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ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat mode
[linux/fpc-iii.git] / fs / btrfs / relocation.c
blob0e7f7765b3bbe232938fd92763ec4eb5f117cfcc
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 bool need_check = true;
695
696 path1 = btrfs_alloc_path();
697 path2 = btrfs_alloc_path();
698 if (!path1 || !path2) {
699 err = -ENOMEM;
700 goto out;
701 }
702 path1->reada = 1;
703 path2->reada = 2;
704
705 node = alloc_backref_node(cache);
706 if (!node) {
707 err = -ENOMEM;
708 goto out;
709 }
710
711 node->bytenr = bytenr;
712 node->level = level;
713 node->lowest = 1;
714 cur = node;
715 again:
716 end = 0;
717 ptr = 0;
718 key.objectid = cur->bytenr;
719 key.type = BTRFS_METADATA_ITEM_KEY;
720 key.offset = (u64)-1;
721
722 path1->search_commit_root = 1;
723 path1->skip_locking = 1;
724 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
725 0, 0);
726 if (ret < 0) {
727 err = ret;
728 goto out;
729 }
730 BUG_ON(!ret || !path1->slots[0]);
731
732 path1->slots[0]--;
733
734 WARN_ON(cur->checked);
735 if (!list_empty(&cur->upper)) {
736 /*
737 * the backref was added previously when processing
738 * backref of type BTRFS_TREE_BLOCK_REF_KEY
739 */
740 BUG_ON(!list_is_singular(&cur->upper));
741 edge = list_entry(cur->upper.next, struct backref_edge,
742 list[LOWER]);
743 BUG_ON(!list_empty(&edge->list[UPPER]));
744 exist = edge->node[UPPER];
745 /*
746 * add the upper level block to pending list if we need
747 * check its backrefs
748 */
749 if (!exist->checked)
750 list_add_tail(&edge->list[UPPER], &list);
751 } else {
752 exist = NULL;
753 }
754
755 while (1) {
756 cond_resched();
757 eb = path1->nodes[0];
758
759 if (ptr >= end) {
760 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
761 ret = btrfs_next_leaf(rc->extent_root, path1);
762 if (ret < 0) {
763 err = ret;
764 goto out;
765 }
766 if (ret > 0)
767 break;
768 eb = path1->nodes[0];
769 }
770
771 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
772 if (key.objectid != cur->bytenr) {
773 WARN_ON(exist);
774 break;
775 }
776
777 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
778 key.type == BTRFS_METADATA_ITEM_KEY) {
779 ret = find_inline_backref(eb, path1->slots[0],
780 &ptr, &end);
781 if (ret)
782 goto next;
783 }
784 }
785
786 if (ptr < end) {
787 /* update key for inline back ref */
788 struct btrfs_extent_inline_ref *iref;
789 iref = (struct btrfs_extent_inline_ref *)ptr;
790 key.type = btrfs_extent_inline_ref_type(eb, iref);
791 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
792 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
793 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
794 }
795
796 if (exist &&
797 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
798 exist->owner == key.offset) ||
799 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
800 exist->bytenr == key.offset))) {
801 exist = NULL;
802 goto next;
803 }
804
805 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
806 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
807 key.type == BTRFS_EXTENT_REF_V0_KEY) {
808 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
809 struct btrfs_extent_ref_v0 *ref0;
810 ref0 = btrfs_item_ptr(eb, path1->slots[0],
811 struct btrfs_extent_ref_v0);
812 if (key.objectid == key.offset) {
813 root = find_tree_root(rc, eb, ref0);
814 if (root && !should_ignore_root(root))
815 cur->root = root;
816 else
817 list_add(&cur->list, &useless);
818 break;
819 }
820 if (is_cowonly_root(btrfs_ref_root_v0(eb,
821 ref0)))
822 cur->cowonly = 1;
823 }
824 #else
825 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
826 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
827 #endif
828 if (key.objectid == key.offset) {
829 /*
830 * only root blocks of reloc trees use
831 * backref of this type.
832 */
833 root = find_reloc_root(rc, cur->bytenr);
834 BUG_ON(!root);
835 cur->root = root;
836 break;
837 }
838
839 edge = alloc_backref_edge(cache);
840 if (!edge) {
841 err = -ENOMEM;
842 goto out;
843 }
844 rb_node = tree_search(&cache->rb_root, key.offset);
845 if (!rb_node) {
846 upper = alloc_backref_node(cache);
847 if (!upper) {
848 free_backref_edge(cache, edge);
849 err = -ENOMEM;
850 goto out;
851 }
852 upper->bytenr = key.offset;
853 upper->level = cur->level + 1;
854 /*
855 * backrefs for the upper level block isn't
856 * cached, add the block to pending list
857 */
858 list_add_tail(&edge->list[UPPER], &list);
859 } else {
860 upper = rb_entry(rb_node, struct backref_node,
861 rb_node);
862 BUG_ON(!upper->checked);
863 INIT_LIST_HEAD(&edge->list[UPPER]);
864 }
865 list_add_tail(&edge->list[LOWER], &cur->upper);
866 edge->node[LOWER] = cur;
867 edge->node[UPPER] = upper;
868
869 goto next;
870 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
871 goto next;
872 }
873
874 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
875 root = read_fs_root(rc->extent_root->fs_info, key.offset);
876 if (IS_ERR(root)) {
877 err = PTR_ERR(root);
878 goto out;
879 }
880
881 if (!root->ref_cows)
882 cur->cowonly = 1;
883
884 if (btrfs_root_level(&root->root_item) == cur->level) {
885 /* tree root */
886 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
887 cur->bytenr);
888 if (should_ignore_root(root))
889 list_add(&cur->list, &useless);
890 else
891 cur->root = root;
892 break;
893 }
894
895 level = cur->level + 1;
896
897 /*
898 * searching the tree to find upper level blocks
899 * reference the block.
900 */
901 path2->search_commit_root = 1;
902 path2->skip_locking = 1;
903 path2->lowest_level = level;
904 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
905 path2->lowest_level = 0;
906 if (ret < 0) {
907 err = ret;
908 goto out;
909 }
910 if (ret > 0 && path2->slots[level] > 0)
911 path2->slots[level]--;
912
913 eb = path2->nodes[level];
914 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
915 cur->bytenr);
916
917 lower = cur;
918 need_check = true;
919 for (; level < BTRFS_MAX_LEVEL; level++) {
920 if (!path2->nodes[level]) {
921 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
922 lower->bytenr);
923 if (should_ignore_root(root))
924 list_add(&lower->list, &useless);
925 else
926 lower->root = root;
927 break;
928 }
929
930 edge = alloc_backref_edge(cache);
931 if (!edge) {
932 err = -ENOMEM;
933 goto out;
934 }
935
936 eb = path2->nodes[level];
937 rb_node = tree_search(&cache->rb_root, eb->start);
938 if (!rb_node) {
939 upper = alloc_backref_node(cache);
940 if (!upper) {
941 free_backref_edge(cache, edge);
942 err = -ENOMEM;
943 goto out;
944 }
945 upper->bytenr = eb->start;
946 upper->owner = btrfs_header_owner(eb);
947 upper->level = lower->level + 1;
948 if (!root->ref_cows)
949 upper->cowonly = 1;
950
951 /*
952 * if we know the block isn't shared
953 * we can void checking its backrefs.
954 */
955 if (btrfs_block_can_be_shared(root, eb))
956 upper->checked = 0;
957 else
958 upper->checked = 1;
959
960 /*
961 * add the block to pending list if we
962 * need check its backrefs, we only do this once
963 * while walking up a tree as we will catch
964 * anything else later on.
965 */
966 if (!upper->checked && need_check) {
967 need_check = false;
968 list_add_tail(&edge->list[UPPER],
969 &list);
970 } else {
971 if (upper->checked)
972 need_check = true;
973 INIT_LIST_HEAD(&edge->list[UPPER]);
974 }
975 } else {
976 upper = rb_entry(rb_node, struct backref_node,
977 rb_node);
978 BUG_ON(!upper->checked);
979 INIT_LIST_HEAD(&edge->list[UPPER]);
980 if (!upper->owner)
981 upper->owner = btrfs_header_owner(eb);
982 }
983 list_add_tail(&edge->list[LOWER], &lower->upper);
984 edge->node[LOWER] = lower;
985 edge->node[UPPER] = upper;
986
987 if (rb_node)
988 break;
989 lower = upper;
990 upper = NULL;
991 }
992 btrfs_release_path(path2);
993 next:
994 if (ptr < end) {
995 ptr += btrfs_extent_inline_ref_size(key.type);
996 if (ptr >= end) {
997 WARN_ON(ptr > end);
998 ptr = 0;
999 end = 0;
1000 }
1001 }
1002 if (ptr >= end)
1003 path1->slots[0]++;
1004 }
1005 btrfs_release_path(path1);
1006
1007 cur->checked = 1;
1008 WARN_ON(exist);
1009
1010 /* the pending list isn't empty, take the first block to process */
1011 if (!list_empty(&list)) {
1012 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1013 list_del_init(&edge->list[UPPER]);
1014 cur = edge->node[UPPER];
1015 goto again;
1016 }
1017
1018 /*
1019 * everything goes well, connect backref nodes and insert backref nodes
1020 * into the cache.
1021 */
1022 BUG_ON(!node->checked);
1023 cowonly = node->cowonly;
1024 if (!cowonly) {
1025 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1026 &node->rb_node);
1027 if (rb_node)
1028 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1029 list_add_tail(&node->lower, &cache->leaves);
1030 }
1031
1032 list_for_each_entry(edge, &node->upper, list[LOWER])
1033 list_add_tail(&edge->list[UPPER], &list);
1034
1035 while (!list_empty(&list)) {
1036 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1037 list_del_init(&edge->list[UPPER]);
1038 upper = edge->node[UPPER];
1039 if (upper->detached) {
1040 list_del(&edge->list[LOWER]);
1041 lower = edge->node[LOWER];
1042 free_backref_edge(cache, edge);
1043 if (list_empty(&lower->upper))
1044 list_add(&lower->list, &useless);
1045 continue;
1046 }
1047
1048 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1049 if (upper->lowest) {
1050 list_del_init(&upper->lower);
1051 upper->lowest = 0;
1052 }
1053
1054 list_add_tail(&edge->list[UPPER], &upper->lower);
1055 continue;
1056 }
1057
1058 BUG_ON(!upper->checked);
1059 BUG_ON(cowonly != upper->cowonly);
1060 if (!cowonly) {
1061 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1062 &upper->rb_node);
1063 if (rb_node)
1064 backref_tree_panic(rb_node, -EEXIST,
1065 upper->bytenr);
1066 }
1067
1068 list_add_tail(&edge->list[UPPER], &upper->lower);
1069
1070 list_for_each_entry(edge, &upper->upper, list[LOWER])
1071 list_add_tail(&edge->list[UPPER], &list);
1072 }
1073 /*
1074 * process useless backref nodes. backref nodes for tree leaves
1075 * are deleted from the cache. backref nodes for upper level
1076 * tree blocks are left in the cache to avoid unnecessary backref
1077 * lookup.
1078 */
1079 while (!list_empty(&useless)) {
1080 upper = list_entry(useless.next, struct backref_node, list);
1081 list_del_init(&upper->list);
1082 BUG_ON(!list_empty(&upper->upper));
1083 if (upper == node)
1084 node = NULL;
1085 if (upper->lowest) {
1086 list_del_init(&upper->lower);
1087 upper->lowest = 0;
1088 }
1089 while (!list_empty(&upper->lower)) {
1090 edge = list_entry(upper->lower.next,
1091 struct backref_edge, list[UPPER]);
1092 list_del(&edge->list[UPPER]);
1093 list_del(&edge->list[LOWER]);
1094 lower = edge->node[LOWER];
1095 free_backref_edge(cache, edge);
1096
1097 if (list_empty(&lower->upper))
1098 list_add(&lower->list, &useless);
1099 }
1100 __mark_block_processed(rc, upper);
1101 if (upper->level > 0) {
1102 list_add(&upper->list, &cache->detached);
1103 upper->detached = 1;
1104 } else {
1105 rb_erase(&upper->rb_node, &cache->rb_root);
1106 free_backref_node(cache, upper);
1107 }
1108 }
1109 out:
1110 btrfs_free_path(path1);
1111 btrfs_free_path(path2);
1112 if (err) {
1113 while (!list_empty(&useless)) {
1114 lower = list_entry(useless.next,
1115 struct backref_node, upper);
1116 list_del_init(&lower->upper);
1117 }
1118 upper = node;
1119 INIT_LIST_HEAD(&list);
1120 while (upper) {
1121 if (RB_EMPTY_NODE(&upper->rb_node)) {
1122 list_splice_tail(&upper->upper, &list);
1123 free_backref_node(cache, upper);
1124 }
1125
1126 if (list_empty(&list))
1127 break;
1128
1129 edge = list_entry(list.next, struct backref_edge,
1130 list[LOWER]);
1131 list_del(&edge->list[LOWER]);
1132 upper = edge->node[UPPER];
1133 free_backref_edge(cache, edge);
1134 }
1135 return ERR_PTR(err);
1136 }
1137 BUG_ON(node && node->detached);
1138 return node;
1139 }
1140
1141 /*
1142 * helper to add backref node for the newly created snapshot.
