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"
35 * backref_node, mapping_node and tree_block start with this
38 struct rb_node rb_node;
43 * present a tree block in the backref cache
46 struct rb_node rb_node;
50 /* objectid of tree block owner, can be not uptodate */
52 /* link to pending, changed or detached list */
53 struct list_head list;
54 /* list of upper level blocks reference this block */
55 struct list_head upper;
56 /* list of child blocks in the cache */
57 struct list_head lower;
58 /* NULL if this node is not tree root */
59 struct btrfs_root *root;
60 /* extent buffer got by COW the block */
61 struct extent_buffer *eb;
62 /* level of tree block */
64 /* is the block in non-reference counted tree */
65 unsigned int cowonly:1;
66 /* 1 if no child node in the cache */
67 unsigned int lowest:1;
68 /* is the extent buffer locked */
69 unsigned int locked:1;
70 /* has the block been processed */
71 unsigned int processed:1;
72 /* have backrefs of this block been checked */
73 unsigned int checked:1;
75 * 1 if corresponding block has been cowed but some upper
76 * level block pointers may not point to the new location
78 unsigned int pending:1;
80 * 1 if the backref node isn't connected to any other
83 unsigned int detached:1;
87 * present a block pointer in the backref cache
90 struct list_head list[2];
91 struct backref_node *node[2];
97 struct backref_cache {
98 /* red black tree of all backref nodes in the cache */
99 struct rb_root rb_root;
100 /* for passing backref nodes to btrfs_reloc_cow_block */
101 struct backref_node *path[BTRFS_MAX_LEVEL];
103 * list of blocks that have been cowed but some block
104 * pointers in upper level blocks may not reflect the
107 struct list_head pending[BTRFS_MAX_LEVEL];
108 /* list of backref nodes with no child node */
109 struct list_head leaves;
110 /* list of blocks that have been cowed in current transaction */
111 struct list_head changed;
112 /* list of detached backref node. */
113 struct list_head detached;
122 * map address of tree root to tree
124 struct mapping_node {
125 struct rb_node rb_node;
130 struct mapping_tree {
131 struct rb_root rb_root;
136 * present a tree block to process
139 struct rb_node rb_node;
141 struct btrfs_key key;
142 unsigned int level:8;
143 unsigned int key_ready:1;
146 #define MAX_EXTENTS 128
148 struct file_extent_cluster {
151 u64 boundary[MAX_EXTENTS];
155 struct reloc_control {
156 /* block group to relocate */
157 struct btrfs_block_group_cache *block_group;
159 struct btrfs_root *extent_root;
160 /* inode for moving data */
161 struct inode *data_inode;
163 struct btrfs_block_rsv *block_rsv;
165 struct backref_cache backref_cache;
167 struct file_extent_cluster cluster;
168 /* tree blocks have been processed */
169 struct extent_io_tree processed_blocks;
170 /* map start of tree root to corresponding reloc tree */
171 struct mapping_tree reloc_root_tree;
172 /* list of reloc trees */
173 struct list_head reloc_roots;
174 /* size of metadata reservation for merging reloc trees */
175 u64 merging_rsv_size;
176 /* size of relocated tree nodes */
182 unsigned int stage:8;
183 unsigned int create_reloc_tree:1;
184 unsigned int merge_reloc_tree:1;
185 unsigned int found_file_extent:1;
186 unsigned int commit_transaction:1;
189 /* stages of data relocation */
190 #define MOVE_DATA_EXTENTS 0
191 #define UPDATE_DATA_PTRS 1
193 static void remove_backref_node(struct backref_cache *cache,
194 struct backref_node *node);
195 static void __mark_block_processed(struct reloc_control *rc,
196 struct backref_node *node);
198 static void mapping_tree_init(struct mapping_tree *tree)
200 tree->rb_root = RB_ROOT;
201 spin_lock_init(&tree->lock);
204 static void backref_cache_init(struct backref_cache *cache)
207 cache->rb_root = RB_ROOT;
208 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
209 INIT_LIST_HEAD(&cache->pending[i]);
210 INIT_LIST_HEAD(&cache->changed);
211 INIT_LIST_HEAD(&cache->detached);
212 INIT_LIST_HEAD(&cache->leaves);
215 static void backref_cache_cleanup(struct backref_cache *cache)
217 struct backref_node *node;
220 while (!list_empty(&cache->detached)) {
221 node = list_entry(cache->detached.next,
222 struct backref_node, list);
223 remove_backref_node(cache, node);
226 while (!list_empty(&cache->leaves)) {
227 node = list_entry(cache->leaves.next,
228 struct backref_node, lower);
229 remove_backref_node(cache, node);
232 cache->last_trans = 0;
234 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
235 BUG_ON(!list_empty(&cache->pending[i]));
236 BUG_ON(!list_empty(&cache->changed));
237 BUG_ON(!list_empty(&cache->detached));
238 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
239 BUG_ON(cache->nr_nodes);
240 BUG_ON(cache->nr_edges);
243 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
245 struct backref_node *node;
247 node = kzalloc(sizeof(*node), GFP_NOFS);
249 INIT_LIST_HEAD(&node->list);
250 INIT_LIST_HEAD(&node->upper);
251 INIT_LIST_HEAD(&node->lower);
252 RB_CLEAR_NODE(&node->rb_node);
258 static void free_backref_node(struct backref_cache *cache,
259 struct backref_node *node)
267 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
269 struct backref_edge *edge;
271 edge = kzalloc(sizeof(*edge), GFP_NOFS);
277 static void free_backref_edge(struct backref_cache *cache,
278 struct backref_edge *edge)
286 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
287 struct rb_node *node)
289 struct rb_node **p = &root->rb_node;
290 struct rb_node *parent = NULL;
291 struct tree_entry *entry;
295 entry = rb_entry(parent, struct tree_entry, rb_node);
297 if (bytenr < entry->bytenr)
299 else if (bytenr > entry->bytenr)
305 rb_link_node(node, parent, p);
306 rb_insert_color(node, root);
310 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
312 struct rb_node *n = root->rb_node;
313 struct tree_entry *entry;
316 entry = rb_entry(n, struct tree_entry, rb_node);
318 if (bytenr < entry->bytenr)
320 else if (bytenr > entry->bytenr)
329 * walk up backref nodes until reach node presents tree root
331 static struct backref_node *walk_up_backref(struct backref_node *node,
332 struct backref_edge *edges[],
335 struct backref_edge *edge;
338 while (!list_empty(&node->upper)) {
339 edge = list_entry(node->upper.next,
340 struct backref_edge, list[LOWER]);
342 node = edge->node[UPPER];
344 BUG_ON(node->detached);
350 * walk down backref nodes to find start of next reference path
352 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
355 struct backref_edge *edge;
356 struct backref_node *lower;
360 edge = edges[idx - 1];
361 lower = edge->node[LOWER];
362 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
366 edge = list_entry(edge->list[LOWER].next,
367 struct backref_edge, list[LOWER]);
368 edges[idx - 1] = edge;
370 return edge->node[UPPER];
376 static void unlock_node_buffer(struct backref_node *node)
379 btrfs_tree_unlock(node->eb);
384 static void drop_node_buffer(struct backref_node *node)
387 unlock_node_buffer(node);
388 free_extent_buffer(node->eb);
393 static void drop_backref_node(struct backref_cache *tree,
394 struct backref_node *node)
396 BUG_ON(!list_empty(&node->upper));
398 drop_node_buffer(node);
399 list_del(&node->list);
400 list_del(&node->lower);
401 if (!RB_EMPTY_NODE(&node->rb_node))
402 rb_erase(&node->rb_node, &tree->rb_root);
403 free_backref_node(tree, node);
407 * remove a backref node from the backref cache
409 static void remove_backref_node(struct backref_cache *cache,
410 struct backref_node *node)
412 struct backref_node *upper;
413 struct backref_edge *edge;
418 BUG_ON(!node->lowest && !node->detached);
419 while (!list_empty(&node->upper)) {
420 edge = list_entry(node->upper.next, struct backref_edge,
422 upper = edge->node[UPPER];
423 list_del(&edge->list[LOWER]);
424 list_del(&edge->list[UPPER]);
425 free_backref_edge(cache, edge);
427 if (RB_EMPTY_NODE(&upper->rb_node)) {
428 BUG_ON(!list_empty(&node->upper));
429 drop_backref_node(cache, node);
435 * add the node to leaf node list if no other
436 * child block cached.
438 if (list_empty(&upper->lower)) {
439 list_add_tail(&upper->lower, &cache->leaves);
444 drop_backref_node(cache, node);
447 static void update_backref_node(struct backref_cache *cache,
448 struct backref_node *node, u64 bytenr)
450 struct rb_node *rb_node;
451 rb_erase(&node->rb_node, &cache->rb_root);
452 node->bytenr = bytenr;
453 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
458 * update backref cache after a transaction commit
460 static int update_backref_cache(struct btrfs_trans_handle *trans,
461 struct backref_cache *cache)
463 struct backref_node *node;
466 if (cache->last_trans == 0) {
467 cache->last_trans = trans->transid;
471 if (cache->last_trans == trans->transid)
475 * detached nodes are used to avoid unnecessary backref
476 * lookup. transaction commit changes the extent tree.
477 * so the detached nodes are no longer useful.
479 while (!list_empty(&cache->detached)) {
480 node = list_entry(cache->detached.next,
481 struct backref_node, list);
482 remove_backref_node(cache, node);
485 while (!list_empty(&cache->changed)) {
486 node = list_entry(cache->changed.next,
487 struct backref_node, list);
488 list_del_init(&node->list);
489 BUG_ON(node->pending);
490 update_backref_node(cache, node, node->new_bytenr);
494 * some nodes can be left in the pending list if there were
495 * errors during processing the pending nodes.
497 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
498 list_for_each_entry(node, &cache->pending[level], list) {
499 BUG_ON(!node->pending);
500 if (node->bytenr == node->new_bytenr)
502 update_backref_node(cache, node, node->new_bytenr);
506 cache->last_trans = 0;
510 static int should_ignore_root(struct btrfs_root *root)
512 struct btrfs_root *reloc_root;
517 reloc_root = root->reloc_root;
521 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
522 root->fs_info->running_transaction->transid - 1)
525 * if there is reloc tree and it was created in previous
526 * transaction backref lookup can find the reloc tree,
527 * so backref node for the fs tree root is useless for
534 * find reloc tree by address of tree root
536 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
539 struct rb_node *rb_node;
540 struct mapping_node *node;
541 struct btrfs_root *root = NULL;
543 spin_lock(&rc->reloc_root_tree.lock);
544 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
546 node = rb_entry(rb_node, struct mapping_node, rb_node);
547 root = (struct btrfs_root *)node->data;
549 spin_unlock(&rc->reloc_root_tree.lock);
553 static int is_cowonly_root(u64 root_objectid)
555 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
556 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
557 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
558 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
559 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
560 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
565 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
568 struct btrfs_key key;
570 key.objectid = root_objectid;
571 key.type = BTRFS_ROOT_ITEM_KEY;
572 if (is_cowonly_root(root_objectid))
575 key.offset = (u64)-1;
577 return btrfs_read_fs_root_no_name(fs_info, &key);
580 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
581 static noinline_for_stack
582 struct btrfs_root *find_tree_root(struct reloc_control *rc,
583 struct extent_buffer *leaf,
584 struct btrfs_extent_ref_v0 *ref0)
586 struct btrfs_root *root;
587 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
588 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
590 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
592 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
593 BUG_ON(IS_ERR(root));
595 if (root->ref_cows &&
596 generation != btrfs_root_generation(&root->root_item))
603 static noinline_for_stack
604 int find_inline_backref(struct extent_buffer *leaf, int slot,
605 unsigned long *ptr, unsigned long *end)
607 struct btrfs_extent_item *ei;
608 struct btrfs_tree_block_info *bi;
611 item_size = btrfs_item_size_nr(leaf, slot);
612 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
613 if (item_size < sizeof(*ei)) {
614 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
618 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
619 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
620 BTRFS_EXTENT_FLAG_TREE_BLOCK));
622 if (item_size <= sizeof(*ei) + sizeof(*bi)) {
623 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
627 bi = (struct btrfs_tree_block_info *)(ei + 1);
628 *ptr = (unsigned long)(bi + 1);
629 *end = (unsigned long)ei + item_size;
634 * build backref tree for a given tree block. root of the backref tree
635 * corresponds the tree block, leaves of the backref tree correspond
636 * roots of b-trees that reference the tree block.
