Btrfs: rename the scrub context structure
[linux-3.10.git] / fs / btrfs / delayed-inode.c
1 /*
2  * Copyright (C) 2011 Fujitsu.  All rights reserved.
3  * Written by Miao Xie <miaox@cn.fujitsu.com>
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public
7  * License v2 as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public
15  * License along with this program; if not, write to the
16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17  * Boston, MA 021110-1307, USA.
18  */
19
20 #include <linux/slab.h>
21 #include "delayed-inode.h"
22 #include "disk-io.h"
23 #include "transaction.h"
24
25 #define BTRFS_DELAYED_WRITEBACK         400
26 #define BTRFS_DELAYED_BACKGROUND        100
27
28 static struct kmem_cache *delayed_node_cache;
29
30 int __init btrfs_delayed_inode_init(void)
31 {
32         delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
33                                         sizeof(struct btrfs_delayed_node),
34                                         0,
35                                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
36                                         NULL);
37         if (!delayed_node_cache)
38                 return -ENOMEM;
39         return 0;
40 }
41
42 void btrfs_delayed_inode_exit(void)
43 {
44         if (delayed_node_cache)
45                 kmem_cache_destroy(delayed_node_cache);
46 }
47
48 static inline void btrfs_init_delayed_node(
49                                 struct btrfs_delayed_node *delayed_node,
50                                 struct btrfs_root *root, u64 inode_id)
51 {
52         delayed_node->root = root;
53         delayed_node->inode_id = inode_id;
54         atomic_set(&delayed_node->refs, 0);
55         delayed_node->count = 0;
56         delayed_node->in_list = 0;
57         delayed_node->inode_dirty = 0;
58         delayed_node->ins_root = RB_ROOT;
59         delayed_node->del_root = RB_ROOT;
60         mutex_init(&delayed_node->mutex);
61         delayed_node->index_cnt = 0;
62         INIT_LIST_HEAD(&delayed_node->n_list);
63         INIT_LIST_HEAD(&delayed_node->p_list);
64         delayed_node->bytes_reserved = 0;
65         memset(&delayed_node->inode_item, 0, sizeof(delayed_node->inode_item));
66 }
67
68 static inline int btrfs_is_continuous_delayed_item(
69                                         struct btrfs_delayed_item *item1,
70                                         struct btrfs_delayed_item *item2)
71 {
72         if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
73             item1->key.objectid == item2->key.objectid &&
74             item1->key.type == item2->key.type &&
75             item1->key.offset + 1 == item2->key.offset)
76                 return 1;
77         return 0;
78 }
79
80 static inline struct btrfs_delayed_root *btrfs_get_delayed_root(
81                                                         struct btrfs_root *root)
82 {
83         return root->fs_info->delayed_root;
84 }
85
86 static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
87 {
88         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
89         struct btrfs_root *root = btrfs_inode->root;
90         u64 ino = btrfs_ino(inode);
91         struct btrfs_delayed_node *node;
92
93         node = ACCESS_ONCE(btrfs_inode->delayed_node);
94         if (node) {
95                 atomic_inc(&node->refs);
96                 return node;
97         }
98
99         spin_lock(&root->inode_lock);
100         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
101         if (node) {
102                 if (btrfs_inode->delayed_node) {
103                         atomic_inc(&node->refs);        /* can be accessed */
104                         BUG_ON(btrfs_inode->delayed_node != node);
105                         spin_unlock(&root->inode_lock);
106                         return node;
107                 }
108                 btrfs_inode->delayed_node = node;
109                 atomic_inc(&node->refs);        /* can be accessed */
110                 atomic_inc(&node->refs);        /* cached in the inode */
111                 spin_unlock(&root->inode_lock);
112                 return node;
113         }
114         spin_unlock(&root->inode_lock);
115
116         return NULL;
117 }
118
119 /* Will return either the node or PTR_ERR(-ENOMEM) */
120 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
121                                                         struct inode *inode)
122 {
123         struct btrfs_delayed_node *node;
124         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
125         struct btrfs_root *root = btrfs_inode->root;
126         u64 ino = btrfs_ino(inode);
127         int ret;
128
129 again:
130         node = btrfs_get_delayed_node(inode);
131         if (node)
132                 return node;
133
134         node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
135         if (!node)
136                 return ERR_PTR(-ENOMEM);
137         btrfs_init_delayed_node(node, root, ino);
138
139         atomic_inc(&node->refs);        /* cached in the btrfs inode */
140         atomic_inc(&node->refs);        /* can be accessed */
141
142         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
143         if (ret) {
144                 kmem_cache_free(delayed_node_cache, node);
145                 return ERR_PTR(ret);
146         }
147
148         spin_lock(&root->inode_lock);
149         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
150         if (ret == -EEXIST) {
151                 kmem_cache_free(delayed_node_cache, node);
152                 spin_unlock(&root->inode_lock);
153                 radix_tree_preload_end();
154                 goto again;
155         }
156         btrfs_inode->delayed_node = node;
157         spin_unlock(&root->inode_lock);
158         radix_tree_preload_end();
159
160         return node;
161 }
162
163 /*
164  * Call it when holding delayed_node->mutex
165  *
166  * If mod = 1, add this node into the prepared list.
