mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / fs / btrfs / delayed-ref.c
blob45714f1c43a31367332e3873cd45e0b0b5d744fe
1 /*
2 * Copyright (C) 2009 Oracle. All rights reserved.
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.
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.
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.
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 #include "qgroup.h"
27 struct kmem_cache *btrfs_delayed_ref_head_cachep;
28 struct kmem_cache *btrfs_delayed_tree_ref_cachep;
29 struct kmem_cache *btrfs_delayed_data_ref_cachep;
30 struct kmem_cache *btrfs_delayed_extent_op_cachep;
32 * delayed back reference update tracking. For subvolume trees
33 * we queue up extent allocations and backref maintenance for
34 * delayed processing. This avoids deep call chains where we
35 * add extents in the middle of btrfs_search_slot, and it allows
36 * us to buffer up frequently modified backrefs in an rb tree instead
37 * of hammering updates on the extent allocation tree.
41 * compare two delayed tree backrefs with same bytenr and type
43 static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
44 struct btrfs_delayed_tree_ref *ref1, int type)
46 if (type == BTRFS_TREE_BLOCK_REF_KEY) {
47 if (ref1->root < ref2->root)
48 return -1;
49 if (ref1->root > ref2->root)
50 return 1;
51 } else {
52 if (ref1->parent < ref2->parent)
53 return -1;
54 if (ref1->parent > ref2->parent)
55 return 1;
57 return 0;
61 * compare two delayed data backrefs with same bytenr and type
63 static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
64 struct btrfs_delayed_data_ref *ref1)
66 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
67 if (ref1->root < ref2->root)
68 return -1;
69 if (ref1->root > ref2->root)
70 return 1;
71 if (ref1->objectid < ref2->objectid)
72 return -1;
73 if (ref1->objectid > ref2->objectid)
74 return 1;
75 if (ref1->offset < ref2->offset)
76 return -1;
77 if (ref1->offset > ref2->offset)
78 return 1;
79 } else {
80 if (ref1->parent < ref2->parent)
81 return -1;
82 if (ref1->parent > ref2->parent)
83 return 1;
85 return 0;
88 /* insert a new ref to head ref rbtree */
89 static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
90 struct rb_node *node)
92 struct rb_node **p = &root->rb_node;
93 struct rb_node *parent_node = NULL;
94 struct btrfs_delayed_ref_head *entry;
95 struct btrfs_delayed_ref_head *ins;
96 u64 bytenr;
98 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
99 bytenr = ins->node.bytenr;
100 while (*p) {
101 parent_node = *p;
102 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
103 href_node);
105 if (bytenr < entry->node.bytenr)
106 p = &(*p)->rb_left;
107 else if (bytenr > entry->node.bytenr)
108 p = &(*p)->rb_right;
109 else
110 return entry;
113 rb_link_node(node, parent_node, p);
114 rb_insert_color(node, root);
115 return NULL;
119 * find an head entry based on bytenr. This returns the delayed ref
120 * head if it was able to find one, or NULL if nothing was in that spot.
121 * If return_bigger is given, the next bigger entry is returned if no exact
122 * match is found.