1143 * the backref node is created by cloning backref node that
1144 * corresponds to root of source tree
1145 */
1146 static int clone_backref_node(struct btrfs_trans_handle *trans,
1147 struct reloc_control *rc,
1148 struct btrfs_root *src,
1149 struct btrfs_root *dest)
1150 {
1151 struct btrfs_root *reloc_root = src->reloc_root;
1152 struct backref_cache *cache = &rc->backref_cache;
1153 struct backref_node *node = NULL;
1154 struct backref_node *new_node;
1155 struct backref_edge *edge;
1156 struct backref_edge *new_edge;
1157 struct rb_node *rb_node;
1158
1159 if (cache->last_trans > 0)
1160 update_backref_cache(trans, cache);
1161
1162 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1163 if (rb_node) {
1164 node = rb_entry(rb_node, struct backref_node, rb_node);
1165 if (node->detached)
1166 node = NULL;
1167 else
1168 BUG_ON(node->new_bytenr != reloc_root->node->start);
1169 }
1170
1171 if (!node) {
1172 rb_node = tree_search(&cache->rb_root,
1173 reloc_root->commit_root->start);
1174 if (rb_node) {
1175 node = rb_entry(rb_node, struct backref_node,
1176 rb_node);
1177 BUG_ON(node->detached);
1178 }
1179 }
1180
1181 if (!node)
1182 return 0;
1183
1184 new_node = alloc_backref_node(cache);
1185 if (!new_node)
1186 return -ENOMEM;
1187
1188 new_node->bytenr = dest->node->start;
1189 new_node->level = node->level;
1190 new_node->lowest = node->lowest;
1191 new_node->checked = 1;
1192 new_node->root = dest;
1193
1194 if (!node->lowest) {
1195 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1196 new_edge = alloc_backref_edge(cache);
1197 if (!new_edge)
1198 goto fail;
1199
1200 new_edge->node[UPPER] = new_node;
1201 new_edge->node[LOWER] = edge->node[LOWER];
1202 list_add_tail(&new_edge->list[UPPER],
1203 &new_node->lower);
1204 }
1205 } else {
1206 list_add_tail(&new_node->lower, &cache->leaves);
1207 }
1208
1209 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1210 &new_node->rb_node);
1211 if (rb_node)
1212 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1213
1214 if (!new_node->lowest) {
1215 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1216 list_add_tail(&new_edge->list[LOWER],
1217 &new_edge->node[LOWER]->upper);
1218 }
1219 }
1220 return 0;
1221 fail:
1222 while (!list_empty(&new_node->lower)) {
1223 new_edge = list_entry(new_node->lower.next,
1224 struct backref_edge, list[UPPER]);
1225 list_del(&new_edge->list[UPPER]);
1226 free_backref_edge(cache, new_edge);
1227 }
1228 free_backref_node(cache, new_node);
1229 return -ENOMEM;
1230 }
1231
1232 /*
1233 * helper to add 'address of tree root -> reloc tree' mapping
1234 */
1235 static int __must_check __add_reloc_root(struct btrfs_root *root)
1236 {
1237 struct rb_node *rb_node;
1238 struct mapping_node *node;
1239 struct reloc_control *rc = root->fs_info->reloc_ctl;
1240
1241 node = kmalloc(sizeof(*node), GFP_NOFS);
1242 if (!node)
1243 return -ENOMEM;
1244
1245 node->bytenr = root->node->start;
1246 node->data = root;
1247
1248 spin_lock(&rc->reloc_root_tree.lock);
1249 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1250 node->bytenr, &node->rb_node);
1251 spin_unlock(&rc->reloc_root_tree.lock);
1252 if (rb_node) {
1253 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1254 "for start=%llu while inserting into relocation "
1255 "tree\n", node->bytenr);
1256 kfree(node);
1257 return -EEXIST;
1258 }
1259
1260 list_add_tail(&root->root_list, &rc->reloc_roots);
1261 return 0;
1262 }
1263
1264 /*
1265 * helper to update/delete the 'address of tree root -> reloc tree'
1266 * mapping
1267 */
1268 static int __update_reloc_root(struct btrfs_root *root, int del)
1269 {
1270 struct rb_node *rb_node;
1271 struct mapping_node *node = NULL;
1272 struct reloc_control *rc = root->fs_info->reloc_ctl;
1273
1274 spin_lock(&rc->reloc_root_tree.lock);
1275 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1276 root->commit_root->start);
1277 if (rb_node) {
1278 node = rb_entry(rb_node, struct mapping_node, rb_node);
1279 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1280 }
1281 spin_unlock(&rc->reloc_root_tree.lock);
1282
1283 if (!node)
1284 return 0;
1285 BUG_ON((struct btrfs_root *)node->data != root);
1286
1287 if (!del) {
1288 spin_lock(&rc->reloc_root_tree.lock);
1289 node->bytenr = root->node->start;
1290 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1291 node->bytenr, &node->rb_node);
1292 spin_unlock(&rc->reloc_root_tree.lock);
1293 if (rb_node)
1294 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1295 } else {
1296 spin_lock(&root->fs_info->trans_lock);
1297 list_del_init(&root->root_list);
1298 spin_unlock(&root->fs_info->trans_lock);
1299 kfree(node);
1300 }
1301 return 0;
1302 }
1303
1304 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1305 struct btrfs_root *root, u64 objectid)
1306 {
1307 struct btrfs_root *reloc_root;
1308 struct extent_buffer *eb;
1309 struct btrfs_root_item *root_item;
1310 struct btrfs_key root_key;
1311 int ret;
1312
1313 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1314 BUG_ON(!root_item);
1315
1316 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1317 root_key.type = BTRFS_ROOT_ITEM_KEY;
1318 root_key.offset = objectid;
1319
1320 if (root->root_key.objectid == objectid) {
1321 /* called by btrfs_init_reloc_root */
1322 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1323 BTRFS_TREE_RELOC_OBJECTID);
1324 BUG_ON(ret);
1325
1326 btrfs_set_root_last_snapshot(&root->root_item,
1327 trans->transid - 1);
1328 } else {
1329 /*
1330 * called by btrfs_reloc_post_snapshot_hook.
1331 * the source tree is a reloc tree, all tree blocks
1332 * modified after it was created have RELOC flag
1333 * set in their headers. so it's OK to not update
1334 * the 'last_snapshot'.
1335 */
1336 ret = btrfs_copy_root(trans, root, root->node, &eb,
1337 BTRFS_TREE_RELOC_OBJECTID);
1338 BUG_ON(ret);
1339 }
1340
1341 memcpy(root_item, &root->root_item, sizeof(*root_item));
1342 btrfs_set_root_bytenr(root_item, eb->start);
1343 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1344 btrfs_set_root_generation(root_item, trans->transid);
1345
1346 if (root->root_key.objectid == objectid) {
1347 btrfs_set_root_refs(root_item, 0);
1348 memset(&root_item->drop_progress, 0,
1349 sizeof(struct btrfs_disk_key));
1350 root_item->drop_level = 0;
1351 }
1352
1353 btrfs_tree_unlock(eb);
1354 free_extent_buffer(eb);
1355
1356 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1357 &root_key, root_item);
1358 BUG_ON(ret);
1359 kfree(root_item);
1360
1361 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
1362 &root_key);
1363 BUG_ON(IS_ERR(reloc_root));
1364 reloc_root->last_trans = trans->transid;
1365 return reloc_root;
1366 }
1367
1368 /*
1369 * create reloc tree for a given fs tree. reloc tree is just a
1370 * snapshot of the fs tree with special root objectid.
1371 */
1372 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1373 struct btrfs_root *root)
1374 {
1375 struct btrfs_root *reloc_root;
1376 struct reloc_control *rc = root->fs_info->reloc_ctl;
1377 int clear_rsv = 0;
1378 int ret;
1379
1380 if (root->reloc_root) {
1381 reloc_root = root->reloc_root;
1382 reloc_root->last_trans = trans->transid;
1383 return 0;
1384 }
1385
1386 if (!rc || !rc->create_reloc_tree ||
1387 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1388 return 0;
1389
1390 if (!trans->block_rsv) {
1391 trans->block_rsv = rc->block_rsv;
1392 clear_rsv = 1;
1393 }
1394 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1395 if (clear_rsv)
1396 trans->block_rsv = NULL;
1397
1398 ret = __add_reloc_root(reloc_root);
1399 BUG_ON(ret < 0);
1400 root->reloc_root = reloc_root;
1401 return 0;
1402 }
1403
1404 /*
1405 * update root item of reloc tree
1406 */
1407 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1408 struct btrfs_root *root)
1409 {
1410 struct btrfs_root *reloc_root;
1411 struct btrfs_root_item *root_item;
1412 int del = 0;
1413 int ret;
1414
1415 if (!root->reloc_root)
1416 goto out;
1417
1418 reloc_root = root->reloc_root;
1419 root_item = &reloc_root->root_item;
1420
1421 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1422 btrfs_root_refs(root_item) == 0) {
1423 root->reloc_root = NULL;
1424 del = 1;
1425 }
1426
1427 __update_reloc_root(reloc_root, del);
1428
1429 if (reloc_root->commit_root != reloc_root->node) {
1430 btrfs_set_root_node(root_item, reloc_root->node);
1431 free_extent_buffer(reloc_root->commit_root);
1432 reloc_root->commit_root = btrfs_root_node(reloc_root);
1433 }
1434
1435 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1436 &reloc_root->root_key, root_item);
1437 BUG_ON(ret);
1438
1439 out:
1440 return 0;
1441 }
1442
1443 /*
1444 * helper to find first cached inode with inode number >= objectid
1445 * in a subvolume
1446 */
1447 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1448 {
1449 struct rb_node *node;
1450 struct rb_node *prev;
1451 struct btrfs_inode *entry;
1452 struct inode *inode;
1453
1454 spin_lock(&root->inode_lock);
1455 again:
1456 node = root->inode_tree.rb_node;
1457 prev = NULL;
1458 while (node) {
1459 prev = node;
1460 entry = rb_entry(node, struct btrfs_inode, rb_node);
1461
1462 if (objectid < btrfs_ino(&entry->vfs_inode))
1463 node = node->rb_left;
1464 else if (objectid > btrfs_ino(&entry->vfs_inode))
1465 node = node->rb_right;
1466 else
1467 break;
1468 }
1469 if (!node) {
1470 while (prev) {
1471 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1472 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1473 node = prev;
1474 break;
1475 }
1476 prev = rb_next(prev);
1477 }
1478 }
1479 while (node) {
1480 entry = rb_entry(node, struct btrfs_inode, rb_node);
1481 inode = igrab(&entry->vfs_inode);
1482 if (inode) {
1483 spin_unlock(&root->inode_lock);
1484 return inode;
1485 }
1486
1487 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1488 if (cond_resched_lock(&root->inode_lock))
1489 goto again;
1490
1491 node = rb_next(node);
1492 }
1493 spin_unlock(&root->inode_lock);
1494 return NULL;
1495 }
1496
1497 static int in_block_group(u64 bytenr,
1498 struct btrfs_block_group_cache *block_group)
1499 {
1500 if (bytenr >= block_group->key.objectid &&
1501 bytenr < block_group->key.objectid + block_group->key.offset)
1502 return 1;
1503 return 0;
1504 }
1505
1506 /*
1507 * get new location of data
1508 */
1509 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1510 u64 bytenr, u64 num_bytes)
1511 {
1512 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1513 struct btrfs_path *path;
1514 struct btrfs_file_extent_item *fi;
1515 struct extent_buffer *leaf;
1516 int ret;
1517
1518 path = btrfs_alloc_path();
1519 if (!path)
1520 return -ENOMEM;
1521
1522 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1523 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1524 bytenr, 0);
1525 if (ret < 0)
1526 goto out;
1527 if (ret > 0) {
1528 ret = -ENOENT;
1529 goto out;
1530 }
1531
1532 leaf = path->nodes[0];
1533 fi = btrfs_item_ptr(leaf, path->slots[0],
1534 struct btrfs_file_extent_item);
1535
1536 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1537 btrfs_file_extent_compression(leaf, fi) ||
1538 btrfs_file_extent_encryption(leaf, fi) ||
1539 btrfs_file_extent_other_encoding(leaf, fi));
1540
1541 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1542 ret = 1;
1543 goto out;
1544 }
1545
1546 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1547 ret = 0;
1548 out:
1549 btrfs_free_path(path);
1550 return ret;
1551 }
1552
1553 /*
1554 * update file extent items in the tree leaf to point to
1555 * the new locations.
1556 */
1557 static noinline_for_stack
1558 int replace_file_extents(struct btrfs_trans_handle *trans,
1559 struct reloc_control *rc,
1560 struct btrfs_root *root,
1561 struct extent_buffer *leaf)
1562 {
1563 struct btrfs_key key;
1564 struct btrfs_file_extent_item *fi;
1565 struct inode *inode = NULL;
1566 u64 parent;
1567 u64 bytenr;
1568 u64 new_bytenr = 0;
1569 u64 num_bytes;
1570 u64 end;
1571 u32 nritems;
1572 u32 i;
1573 int ret;
1574 int first = 1;
1575 int dirty = 0;
1576
1577 if (rc->stage != UPDATE_DATA_PTRS)
1578 return 0;
1579
1580 /* reloc trees always use full backref */
1581 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1582 parent = leaf->start;
1583 else
1584 parent = 0;
1585
1586 nritems = btrfs_header_nritems(leaf);
1587 for (i = 0; i < nritems; i++) {
1588 cond_resched();
1589 btrfs_item_key_to_cpu(leaf, &key, i);
1590 if (key.type != BTRFS_EXTENT_DATA_KEY)
1591 continue;
1592 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1593 if (btrfs_file_extent_type(leaf, fi) ==
1594 BTRFS_FILE_EXTENT_INLINE)
1595 continue;
1596 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1597 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1598 if (bytenr == 0)
1599 continue;
1600 if (!in_block_group(bytenr, rc->block_group))
1601 continue;
1602
1603 /*
1604 * if we are modifying block in fs tree, wait for readpage
1605 * to complete and drop the extent cache
1606 */
1607 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1608 if (first) {
1609 inode = find_next_inode(root, key.objectid);
1610 first = 0;
1611 } else if (inode && btrfs_ino(inode) < key.objectid) {
1612 btrfs_add_delayed_iput(inode);
1613 inode = find_next_inode(root, key.objectid);
1614 }
1615 if (inode && btrfs_ino(inode) == key.objectid) {
1616 end = key.offset +
1617 btrfs_file_extent_num_bytes(leaf, fi);
1618 WARN_ON(!IS_ALIGNED(key.offset,
1619 root->sectorsize));
1620 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1621 end--;
1622 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1623 key.offset, end);
1624 if (!ret)
1625 continue;
1626
1627 btrfs_drop_extent_cache(inode, key.offset, end,
1628 1);
1629 unlock_extent(&BTRFS_I(inode)->io_tree,
1630 key.offset, end);
1631 }
1632 }
1633
1634 ret = get_new_location(rc->data_inode, &new_bytenr,
1635 bytenr, num_bytes);
1636 if (ret > 0) {
1637 WARN_ON(1);
1638 continue;
1639 }
1640 BUG_ON(ret < 0);
1641
1642 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1643 dirty = 1;
1644
1645 key.offset -= btrfs_file_extent_offset(leaf, fi);
1646 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1647 num_bytes, parent,
1648 btrfs_header_owner(leaf),
1649 key.objectid, key.offset, 1);
1650 BUG_ON(ret);
1651
1652 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1653 parent, btrfs_header_owner(leaf),
1654 key.objectid, key.offset, 1);
1655 BUG_ON(ret);
1656 }
1657 if (dirty)
1658 btrfs_mark_buffer_dirty(leaf);
1659 if (inode)
1660 btrfs_add_delayed_iput(inode);
1661 return 0;
1662 }
1663
1664 static noinline_for_stack
1665 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1666 struct btrfs_path *path, int level)
1667 {
1668 struct btrfs_disk_key key1;
1669 struct btrfs_disk_key key2;
1670 btrfs_node_key(eb, &key1, slot);
1671 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1672 return memcmp(&key1, &key2, sizeof(key1));
1673 }
1674
1675 /*
1676 * try to replace tree blocks in fs tree with the new blocks
1677 * in reloc tree. tree blocks haven't been modified since the
1678 * reloc tree was create can be replaced.
