2 * Copyright (C) 2009 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/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node;
44 * present a tree block in the backref cache
47 struct rb_node rb_node;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list;
55 /* list of upper level blocks reference this block */
56 struct list_head upper;
57 /* list of child blocks in the cache */
58 struct list_head lower;
59 /* NULL if this node is not tree root */
60 struct btrfs_root *root;
61 /* extent buffer got by COW the block */
62 struct extent_buffer *eb;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest:1;
69 /* is the extent buffer locked */
70 unsigned int locked:1;
71 /* has the block been processed */
72 unsigned int processed:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached:1;
88 * present a block pointer in the backref cache
91 struct list_head list[2];
92 struct backref_node *node[2];
97 #define RELOCATION_RESERVED_NODES 256
99 struct backref_cache {
100 /* red black tree of all backref nodes in the cache */
101 struct rb_root rb_root;
102 /* for passing backref nodes to btrfs_reloc_cow_block */
103 struct backref_node *path[BTRFS_MAX_LEVEL];
105 * list of blocks that have been cowed but some block
106 * pointers in upper level blocks may not reflect the
109 struct list_head pending[BTRFS_MAX_LEVEL];
110 /* list of backref nodes with no child node */
111 struct list_head leaves;
112 /* list of blocks that have been cowed in current transaction */
113 struct list_head changed;
114 /* list of detached backref node. */
115 struct list_head detached;
124 * map address of tree root to tree
126 struct mapping_node {
127 struct rb_node rb_node;
132 struct mapping_tree {
133 struct rb_root rb_root;
138 * present a tree block to process
141 struct rb_node rb_node;
143 struct btrfs_key key;
144 unsigned int level:8;
145 unsigned int key_ready:1;
148 #define MAX_EXTENTS 128
150 struct file_extent_cluster {
153 u64 boundary[MAX_EXTENTS];
157 struct reloc_control {
158 /* block group to relocate */
159 struct btrfs_block_group_cache *block_group;
161 struct btrfs_root *extent_root;
162 /* inode for moving data */
163 struct inode *data_inode;
165 struct btrfs_block_rsv *block_rsv;
167 struct backref_cache backref_cache;
169 struct file_extent_cluster cluster;
170 /* tree blocks have been processed */
171 struct extent_io_tree processed_blocks;
172 /* map start of tree root to corresponding reloc tree */
173 struct mapping_tree reloc_root_tree;
174 /* list of reloc trees */
175 struct list_head reloc_roots;
176 /* size of metadata reservation for merging reloc trees */
177 u64 merging_rsv_size;
178 /* size of relocated tree nodes */
180 /* reserved size for block group relocation*/
186 unsigned int stage:8;
187 unsigned int create_reloc_tree:1;
188 unsigned int merge_reloc_tree:1;
189 unsigned int found_file_extent:1;
192 /* stages of data relocation */
193 #define MOVE_DATA_EXTENTS 0
194 #define UPDATE_DATA_PTRS 1
196 static void remove_backref_node(struct backref_cache *cache,
197 struct backref_node *node);
198 static void __mark_block_processed(struct reloc_control *rc,
199 struct backref_node *node);
201 static void mapping_tree_init(struct mapping_tree *tree)
203 tree->rb_root = RB_ROOT;
204 spin_lock_init(&tree->lock);
207 static void backref_cache_init(struct backref_cache *cache)
210 cache->rb_root = RB_ROOT;
211 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
212 INIT_LIST_HEAD(&cache->pending[i]);
213 INIT_LIST_HEAD(&cache->changed);
214 INIT_LIST_HEAD(&cache->detached);
215 INIT_LIST_HEAD(&cache->leaves);
218 static void backref_cache_cleanup(struct backref_cache *cache)
220 struct backref_node *node;
223 while (!list_empty(&cache->detached)) {
224 node = list_entry(cache->detached.next,
225 struct backref_node, list);
226 remove_backref_node(cache, node);
229 while (!list_empty(&cache->leaves)) {
230 node = list_entry(cache->leaves.next,
231 struct backref_node, lower);
232 remove_backref_node(cache, node);
235 cache->last_trans = 0;
237 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
238 BUG_ON(!list_empty(&cache->pending[i]));
239 BUG_ON(!list_empty(&cache->changed));
240 BUG_ON(!list_empty(&cache->detached));
241 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
242 BUG_ON(cache->nr_nodes);
243 BUG_ON(cache->nr_edges);
246 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
248 struct backref_node *node;
250 node = kzalloc(sizeof(*node), GFP_NOFS);
252 INIT_LIST_HEAD(&node->list);
253 INIT_LIST_HEAD(&node->upper);
254 INIT_LIST_HEAD(&node->lower);
255 RB_CLEAR_NODE(&node->rb_node);
261 static void free_backref_node(struct backref_cache *cache,
262 struct backref_node *node)
270 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
272 struct backref_edge *edge;
274 edge = kzalloc(sizeof(*edge), GFP_NOFS);
280 static void free_backref_edge(struct backref_cache *cache,
281 struct backref_edge *edge)
289 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
290 struct rb_node *node)
292 struct rb_node **p = &root->rb_node;
293 struct rb_node *parent = NULL;
294 struct tree_entry *entry;
298 entry = rb_entry(parent, struct tree_entry, rb_node);
300 if (bytenr < entry->bytenr)
302 else if (bytenr > entry->bytenr)
308 rb_link_node(node, parent, p);
309 rb_insert_color(node, root);
313 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
315 struct rb_node *n = root->rb_node;
316 struct tree_entry *entry;
319 entry = rb_entry(n, struct tree_entry, rb_node);
321 if (bytenr < entry->bytenr)
323 else if (bytenr > entry->bytenr)
331 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
334 struct btrfs_fs_info *fs_info = NULL;
335 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
338 fs_info = bnode->root->fs_info;
339 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
340 "found at offset %llu", bytenr);
344 * walk up backref nodes until reach node presents tree root
346 static struct backref_node *walk_up_backref(struct backref_node *node,
347 struct backref_edge *edges[],
350 struct backref_edge *edge;
353 while (!list_empty(&node->upper)) {
354 edge = list_entry(node->upper.next,
355 struct backref_edge, list[LOWER]);
357 node = edge->node[UPPER];
359 BUG_ON(node->detached);
365 * walk down backref nodes to find start of next reference path
367 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
370 struct backref_edge *edge;
371 struct backref_node *lower;
375 edge = edges[idx - 1];
376 lower = edge->node[LOWER];
377 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
381 edge = list_entry(edge->list[LOWER].next,
382 struct backref_edge, list[LOWER]);
383 edges[idx - 1] = edge;
385 return edge->node[UPPER];
391 static void unlock_node_buffer(struct backref_node *node)
394 btrfs_tree_unlock(node->eb);
399 static void drop_node_buffer(struct backref_node *node)
402 unlock_node_buffer(node);
403 free_extent_buffer(node->eb);
408 static void drop_backref_node(struct backref_cache *tree,
409 struct backref_node *node)
411 BUG_ON(!list_empty(&node->upper));
413 drop_node_buffer(node);
414 list_del(&node->list);
415 list_del(&node->lower);
416 if (!RB_EMPTY_NODE(&node->rb_node))
417 rb_erase(&node->rb_node, &tree->rb_root);
418 free_backref_node(tree, node);
422 * remove a backref node from the backref cache
424 static void remove_backref_node(struct backref_cache *cache,
425 struct backref_node *node)
427 struct backref_node *upper;
428 struct backref_edge *edge;
433 BUG_ON(!node->lowest && !node->detached);
434 while (!list_empty(&node->upper)) {
435 edge = list_entry(node->upper.next, struct backref_edge,
437 upper = edge->node[UPPER];
438 list_del(&edge->list[LOWER]);
439 list_del(&edge->list[UPPER]);
440 free_backref_edge(cache, edge);
442 if (RB_EMPTY_NODE(&upper->rb_node)) {
443 BUG_ON(!list_empty(&node->upper));
444 drop_backref_node(cache, node);
450 * add the node to leaf node list if no other
451 * child block cached.
453 if (list_empty(&upper->lower)) {
454 list_add_tail(&upper->lower, &cache->leaves);
459 drop_backref_node(cache, node);
462 static void update_backref_node(struct backref_cache *cache,
463 struct backref_node *node, u64 bytenr)
465 struct rb_node *rb_node;
466 rb_erase(&node->rb_node, &cache->rb_root);
467 node->bytenr = bytenr;
468 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
470 backref_tree_panic(rb_node, -EEXIST, bytenr);
474 * update backref cache after a transaction commit
476 static int update_backref_cache(struct btrfs_trans_handle *trans,
477 struct backref_cache *cache)
479 struct backref_node *node;
482 if (cache->last_trans == 0) {
483 cache->last_trans = trans->transid;
487 if (cache->last_trans == trans->transid)
491 * detached nodes are used to avoid unnecessary backref
492 * lookup. transaction commit changes the extent tree.
493 * so the detached nodes are no longer useful.
495 while (!list_empty(&cache->detached)) {
496 node = list_entry(cache->detached.next,
497 struct backref_node, list);
498 remove_backref_node(cache, node);
501 while (!list_empty(&cache->changed)) {
502 node = list_entry(cache->changed.next,
503 struct backref_node, list);
504 list_del_init(&node->list);
505 BUG_ON(node->pending);
506 update_backref_node(cache, node, node->new_bytenr);
510 * some nodes can be left in the pending list if there were
511 * errors during processing the pending nodes.
513 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
514 list_for_each_entry(node, &cache->pending[level], list) {
515 BUG_ON(!node->pending);
516 if (node->bytenr == node->new_bytenr)
518 update_backref_node(cache, node, node->new_bytenr);
522 cache->last_trans = 0;
527 static int should_ignore_root(struct btrfs_root *root)
529 struct btrfs_root *reloc_root;
531 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
534 reloc_root = root->reloc_root;
538 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
539 root->fs_info->running_transaction->transid - 1)
542 * if there is reloc tree and it was created in previous
543 * transaction backref lookup can find the reloc tree,
544 * so backref node for the fs tree root is useless for
550 * find reloc tree by address of tree root
552 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
555 struct rb_node *rb_node;
556 struct mapping_node *node;
557 struct btrfs_root *root = NULL;
559 spin_lock(&rc->reloc_root_tree.lock);
560 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
562 node = rb_entry(rb_node, struct mapping_node, rb_node);
563 root = (struct btrfs_root *)node->data;
565 spin_unlock(&rc->reloc_root_tree.lock);
569 static int is_cowonly_root(u64 root_objectid)
571 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
572 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
573 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
574 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
575 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
576 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
577 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
578 root_objectid == BTRFS_QUOTA_TREE_OBJECTID)
583 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
586 struct btrfs_key key;
588 key.objectid = root_objectid;
589 key.type = BTRFS_ROOT_ITEM_KEY;
590 if (is_cowonly_root(root_objectid))
593 key.offset = (u64)-1;
595 return btrfs_get_fs_root(fs_info, &key, false);
598 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
599 static noinline_for_stack
600 struct btrfs_root *find_tree_root(struct reloc_control *rc,
601 struct extent_buffer *leaf,
602 struct btrfs_extent_ref_v0 *ref0)
604 struct btrfs_root *root;
605 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
606 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
608 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
610 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
611 BUG_ON(IS_ERR(root));
613 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
614 generation != btrfs_root_generation(&root->root_item))
621 static noinline_for_stack
622 int find_inline_backref(struct extent_buffer *leaf, int slot,
623 unsigned long *ptr, unsigned long *end)
625 struct btrfs_key key;
626 struct btrfs_extent_item *ei;
627 struct btrfs_tree_block_info *bi;
630 btrfs_item_key_to_cpu(leaf, &key, slot);
632 item_size = btrfs_item_size_nr(leaf, slot);
633 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
634 if (item_size < sizeof(*ei)) {
635 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
639 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
640 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
641 BTRFS_EXTENT_FLAG_TREE_BLOCK));
643 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
644 item_size <= sizeof(*ei) + sizeof(*bi)) {
645 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
648 if (key.type == BTRFS_METADATA_ITEM_KEY &&
649 item_size <= sizeof(*ei)) {
650 WARN_ON(item_size < sizeof(*ei));
654 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
655 bi = (struct btrfs_tree_block_info *)(ei + 1);
656 *ptr = (unsigned long)(bi + 1);
658 *ptr = (unsigned long)(ei + 1);
660 *end = (unsigned long)ei + item_size;
665 * build backref tree for a given tree block. root of the backref tree
666 * corresponds the tree block, leaves of the backref tree correspond
667 * roots of b-trees that reference the tree block.
