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Btrfs: don't wait for unrelated IO to finish before relocation
[mirror_ubuntu-zesty-kernel.git] / fs / btrfs / relocation.c
CommitLineData
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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>
5a0e3ad6 24#include <linux/slab.h>
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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"
0af3d00b 32#include "free-space-cache.h"
581bb050 33#include "inode-map.h"
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34
35/*
36 * backref_node, mapping_node and tree_block start with this
37 */
38struct tree_entry {
39 struct rb_node rb_node;
40 u64 bytenr;
41};
42
43/*
44 * present a tree block in the backref cache
45 */
46struct backref_node {
47 struct rb_node rb_node;
48 u64 bytenr;
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49
50 u64 new_bytenr;
51 /* objectid of tree block owner, can be not uptodate */
5d4f98a2 52 u64 owner;
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53 /* link to pending, changed or detached list */
54 struct list_head list;
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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;
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65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
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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;
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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;
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85};
86
87/*
88 * present a block pointer in the backref cache
89 */
90struct backref_edge {
91 struct list_head list[2];
92 struct backref_node *node[2];
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93};
94
95#define LOWER 0
96#define UPPER 1
0647bf56 97#define RELOCATION_RESERVED_NODES 256
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98
99struct backref_cache {
100 /* red black tree of all backref nodes in the cache */
101 struct rb_root rb_root;
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102 /* for passing backref nodes to btrfs_reloc_cow_block */
103 struct backref_node *path[BTRFS_MAX_LEVEL];
104 /*
105 * list of blocks that have been cowed but some block
106 * pointers in upper level blocks may not reflect the
107 * new location
108 */
5d4f98a2 109 struct list_head pending[BTRFS_MAX_LEVEL];
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110 /* list of backref nodes with no child node */
111 struct list_head leaves;
112 /* list of blocks that have been cowed in current transaction */
113 struct list_head changed;
114 /* list of detached backref node. */
115 struct list_head detached;
116
117 u64 last_trans;
118
119 int nr_nodes;
120 int nr_edges;
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121};
122
123/*
124 * map address of tree root to tree
125 */
126struct mapping_node {
127 struct rb_node rb_node;
128 u64 bytenr;
129 void *data;
130};
131
132struct mapping_tree {
133 struct rb_root rb_root;
134 spinlock_t lock;
135};
136
137/*
138 * present a tree block to process
139 */
140struct tree_block {
141 struct rb_node rb_node;
142 u64 bytenr;
143 struct btrfs_key key;
144 unsigned int level:8;
145 unsigned int key_ready:1;
146};
147
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148#define MAX_EXTENTS 128
149
150struct file_extent_cluster {
151 u64 start;
152 u64 end;
153 u64 boundary[MAX_EXTENTS];
154 unsigned int nr;
155};
156
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157struct reloc_control {
158 /* block group to relocate */
159 struct btrfs_block_group_cache *block_group;
160 /* extent tree */
161 struct btrfs_root *extent_root;
162 /* inode for moving data */
163 struct inode *data_inode;
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164
165 struct btrfs_block_rsv *block_rsv;
166
167 struct backref_cache backref_cache;
168
169 struct file_extent_cluster cluster;
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170 /* tree blocks have been processed */
171 struct extent_io_tree processed_blocks;
172 /* map start of tree root to corresponding reloc tree */
173 struct mapping_tree reloc_root_tree;
174 /* list of reloc trees */
175 struct list_head reloc_roots;
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176 /* size of metadata reservation for merging reloc trees */
177 u64 merging_rsv_size;
178 /* size of relocated tree nodes */
179 u64 nodes_relocated;
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WS
180 /* reserved size for block group relocation*/
181 u64 reserved_bytes;
3fd0a558 182
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183 u64 search_start;
184 u64 extents_found;
3fd0a558 185
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186 unsigned int stage:8;
187 unsigned int create_reloc_tree:1;
188 unsigned int merge_reloc_tree:1;
5d4f98a2 189 unsigned int found_file_extent:1;
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190};
191
192/* stages of data relocation */
193#define MOVE_DATA_EXTENTS 0
194#define UPDATE_DATA_PTRS 1
195
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196static void remove_backref_node(struct backref_cache *cache,
197 struct backref_node *node);
198static void __mark_block_processed(struct reloc_control *rc,
199 struct backref_node *node);
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200
201static void mapping_tree_init(struct mapping_tree *tree)
202{
6bef4d31 203 tree->rb_root = RB_ROOT;
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204 spin_lock_init(&tree->lock);
205}
206
207static void backref_cache_init(struct backref_cache *cache)
208{
209 int i;
6bef4d31 210 cache->rb_root = RB_ROOT;
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211 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
212 INIT_LIST_HEAD(&cache->pending[i]);
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213 INIT_LIST_HEAD(&cache->changed);
214 INIT_LIST_HEAD(&cache->detached);
215 INIT_LIST_HEAD(&cache->leaves);
216}
217
218static void backref_cache_cleanup(struct backref_cache *cache)
219{
220 struct backref_node *node;
221 int i;
222
223 while (!list_empty(&cache->detached)) {
224 node = list_entry(cache->detached.next,
225 struct backref_node, list);
226 remove_backref_node(cache, node);
227 }
228
229 while (!list_empty(&cache->leaves)) {
230 node = list_entry(cache->leaves.next,
231 struct backref_node, lower);
232 remove_backref_node(cache, node);
233 }
234
235 cache->last_trans = 0;
236
237 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
238 BUG_ON(!list_empty(&cache->pending[i]));
239 BUG_ON(!list_empty(&cache->changed));
240 BUG_ON(!list_empty(&cache->detached));
241 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
242 BUG_ON(cache->nr_nodes);
243 BUG_ON(cache->nr_edges);
244}
245
246static struct backref_node *alloc_backref_node(struct backref_cache *cache)
247{
248 struct backref_node *node;
249
250 node = kzalloc(sizeof(*node), GFP_NOFS);
251 if (node) {
252 INIT_LIST_HEAD(&node->list);
253 INIT_LIST_HEAD(&node->upper);
254 INIT_LIST_HEAD(&node->lower);
255 RB_CLEAR_NODE(&node->rb_node);
256 cache->nr_nodes++;
257 }
258 return node;
259}
260
261static void free_backref_node(struct backref_cache *cache,
262 struct backref_node *node)
263{
264 if (node) {
265 cache->nr_nodes--;
266 kfree(node);
267 }
268}
269
270static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
271{
272 struct backref_edge *edge;
273
274 edge = kzalloc(sizeof(*edge), GFP_NOFS);
275 if (edge)
276 cache->nr_edges++;
277 return edge;
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278}
279
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280static void free_backref_edge(struct backref_cache *cache,
281 struct backref_edge *edge)
5d4f98a2 282{
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283 if (edge) {
284 cache->nr_edges--;
285 kfree(edge);
286 }
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287}
288
289static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
290 struct rb_node *node)
291{
292 struct rb_node **p = &root->rb_node;
293 struct rb_node *parent = NULL;
294 struct tree_entry *entry;
295
296 while (*p) {
297 parent = *p;
298 entry = rb_entry(parent, struct tree_entry, rb_node);
299
300 if (bytenr < entry->bytenr)
301 p = &(*p)->rb_left;
302 else if (bytenr > entry->bytenr)
303 p = &(*p)->rb_right;
304 else
305 return parent;
306 }
307
308 rb_link_node(node, parent, p);
309 rb_insert_color(node, root);
310 return NULL;
311}
312
313static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
314{
315 struct rb_node *n = root->rb_node;
316 struct tree_entry *entry;
317
318 while (n) {
319 entry = rb_entry(n, struct tree_entry, rb_node);
320
321 if (bytenr < entry->bytenr)
322 n = n->rb_left;
323 else if (bytenr > entry->bytenr)
324 n = n->rb_right;
325 else
326 return n;
327 }
328 return NULL;
329}
330
48a3b636 331static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
43c04fb1
JM
332{
333
334 struct btrfs_fs_info *fs_info = NULL;
335 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
336 rb_node);
337 if (bnode->root)
338 fs_info = bnode->root->fs_info;
339 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
351fd353 340 "found at offset %llu", bytenr);
43c04fb1
JM
341}
342
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343/*
344 * walk up backref nodes until reach node presents tree root
345 */
346static struct backref_node *walk_up_backref(struct backref_node *node,
347 struct backref_edge *edges[],
348 int *index)
349{
350 struct backref_edge *edge;
351 int idx = *index;
352
353 while (!list_empty(&node->upper)) {
354 edge = list_entry(node->upper.next,
355 struct backref_edge, list[LOWER]);
356 edges[idx++] = edge;
357 node = edge->node[UPPER];
358 }
3fd0a558 359 BUG_ON(node->detached);
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360 *index = idx;
361 return node;
362}
363
364/*
365 * walk down backref nodes to find start of next reference path
366 */
367static struct backref_node *walk_down_backref(struct backref_edge *edges[],
368 int *index)
369{
370 struct backref_edge *edge;
371 struct backref_node *lower;
372 int idx = *index;
373
374 while (idx > 0) {
375 edge = edges[idx - 1];
376 lower = edge->node[LOWER];
377 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
378 idx--;
379 continue;
380 }
381 edge = list_entry(edge->list[LOWER].next,
382 struct backref_edge, list[LOWER]);
383 edges[idx - 1] = edge;
384 *index = idx;
385 return edge->node[UPPER];
386 }
387 *index = 0;
388 return NULL;
389}
390
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391static void unlock_node_buffer(struct backref_node *node)
392{
393 if (node->locked) {
394 btrfs_tree_unlock(node->eb);
395 node->locked = 0;
396 }
397}
398
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399static void drop_node_buffer(struct backref_node *node)
400{
401 if (node->eb) {
3fd0a558 402 unlock_node_buffer(node);
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403 free_extent_buffer(node->eb);
404 node->eb = NULL;
405 }
406}
407
408static void drop_backref_node(struct backref_cache *tree,
409 struct backref_node *node)
410{
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411 BUG_ON(!list_empty(&node->upper));
412
413 drop_node_buffer(node);
3fd0a558 414 list_del(&node->list);
5d4f98a2 415 list_del(&node->lower);
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416 if (!RB_EMPTY_NODE(&node->rb_node))
417 rb_erase(&node->rb_node, &tree->rb_root);
418 free_backref_node(tree, node);
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419}
420
421/*
422 * remove a backref node from the backref cache
423 */
424static void remove_backref_node(struct backref_cache *cache,
425 struct backref_node *node)
426{
427 struct backref_node *upper;
428 struct backref_edge *edge;
429
430 if (!node)
431 return;
432
3fd0a558 433 BUG_ON(!node->lowest && !node->detached);
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434 while (!list_empty(&node->upper)) {
435 edge = list_entry(node->upper.next, struct backref_edge,
436 list[LOWER]);
437 upper = edge->node[UPPER];
438 list_del(&edge->list[LOWER]);
439 list_del(&edge->list[UPPER]);
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440 free_backref_edge(cache, edge);
441
442 if (RB_EMPTY_NODE(&upper->rb_node)) {
443 BUG_ON(!list_empty(&node->upper));
444 drop_backref_node(cache, node);
445 node = upper;
446 node->lowest = 1;
447 continue;
448 }
5d4f98a2 449 /*
3fd0a558 450 * add the node to leaf node list if no other
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451 * child block cached.
452 */
453 if (list_empty(&upper->lower)) {
3fd0a558 454 list_add_tail(&upper->lower, &cache->leaves);
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455 upper->lowest = 1;
456 }
457 }
3fd0a558 458
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459 drop_backref_node(cache, node);
460}
461
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462static void update_backref_node(struct backref_cache *cache,
463 struct backref_node *node, u64 bytenr)
464{
465 struct rb_node *rb_node;
466 rb_erase(&node->rb_node, &cache->rb_root);
467 node->bytenr = bytenr;
468 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
43c04fb1
JM
469 if (rb_node)
470 backref_tree_panic(rb_node, -EEXIST, bytenr);
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471}
472
473/*
474 * update backref cache after a transaction commit
475 */
476static int update_backref_cache(struct btrfs_trans_handle *trans,
477 struct backref_cache *cache)
478{
479 struct backref_node *node;
480 int level = 0;
481
482 if (cache->last_trans == 0) {
483 cache->last_trans = trans->transid;
484 return 0;
485 }
486
487 if (cache->last_trans == trans->transid)
488 return 0;
489
490 /*
491 * detached nodes are used to avoid unnecessary backref
492 * lookup. transaction commit changes the extent tree.
493 * so the detached nodes are no longer useful.
494 */
495 while (!list_empty(&cache->detached)) {
496 node = list_entry(cache->detached.next,
497 struct backref_node, list);
498 remove_backref_node(cache, node);
499 }
500
501 while (!list_empty(&cache->changed)) {
502 node = list_entry(cache->changed.next,
503 struct backref_node, list);
504 list_del_init(&node->list);
505 BUG_ON(node->pending);
506 update_backref_node(cache, node, node->new_bytenr);
507 }
508
509 /*
510 * some nodes can be left in the pending list if there were
511 * errors during processing the pending nodes.
512 */
513 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
514 list_for_each_entry(node, &cache->pending[level], list) {
515 BUG_ON(!node->pending);
516 if (node->bytenr == node->new_bytenr)
517 continue;
518 update_backref_node(cache, node, node->new_bytenr);
519 }
520 }
521
522 cache->last_trans = 0;
523 return 1;
524}
525
f2a97a9d 526
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527static int should_ignore_root(struct btrfs_root *root)
528{
529 struct btrfs_root *reloc_root;
530
27cdeb70 531 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
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532 return 0;
533
534 reloc_root = root->reloc_root;
535 if (!reloc_root)
536 return 0;
537
538 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
539 root->fs_info->running_transaction->transid - 1)
540 return 0;
541 /*
542 * if there is reloc tree and it was created in previous
543 * transaction backref lookup can find the reloc tree,
544 * so backref node for the fs tree root is useless for
545 * relocation.
546 */
547 return 1;
548}
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549/*
550 * find reloc tree by address of tree root
551 */
552static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
553 u64 bytenr)
554{
555 struct rb_node *rb_node;
556 struct mapping_node *node;
557 struct btrfs_root *root = NULL;
558
559 spin_lock(&rc->reloc_root_tree.lock);
560 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
561 if (rb_node) {
562 node = rb_entry(rb_node, struct mapping_node, rb_node);
563 root = (struct btrfs_root *)node->data;
564 }
565 spin_unlock(&rc->reloc_root_tree.lock);
566 return root;
567}
568
569static int is_cowonly_root(u64 root_objectid)
570{
571 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
572 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
573 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
574 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
575 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
66463748
WS
576 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
577 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
3e4c5efb
DS
578 root_objectid == BTRFS_QUOTA_TREE_OBJECTID ||
579 root_objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
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580 return 1;
581 return 0;
582}
583
584static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
585 u64 root_objectid)
586{
587 struct btrfs_key key;
588
589 key.objectid = root_objectid;
590 key.type = BTRFS_ROOT_ITEM_KEY;
591 if (is_cowonly_root(root_objectid))
592 key.offset = 0;
593 else
594 key.offset = (u64)-1;
595
c00869f1 596 return btrfs_get_fs_root(fs_info, &key, false);
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597}
598
599#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
600static noinline_for_stack
601struct btrfs_root *find_tree_root(struct reloc_control *rc,
602 struct extent_buffer *leaf,
603 struct btrfs_extent_ref_v0 *ref0)
604{
605 struct btrfs_root *root;
606 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
607 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
608
609 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
610
611 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
612 BUG_ON(IS_ERR(root));
613
27cdeb70 614 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
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615 generation != btrfs_root_generation(&root->root_item))
616 return NULL;
617
618 return root;
619}
620#endif
621
622static noinline_for_stack
623int find_inline_backref(struct extent_buffer *leaf, int slot,
624 unsigned long *ptr, unsigned long *end)
625{
3173a18f 626 struct btrfs_key key;
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YZ
627 struct btrfs_extent_item *ei;
628 struct btrfs_tree_block_info *bi;
629 u32 item_size;
630
3173a18f
JB
631 btrfs_item_key_to_cpu(leaf, &key, slot);
632
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633 item_size = btrfs_item_size_nr(leaf, slot);
634#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
635 if (item_size < sizeof(*ei)) {
636 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
637 return 1;
638 }
639#endif
640 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
641 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
642 BTRFS_EXTENT_FLAG_TREE_BLOCK));
643
3173a18f
JB
644 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
645 item_size <= sizeof(*ei) + sizeof(*bi)) {
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YZ
646 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
647 return 1;
648 }
d062d13c
JB
649 if (key.type == BTRFS_METADATA_ITEM_KEY &&
650 item_size <= sizeof(*ei)) {
651 WARN_ON(item_size < sizeof(*ei));
652 return 1;
653 }
5d4f98a2 654
3173a18f
JB
655 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
656 bi = (struct btrfs_tree_block_info *)(ei + 1);
657 *ptr = (unsigned long)(bi + 1);
658 } else {
659 *ptr = (unsigned long)(ei + 1);
660 }
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661 *end = (unsigned long)ei + item_size;
662 return 0;
663}
664
665/*
666 * build backref tree for a given tree block. root of the backref tree
667 * corresponds the tree block, leaves of the backref tree correspond
668 * roots of b-trees that reference the tree block.
669 *
670 * the basic idea of this function is check backrefs of a given block
671 * to find upper level blocks that refernece the block, and then check
672 * bakcrefs of these upper level blocks recursively. the recursion stop
673 * when tree root is reached or backrefs for the block is cached.
674 *
675 * NOTE: if we find backrefs for a block are cached, we know backrefs
676 * for all upper level blocks that directly/indirectly reference the
677 * block are also cached.
