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];
98 struct backref_cache {
99 /* red black tree of all backref nodes in the cache */
100 struct rb_root rb_root;
101 /* for passing backref nodes to btrfs_reloc_cow_block */
102 struct backref_node *path[BTRFS_MAX_LEVEL];
104 * list of blocks that have been cowed but some block
105 * pointers in upper level blocks may not reflect the
108 struct list_head pending[BTRFS_MAX_LEVEL];
109 /* list of backref nodes with no child node */
110 struct list_head leaves;
111 /* list of blocks that have been cowed in current transaction */
112 struct list_head changed;
113 /* list of detached backref node. */
114 struct list_head detached;
123 * map address of tree root to tree
125 struct mapping_node {
126 struct rb_node rb_node;
131 struct mapping_tree {
132 struct rb_root rb_root;
137 * present a tree block to process
140 struct rb_node rb_node;
142 struct btrfs_key key;
143 unsigned int level:8;
144 unsigned int key_ready:1;
147 #define MAX_EXTENTS 128
149 struct file_extent_cluster {
152 u64 boundary[MAX_EXTENTS];
156 struct reloc_control {
157 /* block group to relocate */
158 struct btrfs_block_group_cache *block_group;
160 struct btrfs_root *extent_root;
161 /* inode for moving data */
162 struct inode *data_inode;
164 struct btrfs_block_rsv *block_rsv;
166 struct backref_cache backref_cache;
168 struct file_extent_cluster cluster;
169 /* tree blocks have been processed */
170 struct extent_io_tree processed_blocks;
171 /* map start of tree root to corresponding reloc tree */
172 struct mapping_tree reloc_root_tree;
173 /* list of reloc trees */
174 struct list_head reloc_roots;
175 /* size of metadata reservation for merging reloc trees */
176 u64 merging_rsv_size;
177 /* size of relocated tree nodes */
183 unsigned int stage:8;
184 unsigned int create_reloc_tree:1;
185 unsigned int merge_reloc_tree:1;
186 unsigned int found_file_extent:1;
187 unsigned int commit_transaction:1;
190 /* stages of data relocation */
191 #define MOVE_DATA_EXTENTS 0
192 #define UPDATE_DATA_PTRS 1
194 static void remove_backref_node(struct backref_cache *cache,
195 struct backref_node *node);
196 static void __mark_block_processed(struct reloc_control *rc,
197 struct backref_node *node);
199 static void mapping_tree_init(struct mapping_tree *tree)
201 tree->rb_root = RB_ROOT;
202 spin_lock_init(&tree->lock);
205 static void backref_cache_init(struct backref_cache *cache)
208 cache->rb_root = RB_ROOT;
209 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
210 INIT_LIST_HEAD(&cache->pending[i]);
211 INIT_LIST_HEAD(&cache->changed);
212 INIT_LIST_HEAD(&cache->detached);
213 INIT_LIST_HEAD(&cache->leaves);
216 static void backref_cache_cleanup(struct backref_cache *cache)
218 struct backref_node *node;
221 while (!list_empty(&cache->detached)) {
222 node = list_entry(cache->detached.next,
223 struct backref_node, list);
224 remove_backref_node(cache, node);
227 while (!list_empty(&cache->leaves)) {
228 node = list_entry(cache->leaves.next,
229 struct backref_node, lower);
230 remove_backref_node(cache, node);
233 cache->last_trans = 0;
235 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
236 BUG_ON(!list_empty(&cache->pending[i]));
237 BUG_ON(!list_empty(&cache->changed));
238 BUG_ON(!list_empty(&cache->detached));
239 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
240 BUG_ON(cache->nr_nodes);
241 BUG_ON(cache->nr_edges);
244 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
246 struct backref_node *node;
248 node = kzalloc(sizeof(*node), GFP_NOFS);
250 INIT_LIST_HEAD(&node->list);
251 INIT_LIST_HEAD(&node->upper);
252 INIT_LIST_HEAD(&node->lower);
253 RB_CLEAR_NODE(&node->rb_node);
259 static void free_backref_node(struct backref_cache *cache,
260 struct backref_node *node)
268 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
270 struct backref_edge *edge;
272 edge = kzalloc(sizeof(*edge), GFP_NOFS);
278 static void free_backref_edge(struct backref_cache *cache,
279 struct backref_edge *edge)
287 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
288 struct rb_node *node)
290 struct rb_node **p = &root->rb_node;
291 struct rb_node *parent = NULL;
292 struct tree_entry *entry;
296 entry = rb_entry(parent, struct tree_entry, rb_node);
298 if (bytenr < entry->bytenr)
300 else if (bytenr > entry->bytenr)
306 rb_link_node(node, parent, p);
307 rb_insert_color(node, root);
311 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
313 struct rb_node *n = root->rb_node;
314 struct tree_entry *entry;
317 entry = rb_entry(n, struct tree_entry, rb_node);
319 if (bytenr < entry->bytenr)
321 else if (bytenr > entry->bytenr)
329 void backref_tree_panic(struct rb_node *rb_node, int errno,
333 struct btrfs_fs_info *fs_info = NULL;
334 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
337 fs_info = bnode->root->fs_info;
338 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
339 "found at offset %llu\n", (unsigned long long)bytenr);
343 * walk up backref nodes until reach node presents tree root
345 static struct backref_node *walk_up_backref(struct backref_node *node,
346 struct backref_edge *edges[],
349 struct backref_edge *edge;
352 while (!list_empty(&node->upper)) {
353 edge = list_entry(node->upper.next,
354 struct backref_edge, list[LOWER]);
356 node = edge->node[UPPER];
358 BUG_ON(node->detached);
364 * walk down backref nodes to find start of next reference path
366 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
369 struct backref_edge *edge;
370 struct backref_node *lower;
374 edge = edges[idx - 1];
375 lower = edge->node[LOWER];
376 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
380 edge = list_entry(edge->list[LOWER].next,
381 struct backref_edge, list[LOWER]);
382 edges[idx - 1] = edge;
384 return edge->node[UPPER];
390 static void unlock_node_buffer(struct backref_node *node)
393 btrfs_tree_unlock(node->eb);
398 static void drop_node_buffer(struct backref_node *node)
401 unlock_node_buffer(node);
402 free_extent_buffer(node->eb);
407 static void drop_backref_node(struct backref_cache *tree,
408 struct backref_node *node)
410 BUG_ON(!list_empty(&node->upper));
412 drop_node_buffer(node);
413 list_del(&node->list);
414 list_del(&node->lower);
415 if (!RB_EMPTY_NODE(&node->rb_node))
416 rb_erase(&node->rb_node, &tree->rb_root);
417 free_backref_node(tree, node);
421 * remove a backref node from the backref cache
423 static void remove_backref_node(struct backref_cache *cache,
424 struct backref_node *node)
426 struct backref_node *upper;
427 struct backref_edge *edge;
432 BUG_ON(!node->lowest && !node->detached);
433 while (!list_empty(&node->upper)) {
434 edge = list_entry(node->upper.next, struct backref_edge,
436 upper = edge->node[UPPER];
437 list_del(&edge->list[LOWER]);
438 list_del(&edge->list[UPPER]);
439 free_backref_edge(cache, edge);
441 if (RB_EMPTY_NODE(&upper->rb_node)) {
442 BUG_ON(!list_empty(&node->upper));
443 drop_backref_node(cache, node);
449 * add the node to leaf node list if no other
450 * child block cached.
452 if (list_empty(&upper->lower)) {
453 list_add_tail(&upper->lower, &cache->leaves);
458 drop_backref_node(cache, node);
461 static void update_backref_node(struct backref_cache *cache,
462 struct backref_node *node, u64 bytenr)
464 struct rb_node *rb_node;
465 rb_erase(&node->rb_node, &cache->rb_root);
466 node->bytenr = bytenr;
467 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
469 backref_tree_panic(rb_node, -EEXIST, bytenr);
473 * update backref cache after a transaction commit
475 static int update_backref_cache(struct btrfs_trans_handle *trans,
476 struct backref_cache *cache)
478 struct backref_node *node;
481 if (cache->last_trans == 0) {
482 cache->last_trans = trans->transid;
486 if (cache->last_trans == trans->transid)
490 * detached nodes are used to avoid unnecessary backref
491 * lookup. transaction commit changes the extent tree.
492 * so the detached nodes are no longer useful.
494 while (!list_empty(&cache->detached)) {
495 node = list_entry(cache->detached.next,
496 struct backref_node, list);
497 remove_backref_node(cache, node);
500 while (!list_empty(&cache->changed)) {
501 node = list_entry(cache->changed.next,
502 struct backref_node, list);
503 list_del_init(&node->list);
504 BUG_ON(node->pending);
505 update_backref_node(cache, node, node->new_bytenr);
509 * some nodes can be left in the pending list if there were
510 * errors during processing the pending nodes.
512 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
513 list_for_each_entry(node, &cache->pending[level], list) {
514 BUG_ON(!node->pending);
515 if (node->bytenr == node->new_bytenr)
517 update_backref_node(cache, node, node->new_bytenr);
521 cache->last_trans = 0;
526 static int should_ignore_root(struct btrfs_root *root)
528 struct btrfs_root *reloc_root;
533 reloc_root = root->reloc_root;
537 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
538 root->fs_info->running_transaction->transid - 1)
541 * if there is reloc tree and it was created in previous
542 * transaction backref lookup can find the reloc tree,
543 * so backref node for the fs tree root is useless for
549 * find reloc tree by address of tree root
551 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
554 struct rb_node *rb_node;
555 struct mapping_node *node;
556 struct btrfs_root *root = NULL;
558 spin_lock(&rc->reloc_root_tree.lock);
559 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
561 node = rb_entry(rb_node, struct mapping_node, rb_node);
562 root = (struct btrfs_root *)node->data;
564 spin_unlock(&rc->reloc_root_tree.lock);
568 static int is_cowonly_root(u64 root_objectid)
570 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
571 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
572 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
573 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
574 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
575 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
580 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
583 struct btrfs_key key;
585 key.objectid = root_objectid;
586 key.type = BTRFS_ROOT_ITEM_KEY;
587 if (is_cowonly_root(root_objectid))
590 key.offset = (u64)-1;
592 return btrfs_read_fs_root_no_name(fs_info, &key);
595 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
596 static noinline_for_stack
597 struct btrfs_root *find_tree_root(struct reloc_control *rc,
598 struct extent_buffer *leaf,
599 struct btrfs_extent_ref_v0 *ref0)
601 struct btrfs_root *root;
602 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
603 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
605 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
607 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
608 BUG_ON(IS_ERR(root));
610 if (root->ref_cows &&
611 generation != btrfs_root_generation(&root->root_item))
618 static noinline_for_stack
619 int find_inline_backref(struct extent_buffer *leaf, int slot,
620 unsigned long *ptr, unsigned long *end)
622 struct btrfs_extent_item *ei;
623 struct btrfs_tree_block_info *bi;
626 item_size = btrfs_item_size_nr(leaf, slot);
627 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
628 if (item_size < sizeof(*ei)) {
629 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
633 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
634 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
635 BTRFS_EXTENT_FLAG_TREE_BLOCK));
637 if (item_size <= sizeof(*ei) + sizeof(*bi)) {
638 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
642 bi = (struct btrfs_tree_block_info *)(ei + 1);
643 *ptr = (unsigned long)(bi + 1);
644 *end = (unsigned long)ei + item_size;
649 * build backref tree for a given tree block. root of the backref tree
650 * corresponds the tree block, leaves of the backref tree correspond
651 * roots of b-trees that reference the tree block.