669 * the basic idea of this function is check backrefs of a given block
670 * to find upper level blocks that refernece the block, and then check
671 * bakcrefs of these upper level blocks recursively. the recursion stop
672 * when tree root is reached or backrefs for the block is cached.
674 * NOTE: if we find backrefs for a block are cached, we know backrefs
675 * for all upper level blocks that directly/indirectly reference the
676 * block are also cached.
678 static noinline_for_stack
679 struct backref_node *build_backref_tree(struct reloc_control *rc,
680 struct btrfs_key *node_key,
681 int level, u64 bytenr)
683 struct backref_cache *cache = &rc->backref_cache;
684 struct btrfs_path *path1;
685 struct btrfs_path *path2;
686 struct extent_buffer *eb;
687 struct btrfs_root *root;
688 struct backref_node *cur;
689 struct backref_node *upper;
690 struct backref_node *lower;
691 struct backref_node *node = NULL;
692 struct backref_node *exist = NULL;
693 struct backref_edge *edge;
694 struct rb_node *rb_node;
695 struct btrfs_key key;
703 bool need_check = true;
705 path1 = btrfs_alloc_path();
706 path2 = btrfs_alloc_path();
707 if (!path1 || !path2) {
714 node = alloc_backref_node(cache);
720 node->bytenr = bytenr;
727 key.objectid = cur->bytenr;
728 key.type = BTRFS_METADATA_ITEM_KEY;
729 key.offset = (u64)-1;
731 path1->search_commit_root = 1;
732 path1->skip_locking = 1;
733 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
740 ASSERT(path1->slots[0]);
744 WARN_ON(cur->checked);
745 if (!list_empty(&cur->upper)) {
747 * the backref was added previously when processing
748 * backref of type BTRFS_TREE_BLOCK_REF_KEY
750 ASSERT(list_is_singular(&cur->upper));
751 edge = list_entry(cur->upper.next, struct backref_edge,
753 ASSERT(list_empty(&edge->list[UPPER]));
754 exist = edge->node[UPPER];
756 * add the upper level block to pending list if we need
760 list_add_tail(&edge->list[UPPER], &list);
767 eb = path1->nodes[0];
770 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
771 ret = btrfs_next_leaf(rc->extent_root, path1);
778 eb = path1->nodes[0];
781 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
782 if (key.objectid != cur->bytenr) {
787 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
788 key.type == BTRFS_METADATA_ITEM_KEY) {
789 ret = find_inline_backref(eb, path1->slots[0],
797 /* update key for inline back ref */
798 struct btrfs_extent_inline_ref *iref;
799 iref = (struct btrfs_extent_inline_ref *)ptr;
800 key.type = btrfs_extent_inline_ref_type(eb, iref);
801 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
802 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
803 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
807 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
808 exist->owner == key.offset) ||
809 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
810 exist->bytenr == key.offset))) {
815 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
816 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
817 key.type == BTRFS_EXTENT_REF_V0_KEY) {
818 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
819 struct btrfs_extent_ref_v0 *ref0;
820 ref0 = btrfs_item_ptr(eb, path1->slots[0],
821 struct btrfs_extent_ref_v0);
822 if (key.objectid == key.offset) {
823 root = find_tree_root(rc, eb, ref0);
824 if (root && !should_ignore_root(root))
827 list_add(&cur->list, &useless);
830 if (is_cowonly_root(btrfs_ref_root_v0(eb,
835 ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
836 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
838 if (key.objectid == key.offset) {
840 * only root blocks of reloc trees use
841 * backref of this type.
843 root = find_reloc_root(rc, cur->bytenr);
849 edge = alloc_backref_edge(cache);
854 rb_node = tree_search(&cache->rb_root, key.offset);
856 upper = alloc_backref_node(cache);
858 free_backref_edge(cache, edge);
862 upper->bytenr = key.offset;
863 upper->level = cur->level + 1;
865 * backrefs for the upper level block isn't
866 * cached, add the block to pending list
868 list_add_tail(&edge->list[UPPER], &list);
870 upper = rb_entry(rb_node, struct backref_node,
872 ASSERT(upper->checked);
873 INIT_LIST_HEAD(&edge->list[UPPER]);
875 list_add_tail(&edge->list[LOWER], &cur->upper);
876 edge->node[LOWER] = cur;
877 edge->node[UPPER] = upper;
880 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
884 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
885 root = read_fs_root(rc->extent_root->fs_info, key.offset);
891 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
894 if (btrfs_root_level(&root->root_item) == cur->level) {
896 ASSERT(btrfs_root_bytenr(&root->root_item) ==
898 if (should_ignore_root(root))
899 list_add(&cur->list, &useless);
905 level = cur->level + 1;
908 * searching the tree to find upper level blocks
909 * reference the block.
911 path2->search_commit_root = 1;
912 path2->skip_locking = 1;
913 path2->lowest_level = level;
914 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
915 path2->lowest_level = 0;
920 if (ret > 0 && path2->slots[level] > 0)
921 path2->slots[level]--;
923 eb = path2->nodes[level];
924 if (btrfs_node_blockptr(eb, path2->slots[level]) !=
926 btrfs_err(root->fs_info,
927 "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
928 cur->bytenr, level - 1, root->objectid,
929 node_key->objectid, node_key->type,
936 for (; level < BTRFS_MAX_LEVEL; level++) {
937 if (!path2->nodes[level]) {
938 ASSERT(btrfs_root_bytenr(&root->root_item) ==
940 if (should_ignore_root(root))
941 list_add(&lower->list, &useless);
947 edge = alloc_backref_edge(cache);
953 eb = path2->nodes[level];
954 rb_node = tree_search(&cache->rb_root, eb->start);
956 upper = alloc_backref_node(cache);
958 free_backref_edge(cache, edge);
962 upper->bytenr = eb->start;
963 upper->owner = btrfs_header_owner(eb);
964 upper->level = lower->level + 1;
965 if (!test_bit(BTRFS_ROOT_REF_COWS,
970 * if we know the block isn't shared
971 * we can void checking its backrefs.
973 if (btrfs_block_can_be_shared(root, eb))
979 * add the block to pending list if we
980 * need check its backrefs, we only do this once
981 * while walking up a tree as we will catch
982 * anything else later on.
984 if (!upper->checked && need_check) {
986 list_add_tail(&edge->list[UPPER],
991 INIT_LIST_HEAD(&edge->list[UPPER]);
994 upper = rb_entry(rb_node, struct backref_node,
996 ASSERT(upper->checked);
997 INIT_LIST_HEAD(&edge->list[UPPER]);
999 upper->owner = btrfs_header_owner(eb);
1001 list_add_tail(&edge->list[LOWER], &lower->upper);
1002 edge->node[LOWER] = lower;
1003 edge->node[UPPER] = upper;
1010 btrfs_release_path(path2);
1013 ptr += btrfs_extent_inline_ref_size(key.type);
1023 btrfs_release_path(path1);
1028 /* the pending list isn't empty, take the first block to process */
1029 if (!list_empty(&list)) {
1030 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1031 list_del_init(&edge->list[UPPER]);
1032 cur = edge->node[UPPER];
1037 * everything goes well, connect backref nodes and insert backref nodes
1040 ASSERT(node->checked);
1041 cowonly = node->cowonly;
1043 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1046 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1047 list_add_tail(&node->lower, &cache->leaves);
1050 list_for_each_entry(edge, &node->upper, list[LOWER])
1051 list_add_tail(&edge->list[UPPER], &list);
1053 while (!list_empty(&list)) {
1054 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1055 list_del_init(&edge->list[UPPER]);
1056 upper = edge->node[UPPER];
1057 if (upper->detached) {
1058 list_del(&edge->list[LOWER]);
1059 lower = edge->node[LOWER];
1060 free_backref_edge(cache, edge);
1061 if (list_empty(&lower->upper))
1062 list_add(&lower->list, &useless);
1066 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1067 if (upper->lowest) {
1068 list_del_init(&upper->lower);
1072 list_add_tail(&edge->list[UPPER], &upper->lower);
1076 if (!upper->checked) {
1078 * Still want to blow up for developers since this is a
1085 if (cowonly != upper->cowonly) {
1092 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1095 backref_tree_panic(rb_node, -EEXIST,
1099 list_add_tail(&edge->list[UPPER], &upper->lower);
1101 list_for_each_entry(edge, &upper->upper, list[LOWER])
1102 list_add_tail(&edge->list[UPPER], &list);
1105 * process useless backref nodes. backref nodes for tree leaves
1106 * are deleted from the cache. backref nodes for upper level
1107 * tree blocks are left in the cache to avoid unnecessary backref
1110 while (!list_empty(&useless)) {
1111 upper = list_entry(useless.next, struct backref_node, list);
1112 list_del_init(&upper->list);
1113 ASSERT(list_empty(&upper->upper));
1116 if (upper->lowest) {
1117 list_del_init(&upper->lower);
1120 while (!list_empty(&upper->lower)) {
1121 edge = list_entry(upper->lower.next,
1122 struct backref_edge, list[UPPER]);
1123 list_del(&edge->list[UPPER]);
1124 list_del(&edge->list[LOWER]);
1125 lower = edge->node[LOWER];
1126 free_backref_edge(cache, edge);
1128 if (list_empty(&lower->upper))
1129 list_add(&lower->list, &useless);
1131 __mark_block_processed(rc, upper);
1132 if (upper->level > 0) {
1133 list_add(&upper->list, &cache->detached);
1134 upper->detached = 1;
1136 rb_erase(&upper->rb_node, &cache->rb_root);
1137 free_backref_node(cache, upper);
1141 btrfs_free_path(path1);
1142 btrfs_free_path(path2);
1144 while (!list_empty(&useless)) {
1145 lower = list_entry(useless.next,
1146 struct backref_node, list);
1147 list_del_init(&lower->list);
1149 while (!list_empty(&list)) {
1150 edge = list_first_entry(&list, struct backref_edge,
1152 list_del(&edge->list[UPPER]);
1153 list_del(&edge->list[LOWER]);
1154 lower = edge->node[LOWER];
1155 upper = edge->node[UPPER];
1156 free_backref_edge(cache, edge);
1159 * Lower is no longer linked to any upper backref nodes
1160 * and isn't in the cache, we can free it ourselves.
1162 if (list_empty(&lower->upper) &&
1163 RB_EMPTY_NODE(&lower->rb_node))
1164 list_add(&lower->list, &useless);
1166 if (!RB_EMPTY_NODE(&upper->rb_node))
1169 /* Add this guy's upper edges to the list to proces */
1170 list_for_each_entry(edge, &upper->upper, list[LOWER])
1171 list_add_tail(&edge->list[UPPER], &list);
1172 if (list_empty(&upper->upper))
1173 list_add(&upper->list, &useless);
1176 while (!list_empty(&useless)) {
1177 lower = list_entry(useless.next,
1178 struct backref_node, list);
1179 list_del_init(&lower->list);
1180 free_backref_node(cache, lower);
1182 return ERR_PTR(err);
1184 ASSERT(!node || !node->detached);
1189 * helper to add backref node for the newly created snapshot.
