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)
330 * walk up backref nodes until reach node presents tree root
332 static struct backref_node *walk_up_backref(struct backref_node *node,
333 struct backref_edge *edges[],
336 struct backref_edge *edge;
339 while (!list_empty(&node->upper)) {
340 edge = list_entry(node->upper.next,
341 struct backref_edge, list[LOWER]);
343 node = edge->node[UPPER];
345 BUG_ON(node->detached);
351 * walk down backref nodes to find start of next reference path
353 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
356 struct backref_edge *edge;
357 struct backref_node *lower;
361 edge = edges[idx - 1];
362 lower = edge->node[LOWER];
363 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
367 edge = list_entry(edge->list[LOWER].next,
368 struct backref_edge, list[LOWER]);
369 edges[idx - 1] = edge;
371 return edge->node[UPPER];
377 static void unlock_node_buffer(struct backref_node *node)
380 btrfs_tree_unlock(node->eb);
385 static void drop_node_buffer(struct backref_node *node)
388 unlock_node_buffer(node);
389 free_extent_buffer(node->eb);
394 static void drop_backref_node(struct backref_cache *tree,
395 struct backref_node *node)
397 BUG_ON(!list_empty(&node->upper));
399 drop_node_buffer(node);
400 list_del(&node->list);
401 list_del(&node->lower);
402 if (!RB_EMPTY_NODE(&node->rb_node))
403 rb_erase(&node->rb_node, &tree->rb_root);
404 free_backref_node(tree, node);
408 * remove a backref node from the backref cache
410 static void remove_backref_node(struct backref_cache *cache,
411 struct backref_node *node)
413 struct backref_node *upper;
414 struct backref_edge *edge;
419 BUG_ON(!node->lowest && !node->detached);
420 while (!list_empty(&node->upper)) {
421 edge = list_entry(node->upper.next, struct backref_edge,
423 upper = edge->node[UPPER];
424 list_del(&edge->list[LOWER]);
425 list_del(&edge->list[UPPER]);
426 free_backref_edge(cache, edge);
428 if (RB_EMPTY_NODE(&upper->rb_node)) {
429 BUG_ON(!list_empty(&node->upper));
430 drop_backref_node(cache, node);
436 * add the node to leaf node list if no other
437 * child block cached.
439 if (list_empty(&upper->lower)) {
440 list_add_tail(&upper->lower, &cache->leaves);
445 drop_backref_node(cache, node);
448 static void update_backref_node(struct backref_cache *cache,
449 struct backref_node *node, u64 bytenr)
451 struct rb_node *rb_node;
452 rb_erase(&node->rb_node, &cache->rb_root);
453 node->bytenr = bytenr;
454 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
459 * update backref cache after a transaction commit
461 static int update_backref_cache(struct btrfs_trans_handle *trans,
462 struct backref_cache *cache)
464 struct backref_node *node;
467 if (cache->last_trans == 0) {
468 cache->last_trans = trans->transid;
472 if (cache->last_trans == trans->transid)
476 * detached nodes are used to avoid unnecessary backref
477 * lookup. transaction commit changes the extent tree.
478 * so the detached nodes are no longer useful.
480 while (!list_empty(&cache->detached)) {
481 node = list_entry(cache->detached.next,
482 struct backref_node, list);
483 remove_backref_node(cache, node);
486 while (!list_empty(&cache->changed)) {
487 node = list_entry(cache->changed.next,
488 struct backref_node, list);
489 list_del_init(&node->list);
490 BUG_ON(node->pending);
491 update_backref_node(cache, node, node->new_bytenr);
495 * some nodes can be left in the pending list if there were
496 * errors during processing the pending nodes.
498 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
499 list_for_each_entry(node, &cache->pending[level], list) {
500 BUG_ON(!node->pending);
501 if (node->bytenr == node->new_bytenr)
503 update_backref_node(cache, node, node->new_bytenr);
507 cache->last_trans = 0;
512 static int should_ignore_root(struct btrfs_root *root)
514 struct btrfs_root *reloc_root;
519 reloc_root = root->reloc_root;
523 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
524 root->fs_info->running_transaction->transid - 1)
527 * if there is reloc tree and it was created in previous
528 * transaction backref lookup can find the reloc tree,
529 * so backref node for the fs tree root is useless for
535 * find reloc tree by address of tree root
537 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
540 struct rb_node *rb_node;
541 struct mapping_node *node;
542 struct btrfs_root *root = NULL;
544 spin_lock(&rc->reloc_root_tree.lock);
545 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
547 node = rb_entry(rb_node, struct mapping_node, rb_node);
548 root = (struct btrfs_root *)node->data;
550 spin_unlock(&rc->reloc_root_tree.lock);
554 static int is_cowonly_root(u64 root_objectid)
556 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
557 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
558 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
559 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
560 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
561 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
566 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
569 struct btrfs_key key;
571 key.objectid = root_objectid;
572 key.type = BTRFS_ROOT_ITEM_KEY;
573 if (is_cowonly_root(root_objectid))
576 key.offset = (u64)-1;
578 return btrfs_read_fs_root_no_name(fs_info, &key);
581 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
582 static noinline_for_stack
583 struct btrfs_root *find_tree_root(struct reloc_control *rc,
584 struct extent_buffer *leaf,
585 struct btrfs_extent_ref_v0 *ref0)
587 struct btrfs_root *root;
588 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
589 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
591 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
593 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
594 BUG_ON(IS_ERR(root));
596 if (root->ref_cows &&
597 generation != btrfs_root_generation(&root->root_item))
604 static noinline_for_stack
605 int find_inline_backref(struct extent_buffer *leaf, int slot,
606 unsigned long *ptr, unsigned long *end)
608 struct btrfs_extent_item *ei;
609 struct btrfs_tree_block_info *bi;
612 item_size = btrfs_item_size_nr(leaf, slot);
613 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
614 if (item_size < sizeof(*ei)) {
615 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
619 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
620 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
621 BTRFS_EXTENT_FLAG_TREE_BLOCK));
623 if (item_size <= sizeof(*ei) + sizeof(*bi)) {
624 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
628 bi = (struct btrfs_tree_block_info *)(ei + 1);
629 *ptr = (unsigned long)(bi + 1);
630 *end = (unsigned long)ei + item_size;
635 * build backref tree for a given tree block. root of the backref tree
636 * corresponds the tree block, leaves of the backref tree correspond
637 * roots of b-trees that reference the tree block.
639 * the basic idea of this function is check backrefs of a given block
640 * to find upper level blocks that refernece the block, and then check
641 * bakcrefs of these upper level blocks recursively. the recursion stop
642 * when tree root is reached or backrefs for the block is cached.
644 * NOTE: if we find backrefs for a block are cached, we know backrefs
645 * for all upper level blocks that directly/indirectly reference the
646 * block are also cached.
648 static noinline_for_stack
649 struct backref_node *build_backref_tree(struct reloc_control *rc,
650 struct btrfs_key *node_key,
651 int level, u64 bytenr)
653 struct backref_cache *cache = &rc->backref_cache;
654 struct btrfs_path *path1;
655 struct btrfs_path *path2;
656 struct extent_buffer *eb;
657 struct btrfs_root *root;
658 struct backref_node *cur;
659 struct backref_node *upper;
660 struct backref_node *lower;
661 struct backref_node *node = NULL;
662 struct backref_node *exist = NULL;
663 struct backref_edge *edge;
664 struct rb_node *rb_node;
665 struct btrfs_key key;
674 path1 = btrfs_alloc_path();
675 path2 = btrfs_alloc_path();
676 if (!path1 || !path2) {
683 node = alloc_backref_node(cache);
689 node->bytenr = bytenr;
696 key.objectid = cur->bytenr;
697 key.type = BTRFS_EXTENT_ITEM_KEY;
698 key.offset = (u64)-1;
700 path1->search_commit_root = 1;
701 path1->skip_locking = 1;
702 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
708 BUG_ON(!ret || !path1->slots[0]);
712 WARN_ON(cur->checked);
713 if (!list_empty(&cur->upper)) {
715 * the backref was added previously when processing
716 * backref of type BTRFS_TREE_BLOCK_REF_KEY
718 BUG_ON(!list_is_singular(&cur->upper));
719 edge = list_entry(cur->upper.next, struct backref_edge,
721 BUG_ON(!list_empty(&edge->list[UPPER]));
722 exist = edge->node[UPPER];
724 * add the upper level block to pending list if we need
728 list_add_tail(&edge->list[UPPER], &list);
735 eb = path1->nodes[0];
738 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
739 ret = btrfs_next_leaf(rc->extent_root, path1);
746 eb = path1->nodes[0];
749 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
750 if (key.objectid != cur->bytenr) {
755 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
756 ret = find_inline_backref(eb, path1->slots[0],
764 /* update key for inline back ref */
765 struct btrfs_extent_inline_ref *iref;
766 iref = (struct btrfs_extent_inline_ref *)ptr;
767 key.type = btrfs_extent_inline_ref_type(eb, iref);
768 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
769 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
770 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
774 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
775 exist->owner == key.offset) ||
776 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
777 exist->bytenr == key.offset))) {
782 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
783 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
784 key.type == BTRFS_EXTENT_REF_V0_KEY) {
785 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
786 struct btrfs_extent_ref_v0 *ref0;
787 ref0 = btrfs_item_ptr(eb, path1->slots[0],
788 struct btrfs_extent_ref_v0);
789 if (key.objectid == key.offset) {
790 root = find_tree_root(rc, eb, ref0);
791 if (root && !should_ignore_root(root))
794 list_add(&cur->list, &useless);
797 if (is_cowonly_root(btrfs_ref_root_v0(eb,
802 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
803 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
805 if (key.objectid == key.offset) {
807 * only root blocks of reloc trees use
808 * backref of this type.
810 root = find_reloc_root(rc, cur->bytenr);
816 edge = alloc_backref_edge(cache);
821 rb_node = tree_search(&cache->rb_root, key.offset);
823 upper = alloc_backref_node(cache);
825 free_backref_edge(cache, edge);
829 upper->bytenr = key.offset;
830 upper->level = cur->level + 1;
832 * backrefs for the upper level block isn't
833 * cached, add the block to pending list
835 list_add_tail(&edge->list[UPPER], &list);
837 upper = rb_entry(rb_node, struct backref_node,
839 BUG_ON(!upper->checked);
840 INIT_LIST_HEAD(&edge->list[UPPER]);
842 list_add_tail(&edge->list[LOWER], &cur->upper);
843 edge->node[LOWER] = cur;
844 edge->node[UPPER] = upper;
847 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
851 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
852 root = read_fs_root(rc->extent_root->fs_info, key.offset);
861 if (btrfs_root_level(&root->root_item) == cur->level) {
863 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
865 if (should_ignore_root(root))
866 list_add(&cur->list, &useless);
872 level = cur->level + 1;
875 * searching the tree to find upper level blocks
876 * reference the block.
