2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node;
44 * present a tree block in the backref cache
47 struct rb_node rb_node;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list;
55 /* list of upper level blocks reference this block */
56 struct list_head upper;
57 /* list of child blocks in the cache */
58 struct list_head lower;
59 /* NULL if this node is not tree root */
60 struct btrfs_root *root;
61 /* extent buffer got by COW the block */
62 struct extent_buffer *eb;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest:1;
69 /* is the extent buffer locked */
70 unsigned int locked:1;
71 /* has the block been processed */
72 unsigned int processed:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached:1;
88 * present a block pointer in the backref cache
91 struct list_head list[2];
92 struct backref_node *node[2];
97 #define RELOCATION_RESERVED_NODES 256
99 struct backref_cache {
100 /* red black tree of all backref nodes in the cache */
101 struct rb_root rb_root;
102 /* for passing backref nodes to btrfs_reloc_cow_block */
103 struct backref_node *path[BTRFS_MAX_LEVEL];
105 * list of blocks that have been cowed but some block
106 * pointers in upper level blocks may not reflect the
109 struct list_head pending[BTRFS_MAX_LEVEL];
110 /* list of backref nodes with no child node */
111 struct list_head leaves;
112 /* list of blocks that have been cowed in current transaction */
113 struct list_head changed;
114 /* list of detached backref node. */
115 struct list_head detached;
124 * map address of tree root to tree
126 struct mapping_node {
127 struct rb_node rb_node;
132 struct mapping_tree {
133 struct rb_root rb_root;
138 * present a tree block to process
141 struct rb_node rb_node;
143 struct btrfs_key key;
144 unsigned int level:8;
145 unsigned int key_ready:1;
148 #define MAX_EXTENTS 128
150 struct file_extent_cluster {
153 u64 boundary[MAX_EXTENTS];
157 struct reloc_control {
158 /* block group to relocate */
159 struct btrfs_block_group_cache *block_group;
161 struct btrfs_root *extent_root;
162 /* inode for moving data */
163 struct inode *data_inode;
165 struct btrfs_block_rsv *block_rsv;
167 struct backref_cache backref_cache;
169 struct file_extent_cluster cluster;
170 /* tree blocks have been processed */
171 struct extent_io_tree processed_blocks;
172 /* map start of tree root to corresponding reloc tree */
173 struct mapping_tree reloc_root_tree;
174 /* list of reloc trees */
175 struct list_head reloc_roots;
176 /* size of metadata reservation for merging reloc trees */
177 u64 merging_rsv_size;
178 /* size of relocated tree nodes */
180 /* reserved size for block group relocation*/
186 unsigned int stage:8;
187 unsigned int create_reloc_tree:1;
188 unsigned int merge_reloc_tree:1;
189 unsigned int found_file_extent:1;
192 /* stages of data relocation */
193 #define MOVE_DATA_EXTENTS 0
194 #define UPDATE_DATA_PTRS 1
196 static void remove_backref_node(struct backref_cache *cache,
197 struct backref_node *node);
198 static void __mark_block_processed(struct reloc_control *rc,
199 struct backref_node *node);
201 static void mapping_tree_init(struct mapping_tree *tree)
203 tree->rb_root = RB_ROOT;
204 spin_lock_init(&tree->lock);
207 static void backref_cache_init(struct backref_cache *cache)
210 cache->rb_root = RB_ROOT;
211 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
212 INIT_LIST_HEAD(&cache->pending[i]);
213 INIT_LIST_HEAD(&cache->changed);
214 INIT_LIST_HEAD(&cache->detached);
215 INIT_LIST_HEAD(&cache->leaves);
218 static void backref_cache_cleanup(struct backref_cache *cache)
220 struct backref_node *node;
223 while (!list_empty(&cache->detached)) {
224 node = list_entry(cache->detached.next,
225 struct backref_node, list);
226 remove_backref_node(cache, node);
229 while (!list_empty(&cache->leaves)) {
230 node = list_entry(cache->leaves.next,
231 struct backref_node, lower);
232 remove_backref_node(cache, node);
235 cache->last_trans = 0;
237 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
238 BUG_ON(!list_empty(&cache->pending[i]));
239 BUG_ON(!list_empty(&cache->changed));
240 BUG_ON(!list_empty(&cache->detached));
241 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
242 BUG_ON(cache->nr_nodes);
243 BUG_ON(cache->nr_edges);
246 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
248 struct backref_node *node;
250 node = kzalloc(sizeof(*node), GFP_NOFS);
252 INIT_LIST_HEAD(&node->list);
253 INIT_LIST_HEAD(&node->upper);
254 INIT_LIST_HEAD(&node->lower);
255 RB_CLEAR_NODE(&node->rb_node);
261 static void free_backref_node(struct backref_cache *cache,
262 struct backref_node *node)
270 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
272 struct backref_edge *edge;
274 edge = kzalloc(sizeof(*edge), GFP_NOFS);
280 static void free_backref_edge(struct backref_cache *cache,
281 struct backref_edge *edge)
289 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
290 struct rb_node *node)
292 struct rb_node **p = &root->rb_node;
293 struct rb_node *parent = NULL;
294 struct tree_entry *entry;
298 entry = rb_entry(parent, struct tree_entry, rb_node);
300 if (bytenr < entry->bytenr)
302 else if (bytenr > entry->bytenr)
308 rb_link_node(node, parent, p);
309 rb_insert_color(node, root);
313 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
315 struct rb_node *n = root->rb_node;
316 struct tree_entry *entry;
319 entry = rb_entry(n, struct tree_entry, rb_node);
321 if (bytenr < entry->bytenr)
323 else if (bytenr > entry->bytenr)
331 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
334 struct btrfs_fs_info *fs_info = NULL;
335 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
338 fs_info = bnode->root->fs_info;
339 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
340 "found at offset %llu", bytenr);
344 * walk up backref nodes until reach node presents tree root
346 static struct backref_node *walk_up_backref(struct backref_node *node,
347 struct backref_edge *edges[],
350 struct backref_edge *edge;
353 while (!list_empty(&node->upper)) {
354 edge = list_entry(node->upper.next,
355 struct backref_edge, list[LOWER]);
357 node = edge->node[UPPER];
359 BUG_ON(node->detached);
365 * walk down backref nodes to find start of next reference path
367 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
370 struct backref_edge *edge;
371 struct backref_node *lower;
375 edge = edges[idx - 1];
376 lower = edge->node[LOWER];
377 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
381 edge = list_entry(edge->list[LOWER].next,
382 struct backref_edge, list[LOWER]);
383 edges[idx - 1] = edge;
385 return edge->node[UPPER];
391 static void unlock_node_buffer(struct backref_node *node)
394 btrfs_tree_unlock(node->eb);
399 static void drop_node_buffer(struct backref_node *node)
402 unlock_node_buffer(node);
403 free_extent_buffer(node->eb);
408 static void drop_backref_node(struct backref_cache *tree,
409 struct backref_node *node)
411 BUG_ON(!list_empty(&node->upper));
413 drop_node_buffer(node);
414 list_del(&node->list);
415 list_del(&node->lower);
416 if (!RB_EMPTY_NODE(&node->rb_node))
417 rb_erase(&node->rb_node, &tree->rb_root);
418 free_backref_node(tree, node);
422 * remove a backref node from the backref cache
424 static void remove_backref_node(struct backref_cache *cache,
425 struct backref_node *node)
427 struct backref_node *upper;
428 struct backref_edge *edge;
433 BUG_ON(!node->lowest && !node->detached);
434 while (!list_empty(&node->upper)) {
435 edge = list_entry(node->upper.next, struct backref_edge,
437 upper = edge->node[UPPER];
438 list_del(&edge->list[LOWER]);
439 list_del(&edge->list[UPPER]);
440 free_backref_edge(cache, edge);
442 if (RB_EMPTY_NODE(&upper->rb_node)) {
443 BUG_ON(!list_empty(&node->upper));
444 drop_backref_node(cache, node);
450 * add the node to leaf node list if no other
451 * child block cached.
453 if (list_empty(&upper->lower)) {
454 list_add_tail(&upper->lower, &cache->leaves);
459 drop_backref_node(cache, node);
462 static void update_backref_node(struct backref_cache *cache,
463 struct backref_node *node, u64 bytenr)
465 struct rb_node *rb_node;
466 rb_erase(&node->rb_node, &cache->rb_root);
467 node->bytenr = bytenr;
468 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
470 backref_tree_panic(rb_node, -EEXIST, bytenr);
474 * update backref cache after a transaction commit
476 static int update_backref_cache(struct btrfs_trans_handle *trans,
477 struct backref_cache *cache)
479 struct backref_node *node;
482 if (cache->last_trans == 0) {
483 cache->last_trans = trans->transid;
487 if (cache->last_trans == trans->transid)
491 * detached nodes are used to avoid unnecessary backref
492 * lookup. transaction commit changes the extent tree.
493 * so the detached nodes are no longer useful.
495 while (!list_empty(&cache->detached)) {
496 node = list_entry(cache->detached.next,
497 struct backref_node, list);
498 remove_backref_node(cache, node);
501 while (!list_empty(&cache->changed)) {
502 node = list_entry(cache->changed.next,
503 struct backref_node, list);
504 list_del_init(&node->list);
505 BUG_ON(node->pending);
506 update_backref_node(cache, node, node->new_bytenr);
510 * some nodes can be left in the pending list if there were
511 * errors during processing the pending nodes.
513 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
514 list_for_each_entry(node, &cache->pending[level], list) {
515 BUG_ON(!node->pending);
516 if (node->bytenr == node->new_bytenr)
518 update_backref_node(cache, node, node->new_bytenr);
522 cache->last_trans = 0;
527 static int should_ignore_root(struct btrfs_root *root)
529 struct btrfs_root *reloc_root;
531 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
534 reloc_root = root->reloc_root;
538 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
539 root->fs_info->running_transaction->transid - 1)
542 * if there is reloc tree and it was created in previous
543 * transaction backref lookup can find the reloc tree,
544 * so backref node for the fs tree root is useless for
550 * find reloc tree by address of tree root
552 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
555 struct rb_node *rb_node;
556 struct mapping_node *node;
557 struct btrfs_root *root = NULL;
559 spin_lock(&rc->reloc_root_tree.lock);
560 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
562 node = rb_entry(rb_node, struct mapping_node, rb_node);
563 root = (struct btrfs_root *)node->data;
565 spin_unlock(&rc->reloc_root_tree.lock);
569 static int is_cowonly_root(u64 root_objectid)
571 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
572 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
573 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
574 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
575 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
576 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
577 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
578 root_objectid == BTRFS_QUOTA_TREE_OBJECTID)
583 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
586 struct btrfs_key key;
588 key.objectid = root_objectid;
589 key.type = BTRFS_ROOT_ITEM_KEY;
590 if (is_cowonly_root(root_objectid))
593 key.offset = (u64)-1;
595 return btrfs_get_fs_root(fs_info, &key, false);
598 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
599 static noinline_for_stack
600 struct btrfs_root *find_tree_root(struct reloc_control *rc,
601 struct extent_buffer *leaf,
602 struct btrfs_extent_ref_v0 *ref0)
604 struct btrfs_root *root;
605 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
606 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
608 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
610 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
611 BUG_ON(IS_ERR(root));
613 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
614 generation != btrfs_root_generation(&root->root_item))
621 static noinline_for_stack
622 int find_inline_backref(struct extent_buffer *leaf, int slot,
623 unsigned long *ptr, unsigned long *end)
625 struct btrfs_key key;
626 struct btrfs_extent_item *ei;
627 struct btrfs_tree_block_info *bi;
630 btrfs_item_key_to_cpu(leaf, &key, slot);
632 item_size = btrfs_item_size_nr(leaf, slot);
633 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
634 if (item_size < sizeof(*ei)) {
635 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
639 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
640 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
641 BTRFS_EXTENT_FLAG_TREE_BLOCK));
643 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
644 item_size <= sizeof(*ei) + sizeof(*bi)) {
645 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
648 if (key.type == BTRFS_METADATA_ITEM_KEY &&
649 item_size <= sizeof(*ei)) {
650 WARN_ON(item_size < sizeof(*ei));
654 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
655 bi = (struct btrfs_tree_block_info *)(ei + 1);
656 *ptr = (unsigned long)(bi + 1);
658 *ptr = (unsigned long)(ei + 1);
660 *end = (unsigned long)ei + item_size;
665 * build backref tree for a given tree block. root of the backref tree
666 * corresponds the tree block, leaves of the backref tree correspond
667 * roots of b-trees that reference the tree block.
