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"
34 * backref_node, mapping_node and tree_block start with this
37 struct rb_node rb_node;
42 * present a tree block in the backref cache
45 struct rb_node rb_node;
49 /* objectid of tree block owner, can be not uptodate */
51 /* link to pending, changed or detached list */
52 struct list_head list;
53 /* list of upper level blocks reference this block */
54 struct list_head upper;
55 /* list of child blocks in the cache */
56 struct list_head lower;
57 /* NULL if this node is not tree root */
58 struct btrfs_root *root;
59 /* extent buffer got by COW the block */
60 struct extent_buffer *eb;
61 /* level of tree block */
63 /* is the block in non-reference counted tree */
64 unsigned int cowonly:1;
65 /* 1 if no child node in the cache */
66 unsigned int lowest:1;
67 /* is the extent buffer locked */
68 unsigned int locked:1;
69 /* has the block been processed */
70 unsigned int processed:1;
71 /* have backrefs of this block been checked */
72 unsigned int checked:1;
74 * 1 if corresponding block has been cowed but some upper
75 * level block pointers may not point to the new location
77 unsigned int pending:1;
79 * 1 if the backref node isn't connected to any other
82 unsigned int detached:1;
86 * present a block pointer in the backref cache
89 struct list_head list[2];
90 struct backref_node *node[2];
96 struct backref_cache {
97 /* red black tree of all backref nodes in the cache */
98 struct rb_root rb_root;
99 /* for passing backref nodes to btrfs_reloc_cow_block */
100 struct backref_node *path[BTRFS_MAX_LEVEL];
102 * list of blocks that have been cowed but some block
103 * pointers in upper level blocks may not reflect the
106 struct list_head pending[BTRFS_MAX_LEVEL];
107 /* list of backref nodes with no child node */
108 struct list_head leaves;
109 /* list of blocks that have been cowed in current transaction */
110 struct list_head changed;
111 /* list of detached backref node. */
112 struct list_head detached;
121 * map address of tree root to tree
123 struct mapping_node {
124 struct rb_node rb_node;
129 struct mapping_tree {
130 struct rb_root rb_root;
135 * present a tree block to process
138 struct rb_node rb_node;
140 struct btrfs_key key;
141 unsigned int level:8;
142 unsigned int key_ready:1;
145 #define MAX_EXTENTS 128
147 struct file_extent_cluster {
150 u64 boundary[MAX_EXTENTS];
154 struct reloc_control {
155 /* block group to relocate */
156 struct btrfs_block_group_cache *block_group;
158 struct btrfs_root *extent_root;
159 /* inode for moving data */
160 struct inode *data_inode;
162 struct btrfs_block_rsv *block_rsv;
164 struct backref_cache backref_cache;
166 struct file_extent_cluster cluster;
167 /* tree blocks have been processed */
168 struct extent_io_tree processed_blocks;
169 /* map start of tree root to corresponding reloc tree */
170 struct mapping_tree reloc_root_tree;
171 /* list of reloc trees */
172 struct list_head reloc_roots;
173 /* size of metadata reservation for merging reloc trees */
174 u64 merging_rsv_size;
175 /* size of relocated tree nodes */
181 unsigned int stage:8;
182 unsigned int create_reloc_tree:1;
183 unsigned int merge_reloc_tree:1;
184 unsigned int found_file_extent:1;
185 unsigned int commit_transaction:1;
188 /* stages of data relocation */
189 #define MOVE_DATA_EXTENTS 0
190 #define UPDATE_DATA_PTRS 1
192 static void remove_backref_node(struct backref_cache *cache,
193 struct backref_node *node);
194 static void __mark_block_processed(struct reloc_control *rc,
195 struct backref_node *node);
197 static void mapping_tree_init(struct mapping_tree *tree)
199 tree->rb_root = RB_ROOT;
200 spin_lock_init(&tree->lock);
203 static void backref_cache_init(struct backref_cache *cache)
206 cache->rb_root = RB_ROOT;
207 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
208 INIT_LIST_HEAD(&cache->pending[i]);
209 INIT_LIST_HEAD(&cache->changed);
210 INIT_LIST_HEAD(&cache->detached);
211 INIT_LIST_HEAD(&cache->leaves);
214 static void backref_cache_cleanup(struct backref_cache *cache)
216 struct backref_node *node;
219 while (!list_empty(&cache->detached)) {
220 node = list_entry(cache->detached.next,
221 struct backref_node, list);
222 remove_backref_node(cache, node);
225 while (!list_empty(&cache->leaves)) {
226 node = list_entry(cache->leaves.next,
227 struct backref_node, lower);
228 remove_backref_node(cache, node);
231 cache->last_trans = 0;
233 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
234 BUG_ON(!list_empty(&cache->pending[i]));
235 BUG_ON(!list_empty(&cache->changed));
236 BUG_ON(!list_empty(&cache->detached));
237 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
238 BUG_ON(cache->nr_nodes);
239 BUG_ON(cache->nr_edges);
242 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
244 struct backref_node *node;
246 node = kzalloc(sizeof(*node), GFP_NOFS);
248 INIT_LIST_HEAD(&node->list);
249 INIT_LIST_HEAD(&node->upper);
250 INIT_LIST_HEAD(&node->lower);
251 RB_CLEAR_NODE(&node->rb_node);
257 static void free_backref_node(struct backref_cache *cache,
258 struct backref_node *node)
266 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
268 struct backref_edge *edge;
270 edge = kzalloc(sizeof(*edge), GFP_NOFS);
276 static void free_backref_edge(struct backref_cache *cache,
277 struct backref_edge *edge)
285 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
286 struct rb_node *node)
288 struct rb_node **p = &root->rb_node;
289 struct rb_node *parent = NULL;
290 struct tree_entry *entry;
294 entry = rb_entry(parent, struct tree_entry, rb_node);
296 if (bytenr < entry->bytenr)
298 else if (bytenr > entry->bytenr)
304 rb_link_node(node, parent, p);
305 rb_insert_color(node, root);
309 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
311 struct rb_node *n = root->rb_node;
312 struct tree_entry *entry;
315 entry = rb_entry(n, struct tree_entry, rb_node);
317 if (bytenr < entry->bytenr)
319 else if (bytenr > entry->bytenr)
328 * walk up backref nodes until reach node presents tree root
330 static struct backref_node *walk_up_backref(struct backref_node *node,
331 struct backref_edge *edges[],
334 struct backref_edge *edge;
337 while (!list_empty(&node->upper)) {
338 edge = list_entry(node->upper.next,
339 struct backref_edge, list[LOWER]);
341 node = edge->node[UPPER];
343 BUG_ON(node->detached);
349 * walk down backref nodes to find start of next reference path
351 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
354 struct backref_edge *edge;
355 struct backref_node *lower;
359 edge = edges[idx - 1];
360 lower = edge->node[LOWER];
361 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
365 edge = list_entry(edge->list[LOWER].next,
366 struct backref_edge, list[LOWER]);
367 edges[idx - 1] = edge;
369 return edge->node[UPPER];
375 static void unlock_node_buffer(struct backref_node *node)
378 btrfs_tree_unlock(node->eb);
383 static void drop_node_buffer(struct backref_node *node)
386 unlock_node_buffer(node);
387 free_extent_buffer(node->eb);
392 static void drop_backref_node(struct backref_cache *tree,
393 struct backref_node *node)
395 BUG_ON(!list_empty(&node->upper));
397 drop_node_buffer(node);
398 list_del(&node->list);
399 list_del(&node->lower);
400 if (!RB_EMPTY_NODE(&node->rb_node))
401 rb_erase(&node->rb_node, &tree->rb_root);
402 free_backref_node(tree, node);
406 * remove a backref node from the backref cache
408 static void remove_backref_node(struct backref_cache *cache,
409 struct backref_node *node)
411 struct backref_node *upper;
412 struct backref_edge *edge;
417 BUG_ON(!node->lowest && !node->detached);
418 while (!list_empty(&node->upper)) {
419 edge = list_entry(node->upper.next, struct backref_edge,
421 upper = edge->node[UPPER];
422 list_del(&edge->list[LOWER]);
423 list_del(&edge->list[UPPER]);
424 free_backref_edge(cache, edge);
426 if (RB_EMPTY_NODE(&upper->rb_node)) {
427 BUG_ON(!list_empty(&node->upper));
428 drop_backref_node(cache, node);
434 * add the node to leaf node list if no other
435 * child block cached.
437 if (list_empty(&upper->lower)) {
438 list_add_tail(&upper->lower, &cache->leaves);
443 drop_backref_node(cache, node);
446 static void update_backref_node(struct backref_cache *cache,
447 struct backref_node *node, u64 bytenr)
449 struct rb_node *rb_node;
450 rb_erase(&node->rb_node, &cache->rb_root);
451 node->bytenr = bytenr;
452 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
457 * update backref cache after a transaction commit
459 static int update_backref_cache(struct btrfs_trans_handle *trans,
460 struct backref_cache *cache)
462 struct backref_node *node;
465 if (cache->last_trans == 0) {
466 cache->last_trans = trans->transid;
470 if (cache->last_trans == trans->transid)
474 * detached nodes are used to avoid unnecessary backref
475 * lookup. transaction commit changes the extent tree.
476 * so the detached nodes are no longer useful.
478 while (!list_empty(&cache->detached)) {
479 node = list_entry(cache->detached.next,
480 struct backref_node, list);
481 remove_backref_node(cache, node);
484 while (!list_empty(&cache->changed)) {
485 node = list_entry(cache->changed.next,
486 struct backref_node, list);
487 list_del_init(&node->list);
488 BUG_ON(node->pending);
489 update_backref_node(cache, node, node->new_bytenr);
493 * some nodes can be left in the pending list if there were
494 * errors during processing the pending nodes.
