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mmc: rtsx: Clear SD_CLK toggle enable bit if switching voltage fail
[linux/fpc-iii.git] / fs / btrfs / relocation.c
blob12096496cc99eb24e6412ebc3ed5780f0e2b2430
1 /*
2 * Copyright (C) 2009 Oracle. All rights reserved.
3 *
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.
7 *
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.
12 *
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.
17 */
18
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>
25 #include "ctree.h"
26 #include "disk-io.h"
27 #include "transaction.h"
28 #include "volumes.h"
29 #include "locking.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
34
35 /*
36 * backref_node, mapping_node and tree_block start with this
37 */
38 struct tree_entry {
39 struct rb_node rb_node;
40 u64 bytenr;
41 };
42
43 /*
44 * present a tree block in the backref cache
45 */
46 struct backref_node {
47 struct rb_node rb_node;
48 u64 bytenr;
49
50 u64 new_bytenr;
51 /* objectid of tree block owner, can be not uptodate */
52 u64 owner;
53 /* link to pending, changed or detached list */
54 struct list_head list;
55 /* list of upper level blocks reference this block */
56 struct list_head upper;
57 /* list of child blocks in the cache */
58 struct list_head lower;
59 /* NULL if this node is not tree root */
60 struct btrfs_root *root;
61 /* extent buffer got by COW the block */
62 struct extent_buffer *eb;
63 /* level of tree block */
64 unsigned int level:8;
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest:1;
69 /* is the extent buffer locked */
70 unsigned int locked:1;
71 /* has the block been processed */
72 unsigned int processed:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked:1;
75 /*
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
78 */
79 unsigned int pending:1;
80 /*
81 * 1 if the backref node isn't connected to any other
82 * backref node.
83 */
84 unsigned int detached:1;
85 };
86
87 /*
88 * present a block pointer in the backref cache
89 */
90 struct backref_edge {
91 struct list_head list[2];
92 struct backref_node *node[2];
93 };
94
95 #define LOWER 0
96 #define UPPER 1
97
98 struct backref_cache {
99 /* red black tree of all backref nodes in the cache */
100 struct rb_root rb_root;
101 /* for passing backref nodes to btrfs_reloc_cow_block */
102 struct backref_node *path[BTRFS_MAX_LEVEL];
103 /*
104 * list of blocks that have been cowed but some block
105 * pointers in upper level blocks may not reflect the
106 * new location
107 */
108 struct list_head pending[BTRFS_MAX_LEVEL];
109 /* list of backref nodes with no child node */
110 struct list_head leaves;
111 /* list of blocks that have been cowed in current transaction */
112 struct list_head changed;
113 /* list of detached backref node. */
114 struct list_head detached;
115
116 u64 last_trans;
117
118 int nr_nodes;
119 int nr_edges;
120 };
121
122 /*
123 * map address of tree root to tree
124 */
125 struct mapping_node {
126 struct rb_node rb_node;
127 u64 bytenr;
128 void *data;
129 };
130
131 struct mapping_tree {
132 struct rb_root rb_root;
133 spinlock_t lock;
134 };
135
136 /*
137 * present a tree block to process
138 */
139 struct tree_block {
140 struct rb_node rb_node;
141 u64 bytenr;
142 struct btrfs_key key;
143 unsigned int level:8;
144 unsigned int key_ready:1;
145 };
146
147 #define MAX_EXTENTS 128
148
149 struct file_extent_cluster {
150 u64 start;
151 u64 end;
152 u64 boundary[MAX_EXTENTS];
153 unsigned int nr;
154 };
155
156 struct reloc_control {
157 /* block group to relocate */
158 struct btrfs_block_group_cache *block_group;
159 /* extent tree */
160 struct btrfs_root *extent_root;
161 /* inode for moving data */
162 struct inode *data_inode;
163
164 struct btrfs_block_rsv *block_rsv;
165
166 struct backref_cache backref_cache;
167
168 struct file_extent_cluster cluster;
169 /* tree blocks have been processed */
170 struct extent_io_tree processed_blocks;
171 /* map start of tree root to corresponding reloc tree */
172 struct mapping_tree reloc_root_tree;
173 /* list of reloc trees */
174 struct list_head reloc_roots;
175 /* size of metadata reservation for merging reloc trees */
176 u64 merging_rsv_size;
177 /* size of relocated tree nodes */
178 u64 nodes_relocated;
179
180 u64 search_start;
181 u64 extents_found;
182
183 unsigned int stage:8;
184 unsigned int create_reloc_tree:1;
185 unsigned int merge_reloc_tree:1;
186 unsigned int found_file_extent:1;
187 unsigned int commit_transaction:1;
188 };
189
190 /* stages of data relocation */
191 #define MOVE_DATA_EXTENTS 0
192 #define UPDATE_DATA_PTRS 1
193
194 static void remove_backref_node(struct backref_cache *cache,
195 struct backref_node *node);
196 static void __mark_block_processed(struct reloc_control *rc,
197 struct backref_node *node);
198
199 static void mapping_tree_init(struct mapping_tree *tree)
200 {
201 tree->rb_root = RB_ROOT;
202 spin_lock_init(&tree->lock);
203 }
204
205 static void backref_cache_init(struct backref_cache *cache)
206 {
207 int i;
208 cache->rb_root = RB_ROOT;
209 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
210 INIT_LIST_HEAD(&cache->pending[i]);
211 INIT_LIST_HEAD(&cache->changed);
212 INIT_LIST_HEAD(&cache->detached);
213 INIT_LIST_HEAD(&cache->leaves);
214 }
215
216 static void backref_cache_cleanup(struct backref_cache *cache)
217 {
218 struct backref_node *node;
219 int i;
220
221 while (!list_empty(&cache->detached)) {
222 node = list_entry(cache->detached.next,
223 struct backref_node, list);
224 remove_backref_node(cache, node);
225 }
226
227 while (!list_empty(&cache->leaves)) {
228 node = list_entry(cache->leaves.next,
229 struct backref_node, lower);
230 remove_backref_node(cache, node);
231 }
232
233 cache->last_trans = 0;
234
235 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
236 BUG_ON(!list_empty(&cache->pending[i]));
237 BUG_ON(!list_empty(&cache->changed));
238 BUG_ON(!list_empty(&cache->detached));
239 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
240 BUG_ON(cache->nr_nodes);
241 BUG_ON(cache->nr_edges);
242 }
243
244 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
245 {
246 struct backref_node *node;
247
248 node = kzalloc(sizeof(*node), GFP_NOFS);
249 if (node) {
250 INIT_LIST_HEAD(&node->list);
251 INIT_LIST_HEAD(&node->upper);
252 INIT_LIST_HEAD(&node->lower);
253 RB_CLEAR_NODE(&node->rb_node);
254 cache->nr_nodes++;
255 }
256 return node;
257 }
258
259 static void free_backref_node(struct backref_cache *cache,
260 struct backref_node *node)
261 {
262 if (node) {
263 cache->nr_nodes--;
264 kfree(node);
265 }
266 }
267
268 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
269 {
270 struct backref_edge *edge;
271
272 edge = kzalloc(sizeof(*edge), GFP_NOFS);
273 if (edge)
274 cache->nr_edges++;
275 return edge;
276 }
277
278 static void free_backref_edge(struct backref_cache *cache,
279 struct backref_edge *edge)
280 {
281 if (edge) {
282 cache->nr_edges--;
283 kfree(edge);
284 }
285 }
286
287 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
288 struct rb_node *node)
289 {
290 struct rb_node **p = &root->rb_node;
291 struct rb_node *parent = NULL;
292 struct tree_entry *entry;
293
294 while (*p) {
295 parent = *p;
296 entry = rb_entry(parent, struct tree_entry, rb_node);
297
298 if (bytenr < entry->bytenr)
299 p = &(*p)->rb_left;
300 else if (bytenr > entry->bytenr)
301 p = &(*p)->rb_right;
302 else
303 return parent;
304 }
305
306 rb_link_node(node, parent, p);
307 rb_insert_color(node, root);
308 return NULL;
309 }
310
311 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
312 {
313 struct rb_node *n = root->rb_node;
314 struct tree_entry *entry;
315
316 while (n) {
317 entry = rb_entry(n, struct tree_entry, rb_node);
318
319 if (bytenr < entry->bytenr)
320 n = n->rb_left;
321 else if (bytenr > entry->bytenr)
322 n = n->rb_right;
323 else
324 return n;
325 }
326 return NULL;
327 }
328
329 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
330 {
331
332 struct btrfs_fs_info *fs_info = NULL;
333 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
334 rb_node);
335 if (bnode->root)
336 fs_info = bnode->root->fs_info;
337 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
338 "found at offset %llu\n", (unsigned long long)bytenr);
339 }
340
341 /*
342 * walk up backref nodes until reach node presents tree root
343 */
344 static struct backref_node *walk_up_backref(struct backref_node *node,
345 struct backref_edge *edges[],
346 int *index)
347 {
348 struct backref_edge *edge;
349 int idx = *index;
350
351 while (!list_empty(&node->upper)) {
352 edge = list_entry(node->upper.next,
353 struct backref_edge, list[LOWER]);
354 edges[idx++] = edge;
355 node = edge->node[UPPER];
356 }
357 BUG_ON(node->detached);
358 *index = idx;
359 return node;
360 }
361
362 /*
363 * walk down backref nodes to find start of next reference path
364 */
365 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
366 int *index)
367 {
368 struct backref_edge *edge;
369 struct backref_node *lower;
370 int idx = *index;
371
372 while (idx > 0) {
373 edge = edges[idx - 1];
374 lower = edge->node[LOWER];
375 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
376 idx--;
377 continue;
378 }
379 edge = list_entry(edge->list[LOWER].next,
380 struct backref_edge, list[LOWER]);
381 edges[idx - 1] = edge;
382 *index = idx;
383 return edge->node[UPPER];
384 }
385 *index = 0;
386 return NULL;
387 }
388
389 static void unlock_node_buffer(struct backref_node *node)
390 {
391 if (node->locked) {
392 btrfs_tree_unlock(node->eb);
393 node->locked = 0;
394 }
395 }
396
397 static void drop_node_buffer(struct backref_node *node)
398 {
399 if (node->eb) {
400 unlock_node_buffer(node);
401 free_extent_buffer(node->eb);
402 node->eb = NULL;
403 }
404 }
405
406 static void drop_backref_node(struct backref_cache *tree,
407 struct backref_node *node)
408 {
409 BUG_ON(!list_empty(&node->upper));
410
411 drop_node_buffer(node);
412 list_del(&node->list);
413 list_del(&node->lower);
414 if (!RB_EMPTY_NODE(&node->rb_node))
415 rb_erase(&node->rb_node, &tree->rb_root);
416 free_backref_node(tree, node);
417 }
418
419 /*
420 * remove a backref node from the backref cache
421 */
422 static void remove_backref_node(struct backref_cache *cache,
423 struct backref_node *node)
424 {
425 struct backref_node *upper;
426 struct backref_edge *edge;
427
428 if (!node)
429 return;
430
431 BUG_ON(!node->lowest && !node->detached);
432 while (!list_empty(&node->upper)) {
433 edge = list_entry(node->upper.next, struct backref_edge,
434 list[LOWER]);
435 upper = edge->node[UPPER];
436 list_del(&edge->list[LOWER]);
437 list_del(&edge->list[UPPER]);
438 free_backref_edge(cache, edge);
439
440 if (RB_EMPTY_NODE(&upper->rb_node)) {
441 BUG_ON(!list_empty(&node->upper));
442 drop_backref_node(cache, node);
443 node = upper;
444 node->lowest = 1;
445 continue;
446 }
447 /*
448 * add the node to leaf node list if no other
449 * child block cached.
450 */
451 if (list_empty(&upper->lower)) {
452 list_add_tail(&upper->lower, &cache->leaves);
453 upper->lowest = 1;
454 }
455 }
456
457 drop_backref_node(cache, node);
458 }
459
460 static void update_backref_node(struct backref_cache *cache,
461 struct backref_node *node, u64 bytenr)
462 {
463 struct rb_node *rb_node;
464 rb_erase(&node->rb_node, &cache->rb_root);
465 node->bytenr = bytenr;
466 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
467 if (rb_node)
468 backref_tree_panic(rb_node, -EEXIST, bytenr);
469 }
470
471 /*
472 * update backref cache after a transaction commit
473 */
474 static int update_backref_cache(struct btrfs_trans_handle *trans,
475 struct backref_cache *cache)
476 {
477 struct backref_node *node;
478 int level = 0;
479
480 if (cache->last_trans == 0) {
481 cache->last_trans = trans->transid;
482 return 0;
483 }
484
485 if (cache->last_trans == trans->transid)
486 return 0;
487
488 /*
489 * detached nodes are used to avoid unnecessary backref
490 * lookup. transaction commit changes the extent tree.
491 * so the detached nodes are no longer useful.
492 */
493 while (!list_empty(&cache->detached)) {
494 node = list_entry(cache->detached.next,
495 struct backref_node, list);
496 remove_backref_node(cache, node);
497 }
498
499 while (!list_empty(&cache->changed)) {
500 node = list_entry(cache->changed.next,
501 struct backref_node, list);
502 list_del_init(&node->list);
503 BUG_ON(node->pending);
504 update_backref_node(cache, node, node->new_bytenr);
505 }
506
507 /*
508 * some nodes can be left in the pending list if there were
509 * errors during processing the pending nodes.
510 */
511 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
512 list_for_each_entry(node, &cache->pending[level], list) {
513 BUG_ON(!node->pending);
514 if (node->bytenr == node->new_bytenr)
515 continue;
516 update_backref_node(cache, node, node->new_bytenr);
517 }
518 }
519
520 cache->last_trans = 0;
521 return 1;
522 }
523
524
525 static int should_ignore_root(struct btrfs_root *root)
526 {
527 struct btrfs_root *reloc_root;
528
529 if (!root->ref_cows)
530 return 0;
531
532 reloc_root = root->reloc_root;
533 if (!reloc_root)
534 return 0;
535
536 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
537 root->fs_info->running_transaction->transid - 1)
538 return 0;
539 /*
540 * if there is reloc tree and it was created in previous
541 * transaction backref lookup can find the reloc tree,
542 * so backref node for the fs tree root is useless for
543 * relocation.
544 */
545 return 1;
546 }
547 /*
548 * find reloc tree by address of tree root
549 */
550 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
551 u64 bytenr)
552 {
553 struct rb_node *rb_node;
554 struct mapping_node *node;
555 struct btrfs_root *root = NULL;
556
557 spin_lock(&rc->reloc_root_tree.lock);
558 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
559 if (rb_node) {
560 node = rb_entry(rb_node, struct mapping_node, rb_node);
561 root = (struct btrfs_root *)node->data;
562 }
563 spin_unlock(&rc->reloc_root_tree.lock);
564 return root;
565 }
566
567 static int is_cowonly_root(u64 root_objectid)
568 {
569 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
570 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
571 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
572 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
573 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
574 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
575 return 1;
576 return 0;
577 }
578
579 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
580 u64 root_objectid)
581 {
582 struct btrfs_key key;
583
584 key.objectid = root_objectid;
585 key.type = BTRFS_ROOT_ITEM_KEY;
586 if (is_cowonly_root(root_objectid))
587 key.offset = 0;
588 else
589 key.offset = (u64)-1;
590
591 return btrfs_read_fs_root_no_name(fs_info, &key);
592 }
593
594 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
595 static noinline_for_stack
596 struct btrfs_root *find_tree_root(struct reloc_control *rc,
597 struct extent_buffer *leaf,
598 struct btrfs_extent_ref_v0 *ref0)
599 {
600 struct btrfs_root *root;
601 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
602 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
603
604 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
605
606 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
607 BUG_ON(IS_ERR(root));
608
609 if (root->ref_cows &&
610 generation != btrfs_root_generation(&root->root_item))
611 return NULL;
612
613 return root;
614 }
615 #endif
616
617 static noinline_for_stack
618 int find_inline_backref(struct extent_buffer *leaf, int slot,
619 unsigned long *ptr, unsigned long *end)
620 {
621 struct btrfs_key key;
622 struct btrfs_extent_item *ei;
623 struct btrfs_tree_block_info *bi;
624 u32 item_size;
625
626 btrfs_item_key_to_cpu(leaf, &key, slot);
627
628 item_size = btrfs_item_size_nr(leaf, slot);
629 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
630 if (item_size < sizeof(*ei)) {
631 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
632 return 1;
633 }
634 #endif
635 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
636 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
637 BTRFS_EXTENT_FLAG_TREE_BLOCK));
638
639 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
640 item_size <= sizeof(*ei) + sizeof(*bi)) {
641 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
642 return 1;
643 }
644
645 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
646 bi = (struct btrfs_tree_block_info *)(ei + 1);
647 *ptr = (unsigned long)(bi + 1);
648 } else {
649 *ptr = (unsigned long)(ei + 1);
650 }
651 *end = (unsigned long)ei + item_size;
652 return 0;
653 }
654
655 /*
656 * build backref tree for a given tree block. root of the backref tree
657 * corresponds the tree block, leaves of the backref tree correspond
658 * roots of b-trees that reference the tree block.