678 */
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679static noinline_for_stack
680struct backref_node *build_backref_tree(struct reloc_control *rc,
681 struct btrfs_key *node_key,
682 int level, u64 bytenr)
5d4f98a2 683{
3fd0a558 684 struct backref_cache *cache = &rc->backref_cache;
5d4f98a2
YZ
685 struct btrfs_path *path1;
686 struct btrfs_path *path2;
687 struct extent_buffer *eb;
688 struct btrfs_root *root;
689 struct backref_node *cur;
690 struct backref_node *upper;
691 struct backref_node *lower;
692 struct backref_node *node = NULL;
693 struct backref_node *exist = NULL;
694 struct backref_edge *edge;
695 struct rb_node *rb_node;
696 struct btrfs_key key;
697 unsigned long end;
698 unsigned long ptr;
699 LIST_HEAD(list);
3fd0a558
YZ
700 LIST_HEAD(useless);
701 int cowonly;
5d4f98a2
YZ
702 int ret;
703 int err = 0;
b6c60c80 704 bool need_check = true;
5d4f98a2
YZ
705
706 path1 = btrfs_alloc_path();
707 path2 = btrfs_alloc_path();
708 if (!path1 || !path2) {
709 err = -ENOMEM;
710 goto out;
711 }
e4058b54
DS
712 path1->reada = READA_FORWARD;
713 path2->reada = READA_FORWARD;
5d4f98a2 714
3fd0a558 715 node = alloc_backref_node(cache);
5d4f98a2
YZ
716 if (!node) {
717 err = -ENOMEM;
718 goto out;
719 }
720
5d4f98a2 721 node->bytenr = bytenr;
5d4f98a2
YZ
722 node->level = level;
723 node->lowest = 1;
724 cur = node;
725again:
726 end = 0;
727 ptr = 0;
728 key.objectid = cur->bytenr;
3173a18f 729 key.type = BTRFS_METADATA_ITEM_KEY;
5d4f98a2
YZ
730 key.offset = (u64)-1;
731
732 path1->search_commit_root = 1;
733 path1->skip_locking = 1;
734 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
735 0, 0);
736 if (ret < 0) {
737 err = ret;
738 goto out;
739 }
75bfb9af
JB
740 ASSERT(ret);
741 ASSERT(path1->slots[0]);
5d4f98a2
YZ
742
743 path1->slots[0]--;
744
745 WARN_ON(cur->checked);
746 if (!list_empty(&cur->upper)) {
747 /*
70f23fd6 748 * the backref was added previously when processing
5d4f98a2
YZ
749 * backref of type BTRFS_TREE_BLOCK_REF_KEY
750 */
75bfb9af 751 ASSERT(list_is_singular(&cur->upper));
5d4f98a2
YZ
752 edge = list_entry(cur->upper.next, struct backref_edge,
753 list[LOWER]);
75bfb9af 754 ASSERT(list_empty(&edge->list[UPPER]));
5d4f98a2
YZ
755 exist = edge->node[UPPER];
756 /*
757 * add the upper level block to pending list if we need
758 * check its backrefs
759 */
760 if (!exist->checked)
761 list_add_tail(&edge->list[UPPER], &list);
762 } else {
763 exist = NULL;
764 }
765
766 while (1) {
767 cond_resched();
768 eb = path1->nodes[0];
769
770 if (ptr >= end) {
771 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
772 ret = btrfs_next_leaf(rc->extent_root, path1);
773 if (ret < 0) {
774 err = ret;
775 goto out;
776 }
777 if (ret > 0)
778 break;
779 eb = path1->nodes[0];
780 }
781
782 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
783 if (key.objectid != cur->bytenr) {
784 WARN_ON(exist);
785 break;
786 }
787
3173a18f
JB
788 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
789 key.type == BTRFS_METADATA_ITEM_KEY) {
5d4f98a2
YZ
790 ret = find_inline_backref(eb, path1->slots[0],
791 &ptr, &end);
792 if (ret)
793 goto next;
794 }
795 }
796
797 if (ptr < end) {
798 /* update key for inline back ref */
799 struct btrfs_extent_inline_ref *iref;
800 iref = (struct btrfs_extent_inline_ref *)ptr;
801 key.type = btrfs_extent_inline_ref_type(eb, iref);
802 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
803 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
804 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
805 }
806
807 if (exist &&
808 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
809 exist->owner == key.offset) ||
810 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
811 exist->bytenr == key.offset))) {
812 exist = NULL;
813 goto next;
814 }
815
816#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
817 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
818 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3fd0a558 819 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
5d4f98a2
YZ
820 struct btrfs_extent_ref_v0 *ref0;
821 ref0 = btrfs_item_ptr(eb, path1->slots[0],
822 struct btrfs_extent_ref_v0);
3fd0a558 823 if (key.objectid == key.offset) {
046f264f 824 root = find_tree_root(rc, eb, ref0);
3fd0a558
YZ
825 if (root && !should_ignore_root(root))
826 cur->root = root;
827 else
828 list_add(&cur->list, &useless);
829 break;
830 }
046f264f
YZ
831 if (is_cowonly_root(btrfs_ref_root_v0(eb,
832 ref0)))
833 cur->cowonly = 1;
5d4f98a2
YZ
834 }
835#else
75bfb9af 836 ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
5d4f98a2
YZ
837 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
838#endif
839 if (key.objectid == key.offset) {
840 /*
841 * only root blocks of reloc trees use
842 * backref of this type.
843 */
844 root = find_reloc_root(rc, cur->bytenr);
75bfb9af 845 ASSERT(root);
5d4f98a2
YZ
846 cur->root = root;
847 break;
848 }
849
3fd0a558 850 edge = alloc_backref_edge(cache);
5d4f98a2
YZ
851 if (!edge) {
852 err = -ENOMEM;
853 goto out;
854 }
855 rb_node = tree_search(&cache->rb_root, key.offset);
856 if (!rb_node) {
3fd0a558 857 upper = alloc_backref_node(cache);
5d4f98a2 858 if (!upper) {
3fd0a558 859 free_backref_edge(cache, edge);
5d4f98a2
YZ
860 err = -ENOMEM;
861 goto out;
862 }
5d4f98a2 863 upper->bytenr = key.offset;
5d4f98a2
YZ
864 upper->level = cur->level + 1;
865 /*
866 * backrefs for the upper level block isn't
867 * cached, add the block to pending list
868 */
869 list_add_tail(&edge->list[UPPER], &list);
870 } else {
871 upper = rb_entry(rb_node, struct backref_node,
872 rb_node);
75bfb9af 873 ASSERT(upper->checked);
5d4f98a2
YZ
874 INIT_LIST_HEAD(&edge->list[UPPER]);
875 }
3fd0a558 876 list_add_tail(&edge->list[LOWER], &cur->upper);
5d4f98a2 877 edge->node[LOWER] = cur;
3fd0a558 878 edge->node[UPPER] = upper;
5d4f98a2
YZ
879
880 goto next;
881 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
882 goto next;
883 }
884
885 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
886 root = read_fs_root(rc->extent_root->fs_info, key.offset);
887 if (IS_ERR(root)) {
888 err = PTR_ERR(root);
889 goto out;
890 }
891
27cdeb70 892 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
3fd0a558
YZ
893 cur->cowonly = 1;
894
5d4f98a2
YZ
895 if (btrfs_root_level(&root->root_item) == cur->level) {
896 /* tree root */
75bfb9af 897 ASSERT(btrfs_root_bytenr(&root->root_item) ==
5d4f98a2 898 cur->bytenr);
3fd0a558
YZ
899 if (should_ignore_root(root))
900 list_add(&cur->list, &useless);
901 else
902 cur->root = root;
5d4f98a2
YZ
903 break;
904 }
905
906 level = cur->level + 1;
907
908 /*
909 * searching the tree to find upper level blocks
910 * reference the block.
911 */
912 path2->search_commit_root = 1;
913 path2->skip_locking = 1;
914 path2->lowest_level = level;
915 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
916 path2->lowest_level = 0;
917 if (ret < 0) {
918 err = ret;
919 goto out;
920 }
33c66f43
YZ
921 if (ret > 0 && path2->slots[level] > 0)
922 path2->slots[level]--;
5d4f98a2
YZ
923
924 eb = path2->nodes[level];
925 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
926 cur->bytenr);
927
928 lower = cur;
b6c60c80 929 need_check = true;
5d4f98a2
YZ
930 for (; level < BTRFS_MAX_LEVEL; level++) {
931 if (!path2->nodes[level]) {
75bfb9af 932 ASSERT(btrfs_root_bytenr(&root->root_item) ==
5d4f98a2 933 lower->bytenr);
3fd0a558
YZ
934 if (should_ignore_root(root))
935 list_add(&lower->list, &useless);
936 else
937 lower->root = root;
5d4f98a2
YZ
938 break;
939 }
940
3fd0a558 941 edge = alloc_backref_edge(cache);
5d4f98a2
YZ
942 if (!edge) {
943 err = -ENOMEM;
944 goto out;
945 }
946
947 eb = path2->nodes[level];
948 rb_node = tree_search(&cache->rb_root, eb->start);
949 if (!rb_node) {
3fd0a558 950 upper = alloc_backref_node(cache);
5d4f98a2 951 if (!upper) {
3fd0a558 952 free_backref_edge(cache, edge);
5d4f98a2
YZ
953 err = -ENOMEM;
954 goto out;
955 }
5d4f98a2
YZ
956 upper->bytenr = eb->start;
957 upper->owner = btrfs_header_owner(eb);
958 upper->level = lower->level + 1;
27cdeb70
MX
959 if (!test_bit(BTRFS_ROOT_REF_COWS,
960 &root->state))
3fd0a558 961 upper->cowonly = 1;
5d4f98a2
YZ
962
963 /*
964 * if we know the block isn't shared
965 * we can void checking its backrefs.
966 */
967 if (btrfs_block_can_be_shared(root, eb))
968 upper->checked = 0;
969 else
970 upper->checked = 1;
971
972 /*
973 * add the block to pending list if we
b6c60c80
JB
974 * need check its backrefs, we only do this once
975 * while walking up a tree as we will catch
976 * anything else later on.
5d4f98a2 977 */
b6c60c80
JB
978 if (!upper->checked && need_check) {
979 need_check = false;
5d4f98a2
YZ
980 list_add_tail(&edge->list[UPPER],
981 &list);
bbe90514
JB
982 } else {
983 if (upper->checked)
984 need_check = true;
5d4f98a2 985 INIT_LIST_HEAD(&edge->list[UPPER]);
bbe90514 986 }
5d4f98a2
YZ
987 } else {
988 upper = rb_entry(rb_node, struct backref_node,
989 rb_node);
75bfb9af 990 ASSERT(upper->checked);
5d4f98a2 991 INIT_LIST_HEAD(&edge->list[UPPER]);
3fd0a558
YZ
992 if (!upper->owner)
993 upper->owner = btrfs_header_owner(eb);
5d4f98a2
YZ
994 }
995 list_add_tail(&edge->list[LOWER], &lower->upper);
5d4f98a2 996 edge->node[LOWER] = lower;
3fd0a558 997 edge->node[UPPER] = upper;
5d4f98a2
YZ
998
999 if (rb_node)
1000 break;
1001 lower = upper;
1002 upper = NULL;
1003 }
b3b4aa74 1004 btrfs_release_path(path2);
5d4f98a2
YZ
1005next:
1006 if (ptr < end) {
1007 ptr += btrfs_extent_inline_ref_size(key.type);
1008 if (ptr >= end) {
1009 WARN_ON(ptr > end);
1010 ptr = 0;
1011 end = 0;
1012 }
1013 }
1014 if (ptr >= end)
1015 path1->slots[0]++;
1016 }
b3b4aa74 1017 btrfs_release_path(path1);
5d4f98a2
YZ
1018
1019 cur->checked = 1;
1020 WARN_ON(exist);
1021
1022 /* the pending list isn't empty, take the first block to process */
1023 if (!list_empty(&list)) {
1024 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1025 list_del_init(&edge->list[UPPER]);
1026 cur = edge->node[UPPER];
1027 goto again;
1028 }
1029
1030 /*
1031 * everything goes well, connect backref nodes and insert backref nodes
1032 * into the cache.
1033 */
75bfb9af 1034 ASSERT(node->checked);
3fd0a558
YZ
1035 cowonly = node->cowonly;
1036 if (!cowonly) {
1037 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1038 &node->rb_node);
43c04fb1
JM
1039 if (rb_node)
1040 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
3fd0a558
YZ
1041 list_add_tail(&node->lower, &cache->leaves);
1042 }
5d4f98a2
YZ
1043
1044 list_for_each_entry(edge, &node->upper, list[LOWER])
1045 list_add_tail(&edge->list[UPPER], &list);
1046
1047 while (!list_empty(&list)) {
1048 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1049 list_del_init(&edge->list[UPPER]);
1050 upper = edge->node[UPPER];
3fd0a558
YZ
1051 if (upper->detached) {
1052 list_del(&edge->list[LOWER]);
1053 lower = edge->node[LOWER];
1054 free_backref_edge(cache, edge);
1055 if (list_empty(&lower->upper))
1056 list_add(&lower->list, &useless);
1057 continue;
1058 }
5d4f98a2
YZ
1059
1060 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1061 if (upper->lowest) {
1062 list_del_init(&upper->lower);
1063 upper->lowest = 0;
1064 }
1065
1066 list_add_tail(&edge->list[UPPER], &upper->lower);
1067 continue;
1068 }
1069
75bfb9af
JB
1070 if (!upper->checked) {
1071 /*
1072 * Still want to blow up for developers since this is a
1073 * logic bug.
1074 */
1075 ASSERT(0);
1076 err = -EINVAL;
1077 goto out;
1078 }
1079 if (cowonly != upper->cowonly) {
1080 ASSERT(0);
1081 err = -EINVAL;
1082 goto out;
1083 }
1084
3fd0a558
YZ
1085 if (!cowonly) {
1086 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1087 &upper->rb_node);
43c04fb1
JM
1088 if (rb_node)
1089 backref_tree_panic(rb_node, -EEXIST,
1090 upper->bytenr);
3fd0a558 1091 }
5d4f98a2
YZ
1092
1093 list_add_tail(&edge->list[UPPER], &upper->lower);
1094
1095 list_for_each_entry(edge, &upper->upper, list[LOWER])
1096 list_add_tail(&edge->list[UPPER], &list);
1097 }
3fd0a558
YZ
1098 /*
1099 * process useless backref nodes. backref nodes for tree leaves
1100 * are deleted from the cache. backref nodes for upper level
1101 * tree blocks are left in the cache to avoid unnecessary backref
1102 * lookup.
1103 */
1104 while (!list_empty(&useless)) {
1105 upper = list_entry(useless.next, struct backref_node, list);
1106 list_del_init(&upper->list);
75bfb9af 1107 ASSERT(list_empty(&upper->upper));
3fd0a558
YZ
1108 if (upper == node)
1109 node = NULL;
1110 if (upper->lowest) {
1111 list_del_init(&upper->lower);
1112 upper->lowest = 0;
1113 }
1114 while (!list_empty(&upper->lower)) {
1115 edge = list_entry(upper->lower.next,
1116 struct backref_edge, list[UPPER]);
1117 list_del(&edge->list[UPPER]);
1118 list_del(&edge->list[LOWER]);
1119 lower = edge->node[LOWER];
1120 free_backref_edge(cache, edge);
1121
1122 if (list_empty(&lower->upper))
1123 list_add(&lower->list, &useless);
1124 }
1125 __mark_block_processed(rc, upper);
1126 if (upper->level > 0) {
1127 list_add(&upper->list, &cache->detached);
1128 upper->detached = 1;
1129 } else {
1130 rb_erase(&upper->rb_node, &cache->rb_root);
1131 free_backref_node(cache, upper);
1132 }
1133 }
5d4f98a2
YZ
1134out:
1135 btrfs_free_path(path1);
1136 btrfs_free_path(path2);
1137 if (err) {
3fd0a558
YZ
1138 while (!list_empty(&useless)) {
1139 lower = list_entry(useless.next,
75bfb9af
JB
1140 struct backref_node, list);
1141 list_del_init(&lower->list);
3fd0a558 1142 }
75bfb9af
JB
1143 while (!list_empty(&list)) {
1144 edge = list_first_entry(&list, struct backref_edge,
1145 list[UPPER]);
1146 list_del(&edge->list[UPPER]);
3fd0a558 1147 list_del(&edge->list[LOWER]);
75bfb9af 1148 lower = edge->node[LOWER];
5d4f98a2 1149 upper = edge->node[UPPER];
3fd0a558 1150 free_backref_edge(cache, edge);
75bfb9af
JB
1151
1152 /*
1153 * Lower is no longer linked to any upper backref nodes
1154 * and isn't in the cache, we can free it ourselves.
1155 */
1156 if (list_empty(&lower->upper) &&
1157 RB_EMPTY_NODE(&lower->rb_node))
1158 list_add(&lower->list, &useless);
1159
1160 if (!RB_EMPTY_NODE(&upper->rb_node))
1161 continue;
1162
1163 /* Add this guy's upper edges to the list to proces */
1164 list_for_each_entry(edge, &upper->upper, list[LOWER])
1165 list_add_tail(&edge->list[UPPER], &list);
1166 if (list_empty(&upper->upper))
1167 list_add(&upper->list, &useless);
1168 }
1169
1170 while (!list_empty(&useless)) {
1171 lower = list_entry(useless.next,
1172 struct backref_node, list);
1173 list_del_init(&lower->list);
1174 free_backref_node(cache, lower);
5d4f98a2
YZ
1175 }
1176 return ERR_PTR(err);
1177 }
75bfb9af 1178 ASSERT(!node || !node->detached);
5d4f98a2
YZ
1179 return node;
1180}
1181
3fd0a558
YZ
1182/*
1183 * helper to add backref node for the newly created snapshot.