653 * the basic idea of this function is check backrefs of a given block
654 * to find upper level blocks that refernece the block, and then check
655 * bakcrefs of these upper level blocks recursively. the recursion stop
656 * when tree root is reached or backrefs for the block is cached.
658 * NOTE: if we find backrefs for a block are cached, we know backrefs
659 * for all upper level blocks that directly/indirectly reference the
660 * block are also cached.
662 static noinline_for_stack
663 struct backref_node *build_backref_tree(struct reloc_control *rc,
664 struct btrfs_key *node_key,
665 int level, u64 bytenr)
667 struct backref_cache *cache = &rc->backref_cache;
668 struct btrfs_path *path1;
669 struct btrfs_path *path2;
670 struct extent_buffer *eb;
671 struct btrfs_root *root;
672 struct backref_node *cur;
673 struct backref_node *upper;
674 struct backref_node *lower;
675 struct backref_node *node = NULL;
676 struct backref_node *exist = NULL;
677 struct backref_edge *edge;
678 struct rb_node *rb_node;
679 struct btrfs_key key;
688 path1 = btrfs_alloc_path();
689 path2 = btrfs_alloc_path();
690 if (!path1 || !path2) {
697 node = alloc_backref_node(cache);
703 node->bytenr = bytenr;
710 key.objectid = cur->bytenr;
711 key.type = BTRFS_EXTENT_ITEM_KEY;
712 key.offset = (u64)-1;
714 path1->search_commit_root = 1;
715 path1->skip_locking = 1;
716 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
722 BUG_ON(!ret || !path1->slots[0]);
726 WARN_ON(cur->checked);
727 if (!list_empty(&cur->upper)) {
729 * the backref was added previously when processing
730 * backref of type BTRFS_TREE_BLOCK_REF_KEY
732 BUG_ON(!list_is_singular(&cur->upper));
733 edge = list_entry(cur->upper.next, struct backref_edge,
735 BUG_ON(!list_empty(&edge->list[UPPER]));
736 exist = edge->node[UPPER];
738 * add the upper level block to pending list if we need
742 list_add_tail(&edge->list[UPPER], &list);
749 eb = path1->nodes[0];
752 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
753 ret = btrfs_next_leaf(rc->extent_root, path1);
760 eb = path1->nodes[0];
763 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
764 if (key.objectid != cur->bytenr) {
769 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
770 ret = find_inline_backref(eb, path1->slots[0],
778 /* update key for inline back ref */
779 struct btrfs_extent_inline_ref *iref;
780 iref = (struct btrfs_extent_inline_ref *)ptr;
781 key.type = btrfs_extent_inline_ref_type(eb, iref);
782 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
783 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
784 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
788 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
789 exist->owner == key.offset) ||
790 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
791 exist->bytenr == key.offset))) {
796 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
797 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
798 key.type == BTRFS_EXTENT_REF_V0_KEY) {
799 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
800 struct btrfs_extent_ref_v0 *ref0;
801 ref0 = btrfs_item_ptr(eb, path1->slots[0],
802 struct btrfs_extent_ref_v0);
803 if (key.objectid == key.offset) {
804 root = find_tree_root(rc, eb, ref0);
805 if (root && !should_ignore_root(root))
808 list_add(&cur->list, &useless);
811 if (is_cowonly_root(btrfs_ref_root_v0(eb,
816 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
817 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
819 if (key.objectid == key.offset) {
821 * only root blocks of reloc trees use
822 * backref of this type.
824 root = find_reloc_root(rc, cur->bytenr);
830 edge = alloc_backref_edge(cache);
835 rb_node = tree_search(&cache->rb_root, key.offset);
837 upper = alloc_backref_node(cache);
839 free_backref_edge(cache, edge);
843 upper->bytenr = key.offset;
844 upper->level = cur->level + 1;
846 * backrefs for the upper level block isn't
847 * cached, add the block to pending list
849 list_add_tail(&edge->list[UPPER], &list);
851 upper = rb_entry(rb_node, struct backref_node,
853 BUG_ON(!upper->checked);
854 INIT_LIST_HEAD(&edge->list[UPPER]);
856 list_add_tail(&edge->list[LOWER], &cur->upper);
857 edge->node[LOWER] = cur;
858 edge->node[UPPER] = upper;
861 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
865 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
866 root = read_fs_root(rc->extent_root->fs_info, key.offset);
875 if (btrfs_root_level(&root->root_item) == cur->level) {
877 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
879 if (should_ignore_root(root))
880 list_add(&cur->list, &useless);
886 level = cur->level + 1;
889 * searching the tree to find upper level blocks
890 * reference the block.
892 path2->search_commit_root = 1;
893 path2->skip_locking = 1;
894 path2->lowest_level = level;
895 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
896 path2->lowest_level = 0;
901 if (ret > 0 && path2->slots[level] > 0)
902 path2->slots[level]--;
904 eb = path2->nodes[level];
905 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
909 for (; level < BTRFS_MAX_LEVEL; level++) {
910 if (!path2->nodes[level]) {
911 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
913 if (should_ignore_root(root))
914 list_add(&lower->list, &useless);
920 edge = alloc_backref_edge(cache);
926 eb = path2->nodes[level];
927 rb_node = tree_search(&cache->rb_root, eb->start);
929 upper = alloc_backref_node(cache);
931 free_backref_edge(cache, edge);
935 upper->bytenr = eb->start;
936 upper->owner = btrfs_header_owner(eb);
937 upper->level = lower->level + 1;
942 * if we know the block isn't shared
943 * we can void checking its backrefs.
945 if (btrfs_block_can_be_shared(root, eb))
951 * add the block to pending list if we
952 * need check its backrefs. only block
953 * at 'cur->level + 1' is added to the
954 * tail of pending list. this guarantees
955 * we check backrefs from lower level
956 * blocks to upper level blocks.
958 if (!upper->checked &&
959 level == cur->level + 1) {
960 list_add_tail(&edge->list[UPPER],
963 INIT_LIST_HEAD(&edge->list[UPPER]);
965 upper = rb_entry(rb_node, struct backref_node,
967 BUG_ON(!upper->checked);
968 INIT_LIST_HEAD(&edge->list[UPPER]);
970 upper->owner = btrfs_header_owner(eb);
972 list_add_tail(&edge->list[LOWER], &lower->upper);
973 edge->node[LOWER] = lower;
974 edge->node[UPPER] = upper;
981 btrfs_release_path(path2);
984 ptr += btrfs_extent_inline_ref_size(key.type);
994 btrfs_release_path(path1);
999 /* the pending list isn't empty, take the first block to process */
1000 if (!list_empty(&list)) {
1001 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1002 list_del_init(&edge->list[UPPER]);
1003 cur = edge->node[UPPER];
1008 * everything goes well, connect backref nodes and insert backref nodes
1011 BUG_ON(!node->checked);
1012 cowonly = node->cowonly;
1014 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1017 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1018 list_add_tail(&node->lower, &cache->leaves);
1021 list_for_each_entry(edge, &node->upper, list[LOWER])
1022 list_add_tail(&edge->list[UPPER], &list);
1024 while (!list_empty(&list)) {
1025 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1026 list_del_init(&edge->list[UPPER]);
1027 upper = edge->node[UPPER];
1028 if (upper->detached) {
1029 list_del(&edge->list[LOWER]);
1030 lower = edge->node[LOWER];
1031 free_backref_edge(cache, edge);
1032 if (list_empty(&lower->upper))
1033 list_add(&lower->list, &useless);
1037 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1038 if (upper->lowest) {
1039 list_del_init(&upper->lower);
1043 list_add_tail(&edge->list[UPPER], &upper->lower);
1047 BUG_ON(!upper->checked);
1048 BUG_ON(cowonly != upper->cowonly);
1050 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1053 backref_tree_panic(rb_node, -EEXIST,
1057 list_add_tail(&edge->list[UPPER], &upper->lower);
1059 list_for_each_entry(edge, &upper->upper, list[LOWER])
1060 list_add_tail(&edge->list[UPPER], &list);
1063 * process useless backref nodes. backref nodes for tree leaves
1064 * are deleted from the cache. backref nodes for upper level
1065 * tree blocks are left in the cache to avoid unnecessary backref
1068 while (!list_empty(&useless)) {
1069 upper = list_entry(useless.next, struct backref_node, list);
1070 list_del_init(&upper->list);
1071 BUG_ON(!list_empty(&upper->upper));
1074 if (upper->lowest) {
1075 list_del_init(&upper->lower);
1078 while (!list_empty(&upper->lower)) {
1079 edge = list_entry(upper->lower.next,
1080 struct backref_edge, list[UPPER]);
1081 list_del(&edge->list[UPPER]);
1082 list_del(&edge->list[LOWER]);
1083 lower = edge->node[LOWER];
1084 free_backref_edge(cache, edge);
1086 if (list_empty(&lower->upper))
1087 list_add(&lower->list, &useless);
1089 __mark_block_processed(rc, upper);
1090 if (upper->level > 0) {
1091 list_add(&upper->list, &cache->detached);
1092 upper->detached = 1;
1094 rb_erase(&upper->rb_node, &cache->rb_root);
1095 free_backref_node(cache, upper);
1099 btrfs_free_path(path1);
1100 btrfs_free_path(path2);
1102 while (!list_empty(&useless)) {
1103 lower = list_entry(useless.next,
1104 struct backref_node, upper);
1105 list_del_init(&lower->upper);
1108 INIT_LIST_HEAD(&list);
1110 if (RB_EMPTY_NODE(&upper->rb_node)) {
1111 list_splice_tail(&upper->upper, &list);
1112 free_backref_node(cache, upper);
1115 if (list_empty(&list))
1118 edge = list_entry(list.next, struct backref_edge,
1120 list_del(&edge->list[LOWER]);
1121 upper = edge->node[UPPER];
1122 free_backref_edge(cache, edge);
1124 return ERR_PTR(err);
1126 BUG_ON(node && node->detached);
1131 * helper to add backref node for the newly created snapshot.
