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1/*
2 * Copyright (C) 2009 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/sort.h>
22#include "ctree.h"
23#include "delayed-ref.h"
24#include "transaction.h"
25
26/*
27 * delayed back reference update tracking. For subvolume trees
28 * we queue up extent allocations and backref maintenance for
29 * delayed processing. This avoids deep call chains where we
30 * add extents in the middle of btrfs_search_slot, and it allows
31 * us to buffer up frequently modified backrefs in an rb tree instead
32 * of hammering updates on the extent allocation tree.
33 */
34
35/*
36 * compare two delayed tree backrefs with same bytenr and type
37 */
38static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
39 struct btrfs_delayed_tree_ref *ref1)
40{
41 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
42 if (ref1->root < ref2->root)
43 return -1;
44 if (ref1->root > ref2->root)
45 return 1;
46 } else {
47 if (ref1->parent < ref2->parent)
48 return -1;
49 if (ref1->parent > ref2->parent)
50 return 1;
51 }
52 return 0;
53}
54
55/*
56 * compare two delayed data backrefs with same bytenr and type
57 */
58static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
59 struct btrfs_delayed_data_ref *ref1)
60{
61 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
62 if (ref1->root < ref2->root)
63 return -1;
64 if (ref1->root > ref2->root)
65 return 1;
66 if (ref1->objectid < ref2->objectid)
67 return -1;
68 if (ref1->objectid > ref2->objectid)
69 return 1;
70 if (ref1->offset < ref2->offset)
71 return -1;
72 if (ref1->offset > ref2->offset)
73 return 1;
74 } else {
75 if (ref1->parent < ref2->parent)
76 return -1;
77 if (ref1->parent > ref2->parent)
78 return 1;
79 }
80 return 0;
81}
82
83/*
84 * entries in the rb tree are ordered by the byte number of the extent,
85 * type of the delayed backrefs and content of delayed backrefs.
86 */
87static int comp_entry(struct btrfs_delayed_ref_node *ref2,
88 struct btrfs_delayed_ref_node *ref1)
89{
90 if (ref1->bytenr < ref2->bytenr)
91 return -1;
92 if (ref1->bytenr > ref2->bytenr)
93 return 1;
94 if (ref1->is_head && ref2->is_head)
95 return 0;
96 if (ref2->is_head)
97 return -1;
98 if (ref1->is_head)
99 return 1;
100 if (ref1->type < ref2->type)
101 return -1;
102 if (ref1->type > ref2->type)
103 return 1;
104 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
105 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
106 return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
107 btrfs_delayed_node_to_tree_ref(ref1));
108 } else if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY ||
109 ref1->type == BTRFS_SHARED_DATA_REF_KEY) {
110 return comp_data_refs(btrfs_delayed_node_to_data_ref(ref2),
111 btrfs_delayed_node_to_data_ref(ref1));
112 }
113 BUG();
114 return 0;
115}
116
117/*
118 * insert a new ref into the rbtree. This returns any existing refs
119 * for the same (bytenr,parent) tuple, or NULL if the new node was properly
120 * inserted.
121 */
122static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
123 struct rb_node *node)
124{
125 struct rb_node **p = &root->rb_node;
126 struct rb_node *parent_node = NULL;
127 struct btrfs_delayed_ref_node *entry;
128 struct btrfs_delayed_ref_node *ins;
129 int cmp;
130
131 ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
132 while (*p) {
133 parent_node = *p;
134 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
135 rb_node);
136
137 cmp = comp_entry(entry, ins);
138 if (cmp < 0)
139 p = &(*p)->rb_left;
140 else if (cmp > 0)
141 p = &(*p)->rb_right;
142 else
143 return entry;
144 }
145
146 rb_link_node(node, parent_node, p);
147 rb_insert_color(node, root);
148 return NULL;
149}
150
151/*
152 * find an head entry based on bytenr. This returns the delayed ref
153 * head if it was able to find one, or NULL if nothing was in that spot
154 */
155static struct btrfs_delayed_ref_node *find_ref_head(struct rb_root *root,
156 u64 bytenr,
157 struct btrfs_delayed_ref_node **last)
158{
159 struct rb_node *n = root->rb_node;
160 struct btrfs_delayed_ref_node *entry;
161 int cmp;
162
163 while (n) {
164 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
165 WARN_ON(!entry->in_tree);
166 if (last)
167 *last = entry;
168
169 if (bytenr < entry->bytenr)
170 cmp = -1;
171 else if (bytenr > entry->bytenr)
172 cmp = 1;
173 else if (!btrfs_delayed_ref_is_head(entry))
174 cmp = 1;
175 else
176 cmp = 0;
177
178 if (cmp < 0)
179 n = n->rb_left;
180 else if (cmp > 0)
181 n = n->rb_right;
182 else
183 return entry;
184 }
185 return NULL;
186}
187
188int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
189 struct btrfs_delayed_ref_head *head)
190{
191 struct btrfs_delayed_ref_root *delayed_refs;
192
193 delayed_refs = &trans->transaction->delayed_refs;
194 assert_spin_locked(&delayed_refs->lock);
195 if (mutex_trylock(&head->mutex))
196 return 0;
197
198 atomic_inc(&head->node.refs);
199 spin_unlock(&delayed_refs->lock);
200
201 mutex_lock(&head->mutex);
202 spin_lock(&delayed_refs->lock);
203 if (!head->node.in_tree) {
204 mutex_unlock(&head->mutex);
205 btrfs_put_delayed_ref(&head->node);
206 return -EAGAIN;
207 }
208 btrfs_put_delayed_ref(&head->node);
209 return 0;
210}
211
212int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
213 struct list_head *cluster, u64 start)
214{
215 int count = 0;
216 struct btrfs_delayed_ref_root *delayed_refs;
217 struct rb_node *node;
218 struct btrfs_delayed_ref_node *ref;
219 struct btrfs_delayed_ref_head *head;
220
221 delayed_refs = &trans->transaction->delayed_refs;
222 if (start == 0) {
223 node = rb_first(&delayed_refs->root);
224 } else {
225 ref = NULL;
226 find_ref_head(&delayed_refs->root, start, &ref);
227 if (ref) {
228 struct btrfs_delayed_ref_node *tmp;
229
230 node = rb_prev(&ref->rb_node);
231 while (node) {
232 tmp = rb_entry(node,
233 struct btrfs_delayed_ref_node,
234 rb_node);
235 if (tmp->bytenr < start)
236 break;
237 ref = tmp;
238 node = rb_prev(&ref->rb_node);
239 }
240 node = &ref->rb_node;
241 } else
242 node = rb_first(&delayed_refs->root);
243 }
244again:
245 while (node && count < 32) {
246 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
247 if (btrfs_delayed_ref_is_head(ref)) {
248 head = btrfs_delayed_node_to_head(ref);
249 if (list_empty(&head->cluster)) {
250 list_add_tail(&head->cluster, cluster);
251 delayed_refs->run_delayed_start =
252 head->node.bytenr;
253 count++;
254
255 WARN_ON(delayed_refs->num_heads_ready == 0);
256 delayed_refs->num_heads_ready--;
257 } else if (count) {
258 /* the goal of the clustering is to find extents
259 * that are likely to end up in the same extent
260 * leaf on disk. So, we don't want them spread
261 * all over the tree. Stop now if we've hit
262 * a head that was already in use
263 */
264 break;
265 }
266 }
267 node = rb_next(node);
268 }
269 if (count) {
270 return 0;
271 } else if (start) {
272 /*
273 * we've gone to the end of the rbtree without finding any
274 * clusters. start from the beginning and try again
275 */
276 start = 0;
277 node = rb_first(&delayed_refs->root);
278 goto again;
279 }
280 return 1;
281}
282
283/*
284 * helper function to update an extent delayed ref in the
285 * rbtree. existing and update must both have the same
286 * bytenr and parent
287 *
288 * This may free existing if the update cancels out whatever
289 * operation it was doing.
