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Merge tag 'xfs-5.3-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
[linux-2.6-block.git] / fs / btrfs / relocation.c
CommitLineData
c1d7c514 1// SPDX-License-Identifier: GPL-2.0
5d4f98a2
YZ		 2/*
3 * Copyright (C) 2009 Oracle. All rights reserved.
5d4f98a2
YZ		 4 */
5
6#include <linux/sched.h>
7#include <linux/pagemap.h>
8#include <linux/writeback.h>
9#include <linux/blkdev.h>
10#include <linux/rbtree.h>
5a0e3ad6 11#include <linux/slab.h>
5d4f98a2
YZ		 12#include "ctree.h"
13#include "disk-io.h"
14#include "transaction.h"
15#include "volumes.h"
16#include "locking.h"
17#include "btrfs_inode.h"
18#include "async-thread.h"
0af3d00b 19#include "free-space-cache.h"
581bb050 20#include "inode-map.h"
62b99540 21#include "qgroup.h"
cdccee99 22#include "print-tree.h"
86736342 23#include "delalloc-space.h"
5d4f98a2
YZ		 24
25/*
26 * backref_node, mapping_node and tree_block start with this
27 */
28struct tree_entry {
29 struct rb_node rb_node;
30 u64 bytenr;
31};
32
33/*
34 * present a tree block in the backref cache
35 */
36struct backref_node {
37 struct rb_node rb_node;
38 u64 bytenr;
3fd0a558
YZ		 39
40 u64 new_bytenr;
41 /* objectid of tree block owner, can be not uptodate */
5d4f98a2 42 u64 owner;
3fd0a558
YZ		 43 /* link to pending, changed or detached list */
44 struct list_head list;
5d4f98a2
YZ		 45 /* list of upper level blocks reference this block */
46 struct list_head upper;
47 /* list of child blocks in the cache */
48 struct list_head lower;
49 /* NULL if this node is not tree root */
50 struct btrfs_root *root;
51 /* extent buffer got by COW the block */
52 struct extent_buffer *eb;
53 /* level of tree block */
54 unsigned int level:8;
3fd0a558
YZ		 55 /* is the block in non-reference counted tree */
56 unsigned int cowonly:1;
57 /* 1 if no child node in the cache */
5d4f98a2
YZ		 58 unsigned int lowest:1;
59 /* is the extent buffer locked */
60 unsigned int locked:1;
61 /* has the block been processed */
62 unsigned int processed:1;
63 /* have backrefs of this block been checked */
64 unsigned int checked:1;
3fd0a558
YZ		 65 /*
66 * 1 if corresponding block has been cowed but some upper
67 * level block pointers may not point to the new location
68 */
69 unsigned int pending:1;
70 /*
71 * 1 if the backref node isn't connected to any other
72 * backref node.
73 */
74 unsigned int detached:1;
5d4f98a2
YZ		 75};
76
77/*
78 * present a block pointer in the backref cache
79 */
80struct backref_edge {
81 struct list_head list[2];
82 struct backref_node *node[2];
5d4f98a2
YZ		 83};
84
85#define LOWER 0
86#define UPPER 1
0647bf56 87#define RELOCATION_RESERVED_NODES 256
5d4f98a2
YZ		 88
89struct backref_cache {
90 /* red black tree of all backref nodes in the cache */
91 struct rb_root rb_root;
3fd0a558
YZ		 92 /* for passing backref nodes to btrfs_reloc_cow_block */
93 struct backref_node *path[BTRFS_MAX_LEVEL];
94 /*
95 * list of blocks that have been cowed but some block
96 * pointers in upper level blocks may not reflect the
97 * new location
98 */
5d4f98a2 99 struct list_head pending[BTRFS_MAX_LEVEL];
3fd0a558
YZ		 100 /* list of backref nodes with no child node */
101 struct list_head leaves;
102 /* list of blocks that have been cowed in current transaction */
103 struct list_head changed;
104 /* list of detached backref node. */
105 struct list_head detached;
106
107 u64 last_trans;
108
109 int nr_nodes;
110 int nr_edges;
5d4f98a2
YZ		 111};
112
113/*
114 * map address of tree root to tree
115 */
116struct mapping_node {
117 struct rb_node rb_node;
118 u64 bytenr;
119 void *data;
120};
121
122struct mapping_tree {
123 struct rb_root rb_root;
124 spinlock_t lock;
125};
126
127/*
128 * present a tree block to process
129 */
130struct tree_block {
131 struct rb_node rb_node;
132 u64 bytenr;
133 struct btrfs_key key;
134 unsigned int level:8;
135 unsigned int key_ready:1;
136};
137
0257bb82
YZ		 138#define MAX_EXTENTS 128
139
140struct file_extent_cluster {
141 u64 start;
142 u64 end;
143 u64 boundary[MAX_EXTENTS];
144 unsigned int nr;
145};
146
5d4f98a2
YZ		 147struct reloc_control {
148 /* block group to relocate */
149 struct btrfs_block_group_cache *block_group;
150 /* extent tree */
151 struct btrfs_root *extent_root;
152 /* inode for moving data */
153 struct inode *data_inode;
3fd0a558
YZ		 154
155 struct btrfs_block_rsv *block_rsv;
156
157 struct backref_cache backref_cache;
158
159 struct file_extent_cluster cluster;
5d4f98a2
YZ		 160 /* tree blocks have been processed */
161 struct extent_io_tree processed_blocks;
162 /* map start of tree root to corresponding reloc tree */
163 struct mapping_tree reloc_root_tree;
164 /* list of reloc trees */
165 struct list_head reloc_roots;
d2311e69
QW		 166 /* list of subvolume trees that get relocated */
167 struct list_head dirty_subvol_roots;
3fd0a558
YZ		 168 /* size of metadata reservation for merging reloc trees */
169 u64 merging_rsv_size;
170 /* size of relocated tree nodes */
171 u64 nodes_relocated;
0647bf56
WS		 172 /* reserved size for block group relocation*/
173 u64 reserved_bytes;
3fd0a558 174
5d4f98a2
YZ		 175 u64 search_start;
176 u64 extents_found;
3fd0a558 177
3fd0a558
YZ		 178 unsigned int stage:8;
179 unsigned int create_reloc_tree:1;
180 unsigned int merge_reloc_tree:1;
5d4f98a2 181 unsigned int found_file_extent:1;
5d4f98a2
YZ		 182};
183
184/* stages of data relocation */
185#define MOVE_DATA_EXTENTS 0
186#define UPDATE_DATA_PTRS 1
187
3fd0a558
YZ		 188static void remove_backref_node(struct backref_cache *cache,
189 struct backref_node *node);
190static void __mark_block_processed(struct reloc_control *rc,
191 struct backref_node *node);
5d4f98a2
YZ		 192
193static void mapping_tree_init(struct mapping_tree *tree)
194{
6bef4d31 195 tree->rb_root = RB_ROOT;
5d4f98a2
YZ		 196 spin_lock_init(&tree->lock);
197}
198
199static void backref_cache_init(struct backref_cache *cache)
200{
201 int i;
6bef4d31 202 cache->rb_root = RB_ROOT;
5d4f98a2
YZ		 203 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
204 INIT_LIST_HEAD(&cache->pending[i]);
3fd0a558
YZ		 205 INIT_LIST_HEAD(&cache->changed);
206 INIT_LIST_HEAD(&cache->detached);
207 INIT_LIST_HEAD(&cache->leaves);
208}
209
210static void backref_cache_cleanup(struct backref_cache *cache)
211{
212 struct backref_node *node;
213 int i;
214
215 while (!list_empty(&cache->detached)) {
216 node = list_entry(cache->detached.next,
217 struct backref_node, list);
218 remove_backref_node(cache, node);
219 }
220
221 while (!list_empty(&cache->leaves)) {
222 node = list_entry(cache->leaves.next,
223 struct backref_node, lower);
224 remove_backref_node(cache, node);
225 }
226
227 cache->last_trans = 0;
228
229 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
f4907095
LB		 230 ASSERT(list_empty(&cache->pending[i]));
231 ASSERT(list_empty(&cache->changed));
232 ASSERT(list_empty(&cache->detached));
233 ASSERT(RB_EMPTY_ROOT(&cache->rb_root));
234 ASSERT(!cache->nr_nodes);
235 ASSERT(!cache->nr_edges);
3fd0a558
YZ		 236}
237
238static struct backref_node *alloc_backref_node(struct backref_cache *cache)
239{
240 struct backref_node *node;
241
242 node = kzalloc(sizeof(*node), GFP_NOFS);
243 if (node) {
244 INIT_LIST_HEAD(&node->list);
245 INIT_LIST_HEAD(&node->upper);
246 INIT_LIST_HEAD(&node->lower);
247 RB_CLEAR_NODE(&node->rb_node);
248 cache->nr_nodes++;
249 }
250 return node;
251}
252
253static void free_backref_node(struct backref_cache *cache,
254 struct backref_node *node)
255{
256 if (node) {
257 cache->nr_nodes--;
258 kfree(node);
259 }
260}
261
262static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
263{
264 struct backref_edge *edge;
265
266 edge = kzalloc(sizeof(*edge), GFP_NOFS);
267 if (edge)
268 cache->nr_edges++;
269 return edge;
5d4f98a2
YZ		 270}
271
3fd0a558
YZ		 272static void free_backref_edge(struct backref_cache *cache,
273 struct backref_edge *edge)
5d4f98a2 274{
3fd0a558
YZ		 275 if (edge) {
276 cache->nr_edges--;
277 kfree(edge);
278 }
5d4f98a2
YZ		 279}
280
281static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
282 struct rb_node *node)
283{
284 struct rb_node **p = &root->rb_node;
285 struct rb_node *parent = NULL;
286 struct tree_entry *entry;
287
288 while (*p) {
289 parent = *p;
290 entry = rb_entry(parent, struct tree_entry, rb_node);
291
292 if (bytenr < entry->bytenr)
293 p = &(*p)->rb_left;
294 else if (bytenr > entry->bytenr)
295 p = &(*p)->rb_right;
296 else
297 return parent;
298 }
299
300 rb_link_node(node, parent, p);
301 rb_insert_color(node, root);
302 return NULL;
303}
304
305static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
306{
307 struct rb_node *n = root->rb_node;
308 struct tree_entry *entry;
309
310 while (n) {
311 entry = rb_entry(n, struct tree_entry, rb_node);
312
313 if (bytenr < entry->bytenr)
314 n = n->rb_left;
315 else if (bytenr > entry->bytenr)
316 n = n->rb_right;
317 else
318 return n;
319 }
320 return NULL;
321}
322
48a3b636 323static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
43c04fb1
JM		 324{
325
326 struct btrfs_fs_info *fs_info = NULL;
327 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
328 rb_node);
329 if (bnode->root)
330 fs_info = bnode->root->fs_info;
5d163e0e
JM		 331 btrfs_panic(fs_info, errno,
332 "Inconsistency in backref cache found at offset %llu",
333 bytenr);
43c04fb1
JM		 334}
335
5d4f98a2
YZ		 336/*
337 * walk up backref nodes until reach node presents tree root
338 */
339static struct backref_node *walk_up_backref(struct backref_node *node,
340 struct backref_edge *edges[],
341 int *index)
342{
343 struct backref_edge *edge;
344 int idx = *index;
345
346 while (!list_empty(&node->upper)) {
347 edge = list_entry(node->upper.next,
348 struct backref_edge, list[LOWER]);
349 edges[idx++] = edge;
350 node = edge->node[UPPER];
351 }
3fd0a558 352 BUG_ON(node->detached);
5d4f98a2
YZ		 353 *index = idx;
354 return node;
355}
356
357/*
358 * walk down backref nodes to find start of next reference path
359 */
360static struct backref_node *walk_down_backref(struct backref_edge *edges[],
361 int *index)
362{
363 struct backref_edge *edge;
364 struct backref_node *lower;
365 int idx = *index;
366
367 while (idx > 0) {
368 edge = edges[idx - 1];
369 lower = edge->node[LOWER];
370 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
371 idx--;
372 continue;
373 }
374 edge = list_entry(edge->list[LOWER].next,
375 struct backref_edge, list[LOWER]);
376 edges[idx - 1] = edge;
377 *index = idx;
378 return edge->node[UPPER];
379 }
380 *index = 0;
381 return NULL;
382}
383
3fd0a558
YZ		 384static void unlock_node_buffer(struct backref_node *node)
385{
386 if (node->locked) {
387 btrfs_tree_unlock(node->eb);
388 node->locked = 0;
389 }
390}
391
5d4f98a2
YZ		 392static void drop_node_buffer(struct backref_node *node)
393{
394 if (node->eb) {
3fd0a558 395 unlock_node_buffer(node);
5d4f98a2
YZ		 396 free_extent_buffer(node->eb);
397 node->eb = NULL;
398 }
399}
400
401static void drop_backref_node(struct backref_cache *tree,
402 struct backref_node *node)
403{
5d4f98a2
YZ		 404 BUG_ON(!list_empty(&node->upper));
405
406 drop_node_buffer(node);
3fd0a558 407 list_del(&node->list);
5d4f98a2 408 list_del(&node->lower);
3fd0a558
YZ		 409 if (!RB_EMPTY_NODE(&node->rb_node))
410 rb_erase(&node->rb_node, &tree->rb_root);
411 free_backref_node(tree, node);
5d4f98a2
YZ		 412}
413
414/*
415 * remove a backref node from the backref cache
416 */
417static void remove_backref_node(struct backref_cache *cache,
418 struct backref_node *node)
419{
420 struct backref_node *upper;
421 struct backref_edge *edge;
422
423 if (!node)
424 return;
425
3fd0a558 426 BUG_ON(!node->lowest && !node->detached);
5d4f98a2
YZ		 427 while (!list_empty(&node->upper)) {
428 edge = list_entry(node->upper.next, struct backref_edge,
429 list[LOWER]);
430 upper = edge->node[UPPER];
431 list_del(&edge->list[LOWER]);
432 list_del(&edge->list[UPPER]);
3fd0a558
YZ		 433 free_backref_edge(cache, edge);
434
435 if (RB_EMPTY_NODE(&upper->rb_node)) {
436 BUG_ON(!list_empty(&node->upper));
437 drop_backref_node(cache, node);
438 node = upper;
439 node->lowest = 1;
440 continue;
441 }
5d4f98a2 442 /*
3fd0a558 443 * add the node to leaf node list if no other
5d4f98a2
YZ		 444 * child block cached.
445 */
446 if (list_empty(&upper->lower)) {
3fd0a558 447 list_add_tail(&upper->lower, &cache->leaves);
5d4f98a2
YZ		 448 upper->lowest = 1;
449 }
450 }
3fd0a558 451
5d4f98a2
YZ		 452 drop_backref_node(cache, node);
453}
454
3fd0a558
YZ		 455static void update_backref_node(struct backref_cache *cache,
456 struct backref_node *node, u64 bytenr)
457{
458 struct rb_node *rb_node;
459 rb_erase(&node->rb_node, &cache->rb_root);
460 node->bytenr = bytenr;
461 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
43c04fb1
JM		 462 if (rb_node)
463 backref_tree_panic(rb_node, -EEXIST, bytenr);
3fd0a558
YZ		 464}
465
466/*
467 * update backref cache after a transaction commit
468 */
469static int update_backref_cache(struct btrfs_trans_handle *trans,
470 struct backref_cache *cache)
471{
472 struct backref_node *node;
473 int level = 0;
474
475 if (cache->last_trans == 0) {
476 cache->last_trans = trans->transid;
477 return 0;
478 }
479
480 if (cache->last_trans == trans->transid)
481 return 0;
482
483 /*
484 * detached nodes are used to avoid unnecessary backref
485 * lookup. transaction commit changes the extent tree.
486 * so the detached nodes are no longer useful.
487 */
488 while (!list_empty(&cache->detached)) {
489 node = list_entry(cache->detached.next,
490 struct backref_node, list);
491 remove_backref_node(cache, node);
492 }
493
494 while (!list_empty(&cache->changed)) {
495 node = list_entry(cache->changed.next,
496 struct backref_node, list);
497 list_del_init(&node->list);
498 BUG_ON(node->pending);
499 update_backref_node(cache, node, node->new_bytenr);
500 }
501
502 /*
503 * some nodes can be left in the pending list if there were
504 * errors during processing the pending nodes.
505 */
506 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
507 list_for_each_entry(node, &cache->pending[level], list) {
508 BUG_ON(!node->pending);
509 if (node->bytenr == node->new_bytenr)
510 continue;
511 update_backref_node(cache, node, node->new_bytenr);
512 }
513 }
514
515 cache->last_trans = 0;
516 return 1;
517}
518
f2a97a9d 519
3fd0a558
YZ		 520static int should_ignore_root(struct btrfs_root *root)
521{
522 struct btrfs_root *reloc_root;
523
27cdeb70 524 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
3fd0a558
YZ		 525 return 0;
526
527 reloc_root = root->reloc_root;
528 if (!reloc_root)
529 return 0;
530
531 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
532 root->fs_info->running_transaction->transid - 1)
533 return 0;
534 /*
535 * if there is reloc tree and it was created in previous
536 * transaction backref lookup can find the reloc tree,
537 * so backref node for the fs tree root is useless for
538 * relocation.
539 */
540 return 1;
541}
5d4f98a2
YZ		 542/*
543 * find reloc tree by address of tree root
544 */
545static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
546 u64 bytenr)
547{
548 struct rb_node *rb_node;
549 struct mapping_node *node;
550 struct btrfs_root *root = NULL;
551
552 spin_lock(&rc->reloc_root_tree.lock);
553 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
554 if (rb_node) {
555 node = rb_entry(rb_node, struct mapping_node, rb_node);
556 root = (struct btrfs_root *)node->data;
557 }
558 spin_unlock(&rc->reloc_root_tree.lock);
559 return root;
560}
561
562static int is_cowonly_root(u64 root_objectid)
563{
564 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
565 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
566 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
567 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
568 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
66463748
WS		 569 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
570 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
3e4c5efb
DS		 571 root_objectid == BTRFS_QUOTA_TREE_OBJECTID ||
572 root_objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
5d4f98a2
YZ		 573 return 1;
574 return 0;
575}
576
577static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
578 u64 root_objectid)
579{
580 struct btrfs_key key;
581
582 key.objectid = root_objectid;
583 key.type = BTRFS_ROOT_ITEM_KEY;
584 if (is_cowonly_root(root_objectid))
585 key.offset = 0;
586 else
587 key.offset = (u64)-1;
588
c00869f1 589 return btrfs_get_fs_root(fs_info, &key, false);
5d4f98a2
YZ		 590}
591
5d4f98a2
YZ		 592static noinline_for_stack
593int find_inline_backref(struct extent_buffer *leaf, int slot,
594 unsigned long *ptr, unsigned long *end)
595{
3173a18f 596 struct btrfs_key key;
5d4f98a2
YZ		 597 struct btrfs_extent_item *ei;
598 struct btrfs_tree_block_info *bi;
599 u32 item_size;
600
3173a18f
JB		 601 btrfs_item_key_to_cpu(leaf, &key, slot);
602
5d4f98a2 603 item_size = btrfs_item_size_nr(leaf, slot);
ba3c2b19
NB		 604 if (item_size < sizeof(*ei)) {
605 btrfs_print_v0_err(leaf->fs_info);
606 btrfs_handle_fs_error(leaf->fs_info, -EINVAL, NULL);
607 return 1;
608 }
5d4f98a2
YZ		 609 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
610 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
611 BTRFS_EXTENT_FLAG_TREE_BLOCK));
612
3173a18f
JB		 613 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
614 item_size <= sizeof(*ei) + sizeof(*bi)) {
5d4f98a2
YZ		 615 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
616 return 1;
617 }
d062d13c
JB		 618 if (key.type == BTRFS_METADATA_ITEM_KEY &&
619 item_size <= sizeof(*ei)) {
620 WARN_ON(item_size < sizeof(*ei));
621 return 1;
622 }
5d4f98a2 623
3173a18f
JB		 624 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
625 bi = (struct btrfs_tree_block_info *)(ei + 1);
626 *ptr = (unsigned long)(bi + 1);
627 } else {
628 *ptr = (unsigned long)(ei + 1);
629 }
5d4f98a2
YZ		 630 *end = (unsigned long)ei + item_size;
631 return 0;
632}
633
634/*
635 * build backref tree for a given tree block. root of the backref tree
636 * corresponds the tree block, leaves of the backref tree correspond
637 * roots of b-trees that reference the tree block.
638 *
639 * the basic idea of this function is check backrefs of a given block
01327610
NS		 640 * to find upper level blocks that reference the block, and then check
641 * backrefs of these upper level blocks recursively. the recursion stop
5d4f98a2
YZ		 642 * when tree root is reached or backrefs for the block is cached.
643 *
644 * NOTE: if we find backrefs for a block are cached, we know backrefs
645 * for all upper level blocks that directly/indirectly reference the
646 * block are also cached.
