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.
21 #include "kerncompat.h"
22 #include "radix-tree.h"
25 #include "print-tree.h"
26 #include "transaction.h"
28 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
29 *orig_root, u64 num_blocks, u64 search_start, u64
30 search_end, struct btrfs_key *ins);
31 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
32 btrfs_root *extent_root);
33 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
37 * pending extents are blocks that we're trying to allocate in the extent
38 * map while trying to grow the map because of other allocations. To avoid
39 * recursing, they are tagged in the radix tree and cleaned up after
40 * other allocations are done. The pending tag is also used in the same
43 #define CTREE_EXTENT_PENDING_DEL 0
45 static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
48 struct btrfs_path path;
52 struct btrfs_extent_item *item;
56 find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1,
58 btrfs_init_path(&path);
59 key.objectid = blocknr;
61 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
63 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
68 l = &path.nodes[0]->leaf;
69 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
70 refs = btrfs_extent_refs(item);
71 btrfs_set_extent_refs(item, refs + 1);
73 BUG_ON(list_empty(&path.nodes[0]->dirty));
74 btrfs_release_path(root->fs_info->extent_root, &path);
75 finish_current_insert(trans, root->fs_info->extent_root);
76 run_pending(trans, root->fs_info->extent_root);
80 static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
81 *root, u64 blocknr, u32 *refs)
83 struct btrfs_path path;
87 struct btrfs_extent_item *item;
88 btrfs_init_path(&path);
89 key.objectid = blocknr;
92 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
93 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
97 l = &path.nodes[0]->leaf;
98 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
99 *refs = btrfs_extent_refs(item);
100 btrfs_release_path(root->fs_info->extent_root, &path);
104 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
105 struct btrfs_buffer *buf)
112 if (btrfs_is_leaf(&buf->node))
115 for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) {
116 blocknr = btrfs_node_blockptr(&buf->node, i);
117 inc_block_ref(trans, root, blocknr);
122 static int write_one_cache_group(struct btrfs_trans_handle *trans,
123 struct btrfs_root *root,
124 struct btrfs_path *path,
125 struct btrfs_block_group_cache *cache)
129 struct btrfs_root *extent_root = root->fs_info->extent_root;
130 struct btrfs_block_group_item *bi;
131 struct btrfs_key ins;
133 ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
136 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
137 &cache->key, path, 0, 1);
139 bi = btrfs_item_ptr(&path->nodes[0]->leaf, path->slots[0],
140 struct btrfs_block_group_item);
141 memcpy(bi, &cache->item, sizeof(*bi));
142 dirty_tree_block(trans, extent_root, path->nodes[0]);
143 btrfs_release_path(extent_root, path);
144 finish_current_insert(trans, root);
145 pending_ret = run_pending(trans, root);
154 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
155 struct btrfs_root *root)
157 struct btrfs_block_group_cache *cache[8];
161 struct radix_tree_root *radix = &root->fs_info->block_group_radix;
163 struct btrfs_path path;
164 btrfs_init_path(&path);
167 ret = radix_tree_gang_lookup_tag(radix, (void **)cache,
168 0, ARRAY_SIZE(cache),
169 BTRFS_BLOCK_GROUP_DIRTY);
172 for (i = 0; i < ret; i++) {
173 radix_tree_tag_clear(radix, cache[i]->key.objectid +
174 cache[i]->key.offset -1,
175 BTRFS_BLOCK_GROUP_DIRTY);
176 err = write_one_cache_group(trans, root,
185 static int update_block_group(struct btrfs_trans_handle *trans,
186 struct btrfs_root *root,
187 u64 blocknr, u64 num, int alloc)
189 struct btrfs_block_group_cache *cache;
190 struct btrfs_fs_info *info = root->fs_info;
197 ret = radix_tree_gang_lookup(&info->block_group_radix,
198 (void **)&cache, blocknr, 1);
201 radix_tree_tag_set(&info->block_group_radix,
202 cache->key.objectid + cache->key.offset - 1,
203 BTRFS_BLOCK_GROUP_DIRTY);
205 block_in_group = blocknr - cache->key.objectid;
206 old_val = btrfs_block_group_used(&cache->item);
207 if (total > cache->key.offset - block_in_group)
208 num = cache->key.offset - block_in_group;
217 btrfs_set_block_group_used(&cache->item, old_val);
222 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
225 unsigned long gang[8];
