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.
19 #include <linux/sched.h>
20 #include <linux/crc32c.h>
21 #include <linux/pagemap.h>
25 #include "print-tree.h"
26 #include "transaction.h"
28 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
29 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
30 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
32 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
33 btrfs_root *extent_root);
34 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
35 btrfs_root *extent_root);
37 static int cache_block_group(struct btrfs_root *root,
38 struct btrfs_block_group_cache *block_group)
40 struct btrfs_path *path;
43 struct extent_buffer *leaf;
44 struct extent_map_tree *free_space_cache;
54 root = root->fs_info->extent_root;
55 free_space_cache = &root->fs_info->free_space_cache;
57 if (block_group->cached)
60 path = btrfs_alloc_path();
65 first_free = block_group->key.objectid;
66 key.objectid = block_group->key.objectid;
69 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
70 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
75 if (ret && path->slots[0] > 0)
79 leaf = path->nodes[0];
80 slot = path->slots[0];
81 if (slot >= btrfs_header_nritems(leaf)) {
82 ret = btrfs_next_leaf(root, path);
92 btrfs_item_key_to_cpu(leaf, &key, slot);
93 if (key.objectid < block_group->key.objectid) {
94 if (btrfs_key_type(&key) != BTRFS_EXTENT_REF_KEY &&
95 key.objectid + key.offset > first_free)
96 first_free = key.objectid + key.offset;
100 if (key.objectid >= block_group->key.objectid +
101 block_group->key.offset) {
105 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
110 if (key.objectid > last) {
111 hole_size = key.objectid - last;
112 set_extent_dirty(free_space_cache, last,
113 last + hole_size - 1,
116 last = key.objectid + key.offset;
124 if (block_group->key.objectid +
125 block_group->key.offset > last) {
126 hole_size = block_group->key.objectid +
127 block_group->key.offset - last;
128 set_extent_dirty(free_space_cache, last,
129 last + hole_size - 1, GFP_NOFS);
131 block_group->cached = 1;
133 btrfs_free_path(path);
137 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
141 struct extent_map_tree *block_group_cache;
142 struct btrfs_block_group_cache *block_group = NULL;
148 block_group_cache = &info->block_group_cache;
149 ret = find_first_extent_bit(block_group_cache,
150 bytenr, &start, &end,
151 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA);
155 ret = get_state_private(block_group_cache, start, &ptr);
159 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
160 if (block_group->key.objectid <= bytenr && bytenr <
161 block_group->key.objectid + block_group->key.offset)
165 static u64 find_search_start(struct btrfs_root *root,
166 struct btrfs_block_group_cache **cache_ret,
167 u64 search_start, int num,
168 int data, int full_scan)
171 struct btrfs_block_group_cache *cache = *cache_ret;
182 ret = cache_block_group(root, cache);
186 last = max(search_start, cache->key.objectid);
189 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
190 last, &start, &end, EXTENT_DIRTY);
197 start = max(last, start);
199 if (last - start < num) {
200 if (last == cache->key.objectid + cache->key.offset)
204 if (data != BTRFS_BLOCK_GROUP_MIXED &&
205 start + num > cache->key.objectid + cache->key.offset)
210 cache = btrfs_lookup_block_group(root->fs_info, search_start);
212 printk("Unable to find block group for %Lu\n",
220 last = cache->key.objectid + cache->key.offset;
222 cache = btrfs_lookup_block_group(root->fs_info, last);
228 data = BTRFS_BLOCK_GROUP_MIXED;
233 if (cache_miss && !cache->cached) {
234 cache_block_group(root, cache);
236 cache = btrfs_lookup_block_group(root->fs_info, last);
238 cache = btrfs_find_block_group(root, cache, last, data, 0);
246 static u64 div_factor(u64 num, int factor)
255 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
256 struct btrfs_block_group_cache
257 *hint, u64 search_start,
260 struct btrfs_block_group_cache *cache;
261 struct extent_map_tree *block_group_cache;
262 struct btrfs_block_group_cache *found_group = NULL;
263 struct btrfs_fs_info *info = root->fs_info;
277 block_group_cache = &info->block_group_cache;
282 if (data == BTRFS_BLOCK_GROUP_MIXED) {
283 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
286 bit = BLOCK_GROUP_DATA;
288 bit = BLOCK_GROUP_METADATA;
291 struct btrfs_block_group_cache *shint;
292 shint = btrfs_lookup_block_group(info, search_start);
293 if (shint && (shint->data == data ||
294 shint->data == BTRFS_BLOCK_GROUP_MIXED)) {
295 used = btrfs_block_group_used(&shint->item);
296 if (used + shint->pinned <
297 div_factor(shint->key.offset, factor)) {
302 if (hint && (hint->data == data ||
303 hint->data == BTRFS_BLOCK_GROUP_MIXED)) {
304 used = btrfs_block_group_used(&hint->item);
305 if (used + hint->pinned <
306 div_factor(hint->key.offset, factor)) {
309 last = hint->key.objectid + hint->key.offset;
313 hint_last = max(hint->key.objectid, search_start);
315 hint_last = search_start;
321 ret = find_first_extent_bit(block_group_cache, last,
326 ret = get_state_private(block_group_cache, start, &ptr);
330 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
331 last = cache->key.objectid + cache->key.offset;
332 used = btrfs_block_group_used(&cache->item);
335 free_check = cache->key.offset;
337 free_check = div_factor(cache->key.offset, factor);
338 if (used + cache->pinned < free_check) {
351 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
359 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
360 u64 owner, u64 owner_offset)
362 u32 high_crc = ~(u32)0;
363 u32 low_crc = ~(u32)0;
366 lenum = cpu_to_le64(root_objectid);
367 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
368 lenum = cpu_to_le64(ref_generation);
369 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
372 lenum = cpu_to_le64(owner);
373 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
374 lenum = cpu_to_le64(owner_offset);
375 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
377 return ((u64)high_crc << 32) | (u64)low_crc;
380 static int match_extent_ref(struct extent_buffer *leaf,
381 struct btrfs_extent_ref *disk_ref,
382 struct btrfs_extent_ref *cpu_ref)
387 if (cpu_ref->objectid)
388 len = sizeof(*cpu_ref);
390 len = 2 * sizeof(u64);
391 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
396 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
397 struct btrfs_root *root,
398 struct btrfs_path *path, u64 bytenr,
399 u64 root_objectid, u64 ref_generation,
400 u64 owner, u64 owner_offset, int del)
403 struct btrfs_key key;
404 struct btrfs_key found_key;
405 struct btrfs_extent_ref ref;
406 struct extent_buffer *leaf;
407 struct btrfs_extent_ref *disk_ref;
411 btrfs_set_stack_ref_root(&ref, root_objectid);
412 btrfs_set_stack_ref_generation(&ref, ref_generation);
413 btrfs_set_stack_ref_objectid(&ref, owner);
414 btrfs_set_stack_ref_offset(&ref, owner_offset);
416 hash = hash_extent_ref(root_objectid, ref_generation, owner,
419 key.objectid = bytenr;
420 key.type = BTRFS_EXTENT_REF_KEY;
423 ret = btrfs_search_slot(trans, root, &key, path,
427 leaf = path->nodes[0];
429 u32 nritems = btrfs_header_nritems(leaf);
430 if (path->slots[0] >= nritems) {
431 ret2 = btrfs_next_leaf(root, path);
434 leaf = path->nodes[0];
436 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
437 if (found_key.objectid != bytenr ||
438 found_key.type != BTRFS_EXTENT_REF_KEY)
440 key.offset = found_key.offset;
442 btrfs_release_path(root, path);
446 disk_ref = btrfs_item_ptr(path->nodes[0],
448 struct btrfs_extent_ref);
449 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
453 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
454 key.offset = found_key.offset + 1;
455 btrfs_release_path(root, path);
462 * Back reference rules. Back refs have three main goals:
464 * 1) differentiate between all holders of references to an extent so that
465 * when a reference is dropped we can make sure it was a valid reference
466 * before freeing the extent.
