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;
375 static u64 stripe_align(struct btrfs_root *root, u64 val)
377 u64 mask = ((u64)root->stripesize - 1);
378 u64 ret = (val + mask) & ~mask;
383 * walks the btree of allocated extents and find a hole of a given size.
384 * The key ins is changed to record the hole:
385 * ins->objectid == block start
386 * ins->flags = BTRFS_EXTENT_ITEM_KEY
387 * ins->offset == number of blocks
388 * Any available blocks before search_start are skipped.
390 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
391 *orig_root, u64 total_needed, u64 search_start,
392 u64 search_end, struct btrfs_key *ins)
394 struct btrfs_path path;
395 struct btrfs_key key;
402 struct btrfs_leaf *l;
403 struct btrfs_root * root = orig_root->fs_info->extent_root;
405 if (root->fs_info->last_insert.objectid > search_start)
406 search_start = root->fs_info->last_insert.objectid;
408 search_start = stripe_align(root, search_start);
409 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
412 btrfs_init_path(&path);
413 ins->objectid = search_start;
416 ret = btrfs_search_slot(trans, root, ins, &path, 0, 0);
420 if (path.slots[0] > 0)
424 l = &path.nodes[0]->leaf;
425 slot = path.slots[0];
426 if (slot >= btrfs_header_nritems(&l->header)) {
427 ret = btrfs_next_leaf(root, &path);
433 aligned = stripe_align(root, search_start);
434 ins->objectid = aligned;
435 ins->offset = (u64)-1 - aligned;
439 ins->objectid = stripe_align(root,
440 last_byte > search_start ?
441 last_byte : search_start);
442 ins->offset = (u64)-1 - ins->objectid;
445 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
446 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
448 if (key.objectid >= search_start) {
450 if (last_byte < search_start)
451 last_byte = search_start;
452 aligned = stripe_align(root, last_byte);
453 hole_size = key.objectid - aligned;
454 if (key.objectid > aligned &&
455 hole_size > total_needed) {
456 ins->objectid = aligned;
457 ins->offset = hole_size;
463 last_byte = key.objectid + key.offset;
469 /* we have to make sure we didn't find an extent that has already
470 * been allocated by the map tree or the original allocation
472 btrfs_release_path(root, &path);
473 BUG_ON(ins->objectid < search_start);
474 if (find_cache_extent(&root->fs_info->pinned_tree,
475 ins->objectid, total_needed)) {
476 search_start = ins->objectid + total_needed;
479 if (find_cache_extent(&root->fs_info->pending_tree,
480 ins->objectid, total_needed)) {
481 search_start = ins->objectid + total_needed;
484 root->fs_info->last_insert.objectid = ins->objectid;
485 ins->offset = total_needed;
488 btrfs_release_path(root, &path);
492 * finds a free extent and does all the dirty work required for allocation
493 * returns the key for the extent through ins, and a tree buffer for
494 * the first block of the extent through buf.
496 * returns 0 if everything worked, non-zero otherwise.
498 static int alloc_extent(struct btrfs_trans_handle *trans,
499 struct btrfs_root *root, u64 owner,
500 u64 num_bytes, u64 search_start,
501 u64 search_end, struct btrfs_key *ins)
505 u64 super_bytes_used, root_bytes_used;
506 struct btrfs_fs_info *info = root->fs_info;
507 struct btrfs_root *extent_root = info->extent_root;
508 struct btrfs_extent_item extent_item;
510 btrfs_set_extent_refs(&extent_item, 1);
511 btrfs_set_extent_owner(&extent_item, owner);
513 ret = find_free_extent(trans, root, num_bytes, search_start,
518 super_bytes_used = btrfs_super_bytes_used(info->disk_super);
519 btrfs_set_super_bytes_used(info->disk_super, super_bytes_used +
521 root_bytes_used = btrfs_root_bytes_used(&root->root_item);
522 btrfs_set_root_bytes_used(&root->root_item, root_bytes_used +
524 if (root == extent_root) {
525 ret = insert_cache_extent(&root->fs_info->pending_tree,
526 ins->objectid, ins->offset);
531 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
532 sizeof(extent_item));
534 finish_current_insert(trans, extent_root);
535 pending_ret = run_pending(trans, extent_root);
544 * helper function to allocate a block for a given tree
545 * returns the tree buffer or NULL.