1132 * the backref node is created by cloning backref node that
1133 * corresponds to root of source tree
1135 static int clone_backref_node(struct btrfs_trans_handle *trans,
1136 struct reloc_control *rc,
1137 struct btrfs_root *src,
1138 struct btrfs_root *dest)
1140 struct btrfs_root *reloc_root = src->reloc_root;
1141 struct backref_cache *cache = &rc->backref_cache;
1142 struct backref_node *node = NULL;
1143 struct backref_node *new_node;
1144 struct backref_edge *edge;
1145 struct backref_edge *new_edge;
1146 struct rb_node *rb_node;
1148 if (cache->last_trans > 0)
1149 update_backref_cache(trans, cache);
1151 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1153 node = rb_entry(rb_node, struct backref_node, rb_node);
1157 BUG_ON(node->new_bytenr != reloc_root->node->start);
1161 rb_node = tree_search(&cache->rb_root,
1162 reloc_root->commit_root->start);
1164 node = rb_entry(rb_node, struct backref_node,
1166 BUG_ON(node->detached);
1173 new_node = alloc_backref_node(cache);
1177 new_node->bytenr = dest->node->start;
1178 new_node->level = node->level;
1179 new_node->lowest = node->lowest;
1180 new_node->checked = 1;
1181 new_node->root = dest;
1183 if (!node->lowest) {
1184 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1185 new_edge = alloc_backref_edge(cache);
1189 new_edge->node[UPPER] = new_node;
1190 new_edge->node[LOWER] = edge->node[LOWER];
1191 list_add_tail(&new_edge->list[UPPER],
1195 list_add_tail(&new_node->lower, &cache->leaves);
1198 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1199 &new_node->rb_node);
1201 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1203 if (!new_node->lowest) {
1204 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1205 list_add_tail(&new_edge->list[LOWER],
1206 &new_edge->node[LOWER]->upper);
1211 while (!list_empty(&new_node->lower)) {
1212 new_edge = list_entry(new_node->lower.next,
1213 struct backref_edge, list[UPPER]);
1214 list_del(&new_edge->list[UPPER]);
1215 free_backref_edge(cache, new_edge);
1217 free_backref_node(cache, new_node);
1222 * helper to add 'address of tree root -> reloc tree' mapping
1224 static int __must_check __add_reloc_root(struct btrfs_root *root)
1226 struct rb_node *rb_node;
1227 struct mapping_node *node;
1228 struct reloc_control *rc = root->fs_info->reloc_ctl;
1230 node = kmalloc(sizeof(*node), GFP_NOFS);
1234 node->bytenr = root->node->start;
1237 spin_lock(&rc->reloc_root_tree.lock);
1238 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1239 node->bytenr, &node->rb_node);
1240 spin_unlock(&rc->reloc_root_tree.lock);
1243 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1244 "for start=%llu while inserting into relocation "
1248 list_add_tail(&root->root_list, &rc->reloc_roots);
1253 * helper to update/delete the 'address of tree root -> reloc tree'
1256 static int __update_reloc_root(struct btrfs_root *root, int del)
1258 struct rb_node *rb_node;
1259 struct mapping_node *node = NULL;
1260 struct reloc_control *rc = root->fs_info->reloc_ctl;
1262 spin_lock(&rc->reloc_root_tree.lock);
1263 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1264 root->commit_root->start);
1266 node = rb_entry(rb_node, struct mapping_node, rb_node);
1267 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1269 spin_unlock(&rc->reloc_root_tree.lock);
1271 BUG_ON((struct btrfs_root *)node->data != root);
1274 spin_lock(&rc->reloc_root_tree.lock);
1275 node->bytenr = root->node->start;
1276 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1277 node->bytenr, &node->rb_node);
1278 spin_unlock(&rc->reloc_root_tree.lock);
1280 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1282 list_del_init(&root->root_list);
1288 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1289 struct btrfs_root *root, u64 objectid)
1291 struct btrfs_root *reloc_root;
1292 struct extent_buffer *eb;
1293 struct btrfs_root_item *root_item;
1294 struct btrfs_key root_key;
1297 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1300 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1301 root_key.type = BTRFS_ROOT_ITEM_KEY;
1302 root_key.offset = objectid;
1304 if (root->root_key.objectid == objectid) {
1305 /* called by btrfs_init_reloc_root */
1306 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1307 BTRFS_TREE_RELOC_OBJECTID);
1310 btrfs_set_root_last_snapshot(&root->root_item,
1311 trans->transid - 1);
1314 * called by btrfs_reloc_post_snapshot_hook.
1315 * the source tree is a reloc tree, all tree blocks
1316 * modified after it was created have RELOC flag
1317 * set in their headers. so it's OK to not update
1318 * the 'last_snapshot'.
1320 ret = btrfs_copy_root(trans, root, root->node, &eb,
1321 BTRFS_TREE_RELOC_OBJECTID);
1325 memcpy(root_item, &root->root_item, sizeof(*root_item));
1326 btrfs_set_root_bytenr(root_item, eb->start);
1327 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1328 btrfs_set_root_generation(root_item, trans->transid);
1330 if (root->root_key.objectid == objectid) {
1331 btrfs_set_root_refs(root_item, 0);
1332 memset(&root_item->drop_progress, 0,
1333 sizeof(struct btrfs_disk_key));
1334 root_item->drop_level = 0;
1337 btrfs_tree_unlock(eb);
1338 free_extent_buffer(eb);
1340 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1341 &root_key, root_item);
1345 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
1347 BUG_ON(IS_ERR(reloc_root));
1348 reloc_root->last_trans = trans->transid;
1353 * create reloc tree for a given fs tree. reloc tree is just a
1354 * snapshot of the fs tree with special root objectid.
1356 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1357 struct btrfs_root *root)
1359 struct btrfs_root *reloc_root;
1360 struct reloc_control *rc = root->fs_info->reloc_ctl;
1364 if (root->reloc_root) {
1365 reloc_root = root->reloc_root;
1366 reloc_root->last_trans = trans->transid;
1370 if (!rc || !rc->create_reloc_tree ||
1371 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1374 if (!trans->block_rsv) {
1375 trans->block_rsv = rc->block_rsv;
1378 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1380 trans->block_rsv = NULL;
1382 ret = __add_reloc_root(reloc_root);
1384 root->reloc_root = reloc_root;
1389 * update root item of reloc tree
1391 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1392 struct btrfs_root *root)
1394 struct btrfs_root *reloc_root;
1395 struct btrfs_root_item *root_item;
1399 if (!root->reloc_root)
1402 reloc_root = root->reloc_root;
1403 root_item = &reloc_root->root_item;
1405 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1406 btrfs_root_refs(root_item) == 0) {
1407 root->reloc_root = NULL;
1411 __update_reloc_root(reloc_root, del);
1413 if (reloc_root->commit_root != reloc_root->node) {
1414 btrfs_set_root_node(root_item, reloc_root->node);
1415 free_extent_buffer(reloc_root->commit_root);
1416 reloc_root->commit_root = btrfs_root_node(reloc_root);
1419 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1420 &reloc_root->root_key, root_item);
1428 * helper to find first cached inode with inode number >= objectid
1431 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1433 struct rb_node *node;
1434 struct rb_node *prev;
1435 struct btrfs_inode *entry;
1436 struct inode *inode;
1438 spin_lock(&root->inode_lock);
1440 node = root->inode_tree.rb_node;
1444 entry = rb_entry(node, struct btrfs_inode, rb_node);
1446 if (objectid < btrfs_ino(&entry->vfs_inode))
1447 node = node->rb_left;
1448 else if (objectid > btrfs_ino(&entry->vfs_inode))
1449 node = node->rb_right;
1455 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1456 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1460 prev = rb_next(prev);
1464 entry = rb_entry(node, struct btrfs_inode, rb_node);
1465 inode = igrab(&entry->vfs_inode);
1467 spin_unlock(&root->inode_lock);
1471 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1472 if (cond_resched_lock(&root->inode_lock))
1475 node = rb_next(node);
1477 spin_unlock(&root->inode_lock);
1481 static int in_block_group(u64 bytenr,
1482 struct btrfs_block_group_cache *block_group)
1484 if (bytenr >= block_group->key.objectid &&
1485 bytenr < block_group->key.objectid + block_group->key.offset)
1491 * get new location of data
1493 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1494 u64 bytenr, u64 num_bytes)
1496 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1497 struct btrfs_path *path;
1498 struct btrfs_file_extent_item *fi;
1499 struct extent_buffer *leaf;
1502 path = btrfs_alloc_path();
1506 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1507 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1516 leaf = path->nodes[0];
1517 fi = btrfs_item_ptr(leaf, path->slots[0],
1518 struct btrfs_file_extent_item);
1520 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1521 btrfs_file_extent_compression(leaf, fi) ||
1522 btrfs_file_extent_encryption(leaf, fi) ||
1523 btrfs_file_extent_other_encoding(leaf, fi));
1525 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1530 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1533 btrfs_free_path(path);
1538 * update file extent items in the tree leaf to point to
1539 * the new locations.
1541 static noinline_for_stack
1542 int replace_file_extents(struct btrfs_trans_handle *trans,
1543 struct reloc_control *rc,
1544 struct btrfs_root *root,
1545 struct extent_buffer *leaf)
1547 struct btrfs_key key;
1548 struct btrfs_file_extent_item *fi;
1549 struct inode *inode = NULL;
1561 if (rc->stage != UPDATE_DATA_PTRS)
1564 /* reloc trees always use full backref */
1565 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1566 parent = leaf->start;
1570 nritems = btrfs_header_nritems(leaf);
1571 for (i = 0; i < nritems; i++) {
1573 btrfs_item_key_to_cpu(leaf, &key, i);
1574 if (key.type != BTRFS_EXTENT_DATA_KEY)
1576 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1577 if (btrfs_file_extent_type(leaf, fi) ==
1578 BTRFS_FILE_EXTENT_INLINE)
1580 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1581 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1584 if (!in_block_group(bytenr, rc->block_group))
1588 * if we are modifying block in fs tree, wait for readpage
1589 * to complete and drop the extent cache
1591 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1593 inode = find_next_inode(root, key.objectid);
1595 } else if (inode && btrfs_ino(inode) < key.objectid) {
1596 btrfs_add_delayed_iput(inode);
1597 inode = find_next_inode(root, key.objectid);
1599 if (inode && btrfs_ino(inode) == key.objectid) {
1601 btrfs_file_extent_num_bytes(leaf, fi);
1602 WARN_ON(!IS_ALIGNED(key.offset,
1604 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1606 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1611 btrfs_drop_extent_cache(inode, key.offset, end,
1613 unlock_extent(&BTRFS_I(inode)->io_tree,
1618 ret = get_new_location(rc->data_inode, &new_bytenr,
1626 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1629 key.offset -= btrfs_file_extent_offset(leaf, fi);
1630 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1632 btrfs_header_owner(leaf),
1633 key.objectid, key.offset, 1);
1636 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1637 parent, btrfs_header_owner(leaf),
1638 key.objectid, key.offset, 1);
1642 btrfs_mark_buffer_dirty(leaf);
1644 btrfs_add_delayed_iput(inode);
1648 static noinline_for_stack
1649 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1650 struct btrfs_path *path, int level)
1652 struct btrfs_disk_key key1;
1653 struct btrfs_disk_key key2;
1654 btrfs_node_key(eb, &key1, slot);
1655 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1656 return memcmp(&key1, &key2, sizeof(key1));
1660 * try to replace tree blocks in fs tree with the new blocks
1661 * in reloc tree. tree blocks haven't been modified since the
1662 * reloc tree was create can be replaced.
1664 * if a block was replaced, level of the block + 1 is returned.
1665 * if no block got replaced, 0 is returned. if there are other
1666 * errors, a negative error number is returned.
