;
722 struct btrfs_extent_item extent_item;
725 u64 super_blocks_used;
726 struct btrfs_fs_info *info = extent_root->fs_info;
728 btrfs_set_extent_refs(&extent_item, 1);
731 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
732 btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
734 for (i = 0; i < extent_root->fs_info->extent_tree_insert_nr; i++) {
735 ins.objectid = extent_root->fs_info->extent_tree_insert[i];
736 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
737 btrfs_set_super_blocks_used(info->disk_super,
738 super_blocks_used + 1);
739 ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
740 sizeof(extent_item));
743 extent_root->fs_info->extent_tree_insert_nr = 0;
744 extent_root->fs_info->extent_tree_prealloc_nr = 0;
748 static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending)
751 struct btrfs_header *header;
752 struct buffer_head *bh;
755 bh = btrfs_find_tree_block(root, blocknr);
757 if (buffer_uptodate(bh)) {
759 root->fs_info->running_transaction->transid;
760 header = btrfs_buffer_header(bh);
761 if (btrfs_header_generation(header) ==
763 btrfs_block_release(root, bh);
767 btrfs_block_release(root, bh);
769 err = set_radix_bit(&root->fs_info->pinned_radix, blocknr);
771 struct btrfs_block_group_cache *cache;
772 cache = btrfs_lookup_block_group(root->fs_info,
778 err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr);
785 * remove an extent from the root, returns 0 on success
787 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
788 *root, u64 blocknr, u64 num_blocks, int pin,
791 struct btrfs_path *path;
792 struct btrfs_key key;
793 struct btrfs_fs_info *info = root->fs_info;
794 struct btrfs_root *extent_root = info->extent_root;
796 struct btrfs_extent_item *ei;
797 struct btrfs_key ins;
800 key.objectid = blocknr;
802 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
803 key.offset = num_blocks;
805 find_free_extent(trans, root, 0, 0, (u64)-1, 0, &ins, 0);
806 path = btrfs_alloc_path();
809 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
813 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
814 struct btrfs_extent_item);
815 BUG_ON(ei->refs == 0);
816 refs = btrfs_extent_refs(ei) - 1;
817 btrfs_set_extent_refs(ei, refs);
818 btrfs_mark_buffer_dirty(path->nodes[0]);
820 u64 super_blocks_used;
823 ret = pin_down_block(root, blocknr, 0);
827 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
828 btrfs_set_super_blocks_used(info->disk_super,
829 super_blocks_used - num_blocks);
830 ret = btrfs_del_item(trans, extent_root, path);
833 ret = update_block_group(trans, root, blocknr, num_blocks, 0,
837 btrfs_free_path(path);
838 finish_current_insert(trans, extent_root);
843 * find all the blocks marked as pending in the radix tree and remove
844 * them from the extent map
846 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
847 btrfs_root *extent_root)
852 unsigned long gang[4];
854 struct radix_tree_root *pending_radix;
855 struct radix_tree_root *pinned_radix;
856 struct btrfs_block_group_cache *cache;
858 pending_radix = &extent_root->fs_info->pending_del_radix;
859 pinned_radix = &extent_root->fs_info->pinned_radix;
862 ret = find_first_radix_bit(pending_radix, gang, 0,
866 for (i = 0; i < ret; i++) {
867 wret = set_radix_bit(pinned_radix, gang[i]);
870 btrfs_lookup_block_group(extent_root->fs_info,
876 printk(KERN_CRIT "set_radix_bit, err %d\n",
880 wret = clear_radix_bit(pending_radix, gang[i]);
882 wret = __free_extent(trans, extent_root,
892 * remove an extent from the root, returns 0 on success
894 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
895 *root, u64 blocknr, u64 num_blocks, int pin)
897 struct btrfs_root *extent_root = root->fs_info->extent_root;
901 if (root == extent_root) {
902 pin_down_block(root, blocknr, 1);
905 ret = __free_extent(trans, root, blocknr, num_blocks, pin, pin == 0);
906 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
907 return ret ? ret : pending_ret;
911 * walks the btree of allocated extents and find a hole of a given size.
912 * The key ins is changed to record the hole:
913 * ins->objectid == block start
914 * ins->flags = BTRFS_EXTENT_ITEM_KEY
915 * ins->offset == number of blocks
916 * Any available blocks before search_start are skipped.