638 * the basic idea of this function is check backrefs of a given block
639 * to find upper level blocks that refernece the block, and then check
640 * bakcrefs of these upper level blocks recursively. the recursion stop
641 * when tree root is reached or backrefs for the block is cached.
643 * NOTE: if we find backrefs for a block are cached, we know backrefs
644 * for all upper level blocks that directly/indirectly reference the
645 * block are also cached.
647 static noinline_for_stack
648 struct backref_node *build_backref_tree(struct reloc_control *rc,
649 struct btrfs_key *node_key,
650 int level, u64 bytenr)
652 struct backref_cache *cache = &rc->backref_cache;
653 struct btrfs_path *path1;
654 struct btrfs_path *path2;
655 struct extent_buffer *eb;
656 struct btrfs_root *root;
657 struct backref_node *cur;
658 struct backref_node *upper;
659 struct backref_node *lower;
660 struct backref_node *node = NULL;
661 struct backref_node *exist = NULL;
662 struct backref_edge *edge;
663 struct rb_node *rb_node;
664 struct btrfs_key key;
673 path1 = btrfs_alloc_path();
674 path2 = btrfs_alloc_path();
675 if (!path1 || !path2) {
680 node = alloc_backref_node(cache);
686 node->bytenr = bytenr;
693 key.objectid = cur->bytenr;
694 key.type = BTRFS_EXTENT_ITEM_KEY;
695 key.offset = (u64)-1;
697 path1->search_commit_root = 1;
698 path1->skip_locking = 1;
699 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
705 BUG_ON(!ret || !path1->slots[0]);
709 WARN_ON(cur->checked);
710 if (!list_empty(&cur->upper)) {
712 * the backref was added previously when processsing
713 * backref of type BTRFS_TREE_BLOCK_REF_KEY
715 BUG_ON(!list_is_singular(&cur->upper));
716 edge = list_entry(cur->upper.next, struct backref_edge,
718 BUG_ON(!list_empty(&edge->list[UPPER]));
719 exist = edge->node[UPPER];
721 * add the upper level block to pending list if we need
725 list_add_tail(&edge->list[UPPER], &list);
732 eb = path1->nodes[0];
735 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
736 ret = btrfs_next_leaf(rc->extent_root, path1);
743 eb = path1->nodes[0];
746 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
747 if (key.objectid != cur->bytenr) {
752 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
753 ret = find_inline_backref(eb, path1->slots[0],
761 /* update key for inline back ref */
762 struct btrfs_extent_inline_ref *iref;
763 iref = (struct btrfs_extent_inline_ref *)ptr;
764 key.type = btrfs_extent_inline_ref_type(eb, iref);
765 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
766 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
767 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
771 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
772 exist->owner == key.offset) ||
773 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
774 exist->bytenr == key.offset))) {
779 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
780 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
781 key.type == BTRFS_EXTENT_REF_V0_KEY) {
782 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
783 struct btrfs_extent_ref_v0 *ref0;
784 ref0 = btrfs_item_ptr(eb, path1->slots[0],
785 struct btrfs_extent_ref_v0);
786 if (key.objectid == key.offset) {
787 root = find_tree_root(rc, eb, ref0);
788 if (root && !should_ignore_root(root))
791 list_add(&cur->list, &useless);
794 if (is_cowonly_root(btrfs_ref_root_v0(eb,
799 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
800 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
802 if (key.objectid == key.offset) {
804 * only root blocks of reloc trees use
805 * backref of this type.
807 root = find_reloc_root(rc, cur->bytenr);
813 edge = alloc_backref_edge(cache);
818 rb_node = tree_search(&cache->rb_root, key.offset);
820 upper = alloc_backref_node(cache);
822 free_backref_edge(cache, edge);
826 upper->bytenr = key.offset;
827 upper->level = cur->level + 1;
829 * backrefs for the upper level block isn't
830 * cached, add the block to pending list
832 list_add_tail(&edge->list[UPPER], &list);
834 upper = rb_entry(rb_node, struct backref_node,
836 BUG_ON(!upper->checked);
837 INIT_LIST_HEAD(&edge->list[UPPER]);
839 list_add_tail(&edge->list[LOWER], &cur->upper);
840 edge->node[LOWER] = cur;
841 edge->node[UPPER] = upper;
844 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
848 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
849 root = read_fs_root(rc->extent_root->fs_info, key.offset);
858 if (btrfs_root_level(&root->root_item) == cur->level) {
860 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
862 if (should_ignore_root(root))
863 list_add(&cur->list, &useless);
869 level = cur->level + 1;
872 * searching the tree to find upper level blocks
873 * reference the block.
875 path2->search_commit_root = 1;
876 path2->skip_locking = 1;
877 path2->lowest_level = level;
878 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
879 path2->lowest_level = 0;
884 if (ret > 0 && path2->slots[level] > 0)
885 path2->slots[level]--;
887 eb = path2->nodes[level];
888 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
892 for (; level < BTRFS_MAX_LEVEL; level++) {
893 if (!path2->nodes[level]) {
894 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
896 if (should_ignore_root(root))
897 list_add(&lower->list, &useless);
903 edge = alloc_backref_edge(cache);
909 eb = path2->nodes[level];
910 rb_node = tree_search(&cache->rb_root, eb->start);
912 upper = alloc_backref_node(cache);
914 free_backref_edge(cache, edge);
918 upper->bytenr = eb->start;
919 upper->owner = btrfs_header_owner(eb);
920 upper->level = lower->level + 1;
925 * if we know the block isn't shared
926 * we can void checking its backrefs.
928 if (btrfs_block_can_be_shared(root, eb))
934 * add the block to pending list if we
935 * need check its backrefs. only block
936 * at 'cur->level + 1' is added to the
937 * tail of pending list. this guarantees
938 * we check backrefs from lower level
939 * blocks to upper level blocks.
941 if (!upper->checked &&
942 level == cur->level + 1) {
943 list_add_tail(&edge->list[UPPER],
946 INIT_LIST_HEAD(&edge->list[UPPER]);
948 upper = rb_entry(rb_node, struct backref_node,
950 BUG_ON(!upper->checked);
951 INIT_LIST_HEAD(&edge->list[UPPER]);
953 upper->owner = btrfs_header_owner(eb);
955 list_add_tail(&edge->list[LOWER], &lower->upper);
956 edge->node[LOWER] = lower;
957 edge->node[UPPER] = upper;
964 btrfs_release_path(root, path2);
967 ptr += btrfs_extent_inline_ref_size(key.type);
977 btrfs_release_path(rc->extent_root, path1);
982 /* the pending list isn't empty, take the first block to process */
983 if (!list_empty(&list)) {
984 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
985 list_del_init(&edge->list[UPPER]);
986 cur = edge->node[UPPER];
991 * everything goes well, connect backref nodes and insert backref nodes
994 BUG_ON(!node->checked);
995 cowonly = node->cowonly;
997 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1000 list_add_tail(&node->lower, &cache->leaves);
1003 list_for_each_entry(edge, &node->upper, list[LOWER])
1004 list_add_tail(&edge->list[UPPER], &list);
1006 while (!list_empty(&list)) {
1007 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1008 list_del_init(&edge->list[UPPER]);
1009 upper = edge->node[UPPER];
1010 if (upper->detached) {
1011 list_del(&edge->list[LOWER]);
1012 lower = edge->node[LOWER];
1013 free_backref_edge(cache, edge);
1014 if (list_empty(&lower->upper))
1015 list_add(&lower->list, &useless);
1019 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1020 if (upper->lowest) {
1021 list_del_init(&upper->lower);
1025 list_add_tail(&edge->list[UPPER], &upper->lower);
1029 BUG_ON(!upper->checked);
1030 BUG_ON(cowonly != upper->cowonly);
1032 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1037 list_add_tail(&edge->list[UPPER], &upper->lower);
1039 list_for_each_entry(edge, &upper->upper, list[LOWER])
1040 list_add_tail(&edge->list[UPPER], &list);
1043 * process useless backref nodes. backref nodes for tree leaves
1044 * are deleted from the cache. backref nodes for upper level
1045 * tree blocks are left in the cache to avoid unnecessary backref
1048 while (!list_empty(&useless)) {
1049 upper = list_entry(useless.next, struct backref_node, list);
1050 list_del_init(&upper->list);
1051 BUG_ON(!list_empty(&upper->upper));
1054 if (upper->lowest) {
1055 list_del_init(&upper->lower);
1058 while (!list_empty(&upper->lower)) {
1059 edge = list_entry(upper->lower.next,
1060 struct backref_edge, list[UPPER]);
1061 list_del(&edge->list[UPPER]);
1062 list_del(&edge->list[LOWER]);
1063 lower = edge->node[LOWER];
1064 free_backref_edge(cache, edge);
1066 if (list_empty(&lower->upper))
1067 list_add(&lower->list, &useless);
1069 __mark_block_processed(rc, upper);
1070 if (upper->level > 0) {
1071 list_add(&upper->list, &cache->detached);
1072 upper->detached = 1;
1074 rb_erase(&upper->rb_node, &cache->rb_root);
1075 free_backref_node(cache, upper);
1079 btrfs_free_path(path1);
1080 btrfs_free_path(path2);
1082 while (!list_empty(&useless)) {
1083 lower = list_entry(useless.next,
1084 struct backref_node, upper);
1085 list_del_init(&lower->upper);
1088 INIT_LIST_HEAD(&list);
1090 if (RB_EMPTY_NODE(&upper->rb_node)) {
1091 list_splice_tail(&upper->upper, &list);
1092 free_backref_node(cache, upper);
1095 if (list_empty(&list))
1098 edge = list_entry(list.next, struct backref_edge,
1100 list_del(&edge->list[LOWER]);
1101 upper = edge->node[UPPER];
1102 free_backref_edge(cache, edge);
1104 return ERR_PTR(err);
1106 BUG_ON(node && node->detached);
1111 * helper to add backref node for the newly created snapshot.
