3 #include "kerncompat.h"
4 #include "radix-tree.h"
7 #include "print-tree.h"
8 #include "transaction.h"
10 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
11 *orig_root, u64 num_blocks, u64 search_start, u64
12 search_end, struct btrfs_key *ins);
13 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
14 btrfs_root *extent_root);
15 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
19 * pending extents are blocks that we're trying to allocate in the extent
20 * map while trying to grow the map because of other allocations. To avoid
21 * recursing, they are tagged in the radix tree and cleaned up after
22 * other allocations are done. The pending tag is also used in the same
25 #define CTREE_EXTENT_PENDING_DEL 0
27 static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
30 struct btrfs_path path;
34 struct btrfs_extent_item *item;
38 find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1,
40 btrfs_init_path(&path);
41 key.objectid = blocknr;
43 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
45 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
50 l = &path.nodes[0]->leaf;
51 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
52 refs = btrfs_extent_refs(item);
53 btrfs_set_extent_refs(item, refs + 1);
55 BUG_ON(list_empty(&path.nodes[0]->dirty));
56 btrfs_release_path(root->fs_info->extent_root, &path);
57 finish_current_insert(trans, root->fs_info->extent_root);
58 run_pending(trans, root->fs_info->extent_root);
62 static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
63 *root, u64 blocknr, u32 *refs)
65 struct btrfs_path path;
69 struct btrfs_extent_item *item;
70 btrfs_init_path(&path);
71 key.objectid = blocknr;
74 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
75 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
79 l = &path.nodes[0]->leaf;
80 item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item);
81 *refs = btrfs_extent_refs(item);
82 btrfs_release_path(root->fs_info->extent_root, &path);
86 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
87 struct btrfs_buffer *buf)
94 if (btrfs_is_leaf(&buf->node))
97 for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) {
98 blocknr = btrfs_node_blockptr(&buf->node, i);
99 inc_block_ref(trans, root, blocknr);
104 static int write_one_cache_group(struct btrfs_trans_handle *trans,
105 struct btrfs_root *root,
106 struct btrfs_path *path,
107 struct btrfs_block_group_cache *cache)
111 struct btrfs_root *extent_root = root->fs_info->extent_root;
112 struct btrfs_block_group_item *bi;
113 struct btrfs_key ins;
115 ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
118 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
119 &cache->key, path, 0, 1);
121 bi = btrfs_item_ptr(&path->nodes[0]->leaf, path->slots[0],
122 struct btrfs_block_group_item);
123 memcpy(bi, &cache->item, sizeof(*bi));
124 dirty_tree_block(trans, extent_root, path->nodes[0]);
125 btrfs_release_path(extent_root, path);
126 finish_current_insert(trans, root);
127 pending_ret = run_pending(trans, root);
136 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
137 struct btrfs_root *root)
139 struct btrfs_block_group_cache *cache[8];
143 struct radix_tree_root *radix = &root->fs_info->block_group_radix;
145 struct btrfs_path path;
146 btrfs_init_path(&path);
149 ret = radix_tree_gang_lookup_tag(radix, (void **)cache,
150 0, ARRAY_SIZE(cache),
151 BTRFS_BLOCK_GROUP_DIRTY);
154 for (i = 0; i < ret; i++) {
155 radix_tree_tag_clear(radix, cache[i]->key.objectid +
156 cache[i]->key.offset -1,
157 BTRFS_BLOCK_GROUP_DIRTY);
158 err = write_one_cache_group(trans, root,
167 static int update_block_group(struct btrfs_trans_handle *trans,
168 struct btrfs_root *root,
169 u64 blocknr, u64 num, int alloc)
171 struct btrfs_block_group_cache *cache;
172 struct btrfs_fs_info *info = root->fs_info;
179 ret = radix_tree_gang_lookup(&info->block_group_radix,
180 (void **)&cache, blocknr, 1);
183 radix_tree_tag_set(&info->block_group_radix,
184 cache->key.objectid + cache->key.offset - 1,
185 BTRFS_BLOCK_GROUP_DIRTY);
187 block_in_group = blocknr - cache->key.objectid;
188 old_val = btrfs_block_group_used(&cache->item);
189 if (total > cache->key.offset - block_in_group)
190 num = cache->key.offset - block_in_group;
199 btrfs_set_block_group_used(&cache->item, old_val);
204 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
207 unsigned long gang[8];
