2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node;
44 * present a tree block in the backref cache
47 struct rb_node rb_node;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list;
55 /* list of upper level blocks reference this block */
56 struct list_head upper;
57 /* list of child blocks in the cache */
58 struct list_head lower;
59 /* NULL if this node is not tree root */
60 struct btrfs_root *root;
61 /* extent buffer got by COW the block */
62 struct extent_buffer *eb;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest:1;
69 /* is the extent buffer locked */
70 unsigned int locked:1;
71 /* has the block been processed */
72 unsigned int processed:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached:1;
88 * present a block pointer in the backref cache
91 struct list_head list[2];
92 struct backref_node *node[2];
97 #define RELOCATION_RESERVED_NODES 256
99 struct backref_cache {
100 /* red black tree of all backref nodes in the cache */
101 struct rb_root rb_root;
102 /* for passing backref nodes to btrfs_reloc_cow_block */
103 struct backref_node *path[BTRFS_MAX_LEVEL];
105 * list of blocks that have been cowed but some block
106 * pointers in upper level blocks may not reflect the
109 struct list_head pending[BTRFS_MAX_LEVEL];
110 /* list of backref nodes with no child node */
111 struct list_head leaves;
112 /* list of blocks that have been cowed in current transaction */
113 struct list_head changed;
114 /* list of detached backref node. */
115 struct list_head detached;
124 * map address of tree root to tree
126 struct mapping_node {
127 struct rb_node rb_node;
132 struct mapping_tree {
133 struct rb_root rb_root;
138 * present a tree block to process
141 struct rb_node rb_node;
143 struct btrfs_key key;
144 unsigned int level:8;
145 unsigned int key_ready:1;
148 #define MAX_EXTENTS 128
150 struct file_extent_cluster {
153 u64 boundary[MAX_EXTENTS];
157 struct reloc_control {
158 /* block group to relocate */
159 struct btrfs_block_group_cache *block_group;
161 struct btrfs_root *extent_root;
162 /* inode for moving data */
163 struct inode *data_inode;
165 struct btrfs_block_rsv *block_rsv;
167 struct backref_cache backref_cache;
169 struct file_extent_cluster cluster;
170 /* tree blocks have been processed */
171 struct extent_io_tree processed_blocks;
172 /* map start of tree root to corresponding reloc tree */
173 struct mapping_tree reloc_root_tree;
174 /* list of reloc trees */
175 struct list_head reloc_roots;
176 /* size of metadata reservation for merging reloc trees */
177 u64 merging_rsv_size;
178 /* size of relocated tree nodes */
180 /* reserved size for block group relocation*/
186 unsigned int stage:8;
187 unsigned int create_reloc_tree:1;
188 unsigned int merge_reloc_tree:1;
189 unsigned int found_file_extent:1;
192 /* stages of data relocation */
193 #define MOVE_DATA_EXTENTS 0
194 #define UPDATE_DATA_PTRS 1
196 static void remove_backref_node(struct backref_cache *cache,
197 struct backref_node *node);
198 static void __mark_block_processed(struct reloc_control *rc,
199 struct backref_node *node);
201 static void mapping_tree_init(struct mapping_tree *tree)
203 tree->rb_root = RB_ROOT;
204 spin_lock_init(&tree->lock);
207 static void backref_cache_init(struct backref_cache *cache)
210 cache->rb_root = RB_ROOT;
211 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
212 INIT_LIST_HEAD(&cache->pending[i]);
213 INIT_LIST_HEAD(&cache->changed);
214 INIT_LIST_HEAD(&cache->detached);
215 INIT_LIST_HEAD(&cache->leaves);
218 static void backref_cache_cleanup(struct backref_cache *cache)
220 struct backref_node *node;
223 while (!list_empty(&cache->detached)) {
224 node = list_entry(cache->detached.next,
225 struct backref_node, list);
226 remove_backref_node(cache, node);
229 while (!list_empty(&cache->leaves)) {
230 node = list_entry(cache->leaves.next,
231 struct backref_node, lower);
232 remove_backref_node(cache, node);
235 cache->last_trans = 0;
237 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
238 BUG_ON(!list_empty(&cache->pending[i]));
239 BUG_ON(!list_empty(&cache->changed));
240 BUG_ON(!list_empty(&cache->detached));
241 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
242 BUG_ON(cache->nr_nodes);
243 BUG_ON(cache->nr_edges);
246 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
248 struct backref_node *node;
250 node = kzalloc(sizeof(*node), GFP_NOFS);
252 INIT_LIST_HEAD(&node->list);
253 INIT_LIST_HEAD(&node->upper);
254 INIT_LIST_HEAD(&node->lower);
255 RB_CLEAR_NODE(&node->rb_node);
261 static void free_backref_node(struct backref_cache *cache,
262 struct backref_node *node)
270 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
272 struct backref_edge *edge;
274 edge = kzalloc(sizeof(*edge), GFP_NOFS);
280 static void free_backref_edge(struct backref_cache *cache,
281 struct backref_edge *edge)
289 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
290 struct rb_node *node)
292 struct rb_node **p = &root->rb_node;
293 struct rb_node *parent = NULL;
294 struct tree_entry *entry;
298 entry = rb_entry(parent, struct tree_entry, rb_node);
300 if (bytenr < entry->bytenr)
302 else if (bytenr > entry->bytenr)
308 rb_link_node(node, parent, p);
309 rb_insert_color(node, root);
313 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
315 struct rb_node *n = root->rb_node;
316 struct tree_entry *entry;
319 entry = rb_entry(n, struct tree_entry, rb_node);
321 if (bytenr < entry->bytenr)
323 else if (bytenr > entry->bytenr)
331 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
334 struct btrfs_fs_info *fs_info = NULL;
335 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
338 fs_info = bnode->root->fs_info;
339 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
340 "found at offset %llu", bytenr);
344 * walk up backref nodes until reach node presents tree root
346 static struct backref_node *walk_up_backref(struct backref_node *node,
347 struct backref_edge *edges[],
350 struct backref_edge *edge;
353 while (!list_empty(&node->upper)) {
354 edge = list_entry(node->upper.next,
355 struct backref_edge, list[LOWER]);
357 node = edge->node[UPPER];
359 BUG_ON(node->detached);
365 * walk down backref nodes to find start of next reference path
367 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
370 struct backref_edge *edge;
371 struct backref_node *lower;
375 edge = edges[idx - 1];
376 lower = edge->node[LOWER];
377 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
381 edge = list_entry(edge->list[LOWER].next,
382 struct backref_edge, list[LOWER]);
383 edges[idx - 1] = edge;
385 return edge->node[UPPER];
391 static void unlock_node_buffer(struct backref_node *node)
394 btrfs_tree_unlock(node->eb);
399 static void drop_node_buffer(struct backref_node *node)
402 unlock_node_buffer(node);
403 free_extent_buffer(node->eb);
408 static void drop_backref_node(struct backref_cache *tree,
409 struct backref_node *node)
411 BUG_ON(!list_empty(&node->upper));
413 drop_node_buffer(node);
414 list_del(&node->list);
415 list_del(&node->lower);
416 if (!RB_EMPTY_NODE(&node->rb_node))
417 rb_erase(&node->rb_node, &tree->rb_root);
418 free_backref_node(tree, node);
422 * remove a backref node from the backref cache
424 static void remove_backref_node(struct backref_cache *cache,
425 struct backref_node *node)
427 struct backref_node *upper;
428 struct backref_edge *edge;
433 BUG_ON(!node->lowest && !node->detached);
434 while (!list_empty(&node->upper)) {
435 edge = list_entry(node->upper.next, struct backref_edge,
437 upper = edge->node[UPPER];
438 list_del(&edge->list[LOWER]);
439 list_del(&edge->list[UPPER]);
440 free_backref_edge(cache, edge);
442 if (RB_EMPTY_NODE(&upper->rb_node)) {
443 BUG_ON(!list_empty(&node->upper));
444 drop_backref_node(cache, node);
450 * add the node to leaf node list if no other
451 * child block cached.
453 if (list_empty(&upper->lower)) {
454 list_add_tail(&upper->lower, &cache->leaves);
459 drop_backref_node(cache, node);
462 static void update_backref_node(struct backref_cache *cache,
463 struct backref_node *node, u64 bytenr)
465 struct rb_node *rb_node;
466 rb_erase(&node->rb_node, &cache->rb_root);
467 node->bytenr = bytenr;
468 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
470 backref_tree_panic(rb_node, -EEXIST, bytenr);
474 * update backref cache after a transaction commit
476 static int update_backref_cache(struct btrfs_trans_handle *trans,
477 struct backref_cache *cache)
479 struct backref_node *node;
482 if (cache->last_trans == 0) {
483 cache->last_trans = trans->transid;
487 if (cache->last_trans == trans->transid)
491 * detached nodes are used to avoid unnecessary backref
492 * lookup. transaction commit changes the extent tree.
493 * so the detached nodes are no longer useful.
495 while (!list_empty(&cache->detached)) {
496 node = list_entry(cache->detached.next,
497 struct backref_node, list);
498 remove_backref_node(cache, node);
501 while (!list_empty(&cache->changed)) {
502 node = list_entry(cache->changed.next,
503 struct backref_node, list);
504 list_del_init(&node->list);
505 BUG_ON(node->pending);
506 update_backref_node(cache, node, node->new_bytenr);
510 * some nodes can be left in the pending list if there were
511 * errors during processing the pending nodes.
513 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
514 list_for_each_entry(node, &cache->pending[level], list) {
515 BUG_ON(!node->pending);
516 if (node->bytenr == node->new_bytenr)
518 update_backref_node(cache, node, node->new_bytenr);
522 cache->last_trans = 0;
527 static int should_ignore_root(struct btrfs_root *root)
529 struct btrfs_root *reloc_root;
531 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
534 reloc_root = root->reloc_root;
538 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
539 root->fs_info->running_transaction->transid - 1)
542 * if there is reloc tree and it was created in previous
543 * transaction backref lookup can find the reloc tree,
544 * so backref node for the fs tree root is useless for
550 * find reloc tree by address of tree root
552 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
555 struct rb_node *rb_node;
556 struct mapping_node *node;
557 struct btrfs_root *root = NULL;
559 spin_lock(&rc->reloc_root_tree.lock);
560 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
562 node = rb_entry(rb_node, struct mapping_node, rb_node);
563 root = (struct btrfs_root *)node->data;
565 spin_unlock(&rc->reloc_root_tree.lock);
569 static int is_cowonly_root(u64 root_objectid)
571 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
572 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
573 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
574 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
575 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
576 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
577 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
578 root_objectid == BTRFS_QUOTA_TREE_OBJECTID)
583 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
586 struct btrfs_key key;
588 key.objectid = root_objectid;
589 key.type = BTRFS_ROOT_ITEM_KEY;
590 if (is_cowonly_root(root_objectid))
593 key.offset = (u64)-1;
595 return btrfs_get_fs_root(fs_info, &key, false);
598 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
599 static noinline_for_stack
600 struct btrfs_root *find_tree_root(struct reloc_control *rc,
601 struct extent_buffer *leaf,
602 struct btrfs_extent_ref_v0 *ref0)
604 struct btrfs_root *root;
605 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
606 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
608 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
610 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
611 BUG_ON(IS_ERR(root));
613 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
614 generation != btrfs_root_generation(&root->root_item))
621 static noinline_for_stack
622 int find_inline_backref(struct extent_buffer *leaf, int slot,
623 unsigned long *ptr, unsigned long *end)
625 struct btrfs_key key;
626 struct btrfs_extent_item *ei;
627 struct btrfs_tree_block_info *bi;
630 btrfs_item_key_to_cpu(leaf, &key, slot);
632 item_size = btrfs_item_size_nr(leaf, slot);
633 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
634 if (item_size < sizeof(*ei)) {
635 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
639 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
640 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
641 BTRFS_EXTENT_FLAG_TREE_BLOCK));
643 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
644 item_size <= sizeof(*ei) + sizeof(*bi)) {
645 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
648 if (key.type == BTRFS_METADATA_ITEM_KEY &&
649 item_size <= sizeof(*ei)) {
650 WARN_ON(item_size < sizeof(*ei));
654 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
655 bi = (struct btrfs_tree_block_info *)(ei + 1);
656 *ptr = (unsigned long)(bi + 1);
658 *ptr = (unsigned long)(ei + 1);
660 *end = (unsigned long)ei + item_size;
665 * build backref tree for a given tree block. root of the backref tree
666 * corresponds the tree block, leaves of the backref tree correspond
667 * roots of b-trees that reference the tree block.
