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;
60 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
62 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
67 l = &path.nodes[0]->leaf;
68 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
69 refs = btrfs_extent_refs(item);
70 btrfs_set_extent_refs(item, refs + 1);
72 BUG_ON(list_empty(&path.nodes[0]->dirty));
73 btrfs_release_path(root->fs_info->extent_root, &path);
74 finish_current_insert(trans, root->fs_info->extent_root);
75 run_pending(trans, root->fs_info->extent_root);
79 static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
80 *root, u64 blocknr, u32 *refs)
82 struct btrfs_path path;
86 struct btrfs_extent_item *item;
87 btrfs_init_path(&path);
88 key.objectid = blocknr;
90 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
91 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
95 l = &path.nodes[0]->leaf;
96 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
97 *refs = btrfs_extent_refs(item);
98 btrfs_release_path(root->fs_info->extent_root, &path);
102 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
103 struct btrfs_buffer *buf)
110 if (btrfs_is_leaf(&buf->node))
113 for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) {
114 blocknr = btrfs_node_blockptr(&buf->node, i);
115 inc_block_ref(trans, root, blocknr);
120 static int write_one_cache_group(struct btrfs_trans_handle *trans,
121 struct btrfs_root *root,
122 struct btrfs_path *path,
123 struct btrfs_block_group_cache *cache)
127 struct btrfs_root *extent_root = root->fs_info->extent_root;
128 struct btrfs_block_group_item *bi;
129 struct btrfs_key ins;
131 ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
134 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
135 &cache->key, path, 0, 1);
137 bi = btrfs_item_ptr(&path->nodes[0]->leaf, path->slots[0],
138 struct btrfs_block_group_item);
139 memcpy(bi, &cache->item, sizeof(*bi));
140 dirty_tree_block(trans, extent_root, path->nodes[0]);
141 btrfs_release_path(extent_root, path);
142 finish_current_insert(trans, root);
143 pending_ret = run_pending(trans, root);
152 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
153 struct btrfs_root *root)
155 struct btrfs_block_group_cache *cache[8];
159 struct radix_tree_root *radix = &root->fs_info->block_group_radix;
161 struct btrfs_path path;
162 btrfs_init_path(&path);
165 ret = radix_tree_gang_lookup_tag(radix, (void *)cache,
166 0, ARRAY_SIZE(cache),
167 BTRFS_BLOCK_GROUP_DIRTY);
170 for (i = 0; i < ret; i++) {
171 radix_tree_tag_clear(radix, cache[i]->key.objectid +
172 cache[i]->key.offset -1,
173 BTRFS_BLOCK_GROUP_DIRTY);
174 err = write_one_cache_group(trans, root,
183 static int update_block_group(struct btrfs_trans_handle *trans,
184 struct btrfs_root *root,
185 u64 blocknr, u64 num, int alloc)
187 struct btrfs_block_group_cache *cache;
188 struct btrfs_fs_info *info = root->fs_info;
195 ret = radix_tree_gang_lookup(&info->block_group_radix,
196 (void *)&cache, blocknr, 1);
199 radix_tree_tag_set(&info->block_group_radix,
200 cache->key.objectid + cache->key.offset - 1,
201 BTRFS_BLOCK_GROUP_DIRTY);
203 block_in_group = blocknr - cache->key.objectid;
204 old_val = btrfs_block_group_used(&cache->item);
205 if (total > cache->key.offset - block_in_group)
206 num = cache->key.offset - block_in_group;
215 btrfs_set_block_group_used(&cache->item, old_val);
220 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
223 unsigned long gang[8];
229 ret = radix_tree_gang_lookup(&root->fs_info->pinned_radix,
236 for (i = 0; i < ret; i++) {
237 radix_tree_delete(&root->fs_info->pinned_radix,
241 root->fs_info->last_insert.objectid = first;
242 root->fs_info->last_insert.offset = 0;
246 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
247 btrfs_root *extent_root)
249 struct btrfs_key ins;
250 struct btrfs_extent_item extent_item;
253 u64 super_blocks_used, root_blocks_used;
254 struct btrfs_fs_info *info = extent_root->fs_info;
256 btrfs_set_extent_refs(&extent_item, 1);
257 btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
259 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
261 for (i = 0; i < extent_root->fs_info->current_insert.type; i++) {
262 ins.objectid = extent_root->fs_info->current_insert.objectid +
264 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
