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);
1852 } else if (!extent_buffer_uptodate(eb)) {
1854 free_extent_buffer(eb);
1857 btrfs_tree_lock(eb);
1859 ret = btrfs_cow_block(trans, dest, eb, parent,
1863 btrfs_set_lock_blocking(eb);
1865 btrfs_tree_unlock(parent);
1866 free_extent_buffer(parent);
1873 btrfs_tree_unlock(parent);
1874 free_extent_buffer(parent);
1879 btrfs_node_key_to_cpu(path->nodes[level], &key,
1880 path->slots[level]);
1881 btrfs_release_path(path);
1883 path->lowest_level = level;
1884 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1885 path->lowest_level = 0;
1889 * swap blocks in fs tree and reloc tree.
1891 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1892 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1893 btrfs_mark_buffer_dirty(parent);
1895 btrfs_set_node_blockptr(path->nodes[level],
1896 path->slots[level], old_bytenr);
1897 btrfs_set_node_ptr_generation(path->nodes[level],
1898 path->slots[level], old_ptr_gen);
1899 btrfs_mark_buffer_dirty(path->nodes[level]);
1901 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1902 path->nodes[level]->start,
1903 src->root_key.objectid, level - 1, 0,
1906 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1907 0, dest->root_key.objectid, level - 1,
1911 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1912 path->nodes[level]->start,
1913 src->root_key.objectid, level - 1, 0,
1917 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1918 0, dest->root_key.objectid, level - 1,
1922 btrfs_unlock_up_safe(path, 0);
1927 btrfs_tree_unlock(parent);
1928 free_extent_buffer(parent);
1933 * helper to find next relocated block in reloc tree
1935 static noinline_for_stack
1936 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1939 struct extent_buffer *eb;
1944 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1946 for (i = 0; i < *level; i++) {
1947 free_extent_buffer(path->nodes[i]);
1948 path->nodes[i] = NULL;
1951 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1952 eb = path->nodes[i];
1953 nritems = btrfs_header_nritems(eb);
1954 while (path->slots[i] + 1 < nritems) {
1956 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1963 free_extent_buffer(path->nodes[i]);
1964 path->nodes[i] = NULL;
1970 * walk down reloc tree to find relocated block of lowest level
1972 static noinline_for_stack
1973 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1976 struct extent_buffer *eb = NULL;
1983 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1985 for (i = *level; i > 0; i--) {
1986 eb = path->nodes[i];
1987 nritems = btrfs_header_nritems(eb);
1988 while (path->slots[i] < nritems) {
1989 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1990 if (ptr_gen > last_snapshot)
1994 if (path->slots[i] >= nritems) {
2005 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
2006 eb = read_tree_block(root, bytenr, ptr_gen);
2009 } else if (!extent_buffer_uptodate(eb)) {
2010 free_extent_buffer(eb);
2013 BUG_ON(btrfs_header_level(eb) != i - 1);
2014 path->nodes[i - 1] = eb;
2015 path->slots[i - 1] = 0;
2021 * invalidate extent cache for file extents whose key in range of
2022 * [min_key, max_key)
2024 static int invalidate_extent_cache(struct btrfs_root *root,
2025 struct btrfs_key *min_key,
2026 struct btrfs_key *max_key)
2028 struct inode *inode = NULL;
2033 objectid = min_key->objectid;
2038 if (objectid > max_key->objectid)
2041 inode = find_next_inode(root, objectid);
2044 ino = btrfs_ino(inode);
2046 if (ino > max_key->objectid) {
2052 if (!S_ISREG(inode->i_mode))
2055 if (unlikely(min_key->objectid == ino)) {
2056 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2058 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2061 start = min_key->offset;
2062 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2068 if (unlikely(max_key->objectid == ino)) {
2069 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2071 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2074 if (max_key->offset == 0)
2076 end = max_key->offset;
2077 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2084 /* the lock_extent waits for readpage to complete */
2085 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2086 btrfs_drop_extent_cache(inode, start, end, 1);
2087 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2092 static int find_next_key(struct btrfs_path *path, int level,
2093 struct btrfs_key *key)
2096 while (level < BTRFS_MAX_LEVEL) {
2097 if (!path->nodes[level])
2099 if (path->slots[level] + 1 <
2100 btrfs_header_nritems(path->nodes[level])) {
2101 btrfs_node_key_to_cpu(path->nodes[level], key,
2102 path->slots[level] + 1);
2111 * merge the relocated tree blocks in reloc tree with corresponding
2114 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2115 struct btrfs_root *root)
2117 LIST_HEAD(inode_list);
2118 struct btrfs_key key;
2119 struct btrfs_key next_key;
2120 struct btrfs_trans_handle *trans = NULL;
2121 struct btrfs_root *reloc_root;
2122 struct btrfs_root_item *root_item;
2123 struct btrfs_path *path;
2124 struct extent_buffer *leaf;
2132 path = btrfs_alloc_path();
2137 reloc_root = root->reloc_root;
2138 root_item = &reloc_root->root_item;
2140 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2141 level = btrfs_root_level(root_item);
2142 extent_buffer_get(reloc_root->node);
2143 path->nodes[level] = reloc_root->node;
2144 path->slots[level] = 0;
2146 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2148 level = root_item->drop_level;
2150 path->lowest_level = level;
2151 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2152 path->lowest_level = 0;
2154 btrfs_free_path(path);
2158 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2159 path->slots[level]);
2160 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2162 btrfs_unlock_up_safe(path, 0);
2165 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2166 memset(&next_key, 0, sizeof(next_key));
2169 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2170 BTRFS_RESERVE_FLUSH_ALL);
2175 trans = btrfs_start_transaction(root, 0);
2176 if (IS_ERR(trans)) {
2177 err = PTR_ERR(trans);
2181 trans->block_rsv = rc->block_rsv;
2186 ret = walk_down_reloc_tree(reloc_root, path, &level);
2194 if (!find_next_key(path, level, &key) &&
2195 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2198 ret = replace_path(trans, root, reloc_root, path,
2199 &next_key, level, max_level);
2208 btrfs_node_key_to_cpu(path->nodes[level], &key,
2209 path->slots[level]);
2213 ret = walk_up_reloc_tree(reloc_root, path, &level);
2219 * save the merging progress in the drop_progress.
2220 * this is OK since root refs == 1 in this case.
2222 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2223 path->slots[level]);
2224 root_item->drop_level = level;
2226 btrfs_end_transaction_throttle(trans, root);
2229 btrfs_btree_balance_dirty(root);
2231 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2232 invalidate_extent_cache(root, &key, &next_key);
2236 * handle the case only one block in the fs tree need to be
2237 * relocated and the block is tree root.