231 ret = radix_tree_gang_lookup(&root->fs_info->pinned_radix,
238 for (i = 0; i < ret; i++) {
239 radix_tree_delete(&root->fs_info->pinned_radix,
243 root->fs_info->last_insert.objectid = first;
244 root->fs_info->last_insert.offset = 0;
248 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
249 btrfs_root *extent_root)
251 struct btrfs_key ins;
252 struct btrfs_extent_item extent_item;
255 u64 super_blocks_used;
256 struct btrfs_fs_info *info = extent_root->fs_info;
258 btrfs_set_extent_refs(&extent_item, 1);
259 btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
262 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
264 for (i = 0; i < extent_root->fs_info->current_insert.flags; i++) {
265 ins.objectid = extent_root->fs_info->current_insert.objectid +
267 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
268 btrfs_set_super_blocks_used(info->disk_super,
269 super_blocks_used + 1);
270 ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
271 sizeof(extent_item));
273 btrfs_print_tree(extent_root, extent_root->node);
277 extent_root->fs_info->current_insert.offset = 0;
282 * remove an extent from the root, returns 0 on success
284 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
285 *root, u64 blocknr, u64 num_blocks, int pin)
287 struct btrfs_path path;
288 struct btrfs_key key;
289 struct btrfs_fs_info *info = root->fs_info;
290 struct btrfs_root *extent_root = info->extent_root;
292 struct btrfs_extent_item *ei;
293 struct btrfs_key ins;
296 BUG_ON(pin && num_blocks != 1);
297 key.objectid = blocknr;
299 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
300 key.offset = num_blocks;
302 find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
303 btrfs_init_path(&path);
304 ret = btrfs_search_slot(trans, extent_root, &key, &path, -1, 1);
306 btrfs_print_tree(extent_root, extent_root->node);
307 printf("failed to find %llu\n",
308 (unsigned long long)key.objectid);
311 ei = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
312 struct btrfs_extent_item);
313 BUG_ON(ei->refs == 0);
314 refs = btrfs_extent_refs(ei) - 1;
315 btrfs_set_extent_refs(ei, refs);
317 u64 super_blocks_used;
320 unsigned long bl = blocknr;
321 radix_tree_preload(GFP_KERNEL);
322 err = radix_tree_insert(&info->pinned_radix,
323 blocknr, (void *)bl);
325 radix_tree_preload_end();
327 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
328 btrfs_set_super_blocks_used(info->disk_super,
329 super_blocks_used - num_blocks);
330 ret = btrfs_del_item(trans, extent_root, &path);
331 if (!pin && extent_root->fs_info->last_insert.objectid >
333 extent_root->fs_info->last_insert.objectid = blocknr;
336 ret = update_block_group(trans, root, blocknr, num_blocks, 0);
339 btrfs_release_path(extent_root, &path);
340 finish_current_insert(trans, extent_root);
345 * find all the blocks marked as pending in the radix tree and remove
346 * them from the extent map
348 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
349 btrfs_root *extent_root)
352 struct btrfs_buffer *gang[4];
356 ret = radix_tree_gang_lookup_tag(
357 &extent_root->fs_info->cache_radix,
360 CTREE_EXTENT_PENDING_DEL);
363 for (i = 0; i < ret; i++) {
364 ret = __free_extent(trans, extent_root,
365 gang[i]->blocknr, 1, 1);
366 radix_tree_tag_clear(&extent_root->fs_info->cache_radix,
368 CTREE_EXTENT_PENDING_DEL);
369 btrfs_block_release(extent_root, gang[i]);
375 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
378 while(radix_tree_tagged(&extent_root->fs_info->cache_radix,
379 CTREE_EXTENT_PENDING_DEL))
380 del_pending_extents(trans, extent_root);
386 * remove an extent from the root, returns 0 on success
388 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
389 *root, u64 blocknr, u64 num_blocks, int pin)
391 struct btrfs_root *extent_root = root->fs_info->extent_root;
392 struct btrfs_buffer *t;
396 if (root == extent_root) {
397 t = find_tree_block(root, blocknr);
398 radix_tree_tag_set(&root->fs_info->cache_radix, blocknr,
399 CTREE_EXTENT_PENDING_DEL);
402 ret = __free_extent(trans, root, blocknr, num_blocks, pin);
403 pending_ret = run_pending(trans, root->fs_info->extent_root);
404 return ret ? ret : pending_ret;
408 * walks the btree of allocated extents and find a hole of a given size.
409 * The key ins is changed to record the hole:
410 * ins->objectid == block start
411 * ins->flags = BTRFS_EXTENT_ITEM_KEY
412 * ins->offset == number of blocks
413 * Any available blocks before search_start are skipped.