659 *
660 * the basic idea of this function is check backrefs of a given block
661 * to find upper level blocks that refernece the block, and then check
662 * bakcrefs of these upper level blocks recursively. the recursion stop
663 * when tree root is reached or backrefs for the block is cached.
664 *
665 * NOTE: if we find backrefs for a block are cached, we know backrefs
666 * for all upper level blocks that directly/indirectly reference the
667 * block are also cached.
668 */
669 static noinline_for_stack
670 struct backref_node *build_backref_tree(struct reloc_control *rc,
671 struct btrfs_key *node_key,
672 int level, u64 bytenr)
673 {
674 struct backref_cache *cache = &rc->backref_cache;
675 struct btrfs_path *path1;
676 struct btrfs_path *path2;
677 struct extent_buffer *eb;
678 struct btrfs_root *root;
679 struct backref_node *cur;
680 struct backref_node *upper;
681 struct backref_node *lower;
682 struct backref_node *node = NULL;
683 struct backref_node *exist = NULL;
684 struct backref_edge *edge;
685 struct rb_node *rb_node;
686 struct btrfs_key key;
687 unsigned long end;
688 unsigned long ptr;
689 LIST_HEAD(list);
690 LIST_HEAD(useless);
691 int cowonly;
692 int ret;
693 int err = 0;
694
695 path1 = btrfs_alloc_path();
696 path2 = btrfs_alloc_path();
697 if (!path1 || !path2) {
698 err = -ENOMEM;
699 goto out;
700 }
701 path1->reada = 1;
702 path2->reada = 2;
703
704 node = alloc_backref_node(cache);
705 if (!node) {
706 err = -ENOMEM;
707 goto out;
708 }
709
710 node->bytenr = bytenr;
711 node->level = level;
712 node->lowest = 1;
713 cur = node;
714 again:
715 end = 0;
716 ptr = 0;
717 key.objectid = cur->bytenr;
718 key.type = BTRFS_METADATA_ITEM_KEY;
719 key.offset = (u64)-1;
720
721 path1->search_commit_root = 1;
722 path1->skip_locking = 1;
723 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
724 0, 0);
725 if (ret < 0) {
726 err = ret;
727 goto out;
728 }
729 BUG_ON(!ret || !path1->slots[0]);
730
731 path1->slots[0]--;
732
733 WARN_ON(cur->checked);
734 if (!list_empty(&cur->upper)) {
735 /*
736 * the backref was added previously when processing
737 * backref of type BTRFS_TREE_BLOCK_REF_KEY
738 */
739 BUG_ON(!list_is_singular(&cur->upper));
740 edge = list_entry(cur->upper.next, struct backref_edge,
741 list[LOWER]);
742 BUG_ON(!list_empty(&edge->list[UPPER]));
743 exist = edge->node[UPPER];
744 /*
745 * add the upper level block to pending list if we need
746 * check its backrefs
747 */
748 if (!exist->checked)
749 list_add_tail(&edge->list[UPPER], &list);
750 } else {
751 exist = NULL;
752 }
753
754 while (1) {
755 cond_resched();
756 eb = path1->nodes[0];
757
758 if (ptr >= end) {
759 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
760 ret = btrfs_next_leaf(rc->extent_root, path1);
761 if (ret < 0) {
762 err = ret;
763 goto out;
764 }
765 if (ret > 0)
766 break;
767 eb = path1->nodes[0];
768 }
769
770 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
771 if (key.objectid != cur->bytenr) {
772 WARN_ON(exist);
773 break;
774 }
775
776 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
777 key.type == BTRFS_METADATA_ITEM_KEY) {
778 ret = find_inline_backref(eb, path1->slots[0],
779 &ptr, &end);
780 if (ret)
781 goto next;
782 }
783 }
784
785 if (ptr < end) {
786 /* update key for inline back ref */
787 struct btrfs_extent_inline_ref *iref;
788 iref = (struct btrfs_extent_inline_ref *)ptr;
789 key.type = btrfs_extent_inline_ref_type(eb, iref);
790 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
791 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
792 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
793 }
794
795 if (exist &&
796 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
797 exist->owner == key.offset) ||
798 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
799 exist->bytenr == key.offset))) {
800 exist = NULL;
801 goto next;
802 }
803
804 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
805 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
806 key.type == BTRFS_EXTENT_REF_V0_KEY) {
807 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
808 struct btrfs_extent_ref_v0 *ref0;
809 ref0 = btrfs_item_ptr(eb, path1->slots[0],
810 struct btrfs_extent_ref_v0);
811 if (key.objectid == key.offset) {
812 root = find_tree_root(rc, eb, ref0);
813 if (root && !should_ignore_root(root))
814 cur->root = root;
815 else
816 list_add(&cur->list, &useless);
817 break;
818 }
819 if (is_cowonly_root(btrfs_ref_root_v0(eb,
820 ref0)))
821 cur->cowonly = 1;
822 }
823 #else
824 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
825 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
826 #endif
827 if (key.objectid == key.offset) {
828 /*
829 * only root blocks of reloc trees use
830 * backref of this type.
831 */
832 root = find_reloc_root(rc, cur->bytenr);
833 BUG_ON(!root);
834 cur->root = root;
835 break;
836 }
837
838 edge = alloc_backref_edge(cache);
839 if (!edge) {
840 err = -ENOMEM;
841 goto out;
842 }
843 rb_node = tree_search(&cache->rb_root, key.offset);
844 if (!rb_node) {
845 upper = alloc_backref_node(cache);
846 if (!upper) {
847 free_backref_edge(cache, edge);
848 err = -ENOMEM;
849 goto out;
850 }
851 upper->bytenr = key.offset;
852 upper->level = cur->level + 1;
853 /*
854 * backrefs for the upper level block isn't
855 * cached, add the block to pending list
856 */
857 list_add_tail(&edge->list[UPPER], &list);
858 } else {
859 upper = rb_entry(rb_node, struct backref_node,
860 rb_node);
861 BUG_ON(!upper->checked);
862 INIT_LIST_HEAD(&edge->list[UPPER]);
863 }
864 list_add_tail(&edge->list[LOWER], &cur->upper);
865 edge->node[LOWER] = cur;
866 edge->node[UPPER] = upper;
867
868 goto next;
869 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
870 goto next;
871 }
872
873 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
874 root = read_fs_root(rc->extent_root->fs_info, key.offset);
875 if (IS_ERR(root)) {
876 err = PTR_ERR(root);
877 goto out;
878 }
879
880 if (!root->ref_cows)
881 cur->cowonly = 1;
882
883 if (btrfs_root_level(&root->root_item) == cur->level) {
884 /* tree root */
885 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
886 cur->bytenr);
887 if (should_ignore_root(root))
888 list_add(&cur->list, &useless);
889 else
890 cur->root = root;
891 break;
892 }
893
894 level = cur->level + 1;
895
896 /*
897 * searching the tree to find upper level blocks
898 * reference the block.
899 */
900 path2->search_commit_root = 1;
901 path2->skip_locking = 1;
902 path2->lowest_level = level;
903 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
904 path2->lowest_level = 0;
905 if (ret < 0) {
906 err = ret;
907 goto out;
908 }
909 if (ret > 0 && path2->slots[level] > 0)
910 path2->slots[level]--;
911
912 eb = path2->nodes[level];
913 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
914 cur->bytenr);
915
916 lower = cur;
917 for (; level < BTRFS_MAX_LEVEL; level++) {
918 if (!path2->nodes[level]) {
919 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
920 lower->bytenr);
921 if (should_ignore_root(root))
922 list_add(&lower->list, &useless);
923 else
924 lower->root = root;
925 break;
926 }
927
928 edge = alloc_backref_edge(cache);
929 if (!edge) {
930 err = -ENOMEM;
931 goto out;
932 }
933
934 eb = path2->nodes[level];
935 rb_node = tree_search(&cache->rb_root, eb->start);
936 if (!rb_node) {
937 upper = alloc_backref_node(cache);
938 if (!upper) {
939 free_backref_edge(cache, edge);
940 err = -ENOMEM;
941 goto out;
942 }
943 upper->bytenr = eb->start;
944 upper->owner = btrfs_header_owner(eb);
945 upper->level = lower->level + 1;
946 if (!root->ref_cows)
947 upper->cowonly = 1;
948
949 /*
950 * if we know the block isn't shared
951 * we can void checking its backrefs.
952 */
953 if (btrfs_block_can_be_shared(root, eb))
954 upper->checked = 0;
955 else
956 upper->checked = 1;
957
958 /*
959 * add the block to pending list if we
960 * need check its backrefs. only block
961 * at 'cur->level + 1' is added to the
962 * tail of pending list. this guarantees
963 * we check backrefs from lower level
964 * blocks to upper level blocks.
965 */
966 if (!upper->checked &&
967 level == cur->level + 1) {
968 list_add_tail(&edge->list[UPPER],
969 &list);
970 } else
971 INIT_LIST_HEAD(&edge->list[UPPER]);
972 } else {
973 upper = rb_entry(rb_node, struct backref_node,
974 rb_node);
975 BUG_ON(!upper->checked);
976 INIT_LIST_HEAD(&edge->list[UPPER]);
977 if (!upper->owner)
978 upper->owner = btrfs_header_owner(eb);
979 }
980 list_add_tail(&edge->list[LOWER], &lower->upper);
981 edge->node[LOWER] = lower;
982 edge->node[UPPER] = upper;
983
984 if (rb_node)
985 break;
986 lower = upper;
987 upper = NULL;
988 }
989 btrfs_release_path(path2);
990 next:
991 if (ptr < end) {
992 ptr += btrfs_extent_inline_ref_size(key.type);
993 if (ptr >= end) {
994 WARN_ON(ptr > end);
995 ptr = 0;
996 end = 0;
997 }
998 }
999 if (ptr >= end)
1000 path1->slots[0]++;
1001 }
1002 btrfs_release_path(path1);
1003
1004 cur->checked = 1;
1005 WARN_ON(exist);
1006
1007 /* the pending list isn't empty, take the first block to process */
1008 if (!list_empty(&list)) {
1009 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1010 list_del_init(&edge->list[UPPER]);
1011 cur = edge->node[UPPER];
1012 goto again;
1013 }
1014
1015 /*
1016 * everything goes well, connect backref nodes and insert backref nodes
1017 * into the cache.
1018 */
1019 BUG_ON(!node->checked);
1020 cowonly = node->cowonly;
1021 if (!cowonly) {
1022 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1023 &node->rb_node);
1024 if (rb_node)
1025 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1026 list_add_tail(&node->lower, &cache->leaves);
1027 }
1028
1029 list_for_each_entry(edge, &node->upper, list[LOWER])
1030 list_add_tail(&edge->list[UPPER], &list);
1031
1032 while (!list_empty(&list)) {
1033 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1034 list_del_init(&edge->list[UPPER]);
1035 upper = edge->node[UPPER];
1036 if (upper->detached) {
1037 list_del(&edge->list[LOWER]);
1038 lower = edge->node[LOWER];
1039 free_backref_edge(cache, edge);
1040 if (list_empty(&lower->upper))
1041 list_add(&lower->list, &useless);
1042 continue;
1043 }
1044
1045 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1046 if (upper->lowest) {
1047 list_del_init(&upper->lower);
1048 upper->lowest = 0;
1049 }
1050
1051 list_add_tail(&edge->list[UPPER], &upper->lower);
1052 continue;
1053 }
1054
1055 BUG_ON(!upper->checked);
1056 BUG_ON(cowonly != upper->cowonly);
1057 if (!cowonly) {
1058 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1059 &upper->rb_node);
1060 if (rb_node)
1061 backref_tree_panic(rb_node, -EEXIST,
1062 upper->bytenr);
1063 }
1064
1065 list_add_tail(&edge->list[UPPER], &upper->lower);
1066
1067 list_for_each_entry(edge, &upper->upper, list[LOWER])
1068 list_add_tail(&edge->list[UPPER], &list);
1069 }
1070 /*
1071 * process useless backref nodes. backref nodes for tree leaves
1072 * are deleted from the cache. backref nodes for upper level
1073 * tree blocks are left in the cache to avoid unnecessary backref
1074 * lookup.
1075 */
1076 while (!list_empty(&useless)) {
1077 upper = list_entry(useless.next, struct backref_node, list);
1078 list_del_init(&upper->list);
1079 BUG_ON(!list_empty(&upper->upper));
1080 if (upper == node)
1081 node = NULL;
1082 if (upper->lowest) {
1083 list_del_init(&upper->lower);
1084 upper->lowest = 0;
1085 }
1086 while (!list_empty(&upper->lower)) {
1087 edge = list_entry(upper->lower.next,
1088 struct backref_edge, list[UPPER]);
1089 list_del(&edge->list[UPPER]);
1090 list_del(&edge->list[LOWER]);
1091 lower = edge->node[LOWER];
1092 free_backref_edge(cache, edge);
1093
1094 if (list_empty(&lower->upper))
1095 list_add(&lower->list, &useless);
1096 }
1097 __mark_block_processed(rc, upper);
1098 if (upper->level > 0) {
1099 list_add(&upper->list, &cache->detached);
1100 upper->detached = 1;
1101 } else {
1102 rb_erase(&upper->rb_node, &cache->rb_root);
1103 free_backref_node(cache, upper);
1104 }
1105 }
1106 out:
1107 btrfs_free_path(path1);
1108 btrfs_free_path(path2);
1109 if (err) {
1110 while (!list_empty(&useless)) {
1111 lower = list_entry(useless.next,
1112 struct backref_node, upper);
1113 list_del_init(&lower->upper);
1114 }
1115 upper = node;
1116 INIT_LIST_HEAD(&list);
1117 while (upper) {
1118 if (RB_EMPTY_NODE(&upper->rb_node)) {
1119 list_splice_tail(&upper->upper, &list);
1120 free_backref_node(cache, upper);
1121 }
1122
1123 if (list_empty(&list))
1124 break;
1125
1126 edge = list_entry(list.next, struct backref_edge,
1127 list[LOWER]);
1128 list_del(&edge->list[LOWER]);
1129 upper = edge->node[UPPER];
1130 free_backref_edge(cache, edge);
1131 }
1132 return ERR_PTR(err);
1133 }
1134 BUG_ON(node && node->detached);
1135 return node;
1136 }
1137
1138 /*
1139 * helper to add backref node for the newly created snapshot.