1190 * the backref node is created by cloning backref node that
1191 * corresponds to root of source tree
1193 static int clone_backref_node(struct btrfs_trans_handle *trans,
1194 struct reloc_control *rc,
1195 struct btrfs_root *src,
1196 struct btrfs_root *dest)
1198 struct btrfs_root *reloc_root = src->reloc_root;
1199 struct backref_cache *cache = &rc->backref_cache;
1200 struct backref_node *node = NULL;
1201 struct backref_node *new_node;
1202 struct backref_edge *edge;
1203 struct backref_edge *new_edge;
1204 struct rb_node *rb_node;
1206 if (cache->last_trans > 0)
1207 update_backref_cache(trans, cache);
1209 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1211 node = rb_entry(rb_node, struct backref_node, rb_node);
1215 BUG_ON(node->new_bytenr != reloc_root->node->start);
1219 rb_node = tree_search(&cache->rb_root,
1220 reloc_root->commit_root->start);
1222 node = rb_entry(rb_node, struct backref_node,
1224 BUG_ON(node->detached);
1231 new_node = alloc_backref_node(cache);
1235 new_node->bytenr = dest->node->start;
1236 new_node->level = node->level;
1237 new_node->lowest = node->lowest;
1238 new_node->checked = 1;
1239 new_node->root = dest;
1241 if (!node->lowest) {
1242 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1243 new_edge = alloc_backref_edge(cache);
1247 new_edge->node[UPPER] = new_node;
1248 new_edge->node[LOWER] = edge->node[LOWER];
1249 list_add_tail(&new_edge->list[UPPER],
1253 list_add_tail(&new_node->lower, &cache->leaves);
1256 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1257 &new_node->rb_node);
1259 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1261 if (!new_node->lowest) {
1262 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1263 list_add_tail(&new_edge->list[LOWER],
1264 &new_edge->node[LOWER]->upper);
1269 while (!list_empty(&new_node->lower)) {
1270 new_edge = list_entry(new_node->lower.next,
1271 struct backref_edge, list[UPPER]);
1272 list_del(&new_edge->list[UPPER]);
1273 free_backref_edge(cache, new_edge);
1275 free_backref_node(cache, new_node);
1280 * helper to add 'address of tree root -> reloc tree' mapping
1282 static int __must_check __add_reloc_root(struct btrfs_root *root)
1284 struct rb_node *rb_node;
1285 struct mapping_node *node;
1286 struct reloc_control *rc = root->fs_info->reloc_ctl;
1288 node = kmalloc(sizeof(*node), GFP_NOFS);
1292 node->bytenr = root->node->start;
1295 spin_lock(&rc->reloc_root_tree.lock);
1296 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1297 node->bytenr, &node->rb_node);
1298 spin_unlock(&rc->reloc_root_tree.lock);
1300 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1301 "for start=%llu while inserting into relocation "
1302 "tree", node->bytenr);
1307 list_add_tail(&root->root_list, &rc->reloc_roots);
1312 * helper to delete the 'address of tree root -> reloc tree'
1315 static void __del_reloc_root(struct btrfs_root *root)
1317 struct rb_node *rb_node;
1318 struct mapping_node *node = NULL;
1319 struct reloc_control *rc = root->fs_info->reloc_ctl;
1321 spin_lock(&rc->reloc_root_tree.lock);
1322 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1325 node = rb_entry(rb_node, struct mapping_node, rb_node);
1326 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1328 spin_unlock(&rc->reloc_root_tree.lock);
1332 BUG_ON((struct btrfs_root *)node->data != root);
1334 spin_lock(&root->fs_info->trans_lock);
1335 list_del_init(&root->root_list);
1336 spin_unlock(&root->fs_info->trans_lock);
1341 * helper to update the 'address of tree root -> reloc tree'
1344 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1346 struct rb_node *rb_node;
1347 struct mapping_node *node = NULL;
1348 struct reloc_control *rc = root->fs_info->reloc_ctl;
1350 spin_lock(&rc->reloc_root_tree.lock);
1351 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1354 node = rb_entry(rb_node, struct mapping_node, rb_node);
1355 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1357 spin_unlock(&rc->reloc_root_tree.lock);
1361 BUG_ON((struct btrfs_root *)node->data != root);
1363 spin_lock(&rc->reloc_root_tree.lock);
1364 node->bytenr = new_bytenr;
1365 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1366 node->bytenr, &node->rb_node);
1367 spin_unlock(&rc->reloc_root_tree.lock);
1369 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1373 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1374 struct btrfs_root *root, u64 objectid)
1376 struct btrfs_root *reloc_root;
1377 struct extent_buffer *eb;
1378 struct btrfs_root_item *root_item;
1379 struct btrfs_key root_key;
1383 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1386 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1387 root_key.type = BTRFS_ROOT_ITEM_KEY;
1388 root_key.offset = objectid;
1390 if (root->root_key.objectid == objectid) {
1391 /* called by btrfs_init_reloc_root */
1392 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1393 BTRFS_TREE_RELOC_OBJECTID);
1396 last_snap = btrfs_root_last_snapshot(&root->root_item);
1397 btrfs_set_root_last_snapshot(&root->root_item,
1398 trans->transid - 1);
1401 * called by btrfs_reloc_post_snapshot_hook.
1402 * the source tree is a reloc tree, all tree blocks
1403 * modified after it was created have RELOC flag
1404 * set in their headers. so it's OK to not update
1405 * the 'last_snapshot'.
1407 ret = btrfs_copy_root(trans, root, root->node, &eb,
1408 BTRFS_TREE_RELOC_OBJECTID);
1412 memcpy(root_item, &root->root_item, sizeof(*root_item));
1413 btrfs_set_root_bytenr(root_item, eb->start);
1414 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1415 btrfs_set_root_generation(root_item, trans->transid);
1417 if (root->root_key.objectid == objectid) {
1418 btrfs_set_root_refs(root_item, 0);
1419 memset(&root_item->drop_progress, 0,
1420 sizeof(struct btrfs_disk_key));
1421 root_item->drop_level = 0;
1423 * abuse rtransid, it is safe because it is impossible to
1424 * receive data into a relocation tree.
1426 btrfs_set_root_rtransid(root_item, last_snap);
1427 btrfs_set_root_otransid(root_item, trans->transid);
1430 btrfs_tree_unlock(eb);
1431 free_extent_buffer(eb);
1433 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1434 &root_key, root_item);
1438 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1439 BUG_ON(IS_ERR(reloc_root));
1440 reloc_root->last_trans = trans->transid;
1445 * create reloc tree for a given fs tree. reloc tree is just a
1446 * snapshot of the fs tree with special root objectid.
1448 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1449 struct btrfs_root *root)
1451 struct btrfs_root *reloc_root;
1452 struct reloc_control *rc = root->fs_info->reloc_ctl;
1453 struct btrfs_block_rsv *rsv;
1457 if (root->reloc_root) {
1458 reloc_root = root->reloc_root;
1459 reloc_root->last_trans = trans->transid;
1463 if (!rc || !rc->create_reloc_tree ||
1464 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1467 if (!trans->reloc_reserved) {
1468 rsv = trans->block_rsv;
1469 trans->block_rsv = rc->block_rsv;
1472 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1474 trans->block_rsv = rsv;
1476 ret = __add_reloc_root(reloc_root);
1478 root->reloc_root = reloc_root;
1483 * update root item of reloc tree
1485 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1486 struct btrfs_root *root)
1488 struct btrfs_root *reloc_root;
1489 struct btrfs_root_item *root_item;
1492 if (!root->reloc_root)
1495 reloc_root = root->reloc_root;
1496 root_item = &reloc_root->root_item;
1498 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1499 btrfs_root_refs(root_item) == 0) {
1500 root->reloc_root = NULL;
1501 __del_reloc_root(reloc_root);
1504 if (reloc_root->commit_root != reloc_root->node) {
1505 btrfs_set_root_node(root_item, reloc_root->node);
1506 free_extent_buffer(reloc_root->commit_root);
1507 reloc_root->commit_root = btrfs_root_node(reloc_root);
1510 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1511 &reloc_root->root_key, root_item);
1519 * helper to find first cached inode with inode number >= objectid
1522 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1524 struct rb_node *node;
1525 struct rb_node *prev;
1526 struct btrfs_inode *entry;
1527 struct inode *inode;
1529 spin_lock(&root->inode_lock);
1531 node = root->inode_tree.rb_node;
1535 entry = rb_entry(node, struct btrfs_inode, rb_node);
1537 if (objectid < btrfs_ino(&entry->vfs_inode))
1538 node = node->rb_left;
1539 else if (objectid > btrfs_ino(&entry->vfs_inode))
1540 node = node->rb_right;
1546 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1547 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1551 prev = rb_next(prev);
1555 entry = rb_entry(node, struct btrfs_inode, rb_node);
1556 inode = igrab(&entry->vfs_inode);
1558 spin_unlock(&root->inode_lock);
1562 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1563 if (cond_resched_lock(&root->inode_lock))
1566 node = rb_next(node);
1568 spin_unlock(&root->inode_lock);
1572 static int in_block_group(u64 bytenr,
1573 struct btrfs_block_group_cache *block_group)
1575 if (bytenr >= block_group->key.objectid &&
1576 bytenr < block_group->key.objectid + block_group->key.offset)
1582 * get new location of data
1584 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1585 u64 bytenr, u64 num_bytes)
1587 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1588 struct btrfs_path *path;
1589 struct btrfs_file_extent_item *fi;
1590 struct extent_buffer *leaf;
1593 path = btrfs_alloc_path();
1597 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1598 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1607 leaf = path->nodes[0];
1608 fi = btrfs_item_ptr(leaf, path->slots[0],
1609 struct btrfs_file_extent_item);
1611 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1612 btrfs_file_extent_compression(leaf, fi) ||
1613 btrfs_file_extent_encryption(leaf, fi) ||
1614 btrfs_file_extent_other_encoding(leaf, fi));
1616 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1621 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1624 btrfs_free_path(path);
1629 * update file extent items in the tree leaf to point to
1630 * the new locations.
1632 static noinline_for_stack
1633 int replace_file_extents(struct btrfs_trans_handle *trans,
1634 struct reloc_control *rc,
1635 struct btrfs_root *root,
1636 struct extent_buffer *leaf)
1638 struct btrfs_key key;
1639 struct btrfs_file_extent_item *fi;
1640 struct inode *inode = NULL;
1652 if (rc->stage != UPDATE_DATA_PTRS)
1655 /* reloc trees always use full backref */
1656 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1657 parent = leaf->start;
1661 nritems = btrfs_header_nritems(leaf);
1662 for (i = 0; i < nritems; i++) {
1664 btrfs_item_key_to_cpu(leaf, &key, i);
1665 if (key.type != BTRFS_EXTENT_DATA_KEY)
1667 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1668 if (btrfs_file_extent_type(leaf, fi) ==
1669 BTRFS_FILE_EXTENT_INLINE)
1671 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1672 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1675 if (!in_block_group(bytenr, rc->block_group))
1679 * if we are modifying block in fs tree, wait for readpage
1680 * to complete and drop the extent cache
1682 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1684 inode = find_next_inode(root, key.objectid);
1686 } else if (inode && btrfs_ino(inode) < key.objectid) {
1687 btrfs_add_delayed_iput(inode);
1688 inode = find_next_inode(root, key.objectid);
1690 if (inode && btrfs_ino(inode) == key.objectid) {
1692 btrfs_file_extent_num_bytes(leaf, fi);
1693 WARN_ON(!IS_ALIGNED(key.offset,
1695 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1697 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1702 btrfs_drop_extent_cache(inode, key.offset, end,
1704 unlock_extent(&BTRFS_I(inode)->io_tree,
1709 ret = get_new_location(rc->data_inode, &new_bytenr,
1713 * Don't have to abort since we've not changed anything
1714 * in the file extent yet.