878 path2->search_commit_root = 1;
879 path2->skip_locking = 1;
880 path2->lowest_level = level;
881 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
882 path2->lowest_level = 0;
887 if (ret > 0 && path2->slots[level] > 0)
888 path2->slots[level]--;
890 eb = path2->nodes[level];
891 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
895 for (; level < BTRFS_MAX_LEVEL; level++) {
896 if (!path2->nodes[level]) {
897 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
899 if (should_ignore_root(root))
900 list_add(&lower->list, &useless);
906 edge = alloc_backref_edge(cache);
912 eb = path2->nodes[level];
913 rb_node = tree_search(&cache->rb_root, eb->start);
915 upper = alloc_backref_node(cache);
917 free_backref_edge(cache, edge);
921 upper->bytenr = eb->start;
922 upper->owner = btrfs_header_owner(eb);
923 upper->level = lower->level + 1;
928 * if we know the block isn't shared
929 * we can void checking its backrefs.
931 if (btrfs_block_can_be_shared(root, eb))
937 * add the block to pending list if we
938 * need check its backrefs. only block
939 * at 'cur->level + 1' is added to the
940 * tail of pending list. this guarantees
941 * we check backrefs from lower level
942 * blocks to upper level blocks.
944 if (!upper->checked &&
945 level == cur->level + 1) {
946 list_add_tail(&edge->list[UPPER],
949 INIT_LIST_HEAD(&edge->list[UPPER]);
951 upper = rb_entry(rb_node, struct backref_node,
953 BUG_ON(!upper->checked);
954 INIT_LIST_HEAD(&edge->list[UPPER]);
956 upper->owner = btrfs_header_owner(eb);
958 list_add_tail(&edge->list[LOWER], &lower->upper);
959 edge->node[LOWER] = lower;
960 edge->node[UPPER] = upper;
967 btrfs_release_path(path2);
970 ptr += btrfs_extent_inline_ref_size(key.type);
980 btrfs_release_path(path1);
985 /* the pending list isn't empty, take the first block to process */
986 if (!list_empty(&list)) {
987 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
988 list_del_init(&edge->list[UPPER]);
989 cur = edge->node[UPPER];
994 * everything goes well, connect backref nodes and insert backref nodes
997 BUG_ON(!node->checked);
998 cowonly = node->cowonly;
1000 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1003 list_add_tail(&node->lower, &cache->leaves);
1006 list_for_each_entry(edge, &node->upper, list[LOWER])
1007 list_add_tail(&edge->list[UPPER], &list);
1009 while (!list_empty(&list)) {
1010 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1011 list_del_init(&edge->list[UPPER]);
1012 upper = edge->node[UPPER];
1013 if (upper->detached) {
1014 list_del(&edge->list[LOWER]);
1015 lower = edge->node[LOWER];
1016 free_backref_edge(cache, edge);
1017 if (list_empty(&lower->upper))
1018 list_add(&lower->list, &useless);
1022 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1023 if (upper->lowest) {
1024 list_del_init(&upper->lower);
1028 list_add_tail(&edge->list[UPPER], &upper->lower);
1032 BUG_ON(!upper->checked);
1033 BUG_ON(cowonly != upper->cowonly);
1035 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1040 list_add_tail(&edge->list[UPPER], &upper->lower);
1042 list_for_each_entry(edge, &upper->upper, list[LOWER])
1043 list_add_tail(&edge->list[UPPER], &list);
1046 * process useless backref nodes. backref nodes for tree leaves
1047 * are deleted from the cache. backref nodes for upper level
1048 * tree blocks are left in the cache to avoid unnecessary backref
1051 while (!list_empty(&useless)) {
1052 upper = list_entry(useless.next, struct backref_node, list);
1053 list_del_init(&upper->list);
1054 BUG_ON(!list_empty(&upper->upper));
1057 if (upper->lowest) {
1058 list_del_init(&upper->lower);
1061 while (!list_empty(&upper->lower)) {
1062 edge = list_entry(upper->lower.next,
1063 struct backref_edge, list[UPPER]);
1064 list_del(&edge->list[UPPER]);
1065 list_del(&edge->list[LOWER]);
1066 lower = edge->node[LOWER];
1067 free_backref_edge(cache, edge);
1069 if (list_empty(&lower->upper))
1070 list_add(&lower->list, &useless);
1072 __mark_block_processed(rc, upper);
1073 if (upper->level > 0) {
1074 list_add(&upper->list, &cache->detached);
1075 upper->detached = 1;
1077 rb_erase(&upper->rb_node, &cache->rb_root);
1078 free_backref_node(cache, upper);
1082 btrfs_free_path(path1);
1083 btrfs_free_path(path2);
1085 while (!list_empty(&useless)) {
1086 lower = list_entry(useless.next,
1087 struct backref_node, upper);
1088 list_del_init(&lower->upper);
1091 INIT_LIST_HEAD(&list);
1093 if (RB_EMPTY_NODE(&upper->rb_node)) {
1094 list_splice_tail(&upper->upper, &list);
1095 free_backref_node(cache, upper);
1098 if (list_empty(&list))
1101 edge = list_entry(list.next, struct backref_edge,
1103 list_del(&edge->list[LOWER]);
1104 upper = edge->node[UPPER];
1105 free_backref_edge(cache, edge);
1107 return ERR_PTR(err);
1109 BUG_ON(node && node->detached);
1114 * helper to add backref node for the newly created snapshot.
1115 * the backref node is created by cloning backref node that
1116 * corresponds to root of source tree
1118 static int clone_backref_node(struct btrfs_trans_handle *trans,
1119 struct reloc_control *rc,
1120 struct btrfs_root *src,
1121 struct btrfs_root *dest)
1123 struct btrfs_root *reloc_root = src->reloc_root;
1124 struct backref_cache *cache = &rc->backref_cache;
1125 struct backref_node *node = NULL;
1126 struct backref_node *new_node;
1127 struct backref_edge *edge;
1128 struct backref_edge *new_edge;
1129 struct rb_node *rb_node;
1131 if (cache->last_trans > 0)
1132 update_backref_cache(trans, cache);
1134 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1136 node = rb_entry(rb_node, struct backref_node, rb_node);
1140 BUG_ON(node->new_bytenr != reloc_root->node->start);
1144 rb_node = tree_search(&cache->rb_root,
1145 reloc_root->commit_root->start);
1147 node = rb_entry(rb_node, struct backref_node,
1149 BUG_ON(node->detached);
1156 new_node = alloc_backref_node(cache);
1160 new_node->bytenr = dest->node->start;
1161 new_node->level = node->level;
1162 new_node->lowest = node->lowest;
1163 new_node->checked = 1;
1164 new_node->root = dest;
1166 if (!node->lowest) {
1167 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1168 new_edge = alloc_backref_edge(cache);
1172 new_edge->node[UPPER] = new_node;
1173 new_edge->node[LOWER] = edge->node[LOWER];
1174 list_add_tail(&new_edge->list[UPPER],
1179 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1180 &new_node->rb_node);
1183 if (!new_node->lowest) {
1184 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1185 list_add_tail(&new_edge->list[LOWER],
1186 &new_edge->node[LOWER]->upper);
1191 while (!list_empty(&new_node->lower)) {
1192 new_edge = list_entry(new_node->lower.next,
1193 struct backref_edge, list[UPPER]);
1194 list_del(&new_edge->list[UPPER]);
1195 free_backref_edge(cache, new_edge);
1197 free_backref_node(cache, new_node);
1202 * helper to add 'address of tree root -> reloc tree' mapping
1204 static int __add_reloc_root(struct btrfs_root *root)
1206 struct rb_node *rb_node;
1207 struct mapping_node *node;
1208 struct reloc_control *rc = root->fs_info->reloc_ctl;
1210 node = kmalloc(sizeof(*node), GFP_NOFS);
1213 node->bytenr = root->node->start;
1216 spin_lock(&rc->reloc_root_tree.lock);
1217 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1218 node->bytenr, &node->rb_node);
1219 spin_unlock(&rc->reloc_root_tree.lock);
1222 list_add_tail(&root->root_list, &rc->reloc_roots);
1227 * helper to update/delete the 'address of tree root -> reloc tree'
1230 static int __update_reloc_root(struct btrfs_root *root, int del)
1232 struct rb_node *rb_node;
1233 struct mapping_node *node = NULL;
1234 struct reloc_control *rc = root->fs_info->reloc_ctl;
1236 spin_lock(&rc->reloc_root_tree.lock);
1237 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1238 root->commit_root->start);
1240 node = rb_entry(rb_node, struct mapping_node, rb_node);
1241 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1243 spin_unlock(&rc->reloc_root_tree.lock);
1245 BUG_ON((struct btrfs_root *)node->data != root);
1248 spin_lock(&rc->reloc_root_tree.lock);
1249 node->bytenr = root->node->start;
1250 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1251 node->bytenr, &node->rb_node);
1252 spin_unlock(&rc->reloc_root_tree.lock);
1255 list_del_init(&root->root_list);
1261 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1262 struct btrfs_root *root, u64 objectid)
1264 struct btrfs_root *reloc_root;
1265 struct extent_buffer *eb;
1266 struct btrfs_root_item *root_item;
1267 struct btrfs_key root_key;
1270 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1273 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1274 root_key.type = BTRFS_ROOT_ITEM_KEY;
1275 root_key.offset = objectid;
1277 if (root->root_key.objectid == objectid) {
1278 /* called by btrfs_init_reloc_root */
1279 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1280 BTRFS_TREE_RELOC_OBJECTID);
1283 btrfs_set_root_last_snapshot(&root->root_item,
1284 trans->transid - 1);
1287 * called by btrfs_reloc_post_snapshot_hook.
1288 * the source tree is a reloc tree, all tree blocks
1289 * modified after it was created have RELOC flag
1290 * set in their headers. so it's OK to not update
1291 * the 'last_snapshot'.