669 * the basic idea of this function is check backrefs of a given block
670 * to find upper level blocks that refernece the block, and then check
671 * bakcrefs of these upper level blocks recursively. the recursion stop
672 * when tree root is reached or backrefs for the block is cached.
674 * NOTE: if we find backrefs for a block are cached, we know backrefs
675 * for all upper level blocks that directly/indirectly reference the
676 * block are also cached.
678 static noinline_for_stack
679 struct backref_node *build_backref_tree(struct reloc_control *rc,
680 struct btrfs_key *node_key,
681 int level, u64 bytenr)
683 struct backref_cache *cache = &rc->backref_cache;
684 struct btrfs_path *path1;
685 struct btrfs_path *path2;
686 struct extent_buffer *eb;
687 struct btrfs_root *root;
688 struct backref_node *cur;
689 struct backref_node *upper;
690 struct backref_node *lower;
691 struct backref_node *node = NULL;
692 struct backref_node *exist = NULL;
693 struct backref_edge *edge;
694 struct rb_node *rb_node;
695 struct btrfs_key key;
703 bool need_check = true;
705 path1 = btrfs_alloc_path();
706 path2 = btrfs_alloc_path();
707 if (!path1 || !path2) {
714 node = alloc_backref_node(cache);
720 node->bytenr = bytenr;
727 key.objectid = cur->bytenr;
728 key.type = BTRFS_METADATA_ITEM_KEY;
729 key.offset = (u64)-1;
731 path1->search_commit_root = 1;
732 path1->skip_locking = 1;
733 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
739 BUG_ON(!ret || !path1->slots[0]);
743 WARN_ON(cur->checked);
744 if (!list_empty(&cur->upper)) {
746 * the backref was added previously when processing
747 * backref of type BTRFS_TREE_BLOCK_REF_KEY
749 BUG_ON(!list_is_singular(&cur->upper));
750 edge = list_entry(cur->upper.next, struct backref_edge,
752 BUG_ON(!list_empty(&edge->list[UPPER]));
753 exist = edge->node[UPPER];
755 * add the upper level block to pending list if we need
759 list_add_tail(&edge->list[UPPER], &list);
766 eb = path1->nodes[0];
769 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
770 ret = btrfs_next_leaf(rc->extent_root, path1);
777 eb = path1->nodes[0];
780 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
781 if (key.objectid != cur->bytenr) {
786 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
787 key.type == BTRFS_METADATA_ITEM_KEY) {
788 ret = find_inline_backref(eb, path1->slots[0],
796 /* update key for inline back ref */
797 struct btrfs_extent_inline_ref *iref;
798 iref = (struct btrfs_extent_inline_ref *)ptr;
799 key.type = btrfs_extent_inline_ref_type(eb, iref);
800 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
801 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
802 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
806 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
807 exist->owner == key.offset) ||
808 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
809 exist->bytenr == key.offset))) {
814 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
815 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
816 key.type == BTRFS_EXTENT_REF_V0_KEY) {
817 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
818 struct btrfs_extent_ref_v0 *ref0;
819 ref0 = btrfs_item_ptr(eb, path1->slots[0],
820 struct btrfs_extent_ref_v0);
821 if (key.objectid == key.offset) {
822 root = find_tree_root(rc, eb, ref0);
823 if (root && !should_ignore_root(root))
826 list_add(&cur->list, &useless);
829 if (is_cowonly_root(btrfs_ref_root_v0(eb,
834 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
835 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
837 if (key.objectid == key.offset) {
839 * only root blocks of reloc trees use
840 * backref of this type.
842 root = find_reloc_root(rc, cur->bytenr);
848 edge = alloc_backref_edge(cache);
853 rb_node = tree_search(&cache->rb_root, key.offset);
855 upper = alloc_backref_node(cache);
857 free_backref_edge(cache, edge);
861 upper->bytenr = key.offset;
862 upper->level = cur->level + 1;
864 * backrefs for the upper level block isn't
865 * cached, add the block to pending list
867 list_add_tail(&edge->list[UPPER], &list);
869 upper = rb_entry(rb_node, struct backref_node,
871 BUG_ON(!upper->checked);
872 INIT_LIST_HEAD(&edge->list[UPPER]);
874 list_add_tail(&edge->list[LOWER], &cur->upper);
875 edge->node[LOWER] = cur;
876 edge->node[UPPER] = upper;
879 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
883 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
884 root = read_fs_root(rc->extent_root->fs_info, key.offset);
890 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
893 if (btrfs_root_level(&root->root_item) == cur->level) {
895 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
897 if (should_ignore_root(root))
898 list_add(&cur->list, &useless);
904 level = cur->level + 1;
907 * searching the tree to find upper level blocks
908 * reference the block.
910 path2->search_commit_root = 1;
911 path2->skip_locking = 1;
912 path2->lowest_level = level;
913 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
914 path2->lowest_level = 0;
919 if (ret > 0 && path2->slots[level] > 0)
920 path2->slots[level]--;
922 eb = path2->nodes[level];
923 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
928 for (; level < BTRFS_MAX_LEVEL; level++) {
929 if (!path2->nodes[level]) {
930 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
932 if (should_ignore_root(root))
933 list_add(&lower->list, &useless);
939 edge = alloc_backref_edge(cache);
945 eb = path2->nodes[level];
946 rb_node = tree_search(&cache->rb_root, eb->start);
948 upper = alloc_backref_node(cache);
950 free_backref_edge(cache, edge);
954 upper->bytenr = eb->start;
955 upper->owner = btrfs_header_owner(eb);
956 upper->level = lower->level + 1;
957 if (!test_bit(BTRFS_ROOT_REF_COWS,
962 * if we know the block isn't shared
963 * we can void checking its backrefs.
965 if (btrfs_block_can_be_shared(root, eb))
971 * add the block to pending list if we
972 * need check its backrefs, we only do this once
973 * while walking up a tree as we will catch
974 * anything else later on.
976 if (!upper->checked && need_check) {
978 list_add_tail(&edge->list[UPPER],
981 INIT_LIST_HEAD(&edge->list[UPPER]);
983 upper = rb_entry(rb_node, struct backref_node,
985 BUG_ON(!upper->checked);
986 INIT_LIST_HEAD(&edge->list[UPPER]);
988 upper->owner = btrfs_header_owner(eb);
990 list_add_tail(&edge->list[LOWER], &lower->upper);
991 edge->node[LOWER] = lower;
992 edge->node[UPPER] = upper;
999 btrfs_release_path(path2);
1002 ptr += btrfs_extent_inline_ref_size(key.type);
1012 btrfs_release_path(path1);
1017 /* the pending list isn't empty, take the first block to process */
1018 if (!list_empty(&list)) {
1019 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1020 list_del_init(&edge->list[UPPER]);
1021 cur = edge->node[UPPER];
1026 * everything goes well, connect backref nodes and insert backref nodes
1029 BUG_ON(!node->checked);
1030 cowonly = node->cowonly;
1032 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1035 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1036 list_add_tail(&node->lower, &cache->leaves);
1039 list_for_each_entry(edge, &node->upper, list[LOWER])
1040 list_add_tail(&edge->list[UPPER], &list);
1042 while (!list_empty(&list)) {
1043 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1044 list_del_init(&edge->list[UPPER]);
1045 upper = edge->node[UPPER];
1046 if (upper->detached) {
1047 list_del(&edge->list[LOWER]);
1048 lower = edge->node[LOWER];
1049 free_backref_edge(cache, edge);
1050 if (list_empty(&lower->upper))
1051 list_add(&lower->list, &useless);
1055 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1056 if (upper->lowest) {
1057 list_del_init(&upper->lower);
1061 list_add_tail(&edge->list[UPPER], &upper->lower);
1065 BUG_ON(!upper->checked);
1066 BUG_ON(cowonly != upper->cowonly);
1068 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1071 backref_tree_panic(rb_node, -EEXIST,
1075 list_add_tail(&edge->list[UPPER], &upper->lower);
1077 list_for_each_entry(edge, &upper->upper, list[LOWER])
1078 list_add_tail(&edge->list[UPPER], &list);
1081 * process useless backref nodes. backref nodes for tree leaves
1082 * are deleted from the cache. backref nodes for upper level
1083 * tree blocks are left in the cache to avoid unnecessary backref
1086 while (!list_empty(&useless)) {
1087 upper = list_entry(useless.next, struct backref_node, list);
1088 list_del_init(&upper->list);
1089 BUG_ON(!list_empty(&upper->upper));
1092 if (upper->lowest) {
1093 list_del_init(&upper->lower);
1096 while (!list_empty(&upper->lower)) {
1097 edge = list_entry(upper->lower.next,
1098 struct backref_edge, list[UPPER]);
1099 list_del(&edge->list[UPPER]);
1100 list_del(&edge->list[LOWER]);
1101 lower = edge->node[LOWER];
1102 free_backref_edge(cache, edge);
1104 if (list_empty(&lower->upper))
1105 list_add(&lower->list, &useless);
1107 __mark_block_processed(rc, upper);
1108 if (upper->level > 0) {
1109 list_add(&upper->list, &cache->detached);
1110 upper->detached = 1;
1112 rb_erase(&upper->rb_node, &cache->rb_root);
1113 free_backref_node(cache, upper);
1117 btrfs_free_path(path1);
1118 btrfs_free_path(path2);
1120 while (!list_empty(&useless)) {
1121 lower = list_entry(useless.next,
1122 struct backref_node, upper);
1123 list_del_init(&lower->upper);
1126 INIT_LIST_HEAD(&list);
1128 if (RB_EMPTY_NODE(&upper->rb_node)) {
1129 list_splice_tail(&upper->upper, &list);
1130 free_backref_node(cache, upper);
1133 if (list_empty(&list))
1136 edge = list_entry(list.next, struct backref_edge,
1138 list_del(&edge->list[LOWER]);
1139 upper = edge->node[UPPER];
1140 free_backref_edge(cache, edge);
1142 return ERR_PTR(err);
1144 BUG_ON(node && node->detached);
1149 * helper to add backref node for the newly created snapshot.