496 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
497 list_for_each_entry(node, &cache->pending[level], list) {
498 BUG_ON(!node->pending);
499 if (node->bytenr == node->new_bytenr)
501 update_backref_node(cache, node, node->new_bytenr);
505 cache->last_trans = 0;
509 static int should_ignore_root(struct btrfs_root *root)
511 struct btrfs_root *reloc_root;
516 reloc_root = root->reloc_root;
520 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
521 root->fs_info->running_transaction->transid - 1)
524 * if there is reloc tree and it was created in previous
525 * transaction backref lookup can find the reloc tree,
526 * so backref node for the fs tree root is useless for
533 * find reloc tree by address of tree root
535 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
538 struct rb_node *rb_node;
539 struct mapping_node *node;
540 struct btrfs_root *root = NULL;
542 spin_lock(&rc->reloc_root_tree.lock);
543 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
545 node = rb_entry(rb_node, struct mapping_node, rb_node);
546 root = (struct btrfs_root *)node->data;
548 spin_unlock(&rc->reloc_root_tree.lock);
552 static int is_cowonly_root(u64 root_objectid)
554 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
555 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
556 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
557 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
558 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
559 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
564 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
567 struct btrfs_key key;
569 key.objectid = root_objectid;
570 key.type = BTRFS_ROOT_ITEM_KEY;
571 if (is_cowonly_root(root_objectid))
574 key.offset = (u64)-1;
576 return btrfs_read_fs_root_no_name(fs_info, &key);
579 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
580 static noinline_for_stack
581 struct btrfs_root *find_tree_root(struct reloc_control *rc,
582 struct extent_buffer *leaf,
583 struct btrfs_extent_ref_v0 *ref0)
585 struct btrfs_root *root;
586 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
587 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
589 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
591 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
592 BUG_ON(IS_ERR(root));
594 if (root->ref_cows &&
595 generation != btrfs_root_generation(&root->root_item))
602 static noinline_for_stack
603 int find_inline_backref(struct extent_buffer *leaf, int slot,
604 unsigned long *ptr, unsigned long *end)
606 struct btrfs_extent_item *ei;
607 struct btrfs_tree_block_info *bi;
610 item_size = btrfs_item_size_nr(leaf, slot);
611 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
612 if (item_size < sizeof(*ei)) {
613 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
617 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
618 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
619 BTRFS_EXTENT_FLAG_TREE_BLOCK));
621 if (item_size <= sizeof(*ei) + sizeof(*bi)) {
622 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
626 bi = (struct btrfs_tree_block_info *)(ei + 1);
627 *ptr = (unsigned long)(bi + 1);
628 *end = (unsigned long)ei + item_size;
633 * build backref tree for a given tree block. root of the backref tree
634 * corresponds the tree block, leaves of the backref tree correspond
635 * roots of b-trees that reference the tree block.
637 * the basic idea of this function is check backrefs of a given block
638 * to find upper level blocks that refernece the block, and then check
639 * bakcrefs of these upper level blocks recursively. the recursion stop
640 * when tree root is reached or backrefs for the block is cached.
642 * NOTE: if we find backrefs for a block are cached, we know backrefs
643 * for all upper level blocks that directly/indirectly reference the
644 * block are also cached.
646 static noinline_for_stack
647 struct backref_node *build_backref_tree(struct reloc_control *rc,
648 struct btrfs_key *node_key,
649 int level, u64 bytenr)
651 struct backref_cache *cache = &rc->backref_cache;
652 struct btrfs_path *path1;
653 struct btrfs_path *path2;
654 struct extent_buffer *eb;
655 struct btrfs_root *root;
656 struct backref_node *cur;
657 struct backref_node *upper;
658 struct backref_node *lower;
659 struct backref_node *node = NULL;
660 struct backref_node *exist = NULL;
661 struct backref_edge *edge;
662 struct rb_node *rb_node;
663 struct btrfs_key key;
672 path1 = btrfs_alloc_path();
673 path2 = btrfs_alloc_path();
674 if (!path1 || !path2) {
679 node = alloc_backref_node(cache);
685 node->bytenr = bytenr;
692 key.objectid = cur->bytenr;
693 key.type = BTRFS_EXTENT_ITEM_KEY;
694 key.offset = (u64)-1;
696 path1->search_commit_root = 1;
697 path1->skip_locking = 1;
698 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
704 BUG_ON(!ret || !path1->slots[0]);
708 WARN_ON(cur->checked);
709 if (!list_empty(&cur->upper)) {
711 * the backref was added previously when processsing
712 * backref of type BTRFS_TREE_BLOCK_REF_KEY
714 BUG_ON(!list_is_singular(&cur->upper));
715 edge = list_entry(cur->upper.next, struct backref_edge,
717 BUG_ON(!list_empty(&edge->list[UPPER]));
718 exist = edge->node[UPPER];
720 * add the upper level block to pending list if we need
724 list_add_tail(&edge->list[UPPER], &list);
731 eb = path1->nodes[0];
734 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
735 ret = btrfs_next_leaf(rc->extent_root, path1);
742 eb = path1->nodes[0];
745 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
746 if (key.objectid != cur->bytenr) {
751 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
752 ret = find_inline_backref(eb, path1->slots[0],
760 /* update key for inline back ref */
761 struct btrfs_extent_inline_ref *iref;
762 iref = (struct btrfs_extent_inline_ref *)ptr;
763 key.type = btrfs_extent_inline_ref_type(eb, iref);
764 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
765 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
766 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
770 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
771 exist->owner == key.offset) ||
772 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
773 exist->bytenr == key.offset))) {
778 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
779 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
780 key.type == BTRFS_EXTENT_REF_V0_KEY) {
781 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
782 struct btrfs_extent_ref_v0 *ref0;
783 ref0 = btrfs_item_ptr(eb, path1->slots[0],
784 struct btrfs_extent_ref_v0);
785 if (key.objectid == key.offset) {
786 root = find_tree_root(rc, eb, ref0);
787 if (root && !should_ignore_root(root))
790 list_add(&cur->list, &useless);
793 if (is_cowonly_root(btrfs_ref_root_v0(eb,
798 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
799 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
801 if (key.objectid == key.offset) {
803 * only root blocks of reloc trees use
804 * backref of this type.
806 root = find_reloc_root(rc, cur->bytenr);
812 edge = alloc_backref_edge(cache);
817 rb_node = tree_search(&cache->rb_root, key.offset);
819 upper = alloc_backref_node(cache);
821 free_backref_edge(cache, edge);
825 upper->bytenr = key.offset;
826 upper->level = cur->level + 1;
828 * backrefs for the upper level block isn't
829 * cached, add the block to pending list
831 list_add_tail(&edge->list[UPPER], &list);
833 upper = rb_entry(rb_node, struct backref_node,
835 BUG_ON(!upper->checked);
836 INIT_LIST_HEAD(&edge->list[UPPER]);
838 list_add_tail(&edge->list[LOWER], &cur->upper);
839 edge->node[LOWER] = cur;
840 edge->node[UPPER] = upper;
843 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
847 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
848 root = read_fs_root(rc->extent_root->fs_info, key.offset);
857 if (btrfs_root_level(&root->root_item) == cur->level) {
859 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
861 if (should_ignore_root(root))
862 list_add(&cur->list, &useless);
868 level = cur->level + 1;
871 * searching the tree to find upper level blocks
872 * reference the block.
874 path2->search_commit_root = 1;
875 path2->skip_locking = 1;
876 path2->lowest_level = level;
877 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
878 path2->lowest_level = 0;
883 if (ret > 0 && path2->slots[level] > 0)
884 path2->slots[level]--;
886 eb = path2->nodes[level];
887 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
891 for (; level < BTRFS_MAX_LEVEL; level++) {
892 if (!path2->nodes[level]) {
893 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
895 if (should_ignore_root(root))
896 list_add(&lower->list, &useless);
902 edge = alloc_backref_edge(cache);
908 eb = path2->nodes[level];
909 rb_node = tree_search(&cache->rb_root, eb->start);
911 upper = alloc_backref_node(cache);
913 free_backref_edge(cache, edge);
917 upper->bytenr = eb->start;
918 upper->owner = btrfs_header_owner(eb);
919 upper->level = lower->level + 1;
924 * if we know the block isn't shared
925 * we can void checking its backrefs.
927 if (btrfs_block_can_be_shared(root, eb))
933 * add the block to pending list if we
934 * need check its backrefs. only block
935 * at 'cur->level + 1' is added to the
936 * tail of pending list. this guarantees
937 * we check backrefs from lower level
938 * blocks to upper level blocks.
940 if (!upper->checked &&
941 level == cur->level + 1) {
942 list_add_tail(&edge->list[UPPER],
945 INIT_LIST_HEAD(&edge->list[UPPER]);
947 upper = rb_entry(rb_node, struct backref_node,
949 BUG_ON(!upper->checked);
950 INIT_LIST_HEAD(&edge->list[UPPER]);
952 upper->owner = btrfs_header_owner(eb);
954 list_add_tail(&edge->list[LOWER], &lower->upper);
955 edge->node[LOWER] = lower;
956 edge->node[UPPER] = upper;
963 btrfs_release_path(root, path2);
966 ptr += btrfs_extent_inline_ref_size(key.type);
976 btrfs_release_path(rc->extent_root, path1);
981 /* the pending list isn't empty, take the first block to process */
982 if (!list_empty(&list)) {
983 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
984 list_del_init(&edge->list[UPPER]);
985 cur = edge->node[UPPER];
990 * everything goes well, connect backref nodes and insert backref nodes
993 BUG_ON(!node->checked);
994 cowonly = node->cowonly;
996 rb_node = tree_insert(&cache->rb_root, node->bytenr,
999 list_add_tail(&node->lower, &cache->leaves);
1002 list_for_each_entry(edge, &node->upper, list[LOWER])
1003 list_add_tail(&edge->list[UPPER], &list);
1005 while (!list_empty(&list)) {
1006 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1007 list_del_init(&edge->list[UPPER]);
1008 upper = edge->node[UPPER];
1009 if (upper->detached) {
1010 list_del(&edge->list[LOWER]);
1011 lower = edge->node[LOWER];
1012 free_backref_edge(cache, edge);
1013 if (list_empty(&lower->upper))
1014 list_add(&lower->list, &useless);
1018 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1019 if (upper->lowest) {
1020 list_del_init(&upper->lower);
1024 list_add_tail(&edge->list[UPPER], &upper->lower);
1028 BUG_ON(!upper->checked);
1029 BUG_ON(cowonly != upper->cowonly);
1031 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1036 list_add_tail(&edge->list[UPPER], &upper->lower);
1038 list_for_each_entry(edge, &upper->upper, list[LOWER])
1039 list_add_tail(&edge->list[UPPER], &list);
1042 * process useless backref nodes. backref nodes for tree leaves
1043 * are deleted from the cache. backref nodes for upper level
1044 * tree blocks are left in the cache to avoid unnecessary backref
1047 while (!list_empty(&useless)) {
1048 upper = list_entry(useless.next, struct backref_node, list);
1049 list_del_init(&upper->list);
1050 BUG_ON(!list_empty(&upper->upper));
1053 if (upper->lowest) {
1054 list_del_init(&upper->lower);
1057 while (!list_empty(&upper->lower)) {
1058 edge = list_entry(upper->lower.next,
1059 struct backref_edge, list[UPPER]);
1060 list_del(&edge->list[UPPER]);
1061 list_del(&edge->list[LOWER]);
1062 lower = edge->node[LOWER];
1063 free_backref_edge(cache, edge);
1065 if (list_empty(&lower->upper))
1066 list_add(&lower->list, &useless);
1068 __mark_block_processed(rc, upper);
1069 if (upper->level > 0) {
1070 list_add(&upper->list, &cache->detached);
1071 upper->detached = 1;
1073 rb_erase(&upper->rb_node, &cache->rb_root);
1074 free_backref_node(cache, upper);
1078 btrfs_free_path(path1);
1079 btrfs_free_path(path2);
1081 while (!list_empty(&useless)) {
1082 lower = list_entry(useless.next,
1083 struct backref_node, upper);
1084 list_del_init(&lower->upper);
1087 INIT_LIST_HEAD(&list);
1089 if (RB_EMPTY_NODE(&upper->rb_node)) {
1090 list_splice_tail(&upper->upper, &list);
1091 free_backref_node(cache, upper);
1094 if (list_empty(&list))
1097 edge = list_entry(list.next, struct backref_edge,
1099 list_del(&edge->list[LOWER]);
1100 upper = edge->node[UPPER];
1101 free_backref_edge(cache, edge);
1103 return ERR_PTR(err);
1105 BUG_ON(node && node->detached);
1110 * helper to add backref node for the newly created snapshot.
