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 finish_current_insert(struct btrfs_trans_handle *trans, struct
29 btrfs_root *extent_root);
30 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
33 static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
34 *root, u64 bytenr, u32 blocksize)
36 struct btrfs_path path;
40 struct btrfs_extent_item *item;
43 btrfs_init_path(&path);
44 key.objectid = bytenr;
45 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
46 key.offset = blocksize;
47 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
52 l = &path.nodes[0]->leaf;
53 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
54 refs = btrfs_extent_refs(item);
55 btrfs_set_extent_refs(item, refs + 1);
57 BUG_ON(list_empty(&path.nodes[0]->dirty));
58 btrfs_release_path(root->fs_info->extent_root, &path);
59 finish_current_insert(trans, root->fs_info->extent_root);
60 run_pending(trans, root->fs_info->extent_root);
64 static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
65 *root, u64 bytenr, u32 blocksize, u32 *refs)
67 struct btrfs_path path;
71 struct btrfs_extent_item *item;
72 btrfs_init_path(&path);
73 key.objectid = bytenr;
74 key.offset = blocksize;
75 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
76 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
80 l = &path.nodes[0]->leaf;
81 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
82 *refs = btrfs_extent_refs(item);
83 btrfs_release_path(root->fs_info->extent_root, &path);
87 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
88 struct btrfs_buffer *buf)
98 level = btrfs_header_level(&buf->node.header) - 1;
99 blocksize = btrfs_level_size(root, level);
101 if (btrfs_is_leaf(&buf->node))
104 for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) {
105 bytenr = btrfs_node_blockptr(&buf->node, i);
106 inc_block_ref(trans, root, bytenr, blocksize);
112 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
113 struct btrfs_root *root)
115 return inc_block_ref(trans, root, root->node->bytenr,
119 static int write_one_cache_group(struct btrfs_trans_handle *trans,
120 struct btrfs_root *root,
121 struct btrfs_path *path,
122 struct btrfs_block_group_cache *cache)
126 struct btrfs_root *extent_root = root->fs_info->extent_root;
127 struct btrfs_block_group_item *bi;
129 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
130 &cache->key, path, 0, 1);
132 bi = btrfs_item_ptr(&path->nodes[0]->leaf, path->slots[0],
133 struct btrfs_block_group_item);
134 memcpy(bi, &cache->item, sizeof(*bi));
135 dirty_tree_block(trans, extent_root, path->nodes[0]);
136 btrfs_release_path(extent_root, path);
137 finish_current_insert(trans, root);
138 pending_ret = run_pending(trans, root);
147 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
148 struct btrfs_root *root)
150 struct btrfs_block_group_cache *bg;
151 struct cache_extent *cache;
154 struct cache_tree *bg_cache = &root->fs_info->block_group_cache;
155 struct btrfs_path path;
156 btrfs_init_path(&path);
160 cache = find_first_cache_extent(bg_cache, start);
163 bg = container_of(cache, struct btrfs_block_group_cache,
165 start = cache->start + cache->size;
167 err = write_one_cache_group(trans, root,
177 static int update_block_group(struct btrfs_trans_handle *trans,
178 struct btrfs_root *root,
179 u64 bytenr, u64 num, int alloc)
181 struct btrfs_block_group_cache *bg;
182 struct cache_extent *cache;
183 struct btrfs_fs_info *info = root->fs_info;
189 cache = find_first_cache_extent(&info->block_group_cache,
193 bg = container_of(cache, struct btrfs_block_group_cache,
196 byte_in_group = bytenr - bg->key.objectid;
197 old_val = btrfs_block_group_used(&bg->item);
198 if (total > bg->key.offset - byte_in_group)
199 num = bg->key.offset - byte_in_group;
208 btrfs_set_block_group_used(&bg->item, old_val);
213 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
217 struct cache_extent *pe;
218 struct cache_extent *next;
220 pe = find_first_cache_extent(&root->fs_info->pinned_tree, 0);
224 next = next_cache_extent(pe);
225 remove_cache_extent(&root->fs_info->pinned_tree, pe);
226 free_cache_extent(pe);
229 root->fs_info->last_insert.objectid = first;