1150 * the backref node is created by cloning backref node that
1151 * corresponds to root of source tree
1153 static int clone_backref_node(struct btrfs_trans_handle *trans,
1154 struct reloc_control *rc,
1155 struct btrfs_root *src,
1156 struct btrfs_root *dest)
1158 struct btrfs_root *reloc_root = src->reloc_root;
1159 struct backref_cache *cache = &rc->backref_cache;
1160 struct backref_node *node = NULL;
1161 struct backref_node *new_node;
1162 struct backref_edge *edge;
1163 struct backref_edge *new_edge;
1164 struct rb_node *rb_node;
1166 if (cache->last_trans > 0)
1167 update_backref_cache(trans, cache);
1169 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1171 node = rb_entry(rb_node, struct backref_node, rb_node);
1175 BUG_ON(node->new_bytenr != reloc_root->node->start);
1179 rb_node = tree_search(&cache->rb_root,
1180 reloc_root->commit_root->start);
1182 node = rb_entry(rb_node, struct backref_node,
1184 BUG_ON(node->detached);
1191 new_node = alloc_backref_node(cache);
1195 new_node->bytenr = dest->node->start;
1196 new_node->level = node->level;
1197 new_node->lowest = node->lowest;
1198 new_node->checked = 1;
1199 new_node->root = dest;
1201 if (!node->lowest) {
1202 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1203 new_edge = alloc_backref_edge(cache);
1207 new_edge->node[UPPER] = new_node;
1208 new_edge->node[LOWER] = edge->node[LOWER];
1209 list_add_tail(&new_edge->list[UPPER],
1213 list_add_tail(&new_node->lower, &cache->leaves);
1216 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1217 &new_node->rb_node);
1219 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1221 if (!new_node->lowest) {
1222 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1223 list_add_tail(&new_edge->list[LOWER],
1224 &new_edge->node[LOWER]->upper);
1229 while (!list_empty(&new_node->lower)) {
1230 new_edge = list_entry(new_node->lower.next,
1231 struct backref_edge, list[UPPER]);
1232 list_del(&new_edge->list[UPPER]);
1233 free_backref_edge(cache, new_edge);
1235 free_backref_node(cache, new_node);
1240 * helper to add 'address of tree root -> reloc tree' mapping
1242 static int __must_check __add_reloc_root(struct btrfs_root *root)
1244 struct rb_node *rb_node;
1245 struct mapping_node *node;
1246 struct reloc_control *rc = root->fs_info->reloc_ctl;
1248 node = kmalloc(sizeof(*node), GFP_NOFS);
1252 node->bytenr = root->node->start;
1255 spin_lock(&rc->reloc_root_tree.lock);
1256 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1257 node->bytenr, &node->rb_node);
1258 spin_unlock(&rc->reloc_root_tree.lock);
1260 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1261 "for start=%llu while inserting into relocation "
1262 "tree", node->bytenr);
1267 list_add_tail(&root->root_list, &rc->reloc_roots);
1272 * helper to delete the 'address of tree root -> reloc tree'
1275 static void __del_reloc_root(struct btrfs_root *root)
1277 struct rb_node *rb_node;
1278 struct mapping_node *node = NULL;
1279 struct reloc_control *rc = root->fs_info->reloc_ctl;
1281 spin_lock(&rc->reloc_root_tree.lock);
1282 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1285 node = rb_entry(rb_node, struct mapping_node, rb_node);
1286 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1288 spin_unlock(&rc->reloc_root_tree.lock);
1292 BUG_ON((struct btrfs_root *)node->data != root);
1294 spin_lock(&root->fs_info->trans_lock);
1295 list_del_init(&root->root_list);
1296 spin_unlock(&root->fs_info->trans_lock);
1301 * helper to update the 'address of tree root -> reloc tree'
1304 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1306 struct rb_node *rb_node;
1307 struct mapping_node *node = NULL;
1308 struct reloc_control *rc = root->fs_info->reloc_ctl;
1310 spin_lock(&rc->reloc_root_tree.lock);
1311 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1314 node = rb_entry(rb_node, struct mapping_node, rb_node);
1315 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1317 spin_unlock(&rc->reloc_root_tree.lock);
1321 BUG_ON((struct btrfs_root *)node->data != root);
1323 spin_lock(&rc->reloc_root_tree.lock);
1324 node->bytenr = new_bytenr;
1325 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1326 node->bytenr, &node->rb_node);
1327 spin_unlock(&rc->reloc_root_tree.lock);
1329 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1333 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1334 struct btrfs_root *root, u64 objectid)
1336 struct btrfs_root *reloc_root;
1337 struct extent_buffer *eb;
1338 struct btrfs_root_item *root_item;
1339 struct btrfs_key root_key;
1343 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1346 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1347 root_key.type = BTRFS_ROOT_ITEM_KEY;
1348 root_key.offset = objectid;
1350 if (root->root_key.objectid == objectid) {
1351 /* called by btrfs_init_reloc_root */
1352 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1353 BTRFS_TREE_RELOC_OBJECTID);
1356 last_snap = btrfs_root_last_snapshot(&root->root_item);
1357 btrfs_set_root_last_snapshot(&root->root_item,
1358 trans->transid - 1);
1361 * called by btrfs_reloc_post_snapshot_hook.
1362 * the source tree is a reloc tree, all tree blocks
1363 * modified after it was created have RELOC flag
1364 * set in their headers. so it's OK to not update
1365 * the 'last_snapshot'.
1367 ret = btrfs_copy_root(trans, root, root->node, &eb,
1368 BTRFS_TREE_RELOC_OBJECTID);
1372 memcpy(root_item, &root->root_item, sizeof(*root_item));
1373 btrfs_set_root_bytenr(root_item, eb->start);
1374 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1375 btrfs_set_root_generation(root_item, trans->transid);
1377 if (root->root_key.objectid == objectid) {
1378 btrfs_set_root_refs(root_item, 0);
1379 memset(&root_item->drop_progress, 0,
1380 sizeof(struct btrfs_disk_key));
1381 root_item->drop_level = 0;
1383 * abuse rtransid, it is safe because it is impossible to
1384 * receive data into a relocation tree.
1386 btrfs_set_root_rtransid(root_item, last_snap);
1387 btrfs_set_root_otransid(root_item, trans->transid);
1390 btrfs_tree_unlock(eb);
1391 free_extent_buffer(eb);
1393 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1394 &root_key, root_item);
1398 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1399 BUG_ON(IS_ERR(reloc_root));
1400 reloc_root->last_trans = trans->transid;
1405 * create reloc tree for a given fs tree. reloc tree is just a
1406 * snapshot of the fs tree with special root objectid.
1408 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1409 struct btrfs_root *root)
1411 struct btrfs_root *reloc_root;
1412 struct reloc_control *rc = root->fs_info->reloc_ctl;
1413 struct btrfs_block_rsv *rsv;
1417 if (root->reloc_root) {
1418 reloc_root = root->reloc_root;
1419 reloc_root->last_trans = trans->transid;
1423 if (!rc || !rc->create_reloc_tree ||
1424 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1427 if (!trans->reloc_reserved) {
1428 rsv = trans->block_rsv;
1429 trans->block_rsv = rc->block_rsv;
1432 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1434 trans->block_rsv = rsv;
1436 ret = __add_reloc_root(reloc_root);
1438 root->reloc_root = reloc_root;
1443 * update root item of reloc tree
1445 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1446 struct btrfs_root *root)
1448 struct btrfs_root *reloc_root;
1449 struct btrfs_root_item *root_item;
1452 if (!root->reloc_root)
1455 reloc_root = root->reloc_root;
1456 root_item = &reloc_root->root_item;
1458 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1459 btrfs_root_refs(root_item) == 0) {
1460 root->reloc_root = NULL;
1461 __del_reloc_root(reloc_root);
1464 if (reloc_root->commit_root != reloc_root->node) {
1465 btrfs_set_root_node(root_item, reloc_root->node);
1466 free_extent_buffer(reloc_root->commit_root);
1467 reloc_root->commit_root = btrfs_root_node(reloc_root);
1470 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1471 &reloc_root->root_key, root_item);
1479 * helper to find first cached inode with inode number >= objectid
1482 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1484 struct rb_node *node;
1485 struct rb_node *prev;
1486 struct btrfs_inode *entry;
1487 struct inode *inode;
1489 spin_lock(&root->inode_lock);
1491 node = root->inode_tree.rb_node;
1495 entry = rb_entry(node, struct btrfs_inode, rb_node);
1497 if (objectid < btrfs_ino(&entry->vfs_inode))
1498 node = node->rb_left;
1499 else if (objectid > btrfs_ino(&entry->vfs_inode))
1500 node = node->rb_right;
1506 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1507 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1511 prev = rb_next(prev);
1515 entry = rb_entry(node, struct btrfs_inode, rb_node);
1516 inode = igrab(&entry->vfs_inode);
1518 spin_unlock(&root->inode_lock);
1522 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1523 if (cond_resched_lock(&root->inode_lock))
1526 node = rb_next(node);
1528 spin_unlock(&root->inode_lock);
1532 static int in_block_group(u64 bytenr,
1533 struct btrfs_block_group_cache *block_group)
1535 if (bytenr >= block_group->key.objectid &&
1536 bytenr < block_group->key.objectid + block_group->key.offset)
1542 * get new location of data
1544 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1545 u64 bytenr, u64 num_bytes)
1547 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1548 struct btrfs_path *path;
1549 struct btrfs_file_extent_item *fi;
1550 struct extent_buffer *leaf;
1553 path = btrfs_alloc_path();
1557 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1558 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1567 leaf = path->nodes[0];
1568 fi = btrfs_item_ptr(leaf, path->slots[0],
1569 struct btrfs_file_extent_item);
1571 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1572 btrfs_file_extent_compression(leaf, fi) ||
1573 btrfs_file_extent_encryption(leaf, fi) ||
1574 btrfs_file_extent_other_encoding(leaf, fi));
1576 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1581 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1584 btrfs_free_path(path);
1589 * update file extent items in the tree leaf to point to
1590 * the new locations.
1592 static noinline_for_stack
1593 int replace_file_extents(struct btrfs_trans_handle *trans,
1594 struct reloc_control *rc,
1595 struct btrfs_root *root,
1596 struct extent_buffer *leaf)
1598 struct btrfs_key key;
1599 struct btrfs_file_extent_item *fi;
1600 struct inode *inode = NULL;
1612 if (rc->stage != UPDATE_DATA_PTRS)
1615 /* reloc trees always use full backref */
1616 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1617 parent = leaf->start;
1621 nritems = btrfs_header_nritems(leaf);
1622 for (i = 0; i < nritems; i++) {
1624 btrfs_item_key_to_cpu(leaf, &key, i);
1625 if (key.type != BTRFS_EXTENT_DATA_KEY)
1627 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1628 if (btrfs_file_extent_type(leaf, fi) ==
1629 BTRFS_FILE_EXTENT_INLINE)
1631 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1632 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1635 if (!in_block_group(bytenr, rc->block_group))
1639 * if we are modifying block in fs tree, wait for readpage
1640 * to complete and drop the extent cache
1642 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1644 inode = find_next_inode(root, key.objectid);
1646 } else if (inode && btrfs_ino(inode) < key.objectid) {
1647 btrfs_add_delayed_iput(inode);
1648 inode = find_next_inode(root, key.objectid);
1650 if (inode && btrfs_ino(inode) == key.objectid) {
1652 btrfs_file_extent_num_bytes(leaf, fi);
1653 WARN_ON(!IS_ALIGNED(key.offset,
1655 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1657 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1662 btrfs_drop_extent_cache(inode, key.offset, end,
1664 unlock_extent(&BTRFS_I(inode)->io_tree,
1669 ret = get_new_location(rc->data_inode, &new_bytenr,
1673 * Don't have to abort since we've not changed anything
1674 * in the file extent yet.
1679 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1682 key.offset -= btrfs_file_extent_offset(leaf, fi);
1683 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1685 btrfs_header_owner(leaf),
1686 key.objectid, key.offset, 1);
1688 btrfs_abort_transaction(trans, root, ret);
1692 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1693 parent, btrfs_header_owner(leaf),
1694 key.objectid, key.offset, 1);
1696 btrfs_abort_transaction(trans, root, ret);
1701 btrfs_mark_buffer_dirty(leaf);
1703 btrfs_add_delayed_iput(inode);
1707 static noinline_for_stack
1708 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1709 struct btrfs_path *path, int level)
1711 struct btrfs_disk_key key1;
1712 struct btrfs_disk_key key2;
1713 btrfs_node_key(eb, &key1, slot);
1714 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1715 return memcmp(&key1, &key2, sizeof(key1));
1719 * try to replace tree blocks in fs tree with the new blocks
1720 * in reloc tree. tree blocks haven't been modified since the
1721 * reloc tree was create can be replaced.