1293 ret = btrfs_copy_root(trans, root, root->node, &eb,
1294 BTRFS_TREE_RELOC_OBJECTID);
1298 memcpy(root_item, &root->root_item, sizeof(*root_item));
1299 btrfs_set_root_bytenr(root_item, eb->start);
1300 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1301 btrfs_set_root_generation(root_item, trans->transid);
1303 if (root->root_key.objectid == objectid) {
1304 btrfs_set_root_refs(root_item, 0);
1305 memset(&root_item->drop_progress, 0,
1306 sizeof(struct btrfs_disk_key));
1307 root_item->drop_level = 0;
1310 btrfs_tree_unlock(eb);
1311 free_extent_buffer(eb);
1313 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1314 &root_key, root_item);
1318 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
1320 BUG_ON(IS_ERR(reloc_root));
1321 reloc_root->last_trans = trans->transid;
1326 * create reloc tree for a given fs tree. reloc tree is just a
1327 * snapshot of the fs tree with special root objectid.
1329 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1330 struct btrfs_root *root)
1332 struct btrfs_root *reloc_root;
1333 struct reloc_control *rc = root->fs_info->reloc_ctl;
1336 if (root->reloc_root) {
1337 reloc_root = root->reloc_root;
1338 reloc_root->last_trans = trans->transid;
1342 if (!rc || !rc->create_reloc_tree ||
1343 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1346 if (!trans->block_rsv) {
1347 trans->block_rsv = rc->block_rsv;
1350 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1352 trans->block_rsv = NULL;
1354 __add_reloc_root(reloc_root);
1355 root->reloc_root = reloc_root;
1360 * update root item of reloc tree
1362 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1363 struct btrfs_root *root)
1365 struct btrfs_root *reloc_root;
1366 struct btrfs_root_item *root_item;
1370 if (!root->reloc_root)
1373 reloc_root = root->reloc_root;
1374 root_item = &reloc_root->root_item;
1376 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1377 btrfs_root_refs(root_item) == 0) {
1378 root->reloc_root = NULL;
1382 __update_reloc_root(reloc_root, del);
1384 if (reloc_root->commit_root != reloc_root->node) {
1385 btrfs_set_root_node(root_item, reloc_root->node);
1386 free_extent_buffer(reloc_root->commit_root);
1387 reloc_root->commit_root = btrfs_root_node(reloc_root);
1390 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1391 &reloc_root->root_key, root_item);
1399 * helper to find first cached inode with inode number >= objectid
1402 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1404 struct rb_node *node;
1405 struct rb_node *prev;
1406 struct btrfs_inode *entry;
1407 struct inode *inode;
1409 spin_lock(&root->inode_lock);
1411 node = root->inode_tree.rb_node;
1415 entry = rb_entry(node, struct btrfs_inode, rb_node);
1417 if (objectid < btrfs_ino(&entry->vfs_inode))
1418 node = node->rb_left;
1419 else if (objectid > btrfs_ino(&entry->vfs_inode))
1420 node = node->rb_right;
1426 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1427 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1431 prev = rb_next(prev);
1435 entry = rb_entry(node, struct btrfs_inode, rb_node);
1436 inode = igrab(&entry->vfs_inode);
1438 spin_unlock(&root->inode_lock);
1442 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1443 if (cond_resched_lock(&root->inode_lock))
1446 node = rb_next(node);
1448 spin_unlock(&root->inode_lock);
1452 static int in_block_group(u64 bytenr,
1453 struct btrfs_block_group_cache *block_group)
1455 if (bytenr >= block_group->key.objectid &&
1456 bytenr < block_group->key.objectid + block_group->key.offset)
1462 * get new location of data
1464 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1465 u64 bytenr, u64 num_bytes)
1467 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1468 struct btrfs_path *path;
1469 struct btrfs_file_extent_item *fi;
1470 struct extent_buffer *leaf;
1473 path = btrfs_alloc_path();
1477 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1478 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1487 leaf = path->nodes[0];
1488 fi = btrfs_item_ptr(leaf, path->slots[0],
1489 struct btrfs_file_extent_item);
1491 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1492 btrfs_file_extent_compression(leaf, fi) ||
1493 btrfs_file_extent_encryption(leaf, fi) ||
1494 btrfs_file_extent_other_encoding(leaf, fi));
1496 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1501 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1504 btrfs_free_path(path);
1509 * update file extent items in the tree leaf to point to
1510 * the new locations.
1512 static noinline_for_stack
1513 int replace_file_extents(struct btrfs_trans_handle *trans,
1514 struct reloc_control *rc,
1515 struct btrfs_root *root,
1516 struct extent_buffer *leaf)
1518 struct btrfs_key key;
1519 struct btrfs_file_extent_item *fi;
1520 struct inode *inode = NULL;
1532 if (rc->stage != UPDATE_DATA_PTRS)
1535 /* reloc trees always use full backref */
1536 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1537 parent = leaf->start;
1541 nritems = btrfs_header_nritems(leaf);
1542 for (i = 0; i < nritems; i++) {
1544 btrfs_item_key_to_cpu(leaf, &key, i);
1545 if (key.type != BTRFS_EXTENT_DATA_KEY)
1547 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1548 if (btrfs_file_extent_type(leaf, fi) ==
1549 BTRFS_FILE_EXTENT_INLINE)
1551 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1552 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1555 if (!in_block_group(bytenr, rc->block_group))
1559 * if we are modifying block in fs tree, wait for readpage
1560 * to complete and drop the extent cache
1562 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1564 inode = find_next_inode(root, key.objectid);
1566 } else if (inode && btrfs_ino(inode) < key.objectid) {
1567 btrfs_add_delayed_iput(inode);
1568 inode = find_next_inode(root, key.objectid);
1570 if (inode && btrfs_ino(inode) == key.objectid) {
1572 btrfs_file_extent_num_bytes(leaf, fi);
1573 WARN_ON(!IS_ALIGNED(key.offset,
1575 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1577 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1583 btrfs_drop_extent_cache(inode, key.offset, end,
1585 unlock_extent(&BTRFS_I(inode)->io_tree,
1586 key.offset, end, GFP_NOFS);
1590 ret = get_new_location(rc->data_inode, &new_bytenr,
1598 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1601 key.offset -= btrfs_file_extent_offset(leaf, fi);
1602 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1604 btrfs_header_owner(leaf),
1605 key.objectid, key.offset);
1608 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1609 parent, btrfs_header_owner(leaf),
1610 key.objectid, key.offset);
1614 btrfs_mark_buffer_dirty(leaf);
1616 btrfs_add_delayed_iput(inode);
1620 static noinline_for_stack
1621 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1622 struct btrfs_path *path, int level)
1624 struct btrfs_disk_key key1;
1625 struct btrfs_disk_key key2;
1626 btrfs_node_key(eb, &key1, slot);
1627 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1628 return memcmp(&key1, &key2, sizeof(key1));
1632 * try to replace tree blocks in fs tree with the new blocks
1633 * in reloc tree. tree blocks haven't been modified since the
1634 * reloc tree was create can be replaced.
1636 * if a block was replaced, level of the block + 1 is returned.
1637 * if no block got replaced, 0 is returned. if there are other
1638 * errors, a negative error number is returned.
1640 static noinline_for_stack
1641 int replace_path(struct btrfs_trans_handle *trans,
1642 struct btrfs_root *dest, struct btrfs_root *src,
1643 struct btrfs_path *path, struct btrfs_key *next_key,
1644 int lowest_level, int max_level)
1646 struct extent_buffer *eb;
1647 struct extent_buffer *parent;
1648 struct btrfs_key key;
1660 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1661 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1663 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1665 slot = path->slots[lowest_level];
1666 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1668 eb = btrfs_lock_root_node(dest);
1669 btrfs_set_lock_blocking(eb);
1670 level = btrfs_header_level(eb);
1672 if (level < lowest_level) {
1673 btrfs_tree_unlock(eb);
1674 free_extent_buffer(eb);
1679 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1682 btrfs_set_lock_blocking(eb);
1685 next_key->objectid = (u64)-1;
1686 next_key->type = (u8)-1;
1687 next_key->offset = (u64)-1;
1692 level = btrfs_header_level(parent);
1693 BUG_ON(level < lowest_level);
1695 ret = btrfs_bin_search(parent, &key, level, &slot);
1696 if (ret && slot > 0)
1699 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1700 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1702 old_bytenr = btrfs_node_blockptr(parent, slot);
1703 blocksize = btrfs_level_size(dest, level - 1);
1704 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1706 if (level <= max_level) {
1707 eb = path->nodes[level];
1708 new_bytenr = btrfs_node_blockptr(eb,
1709 path->slots[level]);
1710 new_ptr_gen = btrfs_node_ptr_generation(eb,
1711 path->slots[level]);
1717 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1723 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1724 memcmp_node_keys(parent, slot, path, level)) {
1725 if (level <= lowest_level) {
1730 eb = read_tree_block(dest, old_bytenr, blocksize,
1733 btrfs_tree_lock(eb);
1735 ret = btrfs_cow_block(trans, dest, eb, parent,
1739 btrfs_set_lock_blocking(eb);
1741 btrfs_tree_unlock(parent);
1742 free_extent_buffer(parent);
1749 btrfs_tree_unlock(parent);
1750 free_extent_buffer(parent);
1755 btrfs_node_key_to_cpu(path->nodes[level], &key,
1756 path->slots[level]);
1757 btrfs_release_path(path);
1759 path->lowest_level = level;
1760 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1761 path->lowest_level = 0;
1765 * swap blocks in fs tree and reloc tree.