2239 leaf = btrfs_lock_root_node(root);
2240 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2241 btrfs_tree_unlock(leaf);
2242 free_extent_buffer(leaf);
2246 btrfs_free_path(path);
2249 memset(&root_item->drop_progress, 0,
2250 sizeof(root_item->drop_progress));
2251 root_item->drop_level = 0;
2252 btrfs_set_root_refs(root_item, 0);
2253 btrfs_update_reloc_root(trans, root);
2257 btrfs_end_transaction_throttle(trans, root);
2259 btrfs_btree_balance_dirty(root);
2261 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2262 invalidate_extent_cache(root, &key, &next_key);
2267 static noinline_for_stack
2268 int prepare_to_merge(struct reloc_control *rc, int err)
2270 struct btrfs_root *root = rc->extent_root;
2271 struct btrfs_root *reloc_root;
2272 struct btrfs_trans_handle *trans;
2273 LIST_HEAD(reloc_roots);
2277 mutex_lock(&root->fs_info->reloc_mutex);
2278 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2279 rc->merging_rsv_size += rc->nodes_relocated * 2;
2280 mutex_unlock(&root->fs_info->reloc_mutex);
2284 num_bytes = rc->merging_rsv_size;
2285 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2286 BTRFS_RESERVE_FLUSH_ALL);
2291 trans = btrfs_join_transaction(rc->extent_root);
2292 if (IS_ERR(trans)) {
2294 btrfs_block_rsv_release(rc->extent_root,
2295 rc->block_rsv, num_bytes);
2296 return PTR_ERR(trans);
2300 if (num_bytes != rc->merging_rsv_size) {
2301 btrfs_end_transaction(trans, rc->extent_root);
2302 btrfs_block_rsv_release(rc->extent_root,
2303 rc->block_rsv, num_bytes);
2308 rc->merge_reloc_tree = 1;
2310 while (!list_empty(&rc->reloc_roots)) {
2311 reloc_root = list_entry(rc->reloc_roots.next,
2312 struct btrfs_root, root_list);
2313 list_del_init(&reloc_root->root_list);
2315 root = read_fs_root(reloc_root->fs_info,
2316 reloc_root->root_key.offset);
2317 BUG_ON(IS_ERR(root));
2318 BUG_ON(root->reloc_root != reloc_root);
2321 * set reference count to 1, so btrfs_recover_relocation
2322 * knows it should resumes merging
2325 btrfs_set_root_refs(&reloc_root->root_item, 1);
2326 btrfs_update_reloc_root(trans, root);
2328 list_add(&reloc_root->root_list, &reloc_roots);
2331 list_splice(&reloc_roots, &rc->reloc_roots);
2334 btrfs_commit_transaction(trans, rc->extent_root);
2336 btrfs_end_transaction(trans, rc->extent_root);
2340 static noinline_for_stack
2341 void free_reloc_roots(struct list_head *list)
2343 struct btrfs_root *reloc_root;
2345 while (!list_empty(list)) {
2346 reloc_root = list_entry(list->next, struct btrfs_root,
2348 __del_reloc_root(reloc_root);
2352 static noinline_for_stack
2353 void merge_reloc_roots(struct reloc_control *rc)
2355 struct btrfs_root *root;
2356 struct btrfs_root *reloc_root;
2360 LIST_HEAD(reloc_roots);
2364 root = rc->extent_root;
2367 * this serializes us with btrfs_record_root_in_transaction,
2368 * we have to make sure nobody is in the middle of
2369 * adding their roots to the list while we are
2372 mutex_lock(&root->fs_info->reloc_mutex);
2373 list_splice_init(&rc->reloc_roots, &reloc_roots);
2374 mutex_unlock(&root->fs_info->reloc_mutex);
2376 while (!list_empty(&reloc_roots)) {
2378 reloc_root = list_entry(reloc_roots.next,
2379 struct btrfs_root, root_list);
2381 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2382 root = read_fs_root(reloc_root->fs_info,
2383 reloc_root->root_key.offset);
2384 BUG_ON(IS_ERR(root));
2385 BUG_ON(root->reloc_root != reloc_root);
2387 ret = merge_reloc_root(rc, root);
2389 if (list_empty(&reloc_root->root_list))
2390 list_add_tail(&reloc_root->root_list,
2395 list_del_init(&reloc_root->root_list);
2399 * we keep the old last snapshod transid in rtranid when we
2400 * created the relocation tree.
2402 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2403 otransid = btrfs_root_otransid(&reloc_root->root_item);
2404 objectid = reloc_root->root_key.offset;
2406 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2408 if (list_empty(&reloc_root->root_list))
2409 list_add_tail(&reloc_root->root_list,
2421 btrfs_std_error(root->fs_info, ret);
2422 if (!list_empty(&reloc_roots))
2423 free_reloc_roots(&reloc_roots);
2425 /* new reloc root may be added */
2426 mutex_lock(&root->fs_info->reloc_mutex);
2427 list_splice_init(&rc->reloc_roots, &reloc_roots);
2428 mutex_unlock(&root->fs_info->reloc_mutex);
2429 if (!list_empty(&reloc_roots))
2430 free_reloc_roots(&reloc_roots);
2433 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2436 static void free_block_list(struct rb_root *blocks)
2438 struct tree_block *block;
2439 struct rb_node *rb_node;
2440 while ((rb_node = rb_first(blocks))) {
2441 block = rb_entry(rb_node, struct tree_block, rb_node);
2442 rb_erase(rb_node, blocks);
2447 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2448 struct btrfs_root *reloc_root)
2450 struct btrfs_root *root;
2452 if (reloc_root->last_trans == trans->transid)
2455 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2456 BUG_ON(IS_ERR(root));
2457 BUG_ON(root->reloc_root != reloc_root);
2459 return btrfs_record_root_in_trans(trans, root);
2462 static noinline_for_stack
2463 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2464 struct reloc_control *rc,
2465 struct backref_node *node,
2466 struct backref_edge *edges[])
2468 struct backref_node *next;
2469 struct btrfs_root *root;
2475 next = walk_up_backref(next, edges, &index);
2478 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2480 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2481 record_reloc_root_in_trans(trans, root);
2485 btrfs_record_root_in_trans(trans, root);
2486 root = root->reloc_root;
2488 if (next->new_bytenr != root->node->start) {
2489 BUG_ON(next->new_bytenr);
2490 BUG_ON(!list_empty(&next->list));
2491 next->new_bytenr = root->node->start;
2493 list_add_tail(&next->list,
2494 &rc->backref_cache.changed);
2495 __mark_block_processed(rc, next);
2501 next = walk_down_backref(edges, &index);
2502 if (!next || next->level <= node->level)
2509 /* setup backref node path for btrfs_reloc_cow_block */
2511 rc->backref_cache.path[next->level] = next;
2514 next = edges[index]->node[UPPER];
2520 * select a tree root for relocation. return NULL if the block
2521 * is reference counted. we should use do_relocation() in this
2522 * case. return a tree root pointer if the block isn't reference
2523 * counted. return -ENOENT if the block is root of reloc tree.