1140 * the backref node is created by cloning backref node that
1141 * corresponds to root of source tree
1142 */
1143 static int clone_backref_node(struct btrfs_trans_handle *trans,
1144 struct reloc_control *rc,
1145 struct btrfs_root *src,
1146 struct btrfs_root *dest)
1147 {
1148 struct btrfs_root *reloc_root = src->reloc_root;
1149 struct backref_cache *cache = &rc->backref_cache;
1150 struct backref_node *node = NULL;
1151 struct backref_node *new_node;
1152 struct backref_edge *edge;
1153 struct backref_edge *new_edge;
1154 struct rb_node *rb_node;
1155
1156 if (cache->last_trans > 0)
1157 update_backref_cache(trans, cache);
1158
1159 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1160 if (rb_node) {
1161 node = rb_entry(rb_node, struct backref_node, rb_node);
1162 if (node->detached)
1163 node = NULL;
1164 else
1165 BUG_ON(node->new_bytenr != reloc_root->node->start);
1166 }
1167
1168 if (!node) {
1169 rb_node = tree_search(&cache->rb_root,
1170 reloc_root->commit_root->start);
1171 if (rb_node) {
1172 node = rb_entry(rb_node, struct backref_node,
1173 rb_node);
1174 BUG_ON(node->detached);
1175 }
1176 }
1177
1178 if (!node)
1179 return 0;
1180
1181 new_node = alloc_backref_node(cache);
1182 if (!new_node)
1183 return -ENOMEM;
1184
1185 new_node->bytenr = dest->node->start;
1186 new_node->level = node->level;
1187 new_node->lowest = node->lowest;
1188 new_node->checked = 1;
1189 new_node->root = dest;
1190
1191 if (!node->lowest) {
1192 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1193 new_edge = alloc_backref_edge(cache);
1194 if (!new_edge)
1195 goto fail;
1196
1197 new_edge->node[UPPER] = new_node;
1198 new_edge->node[LOWER] = edge->node[LOWER];
1199 list_add_tail(&new_edge->list[UPPER],
1200 &new_node->lower);
1201 }
1202 } else {
1203 list_add_tail(&new_node->lower, &cache->leaves);
1204 }
1205
1206 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1207 &new_node->rb_node);
1208 if (rb_node)
1209 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1210
1211 if (!new_node->lowest) {
1212 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1213 list_add_tail(&new_edge->list[LOWER],
1214 &new_edge->node[LOWER]->upper);
1215 }
1216 }
1217 return 0;
1218 fail:
1219 while (!list_empty(&new_node->lower)) {
1220 new_edge = list_entry(new_node->lower.next,
1221 struct backref_edge, list[UPPER]);
1222 list_del(&new_edge->list[UPPER]);
1223 free_backref_edge(cache, new_edge);
1224 }
1225 free_backref_node(cache, new_node);
1226 return -ENOMEM;
1227 }
1228
1229 /*
1230 * helper to add 'address of tree root -> reloc tree' mapping
1231 */
1232 static int __must_check __add_reloc_root(struct btrfs_root *root)
1233 {
1234 struct rb_node *rb_node;
1235 struct mapping_node *node;
1236 struct reloc_control *rc = root->fs_info->reloc_ctl;
1237
1238 node = kmalloc(sizeof(*node), GFP_NOFS);
1239 if (!node)
1240 return -ENOMEM;
1241
1242 node->bytenr = root->node->start;
1243 node->data = root;
1244
1245 spin_lock(&rc->reloc_root_tree.lock);
1246 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1247 node->bytenr, &node->rb_node);
1248 spin_unlock(&rc->reloc_root_tree.lock);
1249 if (rb_node) {
1250 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1251 "for start=%llu while inserting into relocation "
1252 "tree\n", node->bytenr);
1253 kfree(node);
1254 return -EEXIST;
1255 }
1256
1257 list_add_tail(&root->root_list, &rc->reloc_roots);
1258 return 0;
1259 }
1260
1261 /*
1262 * helper to update/delete the 'address of tree root -> reloc tree'
1263 * mapping
1264 */
1265 static int __update_reloc_root(struct btrfs_root *root, int del)
1266 {
1267 struct rb_node *rb_node;
1268 struct mapping_node *node = NULL;
1269 struct reloc_control *rc = root->fs_info->reloc_ctl;
1270
1271 spin_lock(&rc->reloc_root_tree.lock);
1272 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1273 root->commit_root->start);
1274 if (rb_node) {
1275 node = rb_entry(rb_node, struct mapping_node, rb_node);
1276 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1277 }
1278 spin_unlock(&rc->reloc_root_tree.lock);
1279
1280 if (!node)
1281 return 0;
1282 BUG_ON((struct btrfs_root *)node->data != root);
1283
1284 if (!del) {
1285 spin_lock(&rc->reloc_root_tree.lock);
1286 node->bytenr = root->node->start;
1287 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1288 node->bytenr, &node->rb_node);
1289 spin_unlock(&rc->reloc_root_tree.lock);
1290 if (rb_node)
1291 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1292 } else {
1293 spin_lock(&root->fs_info->trans_lock);
1294 list_del_init(&root->root_list);
1295 spin_unlock(&root->fs_info->trans_lock);
1296 kfree(node);
1297 }
1298 return 0;
1299 }
1300
1301 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1302 struct btrfs_root *root, u64 objectid)
1303 {
1304 struct btrfs_root *reloc_root;
1305 struct extent_buffer *eb;
1306 struct btrfs_root_item *root_item;
1307 struct btrfs_key root_key;
1308 u64 last_snap = 0;
1309 int ret;
1310
1311 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1312 BUG_ON(!root_item);
1313
1314 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1315 root_key.type = BTRFS_ROOT_ITEM_KEY;
1316 root_key.offset = objectid;
1317
1318 if (root->root_key.objectid == objectid) {
1319 /* called by btrfs_init_reloc_root */
1320 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1321 BTRFS_TREE_RELOC_OBJECTID);
1322 BUG_ON(ret);
1323
1324 last_snap = btrfs_root_last_snapshot(&root->root_item);
1325 btrfs_set_root_last_snapshot(&root->root_item,
1326 trans->transid - 1);
1327 } else {
1328 /*
1329 * called by btrfs_reloc_post_snapshot_hook.
1330 * the source tree is a reloc tree, all tree blocks
1331 * modified after it was created have RELOC flag
1332 * set in their headers. so it's OK to not update
1333 * the 'last_snapshot'.
1334 */
1335 ret = btrfs_copy_root(trans, root, root->node, &eb,
1336 BTRFS_TREE_RELOC_OBJECTID);
1337 BUG_ON(ret);
1338 }
1339
1340 memcpy(root_item, &root->root_item, sizeof(*root_item));
1341 btrfs_set_root_bytenr(root_item, eb->start);
1342 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1343 btrfs_set_root_generation(root_item, trans->transid);
1344
1345 if (root->root_key.objectid == objectid) {
1346 btrfs_set_root_refs(root_item, 0);
1347 memset(&root_item->drop_progress, 0,
1348 sizeof(struct btrfs_disk_key));
1349 root_item->drop_level = 0;
1350 /*
1351 * abuse rtransid, it is safe because it is impossible to
1352 * receive data into a relocation tree.
1353 */
1354 btrfs_set_root_rtransid(root_item, last_snap);
1355 btrfs_set_root_otransid(root_item, trans->transid);
1356 }
1357
1358 btrfs_tree_unlock(eb);
1359 free_extent_buffer(eb);
1360
1361 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1362 &root_key, root_item);
1363 BUG_ON(ret);
1364 kfree(root_item);
1365
1366 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1367 BUG_ON(IS_ERR(reloc_root));
1368 reloc_root->last_trans = trans->transid;
1369 return reloc_root;
1370 }
1371
1372 /*
1373 * create reloc tree for a given fs tree. reloc tree is just a
1374 * snapshot of the fs tree with special root objectid.
1375 */
1376 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1377 struct btrfs_root *root)
1378 {
1379 struct btrfs_root *reloc_root;
1380 struct reloc_control *rc = root->fs_info->reloc_ctl;
1381 int clear_rsv = 0;
1382 int ret;
1383
1384 if (root->reloc_root) {
1385 reloc_root = root->reloc_root;
1386 reloc_root->last_trans = trans->transid;
1387 return 0;
1388 }
1389
1390 if (!rc || !rc->create_reloc_tree ||
1391 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1392 return 0;
1393
1394 if (!trans->block_rsv) {
1395 trans->block_rsv = rc->block_rsv;
1396 clear_rsv = 1;
1397 }
1398 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1399 if (clear_rsv)
1400 trans->block_rsv = NULL;
1401
1402 ret = __add_reloc_root(reloc_root);
1403 BUG_ON(ret < 0);
1404 root->reloc_root = reloc_root;
1405 return 0;
1406 }
1407
1408 /*
1409 * update root item of reloc tree
1410 */
1411 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1412 struct btrfs_root *root)
1413 {
1414 struct btrfs_root *reloc_root;
1415 struct btrfs_root_item *root_item;
1416 int del = 0;
1417 int ret;
1418
1419 if (!root->reloc_root)
1420 goto out;
1421
1422 reloc_root = root->reloc_root;
1423 root_item = &reloc_root->root_item;
1424
1425 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1426 btrfs_root_refs(root_item) == 0) {
1427 root->reloc_root = NULL;
1428 del = 1;
1429 }
1430
1431 __update_reloc_root(reloc_root, del);
1432
1433 if (reloc_root->commit_root != reloc_root->node) {
1434 btrfs_set_root_node(root_item, reloc_root->node);
1435 free_extent_buffer(reloc_root->commit_root);
1436 reloc_root->commit_root = btrfs_root_node(reloc_root);
1437 }
1438
1439 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1440 &reloc_root->root_key, root_item);
1441 BUG_ON(ret);
1442
1443 out:
1444 return 0;
1445 }
1446
1447 /*
1448 * helper to find first cached inode with inode number >= objectid
1449 * in a subvolume
1450 */
1451 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1452 {
1453 struct rb_node *node;
1454 struct rb_node *prev;
1455 struct btrfs_inode *entry;
1456 struct inode *inode;
1457
1458 spin_lock(&root->inode_lock);
1459 again:
1460 node = root->inode_tree.rb_node;
1461 prev = NULL;
1462 while (node) {
1463 prev = node;
1464 entry = rb_entry(node, struct btrfs_inode, rb_node);
1465
1466 if (objectid < btrfs_ino(&entry->vfs_inode))
1467 node = node->rb_left;
1468 else if (objectid > btrfs_ino(&entry->vfs_inode))
1469 node = node->rb_right;
1470 else
1471 break;
1472 }
1473 if (!node) {
1474 while (prev) {
1475 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1476 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1477 node = prev;
1478 break;
1479 }
1480 prev = rb_next(prev);
1481 }
1482 }
1483 while (node) {
1484 entry = rb_entry(node, struct btrfs_inode, rb_node);
1485 inode = igrab(&entry->vfs_inode);
1486 if (inode) {
1487 spin_unlock(&root->inode_lock);
1488 return inode;
1489 }
1490
1491 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1492 if (cond_resched_lock(&root->inode_lock))
1493 goto again;
1494
1495 node = rb_next(node);
1496 }
1497 spin_unlock(&root->inode_lock);
1498 return NULL;
1499 }
1500
1501 static int in_block_group(u64 bytenr,
1502 struct btrfs_block_group_cache *block_group)
1503 {
1504 if (bytenr >= block_group->key.objectid &&
1505 bytenr < block_group->key.objectid + block_group->key.offset)
1506 return 1;
1507 return 0;
1508 }
1509
1510 /*
1511 * get new location of data
1512 */
1513 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1514 u64 bytenr, u64 num_bytes)
1515 {
1516 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1517 struct btrfs_path *path;
1518 struct btrfs_file_extent_item *fi;
1519 struct extent_buffer *leaf;
1520 int ret;
1521
1522 path = btrfs_alloc_path();
1523 if (!path)
1524 return -ENOMEM;
1525
1526 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1527 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1528 bytenr, 0);
1529 if (ret < 0)
1530 goto out;
1531 if (ret > 0) {
1532 ret = -ENOENT;
1533 goto out;
1534 }
1535
1536 leaf = path->nodes[0];
1537 fi = btrfs_item_ptr(leaf, path->slots[0],
1538 struct btrfs_file_extent_item);
1539
1540 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1541 btrfs_file_extent_compression(leaf, fi) ||
1542 btrfs_file_extent_encryption(leaf, fi) ||
1543 btrfs_file_extent_other_encoding(leaf, fi));
1544
1545 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1546 ret = 1;
1547 goto out;
1548 }
1549
1550 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1551 ret = 0;
1552 out:
1553 btrfs_free_path(path);
1554 return ret;
1555 }
1556
1557 /*
1558 * update file extent items in the tree leaf to point to
1559 * the new locations.
1560 */
1561 static noinline_for_stack
1562 int replace_file_extents(struct btrfs_trans_handle *trans,
1563 struct reloc_control *rc,
1564 struct btrfs_root *root,
1565 struct extent_buffer *leaf)
1566 {
1567 struct btrfs_key key;
1568 struct btrfs_file_extent_item *fi;
1569 struct inode *inode = NULL;
1570 u64 parent;
1571 u64 bytenr;
1572 u64 new_bytenr = 0;
1573 u64 num_bytes;
1574 u64 end;
1575 u32 nritems;
1576 u32 i;
1577 int ret;
1578 int first = 1;
1579 int dirty = 0;
1580
1581 if (rc->stage != UPDATE_DATA_PTRS)
1582 return 0;
1583
1584 /* reloc trees always use full backref */
1585 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1586 parent = leaf->start;
1587 else
1588 parent = 0;
1589
1590 nritems = btrfs_header_nritems(leaf);
1591 for (i = 0; i < nritems; i++) {
1592 cond_resched();
1593 btrfs_item_key_to_cpu(leaf, &key, i);
1594 if (key.type != BTRFS_EXTENT_DATA_KEY)
1595 continue;
1596 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1597 if (btrfs_file_extent_type(leaf, fi) ==
1598 BTRFS_FILE_EXTENT_INLINE)
1599 continue;
1600 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1601 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1602 if (bytenr == 0)
1603 continue;
1604 if (!in_block_group(bytenr, rc->block_group))
1605 continue;
1606
1607 /*
1608 * if we are modifying block in fs tree, wait for readpage
1609 * to complete and drop the extent cache
1610 */
1611 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1612 if (first) {
1613 inode = find_next_inode(root, key.objectid);
1614 first = 0;
1615 } else if (inode && btrfs_ino(inode) < key.objectid) {
1616 btrfs_add_delayed_iput(inode);
1617 inode = find_next_inode(root, key.objectid);
1618 }
1619 if (inode && btrfs_ino(inode) == key.objectid) {
1620 end = key.offset +
1621 btrfs_file_extent_num_bytes(leaf, fi);
1622 WARN_ON(!IS_ALIGNED(key.offset,
1623 root->sectorsize));
1624 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1625 end--;
1626 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1627 key.offset, end);
1628 if (!ret)
1629 continue;
1630
1631 btrfs_drop_extent_cache(inode, key.offset, end,
1632 1);
1633 unlock_extent(&BTRFS_I(inode)->io_tree,
1634 key.offset, end);
1635 }
1636 }
1637
1638 ret = get_new_location(rc->data_inode, &new_bytenr,
1639 bytenr, num_bytes);
1640 if (ret > 0) {
1641 WARN_ON(1);
1642 continue;
1643 }
1644 BUG_ON(ret < 0);
1645
1646 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1647 dirty = 1;
1648
1649 key.offset -= btrfs_file_extent_offset(leaf, fi);
1650 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1651 num_bytes, parent,
1652 btrfs_header_owner(leaf),
1653 key.objectid, key.offset, 1);
1654 BUG_ON(ret);
1655
1656 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1657 parent, btrfs_header_owner(leaf),
1658 key.objectid, key.offset, 1);
1659 BUG_ON(ret);
1660 }
1661 if (dirty)
1662 btrfs_mark_buffer_dirty(leaf);
1663 if (inode)
1664 btrfs_add_delayed_iput(inode);
1665 return 0;
1666 }
1667
1668 static noinline_for_stack
1669 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1670 struct btrfs_path *path, int level)
1671 {
1672 struct btrfs_disk_key key1;
1673 struct btrfs_disk_key key2;
1674 btrfs_node_key(eb, &key1, slot);
1675 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1676 return memcmp(&key1, &key2, sizeof(key1));
1677 }
1678
1679 /*
1680 * try to replace tree blocks in fs tree with the new blocks
1681 * in reloc tree. tree blocks haven't been modified since the
1682 * reloc tree was create can be replaced.
1683 *
1684 * if a block was replaced, level of the block + 1 is returned.
1685 * if no block got replaced, 0 is returned. if there are other
1686 * errors, a negative error number is returned.
