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\n", 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;
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 (root->ref_cows &&
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);
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;
961 * if we know the block isn't shared
962 * we can void checking its backrefs.
964 if (btrfs_block_can_be_shared(root, eb))
970 * add the block to pending list if we
971 * need check its backrefs, we only do this once
972 * while walking up a tree as we will catch
973 * anything else later on.
975 if (!upper->checked && need_check) {
977 list_add_tail(&edge->list[UPPER],
980 INIT_LIST_HEAD(&edge->list[UPPER]);
982 upper = rb_entry(rb_node, struct backref_node,
984 BUG_ON(!upper->checked);
985 INIT_LIST_HEAD(&edge->list[UPPER]);
987 upper->owner = btrfs_header_owner(eb);
989 list_add_tail(&edge->list[LOWER], &lower->upper);
990 edge->node[LOWER] = lower;
991 edge->node[UPPER] = upper;
998 btrfs_release_path(path2);
1001 ptr += btrfs_extent_inline_ref_size(key.type);
1011 btrfs_release_path(path1);
1016 /* the pending list isn't empty, take the first block to process */
1017 if (!list_empty(&list)) {
1018 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1019 list_del_init(&edge->list[UPPER]);
1020 cur = edge->node[UPPER];
1025 * everything goes well, connect backref nodes and insert backref nodes
1028 BUG_ON(!node->checked);
1029 cowonly = node->cowonly;
1031 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1034 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1035 list_add_tail(&node->lower, &cache->leaves);
1038 list_for_each_entry(edge, &node->upper, list[LOWER])
1039 list_add_tail(&edge->list[UPPER], &list);
1041 while (!list_empty(&list)) {
1042 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1043 list_del_init(&edge->list[UPPER]);
1044 upper = edge->node[UPPER];
1045 if (upper->detached) {
1046 list_del(&edge->list[LOWER]);
1047 lower = edge->node[LOWER];
1048 free_backref_edge(cache, edge);
1049 if (list_empty(&lower->upper))
1050 list_add(&lower->list, &useless);
1054 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1055 if (upper->lowest) {
1056 list_del_init(&upper->lower);
1060 list_add_tail(&edge->list[UPPER], &upper->lower);
1064 BUG_ON(!upper->checked);
1065 BUG_ON(cowonly != upper->cowonly);
1067 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1070 backref_tree_panic(rb_node, -EEXIST,
1074 list_add_tail(&edge->list[UPPER], &upper->lower);
1076 list_for_each_entry(edge, &upper->upper, list[LOWER])
1077 list_add_tail(&edge->list[UPPER], &list);
1080 * process useless backref nodes. backref nodes for tree leaves
1081 * are deleted from the cache. backref nodes for upper level
1082 * tree blocks are left in the cache to avoid unnecessary backref
1085 while (!list_empty(&useless)) {
1086 upper = list_entry(useless.next, struct backref_node, list);
1087 list_del_init(&upper->list);
1088 BUG_ON(!list_empty(&upper->upper));
1091 if (upper->lowest) {
1092 list_del_init(&upper->lower);
1095 while (!list_empty(&upper->lower)) {
1096 edge = list_entry(upper->lower.next,
1097 struct backref_edge, list[UPPER]);
1098 list_del(&edge->list[UPPER]);
1099 list_del(&edge->list[LOWER]);
1100 lower = edge->node[LOWER];
1101 free_backref_edge(cache, edge);
1103 if (list_empty(&lower->upper))
1104 list_add(&lower->list, &useless);
1106 __mark_block_processed(rc, upper);
1107 if (upper->level > 0) {
1108 list_add(&upper->list, &cache->detached);
1109 upper->detached = 1;
1111 rb_erase(&upper->rb_node, &cache->rb_root);
1112 free_backref_node(cache, upper);
1116 btrfs_free_path(path1);
1117 btrfs_free_path(path2);
1119 while (!list_empty(&useless)) {
1120 lower = list_entry(useless.next,
1121 struct backref_node, upper);
1122 list_del_init(&lower->upper);
1125 INIT_LIST_HEAD(&list);
1127 if (RB_EMPTY_NODE(&upper->rb_node)) {
1128 list_splice_tail(&upper->upper, &list);
1129 free_backref_node(cache, upper);
1132 if (list_empty(&list))
1135 edge = list_entry(list.next, struct backref_edge,
1137 list_del(&edge->list[LOWER]);
1138 upper = edge->node[UPPER];
1139 free_backref_edge(cache, edge);
1141 return ERR_PTR(err);
1143 BUG_ON(node && node->detached);
1148 * helper to add backref node for the newly created snapshot.
1149 * the backref node is created by cloning backref node that
1150 * corresponds to root of source tree
1152 static int clone_backref_node(struct btrfs_trans_handle *trans,
1153 struct reloc_control *rc,
1154 struct btrfs_root *src,
1155 struct btrfs_root *dest)
1157 struct btrfs_root *reloc_root = src->reloc_root;
1158 struct backref_cache *cache = &rc->backref_cache;
1159 struct backref_node *node = NULL;
1160 struct backref_node *new_node;
1161 struct backref_edge *edge;
1162 struct backref_edge *new_edge;
1163 struct rb_node *rb_node;
1165 if (cache->last_trans > 0)
1166 update_backref_cache(trans, cache);
1168 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1170 node = rb_entry(rb_node, struct backref_node, rb_node);
1174 BUG_ON(node->new_bytenr != reloc_root->node->start);
1178 rb_node = tree_search(&cache->rb_root,
1179 reloc_root->commit_root->start);
1181 node = rb_entry(rb_node, struct backref_node,
1183 BUG_ON(node->detached);
1190 new_node = alloc_backref_node(cache);
1194 new_node->bytenr = dest->node->start;
1195 new_node->level = node->level;
1196 new_node->lowest = node->lowest;
1197 new_node->checked = 1;
1198 new_node->root = dest;
1200 if (!node->lowest) {
1201 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1202 new_edge = alloc_backref_edge(cache);
1206 new_edge->node[UPPER] = new_node;
1207 new_edge->node[LOWER] = edge->node[LOWER];
1208 list_add_tail(&new_edge->list[UPPER],
1212 list_add_tail(&new_node->lower, &cache->leaves);
1215 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1216 &new_node->rb_node);
1218 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1220 if (!new_node->lowest) {
1221 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1222 list_add_tail(&new_edge->list[LOWER],
1223 &new_edge->node[LOWER]->upper);
1228 while (!list_empty(&new_node->lower)) {
1229 new_edge = list_entry(new_node->lower.next,
1230 struct backref_edge, list[UPPER]);
1231 list_del(&new_edge->list[UPPER]);
1232 free_backref_edge(cache, new_edge);
1234 free_backref_node(cache, new_node);
1239 * helper to add 'address of tree root -> reloc tree' mapping
1241 static int __must_check __add_reloc_root(struct btrfs_root *root)
1243 struct rb_node *rb_node;
1244 struct mapping_node *node;
1245 struct reloc_control *rc = root->fs_info->reloc_ctl;
1247 node = kmalloc(sizeof(*node), GFP_NOFS);
1251 node->bytenr = root->node->start;
1254 spin_lock(&rc->reloc_root_tree.lock);
1255 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1256 node->bytenr, &node->rb_node);
1257 spin_unlock(&rc->reloc_root_tree.lock);
1259 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1260 "for start=%llu while inserting into relocation "
1261 "tree\n", node->bytenr);
1266 list_add_tail(&root->root_list, &rc->reloc_roots);
1271 * helper to delete the 'address of tree root -> reloc tree'
1274 static void __del_reloc_root(struct btrfs_root *root)
1276 struct rb_node *rb_node;
1277 struct mapping_node *node = NULL;
1278 struct reloc_control *rc = root->fs_info->reloc_ctl;
1280 spin_lock(&rc->reloc_root_tree.lock);
1281 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1284 node = rb_entry(rb_node, struct mapping_node, rb_node);
1285 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1287 spin_unlock(&rc->reloc_root_tree.lock);
1291 BUG_ON((struct btrfs_root *)node->data != root);
1293 spin_lock(&root->fs_info->trans_lock);
1294 list_del_init(&root->root_list);
1295 spin_unlock(&root->fs_info->trans_lock);
1300 * helper to update the 'address of tree root -> reloc tree'
1303 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1305 struct rb_node *rb_node;
1306 struct mapping_node *node = NULL;
1307 struct reloc_control *rc = root->fs_info->reloc_ctl;
1309 spin_lock(&rc->reloc_root_tree.lock);
1310 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1313 node = rb_entry(rb_node, struct mapping_node, rb_node);
1314 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1316 spin_unlock(&rc->reloc_root_tree.lock);
1320 BUG_ON((struct btrfs_root *)node->data != root);
1322 spin_lock(&rc->reloc_root_tree.lock);
1323 node->bytenr = new_bytenr;
1324 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1325 node->bytenr, &node->rb_node);
1326 spin_unlock(&rc->reloc_root_tree.lock);
1328 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1332 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1333 struct btrfs_root *root, u64 objectid)
1335 struct btrfs_root *reloc_root;
1336 struct extent_buffer *eb;
1337 struct btrfs_root_item *root_item;
1338 struct btrfs_key root_key;
1342 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1345 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1346 root_key.type = BTRFS_ROOT_ITEM_KEY;
1347 root_key.offset = objectid;
1349 if (root->root_key.objectid == objectid) {
1350 /* called by btrfs_init_reloc_root */
1351 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1352 BTRFS_TREE_RELOC_OBJECTID);
1355 last_snap = btrfs_root_last_snapshot(&root->root_item);
1356 btrfs_set_root_last_snapshot(&root->root_item,
1357 trans->transid - 1);
1360 * called by btrfs_reloc_post_snapshot_hook.