167  */
168 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
169                                      struct btrfs_delayed_node *node,
170                                      int mod)
171 {
172         spin_lock(&root->lock);
173         if (node->in_list) {
174                 if (!list_empty(&node->p_list))
175                         list_move_tail(&node->p_list, &root->prepare_list);
176                 else if (mod)
177                         list_add_tail(&node->p_list, &root->prepare_list);
178         } else {
179                 list_add_tail(&node->n_list, &root->node_list);
180                 list_add_tail(&node->p_list, &root->prepare_list);
181                 atomic_inc(&node->refs);        /* inserted into list */
182                 root->nodes++;
183                 node->in_list = 1;
184         }
185         spin_unlock(&root->lock);
186 }
187
188 /* Call it when holding delayed_node->mutex */
189 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
190                                        struct btrfs_delayed_node *node)
191 {
192         spin_lock(&root->lock);
193         if (node->in_list) {
194                 root->nodes--;
195                 atomic_dec(&node->refs);        /* not in the list */
196                 list_del_init(&node->n_list);
197                 if (!list_empty(&node->p_list))
198                         list_del_init(&node->p_list);
199                 node->in_list = 0;
200         }
201         spin_unlock(&root->lock);
202 }
203
204 struct btrfs_delayed_node *btrfs_first_delayed_node(
205                         struct btrfs_delayed_root *delayed_root)
206 {
207         struct list_head *p;
208         struct btrfs_delayed_node *node = NULL;
209
210         spin_lock(&delayed_root->lock);
211         if (list_empty(&delayed_root->node_list))
212                 goto out;
213
214         p = delayed_root->node_list.next;
215         node = list_entry(p, struct btrfs_delayed_node, n_list);
216         atomic_inc(&node->refs);
217 out:
218         spin_unlock(&delayed_root->lock);
219
220         return node;
221 }
222
223 struct btrfs_delayed_node *btrfs_next_delayed_node(
224                                                 struct btrfs_delayed_node *node)
225 {
226         struct btrfs_delayed_root *delayed_root;
227         struct list_head *p;
228         struct btrfs_delayed_node *next = NULL;
229
230         delayed_root = node->root->fs_info->delayed_root;
231         spin_lock(&delayed_root->lock);
232         if (!node->in_list) {   /* not in the list */
233                 if (list_empty(&delayed_root->node_list))
234                         goto out;
235                 p = delayed_root->node_list.next;
236         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
237                 goto out;
238         else
239                 p = node->n_list.next;
240
241         next = list_entry(p, struct btrfs_delayed_node, n_list);
242         atomic_inc(&next->refs);
243 out:
244         spin_unlock(&delayed_root->lock);
245
246         return next;
247 }
248
249 static void __btrfs_release_delayed_node(
250                                 struct btrfs_delayed_node *delayed_node,
251                                 int mod)
252 {
253         struct btrfs_delayed_root *delayed_root;
254
255         if (!delayed_node)
256                 return;
257
258         delayed_root = delayed_node->root->fs_info->delayed_root;
259
260         mutex_lock(&delayed_node->mutex);
261         if (delayed_node->count)
262                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
263         else
264                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
265         mutex_unlock(&delayed_node->mutex);
266
267         if (atomic_dec_and_test(&delayed_node->refs)) {
268                 struct btrfs_root *root = delayed_node->root;
269                 spin_lock(&root->inode_lock);
270                 if (atomic_read(&delayed_node->refs) == 0) {
271                         radix_tree_delete(&root->delayed_nodes_tree,
272                                           delayed_node->inode_id);
273                         kmem_cache_free(delayed_node_cache, delayed_node);
274                 }
275                 spin_unlock(&root->inode_lock);
276         }
277 }
278
279 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
280 {
281         __btrfs_release_delayed_node(node, 0);
282 }
283
284 struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
285                                         struct btrfs_delayed_root *delayed_root)
286 {
287         struct list_head *p;
288         struct btrfs_delayed_node *node = NULL;
289
290         spin_lock(&delayed_root->lock);
291         if (list_empty(&delayed_root->prepare_list))
292                 goto out;
293
294         p = delayed_root->prepare_list.next;
295         list_del_init(p);
296         node = list_entry(p, struct btrfs_delayed_node, p_list);
297         atomic_inc(&node->refs);
298 out:
299         spin_unlock(&delayed_root->lock);
300
301         return node;
302 }
303
304 static inline void btrfs_release_prepared_delayed_node(
305                                         struct btrfs_delayed_node *node)
306 {
307         __btrfs_release_delayed_node(node, 1);
308 }
309
310 struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
311 {
312         struct btrfs_delayed_item *item;
313         item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
314         if (item) {
315                 item->data_len = data_len;
316                 item->ins_or_del = 0;
317                 item->bytes_reserved = 0;
318                 item->delayed_node = NULL;
319                 atomic_set(&item->refs, 1);
320         }
321         return item;
322 }
323
324 /*
325  * __btrfs_lookup_delayed_item - look up the delayed item by key
326  * @delayed_node: pointer to the delayed node
327  * @key:          the key to look up
328  * @prev:         used to store the prev item if the right item isn't found
329  * @next:         used to store the next item if the right item isn't found
330  *
331  * Note: if we don't find the right item, we will return the prev item and
332  * the next item.
333  */
334 static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
335                                 struct rb_root *root,
336                                 struct btrfs_key *key,
337                                 struct btrfs_delayed_item **prev,
338                                 struct btrfs_delayed_item **next)
339 {
340         struct rb_node *node, *prev_node = NULL;
341         struct btrfs_delayed_item *delayed_item = NULL;
342         int ret = 0;
343
344         node = root->rb_node;
345
346         while (node) {
347                 delayed_item = rb_entry(node, struct btrfs_delayed_item,
348                                         rb_node);
349                 prev_node = node;
350                 ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
351                 if (ret < 0)
352                         node = node->rb_right;
353                 else if (ret > 0)
354                         node = node->rb_left;
355                 else
356                         return delayed_item;
357         }
358
359         if (prev) {
360                 if (!prev_node)
361                         *prev = NULL;
362                 else if (ret < 0)
363                         *prev = delayed_item;
364                 else if ((node = rb_prev(prev_node)) != NULL) {
365                         *prev = rb_entry(node, struct btrfs_delayed_item,
366                                          rb_node);
367                 } else
368                         *prev = NULL;
369         }
370
371         if (next) {
372                 if (!prev_node)
373                         *next = NULL;
374                 else if (ret > 0)
375                         *next = delayed_item;
376                 else if ((node = rb_next(prev_node)) != NULL) {
377                         *next = rb_entry(node, struct btrfs_delayed_item,
378                                          rb_node);
379                 } else
380                         *next = NULL;
381         }
382         return NULL;
383 }
384
385 struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
386                                         struct btrfs_delayed_node *delayed_node,
387                                         struct btrfs_key *key)
388 {
389         struct btrfs_delayed_item *item;
390
391         item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
392                                            NULL, NULL);
393         return item;
394 }
395
396 struct btrfs_delayed_item *__btrfs_lookup_delayed_deletion_item(
397                                         struct btrfs_delayed_node *delayed_node,
398                                         struct btrfs_key *key)
399 {
400         struct btrfs_delayed_item *item;
401
402         item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
403                                            NULL, NULL);
404         return item;
405 }
406
407 struct btrfs_delayed_item *__btrfs_search_delayed_insertion_item(
408                                         struct btrfs_delayed_node *delayed_node,
409                                         struct btrfs_key *key)
410 {
411         struct btrfs_delayed_item *item, *next;
412
413         item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
414                                            NULL, &next);
415         if (!item)
416                 item = next;
417
418         return item;
419 }
420
421 struct btrfs_delayed_item *__btrfs_search_delayed_deletion_item(
422                                         struct btrfs_delayed_node *delayed_node,
423                                         struct btrfs_key *key)
424 {
425         struct btrfs_delayed_item *item, *next;
426
427         item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
428                                            NULL, &next);
429         if (!item)
430                 item = next;
431
432         return item;
433 }
434
435 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
436                                     struct btrfs_delayed_item *ins,
437                                     int action)
438 {
439         struct rb_node **p, *node;
440         struct rb_node *parent_node = NULL;
441         struct rb_root *root;
442         struct btrfs_delayed_item *item;
443         int cmp;
444