2525 static noinline_for_stack
2526 struct btrfs_root *select_one_root(struct backref_node *node)
2528 struct backref_node *next;
2529 struct btrfs_root *root;
2530 struct btrfs_root *fs_root = NULL;
2531 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2537 next = walk_up_backref(next, edges, &index);
2541 /* no other choice for non-references counted tree */
2542 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2545 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2551 next = walk_down_backref(edges, &index);
2552 if (!next || next->level <= node->level)
2557 return ERR_PTR(-ENOENT);
2561 static noinline_for_stack
2562 u64 calcu_metadata_size(struct reloc_control *rc,
2563 struct backref_node *node, int reserve)
2565 struct backref_node *next = node;
2566 struct backref_edge *edge;
2567 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2571 BUG_ON(reserve && node->processed);
2576 if (next->processed && (reserve || next != node))
2579 num_bytes += rc->extent_root->nodesize;
2581 if (list_empty(&next->upper))
2584 edge = list_entry(next->upper.next,
2585 struct backref_edge, list[LOWER]);
2586 edges[index++] = edge;
2587 next = edge->node[UPPER];
2589 next = walk_down_backref(edges, &index);
2594 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2595 struct reloc_control *rc,
2596 struct backref_node *node)
2598 struct btrfs_root *root = rc->extent_root;
2603 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2605 trans->block_rsv = rc->block_rsv;
2606 rc->reserved_bytes += num_bytes;
2607 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2608 BTRFS_RESERVE_FLUSH_ALL);
2610 if (ret == -EAGAIN) {
2611 tmp = rc->extent_root->nodesize *
2612 RELOCATION_RESERVED_NODES;
2613 while (tmp <= rc->reserved_bytes)
2616 * only one thread can access block_rsv at this point,
2617 * so we don't need hold lock to protect block_rsv.
2618 * we expand more reservation size here to allow enough
2619 * space for relocation and we will return eailer in
2622 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2623 RELOCATION_RESERVED_NODES;
2632 * relocate a block tree, and then update pointers in upper level
2633 * blocks that reference the block to point to the new location.
2635 * if called by link_to_upper, the block has already been relocated.
2636 * in that case this function just updates pointers.
2638 static int do_relocation(struct btrfs_trans_handle *trans,
2639 struct reloc_control *rc,
2640 struct backref_node *node,
2641 struct btrfs_key *key,
2642 struct btrfs_path *path, int lowest)
2644 struct backref_node *upper;
2645 struct backref_edge *edge;
2646 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2647 struct btrfs_root *root;
2648 struct extent_buffer *eb;
2656 BUG_ON(lowest && node->eb);
2658 path->lowest_level = node->level + 1;
2659 rc->backref_cache.path[node->level] = node;
2660 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2663 upper = edge->node[UPPER];
2664 root = select_reloc_root(trans, rc, upper, edges);
2667 if (upper->eb && !upper->locked) {
2669 ret = btrfs_bin_search(upper->eb, key,
2670 upper->level, &slot);
2672 bytenr = btrfs_node_blockptr(upper->eb, slot);
2673 if (node->eb->start == bytenr)
2676 drop_node_buffer(upper);
2680 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2688 upper->eb = path->nodes[upper->level];
2689 path->nodes[upper->level] = NULL;
2691 BUG_ON(upper->eb != path->nodes[upper->level]);
2695 path->locks[upper->level] = 0;
2697 slot = path->slots[upper->level];
2698 btrfs_release_path(path);
2700 ret = btrfs_bin_search(upper->eb, key, upper->level,
2705 bytenr = btrfs_node_blockptr(upper->eb, slot);
2707 BUG_ON(bytenr != node->bytenr);
2709 if (node->eb->start == bytenr)
2713 blocksize = root->nodesize;
2714 generation = btrfs_node_ptr_generation(upper->eb, slot);
2715 eb = read_tree_block(root, bytenr, generation);
2719 } else if (!extent_buffer_uptodate(eb)) {
2720 free_extent_buffer(eb);
2724 btrfs_tree_lock(eb);
2725 btrfs_set_lock_blocking(eb);
2728 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2730 btrfs_tree_unlock(eb);
2731 free_extent_buffer(eb);
2736 BUG_ON(node->eb != eb);
2738 btrfs_set_node_blockptr(upper->eb, slot,
2740 btrfs_set_node_ptr_generation(upper->eb, slot,
2742 btrfs_mark_buffer_dirty(upper->eb);
2744 ret = btrfs_inc_extent_ref(trans, root,
2745 node->eb->start, blocksize,
2747 btrfs_header_owner(upper->eb),
2751 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2755 if (!upper->pending)
2756 drop_node_buffer(upper);
2758 unlock_node_buffer(upper);
2763 if (!err && node->pending) {
2764 drop_node_buffer(node);
2765 list_move_tail(&node->list, &rc->backref_cache.changed);
2769 path->lowest_level = 0;
2770 BUG_ON(err == -ENOSPC);
2774 static int link_to_upper(struct btrfs_trans_handle *trans,
2775 struct reloc_control *rc,
2776 struct backref_node *node,
2777 struct btrfs_path *path)
2779 struct btrfs_key key;
2781 btrfs_node_key_to_cpu(node->eb, &key, 0);
2782 return do_relocation(trans, rc, node, &key, path, 0);
2785 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2786 struct reloc_control *rc,
2787 struct btrfs_path *path, int err)
2790 struct backref_cache *cache = &rc->backref_cache;
2791 struct backref_node *node;
2795 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2796 while (!list_empty(&cache->pending[level])) {
2797 node = list_entry(cache->pending[level].next,
2798 struct backref_node, list);
2799 list_move_tail(&node->list, &list);
2800 BUG_ON(!node->pending);
2803 ret = link_to_upper(trans, rc, node, path);
2808 list_splice_init(&list, &cache->pending[level]);
2813 static void mark_block_processed(struct reloc_control *rc,
2814 u64 bytenr, u32 blocksize)
2816 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2817 EXTENT_DIRTY, GFP_NOFS);
2820 static void __mark_block_processed(struct reloc_control *rc,
2821 struct backref_node *node)
2824 if (node->level == 0 ||
2825 in_block_group(node->bytenr, rc->block_group)) {
2826 blocksize = rc->extent_root->nodesize;
2827 mark_block_processed(rc, node->bytenr, blocksize);
2829 node->processed = 1;
2833 * mark a block and all blocks directly/indirectly reference the block
2836 static void update_processed_blocks(struct reloc_control *rc,
2837 struct backref_node *node)
2839 struct backref_node *next = node;
2840 struct backref_edge *edge;
2841 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2847 if (next->processed)
2850 __mark_block_processed(rc, next);
2852 if (list_empty(&next->upper))
2855 edge = list_entry(next->upper.next,
2856 struct backref_edge, list[LOWER]);
2857 edges[index++] = edge;
2858 next = edge->node[UPPER];
2860 next = walk_down_backref(edges, &index);
2864 static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
2866 u32 blocksize = rc->extent_root->nodesize;
2868 if (test_range_bit(&rc->processed_blocks, bytenr,
2869 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2874 static int get_tree_block_key(struct reloc_control *rc,
2875 struct tree_block *block)
2877 struct extent_buffer *eb;
2879 BUG_ON(block->key_ready);
2880 eb = read_tree_block(rc->extent_root, block->bytenr,
2884 } else if (!extent_buffer_uptodate(eb)) {
2885 free_extent_buffer(eb);
2888 WARN_ON(btrfs_header_level(eb) != block->level);
2889 if (block->level == 0)
2890 btrfs_item_key_to_cpu(eb, &block->key, 0);
2892 btrfs_node_key_to_cpu(eb, &block->key, 0);
2893 free_extent_buffer(eb);
2894 block->key_ready = 1;
2899 * helper function to relocate a tree block