647 */
3fd0a558
YZ		 648static noinline_for_stack
649struct backref_node *build_backref_tree(struct reloc_control *rc,
650 struct btrfs_key *node_key,
651 int level, u64 bytenr)
5d4f98a2 652{
3fd0a558 653 struct backref_cache *cache = &rc->backref_cache;
fa6ac715
QW		 654 struct btrfs_path *path1; /* For searching extent root */
655 struct btrfs_path *path2; /* For searching parent of TREE_BLOCK_REF */
5d4f98a2
YZ		 656 struct extent_buffer *eb;
657 struct btrfs_root *root;
658 struct backref_node *cur;
659 struct backref_node *upper;
660 struct backref_node *lower;
661 struct backref_node *node = NULL;
662 struct backref_node *exist = NULL;
663 struct backref_edge *edge;
664 struct rb_node *rb_node;
665 struct btrfs_key key;
666 unsigned long end;
667 unsigned long ptr;
fa6ac715 668 LIST_HEAD(list); /* Pending edge list, upper node needs to be checked */
3fd0a558
YZ		 669 LIST_HEAD(useless);
670 int cowonly;
5d4f98a2
YZ		 671 int ret;
672 int err = 0;
b6c60c80 673 bool need_check = true;
5d4f98a2
YZ		 674
675 path1 = btrfs_alloc_path();
676 path2 = btrfs_alloc_path();
677 if (!path1 || !path2) {
678 err = -ENOMEM;
679 goto out;
680 }
e4058b54
DS		 681 path1->reada = READA_FORWARD;
682 path2->reada = READA_FORWARD;
5d4f98a2 683
3fd0a558 684 node = alloc_backref_node(cache);
5d4f98a2
YZ		 685 if (!node) {
686 err = -ENOMEM;
687 goto out;
688 }
689
5d4f98a2 690 node->bytenr = bytenr;
5d4f98a2
YZ		 691 node->level = level;
692 node->lowest = 1;
693 cur = node;
694again:
695 end = 0;
696 ptr = 0;
697 key.objectid = cur->bytenr;
3173a18f 698 key.type = BTRFS_METADATA_ITEM_KEY;
5d4f98a2
YZ		 699 key.offset = (u64)-1;
700
701 path1->search_commit_root = 1;
702 path1->skip_locking = 1;
703 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
704 0, 0);
705 if (ret < 0) {
706 err = ret;
707 goto out;
708 }
75bfb9af
JB		 709 ASSERT(ret);
710 ASSERT(path1->slots[0]);
5d4f98a2
YZ		 711
712 path1->slots[0]--;
713
714 WARN_ON(cur->checked);
715 if (!list_empty(&cur->upper)) {
716 /*
70f23fd6 717 * the backref was added previously when processing
5d4f98a2
YZ		 718 * backref of type BTRFS_TREE_BLOCK_REF_KEY
719 */
75bfb9af 720 ASSERT(list_is_singular(&cur->upper));
5d4f98a2
YZ		 721 edge = list_entry(cur->upper.next, struct backref_edge,
722 list[LOWER]);
75bfb9af 723 ASSERT(list_empty(&edge->list[UPPER]));
5d4f98a2
YZ		 724 exist = edge->node[UPPER];
725 /*
726 * add the upper level block to pending list if we need
727 * check its backrefs
728 */
729 if (!exist->checked)
730 list_add_tail(&edge->list[UPPER], &list);
731 } else {
732 exist = NULL;
733 }
734
735 while (1) {
736 cond_resched();
737 eb = path1->nodes[0];
738
739 if (ptr >= end) {
740 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
741 ret = btrfs_next_leaf(rc->extent_root, path1);
742 if (ret < 0) {
743 err = ret;
744 goto out;
745 }
746 if (ret > 0)
747 break;
748 eb = path1->nodes[0];
749 }
750
751 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
752 if (key.objectid != cur->bytenr) {
753 WARN_ON(exist);
754 break;
755 }
756
3173a18f
JB		 757 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
758 key.type == BTRFS_METADATA_ITEM_KEY) {
5d4f98a2
YZ		 759 ret = find_inline_backref(eb, path1->slots[0],
760 &ptr, &end);
761 if (ret)
762 goto next;
763 }
764 }
765
766 if (ptr < end) {
767 /* update key for inline back ref */
768 struct btrfs_extent_inline_ref *iref;
3de28d57 769 int type;
5d4f98a2 770 iref = (struct btrfs_extent_inline_ref *)ptr;
3de28d57
LB		 771 type = btrfs_get_extent_inline_ref_type(eb, iref,
772 BTRFS_REF_TYPE_BLOCK);
773 if (type == BTRFS_REF_TYPE_INVALID) {
af431dcb 774 err = -EUCLEAN;
3de28d57
LB		 775 goto out;
776 }
777 key.type = type;
5d4f98a2 778 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3de28d57 779
5d4f98a2
YZ		 780 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
781 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
782 }
783
fa6ac715
QW		 784 /*
785 * Parent node found and matches current inline ref, no need to
786 * rebuild this node for this inline ref.
787 */
5d4f98a2
YZ		 788 if (exist &&
789 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
790 exist->owner == key.offset) ||
791 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
792 exist->bytenr == key.offset))) {
793 exist = NULL;
794 goto next;
795 }
796
fa6ac715 797 /* SHARED_BLOCK_REF means key.offset is the parent bytenr */
5d4f98a2 798 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
5d4f98a2
YZ		 799 if (key.objectid == key.offset) {
800 /*
fa6ac715
QW		 801 * Only root blocks of reloc trees use backref
802 * pointing to itself.
5d4f98a2
YZ		 803 */
804 root = find_reloc_root(rc, cur->bytenr);
75bfb9af 805 ASSERT(root);
5d4f98a2
YZ		 806 cur->root = root;
807 break;
808 }
809
3fd0a558 810 edge = alloc_backref_edge(cache);
5d4f98a2
YZ		 811 if (!edge) {
812 err = -ENOMEM;
813 goto out;
814 }
815 rb_node = tree_search(&cache->rb_root, key.offset);
816 if (!rb_node) {
3fd0a558 817 upper = alloc_backref_node(cache);
5d4f98a2 818 if (!upper) {
3fd0a558 819 free_backref_edge(cache, edge);
5d4f98a2
YZ		 820 err = -ENOMEM;
821 goto out;
822 }
5d4f98a2 823 upper->bytenr = key.offset;
5d4f98a2
YZ		 824 upper->level = cur->level + 1;
825 /*
826 * backrefs for the upper level block isn't
827 * cached, add the block to pending list
828 */
829 list_add_tail(&edge->list[UPPER], &list);
830 } else {
831 upper = rb_entry(rb_node, struct backref_node,
832 rb_node);
75bfb9af 833 ASSERT(upper->checked);
5d4f98a2
YZ		 834 INIT_LIST_HEAD(&edge->list[UPPER]);
835 }
3fd0a558 836 list_add_tail(&edge->list[LOWER], &cur->upper);
5d4f98a2 837 edge->node[LOWER] = cur;
3fd0a558 838 edge->node[UPPER] = upper;
5d4f98a2
YZ		 839
840 goto next;
6d8ff4e4 841 } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) {
ba3c2b19
NB		 842 err = -EINVAL;
843 btrfs_print_v0_err(rc->extent_root->fs_info);
844 btrfs_handle_fs_error(rc->extent_root->fs_info, err,
845 NULL);
846 goto out;
5d4f98a2
YZ		 847 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
848 goto next;
849 }
850
fa6ac715
QW		 851 /*
852 * key.type == BTRFS_TREE_BLOCK_REF_KEY, inline ref offset
853 * means the root objectid. We need to search the tree to get
854 * its parent bytenr.
855 */
5d4f98a2
YZ		 856 root = read_fs_root(rc->extent_root->fs_info, key.offset);
857 if (IS_ERR(root)) {
858 err = PTR_ERR(root);
859 goto out;
860 }
861
27cdeb70 862 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
3fd0a558
YZ		 863 cur->cowonly = 1;
864
5d4f98a2
YZ		 865 if (btrfs_root_level(&root->root_item) == cur->level) {
866 /* tree root */
75bfb9af 867 ASSERT(btrfs_root_bytenr(&root->root_item) ==
5d4f98a2 868 cur->bytenr);
3fd0a558
YZ		 869 if (should_ignore_root(root))
870 list_add(&cur->list, &useless);
871 else
872 cur->root = root;
5d4f98a2
YZ		 873 break;
874 }
875
876 level = cur->level + 1;
877
fa6ac715 878 /* Search the tree to find parent blocks referring the block. */
5d4f98a2
YZ		 879 path2->search_commit_root = 1;
880 path2->skip_locking = 1;
881 path2->lowest_level = level;
882 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
883 path2->lowest_level = 0;
884 if (ret < 0) {
885 err = ret;
886 goto out;
887 }
33c66f43
YZ		 888 if (ret > 0 && path2->slots[level] > 0)
889 path2->slots[level]--;
5d4f98a2
YZ		 890
891 eb = path2->nodes[level];
3561b9db
LB		 892 if (btrfs_node_blockptr(eb, path2->slots[level]) !=
893 cur->bytenr) {
894 btrfs_err(root->fs_info,
895 "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
4fd786e6
MT		 896 cur->bytenr, level - 1,
897 root->root_key.objectid,
3561b9db
LB		 898 node_key->objectid, node_key->type,
899 node_key->offset);
900 err = -ENOENT;
901 goto out;
902 }
5d4f98a2 903 lower = cur;
b6c60c80 904 need_check = true;
fa6ac715
QW		 905
906 /* Add all nodes and edges in the path */
5d4f98a2
YZ		 907 for (; level < BTRFS_MAX_LEVEL; level++) {
908 if (!path2->nodes[level]) {
75bfb9af 909 ASSERT(btrfs_root_bytenr(&root->root_item) ==
5d4f98a2 910 lower->bytenr);
3fd0a558
YZ		 911 if (should_ignore_root(root))
912 list_add(&lower->list, &useless);
913 else
914 lower->root = root;
5d4f98a2
YZ		 915 break;
916 }
917
3fd0a558 918 edge = alloc_backref_edge(cache);
5d4f98a2
YZ		 919 if (!edge) {
920 err = -ENOMEM;
921 goto out;
922 }
923
924 eb = path2->nodes[level];
925 rb_node = tree_search(&cache->rb_root, eb->start);
926 if (!rb_node) {
3fd0a558 927 upper = alloc_backref_node(cache);
5d4f98a2 928 if (!upper) {
3fd0a558 929 free_backref_edge(cache, edge);
5d4f98a2
YZ		 930 err = -ENOMEM;
931 goto out;
932 }
5d4f98a2
YZ		 933 upper->bytenr = eb->start;
934 upper->owner = btrfs_header_owner(eb);
935 upper->level = lower->level + 1;
27cdeb70
MX		 936 if (!test_bit(BTRFS_ROOT_REF_COWS,
937 &root->state))
3fd0a558 938 upper->cowonly = 1;
5d4f98a2
YZ		 939
940 /*
941 * if we know the block isn't shared
942 * we can void checking its backrefs.
943 */
944 if (btrfs_block_can_be_shared(root, eb))
945 upper->checked = 0;
946 else
947 upper->checked = 1;
948
949 /*
950 * add the block to pending list if we
b6c60c80
JB		 951 * need check its backrefs, we only do this once
952 * while walking up a tree as we will catch
953 * anything else later on.
5d4f98a2 954 */
b6c60c80
JB		 955 if (!upper->checked && need_check) {
956 need_check = false;
5d4f98a2
YZ		 957 list_add_tail(&edge->list[UPPER],
958 &list);
bbe90514
JB		 959 } else {
960 if (upper->checked)
961 need_check = true;
5d4f98a2 962 INIT_LIST_HEAD(&edge->list[UPPER]);
bbe90514 963 }
5d4f98a2
YZ		 964 } else {
965 upper = rb_entry(rb_node, struct backref_node,
966 rb_node);
75bfb9af 967 ASSERT(upper->checked);
5d4f98a2 968 INIT_LIST_HEAD(&edge->list[UPPER]);
3fd0a558
YZ		 969 if (!upper->owner)
970 upper->owner = btrfs_header_owner(eb);
5d4f98a2
YZ		 971 }
972 list_add_tail(&edge->list[LOWER], &lower->upper);
5d4f98a2 973 edge->node[LOWER] = lower;
3fd0a558 974 edge->node[UPPER] = upper;
5d4f98a2
YZ		 975
976 if (rb_node)
977 break;
978 lower = upper;
979 upper = NULL;
980 }
b3b4aa74 981 btrfs_release_path(path2);
5d4f98a2
YZ		 982next:
983 if (ptr < end) {
984 ptr += btrfs_extent_inline_ref_size(key.type);
985 if (ptr >= end) {
986 WARN_ON(ptr > end);
987 ptr = 0;
988 end = 0;
989 }
990 }
991 if (ptr >= end)
992 path1->slots[0]++;
993 }
b3b4aa74 994 btrfs_release_path(path1);
5d4f98a2
YZ		 995
996 cur->checked = 1;
997 WARN_ON(exist);
998
999 /* the pending list isn't empty, take the first block to process */
1000 if (!list_empty(&list)) {
1001 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1002 list_del_init(&edge->list[UPPER]);
1003 cur = edge->node[UPPER];
1004 goto again;
1005 }
1006
1007 /*
1008 * everything goes well, connect backref nodes and insert backref nodes
1009 * into the cache.
1010 */
75bfb9af 1011 ASSERT(node->checked);
3fd0a558
YZ		 1012 cowonly = node->cowonly;
1013 if (!cowonly) {
1014 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1015 &node->rb_node);
43c04fb1
JM		 1016 if (rb_node)
1017 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
3fd0a558
YZ		 1018 list_add_tail(&node->lower, &cache->leaves);
1019 }
5d4f98a2
YZ		 1020
1021 list_for_each_entry(edge, &node->upper, list[LOWER])
1022 list_add_tail(&edge->list[UPPER], &list);
1023
1024 while (!list_empty(&list)) {
1025 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1026 list_del_init(&edge->list[UPPER]);
1027 upper = edge->node[UPPER];
3fd0a558
YZ		 1028 if (upper->detached) {
1029 list_del(&edge->list[LOWER]);
1030 lower = edge->node[LOWER];
1031 free_backref_edge(cache, edge);
1032 if (list_empty(&lower->upper))
1033 list_add(&lower->list, &useless);
1034 continue;
1035 }
5d4f98a2
YZ		 1036
1037 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1038 if (upper->lowest) {
1039 list_del_init(&upper->lower);
1040 upper->lowest = 0;
1041 }
1042
1043 list_add_tail(&edge->list[UPPER], &upper->lower);
1044 continue;
1045 }
1046
75bfb9af
JB		 1047 if (!upper->checked) {
1048 /*
1049 * Still want to blow up for developers since this is a
1050 * logic bug.
1051 */
1052 ASSERT(0);
1053 err = -EINVAL;
1054 goto out;
1055 }
1056 if (cowonly != upper->cowonly) {
1057 ASSERT(0);
1058 err = -EINVAL;
1059 goto out;
1060 }
1061
3fd0a558
YZ		 1062 if (!cowonly) {
1063 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1064 &upper->rb_node);
43c04fb1
JM		 1065 if (rb_node)
1066 backref_tree_panic(rb_node, -EEXIST,
1067 upper->bytenr);
3fd0a558 1068 }
5d4f98a2
YZ		 1069
1070 list_add_tail(&edge->list[UPPER], &upper->lower);
1071
1072 list_for_each_entry(edge, &upper->upper, list[LOWER])
1073 list_add_tail(&edge->list[UPPER], &list);
1074 }
3fd0a558
YZ		 1075 /*
1076 * process useless backref nodes. backref nodes for tree leaves
1077 * are deleted from the cache. backref nodes for upper level
1078 * tree blocks are left in the cache to avoid unnecessary backref
1079 * lookup.
1080 */
1081 while (!list_empty(&useless)) {
1082 upper = list_entry(useless.next, struct backref_node, list);
1083 list_del_init(&upper->list);
75bfb9af 1084 ASSERT(list_empty(&upper->upper));
3fd0a558
YZ		 1085 if (upper == node)
1086 node = NULL;
1087 if (upper->lowest) {
1088 list_del_init(&upper->lower);
1089 upper->lowest = 0;
1090 }
1091 while (!list_empty(&upper->lower)) {
1092 edge = list_entry(upper->lower.next,
1093 struct backref_edge, list[UPPER]);
1094 list_del(&edge->list[UPPER]);
1095 list_del(&edge->list[LOWER]);
1096 lower = edge->node[LOWER];
1097 free_backref_edge(cache, edge);
1098
1099 if (list_empty(&lower->upper))
1100 list_add(&lower->list, &useless);
1101 }
1102 __mark_block_processed(rc, upper);
1103 if (upper->level > 0) {
1104 list_add(&upper->list, &cache->detached);
1105 upper->detached = 1;
1106 } else {
1107 rb_erase(&upper->rb_node, &cache->rb_root);
1108 free_backref_node(cache, upper);
1109 }
1110 }
5d4f98a2
YZ		 1111out:
1112 btrfs_free_path(path1);
1113 btrfs_free_path(path2);
1114 if (err) {
3fd0a558
YZ		 1115 while (!list_empty(&useless)) {
1116 lower = list_entry(useless.next,
75bfb9af
JB		 1117 struct backref_node, list);
1118 list_del_init(&lower->list);
3fd0a558 1119 }
75bfb9af
JB		 1120 while (!list_empty(&list)) {
1121 edge = list_first_entry(&list, struct backref_edge,
1122 list[UPPER]);
1123 list_del(&edge->list[UPPER]);
3fd0a558 1124 list_del(&edge->list[LOWER]);
75bfb9af 1125 lower = edge->node[LOWER];
5d4f98a2 1126 upper = edge->node[UPPER];
3fd0a558 1127 free_backref_edge(cache, edge);
75bfb9af
JB		 1128
1129 /*
1130 * Lower is no longer linked to any upper backref nodes
1131 * and isn't in the cache, we can free it ourselves.
1132 */
1133 if (list_empty(&lower->upper) &&
1134 RB_EMPTY_NODE(&lower->rb_node))
1135 list_add(&lower->list, &useless);
1136
1137 if (!RB_EMPTY_NODE(&upper->rb_node))
1138 continue;
1139
01327610 1140 /* Add this guy's upper edges to the list to process */
75bfb9af
JB		 1141 list_for_each_entry(edge, &upper->upper, list[LOWER])
1142 list_add_tail(&edge->list[UPPER], &list);
1143 if (list_empty(&upper->upper))
1144 list_add(&upper->list, &useless);
1145 }
1146
1147 while (!list_empty(&useless)) {
1148 lower = list_entry(useless.next,
1149 struct backref_node, list);
1150 list_del_init(&lower->list);
0fd8c3da
LB		 1151 if (lower == node)
1152 node = NULL;
75bfb9af 1153 free_backref_node(cache, lower);
5d4f98a2 1154 }
0fd8c3da
LB		 1155
1156 free_backref_node(cache, node);
5d4f98a2
YZ		 1157 return ERR_PTR(err);
1158 }
75bfb9af 1159 ASSERT(!node || !node->detached);
5d4f98a2
YZ		 1160 return node;
1161}
1162
3fd0a558
YZ		 1163/*
1164 * helper to add backref node for the newly created snapshot.