415 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
416 *orig_root, u64 num_blocks, u64 search_start, u64
417 search_end, struct btrfs_key *ins)
419 struct btrfs_path path;
420 struct btrfs_key key;
427 struct btrfs_leaf *l;
428 struct btrfs_root * root = orig_root->fs_info->extent_root;
429 int total_needed = num_blocks;
431 total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3;
432 if (root->fs_info->last_insert.objectid > search_start)
433 search_start = root->fs_info->last_insert.objectid;
436 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
439 btrfs_init_path(&path);
440 ins->objectid = search_start;
443 ret = btrfs_search_slot(trans, root, ins, &path, 0, 0);
447 if (path.slots[0] > 0)
451 l = &path.nodes[0]->leaf;
452 slot = path.slots[0];
453 if (slot >= btrfs_header_nritems(&l->header)) {
454 ret = btrfs_next_leaf(root, &path);
460 ins->objectid = search_start;
461 ins->offset = (u64)-1 - search_start;
465 ins->objectid = last_block > search_start ?
466 last_block : search_start;
467 ins->offset = (u64)-1 - ins->objectid;
470 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
471 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
473 if (key.objectid >= search_start) {
475 if (last_block < search_start)
476 last_block = search_start;
477 hole_size = key.objectid - last_block;
478 if (hole_size > total_needed) {
479 ins->objectid = last_block;
480 ins->offset = hole_size;
486 last_block = key.objectid + key.offset;
492 /* we have to make sure we didn't find an extent that has already
493 * been allocated by the map tree or the original allocation
495 btrfs_release_path(root, &path);
496 BUG_ON(ins->objectid < search_start);
497 for (test_block = ins->objectid;
498 test_block < ins->objectid + total_needed; test_block++) {
499 if (radix_tree_lookup(&root->fs_info->pinned_radix,
501 search_start = test_block + 1;
505 BUG_ON(root->fs_info->current_insert.offset);
506 root->fs_info->current_insert.offset = total_needed - num_blocks;
507 root->fs_info->current_insert.objectid = ins->objectid + num_blocks;
508 root->fs_info->current_insert.flags = 0;
509 root->fs_info->last_insert.objectid = ins->objectid;
510 ins->offset = num_blocks;
513 btrfs_release_path(root, &path);
517 * finds a free extent and does all the dirty work required for allocation
518 * returns the key for the extent through ins, and a tree buffer for
519 * the first block of the extent through buf.
521 * returns 0 if everything worked, non-zero otherwise.
523 static int alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
524 *root, u64 owner, u64 num_blocks,
525 u64 search_start, u64
526 search_end, struct btrfs_key *ins)
530 u64 super_blocks_used;
531 struct btrfs_fs_info *info = root->fs_info;
532 struct btrfs_root *extent_root = info->extent_root;
533 struct btrfs_extent_item extent_item;
535 btrfs_set_extent_refs(&extent_item, 1);
536 btrfs_set_extent_owner(&extent_item, owner);
538 if (root == extent_root) {
539 BUG_ON(extent_root->fs_info->current_insert.offset == 0);
540 BUG_ON(num_blocks != 1);
541 BUG_ON(extent_root->fs_info->current_insert.flags ==
542 extent_root->fs_info->current_insert.offset);
544 ins->objectid = extent_root->fs_info->current_insert.objectid +
545 extent_root->fs_info->current_insert.flags++;
548 ret = find_free_extent(trans, root, num_blocks, search_start,
553 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
554 btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
556 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
557 sizeof(extent_item));
559 finish_current_insert(trans, extent_root);
560 pending_ret = run_pending(trans, extent_root);
569 * helper function to allocate a block for a given tree
570 * returns the tree buffer or NULL.