445         if (action == BTRFS_DELAYED_INSERTION_ITEM)
446                 root = &delayed_node->ins_root;
447         else if (action == BTRFS_DELAYED_DELETION_ITEM)
448                 root = &delayed_node->del_root;
449         else
450                 BUG();
451         p = &root->rb_node;
452         node = &ins->rb_node;
453
454         while (*p) {
455                 parent_node = *p;
456                 item = rb_entry(parent_node, struct btrfs_delayed_item,
457                                  rb_node);
458
459                 cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
460                 if (cmp < 0)
461                         p = &(*p)->rb_right;
462                 else if (cmp > 0)
463                         p = &(*p)->rb_left;
464                 else
465                         return -EEXIST;
466         }
467
468         rb_link_node(node, parent_node, p);
469         rb_insert_color(node, root);
470         ins->delayed_node = delayed_node;
471         ins->ins_or_del = action;
472
473         if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
474             action == BTRFS_DELAYED_INSERTION_ITEM &&
475             ins->key.offset >= delayed_node->index_cnt)
476                         delayed_node->index_cnt = ins->key.offset + 1;
477
478         delayed_node->count++;
479         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
480         return 0;
481 }
482
483 static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
484                                               struct btrfs_delayed_item *item)
485 {
486         return __btrfs_add_delayed_item(node, item,
487                                         BTRFS_DELAYED_INSERTION_ITEM);
488 }
489
490 static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
491                                              struct btrfs_delayed_item *item)
492 {
493         return __btrfs_add_delayed_item(node, item,
494                                         BTRFS_DELAYED_DELETION_ITEM);
495 }
496
497 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
498 {
499         struct rb_root *root;
500         struct btrfs_delayed_root *delayed_root;
501
502         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
503
504         BUG_ON(!delayed_root);
505         BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
506                delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
507
508         if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
509                 root = &delayed_item->delayed_node->ins_root;
510         else
511                 root = &delayed_item->delayed_node->del_root;
512
513         rb_erase(&delayed_item->rb_node, root);
514         delayed_item->delayed_node->count--;
515         if (atomic_dec_return(&delayed_root->items) <
516             BTRFS_DELAYED_BACKGROUND &&
517             waitqueue_active(&delayed_root->wait))
518                 wake_up(&delayed_root->wait);
519 }
520
521 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
522 {
523         if (item) {
524                 __btrfs_remove_delayed_item(item);
525                 if (atomic_dec_and_test(&item->refs))
526                         kfree(item);
527         }
528 }
529
530 struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
531                                         struct btrfs_delayed_node *delayed_node)
532 {
533         struct rb_node *p;
534         struct btrfs_delayed_item *item = NULL;
535
536         p = rb_first(&delayed_node->ins_root);
537         if (p)
538                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
539
540         return item;
541 }
542
543 struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
544                                         struct btrfs_delayed_node *delayed_node)
545 {
546         struct rb_node *p;
547         struct btrfs_delayed_item *item = NULL;
548
549         p = rb_first(&delayed_node->del_root);
550         if (p)
551                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
552
553         return item;
554 }
555
556 struct btrfs_delayed_item *__btrfs_next_delayed_item(
557                                                 struct btrfs_delayed_item *item)
558 {
559         struct rb_node *p;
560         struct btrfs_delayed_item *next = NULL;
561
562         p = rb_next(&item->rb_node);
563         if (p)
564                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
565
566         return next;
567 }
568
569 static inline struct btrfs_root *btrfs_get_fs_root(struct btrfs_root *root,
570                                                    u64 root_id)
571 {
572         struct btrfs_key root_key;
573
574         if (root->objectid == root_id)
575                 return root;
576
577         root_key.objectid = root_id;
578         root_key.type = BTRFS_ROOT_ITEM_KEY;
579         root_key.offset = (u64)-1;
580         return btrfs_read_fs_root_no_name(root->fs_info, &root_key);
581 }
582
583 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
584                                                struct btrfs_root *root,
585                                                struct btrfs_delayed_item *item)
586 {
587         struct btrfs_block_rsv *src_rsv;
588         struct btrfs_block_rsv *dst_rsv;
589         u64 num_bytes;
590         int ret;
591
592         if (!trans->bytes_reserved)
593                 return 0;
594
595         src_rsv = trans->block_rsv;
596         dst_rsv = &root->fs_info->delayed_block_rsv;
597
598         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
599         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
600         if (!ret) {
601                 trace_btrfs_space_reservation(root->fs_info, "delayed_item",
602                                               item->key.objectid,
603                                               num_bytes, 1);
604                 item->bytes_reserved = num_bytes;
605         }
606
607         return ret;
608 }
609
610 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
611                                                 struct btrfs_delayed_item *item)
612 {
613         struct btrfs_block_rsv *rsv;
614
615         if (!item->bytes_reserved)
616                 return;
617
618         rsv = &root->fs_info->delayed_block_rsv;
619         trace_btrfs_space_reservation(root->fs_info, "delayed_item",
620                                       item->key.objectid, item->bytes_reserved,
621                                       0);
622         btrfs_block_rsv_release(root, rsv,
623                                 item->bytes_reserved);
624 }
625
626 static int btrfs_delayed_inode_reserve_metadata(
627                                         struct btrfs_trans_handle *trans,
628                                         struct btrfs_root *root,
629                                         struct inode *inode,
630                                         struct btrfs_delayed_node *node)
631 {
632         struct btrfs_block_rsv *src_rsv;
633         struct btrfs_block_rsv *dst_rsv;
634         u64 num_bytes;
635         int ret;
636         bool release = false;
637
638         src_rsv = trans->block_rsv;
639         dst_rsv = &root->fs_info->delayed_block_rsv;
640
641         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
642
643         /*
644          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
645          * which doesn't reserve space for speed.  This is a problem since we
646          * still need to reserve space for this update, so try to reserve the
647          * space.
648          *
649          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
650          * we're accounted for.
651          */
652         if (!src_rsv || (!trans->bytes_reserved &&
653                          src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
654                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
655                                           BTRFS_RESERVE_NO_FLUSH);
656                 /*
657                  * Since we're under a transaction reserve_metadata_bytes could
658                  * try to commit the transaction which will make it return
659                  * EAGAIN to make us stop the transaction we have, so return
660                  * ENOSPC instead so that btrfs_dirty_inode knows what to do.
661                  */
662                 if (ret == -EAGAIN)
663                         ret = -ENOSPC;
664                 if (!ret) {
665                         node->bytes_reserved = num_bytes;
666                         trace_btrfs_space_reservation(root->fs_info,
667                                                       "delayed_inode",
668                                                       btrfs_ino(inode),
669                                                       num_bytes, 1);
670                 }
671                 return ret;
672         } else if (src_rsv->type == BTRFS_BLOCK_RSV_DELALLOC) {
673                 spin_lock(&BTRFS_I(inode)->lock);
674                 if (test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
675                                        &BTRFS_I(inode)->runtime_flags)) {
676                         spin_unlock(&BTRFS_I(inode)->lock);
677                         release = true;
678                         goto migrate;
679                 }
680                 spin_unlock(&BTRFS_I(inode)->lock);
681
682                 /* Ok we didn't have space pre-reserved.  This shouldn't happen
683                  * too often but it can happen if we do delalloc to an existing
684                  * inode which gets dirtied because of the time update, and then
685                  * isn't touched again until after the transaction commits and
686                  * then we try to write out the data.  First try to be nice and
687                  * reserve something strictly for us.  If not be a pain and try
688                  * to steal from the delalloc block rsv.
689                  */
690                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
691                                           BTRFS_RESERVE_NO_FLUSH);
692                 if (!ret)
693                         goto out;
694
695                 ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
696                 if (!ret)
697                         goto out;
698
699                 /*
700                  * Ok this is a problem, let's just steal from the global rsv
701                  * since this really shouldn't happen that often.