1184 * the backref node is created by cloning backref node that
1185 * corresponds to root of source tree
1186 */
1187static int clone_backref_node(struct btrfs_trans_handle *trans,
1188 struct reloc_control *rc,
1189 struct btrfs_root *src,
1190 struct btrfs_root *dest)
1191{
1192 struct btrfs_root *reloc_root = src->reloc_root;
1193 struct backref_cache *cache = &rc->backref_cache;
1194 struct backref_node *node = NULL;
1195 struct backref_node *new_node;
1196 struct backref_edge *edge;
1197 struct backref_edge *new_edge;
1198 struct rb_node *rb_node;
1199
1200 if (cache->last_trans > 0)
1201 update_backref_cache(trans, cache);
1202
1203 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1204 if (rb_node) {
1205 node = rb_entry(rb_node, struct backref_node, rb_node);
1206 if (node->detached)
1207 node = NULL;
1208 else
1209 BUG_ON(node->new_bytenr != reloc_root->node->start);
1210 }
1211
1212 if (!node) {
1213 rb_node = tree_search(&cache->rb_root,
1214 reloc_root->commit_root->start);
1215 if (rb_node) {
1216 node = rb_entry(rb_node, struct backref_node,
1217 rb_node);
1218 BUG_ON(node->detached);
1219 }
1220 }
1221
1222 if (!node)
1223 return 0;
1224
1225 new_node = alloc_backref_node(cache);
1226 if (!new_node)
1227 return -ENOMEM;
1228
1229 new_node->bytenr = dest->node->start;
1230 new_node->level = node->level;
1231 new_node->lowest = node->lowest;
6848ad64 1232 new_node->checked = 1;
3fd0a558
YZ
1233 new_node->root = dest;
1234
1235 if (!node->lowest) {
1236 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1237 new_edge = alloc_backref_edge(cache);
1238 if (!new_edge)
1239 goto fail;
1240
1241 new_edge->node[UPPER] = new_node;
1242 new_edge->node[LOWER] = edge->node[LOWER];
1243 list_add_tail(&new_edge->list[UPPER],
1244 &new_node->lower);
1245 }
76b9e23d
MX
1246 } else {
1247 list_add_tail(&new_node->lower, &cache->leaves);
3fd0a558
YZ
1248 }
1249
1250 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1251 &new_node->rb_node);
43c04fb1
JM
1252 if (rb_node)
1253 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
3fd0a558
YZ
1254
1255 if (!new_node->lowest) {
1256 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1257 list_add_tail(&new_edge->list[LOWER],
1258 &new_edge->node[LOWER]->upper);
1259 }
1260 }
1261 return 0;
1262fail:
1263 while (!list_empty(&new_node->lower)) {
1264 new_edge = list_entry(new_node->lower.next,
1265 struct backref_edge, list[UPPER]);
1266 list_del(&new_edge->list[UPPER]);
1267 free_backref_edge(cache, new_edge);
1268 }
1269 free_backref_node(cache, new_node);
1270 return -ENOMEM;
1271}
1272
5d4f98a2
YZ
1273/*
1274 * helper to add 'address of tree root -> reloc tree' mapping
1275 */
ffd7b339 1276static int __must_check __add_reloc_root(struct btrfs_root *root)
5d4f98a2
YZ
1277{
1278 struct rb_node *rb_node;
1279 struct mapping_node *node;
1280 struct reloc_control *rc = root->fs_info->reloc_ctl;
1281
1282 node = kmalloc(sizeof(*node), GFP_NOFS);
ffd7b339
JM
1283 if (!node)
1284 return -ENOMEM;
5d4f98a2
YZ
1285
1286 node->bytenr = root->node->start;
1287 node->data = root;
1288
1289 spin_lock(&rc->reloc_root_tree.lock);
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);
ffd7b339 1293 if (rb_node) {
ffd7b339
JM
1294 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1295 "for start=%llu while inserting into relocation "
351fd353 1296 "tree", node->bytenr);
23291a04
DC
1297 kfree(node);
1298 return -EEXIST;
ffd7b339 1299 }
5d4f98a2
YZ
1300
1301 list_add_tail(&root->root_list, &rc->reloc_roots);
1302 return 0;
1303}
1304
1305/*
c974c464 1306 * helper to delete the 'address of tree root -> reloc tree'
5d4f98a2
YZ
1307 * mapping
1308 */
c974c464 1309static void __del_reloc_root(struct btrfs_root *root)
5d4f98a2
YZ
1310{
1311 struct rb_node *rb_node;
1312 struct mapping_node *node = NULL;
1313 struct reloc_control *rc = root->fs_info->reloc_ctl;
1314
1315 spin_lock(&rc->reloc_root_tree.lock);
1316 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
c974c464 1317 root->node->start);
5d4f98a2
YZ
1318 if (rb_node) {
1319 node = rb_entry(rb_node, struct mapping_node, rb_node);
1320 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1321 }
1322 spin_unlock(&rc->reloc_root_tree.lock);
1323
8f71f3e0 1324 if (!node)
c974c464 1325 return;
5d4f98a2
YZ
1326 BUG_ON((struct btrfs_root *)node->data != root);
1327
c974c464
WS
1328 spin_lock(&root->fs_info->trans_lock);
1329 list_del_init(&root->root_list);
1330 spin_unlock(&root->fs_info->trans_lock);
1331 kfree(node);
1332}
1333
1334/*
1335 * helper to update the 'address of tree root -> reloc tree'
1336 * mapping
1337 */
1338static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1339{
1340 struct rb_node *rb_node;
1341 struct mapping_node *node = NULL;
1342 struct reloc_control *rc = root->fs_info->reloc_ctl;
1343
1344 spin_lock(&rc->reloc_root_tree.lock);
1345 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1346 root->node->start);
1347 if (rb_node) {
1348 node = rb_entry(rb_node, struct mapping_node, rb_node);
1349 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
5d4f98a2 1350 }
c974c464
WS
1351 spin_unlock(&rc->reloc_root_tree.lock);
1352
1353 if (!node)
1354 return 0;
1355 BUG_ON((struct btrfs_root *)node->data != root);
1356
1357 spin_lock(&rc->reloc_root_tree.lock);
1358 node->bytenr = new_bytenr;
1359 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1360 node->bytenr, &node->rb_node);
1361 spin_unlock(&rc->reloc_root_tree.lock);
1362 if (rb_node)
1363 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
5d4f98a2
YZ
1364 return 0;
1365}
1366
3fd0a558
YZ
1367static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1368 struct btrfs_root *root, u64 objectid)
5d4f98a2
YZ
1369{
1370 struct btrfs_root *reloc_root;
1371 struct extent_buffer *eb;
1372 struct btrfs_root_item *root_item;
1373 struct btrfs_key root_key;
5bc7247a 1374 u64 last_snap = 0;
5d4f98a2
YZ
1375 int ret;
1376
5d4f98a2
YZ
1377 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1378 BUG_ON(!root_item);
1379
1380 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1381 root_key.type = BTRFS_ROOT_ITEM_KEY;
3fd0a558 1382 root_key.offset = objectid;
5d4f98a2 1383
3fd0a558
YZ
1384 if (root->root_key.objectid == objectid) {
1385 /* called by btrfs_init_reloc_root */
1386 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1387 BTRFS_TREE_RELOC_OBJECTID);
1388 BUG_ON(ret);
1389
5bc7247a 1390 last_snap = btrfs_root_last_snapshot(&root->root_item);
3fd0a558
YZ
1391 btrfs_set_root_last_snapshot(&root->root_item,
1392 trans->transid - 1);
1393 } else {
1394 /*
1395 * called by btrfs_reloc_post_snapshot_hook.
1396 * the source tree is a reloc tree, all tree blocks
1397 * modified after it was created have RELOC flag
1398 * set in their headers. so it's OK to not update
1399 * the 'last_snapshot'.
1400 */
1401 ret = btrfs_copy_root(trans, root, root->node, &eb,
1402 BTRFS_TREE_RELOC_OBJECTID);
1403 BUG_ON(ret);
1404 }
5d4f98a2 1405
5d4f98a2 1406 memcpy(root_item, &root->root_item, sizeof(*root_item));
5d4f98a2
YZ
1407 btrfs_set_root_bytenr(root_item, eb->start);
1408 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1409 btrfs_set_root_generation(root_item, trans->transid);
3fd0a558
YZ
1410
1411 if (root->root_key.objectid == objectid) {
1412 btrfs_set_root_refs(root_item, 0);
1413 memset(&root_item->drop_progress, 0,
1414 sizeof(struct btrfs_disk_key));
1415 root_item->drop_level = 0;
5bc7247a
MX
1416 /*
1417 * abuse rtransid, it is safe because it is impossible to
1418 * receive data into a relocation tree.
1419 */
1420 btrfs_set_root_rtransid(root_item, last_snap);
1421 btrfs_set_root_otransid(root_item, trans->transid);
3fd0a558 1422 }
5d4f98a2
YZ
1423
1424 btrfs_tree_unlock(eb);
1425 free_extent_buffer(eb);
1426
1427 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1428 &root_key, root_item);
1429 BUG_ON(ret);
1430 kfree(root_item);
1431
cb517eab 1432 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
5d4f98a2
YZ
1433 BUG_ON(IS_ERR(reloc_root));
1434 reloc_root->last_trans = trans->transid;
3fd0a558
YZ
1435 return reloc_root;
1436}
1437
1438/*
1439 * create reloc tree for a given fs tree. reloc tree is just a
1440 * snapshot of the fs tree with special root objectid.
1441 */
1442int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1443 struct btrfs_root *root)
1444{
1445 struct btrfs_root *reloc_root;
1446 struct reloc_control *rc = root->fs_info->reloc_ctl;
20dd2cbf 1447 struct btrfs_block_rsv *rsv;
3fd0a558 1448 int clear_rsv = 0;
ffd7b339 1449 int ret;
3fd0a558
YZ
1450
1451 if (root->reloc_root) {
1452 reloc_root = root->reloc_root;
1453 reloc_root->last_trans = trans->transid;
1454 return 0;
1455 }
1456
1457 if (!rc || !rc->create_reloc_tree ||
1458 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1459 return 0;
1460
20dd2cbf
MX
1461 if (!trans->reloc_reserved) {
1462 rsv = trans->block_rsv;
3fd0a558
YZ
1463 trans->block_rsv = rc->block_rsv;
1464 clear_rsv = 1;
1465 }
1466 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1467 if (clear_rsv)
20dd2cbf 1468 trans->block_rsv = rsv;
5d4f98a2 1469
ffd7b339
JM
1470 ret = __add_reloc_root(reloc_root);
1471 BUG_ON(ret < 0);
5d4f98a2
YZ
1472 root->reloc_root = reloc_root;
1473 return 0;
1474}
1475
1476/*
1477 * update root item of reloc tree
1478 */
1479int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1480 struct btrfs_root *root)
1481{
1482 struct btrfs_root *reloc_root;
1483 struct btrfs_root_item *root_item;
5d4f98a2
YZ
1484 int ret;
1485
1486 if (!root->reloc_root)
7585717f 1487 goto out;
5d4f98a2
YZ
1488
1489 reloc_root = root->reloc_root;
1490 root_item = &reloc_root->root_item;
1491
3fd0a558
YZ
1492 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1493 btrfs_root_refs(root_item) == 0) {
5d4f98a2 1494 root->reloc_root = NULL;
c974c464 1495 __del_reloc_root(reloc_root);
5d4f98a2
YZ
1496 }
1497
5d4f98a2
YZ
1498 if (reloc_root->commit_root != reloc_root->node) {
1499 btrfs_set_root_node(root_item, reloc_root->node);
1500 free_extent_buffer(reloc_root->commit_root);
1501 reloc_root->commit_root = btrfs_root_node(reloc_root);
1502 }
1503
1504 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1505 &reloc_root->root_key, root_item);
1506 BUG_ON(ret);
7585717f
CM
1507
1508out:
5d4f98a2
YZ
1509 return 0;
1510}
1511
1512/*
1513 * helper to find first cached inode with inode number >= objectid
1514 * in a subvolume
1515 */
1516static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1517{
1518 struct rb_node *node;
1519 struct rb_node *prev;
1520 struct btrfs_inode *entry;
1521 struct inode *inode;
1522
1523 spin_lock(&root->inode_lock);
1524again:
1525 node = root->inode_tree.rb_node;
1526 prev = NULL;
1527 while (node) {
1528 prev = node;
1529 entry = rb_entry(node, struct btrfs_inode, rb_node);
1530
33345d01 1531 if (objectid < btrfs_ino(&entry->vfs_inode))
5d4f98a2 1532 node = node->rb_left;
33345d01 1533 else if (objectid > btrfs_ino(&entry->vfs_inode))
5d4f98a2
YZ
1534 node = node->rb_right;
1535 else
1536 break;
1537 }
1538 if (!node) {
1539 while (prev) {
1540 entry = rb_entry(prev, struct btrfs_inode, rb_node);
33345d01 1541 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5d4f98a2
YZ
1542 node = prev;
1543 break;
1544 }
1545 prev = rb_next(prev);
1546 }
1547 }
1548 while (node) {
1549 entry = rb_entry(node, struct btrfs_inode, rb_node);
1550 inode = igrab(&entry->vfs_inode);
1551 if (inode) {
1552 spin_unlock(&root->inode_lock);
1553 return inode;
1554 }
1555
33345d01 1556 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5d4f98a2
YZ
1557 if (cond_resched_lock(&root->inode_lock))
1558 goto again;
1559
1560 node = rb_next(node);
1561 }
1562 spin_unlock(&root->inode_lock);
1563 return NULL;
1564}
1565
1566static int in_block_group(u64 bytenr,
1567 struct btrfs_block_group_cache *block_group)
1568{
1569 if (bytenr >= block_group->key.objectid &&
1570 bytenr < block_group->key.objectid + block_group->key.offset)
1571 return 1;
1572 return 0;
1573}
1574
1575/*
1576 * get new location of data
1577 */
1578static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1579 u64 bytenr, u64 num_bytes)
1580{
1581 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1582 struct btrfs_path *path;
1583 struct btrfs_file_extent_item *fi;
1584 struct extent_buffer *leaf;
1585 int ret;
1586
1587 path = btrfs_alloc_path();
1588 if (!path)
1589 return -ENOMEM;
1590
1591 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
33345d01 1592 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
5d4f98a2
YZ
1593 bytenr, 0);
1594 if (ret < 0)
1595 goto out;
1596 if (ret > 0) {
1597 ret = -ENOENT;
1598 goto out;
1599 }
1600
1601 leaf = path->nodes[0];
1602 fi = btrfs_item_ptr(leaf, path->slots[0],
1603 struct btrfs_file_extent_item);
1604
1605 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1606 btrfs_file_extent_compression(leaf, fi) ||
1607 btrfs_file_extent_encryption(leaf, fi) ||
1608 btrfs_file_extent_other_encoding(leaf, fi));
1609
1610 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
83d4cfd4 1611 ret = -EINVAL;
5d4f98a2
YZ
1612 goto out;
1613 }
1614
3fd0a558 1615 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5d4f98a2
YZ
1616 ret = 0;
1617out:
1618 btrfs_free_path(path);
1619 return ret;
1620}
1621
1622/*
1623 * update file extent items in the tree leaf to point to
1624 * the new locations.
1625 */
3fd0a558
YZ
1626static noinline_for_stack
1627int replace_file_extents(struct btrfs_trans_handle *trans,
1628 struct reloc_control *rc,
1629 struct btrfs_root *root,
1630 struct extent_buffer *leaf)
5d4f98a2
YZ
1631{
1632 struct btrfs_key key;
1633 struct btrfs_file_extent_item *fi;
1634 struct inode *inode = NULL;
5d4f98a2
YZ
1635 u64 parent;
1636 u64 bytenr;
3fd0a558 1637 u64 new_bytenr = 0;
5d4f98a2
YZ
1638 u64 num_bytes;
1639 u64 end;
1640 u32 nritems;
1641 u32 i;
83d4cfd4 1642 int ret = 0;
5d4f98a2
YZ
1643 int first = 1;
1644 int dirty = 0;
1645
1646 if (rc->stage != UPDATE_DATA_PTRS)
1647 return 0;
1648
1649 /* reloc trees always use full backref */
1650 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1651 parent = leaf->start;
1652 else
1653 parent = 0;
1654
1655 nritems = btrfs_header_nritems(leaf);
1656 for (i = 0; i < nritems; i++) {
1657 cond_resched();
1658 btrfs_item_key_to_cpu(leaf, &key, i);
1659 if (key.type != BTRFS_EXTENT_DATA_KEY)
1660 continue;
1661 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1662 if (btrfs_file_extent_type(leaf, fi) ==
1663 BTRFS_FILE_EXTENT_INLINE)
1664 continue;
1665 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1666 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1667 if (bytenr == 0)
1668 continue;
1669 if (!in_block_group(bytenr, rc->block_group))
1670 continue;
1671
1672 /*
1673 * if we are modifying block in fs tree, wait for readpage
1674 * to complete and drop the extent cache
1675 */
1676 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
5d4f98a2
YZ
1677 if (first) {
1678 inode = find_next_inode(root, key.objectid);
5d4f98a2 1679 first = 0;
33345d01 1680 } else if (inode && btrfs_ino(inode) < key.objectid) {
3fd0a558 1681 btrfs_add_delayed_iput(inode);
5d4f98a2 1682 inode = find_next_inode(root, key.objectid);
5d4f98a2 1683 }
33345d01 1684 if (inode && btrfs_ino(inode) == key.objectid) {
5d4f98a2
YZ
1685 end = key.offset +
1686 btrfs_file_extent_num_bytes(leaf, fi);
1687 WARN_ON(!IS_ALIGNED(key.offset,
1688 root->sectorsize));
1689 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1690 end--;
1691 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
d0082371 1692 key.offset, end);
5d4f98a2
YZ
1693 if (!ret)
1694 continue;
1695
1696 btrfs_drop_extent_cache(inode, key.offset, end,
1697 1);
1698 unlock_extent(&BTRFS_I(inode)->io_tree,
d0082371 1699 key.offset, end);
5d4f98a2
YZ
1700 }
1701 }
1702
1703 ret = get_new_location(rc->data_inode, &new_bytenr,
1704 bytenr, num_bytes);
83d4cfd4
JB
1705 if (ret) {
1706 /*
1707 * Don't have to abort since we've not changed anything
1708 * in the file extent yet.
1709 */
1710 break;
3fd0a558 1711 }
5d4f98a2
YZ
1712
1713 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1714 dirty = 1;
1715
1716 key.offset -= btrfs_file_extent_offset(leaf, fi);
1717 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1718 num_bytes, parent,
1719 btrfs_header_owner(leaf),
b06c4bf5 1720 key.objectid, key.offset);
83d4cfd4
JB
1721 if (ret) {
1722 btrfs_abort_transaction(trans, root, ret);
1723 break;
1724 }
5d4f98a2
YZ
1725
1726 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1727 parent, btrfs_header_owner(leaf),
b06c4bf5 1728 key.objectid, key.offset);
83d4cfd4
JB
1729 if (ret) {
1730 btrfs_abort_transaction(trans, root, ret);
1731 break;
1732 }
5d4f98a2
YZ
1733 }
1734 if (dirty)
1735 btrfs_mark_buffer_dirty(leaf);
3fd0a558
YZ
1736 if (inode)
1737 btrfs_add_delayed_iput(inode);
83d4cfd4 1738 return ret;
5d4f98a2
YZ
1739}
1740
1741static noinline_for_stack
1742int memcmp_node_keys(struct extent_buffer *eb, int slot,
1743 struct btrfs_path *path, int level)
1744{
1745 struct btrfs_disk_key key1;
1746 struct btrfs_disk_key key2;
1747 btrfs_node_key(eb, &key1, slot);
1748 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1749 return memcmp(&key1, &key2, sizeof(key1));
1750}
1751
1752/*
1753 * try to replace tree blocks in fs tree with the new blocks
1754 * in reloc tree. tree blocks haven't been modified since the
1755 * reloc tree was create can be replaced.
1756 *
1757 * if a block was replaced, level of the block + 1 is returned.
1758 * if no block got replaced, 0 is returned. if there are other
1759 * errors, a negative error number is returned.
1760 */
3fd0a558
YZ
1761static noinline_for_stack
1762int replace_path(struct btrfs_trans_handle *trans,
1763 struct btrfs_root *dest, struct btrfs_root *src,
1764 struct btrfs_path *path, struct btrfs_key *next_key,
1765 int lowest_level, int max_level)
5d4f98a2
YZ
1766{
1767 struct extent_buffer *eb;
1768 struct extent_buffer *parent;
1769 struct btrfs_key key;
1770 u64 old_bytenr;
1771 u64 new_bytenr;
1772 u64 old_ptr_gen;
1773 u64 new_ptr_gen;
1774 u64 last_snapshot;
1775 u32 blocksize;
3fd0a558 1776 int cow = 0;
5d4f98a2
YZ
1777 int level;
1778 int ret;
1779 int slot;
1780
1781 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1782 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
5d4f98a2
YZ
1783
1784 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
3fd0a558 1785again:
5d4f98a2
YZ
1786 slot = path->slots[lowest_level];
1787 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1788
1789 eb = btrfs_lock_root_node(dest);
1790 btrfs_set_lock_blocking(eb);
1791 level = btrfs_header_level(eb);
1792
1793 if (level < lowest_level) {
1794 btrfs_tree_unlock(eb);
1795 free_extent_buffer(eb);
1796 return 0;
1797 }
1798
3fd0a558
YZ
1799 if (cow) {
1800 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1801 BUG_ON(ret);
1802 }
5d4f98a2
YZ
1803 btrfs_set_lock_blocking(eb);
1804
1805 if (next_key) {
1806 next_key->objectid = (u64)-1;
1807 next_key->type = (u8)-1;
1808 next_key->offset = (u64)-1;
1809 }
1810
1811 parent = eb;
1812 while (1) {
1813 level = btrfs_header_level(parent);
1814 BUG_ON(level < lowest_level);
1815
1816 ret = btrfs_bin_search(parent, &key, level, &slot);
1817 if (ret && slot > 0)
1818 slot--;
1819
1820 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1821 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1822
1823 old_bytenr = btrfs_node_blockptr(parent, slot);
707e8a07 1824 blocksize = dest->nodesize;
5d4f98a2
YZ
1825 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1826
1827 if (level <= max_level) {
1828 eb = path->nodes[level];
1829 new_bytenr = btrfs_node_blockptr(eb,
1830 path->slots[level]);
1831 new_ptr_gen = btrfs_node_ptr_generation(eb,
1832 path->slots[level]);
1833 } else {
1834 new_bytenr = 0;
1835 new_ptr_gen = 0;
1836 }
1837
fae7f21c 1838 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
5d4f98a2
YZ
1839 ret = level;
1840 break;
1841 }
1842
1843 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1844 memcmp_node_keys(parent, slot, path, level)) {
3fd0a558 1845 if (level <= lowest_level) {
5d4f98a2
YZ
1846 ret = 0;
1847 break;
1848 }
1849
ce86cd59 1850 eb = read_tree_block(dest, old_bytenr, old_ptr_gen);
64c043de
LB
1851 if (IS_ERR(eb)) {
1852 ret = PTR_ERR(eb);
264813ac 1853 break;
64c043de
LB
1854 } else if (!extent_buffer_uptodate(eb)) {
1855 ret = -EIO;
416bc658 1856 free_extent_buffer(eb);
379cde74 1857 break;
416bc658 1858 }
5d4f98a2 1859 btrfs_tree_lock(eb);
3fd0a558
YZ
1860 if (cow) {
1861 ret = btrfs_cow_block(trans, dest, eb, parent,
1862 slot, &eb);
1863 BUG_ON(ret);
5d4f98a2 1864 }
3fd0a558 1865 btrfs_set_lock_blocking(eb);
5d4f98a2
YZ
1866
1867 btrfs_tree_unlock(parent);
1868 free_extent_buffer(parent);
1869
1870 parent = eb;
1871 continue;
1872 }
1873
3fd0a558
YZ
1874 if (!cow) {
1875 btrfs_tree_unlock(parent);
1876 free_extent_buffer(parent);
1877 cow = 1;
1878 goto again;
1879 }
1880
5d4f98a2
YZ
1881 btrfs_node_key_to_cpu(path->nodes[level], &key,
1882 path->slots[level]);
b3b4aa74 1883 btrfs_release_path(path);
5d4f98a2
YZ
1884
1885 path->lowest_level = level;
1886 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1887 path->lowest_level = 0;
1888 BUG_ON(ret);
1889
1890 /*
1891 * swap blocks in fs tree and reloc tree.