265 btrfs_set_super_blocks_used(info->disk_super,
266 super_blocks_used + 1);
267 root_blocks_used = btrfs_root_blocks_used(&extent_root->root_item);
268 btrfs_set_root_blocks_used(&extent_root->root_item,
269 root_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;
298 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
299 key.offset = num_blocks;
301 find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
302 btrfs_init_path(&path);
303 ret = btrfs_search_slot(trans, extent_root, &key, &path, -1, 1);
305 btrfs_print_tree(extent_root, extent_root->node);
306 printf("failed to find %llu\n",
307 (unsigned long long)key.objectid);
310 ei = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
311 struct btrfs_extent_item);
312 BUG_ON(ei->refs == 0);
313 refs = btrfs_extent_refs(ei) - 1;
314 btrfs_set_extent_refs(ei, refs);
316 u64 super_blocks_used, root_blocks_used;
319 unsigned long bl = blocknr;
320 radix_tree_preload(GFP_KERNEL);
321 err = radix_tree_insert(&info->pinned_radix,
322 blocknr, (void *)bl);
324 radix_tree_preload_end();
326 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
327 btrfs_set_super_blocks_used(info->disk_super,
328 super_blocks_used - num_blocks);
329 root_blocks_used = btrfs_root_blocks_used(&root->root_item);
330 btrfs_set_root_blocks_used(&root->root_item,
331 root_blocks_used - num_blocks);
333 ret = btrfs_del_item(trans, extent_root, &path);
334 if (!pin && extent_root->fs_info->last_insert.objectid >
336 extent_root->fs_info->last_insert.objectid = blocknr;
339 ret = update_block_group(trans, root, blocknr, num_blocks, 0);
342 btrfs_release_path(extent_root, &path);
343 finish_current_insert(trans, extent_root);
348 * find all the blocks marked as pending in the radix tree and remove
349 * them from the extent map
351 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
352 btrfs_root *extent_root)
355 struct btrfs_buffer *gang[4];
359 ret = radix_tree_gang_lookup_tag(
360 &extent_root->fs_info->cache_radix,
363 CTREE_EXTENT_PENDING_DEL);
366 for (i = 0; i < ret; i++) {
367 ret = __free_extent(trans, extent_root,
368 gang[i]->blocknr, 1, 1);
369 radix_tree_tag_clear(&extent_root->fs_info->cache_radix,
371 CTREE_EXTENT_PENDING_DEL);
372 btrfs_block_release(extent_root, gang[i]);
378 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
381 while(radix_tree_tagged(&extent_root->fs_info->cache_radix,
382 CTREE_EXTENT_PENDING_DEL))
383 del_pending_extents(trans, extent_root);
389 * remove an extent from the root, returns 0 on success
391 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
392 *root, u64 blocknr, u64 num_blocks, int pin)
394 struct btrfs_root *extent_root = root->fs_info->extent_root;
395 struct btrfs_buffer *t;
399 if (root == extent_root) {
400 t = find_tree_block(root, blocknr);
401 radix_tree_tag_set(&root->fs_info->cache_radix, blocknr,
402 CTREE_EXTENT_PENDING_DEL);
405 ret = __free_extent(trans, root, blocknr, num_blocks, pin);
406 pending_ret = run_pending(trans, root->fs_info->extent_root);
407 return ret ? ret : pending_ret;
411 * walks the btree of allocated extents and find a hole of a given size.
412 * The key ins is changed to record the hole:
413 * ins->objectid == block start
414 * ins->flags = BTRFS_EXTENT_ITEM_KEY
415 * ins->offset == number of blocks
416 * Any available blocks before search_start are skipped.
418 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
419 *orig_root, u64 num_blocks, u64 search_start, u64
420 search_end, struct btrfs_key *ins)
422 struct btrfs_path path;
423 struct btrfs_key key;
430 struct btrfs_leaf *l;
431 struct btrfs_root * root = orig_root->fs_info->extent_root;
432 int total_needed = num_blocks;
434 total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3;
435 if (root->fs_info->last_insert.objectid > search_start)
436 search_start = root->fs_info->last_insert.objectid;
438 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
441 btrfs_init_path(&path);
442 ins->objectid = search_start;
445 ret = btrfs_search_slot(trans, root, ins, &path, 0, 0);
449 if (path.slots[0] > 0)
453 l = &path.nodes[0]->leaf;
454 slot = path.slots[0];
455 if (slot >= btrfs_header_nritems(&l->header)) {
456 ret = btrfs_next_leaf(root, &path);
462 ins->objectid = search_start;
463 ins->offset = (u64)-1 - search_start;
467 ins->objectid = last_block > search_start ?