290 */
291static noinline void
292update_existing_ref(struct btrfs_trans_handle *trans,
293 struct btrfs_delayed_ref_root *delayed_refs,
294 struct btrfs_delayed_ref_node *existing,
295 struct btrfs_delayed_ref_node *update)
296{
297 if (update->action != existing->action) {
298 /*
299 * this is effectively undoing either an add or a
300 * drop. We decrement the ref_mod, and if it goes
301 * down to zero we just delete the entry without
302 * every changing the extent allocation tree.
303 */
304 existing->ref_mod--;
305 if (existing->ref_mod == 0) {
306 rb_erase(&existing->rb_node,
307 &delayed_refs->root);
308 existing->in_tree = 0;
309 btrfs_put_delayed_ref(existing);
310 delayed_refs->num_entries--;
311 if (trans->delayed_ref_updates)
312 trans->delayed_ref_updates--;
313 } else {
314 WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
315 existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
316 }
317 } else {
318 WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
319 existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
320 /*
321 * the action on the existing ref matches
322 * the action on the ref we're trying to add.
323 * Bump the ref_mod by one so the backref that
324 * is eventually added/removed has the correct
325 * reference count
326 */
327 existing->ref_mod += update->ref_mod;
328 }
329}
330
331/*
332 * helper function to update the accounting in the head ref
333 * existing and update must have the same bytenr
334 */
335static noinline void
336update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
337 struct btrfs_delayed_ref_node *update)
338{
339 struct btrfs_delayed_ref_head *existing_ref;
340 struct btrfs_delayed_ref_head *ref;
341
342 existing_ref = btrfs_delayed_node_to_head(existing);
343 ref = btrfs_delayed_node_to_head(update);
344 BUG_ON(existing_ref->is_data != ref->is_data);
345
346 if (ref->must_insert_reserved) {
347 /* if the extent was freed and then
348 * reallocated before the delayed ref
349 * entries were processed, we can end up
350 * with an existing head ref without
351 * the must_insert_reserved flag set.
352 * Set it again here
353 */
354 existing_ref->must_insert_reserved = ref->must_insert_reserved;
355
356 /*
357 * update the num_bytes so we make sure the accounting
358 * is done correctly
359 */
360 existing->num_bytes = update->num_bytes;
361
362 }
363
364 if (ref->extent_op) {
365 if (!existing_ref->extent_op) {
366 existing_ref->extent_op = ref->extent_op;
367 } else {
368 if (ref->extent_op->update_key) {
369 memcpy(&existing_ref->extent_op->key,
370 &ref->extent_op->key,
371 sizeof(ref->extent_op->key));
372 existing_ref->extent_op->update_key = 1;
373 }
374 if (ref->extent_op->update_flags) {
375 existing_ref->extent_op->flags_to_set |=
376 ref->extent_op->flags_to_set;
377 existing_ref->extent_op->update_flags = 1;
378 }
379 kfree(ref->extent_op);
380 }
381 }
382 /*
383 * update the reference mod on the head to reflect this new operation
384 */
385 existing->ref_mod += update->ref_mod;
386}
387
388/*
389 * helper function to actually insert a head node into the rbtree.
390 * this does all the dirty work in terms of maintaining the correct
391 * overall modification count.
392 */
393static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans,
394 struct btrfs_delayed_ref_node *ref,
395 u64 bytenr, u64 num_bytes,
396 int action, int is_data)
397{
398 struct btrfs_delayed_ref_node *existing;
399 struct btrfs_delayed_ref_head *head_ref = NULL;
400 struct btrfs_delayed_ref_root *delayed_refs;
401 int count_mod = 1;
402 int must_insert_reserved = 0;
403
404 /*
405 * the head node stores the sum of all the mods, so dropping a ref
406 * should drop the sum in the head node by one.
407 */
408 if (action == BTRFS_UPDATE_DELAYED_HEAD)
409 count_mod = 0;
410 else if (action == BTRFS_DROP_DELAYED_REF)
411 count_mod = -1;
412
413 /*
414 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
415 * the reserved accounting when the extent is finally added, or
416 * if a later modification deletes the delayed ref without ever
417 * inserting the extent into the extent allocation tree.
418 * ref->must_insert_reserved is the flag used to record
419 * that accounting mods are required.
420 *
421 * Once we record must_insert_reserved, switch the action to
422 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
423 */
424 if (action == BTRFS_ADD_DELAYED_EXTENT)
425 must_insert_reserved = 1;
426 else
427 must_insert_reserved = 0;
428
429 delayed_refs = &trans->transaction->delayed_refs;
430
431 /* first set the basic ref node struct up */
432 atomic_set(&ref->refs, 1);
433 ref->bytenr = bytenr;
434 ref->num_bytes = num_bytes;
435 ref->ref_mod = count_mod;
436 ref->type = 0;
437 ref->action = 0;
438 ref->is_head = 1;
439 ref->in_tree = 1;
440
441 head_ref = btrfs_delayed_node_to_head(ref);
442 head_ref->must_insert_reserved = must_insert_reserved;
443 head_ref->is_data = is_data;
444
445 INIT_LIST_HEAD(&head_ref->cluster);
446 mutex_init(&head_ref->mutex);
447
448 trace_btrfs_delayed_ref_head(ref, head_ref, action);
449
450 existing = tree_insert(&delayed_refs->root, &ref->rb_node);
451
452 if (existing) {
453 update_existing_head_ref(existing, ref);
454 /*
455 * we've updated the existing ref, free the newly
456 * allocated ref
457 */
458 kfree(ref);
459 } else {
460 delayed_refs->num_heads++;
461 delayed_refs->num_heads_ready++;
462 delayed_refs->num_entries++;
463 trans->delayed_ref_updates++;
464 }
465 return 0;
466}
467
468/*
469 * helper to insert a delayed tree ref into the rbtree.