124 static struct btrfs_delayed_ref_head *
125 find_ref_head(struct rb_root *root, u64 bytenr,
126 int return_bigger)
128 struct rb_node *n;
129 struct btrfs_delayed_ref_head *entry;
131 n = root->rb_node;
132 entry = NULL;
133 while (n) {
134 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
136 if (bytenr < entry->node.bytenr)
137 n = n->rb_left;
138 else if (bytenr > entry->node.bytenr)
139 n = n->rb_right;
140 else
141 return entry;
143 if (entry && return_bigger) {
144 if (bytenr > entry->node.bytenr) {
145 n = rb_next(&entry->href_node);
146 if (!n)
147 n = rb_first(root);
148 entry = rb_entry(n, struct btrfs_delayed_ref_head,
149 href_node);
150 return entry;
152 return entry;
154 return NULL;
157 int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
158 struct btrfs_delayed_ref_head *head)
160 struct btrfs_delayed_ref_root *delayed_refs;
162 delayed_refs = &trans->transaction->delayed_refs;
163 assert_spin_locked(&delayed_refs->lock);
164 if (mutex_trylock(&head->mutex))
165 return 0;
167 refcount_inc(&head->node.refs);
168 spin_unlock(&delayed_refs->lock);
170 mutex_lock(&head->mutex);
171 spin_lock(&delayed_refs->lock);
172 if (!head->node.in_tree) {
173 mutex_unlock(&head->mutex);
174 btrfs_put_delayed_ref(&head->node);
175 return -EAGAIN;
177 btrfs_put_delayed_ref(&head->node);
178 return 0;
181 static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
182 struct btrfs_delayed_ref_root *delayed_refs,
183 struct btrfs_delayed_ref_head *head,
184 struct btrfs_delayed_ref_node *ref)
186 if (btrfs_delayed_ref_is_head(ref)) {
187 head = btrfs_delayed_node_to_head(ref);
188 rb_erase(&head->href_node, &delayed_refs->href_root);
189 } else {
190 assert_spin_locked(&head->lock);
191 list_del(&ref->list);
192 if (!list_empty(&ref->add_list))
193 list_del(&ref->add_list);
195 ref->in_tree = 0;
196 btrfs_put_delayed_ref(ref);
197 atomic_dec(&delayed_refs->num_entries);
200 static bool merge_ref(struct btrfs_trans_handle *trans,
201 struct btrfs_delayed_ref_root *delayed_refs,
202 struct btrfs_delayed_ref_head *head,
203 struct btrfs_delayed_ref_node *ref,
204 u64 seq)
206 struct btrfs_delayed_ref_node *next;
207 bool done = false;
209 next = list_first_entry(&head->ref_list, struct btrfs_delayed_ref_node,
210 list);
211 while (!done && &next->list != &head->ref_list) {
212 int mod;
213 struct btrfs_delayed_ref_node *next2;
215 next2 = list_next_entry(next, list);
217 if (next == ref)
218 goto next;
220 if (seq && next->seq >= seq)
221 goto next;
223 if (next->type != ref->type)
224 goto next;
226 if ((ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
227 ref->type == BTRFS_SHARED_BLOCK_REF_KEY) &&
228 comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref),
229 btrfs_delayed_node_to_tree_ref(next),
230 ref->type))
231 goto next;
232 if ((ref->type == BTRFS_EXTENT_DATA_REF_KEY ||
233 ref->type == BTRFS_SHARED_DATA_REF_KEY) &&
234 comp_data_refs(btrfs_delayed_node_to_data_ref(ref),
235 btrfs_delayed_node_to_data_ref(next)))
236 goto next;
238 if (ref->action == next->action) {
239 mod = next->ref_mod;
240 } else {
241 if (ref->ref_mod < next->ref_mod) {
242 swap(ref, next);
243 done = true;
245 mod = -next->ref_mod;
248 drop_delayed_ref(trans, delayed_refs, head, next);
249 ref->ref_mod += mod;
250 if (ref->ref_mod == 0) {
251 drop_delayed_ref(trans, delayed_refs, head, ref);
252 done = true;
253 } else {
255 * Can't have multiples of the same ref on a tree block.