1111 * the backref node is created by cloning backref node that
1112 * corresponds to root of source tree
1114 static int clone_backref_node(struct btrfs_trans_handle *trans,
1115 struct reloc_control *rc,
1116 struct btrfs_root *src,
1117 struct btrfs_root *dest)
1119 struct btrfs_root *reloc_root = src->reloc_root;
1120 struct backref_cache *cache = &rc->backref_cache;
1121 struct backref_node *node = NULL;
1122 struct backref_node *new_node;
1123 struct backref_edge *edge;
1124 struct backref_edge *new_edge;
1125 struct rb_node *rb_node;
1127 if (cache->last_trans > 0)
1128 update_backref_cache(trans, cache);
1130 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1132 node = rb_entry(rb_node, struct backref_node, rb_node);
1136 BUG_ON(node->new_bytenr != reloc_root->node->start);
1140 rb_node = tree_search(&cache->rb_root,
1141 reloc_root->commit_root->start);
1143 node = rb_entry(rb_node, struct backref_node,
1145 BUG_ON(node->detached);
1152 new_node = alloc_backref_node(cache);
1156 new_node->bytenr = dest->node->start;
1157 new_node->level = node->level;
1158 new_node->lowest = node->lowest;
1159 new_node->root = dest;
1161 if (!node->lowest) {
1162 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1163 new_edge = alloc_backref_edge(cache);
1167 new_edge->node[UPPER] = new_node;
1168 new_edge->node[LOWER] = edge->node[LOWER];
1169 list_add_tail(&new_edge->list[UPPER],
1174 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1175 &new_node->rb_node);
1178 if (!new_node->lowest) {
1179 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1180 list_add_tail(&new_edge->list[LOWER],
1181 &new_edge->node[LOWER]->upper);
1186 while (!list_empty(&new_node->lower)) {
1187 new_edge = list_entry(new_node->lower.next,
1188 struct backref_edge, list[UPPER]);
1189 list_del(&new_edge->list[UPPER]);
1190 free_backref_edge(cache, new_edge);
1192 free_backref_node(cache, new_node);
1197 * helper to add 'address of tree root -> reloc tree' mapping
1199 static int __add_reloc_root(struct btrfs_root *root)
1201 struct rb_node *rb_node;
1202 struct mapping_node *node;
1203 struct reloc_control *rc = root->fs_info->reloc_ctl;
1205 node = kmalloc(sizeof(*node), GFP_NOFS);
1208 node->bytenr = root->node->start;
1211 spin_lock(&rc->reloc_root_tree.lock);
1212 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1213 node->bytenr, &node->rb_node);
1214 spin_unlock(&rc->reloc_root_tree.lock);
1217 list_add_tail(&root->root_list, &rc->reloc_roots);
1222 * helper to update/delete the 'address of tree root -> reloc tree'
1225 static int __update_reloc_root(struct btrfs_root *root, int del)
1227 struct rb_node *rb_node;
1228 struct mapping_node *node = NULL;
1229 struct reloc_control *rc = root->fs_info->reloc_ctl;
1231 spin_lock(&rc->reloc_root_tree.lock);
1232 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1233 root->commit_root->start);
1235 node = rb_entry(rb_node, struct mapping_node, rb_node);
1236 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1238 spin_unlock(&rc->reloc_root_tree.lock);
1240 BUG_ON((struct btrfs_root *)node->data != root);
1243 spin_lock(&rc->reloc_root_tree.lock);
1244 node->bytenr = root->node->start;
1245 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1246 node->bytenr, &node->rb_node);
1247 spin_unlock(&rc->reloc_root_tree.lock);
1250 list_del_init(&root->root_list);
1256 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1257 struct btrfs_root *root, u64 objectid)
1259 struct btrfs_root *reloc_root;
1260 struct extent_buffer *eb;
1261 struct btrfs_root_item *root_item;
1262 struct btrfs_key root_key;
1265 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1268 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1269 root_key.type = BTRFS_ROOT_ITEM_KEY;
1270 root_key.offset = objectid;
1272 if (root->root_key.objectid == objectid) {
1273 /* called by btrfs_init_reloc_root */
1274 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1275 BTRFS_TREE_RELOC_OBJECTID);
1278 btrfs_set_root_last_snapshot(&root->root_item,
1279 trans->transid - 1);
1282 * called by btrfs_reloc_post_snapshot_hook.
1283 * the source tree is a reloc tree, all tree blocks
1284 * modified after it was created have RELOC flag
1285 * set in their headers. so it's OK to not update
1286 * the 'last_snapshot'.
1288 ret = btrfs_copy_root(trans, root, root->node, &eb,
1289 BTRFS_TREE_RELOC_OBJECTID);
1293 memcpy(root_item, &root->root_item, sizeof(*root_item));
1294 btrfs_set_root_bytenr(root_item, eb->start);
1295 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1296 btrfs_set_root_generation(root_item, trans->transid);
1298 if (root->root_key.objectid == objectid) {
1299 btrfs_set_root_refs(root_item, 0);
1300 memset(&root_item->drop_progress, 0,
1301 sizeof(struct btrfs_disk_key));
1302 root_item->drop_level = 0;
1305 btrfs_tree_unlock(eb);
1306 free_extent_buffer(eb);
1308 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1309 &root_key, root_item);
1313 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
1315 BUG_ON(IS_ERR(reloc_root));
1316 reloc_root->last_trans = trans->transid;
1321 * create reloc tree for a given fs tree. reloc tree is just a
1322 * snapshot of the fs tree with special root objectid.
1324 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1325 struct btrfs_root *root)
1327 struct btrfs_root *reloc_root;
1328 struct reloc_control *rc = root->fs_info->reloc_ctl;
1331 if (root->reloc_root) {
1332 reloc_root = root->reloc_root;
1333 reloc_root->last_trans = trans->transid;
1337 if (!rc || !rc->create_reloc_tree ||
1338 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1341 if (!trans->block_rsv) {
1342 trans->block_rsv = rc->block_rsv;
1345 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1347 trans->block_rsv = NULL;
1349 __add_reloc_root(reloc_root);
1350 root->reloc_root = reloc_root;
1355 * update root item of reloc tree
1357 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1358 struct btrfs_root *root)
1360 struct btrfs_root *reloc_root;
1361 struct btrfs_root_item *root_item;
1365 if (!root->reloc_root)
1368 reloc_root = root->reloc_root;
1369 root_item = &reloc_root->root_item;
1371 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1372 btrfs_root_refs(root_item) == 0) {
1373 root->reloc_root = NULL;
1377 __update_reloc_root(reloc_root, del);
1379 if (reloc_root->commit_root != reloc_root->node) {
1380 btrfs_set_root_node(root_item, reloc_root->node);
1381 free_extent_buffer(reloc_root->commit_root);
1382 reloc_root->commit_root = btrfs_root_node(reloc_root);
1385 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1386 &reloc_root->root_key, root_item);
1392 * helper to find first cached inode with inode number >= objectid
1395 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1397 struct rb_node *node;
1398 struct rb_node *prev;
1399 struct btrfs_inode *entry;
1400 struct inode *inode;
1402 spin_lock(&root->inode_lock);
1404 node = root->inode_tree.rb_node;
1408 entry = rb_entry(node, struct btrfs_inode, rb_node);
1410 if (objectid < entry->vfs_inode.i_ino)
1411 node = node->rb_left;
1412 else if (objectid > entry->vfs_inode.i_ino)
1413 node = node->rb_right;
1419 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1420 if (objectid <= entry->vfs_inode.i_ino) {
1424 prev = rb_next(prev);
1428 entry = rb_entry(node, struct btrfs_inode, rb_node);
1429 inode = igrab(&entry->vfs_inode);
1431 spin_unlock(&root->inode_lock);
1435 objectid = entry->vfs_inode.i_ino + 1;
1436 if (cond_resched_lock(&root->inode_lock))
1439 node = rb_next(node);
1441 spin_unlock(&root->inode_lock);
1445 static int in_block_group(u64 bytenr,
1446 struct btrfs_block_group_cache *block_group)
1448 if (bytenr >= block_group->key.objectid &&
1449 bytenr < block_group->key.objectid + block_group->key.offset)
1455 * get new location of data
1457 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1458 u64 bytenr, u64 num_bytes)
1460 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1461 struct btrfs_path *path;
1462 struct btrfs_file_extent_item *fi;
1463 struct extent_buffer *leaf;
1466 path = btrfs_alloc_path();
1470 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1471 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
1480 leaf = path->nodes[0];
1481 fi = btrfs_item_ptr(leaf, path->slots[0],
1482 struct btrfs_file_extent_item);
1484 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1485 btrfs_file_extent_compression(leaf, fi) ||
1486 btrfs_file_extent_encryption(leaf, fi) ||
1487 btrfs_file_extent_other_encoding(leaf, fi));
1489 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1494 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1497 btrfs_free_path(path);
1502 * update file extent items in the tree leaf to point to
1503 * the new locations.
1505 static noinline_for_stack
1506 int replace_file_extents(struct btrfs_trans_handle *trans,
1507 struct reloc_control *rc,
1508 struct btrfs_root *root,
1509 struct extent_buffer *leaf)
1511 struct btrfs_key key;
1512 struct btrfs_file_extent_item *fi;
1513 struct inode *inode = NULL;
1525 if (rc->stage != UPDATE_DATA_PTRS)
1528 /* reloc trees always use full backref */
1529 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1530 parent = leaf->start;
1534 nritems = btrfs_header_nritems(leaf);
1535 for (i = 0; i < nritems; i++) {
1537 btrfs_item_key_to_cpu(leaf, &key, i);
1538 if (key.type != BTRFS_EXTENT_DATA_KEY)
1540 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1541 if (btrfs_file_extent_type(leaf, fi) ==
1542 BTRFS_FILE_EXTENT_INLINE)
1544 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1545 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1548 if (!in_block_group(bytenr, rc->block_group))
1552 * if we are modifying block in fs tree, wait for readpage
1553 * to complete and drop the extent cache
1555 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1557 inode = find_next_inode(root, key.objectid);
1559 } else if (inode && inode->i_ino < key.objectid) {
1560 btrfs_add_delayed_iput(inode);
1561 inode = find_next_inode(root, key.objectid);
1563 if (inode && inode->i_ino == key.objectid) {
1565 btrfs_file_extent_num_bytes(leaf, fi);
1566 WARN_ON(!IS_ALIGNED(key.offset,
1568 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1570 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1576 btrfs_drop_extent_cache(inode, key.offset, end,
1578 unlock_extent(&BTRFS_I(inode)->io_tree,
1579 key.offset, end, GFP_NOFS);
1583 ret = get_new_location(rc->data_inode, &new_bytenr,
1591 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1594 key.offset -= btrfs_file_extent_offset(leaf, fi);
1595 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1597 btrfs_header_owner(leaf),
1598 key.objectid, key.offset);
1601 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1602 parent, btrfs_header_owner(leaf),
1603 key.objectid, key.offset);
1607 btrfs_mark_buffer_dirty(leaf);
1609 btrfs_add_delayed_iput(inode);
1613 static noinline_for_stack
1614 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1615 struct btrfs_path *path, int level)
1617 struct btrfs_disk_key key1;
1618 struct btrfs_disk_key key2;
1619 btrfs_node_key(eb, &key1, slot);
1620 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1621 return memcmp(&key1, &key2, sizeof(key1));
1625 * try to replace tree blocks in fs tree with the new blocks
1626 * in reloc tree. tree blocks haven't been modified since the
1627 * reloc tree was create can be replaced.