470 */
471static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans,
472 struct btrfs_delayed_ref_node *ref,
473 u64 bytenr, u64 num_bytes, u64 parent,
474 u64 ref_root, int level, int action)
475{
476 struct btrfs_delayed_ref_node *existing;
477 struct btrfs_delayed_tree_ref *full_ref;
478 struct btrfs_delayed_ref_root *delayed_refs;
479
480 if (action == BTRFS_ADD_DELAYED_EXTENT)
481 action = BTRFS_ADD_DELAYED_REF;
482
483 delayed_refs = &trans->transaction->delayed_refs;
484
485 /* first set the basic ref node struct up */
486 atomic_set(&ref->refs, 1);
487 ref->bytenr = bytenr;
488 ref->num_bytes = num_bytes;
489 ref->ref_mod = 1;
490 ref->action = action;
491 ref->is_head = 0;
492 ref->in_tree = 1;
493
494 full_ref = btrfs_delayed_node_to_tree_ref(ref);
495 if (parent) {
496 full_ref->parent = parent;
497 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
498 } else {
499 full_ref->root = ref_root;
500 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
501 }
502 full_ref->level = level;
503
504 trace_btrfs_delayed_tree_ref(ref, full_ref, action);
505
506 existing = tree_insert(&delayed_refs->root, &ref->rb_node);
507
508 if (existing) {
509 update_existing_ref(trans, delayed_refs, existing, ref);
510 /*
511 * we've updated the existing ref, free the newly
512 * allocated ref
513 */
514 kfree(ref);
515 } else {
516 delayed_refs->num_entries++;
517 trans->delayed_ref_updates++;
518 }
519 return 0;
520}
521
522/*
523 * helper to insert a delayed data ref into the rbtree.
524 */
525static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
526 struct btrfs_delayed_ref_node *ref,
527 u64 bytenr, u64 num_bytes, u64 parent,
528 u64 ref_root, u64 owner, u64 offset,
529 int action)
530{
531 struct btrfs_delayed_ref_node *existing;
532 struct btrfs_delayed_data_ref *full_ref;
533 struct btrfs_delayed_ref_root *delayed_refs;
534
535 if (action == BTRFS_ADD_DELAYED_EXTENT)
536 action = BTRFS_ADD_DELAYED_REF;
537
538 delayed_refs = &trans->transaction->delayed_refs;
539
540 /* first set the basic ref node struct up */
541 atomic_set(&ref->refs, 1);
542 ref->bytenr = bytenr;
543 ref->num_bytes = num_bytes;
544 ref->ref_mod = 1;
545 ref->action = action;
546 ref->is_head = 0;
547 ref->in_tree = 1;
548
549 full_ref = btrfs_delayed_node_to_data_ref(ref);
550 if (parent) {
551 full_ref->parent = parent;
552 ref->type = BTRFS_SHARED_DATA_REF_KEY;
553 } else {
554 full_ref->root = ref_root;
555 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
556 }
557 full_ref->objectid = owner;
558 full_ref->offset = offset;
559
560 trace_btrfs_delayed_data_ref(ref, full_ref, action);
561
562 existing = tree_insert(&delayed_refs->root, &ref->rb_node);
563
564 if (existing) {
565 update_existing_ref(trans, delayed_refs, existing, ref);
566 /*
567 * we've updated the existing ref, free the newly
568 * allocated ref
569 */
570 kfree(ref);
571 } else {
572 delayed_refs->num_entries++;
573 trans->delayed_ref_updates++;
574 }
575 return 0;
576}
577
578/*
579 * add a delayed tree ref. This does all of the accounting required
580 * to make sure the delayed ref is eventually processed before this
581 * transaction commits.
582 */
583int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
584 u64 bytenr, u64 num_bytes, u64 parent,
585 u64 ref_root, int level, int action,
586 struct btrfs_delayed_extent_op *extent_op)
587{
588 struct btrfs_delayed_tree_ref *ref;
589 struct btrfs_delayed_ref_head *head_ref;
590 struct btrfs_delayed_ref_root *delayed_refs;
591 int ret;
592
593 BUG_ON(extent_op && extent_op->is_data);
594 ref = kmalloc(sizeof(*ref), GFP_NOFS);
595 if (!ref)
596 return -ENOMEM;
597
598 head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
599 if (!head_ref) {
600 kfree(ref);
601 return -ENOMEM;
602 }
603
604 head_ref->extent_op = extent_op;
605
606 delayed_refs = &trans->transaction->delayed_refs;
607 spin_lock(&delayed_refs->lock);
608
609 /*
610 * insert both the head node and the new ref without dropping
611 * the spin lock
612 */
613 ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
614 action, 0);
615 BUG_ON(ret);
616
617 ret = add_delayed_tree_ref(trans, &ref->node, bytenr, num_bytes,
618 parent, ref_root, level, action);
619 BUG_ON(ret);
620 spin_unlock(&delayed_refs->lock);
621 return 0;
622}
623
624/*
625 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
626 */
627int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
628 u64 bytenr, u64 num_bytes,
629 u64 parent, u64 ref_root,
630 u64 owner, u64 offset, int action,
631 struct btrfs_delayed_extent_op *extent_op)
632{
633 struct btrfs_delayed_data_ref *ref;
634 struct btrfs_delayed_ref_head *head_ref;
635 struct btrfs_delayed_ref_root *delayed_refs;
636 int ret;
637
638 BUG_ON(extent_op && !extent_op->is_data);
639 ref = kmalloc(sizeof(*ref), GFP_NOFS);
640 if (!ref)
641 return -ENOMEM;
642
643 head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
644 if (!head_ref) {
645 kfree(ref);
646 return -ENOMEM;
647 }
648
649 head_ref->extent_op = extent_op;
650
651 delayed_refs = &trans->transaction->delayed_refs;
652 spin_lock(&delayed_refs->lock);
653
654 /*
655 * insert both the head node and the new ref without dropping
656 * the spin lock
657 */
658 ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
659 action, 1);
660 BUG_ON(ret);
661
662 ret = add_delayed_data_ref(trans, &ref->node, bytenr, num_bytes,
663 parent, ref_root, owner, offset, action);
664 BUG_ON(ret);
665 spin_unlock(&delayed_refs->lock);
666 return 0;
667}
668
669int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
670 u64 bytenr, u64 num_bytes,
671 struct btrfs_delayed_extent_op *extent_op)
672{
673 struct btrfs_delayed_ref_head *head_ref;
674 struct btrfs_delayed_ref_root *delayed_refs;
675 int ret;
676
677 head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
678 if (!head_ref)
679 return -ENOMEM;
680
681 head_ref->extent_op = extent_op;
682
683 delayed_refs = &trans->transaction->delayed_refs;
684 spin_lock(&delayed_refs->lock);
685
686 ret = add_delayed_ref_head(trans, &head_ref->node, bytenr,
687 num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
688 extent_op->is_data);
689 BUG_ON(ret);
690
691 spin_unlock(&delayed_refs->lock);
692 return 0;
693}
694
695/*
696 * this does a simple search for the head node for a given extent.