1679 *
1680 * if a block was replaced, level of the block + 1 is returned.
1681 * if no block got replaced, 0 is returned. if there are other
1682 * errors, a negative error number is returned.
1683 */
1684 static noinline_for_stack
1685 int replace_path(struct btrfs_trans_handle *trans,
1686 struct btrfs_root *dest, struct btrfs_root *src,
1687 struct btrfs_path *path, struct btrfs_key *next_key,
1688 int lowest_level, int max_level)
1689 {
1690 struct extent_buffer *eb;
1691 struct extent_buffer *parent;
1692 struct btrfs_key key;
1693 u64 old_bytenr;
1694 u64 new_bytenr;
1695 u64 old_ptr_gen;
1696 u64 new_ptr_gen;
1697 u64 last_snapshot;
1698 u32 blocksize;
1699 int cow = 0;
1700 int level;
1701 int ret;
1702 int slot;
1703
1704 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1705 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1706
1707 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1708 again:
1709 slot = path->slots[lowest_level];
1710 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1711
1712 eb = btrfs_lock_root_node(dest);
1713 btrfs_set_lock_blocking(eb);
1714 level = btrfs_header_level(eb);
1715
1716 if (level < lowest_level) {
1717 btrfs_tree_unlock(eb);
1718 free_extent_buffer(eb);
1719 return 0;
1720 }
1721
1722 if (cow) {
1723 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1724 BUG_ON(ret);
1725 }
1726 btrfs_set_lock_blocking(eb);
1727
1728 if (next_key) {
1729 next_key->objectid = (u64)-1;
1730 next_key->type = (u8)-1;
1731 next_key->offset = (u64)-1;
1732 }
1733
1734 parent = eb;
1735 while (1) {
1736 level = btrfs_header_level(parent);
1737 BUG_ON(level < lowest_level);
1738
1739 ret = btrfs_bin_search(parent, &key, level, &slot);
1740 if (ret && slot > 0)
1741 slot--;
1742
1743 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1744 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1745
1746 old_bytenr = btrfs_node_blockptr(parent, slot);
1747 blocksize = btrfs_level_size(dest, level - 1);
1748 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1749
1750 if (level <= max_level) {
1751 eb = path->nodes[level];
1752 new_bytenr = btrfs_node_blockptr(eb,
1753 path->slots[level]);
1754 new_ptr_gen = btrfs_node_ptr_generation(eb,
1755 path->slots[level]);
1756 } else {
1757 new_bytenr = 0;
1758 new_ptr_gen = 0;
1759 }
1760
1761 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1762 WARN_ON(1);
1763 ret = level;
1764 break;
1765 }
1766
1767 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1768 memcmp_node_keys(parent, slot, path, level)) {
1769 if (level <= lowest_level) {
1770 ret = 0;
1771 break;
1772 }
1773
1774 eb = read_tree_block(dest, old_bytenr, blocksize,
1775 old_ptr_gen);
1776 if (!eb || !extent_buffer_uptodate(eb)) {
1777 ret = (!eb) ? -ENOMEM : -EIO;
1778 free_extent_buffer(eb);
1779 break;
1780 }
1781 btrfs_tree_lock(eb);
1782 if (cow) {
1783 ret = btrfs_cow_block(trans, dest, eb, parent,
1784 slot, &eb);
1785 BUG_ON(ret);
1786 }
1787 btrfs_set_lock_blocking(eb);
1788
1789 btrfs_tree_unlock(parent);
1790 free_extent_buffer(parent);
1791
1792 parent = eb;
1793 continue;
1794 }
1795
1796 if (!cow) {
1797 btrfs_tree_unlock(parent);
1798 free_extent_buffer(parent);
1799 cow = 1;
1800 goto again;
1801 }
1802
1803 btrfs_node_key_to_cpu(path->nodes[level], &key,
1804 path->slots[level]);
1805 btrfs_release_path(path);
1806
1807 path->lowest_level = level;
1808 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1809 path->lowest_level = 0;
1810 BUG_ON(ret);
1811
1812 /*
1813 * swap blocks in fs tree and reloc tree.
1814 */
1815 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1816 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1817 btrfs_mark_buffer_dirty(parent);
1818
1819 btrfs_set_node_blockptr(path->nodes[level],
1820 path->slots[level], old_bytenr);
1821 btrfs_set_node_ptr_generation(path->nodes[level],
1822 path->slots[level], old_ptr_gen);
1823 btrfs_mark_buffer_dirty(path->nodes[level]);
1824
1825 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1826 path->nodes[level]->start,
1827 src->root_key.objectid, level - 1, 0,
1828 1);
1829 BUG_ON(ret);
1830 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1831 0, dest->root_key.objectid, level - 1,
1832 0, 1);
1833 BUG_ON(ret);
1834
1835 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1836 path->nodes[level]->start,
1837 src->root_key.objectid, level - 1, 0,
1838 1);
1839 BUG_ON(ret);
1840
1841 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1842 0, dest->root_key.objectid, level - 1,
1843 0, 1);
1844 BUG_ON(ret);
1845
1846 btrfs_unlock_up_safe(path, 0);
1847
1848 ret = level;
1849 break;
1850 }
1851 btrfs_tree_unlock(parent);
1852 free_extent_buffer(parent);
1853 return ret;
1854 }
1855
1856 /*
1857 * helper to find next relocated block in reloc tree
1858 */
1859 static noinline_for_stack
1860 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1861 int *level)
1862 {
1863 struct extent_buffer *eb;
1864 int i;
1865 u64 last_snapshot;
1866 u32 nritems;
1867
1868 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1869
1870 for (i = 0; i < *level; i++) {
1871 free_extent_buffer(path->nodes[i]);
1872 path->nodes[i] = NULL;
1873 }
1874
1875 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1876 eb = path->nodes[i];
1877 nritems = btrfs_header_nritems(eb);
1878 while (path->slots[i] + 1 < nritems) {
1879 path->slots[i]++;
1880 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1881 last_snapshot)
1882 continue;
1883
1884 *level = i;
1885 return 0;
1886 }
1887 free_extent_buffer(path->nodes[i]);
1888 path->nodes[i] = NULL;
1889 }
1890 return 1;
1891 }
1892
1893 /*
1894 * walk down reloc tree to find relocated block of lowest level
1895 */
1896 static noinline_for_stack
1897 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1898 int *level)
1899 {
1900 struct extent_buffer *eb = NULL;
1901 int i;
1902 u64 bytenr;
1903 u64 ptr_gen = 0;
1904 u64 last_snapshot;
1905 u32 blocksize;
1906 u32 nritems;
1907
1908 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1909
1910 for (i = *level; i > 0; i--) {
1911 eb = path->nodes[i];
1912 nritems = btrfs_header_nritems(eb);
1913 while (path->slots[i] < nritems) {
1914 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1915 if (ptr_gen > last_snapshot)
1916 break;
1917 path->slots[i]++;
1918 }
1919 if (path->slots[i] >= nritems) {
1920 if (i == *level)
1921 break;
1922 *level = i + 1;
1923 return 0;
1924 }
1925 if (i == 1) {
1926 *level = i;
1927 return 0;
1928 }
1929
1930 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1931 blocksize = btrfs_level_size(root, i - 1);
1932 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1933 if (!eb || !extent_buffer_uptodate(eb)) {
1934 free_extent_buffer(eb);
1935 return -EIO;
1936 }
1937 BUG_ON(btrfs_header_level(eb) != i - 1);
1938 path->nodes[i - 1] = eb;
1939 path->slots[i - 1] = 0;
1940 }
1941 return 1;
1942 }
1943
1944 /*
1945 * invalidate extent cache for file extents whose key in range of
1946 * [min_key, max_key)
1947 */
1948 static int invalidate_extent_cache(struct btrfs_root *root,
1949 struct btrfs_key *min_key,
1950 struct btrfs_key *max_key)
1951 {
1952 struct inode *inode = NULL;
1953 u64 objectid;
1954 u64 start, end;
1955 u64 ino;
1956
1957 objectid = min_key->objectid;
1958 while (1) {
1959 cond_resched();
1960 iput(inode);
1961
1962 if (objectid > max_key->objectid)
1963 break;
1964
1965 inode = find_next_inode(root, objectid);
1966 if (!inode)
1967 break;
1968 ino = btrfs_ino(inode);
1969
1970 if (ino > max_key->objectid) {
1971 iput(inode);
1972 break;
1973 }
1974
1975 objectid = ino + 1;
1976 if (!S_ISREG(inode->i_mode))
1977 continue;
1978
1979 if (unlikely(min_key->objectid == ino)) {
1980 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1981 continue;
1982 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1983 start = 0;
1984 else {
1985 start = min_key->offset;
1986 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1987 }
1988 } else {
1989 start = 0;
1990 }
1991
1992 if (unlikely(max_key->objectid == ino)) {
1993 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1994 continue;
1995 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
1996 end = (u64)-1;
1997 } else {
1998 if (max_key->offset == 0)
1999 continue;
2000 end = max_key->offset;
2001 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2002 end--;
2003 }
2004 } else {
2005 end = (u64)-1;
2006 }
2007
2008 /* the lock_extent waits for readpage to complete */
2009 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2010 btrfs_drop_extent_cache(inode, start, end, 1);
2011 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2012 }
2013 return 0;
2014 }
2015
2016 static int find_next_key(struct btrfs_path *path, int level,
2017 struct btrfs_key *key)
2018
2019 {
2020 while (level < BTRFS_MAX_LEVEL) {
2021 if (!path->nodes[level])
2022 break;
2023 if (path->slots[level] + 1 <
2024 btrfs_header_nritems(path->nodes[level])) {
2025 btrfs_node_key_to_cpu(path->nodes[level], key,
2026 path->slots[level] + 1);
2027 return 0;
2028 }
2029 level++;
2030 }
2031 return 1;
2032 }
2033
2034 /*
2035 * merge the relocated tree blocks in reloc tree with corresponding
2036 * fs tree.
2037 */
2038 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2039 struct btrfs_root *root)
2040 {
2041 LIST_HEAD(inode_list);
2042 struct btrfs_key key;
2043 struct btrfs_key next_key;
2044 struct btrfs_trans_handle *trans;
2045 struct btrfs_root *reloc_root;
2046 struct btrfs_root_item *root_item;
2047 struct btrfs_path *path;
2048 struct extent_buffer *leaf;
2049 int level;
2050 int max_level;
2051 int replaced = 0;
2052 int ret;
2053 int err = 0;
2054 u32 min_reserved;
2055
2056 path = btrfs_alloc_path();
2057 if (!path)
2058 return -ENOMEM;
2059 path->reada = 1;
2060
2061 reloc_root = root->reloc_root;
2062 root_item = &reloc_root->root_item;
2063
2064 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2065 level = btrfs_root_level(root_item);
2066 extent_buffer_get(reloc_root->node);
2067 path->nodes[level] = reloc_root->node;
2068 path->slots[level] = 0;
2069 } else {
2070 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2071
2072 level = root_item->drop_level;
2073 BUG_ON(level == 0);
2074 path->lowest_level = level;
2075 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2076 path->lowest_level = 0;
2077 if (ret < 0) {
2078 btrfs_free_path(path);
2079 return ret;
2080 }
2081
2082 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2083 path->slots[level]);
2084 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2085
2086 btrfs_unlock_up_safe(path, 0);
2087 }
2088
2089 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2090 memset(&next_key, 0, sizeof(next_key));
2091
2092 while (1) {
2093 trans = btrfs_start_transaction(root, 0);
2094 BUG_ON(IS_ERR(trans));
2095 trans->block_rsv = rc->block_rsv;
2096
2097 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2098 BTRFS_RESERVE_FLUSH_ALL);
2099 if (ret) {
2100 BUG_ON(ret != -EAGAIN);
2101 ret = btrfs_commit_transaction(trans, root);
2102 BUG_ON(ret);
2103 continue;
2104 }
2105
2106 replaced = 0;
2107 max_level = level;
2108
2109 ret = walk_down_reloc_tree(reloc_root, path, &level);
2110 if (ret < 0) {
2111 err = ret;
2112 goto out;
2113 }
2114 if (ret > 0)
2115 break;
2116
2117 if (!find_next_key(path, level, &key) &&
2118 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2119 ret = 0;
2120 } else {
2121 ret = replace_path(trans, root, reloc_root, path,
2122 &next_key, level, max_level);
2123 }
2124 if (ret < 0) {
2125 err = ret;
2126 goto out;
2127 }
2128
2129 if (ret > 0) {
2130 level = ret;
2131 btrfs_node_key_to_cpu(path->nodes[level], &key,
2132 path->slots[level]);
2133 replaced = 1;
2134 }
2135
2136 ret = walk_up_reloc_tree(reloc_root, path, &level);
2137 if (ret > 0)
2138 break;
2139
2140 BUG_ON(level == 0);
2141 /*
2142 * save the merging progress in the drop_progress.
2143 * this is OK since root refs == 1 in this case.