1723 * if a block was replaced, level of the block + 1 is returned.
1724 * if no block got replaced, 0 is returned. if there are other
1725 * errors, a negative error number is returned.
1727 static noinline_for_stack
1728 int replace_path(struct btrfs_trans_handle *trans,
1729 struct btrfs_root *dest, struct btrfs_root *src,
1730 struct btrfs_path *path, struct btrfs_key *next_key,
1731 int lowest_level, int max_level)
1733 struct extent_buffer *eb;
1734 struct extent_buffer *parent;
1735 struct btrfs_key key;
1747 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1748 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1750 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1752 slot = path->slots[lowest_level];
1753 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1755 eb = btrfs_lock_root_node(dest);
1756 btrfs_set_lock_blocking(eb);
1757 level = btrfs_header_level(eb);
1759 if (level < lowest_level) {
1760 btrfs_tree_unlock(eb);
1761 free_extent_buffer(eb);
1766 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1769 btrfs_set_lock_blocking(eb);
1772 next_key->objectid = (u64)-1;
1773 next_key->type = (u8)-1;
1774 next_key->offset = (u64)-1;
1779 level = btrfs_header_level(parent);
1780 BUG_ON(level < lowest_level);
1782 ret = btrfs_bin_search(parent, &key, level, &slot);
1783 if (ret && slot > 0)
1786 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1787 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1789 old_bytenr = btrfs_node_blockptr(parent, slot);
1790 blocksize = dest->nodesize;
1791 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1793 if (level <= max_level) {
1794 eb = path->nodes[level];
1795 new_bytenr = btrfs_node_blockptr(eb,
1796 path->slots[level]);
1797 new_ptr_gen = btrfs_node_ptr_generation(eb,
1798 path->slots[level]);
1804 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1809 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1810 memcmp_node_keys(parent, slot, path, level)) {
1811 if (level <= lowest_level) {
1816 eb = read_tree_block(dest, old_bytenr, blocksize,
1818 if (!eb || !extent_buffer_uptodate(eb)) {
1819 ret = (!eb) ? -ENOMEM : -EIO;
1820 free_extent_buffer(eb);
1823 btrfs_tree_lock(eb);
1825 ret = btrfs_cow_block(trans, dest, eb, parent,
1829 btrfs_set_lock_blocking(eb);
1831 btrfs_tree_unlock(parent);
1832 free_extent_buffer(parent);
1839 btrfs_tree_unlock(parent);
1840 free_extent_buffer(parent);
1845 btrfs_node_key_to_cpu(path->nodes[level], &key,
1846 path->slots[level]);
1847 btrfs_release_path(path);
1849 path->lowest_level = level;
1850 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1851 path->lowest_level = 0;
1855 * swap blocks in fs tree and reloc tree.
1857 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1858 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1859 btrfs_mark_buffer_dirty(parent);
1861 btrfs_set_node_blockptr(path->nodes[level],
1862 path->slots[level], old_bytenr);
1863 btrfs_set_node_ptr_generation(path->nodes[level],
1864 path->slots[level], old_ptr_gen);
1865 btrfs_mark_buffer_dirty(path->nodes[level]);
1867 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1868 path->nodes[level]->start,
1869 src->root_key.objectid, level - 1, 0,
1872 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1873 0, dest->root_key.objectid, level - 1,
1877 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1878 path->nodes[level]->start,
1879 src->root_key.objectid, level - 1, 0,
1883 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1884 0, dest->root_key.objectid, level - 1,
1888 btrfs_unlock_up_safe(path, 0);
1893 btrfs_tree_unlock(parent);
1894 free_extent_buffer(parent);
1899 * helper to find next relocated block in reloc tree
1901 static noinline_for_stack
1902 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1905 struct extent_buffer *eb;
1910 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1912 for (i = 0; i < *level; i++) {
1913 free_extent_buffer(path->nodes[i]);
1914 path->nodes[i] = NULL;
1917 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1918 eb = path->nodes[i];
1919 nritems = btrfs_header_nritems(eb);
1920 while (path->slots[i] + 1 < nritems) {
1922 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1929 free_extent_buffer(path->nodes[i]);
1930 path->nodes[i] = NULL;
1936 * walk down reloc tree to find relocated block of lowest level
1938 static noinline_for_stack
1939 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1942 struct extent_buffer *eb = NULL;
1950 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1952 for (i = *level; i > 0; i--) {
1953 eb = path->nodes[i];
1954 nritems = btrfs_header_nritems(eb);
1955 while (path->slots[i] < nritems) {
1956 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1957 if (ptr_gen > last_snapshot)
1961 if (path->slots[i] >= nritems) {
1972 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1973 blocksize = root->nodesize;
1974 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1975 if (!eb || !extent_buffer_uptodate(eb)) {
1976 free_extent_buffer(eb);
1979 BUG_ON(btrfs_header_level(eb) != i - 1);
1980 path->nodes[i - 1] = eb;
1981 path->slots[i - 1] = 0;
1987 * invalidate extent cache for file extents whose key in range of
1988 * [min_key, max_key)
1990 static int invalidate_extent_cache(struct btrfs_root *root,
1991 struct btrfs_key *min_key,
1992 struct btrfs_key *max_key)
1994 struct inode *inode = NULL;
1999 objectid = min_key->objectid;
2004 if (objectid > max_key->objectid)
2007 inode = find_next_inode(root, objectid);
2010 ino = btrfs_ino(inode);
2012 if (ino > max_key->objectid) {
2018 if (!S_ISREG(inode->i_mode))
2021 if (unlikely(min_key->objectid == ino)) {
2022 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2024 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2027 start = min_key->offset;
2028 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2034 if (unlikely(max_key->objectid == ino)) {
2035 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2037 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2040 if (max_key->offset == 0)
2042 end = max_key->offset;
2043 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2050 /* the lock_extent waits for readpage to complete */
2051 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2052 btrfs_drop_extent_cache(inode, start, end, 1);
2053 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2058 static int find_next_key(struct btrfs_path *path, int level,
2059 struct btrfs_key *key)
2062 while (level < BTRFS_MAX_LEVEL) {
2063 if (!path->nodes[level])
2065 if (path->slots[level] + 1 <
2066 btrfs_header_nritems(path->nodes[level])) {
2067 btrfs_node_key_to_cpu(path->nodes[level], key,
2068 path->slots[level] + 1);
2077 * merge the relocated tree blocks in reloc tree with corresponding
2080 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2081 struct btrfs_root *root)
2083 LIST_HEAD(inode_list);
2084 struct btrfs_key key;
2085 struct btrfs_key next_key;
2086 struct btrfs_trans_handle *trans = NULL;
2087 struct btrfs_root *reloc_root;
2088 struct btrfs_root_item *root_item;
2089 struct btrfs_path *path;
2090 struct extent_buffer *leaf;
2098 path = btrfs_alloc_path();
2103 reloc_root = root->reloc_root;
2104 root_item = &reloc_root->root_item;
2106 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2107 level = btrfs_root_level(root_item);
2108 extent_buffer_get(reloc_root->node);
2109 path->nodes[level] = reloc_root->node;
2110 path->slots[level] = 0;
2112 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2114 level = root_item->drop_level;
2116 path->lowest_level = level;
2117 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2118 path->lowest_level = 0;
2120 btrfs_free_path(path);
2124 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2125 path->slots[level]);
2126 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2128 btrfs_unlock_up_safe(path, 0);
2131 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2132 memset(&next_key, 0, sizeof(next_key));
2135 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2136 BTRFS_RESERVE_FLUSH_ALL);
2141 trans = btrfs_start_transaction(root, 0);
2142 if (IS_ERR(trans)) {
2143 err = PTR_ERR(trans);
2147 trans->block_rsv = rc->block_rsv;
2152 ret = walk_down_reloc_tree(reloc_root, path, &level);
2160 if (!find_next_key(path, level, &key) &&
2161 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2164 ret = replace_path(trans, root, reloc_root, path,
2165 &next_key, level, max_level);
2174 btrfs_node_key_to_cpu(path->nodes[level], &key,
2175 path->slots[level]);
2179 ret = walk_up_reloc_tree(reloc_root, path, &level);
2185 * save the merging progress in the drop_progress.
2186 * this is OK since root refs == 1 in this case.
2188 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2189 path->slots[level]);
2190 root_item->drop_level = level;
2192 btrfs_end_transaction_throttle(trans, root);
2195 btrfs_btree_balance_dirty(root);
2197 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2198 invalidate_extent_cache(root, &key, &next_key);
2202 * handle the case only one block in the fs tree need to be
2203 * relocated and the block is tree root.
2205 leaf = btrfs_lock_root_node(root);
2206 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2207 btrfs_tree_unlock(leaf);
2208 free_extent_buffer(leaf);
2212 btrfs_free_path(path);
2215 memset(&root_item->drop_progress, 0,
2216 sizeof(root_item->drop_progress));
2217 root_item->drop_level = 0;
2218 btrfs_set_root_refs(root_item, 0);
2219 btrfs_update_reloc_root(trans, root);
2223 btrfs_end_transaction_throttle(trans, root);
2225 btrfs_btree_balance_dirty(root);
2227 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2228 invalidate_extent_cache(root, &key, &next_key);
2233 static noinline_for_stack
2234 int prepare_to_merge(struct reloc_control *rc, int err)
2236 struct btrfs_root *root = rc->extent_root;
2237 struct btrfs_root *reloc_root;
2238 struct btrfs_trans_handle *trans;
2239 LIST_HEAD(reloc_roots);
2243 mutex_lock(&root->fs_info->reloc_mutex);
2244 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2245 rc->merging_rsv_size += rc->nodes_relocated * 2;
2246 mutex_unlock(&root->fs_info->reloc_mutex);
2250 num_bytes = rc->merging_rsv_size;
2251 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2252 BTRFS_RESERVE_FLUSH_ALL);
2257 trans = btrfs_join_transaction(rc->extent_root);
2258 if (IS_ERR(trans)) {
2260 btrfs_block_rsv_release(rc->extent_root,
2261 rc->block_rsv, num_bytes);
2262 return PTR_ERR(trans);
2266 if (num_bytes != rc->merging_rsv_size) {
2267 btrfs_end_transaction(trans, rc->extent_root);
2268 btrfs_block_rsv_release(rc->extent_root,
2269 rc->block_rsv, num_bytes);
2274 rc->merge_reloc_tree = 1;
2276 while (!list_empty(&rc->reloc_roots)) {
2277 reloc_root = list_entry(rc->reloc_roots.next,
2278 struct btrfs_root, root_list);
2279 list_del_init(&reloc_root->root_list);
2281 root = read_fs_root(reloc_root->fs_info,
2282 reloc_root->root_key.offset);
2283 BUG_ON(IS_ERR(root));
2284 BUG_ON(root->reloc_root != reloc_root);
2287 * set reference count to 1, so btrfs_recover_relocation
2288 * knows it should resumes merging
2291 btrfs_set_root_refs(&reloc_root->root_item, 1);
2292 btrfs_update_reloc_root(trans, root);
2294 list_add(&reloc_root->root_list, &reloc_roots);
2297 list_splice(&reloc_roots, &rc->reloc_roots);
2300 btrfs_commit_transaction(trans, rc->extent_root);
2302 btrfs_end_transaction(trans, rc->extent_root);
2306 static noinline_for_stack
2307 void free_reloc_roots(struct list_head *list)
2309 struct btrfs_root *reloc_root;
2311 while (!list_empty(list)) {
2312 reloc_root = list_entry(list->next, struct btrfs_root,
2314 __del_reloc_root(reloc_root);
2318 static noinline_for_stack
2319 void merge_reloc_roots(struct reloc_control *rc)
2321 struct btrfs_root *root;
2322 struct btrfs_root *reloc_root;
2326 LIST_HEAD(reloc_roots);
2330 root = rc->extent_root;
2333 * this serializes us with btrfs_record_root_in_transaction,
2334 * we have to make sure nobody is in the middle of
2335 * adding their roots to the list while we are
2338 mutex_lock(&root->fs_info->reloc_mutex);
2339 list_splice_init(&rc->reloc_roots, &reloc_roots);
2340 mutex_unlock(&root->fs_info->reloc_mutex);
2342 while (!list_empty(&reloc_roots)) {
2344 reloc_root = list_entry(reloc_roots.next,
2345 struct btrfs_root, root_list);
2347 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2348 root = read_fs_root(reloc_root->fs_info,
2349 reloc_root->root_key.offset);
2350 BUG_ON(IS_ERR(root));
2351 BUG_ON(root->reloc_root != reloc_root);
2353 ret = merge_reloc_root(rc, root);
2355 if (list_empty(&reloc_root->root_list))
2356 list_add_tail(&reloc_root->root_list,
2361 list_del_init(&reloc_root->root_list);
2365 * we keep the old last snapshod transid in rtranid when we
2366 * created the relocation tree.