2901 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2902 struct reloc_control *rc,
2903 struct backref_node *node,
2904 struct btrfs_key *key,
2905 struct btrfs_path *path)
2907 struct btrfs_root *root;
2913 BUG_ON(node->processed);
2914 root = select_one_root(node);
2915 if (root == ERR_PTR(-ENOENT)) {
2916 update_processed_blocks(rc, node);
2920 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2921 ret = reserve_metadata_space(trans, rc, node);
2927 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2928 BUG_ON(node->new_bytenr);
2929 BUG_ON(!list_empty(&node->list));
2930 btrfs_record_root_in_trans(trans, root);
2931 root = root->reloc_root;
2932 node->new_bytenr = root->node->start;
2934 list_add_tail(&node->list, &rc->backref_cache.changed);
2936 path->lowest_level = node->level;
2937 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2938 btrfs_release_path(path);
2943 update_processed_blocks(rc, node);
2945 ret = do_relocation(trans, rc, node, key, path, 1);
2948 if (ret || node->level == 0 || node->cowonly)
2949 remove_backref_node(&rc->backref_cache, node);
2954 * relocate a list of blocks
2956 static noinline_for_stack
2957 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2958 struct reloc_control *rc, struct rb_root *blocks)
2960 struct backref_node *node;
2961 struct btrfs_path *path;
2962 struct tree_block *block;
2963 struct rb_node *rb_node;
2967 path = btrfs_alloc_path();
2970 goto out_free_blocks;
2973 rb_node = rb_first(blocks);
2975 block = rb_entry(rb_node, struct tree_block, rb_node);
2976 if (!block->key_ready)
2977 readahead_tree_block(rc->extent_root, block->bytenr);
2978 rb_node = rb_next(rb_node);
2981 rb_node = rb_first(blocks);
2983 block = rb_entry(rb_node, struct tree_block, rb_node);
2984 if (!block->key_ready) {
2985 err = get_tree_block_key(rc, block);
2989 rb_node = rb_next(rb_node);
2992 rb_node = rb_first(blocks);
2994 block = rb_entry(rb_node, struct tree_block, rb_node);
2996 node = build_backref_tree(rc, &block->key,
2997 block->level, block->bytenr);
2999 err = PTR_ERR(node);
3003 ret = relocate_tree_block(trans, rc, node, &block->key,
3006 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3010 rb_node = rb_next(rb_node);
3013 err = finish_pending_nodes(trans, rc, path, err);
3016 btrfs_free_path(path);
3018 free_block_list(blocks);
3022 static noinline_for_stack
3023 int prealloc_file_extent_cluster(struct inode *inode,
3024 struct file_extent_cluster *cluster)
3029 u64 offset = BTRFS_I(inode)->index_cnt;
3034 BUG_ON(cluster->start != cluster->boundary[0]);
3035 mutex_lock(&inode->i_mutex);
3037 ret = btrfs_check_data_free_space(inode, cluster->end +
3038 1 - cluster->start, 0);
3042 while (nr < cluster->nr) {
3043 start = cluster->boundary[nr] - offset;
3044 if (nr + 1 < cluster->nr)
3045 end = cluster->boundary[nr + 1] - 1 - offset;
3047 end = cluster->end - offset;
3049 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3050 num_bytes = end + 1 - start;
3051 ret = btrfs_prealloc_file_range(inode, 0, start,
3052 num_bytes, num_bytes,
3053 end + 1, &alloc_hint);
3054 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3059 btrfs_free_reserved_data_space(inode, cluster->end +
3060 1 - cluster->start);
3062 mutex_unlock(&inode->i_mutex);
3066 static noinline_for_stack
3067 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3070 struct btrfs_root *root = BTRFS_I(inode)->root;
3071 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3072 struct extent_map *em;
3075 em = alloc_extent_map();
3080 em->len = end + 1 - start;
3081 em->block_len = em->len;
3082 em->block_start = block_start;
3083 em->bdev = root->fs_info->fs_devices->latest_bdev;
3084 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3086 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3088 write_lock(&em_tree->lock);
3089 ret = add_extent_mapping(em_tree, em, 0);
3090 write_unlock(&em_tree->lock);
3091 if (ret != -EEXIST) {
3092 free_extent_map(em);
3095 btrfs_drop_extent_cache(inode, start, end, 0);
3097 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3101 static int relocate_file_extent_cluster(struct inode *inode,
3102 struct file_extent_cluster *cluster)
3106 u64 offset = BTRFS_I(inode)->index_cnt;
3107 unsigned long index;
3108 unsigned long last_index;
3110 struct file_ra_state *ra;
3111 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3118 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3122 ret = prealloc_file_extent_cluster(inode, cluster);
3126 file_ra_state_init(ra, inode->i_mapping);
3128 ret = setup_extent_mapping(inode, cluster->start - offset,
3129 cluster->end - offset, cluster->start);
3133 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3134 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3135 while (index <= last_index) {
3136 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3140 page = find_lock_page(inode->i_mapping, index);
3142 page_cache_sync_readahead(inode->i_mapping,
3144 last_index + 1 - index);
3145 page = find_or_create_page(inode->i_mapping, index,
3148 btrfs_delalloc_release_metadata(inode,
3155 if (PageReadahead(page)) {
3156 page_cache_async_readahead(inode->i_mapping,
3157 ra, NULL, page, index,
3158 last_index + 1 - index);
3161 if (!PageUptodate(page)) {
3162 btrfs_readpage(NULL, page);
3164 if (!PageUptodate(page)) {
3166 page_cache_release(page);
3167 btrfs_delalloc_release_metadata(inode,
3174 page_start = page_offset(page);
3175 page_end = page_start + PAGE_CACHE_SIZE - 1;
3177 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3179 set_page_extent_mapped(page);
3181 if (nr < cluster->nr &&
3182 page_start + offset == cluster->boundary[nr]) {
3183 set_extent_bits(&BTRFS_I(inode)->io_tree,
3184 page_start, page_end,
3185 EXTENT_BOUNDARY, GFP_NOFS);
3189 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3190 set_page_dirty(page);
3192 unlock_extent(&BTRFS_I(inode)->io_tree,
3193 page_start, page_end);
3195 page_cache_release(page);
3198 balance_dirty_pages_ratelimited(inode->i_mapping);
3199 btrfs_throttle(BTRFS_I(inode)->root);
3201 WARN_ON(nr != cluster->nr);
3207 static noinline_for_stack
3208 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3209 struct file_extent_cluster *cluster)
3213 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3214 ret = relocate_file_extent_cluster(inode, cluster);
3221 cluster->start = extent_key->objectid;
3223 BUG_ON(cluster->nr >= MAX_EXTENTS);
3224 cluster->end = extent_key->objectid + extent_key->offset - 1;
3225 cluster->boundary[cluster->nr] = extent_key->objectid;
3228 if (cluster->nr >= MAX_EXTENTS) {
3229 ret = relocate_file_extent_cluster(inode, cluster);
3237 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3238 static int get_ref_objectid_v0(struct reloc_control *rc,
3239 struct btrfs_path *path,
3240 struct btrfs_key *extent_key,
3241 u64 *ref_objectid, int *path_change)
3243 struct btrfs_key key;
3244 struct extent_buffer *leaf;
3245 struct btrfs_extent_ref_v0 *ref0;
3249 leaf = path->nodes[0];
3250 slot = path->slots[0];
3252 if (slot >= btrfs_header_nritems(leaf)) {
3253 ret = btrfs_next_leaf(rc->extent_root, path);
3257 leaf = path->nodes[0];
3258 slot = path->slots[0];
3262 btrfs_item_key_to_cpu(leaf, &key, slot);
3263 if (key.objectid != extent_key->objectid)
3266 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3270 ref0 = btrfs_item_ptr(leaf, slot,
3271 struct btrfs_extent_ref_v0);
3272 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3280 * helper to add a tree block to the list.