2144 */
2145 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2146 path->slots[level]);
2147 root_item->drop_level = level;
2148
2149 btrfs_end_transaction_throttle(trans, root);
2150
2151 btrfs_btree_balance_dirty(root);
2152
2153 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2154 invalidate_extent_cache(root, &key, &next_key);
2155 }
2156
2157 /*
2158 * handle the case only one block in the fs tree need to be
2159 * relocated and the block is tree root.
2160 */
2161 leaf = btrfs_lock_root_node(root);
2162 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2163 btrfs_tree_unlock(leaf);
2164 free_extent_buffer(leaf);
2165 if (ret < 0)
2166 err = ret;
2167 out:
2168 btrfs_free_path(path);
2169
2170 if (err == 0) {
2171 memset(&root_item->drop_progress, 0,
2172 sizeof(root_item->drop_progress));
2173 root_item->drop_level = 0;
2174 btrfs_set_root_refs(root_item, 0);
2175 btrfs_update_reloc_root(trans, root);
2176 }
2177
2178 btrfs_end_transaction_throttle(trans, root);
2179
2180 btrfs_btree_balance_dirty(root);
2181
2182 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2183 invalidate_extent_cache(root, &key, &next_key);
2184
2185 return err;
2186 }
2187
2188 static noinline_for_stack
2189 int prepare_to_merge(struct reloc_control *rc, int err)
2190 {
2191 struct btrfs_root *root = rc->extent_root;
2192 struct btrfs_root *reloc_root;
2193 struct btrfs_trans_handle *trans;
2194 LIST_HEAD(reloc_roots);
2195 u64 num_bytes = 0;
2196 int ret;
2197
2198 mutex_lock(&root->fs_info->reloc_mutex);
2199 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2200 rc->merging_rsv_size += rc->nodes_relocated * 2;
2201 mutex_unlock(&root->fs_info->reloc_mutex);
2202
2203 again:
2204 if (!err) {
2205 num_bytes = rc->merging_rsv_size;
2206 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2207 BTRFS_RESERVE_FLUSH_ALL);
2208 if (ret)
2209 err = ret;
2210 }
2211
2212 trans = btrfs_join_transaction(rc->extent_root);
2213 if (IS_ERR(trans)) {
2214 if (!err)
2215 btrfs_block_rsv_release(rc->extent_root,
2216 rc->block_rsv, num_bytes);
2217 return PTR_ERR(trans);
2218 }
2219
2220 if (!err) {
2221 if (num_bytes != rc->merging_rsv_size) {
2222 btrfs_end_transaction(trans, rc->extent_root);
2223 btrfs_block_rsv_release(rc->extent_root,
2224 rc->block_rsv, num_bytes);
2225 goto again;
2226 }
2227 }
2228
2229 rc->merge_reloc_tree = 1;
2230
2231 while (!list_empty(&rc->reloc_roots)) {
2232 reloc_root = list_entry(rc->reloc_roots.next,
2233 struct btrfs_root, root_list);
2234 list_del_init(&reloc_root->root_list);
2235
2236 root = read_fs_root(reloc_root->fs_info,
2237 reloc_root->root_key.offset);
2238 BUG_ON(IS_ERR(root));
2239 BUG_ON(root->reloc_root != reloc_root);
2240
2241 /*
2242 * set reference count to 1, so btrfs_recover_relocation
2243 * knows it should resumes merging
2244 */
2245 if (!err)
2246 btrfs_set_root_refs(&reloc_root->root_item, 1);
2247 btrfs_update_reloc_root(trans, root);
2248
2249 list_add(&reloc_root->root_list, &reloc_roots);
2250 }
2251
2252 list_splice(&reloc_roots, &rc->reloc_roots);
2253
2254 if (!err)
2255 btrfs_commit_transaction(trans, rc->extent_root);
2256 else
2257 btrfs_end_transaction(trans, rc->extent_root);
2258 return err;
2259 }
2260
2261 static noinline_for_stack
2262 void free_reloc_roots(struct list_head *list)
2263 {
2264 struct btrfs_root *reloc_root;
2265
2266 while (!list_empty(list)) {
2267 reloc_root = list_entry(list->next, struct btrfs_root,
2268 root_list);
2269 __update_reloc_root(reloc_root, 1);
2270 free_extent_buffer(reloc_root->node);
2271 free_extent_buffer(reloc_root->commit_root);
2272 kfree(reloc_root);
2273 }
2274 }
2275
2276 static noinline_for_stack
2277 int merge_reloc_roots(struct reloc_control *rc)
2278 {
2279 struct btrfs_root *root;
2280 struct btrfs_root *reloc_root;
2281 LIST_HEAD(reloc_roots);
2282 int found = 0;
2283 int ret = 0;
2284 again:
2285 root = rc->extent_root;
2286
2287 /*
2288 * this serializes us with btrfs_record_root_in_transaction,
2289 * we have to make sure nobody is in the middle of
2290 * adding their roots to the list while we are
2291 * doing this splice
2292 */
2293 mutex_lock(&root->fs_info->reloc_mutex);
2294 list_splice_init(&rc->reloc_roots, &reloc_roots);
2295 mutex_unlock(&root->fs_info->reloc_mutex);
2296
2297 while (!list_empty(&reloc_roots)) {
2298 found = 1;
2299 reloc_root = list_entry(reloc_roots.next,
2300 struct btrfs_root, root_list);
2301
2302 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2303 root = read_fs_root(reloc_root->fs_info,
2304 reloc_root->root_key.offset);
2305 BUG_ON(IS_ERR(root));
2306 BUG_ON(root->reloc_root != reloc_root);
2307
2308 ret = merge_reloc_root(rc, root);
2309 if (ret)
2310 goto out;
2311 } else {
2312 list_del_init(&reloc_root->root_list);
2313 }
2314 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2315 if (ret < 0) {
2316 if (list_empty(&reloc_root->root_list))
2317 list_add_tail(&reloc_root->root_list,
2318 &reloc_roots);
2319 goto out;
2320 }
2321 }
2322
2323 if (found) {
2324 found = 0;
2325 goto again;
2326 }
2327 out:
2328 if (ret) {
2329 btrfs_std_error(root->fs_info, ret);
2330 if (!list_empty(&reloc_roots))
2331 free_reloc_roots(&reloc_roots);
2332 }
2333
2334 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2335 return ret;
2336 }
2337
2338 static void free_block_list(struct rb_root *blocks)
2339 {
2340 struct tree_block *block;
2341 struct rb_node *rb_node;
2342 while ((rb_node = rb_first(blocks))) {
2343 block = rb_entry(rb_node, struct tree_block, rb_node);
2344 rb_erase(rb_node, blocks);
2345 kfree(block);
2346 }
2347 }
2348
2349 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2350 struct btrfs_root *reloc_root)
2351 {
2352 struct btrfs_root *root;
2353
2354 if (reloc_root->last_trans == trans->transid)
2355 return 0;
2356
2357 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2358 BUG_ON(IS_ERR(root));
2359 BUG_ON(root->reloc_root != reloc_root);
2360
2361 return btrfs_record_root_in_trans(trans, root);
2362 }
2363
2364 static noinline_for_stack
2365 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2366 struct reloc_control *rc,
2367 struct backref_node *node,
2368 struct backref_edge *edges[], int *nr)
2369 {
2370 struct backref_node *next;
2371 struct btrfs_root *root;
2372 int index = 0;
2373
2374 next = node;
2375 while (1) {
2376 cond_resched();
2377 next = walk_up_backref(next, edges, &index);
2378 root = next->root;
2379 BUG_ON(!root);
2380 BUG_ON(!root->ref_cows);
2381
2382 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2383 record_reloc_root_in_trans(trans, root);
2384 break;
2385 }
2386
2387 btrfs_record_root_in_trans(trans, root);
2388 root = root->reloc_root;
2389
2390 if (next->new_bytenr != root->node->start) {
2391 BUG_ON(next->new_bytenr);
2392 BUG_ON(!list_empty(&next->list));
2393 next->new_bytenr = root->node->start;
2394 next->root = root;
2395 list_add_tail(&next->list,
2396 &rc->backref_cache.changed);
2397 __mark_block_processed(rc, next);
2398 break;
2399 }
2400
2401 WARN_ON(1);
2402 root = NULL;
2403 next = walk_down_backref(edges, &index);
2404 if (!next || next->level <= node->level)
2405 break;
2406 }
2407 if (!root)
2408 return NULL;
2409
2410 *nr = index;
2411 next = node;
2412 /* setup backref node path for btrfs_reloc_cow_block */
2413 while (1) {
2414 rc->backref_cache.path[next->level] = next;
2415 if (--index < 0)
2416 break;
2417 next = edges[index]->node[UPPER];
2418 }
2419 return root;
2420 }
2421
2422 /*
2423 * select a tree root for relocation. return NULL if the block
2424 * is reference counted. we should use do_relocation() in this
2425 * case. return a tree root pointer if the block isn't reference
2426 * counted. return -ENOENT if the block is root of reloc tree.
2427 */
2428 static noinline_for_stack
2429 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2430 struct backref_node *node)
2431 {
2432 struct backref_node *next;
2433 struct btrfs_root *root;
2434 struct btrfs_root *fs_root = NULL;
2435 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2436 int index = 0;
2437
2438 next = node;
2439 while (1) {
2440 cond_resched();
2441 next = walk_up_backref(next, edges, &index);
2442 root = next->root;
2443 BUG_ON(!root);
2444
2445 /* no other choice for non-references counted tree */
2446 if (!root->ref_cows)
2447 return root;
2448
2449 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2450 fs_root = root;
2451
2452 if (next != node)
2453 return NULL;
2454
2455 next = walk_down_backref(edges, &index);
2456 if (!next || next->level <= node->level)
2457 break;
2458 }
2459
2460 if (!fs_root)
2461 return ERR_PTR(-ENOENT);
2462 return fs_root;
2463 }
2464
2465 static noinline_for_stack
2466 u64 calcu_metadata_size(struct reloc_control *rc,
2467 struct backref_node *node, int reserve)
2468 {
2469 struct backref_node *next = node;
2470 struct backref_edge *edge;
2471 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2472 u64 num_bytes = 0;
2473 int index = 0;
2474
2475 BUG_ON(reserve && node->processed);
2476
2477 while (next) {
2478 cond_resched();
2479 while (1) {
2480 if (next->processed && (reserve || next != node))
2481 break;
2482
2483 num_bytes += btrfs_level_size(rc->extent_root,
2484 next->level);
2485
2486 if (list_empty(&next->upper))
2487 break;
2488
2489 edge = list_entry(next->upper.next,
2490 struct backref_edge, list[LOWER]);
2491 edges[index++] = edge;
2492 next = edge->node[UPPER];
2493 }
2494 next = walk_down_backref(edges, &index);
2495 }
2496 return num_bytes;
2497 }
2498
2499 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2500 struct reloc_control *rc,
2501 struct backref_node *node)
2502 {
2503 struct btrfs_root *root = rc->extent_root;
2504 u64 num_bytes;
2505 int ret;
2506
2507 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2508
2509 trans->block_rsv = rc->block_rsv;
2510 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2511 BTRFS_RESERVE_FLUSH_ALL);
2512 if (ret) {
2513 if (ret == -EAGAIN)
2514 rc->commit_transaction = 1;
2515 return ret;
2516 }
2517
2518 return 0;
2519 }
2520
2521 static void release_metadata_space(struct reloc_control *rc,
2522 struct backref_node *node)
2523 {
2524 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2525 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2526 }
2527
2528 /*
2529 * relocate a block tree, and then update pointers in upper level
2530 * blocks that reference the block to point to the new location.
2531 *
2532 * if called by link_to_upper, the block has already been relocated.
2533 * in that case this function just updates pointers.