1361 * the source tree is a reloc tree, all tree blocks
1362 * modified after it was created have RELOC flag
1363 * set in their headers. so it's OK to not update
1364 * the 'last_snapshot'.
1366 ret = btrfs_copy_root(trans, root, root->node, &eb,
1367 BTRFS_TREE_RELOC_OBJECTID);
1371 memcpy(root_item, &root->root_item, sizeof(*root_item));
1372 btrfs_set_root_bytenr(root_item, eb->start);
1373 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1374 btrfs_set_root_generation(root_item, trans->transid);
1376 if (root->root_key.objectid == objectid) {
1377 btrfs_set_root_refs(root_item, 0);
1378 memset(&root_item->drop_progress, 0,
1379 sizeof(struct btrfs_disk_key));
1380 root_item->drop_level = 0;
1382 * abuse rtransid, it is safe because it is impossible to
1383 * receive data into a relocation tree.
1385 btrfs_set_root_rtransid(root_item, last_snap);
1386 btrfs_set_root_otransid(root_item, trans->transid);
1389 btrfs_tree_unlock(eb);
1390 free_extent_buffer(eb);
1392 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1393 &root_key, root_item);
1397 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1398 BUG_ON(IS_ERR(reloc_root));
1399 reloc_root->last_trans = trans->transid;
1404 * create reloc tree for a given fs tree. reloc tree is just a
1405 * snapshot of the fs tree with special root objectid.
1407 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1408 struct btrfs_root *root)
1410 struct btrfs_root *reloc_root;
1411 struct reloc_control *rc = root->fs_info->reloc_ctl;
1412 struct btrfs_block_rsv *rsv;
1416 if (root->reloc_root) {
1417 reloc_root = root->reloc_root;
1418 reloc_root->last_trans = trans->transid;
1422 if (!rc || !rc->create_reloc_tree ||
1423 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1426 if (!trans->reloc_reserved) {
1427 rsv = trans->block_rsv;
1428 trans->block_rsv = rc->block_rsv;
1431 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1433 trans->block_rsv = rsv;
1435 ret = __add_reloc_root(reloc_root);
1437 root->reloc_root = reloc_root;
1442 * update root item of reloc tree
1444 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1445 struct btrfs_root *root)
1447 struct btrfs_root *reloc_root;
1448 struct btrfs_root_item *root_item;
1451 if (!root->reloc_root)
1454 reloc_root = root->reloc_root;
1455 root_item = &reloc_root->root_item;
1457 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1458 btrfs_root_refs(root_item) == 0) {
1459 root->reloc_root = NULL;
1460 __del_reloc_root(reloc_root);
1463 if (reloc_root->commit_root != reloc_root->node) {
1464 btrfs_set_root_node(root_item, reloc_root->node);
1465 free_extent_buffer(reloc_root->commit_root);
1466 reloc_root->commit_root = btrfs_root_node(reloc_root);
1469 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1470 &reloc_root->root_key, root_item);
1478 * helper to find first cached inode with inode number >= objectid
1481 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1483 struct rb_node *node;
1484 struct rb_node *prev;
1485 struct btrfs_inode *entry;
1486 struct inode *inode;
1488 spin_lock(&root->inode_lock);
1490 node = root->inode_tree.rb_node;
1494 entry = rb_entry(node, struct btrfs_inode, rb_node);
1496 if (objectid < btrfs_ino(&entry->vfs_inode))
1497 node = node->rb_left;
1498 else if (objectid > btrfs_ino(&entry->vfs_inode))
1499 node = node->rb_right;
1505 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1506 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1510 prev = rb_next(prev);
1514 entry = rb_entry(node, struct btrfs_inode, rb_node);
1515 inode = igrab(&entry->vfs_inode);
1517 spin_unlock(&root->inode_lock);
1521 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1522 if (cond_resched_lock(&root->inode_lock))
1525 node = rb_next(node);
1527 spin_unlock(&root->inode_lock);
1531 static int in_block_group(u64 bytenr,
1532 struct btrfs_block_group_cache *block_group)
1534 if (bytenr >= block_group->key.objectid &&
1535 bytenr < block_group->key.objectid + block_group->key.offset)
1541 * get new location of data
1543 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1544 u64 bytenr, u64 num_bytes)
1546 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1547 struct btrfs_path *path;
1548 struct btrfs_file_extent_item *fi;
1549 struct extent_buffer *leaf;
1552 path = btrfs_alloc_path();
1556 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1557 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1566 leaf = path->nodes[0];
1567 fi = btrfs_item_ptr(leaf, path->slots[0],
1568 struct btrfs_file_extent_item);
1570 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1571 btrfs_file_extent_compression(leaf, fi) ||
1572 btrfs_file_extent_encryption(leaf, fi) ||
1573 btrfs_file_extent_other_encoding(leaf, fi));
1575 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1580 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1583 btrfs_free_path(path);
1588 * update file extent items in the tree leaf to point to
1589 * the new locations.
1591 static noinline_for_stack
1592 int replace_file_extents(struct btrfs_trans_handle *trans,
1593 struct reloc_control *rc,
1594 struct btrfs_root *root,
1595 struct extent_buffer *leaf)
1597 struct btrfs_key key;
1598 struct btrfs_file_extent_item *fi;
1599 struct inode *inode = NULL;
1611 if (rc->stage != UPDATE_DATA_PTRS)
1614 /* reloc trees always use full backref */
1615 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1616 parent = leaf->start;
1620 nritems = btrfs_header_nritems(leaf);
1621 for (i = 0; i < nritems; i++) {
1623 btrfs_item_key_to_cpu(leaf, &key, i);
1624 if (key.type != BTRFS_EXTENT_DATA_KEY)
1626 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1627 if (btrfs_file_extent_type(leaf, fi) ==
1628 BTRFS_FILE_EXTENT_INLINE)
1630 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1631 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1634 if (!in_block_group(bytenr, rc->block_group))
1638 * if we are modifying block in fs tree, wait for readpage
1639 * to complete and drop the extent cache
1641 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1643 inode = find_next_inode(root, key.objectid);
1645 } else if (inode && btrfs_ino(inode) < key.objectid) {
1646 btrfs_add_delayed_iput(inode);
1647 inode = find_next_inode(root, key.objectid);
1649 if (inode && btrfs_ino(inode) == key.objectid) {
1651 btrfs_file_extent_num_bytes(leaf, fi);
1652 WARN_ON(!IS_ALIGNED(key.offset,
1654 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1656 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1661 btrfs_drop_extent_cache(inode, key.offset, end,
1663 unlock_extent(&BTRFS_I(inode)->io_tree,
1668 ret = get_new_location(rc->data_inode, &new_bytenr,
1672 * Don't have to abort since we've not changed anything
1673 * in the file extent yet.
1678 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1681 key.offset -= btrfs_file_extent_offset(leaf, fi);
1682 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1684 btrfs_header_owner(leaf),
1685 key.objectid, key.offset, 1);
1687 btrfs_abort_transaction(trans, root, ret);
1691 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1692 parent, btrfs_header_owner(leaf),
1693 key.objectid, key.offset, 1);
1695 btrfs_abort_transaction(trans, root, ret);
1700 btrfs_mark_buffer_dirty(leaf);
1702 btrfs_add_delayed_iput(inode);
1706 static noinline_for_stack
1707 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1708 struct btrfs_path *path, int level)
1710 struct btrfs_disk_key key1;
1711 struct btrfs_disk_key key2;
1712 btrfs_node_key(eb, &key1, slot);
1713 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1714 return memcmp(&key1, &key2, sizeof(key1));
1718 * try to replace tree blocks in fs tree with the new blocks
1719 * in reloc tree. tree blocks haven't been modified since the
1720 * reloc tree was create can be replaced.
1722 * if a block was replaced, level of the block + 1 is returned.
1723 * if no block got replaced, 0 is returned. if there are other
1724 * errors, a negative error number is returned.