1668 static noinline_for_stack
1669 int replace_path(struct btrfs_trans_handle *trans,
1670 struct btrfs_root *dest, struct btrfs_root *src,
1671 struct btrfs_path *path, struct btrfs_key *next_key,
1672 int lowest_level, int max_level)
1674 struct extent_buffer *eb;
1675 struct extent_buffer *parent;
1676 struct btrfs_key key;
1688 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1689 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1691 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1693 slot = path->slots[lowest_level];
1694 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1696 eb = btrfs_lock_root_node(dest);
1697 btrfs_set_lock_blocking(eb);
1698 level = btrfs_header_level(eb);
1700 if (level < lowest_level) {
1701 btrfs_tree_unlock(eb);
1702 free_extent_buffer(eb);
1707 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1710 btrfs_set_lock_blocking(eb);
1713 next_key->objectid = (u64)-1;
1714 next_key->type = (u8)-1;
1715 next_key->offset = (u64)-1;
1720 level = btrfs_header_level(parent);
1721 BUG_ON(level < lowest_level);
1723 ret = btrfs_bin_search(parent, &key, level, &slot);
1724 if (ret && slot > 0)
1727 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1728 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1730 old_bytenr = btrfs_node_blockptr(parent, slot);
1731 blocksize = btrfs_level_size(dest, level - 1);
1732 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1734 if (level <= max_level) {
1735 eb = path->nodes[level];
1736 new_bytenr = btrfs_node_blockptr(eb,
1737 path->slots[level]);
1738 new_ptr_gen = btrfs_node_ptr_generation(eb,
1739 path->slots[level]);
1745 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1751 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1752 memcmp_node_keys(parent, slot, path, level)) {
1753 if (level <= lowest_level) {
1758 eb = read_tree_block(dest, old_bytenr, blocksize,
1761 btrfs_tree_lock(eb);
1763 ret = btrfs_cow_block(trans, dest, eb, parent,
1767 btrfs_set_lock_blocking(eb);
1769 btrfs_tree_unlock(parent);
1770 free_extent_buffer(parent);
1777 btrfs_tree_unlock(parent);
1778 free_extent_buffer(parent);
1783 btrfs_node_key_to_cpu(path->nodes[level], &key,
1784 path->slots[level]);
1785 btrfs_release_path(path);
1787 path->lowest_level = level;
1788 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1789 path->lowest_level = 0;
1793 * swap blocks in fs tree and reloc tree.
1795 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1796 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1797 btrfs_mark_buffer_dirty(parent);
1799 btrfs_set_node_blockptr(path->nodes[level],
1800 path->slots[level], old_bytenr);
1801 btrfs_set_node_ptr_generation(path->nodes[level],
1802 path->slots[level], old_ptr_gen);
1803 btrfs_mark_buffer_dirty(path->nodes[level]);
1805 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1806 path->nodes[level]->start,
1807 src->root_key.objectid, level - 1, 0,
1810 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1811 0, dest->root_key.objectid, level - 1,
1815 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1816 path->nodes[level]->start,
1817 src->root_key.objectid, level - 1, 0,
1821 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1822 0, dest->root_key.objectid, level - 1,
1826 btrfs_unlock_up_safe(path, 0);
1831 btrfs_tree_unlock(parent);
1832 free_extent_buffer(parent);
1837 * helper to find next relocated block in reloc tree
1839 static noinline_for_stack
1840 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1843 struct extent_buffer *eb;
1848 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1850 for (i = 0; i < *level; i++) {
1851 free_extent_buffer(path->nodes[i]);
1852 path->nodes[i] = NULL;
1855 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1856 eb = path->nodes[i];
1857 nritems = btrfs_header_nritems(eb);
1858 while (path->slots[i] + 1 < nritems) {
1860 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1867 free_extent_buffer(path->nodes[i]);
1868 path->nodes[i] = NULL;
1874 * walk down reloc tree to find relocated block of lowest level
1876 static noinline_for_stack
1877 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1880 struct extent_buffer *eb = NULL;
1888 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1890 for (i = *level; i > 0; i--) {
1891 eb = path->nodes[i];
1892 nritems = btrfs_header_nritems(eb);
1893 while (path->slots[i] < nritems) {
1894 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1895 if (ptr_gen > last_snapshot)
1899 if (path->slots[i] >= nritems) {
1910 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1911 blocksize = btrfs_level_size(root, i - 1);
1912 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1913 BUG_ON(btrfs_header_level(eb) != i - 1);
1914 path->nodes[i - 1] = eb;
1915 path->slots[i - 1] = 0;
1921 * invalidate extent cache for file extents whose key in range of
1922 * [min_key, max_key)
1924 static int invalidate_extent_cache(struct btrfs_root *root,
1925 struct btrfs_key *min_key,
1926 struct btrfs_key *max_key)
1928 struct inode *inode = NULL;
1933 objectid = min_key->objectid;
1938 if (objectid > max_key->objectid)
1941 inode = find_next_inode(root, objectid);
1944 ino = btrfs_ino(inode);
1946 if (ino > max_key->objectid) {
1952 if (!S_ISREG(inode->i_mode))
1955 if (unlikely(min_key->objectid == ino)) {
1956 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1958 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1961 start = min_key->offset;
1962 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1968 if (unlikely(max_key->objectid == ino)) {
1969 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1971 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
1974 if (max_key->offset == 0)
1976 end = max_key->offset;
1977 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1984 /* the lock_extent waits for readpage to complete */
1985 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
1986 btrfs_drop_extent_cache(inode, start, end, 1);
1987 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
1992 static int find_next_key(struct btrfs_path *path, int level,
1993 struct btrfs_key *key)
1996 while (level < BTRFS_MAX_LEVEL) {
1997 if (!path->nodes[level])
1999 if (path->slots[level] + 1 <
2000 btrfs_header_nritems(path->nodes[level])) {
2001 btrfs_node_key_to_cpu(path->nodes[level], key,
2002 path->slots[level] + 1);
2011 * merge the relocated tree blocks in reloc tree with corresponding
2014 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2015 struct btrfs_root *root)
2017 LIST_HEAD(inode_list);
2018 struct btrfs_key key;
2019 struct btrfs_key next_key;
2020 struct btrfs_trans_handle *trans;
2021 struct btrfs_root *reloc_root;
2022 struct btrfs_root_item *root_item;
2023 struct btrfs_path *path;
2024 struct extent_buffer *leaf;
2033 path = btrfs_alloc_path();
2038 reloc_root = root->reloc_root;
2039 root_item = &reloc_root->root_item;
2041 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2042 level = btrfs_root_level(root_item);
2043 extent_buffer_get(reloc_root->node);
2044 path->nodes[level] = reloc_root->node;
2045 path->slots[level] = 0;
2047 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2049 level = root_item->drop_level;
2051 path->lowest_level = level;
2052 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2053 path->lowest_level = 0;
2055 btrfs_free_path(path);
2059 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2060 path->slots[level]);
2061 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2063 btrfs_unlock_up_safe(path, 0);
2066 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2067 memset(&next_key, 0, sizeof(next_key));
2070 trans = btrfs_start_transaction(root, 0);
2071 BUG_ON(IS_ERR(trans));
2072 trans->block_rsv = rc->block_rsv;
2074 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved);
2076 BUG_ON(ret != -EAGAIN);
2077 ret = btrfs_commit_transaction(trans, root);
2085 ret = walk_down_reloc_tree(reloc_root, path, &level);
2093 if (!find_next_key(path, level, &key) &&
2094 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2097 ret = replace_path(trans, root, reloc_root, path,
2098 &next_key, level, max_level);
2107 btrfs_node_key_to_cpu(path->nodes[level], &key,
2108 path->slots[level]);
2112 ret = walk_up_reloc_tree(reloc_root, path, &level);
2118 * save the merging progress in the drop_progress.
2119 * this is OK since root refs == 1 in this case.
2121 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2122 path->slots[level]);
2123 root_item->drop_level = level;
2125 nr = trans->blocks_used;
2126 btrfs_end_transaction_throttle(trans, root);
2128 btrfs_btree_balance_dirty(root, nr);
2130 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2131 invalidate_extent_cache(root, &key, &next_key);
2135 * handle the case only one block in the fs tree need to be
2136 * relocated and the block is tree root.
2138 leaf = btrfs_lock_root_node(root);
2139 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2140 btrfs_tree_unlock(leaf);
2141 free_extent_buffer(leaf);
2145 btrfs_free_path(path);
2148 memset(&root_item->drop_progress, 0,
2149 sizeof(root_item->drop_progress));
2150 root_item->drop_level = 0;
2151 btrfs_set_root_refs(root_item, 0);
2152 btrfs_update_reloc_root(trans, root);
2155 nr = trans->blocks_used;
2156 btrfs_end_transaction_throttle(trans, root);
2158 btrfs_btree_balance_dirty(root, nr);
2160 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2161 invalidate_extent_cache(root, &key, &next_key);
2166 static noinline_for_stack
2167 int prepare_to_merge(struct reloc_control *rc, int err)
2169 struct btrfs_root *root = rc->extent_root;
2170 struct btrfs_root *reloc_root;
2171 struct btrfs_trans_handle *trans;
2172 LIST_HEAD(reloc_roots);
2176 mutex_lock(&root->fs_info->reloc_mutex);
2177 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2178 rc->merging_rsv_size += rc->nodes_relocated * 2;
2179 mutex_unlock(&root->fs_info->reloc_mutex);
2183 num_bytes = rc->merging_rsv_size;
2184 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes);
2189 trans = btrfs_join_transaction(rc->extent_root);
2190 if (IS_ERR(trans)) {
2192 btrfs_block_rsv_release(rc->extent_root,
2193 rc->block_rsv, num_bytes);
2194 return PTR_ERR(trans);
2198 if (num_bytes != rc->merging_rsv_size) {
2199 btrfs_end_transaction(trans, rc->extent_root);
2200 btrfs_block_rsv_release(rc->extent_root,
2201 rc->block_rsv, num_bytes);
2206 rc->merge_reloc_tree = 1;
2208 while (!list_empty(&rc->reloc_roots)) {
2209 reloc_root = list_entry(rc->reloc_roots.next,
2210 struct btrfs_root, root_list);
2211 list_del_init(&reloc_root->root_list);
2213 root = read_fs_root(reloc_root->fs_info,
2214 reloc_root->root_key.offset);
2215 BUG_ON(IS_ERR(root));
2216 BUG_ON(root->reloc_root != reloc_root);
2219 * set reference count to 1, so btrfs_recover_relocation
2220 * knows it should resumes merging
2223 btrfs_set_root_refs(&reloc_root->root_item, 1);
2224 btrfs_update_reloc_root(trans, root);
2226 list_add(&reloc_root->root_list, &reloc_roots);
2229 list_splice(&reloc_roots, &rc->reloc_roots);
2232 btrfs_commit_transaction(trans, rc->extent_root);
2234 btrfs_end_transaction(trans, rc->extent_root);
2238 static noinline_for_stack
2239 int merge_reloc_roots(struct reloc_control *rc)
2241 struct btrfs_root *root;
2242 struct btrfs_root *reloc_root;
2243 LIST_HEAD(reloc_roots);
2247 root = rc->extent_root;
2250 * this serializes us with btrfs_record_root_in_transaction,
2251 * we have to make sure nobody is in the middle of
2252 * adding their roots to the list while we are
2255 mutex_lock(&root->fs_info->reloc_mutex);
2256 list_splice_init(&rc->reloc_roots, &reloc_roots);
2257 mutex_unlock(&root->fs_info->reloc_mutex);
2259 while (!list_empty(&reloc_roots)) {
2261 reloc_root = list_entry(reloc_roots.next,
2262 struct btrfs_root, root_list);
2264 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2265 root = read_fs_root(reloc_root->fs_info,
2266 reloc_root->root_key.offset);
2267 BUG_ON(IS_ERR(root));
2268 BUG_ON(root->reloc_root != reloc_root);
2270 ret = merge_reloc_root(rc, root);
2273 list_del_init(&reloc_root->root_list);
2275 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2283 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2287 static void free_block_list(struct rb_root *blocks)
2289 struct tree_block *block;
2290 struct rb_node *rb_node;
2291 while ((rb_node = rb_first(blocks))) {
2292 block = rb_entry(rb_node, struct tree_block, rb_node);
2293 rb_erase(rb_node, blocks);
2298 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2299 struct btrfs_root *reloc_root)
2301 struct btrfs_root *root;
2303 if (reloc_root->last_trans == trans->transid)
2306 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2307 BUG_ON(IS_ERR(root));
2308 BUG_ON(root->reloc_root != reloc_root);
2310 return btrfs_record_root_in_trans(trans, root);
2313 static noinline_for_stack
2314 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2315 struct reloc_control *rc,
2316 struct backref_node *node,
2317 struct backref_edge *edges[], int *nr)
2319 struct backref_node *next;
2320 struct btrfs_root *root;
2326 next = walk_up_backref(next, edges, &index);
2329 BUG_ON(!root->ref_cows);
2331 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2332 record_reloc_root_in_trans(trans, root);
2336 btrfs_record_root_in_trans(trans, root);
2337 root = root->reloc_root;
2339 if (next->new_bytenr != root->node->start) {
2340 BUG_ON(next->new_bytenr);
2341 BUG_ON(!list_empty(&next->list));
2342 next->new_bytenr = root->node->start;
2344 list_add_tail(&next->list,
2345 &rc->backref_cache.changed);
2346 __mark_block_processed(rc, next);
2352 next = walk_down_backref(edges, &index);
2353 if (!next || next->level <= node->level)
2361 /* setup backref node path for btrfs_reloc_cow_block */
2363 rc->backref_cache.path[next->level] = next;
2366 next = edges[index]->node[UPPER];
2372 * select a tree root for relocation. return NULL if the block
2373 * is reference counted. we should use do_relocation() in this
2374 * case. return a tree root pointer if the block isn't reference
2375 * counted. return -ENOENT if the block is root of reloc tree.