1892 */
1893 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1894 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1895 btrfs_mark_buffer_dirty(parent);
1896
1897 btrfs_set_node_blockptr(path->nodes[level],
1898 path->slots[level], old_bytenr);
1899 btrfs_set_node_ptr_generation(path->nodes[level],
1900 path->slots[level], old_ptr_gen);
1901 btrfs_mark_buffer_dirty(path->nodes[level]);
1902
1903 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1904 path->nodes[level]->start,
b06c4bf5 1905 src->root_key.objectid, level - 1, 0);
5d4f98a2
YZ
1906 BUG_ON(ret);
1907 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1908 0, dest->root_key.objectid, level - 1,
b06c4bf5 1909 0);
5d4f98a2
YZ
1910 BUG_ON(ret);
1911
1912 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1913 path->nodes[level]->start,
b06c4bf5 1914 src->root_key.objectid, level - 1, 0);
5d4f98a2
YZ
1915 BUG_ON(ret);
1916
1917 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1918 0, dest->root_key.objectid, level - 1,
b06c4bf5 1919 0);
5d4f98a2
YZ
1920 BUG_ON(ret);
1921
1922 btrfs_unlock_up_safe(path, 0);
1923
1924 ret = level;
1925 break;
1926 }
1927 btrfs_tree_unlock(parent);
1928 free_extent_buffer(parent);
1929 return ret;
1930}
1931
1932/*
1933 * helper to find next relocated block in reloc tree
1934 */
1935static noinline_for_stack
1936int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1937 int *level)
1938{
1939 struct extent_buffer *eb;
1940 int i;
1941 u64 last_snapshot;
1942 u32 nritems;
1943
1944 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1945
1946 for (i = 0; i < *level; i++) {
1947 free_extent_buffer(path->nodes[i]);
1948 path->nodes[i] = NULL;
1949 }
1950
1951 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1952 eb = path->nodes[i];
1953 nritems = btrfs_header_nritems(eb);
1954 while (path->slots[i] + 1 < nritems) {
1955 path->slots[i]++;
1956 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1957 last_snapshot)
1958 continue;
1959
1960 *level = i;
1961 return 0;
1962 }
1963 free_extent_buffer(path->nodes[i]);
1964 path->nodes[i] = NULL;
1965 }
1966 return 1;
1967}
1968
1969/*
1970 * walk down reloc tree to find relocated block of lowest level
1971 */
1972static noinline_for_stack
1973int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1974 int *level)
1975{
1976 struct extent_buffer *eb = NULL;
1977 int i;
1978 u64 bytenr;
1979 u64 ptr_gen = 0;
1980 u64 last_snapshot;
5d4f98a2
YZ
1981 u32 nritems;
1982
1983 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1984
1985 for (i = *level; i > 0; i--) {
1986 eb = path->nodes[i];
1987 nritems = btrfs_header_nritems(eb);
1988 while (path->slots[i] < nritems) {
1989 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1990 if (ptr_gen > last_snapshot)
1991 break;
1992 path->slots[i]++;
1993 }
1994 if (path->slots[i] >= nritems) {
1995 if (i == *level)
1996 break;
1997 *level = i + 1;
1998 return 0;
1999 }
2000 if (i == 1) {
2001 *level = i;
2002 return 0;
2003 }
2004
2005 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
ce86cd59 2006 eb = read_tree_block(root, bytenr, ptr_gen);
64c043de
LB
2007 if (IS_ERR(eb)) {
2008 return PTR_ERR(eb);
2009 } else if (!extent_buffer_uptodate(eb)) {
416bc658
JB
2010 free_extent_buffer(eb);
2011 return -EIO;
2012 }
5d4f98a2
YZ
2013 BUG_ON(btrfs_header_level(eb) != i - 1);
2014 path->nodes[i - 1] = eb;
2015 path->slots[i - 1] = 0;
2016 }
2017 return 1;
2018}
2019
2020/*
2021 * invalidate extent cache for file extents whose key in range of
2022 * [min_key, max_key)
2023 */
2024static int invalidate_extent_cache(struct btrfs_root *root,
2025 struct btrfs_key *min_key,
2026 struct btrfs_key *max_key)
2027{
2028 struct inode *inode = NULL;
2029 u64 objectid;
2030 u64 start, end;
33345d01 2031 u64 ino;
5d4f98a2
YZ
2032
2033 objectid = min_key->objectid;
2034 while (1) {
2035 cond_resched();
2036 iput(inode);
2037
2038 if (objectid > max_key->objectid)
2039 break;
2040
2041 inode = find_next_inode(root, objectid);
2042 if (!inode)
2043 break;
33345d01 2044 ino = btrfs_ino(inode);
5d4f98a2 2045
33345d01 2046 if (ino > max_key->objectid) {
5d4f98a2
YZ
2047 iput(inode);
2048 break;
2049 }
2050
33345d01 2051 objectid = ino + 1;
5d4f98a2
YZ
2052 if (!S_ISREG(inode->i_mode))
2053 continue;
2054
33345d01 2055 if (unlikely(min_key->objectid == ino)) {
5d4f98a2
YZ
2056 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2057 continue;
2058 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2059 start = 0;
2060 else {
2061 start = min_key->offset;
2062 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2063 }
2064 } else {
2065 start = 0;
2066 }
2067
33345d01 2068 if (unlikely(max_key->objectid == ino)) {
5d4f98a2
YZ
2069 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2070 continue;
2071 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2072 end = (u64)-1;
2073 } else {
2074 if (max_key->offset == 0)
2075 continue;
2076 end = max_key->offset;
2077 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2078 end--;
2079 }
2080 } else {
2081 end = (u64)-1;
2082 }
2083
2084 /* the lock_extent waits for readpage to complete */
d0082371 2085 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
5d4f98a2 2086 btrfs_drop_extent_cache(inode, start, end, 1);
d0082371 2087 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
5d4f98a2
YZ
2088 }
2089 return 0;
2090}
2091
2092static int find_next_key(struct btrfs_path *path, int level,
2093 struct btrfs_key *key)
2094
2095{
2096 while (level < BTRFS_MAX_LEVEL) {
2097 if (!path->nodes[level])
2098 break;
2099 if (path->slots[level] + 1 <
2100 btrfs_header_nritems(path->nodes[level])) {
2101 btrfs_node_key_to_cpu(path->nodes[level], key,
2102 path->slots[level] + 1);
2103 return 0;
2104 }
2105 level++;
2106 }
2107 return 1;
2108}
2109
2110/*
2111 * merge the relocated tree blocks in reloc tree with corresponding
2112 * fs tree.
2113 */
2114static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2115 struct btrfs_root *root)
2116{
2117 LIST_HEAD(inode_list);
2118 struct btrfs_key key;
2119 struct btrfs_key next_key;
9e6a0c52 2120 struct btrfs_trans_handle *trans = NULL;
5d4f98a2
YZ
2121 struct btrfs_root *reloc_root;
2122 struct btrfs_root_item *root_item;
2123 struct btrfs_path *path;
3fd0a558 2124 struct extent_buffer *leaf;
5d4f98a2
YZ
2125 int level;
2126 int max_level;
2127 int replaced = 0;
2128 int ret;
2129 int err = 0;
3fd0a558 2130 u32 min_reserved;
5d4f98a2
YZ
2131
2132 path = btrfs_alloc_path();
2133 if (!path)
2134 return -ENOMEM;
e4058b54 2135 path->reada = READA_FORWARD;
5d4f98a2
YZ
2136
2137 reloc_root = root->reloc_root;
2138 root_item = &reloc_root->root_item;
2139
2140 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2141 level = btrfs_root_level(root_item);
2142 extent_buffer_get(reloc_root->node);
2143 path->nodes[level] = reloc_root->node;
2144 path->slots[level] = 0;
2145 } else {
2146 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2147
2148 level = root_item->drop_level;
2149 BUG_ON(level == 0);
2150 path->lowest_level = level;
2151 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
33c66f43 2152 path->lowest_level = 0;
5d4f98a2
YZ
2153 if (ret < 0) {
2154 btrfs_free_path(path);
2155 return ret;
2156 }
2157
2158 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2159 path->slots[level]);
2160 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2161
2162 btrfs_unlock_up_safe(path, 0);
2163 }
2164
3fd0a558
YZ
2165 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2166 memset(&next_key, 0, sizeof(next_key));
5d4f98a2 2167
3fd0a558 2168 while (1) {
08e007d2
MX
2169 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2170 BTRFS_RESERVE_FLUSH_ALL);
3fd0a558 2171 if (ret) {
9e6a0c52
JB
2172 err = ret;
2173 goto out;
5d4f98a2 2174 }
9e6a0c52
JB
2175 trans = btrfs_start_transaction(root, 0);
2176 if (IS_ERR(trans)) {
2177 err = PTR_ERR(trans);
2178 trans = NULL;
2179 goto out;
2180 }
2181 trans->block_rsv = rc->block_rsv;
5d4f98a2 2182
5d4f98a2 2183 replaced = 0;
5d4f98a2
YZ
2184 max_level = level;
2185
2186 ret = walk_down_reloc_tree(reloc_root, path, &level);
2187 if (ret < 0) {
2188 err = ret;
2189 goto out;
2190 }
2191 if (ret > 0)
2192 break;
2193
2194 if (!find_next_key(path, level, &key) &&
2195 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2196 ret = 0;
5d4f98a2 2197 } else {
3fd0a558
YZ
2198 ret = replace_path(trans, root, reloc_root, path,
2199 &next_key, level, max_level);
5d4f98a2
YZ
2200 }
2201 if (ret < 0) {
2202 err = ret;
2203 goto out;
2204 }
2205
2206 if (ret > 0) {
2207 level = ret;
2208 btrfs_node_key_to_cpu(path->nodes[level], &key,
2209 path->slots[level]);
2210 replaced = 1;
5d4f98a2
YZ
2211 }
2212
2213 ret = walk_up_reloc_tree(reloc_root, path, &level);
2214 if (ret > 0)
2215 break;
2216
2217 BUG_ON(level == 0);
2218 /*
2219 * save the merging progress in the drop_progress.
2220 * this is OK since root refs == 1 in this case.
2221 */
2222 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2223 path->slots[level]);
2224 root_item->drop_level = level;
2225
3fd0a558 2226 btrfs_end_transaction_throttle(trans, root);
9e6a0c52 2227 trans = NULL;
5d4f98a2 2228
b53d3f5d 2229 btrfs_btree_balance_dirty(root);
5d4f98a2
YZ
2230
2231 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2232 invalidate_extent_cache(root, &key, &next_key);
2233 }
2234
2235 /*
2236 * handle the case only one block in the fs tree need to be
2237 * relocated and the block is tree root.
2238 */
2239 leaf = btrfs_lock_root_node(root);
2240 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2241 btrfs_tree_unlock(leaf);
2242 free_extent_buffer(leaf);
2243 if (ret < 0)
2244 err = ret;
2245out:
2246 btrfs_free_path(path);
2247
2248 if (err == 0) {
2249 memset(&root_item->drop_progress, 0,
2250 sizeof(root_item->drop_progress));
2251 root_item->drop_level = 0;
2252 btrfs_set_root_refs(root_item, 0);
3fd0a558 2253 btrfs_update_reloc_root(trans, root);
5d4f98a2
YZ
2254 }
2255
9e6a0c52
JB
2256 if (trans)
2257 btrfs_end_transaction_throttle(trans, root);
5d4f98a2 2258
b53d3f5d 2259 btrfs_btree_balance_dirty(root);
5d4f98a2 2260
5d4f98a2
YZ
2261 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2262 invalidate_extent_cache(root, &key, &next_key);
2263
2264 return err;
2265}
2266
3fd0a558
YZ
2267static noinline_for_stack
2268int prepare_to_merge(struct reloc_control *rc, int err)
5d4f98a2 2269{
3fd0a558 2270 struct btrfs_root *root = rc->extent_root;
5d4f98a2 2271 struct btrfs_root *reloc_root;
3fd0a558
YZ
2272 struct btrfs_trans_handle *trans;
2273 LIST_HEAD(reloc_roots);
2274 u64 num_bytes = 0;
2275 int ret;
3fd0a558 2276
7585717f 2277 mutex_lock(&root->fs_info->reloc_mutex);
3fd0a558
YZ
2278 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2279 rc->merging_rsv_size += rc->nodes_relocated * 2;
7585717f
CM
2280 mutex_unlock(&root->fs_info->reloc_mutex);
2281
3fd0a558
YZ
2282again:
2283 if (!err) {
2284 num_bytes = rc->merging_rsv_size;
08e007d2
MX
2285 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2286 BTRFS_RESERVE_FLUSH_ALL);
3fd0a558
YZ
2287 if (ret)
2288 err = ret;
2289 }
2290
7a7eaa40 2291 trans = btrfs_join_transaction(rc->extent_root);
3612b495
TI
2292 if (IS_ERR(trans)) {
2293 if (!err)
2294 btrfs_block_rsv_release(rc->extent_root,
2295 rc->block_rsv, num_bytes);
2296 return PTR_ERR(trans);
2297 }
3fd0a558
YZ
2298
2299 if (!err) {
2300 if (num_bytes != rc->merging_rsv_size) {
2301 btrfs_end_transaction(trans, rc->extent_root);
2302 btrfs_block_rsv_release(rc->extent_root,
2303 rc->block_rsv, num_bytes);
3fd0a558
YZ
2304 goto again;
2305 }
2306 }
5d4f98a2 2307
3fd0a558
YZ
2308 rc->merge_reloc_tree = 1;
2309
2310 while (!list_empty(&rc->reloc_roots)) {
2311 reloc_root = list_entry(rc->reloc_roots.next,
2312 struct btrfs_root, root_list);
2313 list_del_init(&reloc_root->root_list);
5d4f98a2 2314
5d4f98a2
YZ
2315 root = read_fs_root(reloc_root->fs_info,
2316 reloc_root->root_key.offset);
2317 BUG_ON(IS_ERR(root));
2318 BUG_ON(root->reloc_root != reloc_root);
2319
3fd0a558
YZ
2320 /*
2321 * set reference count to 1, so btrfs_recover_relocation
2322 * knows it should resumes merging
2323 */
2324 if (!err)
2325 btrfs_set_root_refs(&reloc_root->root_item, 1);
5d4f98a2 2326 btrfs_update_reloc_root(trans, root);
5d4f98a2 2327
3fd0a558
YZ
2328 list_add(&reloc_root->root_list, &reloc_roots);
2329 }
5d4f98a2 2330
3fd0a558 2331 list_splice(&reloc_roots, &rc->reloc_roots);
5d4f98a2 2332
3fd0a558
YZ
2333 if (!err)
2334 btrfs_commit_transaction(trans, rc->extent_root);
2335 else
2336 btrfs_end_transaction(trans, rc->extent_root);
2337 return err;
5d4f98a2
YZ
2338}
2339
aca1bba6
LB
2340static noinline_for_stack
2341void free_reloc_roots(struct list_head *list)
2342{
2343 struct btrfs_root *reloc_root;
2344
2345 while (!list_empty(list)) {
2346 reloc_root = list_entry(list->next, struct btrfs_root,
2347 root_list);
c974c464 2348 __del_reloc_root(reloc_root);
aca1bba6
LB
2349 }
2350}
2351
3fd0a558 2352static noinline_for_stack
94404e82 2353void merge_reloc_roots(struct reloc_control *rc)
5d4f98a2 2354{
5d4f98a2 2355 struct btrfs_root *root;
3fd0a558 2356 struct btrfs_root *reloc_root;
5bc7247a
MX
2357 u64 last_snap;
2358 u64 otransid;
2359 u64 objectid;
3fd0a558
YZ
2360 LIST_HEAD(reloc_roots);
2361 int found = 0;
aca1bba6 2362 int ret = 0;
3fd0a558
YZ
2363again:
2364 root = rc->extent_root;
7585717f
CM
2365
2366 /*
2367 * this serializes us with btrfs_record_root_in_transaction,
2368 * we have to make sure nobody is in the middle of
2369 * adding their roots to the list while we are
2370 * doing this splice
2371 */
2372 mutex_lock(&root->fs_info->reloc_mutex);
3fd0a558 2373 list_splice_init(&rc->reloc_roots, &reloc_roots);
7585717f 2374 mutex_unlock(&root->fs_info->reloc_mutex);
5d4f98a2 2375
3fd0a558
YZ
2376 while (!list_empty(&reloc_roots)) {
2377 found = 1;
2378 reloc_root = list_entry(reloc_roots.next,
2379 struct btrfs_root, root_list);
5d4f98a2 2380
3fd0a558
YZ
2381 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2382 root = read_fs_root(reloc_root->fs_info,
2383 reloc_root->root_key.offset);
2384 BUG_ON(IS_ERR(root));
2385 BUG_ON(root->reloc_root != reloc_root);
5d4f98a2 2386
3fd0a558 2387 ret = merge_reloc_root(rc, root);
b37b39cd 2388 if (ret) {
25e293c2
WS
2389 if (list_empty(&reloc_root->root_list))
2390 list_add_tail(&reloc_root->root_list,
2391 &reloc_roots);
aca1bba6 2392 goto out;
b37b39cd 2393 }
3fd0a558
YZ
2394 } else {
2395 list_del_init(&reloc_root->root_list);
2396 }
5bc7247a
MX
2397
2398 /*
2399 * we keep the old last snapshod transid in rtranid when we
2400 * created the relocation tree.