1165 * the backref node is created by cloning backref node that
1166 * corresponds to root of source tree
1167 */
1168static int clone_backref_node(struct btrfs_trans_handle *trans,
1169 struct reloc_control *rc,
1170 struct btrfs_root *src,
1171 struct btrfs_root *dest)
1172{
1173 struct btrfs_root *reloc_root = src->reloc_root;
1174 struct backref_cache *cache = &rc->backref_cache;
1175 struct backref_node *node = NULL;
1176 struct backref_node *new_node;
1177 struct backref_edge *edge;
1178 struct backref_edge *new_edge;
1179 struct rb_node *rb_node;
1180
1181 if (cache->last_trans > 0)
1182 update_backref_cache(trans, cache);
1183
1184 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1185 if (rb_node) {
1186 node = rb_entry(rb_node, struct backref_node, rb_node);
1187 if (node->detached)
1188 node = NULL;
1189 else
1190 BUG_ON(node->new_bytenr != reloc_root->node->start);
1191 }
1192
1193 if (!node) {
1194 rb_node = tree_search(&cache->rb_root,
1195 reloc_root->commit_root->start);
1196 if (rb_node) {
1197 node = rb_entry(rb_node, struct backref_node,
1198 rb_node);
1199 BUG_ON(node->detached);
1200 }
1201 }
1202
1203 if (!node)
1204 return 0;
1205
1206 new_node = alloc_backref_node(cache);
1207 if (!new_node)
1208 return -ENOMEM;
1209
1210 new_node->bytenr = dest->node->start;
1211 new_node->level = node->level;
1212 new_node->lowest = node->lowest;
6848ad64 1213 new_node->checked = 1;
3fd0a558
YZ		 1214 new_node->root = dest;
1215
1216 if (!node->lowest) {
1217 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1218 new_edge = alloc_backref_edge(cache);
1219 if (!new_edge)
1220 goto fail;
1221
1222 new_edge->node[UPPER] = new_node;
1223 new_edge->node[LOWER] = edge->node[LOWER];
1224 list_add_tail(&new_edge->list[UPPER],
1225 &new_node->lower);
1226 }
76b9e23d
MX		 1227 } else {
1228 list_add_tail(&new_node->lower, &cache->leaves);
3fd0a558
YZ		 1229 }
1230
1231 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1232 &new_node->rb_node);
43c04fb1
JM		 1233 if (rb_node)
1234 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
3fd0a558
YZ		 1235
1236 if (!new_node->lowest) {
1237 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1238 list_add_tail(&new_edge->list[LOWER],
1239 &new_edge->node[LOWER]->upper);
1240 }
1241 }
1242 return 0;
1243fail:
1244 while (!list_empty(&new_node->lower)) {
1245 new_edge = list_entry(new_node->lower.next,
1246 struct backref_edge, list[UPPER]);
1247 list_del(&new_edge->list[UPPER]);
1248 free_backref_edge(cache, new_edge);
1249 }
1250 free_backref_node(cache, new_node);
1251 return -ENOMEM;
1252}
1253
5d4f98a2
YZ		 1254/*
1255 * helper to add 'address of tree root -> reloc tree' mapping
1256 */
ffd7b339 1257static int __must_check __add_reloc_root(struct btrfs_root *root)
5d4f98a2 1258{
0b246afa 1259 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 1260 struct rb_node *rb_node;
1261 struct mapping_node *node;
0b246afa 1262 struct reloc_control *rc = fs_info->reloc_ctl;
5d4f98a2
YZ		 1263
1264 node = kmalloc(sizeof(*node), GFP_NOFS);
ffd7b339
JM		 1265 if (!node)
1266 return -ENOMEM;
5d4f98a2
YZ		 1267
1268 node->bytenr = root->node->start;
1269 node->data = root;
1270
1271 spin_lock(&rc->reloc_root_tree.lock);
1272 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1273 node->bytenr, &node->rb_node);
1274 spin_unlock(&rc->reloc_root_tree.lock);
ffd7b339 1275 if (rb_node) {
0b246afa 1276 btrfs_panic(fs_info, -EEXIST,
5d163e0e
JM		 1277 "Duplicate root found for start=%llu while inserting into relocation tree",
1278 node->bytenr);
ffd7b339 1279 }
5d4f98a2
YZ		 1280
1281 list_add_tail(&root->root_list, &rc->reloc_roots);
1282 return 0;
1283}
1284
1285/*
c974c464 1286 * helper to delete the 'address of tree root -> reloc tree'
5d4f98a2
YZ		 1287 * mapping
1288 */
c974c464 1289static void __del_reloc_root(struct btrfs_root *root)
5d4f98a2 1290{
0b246afa 1291 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 1292 struct rb_node *rb_node;
1293 struct mapping_node *node = NULL;
0b246afa 1294 struct reloc_control *rc = fs_info->reloc_ctl;
5d4f98a2 1295
65c6e82b 1296 if (rc && root->node) {
389305b2
QW		 1297 spin_lock(&rc->reloc_root_tree.lock);
1298 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1299 root->node->start);
1300 if (rb_node) {
1301 node = rb_entry(rb_node, struct mapping_node, rb_node);
1302 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1303 }
1304 spin_unlock(&rc->reloc_root_tree.lock);
1305 if (!node)
1306 return;
1307 BUG_ON((struct btrfs_root *)node->data != root);
5d4f98a2 1308 }
5d4f98a2 1309
0b246afa 1310 spin_lock(&fs_info->trans_lock);
c974c464 1311 list_del_init(&root->root_list);
0b246afa 1312 spin_unlock(&fs_info->trans_lock);
c974c464
WS		 1313 kfree(node);
1314}
1315
1316/*
1317 * helper to update the 'address of tree root -> reloc tree'
1318 * mapping
1319 */
1320static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1321{
0b246afa 1322 struct btrfs_fs_info *fs_info = root->fs_info;
c974c464
WS		 1323 struct rb_node *rb_node;
1324 struct mapping_node *node = NULL;
0b246afa 1325 struct reloc_control *rc = fs_info->reloc_ctl;
c974c464
WS		 1326
1327 spin_lock(&rc->reloc_root_tree.lock);
1328 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1329 root->node->start);
1330 if (rb_node) {
1331 node = rb_entry(rb_node, struct mapping_node, rb_node);
1332 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
5d4f98a2 1333 }
c974c464
WS		 1334 spin_unlock(&rc->reloc_root_tree.lock);
1335
1336 if (!node)
1337 return 0;
1338 BUG_ON((struct btrfs_root *)node->data != root);
1339
1340 spin_lock(&rc->reloc_root_tree.lock);
1341 node->bytenr = new_bytenr;
1342 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1343 node->bytenr, &node->rb_node);
1344 spin_unlock(&rc->reloc_root_tree.lock);
1345 if (rb_node)
1346 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
5d4f98a2
YZ		 1347 return 0;
1348}
1349
3fd0a558
YZ		 1350static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1351 struct btrfs_root *root, u64 objectid)
5d4f98a2 1352{
0b246afa 1353 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 1354 struct btrfs_root *reloc_root;
1355 struct extent_buffer *eb;
1356 struct btrfs_root_item *root_item;
1357 struct btrfs_key root_key;
1358 int ret;
1359
5d4f98a2
YZ		 1360 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1361 BUG_ON(!root_item);
1362
1363 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1364 root_key.type = BTRFS_ROOT_ITEM_KEY;
3fd0a558 1365 root_key.offset = objectid;
5d4f98a2 1366
3fd0a558 1367 if (root->root_key.objectid == objectid) {
054570a1
FM		 1368 u64 commit_root_gen;
1369
3fd0a558
YZ		 1370 /* called by btrfs_init_reloc_root */
1371 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1372 BTRFS_TREE_RELOC_OBJECTID);
1373 BUG_ON(ret);
054570a1
FM		 1374 /*
1375 * Set the last_snapshot field to the generation of the commit
1376 * root - like this ctree.c:btrfs_block_can_be_shared() behaves
1377 * correctly (returns true) when the relocation root is created
1378 * either inside the critical section of a transaction commit
1379 * (through transaction.c:qgroup_account_snapshot()) and when
1380 * it's created before the transaction commit is started.
1381 */
1382 commit_root_gen = btrfs_header_generation(root->commit_root);
1383 btrfs_set_root_last_snapshot(&root->root_item, commit_root_gen);
3fd0a558
YZ		 1384 } else {
1385 /*
1386 * called by btrfs_reloc_post_snapshot_hook.
1387 * the source tree is a reloc tree, all tree blocks
1388 * modified after it was created have RELOC flag
1389 * set in their headers. so it's OK to not update
1390 * the 'last_snapshot'.
1391 */
1392 ret = btrfs_copy_root(trans, root, root->node, &eb,
1393 BTRFS_TREE_RELOC_OBJECTID);
1394 BUG_ON(ret);
1395 }
5d4f98a2 1396
5d4f98a2 1397 memcpy(root_item, &root->root_item, sizeof(*root_item));
5d4f98a2
YZ		 1398 btrfs_set_root_bytenr(root_item, eb->start);
1399 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1400 btrfs_set_root_generation(root_item, trans->transid);
3fd0a558
YZ		 1401
1402 if (root->root_key.objectid == objectid) {
1403 btrfs_set_root_refs(root_item, 0);
1404 memset(&root_item->drop_progress, 0,
1405 sizeof(struct btrfs_disk_key));
1406 root_item->drop_level = 0;
1407 }
5d4f98a2
YZ		 1408
1409 btrfs_tree_unlock(eb);
1410 free_extent_buffer(eb);
1411
0b246afa 1412 ret = btrfs_insert_root(trans, fs_info->tree_root,
5d4f98a2
YZ		 1413 &root_key, root_item);
1414 BUG_ON(ret);
1415 kfree(root_item);
1416
0b246afa 1417 reloc_root = btrfs_read_fs_root(fs_info->tree_root, &root_key);
5d4f98a2
YZ		 1418 BUG_ON(IS_ERR(reloc_root));
1419 reloc_root->last_trans = trans->transid;
3fd0a558
YZ		 1420 return reloc_root;
1421}
1422
1423/*
1424 * create reloc tree for a given fs tree. reloc tree is just a
1425 * snapshot of the fs tree with special root objectid.
1426 */
1427int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1428 struct btrfs_root *root)
1429{
0b246afa 1430 struct btrfs_fs_info *fs_info = root->fs_info;
3fd0a558 1431 struct btrfs_root *reloc_root;
0b246afa 1432 struct reloc_control *rc = fs_info->reloc_ctl;
20dd2cbf 1433 struct btrfs_block_rsv *rsv;
3fd0a558 1434 int clear_rsv = 0;
ffd7b339 1435 int ret;
3fd0a558
YZ		 1436
1437 if (root->reloc_root) {
1438 reloc_root = root->reloc_root;
1439 reloc_root->last_trans = trans->transid;
1440 return 0;
1441 }
1442
1443 if (!rc || !rc->create_reloc_tree ||
1444 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1445 return 0;
1446
20dd2cbf
MX		 1447 if (!trans->reloc_reserved) {
1448 rsv = trans->block_rsv;
3fd0a558
YZ		 1449 trans->block_rsv = rc->block_rsv;
1450 clear_rsv = 1;
1451 }
1452 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1453 if (clear_rsv)
20dd2cbf 1454 trans->block_rsv = rsv;
5d4f98a2 1455
ffd7b339
JM		 1456 ret = __add_reloc_root(reloc_root);
1457 BUG_ON(ret < 0);
5d4f98a2
YZ		 1458 root->reloc_root = reloc_root;
1459 return 0;
1460}
1461
1462/*
1463 * update root item of reloc tree
1464 */
1465int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1466 struct btrfs_root *root)
1467{
0b246afa 1468 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 1469 struct btrfs_root *reloc_root;
1470 struct btrfs_root_item *root_item;
5d4f98a2
YZ		 1471 int ret;
1472
d2311e69
QW		 1473 if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state) ||
1474 !root->reloc_root)
7585717f 1475 goto out;
5d4f98a2
YZ		 1476
1477 reloc_root = root->reloc_root;
1478 root_item = &reloc_root->root_item;
1479
d2311e69 1480 /* root->reloc_root will stay until current relocation finished */
0b246afa 1481 if (fs_info->reloc_ctl->merge_reloc_tree &&
3fd0a558 1482 btrfs_root_refs(root_item) == 0) {
d2311e69 1483 set_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
c974c464 1484 __del_reloc_root(reloc_root);
5d4f98a2
YZ		 1485 }
1486
5d4f98a2
YZ		 1487 if (reloc_root->commit_root != reloc_root->node) {
1488 btrfs_set_root_node(root_item, reloc_root->node);
1489 free_extent_buffer(reloc_root->commit_root);
1490 reloc_root->commit_root = btrfs_root_node(reloc_root);
1491 }
1492
0b246afa 1493 ret = btrfs_update_root(trans, fs_info->tree_root,
5d4f98a2
YZ		 1494 &reloc_root->root_key, root_item);
1495 BUG_ON(ret);
7585717f
CM		 1496
1497out:
5d4f98a2
YZ		 1498 return 0;
1499}
1500
1501/*
1502 * helper to find first cached inode with inode number >= objectid
1503 * in a subvolume
1504 */
1505static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1506{
1507 struct rb_node *node;
1508 struct rb_node *prev;
1509 struct btrfs_inode *entry;
1510 struct inode *inode;
1511
1512 spin_lock(&root->inode_lock);
1513again:
1514 node = root->inode_tree.rb_node;
1515 prev = NULL;
1516 while (node) {
1517 prev = node;
1518 entry = rb_entry(node, struct btrfs_inode, rb_node);
1519
4a0cc7ca 1520 if (objectid < btrfs_ino(entry))
5d4f98a2 1521 node = node->rb_left;
4a0cc7ca 1522 else if (objectid > btrfs_ino(entry))
5d4f98a2
YZ		 1523 node = node->rb_right;
1524 else
1525 break;
1526 }
1527 if (!node) {
1528 while (prev) {
1529 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4a0cc7ca 1530 if (objectid <= btrfs_ino(entry)) {
5d4f98a2
YZ		 1531 node = prev;
1532 break;
1533 }
1534 prev = rb_next(prev);
1535 }
1536 }
1537 while (node) {
1538 entry = rb_entry(node, struct btrfs_inode, rb_node);
1539 inode = igrab(&entry->vfs_inode);
1540 if (inode) {
1541 spin_unlock(&root->inode_lock);
1542 return inode;
1543 }
1544
4a0cc7ca 1545 objectid = btrfs_ino(entry) + 1;
5d4f98a2
YZ		 1546 if (cond_resched_lock(&root->inode_lock))
1547 goto again;
1548
1549 node = rb_next(node);
1550 }
1551 spin_unlock(&root->inode_lock);
1552 return NULL;
1553}
1554
1555static int in_block_group(u64 bytenr,
1556 struct btrfs_block_group_cache *block_group)
1557{
1558 if (bytenr >= block_group->key.objectid &&
1559 bytenr < block_group->key.objectid + block_group->key.offset)
1560 return 1;
1561 return 0;
1562}
1563
1564/*
1565 * get new location of data
1566 */
1567static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1568 u64 bytenr, u64 num_bytes)
1569{
1570 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1571 struct btrfs_path *path;
1572 struct btrfs_file_extent_item *fi;
1573 struct extent_buffer *leaf;
1574 int ret;
1575
1576 path = btrfs_alloc_path();
1577 if (!path)
1578 return -ENOMEM;
1579
1580 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
f85b7379
DS		 1581 ret = btrfs_lookup_file_extent(NULL, root, path,
1582 btrfs_ino(BTRFS_I(reloc_inode)), bytenr, 0);
5d4f98a2
YZ		 1583 if (ret < 0)
1584 goto out;
1585 if (ret > 0) {
1586 ret = -ENOENT;
1587 goto out;
1588 }
1589
1590 leaf = path->nodes[0];
1591 fi = btrfs_item_ptr(leaf, path->slots[0],
1592 struct btrfs_file_extent_item);
1593
1594 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1595 btrfs_file_extent_compression(leaf, fi) ||
1596 btrfs_file_extent_encryption(leaf, fi) ||
1597 btrfs_file_extent_other_encoding(leaf, fi));
1598
1599 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
83d4cfd4 1600 ret = -EINVAL;
5d4f98a2
YZ		 1601 goto out;
1602 }
1603
3fd0a558 1604 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5d4f98a2
YZ		 1605 ret = 0;
1606out:
1607 btrfs_free_path(path);
1608 return ret;
1609}
1610
1611/*
1612 * update file extent items in the tree leaf to point to
1613 * the new locations.
1614 */
3fd0a558
YZ		 1615static noinline_for_stack
1616int replace_file_extents(struct btrfs_trans_handle *trans,
1617 struct reloc_control *rc,
1618 struct btrfs_root *root,
1619 struct extent_buffer *leaf)
5d4f98a2 1620{
0b246afa 1621 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 1622 struct btrfs_key key;
1623 struct btrfs_file_extent_item *fi;
1624 struct inode *inode = NULL;
5d4f98a2
YZ		 1625 u64 parent;
1626 u64 bytenr;
3fd0a558 1627 u64 new_bytenr = 0;
5d4f98a2
YZ		 1628 u64 num_bytes;
1629 u64 end;
1630 u32 nritems;
1631 u32 i;
83d4cfd4 1632 int ret = 0;
5d4f98a2
YZ		 1633 int first = 1;
1634 int dirty = 0;
1635
1636 if (rc->stage != UPDATE_DATA_PTRS)
1637 return 0;
1638
1639 /* reloc trees always use full backref */
1640 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1641 parent = leaf->start;
1642 else
1643 parent = 0;
1644
1645 nritems = btrfs_header_nritems(leaf);
1646 for (i = 0; i < nritems; i++) {
82fa113f
QW		 1647 struct btrfs_ref ref = { 0 };
1648
5d4f98a2
YZ		 1649 cond_resched();
1650 btrfs_item_key_to_cpu(leaf, &key, i);
1651 if (key.type != BTRFS_EXTENT_DATA_KEY)
1652 continue;
1653 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1654 if (btrfs_file_extent_type(leaf, fi) ==
1655 BTRFS_FILE_EXTENT_INLINE)
1656 continue;
1657 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1658 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1659 if (bytenr == 0)
1660 continue;
1661 if (!in_block_group(bytenr, rc->block_group))
1662 continue;
1663
1664 /*
1665 * if we are modifying block in fs tree, wait for readpage
1666 * to complete and drop the extent cache
1667 */
1668 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
5d4f98a2
YZ		 1669 if (first) {
1670 inode = find_next_inode(root, key.objectid);
5d4f98a2 1671 first = 0;
4a0cc7ca 1672 } else if (inode && btrfs_ino(BTRFS_I(inode)) < key.objectid) {
3fd0a558 1673 btrfs_add_delayed_iput(inode);
5d4f98a2 1674 inode = find_next_inode(root, key.objectid);
5d4f98a2 1675 }
4a0cc7ca 1676 if (inode && btrfs_ino(BTRFS_I(inode)) == key.objectid) {
5d4f98a2
YZ		 1677 end = key.offset +
1678 btrfs_file_extent_num_bytes(leaf, fi);
1679 WARN_ON(!IS_ALIGNED(key.offset,
0b246afa
JM		 1680 fs_info->sectorsize));
1681 WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
5d4f98a2
YZ		 1682 end--;
1683 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
d0082371 1684 key.offset, end);
5d4f98a2
YZ		 1685 if (!ret)
1686 continue;
1687
dcdbc059
NB		 1688 btrfs_drop_extent_cache(BTRFS_I(inode),
1689 key.offset, end, 1);
5d4f98a2 1690 unlock_extent(&BTRFS_I(inode)->io_tree,
d0082371 1691 key.offset, end);
5d4f98a2
YZ		 1692 }
1693 }
1694
1695 ret = get_new_location(rc->data_inode, &new_bytenr,
1696 bytenr, num_bytes);
83d4cfd4
JB		 1697 if (ret) {
1698 /*
1699 * Don't have to abort since we've not changed anything
1700 * in the file extent yet.
1701 */
1702 break;
3fd0a558 1703 }
5d4f98a2
YZ		 1704
1705 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1706 dirty = 1;
1707
1708 key.offset -= btrfs_file_extent_offset(leaf, fi);
82fa113f
QW		 1709 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr,
1710 num_bytes, parent);
1711 ref.real_root = root->root_key.objectid;
1712 btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
1713 key.objectid, key.offset);
1714 ret = btrfs_inc_extent_ref(trans, &ref);
83d4cfd4 1715 if (ret) {
66642832 1716 btrfs_abort_transaction(trans, ret);
83d4cfd4
JB		 1717 break;
1718 }
5d4f98a2 1719
ffd4bb2a
QW		 1720 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
1721 num_bytes, parent);
1722 ref.real_root = root->root_key.objectid;
1723 btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
1724 key.objectid, key.offset);
1725 ret = btrfs_free_extent(trans, &ref);
83d4cfd4 1726 if (ret) {
66642832 1727 btrfs_abort_transaction(trans, ret);
83d4cfd4
JB		 1728 break;
1729 }
5d4f98a2
YZ		 1730 }
1731 if (dirty)
1732 btrfs_mark_buffer_dirty(leaf);
3fd0a558
YZ		 1733 if (inode)
1734 btrfs_add_delayed_iput(inode);
83d4cfd4 1735 return ret;
5d4f98a2
YZ		 1736}
1737
1738static noinline_for_stack
1739int memcmp_node_keys(struct extent_buffer *eb, int slot,
1740 struct btrfs_path *path, int level)
1741{
1742 struct btrfs_disk_key key1;
1743 struct btrfs_disk_key key2;
1744 btrfs_node_key(eb, &key1, slot);
1745 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1746 return memcmp(&key1, &key2, sizeof(key1));
1747}
1748
1749/*
1750 * try to replace tree blocks in fs tree with the new blocks
1751 * in reloc tree. tree blocks haven't been modified since the
1752 * reloc tree was create can be replaced.
1753 *
1754 * if a block was replaced, level of the block + 1 is returned.
1755 * if no block got replaced, 0 is returned. if there are other
1756 * errors, a negative error number is returned.
1757 */
3fd0a558 1758static noinline_for_stack
3d0174f7 1759int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc,
3fd0a558
YZ		 1760 struct btrfs_root *dest, struct btrfs_root *src,
1761 struct btrfs_path *path, struct btrfs_key *next_key,
1762 int lowest_level, int max_level)
5d4f98a2 1763{
0b246afa 1764 struct btrfs_fs_info *fs_info = dest->fs_info;
5d4f98a2
YZ		 1765 struct extent_buffer *eb;
1766 struct extent_buffer *parent;
82fa113f 1767 struct btrfs_ref ref = { 0 };
5d4f98a2
YZ		 1768 struct btrfs_key key;
1769 u64 old_bytenr;
1770 u64 new_bytenr;
1771 u64 old_ptr_gen;
1772 u64 new_ptr_gen;
1773 u64 last_snapshot;
1774 u32 blocksize;
3fd0a558 1775 int cow = 0;
5d4f98a2
YZ		 1776 int level;
1777 int ret;
1778 int slot;
1779
1780 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1781 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
5d4f98a2
YZ		 1782
1783 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
3fd0a558 1784again:
5d4f98a2
YZ		 1785 slot = path->slots[lowest_level];
1786 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1787
1788 eb = btrfs_lock_root_node(dest);
8bead258 1789 btrfs_set_lock_blocking_write(eb);
5d4f98a2
YZ		 1790 level = btrfs_header_level(eb);
1791
1792 if (level < lowest_level) {
1793 btrfs_tree_unlock(eb);
1794 free_extent_buffer(eb);
1795 return 0;
1796 }
1797
3fd0a558
YZ		 1798 if (cow) {
1799 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1800 BUG_ON(ret);
1801 }
8bead258 1802 btrfs_set_lock_blocking_write(eb);
5d4f98a2
YZ		 1803
1804 if (next_key) {
1805 next_key->objectid = (u64)-1;
1806 next_key->type = (u8)-1;
1807 next_key->offset = (u64)-1;
1808 }
1809
1810 parent = eb;
1811 while (1) {
581c1760
QW		 1812 struct btrfs_key first_key;
1813
5d4f98a2
YZ		 1814 level = btrfs_header_level(parent);
1815 BUG_ON(level < lowest_level);
1816
1817 ret = btrfs_bin_search(parent, &key, level, &slot);
cbca7d59
FM		 1818 if (ret < 0)
1819 break;
5d4f98a2
YZ		 1820 if (ret && slot > 0)
1821 slot--;
1822
1823 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1824 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1825
1826 old_bytenr = btrfs_node_blockptr(parent, slot);
0b246afa 1827 blocksize = fs_info->nodesize;
5d4f98a2 1828 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
17515f1b 1829 btrfs_node_key_to_cpu(parent, &first_key, slot);
5d4f98a2
YZ		 1830
1831 if (level <= max_level) {
1832 eb = path->nodes[level];
1833 new_bytenr = btrfs_node_blockptr(eb,
1834 path->slots[level]);
1835 new_ptr_gen = btrfs_node_ptr_generation(eb,
1836 path->slots[level]);
1837 } else {
1838 new_bytenr = 0;
1839 new_ptr_gen = 0;
1840 }
1841
fae7f21c 1842 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
5d4f98a2
YZ		 1843 ret = level;
1844 break;
1845 }
1846
1847 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1848 memcmp_node_keys(parent, slot, path, level)) {
3fd0a558 1849 if (level <= lowest_level) {
5d4f98a2
YZ		 1850 ret = 0;
1851 break;
1852 }
1853
581c1760
QW		 1854 eb = read_tree_block(fs_info, old_bytenr, old_ptr_gen,
1855 level - 1, &first_key);
64c043de
LB		 1856 if (IS_ERR(eb)) {
1857 ret = PTR_ERR(eb);
264813ac 1858 break;
64c043de
LB		 1859 } else if (!extent_buffer_uptodate(eb)) {
1860 ret = -EIO;
416bc658 1861 free_extent_buffer(eb);
379cde74 1862 break;
416bc658 1863 }
5d4f98a2 1864 btrfs_tree_lock(eb);
3fd0a558
YZ		 1865 if (cow) {
1866 ret = btrfs_cow_block(trans, dest, eb, parent,
1867 slot, &eb);
1868 BUG_ON(ret);
5d4f98a2 1869 }
8bead258 1870 btrfs_set_lock_blocking_write(eb);
5d4f98a2
YZ		 1871
1872 btrfs_tree_unlock(parent);
1873 free_extent_buffer(parent);
1874
1875 parent = eb;
1876 continue;
1877 }
1878
3fd0a558
YZ		 1879 if (!cow) {
1880 btrfs_tree_unlock(parent);
1881 free_extent_buffer(parent);
1882 cow = 1;
1883 goto again;
1884 }
1885
5d4f98a2
YZ		 1886 btrfs_node_key_to_cpu(path->nodes[level], &key,
1887 path->slots[level]);
b3b4aa74 1888 btrfs_release_path(path);
5d4f98a2
YZ		 1889
1890 path->lowest_level = level;
1891 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1892 path->lowest_level = 0;
1893 BUG_ON(ret);
1894
824d8dff
QW		 1895 /*
1896 * Info qgroup to trace both subtrees.