918 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
919 *orig_root, u64 num_blocks, u64 search_start, u64
920 search_end, u64 hint_block,
921 struct btrfs_key *ins, int data)
923 struct btrfs_path *path;
924 struct btrfs_key key;
930 u64 orig_search_start = search_start;
932 struct btrfs_leaf *l;
933 struct btrfs_root * root = orig_root->fs_info->extent_root;
934 struct btrfs_fs_info *info = root->fs_info;
935 int total_needed = num_blocks;
937 int fill_prealloc = 0;
939 struct btrfs_block_group_cache *block_group;
944 path = btrfs_alloc_path();
946 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
948 level = btrfs_header_level(btrfs_buffer_header(root->node));
949 if (num_blocks == 0) {
952 total_needed = (min(level + 1, BTRFS_MAX_LEVEL) + 2) * 3;
954 if (search_end == (u64)-1)
955 search_end = btrfs_super_total_blocks(info->disk_super);
957 block_group = btrfs_lookup_block_group(info, hint_block);
958 block_group = btrfs_find_block_group(root, block_group,
959 hint_block, data, 1);
961 block_group = btrfs_find_block_group(root,
962 trans->block_group, 0,
967 if (!block_group->data)
968 search_start = find_search_start(root, &block_group,
969 search_start, total_needed);
971 search_start = max(block_group->last_alloc, search_start);
973 btrfs_init_path(path);
974 ins->objectid = search_start;
978 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
982 if (path->slots[0] > 0) {
986 l = btrfs_buffer_leaf(path->nodes[0]);
987 btrfs_disk_key_to_cpu(&key, &l->items[path->slots[0]].key);
989 * a rare case, go back one key if we hit a block group item
990 * instead of an extent item
992 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY &&
993 key.objectid + key.offset >= search_start) {
994 ins->objectid = key.objectid;
995 ins->offset = key.offset - 1;
996 btrfs_release_path(root, path);
997 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
1001 if (path->slots[0] > 0) {
1007 l = btrfs_buffer_leaf(path->nodes[0]);
1008 slot = path->slots[0];
1009 if (slot >= btrfs_header_nritems(&l->header)) {
1010 if (fill_prealloc) {
1011 info->extent_tree_prealloc_nr = 0;
1015 limit = last_block +
1016 (block_group->key.offset >> 1);
1018 limit = search_start +
1019 (block_group->key.offset >> 1);
1020 ret = btrfs_next_leaf(root, path);
1026 ins->objectid = search_start;
1027 ins->offset = search_end - search_start;
1031 ins->objectid = last_block > search_start ?
1032 last_block : search_start;
1033 ins->offset = search_end - ins->objectid;
1037 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
1038 if (key.objectid >= search_start && key.objectid > last_block &&
1040 if (last_block < search_start)
1041 last_block = search_start;
1042 hole_size = key.objectid - last_block;
1043 if (hole_size >= num_blocks) {
1044 ins->objectid = last_block;
1045 ins->offset = hole_size;
1050 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
1054 last_block = key.objectid + key.offset;
1055 if (!full_scan && last_block >= block_group->key.objectid +
1056 block_group->key.offset) {
1057 btrfs_release_path(root, path);
1058 search_start = block_group->key.objectid +
1059 block_group->key.offset * 2;
1068 /* we have to make sure we didn't find an extent that has already
1069 * been allocated by the map tree or the original allocation
1071 btrfs_release_path(root, path);
1072 BUG_ON(ins->objectid < search_start);
1074 if (ins->objectid + num_blocks >= search_end) {
1079 search_start = orig_search_start;
1086 for (test_block = ins->objectid;
1087 test_block < ins->objectid + num_blocks; test_block++) {
1088 if (test_radix_bit(&info->pinned_radix, test_block)) {
1089 search_start = test_block + 1;
1093 if (!fill_prealloc && info->extent_tree_insert_nr) {
1095 info->extent_tree_insert[info->extent_tree_insert_nr - 1];