669 * the basic idea of this function is check backrefs of a given block
670 * to find upper level blocks that refernece the block, and then check
671 * bakcrefs of these upper level blocks recursively. the recursion stop
672 * when tree root is reached or backrefs for the block is cached.
674 * NOTE: if we find backrefs for a block are cached, we know backrefs
675 * for all upper level blocks that directly/indirectly reference the
676 * block are also cached.
678 static noinline_for_stack
679 struct backref_node *build_backref_tree(struct reloc_control *rc,
680 struct btrfs_key *node_key,
681 int level, u64 bytenr)
683 struct backref_cache *cache = &rc->backref_cache;
684 struct btrfs_path *path1;
685 struct btrfs_path *path2;
686 struct extent_buffer *eb;
687 struct btrfs_root *root;
688 struct backref_node *cur;
689 struct backref_node *upper;
690 struct backref_node *lower;
691 struct backref_node *node = NULL;
692 struct backref_node *exist = NULL;
693 struct backref_edge *edge;
694 struct rb_node *rb_node;
695 struct btrfs_key key;
703 bool need_check = true;
705 path1 = btrfs_alloc_path();
706 path2 = btrfs_alloc_path();
707 if (!path1 || !path2) {
714 node = alloc_backref_node(cache);
720 node->bytenr = bytenr;
727 key.objectid = cur->bytenr;
728 key.type = BTRFS_METADATA_ITEM_KEY;
729 key.offset = (u64)-1;
731 path1->search_commit_root = 1;
732 path1->skip_locking = 1;
733 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
740 ASSERT(path1->slots[0]);
744 WARN_ON(cur->checked);
745 if (!list_empty(&cur->upper)) {
747 * the backref was added previously when processing
748 * backref of type BTRFS_TREE_BLOCK_REF_KEY
750 ASSERT(list_is_singular(&cur->upper));
751 edge = list_entry(cur->upper.next, struct backref_edge,
753 ASSERT(list_empty(&edge->list[UPPER]));
754 exist = edge->node[UPPER];
756 * add the upper level block to pending list if we need
760 list_add_tail(&edge->list[UPPER], &list);
767 eb = path1->nodes[0];
770 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
771 ret = btrfs_next_leaf(rc->extent_root, path1);
778 eb = path1->nodes[0];
781 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
782 if (key.objectid != cur->bytenr) {
787 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
788 key.type == BTRFS_METADATA_ITEM_KEY) {
789 ret = find_inline_backref(eb, path1->slots[0],
797 /* update key for inline back ref */
798 struct btrfs_extent_inline_ref *iref;
799 iref = (struct btrfs_extent_inline_ref *)ptr;
800 key.type = btrfs_extent_inline_ref_type(eb, iref);
801 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
802 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
803 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
807 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
808 exist->owner == key.offset) ||
809 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
810 exist->bytenr == key.offset))) {
815 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
816 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
817 key.type == BTRFS_EXTENT_REF_V0_KEY) {
818 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
819 struct btrfs_extent_ref_v0 *ref0;
820 ref0 = btrfs_item_ptr(eb, path1->slots[0],
821 struct btrfs_extent_ref_v0);
822 if (key.objectid == key.offset) {
823 root = find_tree_root(rc, eb, ref0);
824 if (root && !should_ignore_root(root))
827 list_add(&cur->list, &useless);
830 if (is_cowonly_root(btrfs_ref_root_v0(eb,
835 ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
836 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
838 if (key.objectid == key.offset) {
840 * only root blocks of reloc trees use
841 * backref of this type.
843 root = find_reloc_root(rc, cur->bytenr);
849 edge = alloc_backref_edge(cache);
854 rb_node = tree_search(&cache->rb_root, key.offset);
856 upper = alloc_backref_node(cache);
858 free_backref_edge(cache, edge);
862 upper->bytenr = key.offset;
863 upper->level = cur->level + 1;
865 * backrefs for the upper level block isn't
866 * cached, add the block to pending list
868 list_add_tail(&edge->list[UPPER], &list);
870 upper = rb_entry(rb_node, struct backref_node,
872 ASSERT(upper->checked);
873 INIT_LIST_HEAD(&edge->list[UPPER]);
875 list_add_tail(&edge->list[LOWER], &cur->upper);
876 edge->node[LOWER] = cur;
877 edge->node[UPPER] = upper;
880 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
884 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
885 root = read_fs_root(rc->extent_root->fs_info, key.offset);
891 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
894 if (btrfs_root_level(&root->root_item) == cur->level) {
896 ASSERT(btrfs_root_bytenr(&root->root_item) ==
898 if (should_ignore_root(root))
899 list_add(&cur->list, &useless);
905 level = cur->level + 1;
908 * searching the tree to find upper level blocks
909 * reference the block.
911 path2->search_commit_root = 1;
912 path2->skip_locking = 1;
913 path2->lowest_level = level;
914 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
915 path2->lowest_level = 0;
920 if (ret > 0 && path2->slots[level] > 0)
921 path2->slots[level]--;
923 eb = path2->nodes[level];
924 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
929 for (; level < BTRFS_MAX_LEVEL; level++) {
930 if (!path2->nodes[level]) {
931 ASSERT(btrfs_root_bytenr(&root->root_item) ==
933 if (should_ignore_root(root))
934 list_add(&lower->list, &useless);
940 edge = alloc_backref_edge(cache);
946 eb = path2->nodes[level];
947 rb_node = tree_search(&cache->rb_root, eb->start);
949 upper = alloc_backref_node(cache);
951 free_backref_edge(cache, edge);
955 upper->bytenr = eb->start;
956 upper->owner = btrfs_header_owner(eb);
957 upper->level = lower->level + 1;
958 if (!test_bit(BTRFS_ROOT_REF_COWS,
963 * if we know the block isn't shared
964 * we can void checking its backrefs.
966 if (btrfs_block_can_be_shared(root, eb))
972 * add the block to pending list if we
973 * need check its backrefs, we only do this once
974 * while walking up a tree as we will catch
975 * anything else later on.
977 if (!upper->checked && need_check) {
979 list_add_tail(&edge->list[UPPER],
984 INIT_LIST_HEAD(&edge->list[UPPER]);
987 upper = rb_entry(rb_node, struct backref_node,
989 ASSERT(upper->checked);
990 INIT_LIST_HEAD(&edge->list[UPPER]);
992 upper->owner = btrfs_header_owner(eb);
994 list_add_tail(&edge->list[LOWER], &lower->upper);
995 edge->node[LOWER] = lower;
996 edge->node[UPPER] = upper;
1003 btrfs_release_path(path2);
1006 ptr += btrfs_extent_inline_ref_size(key.type);
1016 btrfs_release_path(path1);
1021 /* the pending list isn't empty, take the first block to process */
1022 if (!list_empty(&list)) {
1023 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1024 list_del_init(&edge->list[UPPER]);
1025 cur = edge->node[UPPER];
1030 * everything goes well, connect backref nodes and insert backref nodes
1033 ASSERT(node->checked);
1034 cowonly = node->cowonly;
1036 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1039 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1040 list_add_tail(&node->lower, &cache->leaves);
1043 list_for_each_entry(edge, &node->upper, list[LOWER])
1044 list_add_tail(&edge->list[UPPER], &list);
1046 while (!list_empty(&list)) {
1047 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1048 list_del_init(&edge->list[UPPER]);
1049 upper = edge->node[UPPER];
1050 if (upper->detached) {
1051 list_del(&edge->list[LOWER]);
1052 lower = edge->node[LOWER];
1053 free_backref_edge(cache, edge);
1054 if (list_empty(&lower->upper))
1055 list_add(&lower->list, &useless);
1059 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1060 if (upper->lowest) {
1061 list_del_init(&upper->lower);
1065 list_add_tail(&edge->list[UPPER], &upper->lower);
1069 if (!upper->checked) {
1071 * Still want to blow up for developers since this is a
1078 if (cowonly != upper->cowonly) {
1085 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1088 backref_tree_panic(rb_node, -EEXIST,
1092 list_add_tail(&edge->list[UPPER], &upper->lower);
1094 list_for_each_entry(edge, &upper->upper, list[LOWER])
1095 list_add_tail(&edge->list[UPPER], &list);
1098 * process useless backref nodes. backref nodes for tree leaves
1099 * are deleted from the cache. backref nodes for upper level
1100 * tree blocks are left in the cache to avoid unnecessary backref
1103 while (!list_empty(&useless)) {
1104 upper = list_entry(useless.next, struct backref_node, list);
1105 list_del_init(&upper->list);
1106 ASSERT(list_empty(&upper->upper));
1109 if (upper->lowest) {
1110 list_del_init(&upper->lower);
1113 while (!list_empty(&upper->lower)) {
1114 edge = list_entry(upper->lower.next,
1115 struct backref_edge, list[UPPER]);
1116 list_del(&edge->list[UPPER]);
1117 list_del(&edge->list[LOWER]);
1118 lower = edge->node[LOWER];
1119 free_backref_edge(cache, edge);
1121 if (list_empty(&lower->upper))
1122 list_add(&lower->list, &useless);
1124 __mark_block_processed(rc, upper);
1125 if (upper->level > 0) {
1126 list_add(&upper->list, &cache->detached);
1127 upper->detached = 1;
1129 rb_erase(&upper->rb_node, &cache->rb_root);
1130 free_backref_node(cache, upper);
1134 btrfs_free_path(path1);
1135 btrfs_free_path(path2);
1137 while (!list_empty(&useless)) {
1138 lower = list_entry(useless.next,
1139 struct backref_node, list);
1140 list_del_init(&lower->list);
1142 while (!list_empty(&list)) {
1143 edge = list_first_entry(&list, struct backref_edge,
1145 list_del(&edge->list[UPPER]);
1146 list_del(&edge->list[LOWER]);
1147 lower = edge->node[LOWER];
1148 upper = edge->node[UPPER];
1149 free_backref_edge(cache, edge);
1152 * Lower is no longer linked to any upper backref nodes
1153 * and isn't in the cache, we can free it ourselves.
1155 if (list_empty(&lower->upper) &&
1156 RB_EMPTY_NODE(&lower->rb_node))
1157 list_add(&lower->list, &useless);
1159 if (!RB_EMPTY_NODE(&upper->rb_node))
1162 /* Add this guy's upper edges to the list to proces */
1163 list_for_each_entry(edge, &upper->upper, list[LOWER])
1164 list_add_tail(&edge->list[UPPER], &list);
1165 if (list_empty(&upper->upper))
1166 list_add(&upper->list, &useless);
1169 while (!list_empty(&useless)) {
1170 lower = list_entry(useless.next,
1171 struct backref_node, list);
1172 list_del_init(&lower->list);
1173 free_backref_node(cache, lower);
1175 return ERR_PTR(err);
1177 ASSERT(!node || !node->detached);
1182 * helper to add backref node for the newly created snapshot.