257 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
258 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
260 next:
261 next = next2;
264 return done;
267 void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
268 struct btrfs_fs_info *fs_info,
269 struct btrfs_delayed_ref_root *delayed_refs,
270 struct btrfs_delayed_ref_head *head)
272 struct btrfs_delayed_ref_node *ref;
273 u64 seq = 0;
275 assert_spin_locked(&head->lock);
277 if (list_empty(&head->ref_list))
278 return;
280 /* We don't have too many refs to merge for data. */
281 if (head->is_data)
282 return;
284 read_lock(&fs_info->tree_mod_log_lock);
285 if (!list_empty(&fs_info->tree_mod_seq_list)) {
286 struct seq_list *elem;
288 elem = list_first_entry(&fs_info->tree_mod_seq_list,
289 struct seq_list, list);
290 seq = elem->seq;
292 read_unlock(&fs_info->tree_mod_log_lock);
294 ref = list_first_entry(&head->ref_list, struct btrfs_delayed_ref_node,
295 list);
296 while (&ref->list != &head->ref_list) {
297 if (seq && ref->seq >= seq)
298 goto next;
300 if (merge_ref(trans, delayed_refs, head, ref, seq)) {
301 if (list_empty(&head->ref_list))
302 break;
303 ref = list_first_entry(&head->ref_list,
304 struct btrfs_delayed_ref_node,
305 list);
306 continue;
308 next:
309 ref = list_next_entry(ref, list);
313 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
314 struct btrfs_delayed_ref_root *delayed_refs,
315 u64 seq)
317 struct seq_list *elem;
318 int ret = 0;
320 read_lock(&fs_info->tree_mod_log_lock);
321 if (!list_empty(&fs_info->tree_mod_seq_list)) {
322 elem = list_first_entry(&fs_info->tree_mod_seq_list,
323 struct seq_list, list);
324 if (seq >= elem->seq) {
325 btrfs_debug(fs_info,
326 "holding back delayed_ref %#x.%x, lowest is %#x.%x (%p)",
327 (u32)(seq >> 32), (u32)seq,
328 (u32)(elem->seq >> 32), (u32)elem->seq,
329 delayed_refs);
330 ret = 1;
334 read_unlock(&fs_info->tree_mod_log_lock);
335 return ret;
338 struct btrfs_delayed_ref_head *
339 btrfs_select_ref_head(struct btrfs_trans_handle *trans)
341 struct btrfs_delayed_ref_root *delayed_refs;
342 struct btrfs_delayed_ref_head *head;
343 u64 start;
344 bool loop = false;
346 delayed_refs = &trans->transaction->delayed_refs;
348 again:
349 start = delayed_refs->run_delayed_start;
350 head = find_ref_head(&delayed_refs->href_root, start, 1);
351 if (!head && !loop) {
352 delayed_refs->run_delayed_start = 0;
353 start = 0;
354 loop = true;
355 head = find_ref_head(&delayed_refs->href_root, start, 1);
356 if (!head)
357 return NULL;
358 } else if (!head && loop) {
359 return NULL;
362 while (head->processing) {
363 struct rb_node *node;
365 node = rb_next(&head->href_node);
366 if (!node) {
367 if (loop)
368 return NULL;
369 delayed_refs->run_delayed_start = 0;
370 start = 0;
371 loop = true;
372 goto again;
374 head = rb_entry(node, struct btrfs_delayed_ref_head,
375 href_node);
378 head->processing = 1;
379 WARN_ON(delayed_refs->num_heads_ready == 0);
380 delayed_refs->num_heads_ready--;
381 delayed_refs->run_delayed_start = head->node.bytenr +
382 head->node.num_bytes;
383 return head;
387 * Helper to insert the ref_node to the tail or merge with tail.
389 * Return 0 for insert.
390 * Return >0 for merge.