2401 */
2402 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2403 otransid = btrfs_root_otransid(&reloc_root->root_item);
2404 objectid = reloc_root->root_key.offset;
2405
2c536799 2406 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
aca1bba6
LB
2407 if (ret < 0) {
2408 if (list_empty(&reloc_root->root_list))
2409 list_add_tail(&reloc_root->root_list,
2410 &reloc_roots);
2411 goto out;
2412 }
5d4f98a2
YZ
2413 }
2414
3fd0a558
YZ
2415 if (found) {
2416 found = 0;
2417 goto again;
2418 }
aca1bba6
LB
2419out:
2420 if (ret) {
a4553fef 2421 btrfs_std_error(root->fs_info, ret, NULL);
aca1bba6
LB
2422 if (!list_empty(&reloc_roots))
2423 free_reloc_roots(&reloc_roots);
467bb1d2
WS
2424
2425 /* new reloc root may be added */
2426 mutex_lock(&root->fs_info->reloc_mutex);
2427 list_splice_init(&rc->reloc_roots, &reloc_roots);
2428 mutex_unlock(&root->fs_info->reloc_mutex);
2429 if (!list_empty(&reloc_roots))
2430 free_reloc_roots(&reloc_roots);
aca1bba6
LB
2431 }
2432
5d4f98a2 2433 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
5d4f98a2
YZ
2434}
2435
2436static void free_block_list(struct rb_root *blocks)
2437{
2438 struct tree_block *block;
2439 struct rb_node *rb_node;
2440 while ((rb_node = rb_first(blocks))) {
2441 block = rb_entry(rb_node, struct tree_block, rb_node);
2442 rb_erase(rb_node, blocks);
2443 kfree(block);
2444 }
2445}
2446
2447static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2448 struct btrfs_root *reloc_root)
2449{
2450 struct btrfs_root *root;
2451
2452 if (reloc_root->last_trans == trans->transid)
2453 return 0;
2454
2455 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2456 BUG_ON(IS_ERR(root));
2457 BUG_ON(root->reloc_root != reloc_root);
2458
2459 return btrfs_record_root_in_trans(trans, root);
2460}
2461
3fd0a558
YZ
2462static noinline_for_stack
2463struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2464 struct reloc_control *rc,
2465 struct backref_node *node,
dc4103f9 2466 struct backref_edge *edges[])
5d4f98a2
YZ
2467{
2468 struct backref_node *next;
2469 struct btrfs_root *root;
3fd0a558
YZ
2470 int index = 0;
2471
5d4f98a2
YZ
2472 next = node;
2473 while (1) {
2474 cond_resched();
2475 next = walk_up_backref(next, edges, &index);
2476 root = next->root;
3fd0a558 2477 BUG_ON(!root);
27cdeb70 2478 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
5d4f98a2
YZ
2479
2480 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2481 record_reloc_root_in_trans(trans, root);
2482 break;
2483 }
2484
3fd0a558
YZ
2485 btrfs_record_root_in_trans(trans, root);
2486 root = root->reloc_root;
2487
2488 if (next->new_bytenr != root->node->start) {
2489 BUG_ON(next->new_bytenr);
2490 BUG_ON(!list_empty(&next->list));
2491 next->new_bytenr = root->node->start;
2492 next->root = root;
2493 list_add_tail(&next->list,
2494 &rc->backref_cache.changed);
2495 __mark_block_processed(rc, next);
5d4f98a2
YZ
2496 break;
2497 }
2498
3fd0a558 2499 WARN_ON(1);
5d4f98a2
YZ
2500 root = NULL;
2501 next = walk_down_backref(edges, &index);
2502 if (!next || next->level <= node->level)
2503 break;
2504 }
3fd0a558
YZ
2505 if (!root)
2506 return NULL;
5d4f98a2 2507
3fd0a558
YZ
2508 next = node;
2509 /* setup backref node path for btrfs_reloc_cow_block */
2510 while (1) {
2511 rc->backref_cache.path[next->level] = next;
2512 if (--index < 0)
2513 break;
2514 next = edges[index]->node[UPPER];
5d4f98a2 2515 }
5d4f98a2
YZ
2516 return root;
2517}
2518
3fd0a558
YZ
2519/*
2520 * select a tree root for relocation. return NULL if the block
2521 * is reference counted. we should use do_relocation() in this
2522 * case. return a tree root pointer if the block isn't reference
2523 * counted. return -ENOENT if the block is root of reloc tree.
2524 */
5d4f98a2 2525static noinline_for_stack
147d256e 2526struct btrfs_root *select_one_root(struct backref_node *node)
5d4f98a2 2527{
3fd0a558
YZ
2528 struct backref_node *next;
2529 struct btrfs_root *root;
2530 struct btrfs_root *fs_root = NULL;
5d4f98a2 2531 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
3fd0a558
YZ
2532 int index = 0;
2533
2534 next = node;
2535 while (1) {
2536 cond_resched();
2537 next = walk_up_backref(next, edges, &index);
2538 root = next->root;
2539 BUG_ON(!root);
2540
25985edc 2541 /* no other choice for non-references counted tree */
27cdeb70 2542 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
3fd0a558
YZ
2543 return root;
2544
2545 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2546 fs_root = root;
2547
2548 if (next != node)
2549 return NULL;
2550
2551 next = walk_down_backref(edges, &index);
2552 if (!next || next->level <= node->level)
2553 break;
2554 }
2555
2556 if (!fs_root)
2557 return ERR_PTR(-ENOENT);
2558 return fs_root;
5d4f98a2
YZ
2559}
2560
2561static noinline_for_stack
3fd0a558
YZ
2562u64 calcu_metadata_size(struct reloc_control *rc,
2563 struct backref_node *node, int reserve)
5d4f98a2 2564{
3fd0a558
YZ
2565 struct backref_node *next = node;
2566 struct backref_edge *edge;
2567 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2568 u64 num_bytes = 0;
2569 int index = 0;
2570
2571 BUG_ON(reserve && node->processed);
2572
2573 while (next) {
2574 cond_resched();
2575 while (1) {
2576 if (next->processed && (reserve || next != node))
2577 break;
2578
707e8a07 2579 num_bytes += rc->extent_root->nodesize;
3fd0a558
YZ
2580
2581 if (list_empty(&next->upper))
2582 break;
2583
2584 edge = list_entry(next->upper.next,
2585 struct backref_edge, list[LOWER]);
2586 edges[index++] = edge;
2587 next = edge->node[UPPER];
2588 }
2589 next = walk_down_backref(edges, &index);
2590 }
2591 return num_bytes;
5d4f98a2
YZ
2592}
2593
3fd0a558
YZ
2594static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2595 struct reloc_control *rc,
2596 struct backref_node *node)
5d4f98a2 2597{
3fd0a558
YZ
2598 struct btrfs_root *root = rc->extent_root;
2599 u64 num_bytes;
2600 int ret;
0647bf56 2601 u64 tmp;
3fd0a558
YZ
2602
2603 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
5d4f98a2 2604
3fd0a558 2605 trans->block_rsv = rc->block_rsv;
0647bf56
WS
2606 rc->reserved_bytes += num_bytes;
2607 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2608 BTRFS_RESERVE_FLUSH_ALL);
3fd0a558 2609 if (ret) {
0647bf56
WS
2610 if (ret == -EAGAIN) {
2611 tmp = rc->extent_root->nodesize *
2612 RELOCATION_RESERVED_NODES;
2613 while (tmp <= rc->reserved_bytes)
2614 tmp <<= 1;
2615 /*
2616 * only one thread can access block_rsv at this point,
2617 * so we don't need hold lock to protect block_rsv.
2618 * we expand more reservation size here to allow enough
2619 * space for relocation and we will return eailer in
2620 * enospc case.
2621 */
2622 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2623 RELOCATION_RESERVED_NODES;
2624 }
3fd0a558 2625 return ret;
5d4f98a2 2626 }
3fd0a558 2627
3fd0a558
YZ
2628 return 0;
2629}
2630
5d4f98a2
YZ
2631/*
2632 * relocate a block tree, and then update pointers in upper level
2633 * blocks that reference the block to point to the new location.
2634 *
2635 * if called by link_to_upper, the block has already been relocated.
2636 * in that case this function just updates pointers.
2637 */
2638static int do_relocation(struct btrfs_trans_handle *trans,
3fd0a558 2639 struct reloc_control *rc,
5d4f98a2
YZ
2640 struct backref_node *node,
2641 struct btrfs_key *key,
2642 struct btrfs_path *path, int lowest)
2643{
2644 struct backref_node *upper;
2645 struct backref_edge *edge;
2646 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2647 struct btrfs_root *root;
2648 struct extent_buffer *eb;
2649 u32 blocksize;
2650 u64 bytenr;
2651 u64 generation;
5d4f98a2
YZ
2652 int slot;
2653 int ret;
2654 int err = 0;
2655
2656 BUG_ON(lowest && node->eb);
2657
2658 path->lowest_level = node->level + 1;
3fd0a558 2659 rc->backref_cache.path[node->level] = node;
5d4f98a2
YZ
2660 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2661 cond_resched();
5d4f98a2
YZ
2662
2663 upper = edge->node[UPPER];
dc4103f9 2664 root = select_reloc_root(trans, rc, upper, edges);
3fd0a558
YZ
2665 BUG_ON(!root);
2666
2667 if (upper->eb && !upper->locked) {
2668 if (!lowest) {
2669 ret = btrfs_bin_search(upper->eb, key,
2670 upper->level, &slot);
2671 BUG_ON(ret);
2672 bytenr = btrfs_node_blockptr(upper->eb, slot);
2673 if (node->eb->start == bytenr)
2674 goto next;
2675 }
5d4f98a2 2676 drop_node_buffer(upper);
3fd0a558 2677 }
5d4f98a2
YZ
2678
2679 if (!upper->eb) {
2680 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2681 if (ret < 0) {
2682 err = ret;
2683 break;
2684 }
2685 BUG_ON(ret > 0);
2686
3fd0a558
YZ
2687 if (!upper->eb) {
2688 upper->eb = path->nodes[upper->level];
2689 path->nodes[upper->level] = NULL;
2690 } else {
2691 BUG_ON(upper->eb != path->nodes[upper->level]);
2692 }
5d4f98a2 2693
3fd0a558
YZ
2694 upper->locked = 1;
2695 path->locks[upper->level] = 0;
5d4f98a2 2696
3fd0a558 2697 slot = path->slots[upper->level];
b3b4aa74 2698 btrfs_release_path(path);
5d4f98a2
YZ
2699 } else {
2700 ret = btrfs_bin_search(upper->eb, key, upper->level,
2701 &slot);
2702 BUG_ON(ret);
2703 }
2704
2705 bytenr = btrfs_node_blockptr(upper->eb, slot);
3fd0a558
YZ
2706 if (lowest) {
2707 BUG_ON(bytenr != node->bytenr);
5d4f98a2 2708 } else {
3fd0a558
YZ
2709 if (node->eb->start == bytenr)
2710 goto next;
5d4f98a2
YZ
2711 }
2712
707e8a07 2713 blocksize = root->nodesize;
5d4f98a2 2714 generation = btrfs_node_ptr_generation(upper->eb, slot);
ce86cd59 2715 eb = read_tree_block(root, bytenr, generation);
64c043de
LB
2716 if (IS_ERR(eb)) {
2717 err = PTR_ERR(eb);
2718 goto next;
2719 } else if (!extent_buffer_uptodate(eb)) {
416bc658 2720 free_extent_buffer(eb);
97d9a8a4
TI
2721 err = -EIO;
2722 goto next;
2723 }
5d4f98a2
YZ
2724 btrfs_tree_lock(eb);
2725 btrfs_set_lock_blocking(eb);
2726
2727 if (!node->eb) {
2728 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2729 slot, &eb);
3fd0a558
YZ
2730 btrfs_tree_unlock(eb);
2731 free_extent_buffer(eb);
5d4f98a2
YZ
2732 if (ret < 0) {
2733 err = ret;
3fd0a558 2734 goto next;
5d4f98a2 2735 }
3fd0a558 2736 BUG_ON(node->eb != eb);
5d4f98a2
YZ
2737 } else {
2738 btrfs_set_node_blockptr(upper->eb, slot,
2739 node->eb->start);
2740 btrfs_set_node_ptr_generation(upper->eb, slot,
2741 trans->transid);
2742 btrfs_mark_buffer_dirty(upper->eb);
2743
2744 ret = btrfs_inc_extent_ref(trans, root,
2745 node->eb->start, blocksize,
2746 upper->eb->start,
2747 btrfs_header_owner(upper->eb),
b06c4bf5 2748 node->level, 0);
5d4f98a2
YZ
2749 BUG_ON(ret);
2750
2751 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2752 BUG_ON(ret);
5d4f98a2 2753 }
3fd0a558
YZ
2754next:
2755 if (!upper->pending)
2756 drop_node_buffer(upper);
2757 else
2758 unlock_node_buffer(upper);
2759 if (err)
2760 break;
5d4f98a2 2761 }
3fd0a558
YZ
2762
2763 if (!err && node->pending) {
2764 drop_node_buffer(node);
2765 list_move_tail(&node->list, &rc->backref_cache.changed);
2766 node->pending = 0;
2767 }
2768
5d4f98a2 2769 path->lowest_level = 0;
3fd0a558 2770 BUG_ON(err == -ENOSPC);
5d4f98a2
YZ
2771 return err;
2772}
2773
2774static int link_to_upper(struct btrfs_trans_handle *trans,
3fd0a558 2775 struct reloc_control *rc,
5d4f98a2
YZ
2776 struct backref_node *node,
2777 struct btrfs_path *path)
2778{
2779 struct btrfs_key key;
5d4f98a2
YZ
2780
2781 btrfs_node_key_to_cpu(node->eb, &key, 0);
3fd0a558 2782 return do_relocation(trans, rc, node, &key, path, 0);
5d4f98a2
YZ
2783}
2784
2785static int finish_pending_nodes(struct btrfs_trans_handle *trans,
3fd0a558
YZ
2786 struct reloc_control *rc,
2787 struct btrfs_path *path, int err)
5d4f98a2 2788{
3fd0a558
YZ
2789 LIST_HEAD(list);
2790 struct backref_cache *cache = &rc->backref_cache;
5d4f98a2
YZ
2791 struct backref_node *node;
2792 int level;
2793 int ret;
5d4f98a2
YZ
2794
2795 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2796 while (!list_empty(&cache->pending[level])) {
2797 node = list_entry(cache->pending[level].next,
3fd0a558
YZ
2798 struct backref_node, list);
2799 list_move_tail(&node->list, &list);
2800 BUG_ON(!node->pending);
5d4f98a2 2801
3fd0a558
YZ
2802 if (!err) {
2803 ret = link_to_upper(trans, rc, node, path);
2804 if (ret < 0)
2805 err = ret;
2806 }
5d4f98a2 2807 }
3fd0a558 2808 list_splice_init(&list, &cache->pending[level]);
5d4f98a2 2809 }
5d4f98a2
YZ
2810 return err;
2811}
2812
2813static void mark_block_processed(struct reloc_control *rc,
3fd0a558
YZ
2814 u64 bytenr, u32 blocksize)
2815{
2816 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2817 EXTENT_DIRTY, GFP_NOFS);
2818}
2819
2820static void __mark_block_processed(struct reloc_control *rc,
2821 struct backref_node *node)
5d4f98a2
YZ
2822{
2823 u32 blocksize;
2824 if (node->level == 0 ||
2825 in_block_group(node->bytenr, rc->block_group)) {
707e8a07 2826 blocksize = rc->extent_root->nodesize;
3fd0a558 2827 mark_block_processed(rc, node->bytenr, blocksize);
5d4f98a2
YZ
2828 }
2829 node->processed = 1;
2830}
2831
2832/*
2833 * mark a block and all blocks directly/indirectly reference the block
2834 * as processed.