3281 * the major work is getting the generation and level of the block
3283 static int add_tree_block(struct reloc_control *rc,
3284 struct btrfs_key *extent_key,
3285 struct btrfs_path *path,
3286 struct rb_root *blocks)
3288 struct extent_buffer *eb;
3289 struct btrfs_extent_item *ei;
3290 struct btrfs_tree_block_info *bi;
3291 struct tree_block *block;
3292 struct rb_node *rb_node;
3297 eb = path->nodes[0];
3298 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3300 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3301 item_size >= sizeof(*ei) + sizeof(*bi)) {
3302 ei = btrfs_item_ptr(eb, path->slots[0],
3303 struct btrfs_extent_item);
3304 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3305 bi = (struct btrfs_tree_block_info *)(ei + 1);
3306 level = btrfs_tree_block_level(eb, bi);
3308 level = (int)extent_key->offset;
3310 generation = btrfs_extent_generation(eb, ei);
3312 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3316 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3317 ret = get_ref_objectid_v0(rc, path, extent_key,
3321 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3322 level = (int)ref_owner;
3323 /* FIXME: get real generation */
3330 btrfs_release_path(path);
3332 BUG_ON(level == -1);
3334 block = kmalloc(sizeof(*block), GFP_NOFS);
3338 block->bytenr = extent_key->objectid;
3339 block->key.objectid = rc->extent_root->nodesize;
3340 block->key.offset = generation;
3341 block->level = level;
3342 block->key_ready = 0;
3344 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3346 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3352 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3354 static int __add_tree_block(struct reloc_control *rc,
3355 u64 bytenr, u32 blocksize,
3356 struct rb_root *blocks)
3358 struct btrfs_path *path;
3359 struct btrfs_key key;
3361 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3364 if (tree_block_processed(bytenr, rc))
3367 if (tree_search(blocks, bytenr))
3370 path = btrfs_alloc_path();
3374 key.objectid = bytenr;
3376 key.type = BTRFS_METADATA_ITEM_KEY;
3377 key.offset = (u64)-1;
3379 key.type = BTRFS_EXTENT_ITEM_KEY;
3380 key.offset = blocksize;
3383 path->search_commit_root = 1;
3384 path->skip_locking = 1;
3385 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3389 if (ret > 0 && skinny) {
3390 if (path->slots[0]) {
3392 btrfs_item_key_to_cpu(path->nodes[0], &key,
3394 if (key.objectid == bytenr &&
3395 (key.type == BTRFS_METADATA_ITEM_KEY ||
3396 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3397 key.offset == blocksize)))
3403 btrfs_release_path(path);
3409 ret = add_tree_block(rc, &key, path, blocks);
3411 btrfs_free_path(path);
3416 * helper to check if the block use full backrefs for pointers in it
3418 static int block_use_full_backref(struct reloc_control *rc,
3419 struct extent_buffer *eb)
3424 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3425 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3428 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3429 eb->start, btrfs_header_level(eb), 1,
3433 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3440 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3441 struct btrfs_block_group_cache *block_group,
3442 struct inode *inode,
3445 struct btrfs_key key;
3446 struct btrfs_root *root = fs_info->tree_root;
3447 struct btrfs_trans_handle *trans;
3454 key.type = BTRFS_INODE_ITEM_KEY;
3457 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3458 if (IS_ERR(inode) || is_bad_inode(inode)) {
3465 ret = btrfs_check_trunc_cache_free_space(root,
3466 &fs_info->global_block_rsv);
3470 trans = btrfs_join_transaction(root);
3471 if (IS_ERR(trans)) {
3472 ret = PTR_ERR(trans);
3476 ret = btrfs_truncate_free_space_cache(root, trans, block_group, inode);
3478 btrfs_end_transaction(trans, root);
3479 btrfs_btree_balance_dirty(root);
3486 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3487 * this function scans fs tree to find blocks reference the data extent
3489 static int find_data_references(struct reloc_control *rc,
3490 struct btrfs_key *extent_key,
3491 struct extent_buffer *leaf,
3492 struct btrfs_extent_data_ref *ref,
3493 struct rb_root *blocks)
3495 struct btrfs_path *path;
3496 struct tree_block *block;
3497 struct btrfs_root *root;
3498 struct btrfs_file_extent_item *fi;
3499 struct rb_node *rb_node;
3500 struct btrfs_key key;
3511 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3512 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3513 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3514 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3517 * This is an extent belonging to the free space cache, lets just delete
3518 * it and redo the search.