697 * It must be called with the delayed ref spinlock held, and it returns
698 * the head node if any where found, or NULL if not.
699 */
700struct btrfs_delayed_ref_head *
701btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
702{
703 struct btrfs_delayed_ref_node *ref;
704 struct btrfs_delayed_ref_root *delayed_refs;
705
706 delayed_refs = &trans->transaction->delayed_refs;
707 ref = find_ref_head(&delayed_refs->root, bytenr, NULL);
708 if (ref)
709 return btrfs_delayed_node_to_head(ref);
710 return NULL;
711}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2009 Oracle. All rights reserved.
4 */
5
6#include <linux/sched.h>
7#include <linux/slab.h>
8#include <linux/sort.h>
9#include "ctree.h"
10#include "delayed-ref.h"
11#include "transaction.h"
12#include "qgroup.h"
13
14struct kmem_cache *btrfs_delayed_ref_head_cachep;
15struct kmem_cache *btrfs_delayed_tree_ref_cachep;
16struct kmem_cache *btrfs_delayed_data_ref_cachep;
17struct kmem_cache *btrfs_delayed_extent_op_cachep;
18/*
19 * delayed back reference update tracking. For subvolume trees
20 * we queue up extent allocations and backref maintenance for
21 * delayed processing. This avoids deep call chains where we
22 * add extents in the middle of btrfs_search_slot, and it allows
23 * us to buffer up frequently modified backrefs in an rb tree instead
24 * of hammering updates on the extent allocation tree.
25 */
26
27/*
28 * compare two delayed tree backrefs with same bytenr and type
29 */
30static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref1,
31 struct btrfs_delayed_tree_ref *ref2)
32{
33 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
34 if (ref1->root < ref2->root)
35 return -1;
36 if (ref1->root > ref2->root)
37 return 1;
38 } else {
39 if (ref1->parent < ref2->parent)
40 return -1;
41 if (ref1->parent > ref2->parent)
42 return 1;
43 }
44 return 0;
45}
46
47/*
48 * compare two delayed data backrefs with same bytenr and type
49 */
50static int comp_data_refs(struct btrfs_delayed_data_ref *ref1,
51 struct btrfs_delayed_data_ref *ref2)
52{
53 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
54 if (ref1->root < ref2->root)
55 return -1;
56 if (ref1->root > ref2->root)
57 return 1;
58 if (ref1->objectid < ref2->objectid)
59 return -1;
60 if (ref1->objectid > ref2->objectid)
61 return 1;
62 if (ref1->offset < ref2->offset)
63 return -1;
64 if (ref1->offset > ref2->offset)
65 return 1;
66 } else {
67 if (ref1->parent < ref2->parent)
68 return -1;
69 if (ref1->parent > ref2->parent)
70 return 1;
71 }
72 return 0;
73}
74
75static int comp_refs(struct btrfs_delayed_ref_node *ref1,
76 struct btrfs_delayed_ref_node *ref2,
77 bool check_seq)
78{
79 int ret = 0;
80
81 if (ref1->type < ref2->type)
82 return -1;
83 if (ref1->type > ref2->type)
84 return 1;
85 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
86 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY)
87 ret = comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref1),
88 btrfs_delayed_node_to_tree_ref(ref2));
89 else
90 ret = comp_data_refs(btrfs_delayed_node_to_data_ref(ref1),
91 btrfs_delayed_node_to_data_ref(ref2));
92 if (ret)
93 return ret;
94 if (check_seq) {
95 if (ref1->seq < ref2->seq)
96 return -1;
97 if (ref1->seq > ref2->seq)
98 return 1;
99 }
100 return 0;
101}
102
103/* insert a new ref to head ref rbtree */
104static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
105 struct rb_node *node)
106{
107 struct rb_node **p = &root->rb_node;
108 struct rb_node *parent_node = NULL;
109 struct btrfs_delayed_ref_head *entry;
110 struct btrfs_delayed_ref_head *ins;
111 u64 bytenr;
112
113 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
114 bytenr = ins->bytenr;
115 while (*p) {
116 parent_node = *p;
117 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
118 href_node);
119
120 if (bytenr < entry->bytenr)
121 p = &(*p)->rb_left;
122 else if (bytenr > entry->bytenr)
123 p = &(*p)->rb_right;
124 else
125 return entry;
126 }
127
128 rb_link_node(node, parent_node, p);
129 rb_insert_color(node, root);
130 return NULL;
131}
132
133static struct btrfs_delayed_ref_node* tree_insert(struct rb_root *root,
134 struct btrfs_delayed_ref_node *ins)
135{
136 struct rb_node **p = &root->rb_node;
137 struct rb_node *node = &ins->ref_node;
138 struct rb_node *parent_node = NULL;
139 struct btrfs_delayed_ref_node *entry;
140
141 while (*p) {
142 int comp;
143
144 parent_node = *p;
145 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
146 ref_node);
147 comp = comp_refs(ins, entry, true);
148 if (comp < 0)
149 p = &(*p)->rb_left;
150 else if (comp > 0)
151 p = &(*p)->rb_right;
152 else
153 return entry;
154 }
155
156 rb_link_node(node, parent_node, p);
157 rb_insert_color(node, root);
158 return NULL;
159}
160
161/*
162 * find an head entry based on bytenr. This returns the delayed ref
163 * head if it was able to find one, or NULL if nothing was in that spot.
164 * If return_bigger is given, the next bigger entry is returned if no exact
165 * match is found.