1096 if (ins->objectid + num_blocks >
1097 info->extent_tree_insert[0] &&
1098 ins->objectid <= last) {
1099 search_start = last + 1;
1100 WARN_ON(!full_scan);
1104 if (!fill_prealloc && info->extent_tree_prealloc_nr) {
1106 info->extent_tree_prealloc[info->extent_tree_prealloc_nr - 1];
1107 if (ins->objectid + num_blocks > first &&
1108 ins->objectid <= info->extent_tree_prealloc[0]) {
1109 search_start = info->extent_tree_prealloc[0] + 1;
1110 WARN_ON(!full_scan);
1114 if (fill_prealloc) {
1116 test_block = ins->objectid;
1117 if (test_block - info->extent_tree_prealloc[total_needed - 1] >=
1120 info->extent_tree_prealloc_nr = total_found;
1122 while(test_block < ins->objectid + ins->offset &&
1123 total_found < total_needed) {
1124 nr = total_needed - total_found - 1;
1126 info->extent_tree_prealloc[nr] = test_block;
1130 if (total_found < total_needed) {
1131 search_start = test_block;
1134 info->extent_tree_prealloc_nr = total_found;
1137 block_group = btrfs_lookup_block_group(info, ins->objectid);
1140 block_group->last_prealloc =
1141 info->extent_tree_prealloc[total_needed-1];
1143 trans->block_group = block_group;
1146 ins->offset = num_blocks;
1147 btrfs_free_path(path);
1151 if (search_start + num_blocks >= search_end) {
1152 search_start = orig_search_start;
1162 block_group = btrfs_lookup_block_group(info, search_start);
1165 block_group = btrfs_find_block_group(root, block_group,
1166 search_start, data, 0);
1170 btrfs_release_path(root, path);
1171 btrfs_free_path(path);
1175 * finds a free extent and does all the dirty work required for allocation
1176 * returns the key for the extent through ins, and a tree buffer for
1177 * the first block of the extent through buf.
1179 * returns 0 if everything worked, non-zero otherwise.
1181 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1182 struct btrfs_root *root, u64 owner,
1183 u64 num_blocks, u64 hint_block,
1184 u64 search_end, struct btrfs_key *ins, int data)
1188 u64 super_blocks_used;
1189 u64 search_start = 0;
1190 struct btrfs_fs_info *info = root->fs_info;
1191 struct btrfs_root *extent_root = info->extent_root;
1192 struct btrfs_extent_item extent_item;
1193 struct btrfs_key prealloc_key;
1195 btrfs_set_extent_refs(&extent_item, 1);
1196 btrfs_set_extent_owner(&extent_item, owner);
1198 if (root == extent_root) {
1200 BUG_ON(info->extent_tree_prealloc_nr == 0);
1201 BUG_ON(num_blocks != 1);
1203 info->extent_tree_prealloc_nr--;
1204 nr = info->extent_tree_prealloc_nr;
1205 ins->objectid = info->extent_tree_prealloc[nr];
1206 info->extent_tree_insert[info->extent_tree_insert_nr++] =
1208 ret = update_block_group(trans, root,
1209 ins->objectid, ins->offset, 1, 0, 0);
1215 * if we're doing a data allocation, preallocate room in the
1216 * extent tree first. This way the extent tree blocks end up
1217 * in the correct block group.
1220 ret = find_free_extent(trans, root, 0, 0,
1221 search_end, 0, &prealloc_key, 0);
1225 if (prealloc_key.objectid + prealloc_key.offset >= search_end) {
1226 int nr = info->extent_tree_prealloc_nr;
1227 search_end = info->extent_tree_prealloc[nr - 1] - 1;
1229 search_start = info->extent_tree_prealloc[0] + 1;
1232 if (hint_block < search_start)
1233 hint_block = search_start;
1234 /* do the real allocation */
1235 ret = find_free_extent(trans, root, num_blocks, search_start,
1236 search_end, hint_block, ins, data);
1242 * if we're doing a metadata allocation, preallocate space in the
1243 * extent tree second. This way, we don't create a tiny hole
1244 * in the allocation map between any unused preallocation blocks
1245 * and the metadata block we're actually allocating. On disk,
1247 * [block we've allocated], [used prealloc 1], [ unused prealloc ]
1248 * The unused prealloc will get reused the next time around.