1112 * the backref node is created by cloning backref node that
1113 * corresponds to root of source tree
1115 static int clone_backref_node(struct btrfs_trans_handle *trans,
1116 struct reloc_control *rc,
1117 struct btrfs_root *src,
1118 struct btrfs_root *dest)
1120 struct btrfs_root *reloc_root = src->reloc_root;
1121 struct backref_cache *cache = &rc->backref_cache;
1122 struct backref_node *node = NULL;
1123 struct backref_node *new_node;
1124 struct backref_edge *edge;
1125 struct backref_edge *new_edge;
1126 struct rb_node *rb_node;
1128 if (cache->last_trans > 0)
1129 update_backref_cache(trans, cache);
1131 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1133 node = rb_entry(rb_node, struct backref_node, rb_node);
1137 BUG_ON(node->new_bytenr != reloc_root->node->start);
1141 rb_node = tree_search(&cache->rb_root,
1142 reloc_root->commit_root->start);
1144 node = rb_entry(rb_node, struct backref_node,
1146 BUG_ON(node->detached);
1153 new_node = alloc_backref_node(cache);
1157 new_node->bytenr = dest->node->start;
1158 new_node->level = node->level;
1159 new_node->lowest = node->lowest;
1160 new_node->checked = 1;
1161 new_node->root = dest;
1163 if (!node->lowest) {
1164 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1165 new_edge = alloc_backref_edge(cache);
1169 new_edge->node[UPPER] = new_node;
1170 new_edge->node[LOWER] = edge->node[LOWER];
1171 list_add_tail(&new_edge->list[UPPER],
1176 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1177 &new_node->rb_node);
1180 if (!new_node->lowest) {
1181 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1182 list_add_tail(&new_edge->list[LOWER],
1183 &new_edge->node[LOWER]->upper);
1188 while (!list_empty(&new_node->lower)) {
1189 new_edge = list_entry(new_node->lower.next,
1190 struct backref_edge, list[UPPER]);
1191 list_del(&new_edge->list[UPPER]);
1192 free_backref_edge(cache, new_edge);
1194 free_backref_node(cache, new_node);
1199 * helper to add 'address of tree root -> reloc tree' mapping
1201 static int __add_reloc_root(struct btrfs_root *root)
1203 struct rb_node *rb_node;
1204 struct mapping_node *node;
1205 struct reloc_control *rc = root->fs_info->reloc_ctl;
1207 node = kmalloc(sizeof(*node), GFP_NOFS);
1210 node->bytenr = root->node->start;
1213 spin_lock(&rc->reloc_root_tree.lock);
1214 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1215 node->bytenr, &node->rb_node);
1216 spin_unlock(&rc->reloc_root_tree.lock);
1219 list_add_tail(&root->root_list, &rc->reloc_roots);
1224 * helper to update/delete the 'address of tree root -> reloc tree'
1227 static int __update_reloc_root(struct btrfs_root *root, int del)
1229 struct rb_node *rb_node;
1230 struct mapping_node *node = NULL;
1231 struct reloc_control *rc = root->fs_info->reloc_ctl;
1233 spin_lock(&rc->reloc_root_tree.lock);
1234 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1235 root->commit_root->start);
1237 node = rb_entry(rb_node, struct mapping_node, rb_node);
1238 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1240 spin_unlock(&rc->reloc_root_tree.lock);
1242 BUG_ON((struct btrfs_root *)node->data != root);
1245 spin_lock(&rc->reloc_root_tree.lock);
1246 node->bytenr = root->node->start;
1247 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1248 node->bytenr, &node->rb_node);
1249 spin_unlock(&rc->reloc_root_tree.lock);
1252 list_del_init(&root->root_list);
1258 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1259 struct btrfs_root *root, u64 objectid)
1261 struct btrfs_root *reloc_root;
1262 struct extent_buffer *eb;
1263 struct btrfs_root_item *root_item;
1264 struct btrfs_key root_key;
1267 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1270 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1271 root_key.type = BTRFS_ROOT_ITEM_KEY;
1272 root_key.offset = objectid;
1274 if (root->root_key.objectid == objectid) {
1275 /* called by btrfs_init_reloc_root */
1276 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1277 BTRFS_TREE_RELOC_OBJECTID);
1280 btrfs_set_root_last_snapshot(&root->root_item,
1281 trans->transid - 1);
1284 * called by btrfs_reloc_post_snapshot_hook.
1285 * the source tree is a reloc tree, all tree blocks
1286 * modified after it was created have RELOC flag
1287 * set in their headers. so it's OK to not update
1288 * the 'last_snapshot'.
1290 ret = btrfs_copy_root(trans, root, root->node, &eb,
1291 BTRFS_TREE_RELOC_OBJECTID);
1295 memcpy(root_item, &root->root_item, sizeof(*root_item));
1296 btrfs_set_root_bytenr(root_item, eb->start);
1297 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1298 btrfs_set_root_generation(root_item, trans->transid);
1300 if (root->root_key.objectid == objectid) {
1301 btrfs_set_root_refs(root_item, 0);
1302 memset(&root_item->drop_progress, 0,
1303 sizeof(struct btrfs_disk_key));
1304 root_item->drop_level = 0;
1307 btrfs_tree_unlock(eb);
1308 free_extent_buffer(eb);
1310 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1311 &root_key, root_item);
1315 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
1317 BUG_ON(IS_ERR(reloc_root));
1318 reloc_root->last_trans = trans->transid;
1323 * create reloc tree for a given fs tree. reloc tree is just a
1324 * snapshot of the fs tree with special root objectid.
1326 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1327 struct btrfs_root *root)
1329 struct btrfs_root *reloc_root;
1330 struct reloc_control *rc = root->fs_info->reloc_ctl;
1333 if (root->reloc_root) {
1334 reloc_root = root->reloc_root;
1335 reloc_root->last_trans = trans->transid;
1339 if (!rc || !rc->create_reloc_tree ||
1340 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1343 if (!trans->block_rsv) {
1344 trans->block_rsv = rc->block_rsv;
1347 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1349 trans->block_rsv = NULL;
1351 __add_reloc_root(reloc_root);
1352 root->reloc_root = reloc_root;
1357 * update root item of reloc tree
1359 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1360 struct btrfs_root *root)
1362 struct btrfs_root *reloc_root;
1363 struct btrfs_root_item *root_item;
1367 if (!root->reloc_root)
1370 reloc_root = root->reloc_root;
1371 root_item = &reloc_root->root_item;
1373 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1374 btrfs_root_refs(root_item) == 0) {
1375 root->reloc_root = NULL;
1379 __update_reloc_root(reloc_root, del);
1381 if (reloc_root->commit_root != reloc_root->node) {
1382 btrfs_set_root_node(root_item, reloc_root->node);
1383 free_extent_buffer(reloc_root->commit_root);
1384 reloc_root->commit_root = btrfs_root_node(reloc_root);
1387 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1388 &reloc_root->root_key, root_item);
1394 * helper to find first cached inode with inode number >= objectid
1397 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1399 struct rb_node *node;
1400 struct rb_node *prev;
1401 struct btrfs_inode *entry;
1402 struct inode *inode;
1404 spin_lock(&root->inode_lock);
1406 node = root->inode_tree.rb_node;
1410 entry = rb_entry(node, struct btrfs_inode, rb_node);
1412 if (objectid < entry->vfs_inode.i_ino)
1413 node = node->rb_left;
1414 else if (objectid > entry->vfs_inode.i_ino)
1415 node = node->rb_right;
1421 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1422 if (objectid <= entry->vfs_inode.i_ino) {
1426 prev = rb_next(prev);
1430 entry = rb_entry(node, struct btrfs_inode, rb_node);
1431 inode = igrab(&entry->vfs_inode);
1433 spin_unlock(&root->inode_lock);
1437 objectid = entry->vfs_inode.i_ino + 1;
1438 if (cond_resched_lock(&root->inode_lock))
1441 node = rb_next(node);
1443 spin_unlock(&root->inode_lock);
1447 static int in_block_group(u64 bytenr,
1448 struct btrfs_block_group_cache *block_group)
1450 if (bytenr >= block_group->key.objectid &&
1451 bytenr < block_group->key.objectid + block_group->key.offset)
1457 * get new location of data
1459 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1460 u64 bytenr, u64 num_bytes)
1462 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1463 struct btrfs_path *path;
1464 struct btrfs_file_extent_item *fi;
1465 struct extent_buffer *leaf;
1468 path = btrfs_alloc_path();
1472 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1473 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
1482 leaf = path->nodes[0];
1483 fi = btrfs_item_ptr(leaf, path->slots[0],
1484 struct btrfs_file_extent_item);
1486 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1487 btrfs_file_extent_compression(leaf, fi) ||
1488 btrfs_file_extent_encryption(leaf, fi) ||
1489 btrfs_file_extent_other_encoding(leaf, fi));
1491 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1496 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1499 btrfs_free_path(path);
1504 * update file extent items in the tree leaf to point to
1505 * the new locations.
1507 static noinline_for_stack
1508 int replace_file_extents(struct btrfs_trans_handle *trans,
1509 struct reloc_control *rc,
1510 struct btrfs_root *root,
1511 struct extent_buffer *leaf)
1513 struct btrfs_key key;
1514 struct btrfs_file_extent_item *fi;
1515 struct inode *inode = NULL;
1527 if (rc->stage != UPDATE_DATA_PTRS)
1530 /* reloc trees always use full backref */
1531 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1532 parent = leaf->start;
1536 nritems = btrfs_header_nritems(leaf);
1537 for (i = 0; i < nritems; i++) {
1539 btrfs_item_key_to_cpu(leaf, &key, i);
1540 if (key.type != BTRFS_EXTENT_DATA_KEY)
1542 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1543 if (btrfs_file_extent_type(leaf, fi) ==
1544 BTRFS_FILE_EXTENT_INLINE)
1546 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1547 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1550 if (!in_block_group(bytenr, rc->block_group))
1554 * if we are modifying block in fs tree, wait for readpage
1555 * to complete and drop the extent cache
1557 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1559 inode = find_next_inode(root, key.objectid);
1561 } else if (inode && inode->i_ino < key.objectid) {
1562 btrfs_add_delayed_iput(inode);
1563 inode = find_next_inode(root, key.objectid);
1565 if (inode && inode->i_ino == key.objectid) {
1567 btrfs_file_extent_num_bytes(leaf, fi);
1568 WARN_ON(!IS_ALIGNED(key.offset,
1570 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1572 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1578 btrfs_drop_extent_cache(inode, key.offset, end,
1580 unlock_extent(&BTRFS_I(inode)->io_tree,
1581 key.offset, end, GFP_NOFS);
1585 ret = get_new_location(rc->data_inode, &new_bytenr,
1593 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1596 key.offset -= btrfs_file_extent_offset(leaf, fi);
1597 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1599 btrfs_header_owner(leaf),
1600 key.objectid, key.offset);
1603 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1604 parent, btrfs_header_owner(leaf),
1605 key.objectid, key.offset);
1609 btrfs_mark_buffer_dirty(leaf);
1611 btrfs_add_delayed_iput(inode);
1615 static noinline_for_stack
1616 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1617 struct btrfs_path *path, int level)
1619 struct btrfs_disk_key key1;
1620 struct btrfs_disk_key key2;
1621 btrfs_node_key(eb, &key1, slot);
1622 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1623 return memcmp(&key1, &key2, sizeof(key1));
1627 * try to replace tree blocks in fs tree with the new blocks
1628 * in reloc tree. tree blocks haven't been modified since the
1629 * reloc tree was create can be replaced.