2835 */
2836static void update_processed_blocks(struct reloc_control *rc,
2837 struct backref_node *node)
2838{
2839 struct backref_node *next = node;
2840 struct backref_edge *edge;
2841 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2842 int index = 0;
2843
2844 while (next) {
2845 cond_resched();
2846 while (1) {
2847 if (next->processed)
2848 break;
2849
3fd0a558 2850 __mark_block_processed(rc, next);
5d4f98a2
YZ
2851
2852 if (list_empty(&next->upper))
2853 break;
2854
2855 edge = list_entry(next->upper.next,
2856 struct backref_edge, list[LOWER]);
2857 edges[index++] = edge;
2858 next = edge->node[UPPER];
2859 }
2860 next = walk_down_backref(edges, &index);
2861 }
2862}
2863
7476dfda 2864static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
3fd0a558 2865{
7476dfda
DS
2866 u32 blocksize = rc->extent_root->nodesize;
2867
3fd0a558
YZ
2868 if (test_range_bit(&rc->processed_blocks, bytenr,
2869 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2870 return 1;
2871 return 0;
5d4f98a2
YZ
2872}
2873
2874static int get_tree_block_key(struct reloc_control *rc,
2875 struct tree_block *block)
2876{
2877 struct extent_buffer *eb;
2878
2879 BUG_ON(block->key_ready);
2880 eb = read_tree_block(rc->extent_root, block->bytenr,
ce86cd59 2881 block->key.offset);
64c043de
LB
2882 if (IS_ERR(eb)) {
2883 return PTR_ERR(eb);
2884 } else if (!extent_buffer_uptodate(eb)) {
416bc658
JB
2885 free_extent_buffer(eb);
2886 return -EIO;
2887 }
5d4f98a2
YZ
2888 WARN_ON(btrfs_header_level(eb) != block->level);
2889 if (block->level == 0)
2890 btrfs_item_key_to_cpu(eb, &block->key, 0);
2891 else
2892 btrfs_node_key_to_cpu(eb, &block->key, 0);
2893 free_extent_buffer(eb);
2894 block->key_ready = 1;
2895 return 0;
2896}
2897
5d4f98a2
YZ
2898/*
2899 * helper function to relocate a tree block
2900 */
2901static int relocate_tree_block(struct btrfs_trans_handle *trans,
2902 struct reloc_control *rc,
2903 struct backref_node *node,
2904 struct btrfs_key *key,
2905 struct btrfs_path *path)
2906{
2907 struct btrfs_root *root;
3fd0a558
YZ
2908 int ret = 0;
2909
2910 if (!node)
2911 return 0;
5d4f98a2 2912
3fd0a558 2913 BUG_ON(node->processed);
147d256e 2914 root = select_one_root(node);
3fd0a558 2915 if (root == ERR_PTR(-ENOENT)) {
5d4f98a2 2916 update_processed_blocks(rc, node);
3fd0a558 2917 goto out;
5d4f98a2
YZ
2918 }
2919
27cdeb70 2920 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
3fd0a558
YZ
2921 ret = reserve_metadata_space(trans, rc, node);
2922 if (ret)
5d4f98a2 2923 goto out;
5d4f98a2
YZ
2924 }
2925
3fd0a558 2926 if (root) {
27cdeb70 2927 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
3fd0a558
YZ
2928 BUG_ON(node->new_bytenr);
2929 BUG_ON(!list_empty(&node->list));
2930 btrfs_record_root_in_trans(trans, root);
2931 root = root->reloc_root;
2932 node->new_bytenr = root->node->start;
2933 node->root = root;
2934 list_add_tail(&node->list, &rc->backref_cache.changed);
2935 } else {
2936 path->lowest_level = node->level;
2937 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
b3b4aa74 2938 btrfs_release_path(path);
3fd0a558
YZ
2939 if (ret > 0)
2940 ret = 0;
2941 }
2942 if (!ret)
2943 update_processed_blocks(rc, node);
2944 } else {
2945 ret = do_relocation(trans, rc, node, key, path, 1);
2946 }
5d4f98a2 2947out:
0647bf56 2948 if (ret || node->level == 0 || node->cowonly)
3fd0a558 2949 remove_backref_node(&rc->backref_cache, node);
5d4f98a2
YZ
2950 return ret;
2951}
2952
2953/*
2954 * relocate a list of blocks
2955 */
2956static noinline_for_stack
2957int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2958 struct reloc_control *rc, struct rb_root *blocks)
2959{
5d4f98a2
YZ
2960 struct backref_node *node;
2961 struct btrfs_path *path;
2962 struct tree_block *block;
2963 struct rb_node *rb_node;
5d4f98a2
YZ
2964 int ret;
2965 int err = 0;
2966
2967 path = btrfs_alloc_path();
e1a12670
LB
2968 if (!path) {
2969 err = -ENOMEM;
34c2b290 2970 goto out_free_blocks;
e1a12670 2971 }
5d4f98a2 2972
5d4f98a2
YZ
2973 rb_node = rb_first(blocks);
2974 while (rb_node) {
2975 block = rb_entry(rb_node, struct tree_block, rb_node);
5d4f98a2 2976 if (!block->key_ready)
d3e46fea 2977 readahead_tree_block(rc->extent_root, block->bytenr);
5d4f98a2
YZ
2978 rb_node = rb_next(rb_node);
2979 }
2980
2981 rb_node = rb_first(blocks);
2982 while (rb_node) {
2983 block = rb_entry(rb_node, struct tree_block, rb_node);
34c2b290
DS
2984 if (!block->key_ready) {
2985 err = get_tree_block_key(rc, block);
2986 if (err)
2987 goto out_free_path;
2988 }
5d4f98a2
YZ
2989 rb_node = rb_next(rb_node);
2990 }
2991
2992 rb_node = rb_first(blocks);
2993 while (rb_node) {
2994 block = rb_entry(rb_node, struct tree_block, rb_node);
2995
3fd0a558 2996 node = build_backref_tree(rc, &block->key,
5d4f98a2
YZ
2997 block->level, block->bytenr);
2998 if (IS_ERR(node)) {
2999 err = PTR_ERR(node);
3000 goto out;
3001 }
3002
3003 ret = relocate_tree_block(trans, rc, node, &block->key,
3004 path);
3005 if (ret < 0) {
3fd0a558
YZ
3006 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3007 err = ret;
5d4f98a2
YZ
3008 goto out;
3009 }
5d4f98a2
YZ
3010 rb_node = rb_next(rb_node);
3011 }
5d4f98a2 3012out:
3fd0a558 3013 err = finish_pending_nodes(trans, rc, path, err);
5d4f98a2 3014
34c2b290 3015out_free_path:
5d4f98a2 3016 btrfs_free_path(path);
34c2b290 3017out_free_blocks:
e1a12670 3018 free_block_list(blocks);
5d4f98a2
YZ
3019 return err;
3020}
3021
efa56464
YZ
3022static noinline_for_stack
3023int prealloc_file_extent_cluster(struct inode *inode,
3024 struct file_extent_cluster *cluster)
3025{
3026 u64 alloc_hint = 0;
3027 u64 start;
3028 u64 end;
3029 u64 offset = BTRFS_I(inode)->index_cnt;
3030 u64 num_bytes;
3031 int nr = 0;
3032 int ret = 0;
3033
3034 BUG_ON(cluster->start != cluster->boundary[0]);
5955102c 3035 inode_lock(inode);
efa56464 3036
7cf5b976
QW
3037 ret = btrfs_check_data_free_space(inode, cluster->start,
3038 cluster->end + 1 - cluster->start);
efa56464
YZ
3039 if (ret)
3040 goto out;
3041
3042 while (nr < cluster->nr) {
3043 start = cluster->boundary[nr] - offset;
3044 if (nr + 1 < cluster->nr)
3045 end = cluster->boundary[nr + 1] - 1 - offset;
3046 else
3047 end = cluster->end - offset;
3048
d0082371 3049 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
efa56464
YZ
3050 num_bytes = end + 1 - start;
3051 ret = btrfs_prealloc_file_range(inode, 0, start,
3052 num_bytes, num_bytes,
3053 end + 1, &alloc_hint);
d0082371 3054 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
efa56464
YZ
3055 if (ret)
3056 break;
3057 nr++;
3058 }
7cf5b976
QW
3059 btrfs_free_reserved_data_space(inode, cluster->start,
3060 cluster->end + 1 - cluster->start);
efa56464 3061out:
5955102c 3062 inode_unlock(inode);
efa56464
YZ
3063 return ret;
3064}
3065
5d4f98a2 3066static noinline_for_stack
0257bb82
YZ
3067int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3068 u64 block_start)
3069{
3070 struct btrfs_root *root = BTRFS_I(inode)->root;
3071 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3072 struct extent_map *em;
3073 int ret = 0;
3074
172ddd60 3075 em = alloc_extent_map();
0257bb82
YZ
3076 if (!em)
3077 return -ENOMEM;
3078
3079 em->start = start;
3080 em->len = end + 1 - start;
3081 em->block_len = em->len;
3082 em->block_start = block_start;
3083 em->bdev = root->fs_info->fs_devices->latest_bdev;
3084 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3085
d0082371 3086 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
0257bb82
YZ
3087 while (1) {
3088 write_lock(&em_tree->lock);
09a2a8f9 3089 ret = add_extent_mapping(em_tree, em, 0);
0257bb82
YZ
3090 write_unlock(&em_tree->lock);
3091 if (ret != -EEXIST) {
3092 free_extent_map(em);
3093 break;
3094 }
3095 btrfs_drop_extent_cache(inode, start, end, 0);
3096 }
d0082371 3097 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
0257bb82
YZ
3098 return ret;
3099}
3100
3101static int relocate_file_extent_cluster(struct inode *inode,
3102 struct file_extent_cluster *cluster)
5d4f98a2
YZ
3103{
3104 u64 page_start;
3105 u64 page_end;
0257bb82
YZ
3106 u64 offset = BTRFS_I(inode)->index_cnt;
3107 unsigned long index;
5d4f98a2 3108 unsigned long last_index;
5d4f98a2
YZ
3109 struct page *page;
3110 struct file_ra_state *ra;
3b16a4e3 3111 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
0257bb82 3112 int nr = 0;
5d4f98a2
YZ
3113 int ret = 0;
3114
0257bb82
YZ
3115 if (!cluster->nr)
3116 return 0;
3117
5d4f98a2
YZ
3118 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3119 if (!ra)
3120 return -ENOMEM;
3121
efa56464
YZ
3122 ret = prealloc_file_extent_cluster(inode, cluster);
3123 if (ret)
3124 goto out;
0257bb82 3125
efa56464 3126 file_ra_state_init(ra, inode->i_mapping);
5d4f98a2 3127
0257bb82
YZ
3128 ret = setup_extent_mapping(inode, cluster->start - offset,
3129 cluster->end - offset, cluster->start);
5d4f98a2 3130 if (ret)
efa56464 3131 goto out;
5d4f98a2 3132
09cbfeaf
KS
3133 index = (cluster->start - offset) >> PAGE_SHIFT;
3134 last_index = (cluster->end - offset) >> PAGE_SHIFT;
0257bb82 3135 while (index <= last_index) {
09cbfeaf 3136 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_SIZE);
efa56464
YZ
3137 if (ret)
3138 goto out;
3139
0257bb82 3140 page = find_lock_page(inode->i_mapping, index);
5d4f98a2 3141 if (!page) {
0257bb82
YZ
3142 page_cache_sync_readahead(inode->i_mapping,
3143 ra, NULL, index,
3144 last_index + 1 - index);
a94733d0 3145 page = find_or_create_page(inode->i_mapping, index,
3b16a4e3 3146 mask);
0257bb82 3147 if (!page) {
efa56464 3148 btrfs_delalloc_release_metadata(inode,
09cbfeaf 3149 PAGE_SIZE);
0257bb82 3150 ret = -ENOMEM;
efa56464 3151 goto out;
0257bb82 3152 }
5d4f98a2 3153 }
0257bb82
YZ
3154
3155 if (PageReadahead(page)) {
3156 page_cache_async_readahead(inode->i_mapping,
3157 ra, NULL, page, index,
3158 last_index + 1 - index);
3159 }
3160
5d4f98a2
YZ
3161 if (!PageUptodate(page)) {
3162 btrfs_readpage(NULL, page);
3163 lock_page(page);
3164 if (!PageUptodate(page)) {
3165 unlock_page(page);
09cbfeaf 3166 put_page(page);
efa56464 3167 btrfs_delalloc_release_metadata(inode,
09cbfeaf 3168 PAGE_SIZE);
5d4f98a2 3169 ret = -EIO;
efa56464 3170 goto out;
5d4f98a2
YZ
3171 }
3172 }
5d4f98a2 3173
4eee4fa4 3174 page_start = page_offset(page);
09cbfeaf 3175 page_end = page_start + PAGE_SIZE - 1;
0257bb82 3176
d0082371 3177 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
0257bb82 3178
5d4f98a2
YZ
3179 set_page_extent_mapped(page);
3180
0257bb82
YZ
3181 if (nr < cluster->nr &&
3182 page_start + offset == cluster->boundary[nr]) {
3183 set_extent_bits(&BTRFS_I(inode)->io_tree,
3184 page_start, page_end,
5d4f98a2 3185 EXTENT_BOUNDARY, GFP_NOFS);
0257bb82
YZ
3186 nr++;
3187 }
5d4f98a2 3188
efa56464 3189 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
5d4f98a2 3190 set_page_dirty(page);
5d4f98a2 3191
0257bb82 3192 unlock_extent(&BTRFS_I(inode)->io_tree,
d0082371 3193 page_start, page_end);
5d4f98a2 3194 unlock_page(page);
09cbfeaf 3195 put_page(page);
0257bb82
YZ
3196
3197 index++;
efa56464
YZ
3198 balance_dirty_pages_ratelimited(inode->i_mapping);
3199 btrfs_throttle(BTRFS_I(inode)->root);
5d4f98a2 3200 }
0257bb82 3201 WARN_ON(nr != cluster->nr);
efa56464 3202out:
5d4f98a2 3203 kfree(ra);
5d4f98a2
YZ
3204 return ret;
3205}
3206
3207static noinline_for_stack
0257bb82
YZ
3208int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3209 struct file_extent_cluster *cluster)
5d4f98a2 3210{
0257bb82 3211 int ret;
5d4f98a2 3212
0257bb82
YZ
3213 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3214 ret = relocate_file_extent_cluster(inode, cluster);
3215 if (ret)
3216 return ret;
3217 cluster->nr = 0;
5d4f98a2 3218 }
5d4f98a2 3219
0257bb82
YZ
3220 if (!cluster->nr)
3221 cluster->start = extent_key->objectid;
3222 else
3223 BUG_ON(cluster->nr >= MAX_EXTENTS);
3224 cluster->end = extent_key->objectid + extent_key->offset - 1;
3225 cluster->boundary[cluster->nr] = extent_key->objectid;
3226 cluster->nr++;
3227
3228 if (cluster->nr >= MAX_EXTENTS) {
3229 ret = relocate_file_extent_cluster(inode, cluster);
3230 if (ret)
3231 return ret;
3232 cluster->nr = 0;
3233 }
3234 return 0;
5d4f98a2
YZ
3235}
3236
3237#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3238static int get_ref_objectid_v0(struct reloc_control *rc,
3239 struct btrfs_path *path,
3240 struct btrfs_key *extent_key,
3241 u64 *ref_objectid, int *path_change)
3242{
3243 struct btrfs_key key;
3244 struct extent_buffer *leaf;
3245 struct btrfs_extent_ref_v0 *ref0;
3246 int ret;
3247 int slot;
3248
3249 leaf = path->nodes[0];
3250 slot = path->slots[0];
3251 while (1) {
3252 if (slot >= btrfs_header_nritems(leaf)) {
3253 ret = btrfs_next_leaf(rc->extent_root, path);
3254 if (ret < 0)
3255 return ret;
3256 BUG_ON(ret > 0);
3257 leaf = path->nodes[0];
3258 slot = path->slots[0];
3259 if (path_change)
3260 *path_change = 1;
3261 }
3262 btrfs_item_key_to_cpu(leaf, &key, slot);
3263 if (key.objectid != extent_key->objectid)
3264 return -ENOENT;
3265
3266 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3267 slot++;
3268 continue;
3269 }
3270 ref0 = btrfs_item_ptr(leaf, slot,
3271 struct btrfs_extent_ref_v0);
3272 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3273 break;
3274 }
3275 return 0;
3276}
3277#endif
3278
3279/*
3280 * helper to add a tree block to the list.
3281 * the major work is getting the generation and level of the block
3282 */
3283static int add_tree_block(struct reloc_control *rc,
3284 struct btrfs_key *extent_key,
3285 struct btrfs_path *path,
3286 struct rb_root *blocks)
3287{
3288 struct extent_buffer *eb;
3289 struct btrfs_extent_item *ei;
3290 struct btrfs_tree_block_info *bi;
3291 struct tree_block *block;
3292 struct rb_node *rb_node;
3293 u32 item_size;
3294 int level = -1;
7fdf4b60 3295 u64 generation;
5d4f98a2
YZ
3296
3297 eb = path->nodes[0];
3298 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3299
3173a18f
JB
3300 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3301 item_size >= sizeof(*ei) + sizeof(*bi)) {
5d4f98a2
YZ
3302 ei = btrfs_item_ptr(eb, path->slots[0],
3303 struct btrfs_extent_item);
3173a18f
JB
3304 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3305 bi = (struct btrfs_tree_block_info *)(ei + 1);
3306 level = btrfs_tree_block_level(eb, bi);
3307 } else {
3308 level = (int)extent_key->offset;
3309 }
5d4f98a2 3310 generation = btrfs_extent_generation(eb, ei);
5d4f98a2
YZ
3311 } else {
3312#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3313 u64 ref_owner;
3314 int ret;
3315
3316 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3317 ret = get_ref_objectid_v0(rc, path, extent_key,
3318 &ref_owner, NULL);
411fc6bc
AK
3319 if (ret < 0)
3320 return ret;
5d4f98a2
YZ
3321 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3322 level = (int)ref_owner;
3323 /* FIXME: get real generation */
3324 generation = 0;
3325#else
3326 BUG();
3327#endif
3328 }
3329
b3b4aa74 3330 btrfs_release_path(path);
5d4f98a2
YZ
3331
3332 BUG_ON(level == -1);
3333
3334 block = kmalloc(sizeof(*block), GFP_NOFS);
3335 if (!block)
3336 return -ENOMEM;
3337
3338 block->bytenr = extent_key->objectid;
707e8a07 3339 block->key.objectid = rc->extent_root->nodesize;
5d4f98a2
YZ
3340 block->key.offset = generation;
3341 block->level = level;
3342 block->key_ready = 0;
3343
3344 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
43c04fb1
JM
3345 if (rb_node)
3346 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
5d4f98a2
YZ
3347
3348 return 0;
3349}
3350
3351/*
3352 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3353 */
3354static int __add_tree_block(struct reloc_control *rc,
3355 u64 bytenr, u32 blocksize,
3356 struct rb_root *blocks)
3357{
3358 struct btrfs_path *path;
3359 struct btrfs_key key;
3360 int ret;
aee68ee5
JB
3361 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3362 SKINNY_METADATA);
5d4f98a2 3363
7476dfda 3364 if (tree_block_processed(bytenr, rc))
5d4f98a2
YZ
3365 return 0;
3366
3367 if (tree_search(blocks, bytenr))
3368 return 0;
3369
3370 path = btrfs_alloc_path();
3371 if (!path)
3372 return -ENOMEM;
aee68ee5 3373again:
5d4f98a2 3374 key.objectid = bytenr;
aee68ee5
JB
3375 if (skinny) {
3376 key.type = BTRFS_METADATA_ITEM_KEY;
3377 key.offset = (u64)-1;
3378 } else {
3379 key.type = BTRFS_EXTENT_ITEM_KEY;
3380 key.offset = blocksize;
3381 }
5d4f98a2
YZ
3382
3383 path->search_commit_root = 1;
3384 path->skip_locking = 1;
3385 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3386 if (ret < 0)
3387 goto out;
5d4f98a2 3388
aee68ee5
JB
3389 if (ret > 0 && skinny) {
3390 if (path->slots[0]) {
3391 path->slots[0]--;
3392 btrfs_item_key_to_cpu(path->nodes[0], &key,
3393 path->slots[0]);
3394 if (key.objectid == bytenr &&
3395 (key.type == BTRFS_METADATA_ITEM_KEY ||
3396 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3397 key.offset == blocksize)))
3398 ret = 0;
3399 }
3400
3401 if (ret) {
3402 skinny = false;
3403 btrfs_release_path(path);
3404 goto again;
3405 }
3173a18f
JB
3406 }
3407 BUG_ON(ret);
3408
5d4f98a2
YZ
3409 ret = add_tree_block(rc, &key, path, blocks);
3410out:
3411 btrfs_free_path(path);
3412 return ret;
3413}
3414
3415/*
3416 * helper to check if the block use full backrefs for pointers in it
3417 */
3418static int block_use_full_backref(struct reloc_control *rc,
3419 struct extent_buffer *eb)
3420{
5d4f98a2
YZ
3421 u64 flags;
3422 int ret;
3423
3424 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3425 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3426 return 1;
3427
3fd0a558 3428 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3173a18f
JB
3429 eb->start, btrfs_header_level(eb), 1,
3430 NULL, &flags);
5d4f98a2
YZ
3431 BUG_ON(ret);
3432
5d4f98a2
YZ
3433 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3434 ret = 1;
3435 else
3436 ret = 0;
5d4f98a2
YZ
3437 return ret;
3438}
3439
0af3d00b 3440static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
1bbc621e
CM
3441 struct btrfs_block_group_cache *block_group,
3442 struct inode *inode,
3443 u64 ino)
0af3d00b
JB
3444{
3445 struct btrfs_key key;
0af3d00b
JB
3446 struct btrfs_root *root = fs_info->tree_root;
3447 struct btrfs_trans_handle *trans;
0af3d00b
JB
3448 int ret = 0;
3449
3450 if (inode)
3451 goto truncate;
3452
3453 key.objectid = ino;
3454 key.type = BTRFS_INODE_ITEM_KEY;
3455 key.offset = 0;
3456
3457 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
f54fb859
TI
3458 if (IS_ERR(inode) || is_bad_inode(inode)) {
3459 if (!IS_ERR(inode))
0af3d00b
JB
3460 iput(inode);
3461 return -ENOENT;
3462 }
3463
3464truncate:
7b61cd92
MX
3465 ret = btrfs_check_trunc_cache_free_space(root,
3466 &fs_info->global_block_rsv);
3467 if (ret)
3468 goto out;
3469
7a7eaa40 3470 trans = btrfs_join_transaction(root);
0af3d00b 3471 if (IS_ERR(trans)) {
3612b495 3472 ret = PTR_ERR(trans);
0af3d00b
JB
3473 goto out;
3474 }
3475
1bbc621e 3476 ret = btrfs_truncate_free_space_cache(root, trans, block_group, inode);
0af3d00b 3477
0af3d00b 3478 btrfs_end_transaction(trans, root);
b53d3f5d 3479 btrfs_btree_balance_dirty(root);
0af3d00b
JB
3480out:
3481 iput(inode);
3482 return ret;
3483}
3484
5d4f98a2
YZ
3485/*
3486 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3487 * this function scans fs tree to find blocks reference the data extent
3488 */
3489static int find_data_references(struct reloc_control *rc,
3490 struct btrfs_key *extent_key,
3491 struct extent_buffer *leaf,
3492 struct btrfs_extent_data_ref *ref,
3493 struct rb_root *blocks)
3494{
3495 struct btrfs_path *path;
3496 struct tree_block *block;
3497 struct btrfs_root *root;
3498 struct btrfs_file_extent_item *fi;
3499 struct rb_node *rb_node;
3500 struct btrfs_key key;
3501 u64 ref_root;
3502 u64 ref_objectid;
3503 u64 ref_offset;
3504 u32 ref_count;
3505 u32 nritems;
3506 int err = 0;
3507 int added = 0;
3508 int counted;
3509 int ret;
3510
5d4f98a2
YZ
3511 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3512 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3513 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3514 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3515
0af3d00b
JB
3516 /*
3517 * This is an extent belonging to the free space cache, lets just delete
3518 * it and redo the search.