1183 * the backref node is created by cloning backref node that
1184 * corresponds to root of source tree
1186 static int clone_backref_node(struct btrfs_trans_handle *trans,
1187 struct reloc_control *rc,
1188 struct btrfs_root *src,
1189 struct btrfs_root *dest)
1191 struct btrfs_root *reloc_root = src->reloc_root;
1192 struct backref_cache *cache = &rc->backref_cache;
1193 struct backref_node *node = NULL;
1194 struct backref_node *new_node;
1195 struct backref_edge *edge;
1196 struct backref_edge *new_edge;
1197 struct rb_node *rb_node;
1199 if (cache->last_trans > 0)
1200 update_backref_cache(trans, cache);
1202 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1204 node = rb_entry(rb_node, struct backref_node, rb_node);
1208 BUG_ON(node->new_bytenr != reloc_root->node->start);
1212 rb_node = tree_search(&cache->rb_root,
1213 reloc_root->commit_root->start);
1215 node = rb_entry(rb_node, struct backref_node,
1217 BUG_ON(node->detached);
1224 new_node = alloc_backref_node(cache);
1228 new_node->bytenr = dest->node->start;
1229 new_node->level = node->level;
1230 new_node->lowest = node->lowest;
1231 new_node->checked = 1;
1232 new_node->root = dest;
1234 if (!node->lowest) {
1235 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1236 new_edge = alloc_backref_edge(cache);
1240 new_edge->node[UPPER] = new_node;
1241 new_edge->node[LOWER] = edge->node[LOWER];
1242 list_add_tail(&new_edge->list[UPPER],
1246 list_add_tail(&new_node->lower, &cache->leaves);
1249 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1250 &new_node->rb_node);
1252 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1254 if (!new_node->lowest) {
1255 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1256 list_add_tail(&new_edge->list[LOWER],
1257 &new_edge->node[LOWER]->upper);
1262 while (!list_empty(&new_node->lower)) {
1263 new_edge = list_entry(new_node->lower.next,
1264 struct backref_edge, list[UPPER]);
1265 list_del(&new_edge->list[UPPER]);
1266 free_backref_edge(cache, new_edge);
1268 free_backref_node(cache, new_node);
1273 * helper to add 'address of tree root -> reloc tree' mapping
1275 static int __must_check __add_reloc_root(struct btrfs_root *root)
1277 struct rb_node *rb_node;
1278 struct mapping_node *node;
1279 struct reloc_control *rc = root->fs_info->reloc_ctl;
1281 node = kmalloc(sizeof(*node), GFP_NOFS);
1285 node->bytenr = root->node->start;
1288 spin_lock(&rc->reloc_root_tree.lock);
1289 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1290 node->bytenr, &node->rb_node);
1291 spin_unlock(&rc->reloc_root_tree.lock);
1293 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1294 "for start=%llu while inserting into relocation "
1295 "tree", node->bytenr);
1300 list_add_tail(&root->root_list, &rc->reloc_roots);
1305 * helper to delete the 'address of tree root -> reloc tree'
1308 static void __del_reloc_root(struct btrfs_root *root)
1310 struct rb_node *rb_node;
1311 struct mapping_node *node = NULL;
1312 struct reloc_control *rc = root->fs_info->reloc_ctl;
1314 spin_lock(&rc->reloc_root_tree.lock);
1315 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1318 node = rb_entry(rb_node, struct mapping_node, rb_node);
1319 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1321 spin_unlock(&rc->reloc_root_tree.lock);
1325 BUG_ON((struct btrfs_root *)node->data != root);
1327 spin_lock(&root->fs_info->trans_lock);
1328 list_del_init(&root->root_list);
1329 spin_unlock(&root->fs_info->trans_lock);
1334 * helper to update the 'address of tree root -> reloc tree'
1337 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1339 struct rb_node *rb_node;
1340 struct mapping_node *node = NULL;
1341 struct reloc_control *rc = root->fs_info->reloc_ctl;
1343 spin_lock(&rc->reloc_root_tree.lock);
1344 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1347 node = rb_entry(rb_node, struct mapping_node, rb_node);
1348 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1350 spin_unlock(&rc->reloc_root_tree.lock);
1354 BUG_ON((struct btrfs_root *)node->data != root);
1356 spin_lock(&rc->reloc_root_tree.lock);
1357 node->bytenr = new_bytenr;
1358 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1359 node->bytenr, &node->rb_node);
1360 spin_unlock(&rc->reloc_root_tree.lock);
1362 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1366 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1367 struct btrfs_root *root, u64 objectid)
1369 struct btrfs_root *reloc_root;
1370 struct extent_buffer *eb;
1371 struct btrfs_root_item *root_item;
1372 struct btrfs_key root_key;
1376 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1379 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1380 root_key.type = BTRFS_ROOT_ITEM_KEY;
1381 root_key.offset = objectid;
1383 if (root->root_key.objectid == objectid) {
1384 /* called by btrfs_init_reloc_root */
1385 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1386 BTRFS_TREE_RELOC_OBJECTID);
1389 last_snap = btrfs_root_last_snapshot(&root->root_item);
1390 btrfs_set_root_last_snapshot(&root->root_item,
1391 trans->transid - 1);
1394 * called by btrfs_reloc_post_snapshot_hook.
1395 * the source tree is a reloc tree, all tree blocks
1396 * modified after it was created have RELOC flag
1397 * set in their headers. so it's OK to not update
1398 * the 'last_snapshot'.
1400 ret = btrfs_copy_root(trans, root, root->node, &eb,
1401 BTRFS_TREE_RELOC_OBJECTID);
1405 memcpy(root_item, &root->root_item, sizeof(*root_item));
1406 btrfs_set_root_bytenr(root_item, eb->start);
1407 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1408 btrfs_set_root_generation(root_item, trans->transid);
1410 if (root->root_key.objectid == objectid) {
1411 btrfs_set_root_refs(root_item, 0);
1412 memset(&root_item->drop_progress, 0,
1413 sizeof(struct btrfs_disk_key));
1414 root_item->drop_level = 0;
1416 * abuse rtransid, it is safe because it is impossible to
1417 * receive data into a relocation tree.
1419 btrfs_set_root_rtransid(root_item, last_snap);
1420 btrfs_set_root_otransid(root_item, trans->transid);
1423 btrfs_tree_unlock(eb);
1424 free_extent_buffer(eb);
1426 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1427 &root_key, root_item);
1431 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1432 BUG_ON(IS_ERR(reloc_root));
1433 reloc_root->last_trans = trans->transid;
1438 * create reloc tree for a given fs tree. reloc tree is just a
1439 * snapshot of the fs tree with special root objectid.
1441 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1442 struct btrfs_root *root)
1444 struct btrfs_root *reloc_root;
1445 struct reloc_control *rc = root->fs_info->reloc_ctl;
1446 struct btrfs_block_rsv *rsv;
1450 if (root->reloc_root) {
1451 reloc_root = root->reloc_root;
1452 reloc_root->last_trans = trans->transid;
1456 if (!rc || !rc->create_reloc_tree ||
1457 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1460 if (!trans->reloc_reserved) {
1461 rsv = trans->block_rsv;
1462 trans->block_rsv = rc->block_rsv;
1465 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1467 trans->block_rsv = rsv;
1469 ret = __add_reloc_root(reloc_root);
1471 root->reloc_root = reloc_root;
1476 * update root item of reloc tree
1478 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1479 struct btrfs_root *root)
1481 struct btrfs_root *reloc_root;
1482 struct btrfs_root_item *root_item;
1485 if (!root->reloc_root)
1488 reloc_root = root->reloc_root;
1489 root_item = &reloc_root->root_item;
1491 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1492 btrfs_root_refs(root_item) == 0) {
1493 root->reloc_root = NULL;
1494 __del_reloc_root(reloc_root);
1497 if (reloc_root->commit_root != reloc_root->node) {
1498 btrfs_set_root_node(root_item, reloc_root->node);
1499 free_extent_buffer(reloc_root->commit_root);
1500 reloc_root->commit_root = btrfs_root_node(reloc_root);
1503 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1504 &reloc_root->root_key, root_item);
1512 * helper to find first cached inode with inode number >= objectid
1515 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1517 struct rb_node *node;
1518 struct rb_node *prev;
1519 struct btrfs_inode *entry;
1520 struct inode *inode;
1522 spin_lock(&root->inode_lock);
1524 node = root->inode_tree.rb_node;
1528 entry = rb_entry(node, struct btrfs_inode, rb_node);
1530 if (objectid < btrfs_ino(&entry->vfs_inode))
1531 node = node->rb_left;
1532 else if (objectid > btrfs_ino(&entry->vfs_inode))
1533 node = node->rb_right;
1539 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1540 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1544 prev = rb_next(prev);
1548 entry = rb_entry(node, struct btrfs_inode, rb_node);
1549 inode = igrab(&entry->vfs_inode);
1551 spin_unlock(&root->inode_lock);
1555 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1556 if (cond_resched_lock(&root->inode_lock))
1559 node = rb_next(node);
1561 spin_unlock(&root->inode_lock);
1565 static int in_block_group(u64 bytenr,
1566 struct btrfs_block_group_cache *block_group)
1568 if (bytenr >= block_group->key.objectid &&
1569 bytenr < block_group->key.objectid + block_group->key.offset)
1575 * get new location of data
1577 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1578 u64 bytenr, u64 num_bytes)
1580 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1581 struct btrfs_path *path;
1582 struct btrfs_file_extent_item *fi;
1583 struct extent_buffer *leaf;
1586 path = btrfs_alloc_path();
1590 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1591 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1600 leaf = path->nodes[0];
1601 fi = btrfs_item_ptr(leaf, path->slots[0],
1602 struct btrfs_file_extent_item);
1604 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1605 btrfs_file_extent_compression(leaf, fi) ||
1606 btrfs_file_extent_encryption(leaf, fi) ||
1607 btrfs_file_extent_other_encoding(leaf, fi));
1609 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1614 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1617 btrfs_free_path(path);
1622 * update file extent items in the tree leaf to point to
1623 * the new locations.
1625 static noinline_for_stack
1626 int replace_file_extents(struct btrfs_trans_handle *trans,
1627 struct reloc_control *rc,
1628 struct btrfs_root *root,
1629 struct extent_buffer *leaf)
1631 struct btrfs_key key;
1632 struct btrfs_file_extent_item *fi;
1633 struct inode *inode = NULL;
1645 if (rc->stage != UPDATE_DATA_PTRS)
1648 /* reloc trees always use full backref */
1649 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1650 parent = leaf->start;
1654 nritems = btrfs_header_nritems(leaf);
1655 for (i = 0; i < nritems; i++) {
1657 btrfs_item_key_to_cpu(leaf, &key, i);
1658 if (key.type != BTRFS_EXTENT_DATA_KEY)
1660 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1661 if (btrfs_file_extent_type(leaf, fi) ==
1662 BTRFS_FILE_EXTENT_INLINE)
1664 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1665 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1668 if (!in_block_group(bytenr, rc->block_group))
1672 * if we are modifying block in fs tree, wait for readpage
1673 * to complete and drop the extent cache
1675 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1677 inode = find_next_inode(root, key.objectid);
1679 } else if (inode && btrfs_ino(inode) < key.objectid) {
1680 btrfs_add_delayed_iput(inode);
1681 inode = find_next_inode(root, key.objectid);
1683 if (inode && btrfs_ino(inode) == key.objectid) {
1685 btrfs_file_extent_num_bytes(leaf, fi);
1686 WARN_ON(!IS_ALIGNED(key.offset,
1688 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1690 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1695 btrfs_drop_extent_cache(inode, key.offset, end,
1697 unlock_extent(&BTRFS_I(inode)->io_tree,
1702 ret = get_new_location(rc->data_inode, &new_bytenr,
1706 * Don't have to abort since we've not changed anything
1707 * in the file extent yet.