1631 * if a block was replaced, level of the block + 1 is returned.
1632 * if no block got replaced, 0 is returned. if there are other
1633 * errors, a negative error number is returned.
1635 static noinline_for_stack
1636 int replace_path(struct btrfs_trans_handle *trans,
1637 struct btrfs_root *dest, struct btrfs_root *src,
1638 struct btrfs_path *path, struct btrfs_key *next_key,
1639 int lowest_level, int max_level)
1641 struct extent_buffer *eb;
1642 struct extent_buffer *parent;
1643 struct btrfs_key key;
1655 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1656 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1658 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1660 slot = path->slots[lowest_level];
1661 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1663 eb = btrfs_lock_root_node(dest);
1664 btrfs_set_lock_blocking(eb);
1665 level = btrfs_header_level(eb);
1667 if (level < lowest_level) {
1668 btrfs_tree_unlock(eb);
1669 free_extent_buffer(eb);
1674 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1677 btrfs_set_lock_blocking(eb);
1680 next_key->objectid = (u64)-1;
1681 next_key->type = (u8)-1;
1682 next_key->offset = (u64)-1;
1687 level = btrfs_header_level(parent);
1688 BUG_ON(level < lowest_level);
1690 ret = btrfs_bin_search(parent, &key, level, &slot);
1691 if (ret && slot > 0)
1694 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1695 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1697 old_bytenr = btrfs_node_blockptr(parent, slot);
1698 blocksize = btrfs_level_size(dest, level - 1);
1699 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1701 if (level <= max_level) {
1702 eb = path->nodes[level];
1703 new_bytenr = btrfs_node_blockptr(eb,
1704 path->slots[level]);
1705 new_ptr_gen = btrfs_node_ptr_generation(eb,
1706 path->slots[level]);
1712 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1718 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1719 memcmp_node_keys(parent, slot, path, level)) {
1720 if (level <= lowest_level) {
1725 eb = read_tree_block(dest, old_bytenr, blocksize,
1728 btrfs_tree_lock(eb);
1730 ret = btrfs_cow_block(trans, dest, eb, parent,
1734 btrfs_set_lock_blocking(eb);
1736 btrfs_tree_unlock(parent);
1737 free_extent_buffer(parent);
1744 btrfs_tree_unlock(parent);
1745 free_extent_buffer(parent);
1750 btrfs_node_key_to_cpu(path->nodes[level], &key,
1751 path->slots[level]);
1752 btrfs_release_path(src, path);
1754 path->lowest_level = level;
1755 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1756 path->lowest_level = 0;
1760 * swap blocks in fs tree and reloc tree.
1762 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1763 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1764 btrfs_mark_buffer_dirty(parent);
1766 btrfs_set_node_blockptr(path->nodes[level],
1767 path->slots[level], old_bytenr);
1768 btrfs_set_node_ptr_generation(path->nodes[level],
1769 path->slots[level], old_ptr_gen);
1770 btrfs_mark_buffer_dirty(path->nodes[level]);
1772 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1773 path->nodes[level]->start,
1774 src->root_key.objectid, level - 1, 0);
1776 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1777 0, dest->root_key.objectid, level - 1,
1781 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1782 path->nodes[level]->start,
1783 src->root_key.objectid, level - 1, 0);
1786 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1787 0, dest->root_key.objectid, level - 1,
1791 btrfs_unlock_up_safe(path, 0);
1796 btrfs_tree_unlock(parent);
1797 free_extent_buffer(parent);
1802 * helper to find next relocated block in reloc tree
1804 static noinline_for_stack
1805 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1808 struct extent_buffer *eb;
1813 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1815 for (i = 0; i < *level; i++) {
1816 free_extent_buffer(path->nodes[i]);
1817 path->nodes[i] = NULL;
1820 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1821 eb = path->nodes[i];
1822 nritems = btrfs_header_nritems(eb);
1823 while (path->slots[i] + 1 < nritems) {
1825 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1832 free_extent_buffer(path->nodes[i]);
1833 path->nodes[i] = NULL;
1839 * walk down reloc tree to find relocated block of lowest level
1841 static noinline_for_stack
1842 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1845 struct extent_buffer *eb = NULL;
1853 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1855 for (i = *level; i > 0; i--) {
1856 eb = path->nodes[i];
1857 nritems = btrfs_header_nritems(eb);
1858 while (path->slots[i] < nritems) {
1859 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1860 if (ptr_gen > last_snapshot)
1864 if (path->slots[i] >= nritems) {
1875 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1876 blocksize = btrfs_level_size(root, i - 1);
1877 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1878 BUG_ON(btrfs_header_level(eb) != i - 1);
1879 path->nodes[i - 1] = eb;
1880 path->slots[i - 1] = 0;
1886 * invalidate extent cache for file extents whose key in range of
1887 * [min_key, max_key)
1889 static int invalidate_extent_cache(struct btrfs_root *root,
1890 struct btrfs_key *min_key,
1891 struct btrfs_key *max_key)
1893 struct inode *inode = NULL;
1897 objectid = min_key->objectid;
1902 if (objectid > max_key->objectid)
1905 inode = find_next_inode(root, objectid);
1909 if (inode->i_ino > max_key->objectid) {
1914 objectid = inode->i_ino + 1;
1915 if (!S_ISREG(inode->i_mode))
1918 if (unlikely(min_key->objectid == inode->i_ino)) {
1919 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1921 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1924 start = min_key->offset;
1925 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1931 if (unlikely(max_key->objectid == inode->i_ino)) {
1932 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1934 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
1937 if (max_key->offset == 0)
1939 end = max_key->offset;
1940 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1947 /* the lock_extent waits for readpage to complete */
1948 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1949 btrfs_drop_extent_cache(inode, start, end, 1);
1950 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1955 static int find_next_key(struct btrfs_path *path, int level,
1956 struct btrfs_key *key)
1959 while (level < BTRFS_MAX_LEVEL) {
1960 if (!path->nodes[level])
1962 if (path->slots[level] + 1 <
1963 btrfs_header_nritems(path->nodes[level])) {
1964 btrfs_node_key_to_cpu(path->nodes[level], key,
1965 path->slots[level] + 1);
1974 * merge the relocated tree blocks in reloc tree with corresponding
1977 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
1978 struct btrfs_root *root)
1980 LIST_HEAD(inode_list);
1981 struct btrfs_key key;
1982 struct btrfs_key next_key;
1983 struct btrfs_trans_handle *trans;
1984 struct btrfs_root *reloc_root;
1985 struct btrfs_root_item *root_item;
1986 struct btrfs_path *path;
1987 struct extent_buffer *leaf;
1996 path = btrfs_alloc_path();
2000 reloc_root = root->reloc_root;
2001 root_item = &reloc_root->root_item;
2003 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2004 level = btrfs_root_level(root_item);
2005 extent_buffer_get(reloc_root->node);
2006 path->nodes[level] = reloc_root->node;
2007 path->slots[level] = 0;
2009 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2011 level = root_item->drop_level;
2013 path->lowest_level = level;
2014 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2015 path->lowest_level = 0;
2017 btrfs_free_path(path);
2021 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2022 path->slots[level]);
2023 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2025 btrfs_unlock_up_safe(path, 0);
2028 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2029 memset(&next_key, 0, sizeof(next_key));
2032 trans = btrfs_start_transaction(root, 0);
2033 BUG_ON(IS_ERR(trans));
2034 trans->block_rsv = rc->block_rsv;
2036 ret = btrfs_block_rsv_check(trans, root, rc->block_rsv,
2039 BUG_ON(ret != -EAGAIN);
2040 ret = btrfs_commit_transaction(trans, root);
2048 ret = walk_down_reloc_tree(reloc_root, path, &level);
2056 if (!find_next_key(path, level, &key) &&
2057 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2060 ret = replace_path(trans, root, reloc_root, path,
2061 &next_key, level, max_level);
2070 btrfs_node_key_to_cpu(path->nodes[level], &key,
2071 path->slots[level]);
2075 ret = walk_up_reloc_tree(reloc_root, path, &level);
2081 * save the merging progress in the drop_progress.
2082 * this is OK since root refs == 1 in this case.
2084 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2085 path->slots[level]);
2086 root_item->drop_level = level;
2088 nr = trans->blocks_used;
2089 btrfs_end_transaction_throttle(trans, root);
2091 btrfs_btree_balance_dirty(root, nr);
2093 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2094 invalidate_extent_cache(root, &key, &next_key);
2098 * handle the case only one block in the fs tree need to be
2099 * relocated and the block is tree root.