3519 */
3520 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3521 ret = delete_block_group_cache(rc->extent_root->fs_info,
1bbc621e 3522 rc->block_group,
0af3d00b
JB
3523 NULL, ref_objectid);
3524 if (ret != -ENOENT)
3525 return ret;
3526 ret = 0;
3527 }
3528
3529 path = btrfs_alloc_path();
3530 if (!path)
3531 return -ENOMEM;
e4058b54 3532 path->reada = READA_FORWARD;
0af3d00b 3533
5d4f98a2
YZ
3534 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3535 if (IS_ERR(root)) {
3536 err = PTR_ERR(root);
3537 goto out;
3538 }
3539
3540 key.objectid = ref_objectid;
5d4f98a2 3541 key.type = BTRFS_EXTENT_DATA_KEY;
84850e8d
YZ
3542 if (ref_offset > ((u64)-1 << 32))
3543 key.offset = 0;
3544 else
3545 key.offset = ref_offset;
5d4f98a2
YZ
3546
3547 path->search_commit_root = 1;
3548 path->skip_locking = 1;
3549 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3550 if (ret < 0) {
3551 err = ret;
3552 goto out;
3553 }
3554
3555 leaf = path->nodes[0];
3556 nritems = btrfs_header_nritems(leaf);
3557 /*
3558 * the references in tree blocks that use full backrefs
3559 * are not counted in
3560 */
3561 if (block_use_full_backref(rc, leaf))
3562 counted = 0;
3563 else
3564 counted = 1;
3565 rb_node = tree_search(blocks, leaf->start);
3566 if (rb_node) {
3567 if (counted)
3568 added = 1;
3569 else
3570 path->slots[0] = nritems;
3571 }
3572
3573 while (ref_count > 0) {
3574 while (path->slots[0] >= nritems) {
3575 ret = btrfs_next_leaf(root, path);
3576 if (ret < 0) {
3577 err = ret;
3578 goto out;
3579 }
fae7f21c 3580 if (WARN_ON(ret > 0))
5d4f98a2 3581 goto out;
5d4f98a2
YZ
3582
3583 leaf = path->nodes[0];
3584 nritems = btrfs_header_nritems(leaf);
3585 added = 0;
3586
3587 if (block_use_full_backref(rc, leaf))
3588 counted = 0;
3589 else
3590 counted = 1;
3591 rb_node = tree_search(blocks, leaf->start);
3592 if (rb_node) {
3593 if (counted)
3594 added = 1;
3595 else
3596 path->slots[0] = nritems;
3597 }
3598 }
3599
3600 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
fae7f21c
DG
3601 if (WARN_ON(key.objectid != ref_objectid ||
3602 key.type != BTRFS_EXTENT_DATA_KEY))
5d4f98a2 3603 break;
5d4f98a2
YZ
3604
3605 fi = btrfs_item_ptr(leaf, path->slots[0],
3606 struct btrfs_file_extent_item);
3607
3608 if (btrfs_file_extent_type(leaf, fi) ==
3609 BTRFS_FILE_EXTENT_INLINE)
3610 goto next;
3611
3612 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3613 extent_key->objectid)
3614 goto next;
3615
3616 key.offset -= btrfs_file_extent_offset(leaf, fi);
3617 if (key.offset != ref_offset)
3618 goto next;
3619
3620 if (counted)
3621 ref_count--;
3622 if (added)
3623 goto next;
3624
7476dfda 3625 if (!tree_block_processed(leaf->start, rc)) {
5d4f98a2
YZ
3626 block = kmalloc(sizeof(*block), GFP_NOFS);
3627 if (!block) {
3628 err = -ENOMEM;
3629 break;
3630 }
3631 block->bytenr = leaf->start;
3632 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3633 block->level = 0;
3634 block->key_ready = 1;
3635 rb_node = tree_insert(blocks, block->bytenr,
3636 &block->rb_node);
43c04fb1
JM
3637 if (rb_node)
3638 backref_tree_panic(rb_node, -EEXIST,
3639 block->bytenr);
5d4f98a2
YZ
3640 }
3641 if (counted)
3642 added = 1;
3643 else
3644 path->slots[0] = nritems;
3645next:
3646 path->slots[0]++;
3647
3648 }
3649out:
3650 btrfs_free_path(path);
3651 return err;
3652}
3653
3654/*
2c016dc2 3655 * helper to find all tree blocks that reference a given data extent
5d4f98a2
YZ
3656 */
3657static noinline_for_stack
3658int add_data_references(struct reloc_control *rc,
3659 struct btrfs_key *extent_key,
3660 struct btrfs_path *path,
3661 struct rb_root *blocks)
3662{
3663 struct btrfs_key key;
3664 struct extent_buffer *eb;
3665 struct btrfs_extent_data_ref *dref;
3666 struct btrfs_extent_inline_ref *iref;
3667 unsigned long ptr;
3668 unsigned long end;
707e8a07 3669 u32 blocksize = rc->extent_root->nodesize;
647f63bd 3670 int ret = 0;
5d4f98a2
YZ
3671 int err = 0;
3672
5d4f98a2
YZ
3673 eb = path->nodes[0];
3674 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3675 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3676#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3677 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3678 ptr = end;
3679 else
3680#endif
3681 ptr += sizeof(struct btrfs_extent_item);
3682
3683 while (ptr < end) {
3684 iref = (struct btrfs_extent_inline_ref *)ptr;
3685 key.type = btrfs_extent_inline_ref_type(eb, iref);
3686 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3687 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3688 ret = __add_tree_block(rc, key.offset, blocksize,
3689 blocks);
3690 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3691 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3692 ret = find_data_references(rc, extent_key,
3693 eb, dref, blocks);
3694 } else {
3695 BUG();
3696 }
647f63bd
FDBM
3697 if (ret) {
3698 err = ret;
3699 goto out;
3700 }
5d4f98a2
YZ
3701 ptr += btrfs_extent_inline_ref_size(key.type);
3702 }
3703 WARN_ON(ptr > end);
3704
3705 while (1) {
3706 cond_resched();
3707 eb = path->nodes[0];
3708 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3709 ret = btrfs_next_leaf(rc->extent_root, path);
3710 if (ret < 0) {
3711 err = ret;
3712 break;
3713 }
3714 if (ret > 0)
3715 break;
3716 eb = path->nodes[0];
3717 }
3718
3719 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3720 if (key.objectid != extent_key->objectid)
3721 break;
3722
3723#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3724 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3725 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3726#else
3727 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3728 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3729#endif
3730 ret = __add_tree_block(rc, key.offset, blocksize,
3731 blocks);
3732 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3733 dref = btrfs_item_ptr(eb, path->slots[0],
3734 struct btrfs_extent_data_ref);
3735 ret = find_data_references(rc, extent_key,
3736 eb, dref, blocks);
3737 } else {
3738 ret = 0;
3739 }
3740 if (ret) {
3741 err = ret;
3742 break;
3743 }
3744 path->slots[0]++;
3745 }
647f63bd 3746out:
b3b4aa74 3747 btrfs_release_path(path);
5d4f98a2
YZ
3748 if (err)
3749 free_block_list(blocks);
3750 return err;
3751}
3752
3753/*
2c016dc2 3754 * helper to find next unprocessed extent
5d4f98a2
YZ
3755 */
3756static noinline_for_stack
147d256e 3757int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
3fd0a558 3758 struct btrfs_key *extent_key)
5d4f98a2
YZ
3759{
3760 struct btrfs_key key;
3761 struct extent_buffer *leaf;
3762 u64 start, end, last;
3763 int ret;
3764
3765 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3766 while (1) {
3767 cond_resched();
3768 if (rc->search_start >= last) {
3769 ret = 1;
3770 break;
3771 }
3772
3773 key.objectid = rc->search_start;
3774 key.type = BTRFS_EXTENT_ITEM_KEY;
3775 key.offset = 0;
3776
3777 path->search_commit_root = 1;
3778 path->skip_locking = 1;
3779 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3780 0, 0);
3781 if (ret < 0)
3782 break;
3783next:
3784 leaf = path->nodes[0];
3785 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3786 ret = btrfs_next_leaf(rc->extent_root, path);
3787 if (ret != 0)
3788 break;
3789 leaf = path->nodes[0];
3790 }
3791
3792 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3793 if (key.objectid >= last) {
3794 ret = 1;
3795 break;
3796 }
3797
3173a18f
JB
3798 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3799 key.type != BTRFS_METADATA_ITEM_KEY) {
3800 path->slots[0]++;
3801 goto next;
3802 }
3803
3804 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
5d4f98a2
YZ
3805 key.objectid + key.offset <= rc->search_start) {
3806 path->slots[0]++;
3807 goto next;
3808 }
3809
3173a18f 3810 if (key.type == BTRFS_METADATA_ITEM_KEY &&
707e8a07 3811 key.objectid + rc->extent_root->nodesize <=
3173a18f
JB
3812 rc->search_start) {
3813 path->slots[0]++;
3814 goto next;
3815 }
3816
5d4f98a2
YZ
3817 ret = find_first_extent_bit(&rc->processed_blocks,
3818 key.objectid, &start, &end,
e6138876 3819 EXTENT_DIRTY, NULL);
5d4f98a2
YZ
3820
3821 if (ret == 0 && start <= key.objectid) {
b3b4aa74 3822 btrfs_release_path(path);
5d4f98a2
YZ
3823 rc->search_start = end + 1;
3824 } else {
3173a18f
JB
3825 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3826 rc->search_start = key.objectid + key.offset;
3827 else
3828 rc->search_start = key.objectid +
707e8a07 3829 rc->extent_root->nodesize;
3fd0a558 3830 memcpy(extent_key, &key, sizeof(key));
5d4f98a2
YZ
3831 return 0;
3832 }
3833 }
b3b4aa74 3834 btrfs_release_path(path);
5d4f98a2
YZ
3835 return ret;
3836}
3837
3838static void set_reloc_control(struct reloc_control *rc)
3839{
3840 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
7585717f
CM
3841
3842 mutex_lock(&fs_info->reloc_mutex);
5d4f98a2 3843 fs_info->reloc_ctl = rc;
7585717f 3844 mutex_unlock(&fs_info->reloc_mutex);
5d4f98a2
YZ
3845}
3846
3847static void unset_reloc_control(struct reloc_control *rc)
3848{
3849 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
7585717f
CM
3850
3851 mutex_lock(&fs_info->reloc_mutex);
5d4f98a2 3852 fs_info->reloc_ctl = NULL;
7585717f 3853 mutex_unlock(&fs_info->reloc_mutex);
5d4f98a2
YZ
3854}
3855
3856static int check_extent_flags(u64 flags)
3857{
3858 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3859 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3860 return 1;
3861 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3862 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3863 return 1;
3864 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3865 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3866 return 1;
3867 return 0;
3868}
3869
3fd0a558
YZ
3870static noinline_for_stack
3871int prepare_to_relocate(struct reloc_control *rc)
3872{
3873 struct btrfs_trans_handle *trans;
3fd0a558 3874
66d8f3dd
MX
3875 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3876 BTRFS_BLOCK_RSV_TEMP);
3fd0a558
YZ
3877 if (!rc->block_rsv)
3878 return -ENOMEM;
3879
3fd0a558
YZ
3880 memset(&rc->cluster, 0, sizeof(rc->cluster));
3881 rc->search_start = rc->block_group->key.objectid;
3882 rc->extents_found = 0;
3883 rc->nodes_relocated = 0;
3884 rc->merging_rsv_size = 0;
0647bf56
WS
3885 rc->reserved_bytes = 0;
3886 rc->block_rsv->size = rc->extent_root->nodesize *
3887 RELOCATION_RESERVED_NODES;
3fd0a558
YZ
3888
3889 rc->create_reloc_tree = 1;
3890 set_reloc_control(rc);
3891
7a7eaa40 3892 trans = btrfs_join_transaction(rc->extent_root);
28818947
LB
3893 if (IS_ERR(trans)) {
3894 unset_reloc_control(rc);
3895 /*
3896 * extent tree is not a ref_cow tree and has no reloc_root to
3897 * cleanup. And callers are responsible to free the above
3898 * block rsv.
3899 */
3900 return PTR_ERR(trans);
3901 }
3fd0a558
YZ
3902 btrfs_commit_transaction(trans, rc->extent_root);
3903 return 0;
3904}
76dda93c 3905
5d4f98a2
YZ
3906static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3907{
3908 struct rb_root blocks = RB_ROOT;
3909 struct btrfs_key key;
3910 struct btrfs_trans_handle *trans = NULL;
3911 struct btrfs_path *path;
3912 struct btrfs_extent_item *ei;
5d4f98a2
YZ
3913 u64 flags;
3914 u32 item_size;
3915 int ret;
3916 int err = 0;
c87f08ca 3917 int progress = 0;
5d4f98a2
YZ
3918
3919 path = btrfs_alloc_path();
3fd0a558 3920 if (!path)
5d4f98a2 3921 return -ENOMEM;
e4058b54 3922 path->reada = READA_FORWARD;
5d4f98a2 3923
3fd0a558
YZ
3924 ret = prepare_to_relocate(rc);
3925 if (ret) {
3926 err = ret;
3927 goto out_free;
3928 }
5d4f98a2
YZ
3929
3930 while (1) {
0647bf56
WS
3931 rc->reserved_bytes = 0;
3932 ret = btrfs_block_rsv_refill(rc->extent_root,
3933 rc->block_rsv, rc->block_rsv->size,
3934 BTRFS_RESERVE_FLUSH_ALL);
3935 if (ret) {
3936 err = ret;
3937 break;
3938 }
c87f08ca 3939 progress++;
a22285a6 3940 trans = btrfs_start_transaction(rc->extent_root, 0);
0f788c58
LB
3941 if (IS_ERR(trans)) {
3942 err = PTR_ERR(trans);
3943 trans = NULL;
3944 break;
3945 }
c87f08ca 3946restart:
3fd0a558
YZ
3947 if (update_backref_cache(trans, &rc->backref_cache)) {
3948 btrfs_end_transaction(trans, rc->extent_root);
3949 continue;
3950 }
3951
147d256e 3952 ret = find_next_extent(rc, path, &key);
5d4f98a2
YZ
3953 if (ret < 0)
3954 err = ret;
3955 if (ret != 0)
3956 break;
3957
3958 rc->extents_found++;
3959
3960 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3961 struct btrfs_extent_item);
3fd0a558 3962 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
5d4f98a2
YZ
3963 if (item_size >= sizeof(*ei)) {
3964 flags = btrfs_extent_flags(path->nodes[0], ei);
3965 ret = check_extent_flags(flags);
3966 BUG_ON(ret);
3967
3968 } else {
3969#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3970 u64 ref_owner;
3971 int path_change = 0;
3972
3973 BUG_ON(item_size !=
3974 sizeof(struct btrfs_extent_item_v0));
3975 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3976 &path_change);
4b3576e4
Z
3977 if (ret < 0) {
3978 err = ret;
3979 break;
3980 }
5d4f98a2
YZ
3981 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3982 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3983 else
3984 flags = BTRFS_EXTENT_FLAG_DATA;
3985
3986 if (path_change) {
b3b4aa74 3987 btrfs_release_path(path);
5d4f98a2
YZ
3988
3989 path->search_commit_root = 1;
3990 path->skip_locking = 1;
3991 ret = btrfs_search_slot(NULL, rc->extent_root,
3992 &key, path, 0, 0);
3993 if (ret < 0) {
3994 err = ret;
3995 break;
3996 }
3997 BUG_ON(ret > 0);
3998 }
3999#else
4000 BUG();
4001#endif
4002 }
4003
4004 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
4005 ret = add_tree_block(rc, &key, path, &blocks);
4006 } else if (rc->stage == UPDATE_DATA_PTRS &&
3fd0a558 4007 (flags & BTRFS_EXTENT_FLAG_DATA)) {
5d4f98a2
YZ
4008 ret = add_data_references(rc, &key, path, &blocks);
4009 } else {
b3b4aa74 4010 btrfs_release_path(path);
5d4f98a2
YZ
4011 ret = 0;
4012 }
4013 if (ret < 0) {
3fd0a558 4014 err = ret;
5d4f98a2
YZ
4015 break;
4016 }
4017
4018 if (!RB_EMPTY_ROOT(&blocks)) {
4019 ret = relocate_tree_blocks(trans, rc, &blocks);
4020 if (ret < 0) {
1708cc57
WS
4021 /*
4022 * if we fail to relocate tree blocks, force to update
4023 * backref cache when committing transaction.
4024 */
4025 rc->backref_cache.last_trans = trans->transid - 1;
4026
3fd0a558
YZ
4027 if (ret != -EAGAIN) {
4028 err = ret;
4029 break;
4030 }
4031 rc->extents_found--;
4032 rc->search_start = key.objectid;
4033 }
4034 }
4035
0647bf56
WS
4036 btrfs_end_transaction_throttle(trans, rc->extent_root);
4037 btrfs_btree_balance_dirty(rc->extent_root);
5d4f98a2 4038 trans = NULL;
5d4f98a2
YZ
4039
4040 if (rc->stage == MOVE_DATA_EXTENTS &&
4041 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4042 rc->found_file_extent = 1;
0257bb82 4043 ret = relocate_data_extent(rc->data_inode,
3fd0a558 4044 &key, &rc->cluster);
5d4f98a2
YZ
4045 if (ret < 0) {
4046 err = ret;
4047 break;
4048 }
4049 }
4050 }
c87f08ca
CM
4051 if (trans && progress && err == -ENOSPC) {
4052 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4053 rc->block_group->flags);
9689457b 4054 if (ret == 1) {
c87f08ca
CM
4055 err = 0;
4056 progress = 0;
4057 goto restart;
4058 }
4059 }
3fd0a558 4060
b3b4aa74 4061 btrfs_release_path(path);
3fd0a558
YZ
4062 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4063 GFP_NOFS);
5d4f98a2
YZ
4064
4065 if (trans) {
3fd0a558 4066 btrfs_end_transaction_throttle(trans, rc->extent_root);
b53d3f5d 4067 btrfs_btree_balance_dirty(rc->extent_root);
5d4f98a2
YZ
4068 }
4069
0257bb82 4070 if (!err) {
3fd0a558
YZ
4071 ret = relocate_file_extent_cluster(rc->data_inode,
4072 &rc->cluster);
0257bb82
YZ
4073 if (ret < 0)
4074 err = ret;
4075 }
4076
3fd0a558
YZ
4077 rc->create_reloc_tree = 0;
4078 set_reloc_control(rc);
0257bb82 4079
3fd0a558
YZ
4080 backref_cache_cleanup(&rc->backref_cache);
4081 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
5d4f98a2 4082
3fd0a558 4083 err = prepare_to_merge(rc, err);
5d4f98a2
YZ
4084
4085 merge_reloc_roots(rc);
4086
3fd0a558 4087 rc->merge_reloc_tree = 0;
5d4f98a2 4088 unset_reloc_control(rc);
3fd0a558 4089 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
5d4f98a2
YZ
4090
4091 /* get rid of pinned extents */
7a7eaa40 4092 trans = btrfs_join_transaction(rc->extent_root);
3612b495
TI
4093 if (IS_ERR(trans))
4094 err = PTR_ERR(trans);
4095 else
4096 btrfs_commit_transaction(trans, rc->extent_root);
3fd0a558
YZ
4097out_free:
4098 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4099 btrfs_free_path(path);
5d4f98a2
YZ
4100 return err;
4101}
4102
4103static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
0257bb82 4104 struct btrfs_root *root, u64 objectid)
5d4f98a2
YZ
4105{
4106 struct btrfs_path *path;
4107 struct btrfs_inode_item *item;
4108 struct extent_buffer *leaf;
4109 int ret;
4110
4111 path = btrfs_alloc_path();
4112 if (!path)
4113 return -ENOMEM;
4114
4115 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4116 if (ret)
4117 goto out;
4118
4119 leaf = path->nodes[0];
4120 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4121 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4122 btrfs_set_inode_generation(leaf, item, 1);
0257bb82 4123 btrfs_set_inode_size(leaf, item, 0);
5d4f98a2 4124 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
3fd0a558
YZ
4125 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4126 BTRFS_INODE_PREALLOC);
5d4f98a2 4127 btrfs_mark_buffer_dirty(leaf);
5d4f98a2
YZ
4128out:
4129 btrfs_free_path(path);
4130 return ret;
4131}
4132
4133/*
4134 * helper to create inode for data relocation.