1629 * if a block was replaced, level of the block + 1 is returned.
1630 * if no block got replaced, 0 is returned. if there are other
1631 * errors, a negative error number is returned.
1633 static noinline_for_stack
1634 int replace_path(struct btrfs_trans_handle *trans,
1635 struct btrfs_root *dest, struct btrfs_root *src,
1636 struct btrfs_path *path, struct btrfs_key *next_key,
1637 int lowest_level, int max_level)
1639 struct extent_buffer *eb;
1640 struct extent_buffer *parent;
1641 struct btrfs_key key;
1653 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1654 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1656 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1658 slot = path->slots[lowest_level];
1659 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1661 eb = btrfs_lock_root_node(dest);
1662 btrfs_set_lock_blocking(eb);
1663 level = btrfs_header_level(eb);
1665 if (level < lowest_level) {
1666 btrfs_tree_unlock(eb);
1667 free_extent_buffer(eb);
1672 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1675 btrfs_set_lock_blocking(eb);
1678 next_key->objectid = (u64)-1;
1679 next_key->type = (u8)-1;
1680 next_key->offset = (u64)-1;
1685 level = btrfs_header_level(parent);
1686 BUG_ON(level < lowest_level);
1688 ret = btrfs_bin_search(parent, &key, level, &slot);
1689 if (ret && slot > 0)
1692 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1693 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1695 old_bytenr = btrfs_node_blockptr(parent, slot);
1696 blocksize = btrfs_level_size(dest, level - 1);
1697 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1699 if (level <= max_level) {
1700 eb = path->nodes[level];
1701 new_bytenr = btrfs_node_blockptr(eb,
1702 path->slots[level]);
1703 new_ptr_gen = btrfs_node_ptr_generation(eb,
1704 path->slots[level]);
1710 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1716 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1717 memcmp_node_keys(parent, slot, path, level)) {
1718 if (level <= lowest_level) {
1723 eb = read_tree_block(dest, old_bytenr, blocksize,
1725 btrfs_tree_lock(eb);
1727 ret = btrfs_cow_block(trans, dest, eb, parent,
1731 btrfs_set_lock_blocking(eb);
1733 btrfs_tree_unlock(parent);
1734 free_extent_buffer(parent);
1741 btrfs_tree_unlock(parent);
1742 free_extent_buffer(parent);
1747 btrfs_node_key_to_cpu(path->nodes[level], &key,
1748 path->slots[level]);
1749 btrfs_release_path(src, path);
1751 path->lowest_level = level;
1752 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1753 path->lowest_level = 0;
1757 * swap blocks in fs tree and reloc tree.
1759 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1760 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1761 btrfs_mark_buffer_dirty(parent);
1763 btrfs_set_node_blockptr(path->nodes[level],
1764 path->slots[level], old_bytenr);
1765 btrfs_set_node_ptr_generation(path->nodes[level],
1766 path->slots[level], old_ptr_gen);
1767 btrfs_mark_buffer_dirty(path->nodes[level]);
1769 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1770 path->nodes[level]->start,
1771 src->root_key.objectid, level - 1, 0);
1773 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1774 0, dest->root_key.objectid, level - 1,
1778 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1779 path->nodes[level]->start,
1780 src->root_key.objectid, level - 1, 0);
1783 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1784 0, dest->root_key.objectid, level - 1,
1788 btrfs_unlock_up_safe(path, 0);
1793 btrfs_tree_unlock(parent);
1794 free_extent_buffer(parent);
1799 * helper to find next relocated block in reloc tree
1801 static noinline_for_stack
1802 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1805 struct extent_buffer *eb;
1810 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1812 for (i = 0; i < *level; i++) {
1813 free_extent_buffer(path->nodes[i]);
1814 path->nodes[i] = NULL;
1817 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1818 eb = path->nodes[i];
1819 nritems = btrfs_header_nritems(eb);
1820 while (path->slots[i] + 1 < nritems) {
1822 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1829 free_extent_buffer(path->nodes[i]);
1830 path->nodes[i] = NULL;
1836 * walk down reloc tree to find relocated block of lowest level
1838 static noinline_for_stack
1839 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1842 struct extent_buffer *eb = NULL;
1850 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1852 for (i = *level; i > 0; i--) {
1853 eb = path->nodes[i];
1854 nritems = btrfs_header_nritems(eb);
1855 while (path->slots[i] < nritems) {
1856 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1857 if (ptr_gen > last_snapshot)
1861 if (path->slots[i] >= nritems) {
1872 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1873 blocksize = btrfs_level_size(root, i - 1);
1874 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1875 BUG_ON(btrfs_header_level(eb) != i - 1);
1876 path->nodes[i - 1] = eb;
1877 path->slots[i - 1] = 0;
1883 * invalidate extent cache for file extents whose key in range of
1884 * [min_key, max_key)
1886 static int invalidate_extent_cache(struct btrfs_root *root,
1887 struct btrfs_key *min_key,
1888 struct btrfs_key *max_key)
1890 struct inode *inode = NULL;
1894 objectid = min_key->objectid;
1899 if (objectid > max_key->objectid)
1902 inode = find_next_inode(root, objectid);
1906 if (inode->i_ino > max_key->objectid) {
1911 objectid = inode->i_ino + 1;
1912 if (!S_ISREG(inode->i_mode))
1915 if (unlikely(min_key->objectid == inode->i_ino)) {
1916 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1918 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1921 start = min_key->offset;
1922 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1928 if (unlikely(max_key->objectid == inode->i_ino)) {
1929 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1931 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
1934 if (max_key->offset == 0)
1936 end = max_key->offset;
1937 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1944 /* the lock_extent waits for readpage to complete */
1945 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1946 btrfs_drop_extent_cache(inode, start, end, 1);
1947 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1952 static int find_next_key(struct btrfs_path *path, int level,
1953 struct btrfs_key *key)
1956 while (level < BTRFS_MAX_LEVEL) {
1957 if (!path->nodes[level])
1959 if (path->slots[level] + 1 <
1960 btrfs_header_nritems(path->nodes[level])) {
1961 btrfs_node_key_to_cpu(path->nodes[level], key,
1962 path->slots[level] + 1);
1971 * merge the relocated tree blocks in reloc tree with corresponding
1974 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
1975 struct btrfs_root *root)
1977 LIST_HEAD(inode_list);
1978 struct btrfs_key key;
1979 struct btrfs_key next_key;
1980 struct btrfs_trans_handle *trans;
1981 struct btrfs_root *reloc_root;
1982 struct btrfs_root_item *root_item;
1983 struct btrfs_path *path;
1984 struct extent_buffer *leaf;
1993 path = btrfs_alloc_path();
1997 reloc_root = root->reloc_root;
1998 root_item = &reloc_root->root_item;
2000 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2001 level = btrfs_root_level(root_item);
2002 extent_buffer_get(reloc_root->node);
2003 path->nodes[level] = reloc_root->node;
2004 path->slots[level] = 0;
2006 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2008 level = root_item->drop_level;
2010 path->lowest_level = level;
2011 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2012 path->lowest_level = 0;
2014 btrfs_free_path(path);
2018 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2019 path->slots[level]);
2020 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2022 btrfs_unlock_up_safe(path, 0);
2025 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2026 memset(&next_key, 0, sizeof(next_key));
2029 trans = btrfs_start_transaction(root, 0);
2030 trans->block_rsv = rc->block_rsv;
2032 ret = btrfs_block_rsv_check(trans, root, rc->block_rsv,
2035 BUG_ON(ret != -EAGAIN);
2036 ret = btrfs_commit_transaction(trans, root);
2044 ret = walk_down_reloc_tree(reloc_root, path, &level);
2052 if (!find_next_key(path, level, &key) &&
2053 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2056 ret = replace_path(trans, root, reloc_root, path,
2057 &next_key, level, max_level);
2066 btrfs_node_key_to_cpu(path->nodes[level], &key,
2067 path->slots[level]);
2071 ret = walk_up_reloc_tree(reloc_root, path, &level);
2077 * save the merging progress in the drop_progress.
2078 * this is OK since root refs == 1 in this case.
2080 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2081 path->slots[level]);
2082 root_item->drop_level = level;
2084 nr = trans->blocks_used;
2085 btrfs_end_transaction_throttle(trans, root);
2087 btrfs_btree_balance_dirty(root, nr);
2089 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2090 invalidate_extent_cache(root, &key, &next_key);
2094 * handle the case only one block in the fs tree need to be
2095 * relocated and the block is tree root.