2101 leaf = btrfs_lock_root_node(root);
2102 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2103 btrfs_tree_unlock(leaf);
2104 free_extent_buffer(leaf);
2108 btrfs_free_path(path);
2111 memset(&root_item->drop_progress, 0,
2112 sizeof(root_item->drop_progress));
2113 root_item->drop_level = 0;
2114 btrfs_set_root_refs(root_item, 0);
2115 btrfs_update_reloc_root(trans, root);
2118 nr = trans->blocks_used;
2119 btrfs_end_transaction_throttle(trans, root);
2121 btrfs_btree_balance_dirty(root, nr);
2123 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2124 invalidate_extent_cache(root, &key, &next_key);
2129 static noinline_for_stack
2130 int prepare_to_merge(struct reloc_control *rc, int err)
2132 struct btrfs_root *root = rc->extent_root;
2133 struct btrfs_root *reloc_root;
2134 struct btrfs_trans_handle *trans;
2135 LIST_HEAD(reloc_roots);
2139 mutex_lock(&root->fs_info->trans_mutex);
2140 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2141 rc->merging_rsv_size += rc->nodes_relocated * 2;
2142 mutex_unlock(&root->fs_info->trans_mutex);
2145 num_bytes = rc->merging_rsv_size;
2146 ret = btrfs_block_rsv_add(NULL, root, rc->block_rsv,
2152 trans = btrfs_join_transaction(rc->extent_root, 1);
2153 if (IS_ERR(trans)) {
2155 btrfs_block_rsv_release(rc->extent_root,
2156 rc->block_rsv, num_bytes);
2157 return PTR_ERR(trans);
2161 if (num_bytes != rc->merging_rsv_size) {
2162 btrfs_end_transaction(trans, rc->extent_root);
2163 btrfs_block_rsv_release(rc->extent_root,
2164 rc->block_rsv, num_bytes);
2169 rc->merge_reloc_tree = 1;
2171 while (!list_empty(&rc->reloc_roots)) {
2172 reloc_root = list_entry(rc->reloc_roots.next,
2173 struct btrfs_root, root_list);
2174 list_del_init(&reloc_root->root_list);
2176 root = read_fs_root(reloc_root->fs_info,
2177 reloc_root->root_key.offset);
2178 BUG_ON(IS_ERR(root));
2179 BUG_ON(root->reloc_root != reloc_root);
2182 * set reference count to 1, so btrfs_recover_relocation
2183 * knows it should resumes merging
2186 btrfs_set_root_refs(&reloc_root->root_item, 1);
2187 btrfs_update_reloc_root(trans, root);
2189 list_add(&reloc_root->root_list, &reloc_roots);
2192 list_splice(&reloc_roots, &rc->reloc_roots);
2195 btrfs_commit_transaction(trans, rc->extent_root);
2197 btrfs_end_transaction(trans, rc->extent_root);
2201 static noinline_for_stack
2202 int merge_reloc_roots(struct reloc_control *rc)
2204 struct btrfs_root *root;
2205 struct btrfs_root *reloc_root;
2206 LIST_HEAD(reloc_roots);
2210 root = rc->extent_root;
2211 mutex_lock(&root->fs_info->trans_mutex);
2212 list_splice_init(&rc->reloc_roots, &reloc_roots);
2213 mutex_unlock(&root->fs_info->trans_mutex);
2215 while (!list_empty(&reloc_roots)) {
2217 reloc_root = list_entry(reloc_roots.next,
2218 struct btrfs_root, root_list);
2220 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2221 root = read_fs_root(reloc_root->fs_info,
2222 reloc_root->root_key.offset);
2223 BUG_ON(IS_ERR(root));
2224 BUG_ON(root->reloc_root != reloc_root);
2226 ret = merge_reloc_root(rc, root);
2229 list_del_init(&reloc_root->root_list);
2231 btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0);
2238 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2242 static void free_block_list(struct rb_root *blocks)
2244 struct tree_block *block;
2245 struct rb_node *rb_node;
2246 while ((rb_node = rb_first(blocks))) {
2247 block = rb_entry(rb_node, struct tree_block, rb_node);
2248 rb_erase(rb_node, blocks);
2253 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2254 struct btrfs_root *reloc_root)
2256 struct btrfs_root *root;
2258 if (reloc_root->last_trans == trans->transid)
2261 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2262 BUG_ON(IS_ERR(root));
2263 BUG_ON(root->reloc_root != reloc_root);
2265 return btrfs_record_root_in_trans(trans, root);
2268 static noinline_for_stack
2269 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2270 struct reloc_control *rc,
2271 struct backref_node *node,
2272 struct backref_edge *edges[], int *nr)
2274 struct backref_node *next;
2275 struct btrfs_root *root;
2281 next = walk_up_backref(next, edges, &index);
2284 BUG_ON(!root->ref_cows);
2286 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2287 record_reloc_root_in_trans(trans, root);
2291 btrfs_record_root_in_trans(trans, root);
2292 root = root->reloc_root;
2294 if (next->new_bytenr != root->node->start) {
2295 BUG_ON(next->new_bytenr);
2296 BUG_ON(!list_empty(&next->list));
2297 next->new_bytenr = root->node->start;
2299 list_add_tail(&next->list,
2300 &rc->backref_cache.changed);
2301 __mark_block_processed(rc, next);
2307 next = walk_down_backref(edges, &index);
2308 if (!next || next->level <= node->level)
2316 /* setup backref node path for btrfs_reloc_cow_block */
2318 rc->backref_cache.path[next->level] = next;
2321 next = edges[index]->node[UPPER];
2327 * select a tree root for relocation. return NULL if the block
2328 * is reference counted. we should use do_relocation() in this
2329 * case. return a tree root pointer if the block isn't reference
2330 * counted. return -ENOENT if the block is root of reloc tree.
2332 static noinline_for_stack
2333 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2334 struct backref_node *node)
2336 struct backref_node *next;
2337 struct btrfs_root *root;
2338 struct btrfs_root *fs_root = NULL;
2339 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2345 next = walk_up_backref(next, edges, &index);
2349 /* no other choice for non-references counted tree */
2350 if (!root->ref_cows)
2353 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2359 next = walk_down_backref(edges, &index);
2360 if (!next || next->level <= node->level)
2365 return ERR_PTR(-ENOENT);
2369 static noinline_for_stack
2370 u64 calcu_metadata_size(struct reloc_control *rc,
2371 struct backref_node *node, int reserve)
2373 struct backref_node *next = node;
2374 struct backref_edge *edge;
2375 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2379 BUG_ON(reserve && node->processed);
2384 if (next->processed && (reserve || next != node))
2387 num_bytes += btrfs_level_size(rc->extent_root,
2390 if (list_empty(&next->upper))
2393 edge = list_entry(next->upper.next,
2394 struct backref_edge, list[LOWER]);
2395 edges[index++] = edge;
2396 next = edge->node[UPPER];
2398 next = walk_down_backref(edges, &index);
2403 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2404 struct reloc_control *rc,
2405 struct backref_node *node)
2407 struct btrfs_root *root = rc->extent_root;
2411 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2413 trans->block_rsv = rc->block_rsv;
2414 ret = btrfs_block_rsv_add(trans, root, rc->block_rsv, num_bytes);
2417 rc->commit_transaction = 1;
2424 static void release_metadata_space(struct reloc_control *rc,
2425 struct backref_node *node)
2427 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2428 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2432 * relocate a block tree, and then update pointers in upper level
2433 * blocks that reference the block to point to the new location.
2435 * if called by link_to_upper, the block has already been relocated.
2436 * in that case this function just updates pointers.
2438 static int do_relocation(struct btrfs_trans_handle *trans,
2439 struct reloc_control *rc,
2440 struct backref_node *node,
2441 struct btrfs_key *key,
2442 struct btrfs_path *path, int lowest)
2444 struct backref_node *upper;
2445 struct backref_edge *edge;
2446 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2447 struct btrfs_root *root;
2448 struct extent_buffer *eb;
2457 BUG_ON(lowest && node->eb);
2459 path->lowest_level = node->level + 1;
2460 rc->backref_cache.path[node->level] = node;
2461 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2464 upper = edge->node[UPPER];
2465 root = select_reloc_root(trans, rc, upper, edges, &nr);
2468 if (upper->eb && !upper->locked) {
2470 ret = btrfs_bin_search(upper->eb, key,
2471 upper->level, &slot);
2473 bytenr = btrfs_node_blockptr(upper->eb, slot);
2474 if (node->eb->start == bytenr)
2477 drop_node_buffer(upper);
2481 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2489 upper->eb = path->nodes[upper->level];
2490 path->nodes[upper->level] = NULL;
2492 BUG_ON(upper->eb != path->nodes[upper->level]);
2496 path->locks[upper->level] = 0;
2498 slot = path->slots[upper->level];
2499 btrfs_release_path(NULL, path);
2501 ret = btrfs_bin_search(upper->eb, key, upper->level,
2506 bytenr = btrfs_node_blockptr(upper->eb, slot);
2508 BUG_ON(bytenr != node->bytenr);
2510 if (node->eb->start == bytenr)
2514 blocksize = btrfs_level_size(root, node->level);
2515 generation = btrfs_node_ptr_generation(upper->eb, slot);
2516 eb = read_tree_block(root, bytenr, blocksize, generation);
2521 btrfs_tree_lock(eb);
2522 btrfs_set_lock_blocking(eb);
2525 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2527 btrfs_tree_unlock(eb);
2528 free_extent_buffer(eb);
2533 BUG_ON(node->eb != eb);
2535 btrfs_set_node_blockptr(upper->eb, slot,
2537 btrfs_set_node_ptr_generation(upper->eb, slot,
2539 btrfs_mark_buffer_dirty(upper->eb);
2541 ret = btrfs_inc_extent_ref(trans, root,
2542 node->eb->start, blocksize,
2544 btrfs_header_owner(upper->eb),
2548 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2552 if (!upper->pending)
2553 drop_node_buffer(upper);
2555 unlock_node_buffer(upper);
2560 if (!err && node->pending) {
2561 drop_node_buffer(node);
2562 list_move_tail(&node->list, &rc->backref_cache.changed);
2566 path->lowest_level = 0;
2567 BUG_ON(err == -ENOSPC);
2571 static int link_to_upper(struct btrfs_trans_handle *trans,
2572 struct reloc_control *rc,
2573 struct backref_node *node,
2574 struct btrfs_path *path)
2576 struct btrfs_key key;
2578 btrfs_node_key_to_cpu(node->eb, &key, 0);
2579 return do_relocation(trans, rc, node, &key, path, 0);
2582 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2583 struct reloc_control *rc,
2584 struct btrfs_path *path, int err)
2587 struct backref_cache *cache = &rc->backref_cache;
2588 struct backref_node *node;
2592 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2593 while (!list_empty(&cache->pending[level])) {
2594 node = list_entry(cache->pending[level].next,
2595 struct backref_node, list);
2596 list_move_tail(&node->list, &list);
2597 BUG_ON(!node->pending);
2600 ret = link_to_upper(trans, rc, node, path);
2605 list_splice_init(&list, &cache->pending[level]);
2610 static void mark_block_processed(struct reloc_control *rc,
2611 u64 bytenr, u32 blocksize)
2613 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2614 EXTENT_DIRTY, GFP_NOFS);
2617 static void __mark_block_processed(struct reloc_control *rc,
2618 struct backref_node *node)
2621 if (node->level == 0 ||
2622 in_block_group(node->bytenr, rc->block_group)) {
2623 blocksize = btrfs_level_size(rc->extent_root, node->level);
2624 mark_block_processed(rc, node->bytenr, blocksize);
2626 node->processed = 1;
2630 * mark a block and all blocks directly/indirectly reference the block
2633 static void update_processed_blocks(struct reloc_control *rc,
2634 struct backref_node *node)
2636 struct backref_node *next = node;
2637 struct backref_edge *edge;
2638 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2644 if (next->processed)
2647 __mark_block_processed(rc, next);
2649 if (list_empty(&next->upper))
2652 edge = list_entry(next->upper.next,
2653 struct backref_edge, list[LOWER]);
2654 edges[index++] = edge;
2655 next = edge->node[UPPER];
2657 next = walk_down_backref(edges, &index);
2661 static int tree_block_processed(u64 bytenr, u32 blocksize,
2662 struct reloc_control *rc)
2664 if (test_range_bit(&rc->processed_blocks, bytenr,
2665 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2670 static int get_tree_block_key(struct reloc_control *rc,
2671 struct tree_block *block)
2673 struct extent_buffer *eb;
2675 BUG_ON(block->key_ready);
2676 eb = read_tree_block(rc->extent_root, block->bytenr,
2677 block->key.objectid, block->key.offset);
2679 WARN_ON(btrfs_header_level(eb) != block->level);
2680 if (block->level == 0)
