1 #include <linux/module.h>
4 #include "print-tree.h"
5 #include "transaction.h"
7 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
8 *orig_root, u64 num_blocks, u64 search_start, u64
9 search_end, struct btrfs_key *ins);
10 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
11 btrfs_root *extent_root);
12 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
13 btrfs_root *extent_root);
15 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
16 struct btrfs_root *root,
17 u64 blocknr, u64 num_blocks)
19 struct btrfs_path *path;
23 struct btrfs_extent_item *item;
27 find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1,
29 path = btrfs_alloc_path();
31 btrfs_init_path(path);
32 key.objectid = blocknr;
34 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
35 key.offset = num_blocks;
36 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
39 printk("can't find block %Lu %Lu\n", blocknr, num_blocks);
43 l = btrfs_buffer_leaf(path->nodes[0]);
44 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
45 refs = btrfs_extent_refs(item);
46 btrfs_set_extent_refs(item, refs + 1);
47 btrfs_mark_buffer_dirty(path->nodes[0]);
49 btrfs_release_path(root->fs_info->extent_root, path);
50 btrfs_free_path(path);
51 finish_current_insert(trans, root->fs_info->extent_root);
52 del_pending_extents(trans, root->fs_info->extent_root);
56 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
57 struct btrfs_root *root, u64 blocknr,
58 u64 num_blocks, u32 *refs)
60 struct btrfs_path *path;
64 struct btrfs_extent_item *item;
66 path = btrfs_alloc_path();
67 btrfs_init_path(path);
68 key.objectid = blocknr;
69 key.offset = num_blocks;
71 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
72 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
76 l = btrfs_buffer_leaf(path->nodes[0]);
77 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
78 *refs = btrfs_extent_refs(item);
79 btrfs_release_path(root->fs_info->extent_root, path);
80 btrfs_free_path(path);
84 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
85 struct btrfs_root *root)
87 return btrfs_inc_extent_ref(trans, root, bh_blocknr(root->node), 1);
90 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
91 struct buffer_head *buf)
94 struct btrfs_node *buf_node;
95 struct btrfs_leaf *buf_leaf;
96 struct btrfs_disk_key *key;
97 struct btrfs_file_extent_item *fi;
104 buf_node = btrfs_buffer_node(buf);
105 leaf = btrfs_is_leaf(buf_node);
106 buf_leaf = btrfs_buffer_leaf(buf);
107 for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) {
109 key = &buf_leaf->items[i].key;
110 if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
112 fi = btrfs_item_ptr(buf_leaf, i,
113 struct btrfs_file_extent_item);
114 if (btrfs_file_extent_type(fi) ==
115 BTRFS_FILE_EXTENT_INLINE)
117 ret = btrfs_inc_extent_ref(trans, root,
118 btrfs_file_extent_disk_blocknr(fi),
119 btrfs_file_extent_disk_num_blocks(fi));
122 blocknr = btrfs_node_blockptr(buf_node, i);
123 ret = btrfs_inc_extent_ref(trans, root, blocknr, 1);
130 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
133 unsigned long gang[8];
137 struct radix_tree_root *pinned_radix = &root->fs_info->pinned_radix;
140 ret = find_first_radix_bit(pinned_radix, gang,
146 for (i = 0; i < ret; i++) {
147 clear_radix_bit(pinned_radix, gang[i]);
150 if (root->fs_info->last_insert.objectid > first)
151 root->fs_info->last_insert.objectid = first;
152 root->fs_info->last_insert.offset = 0;
156 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
157 btrfs_root *extent_root)
159 struct btrfs_key ins;
160 struct btrfs_extent_item extent_item;
163 u64 super_blocks_used;
164 struct btrfs_fs_info *info = extent_root->fs_info;
166 btrfs_set_extent_refs(&extent_item, 1);
169 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
170 btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
172 for (i = 0; i < extent_root->fs_info->extent_tree_insert_nr; i++) {
173 ins.objectid = extent_root->fs_info->extent_tree_insert[i];
174 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
175 btrfs_set_super_blocks_used(info->disk_super,
176 super_blocks_used + 1);
177 ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
178 sizeof(extent_item));
181 extent_root->fs_info->extent_tree_insert_nr = 0;
182 extent_root->fs_info->extent_tree_prealloc_nr = 0;
186 static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending)
189 struct btrfs_header *header;
190 struct buffer_head *bh;
193 bh = btrfs_find_tree_block(root, blocknr);
195 if (buffer_uptodate(bh)) {
197 root->fs_info->running_transaction->transid;
198 header = btrfs_buffer_header(bh);
199 if (btrfs_header_generation(header) ==
201 btrfs_block_release(root, bh);