1251 if (ins->objectid + ins->offset >= search_end)
1252 search_end = ins->objectid - 1;
1254 search_start = ins->objectid + ins->offset;
1256 if (hint_block < search_start)
1257 hint_block = search_start;
1259 ret = find_free_extent(trans, root, 0, search_start,
1260 search_end, hint_block,
1267 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
1268 btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
1270 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
1271 sizeof(extent_item));
1273 finish_current_insert(trans, extent_root);
1274 pending_ret = del_pending_extents(trans, extent_root);
1281 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
1288 * helper function to allocate a block for a given tree
1289 * returns the tree buffer or NULL.
1291 struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1292 struct btrfs_root *root, u64 hint)
1294 struct btrfs_key ins;
1296 struct buffer_head *buf;
1298 ret = btrfs_alloc_extent(trans, root, root->root_key.objectid,
1299 1, hint, (unsigned long)-1, &ins, 0);
1305 buf = btrfs_find_create_tree_block(root, ins.objectid);
1306 set_buffer_uptodate(buf);
1307 set_buffer_checked(buf);
1308 set_radix_bit(&trans->transaction->dirty_pages, buf->b_page->index);
1312 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
1313 struct btrfs_root *root, struct buffer_head *cur)
1315 struct btrfs_disk_key *key;
1316 struct btrfs_leaf *leaf;
1317 struct btrfs_file_extent_item *fi;
1322 BUG_ON(!btrfs_is_leaf(btrfs_buffer_node(cur)));
1323 leaf = btrfs_buffer_leaf(cur);
1324 nritems = btrfs_header_nritems(&leaf->header);
1325 for (i = 0; i < nritems; i++) {
1327 key = &leaf->items[i].key;
1328 if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
1330 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1331 if (btrfs_file_extent_type(fi) == BTRFS_FILE_EXTENT_INLINE)
1334 * FIXME make sure to insert a trans record that
1335 * repeats the snapshot del on crash
1337 disk_blocknr = btrfs_file_extent_disk_blocknr(fi);
1338 if (disk_blocknr == 0)
1340 ret = btrfs_free_extent(trans, root, disk_blocknr,
1341 btrfs_file_extent_disk_num_blocks(fi),
1349 * helper function for drop_snapshot, this walks down the tree dropping ref
1350 * counts as it goes.
1352 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1353 *root, struct btrfs_path *path, int *level)
1355 struct buffer_head *next;
1356 struct buffer_head *cur;
1361 WARN_ON(*level < 0);
1362 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1363 ret = lookup_extent_ref(trans, root, bh_blocknr(path->nodes[*level]),
1369 * walk down to the last node level and free all the leaves
1371 while(*level >= 0) {
1372 WARN_ON(*level < 0);
1373 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1374 cur = path->nodes[*level];
1375 if (btrfs_header_level(btrfs_buffer_header(cur)) != *level)
1377 if (path->slots[*level] >=
1378 btrfs_header_nritems(btrfs_buffer_header(cur)))
1381 ret = drop_leaf_ref(trans, root, cur);
1385 blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur),
1386 path->slots[*level]);
1387 ret = lookup_extent_ref(trans, root, blocknr, 1, &refs);
1390 path->slots[*level]++;
1391 ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
1395 next = read_tree_block(root, blocknr);
1396 WARN_ON(*level <= 0);
1397 if (path->nodes[*level-1])
1398 btrfs_block_release(root, path->nodes[*level-1]);
1399 path->nodes[*level-1] = next;
1400 *level = btrfs_header_level(btrfs_buffer_header(next));
1401 path->slots[*level] = 0;
1404 WARN_ON(*level < 0);
1405 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1406 ret = btrfs_free_extent(trans, root,
1407 bh_blocknr(path->nodes[*level]), 1, 1);
1408 btrfs_block_release(root, path->nodes[*level]);
1409 path->nodes[*level] = NULL;
