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 ||
579 root_objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
584 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
587 struct btrfs_key key;
589 key.objectid = root_objectid;
590 key.type = BTRFS_ROOT_ITEM_KEY;
591 if (is_cowonly_root(root_objectid))
594 key.offset = (u64)-1;
596 return btrfs_get_fs_root(fs_info, &key, false);
599 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
600 static noinline_for_stack
601 struct btrfs_root *find_tree_root(struct reloc_control *rc,
602 struct extent_buffer *leaf,
603 struct btrfs_extent_ref_v0 *ref0)
605 struct btrfs_root *root;
606 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
607 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
609 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
611 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
612 BUG_ON(IS_ERR(root));
614 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
615 generation != btrfs_root_generation(&root->root_item))
622 static noinline_for_stack
623 int find_inline_backref(struct extent_buffer *leaf, int slot,
624 unsigned long *ptr, unsigned long *end)
626 struct btrfs_key key;
627 struct btrfs_extent_item *ei;
628 struct btrfs_tree_block_info *bi;
631 btrfs_item_key_to_cpu(leaf, &key, slot);
633 item_size = btrfs_item_size_nr(leaf, slot);
634 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
635 if (item_size < sizeof(*ei)) {
636 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
640 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
641 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
642 BTRFS_EXTENT_FLAG_TREE_BLOCK));
644 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
645 item_size <= sizeof(*ei) + sizeof(*bi)) {
646 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
649 if (key.type == BTRFS_METADATA_ITEM_KEY &&
650 item_size <= sizeof(*ei)) {
651 WARN_ON(item_size < sizeof(*ei));
655 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
656 bi = (struct btrfs_tree_block_info *)(ei + 1);
657 *ptr = (unsigned long)(bi + 1);
659 *ptr = (unsigned long)(ei + 1);
661 *end = (unsigned long)ei + item_size;
666 * build backref tree for a given tree block. root of the backref tree
667 * corresponds the tree block, leaves of the backref tree correspond
668 * roots of b-trees that reference the tree block.
670 * the basic idea of this function is check backrefs of a given block
671 * to find upper level blocks that refernece the block, and then check
672 * bakcrefs of these upper level blocks recursively. the recursion stop
673 * when tree root is reached or backrefs for the block is cached.
675 * NOTE: if we find backrefs for a block are cached, we know backrefs
676 * for all upper level blocks that directly/indirectly reference the
677 * block are also cached.
679 static noinline_for_stack
680 struct backref_node *build_backref_tree(struct reloc_control *rc,
681 struct btrfs_key *node_key,
682 int level, u64 bytenr)
684 struct backref_cache *cache = &rc->backref_cache;
685 struct btrfs_path *path1;
686 struct btrfs_path *path2;
687 struct extent_buffer *eb;
688 struct btrfs_root *root;
689 struct backref_node *cur;
690 struct backref_node *upper;
691 struct backref_node *lower;
692 struct backref_node *node = NULL;
693 struct backref_node *exist = NULL;
694 struct backref_edge *edge;
695 struct rb_node *rb_node;
696 struct btrfs_key key;
704 bool need_check = true;
706 path1 = btrfs_alloc_path();
707 path2 = btrfs_alloc_path();
708 if (!path1 || !path2) {
712 path1->reada = READA_FORWARD;
713 path2->reada = READA_FORWARD;
715 node = alloc_backref_node(cache);
721 node->bytenr = bytenr;
728 key.objectid = cur->bytenr;
729 key.type = BTRFS_METADATA_ITEM_KEY;
730 key.offset = (u64)-1;
732 path1->search_commit_root = 1;
733 path1->skip_locking = 1;
734 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
741 ASSERT(path1->slots[0]);
745 WARN_ON(cur->checked);
746 if (!list_empty(&cur->upper)) {
748 * the backref was added previously when processing
749 * backref of type BTRFS_TREE_BLOCK_REF_KEY
751 ASSERT(list_is_singular(&cur->upper));
752 edge = list_entry(cur->upper.next, struct backref_edge,
754 ASSERT(list_empty(&edge->list[UPPER]));
755 exist = edge->node[UPPER];
757 * add the upper level block to pending list if we need
761 list_add_tail(&edge->list[UPPER], &list);
768 eb = path1->nodes[0];
771 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
772 ret = btrfs_next_leaf(rc->extent_root, path1);
779 eb = path1->nodes[0];
782 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
783 if (key.objectid != cur->bytenr) {
788 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
789 key.type == BTRFS_METADATA_ITEM_KEY) {
790 ret = find_inline_backref(eb, path1->slots[0],
798 /* update key for inline back ref */
799 struct btrfs_extent_inline_ref *iref;
800 iref = (struct btrfs_extent_inline_ref *)ptr;
801 key.type = btrfs_extent_inline_ref_type(eb, iref);
802 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
803 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
804 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
808 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
809 exist->owner == key.offset) ||
810 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
811 exist->bytenr == key.offset))) {
816 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
817 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
818 key.type == BTRFS_EXTENT_REF_V0_KEY) {
819 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
820 struct btrfs_extent_ref_v0 *ref0;
821 ref0 = btrfs_item_ptr(eb, path1->slots[0],
822 struct btrfs_extent_ref_v0);
823 if (key.objectid == key.offset) {
824 root = find_tree_root(rc, eb, ref0);
825 if (root && !should_ignore_root(root))
828 list_add(&cur->list, &useless);
831 if (is_cowonly_root(btrfs_ref_root_v0(eb,
836 ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
837 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
839 if (key.objectid == key.offset) {
841 * only root blocks of reloc trees use
842 * backref of this type.
844 root = find_reloc_root(rc, cur->bytenr);
850 edge = alloc_backref_edge(cache);
855 rb_node = tree_search(&cache->rb_root, key.offset);
857 upper = alloc_backref_node(cache);
859 free_backref_edge(cache, edge);
863 upper->bytenr = key.offset;
864 upper->level = cur->level + 1;
866 * backrefs for the upper level block isn't
867 * cached, add the block to pending list
869 list_add_tail(&edge->list[UPPER], &list);
871 upper = rb_entry(rb_node, struct backref_node,
873 ASSERT(upper->checked);
874 INIT_LIST_HEAD(&edge->list[UPPER]);
876 list_add_tail(&edge->list[LOWER], &cur->upper);
877 edge->node[LOWER] = cur;
878 edge->node[UPPER] = upper;
881 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
885 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
886 root = read_fs_root(rc->extent_root->fs_info, key.offset);
892 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
895 if (btrfs_root_level(&root->root_item) == cur->level) {
897 ASSERT(btrfs_root_bytenr(&root->root_item) ==
899 if (should_ignore_root(root))
900 list_add(&cur->list, &useless);
906 level = cur->level + 1;
909 * searching the tree to find upper level blocks
910 * reference the block.
912 path2->search_commit_root = 1;
913 path2->skip_locking = 1;
914 path2->lowest_level = level;
915 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
916 path2->lowest_level = 0;
921 if (ret > 0 && path2->slots[level] > 0)
922 path2->slots[level]--;
924 eb = path2->nodes[level];
925 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
930 for (; level < BTRFS_MAX_LEVEL; level++) {
931 if (!path2->nodes[level]) {
932 ASSERT(btrfs_root_bytenr(&root->root_item) ==
934 if (should_ignore_root(root))
935 list_add(&lower->list, &useless);
941 edge = alloc_backref_edge(cache);
947 eb = path2->nodes[level];
948 rb_node = tree_search(&cache->rb_root, eb->start);
950 upper = alloc_backref_node(cache);
952 free_backref_edge(cache, edge);
956 upper->bytenr = eb->start;
957 upper->owner = btrfs_header_owner(eb);
958 upper->level = lower->level + 1;
959 if (!test_bit(BTRFS_ROOT_REF_COWS,
964 * if we know the block isn't shared
965 * we can void checking its backrefs.
967 if (btrfs_block_can_be_shared(root, eb))
973 * add the block to pending list if we
974 * need check its backrefs, we only do this once
975 * while walking up a tree as we will catch
976 * anything else later on.
978 if (!upper->checked && need_check) {
980 list_add_tail(&edge->list[UPPER],
985 INIT_LIST_HEAD(&edge->list[UPPER]);
988 upper = rb_entry(rb_node, struct backref_node,
990 ASSERT(upper->checked);
991 INIT_LIST_HEAD(&edge->list[UPPER]);
993 upper->owner = btrfs_header_owner(eb);
995 list_add_tail(&edge->list[LOWER], &lower->upper);
996 edge->node[LOWER] = lower;
997 edge->node[UPPER] = upper;
1004 btrfs_release_path(path2);
1007 ptr += btrfs_extent_inline_ref_size(key.type);
1017 btrfs_release_path(path1);
1022 /* the pending list isn't empty, take the first block to process */
1023 if (!list_empty(&list)) {
1024 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1025 list_del_init(&edge->list[UPPER]);
1026 cur = edge->node[UPPER];
1031 * everything goes well, connect backref nodes and insert backref nodes
1034 ASSERT(node->checked);
1035 cowonly = node->cowonly;
1037 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1040 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1041 list_add_tail(&node->lower, &cache->leaves);
1044 list_for_each_entry(edge, &node->upper, list[LOWER])
1045 list_add_tail(&edge->list[UPPER], &list);
1047 while (!list_empty(&list)) {
1048 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1049 list_del_init(&edge->list[UPPER]);
1050 upper = edge->node[UPPER];
1051 if (upper->detached) {
1052 list_del(&edge->list[LOWER]);
1053 lower = edge->node[LOWER];
1054 free_backref_edge(cache, edge);
1055 if (list_empty(&lower->upper))
1056 list_add(&lower->list, &useless);
1060 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1061 if (upper->lowest) {
1062 list_del_init(&upper->lower);
1066 list_add_tail(&edge->list[UPPER], &upper->lower);
1070 if (!upper->checked) {
1072 * Still want to blow up for developers since this is a
1079 if (cowonly != upper->cowonly) {
1086 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1089 backref_tree_panic(rb_node, -EEXIST,
1093 list_add_tail(&edge->list[UPPER], &upper->lower);
1095 list_for_each_entry(edge, &upper->upper, list[LOWER])
1096 list_add_tail(&edge->list[UPPER], &list);
1099 * process useless backref nodes. backref nodes for tree leaves
1100 * are deleted from the cache. backref nodes for upper level
1101 * tree blocks are left in the cache to avoid unnecessary backref
1104 while (!list_empty(&useless)) {
1105 upper = list_entry(useless.next, struct backref_node, list);
1106 list_del_init(&upper->list);
1107 ASSERT(list_empty(&upper->upper));
1110 if (upper->lowest) {
1111 list_del_init(&upper->lower);
1114 while (!list_empty(&upper->lower)) {
1115 edge = list_entry(upper->lower.next,
1116 struct backref_edge, list[UPPER]);
1117 list_del(&edge->list[UPPER]);
1118 list_del(&edge->list[LOWER]);
1119 lower = edge->node[LOWER];
1120 free_backref_edge(cache, edge);
1122 if (list_empty(&lower->upper))
1123 list_add(&lower->list, &useless);
1125 __mark_block_processed(rc, upper);
1126 if (upper->level > 0) {
1127 list_add(&upper->list, &cache->detached);
1128 upper->detached = 1;
1130 rb_erase(&upper->rb_node, &cache->rb_root);
1131 free_backref_node(cache, upper);
1135 btrfs_free_path(path1);
1136 btrfs_free_path(path2);
1138 while (!list_empty(&useless)) {
1139 lower = list_entry(useless.next,
1140 struct backref_node, list);
1141 list_del_init(&lower->list);
1143 while (!list_empty(&list)) {
1144 edge = list_first_entry(&list, struct backref_edge,
1146 list_del(&edge->list[UPPER]);
1147 list_del(&edge->list[LOWER]);
1148 lower = edge->node[LOWER];
1149 upper = edge->node[UPPER];
1150 free_backref_edge(cache, edge);
1153 * Lower is no longer linked to any upper backref nodes
1154 * and isn't in the cache, we can free it ourselves.