166 */
167static struct btrfs_delayed_ref_head *
168find_ref_head(struct rb_root *root, u64 bytenr,
169 int return_bigger)
170{
171 struct rb_node *n;
172 struct btrfs_delayed_ref_head *entry;
173
174 n = root->rb_node;
175 entry = NULL;
176 while (n) {
177 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
178
179 if (bytenr < entry->bytenr)
180 n = n->rb_left;
181 else if (bytenr > entry->bytenr)
182 n = n->rb_right;
183 else
184 return entry;
185 }
186 if (entry && return_bigger) {
187 if (bytenr > entry->bytenr) {
188 n = rb_next(&entry->href_node);
189 if (!n)
190 n = rb_first(root);
191 entry = rb_entry(n, struct btrfs_delayed_ref_head,
192 href_node);
193 return entry;
194 }
195 return entry;
196 }
197 return NULL;
198}
199
200int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
201 struct btrfs_delayed_ref_head *head)
202{
203 struct btrfs_delayed_ref_root *delayed_refs;
204
205 delayed_refs = &trans->transaction->delayed_refs;
206 lockdep_assert_held(&delayed_refs->lock);
207 if (mutex_trylock(&head->mutex))
208 return 0;
209
210 refcount_inc(&head->refs);
211 spin_unlock(&delayed_refs->lock);
212
213 mutex_lock(&head->mutex);
214 spin_lock(&delayed_refs->lock);
215 if (RB_EMPTY_NODE(&head->href_node)) {
216 mutex_unlock(&head->mutex);
217 btrfs_put_delayed_ref_head(head);
218 return -EAGAIN;
219 }
220 btrfs_put_delayed_ref_head(head);
221 return 0;
222}
223
224static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
225 struct btrfs_delayed_ref_root *delayed_refs,
226 struct btrfs_delayed_ref_head *head,
227 struct btrfs_delayed_ref_node *ref)
228{
229 lockdep_assert_held(&head->lock);
230 rb_erase(&ref->ref_node, &head->ref_tree);
231 RB_CLEAR_NODE(&ref->ref_node);
232 if (!list_empty(&ref->add_list))
233 list_del(&ref->add_list);
234 ref->in_tree = 0;
235 btrfs_put_delayed_ref(ref);
236 atomic_dec(&delayed_refs->num_entries);
237 if (trans->delayed_ref_updates)
238 trans->delayed_ref_updates--;
239}
240
241static bool merge_ref(struct btrfs_trans_handle *trans,
242 struct btrfs_delayed_ref_root *delayed_refs,
243 struct btrfs_delayed_ref_head *head,
244 struct btrfs_delayed_ref_node *ref,
245 u64 seq)
246{
247 struct btrfs_delayed_ref_node *next;
248 struct rb_node *node = rb_next(&ref->ref_node);
249 bool done = false;
250
251 while (!done && node) {
252 int mod;
253
254 next = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
255 node = rb_next(node);
256 if (seq && next->seq >= seq)
257 break;
258 if (comp_refs(ref, next, false))
259 break;
260
261 if (ref->action == next->action) {
262 mod = next->ref_mod;
263 } else {
264 if (ref->ref_mod < next->ref_mod) {
265 swap(ref, next);
266 done = true;
267 }
268 mod = -next->ref_mod;
269 }
270
271 drop_delayed_ref(trans, delayed_refs, head, next);
272 ref->ref_mod += mod;
273 if (ref->ref_mod == 0) {
274 drop_delayed_ref(trans, delayed_refs, head, ref);
275 done = true;
276 } else {
277 /*
278 * Can't have multiples of the same ref on a tree block.
279 */
280 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
281 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
282 }
283 }
284
285 return done;
286}
287
288void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
289 struct btrfs_fs_info *fs_info,
290 struct btrfs_delayed_ref_root *delayed_refs,
291 struct btrfs_delayed_ref_head *head)
292{
293 struct btrfs_delayed_ref_node *ref;
294 struct rb_node *node;
295 u64 seq = 0;
296
297 lockdep_assert_held(&head->lock);
298
299 if (RB_EMPTY_ROOT(&head->ref_tree))
300 return;
301
302 /* We don't have too many refs to merge for data. */
303 if (head->is_data)
304 return;
305
306 spin_lock(&fs_info->tree_mod_seq_lock);
307 if (!list_empty(&fs_info->tree_mod_seq_list)) {
308 struct seq_list *elem;
309
310 elem = list_first_entry(&fs_info->tree_mod_seq_list,
311 struct seq_list, list);
312 seq = elem->seq;
313 }
314 spin_unlock(&fs_info->tree_mod_seq_lock);
315
316again:
317 for (node = rb_first(&head->ref_tree); node; node = rb_next(node)) {
318 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
319 if (seq && ref->seq >= seq)
320 continue;
321 if (merge_ref(trans, delayed_refs, head, ref, seq))
322 goto again;
323 }
324}
325
326int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
327 struct btrfs_delayed_ref_root *delayed_refs,
328 u64 seq)
329{
330 struct seq_list *elem;
331 int ret = 0;
332
333 spin_lock(&fs_info->tree_mod_seq_lock);
334 if (!list_empty(&fs_info->tree_mod_seq_list)) {
335 elem = list_first_entry(&fs_info->tree_mod_seq_list,
336 struct seq_list, list);
337 if (seq >= elem->seq) {
338 btrfs_debug(fs_info,
339 "holding back delayed_ref %#x.%x, lowest is %#x.%x (%p)",
340 (u32)(seq >> 32), (u32)seq,
341 (u32)(elem->seq >> 32), (u32)elem->seq,
342 delayed_refs);
343 ret = 1;
344 }
345 }
346
347 spin_unlock(&fs_info->tree_mod_seq_lock);
348 return ret;
349}
350
351struct btrfs_delayed_ref_head *
352btrfs_select_ref_head(struct btrfs_trans_handle *trans)
353{
354 struct btrfs_delayed_ref_root *delayed_refs;
355 struct btrfs_delayed_ref_head *head;
356 u64 start;
357 bool loop = false;
358
359 delayed_refs = &trans->transaction->delayed_refs;
360
361again:
362 start = delayed_refs->run_delayed_start;
363 head = find_ref_head(&delayed_refs->href_root, start, 1);
364 if (!head && !loop) {
365 delayed_refs->run_delayed_start = 0;
366 start = 0;
367 loop = true;
368 head = find_ref_head(&delayed_refs->href_root, start, 1);
369 if (!head)
370 return NULL;
371 } else if (!head && loop) {
372 return NULL;
373 }
374
375 while (head->processing) {
376 struct rb_node *node;
377
378 node = rb_next(&head->href_node);
379 if (!node) {
380 if (loop)
381 return NULL;
382 delayed_refs->run_delayed_start = 0;
383 start = 0;
384 loop = true;
385 goto again;
386 }
387 head = rb_entry(node, struct btrfs_delayed_ref_head,
388 href_node);
389 }
390
391 head->processing = 1;
392 WARN_ON(delayed_refs->num_heads_ready == 0);
393 delayed_refs->num_heads_ready--;
394 delayed_refs->run_delayed_start = head->bytenr +
395 head->num_bytes;
396 return head;
397}
398
399/*
400 * Helper to insert the ref_node to the tail or merge with tail.