1416 * helper for dropping snapshots. This walks back up the tree in the path
1417 * to find the first node higher up where we haven't yet gone through
1420 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1421 *root, struct btrfs_path *path, int *level)
1426 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1427 slot = path->slots[i];
1428 if (slot < btrfs_header_nritems(
1429 btrfs_buffer_header(path->nodes[i])) - 1) {
1434 ret = btrfs_free_extent(trans, root,
1435 bh_blocknr(path->nodes[*level]),
1438 btrfs_block_release(root, path->nodes[*level]);
1439 path->nodes[*level] = NULL;
1447 * drop the reference count on the tree rooted at 'snap'. This traverses
1448 * the tree freeing any blocks that have a ref count of zero after being
1451 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
1452 *root, struct buffer_head *snap)
1457 struct btrfs_path *path;
1461 path = btrfs_alloc_path();
1464 level = btrfs_header_level(btrfs_buffer_header(snap));
1466 path->nodes[level] = snap;
1467 path->slots[level] = 0;
1469 wret = walk_down_tree(trans, root, path, &level);
1475 wret = walk_up_tree(trans, root, path, &level);
1480 btrfs_btree_balance_dirty(root);
1482 for (i = 0; i <= orig_level; i++) {
1483 if (path->nodes[i]) {
1484 btrfs_block_release(root, path->nodes[i]);
1487 btrfs_free_path(path);
1491 static int free_block_group_radix(struct radix_tree_root *radix)
1494 struct btrfs_block_group_cache *cache[8];
1498 ret = radix_tree_gang_lookup(radix, (void **)cache, 0,
1502 for (i = 0; i < ret; i++) {
1503 radix_tree_delete(radix, cache[i]->key.objectid +
1504 cache[i]->key.offset - 1);
1511 int btrfs_free_block_groups(struct btrfs_fs_info *info)
1515 unsigned long gang[16];
1518 ret = free_block_group_radix(&info->block_group_radix);
1519 ret2 = free_block_group_radix(&info->block_group_data_radix);
1526 ret = find_first_radix_bit(&info->extent_map_radix,
1527 gang, 0, ARRAY_SIZE(gang));
1530 for (i = 0; i < ret; i++) {
1531 clear_radix_bit(&info->extent_map_radix, gang[i]);
1537 int btrfs_read_block_groups(struct btrfs_root *root)
1539 struct btrfs_path *path;
1542 struct btrfs_block_group_item *bi;
1543 struct btrfs_block_group_cache *cache;
1544 struct btrfs_fs_info *info = root->fs_info;
1545 struct radix_tree_root *radix;
1546 struct btrfs_key key;
1547 struct btrfs_key found_key;
1548 struct btrfs_leaf *leaf;
1549 u64 group_size_blocks;
1552 group_size_blocks = BTRFS_BLOCK_GROUP_SIZE >>
1553 root->fs_info->sb->s_blocksize_bits;
1554 root = info->extent_root;
1556 key.offset = group_size_blocks;
1558 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
1560 path = btrfs_alloc_path();
1565 ret = btrfs_search_slot(NULL, info->extent_root,
1571 leaf = btrfs_buffer_leaf(path->nodes[0]);
1572 btrfs_disk_key_to_cpu(&found_key,
1573 &leaf->items[path->slots[0]].key);
1574 cache = kmalloc(sizeof(*cache), GFP_NOFS);
1580 bi = btrfs_item_ptr(leaf, path->slots[0],
1581 struct btrfs_block_group_item);
1582 if (bi->flags & BTRFS_BLOCK_GROUP_DATA) {
1583 radix = &info->block_group_data_radix;
1586 radix = &info->block_group_radix;
1590 memcpy(&cache->item, bi, sizeof(*bi));
1591 memcpy(&cache->key, &found_key, sizeof(found_key));
1592 cache->last_alloc = cache->key.objectid;
1593 cache->first_free = cache->key.objectid;
1594 cache->last_prealloc = cache->key.objectid;
1598 cache->radix = radix;
1600 key.objectid = found_key.objectid + found_key.offset;
1601 btrfs_release_path(root, path);
1602 ret = radix_tree_insert(radix, found_key.objectid +
1603 found_key.offset - 1,
1606 used = btrfs_block_group_used(bi);
1607 if (used < div_factor(key.offset, 8)) {
1608 radix_tree_tag_set(radix, found_key.objectid +
1609 found_key.offset - 1,
1610 BTRFS_BLOCK_GROUP_AVAIL);
1613 btrfs_super_total_blocks(info->disk_super))
1617 btrfs_free_path(path);