2534 */
2535 static int do_relocation(struct btrfs_trans_handle *trans,
2536 struct reloc_control *rc,
2537 struct backref_node *node,
2538 struct btrfs_key *key,
2539 struct btrfs_path *path, int lowest)
2540 {
2541 struct backref_node *upper;
2542 struct backref_edge *edge;
2543 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2544 struct btrfs_root *root;
2545 struct extent_buffer *eb;
2546 u32 blocksize;
2547 u64 bytenr;
2548 u64 generation;
2549 int nr;
2550 int slot;
2551 int ret;
2552 int err = 0;
2553
2554 BUG_ON(lowest && node->eb);
2555
2556 path->lowest_level = node->level + 1;
2557 rc->backref_cache.path[node->level] = node;
2558 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2559 cond_resched();
2560
2561 upper = edge->node[UPPER];
2562 root = select_reloc_root(trans, rc, upper, edges, &nr);
2563 BUG_ON(!root);
2564
2565 if (upper->eb && !upper->locked) {
2566 if (!lowest) {
2567 ret = btrfs_bin_search(upper->eb, key,
2568 upper->level, &slot);
2569 BUG_ON(ret);
2570 bytenr = btrfs_node_blockptr(upper->eb, slot);
2571 if (node->eb->start == bytenr)
2572 goto next;
2573 }
2574 drop_node_buffer(upper);
2575 }
2576
2577 if (!upper->eb) {
2578 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2579 if (ret < 0) {
2580 err = ret;
2581 break;
2582 }
2583 BUG_ON(ret > 0);
2584
2585 if (!upper->eb) {
2586 upper->eb = path->nodes[upper->level];
2587 path->nodes[upper->level] = NULL;
2588 } else {
2589 BUG_ON(upper->eb != path->nodes[upper->level]);
2590 }
2591
2592 upper->locked = 1;
2593 path->locks[upper->level] = 0;
2594
2595 slot = path->slots[upper->level];
2596 btrfs_release_path(path);
2597 } else {
2598 ret = btrfs_bin_search(upper->eb, key, upper->level,
2599 &slot);
2600 BUG_ON(ret);
2601 }
2602
2603 bytenr = btrfs_node_blockptr(upper->eb, slot);
2604 if (lowest) {
2605 BUG_ON(bytenr != node->bytenr);
2606 } else {
2607 if (node->eb->start == bytenr)
2608 goto next;
2609 }
2610
2611 blocksize = btrfs_level_size(root, node->level);
2612 generation = btrfs_node_ptr_generation(upper->eb, slot);
2613 eb = read_tree_block(root, bytenr, blocksize, generation);
2614 if (!eb || !extent_buffer_uptodate(eb)) {
2615 free_extent_buffer(eb);
2616 err = -EIO;
2617 goto next;
2618 }
2619 btrfs_tree_lock(eb);
2620 btrfs_set_lock_blocking(eb);
2621
2622 if (!node->eb) {
2623 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2624 slot, &eb);
2625 btrfs_tree_unlock(eb);
2626 free_extent_buffer(eb);
2627 if (ret < 0) {
2628 err = ret;
2629 goto next;
2630 }
2631 BUG_ON(node->eb != eb);
2632 } else {
2633 btrfs_set_node_blockptr(upper->eb, slot,
2634 node->eb->start);
2635 btrfs_set_node_ptr_generation(upper->eb, slot,
2636 trans->transid);
2637 btrfs_mark_buffer_dirty(upper->eb);
2638
2639 ret = btrfs_inc_extent_ref(trans, root,
2640 node->eb->start, blocksize,
2641 upper->eb->start,
2642 btrfs_header_owner(upper->eb),
2643 node->level, 0, 1);
2644 BUG_ON(ret);
2645
2646 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2647 BUG_ON(ret);
2648 }
2649 next:
2650 if (!upper->pending)
2651 drop_node_buffer(upper);
2652 else
2653 unlock_node_buffer(upper);
2654 if (err)
2655 break;
2656 }
2657
2658 if (!err && node->pending) {
2659 drop_node_buffer(node);
2660 list_move_tail(&node->list, &rc->backref_cache.changed);
2661 node->pending = 0;
2662 }
2663
2664 path->lowest_level = 0;
2665 BUG_ON(err == -ENOSPC);
2666 return err;
2667 }
2668
2669 static int link_to_upper(struct btrfs_trans_handle *trans,
2670 struct reloc_control *rc,
2671 struct backref_node *node,
2672 struct btrfs_path *path)
2673 {
2674 struct btrfs_key key;
2675
2676 btrfs_node_key_to_cpu(node->eb, &key, 0);
2677 return do_relocation(trans, rc, node, &key, path, 0);
2678 }
2679
2680 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2681 struct reloc_control *rc,
2682 struct btrfs_path *path, int err)
2683 {
2684 LIST_HEAD(list);
2685 struct backref_cache *cache = &rc->backref_cache;
2686 struct backref_node *node;
2687 int level;
2688 int ret;
2689
2690 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2691 while (!list_empty(&cache->pending[level])) {
2692 node = list_entry(cache->pending[level].next,
2693 struct backref_node, list);
2694 list_move_tail(&node->list, &list);
2695 BUG_ON(!node->pending);
2696
2697 if (!err) {
2698 ret = link_to_upper(trans, rc, node, path);
2699 if (ret < 0)
2700 err = ret;
2701 }
2702 }
2703 list_splice_init(&list, &cache->pending[level]);
2704 }
2705 return err;
2706 }
2707
2708 static void mark_block_processed(struct reloc_control *rc,
2709 u64 bytenr, u32 blocksize)
2710 {
2711 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2712 EXTENT_DIRTY, GFP_NOFS);
2713 }
2714
2715 static void __mark_block_processed(struct reloc_control *rc,
2716 struct backref_node *node)
2717 {
2718 u32 blocksize;
2719 if (node->level == 0 ||
2720 in_block_group(node->bytenr, rc->block_group)) {
2721 blocksize = btrfs_level_size(rc->extent_root, node->level);
2722 mark_block_processed(rc, node->bytenr, blocksize);
2723 }
2724 node->processed = 1;
2725 }
2726
2727 /*
2728 * mark a block and all blocks directly/indirectly reference the block
2729 * as processed.
2730 */
2731 static void update_processed_blocks(struct reloc_control *rc,
2732 struct backref_node *node)
2733 {
2734 struct backref_node *next = node;
2735 struct backref_edge *edge;
2736 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2737 int index = 0;
2738
2739 while (next) {
2740 cond_resched();
2741 while (1) {
2742 if (next->processed)
2743 break;
2744
2745 __mark_block_processed(rc, next);
2746
2747 if (list_empty(&next->upper))
2748 break;
2749
2750 edge = list_entry(next->upper.next,
2751 struct backref_edge, list[LOWER]);
2752 edges[index++] = edge;
2753 next = edge->node[UPPER];
2754 }
2755 next = walk_down_backref(edges, &index);
2756 }
2757 }
2758
2759 static int tree_block_processed(u64 bytenr, u32 blocksize,
2760 struct reloc_control *rc)
2761 {
2762 if (test_range_bit(&rc->processed_blocks, bytenr,
2763 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2764 return 1;
2765 return 0;
2766 }
2767
2768 static int get_tree_block_key(struct reloc_control *rc,
2769 struct tree_block *block)
2770 {
2771 struct extent_buffer *eb;
2772
2773 BUG_ON(block->key_ready);
2774 eb = read_tree_block(rc->extent_root, block->bytenr,
2775 block->key.objectid, block->key.offset);
2776 if (!eb || !extent_buffer_uptodate(eb)) {
2777 free_extent_buffer(eb);
2778 return -EIO;
2779 }
2780 WARN_ON(btrfs_header_level(eb) != block->level);
2781 if (block->level == 0)
2782 btrfs_item_key_to_cpu(eb, &block->key, 0);
2783 else
2784 btrfs_node_key_to_cpu(eb, &block->key, 0);
2785 free_extent_buffer(eb);
2786 block->key_ready = 1;
2787 return 0;
2788 }
2789
2790 static int reada_tree_block(struct reloc_control *rc,
2791 struct tree_block *block)
2792 {
2793 BUG_ON(block->key_ready);
2794 if (block->key.type == BTRFS_METADATA_ITEM_KEY)
2795 readahead_tree_block(rc->extent_root, block->bytenr,
2796 block->key.objectid,
2797 rc->extent_root->leafsize);
2798 else
2799 readahead_tree_block(rc->extent_root, block->bytenr,
2800 block->key.objectid, block->key.offset);
2801 return 0;
2802 }
2803
2804 /*
2805 * helper function to relocate a tree block
2806 */
2807 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2808 struct reloc_control *rc,
2809 struct backref_node *node,
2810 struct btrfs_key *key,
2811 struct btrfs_path *path)
2812 {
2813 struct btrfs_root *root;
2814 int release = 0;
2815 int ret = 0;
2816
2817 if (!node)
2818 return 0;
2819
2820 BUG_ON(node->processed);
2821 root = select_one_root(trans, node);
2822 if (root == ERR_PTR(-ENOENT)) {
2823 update_processed_blocks(rc, node);
2824 goto out;
2825 }
2826
2827 if (!root || root->ref_cows) {
2828 ret = reserve_metadata_space(trans, rc, node);
2829 if (ret)
2830 goto out;
2831 release = 1;
2832 }
2833
2834 if (root) {
2835 if (root->ref_cows) {
2836 BUG_ON(node->new_bytenr);
2837 BUG_ON(!list_empty(&node->list));
2838 btrfs_record_root_in_trans(trans, root);
2839 root = root->reloc_root;
2840 node->new_bytenr = root->node->start;
2841 node->root = root;
2842 list_add_tail(&node->list, &rc->backref_cache.changed);
2843 } else {
2844 path->lowest_level = node->level;
2845 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2846 btrfs_release_path(path);
2847 if (ret > 0)
2848 ret = 0;
2849 }
2850 if (!ret)
2851 update_processed_blocks(rc, node);
2852 } else {
2853 ret = do_relocation(trans, rc, node, key, path, 1);
2854 }
2855 out:
2856 if (ret || node->level == 0 || node->cowonly) {
2857 if (release)
2858 release_metadata_space(rc, node);
2859 remove_backref_node(&rc->backref_cache, node);
2860 }
2861 return ret;
2862 }
2863
2864 /*
2865 * relocate a list of blocks
2866 */
2867 static noinline_for_stack
2868 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2869 struct reloc_control *rc, struct rb_root *blocks)
2870 {
2871 struct backref_node *node;
2872 struct btrfs_path *path;
2873 struct tree_block *block;
2874 struct rb_node *rb_node;
2875 int ret;
2876 int err = 0;
2877
2878 path = btrfs_alloc_path();
2879 if (!path) {
2880 err = -ENOMEM;
2881 goto out_free_blocks;
2882 }
2883
2884 rb_node = rb_first(blocks);
2885 while (rb_node) {
2886 block = rb_entry(rb_node, struct tree_block, rb_node);
2887 if (!block->key_ready)
2888 reada_tree_block(rc, block);
2889 rb_node = rb_next(rb_node);
2890 }
2891
2892 rb_node = rb_first(blocks);
2893 while (rb_node) {
2894 block = rb_entry(rb_node, struct tree_block, rb_node);
2895 if (!block->key_ready) {
2896 err = get_tree_block_key(rc, block);
2897 if (err)
2898 goto out_free_path;
2899 }
2900 rb_node = rb_next(rb_node);
2901 }
2902
2903 rb_node = rb_first(blocks);
2904 while (rb_node) {
2905 block = rb_entry(rb_node, struct tree_block, rb_node);
2906
2907 node = build_backref_tree(rc, &block->key,
2908 block->level, block->bytenr);
2909 if (IS_ERR(node)) {
2910 err = PTR_ERR(node);
2911 goto out;
2912 }
2913
2914 ret = relocate_tree_block(trans, rc, node, &block->key,
2915 path);
2916 if (ret < 0) {
2917 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2918 err = ret;
2919 goto out;
2920 }
2921 rb_node = rb_next(rb_node);
2922 }
2923 out:
2924 err = finish_pending_nodes(trans, rc, path, err);
2925
2926 out_free_path:
2927 btrfs_free_path(path);
2928 out_free_blocks:
2929 free_block_list(blocks);
2930 return err;
2931 }
2932
2933 static noinline_for_stack
2934 int prealloc_file_extent_cluster(struct inode *inode,
2935 struct file_extent_cluster *cluster)
2936 {
2937 u64 alloc_hint = 0;
2938 u64 start;
2939 u64 end;
2940 u64 offset = BTRFS_I(inode)->index_cnt;
2941 u64 num_bytes;
2942 int nr = 0;
2943 int ret = 0;
2944
2945 BUG_ON(cluster->start != cluster->boundary[0]);
2946 mutex_lock(&inode->i_mutex);
2947
2948 ret = btrfs_check_data_free_space(inode, cluster->end +
2949 1 - cluster->start);
2950 if (ret)
2951 goto out;
2952
2953 while (nr < cluster->nr) {
2954 start = cluster->boundary[nr] - offset;
2955 if (nr + 1 < cluster->nr)
2956 end = cluster->boundary[nr + 1] - 1 - offset;
2957 else
2958 end = cluster->end - offset;
2959
2960 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2961 num_bytes = end + 1 - start;
2962 ret = btrfs_prealloc_file_range(inode, 0, start,
2963 num_bytes, num_bytes,
2964 end + 1, &alloc_hint);
2965 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2966 if (ret)
2967 break;
2968 nr++;
2969 }
2970 btrfs_free_reserved_data_space(inode, cluster->end +
2971 1 - cluster->start);
2972 out:
2973 mutex_unlock(&inode->i_mutex);
2974 return ret;
2975 }
2976
2977 static noinline_for_stack
2978 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
2979 u64 block_start)
2980 {
2981 struct btrfs_root *root = BTRFS_I(inode)->root;
2982 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2983 struct extent_map *em;
2984 int ret = 0;
2985
2986 em = alloc_extent_map();
2987 if (!em)
2988 return -ENOMEM;
2989
2990 em->start = start;
2991 em->len = end + 1 - start;
2992 em->block_len = em->len;
2993 em->block_start = block_start;
2994 em->bdev = root->fs_info->fs_devices->latest_bdev;
2995 set_bit(EXTENT_FLAG_PINNED, &em->flags);
2996
2997 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2998 while (1) {
2999 write_lock(&em_tree->lock);
3000 ret = add_extent_mapping(em_tree, em, 0);
3001 write_unlock(&em_tree->lock);
3002 if (ret != -EEXIST) {
3003 free_extent_map(em);
3004 break;
3005 }
3006 btrfs_drop_extent_cache(inode, start, end, 0);
3007 }
3008 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3009 return ret;
3010 }
3011
3012 static int relocate_file_extent_cluster(struct inode *inode,
3013 struct file_extent_cluster *cluster)
3014 {
3015 u64 page_start;
3016 u64 page_end;
3017 u64 offset = BTRFS_I(inode)->index_cnt;
3018 unsigned long index;
3019 unsigned long last_index;
3020 struct page *page;
3021 struct file_ra_state *ra;
3022 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3023 int nr = 0;
3024 int ret = 0;
3025
3026 if (!cluster->nr)
3027 return 0;
3028
3029 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3030 if (!ra)
3031 return -ENOMEM;
3032
3033 ret = prealloc_file_extent_cluster(inode, cluster);
3034 if (ret)
3035 goto out;
3036
3037 file_ra_state_init(ra, inode->i_mapping);
3038
3039 ret = setup_extent_mapping(inode, cluster->start - offset,
3040 cluster->end - offset, cluster->start);
3041 if (ret)
3042 goto out;
3043
3044 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3045 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3046 while (index <= last_index) {
3047 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3048 if (ret)
3049 goto out;
3050
3051 page = find_lock_page(inode->i_mapping, index);
3052 if (!page) {
3053 page_cache_sync_readahead(inode->i_mapping,
3054 ra, NULL, index,
3055 last_index + 1 - index);
3056 page = find_or_create_page(inode->i_mapping, index,
3057 mask);
3058 if (!page) {
3059 btrfs_delalloc_release_metadata(inode,
3060 PAGE_CACHE_SIZE);
3061 ret = -ENOMEM;
3062 goto out;
3063 }
3064 }
3065
3066 if (PageReadahead(page)) {
3067 page_cache_async_readahead(inode->i_mapping,
3068 ra, NULL, page, index,
3069 last_index + 1 - index);
3070 }
3071
3072 if (!PageUptodate(page)) {
3073 btrfs_readpage(NULL, page);
3074 lock_page(page);
3075 if (!PageUptodate(page)) {
3076 unlock_page(page);
3077 page_cache_release(page);
3078 btrfs_delalloc_release_metadata(inode,
3079 PAGE_CACHE_SIZE);
3080 ret = -EIO;
3081 goto out;
3082 }
3083 }
3084
3085 page_start = page_offset(page);
3086 page_end = page_start + PAGE_CACHE_SIZE - 1;
3087
3088 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3089
3090 set_page_extent_mapped(page);
3091
3092 if (nr < cluster->nr &&
3093 page_start + offset == cluster->boundary[nr]) {
3094 set_extent_bits(&BTRFS_I(inode)->io_tree,
3095 page_start, page_end,
3096 EXTENT_BOUNDARY, GFP_NOFS);
3097 nr++;
3098 }
3099
3100 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3101 set_page_dirty(page);
3102
3103 unlock_extent(&BTRFS_I(inode)->io_tree,
3104 page_start, page_end);
3105 unlock_page(page);
3106 page_cache_release(page);
3107
3108 index++;
3109 balance_dirty_pages_ratelimited(inode->i_mapping);
3110 btrfs_throttle(BTRFS_I(inode)->root);
3111 }
3112 WARN_ON(nr != cluster->nr);
3113 out:
3114 kfree(ra);
3115 return ret;
3116 }
3117
3118 static noinline_for_stack
3119 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3120 struct file_extent_cluster *cluster)
3121 {
3122 int ret;
3123
3124 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3125 ret = relocate_file_extent_cluster(inode, cluster);
3126 if (ret)
3127 return ret;
3128 cluster->nr = 0;
3129 }
3130
3131 if (!cluster->nr)
3132 cluster->start = extent_key->objectid;
3133 else
3134 BUG_ON(cluster->nr >= MAX_EXTENTS);
3135 cluster->end = extent_key->objectid + extent_key->offset - 1;
3136 cluster->boundary[cluster->nr] = extent_key->objectid;
3137 cluster->nr++;
3138
3139 if (cluster->nr >= MAX_EXTENTS) {
3140 ret = relocate_file_extent_cluster(inode, cluster);
3141 if (ret)
3142 return ret;
3143 cluster->nr = 0;
3144 }
3145 return 0;
3146 }
3147
3148 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3149 static int get_ref_objectid_v0(struct reloc_control *rc,
3150 struct btrfs_path *path,
3151 struct btrfs_key *extent_key,
3152 u64 *ref_objectid, int *path_change)
3153 {
3154 struct btrfs_key key;
3155 struct extent_buffer *leaf;
3156 struct btrfs_extent_ref_v0 *ref0;
3157 int ret;
3158 int slot;
3159
3160 leaf = path->nodes[0];
3161 slot = path->slots[0];
3162 while (1) {
3163 if (slot >= btrfs_header_nritems(leaf)) {
3164 ret = btrfs_next_leaf(rc->extent_root, path);
3165 if (ret < 0)
3166 return ret;
3167 BUG_ON(ret > 0);
3168 leaf = path->nodes[0];
3169 slot = path->slots[0];
3170 if (path_change)
3171 *path_change = 1;
3172 }
3173 btrfs_item_key_to_cpu(leaf, &key, slot);
3174 if (key.objectid != extent_key->objectid)
3175 return -ENOENT;
3176
3177 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3178 slot++;
3179 continue;
3180 }
3181 ref0 = btrfs_item_ptr(leaf, slot,
3182 struct btrfs_extent_ref_v0);
3183 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3184 break;
3185 }
3186 return 0;
3187 }
3188 #endif
3189
3190 /*
3191 * helper to add a tree block to the list.