2368 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2369 otransid = btrfs_root_otransid(&reloc_root->root_item);
2370 objectid = reloc_root->root_key.offset;
2372 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2374 if (list_empty(&reloc_root->root_list))
2375 list_add_tail(&reloc_root->root_list,
2387 btrfs_std_error(root->fs_info, ret);
2388 if (!list_empty(&reloc_roots))
2389 free_reloc_roots(&reloc_roots);
2391 /* new reloc root may be added */
2392 mutex_lock(&root->fs_info->reloc_mutex);
2393 list_splice_init(&rc->reloc_roots, &reloc_roots);
2394 mutex_unlock(&root->fs_info->reloc_mutex);
2395 if (!list_empty(&reloc_roots))
2396 free_reloc_roots(&reloc_roots);
2399 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2402 static void free_block_list(struct rb_root *blocks)
2404 struct tree_block *block;
2405 struct rb_node *rb_node;
2406 while ((rb_node = rb_first(blocks))) {
2407 block = rb_entry(rb_node, struct tree_block, rb_node);
2408 rb_erase(rb_node, blocks);
2413 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2414 struct btrfs_root *reloc_root)
2416 struct btrfs_root *root;
2418 if (reloc_root->last_trans == trans->transid)
2421 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2422 BUG_ON(IS_ERR(root));
2423 BUG_ON(root->reloc_root != reloc_root);
2425 return btrfs_record_root_in_trans(trans, root);
2428 static noinline_for_stack
2429 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2430 struct reloc_control *rc,
2431 struct backref_node *node,
2432 struct backref_edge *edges[])
2434 struct backref_node *next;
2435 struct btrfs_root *root;
2441 next = walk_up_backref(next, edges, &index);
2444 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2446 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2447 record_reloc_root_in_trans(trans, root);
2451 btrfs_record_root_in_trans(trans, root);
2452 root = root->reloc_root;
2454 if (next->new_bytenr != root->node->start) {
2455 BUG_ON(next->new_bytenr);
2456 BUG_ON(!list_empty(&next->list));
2457 next->new_bytenr = root->node->start;
2459 list_add_tail(&next->list,
2460 &rc->backref_cache.changed);
2461 __mark_block_processed(rc, next);
2467 next = walk_down_backref(edges, &index);
2468 if (!next || next->level <= node->level)
2475 /* setup backref node path for btrfs_reloc_cow_block */
2477 rc->backref_cache.path[next->level] = next;
2480 next = edges[index]->node[UPPER];
2486 * select a tree root for relocation. return NULL if the block
2487 * is reference counted. we should use do_relocation() in this
2488 * case. return a tree root pointer if the block isn't reference
2489 * counted. return -ENOENT if the block is root of reloc tree.
2491 static noinline_for_stack
2492 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2493 struct backref_node *node)
2495 struct backref_node *next;
2496 struct btrfs_root *root;
2497 struct btrfs_root *fs_root = NULL;
2498 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2504 next = walk_up_backref(next, edges, &index);
2508 /* no other choice for non-references counted tree */
2509 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2512 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2518 next = walk_down_backref(edges, &index);
2519 if (!next || next->level <= node->level)
2524 return ERR_PTR(-ENOENT);
2528 static noinline_for_stack
2529 u64 calcu_metadata_size(struct reloc_control *rc,
2530 struct backref_node *node, int reserve)
2532 struct backref_node *next = node;
2533 struct backref_edge *edge;
2534 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2538 BUG_ON(reserve && node->processed);
2543 if (next->processed && (reserve || next != node))
2546 num_bytes += rc->extent_root->nodesize;
2548 if (list_empty(&next->upper))
2551 edge = list_entry(next->upper.next,
2552 struct backref_edge, list[LOWER]);
2553 edges[index++] = edge;
2554 next = edge->node[UPPER];
2556 next = walk_down_backref(edges, &index);
2561 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2562 struct reloc_control *rc,
2563 struct backref_node *node)
2565 struct btrfs_root *root = rc->extent_root;
2570 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2572 trans->block_rsv = rc->block_rsv;
2573 rc->reserved_bytes += num_bytes;
2574 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2575 BTRFS_RESERVE_FLUSH_ALL);
2577 if (ret == -EAGAIN) {
2578 tmp = rc->extent_root->nodesize *
2579 RELOCATION_RESERVED_NODES;
2580 while (tmp <= rc->reserved_bytes)
2583 * only one thread can access block_rsv at this point,
2584 * so we don't need hold lock to protect block_rsv.
2585 * we expand more reservation size here to allow enough
2586 * space for relocation and we will return eailer in
2589 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2590 RELOCATION_RESERVED_NODES;
2599 * relocate a block tree, and then update pointers in upper level
2600 * blocks that reference the block to point to the new location.
2602 * if called by link_to_upper, the block has already been relocated.
2603 * in that case this function just updates pointers.
2605 static int do_relocation(struct btrfs_trans_handle *trans,
2606 struct reloc_control *rc,
2607 struct backref_node *node,
2608 struct btrfs_key *key,
2609 struct btrfs_path *path, int lowest)
2611 struct backref_node *upper;
2612 struct backref_edge *edge;
2613 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2614 struct btrfs_root *root;
2615 struct extent_buffer *eb;
2623 BUG_ON(lowest && node->eb);
2625 path->lowest_level = node->level + 1;
2626 rc->backref_cache.path[node->level] = node;
2627 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2630 upper = edge->node[UPPER];
2631 root = select_reloc_root(trans, rc, upper, edges);
2634 if (upper->eb && !upper->locked) {
2636 ret = btrfs_bin_search(upper->eb, key,
2637 upper->level, &slot);
2639 bytenr = btrfs_node_blockptr(upper->eb, slot);
2640 if (node->eb->start == bytenr)
2643 drop_node_buffer(upper);
2647 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2655 upper->eb = path->nodes[upper->level];
2656 path->nodes[upper->level] = NULL;
2658 BUG_ON(upper->eb != path->nodes[upper->level]);
2662 path->locks[upper->level] = 0;
2664 slot = path->slots[upper->level];
2665 btrfs_release_path(path);
2667 ret = btrfs_bin_search(upper->eb, key, upper->level,
2672 bytenr = btrfs_node_blockptr(upper->eb, slot);
2674 BUG_ON(bytenr != node->bytenr);
2676 if (node->eb->start == bytenr)
2680 blocksize = root->nodesize;
2681 generation = btrfs_node_ptr_generation(upper->eb, slot);
2682 eb = read_tree_block(root, bytenr, blocksize, generation);
2683 if (!eb || !extent_buffer_uptodate(eb)) {
2684 free_extent_buffer(eb);
2688 btrfs_tree_lock(eb);
2689 btrfs_set_lock_blocking(eb);
2692 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2694 btrfs_tree_unlock(eb);
2695 free_extent_buffer(eb);
2700 BUG_ON(node->eb != eb);
2702 btrfs_set_node_blockptr(upper->eb, slot,
2704 btrfs_set_node_ptr_generation(upper->eb, slot,
2706 btrfs_mark_buffer_dirty(upper->eb);
2708 ret = btrfs_inc_extent_ref(trans, root,
2709 node->eb->start, blocksize,
2711 btrfs_header_owner(upper->eb),
2715 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2719 if (!upper->pending)
2720 drop_node_buffer(upper);
2722 unlock_node_buffer(upper);
2727 if (!err && node->pending) {
2728 drop_node_buffer(node);
2729 list_move_tail(&node->list, &rc->backref_cache.changed);
2733 path->lowest_level = 0;
2734 BUG_ON(err == -ENOSPC);
2738 static int link_to_upper(struct btrfs_trans_handle *trans,
2739 struct reloc_control *rc,
2740 struct backref_node *node,
2741 struct btrfs_path *path)
2743 struct btrfs_key key;
2745 btrfs_node_key_to_cpu(node->eb, &key, 0);
2746 return do_relocation(trans, rc, node, &key, path, 0);
2749 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2750 struct reloc_control *rc,
2751 struct btrfs_path *path, int err)
2754 struct backref_cache *cache = &rc->backref_cache;
2755 struct backref_node *node;
2759 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2760 while (!list_empty(&cache->pending[level])) {
2761 node = list_entry(cache->pending[level].next,
2762 struct backref_node, list);
2763 list_move_tail(&node->list, &list);
2764 BUG_ON(!node->pending);
2767 ret = link_to_upper(trans, rc, node, path);
2772 list_splice_init(&list, &cache->pending[level]);
2777 static void mark_block_processed(struct reloc_control *rc,
2778 u64 bytenr, u32 blocksize)
2780 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2781 EXTENT_DIRTY, GFP_NOFS);
2784 static void __mark_block_processed(struct reloc_control *rc,
2785 struct backref_node *node)
2788 if (node->level == 0 ||
2789 in_block_group(node->bytenr, rc->block_group)) {
2790 blocksize = rc->extent_root->nodesize;
2791 mark_block_processed(rc, node->bytenr, blocksize);
2793 node->processed = 1;
2797 * mark a block and all blocks directly/indirectly reference the block
2800 static void update_processed_blocks(struct reloc_control *rc,
2801 struct backref_node *node)
2803 struct backref_node *next = node;
2804 struct backref_edge *edge;
2805 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2811 if (next->processed)
2814 __mark_block_processed(rc, next);
2816 if (list_empty(&next->upper))
2819 edge = list_entry(next->upper.next,
2820 struct backref_edge, list[LOWER]);
2821 edges[index++] = edge;
2822 next = edge->node[UPPER];
2824 next = walk_down_backref(edges, &index);
2828 static int tree_block_processed(u64 bytenr, u32 blocksize,
2829 struct reloc_control *rc)
2831 if (test_range_bit(&rc->processed_blocks, bytenr,
2832 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2837 static int get_tree_block_key(struct reloc_control *rc,
2838 struct tree_block *block)
2840 struct extent_buffer *eb;
2842 BUG_ON(block->key_ready);
2843 eb = read_tree_block(rc->extent_root, block->bytenr,
2844 block->key.objectid, block->key.offset);
2845 if (!eb || !extent_buffer_uptodate(eb)) {
2846 free_extent_buffer(eb);
2849 WARN_ON(btrfs_header_level(eb) != block->level);
2850 if (block->level == 0)
2851 btrfs_item_key_to_cpu(eb, &block->key, 0);
2853 btrfs_node_key_to_cpu(eb, &block->key, 0);
2854 free_extent_buffer(eb);
2855 block->key_ready = 1;
2859 static int reada_tree_block(struct reloc_control *rc,
2860 struct tree_block *block)
2862 BUG_ON(block->key_ready);
2863 if (block->key.type == BTRFS_METADATA_ITEM_KEY)
2864 readahead_tree_block(rc->extent_root, block->bytenr,
2865 block->key.objectid,
2866 rc->extent_root->nodesize);
2868 readahead_tree_block(rc->extent_root, block->bytenr,
2869 block->key.objectid, block->key.offset);
2874 * helper function to relocate a tree block
2876 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2877 struct reloc_control *rc,
2878 struct backref_node *node,
2879 struct btrfs_key *key,
2880 struct btrfs_path *path)
2882 struct btrfs_root *root;
2888 BUG_ON(node->processed);
2889 root = select_one_root(trans, node);
2890 if (root == ERR_PTR(-ENOENT)) {
2891 update_processed_blocks(rc, node);
2895 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2896 ret = reserve_metadata_space(trans, rc, node);
2902 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2903 BUG_ON(node->new_bytenr);
2904 BUG_ON(!list_empty(&node->list));
2905 btrfs_record_root_in_trans(trans, root);
2906 root = root->reloc_root;
2907 node->new_bytenr = root->node->start;
2909 list_add_tail(&node->list, &rc->backref_cache.changed);