213 ret = radix_tree_gang_lookup(&root->fs_info->pinned_radix,
220 for (i = 0; i < ret; i++) {
221 radix_tree_delete(&root->fs_info->pinned_radix,
225 root->fs_info->last_insert.objectid = first;
226 root->fs_info->last_insert.offset = 0;
230 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
231 btrfs_root *extent_root)
233 struct btrfs_key ins;
234 struct btrfs_extent_item extent_item;
237 u64 super_blocks_used;
238 struct btrfs_fs_info *info = extent_root->fs_info;
240 btrfs_set_extent_refs(&extent_item, 1);
241 btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
244 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
246 for (i = 0; i < extent_root->fs_info->current_insert.flags; i++) {
247 ins.objectid = extent_root->fs_info->current_insert.objectid +
249 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
250 btrfs_set_super_blocks_used(info->disk_super,
251 super_blocks_used + 1);
252 ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
253 sizeof(extent_item));
255 btrfs_print_tree(extent_root, extent_root->node);
259 extent_root->fs_info->current_insert.offset = 0;
264 * remove an extent from the root, returns 0 on success
266 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
267 *root, u64 blocknr, u64 num_blocks, int pin)
269 struct btrfs_path path;
270 struct btrfs_key key;
271 struct btrfs_fs_info *info = root->fs_info;
272 struct btrfs_root *extent_root = info->extent_root;
274 struct btrfs_extent_item *ei;
275 struct btrfs_key ins;
278 BUG_ON(pin && num_blocks != 1);
279 key.objectid = blocknr;
281 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
282 key.offset = num_blocks;
284 find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
285 btrfs_init_path(&path);
286 ret = btrfs_search_slot(trans, extent_root, &key, &path, -1, 1);
288 printf("failed to find %Lu\n", key.objectid);
289 btrfs_print_tree(extent_root, extent_root->node);
290 printf("failed to find %Lu\n", key.objectid);
293 ei = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
294 struct btrfs_extent_item);
295 BUG_ON(ei->refs == 0);
296 refs = btrfs_extent_refs(ei) - 1;
297 btrfs_set_extent_refs(ei, refs);
299 u64 super_blocks_used;
302 unsigned long bl = blocknr;
303 radix_tree_preload(GFP_KERNEL);
304 err = radix_tree_insert(&info->pinned_radix,
305 blocknr, (void *)bl);
307 radix_tree_preload_end();
309 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
310 btrfs_set_super_blocks_used(info->disk_super,
311 super_blocks_used - num_blocks);
312 ret = btrfs_del_item(trans, extent_root, &path);
313 if (!pin && extent_root->fs_info->last_insert.objectid >
315 extent_root->fs_info->last_insert.objectid = blocknr;
318 ret = update_block_group(trans, root, blocknr, num_blocks, 0);
321 btrfs_release_path(extent_root, &path);
322 finish_current_insert(trans, extent_root);
327 * find all the blocks marked as pending in the radix tree and remove
328 * them from the extent map
330 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
331 btrfs_root *extent_root)
334 struct btrfs_buffer *gang[4];
338 ret = radix_tree_gang_lookup_tag(
339 &extent_root->fs_info->cache_radix,
342 CTREE_EXTENT_PENDING_DEL);
345 for (i = 0; i < ret; i++) {
346 ret = __free_extent(trans, extent_root,
347 gang[i]->blocknr, 1, 1);
348 radix_tree_tag_clear(&extent_root->fs_info->cache_radix,
350 CTREE_EXTENT_PENDING_DEL);
351 btrfs_block_release(extent_root, gang[i]);
357 static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
360 while(radix_tree_tagged(&extent_root->fs_info->cache_radix,
361 CTREE_EXTENT_PENDING_DEL))
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 blocknr, u64 num_blocks, int pin)
373 struct btrfs_root *extent_root = root->fs_info->extent_root;
374 struct btrfs_buffer *t;
378 if (root == extent_root) {
379 t = find_tree_block(root, blocknr);
380 radix_tree_tag_set(&root->fs_info->cache_radix, blocknr,
381 CTREE_EXTENT_PENDING_DEL);
384 ret = __free_extent(trans, root, blocknr, num_blocks, pin);
385 pending_ret = run_pending(trans, root->fs_info->extent_root);
386 return ret ? ret : pending_ret;
390 * walks the btree of allocated extents and find a hole of a given size.
391 * The key ins is changed to record the hole:
392 * ins->objectid == block start
393 * ins->flags = BTRFS_EXTENT_ITEM_KEY
394 * ins->offset == number of blocks
395 * Any available blocks before search_start are skipped.