702                  */
703                 WARN_ON(1);
704                 ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
705                                               dst_rsv, num_bytes);
706                 goto out;
707         }
708
709 migrate:
710         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
711
712 out:
713         /*
714          * Migrate only takes a reservation, it doesn't touch the size of the
715          * block_rsv.  This is to simplify people who don't normally have things
716          * migrated from their block rsv.  If they go to release their
717          * reservation, that will decrease the size as well, so if migrate
718          * reduced size we'd end up with a negative size.  But for the
719          * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
720          * but we could in fact do this reserve/migrate dance several times
721          * between the time we did the original reservation and we'd clean it
722          * up.  So to take care of this, release the space for the meta
723          * reservation here.  I think it may be time for a documentation page on
724          * how block rsvs. work.
725          */
726         if (!ret) {
727                 trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
728                                               btrfs_ino(inode), num_bytes, 1);
729                 node->bytes_reserved = num_bytes;
730         }
731
732         if (release) {
733                 trace_btrfs_space_reservation(root->fs_info, "delalloc",
734                                               btrfs_ino(inode), num_bytes, 0);
735                 btrfs_block_rsv_release(root, src_rsv, num_bytes);
736         }
737
738         return ret;
739 }
740
741 static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
742                                                 struct btrfs_delayed_node *node)
743 {
744         struct btrfs_block_rsv *rsv;
745
746         if (!node->bytes_reserved)
747                 return;
748
749         rsv = &root->fs_info->delayed_block_rsv;
750         trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
751                                       node->inode_id, node->bytes_reserved, 0);
752         btrfs_block_rsv_release(root, rsv,
753                                 node->bytes_reserved);
754         node->bytes_reserved = 0;
755 }
756
757 /*
758  * This helper will insert some continuous items into the same leaf according
759  * to the free space of the leaf.
760  */
761 static int btrfs_batch_insert_items(struct btrfs_trans_handle *trans,
762                                 struct btrfs_root *root,
763                                 struct btrfs_path *path,
764                                 struct btrfs_delayed_item *item)
765 {
766         struct btrfs_delayed_item *curr, *next;
767         int free_space;
768         int total_data_size = 0, total_size = 0;
769         struct extent_buffer *leaf;
770         char *data_ptr;
771         struct btrfs_key *keys;
772         u32 *data_size;
773         struct list_head head;
774         int slot;
775         int nitems;
776         int i;
777         int ret = 0;
778
779         BUG_ON(!path->nodes[0]);
780
781         leaf = path->nodes[0];
782         free_space = btrfs_leaf_free_space(root, leaf);
783         INIT_LIST_HEAD(&head);
784
785         next = item;
786         nitems = 0;
787
788         /*
789          * count the number of the continuous items that we can insert in batch
790          */
791         while (total_size + next->data_len + sizeof(struct btrfs_item) <=
792                free_space) {
793                 total_data_size += next->data_len;
794                 total_size += next->data_len + sizeof(struct btrfs_item);
795                 list_add_tail(&next->tree_list, &head);
796                 nitems++;
797
798                 curr = next;
799                 next = __btrfs_next_delayed_item(curr);
800                 if (!next)
801                         break;
802
803                 if (!btrfs_is_continuous_delayed_item(curr, next))
804                         break;
805         }
806
807         if (!nitems) {
808                 ret = 0;
809                 goto out;
810         }
811
812         /*
813          * we need allocate some memory space, but it might cause the task
814          * to sleep, so we set all locked nodes in the path to blocking locks
815          * first.
816          */
817         btrfs_set_path_blocking(path);
818
819         keys = kmalloc(sizeof(struct btrfs_key) * nitems, GFP_NOFS);
820         if (!keys) {
821                 ret = -ENOMEM;
822                 goto out;
823         }
824
825         data_size = kmalloc(sizeof(u32) * nitems, GFP_NOFS);
826         if (!data_size) {
827                 ret = -ENOMEM;
828                 goto error;
829         }
830
831         /* get keys of all the delayed items */
832         i = 0;
833         list_for_each_entry(next, &head, tree_list) {
834                 keys[i] = next->key;
835                 data_size[i] = next->data_len;
836                 i++;
837         }
838
839         /* reset all the locked nodes in the patch to spinning locks. */
840         btrfs_clear_path_blocking(path, NULL, 0);
841
842         /* insert the keys of the items */
843         setup_items_for_insert(trans, root, path, keys, data_size,
844                                total_data_size, total_size, nitems);
845
846         /* insert the dir index items */
847         slot = path->slots[0];
848         list_for_each_entry_safe(curr, next, &head, tree_list) {
849                 data_ptr = btrfs_item_ptr(leaf, slot, char);
850                 write_extent_buffer(leaf, &curr->data,
851                                     (unsigned long)data_ptr,
852                                     curr->data_len);
853                 slot++;
854
855                 btrfs_delayed_item_release_metadata(root, curr);
856
857                 list_del(&curr->tree_list);
858                 btrfs_release_delayed_item(curr);
859         }
860
861 error:
862         kfree(data_size);
863         kfree(keys);
864 out:
865         return ret;
866 }
867
868 /*
869  * This helper can just do simple insertion that needn't extend item for new
870  * data, such as directory name index insertion, inode insertion.
871  */
872 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
873                                      struct btrfs_root *root,
874                                      struct btrfs_path *path,
875                                      struct btrfs_delayed_item *delayed_item)
876 {
877         struct extent_buffer *leaf;
878         struct btrfs_item *item;
879         char *ptr;
880         int ret;
881
882         ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
883                                       delayed_item->data_len);
884         if (ret < 0 && ret != -EEXIST)
885                 return ret;
886
887         leaf = path->nodes[0];
888
889         item = btrfs_item_nr(leaf, path->slots[0]);
890         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
891
892         write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
893                             delayed_item->data_len);
894         btrfs_mark_buffer_dirty(leaf);
895
896         btrfs_delayed_item_release_metadata(root, delayed_item);
897         return 0;
898 }
899
900 /*
901  * we insert an item first, then if there are some continuous items, we try
902  * to insert those items into the same leaf.
