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;
747 static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending)
750 struct btrfs_header *header;
751 struct buffer_head *bh;
754 bh = btrfs_find_tree_block(root, blocknr);
756 if (buffer_uptodate(bh)) {
758 root->fs_info->running_transaction->transid;
759 header = btrfs_buffer_header(bh);
760 if (btrfs_header_generation(header) ==
762 btrfs_block_release(root, bh);
766 btrfs_block_release(root, bh);
768 err = set_radix_bit(&root->fs_info->pinned_radix, blocknr);
770 struct btrfs_block_group_cache *cache;
771 cache = btrfs_lookup_block_group(root->fs_info,
777 err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr);
784 * remove an extent from the root, returns 0 on success
786 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
787 *root, u64 blocknr, u64 num_blocks, int pin,
790 struct btrfs_path *path;
791 struct btrfs_key key;
792 struct btrfs_fs_info *info = root->fs_info;
793 struct btrfs_root *extent_root = info->extent_root;
795 struct btrfs_extent_item *ei;
796 struct btrfs_key ins;
799 key.objectid = blocknr;
801 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
802 key.offset = num_blocks;
804 find_free_extent(trans, root, 0, 0, (u64)-1, 0, &ins, 0);
805 path = btrfs_alloc_path();
808 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
812 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
813 struct btrfs_extent_item);
814 BUG_ON(ei->refs == 0);
815 refs = btrfs_extent_refs(ei) - 1;
816 btrfs_set_extent_refs(ei, refs);
817 btrfs_mark_buffer_dirty(path->nodes[0]);
819 u64 super_blocks_used;
822 ret = pin_down_block(root, blocknr, 0);
826 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
827 btrfs_set_super_blocks_used(info->disk_super,
828 super_blocks_used - num_blocks);
829 ret = btrfs_del_item(trans, extent_root, path);
832 ret = update_block_group(trans, root, blocknr, num_blocks, 0,
836 btrfs_free_path(path);
837 finish_current_insert(trans, extent_root);
842 * find all the blocks marked as pending in the radix tree and remove
843 * them from the extent map
845 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
846 btrfs_root *extent_root)
851 unsigned long gang[4];
853 struct radix_tree_root *pending_radix;
854 struct radix_tree_root *pinned_radix;
855 struct btrfs_block_group_cache *cache;
857 pending_radix = &extent_root->fs_info->pending_del_radix;
858 pinned_radix = &extent_root->fs_info->pinned_radix;
861 ret = find_first_radix_bit(pending_radix, gang, 0,
865 for (i = 0; i < ret; i++) {
866 wret = set_radix_bit(pinned_radix, gang[i]);
869 btrfs_lookup_block_group(extent_root->fs_info,
875 printk(KERN_CRIT "set_radix_bit, err %d\n",
879 wret = clear_radix_bit(pending_radix, gang[i]);
881 wret = __free_extent(trans, extent_root,
891 * remove an extent from the root, returns 0 on success
893 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
894 *root, u64 blocknr, u64 num_blocks, int pin)
896 struct btrfs_root *extent_root = root->fs_info->extent_root;
900 if (root == extent_root) {
901 pin_down_block(root, blocknr, 1);
904 ret = __free_extent(trans, root, blocknr, num_blocks, pin, pin == 0);
905 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
906 return ret ? ret : pending_ret;
910 * walks the btree of allocated extents and find a hole of a given size.
911 * The key ins is changed to record the hole:
912 * ins->objectid == block start
913 * ins->flags = BTRFS_EXTENT_ITEM_KEY
914 * ins->offset == number of blocks
915 * Any available blocks before search_start are skipped.