397 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
398 *orig_root, u64 num_blocks, u64 search_start, u64
399 search_end, struct btrfs_key *ins)
401 struct btrfs_path path;
402 struct btrfs_key key;
409 struct btrfs_leaf *l;
410 struct btrfs_root * root = orig_root->fs_info->extent_root;
411 int total_needed = num_blocks;
413 total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3;
414 if (root->fs_info->last_insert.objectid > search_start)
415 search_start = root->fs_info->last_insert.objectid;
418 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
421 btrfs_init_path(&path);
422 ins->objectid = search_start;
425 ret = btrfs_search_slot(trans, root, ins, &path, 0, 0);
429 if (path.slots[0] > 0)
433 l = &path.nodes[0]->leaf;
434 slot = path.slots[0];
435 if (slot >= btrfs_header_nritems(&l->header)) {
436 ret = btrfs_next_leaf(root, &path);
442 ins->objectid = search_start;
443 ins->offset = (u64)-1 - search_start;
447 ins->objectid = last_block > search_start ?
448 last_block : search_start;
449 ins->offset = (u64)-1 - ins->objectid;
452 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
453 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
455 if (key.objectid >= search_start) {
457 if (last_block < search_start)
458 last_block = search_start;
459 hole_size = key.objectid - last_block;
460 if (hole_size > total_needed) {
461 ins->objectid = last_block;
462 ins->offset = hole_size;
468 last_block = key.objectid + key.offset;
474 /* we have to make sure we didn't find an extent that has already
475 * been allocated by the map tree or the original allocation
477 btrfs_release_path(root, &path);
478 BUG_ON(ins->objectid < search_start);
479 for (test_block = ins->objectid;
480 test_block < ins->objectid + total_needed; test_block++) {
481 if (radix_tree_lookup(&root->fs_info->pinned_radix,
483 search_start = test_block + 1;
487 BUG_ON(root->fs_info->current_insert.offset);
488 root->fs_info->current_insert.offset = total_needed - num_blocks;
489 root->fs_info->current_insert.objectid = ins->objectid + num_blocks;
490 root->fs_info->current_insert.flags = 0;
491 root->fs_info->last_insert.objectid = ins->objectid;
492 ins->offset = num_blocks;
495 btrfs_release_path(root, &path);
499 * finds a free extent and does all the dirty work required for allocation
500 * returns the key for the extent through ins, and a tree buffer for
501 * the first block of the extent through buf.
503 * returns 0 if everything worked, non-zero otherwise.
505 static int alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
506 *root, u64 owner, u64 num_blocks,
507 u64 search_start, u64
508 search_end, struct btrfs_key *ins)
512 u64 super_blocks_used;
513 struct btrfs_fs_info *info = root->fs_info;
514 struct btrfs_root *extent_root = info->extent_root;
515 struct btrfs_extent_item extent_item;
517 btrfs_set_extent_refs(&extent_item, 1);
518 btrfs_set_extent_owner(&extent_item, owner);
520 if (root == extent_root) {
521 BUG_ON(extent_root->fs_info->current_insert.offset == 0);
522 BUG_ON(num_blocks != 1);
523 BUG_ON(extent_root->fs_info->current_insert.flags ==
524 extent_root->fs_info->current_insert.offset);
526 ins->objectid = extent_root->fs_info->current_insert.objectid +
527 extent_root->fs_info->current_insert.flags++;
530 ret = find_free_extent(trans, root, num_blocks, search_start,
535 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
536 btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
538 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
539 sizeof(extent_item));
541 finish_current_insert(trans, extent_root);
542 pending_ret = run_pending(trans, extent_root);
551 * helper function to allocate a block for a given tree
552 * returns the tree buffer or NULL.