2911 path->lowest_level = node->level;
2912 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2913 btrfs_release_path(path);
2918 update_processed_blocks(rc, node);
2920 ret = do_relocation(trans, rc, node, key, path, 1);
2923 if (ret || node->level == 0 || node->cowonly)
2924 remove_backref_node(&rc->backref_cache, node);
2929 * relocate a list of blocks
2931 static noinline_for_stack
2932 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2933 struct reloc_control *rc, struct rb_root *blocks)
2935 struct backref_node *node;
2936 struct btrfs_path *path;
2937 struct tree_block *block;
2938 struct rb_node *rb_node;
2942 path = btrfs_alloc_path();
2945 goto out_free_blocks;
2948 rb_node = rb_first(blocks);
2950 block = rb_entry(rb_node, struct tree_block, rb_node);
2951 if (!block->key_ready)
2952 reada_tree_block(rc, block);
2953 rb_node = rb_next(rb_node);
2956 rb_node = rb_first(blocks);
2958 block = rb_entry(rb_node, struct tree_block, rb_node);
2959 if (!block->key_ready) {
2960 err = get_tree_block_key(rc, block);
2964 rb_node = rb_next(rb_node);
2967 rb_node = rb_first(blocks);
2969 block = rb_entry(rb_node, struct tree_block, rb_node);
2971 node = build_backref_tree(rc, &block->key,
2972 block->level, block->bytenr);
2974 err = PTR_ERR(node);
2978 ret = relocate_tree_block(trans, rc, node, &block->key,
2981 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2985 rb_node = rb_next(rb_node);
2988 err = finish_pending_nodes(trans, rc, path, err);
2991 btrfs_free_path(path);
2993 free_block_list(blocks);
2997 static noinline_for_stack
2998 int prealloc_file_extent_cluster(struct inode *inode,
2999 struct file_extent_cluster *cluster)
3004 u64 offset = BTRFS_I(inode)->index_cnt;
3009 BUG_ON(cluster->start != cluster->boundary[0]);
3010 mutex_lock(&inode->i_mutex);
3012 ret = btrfs_check_data_free_space(inode, cluster->end +
3013 1 - cluster->start);
3017 while (nr < cluster->nr) {
3018 start = cluster->boundary[nr] - offset;
3019 if (nr + 1 < cluster->nr)
3020 end = cluster->boundary[nr + 1] - 1 - offset;
3022 end = cluster->end - offset;
3024 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3025 num_bytes = end + 1 - start;
3026 ret = btrfs_prealloc_file_range(inode, 0, start,
3027 num_bytes, num_bytes,
3028 end + 1, &alloc_hint);
3029 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3034 btrfs_free_reserved_data_space(inode, cluster->end +
3035 1 - cluster->start);
3037 mutex_unlock(&inode->i_mutex);
3041 static noinline_for_stack
3042 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3045 struct btrfs_root *root = BTRFS_I(inode)->root;
3046 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3047 struct extent_map *em;
3050 em = alloc_extent_map();
3055 em->len = end + 1 - start;
3056 em->block_len = em->len;
3057 em->block_start = block_start;
3058 em->bdev = root->fs_info->fs_devices->latest_bdev;
3059 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3061 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3063 write_lock(&em_tree->lock);
3064 ret = add_extent_mapping(em_tree, em, 0);
3065 write_unlock(&em_tree->lock);
3066 if (ret != -EEXIST) {
3067 free_extent_map(em);
3070 btrfs_drop_extent_cache(inode, start, end, 0);
3072 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3076 static int relocate_file_extent_cluster(struct inode *inode,
3077 struct file_extent_cluster *cluster)
3081 u64 offset = BTRFS_I(inode)->index_cnt;
3082 unsigned long index;
3083 unsigned long last_index;
3085 struct file_ra_state *ra;
3086 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3093 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3097 ret = prealloc_file_extent_cluster(inode, cluster);
3101 file_ra_state_init(ra, inode->i_mapping);
3103 ret = setup_extent_mapping(inode, cluster->start - offset,
3104 cluster->end - offset, cluster->start);
3108 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3109 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3110 while (index <= last_index) {
3111 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3115 page = find_lock_page(inode->i_mapping, index);
3117 page_cache_sync_readahead(inode->i_mapping,
3119 last_index + 1 - index);
3120 page = find_or_create_page(inode->i_mapping, index,
3123 btrfs_delalloc_release_metadata(inode,
3130 if (PageReadahead(page)) {
3131 page_cache_async_readahead(inode->i_mapping,
3132 ra, NULL, page, index,
3133 last_index + 1 - index);
3136 if (!PageUptodate(page)) {
3137 btrfs_readpage(NULL, page);
3139 if (!PageUptodate(page)) {
3141 page_cache_release(page);
3142 btrfs_delalloc_release_metadata(inode,
3149 page_start = page_offset(page);
3150 page_end = page_start + PAGE_CACHE_SIZE - 1;
3152 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3154 set_page_extent_mapped(page);
3156 if (nr < cluster->nr &&
3157 page_start + offset == cluster->boundary[nr]) {
3158 set_extent_bits(&BTRFS_I(inode)->io_tree,
3159 page_start, page_end,
3160 EXTENT_BOUNDARY, GFP_NOFS);
3164 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3165 set_page_dirty(page);
3167 unlock_extent(&BTRFS_I(inode)->io_tree,
3168 page_start, page_end);
3170 page_cache_release(page);
3173 balance_dirty_pages_ratelimited(inode->i_mapping);
3174 btrfs_throttle(BTRFS_I(inode)->root);
3176 WARN_ON(nr != cluster->nr);
3182 static noinline_for_stack
3183 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3184 struct file_extent_cluster *cluster)
3188 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3189 ret = relocate_file_extent_cluster(inode, cluster);
3196 cluster->start = extent_key->objectid;
3198 BUG_ON(cluster->nr >= MAX_EXTENTS);
3199 cluster->end = extent_key->objectid + extent_key->offset - 1;
3200 cluster->boundary[cluster->nr] = extent_key->objectid;
3203 if (cluster->nr >= MAX_EXTENTS) {
3204 ret = relocate_file_extent_cluster(inode, cluster);
3212 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3213 static int get_ref_objectid_v0(struct reloc_control *rc,
3214 struct btrfs_path *path,
3215 struct btrfs_key *extent_key,
3216 u64 *ref_objectid, int *path_change)
3218 struct btrfs_key key;
3219 struct extent_buffer *leaf;
3220 struct btrfs_extent_ref_v0 *ref0;
3224 leaf = path->nodes[0];
3225 slot = path->slots[0];
3227 if (slot >= btrfs_header_nritems(leaf)) {
3228 ret = btrfs_next_leaf(rc->extent_root, path);
3232 leaf = path->nodes[0];
3233 slot = path->slots[0];
3237 btrfs_item_key_to_cpu(leaf, &key, slot);
3238 if (key.objectid != extent_key->objectid)
3241 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3245 ref0 = btrfs_item_ptr(leaf, slot,
3246 struct btrfs_extent_ref_v0);
3247 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3255 * helper to add a tree block to the list.
3256 * the major work is getting the generation and level of the block
3258 static int add_tree_block(struct reloc_control *rc,
3259 struct btrfs_key *extent_key,
3260 struct btrfs_path *path,
3261 struct rb_root *blocks)
3263 struct extent_buffer *eb;
3264 struct btrfs_extent_item *ei;
3265 struct btrfs_tree_block_info *bi;
3266 struct tree_block *block;
3267 struct rb_node *rb_node;
3272 eb = path->nodes[0];
3273 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3275 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3276 item_size >= sizeof(*ei) + sizeof(*bi)) {
3277 ei = btrfs_item_ptr(eb, path->slots[0],
3278 struct btrfs_extent_item);
3279 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3280 bi = (struct btrfs_tree_block_info *)(ei + 1);
3281 level = btrfs_tree_block_level(eb, bi);
3283 level = (int)extent_key->offset;
3285 generation = btrfs_extent_generation(eb, ei);
3287 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3291 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3292 ret = get_ref_objectid_v0(rc, path, extent_key,
3296 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3297 level = (int)ref_owner;
3298 /* FIXME: get real generation */
3305 btrfs_release_path(path);
3307 BUG_ON(level == -1);
3309 block = kmalloc(sizeof(*block), GFP_NOFS);
3313 block->bytenr = extent_key->objectid;
3314 block->key.objectid = rc->extent_root->nodesize;
3315 block->key.offset = generation;
3316 block->level = level;
3317 block->key_ready = 0;
3319 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3321 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3327 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3329 static int __add_tree_block(struct reloc_control *rc,
3330 u64 bytenr, u32 blocksize,
3331 struct rb_root *blocks)
3333 struct btrfs_path *path;
3334 struct btrfs_key key;
3336 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3339 if (tree_block_processed(bytenr, blocksize, rc))
3342 if (tree_search(blocks, bytenr))
3345 path = btrfs_alloc_path();
3349 key.objectid = bytenr;
3351 key.type = BTRFS_METADATA_ITEM_KEY;
3352 key.offset = (u64)-1;
3354 key.type = BTRFS_EXTENT_ITEM_KEY;
3355 key.offset = blocksize;
3358 path->search_commit_root = 1;
3359 path->skip_locking = 1;
3360 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3364 if (ret > 0 && skinny) {
3365 if (path->slots[0]) {
3367 btrfs_item_key_to_cpu(path->nodes[0], &key,
3369 if (key.objectid == bytenr &&
3370 (key.type == BTRFS_METADATA_ITEM_KEY ||
3371 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3372 key.offset == blocksize)))
3378 btrfs_release_path(path);
3384 ret = add_tree_block(rc, &key, path, blocks);
3386 btrfs_free_path(path);
3391 * helper to check if the block use full backrefs for pointers in it
3393 static int block_use_full_backref(struct reloc_control *rc,
3394 struct extent_buffer *eb)
3399 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3400 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3403 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3404 eb->start, btrfs_header_level(eb), 1,
3408 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3415 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3416 struct inode *inode, u64 ino)
3418 struct btrfs_key key;
3419 struct btrfs_root *root = fs_info->tree_root;
3420 struct btrfs_trans_handle *trans;
3427 key.type = BTRFS_INODE_ITEM_KEY;
3430 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3431 if (IS_ERR(inode) || is_bad_inode(inode)) {
3438 ret = btrfs_check_trunc_cache_free_space(root,
3439 &fs_info->global_block_rsv);
3443 trans = btrfs_join_transaction(root);
3444 if (IS_ERR(trans)) {
3445 ret = PTR_ERR(trans);
3449 ret = btrfs_truncate_free_space_cache(root, trans, inode);
3451 btrfs_end_transaction(trans, root);
3452 btrfs_btree_balance_dirty(root);
3459 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3460 * this function scans fs tree to find blocks reference the data extent
3462 static int find_data_references(struct reloc_control *rc,
3463 struct btrfs_key *extent_key,
3464 struct extent_buffer *leaf,
3465 struct btrfs_extent_data_ref *ref,
3466 struct rb_root *blocks)
3468 struct btrfs_path *path;
3469 struct tree_block *block;
3470 struct btrfs_root *root;
3471 struct btrfs_file_extent_item *fi;
3472 struct rb_node *rb_node;
3473 struct btrfs_key key;
3484 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3485 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3486 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3487 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3490 * This is an extent belonging to the free space cache, lets just delete
3491 * it and redo the search.