1719 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1722 key.offset -= btrfs_file_extent_offset(leaf, fi);
1723 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1725 btrfs_header_owner(leaf),
1726 key.objectid, key.offset);
1728 btrfs_abort_transaction(trans, root, ret);
1732 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1733 parent, btrfs_header_owner(leaf),
1734 key.objectid, key.offset);
1736 btrfs_abort_transaction(trans, root, ret);
1741 btrfs_mark_buffer_dirty(leaf);
1743 btrfs_add_delayed_iput(inode);
1747 static noinline_for_stack
1748 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1749 struct btrfs_path *path, int level)
1751 struct btrfs_disk_key key1;
1752 struct btrfs_disk_key key2;
1753 btrfs_node_key(eb, &key1, slot);
1754 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1755 return memcmp(&key1, &key2, sizeof(key1));
1759 * try to replace tree blocks in fs tree with the new blocks
1760 * in reloc tree. tree blocks haven't been modified since the
1761 * reloc tree was create can be replaced.
1763 * if a block was replaced, level of the block + 1 is returned.
1764 * if no block got replaced, 0 is returned. if there are other
1765 * errors, a negative error number is returned.
1767 static noinline_for_stack
1768 int replace_path(struct btrfs_trans_handle *trans,
1769 struct btrfs_root *dest, struct btrfs_root *src,
1770 struct btrfs_path *path, struct btrfs_key *next_key,
1771 int lowest_level, int max_level)
1773 struct extent_buffer *eb;
1774 struct extent_buffer *parent;
1775 struct btrfs_key key;
1787 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1788 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1790 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1792 slot = path->slots[lowest_level];
1793 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1795 eb = btrfs_lock_root_node(dest);
1796 btrfs_set_lock_blocking(eb);
1797 level = btrfs_header_level(eb);
1799 if (level < lowest_level) {
1800 btrfs_tree_unlock(eb);
1801 free_extent_buffer(eb);
1806 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1809 btrfs_set_lock_blocking(eb);
1812 next_key->objectid = (u64)-1;
1813 next_key->type = (u8)-1;
1814 next_key->offset = (u64)-1;
1819 level = btrfs_header_level(parent);
1820 BUG_ON(level < lowest_level);
1822 ret = btrfs_bin_search(parent, &key, level, &slot);
1823 if (ret && slot > 0)
1826 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1827 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1829 old_bytenr = btrfs_node_blockptr(parent, slot);
1830 blocksize = dest->nodesize;
1831 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1833 if (level <= max_level) {
1834 eb = path->nodes[level];
1835 new_bytenr = btrfs_node_blockptr(eb,
1836 path->slots[level]);
1837 new_ptr_gen = btrfs_node_ptr_generation(eb,
1838 path->slots[level]);
1844 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1849 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1850 memcmp_node_keys(parent, slot, path, level)) {
1851 if (level <= lowest_level) {
1856 eb = read_tree_block(dest, old_bytenr, old_ptr_gen);
1859 } else if (!extent_buffer_uptodate(eb)) {
1861 free_extent_buffer(eb);
1864 btrfs_tree_lock(eb);
1866 ret = btrfs_cow_block(trans, dest, eb, parent,
1870 btrfs_set_lock_blocking(eb);
1872 btrfs_tree_unlock(parent);
1873 free_extent_buffer(parent);
1880 btrfs_tree_unlock(parent);
1881 free_extent_buffer(parent);
1886 btrfs_node_key_to_cpu(path->nodes[level], &key,
1887 path->slots[level]);
1888 btrfs_release_path(path);
1890 path->lowest_level = level;
1891 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1892 path->lowest_level = 0;
1896 * swap blocks in fs tree and reloc tree.
1898 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1899 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1900 btrfs_mark_buffer_dirty(parent);
1902 btrfs_set_node_blockptr(path->nodes[level],
1903 path->slots[level], old_bytenr);
1904 btrfs_set_node_ptr_generation(path->nodes[level],
1905 path->slots[level], old_ptr_gen);
1906 btrfs_mark_buffer_dirty(path->nodes[level]);
1908 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1909 path->nodes[level]->start,
1910 src->root_key.objectid, level - 1, 0);
1912 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1913 0, dest->root_key.objectid, level - 1,
1917 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1918 path->nodes[level]->start,
1919 src->root_key.objectid, level - 1, 0);
1922 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1923 0, dest->root_key.objectid, level - 1,
1927 btrfs_unlock_up_safe(path, 0);
1932 btrfs_tree_unlock(parent);
1933 free_extent_buffer(parent);
1938 * helper to find next relocated block in reloc tree
1940 static noinline_for_stack
1941 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1944 struct extent_buffer *eb;
1949 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1951 for (i = 0; i < *level; i++) {
1952 free_extent_buffer(path->nodes[i]);
1953 path->nodes[i] = NULL;
1956 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1957 eb = path->nodes[i];
1958 nritems = btrfs_header_nritems(eb);
1959 while (path->slots[i] + 1 < nritems) {
1961 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1968 free_extent_buffer(path->nodes[i]);
1969 path->nodes[i] = NULL;
1975 * walk down reloc tree to find relocated block of lowest level
1977 static noinline_for_stack
1978 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1981 struct extent_buffer *eb = NULL;
1988 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1990 for (i = *level; i > 0; i--) {
1991 eb = path->nodes[i];
1992 nritems = btrfs_header_nritems(eb);
1993 while (path->slots[i] < nritems) {
1994 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1995 if (ptr_gen > last_snapshot)
1999 if (path->slots[i] >= nritems) {
2010 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
2011 eb = read_tree_block(root, bytenr, ptr_gen);
2014 } else if (!extent_buffer_uptodate(eb)) {
2015 free_extent_buffer(eb);
2018 BUG_ON(btrfs_header_level(eb) != i - 1);
2019 path->nodes[i - 1] = eb;
2020 path->slots[i - 1] = 0;
2026 * invalidate extent cache for file extents whose key in range of
2027 * [min_key, max_key)
2029 static int invalidate_extent_cache(struct btrfs_root *root,
2030 struct btrfs_key *min_key,
2031 struct btrfs_key *max_key)
2033 struct inode *inode = NULL;
2038 objectid = min_key->objectid;
2043 if (objectid > max_key->objectid)
2046 inode = find_next_inode(root, objectid);
2049 ino = btrfs_ino(inode);
2051 if (ino > max_key->objectid) {
2057 if (!S_ISREG(inode->i_mode))
2060 if (unlikely(min_key->objectid == ino)) {
2061 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2063 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2066 start = min_key->offset;
2067 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2073 if (unlikely(max_key->objectid == ino)) {
2074 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2076 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2079 if (max_key->offset == 0)
2081 end = max_key->offset;
2082 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2089 /* the lock_extent waits for readpage to complete */
2090 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2091 btrfs_drop_extent_cache(inode, start, end, 1);
2092 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2097 static int find_next_key(struct btrfs_path *path, int level,
2098 struct btrfs_key *key)
2101 while (level < BTRFS_MAX_LEVEL) {
2102 if (!path->nodes[level])
2104 if (path->slots[level] + 1 <
2105 btrfs_header_nritems(path->nodes[level])) {
2106 btrfs_node_key_to_cpu(path->nodes[level], key,
2107 path->slots[level] + 1);
2116 * merge the relocated tree blocks in reloc tree with corresponding
2119 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2120 struct btrfs_root *root)
2122 LIST_HEAD(inode_list);
2123 struct btrfs_key key;
2124 struct btrfs_key next_key;
2125 struct btrfs_trans_handle *trans = NULL;
2126 struct btrfs_root *reloc_root;
2127 struct btrfs_root_item *root_item;
2128 struct btrfs_path *path;
2129 struct extent_buffer *leaf;
2137 path = btrfs_alloc_path();
2142 reloc_root = root->reloc_root;
2143 root_item = &reloc_root->root_item;
2145 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2146 level = btrfs_root_level(root_item);
2147 extent_buffer_get(reloc_root->node);
2148 path->nodes[level] = reloc_root->node;
2149 path->slots[level] = 0;
2151 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2153 level = root_item->drop_level;
2155 path->lowest_level = level;
2156 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2157 path->lowest_level = 0;
2159 btrfs_free_path(path);
2163 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2164 path->slots[level]);
2165 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2167 btrfs_unlock_up_safe(path, 0);
2170 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2171 memset(&next_key, 0, sizeof(next_key));
2174 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2175 BTRFS_RESERVE_FLUSH_ALL);
2180 trans = btrfs_start_transaction(root, 0);
2181 if (IS_ERR(trans)) {
2182 err = PTR_ERR(trans);
2186 trans->block_rsv = rc->block_rsv;
2191 ret = walk_down_reloc_tree(reloc_root, path, &level);
2199 if (!find_next_key(path, level, &key) &&
2200 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2203 ret = replace_path(trans, root, reloc_root, path,
2204 &next_key, level, max_level);
2213 btrfs_node_key_to_cpu(path->nodes[level], &key,
2214 path->slots[level]);
2218 ret = walk_up_reloc_tree(reloc_root, path, &level);
2224 * save the merging progress in the drop_progress.
2225 * this is OK since root refs == 1 in this case.
2227 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2228 path->slots[level]);
2229 root_item->drop_level = level;
2231 btrfs_end_transaction_throttle(trans, root);
2234 btrfs_btree_balance_dirty(root);
2236 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2237 invalidate_extent_cache(root, &key, &next_key);
2241 * handle the case only one block in the fs tree need to be
2242 * relocated and the block is tree root.
2244 leaf = btrfs_lock_root_node(root);
2245 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2246 btrfs_tree_unlock(leaf);
2247 free_extent_buffer(leaf);
2251 btrfs_free_path(path);
2254 memset(&root_item->drop_progress, 0,
2255 sizeof(root_item->drop_progress));
2256 root_item->drop_level = 0;
2257 btrfs_set_root_refs(root_item, 0);
2258 btrfs_update_reloc_root(trans, root);
2262 btrfs_end_transaction_throttle(trans, root);
2264 btrfs_btree_balance_dirty(root);
2266 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2267 invalidate_extent_cache(root, &key, &next_key);
2272 static noinline_for_stack
2273 int prepare_to_merge(struct reloc_control *rc, int err)
2275 struct btrfs_root *root = rc->extent_root;
2276 struct btrfs_root *reloc_root;
2277 struct btrfs_trans_handle *trans;
2278 LIST_HEAD(reloc_roots);
2282 mutex_lock(&root->fs_info->reloc_mutex);
2283 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2284 rc->merging_rsv_size += rc->nodes_relocated * 2;
2285 mutex_unlock(&root->fs_info->reloc_mutex);
2289 num_bytes = rc->merging_rsv_size;
2290 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2291 BTRFS_RESERVE_FLUSH_ALL);
2296 trans = btrfs_join_transaction(rc->extent_root);
2297 if (IS_ERR(trans)) {
2299 btrfs_block_rsv_release(rc->extent_root,
2300 rc->block_rsv, num_bytes);
2301 return PTR_ERR(trans);
2305 if (num_bytes != rc->merging_rsv_size) {
2306 btrfs_end_transaction(trans, rc->extent_root);
2307 btrfs_block_rsv_release(rc->extent_root,
2308 rc->block_rsv, num_bytes);
2313 rc->merge_reloc_tree = 1;
2315 while (!list_empty(&rc->reloc_roots)) {
2316 reloc_root = list_entry(rc->reloc_roots.next,
2317 struct btrfs_root, root_list);
2318 list_del_init(&reloc_root->root_list);
2320 root = read_fs_root(reloc_root->fs_info,
2321 reloc_root->root_key.offset);
2322 BUG_ON(IS_ERR(root));
2323 BUG_ON(root->reloc_root != reloc_root);
2326 * set reference count to 1, so btrfs_recover_relocation
2327 * knows it should resumes merging
2330 btrfs_set_root_refs(&reloc_root->root_item, 1);
2331 btrfs_update_reloc_root(trans, root);
2333 list_add(&reloc_root->root_list, &reloc_roots);
2336 list_splice(&reloc_roots, &rc->reloc_roots);
2339 btrfs_commit_transaction(trans, rc->extent_root);
2341 btrfs_end_transaction(trans, rc->extent_root);
2345 static noinline_for_stack
2346 void free_reloc_roots(struct list_head *list)
2348 struct btrfs_root *reloc_root;
2350 while (!list_empty(list)) {
2351 reloc_root = list_entry(list->next, struct btrfs_root,
2353 free_extent_buffer(reloc_root->node);
2354 free_extent_buffer(reloc_root->commit_root);
2355 reloc_root->node = NULL;
2356 reloc_root->commit_root = NULL;
2357 __del_reloc_root(reloc_root);
2361 static noinline_for_stack
2362 void merge_reloc_roots(struct reloc_control *rc)
2364 struct btrfs_root *root;
2365 struct btrfs_root *reloc_root;
2369 LIST_HEAD(reloc_roots);
2373 root = rc->extent_root;
2376 * this serializes us with btrfs_record_root_in_transaction,
2377 * we have to make sure nobody is in the middle of
2378 * adding their roots to the list while we are
2381 mutex_lock(&root->fs_info->reloc_mutex);
2382 list_splice_init(&rc->reloc_roots, &reloc_roots);
2383 mutex_unlock(&root->fs_info->reloc_mutex);
2385 while (!list_empty(&reloc_roots)) {
2387 reloc_root = list_entry(reloc_roots.next,
2388 struct btrfs_root, root_list);
2390 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2391 root = read_fs_root(reloc_root->fs_info,
2392 reloc_root->root_key.offset);
2393 BUG_ON(IS_ERR(root));
2394 BUG_ON(root->reloc_root != reloc_root);
2396 ret = merge_reloc_root(rc, root);
2398 if (list_empty(&reloc_root->root_list))
2399 list_add_tail(&reloc_root->root_list,
2404 list_del_init(&reloc_root->root_list);
2408 * we keep the old last snapshod transid in rtranid when we
2409 * created the relocation tree.