572 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
573 struct btrfs_root *root)
575 struct btrfs_key ins;
577 struct btrfs_buffer *buf;
579 ret = alloc_extent(trans, root, root->root_key.objectid,
580 1, 0, (unsigned long)-1, &ins);
585 ret = update_block_group(trans, root, ins.objectid, ins.offset, 1);
586 buf = find_tree_block(root, ins.objectid);
587 btrfs_set_header_generation(&buf->node.header,
588 root->root_key.offset + 1);
589 btrfs_set_header_blocknr(&buf->node.header, buf->blocknr);
590 memcpy(buf->node.header.fsid, root->fs_info->disk_super->fsid,
591 sizeof(buf->node.header.fsid));
592 dirty_tree_block(trans, root, buf);
598 * helper function for drop_snapshot, this walks down the tree dropping ref
601 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
602 *root, struct btrfs_path *path, int *level)
604 struct btrfs_buffer *next;
605 struct btrfs_buffer *cur;
610 ret = lookup_block_ref(trans, root, path->nodes[*level]->blocknr,
616 * walk down to the last node level and free all the leaves
619 cur = path->nodes[*level];
620 if (path->slots[*level] >=
621 btrfs_header_nritems(&cur->node.header))
623 blocknr = btrfs_node_blockptr(&cur->node, path->slots[*level]);
624 ret = lookup_block_ref(trans, root, blocknr, &refs);
625 if (refs != 1 || *level == 1) {
626 path->slots[*level]++;
627 ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
632 next = read_tree_block(root, blocknr);
633 if (path->nodes[*level-1])
634 btrfs_block_release(root, path->nodes[*level-1]);
635 path->nodes[*level-1] = next;
636 *level = btrfs_header_level(&next->node.header);
637 path->slots[*level] = 0;
640 ret = btrfs_free_extent(trans, root, path->nodes[*level]->blocknr, 1,
642 btrfs_block_release(root, path->nodes[*level]);
643 path->nodes[*level] = NULL;
650 * helper for dropping snapshots. This walks back up the tree in the path
651 * to find the first node higher up where we haven't yet gone through
654 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
655 *root, struct btrfs_path *path, int *level)
660 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
661 slot = path->slots[i];
663 btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
668 ret = btrfs_free_extent(trans, root,
669 path->nodes[*level]->blocknr,
671 btrfs_block_release(root, path->nodes[*level]);
672 path->nodes[*level] = NULL;
681 * drop the reference count on the tree rooted at 'snap'. This traverses
682 * the tree freeing any blocks that have a ref count of zero after being
685 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
686 *root, struct btrfs_buffer *snap)
691 struct btrfs_path path;
695 btrfs_init_path(&path);
697 level = btrfs_header_level(&snap->node.header);
699 path.nodes[level] = snap;
700 path.slots[level] = 0;
702 wret = walk_down_tree(trans, root, &path, &level);
708 wret = walk_up_tree(trans, root, &path, &level);
714 for (i = 0; i <= orig_level; i++) {
716 btrfs_block_release(root, path.nodes[i]);
722 int btrfs_free_block_groups(struct btrfs_fs_info *info)
725 struct btrfs_block_group_cache *cache[8];
729 ret = radix_tree_gang_lookup(&info->block_group_radix,
734 for (i = 0; i < ret; i++) {
735 radix_tree_delete(&info->block_group_radix,
736 cache[i]->key.objectid +
737 cache[i]->key.offset - 1);
744 int btrfs_read_block_groups(struct btrfs_root *root)
746 struct btrfs_path path;
749 struct btrfs_block_group_item *bi;
750 struct btrfs_block_group_cache *cache;
751 struct btrfs_key key;
752 struct btrfs_key found_key;
753 struct btrfs_leaf *leaf;
754 u64 group_size_blocks = BTRFS_BLOCK_GROUP_SIZE / root->blocksize;
756 root = root->fs_info->extent_root;
758 key.offset = group_size_blocks;
760 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
761 btrfs_init_path(&path);
764 ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
770 leaf = &path.nodes[0]->leaf;
771 btrfs_disk_key_to_cpu(&found_key,
772 &leaf->items[path.slots[0]].key);
773 cache = malloc(sizeof(*cache));
778 bi = btrfs_item_ptr(leaf, path.slots[0],
779 struct btrfs_block_group_item);
780 memcpy(&cache->item, bi, sizeof(*bi));
781 memcpy(&cache->key, &found_key, sizeof(found_key));
782 key.objectid = found_key.objectid + found_key.offset;
783 btrfs_release_path(root, &path);
784 ret = radix_tree_insert(&root->fs_info->block_group_radix,
786 found_key.offset - 1, (void *)cache);
789 btrfs_super_total_blocks(root->fs_info->disk_super))
792 btrfs_release_path(root, &path);
796 int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
797 struct btrfs_root *root,
798 struct btrfs_key *key,
799 struct btrfs_block_group_item *bi)
801 struct btrfs_key ins;
805 root = root->fs_info->extent_root;
806 ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
809 ret = btrfs_insert_item(trans, root, key, bi, sizeof(*bi));
810 finish_current_insert(trans, root);
811 pending_ret = run_pending(trans, root);