1156 if (list_empty(&lower->upper) &&
1157 RB_EMPTY_NODE(&lower->rb_node))
1158 list_add(&lower->list, &useless);
1160 if (!RB_EMPTY_NODE(&upper->rb_node))
1163 /* Add this guy's upper edges to the list to proces */
1164 list_for_each_entry(edge, &upper->upper, list[LOWER])
1165 list_add_tail(&edge->list[UPPER], &list);
1166 if (list_empty(&upper->upper))
1167 list_add(&upper->list, &useless);
1170 while (!list_empty(&useless)) {
1171 lower = list_entry(useless.next,
1172 struct backref_node, list);
1173 list_del_init(&lower->list);
1174 free_backref_node(cache, lower);
1176 return ERR_PTR(err);
1178 ASSERT(!node || !node->detached);
1183 * helper to add backref node for the newly created snapshot.
1184 * the backref node is created by cloning backref node that
1185 * corresponds to root of source tree
1187 static int clone_backref_node(struct btrfs_trans_handle *trans,
1188 struct reloc_control *rc,
1189 struct btrfs_root *src,
1190 struct btrfs_root *dest)
1192 struct btrfs_root *reloc_root = src->reloc_root;
1193 struct backref_cache *cache = &rc->backref_cache;
1194 struct backref_node *node = NULL;
1195 struct backref_node *new_node;
1196 struct backref_edge *edge;
1197 struct backref_edge *new_edge;
1198 struct rb_node *rb_node;
1200 if (cache->last_trans > 0)
1201 update_backref_cache(trans, cache);
1203 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1205 node = rb_entry(rb_node, struct backref_node, rb_node);
1209 BUG_ON(node->new_bytenr != reloc_root->node->start);
1213 rb_node = tree_search(&cache->rb_root,
1214 reloc_root->commit_root->start);
1216 node = rb_entry(rb_node, struct backref_node,
1218 BUG_ON(node->detached);
1225 new_node = alloc_backref_node(cache);
1229 new_node->bytenr = dest->node->start;
1230 new_node->level = node->level;
1231 new_node->lowest = node->lowest;
1232 new_node->checked = 1;
1233 new_node->root = dest;
1235 if (!node->lowest) {
1236 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1237 new_edge = alloc_backref_edge(cache);
1241 new_edge->node[UPPER] = new_node;
1242 new_edge->node[LOWER] = edge->node[LOWER];
1243 list_add_tail(&new_edge->list[UPPER],
1247 list_add_tail(&new_node->lower, &cache->leaves);
1250 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1251 &new_node->rb_node);
1253 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1255 if (!new_node->lowest) {
1256 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1257 list_add_tail(&new_edge->list[LOWER],
1258 &new_edge->node[LOWER]->upper);
1263 while (!list_empty(&new_node->lower)) {
1264 new_edge = list_entry(new_node->lower.next,
1265 struct backref_edge, list[UPPER]);
1266 list_del(&new_edge->list[UPPER]);
1267 free_backref_edge(cache, new_edge);
1269 free_backref_node(cache, new_node);
1274 * helper to add 'address of tree root -> reloc tree' mapping
1276 static int __must_check __add_reloc_root(struct btrfs_root *root)
1278 struct rb_node *rb_node;
1279 struct mapping_node *node;
1280 struct reloc_control *rc = root->fs_info->reloc_ctl;
1282 node = kmalloc(sizeof(*node), GFP_NOFS);
1286 node->bytenr = root->node->start;
1289 spin_lock(&rc->reloc_root_tree.lock);
1290 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1291 node->bytenr, &node->rb_node);
1292 spin_unlock(&rc->reloc_root_tree.lock);
1294 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1295 "for start=%llu while inserting into relocation "
1296 "tree", node->bytenr);
1301 list_add_tail(&root->root_list, &rc->reloc_roots);
1306 * helper to delete the 'address of tree root -> reloc tree'
1309 static void __del_reloc_root(struct btrfs_root *root)
1311 struct rb_node *rb_node;
1312 struct mapping_node *node = NULL;
1313 struct reloc_control *rc = root->fs_info->reloc_ctl;
1315 spin_lock(&rc->reloc_root_tree.lock);
1316 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1319 node = rb_entry(rb_node, struct mapping_node, rb_node);
1320 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1322 spin_unlock(&rc->reloc_root_tree.lock);
1326 BUG_ON((struct btrfs_root *)node->data != root);
1328 spin_lock(&root->fs_info->trans_lock);
1329 list_del_init(&root->root_list);
1330 spin_unlock(&root->fs_info->trans_lock);
1335 * helper to update the 'address of tree root -> reloc tree'
1338 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1340 struct rb_node *rb_node;
1341 struct mapping_node *node = NULL;
1342 struct reloc_control *rc = root->fs_info->reloc_ctl;
1344 spin_lock(&rc->reloc_root_tree.lock);
1345 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1348 node = rb_entry(rb_node, struct mapping_node, rb_node);
1349 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1351 spin_unlock(&rc->reloc_root_tree.lock);
1355 BUG_ON((struct btrfs_root *)node->data != root);
1357 spin_lock(&rc->reloc_root_tree.lock);
1358 node->bytenr = new_bytenr;
1359 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1360 node->bytenr, &node->rb_node);
1361 spin_unlock(&rc->reloc_root_tree.lock);
1363 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1367 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1368 struct btrfs_root *root, u64 objectid)
1370 struct btrfs_root *reloc_root;
1371 struct extent_buffer *eb;
1372 struct btrfs_root_item *root_item;
1373 struct btrfs_key root_key;
1377 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1380 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1381 root_key.type = BTRFS_ROOT_ITEM_KEY;
1382 root_key.offset = objectid;
1384 if (root->root_key.objectid == objectid) {
1385 /* called by btrfs_init_reloc_root */
1386 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1387 BTRFS_TREE_RELOC_OBJECTID);
1390 last_snap = btrfs_root_last_snapshot(&root->root_item);
1391 btrfs_set_root_last_snapshot(&root->root_item,
1392 trans->transid - 1);
1395 * called by btrfs_reloc_post_snapshot_hook.
1396 * the source tree is a reloc tree, all tree blocks
1397 * modified after it was created have RELOC flag
1398 * set in their headers. so it's OK to not update
1399 * the 'last_snapshot'.
1401 ret = btrfs_copy_root(trans, root, root->node, &eb,
1402 BTRFS_TREE_RELOC_OBJECTID);
1406 memcpy(root_item, &root->root_item, sizeof(*root_item));
1407 btrfs_set_root_bytenr(root_item, eb->start);
1408 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1409 btrfs_set_root_generation(root_item, trans->transid);
1411 if (root->root_key.objectid == objectid) {
1412 btrfs_set_root_refs(root_item, 0);
1413 memset(&root_item->drop_progress, 0,
1414 sizeof(struct btrfs_disk_key));
1415 root_item->drop_level = 0;
1417 * abuse rtransid, it is safe because it is impossible to
1418 * receive data into a relocation tree.
1420 btrfs_set_root_rtransid(root_item, last_snap);
1421 btrfs_set_root_otransid(root_item, trans->transid);
1424 btrfs_tree_unlock(eb);
1425 free_extent_buffer(eb);
1427 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1428 &root_key, root_item);
1432 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1433 BUG_ON(IS_ERR(reloc_root));
1434 reloc_root->last_trans = trans->transid;
1439 * create reloc tree for a given fs tree. reloc tree is just a
1440 * snapshot of the fs tree with special root objectid.