1687 */
1688 static noinline_for_stack
1689 int replace_path(struct btrfs_trans_handle *trans,
1690 struct btrfs_root *dest, struct btrfs_root *src,
1691 struct btrfs_path *path, struct btrfs_key *next_key,
1692 int lowest_level, int max_level)
1693 {
1694 struct extent_buffer *eb;
1695 struct extent_buffer *parent;
1696 struct btrfs_key key;
1697 u64 old_bytenr;
1698 u64 new_bytenr;
1699 u64 old_ptr_gen;
1700 u64 new_ptr_gen;
1701 u64 last_snapshot;
1702 u32 blocksize;
1703 int cow = 0;
1704 int level;
1705 int ret;
1706 int slot;
1707
1708 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1709 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1710
1711 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1712 again:
1713 slot = path->slots[lowest_level];
1714 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1715
1716 eb = btrfs_lock_root_node(dest);
1717 btrfs_set_lock_blocking(eb);
1718 level = btrfs_header_level(eb);
1719
1720 if (level < lowest_level) {
1721 btrfs_tree_unlock(eb);
1722 free_extent_buffer(eb);
1723 return 0;
1724 }
1725
1726 if (cow) {
1727 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1728 BUG_ON(ret);
1729 }
1730 btrfs_set_lock_blocking(eb);
1731
1732 if (next_key) {
1733 next_key->objectid = (u64)-1;
1734 next_key->type = (u8)-1;
1735 next_key->offset = (u64)-1;
1736 }
1737
1738 parent = eb;
1739 while (1) {
1740 level = btrfs_header_level(parent);
1741 BUG_ON(level < lowest_level);
1742
1743 ret = btrfs_bin_search(parent, &key, level, &slot);
1744 if (ret && slot > 0)
1745 slot--;
1746
1747 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1748 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1749
1750 old_bytenr = btrfs_node_blockptr(parent, slot);
1751 blocksize = btrfs_level_size(dest, level - 1);
1752 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1753
1754 if (level <= max_level) {
1755 eb = path->nodes[level];
1756 new_bytenr = btrfs_node_blockptr(eb,
1757 path->slots[level]);
1758 new_ptr_gen = btrfs_node_ptr_generation(eb,
1759 path->slots[level]);
1760 } else {
1761 new_bytenr = 0;
1762 new_ptr_gen = 0;
1763 }
1764
1765 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1766 WARN_ON(1);
1767 ret = level;
1768 break;
1769 }
1770
1771 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1772 memcmp_node_keys(parent, slot, path, level)) {
1773 if (level <= lowest_level) {
1774 ret = 0;
1775 break;
1776 }
1777
1778 eb = read_tree_block(dest, old_bytenr, blocksize,
1779 old_ptr_gen);
1780 if (!eb || !extent_buffer_uptodate(eb)) {
1781 ret = (!eb) ? -ENOMEM : -EIO;
1782 free_extent_buffer(eb);
1783 break;
1784 }
1785 btrfs_tree_lock(eb);
1786 if (cow) {
1787 ret = btrfs_cow_block(trans, dest, eb, parent,
1788 slot, &eb);
1789 BUG_ON(ret);
1790 }
1791 btrfs_set_lock_blocking(eb);
1792
1793 btrfs_tree_unlock(parent);
1794 free_extent_buffer(parent);
1795
1796 parent = eb;
1797 continue;
1798 }
1799
1800 if (!cow) {
1801 btrfs_tree_unlock(parent);
1802 free_extent_buffer(parent);
1803 cow = 1;
1804 goto again;
1805 }
1806
1807 btrfs_node_key_to_cpu(path->nodes[level], &key,
1808 path->slots[level]);
1809 btrfs_release_path(path);
1810
1811 path->lowest_level = level;
1812 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1813 path->lowest_level = 0;
1814 BUG_ON(ret);
1815
1816 /*
1817 * swap blocks in fs tree and reloc tree.
1818 */
1819 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1820 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1821 btrfs_mark_buffer_dirty(parent);
1822
1823 btrfs_set_node_blockptr(path->nodes[level],
1824 path->slots[level], old_bytenr);
1825 btrfs_set_node_ptr_generation(path->nodes[level],
1826 path->slots[level], old_ptr_gen);
1827 btrfs_mark_buffer_dirty(path->nodes[level]);
1828
1829 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1830 path->nodes[level]->start,
1831 src->root_key.objectid, level - 1, 0,
1832 1);
1833 BUG_ON(ret);
1834 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1835 0, dest->root_key.objectid, level - 1,
1836 0, 1);
1837 BUG_ON(ret);
1838
1839 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1840 path->nodes[level]->start,
1841 src->root_key.objectid, level - 1, 0,
1842 1);
1843 BUG_ON(ret);
1844
1845 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1846 0, dest->root_key.objectid, level - 1,
1847 0, 1);
1848 BUG_ON(ret);
1849
1850 btrfs_unlock_up_safe(path, 0);
1851
1852 ret = level;
1853 break;
1854 }
1855 btrfs_tree_unlock(parent);
1856 free_extent_buffer(parent);
1857 return ret;
1858 }
1859
1860 /*
1861 * helper to find next relocated block in reloc tree
1862 */
1863 static noinline_for_stack
1864 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1865 int *level)
1866 {
1867 struct extent_buffer *eb;
1868 int i;
1869 u64 last_snapshot;
1870 u32 nritems;
1871
1872 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1873
1874 for (i = 0; i < *level; i++) {
1875 free_extent_buffer(path->nodes[i]);
1876 path->nodes[i] = NULL;
1877 }
1878
1879 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1880 eb = path->nodes[i];
1881 nritems = btrfs_header_nritems(eb);
1882 while (path->slots[i] + 1 < nritems) {
1883 path->slots[i]++;
1884 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1885 last_snapshot)
1886 continue;
1887
1888 *level = i;
1889 return 0;
1890 }
1891 free_extent_buffer(path->nodes[i]);
1892 path->nodes[i] = NULL;
1893 }
1894 return 1;
1895 }
1896
1897 /*
1898 * walk down reloc tree to find relocated block of lowest level
1899 */
1900 static noinline_for_stack
1901 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1902 int *level)
1903 {
1904 struct extent_buffer *eb = NULL;
1905 int i;
1906 u64 bytenr;
1907 u64 ptr_gen = 0;
1908 u64 last_snapshot;
1909 u32 blocksize;
1910 u32 nritems;
1911
1912 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1913
1914 for (i = *level; i > 0; i--) {
1915 eb = path->nodes[i];
1916 nritems = btrfs_header_nritems(eb);
1917 while (path->slots[i] < nritems) {
1918 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1919 if (ptr_gen > last_snapshot)
1920 break;
1921 path->slots[i]++;
1922 }
1923 if (path->slots[i] >= nritems) {
1924 if (i == *level)
1925 break;
1926 *level = i + 1;
1927 return 0;
1928 }
1929 if (i == 1) {
1930 *level = i;
1931 return 0;
1932 }
1933
1934 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1935 blocksize = btrfs_level_size(root, i - 1);
1936 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1937 if (!eb || !extent_buffer_uptodate(eb)) {
1938 free_extent_buffer(eb);
1939 return -EIO;
1940 }
1941 BUG_ON(btrfs_header_level(eb) != i - 1);
1942 path->nodes[i - 1] = eb;
1943 path->slots[i - 1] = 0;
1944 }
1945 return 1;
1946 }
1947
1948 /*
1949 * invalidate extent cache for file extents whose key in range of
1950 * [min_key, max_key)
1951 */
1952 static int invalidate_extent_cache(struct btrfs_root *root,
1953 struct btrfs_key *min_key,
1954 struct btrfs_key *max_key)
1955 {
1956 struct inode *inode = NULL;
1957 u64 objectid;
1958 u64 start, end;
1959 u64 ino;
1960
1961 objectid = min_key->objectid;
1962 while (1) {
1963 cond_resched();
1964 iput(inode);
1965
1966 if (objectid > max_key->objectid)
1967 break;
1968
1969 inode = find_next_inode(root, objectid);
1970 if (!inode)
1971 break;
1972 ino = btrfs_ino(inode);
1973
1974 if (ino > max_key->objectid) {
1975 iput(inode);
1976 break;
1977 }
1978
1979 objectid = ino + 1;
1980 if (!S_ISREG(inode->i_mode))
1981 continue;
1982
1983 if (unlikely(min_key->objectid == ino)) {
1984 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1985 continue;
1986 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1987 start = 0;
1988 else {
1989 start = min_key->offset;
1990 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1991 }
1992 } else {
1993 start = 0;
1994 }
1995
1996 if (unlikely(max_key->objectid == ino)) {
1997 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1998 continue;
1999 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2000 end = (u64)-1;
2001 } else {
2002 if (max_key->offset == 0)
2003 continue;
2004 end = max_key->offset;
2005 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2006 end--;
2007 }
2008 } else {
2009 end = (u64)-1;
2010 }
2011
2012 /* the lock_extent waits for readpage to complete */
2013 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2014 btrfs_drop_extent_cache(inode, start, end, 1);
2015 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2016 }
2017 return 0;
2018 }
2019
2020 static int find_next_key(struct btrfs_path *path, int level,
2021 struct btrfs_key *key)
2022
2023 {
2024 while (level < BTRFS_MAX_LEVEL) {
2025 if (!path->nodes[level])
2026 break;
2027 if (path->slots[level] + 1 <
2028 btrfs_header_nritems(path->nodes[level])) {
2029 btrfs_node_key_to_cpu(path->nodes[level], key,
2030 path->slots[level] + 1);
2031 return 0;
2032 }
2033 level++;
2034 }
2035 return 1;
2036 }
2037
2038 /*
2039 * merge the relocated tree blocks in reloc tree with corresponding
2040 * fs tree.
2041 */
2042 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2043 struct btrfs_root *root)
2044 {
2045 LIST_HEAD(inode_list);
2046 struct btrfs_key key;
2047 struct btrfs_key next_key;
2048 struct btrfs_trans_handle *trans;
2049 struct btrfs_root *reloc_root;
2050 struct btrfs_root_item *root_item;
2051 struct btrfs_path *path;
2052 struct extent_buffer *leaf;
2053 int level;
2054 int max_level;
2055 int replaced = 0;
2056 int ret;
2057 int err = 0;
2058 u32 min_reserved;
2059
2060 path = btrfs_alloc_path();
2061 if (!path)
2062 return -ENOMEM;
2063 path->reada = 1;
2064
2065 reloc_root = root->reloc_root;
2066 root_item = &reloc_root->root_item;
2067
2068 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2069 level = btrfs_root_level(root_item);
2070 extent_buffer_get(reloc_root->node);
2071 path->nodes[level] = reloc_root->node;
2072 path->slots[level] = 0;
2073 } else {
2074 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2075
2076 level = root_item->drop_level;
2077 BUG_ON(level == 0);
2078 path->lowest_level = level;
2079 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2080 path->lowest_level = 0;
2081 if (ret < 0) {
2082 btrfs_free_path(path);
2083 return ret;
2084 }
2085
2086 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2087 path->slots[level]);
2088 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2089
2090 btrfs_unlock_up_safe(path, 0);
2091 }
2092
2093 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2094 memset(&next_key, 0, sizeof(next_key));
2095
2096 while (1) {
2097 trans = btrfs_start_transaction(root, 0);
2098 BUG_ON(IS_ERR(trans));
2099 trans->block_rsv = rc->block_rsv;
2100
2101 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2102 BTRFS_RESERVE_FLUSH_ALL);
2103 if (ret) {
2104 BUG_ON(ret != -EAGAIN);
2105 ret = btrfs_commit_transaction(trans, root);
2106 BUG_ON(ret);
2107 continue;
2108 }
2109
2110 replaced = 0;
2111 max_level = level;
2112
2113 ret = walk_down_reloc_tree(reloc_root, path, &level);
2114 if (ret < 0) {
2115 err = ret;
2116 goto out;
2117 }
2118 if (ret > 0)
2119 break;
2120
2121 if (!find_next_key(path, level, &key) &&
2122 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2123 ret = 0;
2124 } else {
2125 ret = replace_path(trans, root, reloc_root, path,
2126 &next_key, level, max_level);
2127 }
2128 if (ret < 0) {
2129 err = ret;
2130 goto out;
2131 }
2132
2133 if (ret > 0) {
2134 level = ret;
2135 btrfs_node_key_to_cpu(path->nodes[level], &key,
2136 path->slots[level]);
2137 replaced = 1;
2138 }
2139
2140 ret = walk_up_reloc_tree(reloc_root, path, &level);
2141 if (ret > 0)
2142 break;
2143
2144 BUG_ON(level == 0);
2145 /*
2146 * save the merging progress in the drop_progress.
2147 * this is OK since root refs == 1 in this case.
2148 */
2149 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2150 path->slots[level]);
2151 root_item->drop_level = level;
2152
2153 btrfs_end_transaction_throttle(trans, root);
2154
2155 btrfs_btree_balance_dirty(root);
2156
2157 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2158 invalidate_extent_cache(root, &key, &next_key);
2159 }
2160
2161 /*
2162 * handle the case only one block in the fs tree need to be
2163 * relocated and the block is tree root.
2164 */
2165 leaf = btrfs_lock_root_node(root);
2166 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2167 btrfs_tree_unlock(leaf);
2168 free_extent_buffer(leaf);
2169 if (ret < 0)
2170 err = ret;
2171 out:
2172 btrfs_free_path(path);
2173
2174 if (err == 0) {
2175 memset(&root_item->drop_progress, 0,
2176 sizeof(root_item->drop_progress));
2177 root_item->drop_level = 0;
2178 btrfs_set_root_refs(root_item, 0);
2179 btrfs_update_reloc_root(trans, root);
2180 }
2181
2182 btrfs_end_transaction_throttle(trans, root);
2183
2184 btrfs_btree_balance_dirty(root);
2185
2186 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2187 invalidate_extent_cache(root, &key, &next_key);
2188
2189 return err;
2190 }
2191
2192 static noinline_for_stack
2193 int prepare_to_merge(struct reloc_control *rc, int err)
2194 {
2195 struct btrfs_root *root = rc->extent_root;
2196 struct btrfs_root *reloc_root;
2197 struct btrfs_trans_handle *trans;
2198 LIST_HEAD(reloc_roots);
2199 u64 num_bytes = 0;
2200 int ret;
2201
2202 mutex_lock(&root->fs_info->reloc_mutex);
2203 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2204 rc->merging_rsv_size += rc->nodes_relocated * 2;
2205 mutex_unlock(&root->fs_info->reloc_mutex);
2206
2207 again:
2208 if (!err) {
2209 num_bytes = rc->merging_rsv_size;
2210 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2211 BTRFS_RESERVE_FLUSH_ALL);
2212 if (ret)
2213 err = ret;
2214 }
2215
2216 trans = btrfs_join_transaction(rc->extent_root);
2217 if (IS_ERR(trans)) {
2218 if (!err)
2219 btrfs_block_rsv_release(rc->extent_root,
2220 rc->block_rsv, num_bytes);
2221 return PTR_ERR(trans);
2222 }
2223
2224 if (!err) {
2225 if (num_bytes != rc->merging_rsv_size) {
2226 btrfs_end_transaction(trans, rc->extent_root);
2227 btrfs_block_rsv_release(rc->extent_root,
2228 rc->block_rsv, num_bytes);
2229 goto again;
2230 }
2231 }
2232
2233 rc->merge_reloc_tree = 1;
2234
2235 while (!list_empty(&rc->reloc_roots)) {
2236 reloc_root = list_entry(rc->reloc_roots.next,
2237 struct btrfs_root, root_list);
2238 list_del_init(&reloc_root->root_list);
2239
2240 root = read_fs_root(reloc_root->fs_info,
2241 reloc_root->root_key.offset);
2242 BUG_ON(IS_ERR(root));
2243 BUG_ON(root->reloc_root != reloc_root);
2244
2245 /*
2246 * set reference count to 1, so btrfs_recover_relocation
2247 * knows it should resumes merging
2248 */
2249 if (!err)
2250 btrfs_set_root_refs(&reloc_root->root_item, 1);
2251 btrfs_update_reloc_root(trans, root);
2252
2253 list_add(&reloc_root->root_list, &reloc_roots);
2254 }
2255
2256 list_splice(&reloc_roots, &rc->reloc_roots);
2257
2258 if (!err)
2259 btrfs_commit_transaction(trans, rc->extent_root);
2260 else
2261 btrfs_end_transaction(trans, rc->extent_root);
2262 return err;
2263 }
2264
2265 static noinline_for_stack
2266 void free_reloc_roots(struct list_head *list)
2267 {
2268 struct btrfs_root *reloc_root;
2269
2270 while (!list_empty(list)) {
2271 reloc_root = list_entry(list->next, struct btrfs_root,
2272 root_list);
2273 __update_reloc_root(reloc_root, 1);
2274 free_extent_buffer(reloc_root->node);
2275 free_extent_buffer(reloc_root->commit_root);
2276 kfree(reloc_root);
2277 }
2278 }
2279
2280 static noinline_for_stack
2281 int merge_reloc_roots(struct reloc_control *rc)
2282 {
2283 struct btrfs_trans_handle *trans;
2284 struct btrfs_root *root;
2285 struct btrfs_root *reloc_root;
2286 u64 last_snap;
2287 u64 otransid;
2288 u64 objectid;
2289 LIST_HEAD(reloc_roots);
2290 int found = 0;
2291 int ret = 0;
2292 again:
2293 root = rc->extent_root;
2294
2295 /*
2296 * this serializes us with btrfs_record_root_in_transaction,
2297 * we have to make sure nobody is in the middle of
2298 * adding their roots to the list while we are
2299 * doing this splice
2300 */
2301 mutex_lock(&root->fs_info->reloc_mutex);
2302 list_splice_init(&rc->reloc_roots, &reloc_roots);
2303 mutex_unlock(&root->fs_info->reloc_mutex);
2304
2305 while (!list_empty(&reloc_roots)) {
2306 found = 1;
2307 reloc_root = list_entry(reloc_roots.next,
2308 struct btrfs_root, root_list);
2309
2310 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2311 root = read_fs_root(reloc_root->fs_info,
2312 reloc_root->root_key.offset);
2313 BUG_ON(IS_ERR(root));
2314 BUG_ON(root->reloc_root != reloc_root);
2315
2316 ret = merge_reloc_root(rc, root);
2317 if (ret)
2318 goto out;
2319 } else {
2320 list_del_init(&reloc_root->root_list);
2321 }
2322
2323 /*
2324 * we keep the old last snapshod transid in rtranid when we
2325 * created the relocation tree.