2097 leaf = btrfs_lock_root_node(root);
2098 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2099 btrfs_tree_unlock(leaf);
2100 free_extent_buffer(leaf);
2104 btrfs_free_path(path);
2107 memset(&root_item->drop_progress, 0,
2108 sizeof(root_item->drop_progress));
2109 root_item->drop_level = 0;
2110 btrfs_set_root_refs(root_item, 0);
2111 btrfs_update_reloc_root(trans, root);
2114 nr = trans->blocks_used;
2115 btrfs_end_transaction_throttle(trans, root);
2117 btrfs_btree_balance_dirty(root, nr);
2119 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2120 invalidate_extent_cache(root, &key, &next_key);
2125 static noinline_for_stack
2126 int prepare_to_merge(struct reloc_control *rc, int err)
2128 struct btrfs_root *root = rc->extent_root;
2129 struct btrfs_root *reloc_root;
2130 struct btrfs_trans_handle *trans;
2131 LIST_HEAD(reloc_roots);
2135 mutex_lock(&root->fs_info->trans_mutex);
2136 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2137 rc->merging_rsv_size += rc->nodes_relocated * 2;
2138 mutex_unlock(&root->fs_info->trans_mutex);
2141 num_bytes = rc->merging_rsv_size;
2142 ret = btrfs_block_rsv_add(NULL, root, rc->block_rsv,
2148 trans = btrfs_join_transaction(rc->extent_root, 1);
2151 if (num_bytes != rc->merging_rsv_size) {
2152 btrfs_end_transaction(trans, rc->extent_root);
2153 btrfs_block_rsv_release(rc->extent_root,
2154 rc->block_rsv, num_bytes);
2159 rc->merge_reloc_tree = 1;
2161 while (!list_empty(&rc->reloc_roots)) {
2162 reloc_root = list_entry(rc->reloc_roots.next,
2163 struct btrfs_root, root_list);
2164 list_del_init(&reloc_root->root_list);
2166 root = read_fs_root(reloc_root->fs_info,
2167 reloc_root->root_key.offset);
2168 BUG_ON(IS_ERR(root));
2169 BUG_ON(root->reloc_root != reloc_root);
2172 * set reference count to 1, so btrfs_recover_relocation
2173 * knows it should resumes merging
2176 btrfs_set_root_refs(&reloc_root->root_item, 1);
2177 btrfs_update_reloc_root(trans, root);
2179 list_add(&reloc_root->root_list, &reloc_roots);
2182 list_splice(&reloc_roots, &rc->reloc_roots);
2185 btrfs_commit_transaction(trans, rc->extent_root);
2187 btrfs_end_transaction(trans, rc->extent_root);
2191 static noinline_for_stack
2192 int merge_reloc_roots(struct reloc_control *rc)
2194 struct btrfs_root *root;
2195 struct btrfs_root *reloc_root;
2196 LIST_HEAD(reloc_roots);
2200 root = rc->extent_root;
2201 mutex_lock(&root->fs_info->trans_mutex);
2202 list_splice_init(&rc->reloc_roots, &reloc_roots);
2203 mutex_unlock(&root->fs_info->trans_mutex);
2205 while (!list_empty(&reloc_roots)) {
2207 reloc_root = list_entry(reloc_roots.next,
2208 struct btrfs_root, root_list);
2210 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2211 root = read_fs_root(reloc_root->fs_info,
2212 reloc_root->root_key.offset);
2213 BUG_ON(IS_ERR(root));
2214 BUG_ON(root->reloc_root != reloc_root);
2216 ret = merge_reloc_root(rc, root);
2219 list_del_init(&reloc_root->root_list);
2221 btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0);
2228 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2232 static void free_block_list(struct rb_root *blocks)
2234 struct tree_block *block;
2235 struct rb_node *rb_node;
2236 while ((rb_node = rb_first(blocks))) {
2237 block = rb_entry(rb_node, struct tree_block, rb_node);
2238 rb_erase(rb_node, blocks);
2243 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2244 struct btrfs_root *reloc_root)
2246 struct btrfs_root *root;
2248 if (reloc_root->last_trans == trans->transid)
2251 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2252 BUG_ON(IS_ERR(root));
2253 BUG_ON(root->reloc_root != reloc_root);
2255 return btrfs_record_root_in_trans(trans, root);
2258 static noinline_for_stack
2259 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2260 struct reloc_control *rc,
2261 struct backref_node *node,
2262 struct backref_edge *edges[], int *nr)
2264 struct backref_node *next;
2265 struct btrfs_root *root;
2271 next = walk_up_backref(next, edges, &index);
2274 BUG_ON(!root->ref_cows);
2276 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2277 record_reloc_root_in_trans(trans, root);
2281 btrfs_record_root_in_trans(trans, root);
2282 root = root->reloc_root;
2284 if (next->new_bytenr != root->node->start) {
2285 BUG_ON(next->new_bytenr);
2286 BUG_ON(!list_empty(&next->list));
2287 next->new_bytenr = root->node->start;
2289 list_add_tail(&next->list,
2290 &rc->backref_cache.changed);
2291 __mark_block_processed(rc, next);
2297 next = walk_down_backref(edges, &index);
2298 if (!next || next->level <= node->level)
2306 /* setup backref node path for btrfs_reloc_cow_block */
2308 rc->backref_cache.path[next->level] = next;
2311 next = edges[index]->node[UPPER];
2317 * select a tree root for relocation. return NULL if the block
2318 * is reference counted. we should use do_relocation() in this
2319 * case. return a tree root pointer if the block isn't reference
2320 * counted. return -ENOENT if the block is root of reloc tree.
2322 static noinline_for_stack
2323 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2324 struct backref_node *node)
2326 struct backref_node *next;
2327 struct btrfs_root *root;
2328 struct btrfs_root *fs_root = NULL;
2329 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2335 next = walk_up_backref(next, edges, &index);
2339 /* no other choice for non-refernce counted tree */
2340 if (!root->ref_cows)
2343 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2349 next = walk_down_backref(edges, &index);
2350 if (!next || next->level <= node->level)
2355 return ERR_PTR(-ENOENT);
2359 static noinline_for_stack
2360 u64 calcu_metadata_size(struct reloc_control *rc,
2361 struct backref_node *node, int reserve)
2363 struct backref_node *next = node;
2364 struct backref_edge *edge;
2365 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2369 BUG_ON(reserve && node->processed);
2374 if (next->processed && (reserve || next != node))
2377 num_bytes += btrfs_level_size(rc->extent_root,
2380 if (list_empty(&next->upper))
2383 edge = list_entry(next->upper.next,
2384 struct backref_edge, list[LOWER]);
2385 edges[index++] = edge;
2386 next = edge->node[UPPER];
2388 next = walk_down_backref(edges, &index);
2393 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2394 struct reloc_control *rc,
2395 struct backref_node *node)
2397 struct btrfs_root *root = rc->extent_root;
2401 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2403 trans->block_rsv = rc->block_rsv;
2404 ret = btrfs_block_rsv_add(trans, root, rc->block_rsv, num_bytes);
2407 rc->commit_transaction = 1;
2414 static void release_metadata_space(struct reloc_control *rc,
2415 struct backref_node *node)
2417 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2418 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2422 * relocate a block tree, and then update pointers in upper level
2423 * blocks that reference the block to point to the new location.
2425 * if called by link_to_upper, the block has already been relocated.
2426 * in that case this function just updates pointers.
2428 static int do_relocation(struct btrfs_trans_handle *trans,
2429 struct reloc_control *rc,
2430 struct backref_node *node,
2431 struct btrfs_key *key,
2432 struct btrfs_path *path, int lowest)
2434 struct backref_node *upper;
2435 struct backref_edge *edge;
2436 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2437 struct btrfs_root *root;
2438 struct extent_buffer *eb;
2447 BUG_ON(lowest && node->eb);
2449 path->lowest_level = node->level + 1;
2450 rc->backref_cache.path[node->level] = node;
2451 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2454 upper = edge->node[UPPER];
2455 root = select_reloc_root(trans, rc, upper, edges, &nr);
2458 if (upper->eb && !upper->locked) {
2460 ret = btrfs_bin_search(upper->eb, key,
2461 upper->level, &slot);
2463 bytenr = btrfs_node_blockptr(upper->eb, slot);
2464 if (node->eb->start == bytenr)
2467 drop_node_buffer(upper);
2471 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2479 upper->eb = path->nodes[upper->level];
2480 path->nodes[upper->level] = NULL;
2482 BUG_ON(upper->eb != path->nodes[upper->level]);
2486 path->locks[upper->level] = 0;
2488 slot = path->slots[upper->level];
2489 btrfs_release_path(NULL, path);
2491 ret = btrfs_bin_search(upper->eb, key, upper->level,
2496 bytenr = btrfs_node_blockptr(upper->eb, slot);
2498 BUG_ON(bytenr != node->bytenr);
2500 if (node->eb->start == bytenr)
2504 blocksize = btrfs_level_size(root, node->level);
2505 generation = btrfs_node_ptr_generation(upper->eb, slot);
2506 eb = read_tree_block(root, bytenr, blocksize, generation);
2507 btrfs_tree_lock(eb);
2508 btrfs_set_lock_blocking(eb);
2511 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2513 btrfs_tree_unlock(eb);
2514 free_extent_buffer(eb);
2519 BUG_ON(node->eb != eb);
2521 btrfs_set_node_blockptr(upper->eb, slot,
2523 btrfs_set_node_ptr_generation(upper->eb, slot,
2525 btrfs_mark_buffer_dirty(upper->eb);
2527 ret = btrfs_inc_extent_ref(trans, root,
2528 node->eb->start, blocksize,
2530 btrfs_header_owner(upper->eb),
2534 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2538 if (!upper->pending)
2539 drop_node_buffer(upper);
2541 unlock_node_buffer(upper);
2546 if (!err && node->pending) {
2547 drop_node_buffer(node);
2548 list_move_tail(&node->list, &rc->backref_cache.changed);
2552 path->lowest_level = 0;
2553 BUG_ON(err == -ENOSPC);
2557 static int link_to_upper(struct btrfs_trans_handle *trans,
2558 struct reloc_control *rc,
2559 struct backref_node *node,
2560 struct btrfs_path *path)
2562 struct btrfs_key key;
2564 btrfs_node_key_to_cpu(node->eb, &key, 0);
2565 return do_relocation(trans, rc, node, &key, path, 0);
2568 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2569 struct reloc_control *rc,
2570 struct btrfs_path *path, int err)
2573 struct backref_cache *cache = &rc->backref_cache;
2574 struct backref_node *node;