1442 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1443 struct btrfs_root *root)
1445 struct btrfs_root *reloc_root;
1446 struct reloc_control *rc = root->fs_info->reloc_ctl;
1447 struct btrfs_block_rsv *rsv;
1451 if (root->reloc_root) {
1452 reloc_root = root->reloc_root;
1453 reloc_root->last_trans = trans->transid;
1457 if (!rc || !rc->create_reloc_tree ||
1458 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1461 if (!trans->reloc_reserved) {
1462 rsv = trans->block_rsv;
1463 trans->block_rsv = rc->block_rsv;
1466 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1468 trans->block_rsv = rsv;
1470 ret = __add_reloc_root(reloc_root);
1472 root->reloc_root = reloc_root;
1477 * update root item of reloc tree
1479 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1480 struct btrfs_root *root)
1482 struct btrfs_root *reloc_root;
1483 struct btrfs_root_item *root_item;
1486 if (!root->reloc_root)
1489 reloc_root = root->reloc_root;
1490 root_item = &reloc_root->root_item;
1492 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1493 btrfs_root_refs(root_item) == 0) {
1494 root->reloc_root = NULL;
1495 __del_reloc_root(reloc_root);
1498 if (reloc_root->commit_root != reloc_root->node) {
1499 btrfs_set_root_node(root_item, reloc_root->node);
1500 free_extent_buffer(reloc_root->commit_root);
1501 reloc_root->commit_root = btrfs_root_node(reloc_root);
1504 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1505 &reloc_root->root_key, root_item);
1513 * helper to find first cached inode with inode number >= objectid
1516 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1518 struct rb_node *node;
1519 struct rb_node *prev;
1520 struct btrfs_inode *entry;
1521 struct inode *inode;
1523 spin_lock(&root->inode_lock);
1525 node = root->inode_tree.rb_node;
1529 entry = rb_entry(node, struct btrfs_inode, rb_node);
1531 if (objectid < btrfs_ino(&entry->vfs_inode))
1532 node = node->rb_left;
1533 else if (objectid > btrfs_ino(&entry->vfs_inode))
1534 node = node->rb_right;
1540 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1541 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1545 prev = rb_next(prev);
1549 entry = rb_entry(node, struct btrfs_inode, rb_node);
1550 inode = igrab(&entry->vfs_inode);
1552 spin_unlock(&root->inode_lock);
1556 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1557 if (cond_resched_lock(&root->inode_lock))
1560 node = rb_next(node);
1562 spin_unlock(&root->inode_lock);
1566 static int in_block_group(u64 bytenr,
1567 struct btrfs_block_group_cache *block_group)
1569 if (bytenr >= block_group->key.objectid &&
1570 bytenr < block_group->key.objectid + block_group->key.offset)
1576 * get new location of data
1578 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1579 u64 bytenr, u64 num_bytes)
1581 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1582 struct btrfs_path *path;
1583 struct btrfs_file_extent_item *fi;
1584 struct extent_buffer *leaf;
1587 path = btrfs_alloc_path();
1591 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1592 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1601 leaf = path->nodes[0];
1602 fi = btrfs_item_ptr(leaf, path->slots[0],
1603 struct btrfs_file_extent_item);
1605 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1606 btrfs_file_extent_compression(leaf, fi) ||
1607 btrfs_file_extent_encryption(leaf, fi) ||
1608 btrfs_file_extent_other_encoding(leaf, fi));
1610 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1615 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1618 btrfs_free_path(path);
1623 * update file extent items in the tree leaf to point to
1624 * the new locations.
1626 static noinline_for_stack
1627 int replace_file_extents(struct btrfs_trans_handle *trans,
1628 struct reloc_control *rc,
1629 struct btrfs_root *root,
1630 struct extent_buffer *leaf)
1632 struct btrfs_key key;
1633 struct btrfs_file_extent_item *fi;
1634 struct inode *inode = NULL;
1646 if (rc->stage != UPDATE_DATA_PTRS)
1649 /* reloc trees always use full backref */
1650 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1651 parent = leaf->start;
1655 nritems = btrfs_header_nritems(leaf);
1656 for (i = 0; i < nritems; i++) {
1658 btrfs_item_key_to_cpu(leaf, &key, i);
1659 if (key.type != BTRFS_EXTENT_DATA_KEY)
1661 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1662 if (btrfs_file_extent_type(leaf, fi) ==
1663 BTRFS_FILE_EXTENT_INLINE)
1665 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1666 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1669 if (!in_block_group(bytenr, rc->block_group))
1673 * if we are modifying block in fs tree, wait for readpage
1674 * to complete and drop the extent cache
1676 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1678 inode = find_next_inode(root, key.objectid);
1680 } else if (inode && btrfs_ino(inode) < key.objectid) {
1681 btrfs_add_delayed_iput(inode);
1682 inode = find_next_inode(root, key.objectid);
1684 if (inode && btrfs_ino(inode) == key.objectid) {
1686 btrfs_file_extent_num_bytes(leaf, fi);
1687 WARN_ON(!IS_ALIGNED(key.offset,
1689 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1691 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1696 btrfs_drop_extent_cache(inode, key.offset, end,
1698 unlock_extent(&BTRFS_I(inode)->io_tree,
1703 ret = get_new_location(rc->data_inode, &new_bytenr,
1707 * Don't have to abort since we've not changed anything
1708 * in the file extent yet.
1713 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1716 key.offset -= btrfs_file_extent_offset(leaf, fi);
1717 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1719 btrfs_header_owner(leaf),
1720 key.objectid, key.offset);
1722 btrfs_abort_transaction(trans, root, ret);
1726 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1727 parent, btrfs_header_owner(leaf),
1728 key.objectid, key.offset);
1730 btrfs_abort_transaction(trans, root, ret);
1735 btrfs_mark_buffer_dirty(leaf);
1737 btrfs_add_delayed_iput(inode);
1741 static noinline_for_stack
1742 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1743 struct btrfs_path *path, int level)
1745 struct btrfs_disk_key key1;
1746 struct btrfs_disk_key key2;
1747 btrfs_node_key(eb, &key1, slot);
1748 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1749 return memcmp(&key1, &key2, sizeof(key1));
1753 * try to replace tree blocks in fs tree with the new blocks
1754 * in reloc tree. tree blocks haven't been modified since the
1755 * reloc tree was create can be replaced.
1757 * if a block was replaced, level of the block + 1 is returned.
1758 * if no block got replaced, 0 is returned. if there are other
1759 * errors, a negative error number is returned.
1761 static noinline_for_stack
1762 int replace_path(struct btrfs_trans_handle *trans,
1763 struct btrfs_root *dest, struct btrfs_root *src,
1764 struct btrfs_path *path, struct btrfs_key *next_key,
1765 int lowest_level, int max_level)
1767 struct extent_buffer *eb;
1768 struct extent_buffer *parent;
1769 struct btrfs_key key;
1781 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1782 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1784 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1786 slot = path->slots[lowest_level];
1787 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1789 eb = btrfs_lock_root_node(dest);
1790 btrfs_set_lock_blocking(eb);
1791 level = btrfs_header_level(eb);
1793 if (level < lowest_level) {
1794 btrfs_tree_unlock(eb);
1795 free_extent_buffer(eb);
1800 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1803 btrfs_set_lock_blocking(eb);
1806 next_key->objectid = (u64)-1;
1807 next_key->type = (u8)-1;
1808 next_key->offset = (u64)-1;
1813 level = btrfs_header_level(parent);
1814 BUG_ON(level < lowest_level);
1816 ret = btrfs_bin_search(parent, &key, level, &slot);
1817 if (ret && slot > 0)
1820 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1821 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1823 old_bytenr = btrfs_node_blockptr(parent, slot);
1824 blocksize = dest->nodesize;
1825 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1827 if (level <= max_level) {
1828 eb = path->nodes[level];
1829 new_bytenr = btrfs_node_blockptr(eb,
1830 path->slots[level]);
1831 new_ptr_gen = btrfs_node_ptr_generation(eb,
1832 path->slots[level]);
1838 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1843 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1844 memcmp_node_keys(parent, slot, path, level)) {
1845 if (level <= lowest_level) {
1850 eb = read_tree_block(dest, old_bytenr, old_ptr_gen);
1853 } else if (!extent_buffer_uptodate(eb)) {
1855 free_extent_buffer(eb);
1858 btrfs_tree_lock(eb);
1860 ret = btrfs_cow_block(trans, dest, eb, parent,
1864 btrfs_set_lock_blocking(eb);
1866 btrfs_tree_unlock(parent);
1867 free_extent_buffer(parent);
1874 btrfs_tree_unlock(parent);
1875 free_extent_buffer(parent);
1880 btrfs_node_key_to_cpu(path->nodes[level], &key,
1881 path->slots[level]);
1882 btrfs_release_path(path);
1884 path->lowest_level = level;
1885 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1886 path->lowest_level = 0;
1890 * swap blocks in fs tree and reloc tree.
1892 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1893 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1894 btrfs_mark_buffer_dirty(parent);
1896 btrfs_set_node_blockptr(path->nodes[level],
1897 path->slots[level], old_bytenr);
1898 btrfs_set_node_ptr_generation(path->nodes[level],
1899 path->slots[level], old_ptr_gen);
1900 btrfs_mark_buffer_dirty(path->nodes[level]);
1902 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1903 path->nodes[level]->start,
1904 src->root_key.objectid, level - 1, 0);
1906 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1907 0, dest->root_key.objectid, level - 1,
1911 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1912 path->nodes[level]->start,
1913 src->root_key.objectid, level - 1, 0);
1916 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1917 0, dest->root_key.objectid, level - 1,
1921 btrfs_unlock_up_safe(path, 0);
1926 btrfs_tree_unlock(parent);
1927 free_extent_buffer(parent);
1932 * helper to find next relocated block in reloc tree
1934 static noinline_for_stack
1935 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1938 struct extent_buffer *eb;
1943 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1945 for (i = 0; i < *level; i++) {
1946 free_extent_buffer(path->nodes[i]);
1947 path->nodes[i] = NULL;
1950 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1951 eb = path->nodes[i];
1952 nritems = btrfs_header_nritems(eb);
1953 while (path->slots[i] + 1 < nritems) {
1955 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1962 free_extent_buffer(path->nodes[i]);
1963 path->nodes[i] = NULL;
1969 * walk down reloc tree to find relocated block of lowest level
1971 static noinline_for_stack
1972 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1975 struct extent_buffer *eb = NULL;
1982 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1984 for (i = *level; i > 0; i--) {
1985 eb = path->nodes[i];
1986 nritems = btrfs_header_nritems(eb);
1987 while (path->slots[i] < nritems) {
1988 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1989 if (ptr_gen > last_snapshot)
1993 if (path->slots[i] >= nritems) {
2004 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
2005 eb = read_tree_block(root, bytenr, ptr_gen);
2008 } else if (!extent_buffer_uptodate(eb)) {
2009 free_extent_buffer(eb);
2012 BUG_ON(btrfs_header_level(eb) != i - 1);
2013 path->nodes[i - 1] = eb;
2014 path->slots[i - 1] = 0;
2020 * invalidate extent cache for file extents whose key in range of
2021 * [min_key, max_key)
2023 static int invalidate_extent_cache(struct btrfs_root *root,
2024 struct btrfs_key *min_key,
2025 struct btrfs_key *max_key)
2027 struct inode *inode = NULL;
2032 objectid = min_key->objectid;
2037 if (objectid > max_key->objectid)
2040 inode = find_next_inode(root, objectid);
2043 ino = btrfs_ino(inode);
2045 if (ino > max_key->objectid) {
2051 if (!S_ISREG(inode->i_mode))
2054 if (unlikely(min_key->objectid == ino)) {
2055 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2057 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2060 start = min_key->offset;
2061 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2067 if (unlikely(max_key->objectid == ino)) {
2068 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2070 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2073 if (max_key->offset == 0)
2075 end = max_key->offset;
2076 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2083 /* the lock_extent waits for readpage to complete */
2084 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2085 btrfs_drop_extent_cache(inode, start, end, 1);
2086 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2091 static int find_next_key(struct btrfs_path *path, int level,
2092 struct btrfs_key *key)
2095 while (level < BTRFS_MAX_LEVEL) {
2096 if (!path->nodes[level])
2098 if (path->slots[level] + 1 <
2099 btrfs_header_nritems(path->nodes[level])) {
2100 btrfs_node_key_to_cpu(path->nodes[level], key,
2101 path->slots[level] + 1);
2110 * merge the relocated tree blocks in reloc tree with corresponding
2113 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2114 struct btrfs_root *root)
2116 LIST_HEAD(inode_list);
2117 struct btrfs_key key;
2118 struct btrfs_key next_key;
2119 struct btrfs_trans_handle *trans = NULL;
2120 struct btrfs_root *reloc_root;
2121 struct btrfs_root_item *root_item;
2122 struct btrfs_path *path;
2123 struct extent_buffer *leaf;
2131 path = btrfs_alloc_path();
2134 path->reada = READA_FORWARD;
2136 reloc_root = root->reloc_root;
2137 root_item = &reloc_root->root_item;
2139 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2140 level = btrfs_root_level(root_item);
2141 extent_buffer_get(reloc_root->node);
2142 path->nodes[level] = reloc_root->node;
2143 path->slots[level] = 0;
2145 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2147 level = root_item->drop_level;
2149 path->lowest_level = level;
2150 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2151 path->lowest_level = 0;
2153 btrfs_free_path(path);
2157 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2158 path->slots[level]);
2159 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2161 btrfs_unlock_up_safe(path, 0);
2164 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2165 memset(&next_key, 0, sizeof(next_key));
2168 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2169 BTRFS_RESERVE_FLUSH_ALL);
2174 trans = btrfs_start_transaction(root, 0);
2175 if (IS_ERR(trans)) {
2176 err = PTR_ERR(trans);
2180 trans->block_rsv = rc->block_rsv;
2185 ret = walk_down_reloc_tree(reloc_root, path, &level);
2193 if (!find_next_key(path, level, &key) &&
2194 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2197 ret = replace_path(trans, root, reloc_root, path,
2198 &next_key, level, max_level);
2207 btrfs_node_key_to_cpu(path->nodes[level], &key,
2208 path->slots[level]);
2212 ret = walk_up_reloc_tree(reloc_root, path, &level);
2218 * save the merging progress in the drop_progress.