392 static int
393 add_delayed_ref_tail_merge(struct btrfs_trans_handle *trans,
394 struct btrfs_delayed_ref_root *root,
395 struct btrfs_delayed_ref_head *href,
396 struct btrfs_delayed_ref_node *ref)
398 struct btrfs_delayed_ref_node *exist;
399 int mod;
400 int ret = 0;
402 spin_lock(&href->lock);
403 /* Check whether we can merge the tail node with ref */
404 if (list_empty(&href->ref_list))
405 goto add_tail;
406 exist = list_entry(href->ref_list.prev, struct btrfs_delayed_ref_node,
407 list);
408 /* No need to compare bytenr nor is_head */
409 if (exist->type != ref->type || exist->seq != ref->seq)
410 goto add_tail;
412 if ((exist->type == BTRFS_TREE_BLOCK_REF_KEY ||
413 exist->type == BTRFS_SHARED_BLOCK_REF_KEY) &&
414 comp_tree_refs(btrfs_delayed_node_to_tree_ref(exist),
415 btrfs_delayed_node_to_tree_ref(ref),
416 ref->type))
417 goto add_tail;
418 if ((exist->type == BTRFS_EXTENT_DATA_REF_KEY ||
419 exist->type == BTRFS_SHARED_DATA_REF_KEY) &&
420 comp_data_refs(btrfs_delayed_node_to_data_ref(exist),
421 btrfs_delayed_node_to_data_ref(ref)))
422 goto add_tail;
424 /* Now we are sure we can merge */
425 ret = 1;
426 if (exist->action == ref->action) {
427 mod = ref->ref_mod;
428 } else {
429 /* Need to change action */
430 if (exist->ref_mod < ref->ref_mod) {
431 exist->action = ref->action;
432 mod = -exist->ref_mod;
433 exist->ref_mod = ref->ref_mod;
434 if (ref->action == BTRFS_ADD_DELAYED_REF)
435 list_add_tail(&exist->add_list,
436 &href->ref_add_list);
437 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
438 ASSERT(!list_empty(&exist->add_list));
439 list_del(&exist->add_list);
440 } else {
441 ASSERT(0);
443 } else
444 mod = -ref->ref_mod;
446 exist->ref_mod += mod;
448 /* remove existing tail if its ref_mod is zero */
449 if (exist->ref_mod == 0)
450 drop_delayed_ref(trans, root, href, exist);
451 spin_unlock(&href->lock);
452 return ret;
454 add_tail:
455 list_add_tail(&ref->list, &href->ref_list);
456 if (ref->action == BTRFS_ADD_DELAYED_REF)
457 list_add_tail(&ref->add_list, &href->ref_add_list);
458 atomic_inc(&root->num_entries);
459 spin_unlock(&href->lock);
460 return ret;
464 * helper function to update the accounting in the head ref
465 * existing and update must have the same bytenr
467 static noinline void
468 update_existing_head_ref(struct btrfs_delayed_ref_root *delayed_refs,
469 struct btrfs_delayed_ref_node *existing,
470 struct btrfs_delayed_ref_node *update,
471 int *old_ref_mod_ret)
473 struct btrfs_delayed_ref_head *existing_ref;
474 struct btrfs_delayed_ref_head *ref;
475 int old_ref_mod;
477 existing_ref = btrfs_delayed_node_to_head(existing);
478 ref = btrfs_delayed_node_to_head(update);
479 BUG_ON(existing_ref->is_data != ref->is_data);
481 spin_lock(&existing_ref->lock);
482 if (ref->must_insert_reserved) {
483 /* if the extent was freed and then
484 * reallocated before the delayed ref
485 * entries were processed, we can end up
486 * with an existing head ref without
487 * the must_insert_reserved flag set.
488 * Set it again here
490 existing_ref->must_insert_reserved = ref->must_insert_reserved;
493 * update the num_bytes so we make sure the accounting
494 * is done correctly
496 existing->num_bytes = update->num_bytes;
500 if (ref->extent_op) {
501 if (!existing_ref->extent_op) {
502 existing_ref->extent_op = ref->extent_op;
503 } else {
504 if (ref->extent_op->update_key) {
505 memcpy(&existing_ref->extent_op->key,
506 &ref->extent_op->key,
507 sizeof(ref->extent_op->key));
508 existing_ref->extent_op->update_key = true;
510 if (ref->extent_op->update_flags) {
511 existing_ref->extent_op->flags_to_set |=
512 ref->extent_op->flags_to_set;
513 existing_ref->extent_op->update_flags = true;
515 btrfs_free_delayed_extent_op(ref->extent_op);
519 * update the reference mod on the head to reflect this new operation,
520 * only need the lock for this case cause we could be processing it
521 * currently, for refs we just added we know we're a-ok.