205 btrfs_block_release(root, bh);
207 err = set_radix_bit(&root->fs_info->pinned_radix, blocknr);
209 err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr);
216 * remove an extent from the root, returns 0 on success
218 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
219 *root, u64 blocknr, u64 num_blocks, int pin)
221 struct btrfs_path *path;
222 struct btrfs_key key;
223 struct btrfs_fs_info *info = root->fs_info;
224 struct btrfs_root *extent_root = info->extent_root;
226 struct btrfs_extent_item *ei;
227 struct btrfs_key ins;
230 key.objectid = blocknr;
232 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
233 key.offset = num_blocks;
235 find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
236 path = btrfs_alloc_path();
238 btrfs_init_path(path);
240 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
242 printk("failed to find %Lu\n", key.objectid);
243 btrfs_print_tree(extent_root, extent_root->node);
244 printk("failed to find %Lu\n", key.objectid);
247 ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
248 struct btrfs_extent_item);
249 BUG_ON(ei->refs == 0);
250 refs = btrfs_extent_refs(ei) - 1;
251 btrfs_set_extent_refs(ei, refs);
252 btrfs_mark_buffer_dirty(path->nodes[0]);
254 u64 super_blocks_used;
257 ret = pin_down_block(root, blocknr, 0);
261 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
262 btrfs_set_super_blocks_used(info->disk_super,
263 super_blocks_used - num_blocks);
264 ret = btrfs_del_item(trans, extent_root, path);
268 btrfs_release_path(extent_root, path);
269 btrfs_free_path(path);
270 finish_current_insert(trans, extent_root);
275 * find all the blocks marked as pending in the radix tree and remove
276 * them from the extent map
278 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
279 btrfs_root *extent_root)
284 unsigned long gang[4];
286 struct radix_tree_root *pending_radix;
287 struct radix_tree_root *pinned_radix;
289 pending_radix = &extent_root->fs_info->pending_del_radix;
290 pinned_radix = &extent_root->fs_info->pinned_radix;
293 ret = find_first_radix_bit(pending_radix, gang,
297 for (i = 0; i < ret; i++) {
298 wret = set_radix_bit(pinned_radix, gang[i]);
300 wret = clear_radix_bit(pending_radix, gang[i]);
302 wret = __free_extent(trans, extent_root,
312 * remove an extent from the root, returns 0 on success
314 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
315 *root, u64 blocknr, u64 num_blocks, int pin)
317 struct btrfs_root *extent_root = root->fs_info->extent_root;
321 if (root == extent_root) {
322 pin_down_block(root, blocknr, 1);
325 ret = __free_extent(trans, root, blocknr, num_blocks, pin);
326 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
327 return ret ? ret : pending_ret;
331 * walks the btree of allocated extents and find a hole of a given size.
332 * The key ins is changed to record the hole:
333 * ins->objectid == block start
334 * ins->flags = BTRFS_EXTENT_ITEM_KEY
335 * ins->offset == number of blocks
336 * Any available blocks before search_start are skipped.
338 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
339 *orig_root, u64 num_blocks, u64 search_start, u64
340 search_end, struct btrfs_key *ins)
342 struct btrfs_path *path;
343 struct btrfs_key key;
350 struct btrfs_leaf *l;
351 struct btrfs_root * root = orig_root->fs_info->extent_root;
352 struct btrfs_fs_info *info = root->fs_info;
353 int total_needed = num_blocks;
355 int fill_prealloc = 0;
358 path = btrfs_alloc_path();
360 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
362 level = btrfs_header_level(btrfs_buffer_header(root->node));
363 if (num_blocks == 0) {
366 total_needed = min(level + 2, BTRFS_MAX_LEVEL) * 3;
368 if (info->last_insert.objectid == 0 && search_end == (u64)-1) {
369 struct btrfs_disk_key *last_key;
370 btrfs_init_path(path);
371 ins->objectid = (u64)-1;
372 ins->offset = (u64)-1;
373 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
377 if (path->slots[0] > 0)
379 l = btrfs_buffer_leaf(path->nodes[0]);
380 last_key = &l->items[path->slots[0]].key;
381 search_start = btrfs_disk_key_objectid(last_key);
383 if (info->last_insert.objectid > search_start)
384 search_start = info->last_insert.objectid;
387 btrfs_init_path(path);
388 ins->objectid = search_start;
391 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
395 if (path->slots[0] > 0)
399 l = btrfs_buffer_leaf(path->nodes[0]);
400 slot = path->slots[0];
401 if (slot >= btrfs_header_nritems(&l->header)) {
403 info->extent_tree_prealloc_nr = 0;
406 ret = btrfs_next_leaf(root, path);
412 ins->objectid = search_start;
413 ins->offset = (u64)-1 - search_start;
417 ins->objectid = last_block > search_start ?