401 *
402 * Return 0 for insert.
403 * Return >0 for merge.
404 */
405static int insert_delayed_ref(struct btrfs_trans_handle *trans,
406 struct btrfs_delayed_ref_root *root,
407 struct btrfs_delayed_ref_head *href,
408 struct btrfs_delayed_ref_node *ref)
409{
410 struct btrfs_delayed_ref_node *exist;
411 int mod;
412 int ret = 0;
413
414 spin_lock(&href->lock);
415 exist = tree_insert(&href->ref_tree, ref);
416 if (!exist)
417 goto inserted;
418
419 /* Now we are sure we can merge */
420 ret = 1;
421 if (exist->action == ref->action) {
422 mod = ref->ref_mod;
423 } else {
424 /* Need to change action */
425 if (exist->ref_mod < ref->ref_mod) {
426 exist->action = ref->action;
427 mod = -exist->ref_mod;
428 exist->ref_mod = ref->ref_mod;
429 if (ref->action == BTRFS_ADD_DELAYED_REF)
430 list_add_tail(&exist->add_list,
431 &href->ref_add_list);
432 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
433 ASSERT(!list_empty(&exist->add_list));
434 list_del(&exist->add_list);
435 } else {
436 ASSERT(0);
437 }
438 } else
439 mod = -ref->ref_mod;
440 }
441 exist->ref_mod += mod;
442
443 /* remove existing tail if its ref_mod is zero */
444 if (exist->ref_mod == 0)
445 drop_delayed_ref(trans, root, href, exist);
446 spin_unlock(&href->lock);
447 return ret;
448inserted:
449 if (ref->action == BTRFS_ADD_DELAYED_REF)
450 list_add_tail(&ref->add_list, &href->ref_add_list);
451 atomic_inc(&root->num_entries);
452 trans->delayed_ref_updates++;
453 spin_unlock(&href->lock);
454 return ret;
455}
456
457/*
458 * helper function to update the accounting in the head ref
459 * existing and update must have the same bytenr
460 */
461static noinline void
462update_existing_head_ref(struct btrfs_delayed_ref_root *delayed_refs,
463 struct btrfs_delayed_ref_head *existing,
464 struct btrfs_delayed_ref_head *update,
465 int *old_ref_mod_ret)
466{
467 int old_ref_mod;
468
469 BUG_ON(existing->is_data != update->is_data);
470
471 spin_lock(&existing->lock);
472 if (update->must_insert_reserved) {
473 /* if the extent was freed and then
474 * reallocated before the delayed ref
475 * entries were processed, we can end up
476 * with an existing head ref without
477 * the must_insert_reserved flag set.
478 * Set it again here
479 */
480 existing->must_insert_reserved = update->must_insert_reserved;
481
482 /*
483 * update the num_bytes so we make sure the accounting
484 * is done correctly
485 */
486 existing->num_bytes = update->num_bytes;
487
488 }
489
490 if (update->extent_op) {
491 if (!existing->extent_op) {
492 existing->extent_op = update->extent_op;
493 } else {
494 if (update->extent_op->update_key) {
495 memcpy(&existing->extent_op->key,
496 &update->extent_op->key,
497 sizeof(update->extent_op->key));
498 existing->extent_op->update_key = true;
499 }
500 if (update->extent_op->update_flags) {
501 existing->extent_op->flags_to_set |=
502 update->extent_op->flags_to_set;
503 existing->extent_op->update_flags = true;
504 }
505 btrfs_free_delayed_extent_op(update->extent_op);
506 }
507 }
508 /*
509 * update the reference mod on the head to reflect this new operation,
510 * only need the lock for this case cause we could be processing it
511 * currently, for refs we just added we know we're a-ok.
512 */
513 old_ref_mod = existing->total_ref_mod;
514 if (old_ref_mod_ret)
515 *old_ref_mod_ret = old_ref_mod;
516 existing->ref_mod += update->ref_mod;
517 existing->total_ref_mod += update->ref_mod;
518
519 /*
520 * If we are going to from a positive ref mod to a negative or vice
521 * versa we need to make sure to adjust pending_csums accordingly.
522 */
523 if (existing->is_data) {
524 if (existing->total_ref_mod >= 0 && old_ref_mod < 0)
525 delayed_refs->pending_csums -= existing->num_bytes;
526 if (existing->total_ref_mod < 0 && old_ref_mod >= 0)
527 delayed_refs->pending_csums += existing->num_bytes;
528 }
529 spin_unlock(&existing->lock);
530}
531
532/*
533 * helper function to actually insert a head node into the rbtree.
534 * this does all the dirty work in terms of maintaining the correct
535 * overall modification count.
536 */
537static noinline struct btrfs_delayed_ref_head *
538add_delayed_ref_head(struct btrfs_fs_info *fs_info,
539 struct btrfs_trans_handle *trans,
540 struct btrfs_delayed_ref_head *head_ref,
541 struct btrfs_qgroup_extent_record *qrecord,
542 u64 bytenr, u64 num_bytes, u64 ref_root, u64 reserved,
543 int action, int is_data, int is_system,
544 int *qrecord_inserted_ret,
545 int *old_ref_mod, int *new_ref_mod)
546
547{
548 struct btrfs_delayed_ref_head *existing;
549 struct btrfs_delayed_ref_root *delayed_refs;
550 int count_mod = 1;
551 int must_insert_reserved = 0;
552 int qrecord_inserted = 0;
553
554 /* If reserved is provided, it must be a data extent. */
555 BUG_ON(!is_data && reserved);
556
557 /*
558 * the head node stores the sum of all the mods, so dropping a ref
559 * should drop the sum in the head node by one.
560 */
561 if (action == BTRFS_UPDATE_DELAYED_HEAD)
562 count_mod = 0;
563 else if (action == BTRFS_DROP_DELAYED_REF)
564 count_mod = -1;
565
566 /*
567 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
568 * the reserved accounting when the extent is finally added, or
569 * if a later modification deletes the delayed ref without ever
570 * inserting the extent into the extent allocation tree.
571 * ref->must_insert_reserved is the flag used to record
572 * that accounting mods are required.