2377 static noinline_for_stack
2378 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2379 struct backref_node *node)
2381 struct backref_node *next;
2382 struct btrfs_root *root;
2383 struct btrfs_root *fs_root = NULL;
2384 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2390 next = walk_up_backref(next, edges, &index);
2394 /* no other choice for non-references counted tree */
2395 if (!root->ref_cows)
2398 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2404 next = walk_down_backref(edges, &index);
2405 if (!next || next->level <= node->level)
2410 return ERR_PTR(-ENOENT);
2414 static noinline_for_stack
2415 u64 calcu_metadata_size(struct reloc_control *rc,
2416 struct backref_node *node, int reserve)
2418 struct backref_node *next = node;
2419 struct backref_edge *edge;
2420 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2424 BUG_ON(reserve && node->processed);
2429 if (next->processed && (reserve || next != node))
2432 num_bytes += btrfs_level_size(rc->extent_root,
2435 if (list_empty(&next->upper))
2438 edge = list_entry(next->upper.next,
2439 struct backref_edge, list[LOWER]);
2440 edges[index++] = edge;
2441 next = edge->node[UPPER];
2443 next = walk_down_backref(edges, &index);
2448 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2449 struct reloc_control *rc,
2450 struct backref_node *node)
2452 struct btrfs_root *root = rc->extent_root;
2456 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2458 trans->block_rsv = rc->block_rsv;
2459 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes);
2462 rc->commit_transaction = 1;
2469 static void release_metadata_space(struct reloc_control *rc,
2470 struct backref_node *node)
2472 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2473 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2477 * relocate a block tree, and then update pointers in upper level
2478 * blocks that reference the block to point to the new location.
2480 * if called by link_to_upper, the block has already been relocated.
2481 * in that case this function just updates pointers.
2483 static int do_relocation(struct btrfs_trans_handle *trans,
2484 struct reloc_control *rc,
2485 struct backref_node *node,
2486 struct btrfs_key *key,
2487 struct btrfs_path *path, int lowest)
2489 struct backref_node *upper;
2490 struct backref_edge *edge;
2491 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2492 struct btrfs_root *root;
2493 struct extent_buffer *eb;
2502 BUG_ON(lowest && node->eb);
2504 path->lowest_level = node->level + 1;
2505 rc->backref_cache.path[node->level] = node;
2506 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2509 upper = edge->node[UPPER];
2510 root = select_reloc_root(trans, rc, upper, edges, &nr);
2513 if (upper->eb && !upper->locked) {
2515 ret = btrfs_bin_search(upper->eb, key,
2516 upper->level, &slot);
2518 bytenr = btrfs_node_blockptr(upper->eb, slot);
2519 if (node->eb->start == bytenr)
2522 drop_node_buffer(upper);
2526 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2534 upper->eb = path->nodes[upper->level];
2535 path->nodes[upper->level] = NULL;
2537 BUG_ON(upper->eb != path->nodes[upper->level]);
2541 path->locks[upper->level] = 0;
2543 slot = path->slots[upper->level];
2544 btrfs_release_path(path);
2546 ret = btrfs_bin_search(upper->eb, key, upper->level,
2551 bytenr = btrfs_node_blockptr(upper->eb, slot);
2553 BUG_ON(bytenr != node->bytenr);
2555 if (node->eb->start == bytenr)
2559 blocksize = btrfs_level_size(root, node->level);
2560 generation = btrfs_node_ptr_generation(upper->eb, slot);
2561 eb = read_tree_block(root, bytenr, blocksize, generation);
2566 btrfs_tree_lock(eb);
2567 btrfs_set_lock_blocking(eb);
2570 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2572 btrfs_tree_unlock(eb);
2573 free_extent_buffer(eb);
2578 BUG_ON(node->eb != eb);
2580 btrfs_set_node_blockptr(upper->eb, slot,
2582 btrfs_set_node_ptr_generation(upper->eb, slot,
2584 btrfs_mark_buffer_dirty(upper->eb);
2586 ret = btrfs_inc_extent_ref(trans, root,
2587 node->eb->start, blocksize,
2589 btrfs_header_owner(upper->eb),
2593 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2597 if (!upper->pending)
2598 drop_node_buffer(upper);
2600 unlock_node_buffer(upper);
2605 if (!err && node->pending) {
2606 drop_node_buffer(node);
2607 list_move_tail(&node->list, &rc->backref_cache.changed);
2611 path->lowest_level = 0;
2612 BUG_ON(err == -ENOSPC);
2616 static int link_to_upper(struct btrfs_trans_handle *trans,
2617 struct reloc_control *rc,
2618 struct backref_node *node,
2619 struct btrfs_path *path)
2621 struct btrfs_key key;
2623 btrfs_node_key_to_cpu(node->eb, &key, 0);
2624 return do_relocation(trans, rc, node, &key, path, 0);
2627 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2628 struct reloc_control *rc,
2629 struct btrfs_path *path, int err)
2632 struct backref_cache *cache = &rc->backref_cache;
2633 struct backref_node *node;
2637 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2638 while (!list_empty(&cache->pending[level])) {
2639 node = list_entry(cache->pending[level].next,
2640 struct backref_node, list);
2641 list_move_tail(&node->list, &list);
2642 BUG_ON(!node->pending);
2645 ret = link_to_upper(trans, rc, node, path);
2650 list_splice_init(&list, &cache->pending[level]);
2655 static void mark_block_processed(struct reloc_control *rc,
2656 u64 bytenr, u32 blocksize)
2658 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2659 EXTENT_DIRTY, GFP_NOFS);
2662 static void __mark_block_processed(struct reloc_control *rc,
2663 struct backref_node *node)
2666 if (node->level == 0 ||
2667 in_block_group(node->bytenr, rc->block_group)) {
2668 blocksize = btrfs_level_size(rc->extent_root, node->level);
2669 mark_block_processed(rc, node->bytenr, blocksize);
2671 node->processed = 1;
2675 * mark a block and all blocks directly/indirectly reference the block
2678 static void update_processed_blocks(struct reloc_control *rc,
2679 struct backref_node *node)
2681 struct backref_node *next = node;
2682 struct backref_edge *edge;
2683 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2689 if (next->processed)
2692 __mark_block_processed(rc, next);
2694 if (list_empty(&next->upper))
2697 edge = list_entry(next->upper.next,
2698 struct backref_edge, list[LOWER]);
2699 edges[index++] = edge;
2700 next = edge->node[UPPER];
2702 next = walk_down_backref(edges, &index);
2706 static int tree_block_processed(u64 bytenr, u32 blocksize,
2707 struct reloc_control *rc)
2709 if (test_range_bit(&rc->processed_blocks, bytenr,
2710 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2715 static int get_tree_block_key(struct reloc_control *rc,
2716 struct tree_block *block)
2718 struct extent_buffer *eb;
2720 BUG_ON(block->key_ready);
2721 eb = read_tree_block(rc->extent_root, block->bytenr,
2722 block->key.objectid, block->key.offset);
2724 WARN_ON(btrfs_header_level(eb) != block->level);
2725 if (block->level == 0)
2726 btrfs_item_key_to_cpu(eb, &block->key, 0);
2728 btrfs_node_key_to_cpu(eb, &block->key, 0);
2729 free_extent_buffer(eb);
2730 block->key_ready = 1;
2734 static int reada_tree_block(struct reloc_control *rc,
2735 struct tree_block *block)
2737 BUG_ON(block->key_ready);
2738 readahead_tree_block(rc->extent_root, block->bytenr,
2739 block->key.objectid, block->key.offset);
2744 * helper function to relocate a tree block
2746 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2747 struct reloc_control *rc,
2748 struct backref_node *node,
2749 struct btrfs_key *key,
2750 struct btrfs_path *path)
2752 struct btrfs_root *root;
2759 BUG_ON(node->processed);
2760 root = select_one_root(trans, node);
2761 if (root == ERR_PTR(-ENOENT)) {
2762 update_processed_blocks(rc, node);
2766 if (!root || root->ref_cows) {
2767 ret = reserve_metadata_space(trans, rc, node);
2774 if (root->ref_cows) {
2775 BUG_ON(node->new_bytenr);
2776 BUG_ON(!list_empty(&node->list));
2777 btrfs_record_root_in_trans(trans, root);
2778 root = root->reloc_root;
2779 node->new_bytenr = root->node->start;
2781 list_add_tail(&node->list, &rc->backref_cache.changed);
2783 path->lowest_level = node->level;
2784 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2785 btrfs_release_path(path);
2790 update_processed_blocks(rc, node);
2792 ret = do_relocation(trans, rc, node, key, path, 1);
2795 if (ret || node->level == 0 || node->cowonly) {
2797 release_metadata_space(rc, node);
2798 remove_backref_node(&rc->backref_cache, node);
2804 * relocate a list of blocks
2806 static noinline_for_stack
2807 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2808 struct reloc_control *rc, struct rb_root *blocks)
2810 struct backref_node *node;
2811 struct btrfs_path *path;
2812 struct tree_block *block;
2813 struct rb_node *rb_node;
2817 path = btrfs_alloc_path();
2821 rb_node = rb_first(blocks);
2823 block = rb_entry(rb_node, struct tree_block, rb_node);
2824 if (!block->key_ready)
2825 reada_tree_block(rc, block);
2826 rb_node = rb_next(rb_node);
2829 rb_node = rb_first(blocks);
2831 block = rb_entry(rb_node, struct tree_block, rb_node);
2832 if (!block->key_ready)
2833 get_tree_block_key(rc, block);
2834 rb_node = rb_next(rb_node);
2837 rb_node = rb_first(blocks);
2839 block = rb_entry(rb_node, struct tree_block, rb_node);
2841 node = build_backref_tree(rc, &block->key,
2842 block->level, block->bytenr);
2844 err = PTR_ERR(node);
2848 ret = relocate_tree_block(trans, rc, node, &block->key,
2851 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2855 rb_node = rb_next(rb_node);