3520 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3521 ret = delete_block_group_cache(rc->extent_root->fs_info,
3523 NULL, ref_objectid);
3529 path = btrfs_alloc_path();
3534 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3536 err = PTR_ERR(root);
3540 key.objectid = ref_objectid;
3541 key.type = BTRFS_EXTENT_DATA_KEY;
3542 if (ref_offset > ((u64)-1 << 32))
3545 key.offset = ref_offset;
3547 path->search_commit_root = 1;
3548 path->skip_locking = 1;
3549 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3555 leaf = path->nodes[0];
3556 nritems = btrfs_header_nritems(leaf);
3558 * the references in tree blocks that use full backrefs
3559 * are not counted in
3561 if (block_use_full_backref(rc, leaf))
3565 rb_node = tree_search(blocks, leaf->start);
3570 path->slots[0] = nritems;
3573 while (ref_count > 0) {
3574 while (path->slots[0] >= nritems) {
3575 ret = btrfs_next_leaf(root, path);
3580 if (WARN_ON(ret > 0))
3583 leaf = path->nodes[0];
3584 nritems = btrfs_header_nritems(leaf);
3587 if (block_use_full_backref(rc, leaf))
3591 rb_node = tree_search(blocks, leaf->start);
3596 path->slots[0] = nritems;
3600 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3601 if (WARN_ON(key.objectid != ref_objectid ||
3602 key.type != BTRFS_EXTENT_DATA_KEY))
3605 fi = btrfs_item_ptr(leaf, path->slots[0],
3606 struct btrfs_file_extent_item);
3608 if (btrfs_file_extent_type(leaf, fi) ==
3609 BTRFS_FILE_EXTENT_INLINE)
3612 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3613 extent_key->objectid)
3616 key.offset -= btrfs_file_extent_offset(leaf, fi);
3617 if (key.offset != ref_offset)
3625 if (!tree_block_processed(leaf->start, rc)) {
3626 block = kmalloc(sizeof(*block), GFP_NOFS);
3631 block->bytenr = leaf->start;
3632 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3634 block->key_ready = 1;
3635 rb_node = tree_insert(blocks, block->bytenr,
3638 backref_tree_panic(rb_node, -EEXIST,
3644 path->slots[0] = nritems;
3650 btrfs_free_path(path);
3655 * helper to find all tree blocks that reference a given data extent
3657 static noinline_for_stack
3658 int add_data_references(struct reloc_control *rc,
3659 struct btrfs_key *extent_key,
3660 struct btrfs_path *path,
3661 struct rb_root *blocks)
3663 struct btrfs_key key;
3664 struct extent_buffer *eb;
3665 struct btrfs_extent_data_ref *dref;
3666 struct btrfs_extent_inline_ref *iref;
3669 u32 blocksize = rc->extent_root->nodesize;
3673 eb = path->nodes[0];
3674 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3675 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3676 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3677 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3681 ptr += sizeof(struct btrfs_extent_item);
3684 iref = (struct btrfs_extent_inline_ref *)ptr;
3685 key.type = btrfs_extent_inline_ref_type(eb, iref);
3686 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3687 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3688 ret = __add_tree_block(rc, key.offset, blocksize,
3690 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3691 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3692 ret = find_data_references(rc, extent_key,
3701 ptr += btrfs_extent_inline_ref_size(key.type);
3707 eb = path->nodes[0];
3708 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3709 ret = btrfs_next_leaf(rc->extent_root, path);
3716 eb = path->nodes[0];
3719 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3720 if (key.objectid != extent_key->objectid)
3723 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3724 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3725 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3727 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3728 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3730 ret = __add_tree_block(rc, key.offset, blocksize,
3732 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3733 dref = btrfs_item_ptr(eb, path->slots[0],
3734 struct btrfs_extent_data_ref);
3735 ret = find_data_references(rc, extent_key,
3747 btrfs_release_path(path);
3749 free_block_list(blocks);
3754 * helper to find next unprocessed extent
3756 static noinline_for_stack
3757 int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
3758 struct btrfs_key *extent_key)
3760 struct btrfs_key key;
3761 struct extent_buffer *leaf;
3762 u64 start, end, last;
3765 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3768 if (rc->search_start >= last) {
3773 key.objectid = rc->search_start;
3774 key.type = BTRFS_EXTENT_ITEM_KEY;
3777 path->search_commit_root = 1;
3778 path->skip_locking = 1;
3779 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3784 leaf = path->nodes[0];
3785 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3786 ret = btrfs_next_leaf(rc->extent_root, path);
3789 leaf = path->nodes[0];
3792 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3793 if (key.objectid >= last) {
3798 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3799 key.type != BTRFS_METADATA_ITEM_KEY) {
3804 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3805 key.objectid + key.offset <= rc->search_start) {
3810 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3811 key.objectid + rc->extent_root->nodesize <=
3817 ret = find_first_extent_bit(&rc->processed_blocks,
3818 key.objectid, &start, &end,
3819 EXTENT_DIRTY, NULL);
3821 if (ret == 0 && start <= key.objectid) {
3822 btrfs_release_path(path);
3823 rc->search_start = end + 1;
3825 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3826 rc->search_start = key.objectid + key.offset;
3828 rc->search_start = key.objectid +
3829 rc->extent_root->nodesize;
3830 memcpy(extent_key, &key, sizeof(key));
3834 btrfs_release_path(path);
3838 static void set_reloc_control(struct reloc_control *rc)
3840 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3842 mutex_lock(&fs_info->reloc_mutex);
3843 fs_info->reloc_ctl = rc;
3844 mutex_unlock(&fs_info->reloc_mutex);
3847 static void unset_reloc_control(struct reloc_control *rc)
3849 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3851 mutex_lock(&fs_info->reloc_mutex);
3852 fs_info->reloc_ctl = NULL;
3853 mutex_unlock(&fs_info->reloc_mutex);
3856 static int check_extent_flags(u64 flags)
3858 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3859 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3861 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3862 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3864 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3865 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3870 static noinline_for_stack
3871 int prepare_to_relocate(struct reloc_control *rc)
3873 struct btrfs_trans_handle *trans;
3875 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3876 BTRFS_BLOCK_RSV_TEMP);
3880 memset(&rc->cluster, 0, sizeof(rc->cluster));
3881 rc->search_start = rc->block_group->key.objectid;
3882 rc->extents_found = 0;
3883 rc->nodes_relocated = 0;
3884 rc->merging_rsv_size = 0;
3885 rc->reserved_bytes = 0;
3886 rc->block_rsv->size = rc->extent_root->nodesize *
3887 RELOCATION_RESERVED_NODES;
3889 rc->create_reloc_tree = 1;
3890 set_reloc_control(rc);
3892 trans = btrfs_join_transaction(rc->extent_root);
3893 if (IS_ERR(trans)) {
3894 unset_reloc_control(rc);
3896 * extent tree is not a ref_cow tree and has no reloc_root to
3897 * cleanup. And callers are responsible to free the above
3900 return PTR_ERR(trans);
3902 btrfs_commit_transaction(trans, rc->extent_root);
3906 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3908 struct rb_root blocks = RB_ROOT;
3909 struct btrfs_key key;
3910 struct btrfs_trans_handle *trans = NULL;
3911 struct btrfs_path *path;
3912 struct btrfs_extent_item *ei;
3919 path = btrfs_alloc_path();
3924 ret = prepare_to_relocate(rc);
3931 rc->reserved_bytes = 0;
3932 ret = btrfs_block_rsv_refill(rc->extent_root,
3933 rc->block_rsv, rc->block_rsv->size,
3934 BTRFS_RESERVE_FLUSH_ALL);
3940 trans = btrfs_start_transaction(rc->extent_root, 0);
3941 if (IS_ERR(trans)) {
3942 err = PTR_ERR(trans);
3947 if (update_backref_cache(trans, &rc->backref_cache)) {
3948 btrfs_end_transaction(trans, rc->extent_root);
3952 ret = find_next_extent(rc, path, &key);
3958 rc->extents_found++;
3960 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3961 struct btrfs_extent_item);
3962 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3963 if (item_size >= sizeof(*ei)) {
3964 flags = btrfs_extent_flags(path->nodes[0], ei);
3965 ret = check_extent_flags(flags);
3969 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3971 int path_change = 0;
3974 sizeof(struct btrfs_extent_item_v0));
3975 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3981 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3982 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3984 flags = BTRFS_EXTENT_FLAG_DATA;
3987 btrfs_release_path(path);
3989 path->search_commit_root = 1;
3990 path->skip_locking = 1;
3991 ret = btrfs_search_slot(NULL, rc->extent_root,
4004 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
4005 ret = add_tree_block(rc, &key, path, &blocks);
4006 } else if (rc->stage == UPDATE_DATA_PTRS &&
4007 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4008 ret = add_data_references(rc, &key, path, &blocks);
4010 btrfs_release_path(path);
4018 if (!RB_EMPTY_ROOT(&blocks)) {
4019 ret = relocate_tree_blocks(trans, rc, &blocks);
4022 * if we fail to relocate tree blocks, force to update
4023 * backref cache when committing transaction.