2219 * this is OK since root refs == 1 in this case.
2221 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2222 path->slots[level]);
2223 root_item->drop_level = level;
2225 btrfs_end_transaction_throttle(trans, root);
2228 btrfs_btree_balance_dirty(root);
2230 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2231 invalidate_extent_cache(root, &key, &next_key);
2235 * handle the case only one block in the fs tree need to be
2236 * relocated and the block is tree root.
2238 leaf = btrfs_lock_root_node(root);
2239 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2240 btrfs_tree_unlock(leaf);
2241 free_extent_buffer(leaf);
2245 btrfs_free_path(path);
2248 memset(&root_item->drop_progress, 0,
2249 sizeof(root_item->drop_progress));
2250 root_item->drop_level = 0;
2251 btrfs_set_root_refs(root_item, 0);
2252 btrfs_update_reloc_root(trans, root);
2256 btrfs_end_transaction_throttle(trans, root);
2258 btrfs_btree_balance_dirty(root);
2260 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2261 invalidate_extent_cache(root, &key, &next_key);
2266 static noinline_for_stack
2267 int prepare_to_merge(struct reloc_control *rc, int err)
2269 struct btrfs_root *root = rc->extent_root;
2270 struct btrfs_root *reloc_root;
2271 struct btrfs_trans_handle *trans;
2272 LIST_HEAD(reloc_roots);
2276 mutex_lock(&root->fs_info->reloc_mutex);
2277 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2278 rc->merging_rsv_size += rc->nodes_relocated * 2;
2279 mutex_unlock(&root->fs_info->reloc_mutex);
2283 num_bytes = rc->merging_rsv_size;
2284 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2285 BTRFS_RESERVE_FLUSH_ALL);
2290 trans = btrfs_join_transaction(rc->extent_root);
2291 if (IS_ERR(trans)) {
2293 btrfs_block_rsv_release(rc->extent_root,
2294 rc->block_rsv, num_bytes);
2295 return PTR_ERR(trans);
2299 if (num_bytes != rc->merging_rsv_size) {
2300 btrfs_end_transaction(trans, rc->extent_root);
2301 btrfs_block_rsv_release(rc->extent_root,
2302 rc->block_rsv, num_bytes);
2307 rc->merge_reloc_tree = 1;
2309 while (!list_empty(&rc->reloc_roots)) {
2310 reloc_root = list_entry(rc->reloc_roots.next,
2311 struct btrfs_root, root_list);
2312 list_del_init(&reloc_root->root_list);
2314 root = read_fs_root(reloc_root->fs_info,
2315 reloc_root->root_key.offset);
2316 BUG_ON(IS_ERR(root));
2317 BUG_ON(root->reloc_root != reloc_root);
2320 * set reference count to 1, so btrfs_recover_relocation
2321 * knows it should resumes merging
2324 btrfs_set_root_refs(&reloc_root->root_item, 1);
2325 btrfs_update_reloc_root(trans, root);
2327 list_add(&reloc_root->root_list, &reloc_roots);
2330 list_splice(&reloc_roots, &rc->reloc_roots);
2333 btrfs_commit_transaction(trans, rc->extent_root);
2335 btrfs_end_transaction(trans, rc->extent_root);
2339 static noinline_for_stack
2340 void free_reloc_roots(struct list_head *list)
2342 struct btrfs_root *reloc_root;
2344 while (!list_empty(list)) {
2345 reloc_root = list_entry(list->next, struct btrfs_root,
2347 __del_reloc_root(reloc_root);
2351 static noinline_for_stack
2352 void merge_reloc_roots(struct reloc_control *rc)
2354 struct btrfs_root *root;
2355 struct btrfs_root *reloc_root;
2359 LIST_HEAD(reloc_roots);
2363 root = rc->extent_root;
2366 * this serializes us with btrfs_record_root_in_transaction,
2367 * we have to make sure nobody is in the middle of
2368 * adding their roots to the list while we are
2371 mutex_lock(&root->fs_info->reloc_mutex);
2372 list_splice_init(&rc->reloc_roots, &reloc_roots);
2373 mutex_unlock(&root->fs_info->reloc_mutex);
2375 while (!list_empty(&reloc_roots)) {
2377 reloc_root = list_entry(reloc_roots.next,
2378 struct btrfs_root, root_list);
2380 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2381 root = read_fs_root(reloc_root->fs_info,
2382 reloc_root->root_key.offset);
2383 BUG_ON(IS_ERR(root));
2384 BUG_ON(root->reloc_root != reloc_root);
2386 ret = merge_reloc_root(rc, root);
2388 if (list_empty(&reloc_root->root_list))
2389 list_add_tail(&reloc_root->root_list,
2394 list_del_init(&reloc_root->root_list);
2398 * we keep the old last snapshod transid in rtranid when we
2399 * created the relocation tree.
2401 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2402 otransid = btrfs_root_otransid(&reloc_root->root_item);
2403 objectid = reloc_root->root_key.offset;
2405 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2407 if (list_empty(&reloc_root->root_list))
2408 list_add_tail(&reloc_root->root_list,
2420 btrfs_std_error(root->fs_info, ret, NULL);
2421 if (!list_empty(&reloc_roots))
2422 free_reloc_roots(&reloc_roots);
2424 /* new reloc root may be added */
2425 mutex_lock(&root->fs_info->reloc_mutex);
2426 list_splice_init(&rc->reloc_roots, &reloc_roots);
2427 mutex_unlock(&root->fs_info->reloc_mutex);
2428 if (!list_empty(&reloc_roots))
2429 free_reloc_roots(&reloc_roots);
2432 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2435 static void free_block_list(struct rb_root *blocks)
2437 struct tree_block *block;
2438 struct rb_node *rb_node;
2439 while ((rb_node = rb_first(blocks))) {
2440 block = rb_entry(rb_node, struct tree_block, rb_node);
2441 rb_erase(rb_node, blocks);
2446 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2447 struct btrfs_root *reloc_root)
2449 struct btrfs_root *root;
2451 if (reloc_root->last_trans == trans->transid)
2454 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2455 BUG_ON(IS_ERR(root));
2456 BUG_ON(root->reloc_root != reloc_root);
2458 return btrfs_record_root_in_trans(trans, root);
2461 static noinline_for_stack
2462 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2463 struct reloc_control *rc,
2464 struct backref_node *node,
2465 struct backref_edge *edges[])
2467 struct backref_node *next;
2468 struct btrfs_root *root;
2474 next = walk_up_backref(next, edges, &index);
2477 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2479 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2480 record_reloc_root_in_trans(trans, root);
2484 btrfs_record_root_in_trans(trans, root);
2485 root = root->reloc_root;
2487 if (next->new_bytenr != root->node->start) {
2488 BUG_ON(next->new_bytenr);
2489 BUG_ON(!list_empty(&next->list));
2490 next->new_bytenr = root->node->start;
2492 list_add_tail(&next->list,
2493 &rc->backref_cache.changed);
2494 __mark_block_processed(rc, next);
2500 next = walk_down_backref(edges, &index);
2501 if (!next || next->level <= node->level)
2508 /* setup backref node path for btrfs_reloc_cow_block */
2510 rc->backref_cache.path[next->level] = next;
2513 next = edges[index]->node[UPPER];
2519 * select a tree root for relocation. return NULL if the block
2520 * is reference counted. we should use do_relocation() in this
2521 * case. return a tree root pointer if the block isn't reference
2522 * counted. return -ENOENT if the block is root of reloc tree.