547 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
548 struct btrfs_root *root,
551 struct btrfs_key ins;
553 struct btrfs_buffer *buf;
555 ret = alloc_extent(trans, root, root->root_key.objectid,
556 blocksize, 0, (unsigned long)-1, &ins);
561 ret = update_block_group(trans, root, ins.objectid, ins.offset, 1);
562 buf = find_tree_block(root, ins.objectid, blocksize);
563 btrfs_set_header_generation(&buf->node.header,
564 root->root_key.offset + 1);
565 btrfs_set_header_bytenr(&buf->node.header, buf->bytenr);
566 memcpy(buf->node.header.fsid, root->fs_info->disk_super->fsid,
567 sizeof(buf->node.header.fsid));
568 dirty_tree_block(trans, root, buf);
574 * helper function for drop_snapshot, this walks down the tree dropping ref
577 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
578 *root, struct btrfs_path *path, int *level)
580 struct btrfs_buffer *next;
581 struct btrfs_buffer *cur;
586 ret = lookup_block_ref(trans, root, path->nodes[*level]->bytenr,
587 btrfs_level_size(root, *level), &refs);
592 * walk down to the last node level and free all the leaves
595 u32 size = btrfs_level_size(root, *level - 1);
597 cur = path->nodes[*level];
598 if (path->slots[*level] >=
599 btrfs_header_nritems(&cur->node.header))
601 bytenr = btrfs_node_blockptr(&cur->node, path->slots[*level]);
602 ret = lookup_block_ref(trans, root, bytenr, size, &refs);
603 if (refs != 1 || *level == 1) {
604 path->slots[*level]++;
605 ret = btrfs_free_extent(trans, root, bytenr, size, 1);
610 next = read_tree_block(root, bytenr, size);
611 if (path->nodes[*level-1])
612 btrfs_block_release(root, path->nodes[*level-1]);
613 path->nodes[*level-1] = next;
614 *level = btrfs_header_level(&next->node.header);
615 path->slots[*level] = 0;
618 ret = btrfs_free_extent(trans, root, path->nodes[*level]->bytenr,
619 btrfs_level_size(root, *level), 1);
620 btrfs_block_release(root, path->nodes[*level]);
621 path->nodes[*level] = NULL;
628 * helper for dropping snapshots. This walks back up the tree in the path
629 * to find the first node higher up where we haven't yet gone through
632 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
633 *root, struct btrfs_path *path, int *level)
638 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
639 slot = path->slots[i];
641 btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
646 ret = btrfs_free_extent(trans, root,
647 path->nodes[*level]->bytenr,
648 btrfs_level_size(root, *level), 1);
649 btrfs_block_release(root, path->nodes[*level]);
650 path->nodes[*level] = NULL;
659 * drop the reference count on the tree rooted at 'snap'. This traverses
660 * the tree freeing any blocks that have a ref count of zero after being
663 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
664 *root, struct btrfs_buffer *snap)
669 struct btrfs_path path;
673 btrfs_init_path(&path);
675 level = btrfs_header_level(&snap->node.header);
677 path.nodes[level] = snap;
678 path.slots[level] = 0;
680 wret = walk_down_tree(trans, root, &path, &level);
686 wret = walk_up_tree(trans, root, &path, &level);
692 for (i = 0; i <= orig_level; i++) {
694 btrfs_block_release(root, path.nodes[i]);
700 int btrfs_free_block_groups(struct btrfs_fs_info *info)
702 struct btrfs_block_group_cache *bg;
703 struct cache_extent *cache;
706 cache = find_first_cache_extent(&info->block_group_cache, 0);
709 bg = container_of(cache, struct btrfs_block_group_cache,
711 remove_cache_extent(&info->block_group_cache, cache);
717 int btrfs_read_block_groups(struct btrfs_root *root)
719 struct btrfs_path path;
722 struct btrfs_block_group_item *bi;
723 struct btrfs_block_group_cache *bg;
724 struct cache_tree *bg_cache;
725 struct btrfs_key key;
726 struct btrfs_key found_key;
727 struct btrfs_leaf *leaf;
728 u64 group_size = BTRFS_BLOCK_GROUP_SIZE;
730 root = root->fs_info->extent_root;
731 bg_cache = &root->fs_info->block_group_cache;
733 key.offset = group_size;
734 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
735 btrfs_init_path(&path);
738 ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
744 leaf = &path.nodes[0]->leaf;
745 btrfs_disk_key_to_cpu(&found_key,
746 &leaf->items[path.slots[0]].key);
747 bg = malloc(sizeof(*bg));
752 bi = btrfs_item_ptr(leaf, path.slots[0],
753 struct btrfs_block_group_item);
754 memcpy(&bg->item, bi, sizeof(*bi));
755 memcpy(&bg->key, &found_key, sizeof(found_key));
756 key.objectid = found_key.objectid + found_key.offset;
757 btrfs_release_path(root, &path);
758 bg->cache.start = found_key.objectid;
759 bg->cache.size = found_key.offset;
761 ret = insert_existing_cache_extent(bg_cache, &bg->cache);
764 btrfs_super_total_bytes(root->fs_info->disk_super))
767 btrfs_release_path(root, &path);
771 int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
772 struct btrfs_root *root,
773 struct btrfs_key *key,
774 struct btrfs_block_group_item *bi)
779 root = root->fs_info->extent_root;
780 ret = btrfs_insert_item(trans, root, key, bi, sizeof(*bi));
781 finish_current_insert(trans, root);
782 pending_ret = run_pending(trans, root);