1897 *
1898 * We must trace both trees.
1899 * 1) Tree reloc subtree
1900 * If not traced, we will leak data numbers
1901 * 2) Fs subtree
1902 * If not traced, we will double count old data
f616f5cd
QW		 1903 *
1904 * We don't scan the subtree right now, but only record
1905 * the swapped tree blocks.
1906 * The real subtree rescan is delayed until we have new
1907 * CoW on the subtree root node before transaction commit.
824d8dff 1908 */
370a11b8
QW		 1909 ret = btrfs_qgroup_add_swapped_blocks(trans, dest,
1910 rc->block_group, parent, slot,
1911 path->nodes[level], path->slots[level],
1912 last_snapshot);
1913 if (ret < 0)
1914 break;
5d4f98a2
YZ		 1915 /*
1916 * swap blocks in fs tree and reloc tree.
1917 */
1918 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1919 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1920 btrfs_mark_buffer_dirty(parent);
1921
1922 btrfs_set_node_blockptr(path->nodes[level],
1923 path->slots[level], old_bytenr);
1924 btrfs_set_node_ptr_generation(path->nodes[level],
1925 path->slots[level], old_ptr_gen);
1926 btrfs_mark_buffer_dirty(path->nodes[level]);
1927
82fa113f
QW		 1928 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, old_bytenr,
1929 blocksize, path->nodes[level]->start);
1930 ref.skip_qgroup = true;
1931 btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid);
1932 ret = btrfs_inc_extent_ref(trans, &ref);
5d4f98a2 1933 BUG_ON(ret);
82fa113f
QW		 1934 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr,
1935 blocksize, 0);
1936 ref.skip_qgroup = true;
1937 btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid);
1938 ret = btrfs_inc_extent_ref(trans, &ref);
5d4f98a2
YZ		 1939 BUG_ON(ret);
1940
ffd4bb2a
QW		 1941 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, new_bytenr,
1942 blocksize, path->nodes[level]->start);
1943 btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid);
1944 ref.skip_qgroup = true;
1945 ret = btrfs_free_extent(trans, &ref);
5d4f98a2
YZ		 1946 BUG_ON(ret);
1947
ffd4bb2a
QW		 1948 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, old_bytenr,
1949 blocksize, 0);
1950 btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid);
1951 ref.skip_qgroup = true;
1952 ret = btrfs_free_extent(trans, &ref);
5d4f98a2
YZ		 1953 BUG_ON(ret);
1954
1955 btrfs_unlock_up_safe(path, 0);
1956
1957 ret = level;
1958 break;
1959 }
1960 btrfs_tree_unlock(parent);
1961 free_extent_buffer(parent);
1962 return ret;
1963}
1964
1965/*
1966 * helper to find next relocated block in reloc tree
1967 */
1968static noinline_for_stack
1969int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1970 int *level)
1971{
1972 struct extent_buffer *eb;
1973 int i;
1974 u64 last_snapshot;
1975 u32 nritems;
1976
1977 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1978
1979 for (i = 0; i < *level; i++) {
1980 free_extent_buffer(path->nodes[i]);
1981 path->nodes[i] = NULL;
1982 }
1983
1984 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1985 eb = path->nodes[i];
1986 nritems = btrfs_header_nritems(eb);
1987 while (path->slots[i] + 1 < nritems) {
1988 path->slots[i]++;
1989 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1990 last_snapshot)
1991 continue;
1992
1993 *level = i;
1994 return 0;
1995 }
1996 free_extent_buffer(path->nodes[i]);
1997 path->nodes[i] = NULL;
1998 }
1999 return 1;
2000}
2001
2002/*
2003 * walk down reloc tree to find relocated block of lowest level
2004 */
2005static noinline_for_stack
2006int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
2007 int *level)
2008{
2ff7e61e 2009 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 2010 struct extent_buffer *eb = NULL;
2011 int i;
2012 u64 bytenr;
2013 u64 ptr_gen = 0;
2014 u64 last_snapshot;
5d4f98a2
YZ		 2015 u32 nritems;
2016
2017 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2018
2019 for (i = *level; i > 0; i--) {
581c1760
QW		 2020 struct btrfs_key first_key;
2021
5d4f98a2
YZ		 2022 eb = path->nodes[i];
2023 nritems = btrfs_header_nritems(eb);
2024 while (path->slots[i] < nritems) {
2025 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
2026 if (ptr_gen > last_snapshot)
2027 break;
2028 path->slots[i]++;
2029 }
2030 if (path->slots[i] >= nritems) {
2031 if (i == *level)
2032 break;
2033 *level = i + 1;
2034 return 0;
2035 }
2036 if (i == 1) {
2037 *level = i;
2038 return 0;
2039 }
2040
2041 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
581c1760
QW		 2042 btrfs_node_key_to_cpu(eb, &first_key, path->slots[i]);
2043 eb = read_tree_block(fs_info, bytenr, ptr_gen, i - 1,
2044 &first_key);
64c043de
LB		 2045 if (IS_ERR(eb)) {
2046 return PTR_ERR(eb);
2047 } else if (!extent_buffer_uptodate(eb)) {
416bc658
JB		 2048 free_extent_buffer(eb);
2049 return -EIO;
2050 }
5d4f98a2
YZ		 2051 BUG_ON(btrfs_header_level(eb) != i - 1);
2052 path->nodes[i - 1] = eb;
2053 path->slots[i - 1] = 0;
2054 }
2055 return 1;
2056}
2057
2058/*
2059 * invalidate extent cache for file extents whose key in range of
2060 * [min_key, max_key)
2061 */
2062static int invalidate_extent_cache(struct btrfs_root *root,
2063 struct btrfs_key *min_key,
2064 struct btrfs_key *max_key)
2065{
0b246afa 2066 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 2067 struct inode *inode = NULL;
2068 u64 objectid;
2069 u64 start, end;
33345d01 2070 u64 ino;
5d4f98a2
YZ		 2071
2072 objectid = min_key->objectid;
2073 while (1) {
2074 cond_resched();
2075 iput(inode);
2076
2077 if (objectid > max_key->objectid)
2078 break;
2079
2080 inode = find_next_inode(root, objectid);
2081 if (!inode)
2082 break;
4a0cc7ca 2083 ino = btrfs_ino(BTRFS_I(inode));
5d4f98a2 2084
33345d01 2085 if (ino > max_key->objectid) {
5d4f98a2
YZ		 2086 iput(inode);
2087 break;
2088 }
2089
33345d01 2090 objectid = ino + 1;
5d4f98a2
YZ		 2091 if (!S_ISREG(inode->i_mode))
2092 continue;
2093
33345d01 2094 if (unlikely(min_key->objectid == ino)) {
5d4f98a2
YZ		 2095 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2096 continue;
2097 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2098 start = 0;
2099 else {
2100 start = min_key->offset;
0b246afa 2101 WARN_ON(!IS_ALIGNED(start, fs_info->sectorsize));
5d4f98a2
YZ		 2102 }
2103 } else {
2104 start = 0;
2105 }
2106
33345d01 2107 if (unlikely(max_key->objectid == ino)) {
5d4f98a2
YZ		 2108 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2109 continue;
2110 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2111 end = (u64)-1;
2112 } else {
2113 if (max_key->offset == 0)
2114 continue;
2115 end = max_key->offset;
0b246afa 2116 WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
5d4f98a2
YZ		 2117 end--;
2118 }
2119 } else {
2120 end = (u64)-1;
2121 }
2122
2123 /* the lock_extent waits for readpage to complete */
d0082371 2124 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
dcdbc059 2125 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 1);
d0082371 2126 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
5d4f98a2
YZ		 2127 }
2128 return 0;
2129}
2130
2131static int find_next_key(struct btrfs_path *path, int level,
2132 struct btrfs_key *key)
2133
2134{
2135 while (level < BTRFS_MAX_LEVEL) {
2136 if (!path->nodes[level])
2137 break;
2138 if (path->slots[level] + 1 <
2139 btrfs_header_nritems(path->nodes[level])) {
2140 btrfs_node_key_to_cpu(path->nodes[level], key,
2141 path->slots[level] + 1);
2142 return 0;
2143 }
2144 level++;
2145 }
2146 return 1;
2147}
2148
d2311e69
QW		 2149/*
2150 * Insert current subvolume into reloc_control::dirty_subvol_roots
2151 */
2152static void insert_dirty_subvol(struct btrfs_trans_handle *trans,
2153 struct reloc_control *rc,
2154 struct btrfs_root *root)
2155{
2156 struct btrfs_root *reloc_root = root->reloc_root;
2157 struct btrfs_root_item *reloc_root_item;
2158
2159 /* @root must be a subvolume tree root with a valid reloc tree */
2160 ASSERT(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
2161 ASSERT(reloc_root);
2162
2163 reloc_root_item = &reloc_root->root_item;
2164 memset(&reloc_root_item->drop_progress, 0,
2165 sizeof(reloc_root_item->drop_progress));
2166 reloc_root_item->drop_level = 0;
2167 btrfs_set_root_refs(reloc_root_item, 0);
2168 btrfs_update_reloc_root(trans, root);
2169
2170 if (list_empty(&root->reloc_dirty_list)) {
2171 btrfs_grab_fs_root(root);
2172 list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots);
2173 }
2174}
2175
2176static int clean_dirty_subvols(struct reloc_control *rc)
2177{
2178 struct btrfs_root *root;
2179 struct btrfs_root *next;
2180 int ret = 0;
30d40577 2181 int ret2;
d2311e69
QW		 2182
2183 list_for_each_entry_safe(root, next, &rc->dirty_subvol_roots,
2184 reloc_dirty_list) {
30d40577
QW		 2185 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2186 /* Merged subvolume, cleanup its reloc root */
2187 struct btrfs_root *reloc_root = root->reloc_root;
d2311e69 2188
30d40577
QW		 2189 clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
2190 list_del_init(&root->reloc_dirty_list);
2191 root->reloc_root = NULL;
2192 if (reloc_root) {
d2311e69 2193
30d40577
QW		 2194 ret2 = btrfs_drop_snapshot(reloc_root, NULL, 0, 1);
2195 if (ret2 < 0 && !ret)
2196 ret = ret2;
2197 }
2198 btrfs_put_fs_root(root);
2199 } else {
2200 /* Orphan reloc tree, just clean it up */
2201 ret2 = btrfs_drop_snapshot(root, NULL, 0, 1);
d2311e69
QW		 2202 if (ret2 < 0 && !ret)
2203 ret = ret2;
2204 }
d2311e69
QW		 2205 }
2206 return ret;
2207}
2208
5d4f98a2
YZ		 2209/*
2210 * merge the relocated tree blocks in reloc tree with corresponding
2211 * fs tree.
2212 */
2213static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2214 struct btrfs_root *root)
2215{
0b246afa 2216 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2
YZ		 2217 struct btrfs_key key;
2218 struct btrfs_key next_key;
9e6a0c52 2219 struct btrfs_trans_handle *trans = NULL;
5d4f98a2
YZ		 2220 struct btrfs_root *reloc_root;
2221 struct btrfs_root_item *root_item;
2222 struct btrfs_path *path;
3fd0a558 2223 struct extent_buffer *leaf;
5d4f98a2
YZ		 2224 int level;
2225 int max_level;
2226 int replaced = 0;
2227 int ret;
2228 int err = 0;
3fd0a558 2229 u32 min_reserved;
5d4f98a2
YZ		 2230
2231 path = btrfs_alloc_path();
2232 if (!path)
2233 return -ENOMEM;
e4058b54 2234 path->reada = READA_FORWARD;
5d4f98a2
YZ		 2235
2236 reloc_root = root->reloc_root;
2237 root_item = &reloc_root->root_item;
2238
2239 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2240 level = btrfs_root_level(root_item);
2241 extent_buffer_get(reloc_root->node);
2242 path->nodes[level] = reloc_root->node;
2243 path->slots[level] = 0;
2244 } else {
2245 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2246
2247 level = root_item->drop_level;
2248 BUG_ON(level == 0);
2249 path->lowest_level = level;
2250 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
33c66f43 2251 path->lowest_level = 0;
5d4f98a2
YZ		 2252 if (ret < 0) {
2253 btrfs_free_path(path);
2254 return ret;
2255 }
2256
2257 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2258 path->slots[level]);
2259 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2260
2261 btrfs_unlock_up_safe(path, 0);
2262 }
2263
0b246afa 2264 min_reserved = fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
3fd0a558 2265 memset(&next_key, 0, sizeof(next_key));
5d4f98a2 2266
3fd0a558 2267 while (1) {
08e007d2
MX		 2268 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2269 BTRFS_RESERVE_FLUSH_ALL);
3fd0a558 2270 if (ret) {
9e6a0c52
JB		 2271 err = ret;
2272 goto out;
5d4f98a2 2273 }
9e6a0c52
JB		 2274 trans = btrfs_start_transaction(root, 0);
2275 if (IS_ERR(trans)) {
2276 err = PTR_ERR(trans);
2277 trans = NULL;
2278 goto out;
2279 }
2280 trans->block_rsv = rc->block_rsv;
5d4f98a2 2281
5d4f98a2 2282 replaced = 0;
5d4f98a2
YZ		 2283 max_level = level;
2284
2285 ret = walk_down_reloc_tree(reloc_root, path, &level);
2286 if (ret < 0) {
2287 err = ret;
2288 goto out;
2289 }
2290 if (ret > 0)
2291 break;
2292
2293 if (!find_next_key(path, level, &key) &&
2294 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2295 ret = 0;
5d4f98a2 2296 } else {
3d0174f7 2297 ret = replace_path(trans, rc, root, reloc_root, path,
3fd0a558 2298 &next_key, level, max_level);
5d4f98a2
YZ		 2299 }
2300 if (ret < 0) {
2301 err = ret;
2302 goto out;
2303 }
2304
2305 if (ret > 0) {
2306 level = ret;
2307 btrfs_node_key_to_cpu(path->nodes[level], &key,
2308 path->slots[level]);
2309 replaced = 1;
5d4f98a2
YZ		 2310 }
2311
2312 ret = walk_up_reloc_tree(reloc_root, path, &level);
2313 if (ret > 0)
2314 break;
2315
2316 BUG_ON(level == 0);
2317 /*
2318 * save the merging progress in the drop_progress.
2319 * this is OK since root refs == 1 in this case.
2320 */
2321 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2322 path->slots[level]);
2323 root_item->drop_level = level;
2324
3a45bb20 2325 btrfs_end_transaction_throttle(trans);
9e6a0c52 2326 trans = NULL;
5d4f98a2 2327
2ff7e61e 2328 btrfs_btree_balance_dirty(fs_info);
5d4f98a2
YZ		 2329
2330 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2331 invalidate_extent_cache(root, &key, &next_key);
2332 }
2333
2334 /*
2335 * handle the case only one block in the fs tree need to be
2336 * relocated and the block is tree root.