2681 btrfs_item_key_to_cpu(eb, &block->key, 0);
2683 btrfs_node_key_to_cpu(eb, &block->key, 0);
2684 free_extent_buffer(eb);
2685 block->key_ready = 1;
2689 static int reada_tree_block(struct reloc_control *rc,
2690 struct tree_block *block)
2692 BUG_ON(block->key_ready);
2693 readahead_tree_block(rc->extent_root, block->bytenr,
2694 block->key.objectid, block->key.offset);
2699 * helper function to relocate a tree block
2701 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2702 struct reloc_control *rc,
2703 struct backref_node *node,
2704 struct btrfs_key *key,
2705 struct btrfs_path *path)
2707 struct btrfs_root *root;
2714 BUG_ON(node->processed);
2715 root = select_one_root(trans, node);
2716 if (root == ERR_PTR(-ENOENT)) {
2717 update_processed_blocks(rc, node);
2721 if (!root || root->ref_cows) {
2722 ret = reserve_metadata_space(trans, rc, node);
2729 if (root->ref_cows) {
2730 BUG_ON(node->new_bytenr);
2731 BUG_ON(!list_empty(&node->list));
2732 btrfs_record_root_in_trans(trans, root);
2733 root = root->reloc_root;
2734 node->new_bytenr = root->node->start;
2736 list_add_tail(&node->list, &rc->backref_cache.changed);
2738 path->lowest_level = node->level;
2739 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2740 btrfs_release_path(root, path);
2745 update_processed_blocks(rc, node);
2747 ret = do_relocation(trans, rc, node, key, path, 1);
2750 if (ret || node->level == 0 || node->cowonly) {
2752 release_metadata_space(rc, node);
2753 remove_backref_node(&rc->backref_cache, node);
2759 * relocate a list of blocks
2761 static noinline_for_stack
2762 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2763 struct reloc_control *rc, struct rb_root *blocks)
2765 struct backref_node *node;
2766 struct btrfs_path *path;
2767 struct tree_block *block;
2768 struct rb_node *rb_node;
2772 path = btrfs_alloc_path();
2776 rb_node = rb_first(blocks);
2778 block = rb_entry(rb_node, struct tree_block, rb_node);
2779 if (!block->key_ready)
2780 reada_tree_block(rc, block);
2781 rb_node = rb_next(rb_node);
2784 rb_node = rb_first(blocks);
2786 block = rb_entry(rb_node, struct tree_block, rb_node);
2787 if (!block->key_ready)
2788 get_tree_block_key(rc, block);
2789 rb_node = rb_next(rb_node);
2792 rb_node = rb_first(blocks);
2794 block = rb_entry(rb_node, struct tree_block, rb_node);
2796 node = build_backref_tree(rc, &block->key,
2797 block->level, block->bytenr);
2799 err = PTR_ERR(node);
2803 ret = relocate_tree_block(trans, rc, node, &block->key,
2806 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2810 rb_node = rb_next(rb_node);
2813 free_block_list(blocks);
2814 err = finish_pending_nodes(trans, rc, path, err);
2816 btrfs_free_path(path);
2820 static noinline_for_stack
2821 int prealloc_file_extent_cluster(struct inode *inode,
2822 struct file_extent_cluster *cluster)
2827 u64 offset = BTRFS_I(inode)->index_cnt;
2832 BUG_ON(cluster->start != cluster->boundary[0]);
2833 mutex_lock(&inode->i_mutex);
2835 ret = btrfs_check_data_free_space(inode, cluster->end +
2836 1 - cluster->start);
2840 while (nr < cluster->nr) {
2841 start = cluster->boundary[nr] - offset;
2842 if (nr + 1 < cluster->nr)
2843 end = cluster->boundary[nr + 1] - 1 - offset;
2845 end = cluster->end - offset;
2847 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2848 num_bytes = end + 1 - start;
2849 ret = btrfs_prealloc_file_range(inode, 0, start,
2850 num_bytes, num_bytes,
2851 end + 1, &alloc_hint);
2852 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2857 btrfs_free_reserved_data_space(inode, cluster->end +
2858 1 - cluster->start);
2860 mutex_unlock(&inode->i_mutex);
2864 static noinline_for_stack
2865 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
2868 struct btrfs_root *root = BTRFS_I(inode)->root;
2869 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2870 struct extent_map *em;
2873 em = alloc_extent_map(GFP_NOFS);
2878 em->len = end + 1 - start;
2879 em->block_len = em->len;
2880 em->block_start = block_start;
2881 em->bdev = root->fs_info->fs_devices->latest_bdev;
2882 set_bit(EXTENT_FLAG_PINNED, &em->flags);
2884 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2886 write_lock(&em_tree->lock);
2887 ret = add_extent_mapping(em_tree, em);
2888 write_unlock(&em_tree->lock);
2889 if (ret != -EEXIST) {
2890 free_extent_map(em);
2893 btrfs_drop_extent_cache(inode, start, end, 0);
2895 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2899 static int relocate_file_extent_cluster(struct inode *inode,
2900 struct file_extent_cluster *cluster)
2904 u64 offset = BTRFS_I(inode)->index_cnt;
2905 unsigned long index;
2906 unsigned long last_index;
2908 struct file_ra_state *ra;
2915 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2919 ret = prealloc_file_extent_cluster(inode, cluster);
2923 file_ra_state_init(ra, inode->i_mapping);
2925 ret = setup_extent_mapping(inode, cluster->start - offset,
2926 cluster->end - offset, cluster->start);
2930 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
2931 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
2932 while (index <= last_index) {
2933 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
2937 page = find_lock_page(inode->i_mapping, index);
2939 page_cache_sync_readahead(inode->i_mapping,
2941 last_index + 1 - index);
2942 page = grab_cache_page(inode->i_mapping, index);
2944 btrfs_delalloc_release_metadata(inode,
2951 if (PageReadahead(page)) {
2952 page_cache_async_readahead(inode->i_mapping,
2953 ra, NULL, page, index,
2954 last_index + 1 - index);
2957 if (!PageUptodate(page)) {
2958 btrfs_readpage(NULL, page);
2960 if (!PageUptodate(page)) {
2962 page_cache_release(page);
2963 btrfs_delalloc_release_metadata(inode,
2970 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2971 page_end = page_start + PAGE_CACHE_SIZE - 1;
2973 lock_extent(&BTRFS_I(inode)->io_tree,
2974 page_start, page_end, GFP_NOFS);
2976 set_page_extent_mapped(page);
2978 if (nr < cluster->nr &&
2979 page_start + offset == cluster->boundary[nr]) {
2980 set_extent_bits(&BTRFS_I(inode)->io_tree,
2981 page_start, page_end,
2982 EXTENT_BOUNDARY, GFP_NOFS);
2986 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
2987 set_page_dirty(page);
2989 unlock_extent(&BTRFS_I(inode)->io_tree,
2990 page_start, page_end, GFP_NOFS);
2992 page_cache_release(page);
2995 balance_dirty_pages_ratelimited(inode->i_mapping);
2996 btrfs_throttle(BTRFS_I(inode)->root);
2998 WARN_ON(nr != cluster->nr);
3004 static noinline_for_stack
3005 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3006 struct file_extent_cluster *cluster)
3010 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3011 ret = relocate_file_extent_cluster(inode, cluster);
3018 cluster->start = extent_key->objectid;
3020 BUG_ON(cluster->nr >= MAX_EXTENTS);
3021 cluster->end = extent_key->objectid + extent_key->offset - 1;
3022 cluster->boundary[cluster->nr] = extent_key->objectid;
3025 if (cluster->nr >= MAX_EXTENTS) {
3026 ret = relocate_file_extent_cluster(inode, cluster);
3034 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3035 static int get_ref_objectid_v0(struct reloc_control *rc,
3036 struct btrfs_path *path,
3037 struct btrfs_key *extent_key,
3038 u64 *ref_objectid, int *path_change)
3040 struct btrfs_key key;
3041 struct extent_buffer *leaf;
3042 struct btrfs_extent_ref_v0 *ref0;
3046 leaf = path->nodes[0];
3047 slot = path->slots[0];
3049 if (slot >= btrfs_header_nritems(leaf)) {
3050 ret = btrfs_next_leaf(rc->extent_root, path);
3054 leaf = path->nodes[0];
3055 slot = path->slots[0];
3059 btrfs_item_key_to_cpu(leaf, &key, slot);
3060 if (key.objectid != extent_key->objectid)
3063 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3067 ref0 = btrfs_item_ptr(leaf, slot,
3068 struct btrfs_extent_ref_v0);
3069 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3077 * helper to add a tree block to the list.
3078 * the major work is getting the generation and level of the block
3080 static int add_tree_block(struct reloc_control *rc,
3081 struct btrfs_key *extent_key,
3082 struct btrfs_path *path,
3083 struct rb_root *blocks)
3085 struct extent_buffer *eb;
3086 struct btrfs_extent_item *ei;
3087 struct btrfs_tree_block_info *bi;
3088 struct tree_block *block;
3089 struct rb_node *rb_node;
3094 eb = path->nodes[0];
3095 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3097 if (item_size >= sizeof(*ei) + sizeof(*bi)) {
3098 ei = btrfs_item_ptr(eb, path->slots[0],
3099 struct btrfs_extent_item);
3100 bi = (struct btrfs_tree_block_info *)(ei + 1);
3101 generation = btrfs_extent_generation(eb, ei);
3102 level = btrfs_tree_block_level(eb, bi);
3104 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3108 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3109 ret = get_ref_objectid_v0(rc, path, extent_key,
3113 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3114 level = (int)ref_owner;
3115 /* FIXME: get real generation */
3122 btrfs_release_path(rc->extent_root, path);
3124 BUG_ON(level == -1);
3126 block = kmalloc(sizeof(*block), GFP_NOFS);
3130 block->bytenr = extent_key->objectid;
3131 block->key.objectid = extent_key->offset;
3132 block->key.offset = generation;
3133 block->level = level;
3134 block->key_ready = 0;
3136 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3143 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3145 static int __add_tree_block(struct reloc_control *rc,
3146 u64 bytenr, u32 blocksize,
3147 struct rb_root *blocks)
3149 struct btrfs_path *path;
3150 struct btrfs_key key;
3153 if (tree_block_processed(bytenr, blocksize, rc))
3156 if (tree_search(blocks, bytenr))
3159 path = btrfs_alloc_path();
3163 key.objectid = bytenr;
3164 key.type = BTRFS_EXTENT_ITEM_KEY;
3165 key.offset = blocksize;
3167 path->search_commit_root = 1;
3168 path->skip_locking = 1;
3169 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3174 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3175 ret = add_tree_block(rc, &key, path, blocks);
3177 btrfs_free_path(path);
3182 * helper to check if the block use full backrefs for pointers in it
3184 static int block_use_full_backref(struct reloc_control *rc,
3185 struct extent_buffer *eb)
3190 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3191 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3194 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3195 eb->start, eb->len, NULL, &flags);
3198 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3205 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3206 struct inode *inode, u64 ino)
3208 struct btrfs_key key;
3209 struct btrfs_path *path;
3210 struct btrfs_root *root = fs_info->tree_root;
3211 struct btrfs_trans_handle *trans;
3219 key.type = BTRFS_INODE_ITEM_KEY;
3222 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3223 if (!inode || IS_ERR(inode) || is_bad_inode(inode)) {
3224 if (inode && !IS_ERR(inode))
3230 path = btrfs_alloc_path();
3236 trans = btrfs_join_transaction(root, 0);
3237 if (IS_ERR(trans)) {
3238 btrfs_free_path(path);
3239 ret = PTR_ERR(trans);
3243 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3245 btrfs_free_path(path);
3246 nr = trans->blocks_used;
3247 btrfs_end_transaction(trans, root);
3248 btrfs_btree_balance_dirty(root, nr);
3255 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3256 * this function scans fs tree to find blocks reference the data extent
3258 static int find_data_references(struct reloc_control *rc,
3259 struct btrfs_key *extent_key,
3260 struct extent_buffer *leaf,
3261 struct btrfs_extent_data_ref *ref,
3262 struct rb_root *blocks)
3264 struct btrfs_path *path;
3265 struct tree_block *block;
3266 struct btrfs_root *root;
3267 struct btrfs_file_extent_item *fi;
3268 struct rb_node *rb_node;
3269 struct btrfs_key key;
3280 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3281 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3282 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3283 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3286 * This is an extent belonging to the free space cache, lets just delete
3287 * it and redo the search.
