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)
96 if (btrfs_is_leaf(&buf->node))
99 for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) {
100 bytenr = btrfs_node_blockptr(&buf->node, i);
101 inc_block_ref(trans, root, bytenr, root->nodesize);
106 static int write_one_cache_group(struct btrfs_trans_handle *trans,
107 struct btrfs_root *root,
108 struct btrfs_path *path,
109 struct btrfs_block_group_cache *cache)
113 struct btrfs_root *extent_root = root->fs_info->extent_root;
114 struct btrfs_block_group_item *bi;
116 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
117 &cache->key, path, 0, 1);
119 bi = btrfs_item_ptr(&path->nodes[0]->leaf, path->slots[0],
120 struct btrfs_block_group_item);
121 memcpy(bi, &cache->item, sizeof(*bi));
122 dirty_tree_block(trans, extent_root, path->nodes[0]);
123 btrfs_release_path(extent_root, path);
124 finish_current_insert(trans, root);
125 pending_ret = run_pending(trans, root);
134 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
135 struct btrfs_root *root)
137 struct btrfs_block_group_cache *bg;
138 struct cache_extent *cache;
141 struct cache_tree *bg_cache = &root->fs_info->block_group_cache;
142 struct btrfs_path path;
143 btrfs_init_path(&path);
147 cache = find_first_cache_extent(bg_cache, start);
150 bg = container_of(cache, struct btrfs_block_group_cache,
152 start = cache->start + cache->size;
154 err = write_one_cache_group(trans, root,
164 static int update_block_group(struct btrfs_trans_handle *trans,
165 struct btrfs_root *root,
166 u64 bytenr, u64 num, int alloc)
168 struct btrfs_block_group_cache *bg;
169 struct cache_extent *cache;
170 struct btrfs_fs_info *info = root->fs_info;
176 cache = find_first_cache_extent(&info->block_group_cache,
180 bg = container_of(cache, struct btrfs_block_group_cache,
183 byte_in_group = bytenr - bg->key.objectid;
184 old_val = btrfs_block_group_used(&bg->item);
185 if (total > bg->key.offset - byte_in_group)
186 num = bg->key.offset - byte_in_group;
195 btrfs_set_block_group_used(&bg->item, old_val);
200 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
204 struct cache_extent *pe;
205 struct cache_extent *next;
207 pe = find_first_cache_extent(&root->fs_info->pinned_tree, 0);
211 next = next_cache_extent(pe);
212 remove_cache_extent(&root->fs_info->pinned_tree, pe);
213 free_cache_extent(pe);
216 root->fs_info->last_insert.objectid = first;
217 root->fs_info->last_insert.offset = 0;
221 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
222 btrfs_root *extent_root)
224 struct btrfs_key ins;
225 struct btrfs_extent_item extent_item;
227 struct btrfs_fs_info *info = extent_root->fs_info;
228 struct cache_extent *pe;
229 struct cache_extent *next;
230 struct cache_tree *pending_tree = &info->pending_tree;
232 btrfs_set_extent_refs(&extent_item, 1);
233 btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
235 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
236 pe = find_first_cache_extent(pending_tree, 0);
238 ins.offset = pe->size;
239 ins.objectid = pe->start;
241 remove_cache_extent(pending_tree, pe);
242 next = next_cache_extent(pe);
244 next = find_first_cache_extent(pending_tree, 0);
246 free_cache_extent(pe);
249 ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
250 sizeof(extent_item));
252 btrfs_print_tree(extent_root, extent_root->node);
260 * remove an extent from the root, returns 0 on success
262 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
263 *root, u64 bytenr, u64 num_bytes, int pin)
265 struct btrfs_path path;
266 struct btrfs_key key;
267 struct btrfs_fs_info *info = root->fs_info;
268 struct btrfs_root *extent_root = info->extent_root;