523 old_ref_mod = existing_ref->total_ref_mod;
524 if (old_ref_mod_ret)
525 *old_ref_mod_ret = old_ref_mod;
526 existing->ref_mod += update->ref_mod;
527 existing_ref->total_ref_mod += update->ref_mod;
530 * If we are going to from a positive ref mod to a negative or vice
531 * versa we need to make sure to adjust pending_csums accordingly.
533 if (existing_ref->is_data) {
534 if (existing_ref->total_ref_mod >= 0 && old_ref_mod < 0)
535 delayed_refs->pending_csums -= existing->num_bytes;
536 if (existing_ref->total_ref_mod < 0 && old_ref_mod >= 0)
537 delayed_refs->pending_csums += existing->num_bytes;
539 spin_unlock(&existing_ref->lock);
543 * helper function to actually insert a head node into the rbtree.
544 * this does all the dirty work in terms of maintaining the correct
545 * overall modification count.
547 static noinline struct btrfs_delayed_ref_head *
548 add_delayed_ref_head(struct btrfs_fs_info *fs_info,
549 struct btrfs_trans_handle *trans,
550 struct btrfs_delayed_ref_node *ref,
551 struct btrfs_qgroup_extent_record *qrecord,
552 u64 bytenr, u64 num_bytes, u64 ref_root, u64 reserved,
553 int action, int is_data, int *qrecord_inserted_ret,
554 int *old_ref_mod, int *new_ref_mod)
556 struct btrfs_delayed_ref_head *existing;
557 struct btrfs_delayed_ref_head *head_ref = NULL;
558 struct btrfs_delayed_ref_root *delayed_refs;
559 int count_mod = 1;
560 int must_insert_reserved = 0;
561 int qrecord_inserted = 0;
563 /* If reserved is provided, it must be a data extent. */
564 BUG_ON(!is_data && reserved);
567 * the head node stores the sum of all the mods, so dropping a ref
568 * should drop the sum in the head node by one.
570 if (action == BTRFS_UPDATE_DELAYED_HEAD)
571 count_mod = 0;
572 else if (action == BTRFS_DROP_DELAYED_REF)
573 count_mod = -1;
576 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
577 * the reserved accounting when the extent is finally added, or
578 * if a later modification deletes the delayed ref without ever
579 * inserting the extent into the extent allocation tree.
580 * ref->must_insert_reserved is the flag used to record
581 * that accounting mods are required.
583 * Once we record must_insert_reserved, switch the action to
584 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
586 if (action == BTRFS_ADD_DELAYED_EXTENT)
587 must_insert_reserved = 1;
588 else
589 must_insert_reserved = 0;
591 delayed_refs = &trans->transaction->delayed_refs;
593 /* first set the basic ref node struct up */
594 refcount_set(&ref->refs, 1);
595 ref->bytenr = bytenr;
596 ref->num_bytes = num_bytes;
597 ref->ref_mod = count_mod;
598 ref->type = 0;
599 ref->action = 0;
600 ref->is_head = 1;
601 ref->in_tree = 1;
602 ref->seq = 0;
604 head_ref = btrfs_delayed_node_to_head(ref);
605 head_ref->must_insert_reserved = must_insert_reserved;
606 head_ref->is_data = is_data;
607 INIT_LIST_HEAD(&head_ref->ref_list);
608 INIT_LIST_HEAD(&head_ref->ref_add_list);
609 head_ref->processing = 0;
610 head_ref->total_ref_mod = count_mod;
611 head_ref->qgroup_reserved = 0;
612 head_ref->qgroup_ref_root = 0;
614 /* Record qgroup extent info if provided */