230 root->fs_info->last_insert.offset = 0;
234 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
235 btrfs_root *extent_root)
237 struct btrfs_key ins;
238 struct btrfs_extent_item extent_item;
240 struct btrfs_fs_info *info = extent_root->fs_info;
241 struct cache_extent *pe;
242 struct cache_extent *next;
243 struct cache_tree *pending_tree = &info->pending_tree;
245 btrfs_set_extent_refs(&extent_item, 1);
246 btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
248 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
249 pe = find_first_cache_extent(pending_tree, 0);
251 ins.offset = pe->size;
252 ins.objectid = pe->start;
254 remove_cache_extent(pending_tree, pe);
255 next = next_cache_extent(pe);
257 next = find_first_cache_extent(pending_tree, 0);
259 free_cache_extent(pe);
262 ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
263 sizeof(extent_item));
265 btrfs_print_tree(extent_root, extent_root->node);
273 * remove an extent from the root, returns 0 on success
275 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
276 *root, u64 bytenr, u64 num_bytes, int pin)
278 struct btrfs_path path;
279 struct btrfs_key key;
280 struct btrfs_fs_info *info = root->fs_info;
281 struct btrfs_root *extent_root = info->extent_root;
283 struct btrfs_extent_item *ei;
286 key.objectid = bytenr;
287 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
288 key.offset = num_bytes;
290 btrfs_init_path(&path);
291 ret = btrfs_search_slot(trans, extent_root, &key, &path, -1, 1);
293 btrfs_print_tree(extent_root, extent_root->node);
294 printf("failed to find %llu\n",
295 (unsigned long long)key.objectid);
298 ei = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
299 struct btrfs_extent_item);
300 BUG_ON(ei->refs == 0);
301 refs = btrfs_extent_refs(ei) - 1;
302 btrfs_set_extent_refs(ei, refs);
304 u64 super_bytes_used, root_bytes_used;
307 err = insert_cache_extent(&info->pinned_tree,
311 super_bytes_used = btrfs_super_bytes_used(info->disk_super);
312 btrfs_set_super_bytes_used(info->disk_super,
313 super_bytes_used - num_bytes);
314 root_bytes_used = btrfs_root_bytes_used(&root->root_item);
315 btrfs_set_root_bytes_used(&root->root_item,
316 root_bytes_used - num_bytes);
318 ret = btrfs_del_item(trans, extent_root, &path);
319 if (!pin && extent_root->fs_info->last_insert.objectid >
321 extent_root->fs_info->last_insert.objectid = bytenr;
324 ret = update_block_group(trans, root, bytenr, num_bytes, 0);
327 btrfs_release_path(extent_root, &path);
328 finish_current_insert(trans, extent_root);
333 * find all the blocks marked as pending in the radix tree and remove
334 * them from the extent map
336 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
337 btrfs_root *extent_root)
340 struct cache_extent *pe;
341 struct cache_extent *next;
342 struct cache_tree *del_pending = &extent_root->fs_info->del_pending;
344 pe = find_first_cache_extent(del_pending, 0);
346 remove_cache_extent(del_pending, pe);
347 ret = __free_extent(trans, extent_root,
348 pe->start, pe->size, 1);
350 next = next_cache_extent(pe);
352 next = find_first_cache_extent(del_pending, 0);
353 free_cache_extent(pe);
359 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
362 del_pending_extents(trans, extent_root);
368 * remove an extent from the root, returns 0 on success
370 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
371 *root, u64 bytenr, u64 num_bytes, int pin)
373 struct btrfs_root *extent_root = root->fs_info->extent_root;
377 if (root == extent_root) {
378 ret = insert_cache_extent(&root->fs_info->del_pending,
383 ret = __free_extent(trans, root, bytenr, num_bytes, pin);
384 pending_ret = run_pending(trans, root->fs_info->extent_root);
385 return ret ? ret : pending_ret;
388 static u64 stripe_align(struct btrfs_root *root, u64 val)
390 u64 mask = ((u64)root->stripesize - 1);
391 u64 ret = (val + mask) & ~mask;
396 * walks the btree of allocated extents and find a hole of a given size.
397 * The key ins is changed to record the hole:
398 * ins->objectid == block start
399 * ins->flags = BTRFS_EXTENT_ITEM_KEY
400 * ins->offset == number of blocks
401 * Any available blocks before search_start are skipped.