2578 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2579 while (!list_empty(&cache->pending[level])) {
2580 node = list_entry(cache->pending[level].next,
2581 struct backref_node, list);
2582 list_move_tail(&node->list, &list);
2583 BUG_ON(!node->pending);
2586 ret = link_to_upper(trans, rc, node, path);
2591 list_splice_init(&list, &cache->pending[level]);
2596 static void mark_block_processed(struct reloc_control *rc,
2597 u64 bytenr, u32 blocksize)
2599 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2600 EXTENT_DIRTY, GFP_NOFS);
2603 static void __mark_block_processed(struct reloc_control *rc,
2604 struct backref_node *node)
2607 if (node->level == 0 ||
2608 in_block_group(node->bytenr, rc->block_group)) {
2609 blocksize = btrfs_level_size(rc->extent_root, node->level);
2610 mark_block_processed(rc, node->bytenr, blocksize);
2612 node->processed = 1;
2616 * mark a block and all blocks directly/indirectly reference the block
2619 static void update_processed_blocks(struct reloc_control *rc,
2620 struct backref_node *node)
2622 struct backref_node *next = node;
2623 struct backref_edge *edge;
2624 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2630 if (next->processed)
2633 __mark_block_processed(rc, next);
2635 if (list_empty(&next->upper))
2638 edge = list_entry(next->upper.next,
2639 struct backref_edge, list[LOWER]);
2640 edges[index++] = edge;
2641 next = edge->node[UPPER];
2643 next = walk_down_backref(edges, &index);
2647 static int tree_block_processed(u64 bytenr, u32 blocksize,
2648 struct reloc_control *rc)
2650 if (test_range_bit(&rc->processed_blocks, bytenr,
2651 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2656 static int get_tree_block_key(struct reloc_control *rc,
2657 struct tree_block *block)
2659 struct extent_buffer *eb;
2661 BUG_ON(block->key_ready);
2662 eb = read_tree_block(rc->extent_root, block->bytenr,
2663 block->key.objectid, block->key.offset);
2664 WARN_ON(btrfs_header_level(eb) != block->level);
2665 if (block->level == 0)
2666 btrfs_item_key_to_cpu(eb, &block->key, 0);
2668 btrfs_node_key_to_cpu(eb, &block->key, 0);
2669 free_extent_buffer(eb);
2670 block->key_ready = 1;
2674 static int reada_tree_block(struct reloc_control *rc,
2675 struct tree_block *block)
2677 BUG_ON(block->key_ready);
2678 readahead_tree_block(rc->extent_root, block->bytenr,
2679 block->key.objectid, block->key.offset);
2684 * helper function to relocate a tree block
2686 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2687 struct reloc_control *rc,
2688 struct backref_node *node,
2689 struct btrfs_key *key,
2690 struct btrfs_path *path)
2692 struct btrfs_root *root;
2699 BUG_ON(node->processed);
2700 root = select_one_root(trans, node);
2701 if (root == ERR_PTR(-ENOENT)) {
2702 update_processed_blocks(rc, node);
2706 if (!root || root->ref_cows) {
2707 ret = reserve_metadata_space(trans, rc, node);
2714 if (root->ref_cows) {
2715 BUG_ON(node->new_bytenr);
2716 BUG_ON(!list_empty(&node->list));
2717 btrfs_record_root_in_trans(trans, root);
2718 root = root->reloc_root;
2719 node->new_bytenr = root->node->start;
2721 list_add_tail(&node->list, &rc->backref_cache.changed);
2723 path->lowest_level = node->level;
2724 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2725 btrfs_release_path(root, path);
2730 update_processed_blocks(rc, node);
2732 ret = do_relocation(trans, rc, node, key, path, 1);
2735 if (ret || node->level == 0 || node->cowonly) {
2737 release_metadata_space(rc, node);
2738 remove_backref_node(&rc->backref_cache, node);
2744 * relocate a list of blocks
2746 static noinline_for_stack
2747 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2748 struct reloc_control *rc, struct rb_root *blocks)
2750 struct backref_node *node;
2751 struct btrfs_path *path;
2752 struct tree_block *block;
2753 struct rb_node *rb_node;
2757 path = btrfs_alloc_path();
2761 rb_node = rb_first(blocks);
2763 block = rb_entry(rb_node, struct tree_block, rb_node);
2764 if (!block->key_ready)
2765 reada_tree_block(rc, block);
2766 rb_node = rb_next(rb_node);
2769 rb_node = rb_first(blocks);
2771 block = rb_entry(rb_node, struct tree_block, rb_node);
2772 if (!block->key_ready)
2773 get_tree_block_key(rc, block);
2774 rb_node = rb_next(rb_node);
2777 rb_node = rb_first(blocks);
2779 block = rb_entry(rb_node, struct tree_block, rb_node);
2781 node = build_backref_tree(rc, &block->key,
2782 block->level, block->bytenr);
2784 err = PTR_ERR(node);
2788 ret = relocate_tree_block(trans, rc, node, &block->key,
2791 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2795 rb_node = rb_next(rb_node);
2798 free_block_list(blocks);
2799 err = finish_pending_nodes(trans, rc, path, err);
2801 btrfs_free_path(path);
2805 static noinline_for_stack
2806 int prealloc_file_extent_cluster(struct inode *inode,
2807 struct file_extent_cluster *cluster)
2812 u64 offset = BTRFS_I(inode)->index_cnt;
2817 BUG_ON(cluster->start != cluster->boundary[0]);
2818 mutex_lock(&inode->i_mutex);
2820 ret = btrfs_check_data_free_space(inode, cluster->end +
2821 1 - cluster->start);
2825 while (nr < cluster->nr) {
2826 start = cluster->boundary[nr] - offset;
2827 if (nr + 1 < cluster->nr)
2828 end = cluster->boundary[nr + 1] - 1 - offset;
2830 end = cluster->end - offset;
2832 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2833 num_bytes = end + 1 - start;
2834 ret = btrfs_prealloc_file_range(inode, 0, start,
2835 num_bytes, num_bytes,
2836 end + 1, &alloc_hint);
2837 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2842 btrfs_free_reserved_data_space(inode, cluster->end +
2843 1 - cluster->start);
2845 mutex_unlock(&inode->i_mutex);
2849 static noinline_for_stack
2850 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
2853 struct btrfs_root *root = BTRFS_I(inode)->root;
2854 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2855 struct extent_map *em;
2858 em = alloc_extent_map(GFP_NOFS);
2863 em->len = end + 1 - start;
2864 em->block_len = em->len;
2865 em->block_start = block_start;
2866 em->bdev = root->fs_info->fs_devices->latest_bdev;
2867 set_bit(EXTENT_FLAG_PINNED, &em->flags);
2869 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2871 write_lock(&em_tree->lock);
2872 ret = add_extent_mapping(em_tree, em);
2873 write_unlock(&em_tree->lock);
2874 if (ret != -EEXIST) {
2875 free_extent_map(em);
2878 btrfs_drop_extent_cache(inode, start, end, 0);
2880 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2884 static int relocate_file_extent_cluster(struct inode *inode,
2885 struct file_extent_cluster *cluster)
2889 u64 offset = BTRFS_I(inode)->index_cnt;
2890 unsigned long index;
2891 unsigned long last_index;
2893 struct file_ra_state *ra;
2900 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2904 ret = prealloc_file_extent_cluster(inode, cluster);
2908 file_ra_state_init(ra, inode->i_mapping);
2910 ret = setup_extent_mapping(inode, cluster->start - offset,
2911 cluster->end - offset, cluster->start);
2915 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
2916 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
2917 while (index <= last_index) {
2918 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
2922 page = find_lock_page(inode->i_mapping, index);
2924 page_cache_sync_readahead(inode->i_mapping,
2926 last_index + 1 - index);
2927 page = grab_cache_page(inode->i_mapping, index);
2929 btrfs_delalloc_release_metadata(inode,
2936 if (PageReadahead(page)) {
2937 page_cache_async_readahead(inode->i_mapping,
2938 ra, NULL, page, index,
2939 last_index + 1 - index);
2942 if (!PageUptodate(page)) {
2943 btrfs_readpage(NULL, page);
2945 if (!PageUptodate(page)) {
2947 page_cache_release(page);
2948 btrfs_delalloc_release_metadata(inode,
2955 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2956 page_end = page_start + PAGE_CACHE_SIZE - 1;
2958 lock_extent(&BTRFS_I(inode)->io_tree,
2959 page_start, page_end, GFP_NOFS);
2961 set_page_extent_mapped(page);
2963 if (nr < cluster->nr &&
2964 page_start + offset == cluster->boundary[nr]) {
2965 set_extent_bits(&BTRFS_I(inode)->io_tree,
2966 page_start, page_end,
2967 EXTENT_BOUNDARY, GFP_NOFS);
2971 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
2972 set_page_dirty(page);
2974 unlock_extent(&BTRFS_I(inode)->io_tree,
2975 page_start, page_end, GFP_NOFS);
2977 page_cache_release(page);
2980 balance_dirty_pages_ratelimited(inode->i_mapping);
2981 btrfs_throttle(BTRFS_I(inode)->root);
2983 WARN_ON(nr != cluster->nr);
2989 static noinline_for_stack
2990 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
2991 struct file_extent_cluster *cluster)
2995 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
2996 ret = relocate_file_extent_cluster(inode, cluster);
3003 cluster->start = extent_key->objectid;
3005 BUG_ON(cluster->nr >= MAX_EXTENTS);
3006 cluster->end = extent_key->objectid + extent_key->offset - 1;
3007 cluster->boundary[cluster->nr] = extent_key->objectid;
3010 if (cluster->nr >= MAX_EXTENTS) {
3011 ret = relocate_file_extent_cluster(inode, cluster);
3019 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3020 static int get_ref_objectid_v0(struct reloc_control *rc,
3021 struct btrfs_path *path,
3022 struct btrfs_key *extent_key,
3023 u64 *ref_objectid, int *path_change)
3025 struct btrfs_key key;
3026 struct extent_buffer *leaf;
3027 struct btrfs_extent_ref_v0 *ref0;
3031 leaf = path->nodes[0];
3032 slot = path->slots[0];
3034 if (slot >= btrfs_header_nritems(leaf)) {
3035 ret = btrfs_next_leaf(rc->extent_root, path);
3039 leaf = path->nodes[0];
3040 slot = path->slots[0];
3044 btrfs_item_key_to_cpu(leaf, &key, slot);
3045 if (key.objectid != extent_key->objectid)
3048 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3052 ref0 = btrfs_item_ptr(leaf, slot,
3053 struct btrfs_extent_ref_v0);
3054 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3062 * helper to add a tree block to the list.