615 if (qrecord) {
616 if (ref_root && reserved) {
617 head_ref->qgroup_ref_root = ref_root;
618 head_ref->qgroup_reserved = reserved;
621 qrecord->bytenr = bytenr;
622 qrecord->num_bytes = num_bytes;
623 qrecord->old_roots = NULL;
625 if(btrfs_qgroup_trace_extent_nolock(fs_info,
626 delayed_refs, qrecord))
627 kfree(qrecord);
628 else
629 qrecord_inserted = 1;
632 spin_lock_init(&head_ref->lock);
633 mutex_init(&head_ref->mutex);
635 trace_add_delayed_ref_head(fs_info, ref, head_ref, action);
637 existing = htree_insert(&delayed_refs->href_root,
638 &head_ref->href_node);
639 if (existing) {
640 WARN_ON(ref_root && reserved && existing->qgroup_ref_root
641 && existing->qgroup_reserved);
642 update_existing_head_ref(delayed_refs, &existing->node, ref,
643 old_ref_mod);
645 * we've updated the existing ref, free the newly
646 * allocated ref
648 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
649 head_ref = existing;
650 } else {
651 if (old_ref_mod)
652 *old_ref_mod = 0;
653 if (is_data && count_mod < 0)
654 delayed_refs->pending_csums += num_bytes;
655 delayed_refs->num_heads++;
656 delayed_refs->num_heads_ready++;
657 atomic_inc(&delayed_refs->num_entries);
658 trans->delayed_ref_updates++;
660 if (qrecord_inserted_ret)
661 *qrecord_inserted_ret = qrecord_inserted;
662 if (new_ref_mod)
663 *new_ref_mod = head_ref->total_ref_mod;
664 return head_ref;
668 * helper to insert a delayed tree ref into the rbtree.
670 static noinline void
671 add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
672 struct btrfs_trans_handle *trans,
673 struct btrfs_delayed_ref_head *head_ref,
674 struct btrfs_delayed_ref_node *ref, u64 bytenr,
675 u64 num_bytes, u64 parent, u64 ref_root, int level,
676 int action)
678 struct btrfs_delayed_tree_ref *full_ref;
679 struct btrfs_delayed_ref_root *delayed_refs;
680 u64 seq = 0;
681 int ret;
683 if (action == BTRFS_ADD_DELAYED_EXTENT)
684 action = BTRFS_ADD_DELAYED_REF;
686 if (is_fstree(ref_root))
687 seq = atomic64_read(&fs_info->tree_mod_seq);
688 delayed_refs = &trans->transaction->delayed_refs;
690 /* first set the basic ref node struct up */
691 refcount_set(&ref->refs, 1);
692 ref->bytenr = bytenr;
693 ref->num_bytes = num_bytes;
694 ref->ref_mod = 1;
695 ref->action = action;
696 ref->is_head = 0;
697 ref->in_tree = 1;
698 ref->seq = seq;
699 INIT_LIST_HEAD(&ref->list);
700 INIT_LIST_HEAD(&ref->add_list);
702 full_ref = btrfs_delayed_node_to_tree_ref(ref);
703 full_ref->parent = parent;
704 full_ref->root = ref_root;
705 if (parent)
706 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
707 else
708 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
709 full_ref->level = level;
711 trace_add_delayed_tree_ref(fs_info, ref, full_ref, action);
713 ret = add_delayed_ref_tail_merge(trans, delayed_refs, head_ref, ref);
716 * XXX: memory should be freed at the same level allocated.
717 * But bad practice is anywhere... Follow it now. Need cleanup.
719 if (ret > 0)
720 kmem_cache_free(btrfs_delayed_tree_ref_cachep, full_ref);
724 * helper to insert a delayed data ref into the rbtree.