1726 static noinline_for_stack
1727 int replace_path(struct btrfs_trans_handle *trans,
1728 struct btrfs_root *dest, struct btrfs_root *src,
1729 struct btrfs_path *path, struct btrfs_key *next_key,
1730 int lowest_level, int max_level)
1732 struct extent_buffer *eb;
1733 struct extent_buffer *parent;
1734 struct btrfs_key key;
1746 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1747 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1749 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1751 slot = path->slots[lowest_level];
1752 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1754 eb = btrfs_lock_root_node(dest);
1755 btrfs_set_lock_blocking(eb);
1756 level = btrfs_header_level(eb);
1758 if (level < lowest_level) {
1759 btrfs_tree_unlock(eb);
1760 free_extent_buffer(eb);
1765 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1768 btrfs_set_lock_blocking(eb);
1771 next_key->objectid = (u64)-1;
1772 next_key->type = (u8)-1;
1773 next_key->offset = (u64)-1;
1778 level = btrfs_header_level(parent);
1779 BUG_ON(level < lowest_level);
1781 ret = btrfs_bin_search(parent, &key, level, &slot);
1782 if (ret && slot > 0)
1785 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1786 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1788 old_bytenr = btrfs_node_blockptr(parent, slot);
1789 blocksize = btrfs_level_size(dest, level - 1);
1790 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1792 if (level <= max_level) {
1793 eb = path->nodes[level];
1794 new_bytenr = btrfs_node_blockptr(eb,
1795 path->slots[level]);
1796 new_ptr_gen = btrfs_node_ptr_generation(eb,
1797 path->slots[level]);
1803 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1808 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1809 memcmp_node_keys(parent, slot, path, level)) {
1810 if (level <= lowest_level) {
1815 eb = read_tree_block(dest, old_bytenr, blocksize,
1817 if (!eb || !extent_buffer_uptodate(eb)) {
1818 ret = (!eb) ? -ENOMEM : -EIO;
1819 free_extent_buffer(eb);
1822 btrfs_tree_lock(eb);
1824 ret = btrfs_cow_block(trans, dest, eb, parent,
1828 btrfs_set_lock_blocking(eb);
1830 btrfs_tree_unlock(parent);
1831 free_extent_buffer(parent);
1838 btrfs_tree_unlock(parent);
1839 free_extent_buffer(parent);
1844 btrfs_node_key_to_cpu(path->nodes[level], &key,
1845 path->slots[level]);
1846 btrfs_release_path(path);
1848 path->lowest_level = level;
1849 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1850 path->lowest_level = 0;
1854 * swap blocks in fs tree and reloc tree.
1856 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1857 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1858 btrfs_mark_buffer_dirty(parent);
1860 btrfs_set_node_blockptr(path->nodes[level],
1861 path->slots[level], old_bytenr);
1862 btrfs_set_node_ptr_generation(path->nodes[level],
1863 path->slots[level], old_ptr_gen);
1864 btrfs_mark_buffer_dirty(path->nodes[level]);
1866 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1867 path->nodes[level]->start,
1868 src->root_key.objectid, level - 1, 0,
1871 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1872 0, dest->root_key.objectid, level - 1,
1876 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1877 path->nodes[level]->start,
1878 src->root_key.objectid, level - 1, 0,
1882 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1883 0, dest->root_key.objectid, level - 1,
1887 btrfs_unlock_up_safe(path, 0);
1892 btrfs_tree_unlock(parent);
1893 free_extent_buffer(parent);
1898 * helper to find next relocated block in reloc tree
1900 static noinline_for_stack
1901 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1904 struct extent_buffer *eb;
1909 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1911 for (i = 0; i < *level; i++) {
1912 free_extent_buffer(path->nodes[i]);
1913 path->nodes[i] = NULL;
1916 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1917 eb = path->nodes[i];
1918 nritems = btrfs_header_nritems(eb);
1919 while (path->slots[i] + 1 < nritems) {
1921 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1928 free_extent_buffer(path->nodes[i]);
1929 path->nodes[i] = NULL;
1935 * walk down reloc tree to find relocated block of lowest level
1937 static noinline_for_stack
1938 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1941 struct extent_buffer *eb = NULL;
1949 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1951 for (i = *level; i > 0; i--) {
1952 eb = path->nodes[i];
1953 nritems = btrfs_header_nritems(eb);
1954 while (path->slots[i] < nritems) {
1955 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1956 if (ptr_gen > last_snapshot)
1960 if (path->slots[i] >= nritems) {
1971 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1972 blocksize = btrfs_level_size(root, i - 1);
1973 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1974 if (!eb || !extent_buffer_uptodate(eb)) {
1975 free_extent_buffer(eb);
1978 BUG_ON(btrfs_header_level(eb) != i - 1);
1979 path->nodes[i - 1] = eb;
1980 path->slots[i - 1] = 0;
1986 * invalidate extent cache for file extents whose key in range of
1987 * [min_key, max_key)
1989 static int invalidate_extent_cache(struct btrfs_root *root,
1990 struct btrfs_key *min_key,
1991 struct btrfs_key *max_key)
1993 struct inode *inode = NULL;
1998 objectid = min_key->objectid;
2003 if (objectid > max_key->objectid)
2006 inode = find_next_inode(root, objectid);
2009 ino = btrfs_ino(inode);
2011 if (ino > max_key->objectid) {
2017 if (!S_ISREG(inode->i_mode))
2020 if (unlikely(min_key->objectid == ino)) {
2021 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2023 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2026 start = min_key->offset;
2027 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2033 if (unlikely(max_key->objectid == ino)) {
2034 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2036 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2039 if (max_key->offset == 0)
2041 end = max_key->offset;
2042 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2049 /* the lock_extent waits for readpage to complete */
2050 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2051 btrfs_drop_extent_cache(inode, start, end, 1);
2052 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2057 static int find_next_key(struct btrfs_path *path, int level,
2058 struct btrfs_key *key)
2061 while (level < BTRFS_MAX_LEVEL) {
2062 if (!path->nodes[level])
2064 if (path->slots[level] + 1 <
2065 btrfs_header_nritems(path->nodes[level])) {
2066 btrfs_node_key_to_cpu(path->nodes[level], key,
2067 path->slots[level] + 1);
2076 * merge the relocated tree blocks in reloc tree with corresponding
2079 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2080 struct btrfs_root *root)
2082 LIST_HEAD(inode_list);
2083 struct btrfs_key key;
2084 struct btrfs_key next_key;
2085 struct btrfs_trans_handle *trans = NULL;
2086 struct btrfs_root *reloc_root;
2087 struct btrfs_root_item *root_item;
2088 struct btrfs_path *path;
2089 struct extent_buffer *leaf;
2097 path = btrfs_alloc_path();
2102 reloc_root = root->reloc_root;
2103 root_item = &reloc_root->root_item;
2105 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2106 level = btrfs_root_level(root_item);
2107 extent_buffer_get(reloc_root->node);
2108 path->nodes[level] = reloc_root->node;
2109 path->slots[level] = 0;
2111 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2113 level = root_item->drop_level;
2115 path->lowest_level = level;
2116 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2117 path->lowest_level = 0;
2119 btrfs_free_path(path);
2123 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2124 path->slots[level]);
2125 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2127 btrfs_unlock_up_safe(path, 0);
2130 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2131 memset(&next_key, 0, sizeof(next_key));
2134 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2135 BTRFS_RESERVE_FLUSH_ALL);
2140 trans = btrfs_start_transaction(root, 0);
2141 if (IS_ERR(trans)) {
2142 err = PTR_ERR(trans);
2146 trans->block_rsv = rc->block_rsv;
2151 ret = walk_down_reloc_tree(reloc_root, path, &level);
2159 if (!find_next_key(path, level, &key) &&
2160 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2163 ret = replace_path(trans, root, reloc_root, path,
2164 &next_key, level, max_level);
2173 btrfs_node_key_to_cpu(path->nodes[level], &key,
2174 path->slots[level]);
2178 ret = walk_up_reloc_tree(reloc_root, path, &level);
2184 * save the merging progress in the drop_progress.
2185 * this is OK since root refs == 1 in this case.
2187 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2188 path->slots[level]);
2189 root_item->drop_level = level;
2191 btrfs_end_transaction_throttle(trans, root);
2194 btrfs_btree_balance_dirty(root);
2196 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2197 invalidate_extent_cache(root, &key, &next_key);
2201 * handle the case only one block in the fs tree need to be
2202 * relocated and the block is tree root.