1767 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1768 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1769 btrfs_mark_buffer_dirty(parent);
1771 btrfs_set_node_blockptr(path->nodes[level],
1772 path->slots[level], old_bytenr);
1773 btrfs_set_node_ptr_generation(path->nodes[level],
1774 path->slots[level], old_ptr_gen);
1775 btrfs_mark_buffer_dirty(path->nodes[level]);
1777 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1778 path->nodes[level]->start,
1779 src->root_key.objectid, level - 1, 0);
1781 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1782 0, dest->root_key.objectid, level - 1,
1786 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1787 path->nodes[level]->start,
1788 src->root_key.objectid, level - 1, 0);
1791 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1792 0, dest->root_key.objectid, level - 1,
1796 btrfs_unlock_up_safe(path, 0);
1801 btrfs_tree_unlock(parent);
1802 free_extent_buffer(parent);
1807 * helper to find next relocated block in reloc tree
1809 static noinline_for_stack
1810 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1813 struct extent_buffer *eb;
1818 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1820 for (i = 0; i < *level; i++) {
1821 free_extent_buffer(path->nodes[i]);
1822 path->nodes[i] = NULL;
1825 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1826 eb = path->nodes[i];
1827 nritems = btrfs_header_nritems(eb);
1828 while (path->slots[i] + 1 < nritems) {
1830 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1837 free_extent_buffer(path->nodes[i]);
1838 path->nodes[i] = NULL;
1844 * walk down reloc tree to find relocated block of lowest level
1846 static noinline_for_stack
1847 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1850 struct extent_buffer *eb = NULL;
1858 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1860 for (i = *level; i > 0; i--) {
1861 eb = path->nodes[i];
1862 nritems = btrfs_header_nritems(eb);
1863 while (path->slots[i] < nritems) {
1864 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1865 if (ptr_gen > last_snapshot)
1869 if (path->slots[i] >= nritems) {
1880 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1881 blocksize = btrfs_level_size(root, i - 1);
1882 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1883 BUG_ON(btrfs_header_level(eb) != i - 1);
1884 path->nodes[i - 1] = eb;
1885 path->slots[i - 1] = 0;
1891 * invalidate extent cache for file extents whose key in range of
1892 * [min_key, max_key)
1894 static int invalidate_extent_cache(struct btrfs_root *root,
1895 struct btrfs_key *min_key,
1896 struct btrfs_key *max_key)
1898 struct inode *inode = NULL;
1903 objectid = min_key->objectid;
1908 if (objectid > max_key->objectid)
1911 inode = find_next_inode(root, objectid);
1914 ino = btrfs_ino(inode);
1916 if (ino > max_key->objectid) {
1922 if (!S_ISREG(inode->i_mode))
1925 if (unlikely(min_key->objectid == ino)) {
1926 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1928 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1931 start = min_key->offset;
1932 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1938 if (unlikely(max_key->objectid == ino)) {
1939 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1941 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
1944 if (max_key->offset == 0)
1946 end = max_key->offset;
1947 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1954 /* the lock_extent waits for readpage to complete */
1955 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1956 btrfs_drop_extent_cache(inode, start, end, 1);
1957 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1962 static int find_next_key(struct btrfs_path *path, int level,
1963 struct btrfs_key *key)
1966 while (level < BTRFS_MAX_LEVEL) {
1967 if (!path->nodes[level])
1969 if (path->slots[level] + 1 <
1970 btrfs_header_nritems(path->nodes[level])) {
1971 btrfs_node_key_to_cpu(path->nodes[level], key,
1972 path->slots[level] + 1);
1981 * merge the relocated tree blocks in reloc tree with corresponding
1984 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
1985 struct btrfs_root *root)
1987 LIST_HEAD(inode_list);
1988 struct btrfs_key key;
1989 struct btrfs_key next_key;
1990 struct btrfs_trans_handle *trans;
1991 struct btrfs_root *reloc_root;
1992 struct btrfs_root_item *root_item;
1993 struct btrfs_path *path;
1994 struct extent_buffer *leaf;
2003 path = btrfs_alloc_path();
2008 reloc_root = root->reloc_root;
2009 root_item = &reloc_root->root_item;
2011 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2012 level = btrfs_root_level(root_item);
2013 extent_buffer_get(reloc_root->node);
2014 path->nodes[level] = reloc_root->node;
2015 path->slots[level] = 0;
2017 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2019 level = root_item->drop_level;
2021 path->lowest_level = level;
2022 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2023 path->lowest_level = 0;
2025 btrfs_free_path(path);
2029 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2030 path->slots[level]);
2031 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2033 btrfs_unlock_up_safe(path, 0);
2036 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2037 memset(&next_key, 0, sizeof(next_key));
2040 trans = btrfs_start_transaction(root, 0);
2041 BUG_ON(IS_ERR(trans));
2042 trans->block_rsv = rc->block_rsv;
2044 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved);
2046 BUG_ON(ret != -EAGAIN);
2047 ret = btrfs_commit_transaction(trans, root);
2055 ret = walk_down_reloc_tree(reloc_root, path, &level);
2063 if (!find_next_key(path, level, &key) &&
2064 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2067 ret = replace_path(trans, root, reloc_root, path,
2068 &next_key, level, max_level);
2077 btrfs_node_key_to_cpu(path->nodes[level], &key,
2078 path->slots[level]);
2082 ret = walk_up_reloc_tree(reloc_root, path, &level);
2088 * save the merging progress in the drop_progress.
2089 * this is OK since root refs == 1 in this case.
2091 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2092 path->slots[level]);
2093 root_item->drop_level = level;
2095 nr = trans->blocks_used;
2096 btrfs_end_transaction_throttle(trans, root);
2098 btrfs_btree_balance_dirty(root, nr);
2100 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2101 invalidate_extent_cache(root, &key, &next_key);
2105 * handle the case only one block in the fs tree need to be
2106 * relocated and the block is tree root.
2108 leaf = btrfs_lock_root_node(root);
2109 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2110 btrfs_tree_unlock(leaf);
2111 free_extent_buffer(leaf);
2115 btrfs_free_path(path);
2118 memset(&root_item->drop_progress, 0,
2119 sizeof(root_item->drop_progress));
2120 root_item->drop_level = 0;
2121 btrfs_set_root_refs(root_item, 0);
2122 btrfs_update_reloc_root(trans, root);
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);
2136 static noinline_for_stack
2137 int prepare_to_merge(struct reloc_control *rc, int err)
2139 struct btrfs_root *root = rc->extent_root;
2140 struct btrfs_root *reloc_root;
2141 struct btrfs_trans_handle *trans;
2142 LIST_HEAD(reloc_roots);
2146 mutex_lock(&root->fs_info->reloc_mutex);
2147 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2148 rc->merging_rsv_size += rc->nodes_relocated * 2;
2149 mutex_unlock(&root->fs_info->reloc_mutex);
2153 num_bytes = rc->merging_rsv_size;
2154 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes);
2159 trans = btrfs_join_transaction(rc->extent_root);
2160 if (IS_ERR(trans)) {
2162 btrfs_block_rsv_release(rc->extent_root,
2163 rc->block_rsv, num_bytes);
2164 return PTR_ERR(trans);
2168 if (num_bytes != rc->merging_rsv_size) {
2169 btrfs_end_transaction(trans, rc->extent_root);
2170 btrfs_block_rsv_release(rc->extent_root,
2171 rc->block_rsv, num_bytes);
2176 rc->merge_reloc_tree = 1;
2178 while (!list_empty(&rc->reloc_roots)) {
2179 reloc_root = list_entry(rc->reloc_roots.next,
2180 struct btrfs_root, root_list);
2181 list_del_init(&reloc_root->root_list);
2183 root = read_fs_root(reloc_root->fs_info,
2184 reloc_root->root_key.offset);
2185 BUG_ON(IS_ERR(root));
2186 BUG_ON(root->reloc_root != reloc_root);
2189 * set reference count to 1, so btrfs_recover_relocation
2190 * knows it should resumes merging
2193 btrfs_set_root_refs(&reloc_root->root_item, 1);
2194 btrfs_update_reloc_root(trans, root);
2196 list_add(&reloc_root->root_list, &reloc_roots);
2199 list_splice(&reloc_roots, &rc->reloc_roots);
2202 btrfs_commit_transaction(trans, rc->extent_root);
2204 btrfs_end_transaction(trans, rc->extent_root);
2208 static noinline_for_stack
2209 int merge_reloc_roots(struct reloc_control *rc)
2211 struct btrfs_root *root;
2212 struct btrfs_root *reloc_root;
2213 LIST_HEAD(reloc_roots);
2217 root = rc->extent_root;
2220 * this serializes us with btrfs_record_root_in_transaction,
2221 * we have to make sure nobody is in the middle of
2222 * adding their roots to the list while we are
2225 mutex_lock(&root->fs_info->reloc_mutex);
2226 list_splice_init(&rc->reloc_roots, &reloc_roots);
2227 mutex_unlock(&root->fs_info->reloc_mutex);
2229 while (!list_empty(&reloc_roots)) {
2231 reloc_root = list_entry(reloc_roots.next,
2232 struct btrfs_root, root_list);
2234 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2235 root = read_fs_root(reloc_root->fs_info,
2236 reloc_root->root_key.offset);
2237 BUG_ON(IS_ERR(root));
2238 BUG_ON(root->reloc_root != reloc_root);
2240 ret = merge_reloc_root(rc, root);
2243 list_del_init(&reloc_root->root_list);
2245 btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0);
2252 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2256 static void free_block_list(struct rb_root *blocks)
2258 struct tree_block *block;
2259 struct rb_node *rb_node;
2260 while ((rb_node = rb_first(blocks))) {
2261 block = rb_entry(rb_node, struct tree_block, rb_node);
2262 rb_erase(rb_node, blocks);
2267 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2268 struct btrfs_root *reloc_root)
2270 struct btrfs_root *root;
2272 if (reloc_root->last_trans == trans->transid)
2275 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2276 BUG_ON(IS_ERR(root));
2277 BUG_ON(root->reloc_root != reloc_root);
2279 return btrfs_record_root_in_trans(trans, root);
2282 static noinline_for_stack
2283 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2284 struct reloc_control *rc,
2285 struct backref_node *node,
2286 struct backref_edge *edges[], int *nr)
2288 struct backref_node *next;
2289 struct btrfs_root *root;
2295 next = walk_up_backref(next, edges, &index);
2298 BUG_ON(!root->ref_cows);
2300 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2301 record_reloc_root_in_trans(trans, root);
2305 btrfs_record_root_in_trans(trans, root);
2306 root = root->reloc_root;
2308 if (next->new_bytenr != root->node->start) {
2309 BUG_ON(next->new_bytenr);
2310 BUG_ON(!list_empty(&next->list));
2311 next->new_bytenr = root->node->start;
2313 list_add_tail(&next->list,
2314 &rc->backref_cache.changed);
2315 __mark_block_processed(rc, next);
2321 next = walk_down_backref(edges, &index);
2322 if (!next || next->level <= node->level)
2330 /* setup backref node path for btrfs_reloc_cow_block */
2332 rc->backref_cache.path[next->level] = next;
2335 next = edges[index]->node[UPPER];
2341 * select a tree root for relocation. return NULL if the block
2342 * is reference counted. we should use do_relocation() in this
2343 * case. return a tree root pointer if the block isn't reference
2344 * counted. return -ENOENT if the block is root of reloc tree.