468 * 2) Provide enough information to quickly find the holders of an extent
469 * if we notice a given block is corrupted or bad.
471 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
472 * maintenance. This is actually the same as #2, but with a slightly
473 * different use case.
475 * File extents can be referenced by:
477 * - multiple snapshots, subvolumes, or different generations in one subvol
478 * - different files inside a single subvolume (in theory, not implemented yet)
479 * - different offsets inside a file (bookend extents in file.c)
481 * The extent ref structure has fields for:
483 * - Objectid of the subvolume root
484 * - Generation number of the tree holding the reference
485 * - objectid of the file holding the reference
486 * - offset in the file corresponding to the key holding the reference
488 * When a file extent is allocated the fields are filled in:
489 * (root_key.objectid, trans->transid, inode objectid, offset in file)
491 * When a leaf is cow'd new references are added for every file extent found
492 * in the leaf. It looks the same as the create case, but trans->transid
493 * will be different when the block is cow'd.
495 * (root_key.objectid, trans->transid, inode objectid, offset in file)
497 * When a file extent is removed either during snapshot deletion or file
498 * truncation, the corresponding back reference is found
501 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
502 * inode objectid, offset in file)
504 * Btree extents can be referenced by:
506 * - Different subvolumes
507 * - Different generations of the same subvolume
509 * Storing sufficient information for a full reverse mapping of a btree
510 * block would require storing the lowest key of the block in the backref,
511 * and it would require updating that lowest key either before write out or
512 * every time it changed. Instead, the objectid of the lowest key is stored
513 * along with the level of the tree block. This provides a hint
514 * about where in the btree the block can be found. Searches through the
515 * btree only need to look for a pointer to that block, so they stop one
516 * level higher than the level recorded in the backref.
518 * Some btrees do not do reference counting on their extents. These
519 * include the extent tree and the tree of tree roots. Backrefs for these
520 * trees always have a generation of zero.
522 * When a tree block is created, back references are inserted:
524 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
526 * When a tree block is cow'd in a reference counted root,
527 * new back references are added for all the blocks it points to.
528 * These are of the form (trans->transid will have increased since creation):
530 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
532 * Because the lowest_key_objectid and the level are just hints
533 * they are not used when backrefs are deleted. When a backref is deleted:
535 * if backref was for a tree root:
536 * root_objectid = root->root_key.objectid
538 * root_objectid = btrfs_header_owner(parent)
540 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
542 * Back Reference Key hashing:
544 * Back references have four fields, each 64 bits long. Unfortunately,
545 * This is hashed into a single 64 bit number and placed into the key offset.
546 * The key objectid corresponds to the first byte in the extent, and the
547 * key type is set to BTRFS_EXTENT_REF_KEY
549 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
550 struct btrfs_root *root,
551 struct btrfs_path *path, u64 bytenr,
552 u64 root_objectid, u64 ref_generation,
553 u64 owner, u64 owner_offset)
556 struct btrfs_key key;
557 struct btrfs_extent_ref ref;
558 struct btrfs_extent_ref *disk_ref;
561 btrfs_set_stack_ref_root(&ref, root_objectid);
562 btrfs_set_stack_ref_generation(&ref, ref_generation);
563 btrfs_set_stack_ref_objectid(&ref, owner);
564 btrfs_set_stack_ref_offset(&ref, owner_offset);
566 hash = hash_extent_ref(root_objectid, ref_generation, owner,
569 key.objectid = bytenr;
570 key.type = BTRFS_EXTENT_REF_KEY;
572 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
573 while (ret == -EEXIST) {
574 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
575 struct btrfs_extent_ref);
576 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
579 btrfs_release_path(root, path);
580 ret = btrfs_insert_empty_item(trans, root, path, &key,
585 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
586 struct btrfs_extent_ref);
587 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
589 btrfs_mark_buffer_dirty(path->nodes[0]);
591 btrfs_release_path(root, path);
595 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
596 struct btrfs_root *root,
597 u64 bytenr, u64 num_bytes,
598 u64 root_objectid, u64 ref_generation,
599 u64 owner, u64 owner_offset)
601 struct btrfs_path *path;
603 struct btrfs_key key;
604 struct extent_buffer *l;
605 struct btrfs_extent_item *item;
608 WARN_ON(num_bytes < root->sectorsize);
609 path = btrfs_alloc_path();
613 key.objectid = bytenr;
614 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
615 key.offset = num_bytes;
616 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
625 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
626 refs = btrfs_extent_refs(l, item);
627 btrfs_set_extent_refs(l, item, refs + 1);
628 btrfs_mark_buffer_dirty(path->nodes[0]);
630 btrfs_release_path(root->fs_info->extent_root, path);
632 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
633 path, bytenr, root_objectid,
634 ref_generation, owner, owner_offset);
636 finish_current_insert(trans, root->fs_info->extent_root);
637 del_pending_extents(trans, root->fs_info->extent_root);
639 btrfs_free_path(path);
643 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
644 struct btrfs_root *root)
646 finish_current_insert(trans, root->fs_info->extent_root);
647 del_pending_extents(trans, root->fs_info->extent_root);
651 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
652 struct btrfs_root *root, u64 bytenr,
653 u64 num_bytes, u32 *refs)
655 struct btrfs_path *path;
657 struct btrfs_key key;
658 struct extent_buffer *l;
659 struct btrfs_extent_item *item;
661 WARN_ON(num_bytes < root->sectorsize);
662 path = btrfs_alloc_path();
663 key.objectid = bytenr;
664 key.offset = num_bytes;
665 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
666 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
671 btrfs_print_leaf(root, path->nodes[0]);
672 printk("failed to find block number %Lu\n", bytenr);
676 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
677 *refs = btrfs_extent_refs(l, item);
679 btrfs_free_path(path);
683 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
684 struct btrfs_path *count_path,
687 struct btrfs_root *extent_root = root->fs_info->extent_root;