903  */
904 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
905                                       struct btrfs_path *path,
906                                       struct btrfs_root *root,
907                                       struct btrfs_delayed_node *node)
908 {
909         struct btrfs_delayed_item *curr, *prev;
910         int ret = 0;
911
912 do_again:
913         mutex_lock(&node->mutex);
914         curr = __btrfs_first_delayed_insertion_item(node);
915         if (!curr)
916                 goto insert_end;
917
918         ret = btrfs_insert_delayed_item(trans, root, path, curr);
919         if (ret < 0) {
920                 btrfs_release_path(path);
921                 goto insert_end;
922         }
923
924         prev = curr;
925         curr = __btrfs_next_delayed_item(prev);
926         if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
927                 /* insert the continuous items into the same leaf */
928                 path->slots[0]++;
929                 btrfs_batch_insert_items(trans, root, path, curr);
930         }
931         btrfs_release_delayed_item(prev);
932         btrfs_mark_buffer_dirty(path->nodes[0]);
933
934         btrfs_release_path(path);
935         mutex_unlock(&node->mutex);
936         goto do_again;
937
938 insert_end:
939         mutex_unlock(&node->mutex);
940         return ret;
941 }
942
943 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
944                                     struct btrfs_root *root,
945                                     struct btrfs_path *path,
946                                     struct btrfs_delayed_item *item)
947 {
948         struct btrfs_delayed_item *curr, *next;
949         struct extent_buffer *leaf;
950         struct btrfs_key key;
951         struct list_head head;
952         int nitems, i, last_item;
953         int ret = 0;
954
955         BUG_ON(!path->nodes[0]);
956
957         leaf = path->nodes[0];
958
959         i = path->slots[0];
960         last_item = btrfs_header_nritems(leaf) - 1;
961         if (i > last_item)
962                 return -ENOENT; /* FIXME: Is errno suitable? */
963
964         next = item;
965         INIT_LIST_HEAD(&head);
966         btrfs_item_key_to_cpu(leaf, &key, i);
967         nitems = 0;
968         /*
969          * count the number of the dir index items that we can delete in batch
970          */
971         while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
972                 list_add_tail(&next->tree_list, &head);
973                 nitems++;
974
975                 curr = next;
976                 next = __btrfs_next_delayed_item(curr);
977                 if (!next)
978                         break;
979
980                 if (!btrfs_is_continuous_delayed_item(curr, next))
981                         break;
982
983                 i++;
984                 if (i > last_item)
985                         break;
986                 btrfs_item_key_to_cpu(leaf, &key, i);
987         }
988
989         if (!nitems)
990                 return 0;
991
992         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
993         if (ret)
994                 goto out;
995
996         list_for_each_entry_safe(curr, next, &head, tree_list) {
997                 btrfs_delayed_item_release_metadata(root, curr);
998                 list_del(&curr->tree_list);
999                 btrfs_release_delayed_item(curr);
1000         }
1001
1002 out:
1003         return ret;
1004 }
1005
1006 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
1007                                       struct btrfs_path *path,
1008                                       struct btrfs_root *root,
1009                                       struct btrfs_delayed_node *node)
1010 {
1011         struct btrfs_delayed_item *curr, *prev;
1012         int ret = 0;
1013
1014 do_again:
1015         mutex_lock(&node->mutex);
1016         curr = __btrfs_first_delayed_deletion_item(node);
1017         if (!curr)
1018                 goto delete_fail;
1019
1020         ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
1021         if (ret < 0)
1022                 goto delete_fail;
1023         else if (ret > 0) {
1024                 /*
1025                  * can't find the item which the node points to, so this node
1026                  * is invalid, just drop it.
1027                  */
1028                 prev = curr;
1029                 curr = __btrfs_next_delayed_item(prev);
1030                 btrfs_release_delayed_item(prev);
1031                 ret = 0;
1032                 btrfs_release_path(path);
1033                 if (curr) {
1034                         mutex_unlock(&node->mutex);
1035                         goto do_again;
1036                 } else
1037                         goto delete_fail;
1038         }
1039
1040         btrfs_batch_delete_items(trans, root, path, curr);
1041         btrfs_release_path(path);
1042         mutex_unlock(&node->mutex);
1043         goto do_again;
1044
1045 delete_fail:
1046         btrfs_release_path(path);
1047         mutex_unlock(&node->mutex);
1048         return ret;
1049 }
1050
1051 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
1052 {
1053         struct btrfs_delayed_root *delayed_root;
1054
1055         if (delayed_node && delayed_node->inode_dirty) {
1056                 BUG_ON(!delayed_node->root);
1057                 delayed_node->inode_dirty = 0;
1058                 delayed_node->count--;
1059
1060                 delayed_root = delayed_node->root->fs_info->delayed_root;
1061                 if (atomic_dec_return(&delayed_root->items) <
1062                     BTRFS_DELAYED_BACKGROUND &&
1063                     waitqueue_active(&delayed_root->wait))
1064                         wake_up(&delayed_root->wait);
1065         }
1066 }
1067
1068 static int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1069                                       struct btrfs_root *root,
1070                                       struct btrfs_path *path,
1071                                       struct btrfs_delayed_node *node)
1072 {
1073         struct btrfs_key key;
1074         struct btrfs_inode_item *inode_item;
1075         struct extent_buffer *leaf;
1076         int ret;
1077
1078         mutex_lock(&node->mutex);
1079         if (!node->inode_dirty) {
1080                 mutex_unlock(&node->mutex);
1081                 return 0;
1082         }
1083
1084         key.objectid = node->inode_id;
1085         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1086         key.offset = 0;
1087         ret = btrfs_lookup_inode(trans, root, path, &key, 1);
1088         if (ret > 0) {
1089                 btrfs_release_path(path);
1090                 mutex_unlock(&node->mutex);
1091                 return -ENOENT;
1092         } else if (ret < 0) {
1093                 mutex_unlock(&node->mutex);
1094                 return ret;
1095         }
1096
1097         btrfs_unlock_up_safe(path, 1);
1098         leaf = path->nodes[0];
1099         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1100                                     struct btrfs_inode_item);
1101         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1102                             sizeof(struct btrfs_inode_item));
1103         btrfs_mark_buffer_dirty(leaf);
1104         btrfs_release_path(path);
1105
1106         btrfs_delayed_inode_release_metadata(root, node);
1107         btrfs_release_delayed_inode(node);
1108         mutex_unlock(&node->mutex);
1109
1110         return 0;
1111 }
1112
1113 /*
1114  * Called when committing the transaction.
1115  * Returns 0 on success.
1116  * Returns < 0 on error and returns with an aborted transaction with any
1117  * outstanding delayed items cleaned up.