2524 static noinline_for_stack
2525 struct btrfs_root *select_one_root(struct backref_node *node)
2527 struct backref_node *next;
2528 struct btrfs_root *root;
2529 struct btrfs_root *fs_root = NULL;
2530 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2536 next = walk_up_backref(next, edges, &index);
2540 /* no other choice for non-references counted tree */
2541 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2544 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2550 next = walk_down_backref(edges, &index);
2551 if (!next || next->level <= node->level)
2556 return ERR_PTR(-ENOENT);
2560 static noinline_for_stack
2561 u64 calcu_metadata_size(struct reloc_control *rc,
2562 struct backref_node *node, int reserve)
2564 struct backref_node *next = node;
2565 struct backref_edge *edge;
2566 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2570 BUG_ON(reserve && node->processed);
2575 if (next->processed && (reserve || next != node))
2578 num_bytes += rc->extent_root->nodesize;
2580 if (list_empty(&next->upper))
2583 edge = list_entry(next->upper.next,
2584 struct backref_edge, list[LOWER]);
2585 edges[index++] = edge;
2586 next = edge->node[UPPER];
2588 next = walk_down_backref(edges, &index);
2593 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2594 struct reloc_control *rc,
2595 struct backref_node *node)
2597 struct btrfs_root *root = rc->extent_root;
2602 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2604 trans->block_rsv = rc->block_rsv;
2605 rc->reserved_bytes += num_bytes;
2606 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2607 BTRFS_RESERVE_FLUSH_ALL);
2609 if (ret == -EAGAIN) {
2610 tmp = rc->extent_root->nodesize *
2611 RELOCATION_RESERVED_NODES;
2612 while (tmp <= rc->reserved_bytes)
2615 * only one thread can access block_rsv at this point,
2616 * so we don't need hold lock to protect block_rsv.
2617 * we expand more reservation size here to allow enough
2618 * space for relocation and we will return eailer in
2621 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2622 RELOCATION_RESERVED_NODES;
2631 * relocate a block tree, and then update pointers in upper level
2632 * blocks that reference the block to point to the new location.
2634 * if called by link_to_upper, the block has already been relocated.
2635 * in that case this function just updates pointers.
2637 static int do_relocation(struct btrfs_trans_handle *trans,
2638 struct reloc_control *rc,
2639 struct backref_node *node,
2640 struct btrfs_key *key,
2641 struct btrfs_path *path, int lowest)
2643 struct backref_node *upper;
2644 struct backref_edge *edge;
2645 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2646 struct btrfs_root *root;
2647 struct extent_buffer *eb;
2655 BUG_ON(lowest && node->eb);
2657 path->lowest_level = node->level + 1;
2658 rc->backref_cache.path[node->level] = node;
2659 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2662 upper = edge->node[UPPER];
2663 root = select_reloc_root(trans, rc, upper, edges);
2666 if (upper->eb && !upper->locked) {
2668 ret = btrfs_bin_search(upper->eb, key,
2669 upper->level, &slot);
2671 bytenr = btrfs_node_blockptr(upper->eb, slot);
2672 if (node->eb->start == bytenr)
2675 drop_node_buffer(upper);
2679 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2687 upper->eb = path->nodes[upper->level];
2688 path->nodes[upper->level] = NULL;
2690 BUG_ON(upper->eb != path->nodes[upper->level]);
2694 path->locks[upper->level] = 0;
2696 slot = path->slots[upper->level];
2697 btrfs_release_path(path);
2699 ret = btrfs_bin_search(upper->eb, key, upper->level,
2704 bytenr = btrfs_node_blockptr(upper->eb, slot);
2706 BUG_ON(bytenr != node->bytenr);
2708 if (node->eb->start == bytenr)
2712 blocksize = root->nodesize;
2713 generation = btrfs_node_ptr_generation(upper->eb, slot);
2714 eb = read_tree_block(root, bytenr, generation);
2718 } else if (!extent_buffer_uptodate(eb)) {
2719 free_extent_buffer(eb);
2723 btrfs_tree_lock(eb);
2724 btrfs_set_lock_blocking(eb);
2727 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2729 btrfs_tree_unlock(eb);
2730 free_extent_buffer(eb);
2735 BUG_ON(node->eb != eb);
2737 btrfs_set_node_blockptr(upper->eb, slot,
2739 btrfs_set_node_ptr_generation(upper->eb, slot,
2741 btrfs_mark_buffer_dirty(upper->eb);
2743 ret = btrfs_inc_extent_ref(trans, root,
2744 node->eb->start, blocksize,
2746 btrfs_header_owner(upper->eb),
2750 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2754 if (!upper->pending)
2755 drop_node_buffer(upper);
2757 unlock_node_buffer(upper);
2762 if (!err && node->pending) {
2763 drop_node_buffer(node);
2764 list_move_tail(&node->list, &rc->backref_cache.changed);
2768 path->lowest_level = 0;
2769 BUG_ON(err == -ENOSPC);
2773 static int link_to_upper(struct btrfs_trans_handle *trans,
2774 struct reloc_control *rc,
2775 struct backref_node *node,
2776 struct btrfs_path *path)
2778 struct btrfs_key key;
2780 btrfs_node_key_to_cpu(node->eb, &key, 0);
2781 return do_relocation(trans, rc, node, &key, path, 0);
2784 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2785 struct reloc_control *rc,
2786 struct btrfs_path *path, int err)
2789 struct backref_cache *cache = &rc->backref_cache;
2790 struct backref_node *node;
2794 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2795 while (!list_empty(&cache->pending[level])) {
2796 node = list_entry(cache->pending[level].next,
2797 struct backref_node, list);
2798 list_move_tail(&node->list, &list);
2799 BUG_ON(!node->pending);
2802 ret = link_to_upper(trans, rc, node, path);
2807 list_splice_init(&list, &cache->pending[level]);
2812 static void mark_block_processed(struct reloc_control *rc,
2813 u64 bytenr, u32 blocksize)
2815 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2816 EXTENT_DIRTY, GFP_NOFS);
2819 static void __mark_block_processed(struct reloc_control *rc,
2820 struct backref_node *node)
2823 if (node->level == 0 ||
2824 in_block_group(node->bytenr, rc->block_group)) {
2825 blocksize = rc->extent_root->nodesize;
2826 mark_block_processed(rc, node->bytenr, blocksize);
2828 node->processed = 1;
2832 * mark a block and all blocks directly/indirectly reference the block
2835 static void update_processed_blocks(struct reloc_control *rc,
2836 struct backref_node *node)
2838 struct backref_node *next = node;
2839 struct backref_edge *edge;
2840 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2846 if (next->processed)
2849 __mark_block_processed(rc, next);
2851 if (list_empty(&next->upper))
2854 edge = list_entry(next->upper.next,
2855 struct backref_edge, list[LOWER]);
2856 edges[index++] = edge;
2857 next = edge->node[UPPER];
2859 next = walk_down_backref(edges, &index);
2863 static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
2865 u32 blocksize = rc->extent_root->nodesize;
2867 if (test_range_bit(&rc->processed_blocks, bytenr,
2868 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2873 static int get_tree_block_key(struct reloc_control *rc,
2874 struct tree_block *block)
2876 struct extent_buffer *eb;
2878 BUG_ON(block->key_ready);
2879 eb = read_tree_block(rc->extent_root, block->bytenr,
2883 } else if (!extent_buffer_uptodate(eb)) {
2884 free_extent_buffer(eb);
2887 WARN_ON(btrfs_header_level(eb) != block->level);
2888 if (block->level == 0)
2889 btrfs_item_key_to_cpu(eb, &block->key, 0);
2891 btrfs_node_key_to_cpu(eb, &block->key, 0);
2892 free_extent_buffer(eb);
2893 block->key_ready = 1;
2898 * helper function to relocate a tree block
2900 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2901 struct reloc_control *rc,
2902 struct backref_node *node,
2903 struct btrfs_key *key,
2904 struct btrfs_path *path)
2906 struct btrfs_root *root;
2912 BUG_ON(node->processed);
2913 root = select_one_root(node);
2914 if (root == ERR_PTR(-ENOENT)) {
2915 update_processed_blocks(rc, node);
2919 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2920 ret = reserve_metadata_space(trans, rc, node);
2926 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2927 BUG_ON(node->new_bytenr);
2928 BUG_ON(!list_empty(&node->list));
2929 btrfs_record_root_in_trans(trans, root);
2930 root = root->reloc_root;
2931 node->new_bytenr = root->node->start;
2933 list_add_tail(&node->list, &rc->backref_cache.changed);
2935 path->lowest_level = node->level;
2936 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2937 btrfs_release_path(path);
2942 update_processed_blocks(rc, node);
2944 ret = do_relocation(trans, rc, node, key, path, 1);
2947 if (ret || node->level == 0 || node->cowonly)
2948 remove_backref_node(&rc->backref_cache, node);
2953 * relocate a list of blocks
2955 static noinline_for_stack
2956 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2957 struct reloc_control *rc, struct rb_root *blocks)
2959 struct backref_node *node;
2960 struct btrfs_path *path;
2961 struct tree_block *block;
2962 struct rb_node *rb_node;
2966 path = btrfs_alloc_path();
2969 goto out_free_blocks;
2972 rb_node = rb_first(blocks);
2974 block = rb_entry(rb_node, struct tree_block, rb_node);
2975 if (!block->key_ready)
2976 readahead_tree_block(rc->extent_root, block->bytenr);
2977 rb_node = rb_next(rb_node);
2980 rb_node = rb_first(blocks);
2982 block = rb_entry(rb_node, struct tree_block, rb_node);
2983 if (!block->key_ready) {
2984 err = get_tree_block_key(rc, block);
2988 rb_node = rb_next(rb_node);
2991 rb_node = rb_first(blocks);
2993 block = rb_entry(rb_node, struct tree_block, rb_node);
2995 node = build_backref_tree(rc, &block->key,
2996 block->level, block->bytenr);
2998 err = PTR_ERR(node);
3002 ret = relocate_tree_block(trans, rc, node, &block->key,
3005 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3009 rb_node = rb_next(rb_node);
3012 err = finish_pending_nodes(trans, rc, path, err);
3015 btrfs_free_path(path);
3017 free_block_list(blocks);
3021 static noinline_for_stack