403 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
404 *orig_root, u64 total_needed, u64 search_start,
405 u64 search_end, struct btrfs_key *ins)
407 struct btrfs_path path;
408 struct btrfs_key key;
415 struct btrfs_leaf *l;
416 struct btrfs_root * root = orig_root->fs_info->extent_root;
418 if (root->fs_info->last_insert.objectid > search_start)
419 search_start = root->fs_info->last_insert.objectid;
421 search_start = stripe_align(root, search_start);
422 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
425 btrfs_init_path(&path);
426 ins->objectid = search_start;
429 ret = btrfs_search_slot(trans, root, ins, &path, 0, 0);
433 if (path.slots[0] > 0)
437 l = &path.nodes[0]->leaf;
438 slot = path.slots[0];
439 if (slot >= btrfs_header_nritems(&l->header)) {
440 ret = btrfs_next_leaf(root, &path);
446 aligned = stripe_align(root, search_start);
447 ins->objectid = aligned;
448 ins->offset = (u64)-1 - aligned;
452 ins->objectid = stripe_align(root,
453 last_byte > search_start ?
454 last_byte : search_start);
455 ins->offset = (u64)-1 - ins->objectid;
458 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
459 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
461 if (key.objectid >= search_start) {
463 if (last_byte < search_start)
464 last_byte = search_start;
465 aligned = stripe_align(root, last_byte);
466 hole_size = key.objectid - aligned;
467 if (key.objectid > aligned &&
468 hole_size > total_needed) {
469 ins->objectid = aligned;
470 ins->offset = hole_size;
476 last_byte = key.objectid + key.offset;
482 /* we have to make sure we didn't find an extent that has already
483 * been allocated by the map tree or the original allocation
485 btrfs_release_path(root, &path);
486 BUG_ON(ins->objectid < search_start);
487 if (find_cache_extent(&root->fs_info->pinned_tree,
488 ins->objectid, total_needed)) {
489 search_start = ins->objectid + total_needed;
492 if (find_cache_extent(&root->fs_info->pending_tree,
493 ins->objectid, total_needed)) {
494 search_start = ins->objectid + total_needed;
497 root->fs_info->last_insert.objectid = ins->objectid;
498 ins->offset = total_needed;
501 btrfs_release_path(root, &path);
505 * finds a free extent and does all the dirty work required for allocation
506 * returns the key for the extent through ins, and a tree buffer for
507 * the first block of the extent through buf.
509 * returns 0 if everything worked, non-zero otherwise.
511 static int alloc_extent(struct btrfs_trans_handle *trans,
512 struct btrfs_root *root, u64 owner,
513 u64 num_bytes, u64 search_start,
514 u64 search_end, struct btrfs_key *ins)
518 u64 super_bytes_used, root_bytes_used;
519 struct btrfs_fs_info *info = root->fs_info;
520 struct btrfs_root *extent_root = info->extent_root;
521 struct btrfs_extent_item extent_item;
523 btrfs_set_extent_refs(&extent_item, 1);
524 btrfs_set_extent_owner(&extent_item, owner);
526 ret = find_free_extent(trans, root, num_bytes, search_start,
531 super_bytes_used = btrfs_super_bytes_used(info->disk_super);
532 btrfs_set_super_bytes_used(info->disk_super, super_bytes_used +
534 root_bytes_used = btrfs_root_bytes_used(&root->root_item);
535 btrfs_set_root_bytes_used(&root->root_item, root_bytes_used +
537 if (root == extent_root) {
538 ret = insert_cache_extent(&root->fs_info->pending_tree,
539 ins->objectid, ins->offset);
543 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
544 sizeof(extent_item));
546 finish_current_insert(trans, extent_root);
547 pending_ret = run_pending(trans, extent_root);
553 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
558 * helper function to allocate a block for a given tree
559 * returns the tree buffer or NULL.