554 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
555 struct btrfs_root *root)
557 struct btrfs_key ins;
559 struct btrfs_buffer *buf;
561 ret = alloc_extent(trans, root, root->root_key.objectid,
562 1, 0, (unsigned long)-1, &ins);
567 ret = update_block_group(trans, root, ins.objectid, ins.offset, 1);
568 buf = find_tree_block(root, ins.objectid);
569 btrfs_set_header_generation(&buf->node.header,
570 root->root_key.offset + 1);
571 btrfs_set_header_blocknr(&buf->node.header, buf->blocknr);
572 memcpy(buf->node.header.fsid, root->fs_info->disk_super->fsid,
573 sizeof(buf->node.header.fsid));
574 dirty_tree_block(trans, root, buf);
580 * helper function for drop_snapshot, this walks down the tree dropping ref
583 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
584 *root, struct btrfs_path *path, int *level)
586 struct btrfs_buffer *next;
587 struct btrfs_buffer *cur;
592 ret = lookup_block_ref(trans, root, path->nodes[*level]->blocknr,
598 * walk down to the last node level and free all the leaves
601 cur = path->nodes[*level];
602 if (path->slots[*level] >=
603 btrfs_header_nritems(&cur->node.header))
605 blocknr = btrfs_node_blockptr(&cur->node, path->slots[*level]);
606 ret = lookup_block_ref(trans, root, blocknr, &refs);
607 if (refs != 1 || *level == 1) {
608 path->slots[*level]++;
609 ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
614 next = read_tree_block(root, blocknr);
615 if (path->nodes[*level-1])
616 btrfs_block_release(root, path->nodes[*level-1]);
617 path->nodes[*level-1] = next;
618 *level = btrfs_header_level(&next->node.header);
619 path->slots[*level] = 0;
622 ret = btrfs_free_extent(trans, root, path->nodes[*level]->blocknr, 1,
624 btrfs_block_release(root, path->nodes[*level]);
625 path->nodes[*level] = NULL;
632 * helper for dropping snapshots. This walks back up the tree in the path
633 * to find the first node higher up where we haven't yet gone through
636 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
637 *root, struct btrfs_path *path, int *level)
642 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
643 slot = path->slots[i];
645 btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
650 ret = btrfs_free_extent(trans, root,
651 path->nodes[*level]->blocknr,
653 btrfs_block_release(root, path->nodes[*level]);
654 path->nodes[*level] = NULL;
663 * drop the reference count on the tree rooted at 'snap'. This traverses
664 * the tree freeing any blocks that have a ref count of zero after being
667 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
668 *root, struct btrfs_buffer *snap)
673 struct btrfs_path path;
677 btrfs_init_path(&path);
679 level = btrfs_header_level(&snap->node.header);
681 path.nodes[level] = snap;
682 path.slots[level] = 0;
684 wret = walk_down_tree(trans, root, &path, &level);
690 wret = walk_up_tree(trans, root, &path, &level);
696 for (i = 0; i <= orig_level; i++) {
698 btrfs_block_release(root, path.nodes[i]);
704 int btrfs_free_block_groups(struct btrfs_fs_info *info)
707 struct btrfs_block_group_cache *cache[8];
711 ret = radix_tree_gang_lookup(&info->block_group_radix,
716 for (i = 0; i < ret; i++) {
717 radix_tree_delete(&info->block_group_radix,
718 cache[i]->key.objectid +
719 cache[i]->key.offset - 1);
726 int btrfs_read_block_groups(struct btrfs_root *root)
728 struct btrfs_path path;
731 struct btrfs_block_group_item *bi;
732 struct btrfs_block_group_cache *cache;
733 struct btrfs_key key;
734 struct btrfs_key found_key;
735 struct btrfs_leaf *leaf;
736 u64 group_size_blocks = BTRFS_BLOCK_GROUP_SIZE / root->blocksize;
738 root = root->fs_info->extent_root;
740 key.offset = group_size_blocks;
742 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
743 btrfs_init_path(&path);
746 ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
752 leaf = &path.nodes[0]->leaf;
753 btrfs_disk_key_to_cpu(&found_key,
754 &leaf->items[path.slots[0]].key);
755 cache = malloc(sizeof(*cache));
760 bi = btrfs_item_ptr(leaf, path.slots[0],
761 struct btrfs_block_group_item);
762 memcpy(&cache->item, bi, sizeof(*bi));
763 memcpy(&cache->key, &found_key, sizeof(found_key));
764 key.objectid = found_key.objectid + found_key.offset;
765 btrfs_release_path(root, &path);
766 ret = radix_tree_insert(&root->fs_info->block_group_radix,
768 found_key.offset - 1, (void *)cache);
771 btrfs_super_total_blocks(root->fs_info->disk_super))
774 btrfs_release_path(root, &path);
778 int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
779 struct btrfs_root *root,
780 struct btrfs_key *key,
781 struct btrfs_block_group_item *bi)
783 struct btrfs_key ins;
787 root = root->fs_info->extent_root;
788 ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
791 ret = btrfs_insert_item(trans, root, key, bi, sizeof(*bi));
792 finish_current_insert(trans, root);
793 pending_ret = run_pending(trans, root);