2204 leaf = btrfs_lock_root_node(root);
2205 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2206 btrfs_tree_unlock(leaf);
2207 free_extent_buffer(leaf);
2211 btrfs_free_path(path);
2214 memset(&root_item->drop_progress, 0,
2215 sizeof(root_item->drop_progress));
2216 root_item->drop_level = 0;
2217 btrfs_set_root_refs(root_item, 0);
2218 btrfs_update_reloc_root(trans, root);
2222 btrfs_end_transaction_throttle(trans, root);
2224 btrfs_btree_balance_dirty(root);
2226 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2227 invalidate_extent_cache(root, &key, &next_key);
2232 static noinline_for_stack
2233 int prepare_to_merge(struct reloc_control *rc, int err)
2235 struct btrfs_root *root = rc->extent_root;
2236 struct btrfs_root *reloc_root;
2237 struct btrfs_trans_handle *trans;
2238 LIST_HEAD(reloc_roots);
2242 mutex_lock(&root->fs_info->reloc_mutex);
2243 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2244 rc->merging_rsv_size += rc->nodes_relocated * 2;
2245 mutex_unlock(&root->fs_info->reloc_mutex);
2249 num_bytes = rc->merging_rsv_size;
2250 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2251 BTRFS_RESERVE_FLUSH_ALL);
2256 trans = btrfs_join_transaction(rc->extent_root);
2257 if (IS_ERR(trans)) {
2259 btrfs_block_rsv_release(rc->extent_root,
2260 rc->block_rsv, num_bytes);
2261 return PTR_ERR(trans);
2265 if (num_bytes != rc->merging_rsv_size) {
2266 btrfs_end_transaction(trans, rc->extent_root);
2267 btrfs_block_rsv_release(rc->extent_root,
2268 rc->block_rsv, num_bytes);
2273 rc->merge_reloc_tree = 1;
2275 while (!list_empty(&rc->reloc_roots)) {
2276 reloc_root = list_entry(rc->reloc_roots.next,
2277 struct btrfs_root, root_list);
2278 list_del_init(&reloc_root->root_list);
2280 root = read_fs_root(reloc_root->fs_info,
2281 reloc_root->root_key.offset);
2282 BUG_ON(IS_ERR(root));
2283 BUG_ON(root->reloc_root != reloc_root);
2286 * set reference count to 1, so btrfs_recover_relocation
2287 * knows it should resumes merging
2290 btrfs_set_root_refs(&reloc_root->root_item, 1);
2291 btrfs_update_reloc_root(trans, root);
2293 list_add(&reloc_root->root_list, &reloc_roots);
2296 list_splice(&reloc_roots, &rc->reloc_roots);
2299 btrfs_commit_transaction(trans, rc->extent_root);
2301 btrfs_end_transaction(trans, rc->extent_root);
2305 static noinline_for_stack
2306 void free_reloc_roots(struct list_head *list)
2308 struct btrfs_root *reloc_root;
2310 while (!list_empty(list)) {
2311 reloc_root = list_entry(list->next, struct btrfs_root,
2313 __del_reloc_root(reloc_root);
2317 static noinline_for_stack
2318 int merge_reloc_roots(struct reloc_control *rc)
2320 struct btrfs_root *root;
2321 struct btrfs_root *reloc_root;
2325 LIST_HEAD(reloc_roots);
2329 root = rc->extent_root;
2332 * this serializes us with btrfs_record_root_in_transaction,
2333 * we have to make sure nobody is in the middle of
2334 * adding their roots to the list while we are
2337 mutex_lock(&root->fs_info->reloc_mutex);
2338 list_splice_init(&rc->reloc_roots, &reloc_roots);
2339 mutex_unlock(&root->fs_info->reloc_mutex);
2341 while (!list_empty(&reloc_roots)) {
2343 reloc_root = list_entry(reloc_roots.next,
2344 struct btrfs_root, root_list);
2346 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2347 root = read_fs_root(reloc_root->fs_info,
2348 reloc_root->root_key.offset);
2349 BUG_ON(IS_ERR(root));
2350 BUG_ON(root->reloc_root != reloc_root);
2352 ret = merge_reloc_root(rc, root);
2354 if (list_empty(&reloc_root->root_list))
2355 list_add_tail(&reloc_root->root_list,
2360 list_del_init(&reloc_root->root_list);
2364 * we keep the old last snapshod transid in rtranid when we
2365 * created the relocation tree.
2367 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2368 otransid = btrfs_root_otransid(&reloc_root->root_item);
2369 objectid = reloc_root->root_key.offset;
2371 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2373 if (list_empty(&reloc_root->root_list))
2374 list_add_tail(&reloc_root->root_list,
2386 btrfs_std_error(root->fs_info, ret);
2387 if (!list_empty(&reloc_roots))
2388 free_reloc_roots(&reloc_roots);
2390 /* new reloc root may be added */
2391 mutex_lock(&root->fs_info->reloc_mutex);
2392 list_splice_init(&rc->reloc_roots, &reloc_roots);
2393 mutex_unlock(&root->fs_info->reloc_mutex);
2394 if (!list_empty(&reloc_roots))
2395 free_reloc_roots(&reloc_roots);
2398 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(!root->ref_cows);
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 (!root->ref_cows)
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 += btrfs_level_size(rc->extent_root,
2549 if (list_empty(&next->upper))
2552 edge = list_entry(next->upper.next,
2553 struct backref_edge, list[LOWER]);
2554 edges[index++] = edge;
2555 next = edge->node[UPPER];
2557 next = walk_down_backref(edges, &index);
2562 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2563 struct reloc_control *rc,
2564 struct backref_node *node)
2566 struct btrfs_root *root = rc->extent_root;
2571 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2573 trans->block_rsv = rc->block_rsv;
2574 rc->reserved_bytes += num_bytes;
2575 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2576 BTRFS_RESERVE_FLUSH_ALL);
2578 if (ret == -EAGAIN) {
2579 tmp = rc->extent_root->nodesize *
2580 RELOCATION_RESERVED_NODES;
2581 while (tmp <= rc->reserved_bytes)
2584 * only one thread can access block_rsv at this point,
2585 * so we don't need hold lock to protect block_rsv.
2586 * we expand more reservation size here to allow enough
2587 * space for relocation and we will return eailer in
2590 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2591 RELOCATION_RESERVED_NODES;
2600 * relocate a block tree, and then update pointers in upper level
2601 * blocks that reference the block to point to the new location.
2603 * if called by link_to_upper, the block has already been relocated.
2604 * in that case this function just updates pointers.
2606 static int do_relocation(struct btrfs_trans_handle *trans,
2607 struct reloc_control *rc,
2608 struct backref_node *node,
2609 struct btrfs_key *key,
2610 struct btrfs_path *path, int lowest)
2612 struct backref_node *upper;
2613 struct backref_edge *edge;
2614 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2615 struct btrfs_root *root;
2616 struct extent_buffer *eb;
2624 BUG_ON(lowest && node->eb);
2626 path->lowest_level = node->level + 1;
2627 rc->backref_cache.path[node->level] = node;
2628 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2631 upper = edge->node[UPPER];
2632 root = select_reloc_root(trans, rc, upper, edges);
2635 if (upper->eb && !upper->locked) {
2637 ret = btrfs_bin_search(upper->eb, key,
2638 upper->level, &slot);
2640 bytenr = btrfs_node_blockptr(upper->eb, slot);
2641 if (node->eb->start == bytenr)
2644 drop_node_buffer(upper);
2648 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2656 upper->eb = path->nodes[upper->level];
2657 path->nodes[upper->level] = NULL;
2659 BUG_ON(upper->eb != path->nodes[upper->level]);
2663 path->locks[upper->level] = 0;
2665 slot = path->slots[upper->level];
2666 btrfs_release_path(path);
2668 ret = btrfs_bin_search(upper->eb, key, upper->level,
2673 bytenr = btrfs_node_blockptr(upper->eb, slot);
2675 BUG_ON(bytenr != node->bytenr);
2677 if (node->eb->start == bytenr)
2681 blocksize = btrfs_level_size(root, node->level);
2682 generation = btrfs_node_ptr_generation(upper->eb, slot);
2683 eb = read_tree_block(root, bytenr, blocksize, generation);
2684 if (!eb || !extent_buffer_uptodate(eb)) {
2685 free_extent_buffer(eb);
2689 btrfs_tree_lock(eb);
2690 btrfs_set_lock_blocking(eb);
2693 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2695 btrfs_tree_unlock(eb);
2696 free_extent_buffer(eb);
2701 BUG_ON(node->eb != eb);
2703 btrfs_set_node_blockptr(upper->eb, slot,
2705 btrfs_set_node_ptr_generation(upper->eb, slot,
2707 btrfs_mark_buffer_dirty(upper->eb);
2709 ret = btrfs_inc_extent_ref(trans, root,
2710 node->eb->start, blocksize,
2712 btrfs_header_owner(upper->eb),
2716 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2720 if (!upper->pending)
2721 drop_node_buffer(upper);
2723 unlock_node_buffer(upper);
2728 if (!err && node->pending) {
2729 drop_node_buffer(node);
2730 list_move_tail(&node->list, &rc->backref_cache.changed);
2734 path->lowest_level = 0;
2735 BUG_ON(err == -ENOSPC);
2739 static int link_to_upper(struct btrfs_trans_handle *trans,
2740 struct reloc_control *rc,
2741 struct backref_node *node,
2742 struct btrfs_path *path)
2744 struct btrfs_key key;
2746 btrfs_node_key_to_cpu(node->eb, &key, 0);
2747 return do_relocation(trans, rc, node, &key, path, 0);
2750 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2751 struct reloc_control *rc,
2752 struct btrfs_path *path, int err)
2755 struct backref_cache *cache = &rc->backref_cache;
2756 struct backref_node *node;
2760 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2761 while (!list_empty(&cache->pending[level])) {
2762 node = list_entry(cache->pending[level].next,
2763 struct backref_node, list);
2764 list_move_tail(&node->list, &list);
2765 BUG_ON(!node->pending);
2768 ret = link_to_upper(trans, rc, node, path);
2773 list_splice_init(&list, &cache->pending[level]);
2778 static void mark_block_processed(struct reloc_control *rc,
2779 u64 bytenr, u32 blocksize)
2781 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2782 EXTENT_DIRTY, GFP_NOFS);
2785 static void __mark_block_processed(struct reloc_control *rc,