3022 int prealloc_file_extent_cluster(struct inode *inode,
3023 struct file_extent_cluster *cluster)
3028 u64 offset = BTRFS_I(inode)->index_cnt;
3033 BUG_ON(cluster->start != cluster->boundary[0]);
3036 ret = btrfs_check_data_free_space(inode, cluster->start,
3037 cluster->end + 1 - cluster->start);
3041 while (nr < cluster->nr) {
3042 start = cluster->boundary[nr] - offset;
3043 if (nr + 1 < cluster->nr)
3044 end = cluster->boundary[nr + 1] - 1 - offset;
3046 end = cluster->end - offset;
3048 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3049 num_bytes = end + 1 - start;
3050 ret = btrfs_prealloc_file_range(inode, 0, start,
3051 num_bytes, num_bytes,
3052 end + 1, &alloc_hint);
3053 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3058 btrfs_free_reserved_data_space(inode, cluster->start,
3059 cluster->end + 1 - cluster->start);
3061 inode_unlock(inode);
3065 static noinline_for_stack
3066 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3069 struct btrfs_root *root = BTRFS_I(inode)->root;
3070 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3071 struct extent_map *em;
3074 em = alloc_extent_map();
3079 em->len = end + 1 - start;
3080 em->block_len = em->len;
3081 em->block_start = block_start;
3082 em->bdev = root->fs_info->fs_devices->latest_bdev;
3083 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3085 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3087 write_lock(&em_tree->lock);
3088 ret = add_extent_mapping(em_tree, em, 0);
3089 write_unlock(&em_tree->lock);
3090 if (ret != -EEXIST) {
3091 free_extent_map(em);
3094 btrfs_drop_extent_cache(inode, start, end, 0);
3096 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3100 static int relocate_file_extent_cluster(struct inode *inode,
3101 struct file_extent_cluster *cluster)
3105 u64 offset = BTRFS_I(inode)->index_cnt;
3106 unsigned long index;
3107 unsigned long last_index;
3109 struct file_ra_state *ra;
3110 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3117 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3121 ret = prealloc_file_extent_cluster(inode, cluster);
3125 file_ra_state_init(ra, inode->i_mapping);
3127 ret = setup_extent_mapping(inode, cluster->start - offset,
3128 cluster->end - offset, cluster->start);
3132 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3133 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3134 while (index <= last_index) {
3135 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3139 page = find_lock_page(inode->i_mapping, index);
3141 page_cache_sync_readahead(inode->i_mapping,
3143 last_index + 1 - index);
3144 page = find_or_create_page(inode->i_mapping, index,
3147 btrfs_delalloc_release_metadata(inode,
3154 if (PageReadahead(page)) {
3155 page_cache_async_readahead(inode->i_mapping,
3156 ra, NULL, page, index,
3157 last_index + 1 - index);
3160 if (!PageUptodate(page)) {
3161 btrfs_readpage(NULL, page);
3163 if (!PageUptodate(page)) {
3165 page_cache_release(page);
3166 btrfs_delalloc_release_metadata(inode,
3173 page_start = page_offset(page);
3174 page_end = page_start + PAGE_CACHE_SIZE - 1;
3176 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3178 set_page_extent_mapped(page);
3180 if (nr < cluster->nr &&
3181 page_start + offset == cluster->boundary[nr]) {
3182 set_extent_bits(&BTRFS_I(inode)->io_tree,
3183 page_start, page_end,
3184 EXTENT_BOUNDARY, GFP_NOFS);
3188 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3189 set_page_dirty(page);
3191 unlock_extent(&BTRFS_I(inode)->io_tree,
3192 page_start, page_end);
3194 page_cache_release(page);
3197 balance_dirty_pages_ratelimited(inode->i_mapping);
3198 btrfs_throttle(BTRFS_I(inode)->root);
3200 WARN_ON(nr != cluster->nr);
3206 static noinline_for_stack
3207 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3208 struct file_extent_cluster *cluster)
3212 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3213 ret = relocate_file_extent_cluster(inode, cluster);
3220 cluster->start = extent_key->objectid;
3222 BUG_ON(cluster->nr >= MAX_EXTENTS);
3223 cluster->end = extent_key->objectid + extent_key->offset - 1;
3224 cluster->boundary[cluster->nr] = extent_key->objectid;
3227 if (cluster->nr >= MAX_EXTENTS) {
3228 ret = relocate_file_extent_cluster(inode, cluster);
3236 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3237 static int get_ref_objectid_v0(struct reloc_control *rc,
3238 struct btrfs_path *path,
3239 struct btrfs_key *extent_key,
3240 u64 *ref_objectid, int *path_change)
3242 struct btrfs_key key;
3243 struct extent_buffer *leaf;
3244 struct btrfs_extent_ref_v0 *ref0;
3248 leaf = path->nodes[0];
3249 slot = path->slots[0];
3251 if (slot >= btrfs_header_nritems(leaf)) {
3252 ret = btrfs_next_leaf(rc->extent_root, path);
3256 leaf = path->nodes[0];
3257 slot = path->slots[0];
3261 btrfs_item_key_to_cpu(leaf, &key, slot);
3262 if (key.objectid != extent_key->objectid)
3265 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3269 ref0 = btrfs_item_ptr(leaf, slot,
3270 struct btrfs_extent_ref_v0);
3271 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3279 * helper to add a tree block to the list.
3280 * the major work is getting the generation and level of the block
3282 static int add_tree_block(struct reloc_control *rc,
3283 struct btrfs_key *extent_key,
3284 struct btrfs_path *path,
3285 struct rb_root *blocks)
3287 struct extent_buffer *eb;
3288 struct btrfs_extent_item *ei;
3289 struct btrfs_tree_block_info *bi;
3290 struct tree_block *block;
3291 struct rb_node *rb_node;
3296 eb = path->nodes[0];
3297 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3299 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3300 item_size >= sizeof(*ei) + sizeof(*bi)) {
3301 ei = btrfs_item_ptr(eb, path->slots[0],
3302 struct btrfs_extent_item);
3303 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3304 bi = (struct btrfs_tree_block_info *)(ei + 1);
3305 level = btrfs_tree_block_level(eb, bi);
3307 level = (int)extent_key->offset;
3309 generation = btrfs_extent_generation(eb, ei);
3311 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3315 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3316 ret = get_ref_objectid_v0(rc, path, extent_key,
3320 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3321 level = (int)ref_owner;
3322 /* FIXME: get real generation */
3329 btrfs_release_path(path);
3331 BUG_ON(level == -1);
3333 block = kmalloc(sizeof(*block), GFP_NOFS);
3337 block->bytenr = extent_key->objectid;
3338 block->key.objectid = rc->extent_root->nodesize;
3339 block->key.offset = generation;
3340 block->level = level;
3341 block->key_ready = 0;
3343 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3345 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3351 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3353 static int __add_tree_block(struct reloc_control *rc,
3354 u64 bytenr, u32 blocksize,
3355 struct rb_root *blocks)
3357 struct btrfs_path *path;
3358 struct btrfs_key key;
3360 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3363 if (tree_block_processed(bytenr, rc))
3366 if (tree_search(blocks, bytenr))
3369 path = btrfs_alloc_path();
3373 key.objectid = bytenr;
3375 key.type = BTRFS_METADATA_ITEM_KEY;
3376 key.offset = (u64)-1;
3378 key.type = BTRFS_EXTENT_ITEM_KEY;
3379 key.offset = blocksize;
3382 path->search_commit_root = 1;
3383 path->skip_locking = 1;
3384 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3388 if (ret > 0 && skinny) {
3389 if (path->slots[0]) {
3391 btrfs_item_key_to_cpu(path->nodes[0], &key,
3393 if (key.objectid == bytenr &&
3394 (key.type == BTRFS_METADATA_ITEM_KEY ||
3395 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3396 key.offset == blocksize)))
3402 btrfs_release_path(path);
3408 ret = add_tree_block(rc, &key, path, blocks);
3410 btrfs_free_path(path);
3415 * helper to check if the block use full backrefs for pointers in it
3417 static int block_use_full_backref(struct reloc_control *rc,
3418 struct extent_buffer *eb)
3423 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3424 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3427 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3428 eb->start, btrfs_header_level(eb), 1,
3432 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3439 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3440 struct btrfs_block_group_cache *block_group,
3441 struct inode *inode,
3444 struct btrfs_key key;
3445 struct btrfs_root *root = fs_info->tree_root;
3446 struct btrfs_trans_handle *trans;
3453 key.type = BTRFS_INODE_ITEM_KEY;
3456 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3457 if (IS_ERR(inode) || is_bad_inode(inode)) {
3464 ret = btrfs_check_trunc_cache_free_space(root,
3465 &fs_info->global_block_rsv);
3469 trans = btrfs_join_transaction(root);
3470 if (IS_ERR(trans)) {
3471 ret = PTR_ERR(trans);
3475 ret = btrfs_truncate_free_space_cache(root, trans, block_group, inode);
3477 btrfs_end_transaction(trans, root);
3478 btrfs_btree_balance_dirty(root);
3485 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3486 * this function scans fs tree to find blocks reference the data extent
3488 static int find_data_references(struct reloc_control *rc,
3489 struct btrfs_key *extent_key,
3490 struct extent_buffer *leaf,
3491 struct btrfs_extent_data_ref *ref,
3492 struct rb_root *blocks)
3494 struct btrfs_path *path;
3495 struct tree_block *block;
3496 struct btrfs_root *root;
3497 struct btrfs_file_extent_item *fi;
3498 struct rb_node *rb_node;
3499 struct btrfs_key key;
3510 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3511 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3512 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3513 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3516 * This is an extent belonging to the free space cache, lets just delete
3517 * it and redo the search.