468 last_block : search_start;
469 ins->offset = (u64)-1 - ins->objectid;
472 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
473 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
475 if (key.objectid >= search_start) {
477 if (last_block < search_start)
478 last_block = search_start;
479 hole_size = key.objectid - last_block;
480 if (hole_size > total_needed) {
481 ins->objectid = last_block;
482 ins->offset = hole_size;
488 last_block = key.objectid + key.offset;
494 /* we have to make sure we didn't find an extent that has already
495 * been allocated by the map tree or the original allocation
497 btrfs_release_path(root, &path);
498 BUG_ON(ins->objectid < search_start);
499 for (test_block = ins->objectid;
500 test_block < ins->objectid + total_needed; test_block++) {
501 if (radix_tree_lookup(&root->fs_info->pinned_radix,
503 search_start = test_block + 1;
507 BUG_ON(root->fs_info->current_insert.offset);
508 root->fs_info->current_insert.offset = total_needed - num_blocks;
509 root->fs_info->current_insert.objectid = ins->objectid + num_blocks;
510 root->fs_info->current_insert.type = 0;
511 root->fs_info->last_insert.objectid = ins->objectid;
512 ins->offset = num_blocks;
515 btrfs_release_path(root, &path);
519 * finds a free extent and does all the dirty work required for allocation
520 * returns the key for the extent through ins, and a tree buffer for
521 * the first block of the extent through buf.
523 * returns 0 if everything worked, non-zero otherwise.
525 static int alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
526 *root, u64 owner, u64 num_blocks,
527 u64 search_start, u64
528 search_end, struct btrfs_key *ins)
532 u64 super_blocks_used, root_blocks_used;
533 struct btrfs_fs_info *info = root->fs_info;
534 struct btrfs_root *extent_root = info->extent_root;
535 struct btrfs_extent_item extent_item;
537 btrfs_set_extent_refs(&extent_item, 1);
538 btrfs_set_extent_owner(&extent_item, owner);
540 if (root == extent_root) {
541 BUG_ON(extent_root->fs_info->current_insert.offset == 0);
542 BUG_ON(num_blocks != 1);
543 BUG_ON(extent_root->fs_info->current_insert.type ==
544 extent_root->fs_info->current_insert.offset);
546 ins->objectid = extent_root->fs_info->current_insert.objectid +
547 extent_root->fs_info->current_insert.type++;
550 ret = find_free_extent(trans, root, num_blocks, search_start,
555 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
556 btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
558 root_blocks_used = btrfs_root_blocks_used(&root->root_item);
559 btrfs_set_root_blocks_used(&root->root_item, root_blocks_used +
562 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
563 sizeof(extent_item));
565 finish_current_insert(trans, extent_root);
566 pending_ret = run_pending(trans, extent_root);
575 * helper function to allocate a block for a given tree
576 * returns the tree buffer or NULL.