1712 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1715 key.offset -= btrfs_file_extent_offset(leaf, fi);
1716 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1718 btrfs_header_owner(leaf),
1719 key.objectid, key.offset, 1);
1721 btrfs_abort_transaction(trans, root, ret);
1725 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1726 parent, btrfs_header_owner(leaf),
1727 key.objectid, key.offset, 1);
1729 btrfs_abort_transaction(trans, root, ret);
1734 btrfs_mark_buffer_dirty(leaf);
1736 btrfs_add_delayed_iput(inode);
1740 static noinline_for_stack
1741 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1742 struct btrfs_path *path, int level)
1744 struct btrfs_disk_key key1;
1745 struct btrfs_disk_key key2;
1746 btrfs_node_key(eb, &key1, slot);
1747 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1748 return memcmp(&key1, &key2, sizeof(key1));
1752 * try to replace tree blocks in fs tree with the new blocks
1753 * in reloc tree. tree blocks haven't been modified since the
1754 * reloc tree was create can be replaced.
1756 * if a block was replaced, level of the block + 1 is returned.
1757 * if no block got replaced, 0 is returned. if there are other
1758 * errors, a negative error number is returned.
1760 static noinline_for_stack
1761 int replace_path(struct btrfs_trans_handle *trans,
1762 struct btrfs_root *dest, struct btrfs_root *src,
1763 struct btrfs_path *path, struct btrfs_key *next_key,
1764 int lowest_level, int max_level)
1766 struct extent_buffer *eb;
1767 struct extent_buffer *parent;
1768 struct btrfs_key key;
1780 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1781 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1783 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1785 slot = path->slots[lowest_level];
1786 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1788 eb = btrfs_lock_root_node(dest);
1789 btrfs_set_lock_blocking(eb);
1790 level = btrfs_header_level(eb);
1792 if (level < lowest_level) {
1793 btrfs_tree_unlock(eb);
1794 free_extent_buffer(eb);
1799 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1802 btrfs_set_lock_blocking(eb);
1805 next_key->objectid = (u64)-1;
1806 next_key->type = (u8)-1;
1807 next_key->offset = (u64)-1;
1812 level = btrfs_header_level(parent);
1813 BUG_ON(level < lowest_level);
1815 ret = btrfs_bin_search(parent, &key, level, &slot);
1816 if (ret && slot > 0)
1819 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1820 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1822 old_bytenr = btrfs_node_blockptr(parent, slot);
1823 blocksize = dest->nodesize;
1824 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1826 if (level <= max_level) {
1827 eb = path->nodes[level];
1828 new_bytenr = btrfs_node_blockptr(eb,
1829 path->slots[level]);
1830 new_ptr_gen = btrfs_node_ptr_generation(eb,
1831 path->slots[level]);
1837 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1842 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1843 memcmp_node_keys(parent, slot, path, level)) {
1844 if (level <= lowest_level) {
1849 eb = read_tree_block(dest, old_bytenr, old_ptr_gen);
1850 if (!eb || !extent_buffer_uptodate(eb)) {
1851 ret = (!eb) ? -ENOMEM : -EIO;
1852 free_extent_buffer(eb);
1855 btrfs_tree_lock(eb);
1857 ret = btrfs_cow_block(trans, dest, eb, parent,
1861 btrfs_set_lock_blocking(eb);
1863 btrfs_tree_unlock(parent);
1864 free_extent_buffer(parent);
1871 btrfs_tree_unlock(parent);
1872 free_extent_buffer(parent);
1877 btrfs_node_key_to_cpu(path->nodes[level], &key,
1878 path->slots[level]);
1879 btrfs_release_path(path);
1881 path->lowest_level = level;
1882 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1883 path->lowest_level = 0;
1887 * swap blocks in fs tree and reloc tree.
1889 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1890 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1891 btrfs_mark_buffer_dirty(parent);
1893 btrfs_set_node_blockptr(path->nodes[level],
1894 path->slots[level], old_bytenr);
1895 btrfs_set_node_ptr_generation(path->nodes[level],
1896 path->slots[level], old_ptr_gen);
1897 btrfs_mark_buffer_dirty(path->nodes[level]);
1899 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1900 path->nodes[level]->start,
1901 src->root_key.objectid, level - 1, 0,
1904 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1905 0, dest->root_key.objectid, level - 1,
1909 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1910 path->nodes[level]->start,
1911 src->root_key.objectid, level - 1, 0,
1915 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1916 0, dest->root_key.objectid, level - 1,
1920 btrfs_unlock_up_safe(path, 0);
1925 btrfs_tree_unlock(parent);
1926 free_extent_buffer(parent);
1931 * helper to find next relocated block in reloc tree
1933 static noinline_for_stack
1934 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1937 struct extent_buffer *eb;
1942 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1944 for (i = 0; i < *level; i++) {
1945 free_extent_buffer(path->nodes[i]);
1946 path->nodes[i] = NULL;
1949 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1950 eb = path->nodes[i];
1951 nritems = btrfs_header_nritems(eb);
1952 while (path->slots[i] + 1 < nritems) {
1954 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1961 free_extent_buffer(path->nodes[i]);
1962 path->nodes[i] = NULL;
1968 * walk down reloc tree to find relocated block of lowest level
1970 static noinline_for_stack
1971 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1974 struct extent_buffer *eb = NULL;
1981 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1983 for (i = *level; i > 0; i--) {
1984 eb = path->nodes[i];
1985 nritems = btrfs_header_nritems(eb);
1986 while (path->slots[i] < nritems) {
1987 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1988 if (ptr_gen > last_snapshot)
1992 if (path->slots[i] >= nritems) {
2003 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
2004 eb = read_tree_block(root, bytenr, ptr_gen);
2005 if (!eb || !extent_buffer_uptodate(eb)) {
2006 free_extent_buffer(eb);
2009 BUG_ON(btrfs_header_level(eb) != i - 1);
2010 path->nodes[i - 1] = eb;
2011 path->slots[i - 1] = 0;
2017 * invalidate extent cache for file extents whose key in range of
2018 * [min_key, max_key)
2020 static int invalidate_extent_cache(struct btrfs_root *root,
2021 struct btrfs_key *min_key,
2022 struct btrfs_key *max_key)
2024 struct inode *inode = NULL;
2029 objectid = min_key->objectid;
2034 if (objectid > max_key->objectid)
2037 inode = find_next_inode(root, objectid);
2040 ino = btrfs_ino(inode);
2042 if (ino > max_key->objectid) {
2048 if (!S_ISREG(inode->i_mode))
2051 if (unlikely(min_key->objectid == ino)) {
2052 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2054 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2057 start = min_key->offset;
2058 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2064 if (unlikely(max_key->objectid == ino)) {
2065 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2067 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2070 if (max_key->offset == 0)
2072 end = max_key->offset;
2073 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2080 /* the lock_extent waits for readpage to complete */
2081 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2082 btrfs_drop_extent_cache(inode, start, end, 1);
2083 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2088 static int find_next_key(struct btrfs_path *path, int level,
2089 struct btrfs_key *key)
2092 while (level < BTRFS_MAX_LEVEL) {
2093 if (!path->nodes[level])
2095 if (path->slots[level] + 1 <
2096 btrfs_header_nritems(path->nodes[level])) {
2097 btrfs_node_key_to_cpu(path->nodes[level], key,
2098 path->slots[level] + 1);
2107 * merge the relocated tree blocks in reloc tree with corresponding
2110 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2111 struct btrfs_root *root)
2113 LIST_HEAD(inode_list);
2114 struct btrfs_key key;
2115 struct btrfs_key next_key;
2116 struct btrfs_trans_handle *trans = NULL;
2117 struct btrfs_root *reloc_root;
2118 struct btrfs_root_item *root_item;
2119 struct btrfs_path *path;
2120 struct extent_buffer *leaf;
2128 path = btrfs_alloc_path();
2133 reloc_root = root->reloc_root;
2134 root_item = &reloc_root->root_item;
2136 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2137 level = btrfs_root_level(root_item);
2138 extent_buffer_get(reloc_root->node);
2139 path->nodes[level] = reloc_root->node;
2140 path->slots[level] = 0;
2142 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2144 level = root_item->drop_level;
2146 path->lowest_level = level;
2147 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2148 path->lowest_level = 0;
2150 btrfs_free_path(path);
2154 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2155 path->slots[level]);
2156 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2158 btrfs_unlock_up_safe(path, 0);
2161 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2162 memset(&next_key, 0, sizeof(next_key));
2165 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2166 BTRFS_RESERVE_FLUSH_ALL);
2171 trans = btrfs_start_transaction(root, 0);
2172 if (IS_ERR(trans)) {
2173 err = PTR_ERR(trans);
2177 trans->block_rsv = rc->block_rsv;
2182 ret = walk_down_reloc_tree(reloc_root, path, &level);
2190 if (!find_next_key(path, level, &key) &&
2191 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2194 ret = replace_path(trans, root, reloc_root, path,
2195 &next_key, level, max_level);
2204 btrfs_node_key_to_cpu(path->nodes[level], &key,
2205 path->slots[level]);
2209 ret = walk_up_reloc_tree(reloc_root, path, &level);
2215 * save the merging progress in the drop_progress.
2216 * this is OK since root refs == 1 in this case.
2218 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2219 path->slots[level]);
2220 root_item->drop_level = level;
2222 btrfs_end_transaction_throttle(trans, root);
2225 btrfs_btree_balance_dirty(root);
2227 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2228 invalidate_extent_cache(root, &key, &next_key);
2232 * handle the case only one block in the fs tree need to be
2233 * relocated and the block is tree root.
2235 leaf = btrfs_lock_root_node(root);
2236 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2237 btrfs_tree_unlock(leaf);
2238 free_extent_buffer(leaf);
2242 btrfs_free_path(path);
2245 memset(&root_item->drop_progress, 0,
2246 sizeof(root_item->drop_progress));
2247 root_item->drop_level = 0;
2248 btrfs_set_root_refs(root_item, 0);
2249 btrfs_update_reloc_root(trans, root);
2253 btrfs_end_transaction_throttle(trans, root);
2255 btrfs_btree_balance_dirty(root);
2257 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2258 invalidate_extent_cache(root, &key, &next_key);
2263 static noinline_for_stack
2264 int prepare_to_merge(struct reloc_control *rc, int err)
2266 struct btrfs_root *root = rc->extent_root;
2267 struct btrfs_root *reloc_root;
2268 struct btrfs_trans_handle *trans;
2269 LIST_HEAD(reloc_roots);
2273 mutex_lock(&root->fs_info->reloc_mutex);
2274 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2275 rc->merging_rsv_size += rc->nodes_relocated * 2;
2276 mutex_unlock(&root->fs_info->reloc_mutex);
2280 num_bytes = rc->merging_rsv_size;
2281 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2282 BTRFS_RESERVE_FLUSH_ALL);
2287 trans = btrfs_join_transaction(rc->extent_root);
2288 if (IS_ERR(trans)) {
2290 btrfs_block_rsv_release(rc->extent_root,
2291 rc->block_rsv, num_bytes);
2292 return PTR_ERR(trans);
2296 if (num_bytes != rc->merging_rsv_size) {
2297 btrfs_end_transaction(trans, rc->extent_root);
2298 btrfs_block_rsv_release(rc->extent_root,
2299 rc->block_rsv, num_bytes);
2304 rc->merge_reloc_tree = 1;
2306 while (!list_empty(&rc->reloc_roots)) {
2307 reloc_root = list_entry(rc->reloc_roots.next,
2308 struct btrfs_root, root_list);
2309 list_del_init(&reloc_root->root_list);
2311 root = read_fs_root(reloc_root->fs_info,
2312 reloc_root->root_key.offset);
2313 BUG_ON(IS_ERR(root));
2314 BUG_ON(root->reloc_root != reloc_root);
2317 * set reference count to 1, so btrfs_recover_relocation
2318 * knows it should resumes merging
2321 btrfs_set_root_refs(&reloc_root->root_item, 1);
2322 btrfs_update_reloc_root(trans, root);
2324 list_add(&reloc_root->root_list, &reloc_roots);
2327 list_splice(&reloc_roots, &rc->reloc_roots);
2330 btrfs_commit_transaction(trans, rc->extent_root);
2332 btrfs_end_transaction(trans, rc->extent_root);
2336 static noinline_for_stack
2337 void free_reloc_roots(struct list_head *list)
2339 struct btrfs_root *reloc_root;
2341 while (!list_empty(list)) {
2342 reloc_root = list_entry(list->next, struct btrfs_root,
2344 __del_reloc_root(reloc_root);
2348 static noinline_for_stack
2349 void merge_reloc_roots(struct reloc_control *rc)
2351 struct btrfs_root *root;
2352 struct btrfs_root *reloc_root;
2356 LIST_HEAD(reloc_roots);
2360 root = rc->extent_root;
2363 * this serializes us with btrfs_record_root_in_transaction,
2364 * we have to make sure nobody is in the middle of
2365 * adding their roots to the list while we are
2368 mutex_lock(&root->fs_info->reloc_mutex);
2369 list_splice_init(&rc->reloc_roots, &reloc_roots);
2370 mutex_unlock(&root->fs_info->reloc_mutex);
2372 while (!list_empty(&reloc_roots)) {
2374 reloc_root = list_entry(reloc_roots.next,
2375 struct btrfs_root, root_list);
2377 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2378 root = read_fs_root(reloc_root->fs_info,
2379 reloc_root->root_key.offset);
2380 BUG_ON(IS_ERR(root));
2381 BUG_ON(root->reloc_root != reloc_root);
2383 ret = merge_reloc_root(rc, root);
2385 if (list_empty(&reloc_root->root_list))
2386 list_add_tail(&reloc_root->root_list,
2391 list_del_init(&reloc_root->root_list);
2395 * we keep the old last snapshod transid in rtranid when we
2396 * created the relocation tree.