2326 */
2327 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2328 otransid = btrfs_root_otransid(&reloc_root->root_item);
2329 objectid = reloc_root->root_key.offset;
2330
2331 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2332 if (ret < 0) {
2333 if (list_empty(&reloc_root->root_list))
2334 list_add_tail(&reloc_root->root_list,
2335 &reloc_roots);
2336 goto out;
2337 } else if (!ret) {
2338 /*
2339 * recover the last snapshot tranid to avoid
2340 * the space balance break NOCOW.
2341 */
2342 root = read_fs_root(rc->extent_root->fs_info,
2343 objectid);
2344 if (IS_ERR(root))
2345 continue;
2346
2347 if (btrfs_root_refs(&root->root_item) == 0)
2348 continue;
2349
2350 trans = btrfs_join_transaction(root);
2351 BUG_ON(IS_ERR(trans));
2352
2353 /* Check if the fs/file tree was snapshoted or not. */
2354 if (btrfs_root_last_snapshot(&root->root_item) ==
2355 otransid - 1)
2356 btrfs_set_root_last_snapshot(&root->root_item,
2357 last_snap);
2358
2359 btrfs_end_transaction(trans, root);
2360 }
2361 }
2362
2363 if (found) {
2364 found = 0;
2365 goto again;
2366 }
2367 out:
2368 if (ret) {
2369 btrfs_std_error(root->fs_info, ret);
2370 if (!list_empty(&reloc_roots))
2371 free_reloc_roots(&reloc_roots);
2372 }
2373
2374 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2375 return ret;
2376 }
2377
2378 static void free_block_list(struct rb_root *blocks)
2379 {
2380 struct tree_block *block;
2381 struct rb_node *rb_node;
2382 while ((rb_node = rb_first(blocks))) {
2383 block = rb_entry(rb_node, struct tree_block, rb_node);
2384 rb_erase(rb_node, blocks);
2385 kfree(block);
2386 }
2387 }
2388
2389 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2390 struct btrfs_root *reloc_root)
2391 {
2392 struct btrfs_root *root;
2393
2394 if (reloc_root->last_trans == trans->transid)
2395 return 0;
2396
2397 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2398 BUG_ON(IS_ERR(root));
2399 BUG_ON(root->reloc_root != reloc_root);
2400
2401 return btrfs_record_root_in_trans(trans, root);
2402 }
2403
2404 static noinline_for_stack
2405 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2406 struct reloc_control *rc,
2407 struct backref_node *node,
2408 struct backref_edge *edges[], int *nr)
2409 {
2410 struct backref_node *next;
2411 struct btrfs_root *root;
2412 int index = 0;
2413
2414 next = node;
2415 while (1) {
2416 cond_resched();
2417 next = walk_up_backref(next, edges, &index);
2418 root = next->root;
2419 BUG_ON(!root);
2420 BUG_ON(!root->ref_cows);
2421
2422 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2423 record_reloc_root_in_trans(trans, root);
2424 break;
2425 }
2426
2427 btrfs_record_root_in_trans(trans, root);
2428 root = root->reloc_root;
2429
2430 if (next->new_bytenr != root->node->start) {
2431 BUG_ON(next->new_bytenr);
2432 BUG_ON(!list_empty(&next->list));
2433 next->new_bytenr = root->node->start;
2434 next->root = root;
2435 list_add_tail(&next->list,
2436 &rc->backref_cache.changed);
2437 __mark_block_processed(rc, next);
2438 break;
2439 }
2440
2441 WARN_ON(1);
2442 root = NULL;
2443 next = walk_down_backref(edges, &index);
2444 if (!next || next->level <= node->level)
2445 break;
2446 }
2447 if (!root)
2448 return NULL;
2449
2450 *nr = index;
2451 next = node;
2452 /* setup backref node path for btrfs_reloc_cow_block */
2453 while (1) {
2454 rc->backref_cache.path[next->level] = next;
2455 if (--index < 0)
2456 break;
2457 next = edges[index]->node[UPPER];
2458 }
2459 return root;
2460 }
2461
2462 /*
2463 * select a tree root for relocation. return NULL if the block
2464 * is reference counted. we should use do_relocation() in this
2465 * case. return a tree root pointer if the block isn't reference
2466 * counted. return -ENOENT if the block is root of reloc tree.
2467 */
2468 static noinline_for_stack
2469 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2470 struct backref_node *node)
2471 {
2472 struct backref_node *next;
2473 struct btrfs_root *root;
2474 struct btrfs_root *fs_root = NULL;
2475 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2476 int index = 0;
2477
2478 next = node;
2479 while (1) {
2480 cond_resched();
2481 next = walk_up_backref(next, edges, &index);
2482 root = next->root;
2483 BUG_ON(!root);
2484
2485 /* no other choice for non-references counted tree */
2486 if (!root->ref_cows)
2487 return root;
2488
2489 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2490 fs_root = root;
2491
2492 if (next != node)
2493 return NULL;
2494
2495 next = walk_down_backref(edges, &index);
2496 if (!next || next->level <= node->level)
2497 break;
2498 }
2499
2500 if (!fs_root)
2501 return ERR_PTR(-ENOENT);
2502 return fs_root;
2503 }
2504
2505 static noinline_for_stack
2506 u64 calcu_metadata_size(struct reloc_control *rc,
2507 struct backref_node *node, int reserve)
2508 {
2509 struct backref_node *next = node;
2510 struct backref_edge *edge;
2511 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2512 u64 num_bytes = 0;
2513 int index = 0;
2514
2515 BUG_ON(reserve && node->processed);
2516
2517 while (next) {
2518 cond_resched();
2519 while (1) {
2520 if (next->processed && (reserve || next != node))
2521 break;
2522
2523 num_bytes += btrfs_level_size(rc->extent_root,
2524 next->level);
2525
2526 if (list_empty(&next->upper))
2527 break;
2528
2529 edge = list_entry(next->upper.next,
2530 struct backref_edge, list[LOWER]);
2531 edges[index++] = edge;
2532 next = edge->node[UPPER];
2533 }
2534 next = walk_down_backref(edges, &index);
2535 }
2536 return num_bytes;
2537 }
2538
2539 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2540 struct reloc_control *rc,
2541 struct backref_node *node)
2542 {
2543 struct btrfs_root *root = rc->extent_root;
2544 u64 num_bytes;
2545 int ret;
2546
2547 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2548
2549 trans->block_rsv = rc->block_rsv;
2550 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2551 BTRFS_RESERVE_FLUSH_ALL);
2552 if (ret) {
2553 if (ret == -EAGAIN)
2554 rc->commit_transaction = 1;
2555 return ret;
2556 }
2557
2558 return 0;
2559 }
2560
2561 static void release_metadata_space(struct reloc_control *rc,
2562 struct backref_node *node)
2563 {
2564 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2565 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2566 }
2567
2568 /*
2569 * relocate a block tree, and then update pointers in upper level
2570 * blocks that reference the block to point to the new location.
2571 *
2572 * if called by link_to_upper, the block has already been relocated.
2573 * in that case this function just updates pointers.
2574 */
2575 static int do_relocation(struct btrfs_trans_handle *trans,
2576 struct reloc_control *rc,
2577 struct backref_node *node,
2578 struct btrfs_key *key,
2579 struct btrfs_path *path, int lowest)
2580 {
2581 struct backref_node *upper;
2582 struct backref_edge *edge;
2583 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2584 struct btrfs_root *root;
2585 struct extent_buffer *eb;
2586 u32 blocksize;
2587 u64 bytenr;
2588 u64 generation;
2589 int nr;
2590 int slot;
2591 int ret;
2592 int err = 0;
2593
2594 BUG_ON(lowest && node->eb);
2595
2596 path->lowest_level = node->level + 1;
2597 rc->backref_cache.path[node->level] = node;
2598 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2599 cond_resched();
2600
2601 upper = edge->node[UPPER];
2602 root = select_reloc_root(trans, rc, upper, edges, &nr);
2603 BUG_ON(!root);
2604
2605 if (upper->eb && !upper->locked) {
2606 if (!lowest) {
2607 ret = btrfs_bin_search(upper->eb, key,
2608 upper->level, &slot);
2609 BUG_ON(ret);
2610 bytenr = btrfs_node_blockptr(upper->eb, slot);
2611 if (node->eb->start == bytenr)
2612 goto next;
2613 }
2614 drop_node_buffer(upper);
2615 }
2616
2617 if (!upper->eb) {
2618 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2619 if (ret < 0) {
2620 err = ret;
2621 break;
2622 }
2623 BUG_ON(ret > 0);
2624
2625 if (!upper->eb) {
2626 upper->eb = path->nodes[upper->level];
2627 path->nodes[upper->level] = NULL;
2628 } else {
2629 BUG_ON(upper->eb != path->nodes[upper->level]);
2630 }
2631
2632 upper->locked = 1;
2633 path->locks[upper->level] = 0;
2634
2635 slot = path->slots[upper->level];
2636 btrfs_release_path(path);
2637 } else {
2638 ret = btrfs_bin_search(upper->eb, key, upper->level,
2639 &slot);
2640 BUG_ON(ret);
2641 }
2642
2643 bytenr = btrfs_node_blockptr(upper->eb, slot);
2644 if (lowest) {
2645 BUG_ON(bytenr != node->bytenr);
2646 } else {
2647 if (node->eb->start == bytenr)
2648 goto next;
2649 }
2650
2651 blocksize = btrfs_level_size(root, node->level);
2652 generation = btrfs_node_ptr_generation(upper->eb, slot);
2653 eb = read_tree_block(root, bytenr, blocksize, generation);
2654 if (!eb || !extent_buffer_uptodate(eb)) {
2655 free_extent_buffer(eb);
2656 err = -EIO;
2657 goto next;
2658 }
2659 btrfs_tree_lock(eb);
2660 btrfs_set_lock_blocking(eb);
2661
2662 if (!node->eb) {
2663 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2664 slot, &eb);
2665 btrfs_tree_unlock(eb);
2666 free_extent_buffer(eb);
2667 if (ret < 0) {
2668 err = ret;
2669 goto next;
2670 }
2671 BUG_ON(node->eb != eb);
2672 } else {
2673 btrfs_set_node_blockptr(upper->eb, slot,
2674 node->eb->start);
2675 btrfs_set_node_ptr_generation(upper->eb, slot,
2676 trans->transid);
2677 btrfs_mark_buffer_dirty(upper->eb);
2678
2679 ret = btrfs_inc_extent_ref(trans, root,
2680 node->eb->start, blocksize,
2681 upper->eb->start,
2682 btrfs_header_owner(upper->eb),
2683 node->level, 0, 1);
2684 BUG_ON(ret);
2685
2686 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2687 BUG_ON(ret);
2688 }
2689 next:
2690 if (!upper->pending)
2691 drop_node_buffer(upper);
2692 else
2693 unlock_node_buffer(upper);
2694 if (err)
2695 break;
2696 }
2697
2698 if (!err && node->pending) {
2699 drop_node_buffer(node);
2700 list_move_tail(&node->list, &rc->backref_cache.changed);
2701 node->pending = 0;
2702 }
2703
2704 path->lowest_level = 0;
2705 BUG_ON(err == -ENOSPC);
2706 return err;
2707 }
2708
2709 static int link_to_upper(struct btrfs_trans_handle *trans,
2710 struct reloc_control *rc,
2711 struct backref_node *node,
2712 struct btrfs_path *path)
2713 {
2714 struct btrfs_key key;
2715
2716 btrfs_node_key_to_cpu(node->eb, &key, 0);
2717 return do_relocation(trans, rc, node, &key, path, 0);
2718 }
2719
2720 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2721 struct reloc_control *rc,
2722 struct btrfs_path *path, int err)
2723 {
2724 LIST_HEAD(list);
2725 struct backref_cache *cache = &rc->backref_cache;
2726 struct backref_node *node;
2727 int level;
2728 int ret;
2729
2730 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2731 while (!list_empty(&cache->pending[level])) {
2732 node = list_entry(cache->pending[level].next,
2733 struct backref_node, list);
2734 list_move_tail(&node->list, &list);
2735 BUG_ON(!node->pending);
2736
2737 if (!err) {
2738 ret = link_to_upper(trans, rc, node, path);
2739 if (ret < 0)
2740 err = ret;
2741 }
2742 }
2743 list_splice_init(&list, &cache->pending[level]);
2744 }
2745 return err;
2746 }
2747
2748 static void mark_block_processed(struct reloc_control *rc,
2749 u64 bytenr, u32 blocksize)
2750 {
2751 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2752 EXTENT_DIRTY, GFP_NOFS);
2753 }
2754
2755 static void __mark_block_processed(struct reloc_control *rc,
2756 struct backref_node *node)
2757 {
2758 u32 blocksize;
2759 if (node->level == 0 ||
2760 in_block_group(node->bytenr, rc->block_group)) {
2761 blocksize = btrfs_level_size(rc->extent_root, node->level);
2762 mark_block_processed(rc, node->bytenr, blocksize);
2763 }
2764 node->processed = 1;
2765 }
2766
2767 /*
2768 * mark a block and all blocks directly/indirectly reference the block
2769 * as processed.