917 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
918 *orig_root, u64 num_blocks, u64 search_start, u64
919 search_end, u64 hint_block,
920 struct btrfs_key *ins, int data)
922 struct btrfs_path *path;
923 struct btrfs_key key;
929 u64 orig_search_start = search_start;
931 struct btrfs_leaf *l;
932 struct btrfs_root * root = orig_root->fs_info->extent_root;
933 struct btrfs_fs_info *info = root->fs_info;
934 int total_needed = num_blocks;
936 int fill_prealloc = 0;
938 struct btrfs_block_group_cache *block_group;
944 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
946 level = btrfs_header_level(btrfs_buffer_header(root->node));
947 if (num_blocks == 0) {
950 total_needed = (min(level + 1, BTRFS_MAX_LEVEL) + 2) * 3;
954 int nr = info->extent_tree_prealloc_nr;
955 first = info->extent_tree_prealloc[nr - 1];
956 if (info->extent_tree_prealloc_nr >= total_needed &&
957 first >= search_start) {
958 ins->objectid = info->extent_tree_prealloc[0];
962 info->extent_tree_prealloc_nr = 0;
964 if (search_end == (u64)-1)
965 search_end = btrfs_super_total_blocks(info->disk_super);
967 block_group = btrfs_lookup_block_group(info, hint_block);
968 block_group = btrfs_find_block_group(root, block_group,
969 hint_block, data, 1);
971 block_group = btrfs_find_block_group(root,
972 trans->block_group, 0,
976 path = btrfs_alloc_path();
979 if (!block_group->data)
980 search_start = find_search_start(root, &block_group,
981 search_start, total_needed);
983 search_start = max(block_group->last_alloc, search_start);
985 btrfs_init_path(path);
986 ins->objectid = search_start;
990 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
994 if (path->slots[0] > 0) {
998 l = btrfs_buffer_leaf(path->nodes[0]);
999 btrfs_disk_key_to_cpu(&key, &l->items[path->slots[0]].key);
1001 * a rare case, go back one key if we hit a block group item
1002 * instead of an extent item
1004 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY &&
1005 key.objectid + key.offset >= search_start) {
1006 ins->objectid = key.objectid;
1007 ins->offset = key.offset - 1;
1008 btrfs_release_path(root, path);
1009 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
1013 if (path->slots[0] > 0) {
1019 l = btrfs_buffer_leaf(path->nodes[0]);
1020 slot = path->slots[0];
1021 if (slot >= btrfs_header_nritems(&l->header)) {
1022 if (fill_prealloc) {
1023 info->extent_tree_prealloc_nr = 0;
1027 limit = last_block +
1028 (block_group->key.offset >> 1);
1030 limit = search_start +
1031 (block_group->key.offset >> 1);
1032 ret = btrfs_next_leaf(root, path);
1038 ins->objectid = search_start;
1039 ins->offset = search_end - search_start;
1043 ins->objectid = last_block > search_start ?
1044 last_block : search_start;
1045 ins->offset = search_end - ins->objectid;
1049 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
1050 if (key.objectid >= search_start && key.objectid > last_block &&
1052 if (last_block < search_start)
1053 last_block = search_start;
1054 hole_size = key.objectid - last_block;
1055 if (hole_size >= num_blocks) {
1056 ins->objectid = last_block;
1057 ins->offset = hole_size;
1062 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
1066 last_block = key.objectid + key.offset;
1067 if (!full_scan && last_block >= block_group->key.objectid +
1068 block_group->key.offset) {
1069 btrfs_release_path(root, path);
1070 search_start = block_group->key.objectid +
1071 block_group->key.offset * 2;
1080 /* we have to make sure we didn't find an extent that has already
1081 * been allocated by the map tree or the original allocation
1083 btrfs_release_path(root, path);
1084 BUG_ON(ins->objectid < search_start);
1086 if (ins->objectid + num_blocks >= search_end) {
1091 search_start = orig_search_start;
1098 for (test_block = ins->objectid;
1099 test_block < ins->objectid + num_blocks; test_block++) {
1100 if (test_radix_bit(&info->pinned_radix, test_block)) {
1101 search_start = test_block + 1;
1105 if (!fill_prealloc && info->extent_tree_insert_nr) {
1107 info->extent_tree_insert[info->extent_tree_insert_nr - 1];
1108 if (ins->objectid + num_blocks >
1109 info->extent_tree_insert[0] &&
1110 ins->objectid <= last) {
1111 search_start = last + 1;
1112 WARN_ON(!full_scan);
1116 if (!fill_prealloc && info->extent_tree_prealloc_nr) {