4135 * the inode is in data relocation tree and its link count is 0
4136 */
3fd0a558
YZ
4137static noinline_for_stack
4138struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4139 struct btrfs_block_group_cache *group)
5d4f98a2
YZ
4140{
4141 struct inode *inode = NULL;
4142 struct btrfs_trans_handle *trans;
4143 struct btrfs_root *root;
4144 struct btrfs_key key;
4624900d 4145 u64 objectid;
5d4f98a2
YZ
4146 int err = 0;
4147
4148 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4149 if (IS_ERR(root))
4150 return ERR_CAST(root);
4151
a22285a6 4152 trans = btrfs_start_transaction(root, 6);
3fd0a558
YZ
4153 if (IS_ERR(trans))
4154 return ERR_CAST(trans);
5d4f98a2 4155
581bb050 4156 err = btrfs_find_free_objectid(root, &objectid);
5d4f98a2
YZ
4157 if (err)
4158 goto out;
4159
0257bb82 4160 err = __insert_orphan_inode(trans, root, objectid);
5d4f98a2
YZ
4161 BUG_ON(err);
4162
4163 key.objectid = objectid;
4164 key.type = BTRFS_INODE_ITEM_KEY;
4165 key.offset = 0;
73f73415 4166 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
5d4f98a2
YZ
4167 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4168 BTRFS_I(inode)->index_cnt = group->key.objectid;
4169
4170 err = btrfs_orphan_add(trans, inode);
4171out:
5d4f98a2 4172 btrfs_end_transaction(trans, root);
b53d3f5d 4173 btrfs_btree_balance_dirty(root);
5d4f98a2
YZ
4174 if (err) {
4175 if (inode)
4176 iput(inode);
4177 inode = ERR_PTR(err);
4178 }
4179 return inode;
4180}
4181
a9995eec 4182static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
3fd0a558
YZ
4183{
4184 struct reloc_control *rc;
4185
4186 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4187 if (!rc)
4188 return NULL;
4189
4190 INIT_LIST_HEAD(&rc->reloc_roots);
4191 backref_cache_init(&rc->backref_cache);
4192 mapping_tree_init(&rc->reloc_root_tree);
a9995eec
JB
4193 extent_io_tree_init(&rc->processed_blocks,
4194 fs_info->btree_inode->i_mapping);
3fd0a558
YZ
4195 return rc;
4196}
4197
5d4f98a2
YZ
4198/*
4199 * function to relocate all extents in a block group.
4200 */
4201int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4202{
4203 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4204 struct reloc_control *rc;
0af3d00b
JB
4205 struct inode *inode;
4206 struct btrfs_path *path;
5d4f98a2 4207 int ret;
f0486c68 4208 int rw = 0;
5d4f98a2
YZ
4209 int err = 0;
4210
a9995eec 4211 rc = alloc_reloc_control(fs_info);
5d4f98a2
YZ
4212 if (!rc)
4213 return -ENOMEM;
4214
f0486c68 4215 rc->extent_root = extent_root;
3fd0a558 4216
5d4f98a2
YZ
4217 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4218 BUG_ON(!rc->block_group);
4219
868f401a
Z
4220 ret = btrfs_inc_block_group_ro(extent_root, rc->block_group);
4221 if (ret) {
4222 err = ret;
4223 goto out;
f0486c68 4224 }
868f401a 4225 rw = 1;
f0486c68 4226
0af3d00b
JB
4227 path = btrfs_alloc_path();
4228 if (!path) {
4229 err = -ENOMEM;
4230 goto out;
4231 }
4232
4233 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4234 path);
4235 btrfs_free_path(path);
4236
4237 if (!IS_ERR(inode))
1bbc621e 4238 ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
0af3d00b
JB
4239 else
4240 ret = PTR_ERR(inode);
4241
4242 if (ret && ret != -ENOENT) {
4243 err = ret;
4244 goto out;
4245 }
4246
5d4f98a2
YZ
4247 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4248 if (IS_ERR(rc->data_inode)) {
4249 err = PTR_ERR(rc->data_inode);
4250 rc->data_inode = NULL;
4251 goto out;
4252 }
4253
efe120a0 4254 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
c1c9ff7c 4255 rc->block_group->key.objectid, rc->block_group->flags);
5d4f98a2 4256
6c255e67 4257 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
8ccf6f19
MX
4258 if (ret < 0) {
4259 err = ret;
4260 goto out;
4261 }
578def7c
FM
4262 btrfs_wait_ordered_roots(fs_info, -1,
4263 rc->block_group->key.objectid,
4264 rc->block_group->key.offset);
5d4f98a2
YZ
4265
4266 while (1) {
76dda93c 4267 mutex_lock(&fs_info->cleaner_mutex);
5d4f98a2 4268 ret = relocate_block_group(rc);
76dda93c 4269 mutex_unlock(&fs_info->cleaner_mutex);
5d4f98a2
YZ
4270 if (ret < 0) {
4271 err = ret;
3fd0a558 4272 goto out;
5d4f98a2
YZ
4273 }
4274
4275 if (rc->extents_found == 0)
4276 break;
4277
efe120a0 4278 btrfs_info(extent_root->fs_info, "found %llu extents",
c1c9ff7c 4279 rc->extents_found);
5d4f98a2
YZ
4280
4281 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
0ef8b726
JB
4282 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4283 (u64)-1);
4284 if (ret) {
4285 err = ret;
4286 goto out;
4287 }
5d4f98a2
YZ
4288 invalidate_mapping_pages(rc->data_inode->i_mapping,
4289 0, -1);
4290 rc->stage = UPDATE_DATA_PTRS;
5d4f98a2
YZ
4291 }
4292 }
4293
5d4f98a2
YZ
4294 WARN_ON(rc->block_group->pinned > 0);
4295 WARN_ON(rc->block_group->reserved > 0);
4296 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4297out:
f0486c68 4298 if (err && rw)
868f401a 4299 btrfs_dec_block_group_ro(extent_root, rc->block_group);
5d4f98a2 4300 iput(rc->data_inode);
5d4f98a2
YZ
4301 btrfs_put_block_group(rc->block_group);
4302 kfree(rc);
4303 return err;
4304}
4305
76dda93c
YZ
4306static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4307{
4308 struct btrfs_trans_handle *trans;
79787eaa 4309 int ret, err;
76dda93c 4310
a22285a6 4311 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
79787eaa
JM
4312 if (IS_ERR(trans))
4313 return PTR_ERR(trans);
76dda93c
YZ
4314
4315 memset(&root->root_item.drop_progress, 0,
4316 sizeof(root->root_item.drop_progress));
4317 root->root_item.drop_level = 0;
4318 btrfs_set_root_refs(&root->root_item, 0);
4319 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4320 &root->root_key, &root->root_item);
76dda93c 4321
79787eaa
JM
4322 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4323 if (err)
4324 return err;
4325 return ret;
76dda93c
YZ
4326}
4327
5d4f98a2
YZ
4328/*
4329 * recover relocation interrupted by system crash.
4330 *
4331 * this function resumes merging reloc trees with corresponding fs trees.
4332 * this is important for keeping the sharing of tree blocks
4333 */
4334int btrfs_recover_relocation(struct btrfs_root *root)
4335{
4336 LIST_HEAD(reloc_roots);
4337 struct btrfs_key key;
4338 struct btrfs_root *fs_root;
4339 struct btrfs_root *reloc_root;
4340 struct btrfs_path *path;
4341 struct extent_buffer *leaf;
4342 struct reloc_control *rc = NULL;
4343 struct btrfs_trans_handle *trans;
4344 int ret;
4345 int err = 0;
4346
4347 path = btrfs_alloc_path();
4348 if (!path)
4349 return -ENOMEM;
e4058b54 4350 path->reada = READA_BACK;
5d4f98a2
YZ
4351
4352 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4353 key.type = BTRFS_ROOT_ITEM_KEY;
4354 key.offset = (u64)-1;
4355
4356 while (1) {
4357 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4358 path, 0, 0);
4359 if (ret < 0) {
4360 err = ret;
4361 goto out;
4362 }
4363 if (ret > 0) {
4364 if (path->slots[0] == 0)
4365 break;
4366 path->slots[0]--;
4367 }
4368 leaf = path->nodes[0];
4369 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
b3b4aa74 4370 btrfs_release_path(path);
5d4f98a2
YZ
4371
4372 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4373 key.type != BTRFS_ROOT_ITEM_KEY)
4374 break;
4375
cb517eab 4376 reloc_root = btrfs_read_fs_root(root, &key);
5d4f98a2
YZ
4377 if (IS_ERR(reloc_root)) {
4378 err = PTR_ERR(reloc_root);
4379 goto out;
4380 }
4381
4382 list_add(&reloc_root->root_list, &reloc_roots);
4383
4384 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4385 fs_root = read_fs_root(root->fs_info,
4386 reloc_root->root_key.offset);
4387 if (IS_ERR(fs_root)) {
76dda93c
YZ
4388 ret = PTR_ERR(fs_root);
4389 if (ret != -ENOENT) {
4390 err = ret;
4391 goto out;
4392 }
79787eaa
JM
4393 ret = mark_garbage_root(reloc_root);
4394 if (ret < 0) {
4395 err = ret;
4396 goto out;
4397 }
5d4f98a2
YZ
4398 }
4399 }
4400
4401 if (key.offset == 0)
4402 break;
4403
4404 key.offset--;
4405 }
b3b4aa74 4406 btrfs_release_path(path);
5d4f98a2
YZ
4407
4408 if (list_empty(&reloc_roots))
4409 goto out;
4410
a9995eec 4411 rc = alloc_reloc_control(root->fs_info);
5d4f98a2
YZ
4412 if (!rc) {
4413 err = -ENOMEM;
4414 goto out;
4415 }
4416
5d4f98a2
YZ
4417 rc->extent_root = root->fs_info->extent_root;
4418
4419 set_reloc_control(rc);
4420
7a7eaa40 4421 trans = btrfs_join_transaction(rc->extent_root);
3612b495
TI
4422 if (IS_ERR(trans)) {
4423 unset_reloc_control(rc);
4424 err = PTR_ERR(trans);
4425 goto out_free;
4426 }
3fd0a558
YZ
4427
4428 rc->merge_reloc_tree = 1;
4429
5d4f98a2
YZ
4430 while (!list_empty(&reloc_roots)) {
4431 reloc_root = list_entry(reloc_roots.next,
4432 struct btrfs_root, root_list);
4433 list_del(&reloc_root->root_list);
4434
4435 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4436 list_add_tail(&reloc_root->root_list,
4437 &rc->reloc_roots);
4438 continue;
4439 }
4440
4441 fs_root = read_fs_root(root->fs_info,
4442 reloc_root->root_key.offset);
79787eaa
JM
4443 if (IS_ERR(fs_root)) {
4444 err = PTR_ERR(fs_root);
4445 goto out_free;
4446 }
5d4f98a2 4447
ffd7b339 4448 err = __add_reloc_root(reloc_root);
79787eaa 4449 BUG_ON(err < 0); /* -ENOMEM or logic error */
5d4f98a2
YZ
4450 fs_root->reloc_root = reloc_root;
4451 }
4452
79787eaa
JM
4453 err = btrfs_commit_transaction(trans, rc->extent_root);
4454 if (err)
4455 goto out_free;
5d4f98a2
YZ
4456
4457 merge_reloc_roots(rc);
4458
4459 unset_reloc_control(rc);
4460
7a7eaa40 4461 trans = btrfs_join_transaction(rc->extent_root);
3612b495
TI
4462 if (IS_ERR(trans))
4463 err = PTR_ERR(trans);
4464 else
79787eaa 4465 err = btrfs_commit_transaction(trans, rc->extent_root);
3612b495 4466out_free:
3fd0a558 4467 kfree(rc);
3612b495 4468out:
aca1bba6
LB
4469 if (!list_empty(&reloc_roots))
4470 free_reloc_roots(&reloc_roots);
4471
5d4f98a2
YZ
4472 btrfs_free_path(path);
4473
4474 if (err == 0) {
4475 /* cleanup orphan inode in data relocation tree */
4476 fs_root = read_fs_root(root->fs_info,
4477 BTRFS_DATA_RELOC_TREE_OBJECTID);
4478 if (IS_ERR(fs_root))
4479 err = PTR_ERR(fs_root);
d7ce5843 4480 else
66b4ffd1 4481 err = btrfs_orphan_cleanup(fs_root);
5d4f98a2
YZ
4482 }
4483 return err;
4484}
4485
4486/*
4487 * helper to add ordered checksum for data relocation.
4488 *
4489 * cloning checksum properly handles the nodatasum extents.
4490 * it also saves CPU time to re-calculate the checksum.
4491 */
4492int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4493{
4494 struct btrfs_ordered_sum *sums;
5d4f98a2
YZ
4495 struct btrfs_ordered_extent *ordered;
4496 struct btrfs_root *root = BTRFS_I(inode)->root;
5d4f98a2
YZ
4497 int ret;
4498 u64 disk_bytenr;
4577b014 4499 u64 new_bytenr;
5d4f98a2
YZ
4500 LIST_HEAD(list);
4501
4502 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4503 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4504
4505 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4506 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
a2de733c 4507 disk_bytenr + len - 1, &list, 0);
79787eaa
JM
4508 if (ret)
4509 goto out;
5d4f98a2
YZ
4510
4511 while (!list_empty(&list)) {
4512 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4513 list_del_init(&sums->list);
4514
4577b014
JB
4515 /*
4516 * We need to offset the new_bytenr based on where the csum is.
4517 * We need to do this because we will read in entire prealloc
4518 * extents but we may have written to say the middle of the
4519 * prealloc extent, so we need to make sure the csum goes with
4520 * the right disk offset.
4521 *
4522 * We can do this because the data reloc inode refers strictly
4523 * to the on disk bytes, so we don't have to worry about
4524 * disk_len vs real len like with real inodes since it's all
4525 * disk length.
4526 */
4527 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4528 sums->bytenr = new_bytenr;
5d4f98a2
YZ
4529
4530 btrfs_add_ordered_sum(inode, ordered, sums);
4531 }
79787eaa 4532out:
5d4f98a2 4533 btrfs_put_ordered_extent(ordered);
411fc6bc 4534 return ret;
5d4f98a2 4535}
3fd0a558 4536
83d4cfd4
JB
4537int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4538 struct btrfs_root *root, struct extent_buffer *buf,
4539 struct extent_buffer *cow)
3fd0a558
YZ
4540{
4541 struct reloc_control *rc;
4542 struct backref_node *node;
4543 int first_cow = 0;
4544 int level;
83d4cfd4 4545 int ret = 0;
3fd0a558
YZ
4546
4547 rc = root->fs_info->reloc_ctl;
4548 if (!rc)
83d4cfd4 4549 return 0;
3fd0a558
YZ
4550
4551 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4552 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4553
c974c464
WS
4554 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4555 if (buf == root->node)
4556 __update_reloc_root(root, cow->start);
4557 }
4558
3fd0a558
YZ
4559 level = btrfs_header_level(buf);
4560 if (btrfs_header_generation(buf) <=
4561 btrfs_root_last_snapshot(&root->root_item))
4562 first_cow = 1;
4563
4564 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4565 rc->create_reloc_tree) {
4566 WARN_ON(!first_cow && level == 0);
4567
4568 node = rc->backref_cache.path[level];
4569 BUG_ON(node->bytenr != buf->start &&
4570 node->new_bytenr != buf->start);
4571
4572 drop_node_buffer(node);
4573 extent_buffer_get(cow);
4574 node->eb = cow;
4575 node->new_bytenr = cow->start;
4576
4577 if (!node->pending) {
4578 list_move_tail(&node->list,
4579 &rc->backref_cache.pending[level]);
4580 node->pending = 1;
4581 }
4582
4583 if (first_cow)
4584 __mark_block_processed(rc, node);
4585
4586 if (first_cow && level > 0)
4587 rc->nodes_relocated += buf->len;
4588 }
4589
83d4cfd4 4590 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
3fd0a558 4591 ret = replace_file_extents(trans, rc, root, cow);
83d4cfd4 4592 return ret;
3fd0a558
YZ
4593}
4594
4595/*
4596 * called before creating snapshot. it calculates metadata reservation
4597 * requried for relocating tree blocks in the snapshot
4598 */
147d256e 4599void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
3fd0a558
YZ
4600 u64 *bytes_to_reserve)
4601{
4602 struct btrfs_root *root;
4603 struct reloc_control *rc;
4604
4605 root = pending->root;
4606 if (!root->reloc_root)
4607 return;
4608
4609 rc = root->fs_info->reloc_ctl;
4610 if (!rc->merge_reloc_tree)
4611 return;
4612
4613 root = root->reloc_root;
4614 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4615 /*
4616 * relocation is in the stage of merging trees. the space
4617 * used by merging a reloc tree is twice the size of
4618 * relocated tree nodes in the worst case. half for cowing
4619 * the reloc tree, half for cowing the fs tree. the space
4620 * used by cowing the reloc tree will be freed after the
4621 * tree is dropped. if we create snapshot, cowing the fs
4622 * tree may use more space than it frees. so we need
4623 * reserve extra space.
4624 */
4625 *bytes_to_reserve += rc->nodes_relocated;
4626}
4627
4628/*
4629 * called after snapshot is created. migrate block reservation
4630 * and create reloc root for the newly created snapshot
4631 */
49b25e05 4632int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
3fd0a558
YZ
4633 struct btrfs_pending_snapshot *pending)
4634{
4635 struct btrfs_root *root = pending->root;
4636 struct btrfs_root *reloc_root;
4637 struct btrfs_root *new_root;
4638 struct reloc_control *rc;
4639 int ret;
4640
4641 if (!root->reloc_root)
49b25e05 4642 return 0;
3fd0a558
YZ
4643
4644 rc = root->fs_info->reloc_ctl;
4645 rc->merging_rsv_size += rc->nodes_relocated;
4646
4647 if (rc->merge_reloc_tree) {
4648 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4649 rc->block_rsv,
4650 rc->nodes_relocated);
49b25e05
JM
4651 if (ret)
4652 return ret;
3fd0a558
YZ
4653 }
4654
4655 new_root = pending->snap;
4656 reloc_root = create_reloc_root(trans, root->reloc_root,
4657 new_root->root_key.objectid);
49b25e05
JM
4658 if (IS_ERR(reloc_root))
4659 return PTR_ERR(reloc_root);
3fd0a558 4660
ffd7b339
JM
4661 ret = __add_reloc_root(reloc_root);
4662 BUG_ON(ret < 0);
3fd0a558
YZ
4663 new_root->reloc_root = reloc_root;
4664
49b25e05 4665 if (rc->create_reloc_tree)
3fd0a558 4666 ret = clone_backref_node(trans, rc, root, reloc_root);
49b25e05 4667 return ret;
3fd0a558 4668}