3063 * the major work is getting the generation and level of the block
3065 static int add_tree_block(struct reloc_control *rc,
3066 struct btrfs_key *extent_key,
3067 struct btrfs_path *path,
3068 struct rb_root *blocks)
3070 struct extent_buffer *eb;
3071 struct btrfs_extent_item *ei;
3072 struct btrfs_tree_block_info *bi;
3073 struct tree_block *block;
3074 struct rb_node *rb_node;
3079 eb = path->nodes[0];
3080 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3082 if (item_size >= sizeof(*ei) + sizeof(*bi)) {
3083 ei = btrfs_item_ptr(eb, path->slots[0],
3084 struct btrfs_extent_item);
3085 bi = (struct btrfs_tree_block_info *)(ei + 1);
3086 generation = btrfs_extent_generation(eb, ei);
3087 level = btrfs_tree_block_level(eb, bi);
3089 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3093 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3094 ret = get_ref_objectid_v0(rc, path, extent_key,
3096 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3097 level = (int)ref_owner;
3098 /* FIXME: get real generation */
3105 btrfs_release_path(rc->extent_root, path);
3107 BUG_ON(level == -1);
3109 block = kmalloc(sizeof(*block), GFP_NOFS);
3113 block->bytenr = extent_key->objectid;
3114 block->key.objectid = extent_key->offset;
3115 block->key.offset = generation;
3116 block->level = level;
3117 block->key_ready = 0;
3119 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3126 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3128 static int __add_tree_block(struct reloc_control *rc,
3129 u64 bytenr, u32 blocksize,
3130 struct rb_root *blocks)
3132 struct btrfs_path *path;
3133 struct btrfs_key key;
3136 if (tree_block_processed(bytenr, blocksize, rc))
3139 if (tree_search(blocks, bytenr))
3142 path = btrfs_alloc_path();
3146 key.objectid = bytenr;
3147 key.type = BTRFS_EXTENT_ITEM_KEY;
3148 key.offset = blocksize;
3150 path->search_commit_root = 1;
3151 path->skip_locking = 1;
3152 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3157 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3158 ret = add_tree_block(rc, &key, path, blocks);
3160 btrfs_free_path(path);
3165 * helper to check if the block use full backrefs for pointers in it
3167 static int block_use_full_backref(struct reloc_control *rc,
3168 struct extent_buffer *eb)
3173 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3174 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3177 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3178 eb->start, eb->len, NULL, &flags);
3181 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3189 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3190 * this function scans fs tree to find blocks reference the data extent
3192 static int find_data_references(struct reloc_control *rc,
3193 struct btrfs_key *extent_key,
3194 struct extent_buffer *leaf,
3195 struct btrfs_extent_data_ref *ref,
3196 struct rb_root *blocks)
3198 struct btrfs_path *path;
3199 struct tree_block *block;
3200 struct btrfs_root *root;
3201 struct btrfs_file_extent_item *fi;
3202 struct rb_node *rb_node;
3203 struct btrfs_key key;
3214 path = btrfs_alloc_path();
3218 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3219 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3220 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3221 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3223 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3225 err = PTR_ERR(root);
3229 key.objectid = ref_objectid;
3230 key.offset = ref_offset;
3231 key.type = BTRFS_EXTENT_DATA_KEY;
3233 path->search_commit_root = 1;
3234 path->skip_locking = 1;
3235 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3241 leaf = path->nodes[0];
3242 nritems = btrfs_header_nritems(leaf);
3244 * the references in tree blocks that use full backrefs
3245 * are not counted in
3247 if (block_use_full_backref(rc, leaf))
3251 rb_node = tree_search(blocks, leaf->start);
3256 path->slots[0] = nritems;
3259 while (ref_count > 0) {
3260 while (path->slots[0] >= nritems) {
3261 ret = btrfs_next_leaf(root, path);
3271 leaf = path->nodes[0];
3272 nritems = btrfs_header_nritems(leaf);
3275 if (block_use_full_backref(rc, leaf))
3279 rb_node = tree_search(blocks, leaf->start);
3284 path->slots[0] = nritems;
3288 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3289 if (key.objectid != ref_objectid ||
3290 key.type != BTRFS_EXTENT_DATA_KEY) {
3295 fi = btrfs_item_ptr(leaf, path->slots[0],
3296 struct btrfs_file_extent_item);
3298 if (btrfs_file_extent_type(leaf, fi) ==
3299 BTRFS_FILE_EXTENT_INLINE)
3302 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3303 extent_key->objectid)
3306 key.offset -= btrfs_file_extent_offset(leaf, fi);
3307 if (key.offset != ref_offset)
3315 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3316 block = kmalloc(sizeof(*block), GFP_NOFS);
3321 block->bytenr = leaf->start;
3322 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3324 block->key_ready = 1;
3325 rb_node = tree_insert(blocks, block->bytenr,
3332 path->slots[0] = nritems;
3338 btrfs_free_path(path);
3343 * hepler to find all tree blocks that reference a given data extent
3345 static noinline_for_stack
3346 int add_data_references(struct reloc_control *rc,
3347 struct btrfs_key *extent_key,
3348 struct btrfs_path *path,
3349 struct rb_root *blocks)
3351 struct btrfs_key key;
3352 struct extent_buffer *eb;
3353 struct btrfs_extent_data_ref *dref;
3354 struct btrfs_extent_inline_ref *iref;
3357 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3361 eb = path->nodes[0];
3362 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3363 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3364 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3365 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3369 ptr += sizeof(struct btrfs_extent_item);
3372 iref = (struct btrfs_extent_inline_ref *)ptr;
3373 key.type = btrfs_extent_inline_ref_type(eb, iref);
3374 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3375 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3376 ret = __add_tree_block(rc, key.offset, blocksize,
3378 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3379 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3380 ret = find_data_references(rc, extent_key,
3385 ptr += btrfs_extent_inline_ref_size(key.type);
3391 eb = path->nodes[0];
3392 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3393 ret = btrfs_next_leaf(rc->extent_root, path);
3400 eb = path->nodes[0];
3403 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3404 if (key.objectid != extent_key->objectid)
3407 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3408 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3409 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3411 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3412 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3414 ret = __add_tree_block(rc, key.offset, blocksize,
3416 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3417 dref = btrfs_item_ptr(eb, path->slots[0],
3418 struct btrfs_extent_data_ref);
3419 ret = find_data_references(rc, extent_key,
3430 btrfs_release_path(rc->extent_root, path);
3432 free_block_list(blocks);
3437 * hepler to find next unprocessed extent
3439 static noinline_for_stack
3440 int find_next_extent(struct btrfs_trans_handle *trans,
3441 struct reloc_control *rc, struct btrfs_path *path,
3442 struct btrfs_key *extent_key)
3444 struct btrfs_key key;
3445 struct extent_buffer *leaf;
3446 u64 start, end, last;
3449 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3452 if (rc->search_start >= last) {
3457 key.objectid = rc->search_start;
3458 key.type = BTRFS_EXTENT_ITEM_KEY;
3461 path->search_commit_root = 1;
3462 path->skip_locking = 1;
3463 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3468 leaf = path->nodes[0];
3469 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3470 ret = btrfs_next_leaf(rc->extent_root, path);
3473 leaf = path->nodes[0];
3476 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3477 if (key.objectid >= last) {
3482 if (key.type != BTRFS_EXTENT_ITEM_KEY ||
3483 key.objectid + key.offset <= rc->search_start) {
3488 ret = find_first_extent_bit(&rc->processed_blocks,
3489 key.objectid, &start, &end,
3492 if (ret == 0 && start <= key.objectid) {
3493 btrfs_release_path(rc->extent_root, path);
3494 rc->search_start = end + 1;
3496 rc->search_start = key.objectid + key.offset;
3497 memcpy(extent_key, &key, sizeof(key));
3501 btrfs_release_path(rc->extent_root, path);
3505 static void set_reloc_control(struct reloc_control *rc)
3507 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3508 mutex_lock(&fs_info->trans_mutex);
3509 fs_info->reloc_ctl = rc;
3510 mutex_unlock(&fs_info->trans_mutex);
3513 static void unset_reloc_control(struct reloc_control *rc)
3515 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3516 mutex_lock(&fs_info->trans_mutex);
3517 fs_info->reloc_ctl = NULL;
3518 mutex_unlock(&fs_info->trans_mutex);
3521 static int check_extent_flags(u64 flags)
3523 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3524 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3526 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3527 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3529 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3530 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3535 static noinline_for_stack
3536 int prepare_to_relocate(struct reloc_control *rc)
3538 struct btrfs_trans_handle *trans;
3541 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root);
3546 * reserve some space for creating reloc trees.
3547 * btrfs_init_reloc_root will use them when there
3548 * is no reservation in transaction handle.
3550 ret = btrfs_block_rsv_add(NULL, rc->extent_root, rc->block_rsv,
3551 rc->extent_root->nodesize * 256);
3555 rc->block_rsv->refill_used = 1;
3556 btrfs_add_durable_block_rsv(rc->extent_root->fs_info, rc->block_rsv);
3558 memset(&rc->cluster, 0, sizeof(rc->cluster));
3559 rc->search_start = rc->block_group->key.objectid;
3560 rc->extents_found = 0;
3561 rc->nodes_relocated = 0;
3562 rc->merging_rsv_size = 0;
3564 rc->create_reloc_tree = 1;
3565 set_reloc_control(rc);
3567 trans = btrfs_join_transaction(rc->extent_root, 1);
3568 btrfs_commit_transaction(trans, rc->extent_root);
3572 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3574 struct rb_root blocks = RB_ROOT;
3575 struct btrfs_key key;
3576 struct btrfs_trans_handle *trans = NULL;
3577 struct btrfs_path *path;
3578 struct btrfs_extent_item *ei;
3585 path = btrfs_alloc_path();
3589 ret = prepare_to_relocate(rc);
3596 trans = btrfs_start_transaction(rc->extent_root, 0);
3598 if (update_backref_cache(trans, &rc->backref_cache)) {
3599 btrfs_end_transaction(trans, rc->extent_root);
3603 ret = find_next_extent(trans, rc, path, &key);
3609 rc->extents_found++;
3611 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3612 struct btrfs_extent_item);
3613 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3614 if (item_size >= sizeof(*ei)) {
3615 flags = btrfs_extent_flags(path->nodes[0], ei);
3616 ret = check_extent_flags(flags);
3620 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3622 int path_change = 0;
3625 sizeof(struct btrfs_extent_item_v0));
3626 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3628 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3629 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3631 flags = BTRFS_EXTENT_FLAG_DATA;
3634 btrfs_release_path(rc->extent_root, path);
3636 path->search_commit_root = 1;
3637 path->skip_locking = 1;
3638 ret = btrfs_search_slot(NULL, rc->extent_root,
3651 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3652 ret = add_tree_block(rc, &key, path, &blocks);
3653 } else if (rc->stage == UPDATE_DATA_PTRS &&
3654 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3655 ret = add_data_references(rc, &key, path, &blocks);
3657 btrfs_release_path(rc->extent_root, path);
3665 if (!RB_EMPTY_ROOT(&blocks)) {
3666 ret = relocate_tree_blocks(trans, rc, &blocks);
3668 if (ret != -EAGAIN) {
3672 rc->extents_found--;
3673 rc->search_start = key.objectid;
3677 ret = btrfs_block_rsv_check(trans, rc->extent_root,
3678 rc->block_rsv, 0, 5);
3680 if (ret != -EAGAIN) {
3685 rc->commit_transaction = 1;
3688 if (rc->commit_transaction) {
3689 rc->commit_transaction = 0;
3690 ret = btrfs_commit_transaction(trans, rc->extent_root);
3693 nr = trans->blocks_used;
3694 btrfs_end_transaction_throttle(trans, rc->extent_root);
3695 btrfs_btree_balance_dirty(rc->extent_root, nr);
3699 if (rc->stage == MOVE_DATA_EXTENTS &&
3700 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3701 rc->found_file_extent = 1;
3702 ret = relocate_data_extent(rc->data_inode,
3703 &key, &rc->cluster);
3711 btrfs_release_path(rc->extent_root, path);
3712 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
3716 nr = trans->blocks_used;
3717 btrfs_end_transaction_throttle(trans, rc->extent_root);
3718 btrfs_btree_balance_dirty(rc->extent_root, nr);
3722 ret = relocate_file_extent_cluster(rc->data_inode,
3728 rc->create_reloc_tree = 0;
3729 set_reloc_control(rc);
3731 backref_cache_cleanup(&rc->backref_cache);
3732 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3734 err = prepare_to_merge(rc, err);
3736 merge_reloc_roots(rc);
3738 rc->merge_reloc_tree = 0;
3739 unset_reloc_control(rc);
3740 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3742 /* get rid of pinned extents */
3743 trans = btrfs_join_transaction(rc->extent_root, 1);
3744 btrfs_commit_transaction(trans, rc->extent_root);
3746 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
3747 btrfs_free_path(path);
3751 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
3752 struct btrfs_root *root, u64 objectid)
3754 struct btrfs_path *path;
3755 struct btrfs_inode_item *item;
3756 struct extent_buffer *leaf;
3759 path = btrfs_alloc_path();
3763 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
3767 leaf = path->nodes[0];
3768 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
3769 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
3770 btrfs_set_inode_generation(leaf, item, 1);
3771 btrfs_set_inode_size(leaf, item, 0);
3772 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
3773 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
3774 BTRFS_INODE_PREALLOC);
3775 btrfs_mark_buffer_dirty(leaf);
3776 btrfs_release_path(root, path);
3778 btrfs_free_path(path);
3783 * helper to create inode for data relocation.