3519 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3520 ret = delete_block_group_cache(rc->extent_root->fs_info,
3522 NULL, ref_objectid);
3528 path = btrfs_alloc_path();
3531 path->reada = READA_FORWARD;
3533 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3535 err = PTR_ERR(root);
3539 key.objectid = ref_objectid;
3540 key.type = BTRFS_EXTENT_DATA_KEY;
3541 if (ref_offset > ((u64)-1 << 32))
3544 key.offset = ref_offset;
3546 path->search_commit_root = 1;
3547 path->skip_locking = 1;
3548 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3554 leaf = path->nodes[0];
3555 nritems = btrfs_header_nritems(leaf);
3557 * the references in tree blocks that use full backrefs
3558 * are not counted in
3560 if (block_use_full_backref(rc, leaf))
3564 rb_node = tree_search(blocks, leaf->start);
3569 path->slots[0] = nritems;
3572 while (ref_count > 0) {
3573 while (path->slots[0] >= nritems) {
3574 ret = btrfs_next_leaf(root, path);
3579 if (WARN_ON(ret > 0))
3582 leaf = path->nodes[0];
3583 nritems = btrfs_header_nritems(leaf);
3586 if (block_use_full_backref(rc, leaf))
3590 rb_node = tree_search(blocks, leaf->start);
3595 path->slots[0] = nritems;
3599 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3600 if (WARN_ON(key.objectid != ref_objectid ||
3601 key.type != BTRFS_EXTENT_DATA_KEY))
3604 fi = btrfs_item_ptr(leaf, path->slots[0],
3605 struct btrfs_file_extent_item);
3607 if (btrfs_file_extent_type(leaf, fi) ==
3608 BTRFS_FILE_EXTENT_INLINE)
3611 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3612 extent_key->objectid)
3615 key.offset -= btrfs_file_extent_offset(leaf, fi);
3616 if (key.offset != ref_offset)
3624 if (!tree_block_processed(leaf->start, rc)) {
3625 block = kmalloc(sizeof(*block), GFP_NOFS);
3630 block->bytenr = leaf->start;
3631 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3633 block->key_ready = 1;
3634 rb_node = tree_insert(blocks, block->bytenr,
3637 backref_tree_panic(rb_node, -EEXIST,
3643 path->slots[0] = nritems;
3649 btrfs_free_path(path);
3654 * helper to find all tree blocks that reference a given data extent
3656 static noinline_for_stack
3657 int add_data_references(struct reloc_control *rc,
3658 struct btrfs_key *extent_key,
3659 struct btrfs_path *path,
3660 struct rb_root *blocks)
3662 struct btrfs_key key;
3663 struct extent_buffer *eb;
3664 struct btrfs_extent_data_ref *dref;
3665 struct btrfs_extent_inline_ref *iref;
3668 u32 blocksize = rc->extent_root->nodesize;
3672 eb = path->nodes[0];
3673 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3674 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3675 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3676 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3680 ptr += sizeof(struct btrfs_extent_item);
3683 iref = (struct btrfs_extent_inline_ref *)ptr;
3684 key.type = btrfs_extent_inline_ref_type(eb, iref);
3685 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3686 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3687 ret = __add_tree_block(rc, key.offset, blocksize,
3689 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3690 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3691 ret = find_data_references(rc, extent_key,
3700 ptr += btrfs_extent_inline_ref_size(key.type);
3706 eb = path->nodes[0];
3707 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3708 ret = btrfs_next_leaf(rc->extent_root, path);
3715 eb = path->nodes[0];
3718 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3719 if (key.objectid != extent_key->objectid)
3722 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3723 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3724 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3726 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3727 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3729 ret = __add_tree_block(rc, key.offset, blocksize,
3731 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3732 dref = btrfs_item_ptr(eb, path->slots[0],
3733 struct btrfs_extent_data_ref);
3734 ret = find_data_references(rc, extent_key,
3746 btrfs_release_path(path);
3748 free_block_list(blocks);
3753 * helper to find next unprocessed extent
3755 static noinline_for_stack
3756 int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
3757 struct btrfs_key *extent_key)
3759 struct btrfs_key key;
3760 struct extent_buffer *leaf;
3761 u64 start, end, last;
3764 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3767 if (rc->search_start >= last) {
3772 key.objectid = rc->search_start;
3773 key.type = BTRFS_EXTENT_ITEM_KEY;
3776 path->search_commit_root = 1;
3777 path->skip_locking = 1;
3778 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3783 leaf = path->nodes[0];
3784 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3785 ret = btrfs_next_leaf(rc->extent_root, path);
3788 leaf = path->nodes[0];
3791 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3792 if (key.objectid >= last) {
3797 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3798 key.type != BTRFS_METADATA_ITEM_KEY) {
3803 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3804 key.objectid + key.offset <= rc->search_start) {
3809 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3810 key.objectid + rc->extent_root->nodesize <=
3816 ret = find_first_extent_bit(&rc->processed_blocks,
3817 key.objectid, &start, &end,
3818 EXTENT_DIRTY, NULL);
3820 if (ret == 0 && start <= key.objectid) {
3821 btrfs_release_path(path);
3822 rc->search_start = end + 1;
3824 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3825 rc->search_start = key.objectid + key.offset;
3827 rc->search_start = key.objectid +
3828 rc->extent_root->nodesize;
3829 memcpy(extent_key, &key, sizeof(key));
3833 btrfs_release_path(path);
3837 static void set_reloc_control(struct reloc_control *rc)
3839 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3841 mutex_lock(&fs_info->reloc_mutex);
3842 fs_info->reloc_ctl = rc;
3843 mutex_unlock(&fs_info->reloc_mutex);
3846 static void unset_reloc_control(struct reloc_control *rc)
3848 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3850 mutex_lock(&fs_info->reloc_mutex);
3851 fs_info->reloc_ctl = NULL;
3852 mutex_unlock(&fs_info->reloc_mutex);
3855 static int check_extent_flags(u64 flags)
3857 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3858 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3860 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3861 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3863 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3864 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3869 static noinline_for_stack
3870 int prepare_to_relocate(struct reloc_control *rc)
3872 struct btrfs_trans_handle *trans;
3874 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3875 BTRFS_BLOCK_RSV_TEMP);
3879 memset(&rc->cluster, 0, sizeof(rc->cluster));
3880 rc->search_start = rc->block_group->key.objectid;
3881 rc->extents_found = 0;
3882 rc->nodes_relocated = 0;
3883 rc->merging_rsv_size = 0;
3884 rc->reserved_bytes = 0;
3885 rc->block_rsv->size = rc->extent_root->nodesize *
3886 RELOCATION_RESERVED_NODES;
3888 rc->create_reloc_tree = 1;
3889 set_reloc_control(rc);
3891 trans = btrfs_join_transaction(rc->extent_root);
3892 if (IS_ERR(trans)) {
3893 unset_reloc_control(rc);
3895 * extent tree is not a ref_cow tree and has no reloc_root to
3896 * cleanup. And callers are responsible to free the above
3899 return PTR_ERR(trans);
3901 btrfs_commit_transaction(trans, rc->extent_root);
3905 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3907 struct rb_root blocks = RB_ROOT;
3908 struct btrfs_key key;
3909 struct btrfs_trans_handle *trans = NULL;
3910 struct btrfs_path *path;
3911 struct btrfs_extent_item *ei;
3918 path = btrfs_alloc_path();
3921 path->reada = READA_FORWARD;
3923 ret = prepare_to_relocate(rc);
3930 rc->reserved_bytes = 0;
3931 ret = btrfs_block_rsv_refill(rc->extent_root,
3932 rc->block_rsv, rc->block_rsv->size,
3933 BTRFS_RESERVE_FLUSH_ALL);
3939 trans = btrfs_start_transaction(rc->extent_root, 0);
3940 if (IS_ERR(trans)) {
3941 err = PTR_ERR(trans);
3946 if (update_backref_cache(trans, &rc->backref_cache)) {
3947 btrfs_end_transaction(trans, rc->extent_root);
3951 ret = find_next_extent(rc, path, &key);
3957 rc->extents_found++;
3959 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3960 struct btrfs_extent_item);
3961 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3962 if (item_size >= sizeof(*ei)) {
3963 flags = btrfs_extent_flags(path->nodes[0], ei);
3964 ret = check_extent_flags(flags);
3968 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3970 int path_change = 0;
3973 sizeof(struct btrfs_extent_item_v0));
3974 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3980 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3981 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3983 flags = BTRFS_EXTENT_FLAG_DATA;
3986 btrfs_release_path(path);
3988 path->search_commit_root = 1;
3989 path->skip_locking = 1;
3990 ret = btrfs_search_slot(NULL, rc->extent_root,
4003 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
4004 ret = add_tree_block(rc, &key, path, &blocks);
4005 } else if (rc->stage == UPDATE_DATA_PTRS &&
4006 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4007 ret = add_data_references(rc, &key, path, &blocks);
4009 btrfs_release_path(path);
4017 if (!RB_EMPTY_ROOT(&blocks)) {
4018 ret = relocate_tree_blocks(trans, rc, &blocks);
4021 * if we fail to relocate tree blocks, force to update
4022 * backref cache when committing transaction.
4024 rc->backref_cache.last_trans = trans->transid - 1;
4026 if (ret != -EAGAIN) {
4030 rc->extents_found--;
4031 rc->search_start = key.objectid;
4035 btrfs_end_transaction_throttle(trans, rc->extent_root);
4036 btrfs_btree_balance_dirty(rc->extent_root);
4039 if (rc->stage == MOVE_DATA_EXTENTS &&
4040 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4041 rc->found_file_extent = 1;
4042 ret = relocate_data_extent(rc->data_inode,
4043 &key, &rc->cluster);
4050 if (trans && progress && err == -ENOSPC) {
4051 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4052 rc->block_group->flags);
4060 btrfs_release_path(path);
4061 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4065 btrfs_end_transaction_throttle(trans, rc->extent_root);
4066 btrfs_btree_balance_dirty(rc->extent_root);
4070 ret = relocate_file_extent_cluster(rc->data_inode,
4076 rc->create_reloc_tree = 0;
4077 set_reloc_control(rc);
4079 backref_cache_cleanup(&rc->backref_cache);
4080 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4082 err = prepare_to_merge(rc, err);
4084 merge_reloc_roots(rc);
4086 rc->merge_reloc_tree = 0;
4087 unset_reloc_control(rc);
4088 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4090 /* get rid of pinned extents */
4091 trans = btrfs_join_transaction(rc->extent_root);
4093 err = PTR_ERR(trans);
4095 btrfs_commit_transaction(trans, rc->extent_root);
4097 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4098 btrfs_free_path(path);
4102 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4103 struct btrfs_root *root, u64 objectid)
4105 struct btrfs_path *path;
4106 struct btrfs_inode_item *item;
4107 struct extent_buffer *leaf;
4110 path = btrfs_alloc_path();
4114 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4118 leaf = path->nodes[0];
4119 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4120 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4121 btrfs_set_inode_generation(leaf, item, 1);
4122 btrfs_set_inode_size(leaf, item, 0);
4123 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4124 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4125 BTRFS_INODE_PREALLOC);
4126 btrfs_mark_buffer_dirty(leaf);
4128 btrfs_free_path(path);
4133 * helper to create inode for data relocation.
4134 * the inode is in data relocation tree and its link count is 0
4136 static noinline_for_stack
4137 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4138 struct btrfs_block_group_cache *group)
4140 struct inode *inode = NULL;
4141 struct btrfs_trans_handle *trans;
4142 struct btrfs_root *root;
4143 struct btrfs_key key;
4147 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4149 return ERR_CAST(root);
4151 trans = btrfs_start_transaction(root, 6);
4153 return ERR_CAST(trans);
4155 err = btrfs_find_free_objectid(root, &objectid);
4159 err = __insert_orphan_inode(trans, root, objectid);
4162 key.objectid = objectid;
4163 key.type = BTRFS_INODE_ITEM_KEY;
4165 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4166 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4167 BTRFS_I(inode)->index_cnt = group->key.objectid;
4169 err = btrfs_orphan_add(trans, inode);
4171 btrfs_end_transaction(trans, root);
4172 btrfs_btree_balance_dirty(root);
4176 inode = ERR_PTR(err);
4181 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4183 struct reloc_control *rc;
4185 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4189 INIT_LIST_HEAD(&rc->reloc_roots);
4190 backref_cache_init(&rc->backref_cache);
4191 mapping_tree_init(&rc->reloc_root_tree);
4192 extent_io_tree_init(&rc->processed_blocks,
4193 fs_info->btree_inode->i_mapping);
4198 * function to relocate all extents in a block group.