3493 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3494 ret = delete_block_group_cache(rc->extent_root->fs_info,
3495 NULL, ref_objectid);
3501 path = btrfs_alloc_path();
3506 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3508 err = PTR_ERR(root);
3512 key.objectid = ref_objectid;
3513 key.type = BTRFS_EXTENT_DATA_KEY;
3514 if (ref_offset > ((u64)-1 << 32))
3517 key.offset = ref_offset;
3519 path->search_commit_root = 1;
3520 path->skip_locking = 1;
3521 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3527 leaf = path->nodes[0];
3528 nritems = btrfs_header_nritems(leaf);
3530 * the references in tree blocks that use full backrefs
3531 * are not counted in
3533 if (block_use_full_backref(rc, leaf))
3537 rb_node = tree_search(blocks, leaf->start);
3542 path->slots[0] = nritems;
3545 while (ref_count > 0) {
3546 while (path->slots[0] >= nritems) {
3547 ret = btrfs_next_leaf(root, path);
3552 if (WARN_ON(ret > 0))
3555 leaf = path->nodes[0];
3556 nritems = btrfs_header_nritems(leaf);
3559 if (block_use_full_backref(rc, leaf))
3563 rb_node = tree_search(blocks, leaf->start);
3568 path->slots[0] = nritems;
3572 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3573 if (WARN_ON(key.objectid != ref_objectid ||
3574 key.type != BTRFS_EXTENT_DATA_KEY))
3577 fi = btrfs_item_ptr(leaf, path->slots[0],
3578 struct btrfs_file_extent_item);
3580 if (btrfs_file_extent_type(leaf, fi) ==
3581 BTRFS_FILE_EXTENT_INLINE)
3584 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3585 extent_key->objectid)
3588 key.offset -= btrfs_file_extent_offset(leaf, fi);
3589 if (key.offset != ref_offset)
3597 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3598 block = kmalloc(sizeof(*block), GFP_NOFS);
3603 block->bytenr = leaf->start;
3604 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3606 block->key_ready = 1;
3607 rb_node = tree_insert(blocks, block->bytenr,
3610 backref_tree_panic(rb_node, -EEXIST,
3616 path->slots[0] = nritems;
3622 btrfs_free_path(path);
3627 * helper to find all tree blocks that reference a given data extent
3629 static noinline_for_stack
3630 int add_data_references(struct reloc_control *rc,
3631 struct btrfs_key *extent_key,
3632 struct btrfs_path *path,
3633 struct rb_root *blocks)
3635 struct btrfs_key key;
3636 struct extent_buffer *eb;
3637 struct btrfs_extent_data_ref *dref;
3638 struct btrfs_extent_inline_ref *iref;
3641 u32 blocksize = rc->extent_root->nodesize;
3645 eb = path->nodes[0];
3646 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3647 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3648 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3649 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3653 ptr += sizeof(struct btrfs_extent_item);
3656 iref = (struct btrfs_extent_inline_ref *)ptr;
3657 key.type = btrfs_extent_inline_ref_type(eb, iref);
3658 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3659 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3660 ret = __add_tree_block(rc, key.offset, blocksize,
3662 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3663 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3664 ret = find_data_references(rc, extent_key,
3673 ptr += btrfs_extent_inline_ref_size(key.type);
3679 eb = path->nodes[0];
3680 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3681 ret = btrfs_next_leaf(rc->extent_root, path);
3688 eb = path->nodes[0];
3691 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3692 if (key.objectid != extent_key->objectid)
3695 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3696 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3697 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3699 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3700 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3702 ret = __add_tree_block(rc, key.offset, blocksize,
3704 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3705 dref = btrfs_item_ptr(eb, path->slots[0],
3706 struct btrfs_extent_data_ref);
3707 ret = find_data_references(rc, extent_key,
3719 btrfs_release_path(path);
3721 free_block_list(blocks);
3726 * helper to find next unprocessed extent
3728 static noinline_for_stack
3729 int find_next_extent(struct btrfs_trans_handle *trans,
3730 struct reloc_control *rc, struct btrfs_path *path,
3731 struct btrfs_key *extent_key)
3733 struct btrfs_key key;
3734 struct extent_buffer *leaf;
3735 u64 start, end, last;
3738 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3741 if (rc->search_start >= last) {
3746 key.objectid = rc->search_start;
3747 key.type = BTRFS_EXTENT_ITEM_KEY;
3750 path->search_commit_root = 1;
3751 path->skip_locking = 1;
3752 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3757 leaf = path->nodes[0];
3758 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3759 ret = btrfs_next_leaf(rc->extent_root, path);
3762 leaf = path->nodes[0];
3765 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3766 if (key.objectid >= last) {
3771 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3772 key.type != BTRFS_METADATA_ITEM_KEY) {
3777 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3778 key.objectid + key.offset <= rc->search_start) {
3783 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3784 key.objectid + rc->extent_root->nodesize <=
3790 ret = find_first_extent_bit(&rc->processed_blocks,
3791 key.objectid, &start, &end,
3792 EXTENT_DIRTY, NULL);
3794 if (ret == 0 && start <= key.objectid) {
3795 btrfs_release_path(path);
3796 rc->search_start = end + 1;
3798 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3799 rc->search_start = key.objectid + key.offset;
3801 rc->search_start = key.objectid +
3802 rc->extent_root->nodesize;
3803 memcpy(extent_key, &key, sizeof(key));
3807 btrfs_release_path(path);
3811 static void set_reloc_control(struct reloc_control *rc)
3813 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3815 mutex_lock(&fs_info->reloc_mutex);
3816 fs_info->reloc_ctl = rc;
3817 mutex_unlock(&fs_info->reloc_mutex);
3820 static void unset_reloc_control(struct reloc_control *rc)
3822 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3824 mutex_lock(&fs_info->reloc_mutex);
3825 fs_info->reloc_ctl = NULL;
3826 mutex_unlock(&fs_info->reloc_mutex);
3829 static int check_extent_flags(u64 flags)
3831 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3832 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3834 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3835 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3837 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3838 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3843 static noinline_for_stack
3844 int prepare_to_relocate(struct reloc_control *rc)
3846 struct btrfs_trans_handle *trans;
3848 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3849 BTRFS_BLOCK_RSV_TEMP);
3853 memset(&rc->cluster, 0, sizeof(rc->cluster));
3854 rc->search_start = rc->block_group->key.objectid;
3855 rc->extents_found = 0;
3856 rc->nodes_relocated = 0;
3857 rc->merging_rsv_size = 0;
3858 rc->reserved_bytes = 0;
3859 rc->block_rsv->size = rc->extent_root->nodesize *
3860 RELOCATION_RESERVED_NODES;
3862 rc->create_reloc_tree = 1;
3863 set_reloc_control(rc);
3865 trans = btrfs_join_transaction(rc->extent_root);
3866 if (IS_ERR(trans)) {
3867 unset_reloc_control(rc);
3869 * extent tree is not a ref_cow tree and has no reloc_root to
3870 * cleanup. And callers are responsible to free the above
3873 return PTR_ERR(trans);
3875 btrfs_commit_transaction(trans, rc->extent_root);
3879 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3881 struct rb_root blocks = RB_ROOT;
3882 struct btrfs_key key;
3883 struct btrfs_trans_handle *trans = NULL;
3884 struct btrfs_path *path;
3885 struct btrfs_extent_item *ei;
3892 path = btrfs_alloc_path();
3897 ret = prepare_to_relocate(rc);
3904 rc->reserved_bytes = 0;
3905 ret = btrfs_block_rsv_refill(rc->extent_root,
3906 rc->block_rsv, rc->block_rsv->size,
3907 BTRFS_RESERVE_FLUSH_ALL);
3913 trans = btrfs_start_transaction(rc->extent_root, 0);
3914 if (IS_ERR(trans)) {
3915 err = PTR_ERR(trans);
3920 if (update_backref_cache(trans, &rc->backref_cache)) {
3921 btrfs_end_transaction(trans, rc->extent_root);
3925 ret = find_next_extent(trans, rc, path, &key);
3931 rc->extents_found++;
3933 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3934 struct btrfs_extent_item);
3935 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3936 if (item_size >= sizeof(*ei)) {
3937 flags = btrfs_extent_flags(path->nodes[0], ei);
3938 ret = check_extent_flags(flags);
3942 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3944 int path_change = 0;
3947 sizeof(struct btrfs_extent_item_v0));
3948 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3950 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3951 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3953 flags = BTRFS_EXTENT_FLAG_DATA;
3956 btrfs_release_path(path);
3958 path->search_commit_root = 1;
3959 path->skip_locking = 1;
3960 ret = btrfs_search_slot(NULL, rc->extent_root,
3973 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3974 ret = add_tree_block(rc, &key, path, &blocks);
3975 } else if (rc->stage == UPDATE_DATA_PTRS &&
3976 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3977 ret = add_data_references(rc, &key, path, &blocks);
3979 btrfs_release_path(path);
3987 if (!RB_EMPTY_ROOT(&blocks)) {
3988 ret = relocate_tree_blocks(trans, rc, &blocks);
3991 * if we fail to relocate tree blocks, force to update
3992 * backref cache when committing transaction.
3994 rc->backref_cache.last_trans = trans->transid - 1;
3996 if (ret != -EAGAIN) {
4000 rc->extents_found--;
4001 rc->search_start = key.objectid;
4005 btrfs_end_transaction_throttle(trans, rc->extent_root);
4006 btrfs_btree_balance_dirty(rc->extent_root);
4009 if (rc->stage == MOVE_DATA_EXTENTS &&
4010 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4011 rc->found_file_extent = 1;
4012 ret = relocate_data_extent(rc->data_inode,
4013 &key, &rc->cluster);
4020 if (trans && progress && err == -ENOSPC) {
4021 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4022 rc->block_group->flags);
4030 btrfs_release_path(path);
4031 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4035 btrfs_end_transaction_throttle(trans, rc->extent_root);
4036 btrfs_btree_balance_dirty(rc->extent_root);
4040 ret = relocate_file_extent_cluster(rc->data_inode,
4046 rc->create_reloc_tree = 0;
4047 set_reloc_control(rc);
4049 backref_cache_cleanup(&rc->backref_cache);
4050 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4052 err = prepare_to_merge(rc, err);
4054 merge_reloc_roots(rc);
4056 rc->merge_reloc_tree = 0;
4057 unset_reloc_control(rc);
4058 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4060 /* get rid of pinned extents */
4061 trans = btrfs_join_transaction(rc->extent_root);
4063 err = PTR_ERR(trans);
4065 btrfs_commit_transaction(trans, rc->extent_root);
4067 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4068 btrfs_free_path(path);
4072 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4073 struct btrfs_root *root, u64 objectid)
4075 struct btrfs_path *path;
4076 struct btrfs_inode_item *item;
4077 struct extent_buffer *leaf;
4080 path = btrfs_alloc_path();
4084 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4088 leaf = path->nodes[0];
4089 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4090 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4091 btrfs_set_inode_generation(leaf, item, 1);
4092 btrfs_set_inode_size(leaf, item, 0);
4093 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4094 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4095 BTRFS_INODE_PREALLOC);
4096 btrfs_mark_buffer_dirty(leaf);
4098 btrfs_free_path(path);
4103 * helper to create inode for data relocation.