2337 */
2338 leaf = btrfs_lock_root_node(root);
2339 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2340 btrfs_tree_unlock(leaf);
2341 free_extent_buffer(leaf);
2342 if (ret < 0)
2343 err = ret;
2344out:
2345 btrfs_free_path(path);
2346
d2311e69
QW		 2347 if (err == 0)
2348 insert_dirty_subvol(trans, rc, root);
5d4f98a2 2349
9e6a0c52 2350 if (trans)
3a45bb20 2351 btrfs_end_transaction_throttle(trans);
5d4f98a2 2352
2ff7e61e 2353 btrfs_btree_balance_dirty(fs_info);
5d4f98a2 2354
5d4f98a2
YZ		 2355 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2356 invalidate_extent_cache(root, &key, &next_key);
2357
2358 return err;
2359}
2360
3fd0a558
YZ		 2361static noinline_for_stack
2362int prepare_to_merge(struct reloc_control *rc, int err)
5d4f98a2 2363{
3fd0a558 2364 struct btrfs_root *root = rc->extent_root;
0b246afa 2365 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2 2366 struct btrfs_root *reloc_root;
3fd0a558
YZ		 2367 struct btrfs_trans_handle *trans;
2368 LIST_HEAD(reloc_roots);
2369 u64 num_bytes = 0;
2370 int ret;
3fd0a558 2371
0b246afa
JM		 2372 mutex_lock(&fs_info->reloc_mutex);
2373 rc->merging_rsv_size += fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
3fd0a558 2374 rc->merging_rsv_size += rc->nodes_relocated * 2;
0b246afa 2375 mutex_unlock(&fs_info->reloc_mutex);
7585717f 2376
3fd0a558
YZ		 2377again:
2378 if (!err) {
2379 num_bytes = rc->merging_rsv_size;
08e007d2
MX		 2380 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2381 BTRFS_RESERVE_FLUSH_ALL);
3fd0a558
YZ		 2382 if (ret)
2383 err = ret;
2384 }
2385
7a7eaa40 2386 trans = btrfs_join_transaction(rc->extent_root);
3612b495
TI		 2387 if (IS_ERR(trans)) {
2388 if (!err)
2ff7e61e
JM		 2389 btrfs_block_rsv_release(fs_info, rc->block_rsv,
2390 num_bytes);
3612b495
TI		 2391 return PTR_ERR(trans);
2392 }
3fd0a558
YZ		 2393
2394 if (!err) {
2395 if (num_bytes != rc->merging_rsv_size) {
3a45bb20 2396 btrfs_end_transaction(trans);
2ff7e61e
JM		 2397 btrfs_block_rsv_release(fs_info, rc->block_rsv,
2398 num_bytes);
3fd0a558
YZ		 2399 goto again;
2400 }
2401 }
5d4f98a2 2402
3fd0a558
YZ		 2403 rc->merge_reloc_tree = 1;
2404
2405 while (!list_empty(&rc->reloc_roots)) {
2406 reloc_root = list_entry(rc->reloc_roots.next,
2407 struct btrfs_root, root_list);
2408 list_del_init(&reloc_root->root_list);
5d4f98a2 2409
0b246afa 2410 root = read_fs_root(fs_info, reloc_root->root_key.offset);
5d4f98a2
YZ		 2411 BUG_ON(IS_ERR(root));
2412 BUG_ON(root->reloc_root != reloc_root);
2413
3fd0a558
YZ		 2414 /*
2415 * set reference count to 1, so btrfs_recover_relocation
2416 * knows it should resumes merging
2417 */
2418 if (!err)
2419 btrfs_set_root_refs(&reloc_root->root_item, 1);
5d4f98a2 2420 btrfs_update_reloc_root(trans, root);
5d4f98a2 2421
3fd0a558
YZ		 2422 list_add(&reloc_root->root_list, &reloc_roots);
2423 }
5d4f98a2 2424
3fd0a558 2425 list_splice(&reloc_roots, &rc->reloc_roots);
5d4f98a2 2426
3fd0a558 2427 if (!err)
3a45bb20 2428 btrfs_commit_transaction(trans);
3fd0a558 2429 else
3a45bb20 2430 btrfs_end_transaction(trans);
3fd0a558 2431 return err;
5d4f98a2
YZ		 2432}
2433
aca1bba6
LB		 2434static noinline_for_stack
2435void free_reloc_roots(struct list_head *list)
2436{
2437 struct btrfs_root *reloc_root;
2438
2439 while (!list_empty(list)) {
2440 reloc_root = list_entry(list->next, struct btrfs_root,
2441 root_list);
bb166d72 2442 __del_reloc_root(reloc_root);
6bdf131f
JB		 2443 free_extent_buffer(reloc_root->node);
2444 free_extent_buffer(reloc_root->commit_root);
2445 reloc_root->node = NULL;
2446 reloc_root->commit_root = NULL;
aca1bba6
LB		 2447 }
2448}
2449
3fd0a558 2450static noinline_for_stack
94404e82 2451void merge_reloc_roots(struct reloc_control *rc)
5d4f98a2 2452{
0b246afa 2453 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2 2454 struct btrfs_root *root;
3fd0a558
YZ		 2455 struct btrfs_root *reloc_root;
2456 LIST_HEAD(reloc_roots);
2457 int found = 0;
aca1bba6 2458 int ret = 0;
3fd0a558
YZ		 2459again:
2460 root = rc->extent_root;
7585717f
CM		 2461
2462 /*
2463 * this serializes us with btrfs_record_root_in_transaction,
2464 * we have to make sure nobody is in the middle of
2465 * adding their roots to the list while we are
2466 * doing this splice
2467 */
0b246afa 2468 mutex_lock(&fs_info->reloc_mutex);
3fd0a558 2469 list_splice_init(&rc->reloc_roots, &reloc_roots);
0b246afa 2470 mutex_unlock(&fs_info->reloc_mutex);
5d4f98a2 2471
3fd0a558
YZ		 2472 while (!list_empty(&reloc_roots)) {
2473 found = 1;
2474 reloc_root = list_entry(reloc_roots.next,
2475 struct btrfs_root, root_list);
5d4f98a2 2476
3fd0a558 2477 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
0b246afa 2478 root = read_fs_root(fs_info,
3fd0a558
YZ		 2479 reloc_root->root_key.offset);
2480 BUG_ON(IS_ERR(root));
2481 BUG_ON(root->reloc_root != reloc_root);
5d4f98a2 2482
3fd0a558 2483 ret = merge_reloc_root(rc, root);
b37b39cd 2484 if (ret) {
25e293c2
WS		 2485 if (list_empty(&reloc_root->root_list))
2486 list_add_tail(&reloc_root->root_list,
2487 &reloc_roots);
aca1bba6 2488 goto out;
b37b39cd 2489 }
3fd0a558
YZ		 2490 } else {
2491 list_del_init(&reloc_root->root_list);
30d40577
QW		 2492 /* Don't forget to queue this reloc root for cleanup */
2493 list_add_tail(&reloc_root->reloc_dirty_list,
2494 &rc->dirty_subvol_roots);
3fd0a558 2495 }
5d4f98a2
YZ		 2496 }
2497
3fd0a558
YZ		 2498 if (found) {
2499 found = 0;
2500 goto again;
2501 }
aca1bba6
LB		 2502out:
2503 if (ret) {
0b246afa 2504 btrfs_handle_fs_error(fs_info, ret, NULL);
aca1bba6
LB		 2505 if (!list_empty(&reloc_roots))
2506 free_reloc_roots(&reloc_roots);
467bb1d2
WS		 2507
2508 /* new reloc root may be added */
0b246afa 2509 mutex_lock(&fs_info->reloc_mutex);
467bb1d2 2510 list_splice_init(&rc->reloc_roots, &reloc_roots);
0b246afa 2511 mutex_unlock(&fs_info->reloc_mutex);
467bb1d2
WS		 2512 if (!list_empty(&reloc_roots))
2513 free_reloc_roots(&reloc_roots);
aca1bba6
LB		 2514 }
2515
5d4f98a2 2516 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
5d4f98a2
YZ		 2517}
2518
2519static void free_block_list(struct rb_root *blocks)
2520{
2521 struct tree_block *block;
2522 struct rb_node *rb_node;
2523 while ((rb_node = rb_first(blocks))) {
2524 block = rb_entry(rb_node, struct tree_block, rb_node);
2525 rb_erase(rb_node, blocks);
2526 kfree(block);
2527 }
2528}
2529
2530static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2531 struct btrfs_root *reloc_root)
2532{
0b246afa 2533 struct btrfs_fs_info *fs_info = reloc_root->fs_info;
5d4f98a2
YZ		 2534 struct btrfs_root *root;
2535
2536 if (reloc_root->last_trans == trans->transid)
2537 return 0;
2538
0b246afa 2539 root = read_fs_root(fs_info, reloc_root->root_key.offset);
5d4f98a2
YZ		 2540 BUG_ON(IS_ERR(root));
2541 BUG_ON(root->reloc_root != reloc_root);
2542
2543 return btrfs_record_root_in_trans(trans, root);
2544}
2545
3fd0a558
YZ		 2546static noinline_for_stack
2547struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2548 struct reloc_control *rc,
2549 struct backref_node *node,
dc4103f9 2550 struct backref_edge *edges[])
5d4f98a2
YZ		 2551{
2552 struct backref_node *next;
2553 struct btrfs_root *root;
3fd0a558
YZ		 2554 int index = 0;
2555
5d4f98a2
YZ		 2556 next = node;
2557 while (1) {
2558 cond_resched();
2559 next = walk_up_backref(next, edges, &index);
2560 root = next->root;
3fd0a558 2561 BUG_ON(!root);
27cdeb70 2562 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
5d4f98a2
YZ		 2563
2564 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2565 record_reloc_root_in_trans(trans, root);
2566 break;
2567 }
2568
3fd0a558
YZ		 2569 btrfs_record_root_in_trans(trans, root);
2570 root = root->reloc_root;
2571
2572 if (next->new_bytenr != root->node->start) {
2573 BUG_ON(next->new_bytenr);
2574 BUG_ON(!list_empty(&next->list));
2575 next->new_bytenr = root->node->start;
2576 next->root = root;
2577 list_add_tail(&next->list,
2578 &rc->backref_cache.changed);
2579 __mark_block_processed(rc, next);
5d4f98a2
YZ		 2580 break;
2581 }
2582
3fd0a558 2583 WARN_ON(1);
5d4f98a2
YZ		 2584 root = NULL;
2585 next = walk_down_backref(edges, &index);
2586 if (!next || next->level <= node->level)
2587 break;
2588 }
3fd0a558
YZ		 2589 if (!root)
2590 return NULL;
5d4f98a2 2591
3fd0a558
YZ		 2592 next = node;
2593 /* setup backref node path for btrfs_reloc_cow_block */
2594 while (1) {
2595 rc->backref_cache.path[next->level] = next;
2596 if (--index < 0)
2597 break;
2598 next = edges[index]->node[UPPER];
5d4f98a2 2599 }
5d4f98a2
YZ		 2600 return root;
2601}
2602
3fd0a558
YZ		 2603/*
2604 * select a tree root for relocation. return NULL if the block
2605 * is reference counted. we should use do_relocation() in this
2606 * case. return a tree root pointer if the block isn't reference
2607 * counted. return -ENOENT if the block is root of reloc tree.
2608 */
5d4f98a2 2609static noinline_for_stack
147d256e 2610struct btrfs_root *select_one_root(struct backref_node *node)
5d4f98a2 2611{
3fd0a558
YZ		 2612 struct backref_node *next;
2613 struct btrfs_root *root;
2614 struct btrfs_root *fs_root = NULL;
5d4f98a2 2615 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
3fd0a558
YZ		 2616 int index = 0;
2617
2618 next = node;
2619 while (1) {
2620 cond_resched();
2621 next = walk_up_backref(next, edges, &index);
2622 root = next->root;
2623 BUG_ON(!root);
2624
25985edc 2625 /* no other choice for non-references counted tree */
27cdeb70 2626 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
3fd0a558
YZ		 2627 return root;
2628
2629 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2630 fs_root = root;
2631
2632 if (next != node)
2633 return NULL;
2634
2635 next = walk_down_backref(edges, &index);
2636 if (!next || next->level <= node->level)
2637 break;
2638 }
2639
2640 if (!fs_root)
2641 return ERR_PTR(-ENOENT);
2642 return fs_root;
5d4f98a2
YZ		 2643}
2644
2645static noinline_for_stack
3fd0a558
YZ		 2646u64 calcu_metadata_size(struct reloc_control *rc,
2647 struct backref_node *node, int reserve)
5d4f98a2 2648{
0b246afa 2649 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3fd0a558
YZ		 2650 struct backref_node *next = node;
2651 struct backref_edge *edge;
2652 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2653 u64 num_bytes = 0;
2654 int index = 0;
2655
2656 BUG_ON(reserve && node->processed);
2657
2658 while (next) {
2659 cond_resched();
2660 while (1) {
2661 if (next->processed && (reserve || next != node))
2662 break;
2663
0b246afa 2664 num_bytes += fs_info->nodesize;
3fd0a558
YZ		 2665
2666 if (list_empty(&next->upper))
2667 break;
2668
2669 edge = list_entry(next->upper.next,
2670 struct backref_edge, list[LOWER]);
2671 edges[index++] = edge;
2672 next = edge->node[UPPER];
2673 }
2674 next = walk_down_backref(edges, &index);
2675 }
2676 return num_bytes;
5d4f98a2
YZ		 2677}
2678
3fd0a558
YZ		 2679static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2680 struct reloc_control *rc,
2681 struct backref_node *node)
5d4f98a2 2682{
3fd0a558 2683 struct btrfs_root *root = rc->extent_root;
da17066c 2684 struct btrfs_fs_info *fs_info = root->fs_info;
3fd0a558
YZ		 2685 u64 num_bytes;
2686 int ret;
0647bf56 2687 u64 tmp;
3fd0a558
YZ		 2688
2689 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
5d4f98a2 2690
3fd0a558 2691 trans->block_rsv = rc->block_rsv;
0647bf56 2692 rc->reserved_bytes += num_bytes;
8ca17f0f
JB		 2693
2694 /*
2695 * We are under a transaction here so we can only do limited flushing.
2696 * If we get an enospc just kick back -EAGAIN so we know to drop the
2697 * transaction and try to refill when we can flush all the things.
2698 */
0647bf56 2699 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
8ca17f0f 2700 BTRFS_RESERVE_FLUSH_LIMIT);
3fd0a558 2701 if (ret) {
da17066c 2702 tmp = fs_info->nodesize * RELOCATION_RESERVED_NODES;
8ca17f0f
JB		 2703 while (tmp <= rc->reserved_bytes)
2704 tmp <<= 1;
2705 /*
2706 * only one thread can access block_rsv at this point,
2707 * so we don't need hold lock to protect block_rsv.
2708 * we expand more reservation size here to allow enough
52042d8e 2709 * space for relocation and we will return earlier in
8ca17f0f
JB		 2710 * enospc case.
2711 */
da17066c
JM		 2712 rc->block_rsv->size = tmp + fs_info->nodesize *
2713 RELOCATION_RESERVED_NODES;
8ca17f0f 2714 return -EAGAIN;
5d4f98a2 2715 }
3fd0a558 2716
3fd0a558
YZ		 2717 return 0;
2718}
2719
5d4f98a2
YZ		 2720/*
2721 * relocate a block tree, and then update pointers in upper level
2722 * blocks that reference the block to point to the new location.
2723 *
2724 * if called by link_to_upper, the block has already been relocated.
2725 * in that case this function just updates pointers.
2726 */
2727static int do_relocation(struct btrfs_trans_handle *trans,
3fd0a558 2728 struct reloc_control *rc,
5d4f98a2
YZ		 2729 struct backref_node *node,
2730 struct btrfs_key *key,
2731 struct btrfs_path *path, int lowest)
2732{
2ff7e61e 2733 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2
YZ		 2734 struct backref_node *upper;
2735 struct backref_edge *edge;
2736 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2737 struct btrfs_root *root;
2738 struct extent_buffer *eb;
2739 u32 blocksize;
2740 u64 bytenr;
2741 u64 generation;
5d4f98a2
YZ		 2742 int slot;
2743 int ret;
2744 int err = 0;
2745
2746 BUG_ON(lowest && node->eb);
2747
2748 path->lowest_level = node->level + 1;
3fd0a558 2749 rc->backref_cache.path[node->level] = node;
5d4f98a2 2750 list_for_each_entry(edge, &node->upper, list[LOWER]) {
581c1760 2751 struct btrfs_key first_key;
82fa113f 2752 struct btrfs_ref ref = { 0 };
581c1760 2753
5d4f98a2 2754 cond_resched();
5d4f98a2
YZ		 2755
2756 upper = edge->node[UPPER];
dc4103f9 2757 root = select_reloc_root(trans, rc, upper, edges);
3fd0a558
YZ		 2758 BUG_ON(!root);
2759
2760 if (upper->eb && !upper->locked) {
2761 if (!lowest) {
2762 ret = btrfs_bin_search(upper->eb, key,
2763 upper->level, &slot);
cbca7d59
FM		 2764 if (ret < 0) {
2765 err = ret;
2766 goto next;
2767 }
3fd0a558
YZ		 2768 BUG_ON(ret);
2769 bytenr = btrfs_node_blockptr(upper->eb, slot);
2770 if (node->eb->start == bytenr)
2771 goto next;
2772 }
5d4f98a2 2773 drop_node_buffer(upper);
3fd0a558 2774 }
5d4f98a2
YZ		 2775
2776 if (!upper->eb) {
2777 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
3561b9db
LB		 2778 if (ret) {
2779 if (ret < 0)
2780 err = ret;
2781 else
2782 err = -ENOENT;
2783
2784 btrfs_release_path(path);
5d4f98a2
YZ		 2785 break;
2786 }
5d4f98a2 2787
3fd0a558
YZ		 2788 if (!upper->eb) {
2789 upper->eb = path->nodes[upper->level];
2790 path->nodes[upper->level] = NULL;
2791 } else {
2792 BUG_ON(upper->eb != path->nodes[upper->level]);
2793 }
5d4f98a2 2794
3fd0a558
YZ		 2795 upper->locked = 1;
2796 path->locks[upper->level] = 0;
5d4f98a2 2797
3fd0a558 2798 slot = path->slots[upper->level];
b3b4aa74 2799 btrfs_release_path(path);
5d4f98a2
YZ		 2800 } else {
2801 ret = btrfs_bin_search(upper->eb, key, upper->level,
2802 &slot);
cbca7d59
FM		 2803 if (ret < 0) {
2804 err = ret;
2805 goto next;
2806 }
5d4f98a2
YZ		 2807 BUG_ON(ret);
2808 }
2809
2810 bytenr = btrfs_node_blockptr(upper->eb, slot);
3fd0a558 2811 if (lowest) {
4547f4d8
LB		 2812 if (bytenr != node->bytenr) {
2813 btrfs_err(root->fs_info,
2814 "lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu",
2815 bytenr, node->bytenr, slot,
2816 upper->eb->start);
2817 err = -EIO;
2818 goto next;
2819 }
5d4f98a2 2820 } else {
3fd0a558
YZ		 2821 if (node->eb->start == bytenr)
2822 goto next;
5d4f98a2
YZ		 2823 }
2824
da17066c 2825 blocksize = root->fs_info->nodesize;
5d4f98a2 2826 generation = btrfs_node_ptr_generation(upper->eb, slot);
581c1760
QW		 2827 btrfs_node_key_to_cpu(upper->eb, &first_key, slot);
2828 eb = read_tree_block(fs_info, bytenr, generation,
2829 upper->level - 1, &first_key);
64c043de
LB		 2830 if (IS_ERR(eb)) {
2831 err = PTR_ERR(eb);
2832 goto next;
2833 } else if (!extent_buffer_uptodate(eb)) {
416bc658 2834 free_extent_buffer(eb);
97d9a8a4
TI		 2835 err = -EIO;
2836 goto next;
2837 }
5d4f98a2 2838 btrfs_tree_lock(eb);
8bead258 2839 btrfs_set_lock_blocking_write(eb);
5d4f98a2
YZ		 2840
2841 if (!node->eb) {
2842 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2843 slot, &eb);
3fd0a558
YZ		 2844 btrfs_tree_unlock(eb);
2845 free_extent_buffer(eb);
5d4f98a2
YZ		 2846 if (ret < 0) {
2847 err = ret;
3fd0a558 2848 goto next;
5d4f98a2 2849 }
3fd0a558 2850 BUG_ON(node->eb != eb);
5d4f98a2
YZ		 2851 } else {
2852 btrfs_set_node_blockptr(upper->eb, slot,
2853 node->eb->start);
2854 btrfs_set_node_ptr_generation(upper->eb, slot,
2855 trans->transid);
2856 btrfs_mark_buffer_dirty(upper->eb);
2857
82fa113f
QW		 2858 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
2859 node->eb->start, blocksize,
2860 upper->eb->start);
2861 ref.real_root = root->root_key.objectid;
2862 btrfs_init_tree_ref(&ref, node->level,
2863 btrfs_header_owner(upper->eb));
2864 ret = btrfs_inc_extent_ref(trans, &ref);
5d4f98a2
YZ		 2865 BUG_ON(ret);
2866
2867 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2868 BUG_ON(ret);
5d4f98a2 2869 }
3fd0a558
YZ		 2870next:
2871 if (!upper->pending)
2872 drop_node_buffer(upper);
2873 else
2874 unlock_node_buffer(upper);
2875 if (err)
2876 break;
5d4f98a2 2877 }
3fd0a558
YZ		 2878
2879 if (!err && node->pending) {
2880 drop_node_buffer(node);
2881 list_move_tail(&node->list, &rc->backref_cache.changed);
2882 node->pending = 0;
2883 }
2884
5d4f98a2 2885 path->lowest_level = 0;
3fd0a558 2886 BUG_ON(err == -ENOSPC);
5d4f98a2
YZ		 2887 return err;
2888}
2889
2890static int link_to_upper(struct btrfs_trans_handle *trans,
3fd0a558 2891 struct reloc_control *rc,
5d4f98a2
YZ		 2892 struct backref_node *node,
2893 struct btrfs_path *path)
2894{
2895 struct btrfs_key key;
5d4f98a2
YZ		 2896
2897 btrfs_node_key_to_cpu(node->eb, &key, 0);
3fd0a558 2898 return do_relocation(trans, rc, node, &key, path, 0);
5d4f98a2
YZ		 2899}
2900
2901static int finish_pending_nodes(struct btrfs_trans_handle *trans,
3fd0a558
YZ		 2902 struct reloc_control *rc,
2903 struct btrfs_path *path, int err)
5d4f98a2 2904{
3fd0a558
YZ		 2905 LIST_HEAD(list);
2906 struct backref_cache *cache = &rc->backref_cache;
5d4f98a2
YZ		 2907 struct backref_node *node;
2908 int level;
2909 int ret;
5d4f98a2
YZ		 2910
2911 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2912 while (!list_empty(&cache->pending[level])) {
2913 node = list_entry(cache->pending[level].next,
3fd0a558
YZ		 2914 struct backref_node, list);
2915 list_move_tail(&node->list, &list);
2916 BUG_ON(!node->pending);
5d4f98a2 2917
3fd0a558
YZ		 2918 if (!err) {
2919 ret = link_to_upper(trans, rc, node, path);
2920 if (ret < 0)
2921 err = ret;
2922 }
5d4f98a2 2923 }
3fd0a558 2924 list_splice_init(&list, &cache->pending[level]);
5d4f98a2 2925 }
5d4f98a2
YZ		 2926 return err;
2927}
2928
2929static void mark_block_processed(struct reloc_control *rc,
3fd0a558
YZ		 2930 u64 bytenr, u32 blocksize)
2931{
2932 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
ceeb0ae7 2933 EXTENT_DIRTY);
3fd0a558
YZ		 2934}
2935
2936static void __mark_block_processed(struct reloc_control *rc,
2937 struct backref_node *node)
5d4f98a2
YZ		 2938{
2939 u32 blocksize;
2940 if (node->level == 0 ||
2941 in_block_group(node->bytenr, rc->block_group)) {
da17066c 2942 blocksize = rc->extent_root->fs_info->nodesize;
3fd0a558 2943 mark_block_processed(rc, node->bytenr, blocksize);
5d4f98a2
YZ		 2944 }
2945 node->processed = 1;
2946}
2947
2948/*
2949 * mark a block and all blocks directly/indirectly reference the block
2950 * as processed.