2786 struct backref_node *node)
2789 if (node->level == 0 ||
2790 in_block_group(node->bytenr, rc->block_group)) {
2791 blocksize = btrfs_level_size(rc->extent_root, node->level);
2792 mark_block_processed(rc, node->bytenr, blocksize);
2794 node->processed = 1;
2798 * mark a block and all blocks directly/indirectly reference the block
2801 static void update_processed_blocks(struct reloc_control *rc,
2802 struct backref_node *node)
2804 struct backref_node *next = node;
2805 struct backref_edge *edge;
2806 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2812 if (next->processed)
2815 __mark_block_processed(rc, next);
2817 if (list_empty(&next->upper))
2820 edge = list_entry(next->upper.next,
2821 struct backref_edge, list[LOWER]);
2822 edges[index++] = edge;
2823 next = edge->node[UPPER];
2825 next = walk_down_backref(edges, &index);
2829 static int tree_block_processed(u64 bytenr, u32 blocksize,
2830 struct reloc_control *rc)
2832 if (test_range_bit(&rc->processed_blocks, bytenr,
2833 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2838 static int get_tree_block_key(struct reloc_control *rc,
2839 struct tree_block *block)
2841 struct extent_buffer *eb;
2843 BUG_ON(block->key_ready);
2844 eb = read_tree_block(rc->extent_root, block->bytenr,
2845 block->key.objectid, block->key.offset);
2846 if (!eb || !extent_buffer_uptodate(eb)) {
2847 free_extent_buffer(eb);
2850 WARN_ON(btrfs_header_level(eb) != block->level);
2851 if (block->level == 0)
2852 btrfs_item_key_to_cpu(eb, &block->key, 0);
2854 btrfs_node_key_to_cpu(eb, &block->key, 0);
2855 free_extent_buffer(eb);
2856 block->key_ready = 1;
2860 static int reada_tree_block(struct reloc_control *rc,
2861 struct tree_block *block)
2863 BUG_ON(block->key_ready);
2864 if (block->key.type == BTRFS_METADATA_ITEM_KEY)
2865 readahead_tree_block(rc->extent_root, block->bytenr,
2866 block->key.objectid,
2867 rc->extent_root->leafsize);
2869 readahead_tree_block(rc->extent_root, block->bytenr,
2870 block->key.objectid, block->key.offset);
2875 * helper function to relocate a tree block
2877 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2878 struct reloc_control *rc,
2879 struct backref_node *node,
2880 struct btrfs_key *key,
2881 struct btrfs_path *path)
2883 struct btrfs_root *root;
2889 BUG_ON(node->processed);
2890 root = select_one_root(trans, node);
2891 if (root == ERR_PTR(-ENOENT)) {
2892 update_processed_blocks(rc, node);
2896 if (!root || root->ref_cows) {
2897 ret = reserve_metadata_space(trans, rc, node);
2903 if (root->ref_cows) {
2904 BUG_ON(node->new_bytenr);
2905 BUG_ON(!list_empty(&node->list));
2906 btrfs_record_root_in_trans(trans, root);
2907 root = root->reloc_root;
2908 node->new_bytenr = root->node->start;
2910 list_add_tail(&node->list, &rc->backref_cache.changed);
2912 path->lowest_level = node->level;
2913 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2914 btrfs_release_path(path);
2919 update_processed_blocks(rc, node);
2921 ret = do_relocation(trans, rc, node, key, path, 1);
2924 if (ret || node->level == 0 || node->cowonly)
2925 remove_backref_node(&rc->backref_cache, node);
2930 * relocate a list of blocks
2932 static noinline_for_stack
2933 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2934 struct reloc_control *rc, struct rb_root *blocks)
2936 struct backref_node *node;
2937 struct btrfs_path *path;
2938 struct tree_block *block;
2939 struct rb_node *rb_node;
2943 path = btrfs_alloc_path();
2946 goto out_free_blocks;
2949 rb_node = rb_first(blocks);
2951 block = rb_entry(rb_node, struct tree_block, rb_node);
2952 if (!block->key_ready)
2953 reada_tree_block(rc, block);
2954 rb_node = rb_next(rb_node);
2957 rb_node = rb_first(blocks);
2959 block = rb_entry(rb_node, struct tree_block, rb_node);
2960 if (!block->key_ready) {
2961 err = get_tree_block_key(rc, block);
2965 rb_node = rb_next(rb_node);
2968 rb_node = rb_first(blocks);
2970 block = rb_entry(rb_node, struct tree_block, rb_node);
2972 node = build_backref_tree(rc, &block->key,
2973 block->level, block->bytenr);
2975 err = PTR_ERR(node);
2979 ret = relocate_tree_block(trans, rc, node, &block->key,
2982 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2986 rb_node = rb_next(rb_node);
2989 err = finish_pending_nodes(trans, rc, path, err);
2992 btrfs_free_path(path);
2994 free_block_list(blocks);
2998 static noinline_for_stack
2999 int prealloc_file_extent_cluster(struct inode *inode,
3000 struct file_extent_cluster *cluster)
3005 u64 offset = BTRFS_I(inode)->index_cnt;
3010 BUG_ON(cluster->start != cluster->boundary[0]);
3011 mutex_lock(&inode->i_mutex);
3013 ret = btrfs_check_data_free_space(inode, cluster->end +
3014 1 - cluster->start);
3018 while (nr < cluster->nr) {
3019 start = cluster->boundary[nr] - offset;
3020 if (nr + 1 < cluster->nr)
3021 end = cluster->boundary[nr + 1] - 1 - offset;
3023 end = cluster->end - offset;
3025 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3026 num_bytes = end + 1 - start;
3027 ret = btrfs_prealloc_file_range(inode, 0, start,
3028 num_bytes, num_bytes,
3029 end + 1, &alloc_hint);
3030 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3035 btrfs_free_reserved_data_space(inode, cluster->end +
3036 1 - cluster->start);
3038 mutex_unlock(&inode->i_mutex);
3042 static noinline_for_stack
3043 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3046 struct btrfs_root *root = BTRFS_I(inode)->root;
3047 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3048 struct extent_map *em;
3051 em = alloc_extent_map();
3056 em->len = end + 1 - start;
3057 em->block_len = em->len;
3058 em->block_start = block_start;
3059 em->bdev = root->fs_info->fs_devices->latest_bdev;
3060 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3062 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3064 write_lock(&em_tree->lock);
3065 ret = add_extent_mapping(em_tree, em, 0);
3066 write_unlock(&em_tree->lock);
3067 if (ret != -EEXIST) {
3068 free_extent_map(em);
3071 btrfs_drop_extent_cache(inode, start, end, 0);
3073 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3077 static int relocate_file_extent_cluster(struct inode *inode,
3078 struct file_extent_cluster *cluster)
3082 u64 offset = BTRFS_I(inode)->index_cnt;
3083 unsigned long index;
3084 unsigned long last_index;
3086 struct file_ra_state *ra;
3087 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3094 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3098 ret = prealloc_file_extent_cluster(inode, cluster);
3102 file_ra_state_init(ra, inode->i_mapping);
3104 ret = setup_extent_mapping(inode, cluster->start - offset,
3105 cluster->end - offset, cluster->start);
3109 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3110 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3111 while (index <= last_index) {
3112 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3116 page = find_lock_page(inode->i_mapping, index);
3118 page_cache_sync_readahead(inode->i_mapping,
3120 last_index + 1 - index);
3121 page = find_or_create_page(inode->i_mapping, index,
3124 btrfs_delalloc_release_metadata(inode,
3131 if (PageReadahead(page)) {
3132 page_cache_async_readahead(inode->i_mapping,
3133 ra, NULL, page, index,
3134 last_index + 1 - index);
3137 if (!PageUptodate(page)) {
3138 btrfs_readpage(NULL, page);
3140 if (!PageUptodate(page)) {
3142 page_cache_release(page);
3143 btrfs_delalloc_release_metadata(inode,
3150 page_start = page_offset(page);
3151 page_end = page_start + PAGE_CACHE_SIZE - 1;
3153 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3155 set_page_extent_mapped(page);
3157 if (nr < cluster->nr &&
3158 page_start + offset == cluster->boundary[nr]) {
3159 set_extent_bits(&BTRFS_I(inode)->io_tree,
3160 page_start, page_end,
3161 EXTENT_BOUNDARY, GFP_NOFS);
3165 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3166 set_page_dirty(page);
3168 unlock_extent(&BTRFS_I(inode)->io_tree,
3169 page_start, page_end);
3171 page_cache_release(page);
3174 balance_dirty_pages_ratelimited(inode->i_mapping);
3175 btrfs_throttle(BTRFS_I(inode)->root);
3177 WARN_ON(nr != cluster->nr);
3183 static noinline_for_stack
3184 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3185 struct file_extent_cluster *cluster)
3189 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3190 ret = relocate_file_extent_cluster(inode, cluster);
3197 cluster->start = extent_key->objectid;
3199 BUG_ON(cluster->nr >= MAX_EXTENTS);
3200 cluster->end = extent_key->objectid + extent_key->offset - 1;
3201 cluster->boundary[cluster->nr] = extent_key->objectid;
3204 if (cluster->nr >= MAX_EXTENTS) {
3205 ret = relocate_file_extent_cluster(inode, cluster);
3213 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3214 static int get_ref_objectid_v0(struct reloc_control *rc,
3215 struct btrfs_path *path,
3216 struct btrfs_key *extent_key,
3217 u64 *ref_objectid, int *path_change)
3219 struct btrfs_key key;
3220 struct extent_buffer *leaf;
3221 struct btrfs_extent_ref_v0 *ref0;
3225 leaf = path->nodes[0];
3226 slot = path->slots[0];
3228 if (slot >= btrfs_header_nritems(leaf)) {
3229 ret = btrfs_next_leaf(rc->extent_root, path);
3233 leaf = path->nodes[0];
3234 slot = path->slots[0];
3238 btrfs_item_key_to_cpu(leaf, &key, slot);
3239 if (key.objectid != extent_key->objectid)
3242 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3246 ref0 = btrfs_item_ptr(leaf, slot,
3247 struct btrfs_extent_ref_v0);
3248 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3256 * helper to add a tree block to the list.