688 struct btrfs_path *path;
691 u64 root_objectid = 0;
697 struct btrfs_key key;
698 struct btrfs_key found_key;
699 struct extent_buffer *l;
700 struct btrfs_extent_item *item;
701 struct btrfs_extent_ref *ref_item;
704 path = btrfs_alloc_path();
707 bytenr = first_extent;
709 bytenr = count_path->nodes[level]->start;
712 key.objectid = bytenr;
715 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
716 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
722 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
724 if (found_key.objectid != bytenr ||
725 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
729 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
730 refs = btrfs_extent_refs(l, item);
732 nritems = btrfs_header_nritems(l);
733 if (path->slots[0] >= nritems) {
734 ret = btrfs_next_leaf(extent_root, path);
739 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
740 if (found_key.objectid != bytenr)
742 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
748 ref_item = btrfs_item_ptr(l, path->slots[0],
749 struct btrfs_extent_ref);
750 found_objectid = btrfs_ref_root(l, ref_item);
752 if (found_objectid != root_objectid)
758 if (root_objectid == 0)
759 root_objectid = found_objectid;
763 if (cur_count == 0) {
769 if (level >= 0 && root->node == count_path->nodes[level])
772 btrfs_release_path(root, path);
776 btrfs_free_path(path);
781 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
782 struct btrfs_root *root, u64 owner_objectid)
788 struct btrfs_disk_key disk_key;
790 level = btrfs_header_level(root->node);
791 generation = trans->transid;
792 nritems = btrfs_header_nritems(root->node);
795 btrfs_item_key(root->node, &disk_key, 0);
797 btrfs_node_key(root->node, &disk_key, 0);
798 key_objectid = btrfs_disk_key_objectid(&disk_key);
802 return btrfs_inc_extent_ref(trans, root, root->node->start,
803 root->node->len, owner_objectid,
804 generation, level, key_objectid);
807 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
808 struct extent_buffer *buf)
812 struct btrfs_key key;
813 struct btrfs_file_extent_item *fi;
822 level = btrfs_header_level(buf);
823 nritems = btrfs_header_nritems(buf);
824 for (i = 0; i < nritems; i++) {
827 btrfs_item_key_to_cpu(buf, &key, i);
828 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
830 fi = btrfs_item_ptr(buf, i,
831 struct btrfs_file_extent_item);
832 if (btrfs_file_extent_type(buf, fi) ==
833 BTRFS_FILE_EXTENT_INLINE)
835 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
836 if (disk_bytenr == 0)
838 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
839 btrfs_file_extent_disk_num_bytes(buf, fi),
840 root->root_key.objectid, trans->transid,
841 key.objectid, key.offset);
847 bytenr = btrfs_node_blockptr(buf, i);
848 btrfs_node_key_to_cpu(buf, &key, i);
849 ret = btrfs_inc_extent_ref(trans, root, bytenr,
850 btrfs_level_size(root, level - 1),
851 root->root_key.objectid,
853 level - 1, key.objectid);
864 for (i =0; i < faili; i++) {
867 btrfs_item_key_to_cpu(buf, &key, i);
868 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
870 fi = btrfs_item_ptr(buf, i,
871 struct btrfs_file_extent_item);
872 if (btrfs_file_extent_type(buf, fi) ==
873 BTRFS_FILE_EXTENT_INLINE)
875 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
876 if (disk_bytenr == 0)
878 err = btrfs_free_extent(trans, root, disk_bytenr,
879 btrfs_file_extent_disk_num_bytes(buf,
883 bytenr = btrfs_node_blockptr(buf, i);
884 err = btrfs_free_extent(trans, root, bytenr,
885 btrfs_level_size(root, level - 1), 0);
893 static int write_one_cache_group(struct btrfs_trans_handle *trans,
894 struct btrfs_root *root,
895 struct btrfs_path *path,
896 struct btrfs_block_group_cache *cache)
900 struct btrfs_root *extent_root = root->fs_info->extent_root;
902 struct extent_buffer *leaf;
904 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
909 leaf = path->nodes[0];
910 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
911 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
912 btrfs_mark_buffer_dirty(leaf);
913 btrfs_release_path(extent_root, path);
915 finish_current_insert(trans, extent_root);
916 pending_ret = del_pending_extents(trans, extent_root);
925 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
926 struct btrfs_root *root)
928 struct extent_map_tree *block_group_cache;
929 struct btrfs_block_group_cache *cache;
933 struct btrfs_path *path;
939 block_group_cache = &root->fs_info->block_group_cache;
940 path = btrfs_alloc_path();
945 ret = find_first_extent_bit(block_group_cache, last,
946 &start, &end, BLOCK_GROUP_DIRTY);
951 ret = get_state_private(block_group_cache, start, &ptr);
955 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
956 err = write_one_cache_group(trans, root,
959 * if we fail to write the cache group, we want
960 * to keep it marked dirty in hopes that a later
967 clear_extent_bits(block_group_cache, start, end,
968 BLOCK_GROUP_DIRTY, GFP_NOFS);
970 btrfs_free_path(path);
974 static int update_block_group(struct btrfs_trans_handle *trans,
975 struct btrfs_root *root,
976 u64 bytenr, u64 num_bytes, int alloc,
977 int mark_free, int data)
979 struct btrfs_block_group_cache *cache;
980 struct btrfs_fs_info *info = root->fs_info;
981 u64 total = num_bytes;
988 cache = btrfs_lookup_block_group(info, bytenr);
992 byte_in_group = bytenr - cache->key.objectid;
993 WARN_ON(byte_in_group > cache->key.offset);
994 start = cache->key.objectid;
995 end = start + cache->key.offset - 1;
996 set_extent_bits(&info->block_group_cache, start, end,
997 BLOCK_GROUP_DIRTY, GFP_NOFS);
999 old_val = btrfs_block_group_used(&cache->item);
1000 num_bytes = min(total, cache->key.offset - byte_in_group);
1002 if (cache->data != data &&
1003 old_val < (cache->key.offset >> 1)) {
1008 bit_to_clear = BLOCK_GROUP_METADATA;
1009 bit_to_set = BLOCK_GROUP_DATA;
1010 cache->item.flags &=
1011 ~BTRFS_BLOCK_GROUP_MIXED;
1012 cache->item.flags |=
1013 BTRFS_BLOCK_GROUP_DATA;
1015 bit_to_clear = BLOCK_GROUP_DATA;
1016 bit_to_set = BLOCK_GROUP_METADATA;
1017 cache->item.flags &=
1018 ~BTRFS_BLOCK_GROUP_MIXED;
1019 cache->item.flags &=
1020 ~BTRFS_BLOCK_GROUP_DATA;
1022 clear_extent_bits(&info->block_group_cache,
1023 start, end, bit_to_clear,
1025 set_extent_bits(&info->block_group_cache,
1026 start, end, bit_to_set,
1028 } else if (cache->data != data &&
1029 cache->data != BTRFS_BLOCK_GROUP_MIXED) {
1030 cache->data = BTRFS_BLOCK_GROUP_MIXED;
1031 set_extent_bits(&info->block_group_cache,
1034 BLOCK_GROUP_METADATA,
1037 old_val += num_bytes;
1039 old_val -= num_bytes;
1041 set_extent_dirty(&info->free_space_cache,
1042 bytenr, bytenr + num_bytes - 1,
1046 btrfs_set_block_group_used(&cache->item, old_val);
1048 bytenr += num_bytes;
1052 static int update_pinned_extents(struct btrfs_root *root,