2951 */
2952static void update_processed_blocks(struct reloc_control *rc,
2953 struct backref_node *node)
2954{
2955 struct backref_node *next = node;
2956 struct backref_edge *edge;
2957 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2958 int index = 0;
2959
2960 while (next) {
2961 cond_resched();
2962 while (1) {
2963 if (next->processed)
2964 break;
2965
3fd0a558 2966 __mark_block_processed(rc, next);
5d4f98a2
YZ		 2967
2968 if (list_empty(&next->upper))
2969 break;
2970
2971 edge = list_entry(next->upper.next,
2972 struct backref_edge, list[LOWER]);
2973 edges[index++] = edge;
2974 next = edge->node[UPPER];
2975 }
2976 next = walk_down_backref(edges, &index);
2977 }
2978}
2979
7476dfda 2980static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
3fd0a558 2981{
da17066c 2982 u32 blocksize = rc->extent_root->fs_info->nodesize;
7476dfda 2983
3fd0a558
YZ		 2984 if (test_range_bit(&rc->processed_blocks, bytenr,
2985 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2986 return 1;
2987 return 0;
5d4f98a2
YZ		 2988}
2989
2ff7e61e 2990static int get_tree_block_key(struct btrfs_fs_info *fs_info,
5d4f98a2
YZ		 2991 struct tree_block *block)
2992{
2993 struct extent_buffer *eb;
2994
2995 BUG_ON(block->key_ready);
581c1760
QW		 2996 eb = read_tree_block(fs_info, block->bytenr, block->key.offset,
2997 block->level, NULL);
64c043de
LB		 2998 if (IS_ERR(eb)) {
2999 return PTR_ERR(eb);
3000 } else if (!extent_buffer_uptodate(eb)) {
416bc658
JB		 3001 free_extent_buffer(eb);
3002 return -EIO;
3003 }
5d4f98a2
YZ		 3004 if (block->level == 0)
3005 btrfs_item_key_to_cpu(eb, &block->key, 0);
3006 else
3007 btrfs_node_key_to_cpu(eb, &block->key, 0);
3008 free_extent_buffer(eb);
3009 block->key_ready = 1;
3010 return 0;
3011}
3012
5d4f98a2
YZ		 3013/*
3014 * helper function to relocate a tree block
3015 */
3016static int relocate_tree_block(struct btrfs_trans_handle *trans,
3017 struct reloc_control *rc,
3018 struct backref_node *node,
3019 struct btrfs_key *key,
3020 struct btrfs_path *path)
3021{
3022 struct btrfs_root *root;
3fd0a558
YZ		 3023 int ret = 0;
3024
3025 if (!node)
3026 return 0;
5d4f98a2 3027
3fd0a558 3028 BUG_ON(node->processed);
147d256e 3029 root = select_one_root(node);
3fd0a558 3030 if (root == ERR_PTR(-ENOENT)) {
5d4f98a2 3031 update_processed_blocks(rc, node);
3fd0a558 3032 goto out;
5d4f98a2
YZ		 3033 }
3034
27cdeb70 3035 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
3fd0a558
YZ		 3036 ret = reserve_metadata_space(trans, rc, node);
3037 if (ret)
5d4f98a2 3038 goto out;
5d4f98a2
YZ		 3039 }
3040
3fd0a558 3041 if (root) {
27cdeb70 3042 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
3fd0a558
YZ		 3043 BUG_ON(node->new_bytenr);
3044 BUG_ON(!list_empty(&node->list));
3045 btrfs_record_root_in_trans(trans, root);
3046 root = root->reloc_root;
3047 node->new_bytenr = root->node->start;
3048 node->root = root;
3049 list_add_tail(&node->list, &rc->backref_cache.changed);
3050 } else {
3051 path->lowest_level = node->level;
3052 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
b3b4aa74 3053 btrfs_release_path(path);
3fd0a558
YZ		 3054 if (ret > 0)
3055 ret = 0;
3056 }
3057 if (!ret)
3058 update_processed_blocks(rc, node);
3059 } else {
3060 ret = do_relocation(trans, rc, node, key, path, 1);
3061 }
5d4f98a2 3062out:
0647bf56 3063 if (ret || node->level == 0 || node->cowonly)
3fd0a558 3064 remove_backref_node(&rc->backref_cache, node);
5d4f98a2
YZ		 3065 return ret;
3066}
3067
3068/*
3069 * relocate a list of blocks
3070 */
3071static noinline_for_stack
3072int relocate_tree_blocks(struct btrfs_trans_handle *trans,
3073 struct reloc_control *rc, struct rb_root *blocks)
3074{
2ff7e61e 3075 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2
YZ		 3076 struct backref_node *node;
3077 struct btrfs_path *path;
3078 struct tree_block *block;
98ff7b94 3079 struct tree_block *next;
5d4f98a2
YZ		 3080 int ret;
3081 int err = 0;
3082
3083 path = btrfs_alloc_path();
e1a12670
LB		 3084 if (!path) {
3085 err = -ENOMEM;
34c2b290 3086 goto out_free_blocks;
e1a12670 3087 }
5d4f98a2 3088
98ff7b94
QW		 3089 /* Kick in readahead for tree blocks with missing keys */
3090 rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
5d4f98a2 3091 if (!block->key_ready)
2ff7e61e 3092 readahead_tree_block(fs_info, block->bytenr);
5d4f98a2
YZ		 3093 }
3094
98ff7b94
QW		 3095 /* Get first keys */
3096 rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
34c2b290 3097 if (!block->key_ready) {
2ff7e61e 3098 err = get_tree_block_key(fs_info, block);
34c2b290
DS		 3099 if (err)
3100 goto out_free_path;
3101 }
5d4f98a2
YZ		 3102 }
3103
98ff7b94
QW		 3104 /* Do tree relocation */
3105 rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
3fd0a558 3106 node = build_backref_tree(rc, &block->key,
5d4f98a2
YZ		 3107 block->level, block->bytenr);
3108 if (IS_ERR(node)) {
3109 err = PTR_ERR(node);
3110 goto out;
3111 }
3112
3113 ret = relocate_tree_block(trans, rc, node, &block->key,
3114 path);
3115 if (ret < 0) {
98ff7b94 3116 if (ret != -EAGAIN || &block->rb_node == rb_first(blocks))
3fd0a558 3117 err = ret;
5d4f98a2
YZ		 3118 goto out;
3119 }
5d4f98a2 3120 }
5d4f98a2 3121out:
3fd0a558 3122 err = finish_pending_nodes(trans, rc, path, err);
5d4f98a2 3123
34c2b290 3124out_free_path:
5d4f98a2 3125 btrfs_free_path(path);
34c2b290 3126out_free_blocks:
e1a12670 3127 free_block_list(blocks);
5d4f98a2
YZ		 3128 return err;
3129}
3130
efa56464
YZ		 3131static noinline_for_stack
3132int prealloc_file_extent_cluster(struct inode *inode,
3133 struct file_extent_cluster *cluster)
3134{
3135 u64 alloc_hint = 0;
3136 u64 start;
3137 u64 end;
3138 u64 offset = BTRFS_I(inode)->index_cnt;
3139 u64 num_bytes;
3140 int nr = 0;
3141 int ret = 0;
dcb40c19
WX		 3142 u64 prealloc_start = cluster->start - offset;
3143 u64 prealloc_end = cluster->end - offset;
18513091 3144 u64 cur_offset;
364ecf36 3145 struct extent_changeset *data_reserved = NULL;
efa56464
YZ		 3146
3147 BUG_ON(cluster->start != cluster->boundary[0]);
5955102c 3148 inode_lock(inode);
efa56464 3149
364ecf36 3150 ret = btrfs_check_data_free_space(inode, &data_reserved, prealloc_start,
dcb40c19 3151 prealloc_end + 1 - prealloc_start);
efa56464
YZ		 3152 if (ret)
3153 goto out;
3154
18513091 3155 cur_offset = prealloc_start;
efa56464
YZ		 3156 while (nr < cluster->nr) {
3157 start = cluster->boundary[nr] - offset;
3158 if (nr + 1 < cluster->nr)
3159 end = cluster->boundary[nr + 1] - 1 - offset;
3160 else
3161 end = cluster->end - offset;
3162
d0082371 3163 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
efa56464 3164 num_bytes = end + 1 - start;
18513091 3165 if (cur_offset < start)
bc42bda2
QW		 3166 btrfs_free_reserved_data_space(inode, data_reserved,
3167 cur_offset, start - cur_offset);
efa56464
YZ		 3168 ret = btrfs_prealloc_file_range(inode, 0, start,
3169 num_bytes, num_bytes,
3170 end + 1, &alloc_hint);
18513091 3171 cur_offset = end + 1;
d0082371 3172 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
efa56464
YZ		 3173 if (ret)
3174 break;
3175 nr++;
3176 }
18513091 3177 if (cur_offset < prealloc_end)
bc42bda2
QW		 3178 btrfs_free_reserved_data_space(inode, data_reserved,
3179 cur_offset, prealloc_end + 1 - cur_offset);
efa56464 3180out:
5955102c 3181 inode_unlock(inode);
364ecf36 3182 extent_changeset_free(data_reserved);
efa56464
YZ		 3183 return ret;
3184}
3185
5d4f98a2 3186static noinline_for_stack
0257bb82
YZ		 3187int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3188 u64 block_start)
3189{
0b246afa 3190 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
0257bb82
YZ		 3191 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3192 struct extent_map *em;
3193 int ret = 0;
3194
172ddd60 3195 em = alloc_extent_map();
0257bb82
YZ		 3196 if (!em)
3197 return -ENOMEM;
3198
3199 em->start = start;
3200 em->len = end + 1 - start;
3201 em->block_len = em->len;
3202 em->block_start = block_start;
0b246afa 3203 em->bdev = fs_info->fs_devices->latest_bdev;
0257bb82
YZ		 3204 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3205
d0082371 3206 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
0257bb82
YZ		 3207 while (1) {
3208 write_lock(&em_tree->lock);
09a2a8f9 3209 ret = add_extent_mapping(em_tree, em, 0);
0257bb82
YZ		 3210 write_unlock(&em_tree->lock);
3211 if (ret != -EEXIST) {
3212 free_extent_map(em);
3213 break;
3214 }
dcdbc059 3215 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
0257bb82 3216 }
d0082371 3217 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
0257bb82
YZ		 3218 return ret;
3219}
3220
3221static int relocate_file_extent_cluster(struct inode *inode,
3222 struct file_extent_cluster *cluster)
5d4f98a2 3223{
2ff7e61e 3224 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5d4f98a2
YZ		 3225 u64 page_start;
3226 u64 page_end;
0257bb82
YZ		 3227 u64 offset = BTRFS_I(inode)->index_cnt;
3228 unsigned long index;
5d4f98a2 3229 unsigned long last_index;
5d4f98a2
YZ		 3230 struct page *page;
3231 struct file_ra_state *ra;
3b16a4e3 3232 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
0257bb82 3233 int nr = 0;
5d4f98a2
YZ		 3234 int ret = 0;
3235
0257bb82
YZ		 3236 if (!cluster->nr)
3237 return 0;
3238
5d4f98a2
YZ		 3239 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3240 if (!ra)
3241 return -ENOMEM;
3242
efa56464
YZ		 3243 ret = prealloc_file_extent_cluster(inode, cluster);
3244 if (ret)
3245 goto out;
0257bb82 3246
efa56464 3247 file_ra_state_init(ra, inode->i_mapping);
5d4f98a2 3248
0257bb82
YZ		 3249 ret = setup_extent_mapping(inode, cluster->start - offset,
3250 cluster->end - offset, cluster->start);
5d4f98a2 3251 if (ret)
efa56464 3252 goto out;
5d4f98a2 3253
09cbfeaf
KS		 3254 index = (cluster->start - offset) >> PAGE_SHIFT;
3255 last_index = (cluster->end - offset) >> PAGE_SHIFT;
0257bb82 3256 while (index <= last_index) {
9f3db423
NB		 3257 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
3258 PAGE_SIZE);
efa56464
YZ		 3259 if (ret)
3260 goto out;
3261
0257bb82 3262 page = find_lock_page(inode->i_mapping, index);
5d4f98a2 3263 if (!page) {
0257bb82
YZ		 3264 page_cache_sync_readahead(inode->i_mapping,
3265 ra, NULL, index,
3266 last_index + 1 - index);
a94733d0 3267 page = find_or_create_page(inode->i_mapping, index,
3b16a4e3 3268 mask);
0257bb82 3269 if (!page) {
691fa059 3270 btrfs_delalloc_release_metadata(BTRFS_I(inode),
43b18595 3271 PAGE_SIZE, true);
0257bb82 3272 ret = -ENOMEM;
efa56464 3273 goto out;
0257bb82 3274 }
5d4f98a2 3275 }
0257bb82
YZ		 3276
3277 if (PageReadahead(page)) {
3278 page_cache_async_readahead(inode->i_mapping,
3279 ra, NULL, page, index,
3280 last_index + 1 - index);
3281 }
3282
5d4f98a2
YZ		 3283 if (!PageUptodate(page)) {
3284 btrfs_readpage(NULL, page);
3285 lock_page(page);
3286 if (!PageUptodate(page)) {
3287 unlock_page(page);
09cbfeaf 3288 put_page(page);
691fa059 3289 btrfs_delalloc_release_metadata(BTRFS_I(inode),
43b18595 3290 PAGE_SIZE, true);
8b62f87b 3291 btrfs_delalloc_release_extents(BTRFS_I(inode),
43b18595 3292 PAGE_SIZE, true);
5d4f98a2 3293 ret = -EIO;
efa56464 3294 goto out;
5d4f98a2
YZ		 3295 }
3296 }
5d4f98a2 3297
4eee4fa4 3298 page_start = page_offset(page);
09cbfeaf 3299 page_end = page_start + PAGE_SIZE - 1;
0257bb82 3300
d0082371 3301 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
0257bb82 3302
5d4f98a2
YZ		 3303 set_page_extent_mapped(page);
3304
0257bb82
YZ		 3305 if (nr < cluster->nr &&
3306 page_start + offset == cluster->boundary[nr]) {
3307 set_extent_bits(&BTRFS_I(inode)->io_tree,
3308 page_start, page_end,
ceeb0ae7 3309 EXTENT_BOUNDARY);
0257bb82
YZ		 3310 nr++;
3311 }
5d4f98a2 3312
765f3ceb
NB		 3313 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
3314 NULL, 0);
3315 if (ret) {
3316 unlock_page(page);
3317 put_page(page);
3318 btrfs_delalloc_release_metadata(BTRFS_I(inode),
43b18595 3319 PAGE_SIZE, true);
765f3ceb 3320 btrfs_delalloc_release_extents(BTRFS_I(inode),
43b18595 3321 PAGE_SIZE, true);
765f3ceb
NB		 3322
3323 clear_extent_bits(&BTRFS_I(inode)->io_tree,
3324 page_start, page_end,
3325 EXTENT_LOCKED | EXTENT_BOUNDARY);
3326 goto out;
3327
3328 }
5d4f98a2 3329 set_page_dirty(page);
5d4f98a2 3330
0257bb82 3331 unlock_extent(&BTRFS_I(inode)->io_tree,
d0082371 3332 page_start, page_end);
5d4f98a2 3333 unlock_page(page);
09cbfeaf 3334 put_page(page);
0257bb82
YZ		 3335
3336 index++;
43b18595
QW		 3337 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE,
3338 false);
efa56464 3339 balance_dirty_pages_ratelimited(inode->i_mapping);
2ff7e61e 3340 btrfs_throttle(fs_info);
5d4f98a2 3341 }
0257bb82 3342 WARN_ON(nr != cluster->nr);
efa56464 3343out:
5d4f98a2 3344 kfree(ra);
5d4f98a2
YZ		 3345 return ret;
3346}
3347
3348static noinline_for_stack
0257bb82
YZ		 3349int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3350 struct file_extent_cluster *cluster)
5d4f98a2 3351{
0257bb82 3352 int ret;
5d4f98a2 3353
0257bb82
YZ		 3354 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3355 ret = relocate_file_extent_cluster(inode, cluster);
3356 if (ret)
3357 return ret;
3358 cluster->nr = 0;
5d4f98a2 3359 }
5d4f98a2 3360
0257bb82
YZ		 3361 if (!cluster->nr)
3362 cluster->start = extent_key->objectid;
3363 else
3364 BUG_ON(cluster->nr >= MAX_EXTENTS);
3365 cluster->end = extent_key->objectid + extent_key->offset - 1;
3366 cluster->boundary[cluster->nr] = extent_key->objectid;
3367 cluster->nr++;
3368
3369 if (cluster->nr >= MAX_EXTENTS) {
3370 ret = relocate_file_extent_cluster(inode, cluster);
3371 if (ret)
3372 return ret;
3373 cluster->nr = 0;
3374 }
3375 return 0;
5d4f98a2
YZ		 3376}
3377
5d4f98a2
YZ		 3378/*
3379 * helper to add a tree block to the list.
3380 * the major work is getting the generation and level of the block
3381 */
3382static int add_tree_block(struct reloc_control *rc,
3383 struct btrfs_key *extent_key,
3384 struct btrfs_path *path,
3385 struct rb_root *blocks)
3386{
3387 struct extent_buffer *eb;
3388 struct btrfs_extent_item *ei;
3389 struct btrfs_tree_block_info *bi;
3390 struct tree_block *block;
3391 struct rb_node *rb_node;
3392 u32 item_size;
3393 int level = -1;
7fdf4b60 3394 u64 generation;
5d4f98a2
YZ		 3395
3396 eb = path->nodes[0];
3397 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3398
3173a18f
JB		 3399 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3400 item_size >= sizeof(*ei) + sizeof(*bi)) {
5d4f98a2
YZ		 3401 ei = btrfs_item_ptr(eb, path->slots[0],
3402 struct btrfs_extent_item);
3173a18f
JB		 3403 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3404 bi = (struct btrfs_tree_block_info *)(ei + 1);
3405 level = btrfs_tree_block_level(eb, bi);
3406 } else {
3407 level = (int)extent_key->offset;
3408 }
5d4f98a2 3409 generation = btrfs_extent_generation(eb, ei);
6d8ff4e4 3410 } else if (unlikely(item_size == sizeof(struct btrfs_extent_item_v0))) {
ba3c2b19
NB		 3411 btrfs_print_v0_err(eb->fs_info);
3412 btrfs_handle_fs_error(eb->fs_info, -EINVAL, NULL);
3413 return -EINVAL;
5d4f98a2 3414 } else {
5d4f98a2 3415 BUG();
5d4f98a2
YZ		 3416 }
3417
b3b4aa74 3418 btrfs_release_path(path);
5d4f98a2
YZ		 3419
3420 BUG_ON(level == -1);
3421
3422 block = kmalloc(sizeof(*block), GFP_NOFS);
3423 if (!block)
3424 return -ENOMEM;
3425
3426 block->bytenr = extent_key->objectid;
da17066c 3427 block->key.objectid = rc->extent_root->fs_info->nodesize;
5d4f98a2
YZ		 3428 block->key.offset = generation;
3429 block->level = level;
3430 block->key_ready = 0;
3431
3432 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
43c04fb1
JM		 3433 if (rb_node)
3434 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
5d4f98a2
YZ		 3435
3436 return 0;
3437}
3438
3439/*
3440 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3441 */
3442static int __add_tree_block(struct reloc_control *rc,
3443 u64 bytenr, u32 blocksize,
3444 struct rb_root *blocks)
3445{
0b246afa 3446 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2
YZ		 3447 struct btrfs_path *path;
3448 struct btrfs_key key;
3449 int ret;
0b246afa 3450 bool skinny = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
5d4f98a2 3451
7476dfda 3452 if (tree_block_processed(bytenr, rc))
5d4f98a2
YZ		 3453 return 0;
3454
3455 if (tree_search(blocks, bytenr))
3456 return 0;
3457
3458 path = btrfs_alloc_path();
3459 if (!path)
3460 return -ENOMEM;
aee68ee5 3461again:
5d4f98a2 3462 key.objectid = bytenr;
aee68ee5
JB		 3463 if (skinny) {
3464 key.type = BTRFS_METADATA_ITEM_KEY;
3465 key.offset = (u64)-1;
3466 } else {
3467 key.type = BTRFS_EXTENT_ITEM_KEY;
3468 key.offset = blocksize;
3469 }
5d4f98a2
YZ		 3470
3471 path->search_commit_root = 1;
3472 path->skip_locking = 1;
3473 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3474 if (ret < 0)
3475 goto out;
5d4f98a2 3476
aee68ee5
JB		 3477 if (ret > 0 && skinny) {
3478 if (path->slots[0]) {
3479 path->slots[0]--;
3480 btrfs_item_key_to_cpu(path->nodes[0], &key,
3481 path->slots[0]);
3482 if (key.objectid == bytenr &&
3483 (key.type == BTRFS_METADATA_ITEM_KEY ||
3484 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3485 key.offset == blocksize)))
3486 ret = 0;
3487 }
3488
3489 if (ret) {
3490 skinny = false;
3491 btrfs_release_path(path);
3492 goto again;
3493 }
3173a18f 3494 }
cdccee99
LB		 3495 if (ret) {
3496 ASSERT(ret == 1);
3497 btrfs_print_leaf(path->nodes[0]);
3498 btrfs_err(fs_info,
3499 "tree block extent item (%llu) is not found in extent tree",
3500 bytenr);
3501 WARN_ON(1);
3502 ret = -EINVAL;
3503 goto out;
3504 }
3173a18f 3505
5d4f98a2
YZ		 3506 ret = add_tree_block(rc, &key, path, blocks);
3507out:
3508 btrfs_free_path(path);
3509 return ret;
3510}
3511
3512/*
3513 * helper to check if the block use full backrefs for pointers in it
3514 */
3515static int block_use_full_backref(struct reloc_control *rc,
3516 struct extent_buffer *eb)
3517{
5d4f98a2
YZ		 3518 u64 flags;
3519 int ret;
3520
3521 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3522 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3523 return 1;
3524
2ff7e61e 3525 ret = btrfs_lookup_extent_info(NULL, rc->extent_root->fs_info,
3173a18f
JB		 3526 eb->start, btrfs_header_level(eb), 1,
3527 NULL, &flags);
5d4f98a2
YZ		 3528 BUG_ON(ret);
3529
5d4f98a2
YZ		 3530 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3531 ret = 1;
3532 else
3533 ret = 0;
5d4f98a2
YZ		 3534 return ret;
3535}
3536
0af3d00b 3537static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
1bbc621e
CM		 3538 struct btrfs_block_group_cache *block_group,
3539 struct inode *inode,
3540 u64 ino)
0af3d00b
JB		 3541{
3542 struct btrfs_key key;
0af3d00b
JB		 3543 struct btrfs_root *root = fs_info->tree_root;
3544 struct btrfs_trans_handle *trans;
0af3d00b
JB		 3545 int ret = 0;
3546
3547 if (inode)
3548 goto truncate;
3549
3550 key.objectid = ino;
3551 key.type = BTRFS_INODE_ITEM_KEY;
3552 key.offset = 0;
3553
3554 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2e19f1f9 3555 if (IS_ERR(inode))
0af3d00b 3556 return -ENOENT;
0af3d00b
JB		 3557
3558truncate:
2ff7e61e 3559 ret = btrfs_check_trunc_cache_free_space(fs_info,
7b61cd92
MX		 3560 &fs_info->global_block_rsv);
3561 if (ret)
3562 goto out;
3563
7a7eaa40 3564 trans = btrfs_join_transaction(root);
0af3d00b 3565 if (IS_ERR(trans)) {
3612b495 3566 ret = PTR_ERR(trans);
0af3d00b
JB		 3567 goto out;
3568 }
3569
77ab86bf 3570 ret = btrfs_truncate_free_space_cache(trans, block_group, inode);
0af3d00b 3571
3a45bb20 3572 btrfs_end_transaction(trans);
2ff7e61e 3573 btrfs_btree_balance_dirty(fs_info);
0af3d00b
JB		 3574out:
3575 iput(inode);
3576 return ret;
3577}
3578
5d4f98a2
YZ		 3579/*
3580 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3581 * this function scans fs tree to find blocks reference the data extent
3582 */
3583static int find_data_references(struct reloc_control *rc,
3584 struct btrfs_key *extent_key,
3585 struct extent_buffer *leaf,
3586 struct btrfs_extent_data_ref *ref,
3587 struct rb_root *blocks)
3588{
0b246afa 3589 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2
YZ		 3590 struct btrfs_path *path;
3591 struct tree_block *block;
3592 struct btrfs_root *root;
3593 struct btrfs_file_extent_item *fi;
3594 struct rb_node *rb_node;
3595 struct btrfs_key key;
3596 u64 ref_root;
3597 u64 ref_objectid;
3598 u64 ref_offset;
3599 u32 ref_count;
3600 u32 nritems;
3601 int err = 0;
3602 int added = 0;
3603 int counted;
3604 int ret;
3605
5d4f98a2
YZ		 3606 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3607 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3608 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3609 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3610
0af3d00b
JB		 3611 /*
3612 * This is an extent belonging to the free space cache, lets just delete
3613 * it and redo the search.