2398 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2399 otransid = btrfs_root_otransid(&reloc_root->root_item);
2400 objectid = reloc_root->root_key.offset;
2402 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2404 if (list_empty(&reloc_root->root_list))
2405 list_add_tail(&reloc_root->root_list,
2417 btrfs_std_error(root->fs_info, ret);
2418 if (!list_empty(&reloc_roots))
2419 free_reloc_roots(&reloc_roots);
2421 /* new reloc root may be added */
2422 mutex_lock(&root->fs_info->reloc_mutex);
2423 list_splice_init(&rc->reloc_roots, &reloc_roots);
2424 mutex_unlock(&root->fs_info->reloc_mutex);
2425 if (!list_empty(&reloc_roots))
2426 free_reloc_roots(&reloc_roots);
2429 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2432 static void free_block_list(struct rb_root *blocks)
2434 struct tree_block *block;
2435 struct rb_node *rb_node;
2436 while ((rb_node = rb_first(blocks))) {
2437 block = rb_entry(rb_node, struct tree_block, rb_node);
2438 rb_erase(rb_node, blocks);
2443 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2444 struct btrfs_root *reloc_root)
2446 struct btrfs_root *root;
2448 if (reloc_root->last_trans == trans->transid)
2451 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2452 BUG_ON(IS_ERR(root));
2453 BUG_ON(root->reloc_root != reloc_root);
2455 return btrfs_record_root_in_trans(trans, root);
2458 static noinline_for_stack
2459 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2460 struct reloc_control *rc,
2461 struct backref_node *node,
2462 struct backref_edge *edges[])
2464 struct backref_node *next;
2465 struct btrfs_root *root;
2471 next = walk_up_backref(next, edges, &index);
2474 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2476 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2477 record_reloc_root_in_trans(trans, root);
2481 btrfs_record_root_in_trans(trans, root);
2482 root = root->reloc_root;
2484 if (next->new_bytenr != root->node->start) {
2485 BUG_ON(next->new_bytenr);
2486 BUG_ON(!list_empty(&next->list));
2487 next->new_bytenr = root->node->start;
2489 list_add_tail(&next->list,
2490 &rc->backref_cache.changed);
2491 __mark_block_processed(rc, next);
2497 next = walk_down_backref(edges, &index);
2498 if (!next || next->level <= node->level)
2505 /* setup backref node path for btrfs_reloc_cow_block */
2507 rc->backref_cache.path[next->level] = next;
2510 next = edges[index]->node[UPPER];
2516 * select a tree root for relocation. return NULL if the block
2517 * is reference counted. we should use do_relocation() in this
2518 * case. return a tree root pointer if the block isn't reference
2519 * counted. return -ENOENT if the block is root of reloc tree.
2521 static noinline_for_stack
2522 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2523 struct backref_node *node)
2525 struct backref_node *next;
2526 struct btrfs_root *root;
2527 struct btrfs_root *fs_root = NULL;
2528 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2534 next = walk_up_backref(next, edges, &index);
2538 /* no other choice for non-references counted tree */
2539 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2542 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2548 next = walk_down_backref(edges, &index);
2549 if (!next || next->level <= node->level)
2554 return ERR_PTR(-ENOENT);
2558 static noinline_for_stack
2559 u64 calcu_metadata_size(struct reloc_control *rc,
2560 struct backref_node *node, int reserve)
2562 struct backref_node *next = node;
2563 struct backref_edge *edge;
2564 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2568 BUG_ON(reserve && node->processed);
2573 if (next->processed && (reserve || next != node))
2576 num_bytes += rc->extent_root->nodesize;
2578 if (list_empty(&next->upper))
2581 edge = list_entry(next->upper.next,
2582 struct backref_edge, list[LOWER]);
2583 edges[index++] = edge;
2584 next = edge->node[UPPER];
2586 next = walk_down_backref(edges, &index);
2591 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2592 struct reloc_control *rc,
2593 struct backref_node *node)
2595 struct btrfs_root *root = rc->extent_root;
2600 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2602 trans->block_rsv = rc->block_rsv;
2603 rc->reserved_bytes += num_bytes;
2604 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2605 BTRFS_RESERVE_FLUSH_ALL);
2607 if (ret == -EAGAIN) {
2608 tmp = rc->extent_root->nodesize *
2609 RELOCATION_RESERVED_NODES;
2610 while (tmp <= rc->reserved_bytes)
2613 * only one thread can access block_rsv at this point,
2614 * so we don't need hold lock to protect block_rsv.
2615 * we expand more reservation size here to allow enough
2616 * space for relocation and we will return eailer in
2619 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2620 RELOCATION_RESERVED_NODES;
2629 * relocate a block tree, and then update pointers in upper level
2630 * blocks that reference the block to point to the new location.
2632 * if called by link_to_upper, the block has already been relocated.
2633 * in that case this function just updates pointers.
2635 static int do_relocation(struct btrfs_trans_handle *trans,
2636 struct reloc_control *rc,
2637 struct backref_node *node,
2638 struct btrfs_key *key,
2639 struct btrfs_path *path, int lowest)
2641 struct backref_node *upper;
2642 struct backref_edge *edge;
2643 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2644 struct btrfs_root *root;
2645 struct extent_buffer *eb;
2653 BUG_ON(lowest && node->eb);
2655 path->lowest_level = node->level + 1;
2656 rc->backref_cache.path[node->level] = node;
2657 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2660 upper = edge->node[UPPER];
2661 root = select_reloc_root(trans, rc, upper, edges);
2664 if (upper->eb && !upper->locked) {
2666 ret = btrfs_bin_search(upper->eb, key,
2667 upper->level, &slot);
2669 bytenr = btrfs_node_blockptr(upper->eb, slot);
2670 if (node->eb->start == bytenr)
2673 drop_node_buffer(upper);
2677 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2685 upper->eb = path->nodes[upper->level];
2686 path->nodes[upper->level] = NULL;
2688 BUG_ON(upper->eb != path->nodes[upper->level]);
2692 path->locks[upper->level] = 0;
2694 slot = path->slots[upper->level];
2695 btrfs_release_path(path);
2697 ret = btrfs_bin_search(upper->eb, key, upper->level,
2702 bytenr = btrfs_node_blockptr(upper->eb, slot);
2704 BUG_ON(bytenr != node->bytenr);
2706 if (node->eb->start == bytenr)
2710 blocksize = root->nodesize;
2711 generation = btrfs_node_ptr_generation(upper->eb, slot);
2712 eb = read_tree_block(root, bytenr, generation);
2713 if (!eb || !extent_buffer_uptodate(eb)) {
2714 free_extent_buffer(eb);
2718 btrfs_tree_lock(eb);
2719 btrfs_set_lock_blocking(eb);
2722 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2724 btrfs_tree_unlock(eb);
2725 free_extent_buffer(eb);
2730 BUG_ON(node->eb != eb);
2732 btrfs_set_node_blockptr(upper->eb, slot,
2734 btrfs_set_node_ptr_generation(upper->eb, slot,
2736 btrfs_mark_buffer_dirty(upper->eb);
2738 ret = btrfs_inc_extent_ref(trans, root,
2739 node->eb->start, blocksize,
2741 btrfs_header_owner(upper->eb),
2745 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2749 if (!upper->pending)
2750 drop_node_buffer(upper);
2752 unlock_node_buffer(upper);
2757 if (!err && node->pending) {
2758 drop_node_buffer(node);
2759 list_move_tail(&node->list, &rc->backref_cache.changed);
2763 path->lowest_level = 0;
2764 BUG_ON(err == -ENOSPC);
2768 static int link_to_upper(struct btrfs_trans_handle *trans,
2769 struct reloc_control *rc,
2770 struct backref_node *node,
2771 struct btrfs_path *path)
2773 struct btrfs_key key;
2775 btrfs_node_key_to_cpu(node->eb, &key, 0);
2776 return do_relocation(trans, rc, node, &key, path, 0);
2779 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2780 struct reloc_control *rc,
2781 struct btrfs_path *path, int err)
2784 struct backref_cache *cache = &rc->backref_cache;
2785 struct backref_node *node;
2789 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2790 while (!list_empty(&cache->pending[level])) {
2791 node = list_entry(cache->pending[level].next,
2792 struct backref_node, list);
2793 list_move_tail(&node->list, &list);
2794 BUG_ON(!node->pending);
2797 ret = link_to_upper(trans, rc, node, path);
2802 list_splice_init(&list, &cache->pending[level]);
2807 static void mark_block_processed(struct reloc_control *rc,
2808 u64 bytenr, u32 blocksize)
2810 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2811 EXTENT_DIRTY, GFP_NOFS);
2814 static void __mark_block_processed(struct reloc_control *rc,
2815 struct backref_node *node)
2818 if (node->level == 0 ||
2819 in_block_group(node->bytenr, rc->block_group)) {
2820 blocksize = rc->extent_root->nodesize;
2821 mark_block_processed(rc, node->bytenr, blocksize);
2823 node->processed = 1;
2827 * mark a block and all blocks directly/indirectly reference the block
2830 static void update_processed_blocks(struct reloc_control *rc,
2831 struct backref_node *node)
2833 struct backref_node *next = node;
2834 struct backref_edge *edge;
2835 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2841 if (next->processed)
2844 __mark_block_processed(rc, next);
2846 if (list_empty(&next->upper))
2849 edge = list_entry(next->upper.next,
2850 struct backref_edge, list[LOWER]);
2851 edges[index++] = edge;
2852 next = edge->node[UPPER];
2854 next = walk_down_backref(edges, &index);
2858 static int tree_block_processed(u64 bytenr, u32 blocksize,
2859 struct reloc_control *rc)
2861 if (test_range_bit(&rc->processed_blocks, bytenr,
2862 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2867 static int get_tree_block_key(struct reloc_control *rc,
2868 struct tree_block *block)
2870 struct extent_buffer *eb;
2872 BUG_ON(block->key_ready);
2873 eb = read_tree_block(rc->extent_root, block->bytenr,
2875 if (!eb || !extent_buffer_uptodate(eb)) {
2876 free_extent_buffer(eb);
2879 WARN_ON(btrfs_header_level(eb) != block->level);
2880 if (block->level == 0)
2881 btrfs_item_key_to_cpu(eb, &block->key, 0);
2883 btrfs_node_key_to_cpu(eb, &block->key, 0);
2884 free_extent_buffer(eb);
2885 block->key_ready = 1;
2890 * helper function to relocate a tree block
2892 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2893 struct reloc_control *rc,
2894 struct backref_node *node,
2895 struct btrfs_key *key,
2896 struct btrfs_path *path)
2898 struct btrfs_root *root;
2904 BUG_ON(node->processed);
2905 root = select_one_root(trans, node);
2906 if (root == ERR_PTR(-ENOENT)) {
2907 update_processed_blocks(rc, node);
2911 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2912 ret = reserve_metadata_space(trans, rc, node);
2918 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2919 BUG_ON(node->new_bytenr);
2920 BUG_ON(!list_empty(&node->list));
2921 btrfs_record_root_in_trans(trans, root);
2922 root = root->reloc_root;
2923 node->new_bytenr = root->node->start;
2925 list_add_tail(&node->list, &rc->backref_cache.changed);
2927 path->lowest_level = node->level;
2928 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2929 btrfs_release_path(path);
2934 update_processed_blocks(rc, node);
2936 ret = do_relocation(trans, rc, node, key, path, 1);
2939 if (ret || node->level == 0 || node->cowonly)