2411 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2412 otransid = btrfs_root_otransid(&reloc_root->root_item);
2413 objectid = reloc_root->root_key.offset;
2415 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2417 if (list_empty(&reloc_root->root_list))
2418 list_add_tail(&reloc_root->root_list,
2430 btrfs_std_error(root->fs_info, ret, NULL);
2431 if (!list_empty(&reloc_roots))
2432 free_reloc_roots(&reloc_roots);
2434 /* new reloc root may be added */
2435 mutex_lock(&root->fs_info->reloc_mutex);
2436 list_splice_init(&rc->reloc_roots, &reloc_roots);
2437 mutex_unlock(&root->fs_info->reloc_mutex);
2438 if (!list_empty(&reloc_roots))
2439 free_reloc_roots(&reloc_roots);
2442 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2445 static void free_block_list(struct rb_root *blocks)
2447 struct tree_block *block;
2448 struct rb_node *rb_node;
2449 while ((rb_node = rb_first(blocks))) {
2450 block = rb_entry(rb_node, struct tree_block, rb_node);
2451 rb_erase(rb_node, blocks);
2456 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2457 struct btrfs_root *reloc_root)
2459 struct btrfs_root *root;
2461 if (reloc_root->last_trans == trans->transid)
2464 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2465 BUG_ON(IS_ERR(root));
2466 BUG_ON(root->reloc_root != reloc_root);
2468 return btrfs_record_root_in_trans(trans, root);
2471 static noinline_for_stack
2472 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2473 struct reloc_control *rc,
2474 struct backref_node *node,
2475 struct backref_edge *edges[])
2477 struct backref_node *next;
2478 struct btrfs_root *root;
2484 next = walk_up_backref(next, edges, &index);
2487 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2489 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2490 record_reloc_root_in_trans(trans, root);
2494 btrfs_record_root_in_trans(trans, root);
2495 root = root->reloc_root;
2497 if (next->new_bytenr != root->node->start) {
2498 BUG_ON(next->new_bytenr);
2499 BUG_ON(!list_empty(&next->list));
2500 next->new_bytenr = root->node->start;
2502 list_add_tail(&next->list,
2503 &rc->backref_cache.changed);
2504 __mark_block_processed(rc, next);
2510 next = walk_down_backref(edges, &index);
2511 if (!next || next->level <= node->level)
2518 /* setup backref node path for btrfs_reloc_cow_block */
2520 rc->backref_cache.path[next->level] = next;
2523 next = edges[index]->node[UPPER];
2529 * select a tree root for relocation. return NULL if the block
2530 * is reference counted. we should use do_relocation() in this
2531 * case. return a tree root pointer if the block isn't reference
2532 * counted. return -ENOENT if the block is root of reloc tree.
2534 static noinline_for_stack
2535 struct btrfs_root *select_one_root(struct backref_node *node)
2537 struct backref_node *next;
2538 struct btrfs_root *root;
2539 struct btrfs_root *fs_root = NULL;
2540 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2546 next = walk_up_backref(next, edges, &index);
2550 /* no other choice for non-references counted tree */
2551 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2554 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2560 next = walk_down_backref(edges, &index);
2561 if (!next || next->level <= node->level)
2566 return ERR_PTR(-ENOENT);
2570 static noinline_for_stack
2571 u64 calcu_metadata_size(struct reloc_control *rc,
2572 struct backref_node *node, int reserve)
2574 struct backref_node *next = node;
2575 struct backref_edge *edge;
2576 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2580 BUG_ON(reserve && node->processed);
2585 if (next->processed && (reserve || next != node))
2588 num_bytes += rc->extent_root->nodesize;
2590 if (list_empty(&next->upper))
2593 edge = list_entry(next->upper.next,
2594 struct backref_edge, list[LOWER]);
2595 edges[index++] = edge;
2596 next = edge->node[UPPER];
2598 next = walk_down_backref(edges, &index);
2603 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2604 struct reloc_control *rc,
2605 struct backref_node *node)
2607 struct btrfs_root *root = rc->extent_root;
2612 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2614 trans->block_rsv = rc->block_rsv;
2615 rc->reserved_bytes += num_bytes;
2616 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2617 BTRFS_RESERVE_FLUSH_ALL);
2619 if (ret == -EAGAIN) {
2620 tmp = rc->extent_root->nodesize *
2621 RELOCATION_RESERVED_NODES;
2622 while (tmp <= rc->reserved_bytes)
2625 * only one thread can access block_rsv at this point,
2626 * so we don't need hold lock to protect block_rsv.
2627 * we expand more reservation size here to allow enough
2628 * space for relocation and we will return eailer in
2631 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2632 RELOCATION_RESERVED_NODES;
2641 * relocate a block tree, and then update pointers in upper level
2642 * blocks that reference the block to point to the new location.
2644 * if called by link_to_upper, the block has already been relocated.
2645 * in that case this function just updates pointers.
2647 static int do_relocation(struct btrfs_trans_handle *trans,
2648 struct reloc_control *rc,
2649 struct backref_node *node,
2650 struct btrfs_key *key,
2651 struct btrfs_path *path, int lowest)
2653 struct backref_node *upper;
2654 struct backref_edge *edge;
2655 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2656 struct btrfs_root *root;
2657 struct extent_buffer *eb;
2665 BUG_ON(lowest && node->eb);
2667 path->lowest_level = node->level + 1;
2668 rc->backref_cache.path[node->level] = node;
2669 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2672 upper = edge->node[UPPER];
2673 root = select_reloc_root(trans, rc, upper, edges);
2676 if (upper->eb && !upper->locked) {
2678 ret = btrfs_bin_search(upper->eb, key,
2679 upper->level, &slot);
2681 bytenr = btrfs_node_blockptr(upper->eb, slot);
2682 if (node->eb->start == bytenr)
2685 drop_node_buffer(upper);
2689 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2696 btrfs_release_path(path);
2701 upper->eb = path->nodes[upper->level];
2702 path->nodes[upper->level] = NULL;
2704 BUG_ON(upper->eb != path->nodes[upper->level]);
2708 path->locks[upper->level] = 0;
2710 slot = path->slots[upper->level];
2711 btrfs_release_path(path);
2713 ret = btrfs_bin_search(upper->eb, key, upper->level,
2718 bytenr = btrfs_node_blockptr(upper->eb, slot);
2720 BUG_ON(bytenr != node->bytenr);
2722 if (node->eb->start == bytenr)
2726 blocksize = root->nodesize;
2727 generation = btrfs_node_ptr_generation(upper->eb, slot);
2728 eb = read_tree_block(root, bytenr, generation);
2732 } else if (!extent_buffer_uptodate(eb)) {
2733 free_extent_buffer(eb);
2737 btrfs_tree_lock(eb);
2738 btrfs_set_lock_blocking(eb);
2741 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2743 btrfs_tree_unlock(eb);
2744 free_extent_buffer(eb);
2749 BUG_ON(node->eb != eb);
2751 btrfs_set_node_blockptr(upper->eb, slot,
2753 btrfs_set_node_ptr_generation(upper->eb, slot,
2755 btrfs_mark_buffer_dirty(upper->eb);
2757 ret = btrfs_inc_extent_ref(trans, root,
2758 node->eb->start, blocksize,
2760 btrfs_header_owner(upper->eb),
2764 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2768 if (!upper->pending)
2769 drop_node_buffer(upper);
2771 unlock_node_buffer(upper);
2776 if (!err && node->pending) {
2777 drop_node_buffer(node);
2778 list_move_tail(&node->list, &rc->backref_cache.changed);
2782 path->lowest_level = 0;
2783 BUG_ON(err == -ENOSPC);
2787 static int link_to_upper(struct btrfs_trans_handle *trans,
2788 struct reloc_control *rc,
2789 struct backref_node *node,
2790 struct btrfs_path *path)
2792 struct btrfs_key key;
2794 btrfs_node_key_to_cpu(node->eb, &key, 0);
2795 return do_relocation(trans, rc, node, &key, path, 0);
2798 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2799 struct reloc_control *rc,
2800 struct btrfs_path *path, int err)
2803 struct backref_cache *cache = &rc->backref_cache;
2804 struct backref_node *node;
2808 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2809 while (!list_empty(&cache->pending[level])) {
2810 node = list_entry(cache->pending[level].next,
2811 struct backref_node, list);
2812 list_move_tail(&node->list, &list);
2813 BUG_ON(!node->pending);
2816 ret = link_to_upper(trans, rc, node, path);
2821 list_splice_init(&list, &cache->pending[level]);
2826 static void mark_block_processed(struct reloc_control *rc,
2827 u64 bytenr, u32 blocksize)
2829 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2830 EXTENT_DIRTY, GFP_NOFS);
2833 static void __mark_block_processed(struct reloc_control *rc,
2834 struct backref_node *node)
2837 if (node->level == 0 ||
2838 in_block_group(node->bytenr, rc->block_group)) {
2839 blocksize = rc->extent_root->nodesize;
2840 mark_block_processed(rc, node->bytenr, blocksize);
2842 node->processed = 1;
2846 * mark a block and all blocks directly/indirectly reference the block
2849 static void update_processed_blocks(struct reloc_control *rc,
2850 struct backref_node *node)
2852 struct backref_node *next = node;
2853 struct backref_edge *edge;
2854 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2860 if (next->processed)
2863 __mark_block_processed(rc, next);
2865 if (list_empty(&next->upper))
2868 edge = list_entry(next->upper.next,
2869 struct backref_edge, list[LOWER]);
2870 edges[index++] = edge;
2871 next = edge->node[UPPER];
2873 next = walk_down_backref(edges, &index);
2877 static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
2879 u32 blocksize = rc->extent_root->nodesize;
2881 if (test_range_bit(&rc->processed_blocks, bytenr,
2882 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2887 static int get_tree_block_key(struct reloc_control *rc,
2888 struct tree_block *block)
2890 struct extent_buffer *eb;
2892 BUG_ON(block->key_ready);
2893 eb = read_tree_block(rc->extent_root, block->bytenr,
2897 } else if (!extent_buffer_uptodate(eb)) {
2898 free_extent_buffer(eb);
2901 WARN_ON(btrfs_header_level(eb) != block->level);
2902 if (block->level == 0)
2903 btrfs_item_key_to_cpu(eb, &block->key, 0);
2905 btrfs_node_key_to_cpu(eb, &block->key, 0);
2906 free_extent_buffer(eb);
2907 block->key_ready = 1;
2912 * helper function to relocate a tree block
2914 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2915 struct reloc_control *rc,
2916 struct backref_node *node,
2917 struct btrfs_key *key,
2918 struct btrfs_path *path)
2920 struct btrfs_root *root;
2926 BUG_ON(node->processed);
2927 root = select_one_root(node);
2928 if (root == ERR_PTR(-ENOENT)) {
2929 update_processed_blocks(rc, node);
2933 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2934 ret = reserve_metadata_space(trans, rc, node);
2940 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2941 BUG_ON(node->new_bytenr);
2942 BUG_ON(!list_empty(&node->list));
2943 btrfs_record_root_in_trans(trans, root);
2944 root = root->reloc_root;
2945 node->new_bytenr = root->node->start;
2947 list_add_tail(&node->list, &rc->backref_cache.changed);
2949 path->lowest_level = node->level;
2950 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2951 btrfs_release_path(path);
2956 update_processed_blocks(rc, node);
2958 ret = do_relocation(trans, rc, node, key, path, 1);
2961 if (ret || node->level == 0 || node->cowonly)