726 static noinline void
727 add_delayed_data_ref(struct btrfs_fs_info *fs_info,
728 struct btrfs_trans_handle *trans,
729 struct btrfs_delayed_ref_head *head_ref,
730 struct btrfs_delayed_ref_node *ref, u64 bytenr,
731 u64 num_bytes, u64 parent, u64 ref_root, u64 owner,
732 u64 offset, int action)
734 struct btrfs_delayed_data_ref *full_ref;
735 struct btrfs_delayed_ref_root *delayed_refs;
736 u64 seq = 0;
737 int ret;
739 if (action == BTRFS_ADD_DELAYED_EXTENT)
740 action = BTRFS_ADD_DELAYED_REF;
742 delayed_refs = &trans->transaction->delayed_refs;
744 if (is_fstree(ref_root))
745 seq = atomic64_read(&fs_info->tree_mod_seq);
747 /* first set the basic ref node struct up */
748 refcount_set(&ref->refs, 1);
749 ref->bytenr = bytenr;
750 ref->num_bytes = num_bytes;
751 ref->ref_mod = 1;
752 ref->action = action;
753 ref->is_head = 0;
754 ref->in_tree = 1;
755 ref->seq = seq;
756 INIT_LIST_HEAD(&ref->list);
757 INIT_LIST_HEAD(&ref->add_list);
759 full_ref = btrfs_delayed_node_to_data_ref(ref);
760 full_ref->parent = parent;
761 full_ref->root = ref_root;
762 if (parent)
763 ref->type = BTRFS_SHARED_DATA_REF_KEY;
764 else
765 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
767 full_ref->objectid = owner;
768 full_ref->offset = offset;
770 trace_add_delayed_data_ref(fs_info, ref, full_ref, action);
772 ret = add_delayed_ref_tail_merge(trans, delayed_refs, head_ref, ref);
774 if (ret > 0)
775 kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref);
779 * add a delayed tree ref. This does all of the accounting required
780 * to make sure the delayed ref is eventually processed before this
781 * transaction commits.
783 int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
784 struct btrfs_trans_handle *trans,
785 u64 bytenr, u64 num_bytes, u64 parent,
786 u64 ref_root, int level, int action,
787 struct btrfs_delayed_extent_op *extent_op,
788 int *old_ref_mod, int *new_ref_mod)
790 struct btrfs_delayed_tree_ref *ref;
791 struct btrfs_delayed_ref_head *head_ref;
792 struct btrfs_delayed_ref_root *delayed_refs;
793 struct btrfs_qgroup_extent_record *record = NULL;
794 int qrecord_inserted;
796 BUG_ON(extent_op && extent_op->is_data);
797 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
798 if (!ref)
799 return -ENOMEM;
801 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
802 if (!head_ref)
803 goto free_ref;
805 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
806 is_fstree(ref_root)) {
807 record = kmalloc(sizeof(*record), GFP_NOFS);
808 if (!record)
809 goto free_head_ref;
812 head_ref->extent_op = extent_op;
814 delayed_refs = &trans->transaction->delayed_refs;
815 spin_lock(&delayed_refs->lock);
818 * insert both the head node and the new ref without dropping
819 * the spin lock
821 head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record,
822 bytenr, num_bytes, 0, 0, action, 0,
823 &qrecord_inserted, old_ref_mod,
824 new_ref_mod);
826 add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr,
827 num_bytes, parent, ref_root, level, action);
828 spin_unlock(&delayed_refs->lock);
830 if (qrecord_inserted)
831 return btrfs_qgroup_trace_extent_post(fs_info, record);
832 return 0;
834 free_head_ref:
835 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
836 free_ref:
837 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
839 return -ENOMEM;
843 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
845 int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
846 struct btrfs_trans_handle *trans,
847 u64 bytenr, u64 num_bytes,
848 u64 parent, u64 ref_root,
849 u64 owner, u64 offset, u64 reserved, int action,
850 int *old_ref_mod, int *new_ref_mod)
852 struct btrfs_delayed_data_ref *ref;