1118  */
1119 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1120                                      struct btrfs_root *root, int nr)
1121 {
1122         struct btrfs_root *curr_root = root;
1123         struct btrfs_delayed_root *delayed_root;
1124         struct btrfs_delayed_node *curr_node, *prev_node;
1125         struct btrfs_path *path;
1126         struct btrfs_block_rsv *block_rsv;
1127         int ret = 0;
1128         bool count = (nr > 0);
1129
1130         if (trans->aborted)
1131                 return -EIO;
1132
1133         path = btrfs_alloc_path();
1134         if (!path)
1135                 return -ENOMEM;
1136         path->leave_spinning = 1;
1137
1138         block_rsv = trans->block_rsv;
1139         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1140
1141         delayed_root = btrfs_get_delayed_root(root);
1142
1143         curr_node = btrfs_first_delayed_node(delayed_root);
1144         while (curr_node && (!count || (count && nr--))) {
1145                 curr_root = curr_node->root;
1146                 ret = btrfs_insert_delayed_items(trans, path, curr_root,
1147                                                  curr_node);
1148                 if (!ret)
1149                         ret = btrfs_delete_delayed_items(trans, path,
1150                                                 curr_root, curr_node);
1151                 if (!ret)
1152                         ret = btrfs_update_delayed_inode(trans, curr_root,
1153                                                 path, curr_node);
1154                 if (ret) {
1155                         btrfs_release_delayed_node(curr_node);
1156                         curr_node = NULL;
1157                         btrfs_abort_transaction(trans, root, ret);
1158                         break;
1159                 }
1160
1161                 prev_node = curr_node;
1162                 curr_node = btrfs_next_delayed_node(curr_node);
1163                 btrfs_release_delayed_node(prev_node);
1164         }
1165
1166         if (curr_node)
1167                 btrfs_release_delayed_node(curr_node);
1168         btrfs_free_path(path);
1169         trans->block_rsv = block_rsv;
1170
1171         return ret;
1172 }
1173
1174 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1175                             struct btrfs_root *root)
1176 {
1177         return __btrfs_run_delayed_items(trans, root, -1);
1178 }
1179
1180 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans,
1181                                struct btrfs_root *root, int nr)
1182 {
1183         return __btrfs_run_delayed_items(trans, root, nr);
1184 }
1185
1186 static int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1187                                               struct btrfs_delayed_node *node)
1188 {
1189         struct btrfs_path *path;
1190         struct btrfs_block_rsv *block_rsv;
1191         int ret;
1192
1193         path = btrfs_alloc_path();
1194         if (!path)
1195                 return -ENOMEM;
1196         path->leave_spinning = 1;
1197
1198         block_rsv = trans->block_rsv;
1199         trans->block_rsv = &node->root->fs_info->delayed_block_rsv;
1200
1201         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1202         if (!ret)
1203                 ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1204         if (!ret)
1205                 ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1206         btrfs_free_path(path);
1207
1208         trans->block_rsv = block_rsv;
1209         return ret;
1210 }
1211
1212 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1213                                      struct inode *inode)
1214 {
1215         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1216         int ret;
1217
1218         if (!delayed_node)
1219                 return 0;
1220
1221         mutex_lock(&delayed_node->mutex);
1222         if (!delayed_node->count) {
1223                 mutex_unlock(&delayed_node->mutex);
1224                 btrfs_release_delayed_node(delayed_node);
1225                 return 0;
1226         }
1227         mutex_unlock(&delayed_node->mutex);
1228
1229         ret = __btrfs_commit_inode_delayed_items(trans, delayed_node);
1230         btrfs_release_delayed_node(delayed_node);
1231         return ret;
1232 }
1233
1234 void btrfs_remove_delayed_node(struct inode *inode)
1235 {
1236         struct btrfs_delayed_node *delayed_node;
1237
1238         delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1239         if (!delayed_node)
1240                 return;
1241
1242         BTRFS_I(inode)->delayed_node = NULL;
1243         btrfs_release_delayed_node(delayed_node);
1244 }
1245
1246 struct btrfs_async_delayed_node {
1247         struct btrfs_root *root;
1248         struct btrfs_delayed_node *delayed_node;
1249         struct btrfs_work work;
1250 };
1251
1252 static void btrfs_async_run_delayed_node_done(struct btrfs_work *work)
1253 {
1254         struct btrfs_async_delayed_node *async_node;
1255         struct btrfs_trans_handle *trans;
1256         struct btrfs_path *path;
1257         struct btrfs_delayed_node *delayed_node = NULL;
1258         struct btrfs_root *root;
1259         struct btrfs_block_rsv *block_rsv;
1260         int need_requeue = 0;
1261         int ret;
1262
1263         async_node = container_of(work, struct btrfs_async_delayed_node, work);
1264
1265         path = btrfs_alloc_path();
1266         if (!path)
1267                 goto out;
1268         path->leave_spinning = 1;
1269
1270         delayed_node = async_node->delayed_node;
1271         root = delayed_node->root;
1272
1273         trans = btrfs_join_transaction(root);
1274         if (IS_ERR(trans))
1275                 goto free_path;
1276
1277         block_rsv = trans->block_rsv;
1278         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1279
1280         ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
1281         if (!ret)
1282                 ret = btrfs_delete_delayed_items(trans, path, root,
1283                                                  delayed_node);
1284
1285         if (!ret)
1286                 btrfs_update_delayed_inode(trans, root, path, delayed_node);
1287
1288         /*
1289          * Maybe new delayed items have been inserted, so we need requeue
1290          * the work. Besides that, we must dequeue the empty delayed nodes
1291          * to avoid the race between delayed items balance and the worker.
1292          * The race like this:
1293          *      Task1                           Worker thread
1294          *                                      count == 0, needn't requeue
1295          *                                        also needn't insert the
1296          *                                        delayed node into prepare
1297          *                                        list again.
1298          *      add lots of delayed items
1299          *      queue the delayed node
1300          *        already in the list,
1301          *        and not in the prepare
1302          *        list, it means the delayed
1303          *        node is being dealt with
1304          *        by the worker.
1305          *      do delayed items balance
1306          *        the delayed node is being
1307          *        dealt with by the worker
1308          *        now, just wait.
1309          *                                      the worker goto idle.
1310          * Task1 will sleep until the transaction is commited.