2962 remove_backref_node(&rc->backref_cache, node);
2967 * relocate a list of blocks
2969 static noinline_for_stack
2970 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2971 struct reloc_control *rc, struct rb_root *blocks)
2973 struct backref_node *node;
2974 struct btrfs_path *path;
2975 struct tree_block *block;
2976 struct rb_node *rb_node;
2980 path = btrfs_alloc_path();
2983 goto out_free_blocks;
2986 rb_node = rb_first(blocks);
2988 block = rb_entry(rb_node, struct tree_block, rb_node);
2989 if (!block->key_ready)
2990 readahead_tree_block(rc->extent_root, block->bytenr);
2991 rb_node = rb_next(rb_node);
2994 rb_node = rb_first(blocks);
2996 block = rb_entry(rb_node, struct tree_block, rb_node);
2997 if (!block->key_ready) {
2998 err = get_tree_block_key(rc, block);
3002 rb_node = rb_next(rb_node);
3005 rb_node = rb_first(blocks);
3007 block = rb_entry(rb_node, struct tree_block, rb_node);
3009 node = build_backref_tree(rc, &block->key,
3010 block->level, block->bytenr);
3012 err = PTR_ERR(node);
3016 ret = relocate_tree_block(trans, rc, node, &block->key,
3019 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3023 rb_node = rb_next(rb_node);
3026 err = finish_pending_nodes(trans, rc, path, err);
3029 btrfs_free_path(path);
3031 free_block_list(blocks);
3035 static noinline_for_stack
3036 int prealloc_file_extent_cluster(struct inode *inode,
3037 struct file_extent_cluster *cluster)
3042 u64 offset = BTRFS_I(inode)->index_cnt;
3047 BUG_ON(cluster->start != cluster->boundary[0]);
3048 mutex_lock(&inode->i_mutex);
3050 ret = btrfs_check_data_free_space(inode, cluster->start,
3051 cluster->end + 1 - cluster->start);
3055 while (nr < cluster->nr) {
3056 start = cluster->boundary[nr] - offset;
3057 if (nr + 1 < cluster->nr)
3058 end = cluster->boundary[nr + 1] - 1 - offset;
3060 end = cluster->end - offset;
3062 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3063 num_bytes = end + 1 - start;
3064 ret = btrfs_prealloc_file_range(inode, 0, start,
3065 num_bytes, num_bytes,
3066 end + 1, &alloc_hint);
3067 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3072 btrfs_free_reserved_data_space(inode, cluster->start,
3073 cluster->end + 1 - cluster->start);
3075 mutex_unlock(&inode->i_mutex);
3079 static noinline_for_stack
3080 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3083 struct btrfs_root *root = BTRFS_I(inode)->root;
3084 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3085 struct extent_map *em;
3088 em = alloc_extent_map();
3093 em->len = end + 1 - start;
3094 em->block_len = em->len;
3095 em->block_start = block_start;
3096 em->bdev = root->fs_info->fs_devices->latest_bdev;
3097 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3099 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3101 write_lock(&em_tree->lock);
3102 ret = add_extent_mapping(em_tree, em, 0);
3103 write_unlock(&em_tree->lock);
3104 if (ret != -EEXIST) {
3105 free_extent_map(em);
3108 btrfs_drop_extent_cache(inode, start, end, 0);
3110 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3114 static int relocate_file_extent_cluster(struct inode *inode,
3115 struct file_extent_cluster *cluster)
3119 u64 offset = BTRFS_I(inode)->index_cnt;
3120 unsigned long index;
3121 unsigned long last_index;
3123 struct file_ra_state *ra;
3124 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3131 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3135 ret = prealloc_file_extent_cluster(inode, cluster);
3139 file_ra_state_init(ra, inode->i_mapping);
3141 ret = setup_extent_mapping(inode, cluster->start - offset,
3142 cluster->end - offset, cluster->start);
3146 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3147 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3148 while (index <= last_index) {
3149 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3153 page = find_lock_page(inode->i_mapping, index);
3155 page_cache_sync_readahead(inode->i_mapping,
3157 last_index + 1 - index);
3158 page = find_or_create_page(inode->i_mapping, index,
3161 btrfs_delalloc_release_metadata(inode,
3168 if (PageReadahead(page)) {
3169 page_cache_async_readahead(inode->i_mapping,
3170 ra, NULL, page, index,
3171 last_index + 1 - index);
3174 if (!PageUptodate(page)) {
3175 btrfs_readpage(NULL, page);
3177 if (!PageUptodate(page)) {
3179 page_cache_release(page);
3180 btrfs_delalloc_release_metadata(inode,
3187 page_start = page_offset(page);
3188 page_end = page_start + PAGE_CACHE_SIZE - 1;
3190 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3192 set_page_extent_mapped(page);
3194 if (nr < cluster->nr &&
3195 page_start + offset == cluster->boundary[nr]) {
3196 set_extent_bits(&BTRFS_I(inode)->io_tree,
3197 page_start, page_end,
3198 EXTENT_BOUNDARY, GFP_NOFS);
3202 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3203 set_page_dirty(page);
3205 unlock_extent(&BTRFS_I(inode)->io_tree,
3206 page_start, page_end);
3208 page_cache_release(page);
3211 balance_dirty_pages_ratelimited(inode->i_mapping);
3212 btrfs_throttle(BTRFS_I(inode)->root);
3214 WARN_ON(nr != cluster->nr);
3220 static noinline_for_stack
3221 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3222 struct file_extent_cluster *cluster)
3226 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3227 ret = relocate_file_extent_cluster(inode, cluster);
3234 cluster->start = extent_key->objectid;
3236 BUG_ON(cluster->nr >= MAX_EXTENTS);
3237 cluster->end = extent_key->objectid + extent_key->offset - 1;
3238 cluster->boundary[cluster->nr] = extent_key->objectid;
3241 if (cluster->nr >= MAX_EXTENTS) {
3242 ret = relocate_file_extent_cluster(inode, cluster);
3250 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3251 static int get_ref_objectid_v0(struct reloc_control *rc,
3252 struct btrfs_path *path,
3253 struct btrfs_key *extent_key,
3254 u64 *ref_objectid, int *path_change)
3256 struct btrfs_key key;
3257 struct extent_buffer *leaf;
3258 struct btrfs_extent_ref_v0 *ref0;
3262 leaf = path->nodes[0];
3263 slot = path->slots[0];
3265 if (slot >= btrfs_header_nritems(leaf)) {
3266 ret = btrfs_next_leaf(rc->extent_root, path);
3270 leaf = path->nodes[0];
3271 slot = path->slots[0];
3275 btrfs_item_key_to_cpu(leaf, &key, slot);
3276 if (key.objectid != extent_key->objectid)
3279 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3283 ref0 = btrfs_item_ptr(leaf, slot,
3284 struct btrfs_extent_ref_v0);
3285 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3293 * helper to add a tree block to the list.
3294 * the major work is getting the generation and level of the block
3296 static int add_tree_block(struct reloc_control *rc,
3297 struct btrfs_key *extent_key,
3298 struct btrfs_path *path,
3299 struct rb_root *blocks)
3301 struct extent_buffer *eb;
3302 struct btrfs_extent_item *ei;
3303 struct btrfs_tree_block_info *bi;
3304 struct tree_block *block;
3305 struct rb_node *rb_node;
3310 eb = path->nodes[0];
3311 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3313 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3314 item_size >= sizeof(*ei) + sizeof(*bi)) {
3315 ei = btrfs_item_ptr(eb, path->slots[0],
3316 struct btrfs_extent_item);
3317 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3318 bi = (struct btrfs_tree_block_info *)(ei + 1);
3319 level = btrfs_tree_block_level(eb, bi);
3321 level = (int)extent_key->offset;
3323 generation = btrfs_extent_generation(eb, ei);
3325 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3329 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3330 ret = get_ref_objectid_v0(rc, path, extent_key,
3334 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3335 level = (int)ref_owner;
3336 /* FIXME: get real generation */
3343 btrfs_release_path(path);
3345 BUG_ON(level == -1);
3347 block = kmalloc(sizeof(*block), GFP_NOFS);
3351 block->bytenr = extent_key->objectid;
3352 block->key.objectid = rc->extent_root->nodesize;
3353 block->key.offset = generation;
3354 block->level = level;
3355 block->key_ready = 0;
3357 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3359 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3365 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3367 static int __add_tree_block(struct reloc_control *rc,
3368 u64 bytenr, u32 blocksize,
3369 struct rb_root *blocks)
3371 struct btrfs_path *path;
3372 struct btrfs_key key;
3374 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3377 if (tree_block_processed(bytenr, rc))
3380 if (tree_search(blocks, bytenr))
3383 path = btrfs_alloc_path();
3387 key.objectid = bytenr;
3389 key.type = BTRFS_METADATA_ITEM_KEY;
3390 key.offset = (u64)-1;
3392 key.type = BTRFS_EXTENT_ITEM_KEY;
3393 key.offset = blocksize;
3396 path->search_commit_root = 1;
3397 path->skip_locking = 1;
3398 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3402 if (ret > 0 && skinny) {
3403 if (path->slots[0]) {
3405 btrfs_item_key_to_cpu(path->nodes[0], &key,
3407 if (key.objectid == bytenr &&
3408 (key.type == BTRFS_METADATA_ITEM_KEY ||
3409 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3410 key.offset == blocksize)))
3416 btrfs_release_path(path);
3422 ret = add_tree_block(rc, &key, path, blocks);
3424 btrfs_free_path(path);
3429 * helper to check if the block use full backrefs for pointers in it
3431 static int block_use_full_backref(struct reloc_control *rc,
3432 struct extent_buffer *eb)
3437 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3438 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3441 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3442 eb->start, btrfs_header_level(eb), 1,
3446 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3453 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3454 struct btrfs_block_group_cache *block_group,
3455 struct inode *inode,
3458 struct btrfs_key key;
3459 struct btrfs_root *root = fs_info->tree_root;
3460 struct btrfs_trans_handle *trans;
3467 key.type = BTRFS_INODE_ITEM_KEY;
3470 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3471 if (IS_ERR(inode) || is_bad_inode(inode)) {
3478 ret = btrfs_check_trunc_cache_free_space(root,
3479 &fs_info->global_block_rsv);
3483 trans = btrfs_join_transaction(root);
3484 if (IS_ERR(trans)) {
3485 ret = PTR_ERR(trans);
3489 ret = btrfs_truncate_free_space_cache(root, trans, block_group, inode);
3491 btrfs_end_transaction(trans, root);
3492 btrfs_btree_balance_dirty(root);
3499 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3500 * this function scans fs tree to find blocks reference the data extent
3502 static int find_data_references(struct reloc_control *rc,
3503 struct btrfs_key *extent_key,
3504 struct extent_buffer *leaf,
3505 struct btrfs_extent_data_ref *ref,
3506 struct rb_root *blocks)
3508 struct btrfs_path *path;
3509 struct tree_block *block;
3510 struct btrfs_root *root;
3511 struct btrfs_file_extent_item *fi;
3512 struct rb_node *rb_node;
3513 struct btrfs_key key;
3524 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3525 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3526 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3527 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3530 * This is an extent belonging to the free space cache, lets just delete
3531 * it and redo the search.