853 struct btrfs_delayed_ref_head *head_ref;
854 struct btrfs_delayed_ref_root *delayed_refs;
855 struct btrfs_qgroup_extent_record *record = NULL;
856 int qrecord_inserted;
858 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
859 if (!ref)
860 return -ENOMEM;
862 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
863 if (!head_ref) {
864 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
865 return -ENOMEM;
868 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
869 is_fstree(ref_root)) {
870 record = kmalloc(sizeof(*record), GFP_NOFS);
871 if (!record) {
872 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
873 kmem_cache_free(btrfs_delayed_ref_head_cachep,
874 head_ref);
875 return -ENOMEM;
879 head_ref->extent_op = NULL;
881 delayed_refs = &trans->transaction->delayed_refs;
882 spin_lock(&delayed_refs->lock);
885 * insert both the head node and the new ref without dropping
886 * the spin lock
888 head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record,
889 bytenr, num_bytes, ref_root, reserved,
890 action, 1, &qrecord_inserted,
891 old_ref_mod, new_ref_mod);
893 add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr,
894 num_bytes, parent, ref_root, owner, offset,
895 action);
896 spin_unlock(&delayed_refs->lock);
898 if (qrecord_inserted)
899 return btrfs_qgroup_trace_extent_post(fs_info, record);
900 return 0;
903 int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
904 struct btrfs_trans_handle *trans,
905 u64 bytenr, u64 num_bytes,
906 struct btrfs_delayed_extent_op *extent_op)
908 struct btrfs_delayed_ref_head *head_ref;
909 struct btrfs_delayed_ref_root *delayed_refs;
911 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
912 if (!head_ref)
913 return -ENOMEM;
915 head_ref->extent_op = extent_op;
917 delayed_refs = &trans->transaction->delayed_refs;
918 spin_lock(&delayed_refs->lock);
920 add_delayed_ref_head(fs_info, trans, &head_ref->node, NULL, bytenr,
921 num_bytes, 0, 0, BTRFS_UPDATE_DELAYED_HEAD,
922 extent_op->is_data, NULL, NULL, NULL);
924 spin_unlock(&delayed_refs->lock);
925 return 0;
929 * this does a simple search for the head node for a given extent.
930 * It must be called with the delayed ref spinlock held, and it returns
931 * the head node if any where found, or NULL if not.
933 struct btrfs_delayed_ref_head *
934 btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
936 return find_ref_head(&delayed_refs->href_root, bytenr, 0);
939 void btrfs_delayed_ref_exit(void)
941 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
942 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
943 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
944 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
947 int btrfs_delayed_ref_init(void)
949 btrfs_delayed_ref_head_cachep = kmem_cache_create(
950 "btrfs_delayed_ref_head",
951 sizeof(struct btrfs_delayed_ref_head), 0,
952 SLAB_MEM_SPREAD, NULL);
953 if (!btrfs_delayed_ref_head_cachep)
954 goto fail;
956 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
957 "btrfs_delayed_tree_ref",
958 sizeof(struct btrfs_delayed_tree_ref), 0,
959 SLAB_MEM_SPREAD, NULL);
960 if (!btrfs_delayed_tree_ref_cachep)
961 goto fail;
963 btrfs_delayed_data_ref_cachep = kmem_cache_create(
964 "btrfs_delayed_data_ref",
965 sizeof(struct btrfs_delayed_data_ref), 0,
966 SLAB_MEM_SPREAD, NULL);
967 if (!btrfs_delayed_data_ref_cachep)
968 goto fail;
970 btrfs_delayed_extent_op_cachep = kmem_cache_create(
971 "btrfs_delayed_extent_op",
972 sizeof(struct btrfs_delayed_extent_op), 0,
973 SLAB_MEM_SPREAD, NULL);
974 if (!btrfs_delayed_extent_op_cachep)
975 goto fail;
977 return 0;
978 fail:
979 btrfs_delayed_ref_exit();
980 return -ENOMEM;