1118 info->extent_tree_prealloc[info->extent_tree_prealloc_nr - 1];
1119 if (ins->objectid + num_blocks > first &&
1120 ins->objectid <= info->extent_tree_prealloc[0]) {
1121 search_start = info->extent_tree_prealloc[0] + 1;
1125 if (fill_prealloc) {
1127 test_block = ins->objectid;
1128 if (test_block - info->extent_tree_prealloc[total_needed - 1] >=
1131 info->extent_tree_prealloc_nr = total_found;
1133 while(test_block < ins->objectid + ins->offset &&
1134 total_found < total_needed) {
1135 nr = total_needed - total_found - 1;
1137 info->extent_tree_prealloc[nr] = test_block;
1141 if (total_found < total_needed) {
1142 search_start = test_block;
1145 info->extent_tree_prealloc_nr = total_found;
1148 block_group = btrfs_lookup_block_group(info, ins->objectid);
1151 block_group->last_prealloc =
1152 info->extent_tree_prealloc[total_needed-1];
1154 trans->block_group = block_group;
1157 ins->offset = num_blocks;
1158 btrfs_free_path(path);
1162 if (search_start + num_blocks >= search_end) {
1163 search_start = orig_search_start;
1173 block_group = btrfs_lookup_block_group(info, search_start);
1176 block_group = btrfs_find_block_group(root, block_group,
1177 search_start, data, 0);
1181 btrfs_release_path(root, path);
1182 btrfs_free_path(path);
1186 * finds a free extent and does all the dirty work required for allocation
1187 * returns the key for the extent through ins, and a tree buffer for
1188 * the first block of the extent through buf.
1190 * returns 0 if everything worked, non-zero otherwise.
1192 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1193 struct btrfs_root *root, u64 owner,
1194 u64 num_blocks, u64 hint_block,
1195 u64 search_end, struct btrfs_key *ins, int data)
1199 u64 super_blocks_used;
1200 u64 search_start = 0;
1201 struct btrfs_fs_info *info = root->fs_info;
1202 struct btrfs_root *extent_root = info->extent_root;
1203 struct btrfs_extent_item extent_item;
1204 struct btrfs_key prealloc_key;
1206 btrfs_set_extent_refs(&extent_item, 1);
1207 btrfs_set_extent_owner(&extent_item, owner);
1209 if (root == extent_root) {
1211 BUG_ON(info->extent_tree_prealloc_nr == 0);
1212 BUG_ON(num_blocks != 1);
1214 info->extent_tree_prealloc_nr--;
1215 nr = info->extent_tree_prealloc_nr;
1216 ins->objectid = info->extent_tree_prealloc[nr];
1217 info->extent_tree_insert[info->extent_tree_insert_nr++] =
1219 ret = update_block_group(trans, root,
1220 ins->objectid, ins->offset, 1, 0, 0);
1226 * if we're doing a data allocation, preallocate room in the
1227 * extent tree first. This way the extent tree blocks end up
1228 * in the correct block group.
1231 ret = find_free_extent(trans, root, 0, 0,
1232 search_end, 0, &prealloc_key, 0);
1236 if (prealloc_key.objectid + prealloc_key.offset >= search_end) {
1237 int nr = info->extent_tree_prealloc_nr;
1238 search_end = info->extent_tree_prealloc[nr - 1] - 1;
1240 search_start = info->extent_tree_prealloc[0] + 1;
1243 if (hint_block < search_start)
1244 hint_block = search_start;
1245 /* do the real allocation */
1246 ret = find_free_extent(trans, root, num_blocks, search_start,
1247 search_end, hint_block, ins, data);
1253 * if we're doing a metadata allocation, preallocate space in the
1254 * extent tree second. This way, we don't create a tiny hole
1255 * in the allocation map between any unused preallocation blocks
1256 * and the metadata block we're actually allocating. On disk,
1258 * [block we've allocated], [used prealloc 1], [ unused prealloc ]
1259 * The unused prealloc will get reused the next time around.
1262 if (ins->objectid + ins->offset >= search_end)
1263 search_end = ins->objectid - 1;
1265 search_start = ins->objectid + ins->offset;
1267 if (hint_block < search_start)
1268 hint_block = search_start;
1270 ret = find_free_extent(trans, root, 0, search_start,
1271 search_end, hint_block,
1278 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
1279 btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
1281 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
1282 sizeof(extent_item));
1284 finish_current_insert(trans, extent_root);
1285 pending_ret = del_pending_extents(trans, extent_root);
1292 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
1299 * helper function to allocate a block for a given tree
1300 * returns the tree buffer or NULL.