3289 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3290 ret = delete_block_group_cache(rc->extent_root->fs_info,
3291 NULL, ref_objectid);
3297 path = btrfs_alloc_path();
3301 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3303 err = PTR_ERR(root);
3307 key.objectid = ref_objectid;
3308 key.offset = ref_offset;
3309 key.type = BTRFS_EXTENT_DATA_KEY;
3311 path->search_commit_root = 1;
3312 path->skip_locking = 1;
3313 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3319 leaf = path->nodes[0];
3320 nritems = btrfs_header_nritems(leaf);
3322 * the references in tree blocks that use full backrefs
3323 * are not counted in
3325 if (block_use_full_backref(rc, leaf))
3329 rb_node = tree_search(blocks, leaf->start);
3334 path->slots[0] = nritems;
3337 while (ref_count > 0) {
3338 while (path->slots[0] >= nritems) {
3339 ret = btrfs_next_leaf(root, path);
3349 leaf = path->nodes[0];
3350 nritems = btrfs_header_nritems(leaf);
3353 if (block_use_full_backref(rc, leaf))
3357 rb_node = tree_search(blocks, leaf->start);
3362 path->slots[0] = nritems;
3366 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3367 if (key.objectid != ref_objectid ||
3368 key.type != BTRFS_EXTENT_DATA_KEY) {
3373 fi = btrfs_item_ptr(leaf, path->slots[0],
3374 struct btrfs_file_extent_item);
3376 if (btrfs_file_extent_type(leaf, fi) ==
3377 BTRFS_FILE_EXTENT_INLINE)
3380 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3381 extent_key->objectid)
3384 key.offset -= btrfs_file_extent_offset(leaf, fi);
3385 if (key.offset != ref_offset)
3393 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3394 block = kmalloc(sizeof(*block), GFP_NOFS);
3399 block->bytenr = leaf->start;
3400 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3402 block->key_ready = 1;
3403 rb_node = tree_insert(blocks, block->bytenr,
3410 path->slots[0] = nritems;
3416 btrfs_free_path(path);
3421 * hepler to find all tree blocks that reference a given data extent
3423 static noinline_for_stack
3424 int add_data_references(struct reloc_control *rc,
3425 struct btrfs_key *extent_key,
3426 struct btrfs_path *path,
3427 struct rb_root *blocks)
3429 struct btrfs_key key;
3430 struct extent_buffer *eb;
3431 struct btrfs_extent_data_ref *dref;
3432 struct btrfs_extent_inline_ref *iref;
3435 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3439 eb = path->nodes[0];
3440 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3441 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3442 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3443 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3447 ptr += sizeof(struct btrfs_extent_item);
3450 iref = (struct btrfs_extent_inline_ref *)ptr;
3451 key.type = btrfs_extent_inline_ref_type(eb, iref);
3452 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3453 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3454 ret = __add_tree_block(rc, key.offset, blocksize,
3456 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3457 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3458 ret = find_data_references(rc, extent_key,
3463 ptr += btrfs_extent_inline_ref_size(key.type);
3469 eb = path->nodes[0];
3470 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3471 ret = btrfs_next_leaf(rc->extent_root, path);
3478 eb = path->nodes[0];
3481 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3482 if (key.objectid != extent_key->objectid)
3485 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3486 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3487 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3489 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3490 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3492 ret = __add_tree_block(rc, key.offset, blocksize,
3494 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3495 dref = btrfs_item_ptr(eb, path->slots[0],
3496 struct btrfs_extent_data_ref);
3497 ret = find_data_references(rc, extent_key,
3508 btrfs_release_path(rc->extent_root, path);
3510 free_block_list(blocks);
3515 * hepler to find next unprocessed extent
3517 static noinline_for_stack
3518 int find_next_extent(struct btrfs_trans_handle *trans,
3519 struct reloc_control *rc, struct btrfs_path *path,
3520 struct btrfs_key *extent_key)
3522 struct btrfs_key key;
3523 struct extent_buffer *leaf;
3524 u64 start, end, last;
3527 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3530 if (rc->search_start >= last) {
3535 key.objectid = rc->search_start;
3536 key.type = BTRFS_EXTENT_ITEM_KEY;
3539 path->search_commit_root = 1;
3540 path->skip_locking = 1;
3541 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3546 leaf = path->nodes[0];
3547 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3548 ret = btrfs_next_leaf(rc->extent_root, path);
3551 leaf = path->nodes[0];
3554 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3555 if (key.objectid >= last) {
3560 if (key.type != BTRFS_EXTENT_ITEM_KEY ||
3561 key.objectid + key.offset <= rc->search_start) {
3566 ret = find_first_extent_bit(&rc->processed_blocks,
3567 key.objectid, &start, &end,
3570 if (ret == 0 && start <= key.objectid) {
3571 btrfs_release_path(rc->extent_root, path);
3572 rc->search_start = end + 1;
3574 rc->search_start = key.objectid + key.offset;
3575 memcpy(extent_key, &key, sizeof(key));
3579 btrfs_release_path(rc->extent_root, path);
3583 static void set_reloc_control(struct reloc_control *rc)
3585 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3586 mutex_lock(&fs_info->trans_mutex);
3587 fs_info->reloc_ctl = rc;
3588 mutex_unlock(&fs_info->trans_mutex);
3591 static void unset_reloc_control(struct reloc_control *rc)
3593 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3594 mutex_lock(&fs_info->trans_mutex);
3595 fs_info->reloc_ctl = NULL;
3596 mutex_unlock(&fs_info->trans_mutex);
3599 static int check_extent_flags(u64 flags)
3601 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3602 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3604 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3605 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3607 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3608 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3613 static noinline_for_stack
3614 int prepare_to_relocate(struct reloc_control *rc)
3616 struct btrfs_trans_handle *trans;
3619 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root);
3624 * reserve some space for creating reloc trees.
3625 * btrfs_init_reloc_root will use them when there
3626 * is no reservation in transaction handle.
3628 ret = btrfs_block_rsv_add(NULL, rc->extent_root, rc->block_rsv,
3629 rc->extent_root->nodesize * 256);
3633 rc->block_rsv->refill_used = 1;
3634 btrfs_add_durable_block_rsv(rc->extent_root->fs_info, rc->block_rsv);
3636 memset(&rc->cluster, 0, sizeof(rc->cluster));
3637 rc->search_start = rc->block_group->key.objectid;
3638 rc->extents_found = 0;
3639 rc->nodes_relocated = 0;
3640 rc->merging_rsv_size = 0;
3642 rc->create_reloc_tree = 1;
3643 set_reloc_control(rc);
3645 trans = btrfs_join_transaction(rc->extent_root, 1);
3646 BUG_ON(IS_ERR(trans));
3647 btrfs_commit_transaction(trans, rc->extent_root);
3651 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3653 struct rb_root blocks = RB_ROOT;
3654 struct btrfs_key key;
3655 struct btrfs_trans_handle *trans = NULL;
3656 struct btrfs_path *path;
3657 struct btrfs_extent_item *ei;
3665 path = btrfs_alloc_path();
3669 ret = prepare_to_relocate(rc);
3677 trans = btrfs_start_transaction(rc->extent_root, 0);
3678 BUG_ON(IS_ERR(trans));
3680 if (update_backref_cache(trans, &rc->backref_cache)) {
3681 btrfs_end_transaction(trans, rc->extent_root);
3685 ret = find_next_extent(trans, rc, path, &key);
3691 rc->extents_found++;
3693 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3694 struct btrfs_extent_item);
3695 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3696 if (item_size >= sizeof(*ei)) {
3697 flags = btrfs_extent_flags(path->nodes[0], ei);
3698 ret = check_extent_flags(flags);
3702 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3704 int path_change = 0;
3707 sizeof(struct btrfs_extent_item_v0));
3708 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3710 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3711 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3713 flags = BTRFS_EXTENT_FLAG_DATA;
3716 btrfs_release_path(rc->extent_root, path);
3718 path->search_commit_root = 1;
3719 path->skip_locking = 1;
3720 ret = btrfs_search_slot(NULL, rc->extent_root,
3733 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3734 ret = add_tree_block(rc, &key, path, &blocks);
3735 } else if (rc->stage == UPDATE_DATA_PTRS &&
3736 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3737 ret = add_data_references(rc, &key, path, &blocks);
3739 btrfs_release_path(rc->extent_root, path);
3747 if (!RB_EMPTY_ROOT(&blocks)) {
3748 ret = relocate_tree_blocks(trans, rc, &blocks);
3750 if (ret != -EAGAIN) {
3754 rc->extents_found--;
3755 rc->search_start = key.objectid;
3759 ret = btrfs_block_rsv_check(trans, rc->extent_root,
3760 rc->block_rsv, 0, 5);
3762 if (ret != -EAGAIN) {
3767 rc->commit_transaction = 1;
3770 if (rc->commit_transaction) {
3771 rc->commit_transaction = 0;
3772 ret = btrfs_commit_transaction(trans, rc->extent_root);
3775 nr = trans->blocks_used;
3776 btrfs_end_transaction_throttle(trans, rc->extent_root);
3777 btrfs_btree_balance_dirty(rc->extent_root, nr);
3781 if (rc->stage == MOVE_DATA_EXTENTS &&
3782 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3783 rc->found_file_extent = 1;
3784 ret = relocate_data_extent(rc->data_inode,
3785 &key, &rc->cluster);
3792 if (trans && progress && err == -ENOSPC) {
3793 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
3794 rc->block_group->flags);
3802 btrfs_release_path(rc->extent_root, path);
3803 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
3807 nr = trans->blocks_used;
3808 btrfs_end_transaction_throttle(trans, rc->extent_root);
3809 btrfs_btree_balance_dirty(rc->extent_root, nr);
3813 ret = relocate_file_extent_cluster(rc->data_inode,
3819 rc->create_reloc_tree = 0;
3820 set_reloc_control(rc);
3822 backref_cache_cleanup(&rc->backref_cache);
3823 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3825 err = prepare_to_merge(rc, err);
3827 merge_reloc_roots(rc);
3829 rc->merge_reloc_tree = 0;
3830 unset_reloc_control(rc);
3831 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3833 /* get rid of pinned extents */
3834 trans = btrfs_join_transaction(rc->extent_root, 1);
3836 err = PTR_ERR(trans);
3838 btrfs_commit_transaction(trans, rc->extent_root);
3840 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
3841 btrfs_free_path(path);
3845 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
3846 struct btrfs_root *root, u64 objectid)
3848 struct btrfs_path *path;
3849 struct btrfs_inode_item *item;
3850 struct extent_buffer *leaf;
3853 path = btrfs_alloc_path();
3857 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
3861 leaf = path->nodes[0];
3862 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
3863 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
3864 btrfs_set_inode_generation(leaf, item, 1);
3865 btrfs_set_inode_size(leaf, item, 0);
3866 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
3867 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
3868 BTRFS_INODE_PREALLOC);
3869 btrfs_mark_buffer_dirty(leaf);
3870 btrfs_release_path(root, path);
3872 btrfs_free_path(path);
3877 * helper to create inode for data relocation.
