Merge tag 'affs-for-4.18-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...
[muen/linux.git] / fs / btrfs / delayed-ref.c
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
14 struct kmem_cache *btrfs_delayed_ref_head_cachep;
15 struct kmem_cache *btrfs_delayed_tree_ref_cachep;
16 struct kmem_cache *btrfs_delayed_data_ref_cachep;
17 struct 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  */
30 static 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  */
50 static 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
75 static 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 */
104 static 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
133 static 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  */
167 static struct btrfs_delayed_ref_head *
168 find_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
200 int 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
224 static 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
241 static 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
288 void 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
316 again:
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
326 int 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
351 struct btrfs_delayed_ref_head *
352 btrfs_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
361 again:
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  */
405 static 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;
448 inserted:
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  */
461 static noinline void
462 update_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  */
537 static noinline struct btrfs_delayed_ref_head *
538 add_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  */
654 static noinline void
655 add_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  */
710 static noinline void
711 add_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  */
766 int 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
819 free_head_ref:
820         kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
821 free_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  */
830 int 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
888 int 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  */
923 struct btrfs_delayed_ref_head *
924 btrfs_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
929 void __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
937 int __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;
968 fail:
969         btrfs_delayed_ref_exit();
970         return -ENOMEM;
971 }