561 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
562 struct btrfs_root *root,
565 struct btrfs_key ins;
567 struct btrfs_buffer *buf;
568 ret = alloc_extent(trans, root, root->root_key.objectid,
569 blocksize, 0, (u64)-1, &ins);
574 buf = find_tree_block(root, ins.objectid, blocksize);
575 btrfs_set_header_generation(&buf->node.header, trans->transid);
576 btrfs_set_header_bytenr(&buf->node.header, buf->bytenr);
577 memcpy(buf->node.header.fsid, root->fs_info->disk_super->fsid,
578 sizeof(buf->node.header.fsid));
579 dirty_tree_block(trans, root, buf);
585 * helper function for drop_snapshot, this walks down the tree dropping ref
588 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
589 *root, struct btrfs_path *path, int *level)
591 struct btrfs_buffer *next;
592 struct btrfs_buffer *cur;
597 ret = lookup_block_ref(trans, root, path->nodes[*level]->bytenr,
598 btrfs_level_size(root, *level), &refs);
603 * walk down to the last node level and free all the leaves
606 u32 size = btrfs_level_size(root, *level - 1);
608 cur = path->nodes[*level];
609 if (path->slots[*level] >=
610 btrfs_header_nritems(&cur->node.header))
612 bytenr = btrfs_node_blockptr(&cur->node, path->slots[*level]);
613 ret = lookup_block_ref(trans, root, bytenr, size, &refs);
614 if (refs != 1 || *level == 1) {
615 path->slots[*level]++;
616 ret = btrfs_free_extent(trans, root, bytenr, size, 1);
621 next = read_tree_block(root, bytenr, size);
622 if (path->nodes[*level-1])
623 btrfs_block_release(root, path->nodes[*level-1]);
624 path->nodes[*level-1] = next;
625 *level = btrfs_header_level(&next->node.header);
626 path->slots[*level] = 0;
629 ret = btrfs_free_extent(trans, root, path->nodes[*level]->bytenr,
630 btrfs_level_size(root, *level), 1);
631 btrfs_block_release(root, path->nodes[*level]);
632 path->nodes[*level] = NULL;
639 * helper for dropping snapshots. This walks back up the tree in the path
640 * to find the first node higher up where we haven't yet gone through
643 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
644 *root, struct btrfs_path *path, int *level)
649 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
650 slot = path->slots[i];
652 btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
657 ret = btrfs_free_extent(trans, root,
658 path->nodes[*level]->bytenr,
659 btrfs_level_size(root, *level), 1);
660 btrfs_block_release(root, path->nodes[*level]);
661 path->nodes[*level] = NULL;
670 * drop the reference count on the tree rooted at 'snap'. This traverses
671 * the tree freeing any blocks that have a ref count of zero after being
674 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
675 *root, struct btrfs_buffer *snap)
680 struct btrfs_path path;
684 btrfs_init_path(&path);
686 level = btrfs_header_level(&snap->node.header);
688 path.nodes[level] = snap;
689 path.slots[level] = 0;
691 wret = walk_down_tree(trans, root, &path, &level);
697 wret = walk_up_tree(trans, root, &path, &level);
703 for (i = 0; i <= orig_level; i++) {
705 btrfs_block_release(root, path.nodes[i]);
711 int btrfs_free_block_groups(struct btrfs_fs_info *info)
713 struct btrfs_block_group_cache *bg;
714 struct cache_extent *cache;
717 cache = find_first_cache_extent(&info->block_group_cache, 0);
720 bg = container_of(cache, struct btrfs_block_group_cache,
722 remove_cache_extent(&info->block_group_cache, cache);
728 int btrfs_read_block_groups(struct btrfs_root *root)
730 struct btrfs_path path;
733 struct btrfs_block_group_item *bi;
734 struct btrfs_block_group_cache *bg;
735 struct cache_tree *bg_cache;
736 struct btrfs_key key;
737 struct btrfs_key found_key;
738 struct btrfs_leaf *leaf;
739 u64 group_size = BTRFS_BLOCK_GROUP_SIZE;
741 root = root->fs_info->extent_root;
742 bg_cache = &root->fs_info->block_group_cache;
744 key.offset = group_size;
745 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
746 btrfs_init_path(&path);
749 ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
755 leaf = &path.nodes[0]->leaf;
756 btrfs_disk_key_to_cpu(&found_key,
757 &leaf->items[path.slots[0]].key);
758 bg = malloc(sizeof(*bg));
763 bi = btrfs_item_ptr(leaf, path.slots[0],
764 struct btrfs_block_group_item);
765 memcpy(&bg->item, bi, sizeof(*bi));
766 memcpy(&bg->key, &found_key, sizeof(found_key));
767 key.objectid = found_key.objectid + found_key.offset;
768 btrfs_release_path(root, &path);
769 bg->cache.start = found_key.objectid;
770 bg->cache.size = found_key.offset;
772 ret = insert_existing_cache_extent(bg_cache, &bg->cache);
775 btrfs_super_total_bytes(root->fs_info->disk_super))
778 btrfs_release_path(root, &path);
782 int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
783 struct btrfs_root *root,
784 struct btrfs_key *key,
785 struct btrfs_block_group_item *bi)
790 root = root->fs_info->extent_root;
791 ret = btrfs_insert_item(trans, root, key, bi, sizeof(*bi));
792 finish_current_insert(trans, root);
793 pending_ret = run_pending(trans, root);