2940 remove_backref_node(&rc->backref_cache, node);
2945 * relocate a list of blocks
2947 static noinline_for_stack
2948 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2949 struct reloc_control *rc, struct rb_root *blocks)
2951 struct backref_node *node;
2952 struct btrfs_path *path;
2953 struct tree_block *block;
2954 struct rb_node *rb_node;
2958 path = btrfs_alloc_path();
2961 goto out_free_blocks;
2964 rb_node = rb_first(blocks);
2966 block = rb_entry(rb_node, struct tree_block, rb_node);
2967 if (!block->key_ready)
2968 readahead_tree_block(rc->extent_root, block->bytenr,
2969 block->key.objectid);
2970 rb_node = rb_next(rb_node);
2973 rb_node = rb_first(blocks);
2975 block = rb_entry(rb_node, struct tree_block, rb_node);
2976 if (!block->key_ready) {
2977 err = get_tree_block_key(rc, block);
2981 rb_node = rb_next(rb_node);
2984 rb_node = rb_first(blocks);
2986 block = rb_entry(rb_node, struct tree_block, rb_node);
2988 node = build_backref_tree(rc, &block->key,
2989 block->level, block->bytenr);
2991 err = PTR_ERR(node);
2995 ret = relocate_tree_block(trans, rc, node, &block->key,
2998 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3002 rb_node = rb_next(rb_node);
3005 err = finish_pending_nodes(trans, rc, path, err);
3008 btrfs_free_path(path);
3010 free_block_list(blocks);
3014 static noinline_for_stack
3015 int prealloc_file_extent_cluster(struct inode *inode,
3016 struct file_extent_cluster *cluster)
3021 u64 offset = BTRFS_I(inode)->index_cnt;
3026 BUG_ON(cluster->start != cluster->boundary[0]);
3027 mutex_lock(&inode->i_mutex);
3029 ret = btrfs_check_data_free_space(inode, cluster->end +
3030 1 - cluster->start);
3034 while (nr < cluster->nr) {
3035 start = cluster->boundary[nr] - offset;
3036 if (nr + 1 < cluster->nr)
3037 end = cluster->boundary[nr + 1] - 1 - offset;
3039 end = cluster->end - offset;
3041 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3042 num_bytes = end + 1 - start;
3043 ret = btrfs_prealloc_file_range(inode, 0, start,
3044 num_bytes, num_bytes,
3045 end + 1, &alloc_hint);
3046 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3051 btrfs_free_reserved_data_space(inode, cluster->end +
3052 1 - cluster->start);
3054 mutex_unlock(&inode->i_mutex);
3058 static noinline_for_stack
3059 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3062 struct btrfs_root *root = BTRFS_I(inode)->root;
3063 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3064 struct extent_map *em;
3067 em = alloc_extent_map();
3072 em->len = end + 1 - start;
3073 em->block_len = em->len;
3074 em->block_start = block_start;
3075 em->bdev = root->fs_info->fs_devices->latest_bdev;
3076 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3078 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3080 write_lock(&em_tree->lock);
3081 ret = add_extent_mapping(em_tree, em, 0);
3082 write_unlock(&em_tree->lock);
3083 if (ret != -EEXIST) {
3084 free_extent_map(em);
3087 btrfs_drop_extent_cache(inode, start, end, 0);
3089 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3093 static int relocate_file_extent_cluster(struct inode *inode,
3094 struct file_extent_cluster *cluster)
3098 u64 offset = BTRFS_I(inode)->index_cnt;
3099 unsigned long index;
3100 unsigned long last_index;
3102 struct file_ra_state *ra;
3103 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3110 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3114 ret = prealloc_file_extent_cluster(inode, cluster);
3118 file_ra_state_init(ra, inode->i_mapping);
3120 ret = setup_extent_mapping(inode, cluster->start - offset,
3121 cluster->end - offset, cluster->start);
3125 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3126 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3127 while (index <= last_index) {
3128 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3132 page = find_lock_page(inode->i_mapping, index);
3134 page_cache_sync_readahead(inode->i_mapping,
3136 last_index + 1 - index);
3137 page = find_or_create_page(inode->i_mapping, index,
3140 btrfs_delalloc_release_metadata(inode,
3147 if (PageReadahead(page)) {
3148 page_cache_async_readahead(inode->i_mapping,
3149 ra, NULL, page, index,
3150 last_index + 1 - index);
3153 if (!PageUptodate(page)) {
3154 btrfs_readpage(NULL, page);
3156 if (!PageUptodate(page)) {
3158 page_cache_release(page);
3159 btrfs_delalloc_release_metadata(inode,
3166 page_start = page_offset(page);
3167 page_end = page_start + PAGE_CACHE_SIZE - 1;
3169 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3171 set_page_extent_mapped(page);
3173 if (nr < cluster->nr &&
3174 page_start + offset == cluster->boundary[nr]) {
3175 set_extent_bits(&BTRFS_I(inode)->io_tree,
3176 page_start, page_end,
3177 EXTENT_BOUNDARY, GFP_NOFS);
3181 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3182 set_page_dirty(page);
3184 unlock_extent(&BTRFS_I(inode)->io_tree,
3185 page_start, page_end);
3187 page_cache_release(page);
3190 balance_dirty_pages_ratelimited(inode->i_mapping);
3191 btrfs_throttle(BTRFS_I(inode)->root);
3193 WARN_ON(nr != cluster->nr);
3199 static noinline_for_stack
3200 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3201 struct file_extent_cluster *cluster)
3205 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3206 ret = relocate_file_extent_cluster(inode, cluster);
3213 cluster->start = extent_key->objectid;
3215 BUG_ON(cluster->nr >= MAX_EXTENTS);
3216 cluster->end = extent_key->objectid + extent_key->offset - 1;
3217 cluster->boundary[cluster->nr] = extent_key->objectid;
3220 if (cluster->nr >= MAX_EXTENTS) {
3221 ret = relocate_file_extent_cluster(inode, cluster);
3229 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3230 static int get_ref_objectid_v0(struct reloc_control *rc,
3231 struct btrfs_path *path,
3232 struct btrfs_key *extent_key,
3233 u64 *ref_objectid, int *path_change)
3235 struct btrfs_key key;
3236 struct extent_buffer *leaf;
3237 struct btrfs_extent_ref_v0 *ref0;
3241 leaf = path->nodes[0];
3242 slot = path->slots[0];
3244 if (slot >= btrfs_header_nritems(leaf)) {
3245 ret = btrfs_next_leaf(rc->extent_root, path);
3249 leaf = path->nodes[0];
3250 slot = path->slots[0];
3254 btrfs_item_key_to_cpu(leaf, &key, slot);
3255 if (key.objectid != extent_key->objectid)
3258 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3262 ref0 = btrfs_item_ptr(leaf, slot,
3263 struct btrfs_extent_ref_v0);
3264 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3272 * helper to add a tree block to the list.
3273 * the major work is getting the generation and level of the block
3275 static int add_tree_block(struct reloc_control *rc,
3276 struct btrfs_key *extent_key,
3277 struct btrfs_path *path,
3278 struct rb_root *blocks)
3280 struct extent_buffer *eb;
3281 struct btrfs_extent_item *ei;
3282 struct btrfs_tree_block_info *bi;
3283 struct tree_block *block;
3284 struct rb_node *rb_node;
3289 eb = path->nodes[0];
3290 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3292 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3293 item_size >= sizeof(*ei) + sizeof(*bi)) {
3294 ei = btrfs_item_ptr(eb, path->slots[0],
3295 struct btrfs_extent_item);
3296 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3297 bi = (struct btrfs_tree_block_info *)(ei + 1);
3298 level = btrfs_tree_block_level(eb, bi);
3300 level = (int)extent_key->offset;
3302 generation = btrfs_extent_generation(eb, ei);
3304 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3308 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3309 ret = get_ref_objectid_v0(rc, path, extent_key,
3313 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3314 level = (int)ref_owner;
3315 /* FIXME: get real generation */
3322 btrfs_release_path(path);
3324 BUG_ON(level == -1);
3326 block = kmalloc(sizeof(*block), GFP_NOFS);
3330 block->bytenr = extent_key->objectid;
3331 block->key.objectid = rc->extent_root->nodesize;
3332 block->key.offset = generation;
3333 block->level = level;
3334 block->key_ready = 0;
3336 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3338 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3344 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3346 static int __add_tree_block(struct reloc_control *rc,
3347 u64 bytenr, u32 blocksize,
3348 struct rb_root *blocks)
3350 struct btrfs_path *path;
3351 struct btrfs_key key;
3353 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3356 if (tree_block_processed(bytenr, blocksize, rc))
3359 if (tree_search(blocks, bytenr))
3362 path = btrfs_alloc_path();
3366 key.objectid = bytenr;
3368 key.type = BTRFS_METADATA_ITEM_KEY;
3369 key.offset = (u64)-1;
3371 key.type = BTRFS_EXTENT_ITEM_KEY;
3372 key.offset = blocksize;
3375 path->search_commit_root = 1;
3376 path->skip_locking = 1;
3377 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3381 if (ret > 0 && skinny) {
3382 if (path->slots[0]) {
3384 btrfs_item_key_to_cpu(path->nodes[0], &key,
3386 if (key.objectid == bytenr &&
3387 (key.type == BTRFS_METADATA_ITEM_KEY ||
3388 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3389 key.offset == blocksize)))
3395 btrfs_release_path(path);
3401 ret = add_tree_block(rc, &key, path, blocks);
3403 btrfs_free_path(path);
3408 * helper to check if the block use full backrefs for pointers in it
3410 static int block_use_full_backref(struct reloc_control *rc,
3411 struct extent_buffer *eb)
3416 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3417 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3420 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3421 eb->start, btrfs_header_level(eb), 1,
3425 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3432 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3433 struct inode *inode, u64 ino)
3435 struct btrfs_key key;
3436 struct btrfs_root *root = fs_info->tree_root;
3437 struct btrfs_trans_handle *trans;
3444 key.type = BTRFS_INODE_ITEM_KEY;
3447 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3448 if (IS_ERR(inode) || is_bad_inode(inode)) {
3455 ret = btrfs_check_trunc_cache_free_space(root,
3456 &fs_info->global_block_rsv);
3460 trans = btrfs_join_transaction(root);
3461 if (IS_ERR(trans)) {
3462 ret = PTR_ERR(trans);
3466 ret = btrfs_truncate_free_space_cache(root, trans, inode);
3468 btrfs_end_transaction(trans, root);
3469 btrfs_btree_balance_dirty(root);
3476 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3477 * this function scans fs tree to find blocks reference the data extent
3479 static int find_data_references(struct reloc_control *rc,
3480 struct btrfs_key *extent_key,
3481 struct extent_buffer *leaf,
3482 struct btrfs_extent_data_ref *ref,
3483 struct rb_root *blocks)
3485 struct btrfs_path *path;
3486 struct tree_block *block;
3487 struct btrfs_root *root;
3488 struct btrfs_file_extent_item *fi;
3489 struct rb_node *rb_node;
3490 struct btrfs_key key;
3501 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3502 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3503 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3504 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3507 * This is an extent belonging to the free space cache, lets just delete
3508 * it and redo the search.