2770 */
2771 static void update_processed_blocks(struct reloc_control *rc,
2772 struct backref_node *node)
2773 {
2774 struct backref_node *next = node;
2775 struct backref_edge *edge;
2776 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2777 int index = 0;
2778
2779 while (next) {
2780 cond_resched();
2781 while (1) {
2782 if (next->processed)
2783 break;
2784
2785 __mark_block_processed(rc, next);
2786
2787 if (list_empty(&next->upper))
2788 break;
2789
2790 edge = list_entry(next->upper.next,
2791 struct backref_edge, list[LOWER]);
2792 edges[index++] = edge;
2793 next = edge->node[UPPER];
2794 }
2795 next = walk_down_backref(edges, &index);
2796 }
2797 }
2798
2799 static int tree_block_processed(u64 bytenr, u32 blocksize,
2800 struct reloc_control *rc)
2801 {
2802 if (test_range_bit(&rc->processed_blocks, bytenr,
2803 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2804 return 1;
2805 return 0;
2806 }
2807
2808 static int get_tree_block_key(struct reloc_control *rc,
2809 struct tree_block *block)
2810 {
2811 struct extent_buffer *eb;
2812
2813 BUG_ON(block->key_ready);
2814 eb = read_tree_block(rc->extent_root, block->bytenr,
2815 block->key.objectid, block->key.offset);
2816 if (!eb || !extent_buffer_uptodate(eb)) {
2817 free_extent_buffer(eb);
2818 return -EIO;
2819 }
2820 WARN_ON(btrfs_header_level(eb) != block->level);
2821 if (block->level == 0)
2822 btrfs_item_key_to_cpu(eb, &block->key, 0);
2823 else
2824 btrfs_node_key_to_cpu(eb, &block->key, 0);
2825 free_extent_buffer(eb);
2826 block->key_ready = 1;
2827 return 0;
2828 }
2829
2830 static int reada_tree_block(struct reloc_control *rc,
2831 struct tree_block *block)
2832 {
2833 BUG_ON(block->key_ready);
2834 if (block->key.type == BTRFS_METADATA_ITEM_KEY)
2835 readahead_tree_block(rc->extent_root, block->bytenr,
2836 block->key.objectid,
2837 rc->extent_root->leafsize);
2838 else
2839 readahead_tree_block(rc->extent_root, block->bytenr,
2840 block->key.objectid, block->key.offset);
2841 return 0;
2842 }
2843
2844 /*
2845 * helper function to relocate a tree block
2846 */
2847 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2848 struct reloc_control *rc,
2849 struct backref_node *node,
2850 struct btrfs_key *key,
2851 struct btrfs_path *path)
2852 {
2853 struct btrfs_root *root;
2854 int release = 0;
2855 int ret = 0;
2856
2857 if (!node)
2858 return 0;
2859
2860 BUG_ON(node->processed);
2861 root = select_one_root(trans, node);
2862 if (root == ERR_PTR(-ENOENT)) {
2863 update_processed_blocks(rc, node);
2864 goto out;
2865 }
2866
2867 if (!root || root->ref_cows) {
2868 ret = reserve_metadata_space(trans, rc, node);
2869 if (ret)
2870 goto out;
2871 release = 1;
2872 }
2873
2874 if (root) {
2875 if (root->ref_cows) {
2876 BUG_ON(node->new_bytenr);
2877 BUG_ON(!list_empty(&node->list));
2878 btrfs_record_root_in_trans(trans, root);
2879 root = root->reloc_root;
2880 node->new_bytenr = root->node->start;
2881 node->root = root;
2882 list_add_tail(&node->list, &rc->backref_cache.changed);
2883 } else {
2884 path->lowest_level = node->level;
2885 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2886 btrfs_release_path(path);
2887 if (ret > 0)
2888 ret = 0;
2889 }
2890 if (!ret)
2891 update_processed_blocks(rc, node);
2892 } else {
2893 ret = do_relocation(trans, rc, node, key, path, 1);
2894 }
2895 out:
2896 if (ret || node->level == 0 || node->cowonly) {
2897 if (release)
2898 release_metadata_space(rc, node);
2899 remove_backref_node(&rc->backref_cache, node);
2900 }
2901 return ret;
2902 }
2903
2904 /*
2905 * relocate a list of blocks
2906 */
2907 static noinline_for_stack
2908 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2909 struct reloc_control *rc, struct rb_root *blocks)
2910 {
2911 struct backref_node *node;
2912 struct btrfs_path *path;
2913 struct tree_block *block;
2914 struct rb_node *rb_node;
2915 int ret;
2916 int err = 0;
2917
2918 path = btrfs_alloc_path();
2919 if (!path) {
2920 err = -ENOMEM;
2921 goto out_free_blocks;
2922 }
2923
2924 rb_node = rb_first(blocks);
2925 while (rb_node) {
2926 block = rb_entry(rb_node, struct tree_block, rb_node);
2927 if (!block->key_ready)
2928 reada_tree_block(rc, block);
2929 rb_node = rb_next(rb_node);
2930 }
2931
2932 rb_node = rb_first(blocks);
2933 while (rb_node) {
2934 block = rb_entry(rb_node, struct tree_block, rb_node);
2935 if (!block->key_ready) {
2936 err = get_tree_block_key(rc, block);
2937 if (err)
2938 goto out_free_path;
2939 }
2940 rb_node = rb_next(rb_node);
2941 }
2942
2943 rb_node = rb_first(blocks);
2944 while (rb_node) {
2945 block = rb_entry(rb_node, struct tree_block, rb_node);
2946
2947 node = build_backref_tree(rc, &block->key,
2948 block->level, block->bytenr);
2949 if (IS_ERR(node)) {
2950 err = PTR_ERR(node);
2951 goto out;
2952 }
2953
2954 ret = relocate_tree_block(trans, rc, node, &block->key,
2955 path);
2956 if (ret < 0) {
2957 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2958 err = ret;
2959 goto out;
2960 }
2961 rb_node = rb_next(rb_node);
2962 }
2963 out:
2964 err = finish_pending_nodes(trans, rc, path, err);
2965
2966 out_free_path:
2967 btrfs_free_path(path);
2968 out_free_blocks:
2969 free_block_list(blocks);
2970 return err;
2971 }
2972
2973 static noinline_for_stack
2974 int prealloc_file_extent_cluster(struct inode *inode,
2975 struct file_extent_cluster *cluster)
2976 {
2977 u64 alloc_hint = 0;
2978 u64 start;
2979 u64 end;
2980 u64 offset = BTRFS_I(inode)->index_cnt;
2981 u64 num_bytes;
2982 int nr = 0;
2983 int ret = 0;
2984
2985 BUG_ON(cluster->start != cluster->boundary[0]);
2986 mutex_lock(&inode->i_mutex);
2987
2988 ret = btrfs_check_data_free_space(inode, cluster->end +
2989 1 - cluster->start);
2990 if (ret)
2991 goto out;
2992
2993 while (nr < cluster->nr) {
2994 start = cluster->boundary[nr] - offset;
2995 if (nr + 1 < cluster->nr)
2996 end = cluster->boundary[nr + 1] - 1 - offset;
2997 else
2998 end = cluster->end - offset;
2999
3000 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3001 num_bytes = end + 1 - start;
3002 ret = btrfs_prealloc_file_range(inode, 0, start,
3003 num_bytes, num_bytes,
3004 end + 1, &alloc_hint);
3005 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3006 if (ret)
3007 break;
3008 nr++;
3009 }
3010 btrfs_free_reserved_data_space(inode, cluster->end +
3011 1 - cluster->start);
3012 out:
3013 mutex_unlock(&inode->i_mutex);
3014 return ret;
3015 }
3016
3017 static noinline_for_stack
3018 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3019 u64 block_start)
3020 {
3021 struct btrfs_root *root = BTRFS_I(inode)->root;
3022 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3023 struct extent_map *em;
3024 int ret = 0;
3025
3026 em = alloc_extent_map();
3027 if (!em)
3028 return -ENOMEM;
3029
3030 em->start = start;
3031 em->len = end + 1 - start;
3032 em->block_len = em->len;
3033 em->block_start = block_start;
3034 em->bdev = root->fs_info->fs_devices->latest_bdev;
3035 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3036
3037 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3038 while (1) {
3039 write_lock(&em_tree->lock);
3040 ret = add_extent_mapping(em_tree, em, 0);
3041 write_unlock(&em_tree->lock);
3042 if (ret != -EEXIST) {
3043 free_extent_map(em);
3044 break;
3045 }
3046 btrfs_drop_extent_cache(inode, start, end, 0);
3047 }
3048 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3049 return ret;
3050 }
3051
3052 static int relocate_file_extent_cluster(struct inode *inode,
3053 struct file_extent_cluster *cluster)
3054 {
3055 u64 page_start;
3056 u64 page_end;
3057 u64 offset = BTRFS_I(inode)->index_cnt;
3058 unsigned long index;
3059 unsigned long last_index;
3060 struct page *page;
3061 struct file_ra_state *ra;
3062 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3063 int nr = 0;
3064 int ret = 0;
3065
3066 if (!cluster->nr)
3067 return 0;
3068
3069 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3070 if (!ra)
3071 return -ENOMEM;
3072
3073 ret = prealloc_file_extent_cluster(inode, cluster);
3074 if (ret)
3075 goto out;
3076
3077 file_ra_state_init(ra, inode->i_mapping);
3078
3079 ret = setup_extent_mapping(inode, cluster->start - offset,
3080 cluster->end - offset, cluster->start);
3081 if (ret)
3082 goto out;
3083
3084 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3085 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3086 while (index <= last_index) {
3087 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3088 if (ret)
3089 goto out;
3090
3091 page = find_lock_page(inode->i_mapping, index);
3092 if (!page) {
3093 page_cache_sync_readahead(inode->i_mapping,
3094 ra, NULL, index,
3095 last_index + 1 - index);
3096 page = find_or_create_page(inode->i_mapping, index,
3097 mask);
3098 if (!page) {
3099 btrfs_delalloc_release_metadata(inode,
3100 PAGE_CACHE_SIZE);
3101 ret = -ENOMEM;
3102 goto out;
3103 }
3104 }
3105
3106 if (PageReadahead(page)) {
3107 page_cache_async_readahead(inode->i_mapping,
3108 ra, NULL, page, index,
3109 last_index + 1 - index);
3110 }
3111
3112 if (!PageUptodate(page)) {
3113 btrfs_readpage(NULL, page);
3114 lock_page(page);
3115 if (!PageUptodate(page)) {
3116 unlock_page(page);
3117 page_cache_release(page);
3118 btrfs_delalloc_release_metadata(inode,
3119 PAGE_CACHE_SIZE);
3120 ret = -EIO;
3121 goto out;
3122 }
3123 }
3124
3125 page_start = page_offset(page);
3126 page_end = page_start + PAGE_CACHE_SIZE - 1;
3127
3128 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3129
3130 set_page_extent_mapped(page);
3131
3132 if (nr < cluster->nr &&
3133 page_start + offset == cluster->boundary[nr]) {
3134 set_extent_bits(&BTRFS_I(inode)->io_tree,
3135 page_start, page_end,
3136 EXTENT_BOUNDARY, GFP_NOFS);
3137 nr++;
3138 }
3139
3140 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3141 set_page_dirty(page);
3142
3143 unlock_extent(&BTRFS_I(inode)->io_tree,
3144 page_start, page_end);
3145 unlock_page(page);
3146 page_cache_release(page);
3147
3148 index++;
3149 balance_dirty_pages_ratelimited(inode->i_mapping);
3150 btrfs_throttle(BTRFS_I(inode)->root);
3151 }
3152 WARN_ON(nr != cluster->nr);
3153 out:
3154 kfree(ra);
3155 return ret;
3156 }
3157
3158 static noinline_for_stack
3159 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3160 struct file_extent_cluster *cluster)
3161 {
3162 int ret;
3163
3164 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3165 ret = relocate_file_extent_cluster(inode, cluster);
3166 if (ret)
3167 return ret;
3168 cluster->nr = 0;
3169 }
3170
3171 if (!cluster->nr)
3172 cluster->start = extent_key->objectid;
3173 else
3174 BUG_ON(cluster->nr >= MAX_EXTENTS);
3175 cluster->end = extent_key->objectid + extent_key->offset - 1;
3176 cluster->boundary[cluster->nr] = extent_key->objectid;
3177 cluster->nr++;
3178
3179 if (cluster->nr >= MAX_EXTENTS) {
3180 ret = relocate_file_extent_cluster(inode, cluster);
3181 if (ret)
3182 return ret;
3183 cluster->nr = 0;
3184 }
3185 return 0;
3186 }
3187
3188 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3189 static int get_ref_objectid_v0(struct reloc_control *rc,
3190 struct btrfs_path *path,
3191 struct btrfs_key *extent_key,
3192 u64 *ref_objectid, int *path_change)
3193 {
3194 struct btrfs_key key;
3195 struct extent_buffer *leaf;
3196 struct btrfs_extent_ref_v0 *ref0;
3197 int ret;
3198 int slot;
3199
3200 leaf = path->nodes[0];
3201 slot = path->slots[0];
3202 while (1) {
3203 if (slot >= btrfs_header_nritems(leaf)) {
3204 ret = btrfs_next_leaf(rc->extent_root, path);
3205 if (ret < 0)
3206 return ret;
3207 BUG_ON(ret > 0);
3208 leaf = path->nodes[0];
3209 slot = path->slots[0];
3210 if (path_change)
3211 *path_change = 1;
3212 }
3213 btrfs_item_key_to_cpu(leaf, &key, slot);
3214 if (key.objectid != extent_key->objectid)
3215 return -ENOENT;
3216
3217 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3218 slot++;
3219 continue;
3220 }
3221 ref0 = btrfs_item_ptr(leaf, slot,
3222 struct btrfs_extent_ref_v0);
3223 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3224 break;
3225 }
3226 return 0;
3227 }
3228 #endif
3229
3230 /*
3231 * helper to add a tree block to the list.
3232 * the major work is getting the generation and level of the block
3233 */
3234 static int add_tree_block(struct reloc_control *rc,
3235 struct btrfs_key *extent_key,
3236 struct btrfs_path *path,
3237 struct rb_root *blocks)
3238 {
3239 struct extent_buffer *eb;
3240 struct btrfs_extent_item *ei;
3241 struct btrfs_tree_block_info *bi;
3242 struct tree_block *block;
3243 struct rb_node *rb_node;
3244 u32 item_size;
3245 int level = -1;
3246 int generation;
3247
3248 eb = path->nodes[0];
3249 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3250
3251 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3252 item_size >= sizeof(*ei) + sizeof(*bi)) {
3253 ei = btrfs_item_ptr(eb, path->slots[0],
3254 struct btrfs_extent_item);
3255 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3256 bi = (struct btrfs_tree_block_info *)(ei + 1);
3257 level = btrfs_tree_block_level(eb, bi);
3258 } else {
3259 level = (int)extent_key->offset;
3260 }
3261 generation = btrfs_extent_generation(eb, ei);
3262 } else {
3263 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3264 u64 ref_owner;
3265 int ret;
3266
3267 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3268 ret = get_ref_objectid_v0(rc, path, extent_key,
3269 &ref_owner, NULL);
3270 if (ret < 0)
3271 return ret;
3272 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3273 level = (int)ref_owner;
3274 /* FIXME: get real generation */
3275 generation = 0;
3276 #else
3277 BUG();
3278 #endif
3279 }
3280
3281 btrfs_release_path(path);
3282
3283 BUG_ON(level == -1);
3284
3285 block = kmalloc(sizeof(*block), GFP_NOFS);
3286 if (!block)
3287 return -ENOMEM;
3288
3289 block->bytenr = extent_key->objectid;
3290 block->key.objectid = rc->extent_root->leafsize;
3291 block->key.offset = generation;
3292 block->level = level;
3293 block->key_ready = 0;
3294
3295 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3296 if (rb_node)
3297 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3298
3299 return 0;
3300 }
3301
3302 /*
3303 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3304 */
3305 static int __add_tree_block(struct reloc_control *rc,
3306 u64 bytenr, u32 blocksize,
3307 struct rb_root *blocks)
3308 {
3309 struct btrfs_path *path;
3310 struct btrfs_key key;
3311 int ret;
3312 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3313 SKINNY_METADATA);
3314
3315 if (tree_block_processed(bytenr, blocksize, rc))
3316 return 0;
3317
3318 if (tree_search(blocks, bytenr))
3319 return 0;
3320
3321 path = btrfs_alloc_path();
3322 if (!path)
3323 return -ENOMEM;
3324 again:
3325 key.objectid = bytenr;
3326 if (skinny) {
3327 key.type = BTRFS_METADATA_ITEM_KEY;
3328 key.offset = (u64)-1;
3329 } else {
3330 key.type = BTRFS_EXTENT_ITEM_KEY;
3331 key.offset = blocksize;
3332 }
3333
3334 path->search_commit_root = 1;
3335 path->skip_locking = 1;
3336 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3337 if (ret < 0)
3338 goto out;
3339
3340 if (ret > 0 && skinny) {
3341 if (path->slots[0]) {
3342 path->slots[0]--;
3343 btrfs_item_key_to_cpu(path->nodes[0], &key,
3344 path->slots[0]);
3345 if (key.objectid == bytenr &&
3346 (key.type == BTRFS_METADATA_ITEM_KEY ||
3347 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3348 key.offset == blocksize)))
3349 ret = 0;
3350 }
3351
3352 if (ret) {
3353 skinny = false;
3354 btrfs_release_path(path);
3355 goto again;
3356 }
3357 }
3358 BUG_ON(ret);
3359
3360 ret = add_tree_block(rc, &key, path, blocks);
3361 out:
3362 btrfs_free_path(path);
3363 return ret;
3364 }
3365
3366 /*
3367 * helper to check if the block use full backrefs for pointers in it
3368 */
3369 static int block_use_full_backref(struct reloc_control *rc,
3370 struct extent_buffer *eb)
3371 {
3372 u64 flags;
3373 int ret;
3374
3375 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3376 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3377 return 1;
3378
3379 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3380 eb->start, btrfs_header_level(eb), 1,
3381 NULL, &flags);
3382 BUG_ON(ret);
3383
3384 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3385 ret = 1;
3386 else
3387 ret = 0;
3388 return ret;
3389 }
3390
3391 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3392 struct inode *inode, u64 ino)
3393 {
3394 struct btrfs_key key;
3395 struct btrfs_path *path;
3396 struct btrfs_root *root = fs_info->tree_root;
3397 struct btrfs_trans_handle *trans;
3398 int ret = 0;
3399
3400 if (inode)
3401 goto truncate;
3402
3403 key.objectid = ino;
3404 key.type = BTRFS_INODE_ITEM_KEY;
3405 key.offset = 0;
3406
3407 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3408 if (IS_ERR(inode) || is_bad_inode(inode)) {
3409 if (!IS_ERR(inode))
3410 iput(inode);
3411 return -ENOENT;
3412 }
3413
3414 truncate:
3415 ret = btrfs_check_trunc_cache_free_space(root,
3416 &fs_info->global_block_rsv);
3417 if (ret)
3418 goto out;
3419
3420 path = btrfs_alloc_path();
3421 if (!path) {
3422 ret = -ENOMEM;
3423 goto out;
3424 }
3425
3426 trans = btrfs_join_transaction(root);
3427 if (IS_ERR(trans)) {
3428 btrfs_free_path(path);
3429 ret = PTR_ERR(trans);
3430 goto out;
3431 }
3432
3433 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3434
3435 btrfs_free_path(path);
3436 btrfs_end_transaction(trans, root);
3437 btrfs_btree_balance_dirty(root);
3438 out:
3439 iput(inode);
3440 return ret;
3441 }
3442
3443 /*
3444 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3445 * this function scans fs tree to find blocks reference the data extent
3446 */
3447 static int find_data_references(struct reloc_control *rc,
3448 struct btrfs_key *extent_key,
3449 struct extent_buffer *leaf,
3450 struct btrfs_extent_data_ref *ref,
3451 struct rb_root *blocks)
3452 {
3453 struct btrfs_path *path;
3454 struct tree_block *block;
3455 struct btrfs_root *root;
3456 struct btrfs_file_extent_item *fi;
3457 struct rb_node *rb_node;
3458 struct btrfs_key key;
3459 u64 ref_root;
3460 u64 ref_objectid;
3461 u64 ref_offset;
3462 u32 ref_count;
3463 u32 nritems;
3464 int err = 0;
3465 int added = 0;
3466 int counted;
3467 int ret;
3468
3469 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3470 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3471 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3472 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3473
3474 /*
3475 * This is an extent belonging to the free space cache, lets just delete
3476 * it and redo the search.