3192 * the major work is getting the generation and level of the block
3193 */
3194 static int add_tree_block(struct reloc_control *rc,
3195 struct btrfs_key *extent_key,
3196 struct btrfs_path *path,
3197 struct rb_root *blocks)
3198 {
3199 struct extent_buffer *eb;
3200 struct btrfs_extent_item *ei;
3201 struct btrfs_tree_block_info *bi;
3202 struct tree_block *block;
3203 struct rb_node *rb_node;
3204 u32 item_size;
3205 int level = -1;
3206 int generation;
3207
3208 eb = path->nodes[0];
3209 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3210
3211 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3212 item_size >= sizeof(*ei) + sizeof(*bi)) {
3213 ei = btrfs_item_ptr(eb, path->slots[0],
3214 struct btrfs_extent_item);
3215 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3216 bi = (struct btrfs_tree_block_info *)(ei + 1);
3217 level = btrfs_tree_block_level(eb, bi);
3218 } else {
3219 level = (int)extent_key->offset;
3220 }
3221 generation = btrfs_extent_generation(eb, ei);
3222 } else {
3223 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3224 u64 ref_owner;
3225 int ret;
3226
3227 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3228 ret = get_ref_objectid_v0(rc, path, extent_key,
3229 &ref_owner, NULL);
3230 if (ret < 0)
3231 return ret;
3232 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3233 level = (int)ref_owner;
3234 /* FIXME: get real generation */
3235 generation = 0;
3236 #else
3237 BUG();
3238 #endif
3239 }
3240
3241 btrfs_release_path(path);
3242
3243 BUG_ON(level == -1);
3244
3245 block = kmalloc(sizeof(*block), GFP_NOFS);
3246 if (!block)
3247 return -ENOMEM;
3248
3249 block->bytenr = extent_key->objectid;
3250 block->key.objectid = rc->extent_root->leafsize;
3251 block->key.offset = generation;
3252 block->level = level;
3253 block->key_ready = 0;
3254
3255 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3256 if (rb_node)
3257 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3258
3259 return 0;
3260 }
3261
3262 /*
3263 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3264 */
3265 static int __add_tree_block(struct reloc_control *rc,
3266 u64 bytenr, u32 blocksize,
3267 struct rb_root *blocks)
3268 {
3269 struct btrfs_path *path;
3270 struct btrfs_key key;
3271 int ret;
3272
3273 if (tree_block_processed(bytenr, blocksize, rc))
3274 return 0;
3275
3276 if (tree_search(blocks, bytenr))
3277 return 0;
3278
3279 path = btrfs_alloc_path();
3280 if (!path)
3281 return -ENOMEM;
3282
3283 key.objectid = bytenr;
3284 key.type = BTRFS_EXTENT_ITEM_KEY;
3285 key.offset = blocksize;
3286
3287 path->search_commit_root = 1;
3288 path->skip_locking = 1;
3289 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3290 if (ret < 0)
3291 goto out;
3292
3293 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3294 if (ret > 0) {
3295 if (key.objectid == bytenr &&
3296 key.type == BTRFS_METADATA_ITEM_KEY)
3297 ret = 0;
3298 }
3299 BUG_ON(ret);
3300
3301 ret = add_tree_block(rc, &key, path, blocks);
3302 out:
3303 btrfs_free_path(path);
3304 return ret;
3305 }
3306
3307 /*
3308 * helper to check if the block use full backrefs for pointers in it
3309 */
3310 static int block_use_full_backref(struct reloc_control *rc,
3311 struct extent_buffer *eb)
3312 {
3313 u64 flags;
3314 int ret;
3315
3316 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3317 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3318 return 1;
3319
3320 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3321 eb->start, btrfs_header_level(eb), 1,
3322 NULL, &flags);
3323 BUG_ON(ret);
3324
3325 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3326 ret = 1;
3327 else
3328 ret = 0;
3329 return ret;
3330 }
3331
3332 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3333 struct inode *inode, u64 ino)
3334 {
3335 struct btrfs_key key;
3336 struct btrfs_path *path;
3337 struct btrfs_root *root = fs_info->tree_root;
3338 struct btrfs_trans_handle *trans;
3339 int ret = 0;
3340
3341 if (inode)
3342 goto truncate;
3343
3344 key.objectid = ino;
3345 key.type = BTRFS_INODE_ITEM_KEY;
3346 key.offset = 0;
3347
3348 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3349 if (IS_ERR(inode) || is_bad_inode(inode)) {
3350 if (!IS_ERR(inode))
3351 iput(inode);
3352 return -ENOENT;
3353 }
3354
3355 truncate:
3356 ret = btrfs_check_trunc_cache_free_space(root,
3357 &fs_info->global_block_rsv);
3358 if (ret)
3359 goto out;
3360
3361 path = btrfs_alloc_path();
3362 if (!path) {
3363 ret = -ENOMEM;
3364 goto out;
3365 }
3366
3367 trans = btrfs_join_transaction(root);
3368 if (IS_ERR(trans)) {
3369 btrfs_free_path(path);
3370 ret = PTR_ERR(trans);
3371 goto out;
3372 }
3373
3374 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3375
3376 btrfs_free_path(path);
3377 btrfs_end_transaction(trans, root);
3378 btrfs_btree_balance_dirty(root);
3379 out:
3380 iput(inode);
3381 return ret;
3382 }
3383
3384 /*
3385 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3386 * this function scans fs tree to find blocks reference the data extent
3387 */
3388 static int find_data_references(struct reloc_control *rc,
3389 struct btrfs_key *extent_key,
3390 struct extent_buffer *leaf,
3391 struct btrfs_extent_data_ref *ref,
3392 struct rb_root *blocks)
3393 {
3394 struct btrfs_path *path;
3395 struct tree_block *block;
3396 struct btrfs_root *root;
3397 struct btrfs_file_extent_item *fi;
3398 struct rb_node *rb_node;
3399 struct btrfs_key key;
3400 u64 ref_root;
3401 u64 ref_objectid;
3402 u64 ref_offset;
3403 u32 ref_count;
3404 u32 nritems;
3405 int err = 0;
3406 int added = 0;
3407 int counted;
3408 int ret;
3409
3410 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3411 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3412 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3413 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3414
3415 /*
3416 * This is an extent belonging to the free space cache, lets just delete
3417 * it and redo the search.
3418 */
3419 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3420 ret = delete_block_group_cache(rc->extent_root->fs_info,
3421 NULL, ref_objectid);
3422 if (ret != -ENOENT)
3423 return ret;
3424 ret = 0;
3425 }
3426
3427 path = btrfs_alloc_path();
3428 if (!path)
3429 return -ENOMEM;
3430 path->reada = 1;
3431
3432 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3433 if (IS_ERR(root)) {
3434 err = PTR_ERR(root);
3435 goto out;
3436 }
3437
3438 key.objectid = ref_objectid;
3439 key.type = BTRFS_EXTENT_DATA_KEY;
3440 if (ref_offset > ((u64)-1 << 32))
3441 key.offset = 0;
3442 else
3443 key.offset = ref_offset;
3444
3445 path->search_commit_root = 1;
3446 path->skip_locking = 1;
3447 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3448 if (ret < 0) {
3449 err = ret;
3450 goto out;
3451 }
3452
3453 leaf = path->nodes[0];
3454 nritems = btrfs_header_nritems(leaf);
3455 /*
3456 * the references in tree blocks that use full backrefs
3457 * are not counted in
3458 */
3459 if (block_use_full_backref(rc, leaf))
3460 counted = 0;
3461 else
3462 counted = 1;
3463 rb_node = tree_search(blocks, leaf->start);
3464 if (rb_node) {
3465 if (counted)
3466 added = 1;
3467 else
3468 path->slots[0] = nritems;
3469 }
3470
3471 while (ref_count > 0) {
3472 while (path->slots[0] >= nritems) {
3473 ret = btrfs_next_leaf(root, path);
3474 if (ret < 0) {
3475 err = ret;
3476 goto out;
3477 }
3478 if (ret > 0) {
3479 WARN_ON(1);
3480 goto out;
3481 }
3482
3483 leaf = path->nodes[0];
3484 nritems = btrfs_header_nritems(leaf);
3485 added = 0;
3486
3487 if (block_use_full_backref(rc, leaf))
3488 counted = 0;
3489 else
3490 counted = 1;
3491 rb_node = tree_search(blocks, leaf->start);
3492 if (rb_node) {
3493 if (counted)
3494 added = 1;
3495 else
3496 path->slots[0] = nritems;
3497 }
3498 }
3499
3500 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3501 if (key.objectid != ref_objectid ||
3502 key.type != BTRFS_EXTENT_DATA_KEY) {
3503 WARN_ON(1);
3504 break;
3505 }
3506
3507 fi = btrfs_item_ptr(leaf, path->slots[0],
3508 struct btrfs_file_extent_item);
3509
3510 if (btrfs_file_extent_type(leaf, fi) ==
3511 BTRFS_FILE_EXTENT_INLINE)
3512 goto next;
3513
3514 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3515 extent_key->objectid)
3516 goto next;
3517
3518 key.offset -= btrfs_file_extent_offset(leaf, fi);
3519 if (key.offset != ref_offset)
3520 goto next;
3521
3522 if (counted)
3523 ref_count--;
3524 if (added)
3525 goto next;
3526
3527 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3528 block = kmalloc(sizeof(*block), GFP_NOFS);
3529 if (!block) {
3530 err = -ENOMEM;
3531 break;
3532 }
3533 block->bytenr = leaf->start;
3534 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3535 block->level = 0;
3536 block->key_ready = 1;
3537 rb_node = tree_insert(blocks, block->bytenr,
3538 &block->rb_node);
3539 if (rb_node)
3540 backref_tree_panic(rb_node, -EEXIST,
3541 block->bytenr);
3542 }
3543 if (counted)
3544 added = 1;
3545 else
3546 path->slots[0] = nritems;
3547 next:
3548 path->slots[0]++;
3549
3550 }
3551 out:
3552 btrfs_free_path(path);
3553 return err;
3554 }
3555
3556 /*
3557 * helper to find all tree blocks that reference a given data extent
3558 */
3559 static noinline_for_stack
3560 int add_data_references(struct reloc_control *rc,
3561 struct btrfs_key *extent_key,
3562 struct btrfs_path *path,
3563 struct rb_root *blocks)
3564 {
3565 struct btrfs_key key;
3566 struct extent_buffer *eb;
3567 struct btrfs_extent_data_ref *dref;
3568 struct btrfs_extent_inline_ref *iref;
3569 unsigned long ptr;
3570 unsigned long end;
3571 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3572 int ret;
3573 int err = 0;
3574
3575 eb = path->nodes[0];
3576 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3577 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3578 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3579 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3580 ptr = end;
3581 else
3582 #endif
3583 ptr += sizeof(struct btrfs_extent_item);
3584
3585 while (ptr < end) {
3586 iref = (struct btrfs_extent_inline_ref *)ptr;
3587 key.type = btrfs_extent_inline_ref_type(eb, iref);
3588 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3589 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3590 ret = __add_tree_block(rc, key.offset, blocksize,
3591 blocks);
3592 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3593 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3594 ret = find_data_references(rc, extent_key,
3595 eb, dref, blocks);
3596 } else {
3597 BUG();
3598 }
3599 ptr += btrfs_extent_inline_ref_size(key.type);
3600 }
3601 WARN_ON(ptr > end);
3602
3603 while (1) {
3604 cond_resched();
3605 eb = path->nodes[0];
3606 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3607 ret = btrfs_next_leaf(rc->extent_root, path);
3608 if (ret < 0) {
3609 err = ret;
3610 break;
3611 }
3612 if (ret > 0)
3613 break;
3614 eb = path->nodes[0];
3615 }
3616
3617 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3618 if (key.objectid != extent_key->objectid)
3619 break;
3620
3621 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3622 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3623 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3624 #else
3625 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3626 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3627 #endif
3628 ret = __add_tree_block(rc, key.offset, blocksize,
3629 blocks);
3630 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3631 dref = btrfs_item_ptr(eb, path->slots[0],
3632 struct btrfs_extent_data_ref);
3633 ret = find_data_references(rc, extent_key,
3634 eb, dref, blocks);
3635 } else {
3636 ret = 0;
3637 }
3638 if (ret) {
3639 err = ret;
3640 break;
3641 }
3642 path->slots[0]++;
3643 }
3644 btrfs_release_path(path);
3645 if (err)
3646 free_block_list(blocks);
3647 return err;
3648 }
3649
3650 /*
3651 * helper to find next unprocessed extent
3652 */
3653 static noinline_for_stack
3654 int find_next_extent(struct btrfs_trans_handle *trans,