573 *
574 * Once we record must_insert_reserved, switch the action to
575 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
576 */
577 if (action == BTRFS_ADD_DELAYED_EXTENT)
578 must_insert_reserved = 1;
579 else
580 must_insert_reserved = 0;
581
582 delayed_refs = &trans->transaction->delayed_refs;
583
584 refcount_set(&head_ref->refs, 1);
585 head_ref->bytenr = bytenr;
586 head_ref->num_bytes = num_bytes;
587 head_ref->ref_mod = count_mod;
588 head_ref->must_insert_reserved = must_insert_reserved;
589 head_ref->is_data = is_data;
590 head_ref->is_system = is_system;
591 head_ref->ref_tree = RB_ROOT;
592 INIT_LIST_HEAD(&head_ref->ref_add_list);
593 RB_CLEAR_NODE(&head_ref->href_node);
594 head_ref->processing = 0;
595 head_ref->total_ref_mod = count_mod;
596 head_ref->qgroup_reserved = 0;
597 head_ref->qgroup_ref_root = 0;
598 spin_lock_init(&head_ref->lock);
599 mutex_init(&head_ref->mutex);
600
601 /* Record qgroup extent info if provided */
602 if (qrecord) {
603 if (ref_root && reserved) {
604 head_ref->qgroup_ref_root = ref_root;
605 head_ref->qgroup_reserved = reserved;
606 }
607
608 qrecord->bytenr = bytenr;
609 qrecord->num_bytes = num_bytes;
610 qrecord->old_roots = NULL;
611
612 if(btrfs_qgroup_trace_extent_nolock(fs_info,
613 delayed_refs, qrecord))
614 kfree(qrecord);
615 else
616 qrecord_inserted = 1;
617 }
618
619 trace_add_delayed_ref_head(fs_info, head_ref, action);
620
621 existing = htree_insert(&delayed_refs->href_root,
622 &head_ref->href_node);
623 if (existing) {
624 WARN_ON(ref_root && reserved && existing->qgroup_ref_root
625 && existing->qgroup_reserved);
626 update_existing_head_ref(delayed_refs, existing, head_ref,
627 old_ref_mod);
628 /*
629 * we've updated the existing ref, free the newly
630 * allocated ref
631 */
632 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
633 head_ref = existing;
634 } else {
635 if (old_ref_mod)
636 *old_ref_mod = 0;
637 if (is_data && count_mod < 0)
638 delayed_refs->pending_csums += num_bytes;
639 delayed_refs->num_heads++;
640 delayed_refs->num_heads_ready++;
641 atomic_inc(&delayed_refs->num_entries);
642 trans->delayed_ref_updates++;
643 }
644 if (qrecord_inserted_ret)
645 *qrecord_inserted_ret = qrecord_inserted;
646 if (new_ref_mod)
647 *new_ref_mod = head_ref->total_ref_mod;
648 return head_ref;
649}
650
651/*
652 * helper to insert a delayed tree ref into the rbtree.
653 */
654static noinline void
655add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
656 struct btrfs_trans_handle *trans,
657 struct btrfs_delayed_ref_head *head_ref,
658 struct btrfs_delayed_ref_node *ref, u64 bytenr,
659 u64 num_bytes, u64 parent, u64 ref_root, int level,
660 int action)
661{
662 struct btrfs_delayed_tree_ref *full_ref;
663 struct btrfs_delayed_ref_root *delayed_refs;
664 u64 seq = 0;
665 int ret;
666
667 if (action == BTRFS_ADD_DELAYED_EXTENT)
668 action = BTRFS_ADD_DELAYED_REF;
669
670 if (is_fstree(ref_root))
671 seq = atomic64_read(&fs_info->tree_mod_seq);
672 delayed_refs = &trans->transaction->delayed_refs;
673
674 /* first set the basic ref node struct up */
675 refcount_set(&ref->refs, 1);
676 ref->bytenr = bytenr;
677 ref->num_bytes = num_bytes;
678 ref->ref_mod = 1;
679 ref->action = action;
680 ref->is_head = 0;
681 ref->in_tree = 1;
682 ref->seq = seq;
683 RB_CLEAR_NODE(&ref->ref_node);
684 INIT_LIST_HEAD(&ref->add_list);
685
686 full_ref = btrfs_delayed_node_to_tree_ref(ref);
687 full_ref->parent = parent;
688 full_ref->root = ref_root;
689 if (parent)
690 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
691 else
692 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
693 full_ref->level = level;
694
695 trace_add_delayed_tree_ref(fs_info, ref, full_ref, action);
696
697 ret = insert_delayed_ref(trans, delayed_refs, head_ref, ref);
698
699 /*
700 * XXX: memory should be freed at the same level allocated.
701 * But bad practice is anywhere... Follow it now. Need cleanup.
702 */
703 if (ret > 0)
704 kmem_cache_free(btrfs_delayed_tree_ref_cachep, full_ref);
705}
706
707/*
708 * helper to insert a delayed data ref into the rbtree.
709 */
710static noinline void
711add_delayed_data_ref(struct btrfs_fs_info *fs_info,
712 struct btrfs_trans_handle *trans,
713 struct btrfs_delayed_ref_head *head_ref,
714 struct btrfs_delayed_ref_node *ref, u64 bytenr,
715 u64 num_bytes, u64 parent, u64 ref_root, u64 owner,
716 u64 offset, int action)
717{
718 struct btrfs_delayed_data_ref *full_ref;
719 struct btrfs_delayed_ref_root *delayed_refs;
720 u64 seq = 0;
721 int ret;
722
723 if (action == BTRFS_ADD_DELAYED_EXTENT)
724 action = BTRFS_ADD_DELAYED_REF;
725
726 delayed_refs = &trans->transaction->delayed_refs;
727
728 if (is_fstree(ref_root))
729 seq = atomic64_read(&fs_info->tree_mod_seq);
730
731 /* first set the basic ref node struct up */
732 refcount_set(&ref->refs, 1);
733 ref->bytenr = bytenr;
734 ref->num_bytes = num_bytes;
735 ref->ref_mod = 1;
736 ref->action = action;
737 ref->is_head = 0;
738 ref->in_tree = 1;
739 ref->seq = seq;
740 RB_CLEAR_NODE(&ref->ref_node);
741 INIT_LIST_HEAD(&ref->add_list);
742
743 full_ref = btrfs_delayed_node_to_data_ref(ref);
744 full_ref->parent = parent;
745 full_ref->root = ref_root;
746 if (parent)
747 ref->type = BTRFS_SHARED_DATA_REF_KEY;
748 else
749 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
750
751 full_ref->objectid = owner;
752 full_ref->offset = offset;
753
754 trace_add_delayed_data_ref(fs_info, ref, full_ref, action);
755
756 ret = insert_delayed_ref(trans, delayed_refs, head_ref, ref);
757 if (ret > 0)
758 kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref);
759}
760
761/*
762 * add a delayed tree ref. This does all of the accounting required
763 * to make sure the delayed ref is eventually processed before this
764 * transaction commits.