2346 static noinline_for_stack
2347 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2348 struct backref_node *node)
2350 struct backref_node *next;
2351 struct btrfs_root *root;
2352 struct btrfs_root *fs_root = NULL;
2353 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2359 next = walk_up_backref(next, edges, &index);
2363 /* no other choice for non-references counted tree */
2364 if (!root->ref_cows)
2367 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2373 next = walk_down_backref(edges, &index);
2374 if (!next || next->level <= node->level)
2379 return ERR_PTR(-ENOENT);
2383 static noinline_for_stack
2384 u64 calcu_metadata_size(struct reloc_control *rc,
2385 struct backref_node *node, int reserve)
2387 struct backref_node *next = node;
2388 struct backref_edge *edge;
2389 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2393 BUG_ON(reserve && node->processed);
2398 if (next->processed && (reserve || next != node))
2401 num_bytes += btrfs_level_size(rc->extent_root,
2404 if (list_empty(&next->upper))
2407 edge = list_entry(next->upper.next,
2408 struct backref_edge, list[LOWER]);
2409 edges[index++] = edge;
2410 next = edge->node[UPPER];
2412 next = walk_down_backref(edges, &index);
2417 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2418 struct reloc_control *rc,
2419 struct backref_node *node)
2421 struct btrfs_root *root = rc->extent_root;
2425 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2427 trans->block_rsv = rc->block_rsv;
2428 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes);
2431 rc->commit_transaction = 1;
2438 static void release_metadata_space(struct reloc_control *rc,
2439 struct backref_node *node)
2441 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2442 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2446 * relocate a block tree, and then update pointers in upper level
2447 * blocks that reference the block to point to the new location.
2449 * if called by link_to_upper, the block has already been relocated.
2450 * in that case this function just updates pointers.
2452 static int do_relocation(struct btrfs_trans_handle *trans,
2453 struct reloc_control *rc,
2454 struct backref_node *node,
2455 struct btrfs_key *key,
2456 struct btrfs_path *path, int lowest)
2458 struct backref_node *upper;
2459 struct backref_edge *edge;
2460 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2461 struct btrfs_root *root;
2462 struct extent_buffer *eb;
2471 BUG_ON(lowest && node->eb);
2473 path->lowest_level = node->level + 1;
2474 rc->backref_cache.path[node->level] = node;
2475 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2478 upper = edge->node[UPPER];
2479 root = select_reloc_root(trans, rc, upper, edges, &nr);
2482 if (upper->eb && !upper->locked) {
2484 ret = btrfs_bin_search(upper->eb, key,
2485 upper->level, &slot);
2487 bytenr = btrfs_node_blockptr(upper->eb, slot);
2488 if (node->eb->start == bytenr)
2491 drop_node_buffer(upper);
2495 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2503 upper->eb = path->nodes[upper->level];
2504 path->nodes[upper->level] = NULL;
2506 BUG_ON(upper->eb != path->nodes[upper->level]);
2510 path->locks[upper->level] = 0;
2512 slot = path->slots[upper->level];
2513 btrfs_release_path(path);
2515 ret = btrfs_bin_search(upper->eb, key, upper->level,
2520 bytenr = btrfs_node_blockptr(upper->eb, slot);
2522 BUG_ON(bytenr != node->bytenr);
2524 if (node->eb->start == bytenr)
2528 blocksize = btrfs_level_size(root, node->level);
2529 generation = btrfs_node_ptr_generation(upper->eb, slot);
2530 eb = read_tree_block(root, bytenr, blocksize, generation);
2535 btrfs_tree_lock(eb);
2536 btrfs_set_lock_blocking(eb);
2539 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2541 btrfs_tree_unlock(eb);
2542 free_extent_buffer(eb);
2547 BUG_ON(node->eb != eb);
2549 btrfs_set_node_blockptr(upper->eb, slot,
2551 btrfs_set_node_ptr_generation(upper->eb, slot,
2553 btrfs_mark_buffer_dirty(upper->eb);
2555 ret = btrfs_inc_extent_ref(trans, root,
2556 node->eb->start, blocksize,
2558 btrfs_header_owner(upper->eb),
2562 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2566 if (!upper->pending)
2567 drop_node_buffer(upper);
2569 unlock_node_buffer(upper);
2574 if (!err && node->pending) {
2575 drop_node_buffer(node);
2576 list_move_tail(&node->list, &rc->backref_cache.changed);
2580 path->lowest_level = 0;
2581 BUG_ON(err == -ENOSPC);
2585 static int link_to_upper(struct btrfs_trans_handle *trans,
2586 struct reloc_control *rc,
2587 struct backref_node *node,
2588 struct btrfs_path *path)
2590 struct btrfs_key key;
2592 btrfs_node_key_to_cpu(node->eb, &key, 0);
2593 return do_relocation(trans, rc, node, &key, path, 0);
2596 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2597 struct reloc_control *rc,
2598 struct btrfs_path *path, int err)
2601 struct backref_cache *cache = &rc->backref_cache;
2602 struct backref_node *node;
2606 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2607 while (!list_empty(&cache->pending[level])) {
2608 node = list_entry(cache->pending[level].next,
2609 struct backref_node, list);
2610 list_move_tail(&node->list, &list);
2611 BUG_ON(!node->pending);
2614 ret = link_to_upper(trans, rc, node, path);
2619 list_splice_init(&list, &cache->pending[level]);
2624 static void mark_block_processed(struct reloc_control *rc,
2625 u64 bytenr, u32 blocksize)
2627 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2628 EXTENT_DIRTY, GFP_NOFS);
2631 static void __mark_block_processed(struct reloc_control *rc,
2632 struct backref_node *node)
2635 if (node->level == 0 ||
2636 in_block_group(node->bytenr, rc->block_group)) {
2637 blocksize = btrfs_level_size(rc->extent_root, node->level);
2638 mark_block_processed(rc, node->bytenr, blocksize);
2640 node->processed = 1;
2644 * mark a block and all blocks directly/indirectly reference the block
2647 static void update_processed_blocks(struct reloc_control *rc,
2648 struct backref_node *node)
2650 struct backref_node *next = node;
2651 struct backref_edge *edge;
2652 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2658 if (next->processed)
2661 __mark_block_processed(rc, next);
2663 if (list_empty(&next->upper))
2666 edge = list_entry(next->upper.next,
2667 struct backref_edge, list[LOWER]);
2668 edges[index++] = edge;
2669 next = edge->node[UPPER];
2671 next = walk_down_backref(edges, &index);
2675 static int tree_block_processed(u64 bytenr, u32 blocksize,
2676 struct reloc_control *rc)
2678 if (test_range_bit(&rc->processed_blocks, bytenr,
2679 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2684 static int get_tree_block_key(struct reloc_control *rc,
2685 struct tree_block *block)
2687 struct extent_buffer *eb;
2689 BUG_ON(block->key_ready);
2690 eb = read_tree_block(rc->extent_root, block->bytenr,
2691 block->key.objectid, block->key.offset);
2693 WARN_ON(btrfs_header_level(eb) != block->level);
2694 if (block->level == 0)
2695 btrfs_item_key_to_cpu(eb, &block->key, 0);
2697 btrfs_node_key_to_cpu(eb, &block->key, 0);
2698 free_extent_buffer(eb);
2699 block->key_ready = 1;
2703 static int reada_tree_block(struct reloc_control *rc,
2704 struct tree_block *block)
2706 BUG_ON(block->key_ready);
2707 readahead_tree_block(rc->extent_root, block->bytenr,
2708 block->key.objectid, block->key.offset);
2713 * helper function to relocate a tree block
2715 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2716 struct reloc_control *rc,
2717 struct backref_node *node,
2718 struct btrfs_key *key,
2719 struct btrfs_path *path)
2721 struct btrfs_root *root;
2728 BUG_ON(node->processed);
2729 root = select_one_root(trans, node);
2730 if (root == ERR_PTR(-ENOENT)) {
2731 update_processed_blocks(rc, node);
2735 if (!root || root->ref_cows) {
2736 ret = reserve_metadata_space(trans, rc, node);
2743 if (root->ref_cows) {
2744 BUG_ON(node->new_bytenr);
2745 BUG_ON(!list_empty(&node->list));
2746 btrfs_record_root_in_trans(trans, root);
2747 root = root->reloc_root;
2748 node->new_bytenr = root->node->start;
2750 list_add_tail(&node->list, &rc->backref_cache.changed);
2752 path->lowest_level = node->level;
2753 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2754 btrfs_release_path(path);
2759 update_processed_blocks(rc, node);
2761 ret = do_relocation(trans, rc, node, key, path, 1);
2764 if (ret || node->level == 0 || node->cowonly) {
2766 release_metadata_space(rc, node);
2767 remove_backref_node(&rc->backref_cache, node);
2773 * relocate a list of blocks
2775 static noinline_for_stack
2776 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2777 struct reloc_control *rc, struct rb_root *blocks)
2779 struct backref_node *node;
2780 struct btrfs_path *path;
2781 struct tree_block *block;
2782 struct rb_node *rb_node;
2786 path = btrfs_alloc_path();
2790 rb_node = rb_first(blocks);
2792 block = rb_entry(rb_node, struct tree_block, rb_node);
2793 if (!block->key_ready)
2794 reada_tree_block(rc, block);
2795 rb_node = rb_next(rb_node);
2798 rb_node = rb_first(blocks);
2800 block = rb_entry(rb_node, struct tree_block, rb_node);
2801 if (!block->key_ready)
2802 get_tree_block_key(rc, block);
2803 rb_node = rb_next(rb_node);
2806 rb_node = rb_first(blocks);
2808 block = rb_entry(rb_node, struct tree_block, rb_node);
2810 node = build_backref_tree(rc, &block->key,
2811 block->level, block->bytenr);
2813 err = PTR_ERR(node);
2817 ret = relocate_tree_block(trans, rc, node, &block->key,
2820 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2824 rb_node = rb_next(rb_node);