3655 struct reloc_control *rc, struct btrfs_path *path,
3656 struct btrfs_key *extent_key)
3657 {
3658 struct btrfs_key key;
3659 struct extent_buffer *leaf;
3660 u64 start, end, last;
3661 int ret;
3662
3663 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3664 while (1) {
3665 cond_resched();
3666 if (rc->search_start >= last) {
3667 ret = 1;
3668 break;
3669 }
3670
3671 key.objectid = rc->search_start;
3672 key.type = BTRFS_EXTENT_ITEM_KEY;
3673 key.offset = 0;
3674
3675 path->search_commit_root = 1;
3676 path->skip_locking = 1;
3677 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3678 0, 0);
3679 if (ret < 0)
3680 break;
3681 next:
3682 leaf = path->nodes[0];
3683 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3684 ret = btrfs_next_leaf(rc->extent_root, path);
3685 if (ret != 0)
3686 break;
3687 leaf = path->nodes[0];
3688 }
3689
3690 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3691 if (key.objectid >= last) {
3692 ret = 1;
3693 break;
3694 }
3695
3696 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3697 key.type != BTRFS_METADATA_ITEM_KEY) {
3698 path->slots[0]++;
3699 goto next;
3700 }
3701
3702 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3703 key.objectid + key.offset <= rc->search_start) {
3704 path->slots[0]++;
3705 goto next;
3706 }
3707
3708 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3709 key.objectid + rc->extent_root->leafsize <=
3710 rc->search_start) {
3711 path->slots[0]++;
3712 goto next;
3713 }
3714
3715 ret = find_first_extent_bit(&rc->processed_blocks,
3716 key.objectid, &start, &end,
3717 EXTENT_DIRTY, NULL);
3718
3719 if (ret == 0 && start <= key.objectid) {
3720 btrfs_release_path(path);
3721 rc->search_start = end + 1;
3722 } else {
3723 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3724 rc->search_start = key.objectid + key.offset;
3725 else
3726 rc->search_start = key.objectid +
3727 rc->extent_root->leafsize;
3728 memcpy(extent_key, &key, sizeof(key));
3729 return 0;
3730 }
3731 }
3732 btrfs_release_path(path);
3733 return ret;
3734 }
3735
3736 static void set_reloc_control(struct reloc_control *rc)
3737 {
3738 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3739
3740 mutex_lock(&fs_info->reloc_mutex);
3741 fs_info->reloc_ctl = rc;
3742 mutex_unlock(&fs_info->reloc_mutex);
3743 }
3744
3745 static void unset_reloc_control(struct reloc_control *rc)
3746 {
3747 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3748
3749 mutex_lock(&fs_info->reloc_mutex);
3750 fs_info->reloc_ctl = NULL;
3751 mutex_unlock(&fs_info->reloc_mutex);
3752 }
3753
3754 static int check_extent_flags(u64 flags)
3755 {
3756 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3757 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3758 return 1;
3759 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3760 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3761 return 1;
3762 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3763 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3764 return 1;
3765 return 0;
3766 }
3767
3768 static noinline_for_stack
3769 int prepare_to_relocate(struct reloc_control *rc)
3770 {
3771 struct btrfs_trans_handle *trans;
3772 int ret;
3773
3774 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3775 BTRFS_BLOCK_RSV_TEMP);
3776 if (!rc->block_rsv)
3777 return -ENOMEM;
3778
3779 /*
3780 * reserve some space for creating reloc trees.
3781 * btrfs_init_reloc_root will use them when there
3782 * is no reservation in transaction handle.
3783 */
3784 ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv,
3785 rc->extent_root->nodesize * 256,
3786 BTRFS_RESERVE_FLUSH_ALL);
3787 if (ret)
3788 return ret;
3789
3790 memset(&rc->cluster, 0, sizeof(rc->cluster));
3791 rc->search_start = rc->block_group->key.objectid;
3792 rc->extents_found = 0;
3793 rc->nodes_relocated = 0;
3794 rc->merging_rsv_size = 0;
3795
3796 rc->create_reloc_tree = 1;
3797 set_reloc_control(rc);
3798
3799 trans = btrfs_join_transaction(rc->extent_root);
3800 if (IS_ERR(trans)) {
3801 unset_reloc_control(rc);
3802 /*
3803 * extent tree is not a ref_cow tree and has no reloc_root to
3804 * cleanup. And callers are responsible to free the above
3805 * block rsv.
3806 */
3807 return PTR_ERR(trans);
3808 }
3809 btrfs_commit_transaction(trans, rc->extent_root);
3810 return 0;
3811 }
3812
3813 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3814 {
3815 struct rb_root blocks = RB_ROOT;
3816 struct btrfs_key key;
3817 struct btrfs_trans_handle *trans = NULL;
3818 struct btrfs_path *path;
3819 struct btrfs_extent_item *ei;
3820 u64 flags;
3821 u32 item_size;
3822 int ret;
3823 int err = 0;
3824 int progress = 0;
3825
3826 path = btrfs_alloc_path();
3827 if (!path)
3828 return -ENOMEM;
3829 path->reada = 1;
3830
3831 ret = prepare_to_relocate(rc);
3832 if (ret) {
3833 err = ret;
3834 goto out_free;
3835 }
3836
3837 while (1) {
3838 progress++;
3839 trans = btrfs_start_transaction(rc->extent_root, 0);
3840 if (IS_ERR(trans)) {
3841 err = PTR_ERR(trans);
3842 trans = NULL;
3843 break;
3844 }
3845 restart:
3846 if (update_backref_cache(trans, &rc->backref_cache)) {
3847 btrfs_end_transaction(trans, rc->extent_root);
3848 continue;
3849 }
3850
3851 ret = find_next_extent(trans, rc, path, &key);
3852 if (ret < 0)
3853 err = ret;
3854 if (ret != 0)
3855 break;
3856
3857 rc->extents_found++;
3858
3859 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3860 struct btrfs_extent_item);
3861 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3862 if (item_size >= sizeof(*ei)) {
3863 flags = btrfs_extent_flags(path->nodes[0], ei);
3864 ret = check_extent_flags(flags);
3865 BUG_ON(ret);
3866
3867 } else {
3868 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3869 u64 ref_owner;
3870 int path_change = 0;
3871
3872 BUG_ON(item_size !=
3873 sizeof(struct btrfs_extent_item_v0));
3874 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3875 &path_change);
3876 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3877 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3878 else
3879 flags = BTRFS_EXTENT_FLAG_DATA;
3880
3881 if (path_change) {
3882 btrfs_release_path(path);
3883
3884 path->search_commit_root = 1;
3885 path->skip_locking = 1;
3886 ret = btrfs_search_slot(NULL, rc->extent_root,
3887 &key, path, 0, 0);
3888 if (ret < 0) {
3889 err = ret;
3890 break;
3891 }
3892 BUG_ON(ret > 0);
3893 }
3894 #else
3895 BUG();
3896 #endif
3897 }
3898
3899 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3900 ret = add_tree_block(rc, &key, path, &blocks);
3901 } else if (rc->stage == UPDATE_DATA_PTRS &&
3902 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3903 ret = add_data_references(rc, &key, path, &blocks);
3904 } else {
3905 btrfs_release_path(path);
3906 ret = 0;
3907 }
3908 if (ret < 0) {
3909 err = ret;
3910 break;
3911 }
3912
3913 if (!RB_EMPTY_ROOT(&blocks)) {
3914 ret = relocate_tree_blocks(trans, rc, &blocks);
3915 if (ret < 0) {
3916 if (ret != -EAGAIN) {
3917 err = ret;
3918 break;
3919 }
3920 rc->extents_found--;
3921 rc->search_start = key.objectid;
3922 }
3923 }
3924
3925 ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5);
3926 if (ret < 0) {
3927 if (ret != -ENOSPC) {
3928 err = ret;
3929 WARN_ON(1);
3930 break;
3931 }
3932 rc->commit_transaction = 1;
3933 }
3934
3935 if (rc->commit_transaction) {
3936 rc->commit_transaction = 0;
3937 ret = btrfs_commit_transaction(trans, rc->extent_root);
3938 BUG_ON(ret);
3939 } else {
3940 btrfs_end_transaction_throttle(trans, rc->extent_root);
3941 btrfs_btree_balance_dirty(rc->extent_root);
3942 }
3943 trans = NULL;
3944
3945 if (rc->stage == MOVE_DATA_EXTENTS &&
3946 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3947 rc->found_file_extent = 1;
3948 ret = relocate_data_extent(rc->data_inode,
3949 &key, &rc->cluster);
3950 if (ret < 0) {
3951 err = ret;
3952 break;
3953 }
3954 }
3955 }
3956 if (trans && progress && err == -ENOSPC) {
3957 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
3958 rc->block_group->flags);
3959 if (ret == 0) {
3960 err = 0;
3961 progress = 0;
3962 goto restart;
3963 }
3964 }
3965
3966 btrfs_release_path(path);
3967 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
3968 GFP_NOFS);
3969
3970 if (trans) {
3971 btrfs_end_transaction_throttle(trans, rc->extent_root);
3972 btrfs_btree_balance_dirty(rc->extent_root);
3973 }
3974
3975 if (!err) {
3976 ret = relocate_file_extent_cluster(rc->data_inode,
3977 &rc->cluster);
3978 if (ret < 0)
3979 err = ret;
3980 }
3981
3982 rc->create_reloc_tree = 0;
3983 set_reloc_control(rc);
3984
3985 backref_cache_cleanup(&rc->backref_cache);
3986 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3987
3988 err = prepare_to_merge(rc, err);
3989
3990 merge_reloc_roots(rc);
3991
3992 rc->merge_reloc_tree = 0;
3993 unset_reloc_control(rc);
3994 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3995
3996 /* get rid of pinned extents */
3997 trans = btrfs_join_transaction(rc->extent_root);
3998 if (IS_ERR(trans))
3999 err = PTR_ERR(trans);
4000 else
4001 btrfs_commit_transaction(trans, rc->extent_root);
4002 out_free:
4003 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4004 btrfs_free_path(path);
4005 return err;
4006 }
4007
4008 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4009 struct btrfs_root *root, u64 objectid)
4010 {
4011 struct btrfs_path *path;
4012 struct btrfs_inode_item *item;
4013 struct extent_buffer *leaf;
4014 int ret;
4015
4016 path = btrfs_alloc_path();
4017 if (!path)
4018 return -ENOMEM;
4019
4020 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4021 if (ret)
4022 goto out;
4023
4024 leaf = path->nodes[0];
4025 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4026 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4027 btrfs_set_inode_generation(leaf, item, 1);
4028 btrfs_set_inode_size(leaf, item, 0);
4029 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4030 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4031 BTRFS_INODE_PREALLOC);
4032 btrfs_mark_buffer_dirty(leaf);
4033 btrfs_release_path(path);
4034 out:
4035 btrfs_free_path(path);
4036 return ret;
4037 }
4038
4039 /*
4040 * helper to create inode for data relocation.
4041 * the inode is in data relocation tree and its link count is 0
4042 */
4043 static noinline_for_stack
4044 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4045 struct btrfs_block_group_cache *group)
4046 {
4047 struct inode *inode = NULL;
4048 struct btrfs_trans_handle *trans;
4049 struct btrfs_root *root;
4050 struct btrfs_key key;
4051 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4052 int err = 0;
4053
4054 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4055 if (IS_ERR(root))
4056 return ERR_CAST(root);
4057
4058 trans = btrfs_start_transaction(root, 6);
4059 if (IS_ERR(trans))
4060 return ERR_CAST(trans);
4061
4062 err = btrfs_find_free_objectid(root, &objectid);
4063 if (err)
4064 goto out;
4065
4066 err = __insert_orphan_inode(trans, root, objectid);
4067 BUG_ON(err);
4068
4069 key.objectid = objectid;
4070 key.type = BTRFS_INODE_ITEM_KEY;
4071 key.offset = 0;
4072 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4073 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4074 BTRFS_I(inode)->index_cnt = group->key.objectid;
4075
4076 err = btrfs_orphan_add(trans, inode);
4077 out:
4078 btrfs_end_transaction(trans, root);
4079 btrfs_btree_balance_dirty(root);
4080 if (err) {
4081 if (inode)
4082 iput(inode);
4083 inode = ERR_PTR(err);
4084 }
4085 return inode;
4086 }
4087
4088 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4089 {
4090 struct reloc_control *rc;
4091
4092 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4093 if (!rc)
4094 return NULL;
4095
4096 INIT_LIST_HEAD(&rc->reloc_roots);
4097 backref_cache_init(&rc->backref_cache);
4098 mapping_tree_init(&rc->reloc_root_tree);
4099 extent_io_tree_init(&rc->processed_blocks,
4100 fs_info->btree_inode->i_mapping);
4101 return rc;
4102 }
4103
4104 /*
4105 * function to relocate all extents in a block group.