1302 struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1303 struct btrfs_root *root, u64 hint)
1305 struct btrfs_key ins;
1307 struct buffer_head *buf;
1309 ret = btrfs_alloc_extent(trans, root, root->root_key.objectid,
1310 1, hint, (unsigned long)-1, &ins, 0);
1316 buf = btrfs_find_create_tree_block(root, ins.objectid);
1317 set_buffer_uptodate(buf);
1318 set_buffer_checked(buf);
1319 set_radix_bit(&trans->transaction->dirty_pages, buf->b_page->index);
1323 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
1324 struct btrfs_root *root, struct buffer_head *cur)
1326 struct btrfs_disk_key *key;
1327 struct btrfs_leaf *leaf;
1328 struct btrfs_file_extent_item *fi;
1333 BUG_ON(!btrfs_is_leaf(btrfs_buffer_node(cur)));
1334 leaf = btrfs_buffer_leaf(cur);
1335 nritems = btrfs_header_nritems(&leaf->header);
1336 for (i = 0; i < nritems; i++) {
1338 key = &leaf->items[i].key;
1339 if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
1341 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1342 if (btrfs_file_extent_type(fi) == BTRFS_FILE_EXTENT_INLINE)
1345 * FIXME make sure to insert a trans record that
1346 * repeats the snapshot del on crash
1348 disk_blocknr = btrfs_file_extent_disk_blocknr(fi);
1349 if (disk_blocknr == 0)
1351 ret = btrfs_free_extent(trans, root, disk_blocknr,
1352 btrfs_file_extent_disk_num_blocks(fi),
1359 static void reada_walk_down(struct btrfs_root *root,
1360 struct btrfs_node *node)
1368 nritems = btrfs_header_nritems(&node->header);
1369 for (i = 0; i < nritems; i++) {
1370 blocknr = btrfs_node_blockptr(node, i);
1371 ret = lookup_extent_ref(NULL, root, blocknr, 1, &refs);
1375 ret = readahead_tree_block(root, blocknr);
1382 * helper function for drop_snapshot, this walks down the tree dropping ref
1383 * counts as it goes.
1385 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1386 *root, struct btrfs_path *path, int *level)
1388 struct buffer_head *next;
1389 struct buffer_head *cur;
1394 WARN_ON(*level < 0);
1395 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1396 ret = lookup_extent_ref(trans, root, bh_blocknr(path->nodes[*level]),
1403 * walk down to the last node level and free all the leaves
1405 while(*level >= 0) {
1406 WARN_ON(*level < 0);
1407 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1408 cur = path->nodes[*level];
1410 if (*level > 0 && path->slots[*level] == 0)
1411 reada_walk_down(root, btrfs_buffer_node(cur));
1413 if (btrfs_header_level(btrfs_buffer_header(cur)) != *level)
1416 if (path->slots[*level] >=
1417 btrfs_header_nritems(btrfs_buffer_header(cur)))
1420 ret = drop_leaf_ref(trans, root, cur);
1424 blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur),
1425 path->slots[*level]);
1426 ret = lookup_extent_ref(trans, root, blocknr, 1, &refs);
1429 path->slots[*level]++;
1430 ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
1434 next = read_tree_block(root, blocknr);
1435 WARN_ON(*level <= 0);
1436 if (path->nodes[*level-1])
1437 btrfs_block_release(root, path->nodes[*level-1]);
1438 path->nodes[*level-1] = next;
1439 *level = btrfs_header_level(btrfs_buffer_header(next));
1440 path->slots[*level] = 0;
1443 WARN_ON(*level < 0);
1444 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1445 ret = btrfs_free_extent(trans, root,
1446 bh_blocknr(path->nodes[*level]), 1, 1);
1447 btrfs_block_release(root, path->nodes[*level]);
1448 path->nodes[*level] = NULL;
1455 * helper for dropping snapshots. This walks back up the tree in the path
1456 * to find the first node higher up where we haven't yet gone through