2827 free_block_list(blocks);
2828 err = finish_pending_nodes(trans, rc, path, err);
2830 btrfs_free_path(path);
2834 static noinline_for_stack
2835 int prealloc_file_extent_cluster(struct inode *inode,
2836 struct file_extent_cluster *cluster)
2841 u64 offset = BTRFS_I(inode)->index_cnt;
2846 BUG_ON(cluster->start != cluster->boundary[0]);
2847 mutex_lock(&inode->i_mutex);
2849 ret = btrfs_check_data_free_space(inode, cluster->end +
2850 1 - cluster->start);
2854 while (nr < cluster->nr) {
2855 start = cluster->boundary[nr] - offset;
2856 if (nr + 1 < cluster->nr)
2857 end = cluster->boundary[nr + 1] - 1 - offset;
2859 end = cluster->end - offset;
2861 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2862 num_bytes = end + 1 - start;
2863 ret = btrfs_prealloc_file_range(inode, 0, start,
2864 num_bytes, num_bytes,
2865 end + 1, &alloc_hint);
2866 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2871 btrfs_free_reserved_data_space(inode, cluster->end +
2872 1 - cluster->start);
2874 mutex_unlock(&inode->i_mutex);
2878 static noinline_for_stack
2879 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
2882 struct btrfs_root *root = BTRFS_I(inode)->root;
2883 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2884 struct extent_map *em;
2887 em = alloc_extent_map();
2892 em->len = end + 1 - start;
2893 em->block_len = em->len;
2894 em->block_start = block_start;
2895 em->bdev = root->fs_info->fs_devices->latest_bdev;
2896 set_bit(EXTENT_FLAG_PINNED, &em->flags);
2898 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2900 write_lock(&em_tree->lock);
2901 ret = add_extent_mapping(em_tree, em);
2902 write_unlock(&em_tree->lock);
2903 if (ret != -EEXIST) {
2904 free_extent_map(em);
2907 btrfs_drop_extent_cache(inode, start, end, 0);
2909 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2913 static int relocate_file_extent_cluster(struct inode *inode,
2914 struct file_extent_cluster *cluster)
2918 u64 offset = BTRFS_I(inode)->index_cnt;
2919 unsigned long index;
2920 unsigned long last_index;
2922 struct file_ra_state *ra;
2923 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
2930 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2934 ret = prealloc_file_extent_cluster(inode, cluster);
2938 file_ra_state_init(ra, inode->i_mapping);
2940 ret = setup_extent_mapping(inode, cluster->start - offset,
2941 cluster->end - offset, cluster->start);
2945 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
2946 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
2947 while (index <= last_index) {
2948 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
2952 page = find_lock_page(inode->i_mapping, index);
2954 page_cache_sync_readahead(inode->i_mapping,
2956 last_index + 1 - index);
2957 page = find_or_create_page(inode->i_mapping, index,
2960 btrfs_delalloc_release_metadata(inode,
2967 if (PageReadahead(page)) {
2968 page_cache_async_readahead(inode->i_mapping,
2969 ra, NULL, page, index,
2970 last_index + 1 - index);
2973 if (!PageUptodate(page)) {
2974 btrfs_readpage(NULL, page);
2976 if (!PageUptodate(page)) {
2978 page_cache_release(page);
2979 btrfs_delalloc_release_metadata(inode,
2986 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2987 page_end = page_start + PAGE_CACHE_SIZE - 1;
2989 lock_extent(&BTRFS_I(inode)->io_tree,
2990 page_start, page_end, GFP_NOFS);
2992 set_page_extent_mapped(page);
2994 if (nr < cluster->nr &&
2995 page_start + offset == cluster->boundary[nr]) {
2996 set_extent_bits(&BTRFS_I(inode)->io_tree,
2997 page_start, page_end,
2998 EXTENT_BOUNDARY, GFP_NOFS);
3002 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3003 set_page_dirty(page);
3005 unlock_extent(&BTRFS_I(inode)->io_tree,
3006 page_start, page_end, GFP_NOFS);
3008 page_cache_release(page);
3011 balance_dirty_pages_ratelimited(inode->i_mapping);
3012 btrfs_throttle(BTRFS_I(inode)->root);
3014 WARN_ON(nr != cluster->nr);
3020 static noinline_for_stack
3021 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3022 struct file_extent_cluster *cluster)
3026 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3027 ret = relocate_file_extent_cluster(inode, cluster);
3034 cluster->start = extent_key->objectid;
3036 BUG_ON(cluster->nr >= MAX_EXTENTS);
3037 cluster->end = extent_key->objectid + extent_key->offset - 1;
3038 cluster->boundary[cluster->nr] = extent_key->objectid;
3041 if (cluster->nr >= MAX_EXTENTS) {
3042 ret = relocate_file_extent_cluster(inode, cluster);
3050 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3051 static int get_ref_objectid_v0(struct reloc_control *rc,
3052 struct btrfs_path *path,
3053 struct btrfs_key *extent_key,
3054 u64 *ref_objectid, int *path_change)
3056 struct btrfs_key key;
3057 struct extent_buffer *leaf;
3058 struct btrfs_extent_ref_v0 *ref0;
3062 leaf = path->nodes[0];
3063 slot = path->slots[0];
3065 if (slot >= btrfs_header_nritems(leaf)) {
3066 ret = btrfs_next_leaf(rc->extent_root, path);
3070 leaf = path->nodes[0];
3071 slot = path->slots[0];
3075 btrfs_item_key_to_cpu(leaf, &key, slot);
3076 if (key.objectid != extent_key->objectid)
3079 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3083 ref0 = btrfs_item_ptr(leaf, slot,
3084 struct btrfs_extent_ref_v0);
3085 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3093 * helper to add a tree block to the list.
3094 * the major work is getting the generation and level of the block
3096 static int add_tree_block(struct reloc_control *rc,
3097 struct btrfs_key *extent_key,
3098 struct btrfs_path *path,
3099 struct rb_root *blocks)
3101 struct extent_buffer *eb;
3102 struct btrfs_extent_item *ei;
3103 struct btrfs_tree_block_info *bi;
3104 struct tree_block *block;
3105 struct rb_node *rb_node;
3110 eb = path->nodes[0];
3111 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3113 if (item_size >= sizeof(*ei) + sizeof(*bi)) {
3114 ei = btrfs_item_ptr(eb, path->slots[0],
3115 struct btrfs_extent_item);
3116 bi = (struct btrfs_tree_block_info *)(ei + 1);
3117 generation = btrfs_extent_generation(eb, ei);
3118 level = btrfs_tree_block_level(eb, bi);
3120 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3124 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3125 ret = get_ref_objectid_v0(rc, path, extent_key,
3129 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3130 level = (int)ref_owner;
3131 /* FIXME: get real generation */
3138 btrfs_release_path(path);
3140 BUG_ON(level == -1);
3142 block = kmalloc(sizeof(*block), GFP_NOFS);
3146 block->bytenr = extent_key->objectid;
3147 block->key.objectid = extent_key->offset;
3148 block->key.offset = generation;
3149 block->level = level;
3150 block->key_ready = 0;
3152 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3159 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3161 static int __add_tree_block(struct reloc_control *rc,
3162 u64 bytenr, u32 blocksize,
3163 struct rb_root *blocks)
3165 struct btrfs_path *path;
3166 struct btrfs_key key;
3169 if (tree_block_processed(bytenr, blocksize, rc))
3172 if (tree_search(blocks, bytenr))
3175 path = btrfs_alloc_path();
3179 key.objectid = bytenr;
3180 key.type = BTRFS_EXTENT_ITEM_KEY;
3181 key.offset = blocksize;
3183 path->search_commit_root = 1;
3184 path->skip_locking = 1;
3185 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3190 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3191 ret = add_tree_block(rc, &key, path, blocks);
3193 btrfs_free_path(path);
3198 * helper to check if the block use full backrefs for pointers in it
3200 static int block_use_full_backref(struct reloc_control *rc,
3201 struct extent_buffer *eb)
3206 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3207 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3210 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3211 eb->start, eb->len, NULL, &flags);
3214 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3221 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3222 struct inode *inode, u64 ino)
3224 struct btrfs_key key;
3225 struct btrfs_path *path;
3226 struct btrfs_root *root = fs_info->tree_root;
3227 struct btrfs_trans_handle *trans;
3235 key.type = BTRFS_INODE_ITEM_KEY;
3238 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3239 if (IS_ERR_OR_NULL(inode) || is_bad_inode(inode)) {
3240 if (inode && !IS_ERR(inode))
3246 path = btrfs_alloc_path();
3252 trans = btrfs_join_transaction(root);
3253 if (IS_ERR(trans)) {
3254 btrfs_free_path(path);
3255 ret = PTR_ERR(trans);
3259 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3261 btrfs_free_path(path);
3262 nr = trans->blocks_used;
3263 btrfs_end_transaction(trans, root);
3264 btrfs_btree_balance_dirty(root, nr);
3271 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3272 * this function scans fs tree to find blocks reference the data extent
3274 static int find_data_references(struct reloc_control *rc,
3275 struct btrfs_key *extent_key,
3276 struct extent_buffer *leaf,
3277 struct btrfs_extent_data_ref *ref,
3278 struct rb_root *blocks)
3280 struct btrfs_path *path;
3281 struct tree_block *block;
3282 struct btrfs_root *root;
3283 struct btrfs_file_extent_item *fi;
3284 struct rb_node *rb_node;
3285 struct btrfs_key key;
3296 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3297 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3298 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3299 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3302 * This is an extent belonging to the free space cache, lets just delete
3303 * it and redo the search.