418 last_block : search_start;
419 ins->offset = (u64)-1 - ins->objectid;
422 btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
423 if (key.objectid >= search_start) {
425 if (last_block < search_start)
426 last_block = search_start;
427 hole_size = key.objectid - last_block;
428 if (hole_size > num_blocks) {
429 ins->objectid = last_block;
430 ins->offset = hole_size;
436 last_block = key.objectid + key.offset;
441 /* we have to make sure we didn't find an extent that has already
442 * been allocated by the map tree or the original allocation
444 btrfs_release_path(root, path);
445 BUG_ON(ins->objectid < search_start);
446 for (test_block = ins->objectid;
447 test_block < ins->objectid + num_blocks; test_block++) {
448 if (test_radix_bit(&info->pinned_radix, test_block)) {
449 search_start = test_block + 1;
453 if (!fill_prealloc && info->extent_tree_insert_nr) {
455 info->extent_tree_insert[info->extent_tree_insert_nr - 1];
456 if (ins->objectid + num_blocks >
457 info->extent_tree_insert[0] &&
458 ins->objectid <= last) {
459 search_start = last + 1;
464 if (!fill_prealloc && info->extent_tree_prealloc_nr) {
466 info->extent_tree_prealloc[info->extent_tree_prealloc_nr - 1];
467 if (ins->objectid + num_blocks > first &&
468 ins->objectid <= info->extent_tree_prealloc[0]) {
469 search_start = info->extent_tree_prealloc[0] + 1;
476 test_block = ins->objectid;
477 while(test_block < ins->objectid + ins->offset &&
478 total_found < total_needed) {
479 nr = total_needed - total_found - 1;
481 root->fs_info->extent_tree_prealloc[nr] =
486 if (total_found < total_needed) {
487 search_start = test_block;
490 root->fs_info->extent_tree_prealloc_nr = total_found;
492 root->fs_info->last_insert.objectid = ins->objectid;
493 ins->offset = num_blocks;
494 btrfs_free_path(path);
497 btrfs_release_path(root, path);
498 btrfs_free_path(path);
503 * finds a free extent and does all the dirty work required for allocation
504 * returns the key for the extent through ins, and a tree buffer for
505 * the first block of the extent through buf.
507 * returns 0 if everything worked, non-zero otherwise.
509 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
510 struct btrfs_root *root, u64 owner,
511 u64 num_blocks, u64 search_start,
512 u64 search_end, struct btrfs_key *ins)
516 u64 super_blocks_used;
517 struct btrfs_fs_info *info = root->fs_info;
518 struct btrfs_root *extent_root = info->extent_root;
519 struct btrfs_extent_item extent_item;
520 struct btrfs_key prealloc_key;
522 btrfs_set_extent_refs(&extent_item, 1);
523 btrfs_set_extent_owner(&extent_item, owner);
525 if (root == extent_root) {
527 BUG_ON(info->extent_tree_prealloc_nr == 0);
528 BUG_ON(num_blocks != 1);
530 info->extent_tree_prealloc_nr--;
531 nr = info->extent_tree_prealloc_nr;
532 ins->objectid = info->extent_tree_prealloc[nr];
533 info->extent_tree_insert[info->extent_tree_insert_nr++] =
537 /* do the real allocation */
538 ret = find_free_extent(trans, root, num_blocks, search_start,
543 /* then do prealloc for the extent tree */
544 ret = find_free_extent(trans, root, 0, ins->objectid + ins->offset,
545 search_end, &prealloc_key);
549 super_blocks_used = btrfs_super_blocks_used(info->disk_super);
550 btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
552 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
553 sizeof(extent_item));
555 finish_current_insert(trans, extent_root);
556 pending_ret = del_pending_extents(trans, extent_root);
565 * helper function to allocate a block for a given tree
566 * returns the tree buffer or NULL.