3510 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3511 ret = delete_block_group_cache(rc->extent_root->fs_info,
3512 NULL, ref_objectid);
3518 path = btrfs_alloc_path();
3523 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3525 err = PTR_ERR(root);
3529 key.objectid = ref_objectid;
3530 key.type = BTRFS_EXTENT_DATA_KEY;
3531 if (ref_offset > ((u64)-1 << 32))
3534 key.offset = ref_offset;
3536 path->search_commit_root = 1;
3537 path->skip_locking = 1;
3538 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3544 leaf = path->nodes[0];
3545 nritems = btrfs_header_nritems(leaf);
3547 * the references in tree blocks that use full backrefs
3548 * are not counted in
3550 if (block_use_full_backref(rc, leaf))
3554 rb_node = tree_search(blocks, leaf->start);
3559 path->slots[0] = nritems;
3562 while (ref_count > 0) {
3563 while (path->slots[0] >= nritems) {
3564 ret = btrfs_next_leaf(root, path);
3569 if (WARN_ON(ret > 0))
3572 leaf = path->nodes[0];
3573 nritems = btrfs_header_nritems(leaf);
3576 if (block_use_full_backref(rc, leaf))
3580 rb_node = tree_search(blocks, leaf->start);
3585 path->slots[0] = nritems;
3589 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3590 if (WARN_ON(key.objectid != ref_objectid ||
3591 key.type != BTRFS_EXTENT_DATA_KEY))
3594 fi = btrfs_item_ptr(leaf, path->slots[0],
3595 struct btrfs_file_extent_item);
3597 if (btrfs_file_extent_type(leaf, fi) ==
3598 BTRFS_FILE_EXTENT_INLINE)
3601 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3602 extent_key->objectid)
3605 key.offset -= btrfs_file_extent_offset(leaf, fi);
3606 if (key.offset != ref_offset)
3614 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3615 block = kmalloc(sizeof(*block), GFP_NOFS);
3620 block->bytenr = leaf->start;
3621 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3623 block->key_ready = 1;
3624 rb_node = tree_insert(blocks, block->bytenr,
3627 backref_tree_panic(rb_node, -EEXIST,
3633 path->slots[0] = nritems;
3639 btrfs_free_path(path);
3644 * helper to find all tree blocks that reference a given data extent
3646 static noinline_for_stack
3647 int add_data_references(struct reloc_control *rc,
3648 struct btrfs_key *extent_key,
3649 struct btrfs_path *path,
3650 struct rb_root *blocks)
3652 struct btrfs_key key;
3653 struct extent_buffer *eb;
3654 struct btrfs_extent_data_ref *dref;
3655 struct btrfs_extent_inline_ref *iref;
3658 u32 blocksize = rc->extent_root->nodesize;
3662 eb = path->nodes[0];
3663 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3664 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3665 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3666 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3670 ptr += sizeof(struct btrfs_extent_item);
3673 iref = (struct btrfs_extent_inline_ref *)ptr;
3674 key.type = btrfs_extent_inline_ref_type(eb, iref);
3675 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3676 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3677 ret = __add_tree_block(rc, key.offset, blocksize,
3679 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3680 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3681 ret = find_data_references(rc, extent_key,
3690 ptr += btrfs_extent_inline_ref_size(key.type);
3696 eb = path->nodes[0];
3697 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3698 ret = btrfs_next_leaf(rc->extent_root, path);
3705 eb = path->nodes[0];
3708 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3709 if (key.objectid != extent_key->objectid)
3712 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3713 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3714 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3716 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3717 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3719 ret = __add_tree_block(rc, key.offset, blocksize,
3721 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3722 dref = btrfs_item_ptr(eb, path->slots[0],
3723 struct btrfs_extent_data_ref);
3724 ret = find_data_references(rc, extent_key,
3736 btrfs_release_path(path);
3738 free_block_list(blocks);
3743 * helper to find next unprocessed extent
3745 static noinline_for_stack
3746 int find_next_extent(struct btrfs_trans_handle *trans,
3747 struct reloc_control *rc, struct btrfs_path *path,
3748 struct btrfs_key *extent_key)
3750 struct btrfs_key key;
3751 struct extent_buffer *leaf;
3752 u64 start, end, last;
3755 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3758 if (rc->search_start >= last) {
3763 key.objectid = rc->search_start;
3764 key.type = BTRFS_EXTENT_ITEM_KEY;
3767 path->search_commit_root = 1;
3768 path->skip_locking = 1;
3769 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3774 leaf = path->nodes[0];
3775 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3776 ret = btrfs_next_leaf(rc->extent_root, path);
3779 leaf = path->nodes[0];
3782 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3783 if (key.objectid >= last) {
3788 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3789 key.type != BTRFS_METADATA_ITEM_KEY) {
3794 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3795 key.objectid + key.offset <= rc->search_start) {
3800 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3801 key.objectid + rc->extent_root->nodesize <=
3807 ret = find_first_extent_bit(&rc->processed_blocks,
3808 key.objectid, &start, &end,
3809 EXTENT_DIRTY, NULL);
3811 if (ret == 0 && start <= key.objectid) {
3812 btrfs_release_path(path);
3813 rc->search_start = end + 1;
3815 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3816 rc->search_start = key.objectid + key.offset;
3818 rc->search_start = key.objectid +
3819 rc->extent_root->nodesize;
3820 memcpy(extent_key, &key, sizeof(key));
3824 btrfs_release_path(path);
3828 static void set_reloc_control(struct reloc_control *rc)
3830 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3832 mutex_lock(&fs_info->reloc_mutex);
3833 fs_info->reloc_ctl = rc;
3834 mutex_unlock(&fs_info->reloc_mutex);
3837 static void unset_reloc_control(struct reloc_control *rc)
3839 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3841 mutex_lock(&fs_info->reloc_mutex);
3842 fs_info->reloc_ctl = NULL;
3843 mutex_unlock(&fs_info->reloc_mutex);
3846 static int check_extent_flags(u64 flags)
3848 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3849 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3851 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3852 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3854 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3855 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3860 static noinline_for_stack
3861 int prepare_to_relocate(struct reloc_control *rc)
3863 struct btrfs_trans_handle *trans;
3865 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3866 BTRFS_BLOCK_RSV_TEMP);
3870 memset(&rc->cluster, 0, sizeof(rc->cluster));
3871 rc->search_start = rc->block_group->key.objectid;
3872 rc->extents_found = 0;
3873 rc->nodes_relocated = 0;
3874 rc->merging_rsv_size = 0;
3875 rc->reserved_bytes = 0;
3876 rc->block_rsv->size = rc->extent_root->nodesize *
3877 RELOCATION_RESERVED_NODES;
3879 rc->create_reloc_tree = 1;
3880 set_reloc_control(rc);
3882 trans = btrfs_join_transaction(rc->extent_root);
3883 if (IS_ERR(trans)) {
3884 unset_reloc_control(rc);
3886 * extent tree is not a ref_cow tree and has no reloc_root to
3887 * cleanup. And callers are responsible to free the above
3890 return PTR_ERR(trans);
3892 btrfs_commit_transaction(trans, rc->extent_root);
3896 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3898 struct rb_root blocks = RB_ROOT;
3899 struct btrfs_key key;
3900 struct btrfs_trans_handle *trans = NULL;
3901 struct btrfs_path *path;
3902 struct btrfs_extent_item *ei;
3909 path = btrfs_alloc_path();
3914 ret = prepare_to_relocate(rc);
3921 rc->reserved_bytes = 0;
3922 ret = btrfs_block_rsv_refill(rc->extent_root,
3923 rc->block_rsv, rc->block_rsv->size,
3924 BTRFS_RESERVE_FLUSH_ALL);
3930 trans = btrfs_start_transaction(rc->extent_root, 0);
3931 if (IS_ERR(trans)) {
3932 err = PTR_ERR(trans);
3937 if (update_backref_cache(trans, &rc->backref_cache)) {
3938 btrfs_end_transaction(trans, rc->extent_root);
3942 ret = find_next_extent(trans, rc, path, &key);
3948 rc->extents_found++;
3950 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3951 struct btrfs_extent_item);
3952 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3953 if (item_size >= sizeof(*ei)) {
3954 flags = btrfs_extent_flags(path->nodes[0], ei);
3955 ret = check_extent_flags(flags);
3959 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3961 int path_change = 0;
3964 sizeof(struct btrfs_extent_item_v0));
3965 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3967 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3968 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3970 flags = BTRFS_EXTENT_FLAG_DATA;
3973 btrfs_release_path(path);
3975 path->search_commit_root = 1;
3976 path->skip_locking = 1;
3977 ret = btrfs_search_slot(NULL, rc->extent_root,
3990 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3991 ret = add_tree_block(rc, &key, path, &blocks);
3992 } else if (rc->stage == UPDATE_DATA_PTRS &&
3993 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3994 ret = add_data_references(rc, &key, path, &blocks);
3996 btrfs_release_path(path);
4004 if (!RB_EMPTY_ROOT(&blocks)) {
4005 ret = relocate_tree_blocks(trans, rc, &blocks);
4008 * if we fail to relocate tree blocks, force to update
4009 * backref cache when committing transaction.
4011 rc->backref_cache.last_trans = trans->transid - 1;
4013 if (ret != -EAGAIN) {
4017 rc->extents_found--;
4018 rc->search_start = key.objectid;
4022 btrfs_end_transaction_throttle(trans, rc->extent_root);
4023 btrfs_btree_balance_dirty(rc->extent_root);
4026 if (rc->stage == MOVE_DATA_EXTENTS &&
4027 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4028 rc->found_file_extent = 1;
4029 ret = relocate_data_extent(rc->data_inode,
4030 &key, &rc->cluster);
4037 if (trans && progress && err == -ENOSPC) {
4038 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4039 rc->block_group->flags);
4047 btrfs_release_path(path);
4048 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4052 btrfs_end_transaction_throttle(trans, rc->extent_root);
4053 btrfs_btree_balance_dirty(rc->extent_root);
4057 ret = relocate_file_extent_cluster(rc->data_inode,
4063 rc->create_reloc_tree = 0;
4064 set_reloc_control(rc);
4066 backref_cache_cleanup(&rc->backref_cache);
4067 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4069 err = prepare_to_merge(rc, err);
4071 merge_reloc_roots(rc);
4073 rc->merge_reloc_tree = 0;
4074 unset_reloc_control(rc);
4075 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4077 /* get rid of pinned extents */
4078 trans = btrfs_join_transaction(rc->extent_root);
4080 err = PTR_ERR(trans);
4082 btrfs_commit_transaction(trans, rc->extent_root);
4084 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4085 btrfs_free_path(path);
4089 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4090 struct btrfs_root *root, u64 objectid)
4092 struct btrfs_path *path;
4093 struct btrfs_inode_item *item;
4094 struct extent_buffer *leaf;
4097 path = btrfs_alloc_path();
4101 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4105 leaf = path->nodes[0];
4106 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4107 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4108 btrfs_set_inode_generation(leaf, item, 1);
4109 btrfs_set_inode_size(leaf, item, 0);
4110 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4111 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4112 BTRFS_INODE_PREALLOC);
4113 btrfs_mark_buffer_dirty(leaf);
4115 btrfs_free_path(path);
4120 * helper to create inode for data relocation.