1053 u64 bytenr, u64 num, int pin)
1056 struct btrfs_block_group_cache *cache;
1057 struct btrfs_fs_info *fs_info = root->fs_info;
1060 set_extent_dirty(&fs_info->pinned_extents,
1061 bytenr, bytenr + num - 1, GFP_NOFS);
1063 clear_extent_dirty(&fs_info->pinned_extents,
1064 bytenr, bytenr + num - 1, GFP_NOFS);
1067 cache = btrfs_lookup_block_group(fs_info, bytenr);
1069 len = min(num, cache->key.offset -
1070 (bytenr - cache->key.objectid));
1072 cache->pinned += len;
1073 fs_info->total_pinned += len;
1075 cache->pinned -= len;
1076 fs_info->total_pinned -= len;
1084 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_map_tree *copy)
1089 struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
1093 ret = find_first_extent_bit(pinned_extents, last,
1094 &start, &end, EXTENT_DIRTY);
1097 set_extent_dirty(copy, start, end, GFP_NOFS);
1103 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1104 struct btrfs_root *root,
1105 struct extent_map_tree *unpin)
1110 struct extent_map_tree *free_space_cache;
1111 free_space_cache = &root->fs_info->free_space_cache;
1114 ret = find_first_extent_bit(unpin, 0, &start, &end,
1118 update_pinned_extents(root, start, end + 1 - start, 0);
1119 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1120 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1125 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
1126 btrfs_root *extent_root)
1130 struct btrfs_fs_info *info = extent_root->fs_info;
1131 struct extent_buffer *eb;
1132 struct btrfs_path *path;
1133 struct btrfs_key ins;
1134 struct btrfs_disk_key first;
1135 struct btrfs_extent_item extent_item;
1140 btrfs_set_stack_extent_refs(&extent_item, 1);
1141 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1142 path = btrfs_alloc_path();
1145 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1146 &end, EXTENT_LOCKED);
1150 ins.objectid = start;
1151 ins.offset = end + 1 - start;
1152 err = btrfs_insert_item(trans, extent_root, &ins,
1153 &extent_item, sizeof(extent_item));
1154 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1156 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1157 level = btrfs_header_level(eb);
1159 btrfs_item_key(eb, &first, 0);
1161 btrfs_node_key(eb, &first, 0);
1163 err = btrfs_insert_extent_backref(trans, extent_root, path,
1164 start, extent_root->root_key.objectid,
1166 btrfs_disk_key_objectid(&first));
1168 free_extent_buffer(eb);
1170 btrfs_free_path(path);
1174 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1178 struct extent_buffer *buf;
1181 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1183 if (btrfs_buffer_uptodate(buf)) {
1185 root->fs_info->running_transaction->transid;
1186 if (btrfs_header_generation(buf) == transid) {
1187 free_extent_buffer(buf);
1191 free_extent_buffer(buf);
1193 update_pinned_extents(root, bytenr, num_bytes, 1);
1195 set_extent_bits(&root->fs_info->pending_del,
1196 bytenr, bytenr + num_bytes - 1,
1197 EXTENT_LOCKED, GFP_NOFS);
1204 * remove an extent from the root, returns 0 on success
1206 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1207 *root, u64 bytenr, u64 num_bytes,
1208 u64 root_objectid, u64 ref_generation,
1209 u64 owner_objectid, u64 owner_offset, int pin,
1212 struct btrfs_path *path;
1213 struct btrfs_key key;
1214 struct btrfs_fs_info *info = root->fs_info;
1215 struct btrfs_root *extent_root = info->extent_root;
1216 struct extent_buffer *leaf;
1218 struct btrfs_extent_item *ei;
1221 key.objectid = bytenr;
1222 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1223 key.offset = num_bytes;
1225 path = btrfs_alloc_path();
1229 ret = lookup_extent_backref(trans, extent_root, path,
1230 bytenr, root_objectid,
1232 owner_objectid, owner_offset, 1);
1234 ret = btrfs_del_item(trans, extent_root, path);
1236 btrfs_print_leaf(extent_root, path->nodes[0]);
1238 printk("Unable to find ref byte nr %Lu root %Lu "
1239 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1240 root_objectid, ref_generation, owner_objectid,
1243 btrfs_release_path(extent_root, path);
1244 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1249 leaf = path->nodes[0];
1250 ei = btrfs_item_ptr(leaf, path->slots[0],
1251 struct btrfs_extent_item);
1252 refs = btrfs_extent_refs(leaf, ei);
1255 btrfs_set_extent_refs(leaf, ei, refs);
1256 btrfs_mark_buffer_dirty(leaf);
1263 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1269 /* block accounting for super block */
1270 super_used = btrfs_super_bytes_used(&info->super_copy);
1271 btrfs_set_super_bytes_used(&info->super_copy,
1272 super_used - num_bytes);
1274 /* block accounting for root item */
1275 root_used = btrfs_root_used(&root->root_item);
1276 btrfs_set_root_used(&root->root_item,
1277 root_used - num_bytes);
1279 ret = btrfs_del_item(trans, extent_root, path);
1283 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1287 btrfs_free_path(path);
1288 finish_current_insert(trans, extent_root);
1293 * find all the blocks marked as pending in the radix tree and remove
1294 * them from the extent map
1296 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1297 btrfs_root *extent_root)
1303 struct extent_map_tree *pending_del;
1304 struct extent_map_tree *pinned_extents;
1306 pending_del = &extent_root->fs_info->pending_del;
1307 pinned_extents = &extent_root->fs_info->pinned_extents;
1310 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1314 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1315 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1317 ret = __free_extent(trans, extent_root,
1318 start, end + 1 - start,
1319 extent_root->root_key.objectid,
1328 * remove an extent from the root, returns 0 on success
1330 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1331 *root, u64 bytenr, u64 num_bytes,
1332 u64 root_objectid, u64 ref_generation,
1333 u64 owner_objectid, u64 owner_offset, int pin)
1335 struct btrfs_root *extent_root = root->fs_info->extent_root;
1339 WARN_ON(num_bytes < root->sectorsize);
1340 if (!root->ref_cows)
1343 if (root == extent_root) {
1344 pin_down_bytes(root, bytenr, num_bytes, 1);
1347 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1348 ref_generation, owner_objectid, owner_offset,
1350 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1351 return ret ? ret : pending_ret;
1354 static u64 stripe_align(struct btrfs_root *root, u64 val)
1356 u64 mask = ((u64)root->stripesize - 1);
1357 u64 ret = (val + mask) & ~mask;
1362 * walks the btree of allocated extents and find a hole of a given size.
1363 * The key ins is changed to record the hole:
1364 * ins->objectid == block start
1365 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1366 * ins->offset == number of blocks
1367 * Any available blocks before search_start are skipped.