568 struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
569 struct btrfs_root *root)
571 struct btrfs_key ins;
573 struct buffer_head *buf;
575 ret = btrfs_alloc_extent(trans, root, root->root_key.objectid,
576 1, 0, (unsigned long)-1, &ins);
581 buf = btrfs_find_create_tree_block(root, ins.objectid);
582 set_buffer_uptodate(buf);
586 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
587 struct btrfs_root *root, struct buffer_head *cur)
589 struct btrfs_disk_key *key;
590 struct btrfs_leaf *leaf;
591 struct btrfs_file_extent_item *fi;
596 BUG_ON(!btrfs_is_leaf(btrfs_buffer_node(cur)));
597 leaf = btrfs_buffer_leaf(cur);
598 nritems = btrfs_header_nritems(&leaf->header);
599 for (i = 0; i < nritems; i++) {
600 key = &leaf->items[i].key;
601 if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
603 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
604 if (btrfs_file_extent_type(fi) == BTRFS_FILE_EXTENT_INLINE)
607 * FIXME make sure to insert a trans record that
608 * repeats the snapshot del on crash
610 ret = btrfs_free_extent(trans, root,
611 btrfs_file_extent_disk_blocknr(fi),
612 btrfs_file_extent_disk_num_blocks(fi),
620 * helper function for drop_snapshot, this walks down the tree dropping ref
623 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
624 *root, struct btrfs_path *path, int *level)
626 struct buffer_head *next;
627 struct buffer_head *cur;
633 WARN_ON(*level >= BTRFS_MAX_LEVEL);
634 ret = lookup_extent_ref(trans, root, bh_blocknr(path->nodes[*level]),
640 * walk down to the last node level and free all the leaves
644 WARN_ON(*level >= BTRFS_MAX_LEVEL);
645 cur = path->nodes[*level];
646 if (btrfs_header_level(btrfs_buffer_header(cur)) != *level)
648 if (path->slots[*level] >=
649 btrfs_header_nritems(btrfs_buffer_header(cur)))
652 ret = drop_leaf_ref(trans, root, cur);
656 blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur),
657 path->slots[*level]);
658 ret = lookup_extent_ref(trans, root, blocknr, 1, &refs);
661 path->slots[*level]++;
662 ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
666 next = read_tree_block(root, blocknr);
667 WARN_ON(*level <= 0);
668 if (path->nodes[*level-1])
669 btrfs_block_release(root, path->nodes[*level-1]);
670 path->nodes[*level-1] = next;
671 *level = btrfs_header_level(btrfs_buffer_header(next));
672 path->slots[*level] = 0;
676 WARN_ON(*level >= BTRFS_MAX_LEVEL);
677 ret = btrfs_free_extent(trans, root,
678 bh_blocknr(path->nodes[*level]), 1, 1);
679 btrfs_block_release(root, path->nodes[*level]);
680 path->nodes[*level] = NULL;
687 * helper for dropping snapshots. This walks back up the tree in the path
688 * to find the first node higher up where we haven't yet gone through
691 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
692 *root, struct btrfs_path *path, int *level)
697 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
698 slot = path->slots[i];
699 if (slot < btrfs_header_nritems(
700 btrfs_buffer_header(path->nodes[i])) - 1) {
705 ret = btrfs_free_extent(trans, root,
706 bh_blocknr(path->nodes[*level]),
709 btrfs_block_release(root, path->nodes[*level]);
710 path->nodes[*level] = NULL;
718 * drop the reference count on the tree rooted at 'snap'. This traverses
719 * the tree freeing any blocks that have a ref count of zero after being
722 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
723 *root, struct buffer_head *snap)
728 struct btrfs_path *path;
732 path = btrfs_alloc_path();
734 btrfs_init_path(path);
736 level = btrfs_header_level(btrfs_buffer_header(snap));
738 path->nodes[level] = snap;
739 path->slots[level] = 0;
741 wret = walk_down_tree(trans, root, path, &level);
747 wret = walk_up_tree(trans, root, path, &level);
753 for (i = 0; i <= orig_level; i++) {
754 if (path->nodes[i]) {
755 btrfs_block_release(root, path->nodes[i]);
758 btrfs_free_path(path);