2858 free_block_list(blocks);
2859 err = finish_pending_nodes(trans, rc, path, err);
2861 btrfs_free_path(path);
2865 static noinline_for_stack
2866 int prealloc_file_extent_cluster(struct inode *inode,
2867 struct file_extent_cluster *cluster)
2872 u64 offset = BTRFS_I(inode)->index_cnt;
2877 BUG_ON(cluster->start != cluster->boundary[0]);
2878 mutex_lock(&inode->i_mutex);
2880 ret = btrfs_check_data_free_space(inode, cluster->end +
2881 1 - cluster->start);
2885 while (nr < cluster->nr) {
2886 start = cluster->boundary[nr] - offset;
2887 if (nr + 1 < cluster->nr)
2888 end = cluster->boundary[nr + 1] - 1 - offset;
2890 end = cluster->end - offset;
2892 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2893 num_bytes = end + 1 - start;
2894 ret = btrfs_prealloc_file_range(inode, 0, start,
2895 num_bytes, num_bytes,
2896 end + 1, &alloc_hint);
2897 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2902 btrfs_free_reserved_data_space(inode, cluster->end +
2903 1 - cluster->start);
2905 mutex_unlock(&inode->i_mutex);
2909 static noinline_for_stack
2910 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
2913 struct btrfs_root *root = BTRFS_I(inode)->root;
2914 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2915 struct extent_map *em;
2918 em = alloc_extent_map();
2923 em->len = end + 1 - start;
2924 em->block_len = em->len;
2925 em->block_start = block_start;
2926 em->bdev = root->fs_info->fs_devices->latest_bdev;
2927 set_bit(EXTENT_FLAG_PINNED, &em->flags);
2929 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2931 write_lock(&em_tree->lock);
2932 ret = add_extent_mapping(em_tree, em);
2933 write_unlock(&em_tree->lock);
2934 if (ret != -EEXIST) {
2935 free_extent_map(em);
2938 btrfs_drop_extent_cache(inode, start, end, 0);
2940 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2944 static int relocate_file_extent_cluster(struct inode *inode,
2945 struct file_extent_cluster *cluster)
2949 u64 offset = BTRFS_I(inode)->index_cnt;
2950 unsigned long index;
2951 unsigned long last_index;
2953 struct file_ra_state *ra;
2954 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
2961 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2965 ret = prealloc_file_extent_cluster(inode, cluster);
2969 file_ra_state_init(ra, inode->i_mapping);
2971 ret = setup_extent_mapping(inode, cluster->start - offset,
2972 cluster->end - offset, cluster->start);
2976 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
2977 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
2978 while (index <= last_index) {
2979 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
2983 page = find_lock_page(inode->i_mapping, index);
2985 page_cache_sync_readahead(inode->i_mapping,
2987 last_index + 1 - index);
2988 page = find_or_create_page(inode->i_mapping, index,
2991 btrfs_delalloc_release_metadata(inode,
2998 if (PageReadahead(page)) {
2999 page_cache_async_readahead(inode->i_mapping,
3000 ra, NULL, page, index,
3001 last_index + 1 - index);
3004 if (!PageUptodate(page)) {
3005 btrfs_readpage(NULL, page);
3007 if (!PageUptodate(page)) {
3009 page_cache_release(page);
3010 btrfs_delalloc_release_metadata(inode,
3017 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3018 page_end = page_start + PAGE_CACHE_SIZE - 1;
3020 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3022 set_page_extent_mapped(page);
3024 if (nr < cluster->nr &&
3025 page_start + offset == cluster->boundary[nr]) {
3026 set_extent_bits(&BTRFS_I(inode)->io_tree,
3027 page_start, page_end,
3028 EXTENT_BOUNDARY, GFP_NOFS);
3032 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3033 set_page_dirty(page);
3035 unlock_extent(&BTRFS_I(inode)->io_tree,
3036 page_start, page_end);
3038 page_cache_release(page);
3041 balance_dirty_pages_ratelimited(inode->i_mapping);
3042 btrfs_throttle(BTRFS_I(inode)->root);
3044 WARN_ON(nr != cluster->nr);
3050 static noinline_for_stack
3051 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3052 struct file_extent_cluster *cluster)
3056 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3057 ret = relocate_file_extent_cluster(inode, cluster);
3064 cluster->start = extent_key->objectid;
3066 BUG_ON(cluster->nr >= MAX_EXTENTS);
3067 cluster->end = extent_key->objectid + extent_key->offset - 1;
3068 cluster->boundary[cluster->nr] = extent_key->objectid;
3071 if (cluster->nr >= MAX_EXTENTS) {
3072 ret = relocate_file_extent_cluster(inode, cluster);
3080 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3081 static int get_ref_objectid_v0(struct reloc_control *rc,
3082 struct btrfs_path *path,
3083 struct btrfs_key *extent_key,
3084 u64 *ref_objectid, int *path_change)
3086 struct btrfs_key key;
3087 struct extent_buffer *leaf;
3088 struct btrfs_extent_ref_v0 *ref0;
3092 leaf = path->nodes[0];
3093 slot = path->slots[0];
3095 if (slot >= btrfs_header_nritems(leaf)) {
3096 ret = btrfs_next_leaf(rc->extent_root, path);
3100 leaf = path->nodes[0];
3101 slot = path->slots[0];
3105 btrfs_item_key_to_cpu(leaf, &key, slot);
3106 if (key.objectid != extent_key->objectid)
3109 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3113 ref0 = btrfs_item_ptr(leaf, slot,
3114 struct btrfs_extent_ref_v0);
3115 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3123 * helper to add a tree block to the list.
3124 * the major work is getting the generation and level of the block
3126 static int add_tree_block(struct reloc_control *rc,
3127 struct btrfs_key *extent_key,
3128 struct btrfs_path *path,
3129 struct rb_root *blocks)
3131 struct extent_buffer *eb;
3132 struct btrfs_extent_item *ei;
3133 struct btrfs_tree_block_info *bi;
3134 struct tree_block *block;
3135 struct rb_node *rb_node;
3140 eb = path->nodes[0];
3141 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3143 if (item_size >= sizeof(*ei) + sizeof(*bi)) {
3144 ei = btrfs_item_ptr(eb, path->slots[0],
3145 struct btrfs_extent_item);
3146 bi = (struct btrfs_tree_block_info *)(ei + 1);
3147 generation = btrfs_extent_generation(eb, ei);
3148 level = btrfs_tree_block_level(eb, bi);
3150 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3154 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3155 ret = get_ref_objectid_v0(rc, path, extent_key,
3159 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3160 level = (int)ref_owner;
3161 /* FIXME: get real generation */
3168 btrfs_release_path(path);
3170 BUG_ON(level == -1);
3172 block = kmalloc(sizeof(*block), GFP_NOFS);
3176 block->bytenr = extent_key->objectid;
3177 block->key.objectid = extent_key->offset;
3178 block->key.offset = generation;
3179 block->level = level;
3180 block->key_ready = 0;
3182 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3184 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3190 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3192 static int __add_tree_block(struct reloc_control *rc,
3193 u64 bytenr, u32 blocksize,
3194 struct rb_root *blocks)
3196 struct btrfs_path *path;
3197 struct btrfs_key key;
3200 if (tree_block_processed(bytenr, blocksize, rc))
3203 if (tree_search(blocks, bytenr))
3206 path = btrfs_alloc_path();
3210 key.objectid = bytenr;
3211 key.type = BTRFS_EXTENT_ITEM_KEY;
3212 key.offset = blocksize;
3214 path->search_commit_root = 1;
3215 path->skip_locking = 1;
3216 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3221 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3222 ret = add_tree_block(rc, &key, path, blocks);
3224 btrfs_free_path(path);
3229 * helper to check if the block use full backrefs for pointers in it
3231 static int block_use_full_backref(struct reloc_control *rc,
3232 struct extent_buffer *eb)
3237 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3238 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3241 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3242 eb->start, eb->len, NULL, &flags);
3245 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3252 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3253 struct inode *inode, u64 ino)
3255 struct btrfs_key key;
3256 struct btrfs_path *path;
3257 struct btrfs_root *root = fs_info->tree_root;
3258 struct btrfs_trans_handle *trans;
3266 key.type = BTRFS_INODE_ITEM_KEY;
3269 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3270 if (IS_ERR_OR_NULL(inode) || is_bad_inode(inode)) {
3271 if (inode && !IS_ERR(inode))
3277 path = btrfs_alloc_path();
3283 trans = btrfs_join_transaction(root);
3284 if (IS_ERR(trans)) {
3285 btrfs_free_path(path);
3286 ret = PTR_ERR(trans);
3290 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3292 btrfs_free_path(path);
3293 nr = trans->blocks_used;
3294 btrfs_end_transaction(trans, root);
3295 btrfs_btree_balance_dirty(root, nr);
3302 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3303 * this function scans fs tree to find blocks reference the data extent
3305 static int find_data_references(struct reloc_control *rc,
3306 struct btrfs_key *extent_key,
3307 struct extent_buffer *leaf,
3308 struct btrfs_extent_data_ref *ref,
3309 struct rb_root *blocks)
3311 struct btrfs_path *path;
3312 struct tree_block *block;
3313 struct btrfs_root *root;
3314 struct btrfs_file_extent_item *fi;
3315 struct rb_node *rb_node;
3316 struct btrfs_key key;
3327 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3328 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3329 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3330 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3333 * This is an extent belonging to the free space cache, lets just delete
3334 * it and redo the search.