4200 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4202 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4203 struct reloc_control *rc;
4204 struct inode *inode;
4205 struct btrfs_path *path;
4210 rc = alloc_reloc_control(fs_info);
4214 rc->extent_root = extent_root;
4216 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4217 BUG_ON(!rc->block_group);
4219 ret = btrfs_inc_block_group_ro(extent_root, rc->block_group);
4226 path = btrfs_alloc_path();
4232 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4234 btrfs_free_path(path);
4237 ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
4239 ret = PTR_ERR(inode);
4241 if (ret && ret != -ENOENT) {
4246 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4247 if (IS_ERR(rc->data_inode)) {
4248 err = PTR_ERR(rc->data_inode);
4249 rc->data_inode = NULL;
4253 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
4254 rc->block_group->key.objectid, rc->block_group->flags);
4256 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
4261 btrfs_wait_ordered_roots(fs_info, -1);
4264 mutex_lock(&fs_info->cleaner_mutex);
4265 ret = relocate_block_group(rc);
4266 mutex_unlock(&fs_info->cleaner_mutex);
4272 if (rc->extents_found == 0)
4275 btrfs_info(extent_root->fs_info, "found %llu extents",
4278 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4279 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4285 invalidate_mapping_pages(rc->data_inode->i_mapping,
4287 rc->stage = UPDATE_DATA_PTRS;
4291 WARN_ON(rc->block_group->pinned > 0);
4292 WARN_ON(rc->block_group->reserved > 0);
4293 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4296 btrfs_dec_block_group_ro(extent_root, rc->block_group);
4297 iput(rc->data_inode);
4298 btrfs_put_block_group(rc->block_group);
4303 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4305 struct btrfs_trans_handle *trans;
4308 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4310 return PTR_ERR(trans);
4312 memset(&root->root_item.drop_progress, 0,
4313 sizeof(root->root_item.drop_progress));
4314 root->root_item.drop_level = 0;
4315 btrfs_set_root_refs(&root->root_item, 0);
4316 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4317 &root->root_key, &root->root_item);
4319 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4326 * recover relocation interrupted by system crash.
4328 * this function resumes merging reloc trees with corresponding fs trees.
4329 * this is important for keeping the sharing of tree blocks
4331 int btrfs_recover_relocation(struct btrfs_root *root)
4333 LIST_HEAD(reloc_roots);
4334 struct btrfs_key key;
4335 struct btrfs_root *fs_root;
4336 struct btrfs_root *reloc_root;
4337 struct btrfs_path *path;
4338 struct extent_buffer *leaf;
4339 struct reloc_control *rc = NULL;
4340 struct btrfs_trans_handle *trans;
4344 path = btrfs_alloc_path();
4347 path->reada = READA_BACK;
4349 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4350 key.type = BTRFS_ROOT_ITEM_KEY;
4351 key.offset = (u64)-1;
4354 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4361 if (path->slots[0] == 0)
4365 leaf = path->nodes[0];
4366 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4367 btrfs_release_path(path);
4369 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4370 key.type != BTRFS_ROOT_ITEM_KEY)
4373 reloc_root = btrfs_read_fs_root(root, &key);
4374 if (IS_ERR(reloc_root)) {
4375 err = PTR_ERR(reloc_root);
4379 list_add(&reloc_root->root_list, &reloc_roots);
4381 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4382 fs_root = read_fs_root(root->fs_info,
4383 reloc_root->root_key.offset);
4384 if (IS_ERR(fs_root)) {
4385 ret = PTR_ERR(fs_root);
4386 if (ret != -ENOENT) {
4390 ret = mark_garbage_root(reloc_root);
4398 if (key.offset == 0)
4403 btrfs_release_path(path);
4405 if (list_empty(&reloc_roots))
4408 rc = alloc_reloc_control(root->fs_info);
4414 rc->extent_root = root->fs_info->extent_root;
4416 set_reloc_control(rc);
4418 trans = btrfs_join_transaction(rc->extent_root);
4419 if (IS_ERR(trans)) {
4420 unset_reloc_control(rc);
4421 err = PTR_ERR(trans);
4425 rc->merge_reloc_tree = 1;
4427 while (!list_empty(&reloc_roots)) {
4428 reloc_root = list_entry(reloc_roots.next,
4429 struct btrfs_root, root_list);
4430 list_del(&reloc_root->root_list);
4432 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4433 list_add_tail(&reloc_root->root_list,
4438 fs_root = read_fs_root(root->fs_info,
4439 reloc_root->root_key.offset);
4440 if (IS_ERR(fs_root)) {
4441 err = PTR_ERR(fs_root);
4445 err = __add_reloc_root(reloc_root);
4446 BUG_ON(err < 0); /* -ENOMEM or logic error */
4447 fs_root->reloc_root = reloc_root;
4450 err = btrfs_commit_transaction(trans, rc->extent_root);
4454 merge_reloc_roots(rc);
4456 unset_reloc_control(rc);
4458 trans = btrfs_join_transaction(rc->extent_root);
4460 err = PTR_ERR(trans);
4462 err = btrfs_commit_transaction(trans, rc->extent_root);
4466 if (!list_empty(&reloc_roots))
4467 free_reloc_roots(&reloc_roots);
4469 btrfs_free_path(path);
4472 /* cleanup orphan inode in data relocation tree */
4473 fs_root = read_fs_root(root->fs_info,
4474 BTRFS_DATA_RELOC_TREE_OBJECTID);
4475 if (IS_ERR(fs_root))
4476 err = PTR_ERR(fs_root);
4478 err = btrfs_orphan_cleanup(fs_root);
4484 * helper to add ordered checksum for data relocation.
4486 * cloning checksum properly handles the nodatasum extents.
4487 * it also saves CPU time to re-calculate the checksum.
4489 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4491 struct btrfs_ordered_sum *sums;
4492 struct btrfs_ordered_extent *ordered;
4493 struct btrfs_root *root = BTRFS_I(inode)->root;
4499 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4500 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4502 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4503 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4504 disk_bytenr + len - 1, &list, 0);
4508 while (!list_empty(&list)) {
4509 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4510 list_del_init(&sums->list);
4513 * We need to offset the new_bytenr based on where the csum is.
4514 * We need to do this because we will read in entire prealloc
4515 * extents but we may have written to say the middle of the
4516 * prealloc extent, so we need to make sure the csum goes with
4517 * the right disk offset.
4519 * We can do this because the data reloc inode refers strictly
4520 * to the on disk bytes, so we don't have to worry about
4521 * disk_len vs real len like with real inodes since it's all
4524 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4525 sums->bytenr = new_bytenr;
4527 btrfs_add_ordered_sum(inode, ordered, sums);
4530 btrfs_put_ordered_extent(ordered);
4534 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4535 struct btrfs_root *root, struct extent_buffer *buf,
4536 struct extent_buffer *cow)
4538 struct reloc_control *rc;
4539 struct backref_node *node;
4544 rc = root->fs_info->reloc_ctl;
4548 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4549 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4551 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4552 if (buf == root->node)
4553 __update_reloc_root(root, cow->start);
4556 level = btrfs_header_level(buf);
4557 if (btrfs_header_generation(buf) <=
4558 btrfs_root_last_snapshot(&root->root_item))
4561 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4562 rc->create_reloc_tree) {
4563 WARN_ON(!first_cow && level == 0);
4565 node = rc->backref_cache.path[level];
4566 BUG_ON(node->bytenr != buf->start &&
4567 node->new_bytenr != buf->start);
4569 drop_node_buffer(node);
4570 extent_buffer_get(cow);
4572 node->new_bytenr = cow->start;
4574 if (!node->pending) {
4575 list_move_tail(&node->list,
4576 &rc->backref_cache.pending[level]);
4581 __mark_block_processed(rc, node);
4583 if (first_cow && level > 0)
4584 rc->nodes_relocated += buf->len;
4587 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4588 ret = replace_file_extents(trans, rc, root, cow);
4593 * called before creating snapshot. it calculates metadata reservation
4594 * requried for relocating tree blocks in the snapshot
4596 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
4597 u64 *bytes_to_reserve)
4599 struct btrfs_root *root;
4600 struct reloc_control *rc;
4602 root = pending->root;
4603 if (!root->reloc_root)
4606 rc = root->fs_info->reloc_ctl;
4607 if (!rc->merge_reloc_tree)
4610 root = root->reloc_root;
4611 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4613 * relocation is in the stage of merging trees. the space
4614 * used by merging a reloc tree is twice the size of
4615 * relocated tree nodes in the worst case. half for cowing
4616 * the reloc tree, half for cowing the fs tree. the space
4617 * used by cowing the reloc tree will be freed after the
4618 * tree is dropped. if we create snapshot, cowing the fs
4619 * tree may use more space than it frees. so we need
4620 * reserve extra space.
4622 *bytes_to_reserve += rc->nodes_relocated;
4626 * called after snapshot is created. migrate block reservation
4627 * and create reloc root for the newly created snapshot
4629 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4630 struct btrfs_pending_snapshot *pending)
4632 struct btrfs_root *root = pending->root;
4633 struct btrfs_root *reloc_root;
4634 struct btrfs_root *new_root;
4635 struct reloc_control *rc;
4638 if (!root->reloc_root)
4641 rc = root->fs_info->reloc_ctl;
4642 rc->merging_rsv_size += rc->nodes_relocated;
4644 if (rc->merge_reloc_tree) {
4645 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4647 rc->nodes_relocated);
4652 new_root = pending->snap;
4653 reloc_root = create_reloc_root(trans, root->reloc_root,
4654 new_root->root_key.objectid);
4655 if (IS_ERR(reloc_root))
4656 return PTR_ERR(reloc_root);
4658 ret = __add_reloc_root(reloc_root);
4660 new_root->reloc_root = reloc_root;
4662 if (rc->create_reloc_tree)
4663 ret = clone_backref_node(trans, rc, root, reloc_root);