3533 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3534 ret = delete_block_group_cache(rc->extent_root->fs_info,
3536 NULL, ref_objectid);
3542 path = btrfs_alloc_path();
3547 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3549 err = PTR_ERR(root);
3553 key.objectid = ref_objectid;
3554 key.type = BTRFS_EXTENT_DATA_KEY;
3555 if (ref_offset > ((u64)-1 << 32))
3558 key.offset = ref_offset;
3560 path->search_commit_root = 1;
3561 path->skip_locking = 1;
3562 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3568 leaf = path->nodes[0];
3569 nritems = btrfs_header_nritems(leaf);
3571 * the references in tree blocks that use full backrefs
3572 * are not counted in
3574 if (block_use_full_backref(rc, leaf))
3578 rb_node = tree_search(blocks, leaf->start);
3583 path->slots[0] = nritems;
3586 while (ref_count > 0) {
3587 while (path->slots[0] >= nritems) {
3588 ret = btrfs_next_leaf(root, path);
3593 if (WARN_ON(ret > 0))
3596 leaf = path->nodes[0];
3597 nritems = btrfs_header_nritems(leaf);
3600 if (block_use_full_backref(rc, leaf))
3604 rb_node = tree_search(blocks, leaf->start);
3609 path->slots[0] = nritems;
3613 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3614 if (WARN_ON(key.objectid != ref_objectid ||
3615 key.type != BTRFS_EXTENT_DATA_KEY))
3618 fi = btrfs_item_ptr(leaf, path->slots[0],
3619 struct btrfs_file_extent_item);
3621 if (btrfs_file_extent_type(leaf, fi) ==
3622 BTRFS_FILE_EXTENT_INLINE)
3625 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3626 extent_key->objectid)
3629 key.offset -= btrfs_file_extent_offset(leaf, fi);
3630 if (key.offset != ref_offset)
3638 if (!tree_block_processed(leaf->start, rc)) {
3639 block = kmalloc(sizeof(*block), GFP_NOFS);
3644 block->bytenr = leaf->start;
3645 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3647 block->key_ready = 1;
3648 rb_node = tree_insert(blocks, block->bytenr,
3651 backref_tree_panic(rb_node, -EEXIST,
3657 path->slots[0] = nritems;
3663 btrfs_free_path(path);
3668 * helper to find all tree blocks that reference a given data extent
3670 static noinline_for_stack
3671 int add_data_references(struct reloc_control *rc,
3672 struct btrfs_key *extent_key,
3673 struct btrfs_path *path,
3674 struct rb_root *blocks)
3676 struct btrfs_key key;
3677 struct extent_buffer *eb;
3678 struct btrfs_extent_data_ref *dref;
3679 struct btrfs_extent_inline_ref *iref;
3682 u32 blocksize = rc->extent_root->nodesize;
3686 eb = path->nodes[0];
3687 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3688 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3689 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3690 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3694 ptr += sizeof(struct btrfs_extent_item);
3697 iref = (struct btrfs_extent_inline_ref *)ptr;
3698 key.type = btrfs_extent_inline_ref_type(eb, iref);
3699 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3700 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3701 ret = __add_tree_block(rc, key.offset, blocksize,
3703 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3704 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3705 ret = find_data_references(rc, extent_key,
3714 ptr += btrfs_extent_inline_ref_size(key.type);
3720 eb = path->nodes[0];
3721 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3722 ret = btrfs_next_leaf(rc->extent_root, path);
3729 eb = path->nodes[0];
3732 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3733 if (key.objectid != extent_key->objectid)
3736 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3737 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3738 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3740 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3741 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3743 ret = __add_tree_block(rc, key.offset, blocksize,
3745 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3746 dref = btrfs_item_ptr(eb, path->slots[0],
3747 struct btrfs_extent_data_ref);
3748 ret = find_data_references(rc, extent_key,
3760 btrfs_release_path(path);
3762 free_block_list(blocks);
3767 * helper to find next unprocessed extent
3769 static noinline_for_stack
3770 int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
3771 struct btrfs_key *extent_key)
3773 struct btrfs_key key;
3774 struct extent_buffer *leaf;
3775 u64 start, end, last;
3778 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3781 if (rc->search_start >= last) {
3786 key.objectid = rc->search_start;
3787 key.type = BTRFS_EXTENT_ITEM_KEY;
3790 path->search_commit_root = 1;
3791 path->skip_locking = 1;
3792 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3797 leaf = path->nodes[0];
3798 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3799 ret = btrfs_next_leaf(rc->extent_root, path);
3802 leaf = path->nodes[0];
3805 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3806 if (key.objectid >= last) {
3811 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3812 key.type != BTRFS_METADATA_ITEM_KEY) {
3817 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3818 key.objectid + key.offset <= rc->search_start) {
3823 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3824 key.objectid + rc->extent_root->nodesize <=
3830 ret = find_first_extent_bit(&rc->processed_blocks,
3831 key.objectid, &start, &end,
3832 EXTENT_DIRTY, NULL);
3834 if (ret == 0 && start <= key.objectid) {
3835 btrfs_release_path(path);
3836 rc->search_start = end + 1;
3838 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3839 rc->search_start = key.objectid + key.offset;
3841 rc->search_start = key.objectid +
3842 rc->extent_root->nodesize;
3843 memcpy(extent_key, &key, sizeof(key));
3847 btrfs_release_path(path);
3851 static void set_reloc_control(struct reloc_control *rc)
3853 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3855 mutex_lock(&fs_info->reloc_mutex);
3856 fs_info->reloc_ctl = rc;
3857 mutex_unlock(&fs_info->reloc_mutex);
3860 static void unset_reloc_control(struct reloc_control *rc)
3862 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3864 mutex_lock(&fs_info->reloc_mutex);
3865 fs_info->reloc_ctl = NULL;
3866 mutex_unlock(&fs_info->reloc_mutex);
3869 static int check_extent_flags(u64 flags)
3871 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3872 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3874 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3875 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3877 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3878 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3883 static noinline_for_stack
3884 int prepare_to_relocate(struct reloc_control *rc)
3886 struct btrfs_trans_handle *trans;
3888 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3889 BTRFS_BLOCK_RSV_TEMP);
3893 memset(&rc->cluster, 0, sizeof(rc->cluster));
3894 rc->search_start = rc->block_group->key.objectid;
3895 rc->extents_found = 0;
3896 rc->nodes_relocated = 0;
3897 rc->merging_rsv_size = 0;
3898 rc->reserved_bytes = 0;
3899 rc->block_rsv->size = rc->extent_root->nodesize *
3900 RELOCATION_RESERVED_NODES;
3902 rc->create_reloc_tree = 1;
3903 set_reloc_control(rc);
3905 trans = btrfs_join_transaction(rc->extent_root);
3906 if (IS_ERR(trans)) {
3907 unset_reloc_control(rc);
3909 * extent tree is not a ref_cow tree and has no reloc_root to
3910 * cleanup. And callers are responsible to free the above
3913 return PTR_ERR(trans);
3915 btrfs_commit_transaction(trans, rc->extent_root);
3919 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3921 struct rb_root blocks = RB_ROOT;
3922 struct btrfs_key key;
3923 struct btrfs_trans_handle *trans = NULL;
3924 struct btrfs_path *path;
3925 struct btrfs_extent_item *ei;
3932 path = btrfs_alloc_path();
3937 ret = prepare_to_relocate(rc);
3944 rc->reserved_bytes = 0;
3945 ret = btrfs_block_rsv_refill(rc->extent_root,
3946 rc->block_rsv, rc->block_rsv->size,
3947 BTRFS_RESERVE_FLUSH_ALL);
3953 trans = btrfs_start_transaction(rc->extent_root, 0);
3954 if (IS_ERR(trans)) {
3955 err = PTR_ERR(trans);
3960 if (update_backref_cache(trans, &rc->backref_cache)) {
3961 btrfs_end_transaction(trans, rc->extent_root);
3965 ret = find_next_extent(rc, path, &key);
3971 rc->extents_found++;
3973 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3974 struct btrfs_extent_item);
3975 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3976 if (item_size >= sizeof(*ei)) {
3977 flags = btrfs_extent_flags(path->nodes[0], ei);
3978 ret = check_extent_flags(flags);
3982 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3984 int path_change = 0;
3987 sizeof(struct btrfs_extent_item_v0));
3988 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3994 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3995 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3997 flags = BTRFS_EXTENT_FLAG_DATA;
4000 btrfs_release_path(path);
4002 path->search_commit_root = 1;
4003 path->skip_locking = 1;
4004 ret = btrfs_search_slot(NULL, rc->extent_root,
4017 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
4018 ret = add_tree_block(rc, &key, path, &blocks);
4019 } else if (rc->stage == UPDATE_DATA_PTRS &&
4020 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4021 ret = add_data_references(rc, &key, path, &blocks);
4023 btrfs_release_path(path);
4031 if (!RB_EMPTY_ROOT(&blocks)) {
4032 ret = relocate_tree_blocks(trans, rc, &blocks);
4035 * if we fail to relocate tree blocks, force to update
4036 * backref cache when committing transaction.
4038 rc->backref_cache.last_trans = trans->transid - 1;
4040 if (ret != -EAGAIN) {
4044 rc->extents_found--;
4045 rc->search_start = key.objectid;
4049 btrfs_end_transaction_throttle(trans, rc->extent_root);
4050 btrfs_btree_balance_dirty(rc->extent_root);
4053 if (rc->stage == MOVE_DATA_EXTENTS &&
4054 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4055 rc->found_file_extent = 1;
4056 ret = relocate_data_extent(rc->data_inode,
4057 &key, &rc->cluster);
4064 if (trans && progress && err == -ENOSPC) {
4065 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4066 rc->block_group->flags);
4074 btrfs_release_path(path);
4075 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4079 btrfs_end_transaction_throttle(trans, rc->extent_root);
4080 btrfs_btree_balance_dirty(rc->extent_root);
4084 ret = relocate_file_extent_cluster(rc->data_inode,
4090 rc->create_reloc_tree = 0;
4091 set_reloc_control(rc);
4093 backref_cache_cleanup(&rc->backref_cache);
4094 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4096 err = prepare_to_merge(rc, err);
4098 merge_reloc_roots(rc);
4100 rc->merge_reloc_tree = 0;
4101 unset_reloc_control(rc);
4102 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4104 /* get rid of pinned extents */
4105 trans = btrfs_join_transaction(rc->extent_root);
4107 err = PTR_ERR(trans);
4109 btrfs_commit_transaction(trans, rc->extent_root);
4111 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4112 btrfs_free_path(path);
4116 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4117 struct btrfs_root *root, u64 objectid)
4119 struct btrfs_path *path;
4120 struct btrfs_inode_item *item;
4121 struct extent_buffer *leaf;
4124 path = btrfs_alloc_path();
4128 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4132 leaf = path->nodes[0];
4133 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4134 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4135 btrfs_set_inode_generation(leaf, item, 1);
4136 btrfs_set_inode_size(leaf, item, 0);
4137 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4138 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4139 BTRFS_INODE_PREALLOC);
4140 btrfs_mark_buffer_dirty(leaf);
4142 btrfs_free_path(path);
4147 * helper to create inode for data relocation.