3336 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3337 ret = delete_block_group_cache(rc->extent_root->fs_info,
3338 NULL, ref_objectid);
3344 path = btrfs_alloc_path();
3349 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3351 err = PTR_ERR(root);
3355 key.objectid = ref_objectid;
3356 key.type = BTRFS_EXTENT_DATA_KEY;
3357 if (ref_offset > ((u64)-1 << 32))
3360 key.offset = ref_offset;
3362 path->search_commit_root = 1;
3363 path->skip_locking = 1;
3364 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3370 leaf = path->nodes[0];
3371 nritems = btrfs_header_nritems(leaf);
3373 * the references in tree blocks that use full backrefs
3374 * are not counted in
3376 if (block_use_full_backref(rc, leaf))
3380 rb_node = tree_search(blocks, leaf->start);
3385 path->slots[0] = nritems;
3388 while (ref_count > 0) {
3389 while (path->slots[0] >= nritems) {
3390 ret = btrfs_next_leaf(root, path);
3400 leaf = path->nodes[0];
3401 nritems = btrfs_header_nritems(leaf);
3404 if (block_use_full_backref(rc, leaf))
3408 rb_node = tree_search(blocks, leaf->start);
3413 path->slots[0] = nritems;
3417 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3418 if (key.objectid != ref_objectid ||
3419 key.type != BTRFS_EXTENT_DATA_KEY) {
3424 fi = btrfs_item_ptr(leaf, path->slots[0],
3425 struct btrfs_file_extent_item);
3427 if (btrfs_file_extent_type(leaf, fi) ==
3428 BTRFS_FILE_EXTENT_INLINE)
3431 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3432 extent_key->objectid)
3435 key.offset -= btrfs_file_extent_offset(leaf, fi);
3436 if (key.offset != ref_offset)
3444 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3445 block = kmalloc(sizeof(*block), GFP_NOFS);
3450 block->bytenr = leaf->start;
3451 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3453 block->key_ready = 1;
3454 rb_node = tree_insert(blocks, block->bytenr,
3457 backref_tree_panic(rb_node, -EEXIST,
3463 path->slots[0] = nritems;
3469 btrfs_free_path(path);
3474 * hepler to find all tree blocks that reference a given data extent
3476 static noinline_for_stack
3477 int add_data_references(struct reloc_control *rc,
3478 struct btrfs_key *extent_key,
3479 struct btrfs_path *path,
3480 struct rb_root *blocks)
3482 struct btrfs_key key;
3483 struct extent_buffer *eb;
3484 struct btrfs_extent_data_ref *dref;
3485 struct btrfs_extent_inline_ref *iref;
3488 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3492 eb = path->nodes[0];
3493 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3494 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3495 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3496 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3500 ptr += sizeof(struct btrfs_extent_item);
3503 iref = (struct btrfs_extent_inline_ref *)ptr;
3504 key.type = btrfs_extent_inline_ref_type(eb, iref);
3505 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3506 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3507 ret = __add_tree_block(rc, key.offset, blocksize,
3509 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3510 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3511 ret = find_data_references(rc, extent_key,
3516 ptr += btrfs_extent_inline_ref_size(key.type);
3522 eb = path->nodes[0];
3523 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3524 ret = btrfs_next_leaf(rc->extent_root, path);
3531 eb = path->nodes[0];
3534 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3535 if (key.objectid != extent_key->objectid)
3538 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3539 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3540 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3542 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3543 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3545 ret = __add_tree_block(rc, key.offset, blocksize,
3547 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3548 dref = btrfs_item_ptr(eb, path->slots[0],
3549 struct btrfs_extent_data_ref);
3550 ret = find_data_references(rc, extent_key,
3561 btrfs_release_path(path);
3563 free_block_list(blocks);
3568 * hepler to find next unprocessed extent
3570 static noinline_for_stack
3571 int find_next_extent(struct btrfs_trans_handle *trans,
3572 struct reloc_control *rc, struct btrfs_path *path,
3573 struct btrfs_key *extent_key)
3575 struct btrfs_key key;
3576 struct extent_buffer *leaf;
3577 u64 start, end, last;
3580 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3583 if (rc->search_start >= last) {
3588 key.objectid = rc->search_start;
3589 key.type = BTRFS_EXTENT_ITEM_KEY;
3592 path->search_commit_root = 1;
3593 path->skip_locking = 1;
3594 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3599 leaf = path->nodes[0];
3600 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3601 ret = btrfs_next_leaf(rc->extent_root, path);
3604 leaf = path->nodes[0];
3607 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3608 if (key.objectid >= last) {
3613 if (key.type != BTRFS_EXTENT_ITEM_KEY ||
3614 key.objectid + key.offset <= rc->search_start) {
3619 ret = find_first_extent_bit(&rc->processed_blocks,
3620 key.objectid, &start, &end,
3623 if (ret == 0 && start <= key.objectid) {
3624 btrfs_release_path(path);
3625 rc->search_start = end + 1;
3627 rc->search_start = key.objectid + key.offset;
3628 memcpy(extent_key, &key, sizeof(key));
3632 btrfs_release_path(path);
3636 static void set_reloc_control(struct reloc_control *rc)
3638 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3640 mutex_lock(&fs_info->reloc_mutex);
3641 fs_info->reloc_ctl = rc;
3642 mutex_unlock(&fs_info->reloc_mutex);
3645 static void unset_reloc_control(struct reloc_control *rc)
3647 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3649 mutex_lock(&fs_info->reloc_mutex);
3650 fs_info->reloc_ctl = NULL;
3651 mutex_unlock(&fs_info->reloc_mutex);
3654 static int check_extent_flags(u64 flags)
3656 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3657 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3659 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3660 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3662 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3663 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3668 static noinline_for_stack
3669 int prepare_to_relocate(struct reloc_control *rc)
3671 struct btrfs_trans_handle *trans;
3674 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root);
3679 * reserve some space for creating reloc trees.
3680 * btrfs_init_reloc_root will use them when there
3681 * is no reservation in transaction handle.
3683 ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv,
3684 rc->extent_root->nodesize * 256);
3688 memset(&rc->cluster, 0, sizeof(rc->cluster));
3689 rc->search_start = rc->block_group->key.objectid;
3690 rc->extents_found = 0;
3691 rc->nodes_relocated = 0;
3692 rc->merging_rsv_size = 0;
3694 rc->create_reloc_tree = 1;
3695 set_reloc_control(rc);
3697 trans = btrfs_join_transaction(rc->extent_root);
3698 BUG_ON(IS_ERR(trans));
3699 btrfs_commit_transaction(trans, rc->extent_root);
3703 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3705 struct rb_root blocks = RB_ROOT;
3706 struct btrfs_key key;
3707 struct btrfs_trans_handle *trans = NULL;
3708 struct btrfs_path *path;
3709 struct btrfs_extent_item *ei;
3717 path = btrfs_alloc_path();
3722 ret = prepare_to_relocate(rc);
3730 trans = btrfs_start_transaction(rc->extent_root, 0);
3731 BUG_ON(IS_ERR(trans));
3733 if (update_backref_cache(trans, &rc->backref_cache)) {
3734 btrfs_end_transaction(trans, rc->extent_root);
3738 ret = find_next_extent(trans, rc, path, &key);
3744 rc->extents_found++;
3746 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3747 struct btrfs_extent_item);
3748 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3749 if (item_size >= sizeof(*ei)) {
3750 flags = btrfs_extent_flags(path->nodes[0], ei);
3751 ret = check_extent_flags(flags);
3755 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3757 int path_change = 0;
3760 sizeof(struct btrfs_extent_item_v0));
3761 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3763 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3764 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3766 flags = BTRFS_EXTENT_FLAG_DATA;
3769 btrfs_release_path(path);
3771 path->search_commit_root = 1;
3772 path->skip_locking = 1;
3773 ret = btrfs_search_slot(NULL, rc->extent_root,
3786 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3787 ret = add_tree_block(rc, &key, path, &blocks);
3788 } else if (rc->stage == UPDATE_DATA_PTRS &&
3789 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3790 ret = add_data_references(rc, &key, path, &blocks);
3792 btrfs_release_path(path);
3800 if (!RB_EMPTY_ROOT(&blocks)) {
3801 ret = relocate_tree_blocks(trans, rc, &blocks);
3803 if (ret != -EAGAIN) {
3807 rc->extents_found--;
3808 rc->search_start = key.objectid;
3812 ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5);
3814 if (ret != -EAGAIN) {
3819 rc->commit_transaction = 1;
3822 if (rc->commit_transaction) {
3823 rc->commit_transaction = 0;
3824 ret = btrfs_commit_transaction(trans, rc->extent_root);
3827 nr = trans->blocks_used;
3828 btrfs_end_transaction_throttle(trans, rc->extent_root);
3829 btrfs_btree_balance_dirty(rc->extent_root, nr);
3833 if (rc->stage == MOVE_DATA_EXTENTS &&
3834 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3835 rc->found_file_extent = 1;
3836 ret = relocate_data_extent(rc->data_inode,
3837 &key, &rc->cluster);
3844 if (trans && progress && err == -ENOSPC) {
3845 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
3846 rc->block_group->flags);
3854 btrfs_release_path(path);
3855 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
3859 nr = trans->blocks_used;
3860 btrfs_end_transaction_throttle(trans, rc->extent_root);
3861 btrfs_btree_balance_dirty(rc->extent_root, nr);
3865 ret = relocate_file_extent_cluster(rc->data_inode,
3871 rc->create_reloc_tree = 0;
3872 set_reloc_control(rc);
3874 backref_cache_cleanup(&rc->backref_cache);
3875 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3877 err = prepare_to_merge(rc, err);
3879 merge_reloc_roots(rc);
3881 rc->merge_reloc_tree = 0;
3882 unset_reloc_control(rc);
3883 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3885 /* get rid of pinned extents */
3886 trans = btrfs_join_transaction(rc->extent_root);
3888 err = PTR_ERR(trans);
3890 btrfs_commit_transaction(trans, rc->extent_root);
3892 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
3893 btrfs_free_path(path);
3897 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
3898 struct btrfs_root *root, u64 objectid)
3900 struct btrfs_path *path;
3901 struct btrfs_inode_item *item;
3902 struct extent_buffer *leaf;
3905 path = btrfs_alloc_path();
3909 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
3913 leaf = path->nodes[0];
3914 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
3915 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
3916 btrfs_set_inode_generation(leaf, item, 1);
3917 btrfs_set_inode_size(leaf, item, 0);
3918 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
3919 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
3920 BTRFS_INODE_PREALLOC);
3921 btrfs_mark_buffer_dirty(leaf);
3922 btrfs_release_path(path);
3924 btrfs_free_path(path);
3929 * helper to create inode for data relocation.