3784 * the inode is in data relocation tree and its link count is 0
3786 static noinline_for_stack
3787 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
3788 struct btrfs_block_group_cache *group)
3790 struct inode *inode = NULL;
3791 struct btrfs_trans_handle *trans;
3792 struct btrfs_root *root;
3793 struct btrfs_key key;
3795 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
3798 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
3800 return ERR_CAST(root);
3802 trans = btrfs_start_transaction(root, 6);
3804 return ERR_CAST(trans);
3806 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
3810 err = __insert_orphan_inode(trans, root, objectid);
3813 key.objectid = objectid;
3814 key.type = BTRFS_INODE_ITEM_KEY;
3816 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
3817 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
3818 BTRFS_I(inode)->index_cnt = group->key.objectid;
3820 err = btrfs_orphan_add(trans, inode);
3822 nr = trans->blocks_used;
3823 btrfs_end_transaction(trans, root);
3824 btrfs_btree_balance_dirty(root, nr);
3828 inode = ERR_PTR(err);
3833 static struct reloc_control *alloc_reloc_control(void)
3835 struct reloc_control *rc;
3837 rc = kzalloc(sizeof(*rc), GFP_NOFS);
3841 INIT_LIST_HEAD(&rc->reloc_roots);
3842 backref_cache_init(&rc->backref_cache);
3843 mapping_tree_init(&rc->reloc_root_tree);
3844 extent_io_tree_init(&rc->processed_blocks, NULL, GFP_NOFS);
3849 * function to relocate all extents in a block group.
3851 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
3853 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3854 struct reloc_control *rc;
3859 rc = alloc_reloc_control();
3863 rc->extent_root = extent_root;
3865 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
3866 BUG_ON(!rc->block_group);
3868 if (!rc->block_group->ro) {
3869 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
3877 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
3878 if (IS_ERR(rc->data_inode)) {
3879 err = PTR_ERR(rc->data_inode);
3880 rc->data_inode = NULL;
3884 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
3885 (unsigned long long)rc->block_group->key.objectid,
3886 (unsigned long long)rc->block_group->flags);
3888 btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
3889 btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0);
3892 mutex_lock(&fs_info->cleaner_mutex);
3894 btrfs_clean_old_snapshots(fs_info->tree_root);
3895 ret = relocate_block_group(rc);
3897 mutex_unlock(&fs_info->cleaner_mutex);
3903 if (rc->extents_found == 0)
3906 printk(KERN_INFO "btrfs: found %llu extents\n",
3907 (unsigned long long)rc->extents_found);
3909 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
3910 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
3911 invalidate_mapping_pages(rc->data_inode->i_mapping,
3913 rc->stage = UPDATE_DATA_PTRS;
3917 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
3918 rc->block_group->key.objectid,
3919 rc->block_group->key.objectid +
3920 rc->block_group->key.offset - 1);
3922 WARN_ON(rc->block_group->pinned > 0);
3923 WARN_ON(rc->block_group->reserved > 0);
3924 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
3927 btrfs_set_block_group_rw(extent_root, rc->block_group);
3928 iput(rc->data_inode);
3929 btrfs_put_block_group(rc->block_group);
3934 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
3936 struct btrfs_trans_handle *trans;
3939 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
3941 memset(&root->root_item.drop_progress, 0,
3942 sizeof(root->root_item.drop_progress));
3943 root->root_item.drop_level = 0;
3944 btrfs_set_root_refs(&root->root_item, 0);
3945 ret = btrfs_update_root(trans, root->fs_info->tree_root,
3946 &root->root_key, &root->root_item);
3949 ret = btrfs_end_transaction(trans, root->fs_info->tree_root);
3955 * recover relocation interrupted by system crash.
3957 * this function resumes merging reloc trees with corresponding fs trees.
3958 * this is important for keeping the sharing of tree blocks
3960 int btrfs_recover_relocation(struct btrfs_root *root)
3962 LIST_HEAD(reloc_roots);
3963 struct btrfs_key key;
3964 struct btrfs_root *fs_root;
3965 struct btrfs_root *reloc_root;
3966 struct btrfs_path *path;
3967 struct extent_buffer *leaf;
3968 struct reloc_control *rc = NULL;
3969 struct btrfs_trans_handle *trans;
3973 path = btrfs_alloc_path();
3977 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
3978 key.type = BTRFS_ROOT_ITEM_KEY;
3979 key.offset = (u64)-1;
3982 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
3989 if (path->slots[0] == 0)
3993 leaf = path->nodes[0];
3994 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3995 btrfs_release_path(root->fs_info->tree_root, path);
3997 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
3998 key.type != BTRFS_ROOT_ITEM_KEY)
4001 reloc_root = btrfs_read_fs_root_no_radix(root, &key);
4002 if (IS_ERR(reloc_root)) {
4003 err = PTR_ERR(reloc_root);
4007 list_add(&reloc_root->root_list, &reloc_roots);
4009 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4010 fs_root = read_fs_root(root->fs_info,
4011 reloc_root->root_key.offset);
4012 if (IS_ERR(fs_root)) {
4013 ret = PTR_ERR(fs_root);
4014 if (ret != -ENOENT) {
4018 mark_garbage_root(reloc_root);
4022 if (key.offset == 0)
4027 btrfs_release_path(root->fs_info->tree_root, path);
4029 if (list_empty(&reloc_roots))
4032 rc = alloc_reloc_control();
4038 rc->extent_root = root->fs_info->extent_root;
4040 set_reloc_control(rc);
4042 trans = btrfs_join_transaction(rc->extent_root, 1);
4044 rc->merge_reloc_tree = 1;
4046 while (!list_empty(&reloc_roots)) {
4047 reloc_root = list_entry(reloc_roots.next,
4048 struct btrfs_root, root_list);
4049 list_del(&reloc_root->root_list);
4051 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4052 list_add_tail(&reloc_root->root_list,
4057 fs_root = read_fs_root(root->fs_info,
4058 reloc_root->root_key.offset);
4059 BUG_ON(IS_ERR(fs_root));
4061 __add_reloc_root(reloc_root);
4062 fs_root->reloc_root = reloc_root;
4065 btrfs_commit_transaction(trans, rc->extent_root);
4067 merge_reloc_roots(rc);
4069 unset_reloc_control(rc);
4071 trans = btrfs_join_transaction(rc->extent_root, 1);
4072 btrfs_commit_transaction(trans, rc->extent_root);
4075 while (!list_empty(&reloc_roots)) {
4076 reloc_root = list_entry(reloc_roots.next,
4077 struct btrfs_root, root_list);
4078 list_del(&reloc_root->root_list);
4079 free_extent_buffer(reloc_root->node);
4080 free_extent_buffer(reloc_root->commit_root);
4083 btrfs_free_path(path);
4086 /* cleanup orphan inode in data relocation tree */
4087 fs_root = read_fs_root(root->fs_info,
4088 BTRFS_DATA_RELOC_TREE_OBJECTID);
4089 if (IS_ERR(fs_root))
4090 err = PTR_ERR(fs_root);
4092 btrfs_orphan_cleanup(fs_root);
4098 * helper to add ordered checksum for data relocation.
4100 * cloning checksum properly handles the nodatasum extents.
4101 * it also saves CPU time to re-calculate the checksum.
4103 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4105 struct btrfs_ordered_sum *sums;
4106 struct btrfs_sector_sum *sector_sum;
4107 struct btrfs_ordered_extent *ordered;
4108 struct btrfs_root *root = BTRFS_I(inode)->root;
4114 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4115 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4117 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4118 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4119 disk_bytenr + len - 1, &list);
4121 while (!list_empty(&list)) {
4122 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4123 list_del_init(&sums->list);
4125 sector_sum = sums->sums;
4126 sums->bytenr = ordered->start;
4129 while (offset < sums->len) {
4130 sector_sum->bytenr += ordered->start - disk_bytenr;
4132 offset += root->sectorsize;
4135 btrfs_add_ordered_sum(inode, ordered, sums);
4137 btrfs_put_ordered_extent(ordered);
4141 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4142 struct btrfs_root *root, struct extent_buffer *buf,
4143 struct extent_buffer *cow)
4145 struct reloc_control *rc;
4146 struct backref_node *node;
4151 rc = root->fs_info->reloc_ctl;
4155 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4156 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4158 level = btrfs_header_level(buf);
4159 if (btrfs_header_generation(buf) <=
4160 btrfs_root_last_snapshot(&root->root_item))
4163 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4164 rc->create_reloc_tree) {
4165 WARN_ON(!first_cow && level == 0);
4167 node = rc->backref_cache.path[level];
4168 BUG_ON(node->bytenr != buf->start &&
4169 node->new_bytenr != buf->start);
4171 drop_node_buffer(node);
4172 extent_buffer_get(cow);
4174 node->new_bytenr = cow->start;
4176 if (!node->pending) {
4177 list_move_tail(&node->list,
4178 &rc->backref_cache.pending[level]);
4183 __mark_block_processed(rc, node);
4185 if (first_cow && level > 0)
4186 rc->nodes_relocated += buf->len;
4189 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4190 ret = replace_file_extents(trans, rc, root, cow);
4196 * called before creating snapshot. it calculates metadata reservation
4197 * requried for relocating tree blocks in the snapshot
4199 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4200 struct btrfs_pending_snapshot *pending,
4201 u64 *bytes_to_reserve)
4203 struct btrfs_root *root;
4204 struct reloc_control *rc;
4206 root = pending->root;
4207 if (!root->reloc_root)
4210 rc = root->fs_info->reloc_ctl;
4211 if (!rc->merge_reloc_tree)
4214 root = root->reloc_root;
4215 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4217 * relocation is in the stage of merging trees. the space
4218 * used by merging a reloc tree is twice the size of
4219 * relocated tree nodes in the worst case. half for cowing
4220 * the reloc tree, half for cowing the fs tree. the space
4221 * used by cowing the reloc tree will be freed after the
4222 * tree is dropped. if we create snapshot, cowing the fs
4223 * tree may use more space than it frees. so we need
4224 * reserve extra space.
4226 *bytes_to_reserve += rc->nodes_relocated;
4230 * called after snapshot is created. migrate block reservation
4231 * and create reloc root for the newly created snapshot
4233 void btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4234 struct btrfs_pending_snapshot *pending)
4236 struct btrfs_root *root = pending->root;
4237 struct btrfs_root *reloc_root;
4238 struct btrfs_root *new_root;
4239 struct reloc_control *rc;
4242 if (!root->reloc_root)
4245 rc = root->fs_info->reloc_ctl;
4246 rc->merging_rsv_size += rc->nodes_relocated;
4248 if (rc->merge_reloc_tree) {
4249 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4251 rc->nodes_relocated);
4255 new_root = pending->snap;
4256 reloc_root = create_reloc_root(trans, root->reloc_root,
4257 new_root->root_key.objectid);
4259 __add_reloc_root(reloc_root);
4260 new_root->reloc_root = reloc_root;
4262 if (rc->create_reloc_tree) {
4263 ret = clone_backref_node(trans, rc, root, reloc_root);