1311          */
1312         mutex_lock(&delayed_node->mutex);
1313         if (delayed_node->count)
1314                 need_requeue = 1;
1315         else
1316                 btrfs_dequeue_delayed_node(root->fs_info->delayed_root,
1317                                            delayed_node);
1318         mutex_unlock(&delayed_node->mutex);
1319
1320         trans->block_rsv = block_rsv;
1321         btrfs_end_transaction_dmeta(trans, root);
1322         btrfs_btree_balance_dirty_nodelay(root);
1323 free_path:
1324         btrfs_free_path(path);
1325 out:
1326         if (need_requeue)
1327                 btrfs_requeue_work(&async_node->work);
1328         else {
1329                 btrfs_release_prepared_delayed_node(delayed_node);
1330                 kfree(async_node);
1331         }
1332 }
1333
1334 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1335                                      struct btrfs_root *root, int all)
1336 {
1337         struct btrfs_async_delayed_node *async_node;
1338         struct btrfs_delayed_node *curr;
1339         int count = 0;
1340
1341 again:
1342         curr = btrfs_first_prepared_delayed_node(delayed_root);
1343         if (!curr)
1344                 return 0;
1345
1346         async_node = kmalloc(sizeof(*async_node), GFP_NOFS);
1347         if (!async_node) {
1348                 btrfs_release_prepared_delayed_node(curr);
1349                 return -ENOMEM;
1350         }
1351
1352         async_node->root = root;
1353         async_node->delayed_node = curr;
1354
1355         async_node->work.func = btrfs_async_run_delayed_node_done;
1356         async_node->work.flags = 0;
1357
1358         btrfs_queue_worker(&root->fs_info->delayed_workers, &async_node->work);
1359         count++;
1360
1361         if (all || count < 4)
1362                 goto again;
1363
1364         return 0;
1365 }
1366
1367 void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1368 {
1369         struct btrfs_delayed_root *delayed_root;
1370         delayed_root = btrfs_get_delayed_root(root);
1371         WARN_ON(btrfs_first_delayed_node(delayed_root));
1372 }
1373
1374 void btrfs_balance_delayed_items(struct btrfs_root *root)
1375 {
1376         struct btrfs_delayed_root *delayed_root;
1377
1378         delayed_root = btrfs_get_delayed_root(root);
1379
1380         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1381                 return;
1382
1383         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1384                 int ret;
1385                 ret = btrfs_wq_run_delayed_node(delayed_root, root, 1);
1386                 if (ret)
1387                         return;
1388
1389                 wait_event_interruptible_timeout(
1390                                 delayed_root->wait,
1391                                 (atomic_read(&delayed_root->items) <
1392                                  BTRFS_DELAYED_BACKGROUND),
1393                                 HZ);
1394                 return;
1395         }
1396
1397         btrfs_wq_run_delayed_node(delayed_root, root, 0);
1398 }
1399
1400 /* Will return 0 or -ENOMEM */
1401 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1402                                    struct btrfs_root *root, const char *name,
1403                                    int name_len, struct inode *dir,
1404                                    struct btrfs_disk_key *disk_key, u8 type,
1405                                    u64 index)
1406 {
1407         struct btrfs_delayed_node *delayed_node;
1408         struct btrfs_delayed_item *delayed_item;
1409         struct btrfs_dir_item *dir_item;
1410         int ret;
1411
1412         delayed_node = btrfs_get_or_create_delayed_node(dir);
1413         if (IS_ERR(delayed_node))
1414                 return PTR_ERR(delayed_node);
1415
1416         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1417         if (!delayed_item) {
1418                 ret = -ENOMEM;
1419                 goto release_node;
1420         }
1421
1422         delayed_item->key.objectid = btrfs_ino(dir);
1423         btrfs_set_key_type(&delayed_item->key, BTRFS_DIR_INDEX_KEY);
1424         delayed_item->key.offset = index;
1425
1426         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1427         dir_item->location = *disk_key;
1428         dir_item->transid = cpu_to_le64(trans->transid);
1429         dir_item->data_len = 0;
1430         dir_item->name_len = cpu_to_le16(name_len);
1431         dir_item->type = type;
1432         memcpy((char *)(dir_item + 1), name, name_len);
1433
1434         ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1435         /*
1436          * we have reserved enough space when we start a new transaction,
1437          * so reserving metadata failure is impossible
1438          */
1439         BUG_ON(ret);
1440
1441
1442         mutex_lock(&delayed_node->mutex);
1443         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1444         if (unlikely(ret)) {
1445                 printk(KERN_ERR "err add delayed dir index item(name: %s) into "
1446                                 "the insertion tree of the delayed node"
1447                                 "(root id: %llu, inode id: %llu, errno: %d)\n",
1448                                 name,
1449                                 (unsigned long long)delayed_node->root->objectid,
1450                                 (unsigned long long)delayed_node->inode_id,
1451                                 ret);
1452                 BUG();
1453         }
1454         mutex_unlock(&delayed_node->mutex);
1455
1456 release_node:
1457         btrfs_release_delayed_node(delayed_node);
1458         return ret;
1459 }
1460
1461 static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1462                                                struct btrfs_delayed_node *node,
1463                                                struct btrfs_key *key)
1464 {
1465         struct btrfs_delayed_item *item;
1466
1467         mutex_lock(&node->mutex);
1468         item = __btrfs_lookup_delayed_insertion_item(node, key);
1469         if (!item) {
1470                 mutex_unlock(&node->mutex);
1471                 return 1;
1472         }
1473
1474         btrfs_delayed_item_release_metadata(root, item);
1475         btrfs_release_delayed_item(item);
1476         mutex_unlock(&node->mutex);
1477         return 0;
1478 }
1479
1480 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1481                                    struct btrfs_root *root, struct inode *dir,
1482                                    u64 index)
1483 {
1484         struct btrfs_delayed_node *node;
1485         struct btrfs_delayed_item *item;
1486         struct btrfs_key item_key;
1487         int ret;
1488
1489         node = btrfs_get_or_create_delayed_node(dir);
1490         if (IS_ERR(node))
1491                 return PTR_ERR(node);
1492
1493         item_key.objectid = btrfs_ino(dir);
1494         btrfs_set_key_type(&item_key, BTRFS_DIR_INDEX_KEY);
1495         item_key.offset = index;
1496
1497         ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1498         if (!ret)
1499                 goto end;
1500
1501         item = btrfs_alloc_delayed_item(0);
1502         if (!item) {
1503                 ret = -ENOMEM;
1504                 goto end;
1505         }
1506
1507         item->key = item_key;
1508
1509         ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1510         /*
1511          * we have reserved enough space when we start a new transaction,
1512          * so reserving metadata failure is impossible.
1513          */
1514         BUG_ON(ret);
1515
1516         mutex_lock(&node->mutex);
1517         ret = __btrfs_add_delayed_deletion_item(node, item);
1518         if (unlikely(ret)) {
1519                 printk(KERN_ERR "err add delayed dir index item(index: %llu) "
1520                                 "into the deletion tree of the delayed node"
1521                                 "(root id: %llu, inode id: %llu, errno: %d)\n",
1522                                 (unsigned long long)index,
1523                                 (unsigned long long)node->root->objectid,
1524                                 (unsigned long long)node->inode_id,
1525                                 ret);
1526                 BUG();
1527         }
1528         mutex_unlock(&node->mutex);
1529 end:
1530         btrfs_release_delayed_node(node);
1531         return ret;
1532 }
1533
1534 int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1535 {
1536         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1537
1538         if (!delayed_node)
1539                 return -ENOENT;
1540
1541         /*
1542          * Since we have held i_mutex of this directory, it is impossible that
1543          * a new directory index is added into the delayed node and index_cnt
1544          * is updated now. So we needn't lock the delayed node.
1545          */
1546         if (!delayed_node->index_cnt) {
1547                 btrfs_release_delayed_node(delayed_node);
1548                 return -EINVAL;
1549         }
1550
1551         BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1552         btrfs_release_delayed_node(delayed_node);
1553         return 0;
1554 }
1555
1556 void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
1557                              struct list_head *del_list)
1558 {
1559         struct btrfs_delayed_node *delayed_node;
1560         struct btrfs_delayed_item *item;
1561
1562         delayed_node = btrfs_get_delayed_node(inode);
1563         if (!delayed_node)
1564                 return;
1565
1566         mutex_lock(&delayed_node->mutex);
1567         item = __btrfs_first_delayed_insertion_item(delayed_node);
1568         while (item) {
1569                 atomic_inc(&item->refs);
1570                 list_add_tail(&item->readdir_list, ins_list);
1571                 item = __btrfs_next_delayed_item(item);
1572         }
1573
1574         item = __btrfs_first_delayed_deletion_item(delayed_node);
1575         while (item) {
1576                 atomic_inc(&item->refs);
1577                 list_add_tail(&item->readdir_list, del_list);
1578                 item = __btrfs_next_delayed_item(item);
1579         }
1580         mutex_unlock(&delayed_node->mutex);
1581         /*
1582          * This delayed node is still cached in the btrfs inode, so refs
1583          * must be > 1 now, and we needn't check it is going to be freed
1584          * or not.