1369 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1370 *orig_root, u64 num_bytes, u64 empty_size,
1371 u64 search_start, u64 search_end, u64 hint_byte,
1372 struct btrfs_key *ins, u64 exclude_start,
1373 u64 exclude_nr, int data)
1375 struct btrfs_path *path;
1376 struct btrfs_key key;
1382 u64 orig_search_start = search_start;
1384 struct extent_buffer *l;
1385 struct btrfs_root * root = orig_root->fs_info->extent_root;
1386 struct btrfs_fs_info *info = root->fs_info;
1387 u64 total_needed = num_bytes;
1389 struct btrfs_block_group_cache *block_group;
1394 WARN_ON(num_bytes < root->sectorsize);
1395 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1397 level = btrfs_header_level(root->node);
1399 if (num_bytes >= 32 * 1024 * 1024 && hint_byte) {
1400 data = BTRFS_BLOCK_GROUP_MIXED;
1403 if (search_end == (u64)-1)
1404 search_end = btrfs_super_total_bytes(&info->super_copy);
1406 block_group = btrfs_lookup_block_group(info, hint_byte);
1408 hint_byte = search_start;
1409 block_group = btrfs_find_block_group(root, block_group,
1410 hint_byte, data, 1);
1412 block_group = btrfs_find_block_group(root,
1414 search_start, data, 1);
1417 total_needed += empty_size;
1418 path = btrfs_alloc_path();
1421 block_group = btrfs_lookup_block_group(info, search_start);
1423 block_group = btrfs_lookup_block_group(info,
1426 search_start = find_search_start(root, &block_group, search_start,
1427 total_needed, data, full_scan);
1428 search_start = stripe_align(root, search_start);
1429 cached_start = search_start;
1430 btrfs_init_path(path);
1431 ins->objectid = search_start;
1436 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
1440 if (path->slots[0] > 0) {
1445 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1448 * walk backwards to find the first extent item key
1450 while(btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
1451 if (path->slots[0] == 0) {
1452 ret = btrfs_prev_leaf(root, path);
1454 ret = btrfs_search_slot(trans, root, ins,
1458 if (path->slots[0] > 0)
1466 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1470 slot = path->slots[0];
1471 if (slot >= btrfs_header_nritems(l)) {
1472 ret = btrfs_next_leaf(root, path);
1478 search_start = max(search_start,
1479 block_group->key.objectid);
1481 aligned = stripe_align(root, search_start);
1482 ins->objectid = aligned;
1483 if (aligned >= search_end) {
1487 ins->offset = search_end - aligned;
1491 ins->objectid = stripe_align(root,
1492 last_byte > search_start ?
1493 last_byte : search_start);
1494 if (search_end <= ins->objectid) {
1498 ins->offset = search_end - ins->objectid;
1499 BUG_ON(ins->objectid >= search_end);
1502 btrfs_item_key_to_cpu(l, &key, slot);
1504 if (key.objectid >= search_start && key.objectid > last_byte &&
1506 if (last_byte < search_start)
1507 last_byte = search_start;
1508 aligned = stripe_align(root, last_byte);
1509 hole_size = key.objectid - aligned;
1510 if (key.objectid > aligned && hole_size >= num_bytes) {
1511 ins->objectid = aligned;
1512 ins->offset = hole_size;
1516 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
1517 if (!start_found && btrfs_key_type(&key) ==
1518 BTRFS_BLOCK_GROUP_ITEM_KEY) {
1519 last_byte = key.objectid;
1527 last_byte = key.objectid + key.offset;
1529 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1530 last_byte >= block_group->key.objectid +
1531 block_group->key.offset) {
1532 btrfs_release_path(root, path);
1533 search_start = block_group->key.objectid +
1534 block_group->key.offset;
1542 /* we have to make sure we didn't find an extent that has already
1543 * been allocated by the map tree or the original allocation
1545 btrfs_release_path(root, path);
1546 BUG_ON(ins->objectid < search_start);
1548 if (ins->objectid + num_bytes >= search_end)
1550 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1551 ins->objectid + num_bytes > block_group->
1552 key.objectid + block_group->key.offset) {
1553 search_start = block_group->key.objectid +
1554 block_group->key.offset;
1557 if (test_range_bit(&info->extent_ins, ins->objectid,
1558 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1559 search_start = ins->objectid + num_bytes;
1562 if (test_range_bit(&info->pinned_extents, ins->objectid,
1563 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1564 search_start = ins->objectid + num_bytes;
1567 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1568 ins->objectid < exclude_start + exclude_nr)) {
1569 search_start = exclude_start + exclude_nr;
1573 block_group = btrfs_lookup_block_group(info, ins->objectid);
1575 trans->block_group = block_group;
1577 ins->offset = num_bytes;
1578 btrfs_free_path(path);
1582 if (search_start + num_bytes >= search_end) {
1584 search_start = orig_search_start;
1591 total_needed -= empty_size;
1593 data = BTRFS_BLOCK_GROUP_MIXED;
1597 block_group = btrfs_lookup_block_group(info, search_start);
1599 block_group = btrfs_find_block_group(root, block_group,
1600 search_start, data, 0);
1604 btrfs_release_path(root, path);
1605 btrfs_free_path(path);
1609 * finds a free extent and does all the dirty work required for allocation
1610 * returns the key for the extent through ins, and a tree buffer for
1611 * the first block of the extent through buf.
1613 * returns 0 if everything worked, non-zero otherwise.
1615 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1616 struct btrfs_root *root,
1617 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1618 u64 owner, u64 owner_offset,
1619 u64 empty_size, u64 hint_byte,
1620 u64 search_end, struct btrfs_key *ins, int data)
1624 u64 super_used, root_used;
1625 u64 search_start = 0;
1627 struct btrfs_fs_info *info = root->fs_info;
1628 struct btrfs_root *extent_root = info->extent_root;
1629 struct btrfs_extent_item extent_item;
1630 struct btrfs_path *path;
1632 btrfs_set_stack_extent_refs(&extent_item, 1);
1634 new_hint = max(hint_byte, root->fs_info->alloc_start);
1635 if (new_hint < btrfs_super_total_bytes(&info->super_copy))
1636 hint_byte = new_hint;
1638 WARN_ON(num_bytes < root->sectorsize);
1639 ret = find_free_extent(trans, root, num_bytes, empty_size,
1640 search_start, search_end, hint_byte, ins,
1641 trans->alloc_exclude_start,
1642 trans->alloc_exclude_nr, data);
1647 /* block accounting for super block */
1648 super_used = btrfs_super_bytes_used(&info->super_copy);
1649 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1651 /* block accounting for root item */
1652 root_used = btrfs_root_used(&root->root_item);
1653 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1655 clear_extent_dirty(&root->fs_info->free_space_cache,
1656 ins->objectid, ins->objectid + ins->offset - 1,
1659 if (root == extent_root) {
1660 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1661 ins->objectid + ins->offset - 1,
1662 EXTENT_LOCKED, GFP_NOFS);
1667 WARN_ON(trans->alloc_exclude_nr);
1668 trans->alloc_exclude_start = ins->objectid;
1669 trans->alloc_exclude_nr = ins->offset;
1670 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
1671 sizeof(extent_item));
1673 trans->alloc_exclude_start = 0;
1674 trans->alloc_exclude_nr = 0;
1677 path = btrfs_alloc_path();
1679 ret = btrfs_insert_extent_backref(trans, extent_root, path,
1680 ins->objectid, root_objectid,
1681 ref_generation, owner, owner_offset);
1684 btrfs_free_path(path);
1685 finish_current_insert(trans, extent_root);
1686 pending_ret = del_pending_extents(trans, extent_root);
1696 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
1703 * helper function to allocate a block for a given tree
1704 * returns the tree buffer or NULL.
1706 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1707 struct btrfs_root *root,
1709 u64 root_objectid, u64 hint,
1715 ref_generation = trans->transid;
1720 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1721 ref_generation, 0, 0, hint, empty_size);
1725 * helper function to allocate a block for a given tree
1726 * returns the tree buffer or NULL.