4025 rc->backref_cache.last_trans = trans->transid - 1;
4027 if (ret != -EAGAIN) {
4031 rc->extents_found--;
4032 rc->search_start = key.objectid;
4036 btrfs_end_transaction_throttle(trans, rc->extent_root);
4037 btrfs_btree_balance_dirty(rc->extent_root);
4040 if (rc->stage == MOVE_DATA_EXTENTS &&
4041 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4042 rc->found_file_extent = 1;
4043 ret = relocate_data_extent(rc->data_inode,
4044 &key, &rc->cluster);
4051 if (trans && progress && err == -ENOSPC) {
4052 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4053 rc->block_group->flags);
4061 btrfs_release_path(path);
4062 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4066 btrfs_end_transaction_throttle(trans, rc->extent_root);
4067 btrfs_btree_balance_dirty(rc->extent_root);
4071 ret = relocate_file_extent_cluster(rc->data_inode,
4077 rc->create_reloc_tree = 0;
4078 set_reloc_control(rc);
4080 backref_cache_cleanup(&rc->backref_cache);
4081 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4083 err = prepare_to_merge(rc, err);
4085 merge_reloc_roots(rc);
4087 rc->merge_reloc_tree = 0;
4088 unset_reloc_control(rc);
4089 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4091 /* get rid of pinned extents */
4092 trans = btrfs_join_transaction(rc->extent_root);
4094 err = PTR_ERR(trans);
4096 btrfs_commit_transaction(trans, rc->extent_root);
4098 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4099 btrfs_free_path(path);
4103 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4104 struct btrfs_root *root, u64 objectid)
4106 struct btrfs_path *path;
4107 struct btrfs_inode_item *item;
4108 struct extent_buffer *leaf;
4111 path = btrfs_alloc_path();
4115 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4119 leaf = path->nodes[0];
4120 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4121 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4122 btrfs_set_inode_generation(leaf, item, 1);
4123 btrfs_set_inode_size(leaf, item, 0);
4124 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4125 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4126 BTRFS_INODE_PREALLOC);
4127 btrfs_mark_buffer_dirty(leaf);
4129 btrfs_free_path(path);
4134 * helper to create inode for data relocation.
4135 * the inode is in data relocation tree and its link count is 0
4137 static noinline_for_stack
4138 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4139 struct btrfs_block_group_cache *group)
4141 struct inode *inode = NULL;
4142 struct btrfs_trans_handle *trans;
4143 struct btrfs_root *root;
4144 struct btrfs_key key;
4148 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4150 return ERR_CAST(root);
4152 trans = btrfs_start_transaction(root, 6);
4154 return ERR_CAST(trans);
4156 err = btrfs_find_free_objectid(root, &objectid);
4160 err = __insert_orphan_inode(trans, root, objectid);
4163 key.objectid = objectid;
4164 key.type = BTRFS_INODE_ITEM_KEY;
4166 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4167 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4168 BTRFS_I(inode)->index_cnt = group->key.objectid;
4170 err = btrfs_orphan_add(trans, inode);
4172 btrfs_end_transaction(trans, root);
4173 btrfs_btree_balance_dirty(root);
4177 inode = ERR_PTR(err);
4182 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4184 struct reloc_control *rc;
4186 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4190 INIT_LIST_HEAD(&rc->reloc_roots);
4191 backref_cache_init(&rc->backref_cache);
4192 mapping_tree_init(&rc->reloc_root_tree);
4193 extent_io_tree_init(&rc->processed_blocks,
4194 fs_info->btree_inode->i_mapping);
4199 * function to relocate all extents in a block group.
4201 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4203 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4204 struct reloc_control *rc;
4205 struct inode *inode;
4206 struct btrfs_path *path;
4211 rc = alloc_reloc_control(fs_info);
4215 rc->extent_root = extent_root;
4217 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4218 BUG_ON(!rc->block_group);
4220 ret = btrfs_inc_block_group_ro(extent_root, rc->block_group);
4227 path = btrfs_alloc_path();
4233 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4235 btrfs_free_path(path);
4238 ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
4240 ret = PTR_ERR(inode);
4242 if (ret && ret != -ENOENT) {
4247 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4248 if (IS_ERR(rc->data_inode)) {
4249 err = PTR_ERR(rc->data_inode);
4250 rc->data_inode = NULL;
4254 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
4255 rc->block_group->key.objectid, rc->block_group->flags);
4257 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
4262 btrfs_wait_ordered_roots(fs_info, -1);
4265 mutex_lock(&fs_info->cleaner_mutex);
4266 ret = relocate_block_group(rc);
4267 mutex_unlock(&fs_info->cleaner_mutex);
4273 if (rc->extents_found == 0)
4276 btrfs_info(extent_root->fs_info, "found %llu extents",
4279 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4280 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4286 invalidate_mapping_pages(rc->data_inode->i_mapping,
4288 rc->stage = UPDATE_DATA_PTRS;
4292 WARN_ON(rc->block_group->pinned > 0);
4293 WARN_ON(rc->block_group->reserved > 0);
4294 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4297 btrfs_dec_block_group_ro(extent_root, rc->block_group);
4298 iput(rc->data_inode);
4299 btrfs_put_block_group(rc->block_group);
4304 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4306 struct btrfs_trans_handle *trans;
4309 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4311 return PTR_ERR(trans);
4313 memset(&root->root_item.drop_progress, 0,
4314 sizeof(root->root_item.drop_progress));
4315 root->root_item.drop_level = 0;
4316 btrfs_set_root_refs(&root->root_item, 0);
4317 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4318 &root->root_key, &root->root_item);
4320 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4327 * recover relocation interrupted by system crash.
4329 * this function resumes merging reloc trees with corresponding fs trees.