3614 */
3615 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
0b246afa 3616 ret = delete_block_group_cache(fs_info, rc->block_group,
0af3d00b
JB		 3617 NULL, ref_objectid);
3618 if (ret != -ENOENT)
3619 return ret;
3620 ret = 0;
3621 }
3622
3623 path = btrfs_alloc_path();
3624 if (!path)
3625 return -ENOMEM;
e4058b54 3626 path->reada = READA_FORWARD;
0af3d00b 3627
0b246afa 3628 root = read_fs_root(fs_info, ref_root);
5d4f98a2
YZ		 3629 if (IS_ERR(root)) {
3630 err = PTR_ERR(root);
3631 goto out;
3632 }
3633
3634 key.objectid = ref_objectid;
5d4f98a2 3635 key.type = BTRFS_EXTENT_DATA_KEY;
84850e8d
YZ		 3636 if (ref_offset > ((u64)-1 << 32))
3637 key.offset = 0;
3638 else
3639 key.offset = ref_offset;
5d4f98a2
YZ		 3640
3641 path->search_commit_root = 1;
3642 path->skip_locking = 1;
3643 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3644 if (ret < 0) {
3645 err = ret;
3646 goto out;
3647 }
3648
3649 leaf = path->nodes[0];
3650 nritems = btrfs_header_nritems(leaf);
3651 /*
3652 * the references in tree blocks that use full backrefs
3653 * are not counted in
3654 */
3655 if (block_use_full_backref(rc, leaf))
3656 counted = 0;
3657 else
3658 counted = 1;
3659 rb_node = tree_search(blocks, leaf->start);
3660 if (rb_node) {
3661 if (counted)
3662 added = 1;
3663 else
3664 path->slots[0] = nritems;
3665 }
3666
3667 while (ref_count > 0) {
3668 while (path->slots[0] >= nritems) {
3669 ret = btrfs_next_leaf(root, path);
3670 if (ret < 0) {
3671 err = ret;
3672 goto out;
3673 }
fae7f21c 3674 if (WARN_ON(ret > 0))
5d4f98a2 3675 goto out;
5d4f98a2
YZ		 3676
3677 leaf = path->nodes[0];
3678 nritems = btrfs_header_nritems(leaf);
3679 added = 0;
3680
3681 if (block_use_full_backref(rc, leaf))
3682 counted = 0;
3683 else
3684 counted = 1;
3685 rb_node = tree_search(blocks, leaf->start);
3686 if (rb_node) {
3687 if (counted)
3688 added = 1;
3689 else
3690 path->slots[0] = nritems;
3691 }
3692 }
3693
3694 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
fae7f21c
DG		 3695 if (WARN_ON(key.objectid != ref_objectid ||
3696 key.type != BTRFS_EXTENT_DATA_KEY))
5d4f98a2 3697 break;
5d4f98a2
YZ		 3698
3699 fi = btrfs_item_ptr(leaf, path->slots[0],
3700 struct btrfs_file_extent_item);
3701
3702 if (btrfs_file_extent_type(leaf, fi) ==
3703 BTRFS_FILE_EXTENT_INLINE)
3704 goto next;
3705
3706 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3707 extent_key->objectid)
3708 goto next;
3709
3710 key.offset -= btrfs_file_extent_offset(leaf, fi);
3711 if (key.offset != ref_offset)
3712 goto next;
3713
3714 if (counted)
3715 ref_count--;
3716 if (added)
3717 goto next;
3718
7476dfda 3719 if (!tree_block_processed(leaf->start, rc)) {
5d4f98a2
YZ		 3720 block = kmalloc(sizeof(*block), GFP_NOFS);
3721 if (!block) {
3722 err = -ENOMEM;
3723 break;
3724 }
3725 block->bytenr = leaf->start;
3726 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3727 block->level = 0;
3728 block->key_ready = 1;
3729 rb_node = tree_insert(blocks, block->bytenr,
3730 &block->rb_node);
43c04fb1
JM		 3731 if (rb_node)
3732 backref_tree_panic(rb_node, -EEXIST,
3733 block->bytenr);
5d4f98a2
YZ		 3734 }
3735 if (counted)
3736 added = 1;
3737 else
3738 path->slots[0] = nritems;
3739next:
3740 path->slots[0]++;
3741
3742 }
3743out:
3744 btrfs_free_path(path);
3745 return err;
3746}
3747
3748/*
2c016dc2 3749 * helper to find all tree blocks that reference a given data extent
5d4f98a2
YZ		 3750 */
3751static noinline_for_stack
3752int add_data_references(struct reloc_control *rc,
3753 struct btrfs_key *extent_key,
3754 struct btrfs_path *path,
3755 struct rb_root *blocks)
3756{
3757 struct btrfs_key key;
3758 struct extent_buffer *eb;
3759 struct btrfs_extent_data_ref *dref;
3760 struct btrfs_extent_inline_ref *iref;
3761 unsigned long ptr;
3762 unsigned long end;
da17066c 3763 u32 blocksize = rc->extent_root->fs_info->nodesize;
647f63bd 3764 int ret = 0;
5d4f98a2
YZ		 3765 int err = 0;
3766
5d4f98a2
YZ		 3767 eb = path->nodes[0];
3768 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3769 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
a79865c6 3770 ptr += sizeof(struct btrfs_extent_item);
5d4f98a2
YZ		 3771
3772 while (ptr < end) {
3773 iref = (struct btrfs_extent_inline_ref *)ptr;
3de28d57
LB		 3774 key.type = btrfs_get_extent_inline_ref_type(eb, iref,
3775 BTRFS_REF_TYPE_DATA);
5d4f98a2
YZ		 3776 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3777 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3778 ret = __add_tree_block(rc, key.offset, blocksize,
3779 blocks);
3780 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3781 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3782 ret = find_data_references(rc, extent_key,
3783 eb, dref, blocks);
3784 } else {
af431dcb 3785 ret = -EUCLEAN;
b14c55a1
LB		 3786 btrfs_err(rc->extent_root->fs_info,
3787 "extent %llu slot %d has an invalid inline ref type",
3788 eb->start, path->slots[0]);
5d4f98a2 3789 }
647f63bd
FDBM		 3790 if (ret) {
3791 err = ret;
3792 goto out;
3793 }
5d4f98a2
YZ		 3794 ptr += btrfs_extent_inline_ref_size(key.type);
3795 }
3796 WARN_ON(ptr > end);
3797
3798 while (1) {
3799 cond_resched();
3800 eb = path->nodes[0];
3801 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3802 ret = btrfs_next_leaf(rc->extent_root, path);
3803 if (ret < 0) {
3804 err = ret;
3805 break;
3806 }
3807 if (ret > 0)
3808 break;
3809 eb = path->nodes[0];
3810 }
3811
3812 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3813 if (key.objectid != extent_key->objectid)
3814 break;
3815
5d4f98a2 3816 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
5d4f98a2
YZ		 3817 ret = __add_tree_block(rc, key.offset, blocksize,
3818 blocks);
3819 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3820 dref = btrfs_item_ptr(eb, path->slots[0],
3821 struct btrfs_extent_data_ref);
3822 ret = find_data_references(rc, extent_key,
3823 eb, dref, blocks);
6d8ff4e4 3824 } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) {
ba3c2b19
NB		 3825 btrfs_print_v0_err(eb->fs_info);
3826 btrfs_handle_fs_error(eb->fs_info, -EINVAL, NULL);
3827 ret = -EINVAL;
5d4f98a2
YZ		 3828 } else {
3829 ret = 0;
3830 }
3831 if (ret) {
3832 err = ret;
3833 break;
3834 }
3835 path->slots[0]++;
3836 }
647f63bd 3837out:
b3b4aa74 3838 btrfs_release_path(path);
5d4f98a2
YZ		 3839 if (err)
3840 free_block_list(blocks);
3841 return err;
3842}
3843
3844/*
2c016dc2 3845 * helper to find next unprocessed extent
5d4f98a2
YZ		 3846 */
3847static noinline_for_stack
147d256e 3848int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
3fd0a558 3849 struct btrfs_key *extent_key)
5d4f98a2 3850{
0b246afa 3851 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2
YZ		 3852 struct btrfs_key key;
3853 struct extent_buffer *leaf;
3854 u64 start, end, last;
3855 int ret;
3856
3857 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3858 while (1) {
3859 cond_resched();
3860 if (rc->search_start >= last) {
3861 ret = 1;
3862 break;
3863 }
3864
3865 key.objectid = rc->search_start;
3866 key.type = BTRFS_EXTENT_ITEM_KEY;
3867 key.offset = 0;
3868
3869 path->search_commit_root = 1;
3870 path->skip_locking = 1;
3871 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3872 0, 0);
3873 if (ret < 0)
3874 break;
3875next:
3876 leaf = path->nodes[0];
3877 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3878 ret = btrfs_next_leaf(rc->extent_root, path);
3879 if (ret != 0)
3880 break;
3881 leaf = path->nodes[0];
3882 }
3883
3884 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3885 if (key.objectid >= last) {
3886 ret = 1;
3887 break;
3888 }
3889
3173a18f
JB		 3890 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3891 key.type != BTRFS_METADATA_ITEM_KEY) {
3892 path->slots[0]++;
3893 goto next;
3894 }
3895
3896 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
5d4f98a2
YZ		 3897 key.objectid + key.offset <= rc->search_start) {
3898 path->slots[0]++;
3899 goto next;
3900 }
3901
3173a18f 3902 if (key.type == BTRFS_METADATA_ITEM_KEY &&
0b246afa 3903 key.objectid + fs_info->nodesize <=
3173a18f
JB		 3904 rc->search_start) {
3905 path->slots[0]++;
3906 goto next;
3907 }
3908
5d4f98a2
YZ		 3909 ret = find_first_extent_bit(&rc->processed_blocks,
3910 key.objectid, &start, &end,
e6138876 3911 EXTENT_DIRTY, NULL);
5d4f98a2
YZ		 3912
3913 if (ret == 0 && start <= key.objectid) {
b3b4aa74 3914 btrfs_release_path(path);
5d4f98a2
YZ		 3915 rc->search_start = end + 1;
3916 } else {
3173a18f
JB		 3917 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3918 rc->search_start = key.objectid + key.offset;
3919 else
3920 rc->search_start = key.objectid +
0b246afa 3921 fs_info->nodesize;
3fd0a558 3922 memcpy(extent_key, &key, sizeof(key));
5d4f98a2
YZ		 3923 return 0;
3924 }
3925 }
b3b4aa74 3926 btrfs_release_path(path);
5d4f98a2
YZ		 3927 return ret;
3928}
3929
3930static void set_reloc_control(struct reloc_control *rc)
3931{
3932 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
7585717f
CM		 3933
3934 mutex_lock(&fs_info->reloc_mutex);
5d4f98a2 3935 fs_info->reloc_ctl = rc;
7585717f 3936 mutex_unlock(&fs_info->reloc_mutex);
5d4f98a2
YZ		 3937}
3938
3939static void unset_reloc_control(struct reloc_control *rc)
3940{
3941 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
7585717f
CM		 3942
3943 mutex_lock(&fs_info->reloc_mutex);
5d4f98a2 3944 fs_info->reloc_ctl = NULL;
7585717f 3945 mutex_unlock(&fs_info->reloc_mutex);
5d4f98a2
YZ		 3946}
3947
3948static int check_extent_flags(u64 flags)
3949{
3950 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3951 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3952 return 1;
3953 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3954 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3955 return 1;
3956 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3957 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3958 return 1;
3959 return 0;
3960}
3961
3fd0a558
YZ		 3962static noinline_for_stack
3963int prepare_to_relocate(struct reloc_control *rc)
3964{
3965 struct btrfs_trans_handle *trans;
ac2fabac 3966 int ret;
3fd0a558 3967
2ff7e61e 3968 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root->fs_info,
66d8f3dd 3969 BTRFS_BLOCK_RSV_TEMP);
3fd0a558
YZ		 3970 if (!rc->block_rsv)
3971 return -ENOMEM;
3972
3fd0a558
YZ		 3973 memset(&rc->cluster, 0, sizeof(rc->cluster));
3974 rc->search_start = rc->block_group->key.objectid;
3975 rc->extents_found = 0;
3976 rc->nodes_relocated = 0;
3977 rc->merging_rsv_size = 0;
0647bf56 3978 rc->reserved_bytes = 0;
da17066c 3979 rc->block_rsv->size = rc->extent_root->fs_info->nodesize *
0647bf56 3980 RELOCATION_RESERVED_NODES;
ac2fabac
JB		 3981 ret = btrfs_block_rsv_refill(rc->extent_root,
3982 rc->block_rsv, rc->block_rsv->size,
3983 BTRFS_RESERVE_FLUSH_ALL);
3984 if (ret)
3985 return ret;
3fd0a558
YZ		 3986
3987 rc->create_reloc_tree = 1;
3988 set_reloc_control(rc);
3989
7a7eaa40 3990 trans = btrfs_join_transaction(rc->extent_root);
28818947
LB		 3991 if (IS_ERR(trans)) {
3992 unset_reloc_control(rc);
3993 /*
3994 * extent tree is not a ref_cow tree and has no reloc_root to
3995 * cleanup. And callers are responsible to free the above
3996 * block rsv.
3997 */
3998 return PTR_ERR(trans);
3999 }
3a45bb20 4000 btrfs_commit_transaction(trans);
3fd0a558
YZ		 4001 return 0;
4002}
76dda93c 4003
5d4f98a2
YZ		 4004static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
4005{
2ff7e61e 4006 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
5d4f98a2
YZ		 4007 struct rb_root blocks = RB_ROOT;
4008 struct btrfs_key key;
4009 struct btrfs_trans_handle *trans = NULL;
4010 struct btrfs_path *path;
4011 struct btrfs_extent_item *ei;
5d4f98a2
YZ		 4012 u64 flags;
4013 u32 item_size;
4014 int ret;
4015 int err = 0;
c87f08ca 4016 int progress = 0;
5d4f98a2
YZ		 4017
4018 path = btrfs_alloc_path();
3fd0a558 4019 if (!path)
5d4f98a2 4020 return -ENOMEM;
e4058b54 4021 path->reada = READA_FORWARD;
5d4f98a2 4022
3fd0a558
YZ		 4023 ret = prepare_to_relocate(rc);
4024 if (ret) {
4025 err = ret;
4026 goto out_free;
4027 }
5d4f98a2
YZ		 4028
4029 while (1) {
0647bf56
WS		 4030 rc->reserved_bytes = 0;
4031 ret = btrfs_block_rsv_refill(rc->extent_root,
4032 rc->block_rsv, rc->block_rsv->size,
4033 BTRFS_RESERVE_FLUSH_ALL);
4034 if (ret) {
4035 err = ret;
4036 break;
4037 }
c87f08ca 4038 progress++;
a22285a6 4039 trans = btrfs_start_transaction(rc->extent_root, 0);
0f788c58
LB		 4040 if (IS_ERR(trans)) {
4041 err = PTR_ERR(trans);
4042 trans = NULL;
4043 break;
4044 }
c87f08ca 4045restart:
3fd0a558 4046 if (update_backref_cache(trans, &rc->backref_cache)) {
3a45bb20 4047 btrfs_end_transaction(trans);
42a657f5 4048 trans = NULL;
3fd0a558
YZ		 4049 continue;
4050 }
4051
147d256e 4052 ret = find_next_extent(rc, path, &key);
5d4f98a2
YZ		 4053 if (ret < 0)
4054 err = ret;
4055 if (ret != 0)
4056 break;
4057
4058 rc->extents_found++;
4059
4060 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4061 struct btrfs_extent_item);
3fd0a558 4062 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
5d4f98a2
YZ		 4063 if (item_size >= sizeof(*ei)) {
4064 flags = btrfs_extent_flags(path->nodes[0], ei);
4065 ret = check_extent_flags(flags);
4066 BUG_ON(ret);
6d8ff4e4 4067 } else if (unlikely(item_size == sizeof(struct btrfs_extent_item_v0))) {
ba3c2b19
NB		 4068 err = -EINVAL;
4069 btrfs_print_v0_err(trans->fs_info);
4070 btrfs_abort_transaction(trans, err);
4071 break;
5d4f98a2 4072 } else {
5d4f98a2 4073 BUG();
5d4f98a2
YZ		 4074 }
4075
4076 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
4077 ret = add_tree_block(rc, &key, path, &blocks);
4078 } else if (rc->stage == UPDATE_DATA_PTRS &&
3fd0a558 4079 (flags & BTRFS_EXTENT_FLAG_DATA)) {
5d4f98a2
YZ		 4080 ret = add_data_references(rc, &key, path, &blocks);
4081 } else {
b3b4aa74 4082 btrfs_release_path(path);
5d4f98a2
YZ		 4083 ret = 0;
4084 }
4085 if (ret < 0) {
3fd0a558 4086 err = ret;
5d4f98a2
YZ		 4087 break;
4088 }
4089
4090 if (!RB_EMPTY_ROOT(&blocks)) {
4091 ret = relocate_tree_blocks(trans, rc, &blocks);
4092 if (ret < 0) {
1708cc57
WS		 4093 /*
4094 * if we fail to relocate tree blocks, force to update
4095 * backref cache when committing transaction.
4096 */
4097 rc->backref_cache.last_trans = trans->transid - 1;
4098
3fd0a558
YZ		 4099 if (ret != -EAGAIN) {
4100 err = ret;
4101 break;
4102 }
4103 rc->extents_found--;
4104 rc->search_start = key.objectid;
4105 }
4106 }
4107
3a45bb20 4108 btrfs_end_transaction_throttle(trans);
2ff7e61e 4109 btrfs_btree_balance_dirty(fs_info);
5d4f98a2 4110 trans = NULL;
5d4f98a2
YZ		 4111
4112 if (rc->stage == MOVE_DATA_EXTENTS &&
4113 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4114 rc->found_file_extent = 1;
0257bb82 4115 ret = relocate_data_extent(rc->data_inode,
3fd0a558 4116 &key, &rc->cluster);
5d4f98a2
YZ		 4117 if (ret < 0) {
4118 err = ret;
4119 break;
4120 }
4121 }
4122 }
c87f08ca 4123 if (trans && progress && err == -ENOSPC) {
43a7e99d 4124 ret = btrfs_force_chunk_alloc(trans, rc->block_group->flags);
9689457b 4125 if (ret == 1) {
c87f08ca
CM		 4126 err = 0;
4127 progress = 0;
4128 goto restart;
4129 }
4130 }
3fd0a558 4131
b3b4aa74 4132 btrfs_release_path(path);
91166212 4133 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY);
5d4f98a2
YZ		 4134
4135 if (trans) {
3a45bb20 4136 btrfs_end_transaction_throttle(trans);
2ff7e61e 4137 btrfs_btree_balance_dirty(fs_info);
5d4f98a2
YZ		 4138 }
4139
0257bb82 4140 if (!err) {
3fd0a558
YZ		 4141 ret = relocate_file_extent_cluster(rc->data_inode,
4142 &rc->cluster);
0257bb82
YZ		 4143 if (ret < 0)
4144 err = ret;
4145 }
4146
3fd0a558
YZ		 4147 rc->create_reloc_tree = 0;
4148 set_reloc_control(rc);
0257bb82 4149
3fd0a558 4150 backref_cache_cleanup(&rc->backref_cache);
2ff7e61e 4151 btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1);
5d4f98a2 4152
3fd0a558 4153 err = prepare_to_merge(rc, err);
5d4f98a2
YZ		 4154
4155 merge_reloc_roots(rc);
4156
3fd0a558 4157 rc->merge_reloc_tree = 0;
5d4f98a2 4158 unset_reloc_control(rc);
2ff7e61e 4159 btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1);
5d4f98a2
YZ		 4160
4161 /* get rid of pinned extents */
7a7eaa40 4162 trans = btrfs_join_transaction(rc->extent_root);
62b99540 4163 if (IS_ERR(trans)) {
3612b495 4164 err = PTR_ERR(trans);
62b99540
QW		 4165 goto out_free;
4166 }
3a45bb20 4167 btrfs_commit_transaction(trans);
d2311e69
QW		 4168 ret = clean_dirty_subvols(rc);
4169 if (ret < 0 && !err)
4170 err = ret;
3fd0a558 4171out_free:
2ff7e61e 4172 btrfs_free_block_rsv(fs_info, rc->block_rsv);
3fd0a558 4173 btrfs_free_path(path);
5d4f98a2
YZ		 4174 return err;
4175}
4176
4177static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
0257bb82 4178 struct btrfs_root *root, u64 objectid)
5d4f98a2
YZ		 4179{
4180 struct btrfs_path *path;
4181 struct btrfs_inode_item *item;
4182 struct extent_buffer *leaf;
4183 int ret;
4184
4185 path = btrfs_alloc_path();
4186 if (!path)
4187 return -ENOMEM;
4188
4189 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4190 if (ret)
4191 goto out;
4192
4193 leaf = path->nodes[0];
4194 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
b159fa28 4195 memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item));
5d4f98a2 4196 btrfs_set_inode_generation(leaf, item, 1);
0257bb82 4197 btrfs_set_inode_size(leaf, item, 0);
5d4f98a2 4198 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
3fd0a558
YZ		 4199 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4200 BTRFS_INODE_PREALLOC);
5d4f98a2 4201 btrfs_mark_buffer_dirty(leaf);
5d4f98a2
YZ		 4202out:
4203 btrfs_free_path(path);
4204 return ret;
4205}
4206
4207/*
4208 * helper to create inode for data relocation.