1728 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1729 struct btrfs_root *root,
1738 struct btrfs_key ins;
1740 struct extent_buffer *buf;
1742 ret = btrfs_alloc_extent(trans, root, blocksize,
1743 root_objectid, ref_generation,
1744 level, first_objectid, empty_size, hint,
1748 return ERR_PTR(ret);
1750 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1752 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1753 root->root_key.objectid, ref_generation,
1755 return ERR_PTR(-ENOMEM);
1757 btrfs_set_buffer_uptodate(buf);
1758 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1759 buf->start + buf->len - 1, GFP_NOFS);
1760 set_extent_bits(&BTRFS_I(root->fs_info->btree_inode)->extent_tree,
1761 buf->start, buf->start + buf->len - 1,
1762 EXTENT_CSUM, GFP_NOFS);
1763 buf->flags |= EXTENT_CSUM;
1764 btrfs_set_buffer_defrag(buf);
1765 trans->blocks_used++;
1769 static int drop_leaf_ref(struct btrfs_trans_handle *trans,
1770 struct btrfs_root *root, struct extent_buffer *leaf)
1773 u64 leaf_generation;
1774 struct btrfs_key key;
1775 struct btrfs_file_extent_item *fi;
1780 BUG_ON(!btrfs_is_leaf(leaf));
1781 nritems = btrfs_header_nritems(leaf);
1782 leaf_owner = btrfs_header_owner(leaf);
1783 leaf_generation = btrfs_header_generation(leaf);
1785 for (i = 0; i < nritems; i++) {
1788 btrfs_item_key_to_cpu(leaf, &key, i);
1789 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1791 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1792 if (btrfs_file_extent_type(leaf, fi) ==
1793 BTRFS_FILE_EXTENT_INLINE)
1796 * FIXME make sure to insert a trans record that
1797 * repeats the snapshot del on crash
1799 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1800 if (disk_bytenr == 0)
1802 ret = btrfs_free_extent(trans, root, disk_bytenr,
1803 btrfs_file_extent_disk_num_bytes(leaf, fi),
1804 leaf_owner, leaf_generation,
1805 key.objectid, key.offset, 0);
1811 static void reada_walk_down(struct btrfs_root *root,
1812 struct extent_buffer *node)
1822 nritems = btrfs_header_nritems(node);
1823 level = btrfs_header_level(node);
1824 for (i = 0; i < nritems; i++) {
1825 bytenr = btrfs_node_blockptr(node, i);
1826 blocksize = btrfs_level_size(root, level - 1);
1827 ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs);
1831 mutex_unlock(&root->fs_info->fs_mutex);
1832 ret = readahead_tree_block(root, bytenr, blocksize);
1834 mutex_lock(&root->fs_info->fs_mutex);
1841 * helper function for drop_snapshot, this walks down the tree dropping ref
1842 * counts as it goes.
1844 static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1845 *root, struct btrfs_path *path, int *level)
1850 struct extent_buffer *next;
1851 struct extent_buffer *cur;
1852 struct extent_buffer *parent;
1857 WARN_ON(*level < 0);
1858 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1859 ret = lookup_extent_ref(trans, root,
1860 path->nodes[*level]->start,
1861 path->nodes[*level]->len, &refs);
1867 * walk down to the last node level and free all the leaves
1869 while(*level >= 0) {
1870 WARN_ON(*level < 0);
1871 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1872 cur = path->nodes[*level];
1874 if (*level > 0 && path->slots[*level] == 0)
1875 reada_walk_down(root, cur);
1877 if (btrfs_header_level(cur) != *level)
1880 if (path->slots[*level] >=
1881 btrfs_header_nritems(cur))
1884 ret = drop_leaf_ref(trans, root, cur);
1888 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1889 blocksize = btrfs_level_size(root, *level - 1);
1890 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1893 parent = path->nodes[*level];
1894 root_owner = btrfs_header_owner(parent);
1895 root_gen = btrfs_header_generation(parent);
1896 path->slots[*level]++;
1897 ret = btrfs_free_extent(trans, root, bytenr,
1898 blocksize, root_owner,
1903 next = btrfs_find_tree_block(root, bytenr, blocksize);
1904 if (!next || !btrfs_buffer_uptodate(next)) {
1905 free_extent_buffer(next);
1906 mutex_unlock(&root->fs_info->fs_mutex);
1907 next = read_tree_block(root, bytenr, blocksize);
1908 mutex_lock(&root->fs_info->fs_mutex);
1910 /* we dropped the lock, check one more time */
1911 ret = lookup_extent_ref(trans, root, bytenr,
1915 parent = path->nodes[*level];
1916 root_owner = btrfs_header_owner(parent);
1917 root_gen = btrfs_header_generation(parent);
1919 path->slots[*level]++;
1920 free_extent_buffer(next);
1921 ret = btrfs_free_extent(trans, root, bytenr,
1929 WARN_ON(*level <= 0);
1930 if (path->nodes[*level-1])
1931 free_extent_buffer(path->nodes[*level-1]);
1932 path->nodes[*level-1] = next;
1933 *level = btrfs_header_level(next);
1934 path->slots[*level] = 0;
1937 WARN_ON(*level < 0);
1938 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1940 if (path->nodes[*level] == root->node) {
1941 root_owner = root->root_key.objectid;
1942 parent = path->nodes[*level];
1944 parent = path->nodes[*level + 1];
1945 root_owner = btrfs_header_owner(parent);
1948 root_gen = btrfs_header_generation(parent);
1949 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1950 path->nodes[*level]->len,
1951 root_owner, root_gen, 0, 0, 1);
1952 free_extent_buffer(path->nodes[*level]);
1953 path->nodes[*level] = NULL;
1960 * helper for dropping snapshots. This walks back up the tree in the path
1961 * to find the first node higher up where we haven't yet gone through
1964 static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
1965 *root, struct btrfs_path *path, int *level)
1969 struct btrfs_root_item *root_item = &root->root_item;
1974 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1975 slot = path->slots[i];
1976 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1977 struct extent_buffer *node;
1978 struct btrfs_disk_key disk_key;
1979 node = path->nodes[i];
1982 WARN_ON(*level == 0);
1983 btrfs_node_key(node, &disk_key, path->slots[i]);
1984 memcpy(&root_item->drop_progress,
1985 &disk_key, sizeof(disk_key));
1986 root_item->drop_level = i;
1989 if (path->nodes[*level] == root->node) {
1990 root_owner = root->root_key.objectid;
1992 btrfs_header_generation(path->nodes[*level]);
1994 struct extent_buffer *node;
1995 node = path->nodes[*level + 1];
1996 root_owner = btrfs_header_owner(node);
1997 root_gen = btrfs_header_generation(node);
1999 ret = btrfs_free_extent(trans, root,
2000 path->nodes[*level]->start,
2001 path->nodes[*level]->len,
2002 root_owner, root_gen, 0, 0, 1);
2004 free_extent_buffer(path->nodes[*level]);
2005 path->nodes[*level] = NULL;
2013 * drop the reference count on the tree rooted at 'snap'. This traverses
2014 * the tree freeing any blocks that have a ref count of zero after being
2017 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2023 struct btrfs_path *path;
2026 struct btrfs_root_item *root_item = &root->root_item;
2028 path = btrfs_alloc_path();
2031 level = btrfs_header_level(root->node);