3257 * the major work is getting the generation and level of the block
3259 static int add_tree_block(struct reloc_control *rc,
3260 struct btrfs_key *extent_key,
3261 struct btrfs_path *path,
3262 struct rb_root *blocks)
3264 struct extent_buffer *eb;
3265 struct btrfs_extent_item *ei;
3266 struct btrfs_tree_block_info *bi;
3267 struct tree_block *block;
3268 struct rb_node *rb_node;
3273 eb = path->nodes[0];
3274 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3276 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3277 item_size >= sizeof(*ei) + sizeof(*bi)) {
3278 ei = btrfs_item_ptr(eb, path->slots[0],
3279 struct btrfs_extent_item);
3280 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3281 bi = (struct btrfs_tree_block_info *)(ei + 1);
3282 level = btrfs_tree_block_level(eb, bi);
3284 level = (int)extent_key->offset;
3286 generation = btrfs_extent_generation(eb, ei);
3288 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3292 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3293 ret = get_ref_objectid_v0(rc, path, extent_key,
3297 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3298 level = (int)ref_owner;
3299 /* FIXME: get real generation */
3306 btrfs_release_path(path);
3308 BUG_ON(level == -1);
3310 block = kmalloc(sizeof(*block), GFP_NOFS);
3314 block->bytenr = extent_key->objectid;
3315 block->key.objectid = rc->extent_root->leafsize;
3316 block->key.offset = generation;
3317 block->level = level;
3318 block->key_ready = 0;
3320 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3322 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3328 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3330 static int __add_tree_block(struct reloc_control *rc,
3331 u64 bytenr, u32 blocksize,
3332 struct rb_root *blocks)
3334 struct btrfs_path *path;
3335 struct btrfs_key key;
3337 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3340 if (tree_block_processed(bytenr, blocksize, rc))
3343 if (tree_search(blocks, bytenr))
3346 path = btrfs_alloc_path();
3350 key.objectid = bytenr;
3352 key.type = BTRFS_METADATA_ITEM_KEY;
3353 key.offset = (u64)-1;
3355 key.type = BTRFS_EXTENT_ITEM_KEY;
3356 key.offset = blocksize;
3359 path->search_commit_root = 1;
3360 path->skip_locking = 1;
3361 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3365 if (ret > 0 && skinny) {
3366 if (path->slots[0]) {
3368 btrfs_item_key_to_cpu(path->nodes[0], &key,
3370 if (key.objectid == bytenr &&
3371 (key.type == BTRFS_METADATA_ITEM_KEY ||
3372 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3373 key.offset == blocksize)))
3379 btrfs_release_path(path);
3385 ret = add_tree_block(rc, &key, path, blocks);
3387 btrfs_free_path(path);
3392 * helper to check if the block use full backrefs for pointers in it
3394 static int block_use_full_backref(struct reloc_control *rc,
3395 struct extent_buffer *eb)
3400 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3401 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3404 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3405 eb->start, btrfs_header_level(eb), 1,
3409 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3416 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3417 struct inode *inode, u64 ino)
3419 struct btrfs_key key;
3420 struct btrfs_root *root = fs_info->tree_root;
3421 struct btrfs_trans_handle *trans;
3428 key.type = BTRFS_INODE_ITEM_KEY;
3431 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3432 if (IS_ERR(inode) || is_bad_inode(inode)) {
3439 ret = btrfs_check_trunc_cache_free_space(root,
3440 &fs_info->global_block_rsv);
3444 trans = btrfs_join_transaction(root);
3445 if (IS_ERR(trans)) {
3446 ret = PTR_ERR(trans);
3450 ret = btrfs_truncate_free_space_cache(root, trans, inode);
3452 btrfs_end_transaction(trans, root);
3453 btrfs_btree_balance_dirty(root);
3460 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3461 * this function scans fs tree to find blocks reference the data extent
3463 static int find_data_references(struct reloc_control *rc,
3464 struct btrfs_key *extent_key,
3465 struct extent_buffer *leaf,
3466 struct btrfs_extent_data_ref *ref,
3467 struct rb_root *blocks)
3469 struct btrfs_path *path;
3470 struct tree_block *block;
3471 struct btrfs_root *root;
3472 struct btrfs_file_extent_item *fi;
3473 struct rb_node *rb_node;
3474 struct btrfs_key key;
3485 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3486 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3487 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3488 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3491 * This is an extent belonging to the free space cache, lets just delete
3492 * it and redo the search.
3494 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3495 ret = delete_block_group_cache(rc->extent_root->fs_info,
3496 NULL, ref_objectid);
3502 path = btrfs_alloc_path();
3507 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3509 err = PTR_ERR(root);
3513 key.objectid = ref_objectid;
3514 key.type = BTRFS_EXTENT_DATA_KEY;
3515 if (ref_offset > ((u64)-1 << 32))
3518 key.offset = ref_offset;
3520 path->search_commit_root = 1;
3521 path->skip_locking = 1;
3522 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3528 leaf = path->nodes[0];
3529 nritems = btrfs_header_nritems(leaf);
3531 * the references in tree blocks that use full backrefs
3532 * are not counted in
3534 if (block_use_full_backref(rc, leaf))
3538 rb_node = tree_search(blocks, leaf->start);
3543 path->slots[0] = nritems;
3546 while (ref_count > 0) {
3547 while (path->slots[0] >= nritems) {
3548 ret = btrfs_next_leaf(root, path);
3553 if (WARN_ON(ret > 0))
3556 leaf = path->nodes[0];
3557 nritems = btrfs_header_nritems(leaf);
3560 if (block_use_full_backref(rc, leaf))
3564 rb_node = tree_search(blocks, leaf->start);
3569 path->slots[0] = nritems;
3573 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3574 if (WARN_ON(key.objectid != ref_objectid ||
3575 key.type != BTRFS_EXTENT_DATA_KEY))
3578 fi = btrfs_item_ptr(leaf, path->slots[0],
3579 struct btrfs_file_extent_item);
3581 if (btrfs_file_extent_type(leaf, fi) ==
3582 BTRFS_FILE_EXTENT_INLINE)
3585 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3586 extent_key->objectid)
3589 key.offset -= btrfs_file_extent_offset(leaf, fi);
3590 if (key.offset != ref_offset)
3598 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3599 block = kmalloc(sizeof(*block), GFP_NOFS);
3604 block->bytenr = leaf->start;
3605 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3607 block->key_ready = 1;
3608 rb_node = tree_insert(blocks, block->bytenr,
3611 backref_tree_panic(rb_node, -EEXIST,
3617 path->slots[0] = nritems;
3623 btrfs_free_path(path);
3628 * helper to find all tree blocks that reference a given data extent
3630 static noinline_for_stack
3631 int add_data_references(struct reloc_control *rc,
3632 struct btrfs_key *extent_key,
3633 struct btrfs_path *path,
3634 struct rb_root *blocks)
3636 struct btrfs_key key;
3637 struct extent_buffer *eb;
3638 struct btrfs_extent_data_ref *dref;
3639 struct btrfs_extent_inline_ref *iref;
3642 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3646 eb = path->nodes[0];
3647 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3648 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3649 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3650 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3654 ptr += sizeof(struct btrfs_extent_item);
3657 iref = (struct btrfs_extent_inline_ref *)ptr;
3658 key.type = btrfs_extent_inline_ref_type(eb, iref);
3659 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3660 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3661 ret = __add_tree_block(rc, key.offset, blocksize,
3663 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3664 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3665 ret = find_data_references(rc, extent_key,
3674 ptr += btrfs_extent_inline_ref_size(key.type);
3680 eb = path->nodes[0];
3681 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3682 ret = btrfs_next_leaf(rc->extent_root, path);
3689 eb = path->nodes[0];
3692 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3693 if (key.objectid != extent_key->objectid)
3696 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3697 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3698 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3700 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3701 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3703 ret = __add_tree_block(rc, key.offset, blocksize,
3705 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3706 dref = btrfs_item_ptr(eb, path->slots[0],
3707 struct btrfs_extent_data_ref);
3708 ret = find_data_references(rc, extent_key,
3720 btrfs_release_path(path);
3722 free_block_list(blocks);
3727 * helper to find next unprocessed extent
3729 static noinline_for_stack
3730 int find_next_extent(struct btrfs_trans_handle *trans,
3731 struct reloc_control *rc, struct btrfs_path *path,