4106 */
4107 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4108 {
4109 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4110 struct reloc_control *rc;
4111 struct inode *inode;
4112 struct btrfs_path *path;
4113 int ret;
4114 int rw = 0;
4115 int err = 0;
4116
4117 rc = alloc_reloc_control(fs_info);
4118 if (!rc)
4119 return -ENOMEM;
4120
4121 rc->extent_root = extent_root;
4122
4123 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4124 BUG_ON(!rc->block_group);
4125
4126 if (!rc->block_group->ro) {
4127 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4128 if (ret) {
4129 err = ret;
4130 goto out;
4131 }
4132 rw = 1;
4133 }
4134
4135 path = btrfs_alloc_path();
4136 if (!path) {
4137 err = -ENOMEM;
4138 goto out;
4139 }
4140
4141 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4142 path);
4143 btrfs_free_path(path);
4144
4145 if (!IS_ERR(inode))
4146 ret = delete_block_group_cache(fs_info, inode, 0);
4147 else
4148 ret = PTR_ERR(inode);
4149
4150 if (ret && ret != -ENOENT) {
4151 err = ret;
4152 goto out;
4153 }
4154
4155 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4156 if (IS_ERR(rc->data_inode)) {
4157 err = PTR_ERR(rc->data_inode);
4158 rc->data_inode = NULL;
4159 goto out;
4160 }
4161
4162 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
4163 (unsigned long long)rc->block_group->key.objectid,
4164 (unsigned long long)rc->block_group->flags);
4165
4166 ret = btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
4167 if (ret < 0) {
4168 err = ret;
4169 goto out;
4170 }
4171 btrfs_wait_ordered_extents(fs_info->tree_root, 0);
4172
4173 while (1) {
4174 mutex_lock(&fs_info->cleaner_mutex);
4175 ret = relocate_block_group(rc);
4176 mutex_unlock(&fs_info->cleaner_mutex);
4177 if (ret < 0) {
4178 err = ret;
4179 goto out;
4180 }
4181
4182 if (rc->extents_found == 0)
4183 break;
4184
4185 printk(KERN_INFO "btrfs: found %llu extents\n",
4186 (unsigned long long)rc->extents_found);
4187
4188 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4189 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4190 invalidate_mapping_pages(rc->data_inode->i_mapping,
4191 0, -1);
4192 rc->stage = UPDATE_DATA_PTRS;
4193 }
4194 }
4195
4196 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4197 rc->block_group->key.objectid,
4198 rc->block_group->key.objectid +
4199 rc->block_group->key.offset - 1);
4200
4201 WARN_ON(rc->block_group->pinned > 0);
4202 WARN_ON(rc->block_group->reserved > 0);
4203 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4204 out:
4205 if (err && rw)
4206 btrfs_set_block_group_rw(extent_root, rc->block_group);
4207 iput(rc->data_inode);
4208 btrfs_put_block_group(rc->block_group);
4209 kfree(rc);
4210 return err;
4211 }
4212
4213 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4214 {
4215 struct btrfs_trans_handle *trans;
4216 int ret, err;
4217
4218 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4219 if (IS_ERR(trans))
4220 return PTR_ERR(trans);
4221
4222 memset(&root->root_item.drop_progress, 0,
4223 sizeof(root->root_item.drop_progress));
4224 root->root_item.drop_level = 0;
4225 btrfs_set_root_refs(&root->root_item, 0);
4226 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4227 &root->root_key, &root->root_item);
4228
4229 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4230 if (err)
4231 return err;
4232 return ret;
4233 }
4234
4235 /*
4236 * recover relocation interrupted by system crash.
4237 *
4238 * this function resumes merging reloc trees with corresponding fs trees.
4239 * this is important for keeping the sharing of tree blocks
4240 */
4241 int btrfs_recover_relocation(struct btrfs_root *root)
4242 {
4243 LIST_HEAD(reloc_roots);
4244 struct btrfs_key key;
4245 struct btrfs_root *fs_root;
4246 struct btrfs_root *reloc_root;
4247 struct btrfs_path *path;
4248 struct extent_buffer *leaf;
4249 struct reloc_control *rc = NULL;
4250 struct btrfs_trans_handle *trans;
4251 int ret;
4252 int err = 0;
4253
4254 path = btrfs_alloc_path();
4255 if (!path)
4256 return -ENOMEM;
4257 path->reada = -1;
4258
4259 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4260 key.type = BTRFS_ROOT_ITEM_KEY;
4261 key.offset = (u64)-1;
4262
4263 while (1) {
4264 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4265 path, 0, 0);
4266 if (ret < 0) {
4267 err = ret;
4268 goto out;
4269 }
4270 if (ret > 0) {
4271 if (path->slots[0] == 0)
4272 break;
4273 path->slots[0]--;
4274 }
4275 leaf = path->nodes[0];
4276 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4277 btrfs_release_path(path);
4278
4279 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4280 key.type != BTRFS_ROOT_ITEM_KEY)
4281 break;
4282
4283 reloc_root = btrfs_read_fs_root_no_radix(root, &key);
4284 if (IS_ERR(reloc_root)) {
4285 err = PTR_ERR(reloc_root);
4286 goto out;
4287 }
4288
4289 list_add(&reloc_root->root_list, &reloc_roots);
4290
4291 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4292 fs_root = read_fs_root(root->fs_info,
4293 reloc_root->root_key.offset);
4294 if (IS_ERR(fs_root)) {
4295 ret = PTR_ERR(fs_root);
4296 if (ret != -ENOENT) {
4297 err = ret;
4298 goto out;
4299 }
4300 ret = mark_garbage_root(reloc_root);
4301 if (ret < 0) {
4302 err = ret;
4303 goto out;
4304 }
4305 }
4306 }
4307
4308 if (key.offset == 0)
4309 break;
4310
4311 key.offset--;
4312 }
4313 btrfs_release_path(path);
4314
4315 if (list_empty(&reloc_roots))
4316 goto out;
4317
4318 rc = alloc_reloc_control(root->fs_info);
4319 if (!rc) {
4320 err = -ENOMEM;
4321 goto out;
4322 }
4323
4324 rc->extent_root = root->fs_info->extent_root;
4325
4326 set_reloc_control(rc);
4327
4328 trans = btrfs_join_transaction(rc->extent_root);
4329 if (IS_ERR(trans)) {
4330 unset_reloc_control(rc);
4331 err = PTR_ERR(trans);
4332 goto out_free;
4333 }
4334
4335 rc->merge_reloc_tree = 1;
4336
4337 while (!list_empty(&reloc_roots)) {
4338 reloc_root = list_entry(reloc_roots.next,
4339 struct btrfs_root, root_list);
4340 list_del(&reloc_root->root_list);
4341
4342 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4343 list_add_tail(&reloc_root->root_list,
4344 &rc->reloc_roots);
4345 continue;
4346 }
4347
4348 fs_root = read_fs_root(root->fs_info,
4349 reloc_root->root_key.offset);
4350 if (IS_ERR(fs_root)) {
4351 err = PTR_ERR(fs_root);
4352 goto out_free;
4353 }
4354
4355 err = __add_reloc_root(reloc_root);
4356 BUG_ON(err < 0); /* -ENOMEM or logic error */
4357 fs_root->reloc_root = reloc_root;
4358 }
4359
4360 err = btrfs_commit_transaction(trans, rc->extent_root);
4361 if (err)
4362 goto out_free;
4363
4364 merge_reloc_roots(rc);
4365
4366 unset_reloc_control(rc);
4367
4368 trans = btrfs_join_transaction(rc->extent_root);
4369 if (IS_ERR(trans))
4370 err = PTR_ERR(trans);
4371 else
4372 err = btrfs_commit_transaction(trans, rc->extent_root);
4373 out_free:
4374 kfree(rc);
4375 out:
4376 if (!list_empty(&reloc_roots))
4377 free_reloc_roots(&reloc_roots);
4378
4379 btrfs_free_path(path);
4380
4381 if (err == 0) {
4382 /* cleanup orphan inode in data relocation tree */
4383 fs_root = read_fs_root(root->fs_info,
4384 BTRFS_DATA_RELOC_TREE_OBJECTID);
4385 if (IS_ERR(fs_root))
4386 err = PTR_ERR(fs_root);
4387 else
4388 err = btrfs_orphan_cleanup(fs_root);
4389 }
4390 return err;
4391 }
4392
4393 /*
4394 * helper to add ordered checksum for data relocation.
4395 *
4396 * cloning checksum properly handles the nodatasum extents.
4397 * it also saves CPU time to re-calculate the checksum.
4398 */
4399 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4400 {
4401 struct btrfs_ordered_sum *sums;
4402 struct btrfs_sector_sum *sector_sum;
4403 struct btrfs_ordered_extent *ordered;
4404 struct btrfs_root *root = BTRFS_I(inode)->root;
4405 size_t offset;
4406 int ret;
4407 u64 disk_bytenr;
4408 LIST_HEAD(list);
4409
4410 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4411 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4412
4413 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4414 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4415 disk_bytenr + len - 1, &list, 0);
4416 if (ret)
4417 goto out;
4418
4419 while (!list_empty(&list)) {
4420 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4421 list_del_init(&sums->list);
4422
4423 sector_sum = sums->sums;
4424 sums->bytenr = ordered->start;
4425
4426 offset = 0;
4427 while (offset < sums->len) {
4428 sector_sum->bytenr += ordered->start - disk_bytenr;
4429 sector_sum++;
4430 offset += root->sectorsize;
4431 }
4432
4433 btrfs_add_ordered_sum(inode, ordered, sums);
4434 }
4435 out:
4436 btrfs_put_ordered_extent(ordered);
4437 return ret;
4438 }
4439
4440 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4441 struct btrfs_root *root, struct extent_buffer *buf,
4442 struct extent_buffer *cow)
4443 {
4444 struct reloc_control *rc;
4445 struct backref_node *node;
4446 int first_cow = 0;
4447 int level;
4448 int ret;
4449
4450 rc = root->fs_info->reloc_ctl;
4451 if (!rc)
4452 return;
4453
4454 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4455 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4456
4457 level = btrfs_header_level(buf);
4458 if (btrfs_header_generation(buf) <=
4459 btrfs_root_last_snapshot(&root->root_item))
4460 first_cow = 1;
4461
4462 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4463 rc->create_reloc_tree) {
4464 WARN_ON(!first_cow && level == 0);
4465
4466 node = rc->backref_cache.path[level];
4467 BUG_ON(node->bytenr != buf->start &&
4468 node->new_bytenr != buf->start);
4469
4470 drop_node_buffer(node);
4471 extent_buffer_get(cow);
4472 node->eb = cow;
4473 node->new_bytenr = cow->start;
4474
4475 if (!node->pending) {
4476 list_move_tail(&node->list,
4477 &rc->backref_cache.pending[level]);
4478 node->pending = 1;
4479 }
4480
4481 if (first_cow)
4482 __mark_block_processed(rc, node);
4483
4484 if (first_cow && level > 0)
4485 rc->nodes_relocated += buf->len;
4486 }
4487
4488 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4489 ret = replace_file_extents(trans, rc, root, cow);
4490 BUG_ON(ret);
4491 }
4492 }
4493
4494 /*
4495 * called before creating snapshot. it calculates metadata reservation
4496 * requried for relocating tree blocks in the snapshot
4497 */
4498 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4499 struct btrfs_pending_snapshot *pending,
4500 u64 *bytes_to_reserve)
4501 {
4502 struct btrfs_root *root;
4503 struct reloc_control *rc;
4504
4505 root = pending->root;
4506 if (!root->reloc_root)
4507 return;
4508
4509 rc = root->fs_info->reloc_ctl;
4510 if (!rc->merge_reloc_tree)
4511 return;
4512
4513 root = root->reloc_root;
4514 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4515 /*
4516 * relocation is in the stage of merging trees. the space
4517 * used by merging a reloc tree is twice the size of
4518 * relocated tree nodes in the worst case. half for cowing
4519 * the reloc tree, half for cowing the fs tree. the space
4520 * used by cowing the reloc tree will be freed after the
4521 * tree is dropped. if we create snapshot, cowing the fs
4522 * tree may use more space than it frees. so we need
4523 * reserve extra space.
4524 */
4525 *bytes_to_reserve += rc->nodes_relocated;
4526 }
4527
4528 /*
4529 * called after snapshot is created. migrate block reservation
4530 * and create reloc root for the newly created snapshot
4531 */
4532 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4533 struct btrfs_pending_snapshot *pending)
4534 {
4535 struct btrfs_root *root = pending->root;
4536 struct btrfs_root *reloc_root;
4537 struct btrfs_root *new_root;
4538 struct reloc_control *rc;
4539 int ret;
4540
4541 if (!root->reloc_root)
4542 return 0;
4543
4544 rc = root->fs_info->reloc_ctl;
4545 rc->merging_rsv_size += rc->nodes_relocated;
4546
4547 if (rc->merge_reloc_tree) {
4548 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4549 rc->block_rsv,
4550 rc->nodes_relocated);
4551 if (ret)
4552 return ret;
4553 }
4554
4555 new_root = pending->snap;
4556 reloc_root = create_reloc_root(trans, root->reloc_root,
4557 new_root->root_key.objectid);
4558 if (IS_ERR(reloc_root))
4559 return PTR_ERR(reloc_root);
4560
4561 ret = __add_reloc_root(reloc_root);
4562 BUG_ON(ret < 0);
4563 new_root->reloc_root = reloc_root;
4564
4565 if (rc->create_reloc_tree)
4566 ret = clone_backref_node(trans, rc, root, reloc_root);
4567 return ret;
4568 }
Linux with added FPC-III support