2033 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2034 path->nodes[level] = root->node;
2035 extent_buffer_get(root->node);
2036 path->slots[level] = 0;
2038 struct btrfs_key key;
2039 struct btrfs_disk_key found_key;
2040 struct extent_buffer *node;
2042 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2043 level = root_item->drop_level;
2044 path->lowest_level = level;
2045 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2050 node = path->nodes[level];
2051 btrfs_node_key(node, &found_key, path->slots[level]);
2052 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2053 sizeof(found_key)));
2056 wret = walk_down_tree(trans, root, path, &level);
2062 wret = walk_up_tree(trans, root, path, &level);
2070 for (i = 0; i <= orig_level; i++) {
2071 if (path->nodes[i]) {
2072 free_extent_buffer(path->nodes[i]);
2073 path->nodes[i] = NULL;
2077 btrfs_free_path(path);
2081 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2088 ret = find_first_extent_bit(&info->block_group_cache, 0,
2089 &start, &end, (unsigned int)-1);
2092 ret = get_state_private(&info->block_group_cache, start, &ptr);
2094 kfree((void *)(unsigned long)ptr);
2095 clear_extent_bits(&info->block_group_cache, start,
2096 end, (unsigned int)-1, GFP_NOFS);
2099 ret = find_first_extent_bit(&info->free_space_cache, 0,
2100 &start, &end, EXTENT_DIRTY);
2103 clear_extent_dirty(&info->free_space_cache, start,
2109 static int relocate_inode_pages(struct inode *inode, u64 start, u64 len)
2114 u64 existing_delalloc;
2115 unsigned long last_index;
2116 unsigned long first_index;
2119 struct btrfs_root *root = BTRFS_I(inode)->root;
2120 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2121 struct file_ra_state ra;
2123 mutex_lock(&inode->i_mutex);
2124 first_index = start >> PAGE_CACHE_SHIFT;
2125 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
2127 memset(&ra, 0, sizeof(ra));
2128 file_ra_state_init(&ra, inode->i_mapping);
2129 btrfs_force_ra(inode->i_mapping, &ra, NULL, first_index, last_index);
2131 for (i = first_index; i <= last_index; i++) {
2132 page = grab_cache_page(inode->i_mapping, i);
2135 if (!PageUptodate(page)) {
2136 btrfs_readpage(NULL, page);
2138 if (!PageUptodate(page)) {
2140 page_cache_release(page);
2144 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2145 page_end = page_start + PAGE_CACHE_SIZE - 1;
2147 lock_extent(em_tree, page_start, page_end, GFP_NOFS);
2149 delalloc_start = page_start;
2151 count_range_bits(&BTRFS_I(inode)->extent_tree,
2152 &delalloc_start, page_end,
2153 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
2155 set_extent_delalloc(em_tree, page_start,
2156 page_end, GFP_NOFS);
2158 spin_lock(&root->fs_info->delalloc_lock);
2159 root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
2161 spin_unlock(&root->fs_info->delalloc_lock);
2163 unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
2164 set_page_dirty(page);
2166 page_cache_release(page);
2170 mutex_unlock(&inode->i_mutex);
2174 static int relocate_one_reference(struct btrfs_root *extent_root,
2175 struct btrfs_path *path,
2176 struct btrfs_key *extent_key,
2177 u64 ref_root, u64 ref_gen, u64 ref_objectid,
2180 struct inode *inode;
2181 struct btrfs_root *found_root;
2182 struct btrfs_key root_location;
2185 root_location.objectid = ref_root;
2187 root_location.offset = 0;
2189 root_location.offset = (u64)-1;
2190 root_location.type = BTRFS_ROOT_ITEM_KEY;
2192 found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
2194 BUG_ON(!found_root);
2196 if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2197 mutex_unlock(&extent_root->fs_info->fs_mutex);
2198 inode = btrfs_iget_locked(extent_root->fs_info->sb,
2199 ref_objectid, found_root);
2200 if (inode->i_state & I_NEW) {
2201 /* the inode and parent dir are two different roots */
2202 BTRFS_I(inode)->root = found_root;
2203 BTRFS_I(inode)->location.objectid = ref_objectid;
2204 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
2205 BTRFS_I(inode)->location.offset = 0;
2206 btrfs_read_locked_inode(inode);
2207 unlock_new_inode(inode);
2210 /* this can happen if the reference is not against
2211 * the latest version of the tree root
2213 if (is_bad_inode(inode)) {
2214 mutex_lock(&extent_root->fs_info->fs_mutex);
2217 relocate_inode_pages(inode, ref_offset, extent_key->offset);
2218 /* FIXME, data=ordered will help get rid of this */
2219 filemap_fdatawrite(inode->i_mapping);
2221 mutex_lock(&extent_root->fs_info->fs_mutex);
2223 struct btrfs_trans_handle *trans;
2224 struct btrfs_key found_key;
2225 struct extent_buffer *eb;
2229 trans = btrfs_start_transaction(found_root, 1);
2230 eb = read_tree_block(found_root, extent_key->objectid,
2231 extent_key->offset);
2232 level = btrfs_header_level(eb);
2235 btrfs_item_key_to_cpu(eb, &found_key, 0);
2237 btrfs_node_key_to_cpu(eb, &found_key, 0);
2239 free_extent_buffer(eb);
2241 path->lowest_level = level;
2243 ret = btrfs_search_slot(trans, found_root, &found_key, path,
2245 path->lowest_level = 0;
2246 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
2247 if (!path->nodes[i])
2249 free_extent_buffer(path->nodes[i]);
2250 path->nodes[i] = NULL;
2252 btrfs_release_path(found_root, path);
2253 btrfs_end_transaction(trans, found_root);
2260 static int relocate_one_extent(struct btrfs_root *extent_root,
2261 struct btrfs_path *path,
2262 struct btrfs_key *extent_key)
2264 struct btrfs_key key;
2265 struct btrfs_key found_key;
2266 struct btrfs_extent_ref *ref;
2267 struct extent_buffer *leaf;
2276 key.objectid = extent_key->objectid;
2277 key.type = BTRFS_EXTENT_REF_KEY;
2281 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2289 leaf = path->nodes[0];
2290 nritems = btrfs_header_nritems(leaf);
2291 if (path->slots[0] == nritems)
2294 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2295 if (found_key.objectid != extent_key->objectid)
2298 if (found_key.type != BTRFS_EXTENT_REF_KEY)
2301 key.offset = found_key.offset + 1;
2302 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2304 ref = btrfs_item_ptr(leaf, path->slots[0],
2305 struct btrfs_extent_ref);
2306 ref_root = btrfs_ref_root(leaf, ref);
2307 ref_gen = btrfs_ref_generation(leaf, ref);
2308 ref_objectid = btrfs_ref_objectid(leaf, ref);
2309 ref_offset = btrfs_ref_offset(leaf, ref);
2310 btrfs_release_path(extent_root, path);
2312 ret = relocate_one_reference(extent_root, path,
2313 extent_key, ref_root, ref_gen,
2314 ref_objectid, ref_offset);
2320 btrfs_release_path(extent_root, path);
2324 static int find_overlapping_extent(struct btrfs_root *root,
2325 struct btrfs_path *path, u64 new_size)
2327 struct btrfs_key found_key;
2328 struct extent_buffer *leaf;
2332 if (path->slots[0] == 0) {
2333 ret = btrfs_prev_leaf(root, path);
2342 leaf = path->nodes[0];
2343 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2344 if (found_key.type == BTRFS_EXTENT_ITEM_KEY) {
2345 if (found_key.objectid + found_key.offset > new_size)