1459 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1460 *root, struct btrfs_path *path, int *level)
1465 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1466 slot = path->slots[i];
1467 if (slot < btrfs_header_nritems(
1468 btrfs_buffer_header(path->nodes[i])) - 1) {
1473 ret = btrfs_free_extent(trans, root,
1474 bh_blocknr(path->nodes[*level]),
1477 btrfs_block_release(root, path->nodes[*level]);
1478 path->nodes[*level] = NULL;
1486 * drop the reference count on the tree rooted at 'snap'. This traverses
1487 * the tree freeing any blocks that have a ref count of zero after being
1490 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
1491 *root, struct buffer_head *snap)
1496 struct btrfs_path *path;
1500 path = btrfs_alloc_path();
1503 level = btrfs_header_level(btrfs_buffer_header(snap));
1505 path->nodes[level] = snap;
1506 path->slots[level] = 0;
1508 wret = walk_down_tree(trans, root, path, &level);
1514 wret = walk_up_tree(trans, root, path, &level);
1520 for (i = 0; i <= orig_level; i++) {
1521 if (path->nodes[i]) {
1522 btrfs_block_release(root, path->nodes[i]);
1525 btrfs_free_path(path);
1529 static int free_block_group_radix(struct radix_tree_root *radix)
1532 struct btrfs_block_group_cache *cache[8];
1536 ret = radix_tree_gang_lookup(radix, (void **)cache, 0,
1540 for (i = 0; i < ret; i++) {
1541 radix_tree_delete(radix, cache[i]->key.objectid +
1542 cache[i]->key.offset - 1);
1549 int btrfs_free_block_groups(struct btrfs_fs_info *info)
1553 unsigned long gang[16];
1556 ret = free_block_group_radix(&info->block_group_radix);
1557 ret2 = free_block_group_radix(&info->block_group_data_radix);
1564 ret = find_first_radix_bit(&info->extent_map_radix,
1565 gang, 0, ARRAY_SIZE(gang));
1568 for (i = 0; i < ret; i++) {
1569 clear_radix_bit(&info->extent_map_radix, gang[i]);
1575 int btrfs_read_block_groups(struct btrfs_root *root)
1577 struct btrfs_path *path;
1580 struct btrfs_block_group_item *bi;
1581 struct btrfs_block_group_cache *cache;
1582 struct btrfs_fs_info *info = root->fs_info;
1583 struct radix_tree_root *radix;
1584 struct btrfs_key key;
1585 struct btrfs_key found_key;
1586 struct btrfs_leaf *leaf;
1587 u64 group_size_blocks;
1590 group_size_blocks = BTRFS_BLOCK_GROUP_SIZE >>
1591 root->fs_info->sb->s_blocksize_bits;
1592 root = info->extent_root;
1594 key.offset = group_size_blocks;
1596 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
1598 path = btrfs_alloc_path();
1603 ret = btrfs_search_slot(NULL, info->extent_root,
1609 leaf = btrfs_buffer_leaf(path->nodes[0]);
1610 btrfs_disk_key_to_cpu(&found_key,
1611 &leaf->items[path->slots[0]].key);
1612 cache = kmalloc(sizeof(*cache), GFP_NOFS);
1618 bi = btrfs_item_ptr(leaf, path->slots[0],
1619 struct btrfs_block_group_item);
1620 if (bi->flags & BTRFS_BLOCK_GROUP_DATA) {
1621 radix = &info->block_group_data_radix;
1624 radix = &info->block_group_radix;
1628 memcpy(&cache->item, bi, sizeof(*bi));
1629 memcpy(&cache->key, &found_key, sizeof(found_key));
1630 cache->last_alloc = cache->key.objectid;
1631 cache->first_free = cache->key.objectid;
1632 cache->last_prealloc = cache->key.objectid;
1636 cache->radix = radix;
1638 key.objectid = found_key.objectid + found_key.offset;
1639 btrfs_release_path(root, path);
1640 ret = radix_tree_insert(radix, found_key.objectid +
1641 found_key.offset - 1,
1644 used = btrfs_block_group_used(bi);
1645 if (used < div_factor(key.offset, 8)) {
1646 radix_tree_tag_set(radix, found_key.objectid +
1647 found_key.offset - 1,
1648 BTRFS_BLOCK_GROUP_AVAIL);
1651 btrfs_super_total_blocks(info->disk_super))
1655 btrfs_free_path(path);