3878 * the inode is in data relocation tree and its link count is 0
3880 static noinline_for_stack
3881 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
3882 struct btrfs_block_group_cache *group)
3884 struct inode *inode = NULL;
3885 struct btrfs_trans_handle *trans;
3886 struct btrfs_root *root;
3887 struct btrfs_key key;
3889 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
3892 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
3894 return ERR_CAST(root);
3896 trans = btrfs_start_transaction(root, 6);
3898 return ERR_CAST(trans);
3900 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
3904 err = __insert_orphan_inode(trans, root, objectid);
3907 key.objectid = objectid;
3908 key.type = BTRFS_INODE_ITEM_KEY;
3910 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
3911 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
3912 BTRFS_I(inode)->index_cnt = group->key.objectid;
3914 err = btrfs_orphan_add(trans, inode);
3916 nr = trans->blocks_used;
3917 btrfs_end_transaction(trans, root);
3918 btrfs_btree_balance_dirty(root, nr);
3922 inode = ERR_PTR(err);
3927 static struct reloc_control *alloc_reloc_control(void)
3929 struct reloc_control *rc;
3931 rc = kzalloc(sizeof(*rc), GFP_NOFS);
3935 INIT_LIST_HEAD(&rc->reloc_roots);
3936 backref_cache_init(&rc->backref_cache);
3937 mapping_tree_init(&rc->reloc_root_tree);
3938 extent_io_tree_init(&rc->processed_blocks, NULL, GFP_NOFS);
3943 * function to relocate all extents in a block group.
3945 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
3947 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3948 struct reloc_control *rc;
3949 struct inode *inode;
3950 struct btrfs_path *path;
3955 rc = alloc_reloc_control();
3959 rc->extent_root = extent_root;
3961 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
3962 BUG_ON(!rc->block_group);
3964 if (!rc->block_group->ro) {
3965 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
3973 path = btrfs_alloc_path();
3979 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
3981 btrfs_free_path(path);
3984 ret = delete_block_group_cache(fs_info, inode, 0);
3986 ret = PTR_ERR(inode);
3988 if (ret && ret != -ENOENT) {
3993 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
3994 if (IS_ERR(rc->data_inode)) {
3995 err = PTR_ERR(rc->data_inode);
3996 rc->data_inode = NULL;
4000 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
4001 (unsigned long long)rc->block_group->key.objectid,
4002 (unsigned long long)rc->block_group->flags);
4004 btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
4005 btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0);
4008 mutex_lock(&fs_info->cleaner_mutex);
4010 btrfs_clean_old_snapshots(fs_info->tree_root);
4011 ret = relocate_block_group(rc);
4013 mutex_unlock(&fs_info->cleaner_mutex);
4019 if (rc->extents_found == 0)
4022 printk(KERN_INFO "btrfs: found %llu extents\n",
4023 (unsigned long long)rc->extents_found);
4025 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4026 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4027 invalidate_mapping_pages(rc->data_inode->i_mapping,
4029 rc->stage = UPDATE_DATA_PTRS;
4033 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4034 rc->block_group->key.objectid,
4035 rc->block_group->key.objectid +
4036 rc->block_group->key.offset - 1);
4038 WARN_ON(rc->block_group->pinned > 0);
4039 WARN_ON(rc->block_group->reserved > 0);
4040 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4043 btrfs_set_block_group_rw(extent_root, rc->block_group);
4044 iput(rc->data_inode);
4045 btrfs_put_block_group(rc->block_group);
4050 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4052 struct btrfs_trans_handle *trans;
4055 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4056 BUG_ON(IS_ERR(trans));
4058 memset(&root->root_item.drop_progress, 0,
4059 sizeof(root->root_item.drop_progress));
4060 root->root_item.drop_level = 0;
4061 btrfs_set_root_refs(&root->root_item, 0);
4062 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4063 &root->root_key, &root->root_item);
4066 ret = btrfs_end_transaction(trans, root->fs_info->tree_root);
4072 * recover relocation interrupted by system crash.
4074 * this function resumes merging reloc trees with corresponding fs trees.
4075 * this is important for keeping the sharing of tree blocks
4077 int btrfs_recover_relocation(struct btrfs_root *root)
4079 LIST_HEAD(reloc_roots);
4080 struct btrfs_key key;
4081 struct btrfs_root *fs_root;
4082 struct btrfs_root *reloc_root;
4083 struct btrfs_path *path;
4084 struct extent_buffer *leaf;
4085 struct reloc_control *rc = NULL;
4086 struct btrfs_trans_handle *trans;
4090 path = btrfs_alloc_path();
4094 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4095 key.type = BTRFS_ROOT_ITEM_KEY;
4096 key.offset = (u64)-1;
4099 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4106 if (path->slots[0] == 0)
4110 leaf = path->nodes[0];
4111 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4112 btrfs_release_path(root->fs_info->tree_root, path);
4114 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4115 key.type != BTRFS_ROOT_ITEM_KEY)
4118 reloc_root = btrfs_read_fs_root_no_radix(root, &key);
4119 if (IS_ERR(reloc_root)) {
4120 err = PTR_ERR(reloc_root);
4124 list_add(&reloc_root->root_list, &reloc_roots);
4126 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4127 fs_root = read_fs_root(root->fs_info,
4128 reloc_root->root_key.offset);
4129 if (IS_ERR(fs_root)) {
4130 ret = PTR_ERR(fs_root);
4131 if (ret != -ENOENT) {
4135 mark_garbage_root(reloc_root);
4139 if (key.offset == 0)
4144 btrfs_release_path(root->fs_info->tree_root, path);
4146 if (list_empty(&reloc_roots))
4149 rc = alloc_reloc_control();
4155 rc->extent_root = root->fs_info->extent_root;
4157 set_reloc_control(rc);
4159 trans = btrfs_join_transaction(rc->extent_root, 1);
4160 if (IS_ERR(trans)) {
4161 unset_reloc_control(rc);
4162 err = PTR_ERR(trans);
4166 rc->merge_reloc_tree = 1;
4168 while (!list_empty(&reloc_roots)) {
4169 reloc_root = list_entry(reloc_roots.next,
4170 struct btrfs_root, root_list);
4171 list_del(&reloc_root->root_list);
4173 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4174 list_add_tail(&reloc_root->root_list,
4179 fs_root = read_fs_root(root->fs_info,
4180 reloc_root->root_key.offset);
4181 BUG_ON(IS_ERR(fs_root));
4183 __add_reloc_root(reloc_root);
4184 fs_root->reloc_root = reloc_root;
4187 btrfs_commit_transaction(trans, rc->extent_root);
4189 merge_reloc_roots(rc);
4191 unset_reloc_control(rc);
4193 trans = btrfs_join_transaction(rc->extent_root, 1);
4195 err = PTR_ERR(trans);
4197 btrfs_commit_transaction(trans, rc->extent_root);
4201 while (!list_empty(&reloc_roots)) {
4202 reloc_root = list_entry(reloc_roots.next,
4203 struct btrfs_root, root_list);
4204 list_del(&reloc_root->root_list);
4205 free_extent_buffer(reloc_root->node);
4206 free_extent_buffer(reloc_root->commit_root);
4209 btrfs_free_path(path);
4212 /* cleanup orphan inode in data relocation tree */
4213 fs_root = read_fs_root(root->fs_info,
4214 BTRFS_DATA_RELOC_TREE_OBJECTID);
4215 if (IS_ERR(fs_root))
4216 err = PTR_ERR(fs_root);
4218 err = btrfs_orphan_cleanup(fs_root);
4224 * helper to add ordered checksum for data relocation.
4226 * cloning checksum properly handles the nodatasum extents.
4227 * it also saves CPU time to re-calculate the checksum.
4229 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4231 struct btrfs_ordered_sum *sums;
4232 struct btrfs_sector_sum *sector_sum;
4233 struct btrfs_ordered_extent *ordered;
4234 struct btrfs_root *root = BTRFS_I(inode)->root;
4240 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4241 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4243 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4244 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4245 disk_bytenr + len - 1, &list);
4247 while (!list_empty(&list)) {
4248 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4249 list_del_init(&sums->list);
4251 sector_sum = sums->sums;
4252 sums->bytenr = ordered->start;
4255 while (offset < sums->len) {
4256 sector_sum->bytenr += ordered->start - disk_bytenr;
4258 offset += root->sectorsize;
4261 btrfs_add_ordered_sum(inode, ordered, sums);
4263 btrfs_put_ordered_extent(ordered);
4267 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4268 struct btrfs_root *root, struct extent_buffer *buf,
4269 struct extent_buffer *cow)
4271 struct reloc_control *rc;
4272 struct backref_node *node;
4277 rc = root->fs_info->reloc_ctl;
4281 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4282 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4284 level = btrfs_header_level(buf);
4285 if (btrfs_header_generation(buf) <=
4286 btrfs_root_last_snapshot(&root->root_item))
4289 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4290 rc->create_reloc_tree) {
4291 WARN_ON(!first_cow && level == 0);
4293 node = rc->backref_cache.path[level];
4294 BUG_ON(node->bytenr != buf->start &&
4295 node->new_bytenr != buf->start);
4297 drop_node_buffer(node);
4298 extent_buffer_get(cow);
4300 node->new_bytenr = cow->start;
4302 if (!node->pending) {
4303 list_move_tail(&node->list,
4304 &rc->backref_cache.pending[level]);
4309 __mark_block_processed(rc, node);
4311 if (first_cow && level > 0)
4312 rc->nodes_relocated += buf->len;
4315 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4316 ret = replace_file_extents(trans, rc, root, cow);
4322 * called before creating snapshot. it calculates metadata reservation
4323 * requried for relocating tree blocks in the snapshot
4325 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4326 struct btrfs_pending_snapshot *pending,
4327 u64 *bytes_to_reserve)
4329 struct btrfs_root *root;
4330 struct reloc_control *rc;
4332 root = pending->root;
4333 if (!root->reloc_root)
4336 rc = root->fs_info->reloc_ctl;
4337 if (!rc->merge_reloc_tree)
4340 root = root->reloc_root;
4341 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4343 * relocation is in the stage of merging trees. the space
4344 * used by merging a reloc tree is twice the size of
4345 * relocated tree nodes in the worst case. half for cowing
4346 * the reloc tree, half for cowing the fs tree. the space
4347 * used by cowing the reloc tree will be freed after the
4348 * tree is dropped. if we create snapshot, cowing the fs
4349 * tree may use more space than it frees. so we need
4350 * reserve extra space.
4352 *bytes_to_reserve += rc->nodes_relocated;
4356 * called after snapshot is created. migrate block reservation
4357 * and create reloc root for the newly created snapshot
4359 void btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4360 struct btrfs_pending_snapshot *pending)
4362 struct btrfs_root *root = pending->root;
4363 struct btrfs_root *reloc_root;
4364 struct btrfs_root *new_root;
4365 struct reloc_control *rc;
4368 if (!root->reloc_root)
4371 rc = root->fs_info->reloc_ctl;
4372 rc->merging_rsv_size += rc->nodes_relocated;
4374 if (rc->merge_reloc_tree) {
4375 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4377 rc->nodes_relocated);
4381 new_root = pending->snap;
4382 reloc_root = create_reloc_root(trans, root->reloc_root,
4383 new_root->root_key.objectid);
4385 __add_reloc_root(reloc_root);
4386 new_root->reloc_root = reloc_root;
4388 if (rc->create_reloc_tree) {
4389 ret = clone_backref_node(trans, rc, root, reloc_root);