270 struct btrfs_extent_item *ei;
273 key.objectid = bytenr;
274 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
275 key.offset = num_bytes;
277 btrfs_init_path(&path);
278 ret = btrfs_search_slot(trans, extent_root, &key, &path, -1, 1);
280 btrfs_print_tree(extent_root, extent_root->node);
281 printf("failed to find %llu\n",
282 (unsigned long long)key.objectid);
285 ei = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
286 struct btrfs_extent_item);
287 BUG_ON(ei->refs == 0);
288 refs = btrfs_extent_refs(ei) - 1;
289 btrfs_set_extent_refs(ei, refs);
291 u64 super_bytes_used, root_bytes_used;
294 err = insert_cache_extent(&info->pinned_tree,
298 super_bytes_used = btrfs_super_bytes_used(info->disk_super);
299 btrfs_set_super_bytes_used(info->disk_super,
300 super_bytes_used - num_bytes);
301 root_bytes_used = btrfs_root_bytes_used(&root->root_item);
302 btrfs_set_root_bytes_used(&root->root_item,
303 root_bytes_used - num_bytes);
305 ret = btrfs_del_item(trans, extent_root, &path);
306 if (!pin && extent_root->fs_info->last_insert.objectid >
308 extent_root->fs_info->last_insert.objectid = bytenr;
311 ret = update_block_group(trans, root, bytenr, num_bytes, 0);
314 btrfs_release_path(extent_root, &path);
315 finish_current_insert(trans, extent_root);
320 * find all the blocks marked as pending in the radix tree and remove
321 * them from the extent map
323 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
324 btrfs_root *extent_root)
327 struct cache_extent *pe;
328 struct cache_extent *next;
329 struct cache_tree *del_pending = &extent_root->fs_info->del_pending;
331 pe = find_first_cache_extent(del_pending, 0);
333 remove_cache_extent(del_pending, pe);
334 ret = __free_extent(trans, extent_root,
335 pe->start, pe->size, 1);
337 next = next_cache_extent(pe);
339 next = find_first_cache_extent(del_pending, 0);
340 free_cache_extent(pe);
346 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
349 del_pending_extents(trans, extent_root);
355 * remove an extent from the root, returns 0 on success
357 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
358 *root, u64 bytenr, u64 num_bytes, int pin)
360 struct btrfs_root *extent_root = root->fs_info->extent_root;
364 if (root == extent_root) {
365 ret = insert_cache_extent(&root->fs_info->del_pending,
370 ret = __free_extent(trans, root, bytenr, num_bytes, pin);
371 pending_ret = run_pending(trans, root->fs_info->extent_root);
372 return ret ? ret : pending_ret;
376 * walks the btree of allocated extents and find a hole of a given size.
377 * The key ins is changed to record the hole:
378 * ins->objectid == block start
379 * ins->flags = BTRFS_EXTENT_ITEM_KEY
380 * ins->offset == number of blocks
381 * Any available blocks before search_start are skipped.
383 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
384 *orig_root, u64 total_needed, u64 search_start,
385 u64 search_end, struct btrfs_key *ins)
387 struct btrfs_path path;
388 struct btrfs_key key;
394 struct btrfs_leaf *l;
395 struct btrfs_root * root = orig_root->fs_info->extent_root;
397 if (root->fs_info->last_insert.objectid > search_start)
398 search_start = root->fs_info->last_insert.objectid;
400 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
403 btrfs_init_path(&path);
404 ins->objectid = search_start;
407 ret = btrfs_search_slot(trans, root, ins, &path, 0, 0);
411 if (path.slots[0] > 0)
415 l = &path.nodes[0]->leaf;
416 slot = path.slots[0];
417 if (slot >= btrfs_header_nritems(&l->header)) {
418 ret = btrfs_next_leaf(root, &path);
424 ins->objectid = search_start;
425 ins->offset = (u64)-1 - search_start;
429 ins->objectid = last_byte > search_start ?