3930 * the inode is in data relocation tree and its link count is 0
3932 static noinline_for_stack
3933 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
3934 struct btrfs_block_group_cache *group)
3936 struct inode *inode = NULL;
3937 struct btrfs_trans_handle *trans;
3938 struct btrfs_root *root;
3939 struct btrfs_key key;
3941 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
3944 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
3946 return ERR_CAST(root);
3948 trans = btrfs_start_transaction(root, 6);
3950 return ERR_CAST(trans);
3952 err = btrfs_find_free_objectid(root, &objectid);
3956 err = __insert_orphan_inode(trans, root, objectid);
3959 key.objectid = objectid;
3960 key.type = BTRFS_INODE_ITEM_KEY;
3962 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
3963 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
3964 BTRFS_I(inode)->index_cnt = group->key.objectid;
3966 err = btrfs_orphan_add(trans, inode);
3968 nr = trans->blocks_used;
3969 btrfs_end_transaction(trans, root);
3970 btrfs_btree_balance_dirty(root, nr);
3974 inode = ERR_PTR(err);
3979 static struct reloc_control *alloc_reloc_control(void)
3981 struct reloc_control *rc;
3983 rc = kzalloc(sizeof(*rc), GFP_NOFS);
3987 INIT_LIST_HEAD(&rc->reloc_roots);
3988 backref_cache_init(&rc->backref_cache);
3989 mapping_tree_init(&rc->reloc_root_tree);
3990 extent_io_tree_init(&rc->processed_blocks, NULL);
3995 * function to relocate all extents in a block group.
3997 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
3999 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4000 struct reloc_control *rc;
4001 struct inode *inode;
4002 struct btrfs_path *path;
4007 rc = alloc_reloc_control();
4011 rc->extent_root = extent_root;
4013 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4014 BUG_ON(!rc->block_group);
4016 if (!rc->block_group->ro) {
4017 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4025 path = btrfs_alloc_path();
4031 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4033 btrfs_free_path(path);
4036 ret = delete_block_group_cache(fs_info, inode, 0);
4038 ret = PTR_ERR(inode);
4040 if (ret && ret != -ENOENT) {
4045 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4046 if (IS_ERR(rc->data_inode)) {
4047 err = PTR_ERR(rc->data_inode);
4048 rc->data_inode = NULL;
4052 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
4053 (unsigned long long)rc->block_group->key.objectid,
4054 (unsigned long long)rc->block_group->flags);
4056 btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
4057 btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0);
4060 mutex_lock(&fs_info->cleaner_mutex);
4062 btrfs_clean_old_snapshots(fs_info->tree_root);
4063 ret = relocate_block_group(rc);
4065 mutex_unlock(&fs_info->cleaner_mutex);
4071 if (rc->extents_found == 0)
4074 printk(KERN_INFO "btrfs: found %llu extents\n",
4075 (unsigned long long)rc->extents_found);
4077 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4078 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4079 invalidate_mapping_pages(rc->data_inode->i_mapping,
4081 rc->stage = UPDATE_DATA_PTRS;
4085 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4086 rc->block_group->key.objectid,
4087 rc->block_group->key.objectid +
4088 rc->block_group->key.offset - 1);
4090 WARN_ON(rc->block_group->pinned > 0);
4091 WARN_ON(rc->block_group->reserved > 0);
4092 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4095 btrfs_set_block_group_rw(extent_root, rc->block_group);
4096 iput(rc->data_inode);
4097 btrfs_put_block_group(rc->block_group);
4102 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4104 struct btrfs_trans_handle *trans;
4107 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4108 BUG_ON(IS_ERR(trans));
4110 memset(&root->root_item.drop_progress, 0,
4111 sizeof(root->root_item.drop_progress));
4112 root->root_item.drop_level = 0;
4113 btrfs_set_root_refs(&root->root_item, 0);
4114 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4115 &root->root_key, &root->root_item);
4118 ret = btrfs_end_transaction(trans, root->fs_info->tree_root);
4124 * recover relocation interrupted by system crash.
4126 * this function resumes merging reloc trees with corresponding fs trees.
4127 * this is important for keeping the sharing of tree blocks
4129 int btrfs_recover_relocation(struct btrfs_root *root)
4131 LIST_HEAD(reloc_roots);
4132 struct btrfs_key key;
4133 struct btrfs_root *fs_root;
4134 struct btrfs_root *reloc_root;
4135 struct btrfs_path *path;
4136 struct extent_buffer *leaf;
4137 struct reloc_control *rc = NULL;
4138 struct btrfs_trans_handle *trans;
4142 path = btrfs_alloc_path();
4147 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4148 key.type = BTRFS_ROOT_ITEM_KEY;
4149 key.offset = (u64)-1;
4152 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4159 if (path->slots[0] == 0)
4163 leaf = path->nodes[0];
4164 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4165 btrfs_release_path(path);
4167 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4168 key.type != BTRFS_ROOT_ITEM_KEY)
4171 reloc_root = btrfs_read_fs_root_no_radix(root, &key);
4172 if (IS_ERR(reloc_root)) {
4173 err = PTR_ERR(reloc_root);
4177 list_add(&reloc_root->root_list, &reloc_roots);
4179 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4180 fs_root = read_fs_root(root->fs_info,
4181 reloc_root->root_key.offset);
4182 if (IS_ERR(fs_root)) {
4183 ret = PTR_ERR(fs_root);
4184 if (ret != -ENOENT) {
4188 mark_garbage_root(reloc_root);
4192 if (key.offset == 0)
4197 btrfs_release_path(path);
4199 if (list_empty(&reloc_roots))
4202 rc = alloc_reloc_control();
4208 rc->extent_root = root->fs_info->extent_root;
4210 set_reloc_control(rc);
4212 trans = btrfs_join_transaction(rc->extent_root);
4213 if (IS_ERR(trans)) {
4214 unset_reloc_control(rc);
4215 err = PTR_ERR(trans);
4219 rc->merge_reloc_tree = 1;
4221 while (!list_empty(&reloc_roots)) {
4222 reloc_root = list_entry(reloc_roots.next,
4223 struct btrfs_root, root_list);
4224 list_del(&reloc_root->root_list);
4226 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4227 list_add_tail(&reloc_root->root_list,
4232 fs_root = read_fs_root(root->fs_info,
4233 reloc_root->root_key.offset);
4234 BUG_ON(IS_ERR(fs_root));
4236 err = __add_reloc_root(reloc_root);
4238 fs_root->reloc_root = reloc_root;
4241 btrfs_commit_transaction(trans, rc->extent_root);
4243 merge_reloc_roots(rc);
4245 unset_reloc_control(rc);
4247 trans = btrfs_join_transaction(rc->extent_root);
4249 err = PTR_ERR(trans);
4251 btrfs_commit_transaction(trans, rc->extent_root);
4255 while (!list_empty(&reloc_roots)) {
4256 reloc_root = list_entry(reloc_roots.next,
4257 struct btrfs_root, root_list);
4258 list_del(&reloc_root->root_list);
4259 free_extent_buffer(reloc_root->node);
4260 free_extent_buffer(reloc_root->commit_root);
4263 btrfs_free_path(path);
4266 /* cleanup orphan inode in data relocation tree */
4267 fs_root = read_fs_root(root->fs_info,
4268 BTRFS_DATA_RELOC_TREE_OBJECTID);
4269 if (IS_ERR(fs_root))
4270 err = PTR_ERR(fs_root);
4272 err = btrfs_orphan_cleanup(fs_root);
4278 * helper to add ordered checksum for data relocation.
4280 * cloning checksum properly handles the nodatasum extents.
4281 * it also saves CPU time to re-calculate the checksum.
4283 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4285 struct btrfs_ordered_sum *sums;
4286 struct btrfs_sector_sum *sector_sum;
4287 struct btrfs_ordered_extent *ordered;
4288 struct btrfs_root *root = BTRFS_I(inode)->root;
4294 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4295 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4297 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4298 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4299 disk_bytenr + len - 1, &list, 0);
4301 while (!list_empty(&list)) {
4302 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4303 list_del_init(&sums->list);
4305 sector_sum = sums->sums;
4306 sums->bytenr = ordered->start;
4309 while (offset < sums->len) {
4310 sector_sum->bytenr += ordered->start - disk_bytenr;
4312 offset += root->sectorsize;
4315 btrfs_add_ordered_sum(inode, ordered, sums);
4317 btrfs_put_ordered_extent(ordered);
4321 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4322 struct btrfs_root *root, struct extent_buffer *buf,
4323 struct extent_buffer *cow)
4325 struct reloc_control *rc;
4326 struct backref_node *node;
4331 rc = root->fs_info->reloc_ctl;
4335 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4336 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4338 level = btrfs_header_level(buf);
4339 if (btrfs_header_generation(buf) <=
4340 btrfs_root_last_snapshot(&root->root_item))
4343 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4344 rc->create_reloc_tree) {
4345 WARN_ON(!first_cow && level == 0);
4347 node = rc->backref_cache.path[level];
4348 BUG_ON(node->bytenr != buf->start &&
4349 node->new_bytenr != buf->start);
4351 drop_node_buffer(node);
4352 extent_buffer_get(cow);
4354 node->new_bytenr = cow->start;
4356 if (!node->pending) {
4357 list_move_tail(&node->list,
4358 &rc->backref_cache.pending[level]);
4363 __mark_block_processed(rc, node);
4365 if (first_cow && level > 0)
4366 rc->nodes_relocated += buf->len;
4369 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4370 ret = replace_file_extents(trans, rc, root, cow);
4376 * called before creating snapshot. it calculates metadata reservation
4377 * requried for relocating tree blocks in the snapshot
4379 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4380 struct btrfs_pending_snapshot *pending,
4381 u64 *bytes_to_reserve)
4383 struct btrfs_root *root;
4384 struct reloc_control *rc;
4386 root = pending->root;
4387 if (!root->reloc_root)
4390 rc = root->fs_info->reloc_ctl;
4391 if (!rc->merge_reloc_tree)
4394 root = root->reloc_root;
4395 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4397 * relocation is in the stage of merging trees. the space
4398 * used by merging a reloc tree is twice the size of
4399 * relocated tree nodes in the worst case. half for cowing
4400 * the reloc tree, half for cowing the fs tree. the space
4401 * used by cowing the reloc tree will be freed after the
4402 * tree is dropped. if we create snapshot, cowing the fs
4403 * tree may use more space than it frees. so we need
4404 * reserve extra space.
4406 *bytes_to_reserve += rc->nodes_relocated;
4410 * called after snapshot is created. migrate block reservation
4411 * and create reloc root for the newly created snapshot
4413 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4414 struct btrfs_pending_snapshot *pending)
4416 struct btrfs_root *root = pending->root;
4417 struct btrfs_root *reloc_root;
4418 struct btrfs_root *new_root;
4419 struct reloc_control *rc;
4422 if (!root->reloc_root)
4425 rc = root->fs_info->reloc_ctl;
4426 rc->merging_rsv_size += rc->nodes_relocated;
4428 if (rc->merge_reloc_tree) {
4429 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4431 rc->nodes_relocated);
4436 new_root = pending->snap;
4437 reloc_root = create_reloc_root(trans, root->reloc_root,
4438 new_root->root_key.objectid);
4439 if (IS_ERR(reloc_root))
4440 return PTR_ERR(reloc_root);
4442 ret = __add_reloc_root(reloc_root);
4444 new_root->reloc_root = reloc_root;
4446 if (rc->create_reloc_tree)
4447 ret = clone_backref_node(trans, rc, root, reloc_root);