4148 * the inode is in data relocation tree and its link count is 0
4150 static noinline_for_stack
4151 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4152 struct btrfs_block_group_cache *group)
4154 struct inode *inode = NULL;
4155 struct btrfs_trans_handle *trans;
4156 struct btrfs_root *root;
4157 struct btrfs_key key;
4161 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4163 return ERR_CAST(root);
4165 trans = btrfs_start_transaction(root, 6);
4167 return ERR_CAST(trans);
4169 err = btrfs_find_free_objectid(root, &objectid);
4173 err = __insert_orphan_inode(trans, root, objectid);
4176 key.objectid = objectid;
4177 key.type = BTRFS_INODE_ITEM_KEY;
4179 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4180 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4181 BTRFS_I(inode)->index_cnt = group->key.objectid;
4183 err = btrfs_orphan_add(trans, inode);
4185 btrfs_end_transaction(trans, root);
4186 btrfs_btree_balance_dirty(root);
4190 inode = ERR_PTR(err);
4195 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4197 struct reloc_control *rc;
4199 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4203 INIT_LIST_HEAD(&rc->reloc_roots);
4204 backref_cache_init(&rc->backref_cache);
4205 mapping_tree_init(&rc->reloc_root_tree);
4206 extent_io_tree_init(&rc->processed_blocks,
4207 fs_info->btree_inode->i_mapping);
4212 * function to relocate all extents in a block group.
4214 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4216 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4217 struct reloc_control *rc;
4218 struct inode *inode;
4219 struct btrfs_path *path;
4224 rc = alloc_reloc_control(fs_info);
4228 rc->extent_root = extent_root;
4230 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4231 BUG_ON(!rc->block_group);
4233 ret = btrfs_inc_block_group_ro(extent_root, rc->block_group);
4240 path = btrfs_alloc_path();
4246 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4248 btrfs_free_path(path);
4251 ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
4253 ret = PTR_ERR(inode);
4255 if (ret && ret != -ENOENT) {
4260 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4261 if (IS_ERR(rc->data_inode)) {
4262 err = PTR_ERR(rc->data_inode);
4263 rc->data_inode = NULL;
4267 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
4268 rc->block_group->key.objectid, rc->block_group->flags);
4270 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
4275 btrfs_wait_ordered_roots(fs_info, -1);
4278 mutex_lock(&fs_info->cleaner_mutex);
4279 ret = relocate_block_group(rc);
4280 mutex_unlock(&fs_info->cleaner_mutex);
4286 if (rc->extents_found == 0)
4289 btrfs_info(extent_root->fs_info, "found %llu extents",
4292 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4293 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4299 invalidate_mapping_pages(rc->data_inode->i_mapping,
4301 rc->stage = UPDATE_DATA_PTRS;
4305 WARN_ON(rc->block_group->pinned > 0);
4306 WARN_ON(rc->block_group->reserved > 0);
4307 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4310 btrfs_dec_block_group_ro(extent_root, rc->block_group);
4311 iput(rc->data_inode);
4312 btrfs_put_block_group(rc->block_group);
4317 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4319 struct btrfs_trans_handle *trans;
4322 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4324 return PTR_ERR(trans);
4326 memset(&root->root_item.drop_progress, 0,
4327 sizeof(root->root_item.drop_progress));
4328 root->root_item.drop_level = 0;
4329 btrfs_set_root_refs(&root->root_item, 0);
4330 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4331 &root->root_key, &root->root_item);
4333 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4340 * recover relocation interrupted by system crash.
4342 * this function resumes merging reloc trees with corresponding fs trees.
4343 * this is important for keeping the sharing of tree blocks
4345 int btrfs_recover_relocation(struct btrfs_root *root)
4347 LIST_HEAD(reloc_roots);
4348 struct btrfs_key key;
4349 struct btrfs_root *fs_root;
4350 struct btrfs_root *reloc_root;
4351 struct btrfs_path *path;
4352 struct extent_buffer *leaf;
4353 struct reloc_control *rc = NULL;
4354 struct btrfs_trans_handle *trans;
4358 path = btrfs_alloc_path();
4363 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4364 key.type = BTRFS_ROOT_ITEM_KEY;
4365 key.offset = (u64)-1;
4368 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4375 if (path->slots[0] == 0)
4379 leaf = path->nodes[0];
4380 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4381 btrfs_release_path(path);
4383 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4384 key.type != BTRFS_ROOT_ITEM_KEY)
4387 reloc_root = btrfs_read_fs_root(root, &key);
4388 if (IS_ERR(reloc_root)) {
4389 err = PTR_ERR(reloc_root);
4393 list_add(&reloc_root->root_list, &reloc_roots);
4395 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4396 fs_root = read_fs_root(root->fs_info,
4397 reloc_root->root_key.offset);
4398 if (IS_ERR(fs_root)) {
4399 ret = PTR_ERR(fs_root);
4400 if (ret != -ENOENT) {
4404 ret = mark_garbage_root(reloc_root);
4412 if (key.offset == 0)
4417 btrfs_release_path(path);
4419 if (list_empty(&reloc_roots))
4422 rc = alloc_reloc_control(root->fs_info);
4428 rc->extent_root = root->fs_info->extent_root;
4430 set_reloc_control(rc);
4432 trans = btrfs_join_transaction(rc->extent_root);
4433 if (IS_ERR(trans)) {
4434 unset_reloc_control(rc);
4435 err = PTR_ERR(trans);
4439 rc->merge_reloc_tree = 1;
4441 while (!list_empty(&reloc_roots)) {
4442 reloc_root = list_entry(reloc_roots.next,
4443 struct btrfs_root, root_list);
4444 list_del(&reloc_root->root_list);
4446 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4447 list_add_tail(&reloc_root->root_list,
4452 fs_root = read_fs_root(root->fs_info,
4453 reloc_root->root_key.offset);
4454 if (IS_ERR(fs_root)) {
4455 err = PTR_ERR(fs_root);
4459 err = __add_reloc_root(reloc_root);
4460 BUG_ON(err < 0); /* -ENOMEM or logic error */
4461 fs_root->reloc_root = reloc_root;
4464 err = btrfs_commit_transaction(trans, rc->extent_root);
4468 merge_reloc_roots(rc);
4470 unset_reloc_control(rc);
4472 trans = btrfs_join_transaction(rc->extent_root);
4474 err = PTR_ERR(trans);
4476 err = btrfs_commit_transaction(trans, rc->extent_root);
4480 if (!list_empty(&reloc_roots))
4481 free_reloc_roots(&reloc_roots);
4483 btrfs_free_path(path);
4486 /* cleanup orphan inode in data relocation tree */
4487 fs_root = read_fs_root(root->fs_info,
4488 BTRFS_DATA_RELOC_TREE_OBJECTID);
4489 if (IS_ERR(fs_root))
4490 err = PTR_ERR(fs_root);
4492 err = btrfs_orphan_cleanup(fs_root);
4498 * helper to add ordered checksum for data relocation.
4500 * cloning checksum properly handles the nodatasum extents.
4501 * it also saves CPU time to re-calculate the checksum.
4503 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4505 struct btrfs_ordered_sum *sums;
4506 struct btrfs_ordered_extent *ordered;
4507 struct btrfs_root *root = BTRFS_I(inode)->root;
4513 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4514 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4516 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4517 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4518 disk_bytenr + len - 1, &list, 0);
4522 while (!list_empty(&list)) {
4523 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4524 list_del_init(&sums->list);
4527 * We need to offset the new_bytenr based on where the csum is.
4528 * We need to do this because we will read in entire prealloc
4529 * extents but we may have written to say the middle of the
4530 * prealloc extent, so we need to make sure the csum goes with
4531 * the right disk offset.
4533 * We can do this because the data reloc inode refers strictly
4534 * to the on disk bytes, so we don't have to worry about
4535 * disk_len vs real len like with real inodes since it's all
4538 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4539 sums->bytenr = new_bytenr;
4541 btrfs_add_ordered_sum(inode, ordered, sums);
4544 btrfs_put_ordered_extent(ordered);
4548 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4549 struct btrfs_root *root, struct extent_buffer *buf,
4550 struct extent_buffer *cow)
4552 struct reloc_control *rc;
4553 struct backref_node *node;
4558 rc = root->fs_info->reloc_ctl;
4562 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4563 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4565 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4566 if (buf == root->node)
4567 __update_reloc_root(root, cow->start);
4570 level = btrfs_header_level(buf);
4571 if (btrfs_header_generation(buf) <=
4572 btrfs_root_last_snapshot(&root->root_item))
4575 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4576 rc->create_reloc_tree) {
4577 WARN_ON(!first_cow && level == 0);
4579 node = rc->backref_cache.path[level];
4580 BUG_ON(node->bytenr != buf->start &&
4581 node->new_bytenr != buf->start);
4583 drop_node_buffer(node);
4584 extent_buffer_get(cow);
4586 node->new_bytenr = cow->start;
4588 if (!node->pending) {
4589 list_move_tail(&node->list,
4590 &rc->backref_cache.pending[level]);
4595 __mark_block_processed(rc, node);
4597 if (first_cow && level > 0)
4598 rc->nodes_relocated += buf->len;
4601 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4602 ret = replace_file_extents(trans, rc, root, cow);
4607 * called before creating snapshot. it calculates metadata reservation
4608 * requried for relocating tree blocks in the snapshot
4610 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
4611 u64 *bytes_to_reserve)
4613 struct btrfs_root *root;
4614 struct reloc_control *rc;
4616 root = pending->root;
4617 if (!root->reloc_root)
4620 rc = root->fs_info->reloc_ctl;
4621 if (!rc->merge_reloc_tree)
4624 root = root->reloc_root;
4625 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4627 * relocation is in the stage of merging trees. the space
4628 * used by merging a reloc tree is twice the size of
4629 * relocated tree nodes in the worst case. half for cowing
4630 * the reloc tree, half for cowing the fs tree. the space
4631 * used by cowing the reloc tree will be freed after the
4632 * tree is dropped. if we create snapshot, cowing the fs
4633 * tree may use more space than it frees. so we need
4634 * reserve extra space.
4636 *bytes_to_reserve += rc->nodes_relocated;
4640 * called after snapshot is created. migrate block reservation
4641 * and create reloc root for the newly created snapshot
4643 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4644 struct btrfs_pending_snapshot *pending)
4646 struct btrfs_root *root = pending->root;
4647 struct btrfs_root *reloc_root;
4648 struct btrfs_root *new_root;
4649 struct reloc_control *rc;
4652 if (!root->reloc_root)
4655 rc = root->fs_info->reloc_ctl;
4656 rc->merging_rsv_size += rc->nodes_relocated;
4658 if (rc->merge_reloc_tree) {
4659 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4661 rc->nodes_relocated);
4666 new_root = pending->snap;
4667 reloc_root = create_reloc_root(trans, root->reloc_root,
4668 new_root->root_key.objectid);
4669 if (IS_ERR(reloc_root))
4670 return PTR_ERR(reloc_root);
4672 ret = __add_reloc_root(reloc_root);
4674 new_root->reloc_root = reloc_root;
4676 if (rc->create_reloc_tree)
4677 ret = clone_backref_node(trans, rc, root, reloc_root);