3477 */
3478 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3479 ret = delete_block_group_cache(rc->extent_root->fs_info,
3480 NULL, ref_objectid);
3481 if (ret != -ENOENT)
3482 return ret;
3483 ret = 0;
3484 }
3485
3486 path = btrfs_alloc_path();
3487 if (!path)
3488 return -ENOMEM;
3489 path->reada = 1;
3490
3491 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3492 if (IS_ERR(root)) {
3493 err = PTR_ERR(root);
3494 goto out;
3495 }
3496
3497 key.objectid = ref_objectid;
3498 key.type = BTRFS_EXTENT_DATA_KEY;
3499 if (ref_offset > ((u64)-1 << 32))
3500 key.offset = 0;
3501 else
3502 key.offset = ref_offset;
3503
3504 path->search_commit_root = 1;
3505 path->skip_locking = 1;
3506 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3507 if (ret < 0) {
3508 err = ret;
3509 goto out;
3510 }
3511
3512 leaf = path->nodes[0];
3513 nritems = btrfs_header_nritems(leaf);
3514 /*
3515 * the references in tree blocks that use full backrefs
3516 * are not counted in
3517 */
3518 if (block_use_full_backref(rc, leaf))
3519 counted = 0;
3520 else
3521 counted = 1;
3522 rb_node = tree_search(blocks, leaf->start);
3523 if (rb_node) {
3524 if (counted)
3525 added = 1;
3526 else
3527 path->slots[0] = nritems;
3528 }
3529
3530 while (ref_count > 0) {
3531 while (path->slots[0] >= nritems) {
3532 ret = btrfs_next_leaf(root, path);
3533 if (ret < 0) {
3534 err = ret;
3535 goto out;
3536 }
3537 if (ret > 0) {
3538 WARN_ON(1);
3539 goto out;
3540 }
3541
3542 leaf = path->nodes[0];
3543 nritems = btrfs_header_nritems(leaf);
3544 added = 0;
3545
3546 if (block_use_full_backref(rc, leaf))
3547 counted = 0;
3548 else
3549 counted = 1;
3550 rb_node = tree_search(blocks, leaf->start);
3551 if (rb_node) {
3552 if (counted)
3553 added = 1;
3554 else
3555 path->slots[0] = nritems;
3556 }
3557 }
3558
3559 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3560 if (key.objectid != ref_objectid ||
3561 key.type != BTRFS_EXTENT_DATA_KEY) {
3562 WARN_ON(1);
3563 break;
3564 }
3565
3566 fi = btrfs_item_ptr(leaf, path->slots[0],
3567 struct btrfs_file_extent_item);
3568
3569 if (btrfs_file_extent_type(leaf, fi) ==
3570 BTRFS_FILE_EXTENT_INLINE)
3571 goto next;
3572
3573 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3574 extent_key->objectid)
3575 goto next;
3576
3577 key.offset -= btrfs_file_extent_offset(leaf, fi);
3578 if (key.offset != ref_offset)
3579 goto next;
3580
3581 if (counted)
3582 ref_count--;
3583 if (added)
3584 goto next;
3585
3586 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3587 block = kmalloc(sizeof(*block), GFP_NOFS);
3588 if (!block) {
3589 err = -ENOMEM;
3590 break;
3591 }
3592 block->bytenr = leaf->start;
3593 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3594 block->level = 0;
3595 block->key_ready = 1;
3596 rb_node = tree_insert(blocks, block->bytenr,
3597 &block->rb_node);
3598 if (rb_node)
3599 backref_tree_panic(rb_node, -EEXIST,
3600 block->bytenr);
3601 }
3602 if (counted)
3603 added = 1;
3604 else
3605 path->slots[0] = nritems;
3606 next:
3607 path->slots[0]++;
3608
3609 }
3610 out:
3611 btrfs_free_path(path);
3612 return err;
3613 }
3614
3615 /*
3616 * helper to find all tree blocks that reference a given data extent
3617 */
3618 static noinline_for_stack
3619 int add_data_references(struct reloc_control *rc,
3620 struct btrfs_key *extent_key,
3621 struct btrfs_path *path,
3622 struct rb_root *blocks)
3623 {
3624 struct btrfs_key key;
3625 struct extent_buffer *eb;
3626 struct btrfs_extent_data_ref *dref;
3627 struct btrfs_extent_inline_ref *iref;
3628 unsigned long ptr;
3629 unsigned long end;
3630 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3631 int ret;
3632 int err = 0;
3633
3634 eb = path->nodes[0];
3635 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3636 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3637 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3638 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3639 ptr = end;
3640 else
3641 #endif
3642 ptr += sizeof(struct btrfs_extent_item);
3643
3644 while (ptr < end) {
3645 iref = (struct btrfs_extent_inline_ref *)ptr;
3646 key.type = btrfs_extent_inline_ref_type(eb, iref);
3647 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3648 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3649 ret = __add_tree_block(rc, key.offset, blocksize,
3650 blocks);
3651 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3652 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3653 ret = find_data_references(rc, extent_key,
3654 eb, dref, blocks);
3655 } else {
3656 BUG();
3657 }
3658 ptr += btrfs_extent_inline_ref_size(key.type);
3659 }
3660 WARN_ON(ptr > end);
3661
3662 while (1) {
3663 cond_resched();
3664 eb = path->nodes[0];
3665 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3666 ret = btrfs_next_leaf(rc->extent_root, path);
3667 if (ret < 0) {
3668 err = ret;
3669 break;
3670 }
3671 if (ret > 0)
3672 break;
3673 eb = path->nodes[0];
3674 }
3675
3676 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3677 if (key.objectid != extent_key->objectid)
3678 break;
3679
3680 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3681 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3682 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3683 #else
3684 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3685 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3686 #endif
3687 ret = __add_tree_block(rc, key.offset, blocksize,
3688 blocks);
3689 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3690 dref = btrfs_item_ptr(eb, path->slots[0],
3691 struct btrfs_extent_data_ref);
3692 ret = find_data_references(rc, extent_key,
3693 eb, dref, blocks);
3694 } else {
3695 ret = 0;
3696 }
3697 if (ret) {
3698 err = ret;
3699 break;
3700 }
3701 path->slots[0]++;
3702 }
3703 btrfs_release_path(path);
3704 if (err)
3705 free_block_list(blocks);
3706 return err;
3707 }
3708
3709 /*
3710 * helper to find next unprocessed extent
3711 */
3712 static noinline_for_stack
3713 int find_next_extent(struct btrfs_trans_handle *trans,
3714 struct reloc_control *rc, struct btrfs_path *path,
3715 struct btrfs_key *extent_key)
3716 {
3717 struct btrfs_key key;
3718 struct extent_buffer *leaf;
3719 u64 start, end, last;
3720 int ret;
3721
3722 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3723 while (1) {
3724 cond_resched();
3725 if (rc->search_start >= last) {
3726 ret = 1;
3727 break;
3728 }
3729
3730 key.objectid = rc->search_start;
3731 key.type = BTRFS_EXTENT_ITEM_KEY;
3732 key.offset = 0;
3733
3734 path->search_commit_root = 1;
3735 path->skip_locking = 1;
3736 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3737 0, 0);
3738 if (ret < 0)
3739 break;
3740 next:
3741 leaf = path->nodes[0];
3742 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3743 ret = btrfs_next_leaf(rc->extent_root, path);
3744 if (ret != 0)
3745 break;
3746 leaf = path->nodes[0];
3747 }
3748
3749 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3750 if (key.objectid >= last) {
3751 ret = 1;
3752 break;
3753 }
3754
3755 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3756 key.type != BTRFS_METADATA_ITEM_KEY) {
3757 path->slots[0]++;
3758 goto next;
3759 }
3760
3761 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3762 key.objectid + key.offset <= rc->search_start) {
3763 path->slots[0]++;
3764 goto next;
3765 }
3766
3767 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3768 key.objectid + rc->extent_root->leafsize <=
3769 rc->search_start) {
3770 path->slots[0]++;
3771 goto next;
3772 }
3773
3774 ret = find_first_extent_bit(&rc->processed_blocks,
3775 key.objectid, &start, &end,
3776 EXTENT_DIRTY, NULL);
3777
3778 if (ret == 0 && start <= key.objectid) {
3779 btrfs_release_path(path);
3780 rc->search_start = end + 1;
3781 } else {
3782 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3783 rc->search_start = key.objectid + key.offset;
3784 else
3785 rc->search_start = key.objectid +
3786 rc->extent_root->leafsize;
3787 memcpy(extent_key, &key, sizeof(key));
3788 return 0;
3789 }
3790 }
3791 btrfs_release_path(path);
3792 return ret;
3793 }
3794
3795 static void set_reloc_control(struct reloc_control *rc)
3796 {
3797 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3798
3799 mutex_lock(&fs_info->reloc_mutex);
3800 fs_info->reloc_ctl = rc;
3801 mutex_unlock(&fs_info->reloc_mutex);
3802 }
3803
3804 static void unset_reloc_control(struct reloc_control *rc)
3805 {
3806 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3807
3808 mutex_lock(&fs_info->reloc_mutex);
3809 fs_info->reloc_ctl = NULL;
3810 mutex_unlock(&fs_info->reloc_mutex);
3811 }
3812
3813 static int check_extent_flags(u64 flags)
3814 {
3815 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3816 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3817 return 1;
3818 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3819 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3820 return 1;
3821 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3822 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3823 return 1;
3824 return 0;
3825 }
3826
3827 static noinline_for_stack
3828 int prepare_to_relocate(struct reloc_control *rc)
3829 {
3830 struct btrfs_trans_handle *trans;
3831 int ret;
3832
3833 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3834 BTRFS_BLOCK_RSV_TEMP);
3835 if (!rc->block_rsv)
3836 return -ENOMEM;
3837
3838 /*
3839 * reserve some space for creating reloc trees.
3840 * btrfs_init_reloc_root will use them when there
3841 * is no reservation in transaction handle.
3842 */
3843 ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv,
3844 rc->extent_root->nodesize * 256,
3845 BTRFS_RESERVE_FLUSH_ALL);
3846 if (ret)
3847 return ret;
3848
3849 memset(&rc->cluster, 0, sizeof(rc->cluster));
3850 rc->search_start = rc->block_group->key.objectid;
3851 rc->extents_found = 0;
3852 rc->nodes_relocated = 0;
3853 rc->merging_rsv_size = 0;
3854
3855 rc->create_reloc_tree = 1;
3856 set_reloc_control(rc);
3857
3858 trans = btrfs_join_transaction(rc->extent_root);
3859 if (IS_ERR(trans)) {
3860 unset_reloc_control(rc);
3861 /*
3862 * extent tree is not a ref_cow tree and has no reloc_root to
3863 * cleanup. And callers are responsible to free the above
3864 * block rsv.
3865 */
3866 return PTR_ERR(trans);
3867 }
3868 btrfs_commit_transaction(trans, rc->extent_root);
3869 return 0;
3870 }
3871
3872 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3873 {
3874 struct rb_root blocks = RB_ROOT;
3875 struct btrfs_key key;
3876 struct btrfs_trans_handle *trans = NULL;
3877 struct btrfs_path *path;
3878 struct btrfs_extent_item *ei;
3879 u64 flags;
3880 u32 item_size;
3881 int ret;
3882 int err = 0;
3883 int progress = 0;
3884
3885 path = btrfs_alloc_path();
3886 if (!path)
3887 return -ENOMEM;
3888 path->reada = 1;
3889
3890 ret = prepare_to_relocate(rc);
3891 if (ret) {
3892 err = ret;
3893 goto out_free;
3894 }
3895
3896 while (1) {
3897 progress++;
3898 trans = btrfs_start_transaction(rc->extent_root, 0);
3899 if (IS_ERR(trans)) {
3900 err = PTR_ERR(trans);
3901 trans = NULL;
3902 break;
3903 }
3904 restart:
3905 if (update_backref_cache(trans, &rc->backref_cache)) {
3906 btrfs_end_transaction(trans, rc->extent_root);
3907 continue;
3908 }
3909
3910 ret = find_next_extent(trans, rc, path, &key);
3911 if (ret < 0)
3912 err = ret;
3913 if (ret != 0)
3914 break;
3915
3916 rc->extents_found++;
3917
3918 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3919 struct btrfs_extent_item);
3920 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3921 if (item_size >= sizeof(*ei)) {
3922 flags = btrfs_extent_flags(path->nodes[0], ei);
3923 ret = check_extent_flags(flags);
3924 BUG_ON(ret);
3925
3926 } else {
3927 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3928 u64 ref_owner;
3929 int path_change = 0;
3930
3931 BUG_ON(item_size !=
3932 sizeof(struct btrfs_extent_item_v0));
3933 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3934 &path_change);
3935 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3936 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3937 else
3938 flags = BTRFS_EXTENT_FLAG_DATA;
3939
3940 if (path_change) {
3941 btrfs_release_path(path);
3942
3943 path->search_commit_root = 1;
3944 path->skip_locking = 1;
3945 ret = btrfs_search_slot(NULL, rc->extent_root,
3946 &key, path, 0, 0);
3947 if (ret < 0) {
3948 err = ret;
3949 break;
3950 }
3951 BUG_ON(ret > 0);
3952 }
3953 #else
3954 BUG();
3955 #endif
3956 }
3957
3958 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3959 ret = add_tree_block(rc, &key, path, &blocks);
3960 } else if (rc->stage == UPDATE_DATA_PTRS &&
3961 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3962 ret = add_data_references(rc, &key, path, &blocks);
3963 } else {
3964 btrfs_release_path(path);
3965 ret = 0;
3966 }
3967 if (ret < 0) {
3968 err = ret;
3969 break;
3970 }
3971
3972 if (!RB_EMPTY_ROOT(&blocks)) {
3973 ret = relocate_tree_blocks(trans, rc, &blocks);
3974 if (ret < 0) {
3975 if (ret != -EAGAIN) {
3976 err = ret;
3977 break;
3978 }
3979 rc->extents_found--;
3980 rc->search_start = key.objectid;
3981 }
3982 }
3983
3984 ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5);
3985 if (ret < 0) {
3986 if (ret != -ENOSPC) {
3987 err = ret;
3988 WARN_ON(1);
3989 break;
3990 }
3991 rc->commit_transaction = 1;
3992 }
3993
3994 if (rc->commit_transaction) {
3995 rc->commit_transaction = 0;
3996 ret = btrfs_commit_transaction(trans, rc->extent_root);
3997 BUG_ON(ret);
3998 } else {
3999 btrfs_end_transaction_throttle(trans, rc->extent_root);
4000 btrfs_btree_balance_dirty(rc->extent_root);
4001 }
4002 trans = NULL;
4003
4004 if (rc->stage == MOVE_DATA_EXTENTS &&
4005 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4006 rc->found_file_extent = 1;
4007 ret = relocate_data_extent(rc->data_inode,
4008 &key, &rc->cluster);
4009 if (ret < 0) {
4010 err = ret;
4011 break;
4012 }
4013 }
4014 }
4015 if (trans && progress && err == -ENOSPC) {
4016 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4017 rc->block_group->flags);
4018 if (ret == 0) {
4019 err = 0;
4020 progress = 0;
4021 goto restart;
4022 }
4023 }
4024
4025 btrfs_release_path(path);
4026 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4027 GFP_NOFS);
4028
4029 if (trans) {
4030 btrfs_end_transaction_throttle(trans, rc->extent_root);
4031 btrfs_btree_balance_dirty(rc->extent_root);
4032 }
4033
4034 if (!err) {
4035 ret = relocate_file_extent_cluster(rc->data_inode,
4036 &rc->cluster);
4037 if (ret < 0)
4038 err = ret;
4039 }
4040
4041 rc->create_reloc_tree = 0;
4042 set_reloc_control(rc);
4043
4044 backref_cache_cleanup(&rc->backref_cache);
4045 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4046
4047 err = prepare_to_merge(rc, err);
4048
4049 merge_reloc_roots(rc);
4050
4051 rc->merge_reloc_tree = 0;
4052 unset_reloc_control(rc);
4053 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4054
4055 /* get rid of pinned extents */
4056 trans = btrfs_join_transaction(rc->extent_root);
4057 if (IS_ERR(trans))
4058 err = PTR_ERR(trans);
4059 else
4060 btrfs_commit_transaction(trans, rc->extent_root);
4061 out_free:
4062 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4063 btrfs_free_path(path);
4064 return err;
4065 }
4066
4067 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4068 struct btrfs_root *root, u64 objectid)
4069 {
4070 struct btrfs_path *path;
4071 struct btrfs_inode_item *item;
4072 struct extent_buffer *leaf;
4073 int ret;
4074
4075 path = btrfs_alloc_path();
4076 if (!path)
4077 return -ENOMEM;
4078
4079 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4080 if (ret)
4081 goto out;
4082
4083 leaf = path->nodes[0];
4084 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4085 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4086 btrfs_set_inode_generation(leaf, item, 1);
4087 btrfs_set_inode_size(leaf, item, 0);
4088 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4089 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4090 BTRFS_INODE_PREALLOC);
4091 btrfs_mark_buffer_dirty(leaf);
4092 btrfs_release_path(path);
4093 out:
4094 btrfs_free_path(path);
4095 return ret;
4096 }
4097
4098 /*
4099 * helper to create inode for data relocation.