3732 struct btrfs_key *extent_key)
3734 struct btrfs_key key;
3735 struct extent_buffer *leaf;
3736 u64 start, end, last;
3739 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3742 if (rc->search_start >= last) {
3747 key.objectid = rc->search_start;
3748 key.type = BTRFS_EXTENT_ITEM_KEY;
3751 path->search_commit_root = 1;
3752 path->skip_locking = 1;
3753 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3758 leaf = path->nodes[0];
3759 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3760 ret = btrfs_next_leaf(rc->extent_root, path);
3763 leaf = path->nodes[0];
3766 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3767 if (key.objectid >= last) {
3772 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3773 key.type != BTRFS_METADATA_ITEM_KEY) {
3778 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3779 key.objectid + key.offset <= rc->search_start) {
3784 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3785 key.objectid + rc->extent_root->leafsize <=
3791 ret = find_first_extent_bit(&rc->processed_blocks,
3792 key.objectid, &start, &end,
3793 EXTENT_DIRTY, NULL);
3795 if (ret == 0 && start <= key.objectid) {
3796 btrfs_release_path(path);
3797 rc->search_start = end + 1;
3799 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3800 rc->search_start = key.objectid + key.offset;
3802 rc->search_start = key.objectid +
3803 rc->extent_root->leafsize;
3804 memcpy(extent_key, &key, sizeof(key));
3808 btrfs_release_path(path);
3812 static void set_reloc_control(struct reloc_control *rc)
3814 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3816 mutex_lock(&fs_info->reloc_mutex);
3817 fs_info->reloc_ctl = rc;
3818 mutex_unlock(&fs_info->reloc_mutex);
3821 static void unset_reloc_control(struct reloc_control *rc)
3823 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3825 mutex_lock(&fs_info->reloc_mutex);
3826 fs_info->reloc_ctl = NULL;
3827 mutex_unlock(&fs_info->reloc_mutex);
3830 static int check_extent_flags(u64 flags)
3832 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3833 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3835 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3836 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3838 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3839 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3844 static noinline_for_stack
3845 int prepare_to_relocate(struct reloc_control *rc)
3847 struct btrfs_trans_handle *trans;
3849 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3850 BTRFS_BLOCK_RSV_TEMP);
3854 memset(&rc->cluster, 0, sizeof(rc->cluster));
3855 rc->search_start = rc->block_group->key.objectid;
3856 rc->extents_found = 0;
3857 rc->nodes_relocated = 0;
3858 rc->merging_rsv_size = 0;
3859 rc->reserved_bytes = 0;
3860 rc->block_rsv->size = rc->extent_root->nodesize *
3861 RELOCATION_RESERVED_NODES;
3863 rc->create_reloc_tree = 1;
3864 set_reloc_control(rc);
3866 trans = btrfs_join_transaction(rc->extent_root);
3867 if (IS_ERR(trans)) {
3868 unset_reloc_control(rc);
3870 * extent tree is not a ref_cow tree and has no reloc_root to
3871 * cleanup. And callers are responsible to free the above
3874 return PTR_ERR(trans);
3876 btrfs_commit_transaction(trans, rc->extent_root);
3880 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3882 struct rb_root blocks = RB_ROOT;
3883 struct btrfs_key key;
3884 struct btrfs_trans_handle *trans = NULL;
3885 struct btrfs_path *path;
3886 struct btrfs_extent_item *ei;
3893 path = btrfs_alloc_path();
3898 ret = prepare_to_relocate(rc);
3905 rc->reserved_bytes = 0;
3906 ret = btrfs_block_rsv_refill(rc->extent_root,
3907 rc->block_rsv, rc->block_rsv->size,
3908 BTRFS_RESERVE_FLUSH_ALL);
3914 trans = btrfs_start_transaction(rc->extent_root, 0);
3915 if (IS_ERR(trans)) {
3916 err = PTR_ERR(trans);
3921 if (update_backref_cache(trans, &rc->backref_cache)) {
3922 btrfs_end_transaction(trans, rc->extent_root);
3926 ret = find_next_extent(trans, rc, path, &key);
3932 rc->extents_found++;
3934 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3935 struct btrfs_extent_item);
3936 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3937 if (item_size >= sizeof(*ei)) {
3938 flags = btrfs_extent_flags(path->nodes[0], ei);
3939 ret = check_extent_flags(flags);
3943 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3945 int path_change = 0;
3948 sizeof(struct btrfs_extent_item_v0));
3949 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3951 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3952 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3954 flags = BTRFS_EXTENT_FLAG_DATA;
3957 btrfs_release_path(path);
3959 path->search_commit_root = 1;
3960 path->skip_locking = 1;
3961 ret = btrfs_search_slot(NULL, rc->extent_root,
3974 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3975 ret = add_tree_block(rc, &key, path, &blocks);
3976 } else if (rc->stage == UPDATE_DATA_PTRS &&
3977 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3978 ret = add_data_references(rc, &key, path, &blocks);
3980 btrfs_release_path(path);
3988 if (!RB_EMPTY_ROOT(&blocks)) {
3989 ret = relocate_tree_blocks(trans, rc, &blocks);
3992 * if we fail to relocate tree blocks, force to update
3993 * backref cache when committing transaction.
3995 rc->backref_cache.last_trans = trans->transid - 1;
3997 if (ret != -EAGAIN) {
4001 rc->extents_found--;
4002 rc->search_start = key.objectid;
4006 btrfs_end_transaction_throttle(trans, rc->extent_root);
4007 btrfs_btree_balance_dirty(rc->extent_root);
4010 if (rc->stage == MOVE_DATA_EXTENTS &&
4011 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4012 rc->found_file_extent = 1;
4013 ret = relocate_data_extent(rc->data_inode,
4014 &key, &rc->cluster);
4021 if (trans && progress && err == -ENOSPC) {
4022 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4023 rc->block_group->flags);
4031 btrfs_release_path(path);
4032 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4036 btrfs_end_transaction_throttle(trans, rc->extent_root);
4037 btrfs_btree_balance_dirty(rc->extent_root);
4041 ret = relocate_file_extent_cluster(rc->data_inode,
4047 rc->create_reloc_tree = 0;
4048 set_reloc_control(rc);
4050 backref_cache_cleanup(&rc->backref_cache);
4051 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4053 err = prepare_to_merge(rc, err);
4055 merge_reloc_roots(rc);
4057 rc->merge_reloc_tree = 0;
4058 unset_reloc_control(rc);
4059 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4061 /* get rid of pinned extents */
4062 trans = btrfs_join_transaction(rc->extent_root);
4064 err = PTR_ERR(trans);
4066 btrfs_commit_transaction(trans, rc->extent_root);
4068 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4069 btrfs_free_path(path);
4073 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4074 struct btrfs_root *root, u64 objectid)
4076 struct btrfs_path *path;
4077 struct btrfs_inode_item *item;
4078 struct extent_buffer *leaf;
4081 path = btrfs_alloc_path();
4085 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4089 leaf = path->nodes[0];
4090 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4091 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4092 btrfs_set_inode_generation(leaf, item, 1);
4093 btrfs_set_inode_size(leaf, item, 0);
4094 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4095 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4096 BTRFS_INODE_PREALLOC);
4097 btrfs_mark_buffer_dirty(leaf);
4098 btrfs_release_path(path);
4100 btrfs_free_path(path);
4105 * helper to create inode for data relocation.
4106 * the inode is in data relocation tree and its link count is 0
4108 static noinline_for_stack
4109 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4110 struct btrfs_block_group_cache *group)
4112 struct inode *inode = NULL;
4113 struct btrfs_trans_handle *trans;
4114 struct btrfs_root *root;
4115 struct btrfs_key key;
4116 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4119 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4121 return ERR_CAST(root);
4123 trans = btrfs_start_transaction(root, 6);
4125 return ERR_CAST(trans);
4127 err = btrfs_find_free_objectid(root, &objectid);
4131 err = __insert_orphan_inode(trans, root, objectid);
4134 key.objectid = objectid;
4135 key.type = BTRFS_INODE_ITEM_KEY;
4137 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4138 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4139 BTRFS_I(inode)->index_cnt = group->key.objectid;
4141 err = btrfs_orphan_add(trans, inode);
4143 btrfs_end_transaction(trans, root);
4144 btrfs_btree_balance_dirty(root);
4148 inode = ERR_PTR(err);
4153 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4155 struct reloc_control *rc;
4157 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4161 INIT_LIST_HEAD(&rc->reloc_roots);
4162 backref_cache_init(&rc->backref_cache);
4163 mapping_tree_init(&rc->reloc_root_tree);
4164 extent_io_tree_init(&rc->processed_blocks,
4165 fs_info->btree_inode->i_mapping);
4170 * function to relocate all extents in a block group.