4104 * the inode is in data relocation tree and its link count is 0
4106 static noinline_for_stack
4107 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4108 struct btrfs_block_group_cache *group)
4110 struct inode *inode = NULL;
4111 struct btrfs_trans_handle *trans;
4112 struct btrfs_root *root;
4113 struct btrfs_key key;
4114 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4117 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4119 return ERR_CAST(root);
4121 trans = btrfs_start_transaction(root, 6);
4123 return ERR_CAST(trans);
4125 err = btrfs_find_free_objectid(root, &objectid);
4129 err = __insert_orphan_inode(trans, root, objectid);
4132 key.objectid = objectid;
4133 key.type = BTRFS_INODE_ITEM_KEY;
4135 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4136 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4137 BTRFS_I(inode)->index_cnt = group->key.objectid;
4139 err = btrfs_orphan_add(trans, inode);
4141 btrfs_end_transaction(trans, root);
4142 btrfs_btree_balance_dirty(root);
4146 inode = ERR_PTR(err);
4151 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4153 struct reloc_control *rc;
4155 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4159 INIT_LIST_HEAD(&rc->reloc_roots);
4160 backref_cache_init(&rc->backref_cache);
4161 mapping_tree_init(&rc->reloc_root_tree);
4162 extent_io_tree_init(&rc->processed_blocks,
4163 fs_info->btree_inode->i_mapping);
4168 * function to relocate all extents in a block group.
4170 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4172 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4173 struct reloc_control *rc;
4174 struct inode *inode;
4175 struct btrfs_path *path;
4180 rc = alloc_reloc_control(fs_info);
4184 rc->extent_root = extent_root;
4186 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4187 BUG_ON(!rc->block_group);
4189 if (!rc->block_group->ro) {
4190 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4198 path = btrfs_alloc_path();
4204 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4206 btrfs_free_path(path);
4209 ret = delete_block_group_cache(fs_info, inode, 0);
4211 ret = PTR_ERR(inode);
4213 if (ret && ret != -ENOENT) {
4218 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4219 if (IS_ERR(rc->data_inode)) {
4220 err = PTR_ERR(rc->data_inode);
4221 rc->data_inode = NULL;
4225 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
4226 rc->block_group->key.objectid, rc->block_group->flags);
4228 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
4233 btrfs_wait_ordered_roots(fs_info, -1);
4236 mutex_lock(&fs_info->cleaner_mutex);
4237 ret = relocate_block_group(rc);
4238 mutex_unlock(&fs_info->cleaner_mutex);
4244 if (rc->extents_found == 0)
4247 btrfs_info(extent_root->fs_info, "found %llu extents",
4250 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4251 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4257 invalidate_mapping_pages(rc->data_inode->i_mapping,
4259 rc->stage = UPDATE_DATA_PTRS;
4263 WARN_ON(rc->block_group->pinned > 0);
4264 WARN_ON(rc->block_group->reserved > 0);
4265 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4268 btrfs_set_block_group_rw(extent_root, rc->block_group);
4269 iput(rc->data_inode);
4270 btrfs_put_block_group(rc->block_group);
4275 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4277 struct btrfs_trans_handle *trans;
4280 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4282 return PTR_ERR(trans);
4284 memset(&root->root_item.drop_progress, 0,
4285 sizeof(root->root_item.drop_progress));
4286 root->root_item.drop_level = 0;
4287 btrfs_set_root_refs(&root->root_item, 0);
4288 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4289 &root->root_key, &root->root_item);
4291 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4298 * recover relocation interrupted by system crash.
4300 * this function resumes merging reloc trees with corresponding fs trees.
4301 * this is important for keeping the sharing of tree blocks
4303 int btrfs_recover_relocation(struct btrfs_root *root)
4305 LIST_HEAD(reloc_roots);
4306 struct btrfs_key key;
4307 struct btrfs_root *fs_root;
4308 struct btrfs_root *reloc_root;
4309 struct btrfs_path *path;
4310 struct extent_buffer *leaf;
4311 struct reloc_control *rc = NULL;
4312 struct btrfs_trans_handle *trans;
4316 path = btrfs_alloc_path();
4321 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4322 key.type = BTRFS_ROOT_ITEM_KEY;
4323 key.offset = (u64)-1;
4326 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4333 if (path->slots[0] == 0)
4337 leaf = path->nodes[0];
4338 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4339 btrfs_release_path(path);
4341 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4342 key.type != BTRFS_ROOT_ITEM_KEY)
4345 reloc_root = btrfs_read_fs_root(root, &key);
4346 if (IS_ERR(reloc_root)) {
4347 err = PTR_ERR(reloc_root);
4351 list_add(&reloc_root->root_list, &reloc_roots);
4353 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4354 fs_root = read_fs_root(root->fs_info,
4355 reloc_root->root_key.offset);
4356 if (IS_ERR(fs_root)) {
4357 ret = PTR_ERR(fs_root);
4358 if (ret != -ENOENT) {
4362 ret = mark_garbage_root(reloc_root);
4370 if (key.offset == 0)
4375 btrfs_release_path(path);
4377 if (list_empty(&reloc_roots))
4380 rc = alloc_reloc_control(root->fs_info);
4386 rc->extent_root = root->fs_info->extent_root;
4388 set_reloc_control(rc);
4390 trans = btrfs_join_transaction(rc->extent_root);
4391 if (IS_ERR(trans)) {
4392 unset_reloc_control(rc);
4393 err = PTR_ERR(trans);
4397 rc->merge_reloc_tree = 1;
4399 while (!list_empty(&reloc_roots)) {
4400 reloc_root = list_entry(reloc_roots.next,
4401 struct btrfs_root, root_list);
4402 list_del(&reloc_root->root_list);
4404 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4405 list_add_tail(&reloc_root->root_list,
4410 fs_root = read_fs_root(root->fs_info,
4411 reloc_root->root_key.offset);
4412 if (IS_ERR(fs_root)) {
4413 err = PTR_ERR(fs_root);
4417 err = __add_reloc_root(reloc_root);
4418 BUG_ON(err < 0); /* -ENOMEM or logic error */
4419 fs_root->reloc_root = reloc_root;
4422 err = btrfs_commit_transaction(trans, rc->extent_root);
4426 merge_reloc_roots(rc);
4428 unset_reloc_control(rc);
4430 trans = btrfs_join_transaction(rc->extent_root);
4432 err = PTR_ERR(trans);
4434 err = btrfs_commit_transaction(trans, rc->extent_root);
4438 if (!list_empty(&reloc_roots))
4439 free_reloc_roots(&reloc_roots);
4441 btrfs_free_path(path);
4444 /* cleanup orphan inode in data relocation tree */
4445 fs_root = read_fs_root(root->fs_info,
4446 BTRFS_DATA_RELOC_TREE_OBJECTID);
4447 if (IS_ERR(fs_root))
4448 err = PTR_ERR(fs_root);
4450 err = btrfs_orphan_cleanup(fs_root);
4456 * helper to add ordered checksum for data relocation.
4458 * cloning checksum properly handles the nodatasum extents.
4459 * it also saves CPU time to re-calculate the checksum.
4461 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4463 struct btrfs_ordered_sum *sums;
4464 struct btrfs_ordered_extent *ordered;
4465 struct btrfs_root *root = BTRFS_I(inode)->root;
4471 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4472 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4474 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4475 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4476 disk_bytenr + len - 1, &list, 0);
4480 while (!list_empty(&list)) {
4481 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4482 list_del_init(&sums->list);
4485 * We need to offset the new_bytenr based on where the csum is.
4486 * We need to do this because we will read in entire prealloc
4487 * extents but we may have written to say the middle of the
4488 * prealloc extent, so we need to make sure the csum goes with
4489 * the right disk offset.
4491 * We can do this because the data reloc inode refers strictly
4492 * to the on disk bytes, so we don't have to worry about
4493 * disk_len vs real len like with real inodes since it's all
4496 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4497 sums->bytenr = new_bytenr;
4499 btrfs_add_ordered_sum(inode, ordered, sums);
4502 btrfs_put_ordered_extent(ordered);
4506 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4507 struct btrfs_root *root, struct extent_buffer *buf,
4508 struct extent_buffer *cow)
4510 struct reloc_control *rc;
4511 struct backref_node *node;
4516 rc = root->fs_info->reloc_ctl;
4520 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4521 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4523 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4524 if (buf == root->node)
4525 __update_reloc_root(root, cow->start);
4528 level = btrfs_header_level(buf);
4529 if (btrfs_header_generation(buf) <=
4530 btrfs_root_last_snapshot(&root->root_item))
4533 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4534 rc->create_reloc_tree) {
4535 WARN_ON(!first_cow && level == 0);
4537 node = rc->backref_cache.path[level];
4538 BUG_ON(node->bytenr != buf->start &&
4539 node->new_bytenr != buf->start);
4541 drop_node_buffer(node);
4542 extent_buffer_get(cow);
4544 node->new_bytenr = cow->start;
4546 if (!node->pending) {
4547 list_move_tail(&node->list,
4548 &rc->backref_cache.pending[level]);
4553 __mark_block_processed(rc, node);
4555 if (first_cow && level > 0)
4556 rc->nodes_relocated += buf->len;
4559 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4560 ret = replace_file_extents(trans, rc, root, cow);
4565 * called before creating snapshot. it calculates metadata reservation
4566 * requried for relocating tree blocks in the snapshot
4568 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4569 struct btrfs_pending_snapshot *pending,
4570 u64 *bytes_to_reserve)
4572 struct btrfs_root *root;
4573 struct reloc_control *rc;
4575 root = pending->root;
4576 if (!root->reloc_root)
4579 rc = root->fs_info->reloc_ctl;
4580 if (!rc->merge_reloc_tree)
4583 root = root->reloc_root;
4584 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4586 * relocation is in the stage of merging trees. the space
4587 * used by merging a reloc tree is twice the size of
4588 * relocated tree nodes in the worst case. half for cowing
4589 * the reloc tree, half for cowing the fs tree. the space
4590 * used by cowing the reloc tree will be freed after the
4591 * tree is dropped. if we create snapshot, cowing the fs
4592 * tree may use more space than it frees. so we need
4593 * reserve extra space.
4595 *bytes_to_reserve += rc->nodes_relocated;
4599 * called after snapshot is created. migrate block reservation
4600 * and create reloc root for the newly created snapshot
4602 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4603 struct btrfs_pending_snapshot *pending)
4605 struct btrfs_root *root = pending->root;
4606 struct btrfs_root *reloc_root;
4607 struct btrfs_root *new_root;
4608 struct reloc_control *rc;
4611 if (!root->reloc_root)
4614 rc = root->fs_info->reloc_ctl;
4615 rc->merging_rsv_size += rc->nodes_relocated;
4617 if (rc->merge_reloc_tree) {
4618 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4620 rc->nodes_relocated);
4625 new_root = pending->snap;
4626 reloc_root = create_reloc_root(trans, root->reloc_root,
4627 new_root->root_key.objectid);
4628 if (IS_ERR(reloc_root))
4629 return PTR_ERR(reloc_root);
4631 ret = __add_reloc_root(reloc_root);
4633 new_root->reloc_root = reloc_root;
4635 if (rc->create_reloc_tree)
4636 ret = clone_backref_node(trans, rc, root, reloc_root);