430 last_byte : search_start;
431 ins->offset = (u64)-1 - ins->objectid;
434 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
435 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
437 if (key.objectid >= search_start) {
439 if (last_byte < search_start)
440 last_byte = search_start;
441 hole_size = key.objectid - last_byte;
442 if (hole_size > total_needed) {
443 ins->objectid = last_byte;
444 ins->offset = hole_size;
450 last_byte = key.objectid + key.offset;
456 /* we have to make sure we didn't find an extent that has already
457 * been allocated by the map tree or the original allocation
459 btrfs_release_path(root, &path);
460 BUG_ON(ins->objectid < search_start);
461 if (find_cache_extent(&root->fs_info->pinned_tree,
462 ins->objectid, total_needed)) {
463 search_start = ins->objectid + total_needed;
466 if (find_cache_extent(&root->fs_info->pending_tree,
467 ins->objectid, total_needed)) {
468 search_start = ins->objectid + total_needed;
471 root->fs_info->last_insert.objectid = ins->objectid;
472 ins->offset = total_needed;
475 btrfs_release_path(root, &path);
479 * finds a free extent and does all the dirty work required for allocation
480 * returns the key for the extent through ins, and a tree buffer for
481 * the first block of the extent through buf.
483 * returns 0 if everything worked, non-zero otherwise.
485 static int alloc_extent(struct btrfs_trans_handle *trans,
486 struct btrfs_root *root, u64 owner,
487 u64 num_bytes, u64 search_start,
488 u64 search_end, struct btrfs_key *ins)
492 u64 super_bytes_used, root_bytes_used;
493 struct btrfs_fs_info *info = root->fs_info;
494 struct btrfs_root *extent_root = info->extent_root;
495 struct btrfs_extent_item extent_item;
497 btrfs_set_extent_refs(&extent_item, 1);
498 btrfs_set_extent_owner(&extent_item, owner);
500 ret = find_free_extent(trans, root, num_bytes, search_start,
505 super_bytes_used = btrfs_super_bytes_used(info->disk_super);
506 btrfs_set_super_bytes_used(info->disk_super, super_bytes_used +
508 root_bytes_used = btrfs_root_bytes_used(&root->root_item);
509 btrfs_set_root_bytes_used(&root->root_item, root_bytes_used +
511 if (root == extent_root) {
512 ret = insert_cache_extent(&root->fs_info->pending_tree,
513 ins->objectid, ins->offset);
518 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
519 sizeof(extent_item));
521 finish_current_insert(trans, extent_root);
522 pending_ret = run_pending(trans, extent_root);
531 * helper function to allocate a block for a given tree
532 * returns the tree buffer or NULL.
534 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
535 struct btrfs_root *root,
538 struct btrfs_key ins;
540 struct btrfs_buffer *buf;
542 ret = alloc_extent(trans, root, root->root_key.objectid,
543 blocksize, 0, (unsigned long)-1, &ins);
548 ret = update_block_group(trans, root, ins.objectid, ins.offset, 1);
549 buf = find_tree_block(root, ins.objectid, blocksize);
550 btrfs_set_header_generation(&buf->node.header,
551 root->root_key.offset + 1);
552 btrfs_set_header_bytenr(&buf->node.header, buf->bytenr);
553 memcpy(buf->node.header.fsid, root->fs_info->disk_super->fsid,
554 sizeof(buf->node.header.fsid));
555 dirty_tree_block(trans, root, buf);
561 * helper function for drop_snapshot, this walks down the tree dropping ref
564 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
565 *root, struct btrfs_path *path, int *level)
567 struct btrfs_buffer *next;
568 struct btrfs_buffer *cur;
573 ret = lookup_block_ref(trans, root, path->nodes[*level]->bytenr,
574 btrfs_level_size(root, *level), &refs);
579 * walk down to the last node level and free all the leaves
582 u32 size = btrfs_level_size(root, *level - 1);
584 cur = path->nodes[*level];
585 if (path->slots[*level] >=
586 btrfs_header_nritems(&cur->node.header))