3305 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3306 ret = delete_block_group_cache(rc->extent_root->fs_info,
3307 NULL, ref_objectid);
3313 path = btrfs_alloc_path();
3318 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3320 err = PTR_ERR(root);
3324 key.objectid = ref_objectid;
3325 key.type = BTRFS_EXTENT_DATA_KEY;
3326 if (ref_offset > ((u64)-1 << 32))
3329 key.offset = ref_offset;
3331 path->search_commit_root = 1;
3332 path->skip_locking = 1;
3333 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3339 leaf = path->nodes[0];
3340 nritems = btrfs_header_nritems(leaf);
3342 * the references in tree blocks that use full backrefs
3343 * are not counted in
3345 if (block_use_full_backref(rc, leaf))
3349 rb_node = tree_search(blocks, leaf->start);
3354 path->slots[0] = nritems;
3357 while (ref_count > 0) {
3358 while (path->slots[0] >= nritems) {
3359 ret = btrfs_next_leaf(root, path);
3369 leaf = path->nodes[0];
3370 nritems = btrfs_header_nritems(leaf);
3373 if (block_use_full_backref(rc, leaf))
3377 rb_node = tree_search(blocks, leaf->start);
3382 path->slots[0] = nritems;
3386 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3387 if (key.objectid != ref_objectid ||
3388 key.type != BTRFS_EXTENT_DATA_KEY) {
3393 fi = btrfs_item_ptr(leaf, path->slots[0],
3394 struct btrfs_file_extent_item);
3396 if (btrfs_file_extent_type(leaf, fi) ==
3397 BTRFS_FILE_EXTENT_INLINE)
3400 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3401 extent_key->objectid)
3404 key.offset -= btrfs_file_extent_offset(leaf, fi);
3405 if (key.offset != ref_offset)
3413 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3414 block = kmalloc(sizeof(*block), GFP_NOFS);
3419 block->bytenr = leaf->start;
3420 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3422 block->key_ready = 1;
3423 rb_node = tree_insert(blocks, block->bytenr,
3430 path->slots[0] = nritems;
3436 btrfs_free_path(path);
3441 * hepler to find all tree blocks that reference a given data extent
3443 static noinline_for_stack
3444 int add_data_references(struct reloc_control *rc,
3445 struct btrfs_key *extent_key,
3446 struct btrfs_path *path,
3447 struct rb_root *blocks)
3449 struct btrfs_key key;
3450 struct extent_buffer *eb;
3451 struct btrfs_extent_data_ref *dref;
3452 struct btrfs_extent_inline_ref *iref;
3455 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3459 eb = path->nodes[0];
3460 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3461 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3462 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3463 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3467 ptr += sizeof(struct btrfs_extent_item);
3470 iref = (struct btrfs_extent_inline_ref *)ptr;
3471 key.type = btrfs_extent_inline_ref_type(eb, iref);
3472 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3473 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3474 ret = __add_tree_block(rc, key.offset, blocksize,
3476 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3477 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3478 ret = find_data_references(rc, extent_key,
3483 ptr += btrfs_extent_inline_ref_size(key.type);
3489 eb = path->nodes[0];
3490 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3491 ret = btrfs_next_leaf(rc->extent_root, path);
3498 eb = path->nodes[0];
3501 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3502 if (key.objectid != extent_key->objectid)
3505 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3506 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3507 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3509 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3510 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3512 ret = __add_tree_block(rc, key.offset, blocksize,
3514 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3515 dref = btrfs_item_ptr(eb, path->slots[0],
3516 struct btrfs_extent_data_ref);
3517 ret = find_data_references(rc, extent_key,
3528 btrfs_release_path(path);
3530 free_block_list(blocks);
3535 * hepler to find next unprocessed extent
3537 static noinline_for_stack
3538 int find_next_extent(struct btrfs_trans_handle *trans,
3539 struct reloc_control *rc, struct btrfs_path *path,
3540 struct btrfs_key *extent_key)
3542 struct btrfs_key key;
3543 struct extent_buffer *leaf;
3544 u64 start, end, last;
3547 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3550 if (rc->search_start >= last) {
3555 key.objectid = rc->search_start;
3556 key.type = BTRFS_EXTENT_ITEM_KEY;
3559 path->search_commit_root = 1;
3560 path->skip_locking = 1;
3561 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3566 leaf = path->nodes[0];
3567 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3568 ret = btrfs_next_leaf(rc->extent_root, path);
3571 leaf = path->nodes[0];
3574 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3575 if (key.objectid >= last) {
3580 if (key.type != BTRFS_EXTENT_ITEM_KEY ||
3581 key.objectid + key.offset <= rc->search_start) {
3586 ret = find_first_extent_bit(&rc->processed_blocks,
3587 key.objectid, &start, &end,
3590 if (ret == 0 && start <= key.objectid) {
3591 btrfs_release_path(path);
3592 rc->search_start = end + 1;
3594 rc->search_start = key.objectid + key.offset;
3595 memcpy(extent_key, &key, sizeof(key));
3599 btrfs_release_path(path);
3603 static void set_reloc_control(struct reloc_control *rc)
3605 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3607 mutex_lock(&fs_info->reloc_mutex);
3608 fs_info->reloc_ctl = rc;
3609 mutex_unlock(&fs_info->reloc_mutex);
3612 static void unset_reloc_control(struct reloc_control *rc)
3614 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3616 mutex_lock(&fs_info->reloc_mutex);
3617 fs_info->reloc_ctl = NULL;
3618 mutex_unlock(&fs_info->reloc_mutex);
3621 static int check_extent_flags(u64 flags)
3623 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3624 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3626 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3627 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3629 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3630 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3635 static noinline_for_stack
3636 int prepare_to_relocate(struct reloc_control *rc)
3638 struct btrfs_trans_handle *trans;
3641 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root);
3646 * reserve some space for creating reloc trees.
3647 * btrfs_init_reloc_root will use them when there
3648 * is no reservation in transaction handle.
3650 ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv,
3651 rc->extent_root->nodesize * 256);
3655 memset(&rc->cluster, 0, sizeof(rc->cluster));
3656 rc->search_start = rc->block_group->key.objectid;
3657 rc->extents_found = 0;
3658 rc->nodes_relocated = 0;
3659 rc->merging_rsv_size = 0;
3661 rc->create_reloc_tree = 1;
3662 set_reloc_control(rc);
3664 trans = btrfs_join_transaction(rc->extent_root);
3665 BUG_ON(IS_ERR(trans));
3666 btrfs_commit_transaction(trans, rc->extent_root);
3670 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3672 struct rb_root blocks = RB_ROOT;
3673 struct btrfs_key key;
3674 struct btrfs_trans_handle *trans = NULL;
3675 struct btrfs_path *path;
3676 struct btrfs_extent_item *ei;
3684 path = btrfs_alloc_path();
3689 ret = prepare_to_relocate(rc);
3697 trans = btrfs_start_transaction(rc->extent_root, 0);
3698 BUG_ON(IS_ERR(trans));
3700 if (update_backref_cache(trans, &rc->backref_cache)) {
3701 btrfs_end_transaction(trans, rc->extent_root);
3705 ret = find_next_extent(trans, rc, path, &key);
3711 rc->extents_found++;
3713 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3714 struct btrfs_extent_item);
3715 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3716 if (item_size >= sizeof(*ei)) {
3717 flags = btrfs_extent_flags(path->nodes[0], ei);
3718 ret = check_extent_flags(flags);
3722 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3724 int path_change = 0;
3727 sizeof(struct btrfs_extent_item_v0));
3728 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3730 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3731 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3733 flags = BTRFS_EXTENT_FLAG_DATA;
3736 btrfs_release_path(path);
3738 path->search_commit_root = 1;
3739 path->skip_locking = 1;
3740 ret = btrfs_search_slot(NULL, rc->extent_root,
3753 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3754 ret = add_tree_block(rc, &key, path, &blocks);
3755 } else if (rc->stage == UPDATE_DATA_PTRS &&
3756 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3757 ret = add_data_references(rc, &key, path, &blocks);
3759 btrfs_release_path(path);
3767 if (!RB_EMPTY_ROOT(&blocks)) {
3768 ret = relocate_tree_blocks(trans, rc, &blocks);
3770 if (ret != -EAGAIN) {
3774 rc->extents_found--;
3775 rc->search_start = key.objectid;
3779 ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5);
3781 if (ret != -EAGAIN) {
3786 rc->commit_transaction = 1;
3789 if (rc->commit_transaction) {
3790 rc->commit_transaction = 0;
3791 ret = btrfs_commit_transaction(trans, rc->extent_root);
3794 nr = trans->blocks_used;
3795 btrfs_end_transaction_throttle(trans, rc->extent_root);
3796 btrfs_btree_balance_dirty(rc->extent_root, nr);
3800 if (rc->stage == MOVE_DATA_EXTENTS &&
3801 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3802 rc->found_file_extent = 1;
3803 ret = relocate_data_extent(rc->data_inode,
3804 &key, &rc->cluster);
3811 if (trans && progress && err == -ENOSPC) {
3812 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
3813 rc->block_group->flags);
3821 btrfs_release_path(path);
3822 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
3826 nr = trans->blocks_used;
3827 btrfs_end_transaction_throttle(trans, rc->extent_root);
3828 btrfs_btree_balance_dirty(rc->extent_root, nr);
3832 ret = relocate_file_extent_cluster(rc->data_inode,
3838 rc->create_reloc_tree = 0;
3839 set_reloc_control(rc);
3841 backref_cache_cleanup(&rc->backref_cache);
3842 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3844 err = prepare_to_merge(rc, err);
3846 merge_reloc_roots(rc);
3848 rc->merge_reloc_tree = 0;
3849 unset_reloc_control(rc);
3850 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3852 /* get rid of pinned extents */
3853 trans = btrfs_join_transaction(rc->extent_root);
3855 err = PTR_ERR(trans);
3857 btrfs_commit_transaction(trans, rc->extent_root);
3859 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
3860 btrfs_free_path(path);
3864 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
3865 struct btrfs_root *root, u64 objectid)
3867 struct btrfs_path *path;
3868 struct btrfs_inode_item *item;
3869 struct extent_buffer *leaf;
3872 path = btrfs_alloc_path();
3876 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
3880 leaf = path->nodes[0];
3881 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
3882 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
3883 btrfs_set_inode_generation(leaf, item, 1);
3884 btrfs_set_inode_size(leaf, item, 0);
3885 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
3886 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
3887 BTRFS_INODE_PREALLOC);
3888 btrfs_mark_buffer_dirty(leaf);
3889 btrfs_release_path(path);
3891 btrfs_free_path(path);
3896 * helper to create inode for data relocation.
3897 * the inode is in data relocation tree and its link count is 0
3899 static noinline_for_stack
3900 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
3901 struct btrfs_block_group_cache *group)
3903 struct inode *inode = NULL;
3904 struct btrfs_trans_handle *trans;
3905 struct btrfs_root *root;
3906 struct btrfs_key key;
3908 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
3911 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
3913 return ERR_CAST(root);
3915 trans = btrfs_start_transaction(root, 6);
3917 return ERR_CAST(trans);
3919 err = btrfs_find_free_objectid(root, &objectid);
3923 err = __insert_orphan_inode(trans, root, objectid);
3926 key.objectid = objectid;
3927 key.type = BTRFS_INODE_ITEM_KEY;
3929 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
3930 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
3931 BTRFS_I(inode)->index_cnt = group->key.objectid;
3933 err = btrfs_orphan_add(trans, inode);
3935 nr = trans->blocks_used;
3936 btrfs_end_transaction(trans, root);
3937 btrfs_btree_balance_dirty(root, nr);
3941 inode = ERR_PTR(err);
3946 static struct reloc_control *alloc_reloc_control(void)
3948 struct reloc_control *rc;
3950 rc = kzalloc(sizeof(*rc), GFP_NOFS);
3954 INIT_LIST_HEAD(&rc->reloc_roots);
3955 backref_cache_init(&rc->backref_cache);
3956 mapping_tree_init(&rc->reloc_root_tree);
3957 extent_io_tree_init(&rc->processed_blocks, NULL);
3962 * function to relocate all extents in a block group.