4209 * the inode is in data relocation tree and its link count is 0
4210 */
3fd0a558
YZ		 4211static noinline_for_stack
4212struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4213 struct btrfs_block_group_cache *group)
5d4f98a2
YZ		 4214{
4215 struct inode *inode = NULL;
4216 struct btrfs_trans_handle *trans;
4217 struct btrfs_root *root;
4218 struct btrfs_key key;
4624900d 4219 u64 objectid;
5d4f98a2
YZ		 4220 int err = 0;
4221
4222 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4223 if (IS_ERR(root))
4224 return ERR_CAST(root);
4225
a22285a6 4226 trans = btrfs_start_transaction(root, 6);
3fd0a558
YZ		 4227 if (IS_ERR(trans))
4228 return ERR_CAST(trans);
5d4f98a2 4229
581bb050 4230 err = btrfs_find_free_objectid(root, &objectid);
5d4f98a2
YZ		 4231 if (err)
4232 goto out;
4233
0257bb82 4234 err = __insert_orphan_inode(trans, root, objectid);
5d4f98a2
YZ		 4235 BUG_ON(err);
4236
4237 key.objectid = objectid;
4238 key.type = BTRFS_INODE_ITEM_KEY;
4239 key.offset = 0;
0b246afa 4240 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2e19f1f9 4241 BUG_ON(IS_ERR(inode));
5d4f98a2
YZ		 4242 BTRFS_I(inode)->index_cnt = group->key.objectid;
4243
73f2e545 4244 err = btrfs_orphan_add(trans, BTRFS_I(inode));
5d4f98a2 4245out:
3a45bb20 4246 btrfs_end_transaction(trans);
2ff7e61e 4247 btrfs_btree_balance_dirty(fs_info);
5d4f98a2
YZ		 4248 if (err) {
4249 if (inode)
4250 iput(inode);
4251 inode = ERR_PTR(err);
4252 }
4253 return inode;
4254}
4255
c258d6e3 4256static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
3fd0a558
YZ		 4257{
4258 struct reloc_control *rc;
4259
4260 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4261 if (!rc)
4262 return NULL;
4263
4264 INIT_LIST_HEAD(&rc->reloc_roots);
d2311e69 4265 INIT_LIST_HEAD(&rc->dirty_subvol_roots);
3fd0a558
YZ		 4266 backref_cache_init(&rc->backref_cache);
4267 mapping_tree_init(&rc->reloc_root_tree);
43eb5f29
QW		 4268 extent_io_tree_init(fs_info, &rc->processed_blocks,
4269 IO_TREE_RELOC_BLOCKS, NULL);
3fd0a558
YZ		 4270 return rc;
4271}
4272
ebce0e01
AB		 4273/*
4274 * Print the block group being relocated
4275 */
4276static void describe_relocation(struct btrfs_fs_info *fs_info,
4277 struct btrfs_block_group_cache *block_group)
4278{
f89e09cf 4279 char buf[128] = {'\0'};
ebce0e01 4280
f89e09cf 4281 btrfs_describe_block_groups(block_group->flags, buf, sizeof(buf));
ebce0e01
AB		 4282
4283 btrfs_info(fs_info,
4284 "relocating block group %llu flags %s",
f89e09cf 4285 block_group->key.objectid, buf);
ebce0e01
AB		 4286}
4287
5d4f98a2
YZ		 4288/*
4289 * function to relocate all extents in a block group.
4290 */
6bccf3ab 4291int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
5d4f98a2 4292{
eede2bf3 4293 struct btrfs_block_group_cache *bg;
6bccf3ab 4294 struct btrfs_root *extent_root = fs_info->extent_root;
5d4f98a2 4295 struct reloc_control *rc;
0af3d00b
JB		 4296 struct inode *inode;
4297 struct btrfs_path *path;
5d4f98a2 4298 int ret;
f0486c68 4299 int rw = 0;
5d4f98a2
YZ		 4300 int err = 0;
4301
eede2bf3
OS		 4302 bg = btrfs_lookup_block_group(fs_info, group_start);
4303 if (!bg)
4304 return -ENOENT;
4305
4306 if (btrfs_pinned_by_swapfile(fs_info, bg)) {
4307 btrfs_put_block_group(bg);
4308 return -ETXTBSY;
4309 }
4310
c258d6e3 4311 rc = alloc_reloc_control(fs_info);
eede2bf3
OS		 4312 if (!rc) {
4313 btrfs_put_block_group(bg);
5d4f98a2 4314 return -ENOMEM;
eede2bf3 4315 }
5d4f98a2 4316
f0486c68 4317 rc->extent_root = extent_root;
eede2bf3 4318 rc->block_group = bg;
5d4f98a2 4319
c83488af 4320 ret = btrfs_inc_block_group_ro(rc->block_group);
868f401a
Z		 4321 if (ret) {
4322 err = ret;
4323 goto out;
f0486c68 4324 }
868f401a 4325 rw = 1;
f0486c68 4326
0af3d00b
JB		 4327 path = btrfs_alloc_path();
4328 if (!path) {
4329 err = -ENOMEM;
4330 goto out;
4331 }
4332
7949f339 4333 inode = lookup_free_space_inode(rc->block_group, path);
0af3d00b
JB		 4334 btrfs_free_path(path);
4335
4336 if (!IS_ERR(inode))
1bbc621e 4337 ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
0af3d00b
JB		 4338 else
4339 ret = PTR_ERR(inode);
4340
4341 if (ret && ret != -ENOENT) {
4342 err = ret;
4343 goto out;
4344 }
4345
5d4f98a2
YZ		 4346 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4347 if (IS_ERR(rc->data_inode)) {
4348 err = PTR_ERR(rc->data_inode);
4349 rc->data_inode = NULL;
4350 goto out;
4351 }
4352
0b246afa 4353 describe_relocation(fs_info, rc->block_group);
5d4f98a2 4354
9cfa3e34 4355 btrfs_wait_block_group_reservations(rc->block_group);
f78c436c 4356 btrfs_wait_nocow_writers(rc->block_group);
6374e57a 4357 btrfs_wait_ordered_roots(fs_info, U64_MAX,
578def7c
FM		 4358 rc->block_group->key.objectid,
4359 rc->block_group->key.offset);
5d4f98a2
YZ		 4360
4361 while (1) {
76dda93c 4362 mutex_lock(&fs_info->cleaner_mutex);
5d4f98a2 4363 ret = relocate_block_group(rc);
76dda93c 4364 mutex_unlock(&fs_info->cleaner_mutex);
ff612ba7 4365 if (ret < 0)
5d4f98a2 4366 err = ret;
5d4f98a2 4367
ff612ba7
JB		 4368 /*
4369 * We may have gotten ENOSPC after we already dirtied some
4370 * extents. If writeout happens while we're relocating a
4371 * different block group we could end up hitting the
4372 * BUG_ON(rc->stage == UPDATE_DATA_PTRS) in
4373 * btrfs_reloc_cow_block. Make sure we write everything out
4374 * properly so we don't trip over this problem, and then break
4375 * out of the loop if we hit an error.
4376 */
5d4f98a2 4377 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
0ef8b726
JB		 4378 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4379 (u64)-1);
ff612ba7 4380 if (ret)
0ef8b726 4381 err = ret;
5d4f98a2
YZ		 4382 invalidate_mapping_pages(rc->data_inode->i_mapping,
4383 0, -1);
4384 rc->stage = UPDATE_DATA_PTRS;
5d4f98a2 4385 }
ff612ba7
JB		 4386
4387 if (err < 0)
4388 goto out;
4389
4390 if (rc->extents_found == 0)
4391 break;
4392
4393 btrfs_info(fs_info, "found %llu extents", rc->extents_found);
4394
5d4f98a2
YZ		 4395 }
4396
5d4f98a2
YZ		 4397 WARN_ON(rc->block_group->pinned > 0);
4398 WARN_ON(rc->block_group->reserved > 0);
4399 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4400out:
f0486c68 4401 if (err && rw)
2ff7e61e 4402 btrfs_dec_block_group_ro(rc->block_group);
5d4f98a2 4403 iput(rc->data_inode);
5d4f98a2
YZ		 4404 btrfs_put_block_group(rc->block_group);
4405 kfree(rc);
4406 return err;
4407}
4408
76dda93c
YZ		 4409static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4410{
0b246afa 4411 struct btrfs_fs_info *fs_info = root->fs_info;
76dda93c 4412 struct btrfs_trans_handle *trans;
79787eaa 4413 int ret, err;
76dda93c 4414
0b246afa 4415 trans = btrfs_start_transaction(fs_info->tree_root, 0);
79787eaa
JM		 4416 if (IS_ERR(trans))
4417 return PTR_ERR(trans);
76dda93c
YZ		 4418
4419 memset(&root->root_item.drop_progress, 0,
4420 sizeof(root->root_item.drop_progress));
4421 root->root_item.drop_level = 0;
4422 btrfs_set_root_refs(&root->root_item, 0);
0b246afa 4423 ret = btrfs_update_root(trans, fs_info->tree_root,
76dda93c 4424 &root->root_key, &root->root_item);
76dda93c 4425
3a45bb20 4426 err = btrfs_end_transaction(trans);
79787eaa
JM		 4427 if (err)
4428 return err;
4429 return ret;
76dda93c
YZ		 4430}
4431
5d4f98a2
YZ		 4432/*
4433 * recover relocation interrupted by system crash.
4434 *
4435 * this function resumes merging reloc trees with corresponding fs trees.
4436 * this is important for keeping the sharing of tree blocks
4437 */
4438int btrfs_recover_relocation(struct btrfs_root *root)
4439{
0b246afa 4440 struct btrfs_fs_info *fs_info = root->fs_info;
5d4f98a2
YZ		 4441 LIST_HEAD(reloc_roots);
4442 struct btrfs_key key;
4443 struct btrfs_root *fs_root;
4444 struct btrfs_root *reloc_root;
4445 struct btrfs_path *path;
4446 struct extent_buffer *leaf;
4447 struct reloc_control *rc = NULL;
4448 struct btrfs_trans_handle *trans;
4449 int ret;
4450 int err = 0;
4451
4452 path = btrfs_alloc_path();
4453 if (!path)
4454 return -ENOMEM;
e4058b54 4455 path->reada = READA_BACK;
5d4f98a2
YZ		 4456
4457 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4458 key.type = BTRFS_ROOT_ITEM_KEY;
4459 key.offset = (u64)-1;
4460
4461 while (1) {
0b246afa 4462 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key,
5d4f98a2
YZ		 4463 path, 0, 0);
4464 if (ret < 0) {
4465 err = ret;
4466 goto out;
4467 }
4468 if (ret > 0) {
4469 if (path->slots[0] == 0)
4470 break;
4471 path->slots[0]--;
4472 }
4473 leaf = path->nodes[0];
4474 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
b3b4aa74 4475 btrfs_release_path(path);
5d4f98a2
YZ		 4476
4477 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4478 key.type != BTRFS_ROOT_ITEM_KEY)
4479 break;
4480
cb517eab 4481 reloc_root = btrfs_read_fs_root(root, &key);
5d4f98a2
YZ		 4482 if (IS_ERR(reloc_root)) {
4483 err = PTR_ERR(reloc_root);
4484 goto out;
4485 }
4486
4487 list_add(&reloc_root->root_list, &reloc_roots);
4488
4489 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
0b246afa 4490 fs_root = read_fs_root(fs_info,
5d4f98a2
YZ		 4491 reloc_root->root_key.offset);
4492 if (IS_ERR(fs_root)) {
76dda93c
YZ		 4493 ret = PTR_ERR(fs_root);
4494 if (ret != -ENOENT) {
4495 err = ret;
4496 goto out;
4497 }
79787eaa
JM		 4498 ret = mark_garbage_root(reloc_root);
4499 if (ret < 0) {
4500 err = ret;
4501 goto out;
4502 }
5d4f98a2
YZ		 4503 }
4504 }
4505
4506 if (key.offset == 0)
4507 break;
4508
4509 key.offset--;
4510 }
b3b4aa74 4511 btrfs_release_path(path);
5d4f98a2
YZ		 4512
4513 if (list_empty(&reloc_roots))
4514 goto out;
4515
c258d6e3 4516 rc = alloc_reloc_control(fs_info);
5d4f98a2
YZ		 4517 if (!rc) {
4518 err = -ENOMEM;
4519 goto out;
4520 }
4521
0b246afa 4522 rc->extent_root = fs_info->extent_root;
5d4f98a2
YZ		 4523
4524 set_reloc_control(rc);
4525
7a7eaa40 4526 trans = btrfs_join_transaction(rc->extent_root);
3612b495
TI		 4527 if (IS_ERR(trans)) {
4528 unset_reloc_control(rc);
4529 err = PTR_ERR(trans);
4530 goto out_free;
4531 }
3fd0a558
YZ		 4532
4533 rc->merge_reloc_tree = 1;
4534
5d4f98a2
YZ		 4535 while (!list_empty(&reloc_roots)) {
4536 reloc_root = list_entry(reloc_roots.next,
4537 struct btrfs_root, root_list);
4538 list_del(&reloc_root->root_list);
4539
4540 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4541 list_add_tail(&reloc_root->root_list,
4542 &rc->reloc_roots);
4543 continue;
4544 }
4545
0b246afa 4546 fs_root = read_fs_root(fs_info, reloc_root->root_key.offset);
79787eaa
JM		 4547 if (IS_ERR(fs_root)) {
4548 err = PTR_ERR(fs_root);
4549 goto out_free;
4550 }
5d4f98a2 4551
ffd7b339 4552 err = __add_reloc_root(reloc_root);
79787eaa 4553 BUG_ON(err < 0); /* -ENOMEM or logic error */
5d4f98a2
YZ		 4554 fs_root->reloc_root = reloc_root;
4555 }
4556
3a45bb20 4557 err = btrfs_commit_transaction(trans);
79787eaa
JM		 4558 if (err)
4559 goto out_free;
5d4f98a2
YZ		 4560
4561 merge_reloc_roots(rc);
4562
4563 unset_reloc_control(rc);
4564
7a7eaa40 4565 trans = btrfs_join_transaction(rc->extent_root);
62b99540 4566 if (IS_ERR(trans)) {
3612b495 4567 err = PTR_ERR(trans);
62b99540
QW		 4568 goto out_free;
4569 }
3a45bb20 4570 err = btrfs_commit_transaction(trans);
d2311e69
QW		 4571
4572 ret = clean_dirty_subvols(rc);
4573 if (ret < 0 && !err)
4574 err = ret;
3612b495 4575out_free:
3fd0a558 4576 kfree(rc);
3612b495 4577out:
aca1bba6
LB		 4578 if (!list_empty(&reloc_roots))
4579 free_reloc_roots(&reloc_roots);
4580
5d4f98a2
YZ		 4581 btrfs_free_path(path);
4582
4583 if (err == 0) {
4584 /* cleanup orphan inode in data relocation tree */
0b246afa 4585 fs_root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
5d4f98a2
YZ		 4586 if (IS_ERR(fs_root))
4587 err = PTR_ERR(fs_root);
d7ce5843 4588 else
66b4ffd1 4589 err = btrfs_orphan_cleanup(fs_root);
5d4f98a2
YZ		 4590 }
4591 return err;
4592}
4593
4594/*
4595 * helper to add ordered checksum for data relocation.
4596 *
4597 * cloning checksum properly handles the nodatasum extents.
4598 * it also saves CPU time to re-calculate the checksum.
4599 */
4600int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4601{
0b246afa 4602 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5d4f98a2 4603 struct btrfs_ordered_sum *sums;
5d4f98a2 4604 struct btrfs_ordered_extent *ordered;
5d4f98a2
YZ		 4605 int ret;
4606 u64 disk_bytenr;
4577b014 4607 u64 new_bytenr;
5d4f98a2
YZ		 4608 LIST_HEAD(list);
4609
4610 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4611 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4612
4613 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
0b246afa 4614 ret = btrfs_lookup_csums_range(fs_info->csum_root, disk_bytenr,
a2de733c 4615 disk_bytenr + len - 1, &list, 0);
79787eaa
JM		 4616 if (ret)
4617 goto out;
5d4f98a2
YZ		 4618
4619 while (!list_empty(&list)) {
4620 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4621 list_del_init(&sums->list);
4622
4577b014
JB		 4623 /*
4624 * We need to offset the new_bytenr based on where the csum is.
4625 * We need to do this because we will read in entire prealloc
4626 * extents but we may have written to say the middle of the
4627 * prealloc extent, so we need to make sure the csum goes with
4628 * the right disk offset.
4629 *
4630 * We can do this because the data reloc inode refers strictly
4631 * to the on disk bytes, so we don't have to worry about
4632 * disk_len vs real len like with real inodes since it's all
4633 * disk length.
4634 */
4635 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4636 sums->bytenr = new_bytenr;
5d4f98a2 4637
f9756261 4638 btrfs_add_ordered_sum(ordered, sums);
5d4f98a2 4639 }
79787eaa 4640out:
5d4f98a2 4641 btrfs_put_ordered_extent(ordered);
411fc6bc 4642 return ret;
5d4f98a2 4643}
3fd0a558 4644
83d4cfd4
JB		 4645int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4646 struct btrfs_root *root, struct extent_buffer *buf,
4647 struct extent_buffer *cow)
3fd0a558 4648{
0b246afa 4649 struct btrfs_fs_info *fs_info = root->fs_info;
3fd0a558
YZ		 4650 struct reloc_control *rc;
4651 struct backref_node *node;
4652 int first_cow = 0;
4653 int level;
83d4cfd4 4654 int ret = 0;
3fd0a558 4655
0b246afa 4656 rc = fs_info->reloc_ctl;
3fd0a558 4657 if (!rc)
83d4cfd4 4658 return 0;
3fd0a558
YZ		 4659
4660 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4661 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4662
c974c464
WS		 4663 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4664 if (buf == root->node)
4665 __update_reloc_root(root, cow->start);
4666 }
4667
3fd0a558
YZ		 4668 level = btrfs_header_level(buf);
4669 if (btrfs_header_generation(buf) <=
4670 btrfs_root_last_snapshot(&root->root_item))
4671 first_cow = 1;
4672
4673 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4674 rc->create_reloc_tree) {
4675 WARN_ON(!first_cow && level == 0);
4676
4677 node = rc->backref_cache.path[level];
4678 BUG_ON(node->bytenr != buf->start &&
4679 node->new_bytenr != buf->start);
4680
4681 drop_node_buffer(node);
4682 extent_buffer_get(cow);
4683 node->eb = cow;
4684 node->new_bytenr = cow->start;
4685
4686 if (!node->pending) {
4687 list_move_tail(&node->list,
4688 &rc->backref_cache.pending[level]);
4689 node->pending = 1;
4690 }
4691
4692 if (first_cow)
4693 __mark_block_processed(rc, node);
4694
4695 if (first_cow && level > 0)
4696 rc->nodes_relocated += buf->len;
4697 }
4698
83d4cfd4 4699 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
3fd0a558 4700 ret = replace_file_extents(trans, rc, root, cow);
83d4cfd4 4701 return ret;
3fd0a558
YZ		 4702}
4703
4704/*
4705 * called before creating snapshot. it calculates metadata reservation
01327610 4706 * required for relocating tree blocks in the snapshot
3fd0a558 4707 */
147d256e 4708void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
3fd0a558
YZ		 4709 u64 *bytes_to_reserve)
4710{
10995c04
QW		 4711 struct btrfs_root *root = pending->root;
4712 struct reloc_control *rc = root->fs_info->reloc_ctl;
3fd0a558 4713
10995c04 4714 if (!root->reloc_root || !rc)
3fd0a558
YZ		 4715 return;
4716
3fd0a558
YZ		 4717 if (!rc->merge_reloc_tree)
4718 return;
4719
4720 root = root->reloc_root;
4721 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4722 /*
4723 * relocation is in the stage of merging trees. the space
4724 * used by merging a reloc tree is twice the size of
4725 * relocated tree nodes in the worst case. half for cowing
4726 * the reloc tree, half for cowing the fs tree. the space
4727 * used by cowing the reloc tree will be freed after the
4728 * tree is dropped. if we create snapshot, cowing the fs
4729 * tree may use more space than it frees. so we need
4730 * reserve extra space.
4731 */
4732 *bytes_to_reserve += rc->nodes_relocated;
4733}
4734
4735/*
4736 * called after snapshot is created. migrate block reservation
4737 * and create reloc root for the newly created snapshot
4738 */
49b25e05 4739int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
3fd0a558
YZ		 4740 struct btrfs_pending_snapshot *pending)
4741{
4742 struct btrfs_root *root = pending->root;
4743 struct btrfs_root *reloc_root;
4744 struct btrfs_root *new_root;
10995c04 4745 struct reloc_control *rc = root->fs_info->reloc_ctl;
3fd0a558
YZ		 4746 int ret;
4747
10995c04 4748 if (!root->reloc_root || !rc)
49b25e05 4749 return 0;
3fd0a558
YZ		 4750
4751 rc = root->fs_info->reloc_ctl;
4752 rc->merging_rsv_size += rc->nodes_relocated;
4753
4754 if (rc->merge_reloc_tree) {
4755 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4756 rc->block_rsv,
3a584174 4757 rc->nodes_relocated, true);
49b25e05
JM		 4758 if (ret)
4759 return ret;
3fd0a558
YZ		 4760 }
4761
4762 new_root = pending->snap;
4763 reloc_root = create_reloc_root(trans, root->reloc_root,
4764 new_root->root_key.objectid);
49b25e05
JM		 4765 if (IS_ERR(reloc_root))
4766 return PTR_ERR(reloc_root);
3fd0a558 4767
ffd7b339
JM		 4768 ret = __add_reloc_root(reloc_root);
4769 BUG_ON(ret < 0);
3fd0a558
YZ		 4770 new_root->reloc_root = reloc_root;
4771
49b25e05 4772 if (rc->create_reloc_tree)
3fd0a558 4773 ret = clone_backref_node(trans, rc, root, reloc_root);
49b25e05 4774 return ret;
3fd0a558 4775}
Linux 6.x block layer and io_uring tree(s)