4330 * this is important for keeping the sharing of tree blocks
4332 int btrfs_recover_relocation(struct btrfs_root *root)
4334 LIST_HEAD(reloc_roots);
4335 struct btrfs_key key;
4336 struct btrfs_root *fs_root;
4337 struct btrfs_root *reloc_root;
4338 struct btrfs_path *path;
4339 struct extent_buffer *leaf;
4340 struct reloc_control *rc = NULL;
4341 struct btrfs_trans_handle *trans;
4345 path = btrfs_alloc_path();
4350 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4351 key.type = BTRFS_ROOT_ITEM_KEY;
4352 key.offset = (u64)-1;
4355 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4362 if (path->slots[0] == 0)
4366 leaf = path->nodes[0];
4367 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4368 btrfs_release_path(path);
4370 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4371 key.type != BTRFS_ROOT_ITEM_KEY)
4374 reloc_root = btrfs_read_fs_root(root, &key);
4375 if (IS_ERR(reloc_root)) {
4376 err = PTR_ERR(reloc_root);
4380 list_add(&reloc_root->root_list, &reloc_roots);
4382 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4383 fs_root = read_fs_root(root->fs_info,
4384 reloc_root->root_key.offset);
4385 if (IS_ERR(fs_root)) {
4386 ret = PTR_ERR(fs_root);
4387 if (ret != -ENOENT) {
4391 ret = mark_garbage_root(reloc_root);
4399 if (key.offset == 0)
4404 btrfs_release_path(path);
4406 if (list_empty(&reloc_roots))
4409 rc = alloc_reloc_control(root->fs_info);
4415 rc->extent_root = root->fs_info->extent_root;
4417 set_reloc_control(rc);
4419 trans = btrfs_join_transaction(rc->extent_root);
4420 if (IS_ERR(trans)) {
4421 unset_reloc_control(rc);
4422 err = PTR_ERR(trans);
4426 rc->merge_reloc_tree = 1;
4428 while (!list_empty(&reloc_roots)) {
4429 reloc_root = list_entry(reloc_roots.next,
4430 struct btrfs_root, root_list);
4431 list_del(&reloc_root->root_list);
4433 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4434 list_add_tail(&reloc_root->root_list,
4439 fs_root = read_fs_root(root->fs_info,
4440 reloc_root->root_key.offset);
4441 if (IS_ERR(fs_root)) {
4442 err = PTR_ERR(fs_root);
4446 err = __add_reloc_root(reloc_root);
4447 BUG_ON(err < 0); /* -ENOMEM or logic error */
4448 fs_root->reloc_root = reloc_root;
4451 err = btrfs_commit_transaction(trans, rc->extent_root);
4455 merge_reloc_roots(rc);
4457 unset_reloc_control(rc);
4459 trans = btrfs_join_transaction(rc->extent_root);
4461 err = PTR_ERR(trans);
4463 err = btrfs_commit_transaction(trans, rc->extent_root);
4467 if (!list_empty(&reloc_roots))
4468 free_reloc_roots(&reloc_roots);
4470 btrfs_free_path(path);
4473 /* cleanup orphan inode in data relocation tree */
4474 fs_root = read_fs_root(root->fs_info,
4475 BTRFS_DATA_RELOC_TREE_OBJECTID);
4476 if (IS_ERR(fs_root))
4477 err = PTR_ERR(fs_root);
4479 err = btrfs_orphan_cleanup(fs_root);
4485 * helper to add ordered checksum for data relocation.
4487 * cloning checksum properly handles the nodatasum extents.
4488 * it also saves CPU time to re-calculate the checksum.
4490 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4492 struct btrfs_ordered_sum *sums;
4493 struct btrfs_ordered_extent *ordered;
4494 struct btrfs_root *root = BTRFS_I(inode)->root;
4500 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4501 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4503 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4504 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4505 disk_bytenr + len - 1, &list, 0);
4509 while (!list_empty(&list)) {
4510 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4511 list_del_init(&sums->list);
4514 * We need to offset the new_bytenr based on where the csum is.
4515 * We need to do this because we will read in entire prealloc
4516 * extents but we may have written to say the middle of the
4517 * prealloc extent, so we need to make sure the csum goes with
4518 * the right disk offset.
4520 * We can do this because the data reloc inode refers strictly
4521 * to the on disk bytes, so we don't have to worry about
4522 * disk_len vs real len like with real inodes since it's all
4525 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4526 sums->bytenr = new_bytenr;
4528 btrfs_add_ordered_sum(inode, ordered, sums);
4531 btrfs_put_ordered_extent(ordered);
4535 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4536 struct btrfs_root *root, struct extent_buffer *buf,
4537 struct extent_buffer *cow)
4539 struct reloc_control *rc;
4540 struct backref_node *node;
4545 rc = root->fs_info->reloc_ctl;
4549 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4550 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4552 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4553 if (buf == root->node)
4554 __update_reloc_root(root, cow->start);
4557 level = btrfs_header_level(buf);
4558 if (btrfs_header_generation(buf) <=
4559 btrfs_root_last_snapshot(&root->root_item))
4562 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4563 rc->create_reloc_tree) {
4564 WARN_ON(!first_cow && level == 0);
4566 node = rc->backref_cache.path[level];
4567 BUG_ON(node->bytenr != buf->start &&
4568 node->new_bytenr != buf->start);
4570 drop_node_buffer(node);
4571 extent_buffer_get(cow);
4573 node->new_bytenr = cow->start;
4575 if (!node->pending) {
4576 list_move_tail(&node->list,
4577 &rc->backref_cache.pending[level]);
4582 __mark_block_processed(rc, node);
4584 if (first_cow && level > 0)
4585 rc->nodes_relocated += buf->len;
4588 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4589 ret = replace_file_extents(trans, rc, root, cow);
4594 * called before creating snapshot. it calculates metadata reservation
4595 * requried for relocating tree blocks in the snapshot
4597 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
4598 u64 *bytes_to_reserve)
4600 struct btrfs_root *root;
4601 struct reloc_control *rc;
4603 root = pending->root;
4604 if (!root->reloc_root)
4607 rc = root->fs_info->reloc_ctl;
4608 if (!rc->merge_reloc_tree)
4611 root = root->reloc_root;
4612 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4614 * relocation is in the stage of merging trees. the space
4615 * used by merging a reloc tree is twice the size of
4616 * relocated tree nodes in the worst case. half for cowing
4617 * the reloc tree, half for cowing the fs tree. the space
4618 * used by cowing the reloc tree will be freed after the
4619 * tree is dropped. if we create snapshot, cowing the fs
4620 * tree may use more space than it frees. so we need
4621 * reserve extra space.
4623 *bytes_to_reserve += rc->nodes_relocated;
4627 * called after snapshot is created. migrate block reservation
4628 * and create reloc root for the newly created snapshot
4630 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4631 struct btrfs_pending_snapshot *pending)
4633 struct btrfs_root *root = pending->root;
4634 struct btrfs_root *reloc_root;
4635 struct btrfs_root *new_root;
4636 struct reloc_control *rc;
4639 if (!root->reloc_root)
4642 rc = root->fs_info->reloc_ctl;
4643 rc->merging_rsv_size += rc->nodes_relocated;
4645 if (rc->merge_reloc_tree) {
4646 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4648 rc->nodes_relocated);
4653 new_root = pending->snap;
4654 reloc_root = create_reloc_root(trans, root->reloc_root,
4655 new_root->root_key.objectid);
4656 if (IS_ERR(reloc_root))
4657 return PTR_ERR(reloc_root);
4659 ret = __add_reloc_root(reloc_root);
4661 new_root->reloc_root = reloc_root;
4663 if (rc->create_reloc_tree)
4664 ret = clone_backref_node(trans, rc, root, reloc_root);