2354 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
2356 struct btrfs_trans_handle *trans;
2357 struct btrfs_root *tree_root = root->fs_info->tree_root;
2358 struct btrfs_path *path;
2362 struct btrfs_fs_info *info = root->fs_info;
2363 struct extent_map_tree *block_group_cache;
2364 struct btrfs_key key;
2365 struct btrfs_key found_key = { 0, 0, 0 };
2366 struct extent_buffer *leaf;
2371 btrfs_set_super_total_bytes(&info->super_copy, new_size);
2372 block_group_cache = &info->block_group_cache;
2373 path = btrfs_alloc_path();
2374 root = root->fs_info->extent_root;
2379 key.objectid = new_size;
2380 cur_byte = key.objectid;
2384 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2388 leaf = path->nodes[0];
2389 if (key.objectid == new_size - 1) {
2390 ret = find_overlapping_extent(root, path, new_size);
2392 btrfs_release_path(root, path);
2393 ret = btrfs_search_slot(NULL, root, &key,
2399 nritems = btrfs_header_nritems(leaf);
2401 slot = path->slots[0];
2403 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2404 if (slot == nritems ||
2405 btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY) {
2407 if (path->slots[0] >= nritems) {
2408 ret = btrfs_next_leaf(root, path);
2418 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2419 if (found_key.objectid + found_key.offset <= cur_byte)
2422 cur_byte = found_key.objectid + found_key.offset;
2423 key.objectid = cur_byte;
2424 btrfs_release_path(root, path);
2425 ret = relocate_one_extent(root, path, &found_key);
2428 btrfs_release_path(root, path);
2430 if (total_found > 0) {
2431 trans = btrfs_start_transaction(tree_root, 1);
2432 btrfs_commit_transaction(trans, tree_root);
2434 mutex_unlock(&root->fs_info->fs_mutex);
2435 btrfs_clean_old_snapshots(tree_root);
2436 mutex_lock(&root->fs_info->fs_mutex);
2438 trans = btrfs_start_transaction(tree_root, 1);
2439 btrfs_commit_transaction(trans, tree_root);
2443 trans = btrfs_start_transaction(root, 1);
2444 key.objectid = new_size;
2448 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2452 leaf = path->nodes[0];
2453 nritems = btrfs_header_nritems(leaf);
2455 slot = path->slots[0];
2457 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2458 if (slot == nritems ||
2459 btrfs_key_type(&found_key) != BTRFS_BLOCK_GROUP_ITEM_KEY) {
2460 if (slot < nritems) {
2461 printk("shrinker found key %Lu %u %Lu\n",
2462 found_key.objectid, found_key.type,
2466 if (path->slots[0] >= nritems) {
2467 ret = btrfs_next_leaf(root, path);
2477 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2478 ret = get_state_private(&info->block_group_cache,
2479 found_key.objectid, &ptr);
2481 kfree((void *)(unsigned long)ptr);
2483 clear_extent_bits(&info->block_group_cache, found_key.objectid,
2484 found_key.objectid + found_key.offset - 1,
2485 (unsigned int)-1, GFP_NOFS);
2487 key.objectid = found_key.objectid + 1;
2488 btrfs_del_item(trans, root, path);
2489 btrfs_release_path(root, path);
2491 clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
2493 btrfs_commit_transaction(trans, root);
2495 btrfs_free_path(path);
2499 int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans,
2500 struct btrfs_root *root, u64 new_size)
2502 struct btrfs_path *path;
2506 struct btrfs_block_group_cache *cache;
2507 struct btrfs_block_group_item *item;
2508 struct btrfs_fs_info *info = root->fs_info;
2509 struct extent_map_tree *block_group_cache;
2510 struct btrfs_key key;
2511 struct extent_buffer *leaf;
2515 old_size = btrfs_super_total_bytes(&info->super_copy);
2516 block_group_cache = &info->block_group_cache;
2518 root = info->extent_root;
2520 cache = btrfs_lookup_block_group(root->fs_info, old_size - 1);
2522 cur_byte = cache->key.objectid + cache->key.offset;
2523 if (cur_byte >= new_size)
2526 key.offset = BTRFS_BLOCK_GROUP_SIZE;
2527 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2529 path = btrfs_alloc_path();
2533 while(cur_byte < new_size) {
2534 key.objectid = cur_byte;
2535 ret = btrfs_insert_empty_item(trans, root, path, &key,
2536 sizeof(struct btrfs_block_group_item));
2538 leaf = path->nodes[0];
2539 item = btrfs_item_ptr(leaf, path->slots[0],
2540 struct btrfs_block_group_item);
2542 btrfs_set_disk_block_group_used(leaf, item, 0);
2544 btrfs_set_disk_block_group_flags(leaf, item,
2545 BTRFS_BLOCK_GROUP_DATA);
2547 btrfs_set_disk_block_group_flags(leaf, item, 0);
2551 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2554 read_extent_buffer(leaf, &cache->item, (unsigned long)item,
2555 sizeof(cache->item));
2557 memcpy(&cache->key, &key, sizeof(key));
2560 cur_byte = key.objectid + key.offset;
2561 btrfs_release_path(root, path);
2563 if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
2564 bit = BLOCK_GROUP_DATA;
2565 cache->data = BTRFS_BLOCK_GROUP_DATA;
2567 bit = BLOCK_GROUP_METADATA;
2571 /* use EXTENT_LOCKED to prevent merging */
2572 set_extent_bits(block_group_cache, key.objectid,
2573 key.objectid + key.offset - 1,
2574 bit | EXTENT_LOCKED, GFP_NOFS);
2575 set_state_private(block_group_cache, key.objectid,
2576 (unsigned long)cache);
2578 btrfs_free_path(path);
2580 btrfs_set_super_total_bytes(&info->super_copy, new_size);
2584 int btrfs_read_block_groups(struct btrfs_root *root)
2586 struct btrfs_path *path;
2590 struct btrfs_block_group_cache *cache;
2591 struct btrfs_fs_info *info = root->fs_info;
2592 struct extent_map_tree *block_group_cache;
2593 struct btrfs_key key;
2594 struct btrfs_key found_key;
2595 struct extent_buffer *leaf;
2597 block_group_cache = &info->block_group_cache;
2599 root = info->extent_root;
2601 key.offset = BTRFS_BLOCK_GROUP_SIZE;
2602 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2604 path = btrfs_alloc_path();
2609 ret = btrfs_search_slot(NULL, info->extent_root,
2615 leaf = path->nodes[0];
2616 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2617 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2623 read_extent_buffer(leaf, &cache->item,
2624 btrfs_item_ptr_offset(leaf, path->slots[0]),
2625 sizeof(cache->item));
2626 memcpy(&cache->key, &found_key, sizeof(found_key));
2629 key.objectid = found_key.objectid + found_key.offset;
2630 btrfs_release_path(root, path);
2632 if (cache->item.flags & BTRFS_BLOCK_GROUP_MIXED) {
2633 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
2634 cache->data = BTRFS_BLOCK_GROUP_MIXED;
2635 } else if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
2636 bit = BLOCK_GROUP_DATA;
2637 cache->data = BTRFS_BLOCK_GROUP_DATA;
2639 bit = BLOCK_GROUP_METADATA;
2643 /* use EXTENT_LOCKED to prevent merging */
2644 set_extent_bits(block_group_cache, found_key.objectid,
2645 found_key.objectid + found_key.offset - 1,
2646 bit | EXTENT_LOCKED, GFP_NOFS);
2647 set_state_private(block_group_cache, found_key.objectid,
2648 (unsigned long)cache);
2651 btrfs_super_total_bytes(&info->super_copy))
2655 btrfs_free_path(path);