4172 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4174 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4175 struct reloc_control *rc;
4176 struct inode *inode;
4177 struct btrfs_path *path;
4182 rc = alloc_reloc_control(fs_info);
4186 rc->extent_root = extent_root;
4188 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4189 BUG_ON(!rc->block_group);
4191 if (!rc->block_group->ro) {
4192 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4200 path = btrfs_alloc_path();
4206 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4208 btrfs_free_path(path);
4211 ret = delete_block_group_cache(fs_info, inode, 0);
4213 ret = PTR_ERR(inode);
4215 if (ret && ret != -ENOENT) {
4220 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4221 if (IS_ERR(rc->data_inode)) {
4222 err = PTR_ERR(rc->data_inode);
4223 rc->data_inode = NULL;
4227 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
4228 rc->block_group->key.objectid, rc->block_group->flags);
4230 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
4235 btrfs_wait_ordered_roots(fs_info, -1);
4238 mutex_lock(&fs_info->cleaner_mutex);
4239 ret = relocate_block_group(rc);
4240 mutex_unlock(&fs_info->cleaner_mutex);
4246 if (rc->extents_found == 0)
4249 btrfs_info(extent_root->fs_info, "found %llu extents",
4252 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4253 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4259 invalidate_mapping_pages(rc->data_inode->i_mapping,
4261 rc->stage = UPDATE_DATA_PTRS;
4265 WARN_ON(rc->block_group->pinned > 0);
4266 WARN_ON(rc->block_group->reserved > 0);
4267 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4270 btrfs_set_block_group_rw(extent_root, rc->block_group);
4271 iput(rc->data_inode);
4272 btrfs_put_block_group(rc->block_group);
4277 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4279 struct btrfs_trans_handle *trans;
4282 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4284 return PTR_ERR(trans);
4286 memset(&root->root_item.drop_progress, 0,
4287 sizeof(root->root_item.drop_progress));
4288 root->root_item.drop_level = 0;
4289 btrfs_set_root_refs(&root->root_item, 0);
4290 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4291 &root->root_key, &root->root_item);
4293 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4300 * recover relocation interrupted by system crash.
4302 * this function resumes merging reloc trees with corresponding fs trees.
4303 * this is important for keeping the sharing of tree blocks
4305 int btrfs_recover_relocation(struct btrfs_root *root)
4307 LIST_HEAD(reloc_roots);
4308 struct btrfs_key key;
4309 struct btrfs_root *fs_root;
4310 struct btrfs_root *reloc_root;
4311 struct btrfs_path *path;
4312 struct extent_buffer *leaf;
4313 struct reloc_control *rc = NULL;
4314 struct btrfs_trans_handle *trans;
4318 path = btrfs_alloc_path();
4323 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4324 key.type = BTRFS_ROOT_ITEM_KEY;
4325 key.offset = (u64)-1;
4328 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4335 if (path->slots[0] == 0)
4339 leaf = path->nodes[0];
4340 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4341 btrfs_release_path(path);
4343 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4344 key.type != BTRFS_ROOT_ITEM_KEY)
4347 reloc_root = btrfs_read_fs_root(root, &key);
4348 if (IS_ERR(reloc_root)) {
4349 err = PTR_ERR(reloc_root);
4353 list_add(&reloc_root->root_list, &reloc_roots);
4355 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4356 fs_root = read_fs_root(root->fs_info,
4357 reloc_root->root_key.offset);
4358 if (IS_ERR(fs_root)) {
4359 ret = PTR_ERR(fs_root);
4360 if (ret != -ENOENT) {
4364 ret = mark_garbage_root(reloc_root);
4372 if (key.offset == 0)
4377 btrfs_release_path(path);
4379 if (list_empty(&reloc_roots))
4382 rc = alloc_reloc_control(root->fs_info);
4388 rc->extent_root = root->fs_info->extent_root;
4390 set_reloc_control(rc);
4392 trans = btrfs_join_transaction(rc->extent_root);
4393 if (IS_ERR(trans)) {
4394 unset_reloc_control(rc);
4395 err = PTR_ERR(trans);
4399 rc->merge_reloc_tree = 1;
4401 while (!list_empty(&reloc_roots)) {
4402 reloc_root = list_entry(reloc_roots.next,
4403 struct btrfs_root, root_list);
4404 list_del(&reloc_root->root_list);
4406 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4407 list_add_tail(&reloc_root->root_list,
4412 fs_root = read_fs_root(root->fs_info,
4413 reloc_root->root_key.offset);
4414 if (IS_ERR(fs_root)) {
4415 err = PTR_ERR(fs_root);
4419 err = __add_reloc_root(reloc_root);
4420 BUG_ON(err < 0); /* -ENOMEM or logic error */
4421 fs_root->reloc_root = reloc_root;
4424 err = btrfs_commit_transaction(trans, rc->extent_root);
4428 merge_reloc_roots(rc);
4430 unset_reloc_control(rc);
4432 trans = btrfs_join_transaction(rc->extent_root);
4434 err = PTR_ERR(trans);
4436 err = btrfs_commit_transaction(trans, rc->extent_root);
4440 if (!list_empty(&reloc_roots))
4441 free_reloc_roots(&reloc_roots);
4443 btrfs_free_path(path);
4446 /* cleanup orphan inode in data relocation tree */
4447 fs_root = read_fs_root(root->fs_info,
4448 BTRFS_DATA_RELOC_TREE_OBJECTID);
4449 if (IS_ERR(fs_root))
4450 err = PTR_ERR(fs_root);
4452 err = btrfs_orphan_cleanup(fs_root);
4458 * helper to add ordered checksum for data relocation.
4460 * cloning checksum properly handles the nodatasum extents.
4461 * it also saves CPU time to re-calculate the checksum.
4463 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4465 struct btrfs_ordered_sum *sums;
4466 struct btrfs_ordered_extent *ordered;
4467 struct btrfs_root *root = BTRFS_I(inode)->root;
4473 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4474 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4476 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4477 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4478 disk_bytenr + len - 1, &list, 0);
4482 while (!list_empty(&list)) {
4483 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4484 list_del_init(&sums->list);
4487 * We need to offset the new_bytenr based on where the csum is.
4488 * We need to do this because we will read in entire prealloc
4489 * extents but we may have written to say the middle of the
4490 * prealloc extent, so we need to make sure the csum goes with
4491 * the right disk offset.
4493 * We can do this because the data reloc inode refers strictly
4494 * to the on disk bytes, so we don't have to worry about
4495 * disk_len vs real len like with real inodes since it's all
4498 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4499 sums->bytenr = new_bytenr;
4501 btrfs_add_ordered_sum(inode, ordered, sums);
4504 btrfs_put_ordered_extent(ordered);
4508 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4509 struct btrfs_root *root, struct extent_buffer *buf,
4510 struct extent_buffer *cow)
4512 struct reloc_control *rc;
4513 struct backref_node *node;
4518 rc = root->fs_info->reloc_ctl;
4522 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4523 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4525 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4526 if (buf == root->node)
4527 __update_reloc_root(root, cow->start);
4530 level = btrfs_header_level(buf);
4531 if (btrfs_header_generation(buf) <=
4532 btrfs_root_last_snapshot(&root->root_item))
4535 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4536 rc->create_reloc_tree) {
4537 WARN_ON(!first_cow && level == 0);
4539 node = rc->backref_cache.path[level];
4540 BUG_ON(node->bytenr != buf->start &&
4541 node->new_bytenr != buf->start);
4543 drop_node_buffer(node);
4544 extent_buffer_get(cow);
4546 node->new_bytenr = cow->start;
4548 if (!node->pending) {
4549 list_move_tail(&node->list,
4550 &rc->backref_cache.pending[level]);
4555 __mark_block_processed(rc, node);
4557 if (first_cow && level > 0)
4558 rc->nodes_relocated += buf->len;
4561 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4562 ret = replace_file_extents(trans, rc, root, cow);
4567 * called before creating snapshot. it calculates metadata reservation
4568 * requried for relocating tree blocks in the snapshot
4570 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4571 struct btrfs_pending_snapshot *pending,
4572 u64 *bytes_to_reserve)
4574 struct btrfs_root *root;
4575 struct reloc_control *rc;
4577 root = pending->root;
4578 if (!root->reloc_root)
4581 rc = root->fs_info->reloc_ctl;
4582 if (!rc->merge_reloc_tree)
4585 root = root->reloc_root;
4586 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4588 * relocation is in the stage of merging trees. the space
4589 * used by merging a reloc tree is twice the size of
4590 * relocated tree nodes in the worst case. half for cowing
4591 * the reloc tree, half for cowing the fs tree. the space
4592 * used by cowing the reloc tree will be freed after the
4593 * tree is dropped. if we create snapshot, cowing the fs
4594 * tree may use more space than it frees. so we need
4595 * reserve extra space.
4597 *bytes_to_reserve += rc->nodes_relocated;
4601 * called after snapshot is created. migrate block reservation
4602 * and create reloc root for the newly created snapshot
4604 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4605 struct btrfs_pending_snapshot *pending)
4607 struct btrfs_root *root = pending->root;
4608 struct btrfs_root *reloc_root;
4609 struct btrfs_root *new_root;
4610 struct reloc_control *rc;
4613 if (!root->reloc_root)
4616 rc = root->fs_info->reloc_ctl;
4617 rc->merging_rsv_size += rc->nodes_relocated;
4619 if (rc->merge_reloc_tree) {
4620 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4622 rc->nodes_relocated);
4627 new_root = pending->snap;
4628 reloc_root = create_reloc_root(trans, root->reloc_root,
4629 new_root->root_key.objectid);
4630 if (IS_ERR(reloc_root))
4631 return PTR_ERR(reloc_root);
4633 ret = __add_reloc_root(reloc_root);
4635 new_root->reloc_root = reloc_root;
4637 if (rc->create_reloc_tree)
4638 ret = clone_backref_node(trans, rc, root, reloc_root);