4121 * the inode is in data relocation tree and its link count is 0
4123 static noinline_for_stack
4124 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4125 struct btrfs_block_group_cache *group)
4127 struct inode *inode = NULL;
4128 struct btrfs_trans_handle *trans;
4129 struct btrfs_root *root;
4130 struct btrfs_key key;
4131 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4134 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4136 return ERR_CAST(root);
4138 trans = btrfs_start_transaction(root, 6);
4140 return ERR_CAST(trans);
4142 err = btrfs_find_free_objectid(root, &objectid);
4146 err = __insert_orphan_inode(trans, root, objectid);
4149 key.objectid = objectid;
4150 key.type = BTRFS_INODE_ITEM_KEY;
4152 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4153 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4154 BTRFS_I(inode)->index_cnt = group->key.objectid;
4156 err = btrfs_orphan_add(trans, inode);
4158 btrfs_end_transaction(trans, root);
4159 btrfs_btree_balance_dirty(root);
4163 inode = ERR_PTR(err);
4168 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4170 struct reloc_control *rc;
4172 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4176 INIT_LIST_HEAD(&rc->reloc_roots);
4177 backref_cache_init(&rc->backref_cache);
4178 mapping_tree_init(&rc->reloc_root_tree);
4179 extent_io_tree_init(&rc->processed_blocks,
4180 fs_info->btree_inode->i_mapping);
4185 * function to relocate all extents in a block group.
4187 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4189 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4190 struct reloc_control *rc;
4191 struct inode *inode;
4192 struct btrfs_path *path;
4197 rc = alloc_reloc_control(fs_info);
4201 rc->extent_root = extent_root;
4203 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4204 BUG_ON(!rc->block_group);
4206 if (!rc->block_group->ro) {
4207 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4215 path = btrfs_alloc_path();
4221 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4223 btrfs_free_path(path);
4226 ret = delete_block_group_cache(fs_info, inode, 0);
4228 ret = PTR_ERR(inode);
4230 if (ret && ret != -ENOENT) {
4235 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4236 if (IS_ERR(rc->data_inode)) {
4237 err = PTR_ERR(rc->data_inode);
4238 rc->data_inode = NULL;
4242 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
4243 rc->block_group->key.objectid, rc->block_group->flags);
4245 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
4250 btrfs_wait_ordered_roots(fs_info, -1);
4253 mutex_lock(&fs_info->cleaner_mutex);
4254 ret = relocate_block_group(rc);
4255 mutex_unlock(&fs_info->cleaner_mutex);
4261 if (rc->extents_found == 0)
4264 btrfs_info(extent_root->fs_info, "found %llu extents",
4267 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4268 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4274 invalidate_mapping_pages(rc->data_inode->i_mapping,
4276 rc->stage = UPDATE_DATA_PTRS;
4280 WARN_ON(rc->block_group->pinned > 0);
4281 WARN_ON(rc->block_group->reserved > 0);
4282 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4285 btrfs_set_block_group_rw(extent_root, rc->block_group);
4286 iput(rc->data_inode);
4287 btrfs_put_block_group(rc->block_group);
4292 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4294 struct btrfs_trans_handle *trans;
4297 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4299 return PTR_ERR(trans);
4301 memset(&root->root_item.drop_progress, 0,
4302 sizeof(root->root_item.drop_progress));
4303 root->root_item.drop_level = 0;
4304 btrfs_set_root_refs(&root->root_item, 0);
4305 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4306 &root->root_key, &root->root_item);
4308 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4315 * recover relocation interrupted by system crash.
4317 * this function resumes merging reloc trees with corresponding fs trees.
4318 * this is important for keeping the sharing of tree blocks
4320 int btrfs_recover_relocation(struct btrfs_root *root)
4322 LIST_HEAD(reloc_roots);
4323 struct btrfs_key key;
4324 struct btrfs_root *fs_root;
4325 struct btrfs_root *reloc_root;
4326 struct btrfs_path *path;
4327 struct extent_buffer *leaf;
4328 struct reloc_control *rc = NULL;
4329 struct btrfs_trans_handle *trans;
4333 path = btrfs_alloc_path();
4338 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4339 key.type = BTRFS_ROOT_ITEM_KEY;
4340 key.offset = (u64)-1;
4343 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4350 if (path->slots[0] == 0)
4354 leaf = path->nodes[0];
4355 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4356 btrfs_release_path(path);
4358 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4359 key.type != BTRFS_ROOT_ITEM_KEY)
4362 reloc_root = btrfs_read_fs_root(root, &key);
4363 if (IS_ERR(reloc_root)) {
4364 err = PTR_ERR(reloc_root);
4368 list_add(&reloc_root->root_list, &reloc_roots);
4370 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4371 fs_root = read_fs_root(root->fs_info,
4372 reloc_root->root_key.offset);
4373 if (IS_ERR(fs_root)) {
4374 ret = PTR_ERR(fs_root);
4375 if (ret != -ENOENT) {
4379 ret = mark_garbage_root(reloc_root);
4387 if (key.offset == 0)
4392 btrfs_release_path(path);
4394 if (list_empty(&reloc_roots))
4397 rc = alloc_reloc_control(root->fs_info);
4403 rc->extent_root = root->fs_info->extent_root;
4405 set_reloc_control(rc);
4407 trans = btrfs_join_transaction(rc->extent_root);
4408 if (IS_ERR(trans)) {
4409 unset_reloc_control(rc);
4410 err = PTR_ERR(trans);
4414 rc->merge_reloc_tree = 1;
4416 while (!list_empty(&reloc_roots)) {
4417 reloc_root = list_entry(reloc_roots.next,
4418 struct btrfs_root, root_list);
4419 list_del(&reloc_root->root_list);
4421 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4422 list_add_tail(&reloc_root->root_list,
4427 fs_root = read_fs_root(root->fs_info,
4428 reloc_root->root_key.offset);
4429 if (IS_ERR(fs_root)) {
4430 err = PTR_ERR(fs_root);
4434 err = __add_reloc_root(reloc_root);
4435 BUG_ON(err < 0); /* -ENOMEM or logic error */
4436 fs_root->reloc_root = reloc_root;
4439 err = btrfs_commit_transaction(trans, rc->extent_root);
4443 merge_reloc_roots(rc);
4445 unset_reloc_control(rc);
4447 trans = btrfs_join_transaction(rc->extent_root);
4449 err = PTR_ERR(trans);
4451 err = btrfs_commit_transaction(trans, rc->extent_root);
4455 if (!list_empty(&reloc_roots))
4456 free_reloc_roots(&reloc_roots);
4458 btrfs_free_path(path);
4461 /* cleanup orphan inode in data relocation tree */
4462 fs_root = read_fs_root(root->fs_info,
4463 BTRFS_DATA_RELOC_TREE_OBJECTID);
4464 if (IS_ERR(fs_root))
4465 err = PTR_ERR(fs_root);
4467 err = btrfs_orphan_cleanup(fs_root);
4473 * helper to add ordered checksum for data relocation.
4475 * cloning checksum properly handles the nodatasum extents.
4476 * it also saves CPU time to re-calculate the checksum.
4478 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4480 struct btrfs_ordered_sum *sums;
4481 struct btrfs_ordered_extent *ordered;
4482 struct btrfs_root *root = BTRFS_I(inode)->root;
4488 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4489 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4491 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4492 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4493 disk_bytenr + len - 1, &list, 0);
4497 while (!list_empty(&list)) {
4498 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4499 list_del_init(&sums->list);
4502 * We need to offset the new_bytenr based on where the csum is.
4503 * We need to do this because we will read in entire prealloc
4504 * extents but we may have written to say the middle of the
4505 * prealloc extent, so we need to make sure the csum goes with
4506 * the right disk offset.
4508 * We can do this because the data reloc inode refers strictly
4509 * to the on disk bytes, so we don't have to worry about
4510 * disk_len vs real len like with real inodes since it's all
4513 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4514 sums->bytenr = new_bytenr;
4516 btrfs_add_ordered_sum(inode, ordered, sums);
4519 btrfs_put_ordered_extent(ordered);
4523 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4524 struct btrfs_root *root, struct extent_buffer *buf,
4525 struct extent_buffer *cow)
4527 struct reloc_control *rc;
4528 struct backref_node *node;
4533 rc = root->fs_info->reloc_ctl;
4537 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4538 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4540 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4541 if (buf == root->node)
4542 __update_reloc_root(root, cow->start);
4545 level = btrfs_header_level(buf);
4546 if (btrfs_header_generation(buf) <=
4547 btrfs_root_last_snapshot(&root->root_item))
4550 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4551 rc->create_reloc_tree) {
4552 WARN_ON(!first_cow && level == 0);
4554 node = rc->backref_cache.path[level];
4555 BUG_ON(node->bytenr != buf->start &&
4556 node->new_bytenr != buf->start);
4558 drop_node_buffer(node);
4559 extent_buffer_get(cow);
4561 node->new_bytenr = cow->start;
4563 if (!node->pending) {
4564 list_move_tail(&node->list,
4565 &rc->backref_cache.pending[level]);
4570 __mark_block_processed(rc, node);
4572 if (first_cow && level > 0)
4573 rc->nodes_relocated += buf->len;
4576 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4577 ret = replace_file_extents(trans, rc, root, cow);
4582 * called before creating snapshot. it calculates metadata reservation
4583 * requried for relocating tree blocks in the snapshot
4585 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4586 struct btrfs_pending_snapshot *pending,
4587 u64 *bytes_to_reserve)
4589 struct btrfs_root *root;
4590 struct reloc_control *rc;
4592 root = pending->root;
4593 if (!root->reloc_root)
4596 rc = root->fs_info->reloc_ctl;
4597 if (!rc->merge_reloc_tree)
4600 root = root->reloc_root;
4601 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4603 * relocation is in the stage of merging trees. the space
4604 * used by merging a reloc tree is twice the size of
4605 * relocated tree nodes in the worst case. half for cowing
4606 * the reloc tree, half for cowing the fs tree. the space
4607 * used by cowing the reloc tree will be freed after the
4608 * tree is dropped. if we create snapshot, cowing the fs
4609 * tree may use more space than it frees. so we need
4610 * reserve extra space.
4612 *bytes_to_reserve += rc->nodes_relocated;
4616 * called after snapshot is created. migrate block reservation
4617 * and create reloc root for the newly created snapshot
4619 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4620 struct btrfs_pending_snapshot *pending)
4622 struct btrfs_root *root = pending->root;
4623 struct btrfs_root *reloc_root;
4624 struct btrfs_root *new_root;
4625 struct reloc_control *rc;
4628 if (!root->reloc_root)
4631 rc = root->fs_info->reloc_ctl;
4632 rc->merging_rsv_size += rc->nodes_relocated;
4634 if (rc->merge_reloc_tree) {
4635 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4637 rc->nodes_relocated);
4642 new_root = pending->snap;
4643 reloc_root = create_reloc_root(trans, root->reloc_root,
4644 new_root->root_key.objectid);
4645 if (IS_ERR(reloc_root))
4646 return PTR_ERR(reloc_root);
4648 ret = __add_reloc_root(reloc_root);
4650 new_root->reloc_root = reloc_root;
4652 if (rc->create_reloc_tree)
4653 ret = clone_backref_node(trans, rc, root, reloc_root);