765 */
766int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
767 struct btrfs_trans_handle *trans,
768 u64 bytenr, u64 num_bytes, u64 parent,
769 u64 ref_root, int level, int action,
770 struct btrfs_delayed_extent_op *extent_op,
771 int *old_ref_mod, int *new_ref_mod)
772{
773 struct btrfs_delayed_tree_ref *ref;
774 struct btrfs_delayed_ref_head *head_ref;
775 struct btrfs_delayed_ref_root *delayed_refs;
776 struct btrfs_qgroup_extent_record *record = NULL;
777 int qrecord_inserted;
778 int is_system = (ref_root == BTRFS_CHUNK_TREE_OBJECTID);
779
780 BUG_ON(extent_op && extent_op->is_data);
781 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
782 if (!ref)
783 return -ENOMEM;
784
785 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
786 if (!head_ref)
787 goto free_ref;
788
789 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
790 is_fstree(ref_root)) {
791 record = kmalloc(sizeof(*record), GFP_NOFS);
792 if (!record)
793 goto free_head_ref;
794 }
795
796 head_ref->extent_op = extent_op;
797
798 delayed_refs = &trans->transaction->delayed_refs;
799 spin_lock(&delayed_refs->lock);
800
801 /*
802 * insert both the head node and the new ref without dropping
803 * the spin lock
804 */
805 head_ref = add_delayed_ref_head(fs_info, trans, head_ref, record,
806 bytenr, num_bytes, 0, 0, action, 0,
807 is_system, &qrecord_inserted,
808 old_ref_mod, new_ref_mod);
809
810 add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr,
811 num_bytes, parent, ref_root, level, action);
812 spin_unlock(&delayed_refs->lock);
813
814 if (qrecord_inserted)
815 btrfs_qgroup_trace_extent_post(fs_info, record);
816
817 return 0;
818
819free_head_ref:
820 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
821free_ref:
822 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
823
824 return -ENOMEM;
825}
826
827/*
828 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
829 */
830int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
831 struct btrfs_trans_handle *trans,
832 u64 bytenr, u64 num_bytes,
833 u64 parent, u64 ref_root,
834 u64 owner, u64 offset, u64 reserved, int action,
835 int *old_ref_mod, int *new_ref_mod)
836{
837 struct btrfs_delayed_data_ref *ref;
838 struct btrfs_delayed_ref_head *head_ref;
839 struct btrfs_delayed_ref_root *delayed_refs;
840 struct btrfs_qgroup_extent_record *record = NULL;
841 int qrecord_inserted;
842
843 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
844 if (!ref)
845 return -ENOMEM;
846
847 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
848 if (!head_ref) {
849 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
850 return -ENOMEM;
851 }
852
853 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
854 is_fstree(ref_root)) {
855 record = kmalloc(sizeof(*record), GFP_NOFS);
856 if (!record) {
857 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
858 kmem_cache_free(btrfs_delayed_ref_head_cachep,
859 head_ref);
860 return -ENOMEM;
861 }
862 }
863
864 head_ref->extent_op = NULL;
865
866 delayed_refs = &trans->transaction->delayed_refs;
867 spin_lock(&delayed_refs->lock);
868
869 /*
870 * insert both the head node and the new ref without dropping
871 * the spin lock
872 */
873 head_ref = add_delayed_ref_head(fs_info, trans, head_ref, record,
874 bytenr, num_bytes, ref_root, reserved,
875 action, 1, 0, &qrecord_inserted,
876 old_ref_mod, new_ref_mod);
877
878 add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr,
879 num_bytes, parent, ref_root, owner, offset,
880 action);
881 spin_unlock(&delayed_refs->lock);
882
883 if (qrecord_inserted)
884 return btrfs_qgroup_trace_extent_post(fs_info, record);
885 return 0;
886}
887
888int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
889 struct btrfs_trans_handle *trans,
890 u64 bytenr, u64 num_bytes,
891 struct btrfs_delayed_extent_op *extent_op)
892{
893 struct btrfs_delayed_ref_head *head_ref;
894 struct btrfs_delayed_ref_root *delayed_refs;
895
896 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
897 if (!head_ref)
898 return -ENOMEM;
899
900 head_ref->extent_op = extent_op;
901
902 delayed_refs = &trans->transaction->delayed_refs;
903 spin_lock(&delayed_refs->lock);
904
905 /*
906 * extent_ops just modify the flags of an extent and they don't result
907 * in ref count changes, hence it's safe to pass false/0 for is_system
908 * argument
909 */
910 add_delayed_ref_head(fs_info, trans, head_ref, NULL, bytenr,
911 num_bytes, 0, 0, BTRFS_UPDATE_DELAYED_HEAD,
912 extent_op->is_data, 0, NULL, NULL, NULL);
913
914 spin_unlock(&delayed_refs->lock);
915 return 0;
916}
917
918/*
919 * this does a simple search for the head node for a given extent.
920 * It must be called with the delayed ref spinlock held, and it returns
921 * the head node if any where found, or NULL if not.
922 */
923struct btrfs_delayed_ref_head *
924btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
925{
926 return find_ref_head(&delayed_refs->href_root, bytenr, 0);
927}
928
929void __cold btrfs_delayed_ref_exit(void)
930{
931 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
932 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
933 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
934 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
935}
936
937int __init btrfs_delayed_ref_init(void)
938{
939 btrfs_delayed_ref_head_cachep = kmem_cache_create(
940 "btrfs_delayed_ref_head",
941 sizeof(struct btrfs_delayed_ref_head), 0,
942 SLAB_MEM_SPREAD, NULL);
943 if (!btrfs_delayed_ref_head_cachep)
944 goto fail;
945
946 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
947 "btrfs_delayed_tree_ref",
948 sizeof(struct btrfs_delayed_tree_ref), 0,
949 SLAB_MEM_SPREAD, NULL);
950 if (!btrfs_delayed_tree_ref_cachep)
951 goto fail;
952
953 btrfs_delayed_data_ref_cachep = kmem_cache_create(
954 "btrfs_delayed_data_ref",
955 sizeof(struct btrfs_delayed_data_ref), 0,
956 SLAB_MEM_SPREAD, NULL);
957 if (!btrfs_delayed_data_ref_cachep)
958 goto fail;
959
960 btrfs_delayed_extent_op_cachep = kmem_cache_create(
961 "btrfs_delayed_extent_op",
962 sizeof(struct btrfs_delayed_extent_op), 0,
963 SLAB_MEM_SPREAD, NULL);
964 if (!btrfs_delayed_extent_op_cachep)
965 goto fail;
966
967 return 0;
968fail:
969 btrfs_delayed_ref_exit();
970 return -ENOMEM;
971}