4100 * the inode is in data relocation tree and its link count is 0
4101 */
4102 static noinline_for_stack
4103 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4104 struct btrfs_block_group_cache *group)
4105 {
4106 struct inode *inode = NULL;
4107 struct btrfs_trans_handle *trans;
4108 struct btrfs_root *root;
4109 struct btrfs_key key;
4110 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4111 int err = 0;
4112
4113 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4114 if (IS_ERR(root))
4115 return ERR_CAST(root);
4116
4117 trans = btrfs_start_transaction(root, 6);
4118 if (IS_ERR(trans))
4119 return ERR_CAST(trans);
4120
4121 err = btrfs_find_free_objectid(root, &objectid);
4122 if (err)
4123 goto out;
4124
4125 err = __insert_orphan_inode(trans, root, objectid);
4126 BUG_ON(err);
4127
4128 key.objectid = objectid;
4129 key.type = BTRFS_INODE_ITEM_KEY;
4130 key.offset = 0;
4131 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4132 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4133 BTRFS_I(inode)->index_cnt = group->key.objectid;
4134
4135 err = btrfs_orphan_add(trans, inode);
4136 out:
4137 btrfs_end_transaction(trans, root);
4138 btrfs_btree_balance_dirty(root);
4139 if (err) {
4140 if (inode)
4141 iput(inode);
4142 inode = ERR_PTR(err);
4143 }
4144 return inode;
4145 }
4146
4147 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4148 {
4149 struct reloc_control *rc;
4150
4151 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4152 if (!rc)
4153 return NULL;
4154
4155 INIT_LIST_HEAD(&rc->reloc_roots);
4156 backref_cache_init(&rc->backref_cache);
4157 mapping_tree_init(&rc->reloc_root_tree);
4158 extent_io_tree_init(&rc->processed_blocks,
4159 fs_info->btree_inode->i_mapping);
4160 return rc;
4161 }
4162
4163 /*
4164 * function to relocate all extents in a block group.
4165 */
4166 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4167 {
4168 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4169 struct reloc_control *rc;
4170 struct inode *inode;
4171 struct btrfs_path *path;
4172 int ret;
4173 int rw = 0;
4174 int err = 0;
4175
4176 rc = alloc_reloc_control(fs_info);
4177 if (!rc)
4178 return -ENOMEM;
4179
4180 rc->extent_root = extent_root;
4181
4182 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4183 BUG_ON(!rc->block_group);
4184
4185 if (!rc->block_group->ro) {
4186 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4187 if (ret) {
4188 err = ret;
4189 goto out;
4190 }
4191 rw = 1;
4192 }
4193
4194 path = btrfs_alloc_path();
4195 if (!path) {
4196 err = -ENOMEM;
4197 goto out;
4198 }
4199
4200 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4201 path);
4202 btrfs_free_path(path);
4203
4204 if (!IS_ERR(inode))
4205 ret = delete_block_group_cache(fs_info, inode, 0);
4206 else
4207 ret = PTR_ERR(inode);
4208
4209 if (ret && ret != -ENOENT) {
4210 err = ret;
4211 goto out;
4212 }
4213
4214 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4215 if (IS_ERR(rc->data_inode)) {
4216 err = PTR_ERR(rc->data_inode);
4217 rc->data_inode = NULL;
4218 goto out;
4219 }
4220
4221 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
4222 (unsigned long long)rc->block_group->key.objectid,
4223 (unsigned long long)rc->block_group->flags);
4224
4225 ret = btrfs_start_all_delalloc_inodes(fs_info, 0);
4226 if (ret < 0) {
4227 err = ret;
4228 goto out;
4229 }
4230 btrfs_wait_all_ordered_extents(fs_info, 0);
4231
4232 while (1) {
4233 mutex_lock(&fs_info->cleaner_mutex);
4234 ret = relocate_block_group(rc);
4235 mutex_unlock(&fs_info->cleaner_mutex);
4236 if (ret < 0) {
4237 err = ret;
4238 goto out;
4239 }
4240
4241 if (rc->extents_found == 0)
4242 break;
4243
4244 printk(KERN_INFO "btrfs: found %llu extents\n",
4245 (unsigned long long)rc->extents_found);
4246
4247 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4248 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4249 invalidate_mapping_pages(rc->data_inode->i_mapping,
4250 0, -1);
4251 rc->stage = UPDATE_DATA_PTRS;
4252 }
4253 }
4254
4255 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4256 rc->block_group->key.objectid,
4257 rc->block_group->key.objectid +
4258 rc->block_group->key.offset - 1);
4259
4260 WARN_ON(rc->block_group->pinned > 0);
4261 WARN_ON(rc->block_group->reserved > 0);
4262 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4263 out:
4264 if (err && rw)
4265 btrfs_set_block_group_rw(extent_root, rc->block_group);
4266 iput(rc->data_inode);
4267 btrfs_put_block_group(rc->block_group);
4268 kfree(rc);
4269 return err;
4270 }
4271
4272 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4273 {
4274 struct btrfs_trans_handle *trans;
4275 int ret, err;
4276
4277 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4278 if (IS_ERR(trans))
4279 return PTR_ERR(trans);
4280
4281 memset(&root->root_item.drop_progress, 0,
4282 sizeof(root->root_item.drop_progress));
4283 root->root_item.drop_level = 0;
4284 btrfs_set_root_refs(&root->root_item, 0);
4285 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4286 &root->root_key, &root->root_item);
4287
4288 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4289 if (err)
4290 return err;
4291 return ret;
4292 }
4293
4294 /*
4295 * recover relocation interrupted by system crash.
4296 *
4297 * this function resumes merging reloc trees with corresponding fs trees.
4298 * this is important for keeping the sharing of tree blocks
4299 */
4300 int btrfs_recover_relocation(struct btrfs_root *root)
4301 {
4302 LIST_HEAD(reloc_roots);
4303 struct btrfs_key key;
4304 struct btrfs_root *fs_root;
4305 struct btrfs_root *reloc_root;
4306 struct btrfs_path *path;
4307 struct extent_buffer *leaf;
4308 struct reloc_control *rc = NULL;
4309 struct btrfs_trans_handle *trans;
4310 int ret;
4311 int err = 0;
4312
4313 path = btrfs_alloc_path();
4314 if (!path)
4315 return -ENOMEM;
4316 path->reada = -1;
4317
4318 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4319 key.type = BTRFS_ROOT_ITEM_KEY;
4320 key.offset = (u64)-1;
4321
4322 while (1) {
4323 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4324 path, 0, 0);
4325 if (ret < 0) {
4326 err = ret;
4327 goto out;
4328 }
4329 if (ret > 0) {
4330 if (path->slots[0] == 0)
4331 break;
4332 path->slots[0]--;
4333 }
4334 leaf = path->nodes[0];
4335 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4336 btrfs_release_path(path);
4337
4338 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4339 key.type != BTRFS_ROOT_ITEM_KEY)
4340 break;
4341
4342 reloc_root = btrfs_read_fs_root(root, &key);
4343 if (IS_ERR(reloc_root)) {
4344 err = PTR_ERR(reloc_root);
4345 goto out;
4346 }
4347
4348 list_add(&reloc_root->root_list, &reloc_roots);
4349
4350 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4351 fs_root = read_fs_root(root->fs_info,
4352 reloc_root->root_key.offset);
4353 if (IS_ERR(fs_root)) {
4354 ret = PTR_ERR(fs_root);
4355 if (ret != -ENOENT) {
4356 err = ret;
4357 goto out;
4358 }
4359 ret = mark_garbage_root(reloc_root);
4360 if (ret < 0) {
4361 err = ret;
4362 goto out;
4363 }
4364 }
4365 }
4366
4367 if (key.offset == 0)
4368 break;
4369
4370 key.offset--;
4371 }
4372 btrfs_release_path(path);
4373
4374 if (list_empty(&reloc_roots))
4375 goto out;
4376
4377 rc = alloc_reloc_control(root->fs_info);
4378 if (!rc) {
4379 err = -ENOMEM;
4380 goto out;
4381 }
4382
4383 rc->extent_root = root->fs_info->extent_root;
4384
4385 set_reloc_control(rc);
4386
4387 trans = btrfs_join_transaction(rc->extent_root);
4388 if (IS_ERR(trans)) {
4389 unset_reloc_control(rc);
4390 err = PTR_ERR(trans);
4391 goto out_free;
4392 }
4393
4394 rc->merge_reloc_tree = 1;
4395
4396 while (!list_empty(&reloc_roots)) {
4397 reloc_root = list_entry(reloc_roots.next,
4398 struct btrfs_root, root_list);
4399 list_del(&reloc_root->root_list);
4400
4401 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4402 list_add_tail(&reloc_root->root_list,
4403 &rc->reloc_roots);
4404 continue;
4405 }
4406
4407 fs_root = read_fs_root(root->fs_info,
4408 reloc_root->root_key.offset);
4409 if (IS_ERR(fs_root)) {
4410 err = PTR_ERR(fs_root);
4411 goto out_free;
4412 }
4413
4414 err = __add_reloc_root(reloc_root);
4415 BUG_ON(err < 0); /* -ENOMEM or logic error */
4416 fs_root->reloc_root = reloc_root;
4417 }
4418
4419 err = btrfs_commit_transaction(trans, rc->extent_root);
4420 if (err)
4421 goto out_free;
4422
4423 merge_reloc_roots(rc);
4424
4425 unset_reloc_control(rc);
4426
4427 trans = btrfs_join_transaction(rc->extent_root);
4428 if (IS_ERR(trans))
4429 err = PTR_ERR(trans);
4430 else
4431 err = btrfs_commit_transaction(trans, rc->extent_root);
4432 out_free:
4433 kfree(rc);
4434 out:
4435 if (!list_empty(&reloc_roots))
4436 free_reloc_roots(&reloc_roots);
4437
4438 btrfs_free_path(path);
4439
4440 if (err == 0) {
4441 /* cleanup orphan inode in data relocation tree */
4442 fs_root = read_fs_root(root->fs_info,
4443 BTRFS_DATA_RELOC_TREE_OBJECTID);
4444 if (IS_ERR(fs_root))
4445 err = PTR_ERR(fs_root);
4446 else
4447 err = btrfs_orphan_cleanup(fs_root);
4448 }
4449 return err;
4450 }
4451
4452 /*
4453 * helper to add ordered checksum for data relocation.
4454 *
4455 * cloning checksum properly handles the nodatasum extents.
4456 * it also saves CPU time to re-calculate the checksum.
4457 */
4458 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4459 {
4460 struct btrfs_ordered_sum *sums;
4461 struct btrfs_ordered_extent *ordered;
4462 struct btrfs_root *root = BTRFS_I(inode)->root;
4463 int ret;
4464 u64 disk_bytenr;
4465 LIST_HEAD(list);
4466
4467 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4468 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4469
4470 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4471 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4472 disk_bytenr + len - 1, &list, 0);
4473 if (ret)
4474 goto out;
4475
4476 disk_bytenr = ordered->start;
4477 while (!list_empty(&list)) {
4478 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4479 list_del_init(&sums->list);
4480
4481 sums->bytenr = disk_bytenr;
4482 disk_bytenr += sums->len;
4483
4484 btrfs_add_ordered_sum(inode, ordered, sums);
4485 }
4486 out:
4487 btrfs_put_ordered_extent(ordered);
4488 return ret;
4489 }
4490
4491 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4492 struct btrfs_root *root, struct extent_buffer *buf,
4493 struct extent_buffer *cow)
4494 {
4495 struct reloc_control *rc;
4496 struct backref_node *node;
4497 int first_cow = 0;
4498 int level;
4499 int ret;
4500
4501 rc = root->fs_info->reloc_ctl;
4502 if (!rc)
4503 return;
4504
4505 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4506 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4507
4508 level = btrfs_header_level(buf);
4509 if (btrfs_header_generation(buf) <=
4510 btrfs_root_last_snapshot(&root->root_item))
4511 first_cow = 1;
4512
4513 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4514 rc->create_reloc_tree) {
4515 WARN_ON(!first_cow && level == 0);
4516
4517 node = rc->backref_cache.path[level];
4518 BUG_ON(node->bytenr != buf->start &&
4519 node->new_bytenr != buf->start);
4520
4521 drop_node_buffer(node);
4522 extent_buffer_get(cow);
4523 node->eb = cow;
4524 node->new_bytenr = cow->start;
4525
4526 if (!node->pending) {
4527 list_move_tail(&node->list,
4528 &rc->backref_cache.pending[level]);
4529 node->pending = 1;
4530 }
4531
4532 if (first_cow)
4533 __mark_block_processed(rc, node);
4534
4535 if (first_cow && level > 0)
4536 rc->nodes_relocated += buf->len;
4537 }
4538
4539 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4540 ret = replace_file_extents(trans, rc, root, cow);
4541 BUG_ON(ret);
4542 }
4543 }
4544
4545 /*
4546 * called before creating snapshot. it calculates metadata reservation
4547 * requried for relocating tree blocks in the snapshot
4548 */
4549 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4550 struct btrfs_pending_snapshot *pending,
4551 u64 *bytes_to_reserve)
4552 {
4553 struct btrfs_root *root;
4554 struct reloc_control *rc;
4555
4556 root = pending->root;
4557 if (!root->reloc_root)
4558 return;
4559
4560 rc = root->fs_info->reloc_ctl;
4561 if (!rc->merge_reloc_tree)
4562 return;
4563
4564 root = root->reloc_root;
4565 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4566 /*
4567 * relocation is in the stage of merging trees. the space
4568 * used by merging a reloc tree is twice the size of
4569 * relocated tree nodes in the worst case. half for cowing
4570 * the reloc tree, half for cowing the fs tree. the space
4571 * used by cowing the reloc tree will be freed after the
4572 * tree is dropped. if we create snapshot, cowing the fs
4573 * tree may use more space than it frees. so we need
4574 * reserve extra space.
4575 */
4576 *bytes_to_reserve += rc->nodes_relocated;
4577 }
4578
4579 /*
4580 * called after snapshot is created. migrate block reservation
4581 * and create reloc root for the newly created snapshot
4582 */
4583 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4584 struct btrfs_pending_snapshot *pending)
4585 {
4586 struct btrfs_root *root = pending->root;
4587 struct btrfs_root *reloc_root;
4588 struct btrfs_root *new_root;
4589 struct reloc_control *rc;
4590 int ret;
4591
4592 if (!root->reloc_root)
4593 return 0;
4594
4595 rc = root->fs_info->reloc_ctl;
4596 rc->merging_rsv_size += rc->nodes_relocated;
4597
4598 if (rc->merge_reloc_tree) {
4599 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4600 rc->block_rsv,
4601 rc->nodes_relocated);
4602 if (ret)
4603 return ret;
4604 }
4605
4606 new_root = pending->snap;
4607 reloc_root = create_reloc_root(trans, root->reloc_root,
4608 new_root->root_key.objectid);
4609 if (IS_ERR(reloc_root))
4610 return PTR_ERR(reloc_root);
4611
4612 ret = __add_reloc_root(reloc_root);
4613 BUG_ON(ret < 0);
4614 new_root->reloc_root = reloc_root;
4615
4616 if (rc->create_reloc_tree)
4617 ret = clone_backref_node(trans, rc, root, reloc_root);
4618 return ret;
4619 }
Linux with added FPC-III support