3964 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
3966 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3967 struct reloc_control *rc;
3968 struct inode *inode;
3969 struct btrfs_path *path;
3974 rc = alloc_reloc_control();
3978 rc->extent_root = extent_root;
3980 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
3981 BUG_ON(!rc->block_group);
3983 if (!rc->block_group->ro) {
3984 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
3992 path = btrfs_alloc_path();
3998 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4000 btrfs_free_path(path);
4003 ret = delete_block_group_cache(fs_info, inode, 0);
4005 ret = PTR_ERR(inode);
4007 if (ret && ret != -ENOENT) {
4012 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4013 if (IS_ERR(rc->data_inode)) {
4014 err = PTR_ERR(rc->data_inode);
4015 rc->data_inode = NULL;
4019 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
4020 (unsigned long long)rc->block_group->key.objectid,
4021 (unsigned long long)rc->block_group->flags);
4023 btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
4024 btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0);
4027 mutex_lock(&fs_info->cleaner_mutex);
4029 btrfs_clean_old_snapshots(fs_info->tree_root);
4030 ret = relocate_block_group(rc);
4032 mutex_unlock(&fs_info->cleaner_mutex);
4038 if (rc->extents_found == 0)
4041 printk(KERN_INFO "btrfs: found %llu extents\n",
4042 (unsigned long long)rc->extents_found);
4044 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4045 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4046 invalidate_mapping_pages(rc->data_inode->i_mapping,
4048 rc->stage = UPDATE_DATA_PTRS;
4052 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4053 rc->block_group->key.objectid,
4054 rc->block_group->key.objectid +
4055 rc->block_group->key.offset - 1);
4057 WARN_ON(rc->block_group->pinned > 0);
4058 WARN_ON(rc->block_group->reserved > 0);
4059 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4062 btrfs_set_block_group_rw(extent_root, rc->block_group);
4063 iput(rc->data_inode);
4064 btrfs_put_block_group(rc->block_group);
4069 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4071 struct btrfs_trans_handle *trans;
4074 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4075 BUG_ON(IS_ERR(trans));
4077 memset(&root->root_item.drop_progress, 0,
4078 sizeof(root->root_item.drop_progress));
4079 root->root_item.drop_level = 0;
4080 btrfs_set_root_refs(&root->root_item, 0);
4081 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4082 &root->root_key, &root->root_item);
4085 ret = btrfs_end_transaction(trans, root->fs_info->tree_root);
4091 * recover relocation interrupted by system crash.
4093 * this function resumes merging reloc trees with corresponding fs trees.
4094 * this is important for keeping the sharing of tree blocks
4096 int btrfs_recover_relocation(struct btrfs_root *root)
4098 LIST_HEAD(reloc_roots);
4099 struct btrfs_key key;
4100 struct btrfs_root *fs_root;
4101 struct btrfs_root *reloc_root;
4102 struct btrfs_path *path;
4103 struct extent_buffer *leaf;
4104 struct reloc_control *rc = NULL;
4105 struct btrfs_trans_handle *trans;
4109 path = btrfs_alloc_path();
4114 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4115 key.type = BTRFS_ROOT_ITEM_KEY;
4116 key.offset = (u64)-1;
4119 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4126 if (path->slots[0] == 0)
4130 leaf = path->nodes[0];
4131 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4132 btrfs_release_path(path);
4134 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4135 key.type != BTRFS_ROOT_ITEM_KEY)
4138 reloc_root = btrfs_read_fs_root_no_radix(root, &key);
4139 if (IS_ERR(reloc_root)) {
4140 err = PTR_ERR(reloc_root);
4144 list_add(&reloc_root->root_list, &reloc_roots);
4146 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4147 fs_root = read_fs_root(root->fs_info,
4148 reloc_root->root_key.offset);
4149 if (IS_ERR(fs_root)) {
4150 ret = PTR_ERR(fs_root);
4151 if (ret != -ENOENT) {
4155 mark_garbage_root(reloc_root);
4159 if (key.offset == 0)
4164 btrfs_release_path(path);
4166 if (list_empty(&reloc_roots))
4169 rc = alloc_reloc_control();
4175 rc->extent_root = root->fs_info->extent_root;
4177 set_reloc_control(rc);
4179 trans = btrfs_join_transaction(rc->extent_root);
4180 if (IS_ERR(trans)) {
4181 unset_reloc_control(rc);
4182 err = PTR_ERR(trans);
4186 rc->merge_reloc_tree = 1;
4188 while (!list_empty(&reloc_roots)) {
4189 reloc_root = list_entry(reloc_roots.next,
4190 struct btrfs_root, root_list);
4191 list_del(&reloc_root->root_list);
4193 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4194 list_add_tail(&reloc_root->root_list,
4199 fs_root = read_fs_root(root->fs_info,
4200 reloc_root->root_key.offset);
4201 BUG_ON(IS_ERR(fs_root));
4203 __add_reloc_root(reloc_root);
4204 fs_root->reloc_root = reloc_root;
4207 btrfs_commit_transaction(trans, rc->extent_root);
4209 merge_reloc_roots(rc);
4211 unset_reloc_control(rc);
4213 trans = btrfs_join_transaction(rc->extent_root);
4215 err = PTR_ERR(trans);
4217 btrfs_commit_transaction(trans, rc->extent_root);
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);
4225 free_extent_buffer(reloc_root->node);
4226 free_extent_buffer(reloc_root->commit_root);
4229 btrfs_free_path(path);
4232 /* cleanup orphan inode in data relocation tree */
4233 fs_root = read_fs_root(root->fs_info,
4234 BTRFS_DATA_RELOC_TREE_OBJECTID);
4235 if (IS_ERR(fs_root))
4236 err = PTR_ERR(fs_root);
4238 err = btrfs_orphan_cleanup(fs_root);
4244 * helper to add ordered checksum for data relocation.
4246 * cloning checksum properly handles the nodatasum extents.
4247 * it also saves CPU time to re-calculate the checksum.
4249 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4251 struct btrfs_ordered_sum *sums;
4252 struct btrfs_sector_sum *sector_sum;
4253 struct btrfs_ordered_extent *ordered;
4254 struct btrfs_root *root = BTRFS_I(inode)->root;
4260 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4261 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4263 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4264 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4265 disk_bytenr + len - 1, &list, 0);
4267 while (!list_empty(&list)) {
4268 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4269 list_del_init(&sums->list);
4271 sector_sum = sums->sums;
4272 sums->bytenr = ordered->start;
4275 while (offset < sums->len) {
4276 sector_sum->bytenr += ordered->start - disk_bytenr;
4278 offset += root->sectorsize;
4281 btrfs_add_ordered_sum(inode, ordered, sums);
4283 btrfs_put_ordered_extent(ordered);
4287 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4288 struct btrfs_root *root, struct extent_buffer *buf,
4289 struct extent_buffer *cow)
4291 struct reloc_control *rc;
4292 struct backref_node *node;
4297 rc = root->fs_info->reloc_ctl;
4301 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4302 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4304 level = btrfs_header_level(buf);
4305 if (btrfs_header_generation(buf) <=
4306 btrfs_root_last_snapshot(&root->root_item))
4309 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4310 rc->create_reloc_tree) {
4311 WARN_ON(!first_cow && level == 0);
4313 node = rc->backref_cache.path[level];
4314 BUG_ON(node->bytenr != buf->start &&
4315 node->new_bytenr != buf->start);
4317 drop_node_buffer(node);
4318 extent_buffer_get(cow);
4320 node->new_bytenr = cow->start;
4322 if (!node->pending) {
4323 list_move_tail(&node->list,
4324 &rc->backref_cache.pending[level]);
4329 __mark_block_processed(rc, node);
4331 if (first_cow && level > 0)
4332 rc->nodes_relocated += buf->len;
4335 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4336 ret = replace_file_extents(trans, rc, root, cow);
4342 * called before creating snapshot. it calculates metadata reservation
4343 * requried for relocating tree blocks in the snapshot
4345 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4346 struct btrfs_pending_snapshot *pending,
4347 u64 *bytes_to_reserve)
4349 struct btrfs_root *root;
4350 struct reloc_control *rc;
4352 root = pending->root;
4353 if (!root->reloc_root)
4356 rc = root->fs_info->reloc_ctl;
4357 if (!rc->merge_reloc_tree)
4360 root = root->reloc_root;
4361 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4363 * relocation is in the stage of merging trees. the space
4364 * used by merging a reloc tree is twice the size of
4365 * relocated tree nodes in the worst case. half for cowing
4366 * the reloc tree, half for cowing the fs tree. the space
4367 * used by cowing the reloc tree will be freed after the
4368 * tree is dropped. if we create snapshot, cowing the fs
4369 * tree may use more space than it frees. so we need
4370 * reserve extra space.
4372 *bytes_to_reserve += rc->nodes_relocated;
4376 * called after snapshot is created. migrate block reservation
4377 * and create reloc root for the newly created snapshot
4379 void btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4380 struct btrfs_pending_snapshot *pending)
4382 struct btrfs_root *root = pending->root;
4383 struct btrfs_root *reloc_root;
4384 struct btrfs_root *new_root;
4385 struct reloc_control *rc;
4388 if (!root->reloc_root)
4391 rc = root->fs_info->reloc_ctl;
4392 rc->merging_rsv_size += rc->nodes_relocated;
4394 if (rc->merge_reloc_tree) {
4395 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4397 rc->nodes_relocated);
4401 new_root = pending->snap;
4402 reloc_root = create_reloc_root(trans, root->reloc_root,
4403 new_root->root_key.objectid);
4405 __add_reloc_root(reloc_root);
4406 new_root->reloc_root = reloc_root;
4408 if (rc->create_reloc_tree) {
4409 ret = clone_backref_node(trans, rc, root, reloc_root);