578 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
579 struct btrfs_root *root)
581 struct btrfs_key ins;
583 struct btrfs_buffer *buf;
585 ret = alloc_extent(trans, root, root->root_key.objectid,
586 1, 0, (unsigned long)-1, &ins);
591 ret = update_block_group(trans, root, ins.objectid, ins.offset, 1);
592 buf = find_tree_block(root, ins.objectid);
593 btrfs_set_header_generation(&buf->node.header,
594 root->root_key.offset + 1);
595 btrfs_set_header_blocknr(&buf->node.header, buf->blocknr);
596 memcpy(buf->node.header.fsid, root->fs_info->disk_super->fsid,
597 sizeof(buf->node.header.fsid));
598 dirty_tree_block(trans, root, buf);
604 * helper function for drop_snapshot, this walks down the tree dropping ref
607 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
608 *root, struct btrfs_path *path, int *level)
610 struct btrfs_buffer *next;
611 struct btrfs_buffer *cur;
616 ret = lookup_block_ref(trans, root, path->nodes[*level]->blocknr,
622 * walk down to the last node level and free all the leaves
625 cur = path->nodes[*level];
626 if (path->slots[*level] >=
627 btrfs_header_nritems(&cur->node.header))
629 blocknr = btrfs_node_blockptr(&cur->node, path->slots[*level]);
630 ret = lookup_block_ref(trans, root, blocknr, &refs);
631 if (refs != 1 || *level == 1) {
632 path->slots[*level]++;
633 ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
638 next = read_tree_block(root, blocknr);
639 if (path->nodes[*level-1])
640 btrfs_block_release(root, path->nodes[*level-1]);
641 path->nodes[*level-1] = next;
642 *level = btrfs_header_level(&next->node.header);
643 path->slots[*level] = 0;
646 ret = btrfs_free_extent(trans, root, path->nodes[*level]->blocknr, 1,
648 btrfs_block_release(root, path->nodes[*level]);
649 path->nodes[*level] = NULL;
656 * helper for dropping snapshots. This walks back up the tree in the path
657 * to find the first node higher up where we haven't yet gone through
660 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
661 *root, struct btrfs_path *path, int *level)
666 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
667 slot = path->slots[i];
669 btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
674 ret = btrfs_free_extent(trans, root,
675 path->nodes[*level]->blocknr,
677 btrfs_block_release(root, path->nodes[*level]);
678 path->nodes[*level] = NULL;
687 * drop the reference count on the tree rooted at 'snap'. This traverses
688 * the tree freeing any blocks that have a ref count of zero after being
691 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
692 *root, struct btrfs_buffer *snap)
697 struct btrfs_path path;
701 btrfs_init_path(&path);
703 level = btrfs_header_level(&snap->node.header);
705 path.nodes[level] = snap;
706 path.slots[level] = 0;
708 wret = walk_down_tree(trans, root, &path, &level);
714 wret = walk_up_tree(trans, root, &path, &level);
720 for (i = 0; i <= orig_level; i++) {
722 btrfs_block_release(root, path.nodes[i]);
728 int btrfs_free_block_groups(struct btrfs_fs_info *info)
731 struct btrfs_block_group_cache *cache[8];
735 ret = radix_tree_gang_lookup(&info->block_group_radix,
740 for (i = 0; i < ret; i++) {
741 radix_tree_delete(&info->block_group_radix,
742 cache[i]->key.objectid +
743 cache[i]->key.offset - 1);
750 int btrfs_read_block_groups(struct btrfs_root *root)
752 struct btrfs_path path;
755 struct btrfs_block_group_item *bi;
756 struct btrfs_block_group_cache *cache;
757 struct btrfs_key key;
758 struct btrfs_key found_key;
759 struct btrfs_leaf *leaf;
760 u64 group_size_blocks = BTRFS_BLOCK_GROUP_SIZE / root->sectorsize;
762 root = root->fs_info->extent_root;
764 key.offset = group_size_blocks;
765 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
766 btrfs_init_path(&path);
769 ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
775 leaf = &path.nodes[0]->leaf;
776 btrfs_disk_key_to_cpu(&found_key,
777 &leaf->items[path.slots[0]].key);
778 cache = malloc(sizeof(*cache));
783 bi = btrfs_item_ptr(leaf, path.slots[0],
784 struct btrfs_block_group_item);
785 memcpy(&cache->item, bi, sizeof(*bi));
786 memcpy(&cache->key, &found_key, sizeof(found_key));
787 key.objectid = found_key.objectid + found_key.offset;
788 btrfs_release_path(root, &path);
789 ret = radix_tree_insert(&root->fs_info->block_group_radix,
791 found_key.offset - 1, (void *)cache);
794 btrfs_super_total_blocks(root->fs_info->disk_super))
797 btrfs_release_path(root, &path);
801 int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
802 struct btrfs_root *root,
803 struct btrfs_key *key,
804 struct btrfs_block_group_item *bi)
806 struct btrfs_key ins;
810 root = root->fs_info->extent_root;
811 ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
814 ret = btrfs_insert_item(trans, root, key, bi, sizeof(*bi));
815 finish_current_insert(trans, root);
816 pending_ret = run_pending(trans, root);