588 bytenr = btrfs_node_blockptr(&cur->node, path->slots[*level]);
589 ret = lookup_block_ref(trans, root, bytenr, size, &refs);
590 if (refs != 1 || *level == 1) {
591 path->slots[*level]++;
592 ret = btrfs_free_extent(trans, root, bytenr, size, 1);
597 next = read_tree_block(root, bytenr, size);
598 if (path->nodes[*level-1])
599 btrfs_block_release(root, path->nodes[*level-1]);
600 path->nodes[*level-1] = next;
601 *level = btrfs_header_level(&next->node.header);
602 path->slots[*level] = 0;
605 ret = btrfs_free_extent(trans, root, path->nodes[*level]->bytenr,
606 btrfs_level_size(root, *level), 1);
607 btrfs_block_release(root, path->nodes[*level]);
608 path->nodes[*level] = NULL;
615 * helper for dropping snapshots. This walks back up the tree in the path
616 * to find the first node higher up where we haven't yet gone through
619 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
620 *root, struct btrfs_path *path, int *level)
625 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
626 slot = path->slots[i];
628 btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
633 ret = btrfs_free_extent(trans, root,
634 path->nodes[*level]->bytenr,
635 btrfs_level_size(root, *level), 1);
636 btrfs_block_release(root, path->nodes[*level]);
637 path->nodes[*level] = NULL;
646 * drop the reference count on the tree rooted at 'snap'. This traverses
647 * the tree freeing any blocks that have a ref count of zero after being
650 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
651 *root, struct btrfs_buffer *snap)
656 struct btrfs_path path;
660 btrfs_init_path(&path);
662 level = btrfs_header_level(&snap->node.header);
664 path.nodes[level] = snap;
665 path.slots[level] = 0;
667 wret = walk_down_tree(trans, root, &path, &level);
673 wret = walk_up_tree(trans, root, &path, &level);
679 for (i = 0; i <= orig_level; i++) {
681 btrfs_block_release(root, path.nodes[i]);
687 int btrfs_free_block_groups(struct btrfs_fs_info *info)
689 struct btrfs_block_group_cache *bg;
690 struct cache_extent *cache;
693 cache = find_first_cache_extent(&info->block_group_cache, 0);
696 bg = container_of(cache, struct btrfs_block_group_cache,
698 remove_cache_extent(&info->block_group_cache, cache);
704 int btrfs_read_block_groups(struct btrfs_root *root)
706 struct btrfs_path path;
709 struct btrfs_block_group_item *bi;
710 struct btrfs_block_group_cache *bg;
711 struct cache_tree *bg_cache;
712 struct btrfs_key key;
713 struct btrfs_key found_key;
714 struct btrfs_leaf *leaf;
715 u64 group_size = BTRFS_BLOCK_GROUP_SIZE;
717 root = root->fs_info->extent_root;
718 bg_cache = &root->fs_info->block_group_cache;
720 key.offset = group_size;
721 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
722 btrfs_init_path(&path);
725 ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
731 leaf = &path.nodes[0]->leaf;
732 btrfs_disk_key_to_cpu(&found_key,
733 &leaf->items[path.slots[0]].key);
734 bg = malloc(sizeof(*bg));
739 bi = btrfs_item_ptr(leaf, path.slots[0],
740 struct btrfs_block_group_item);
741 memcpy(&bg->item, bi, sizeof(*bi));
742 memcpy(&bg->key, &found_key, sizeof(found_key));
743 key.objectid = found_key.objectid + found_key.offset;
744 btrfs_release_path(root, &path);
745 bg->cache.start = found_key.objectid;
746 bg->cache.size = found_key.offset;
747 ret = insert_existing_cache_extent(bg_cache, &bg->cache);
750 btrfs_super_total_bytes(root->fs_info->disk_super))
753 btrfs_release_path(root, &path);
757 int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
758 struct btrfs_root *root,
759 struct btrfs_key *key,
760 struct btrfs_block_group_item *bi)
765 root = root->fs_info->extent_root;
766 ret = btrfs_insert_item(trans, root, key, bi, sizeof(*bi));
767 finish_current_insert(trans, root);
768 pending_ret = run_pending(trans, root);