1585          *
1586          * Besides that, this function is used to read dir, we do not
1587          * insert/delete delayed items in this period. So we also needn't
1588          * requeue or dequeue this delayed node.
1589          */
1590         atomic_dec(&delayed_node->refs);
1591 }
1592
1593 void btrfs_put_delayed_items(struct list_head *ins_list,
1594                              struct list_head *del_list)
1595 {
1596         struct btrfs_delayed_item *curr, *next;
1597
1598         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1599                 list_del(&curr->readdir_list);
1600                 if (atomic_dec_and_test(&curr->refs))
1601                         kfree(curr);
1602         }
1603
1604         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1605                 list_del(&curr->readdir_list);
1606                 if (atomic_dec_and_test(&curr->refs))
1607                         kfree(curr);
1608         }
1609 }
1610
1611 int btrfs_should_delete_dir_index(struct list_head *del_list,
1612                                   u64 index)
1613 {
1614         struct btrfs_delayed_item *curr, *next;
1615         int ret;
1616
1617         if (list_empty(del_list))
1618                 return 0;
1619
1620         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1621                 if (curr->key.offset > index)
1622                         break;
1623
1624                 list_del(&curr->readdir_list);
1625                 ret = (curr->key.offset == index);
1626
1627                 if (atomic_dec_and_test(&curr->refs))
1628                         kfree(curr);
1629
1630                 if (ret)
1631                         return 1;
1632                 else
1633                         continue;
1634         }
1635         return 0;
1636 }
1637
1638 /*
1639  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1640  *
1641  */
1642 int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
1643                                     filldir_t filldir,
1644                                     struct list_head *ins_list)
1645 {
1646         struct btrfs_dir_item *di;
1647         struct btrfs_delayed_item *curr, *next;
1648         struct btrfs_key location;
1649         char *name;
1650         int name_len;
1651         int over = 0;
1652         unsigned char d_type;
1653
1654         if (list_empty(ins_list))
1655                 return 0;
1656
1657         /*
1658          * Changing the data of the delayed item is impossible. So
1659          * we needn't lock them. And we have held i_mutex of the
1660          * directory, nobody can delete any directory indexes now.
1661          */
1662         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1663                 list_del(&curr->readdir_list);
1664
1665                 if (curr->key.offset < filp->f_pos) {
1666                         if (atomic_dec_and_test(&curr->refs))
1667                                 kfree(curr);
1668                         continue;
1669                 }
1670
1671                 filp->f_pos = curr->key.offset;
1672
1673                 di = (struct btrfs_dir_item *)curr->data;
1674                 name = (char *)(di + 1);
1675                 name_len = le16_to_cpu(di->name_len);
1676
1677                 d_type = btrfs_filetype_table[di->type];
1678                 btrfs_disk_key_to_cpu(&location, &di->location);
1679
1680                 over = filldir(dirent, name, name_len, curr->key.offset,
1681                                location.objectid, d_type);
1682
1683                 if (atomic_dec_and_test(&curr->refs))
1684                         kfree(curr);
1685
1686                 if (over)
1687                         return 1;
1688         }
1689         return 0;
1690 }
1691
1692 BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item,
1693                          generation, 64);
1694 BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item,
1695                          sequence, 64);
1696 BTRFS_SETGET_STACK_FUNCS(stack_inode_transid, struct btrfs_inode_item,
1697                          transid, 64);
1698 BTRFS_SETGET_STACK_FUNCS(stack_inode_size, struct btrfs_inode_item, size, 64);
1699 BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes, struct btrfs_inode_item,
1700                          nbytes, 64);
1701 BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group, struct btrfs_inode_item,
1702                          block_group, 64);
1703 BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink, struct btrfs_inode_item, nlink, 32);
1704 BTRFS_SETGET_STACK_FUNCS(stack_inode_uid, struct btrfs_inode_item, uid, 32);
1705 BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32);
1706 BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32);
1707 BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64);
1708 BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64);
1709
1710 BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
1711 BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
1712
1713 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1714                                   struct btrfs_inode_item *inode_item,
1715                                   struct inode *inode)
1716 {
1717         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1718         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1719         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1720         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1721         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1722         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1723         btrfs_set_stack_inode_generation(inode_item,
1724                                          BTRFS_I(inode)->generation);
1725         btrfs_set_stack_inode_sequence(inode_item, inode->i_version);
1726         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1727         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1728         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1729         btrfs_set_stack_inode_block_group(inode_item, 0);
1730
1731         btrfs_set_stack_timespec_sec(btrfs_inode_atime(inode_item),
1732                                      inode->i_atime.tv_sec);
1733         btrfs_set_stack_timespec_nsec(btrfs_inode_atime(inode_item),
1734                                       inode->i_atime.tv_nsec);
1735
1736         btrfs_set_stack_timespec_sec(btrfs_inode_mtime(inode_item),
1737                                      inode->i_mtime.tv_sec);
1738         btrfs_set_stack_timespec_nsec(btrfs_inode_mtime(inode_item),
1739                                       inode->i_mtime.tv_nsec);
1740
1741         btrfs_set_stack_timespec_sec(btrfs_inode_ctime(inode_item),
1742                                      inode->i_ctime.tv_sec);
1743         btrfs_set_stack_timespec_nsec(btrfs_inode_ctime(inode_item),
1744                                       inode->i_ctime.tv_nsec);
1745 }
1746
1747 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1748 {
1749         struct btrfs_delayed_node *delayed_node;
1750         struct btrfs_inode_item *inode_item;
1751         struct btrfs_timespec *tspec;
1752
1753         delayed_node = btrfs_get_delayed_node(inode);
1754         if (!delayed_node)
1755                 return -ENOENT;
1756
1757         mutex_lock(&delayed_node->mutex);
1758         if (!delayed_node->inode_dirty) {
1759                 mutex_unlock(&delayed_node->mutex);
1760                 btrfs_release_delayed_node(delayed_node);
1761                 return -ENOENT;
1762         }
1763
1764         inode_item = &delayed_node->inode_item;
1765
1766         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1767         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1768         btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1769         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1770         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1771         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1772         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1773         inode->i_version = btrfs_stack_inode_sequence(inode_item);
1774         inode->i_rdev = 0;
1775         *rdev = btrfs_stack_inode_rdev(inode_item);
1776         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1777
1778         tspec = btrfs_inode_atime(inode_item);
1779         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(tspec);
1780         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1781
1782         tspec = btrfs_inode_mtime(inode_item);
1783         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(tspec);
1784         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1785
1786         tspec = btrfs_inode_ctime(inode_item);
1787         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(tspec);
1788         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1789
1790         inode->i_generation = BTRFS_I(inode)->generation;
1791         BTRFS_I(inode)->index_cnt = (u64)-1;
1792
1793         mutex_unlock(&delayed_node->mutex);
1794         btrfs_release_delayed_node(delayed_node);
1795         return 0;
1796 }
1797
1798 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1799                                struct btrfs_root *root, struct inode *inode)
1800 {
1801         struct btrfs_delayed_node *delayed_node;
1802         int ret = 0;
1803
1804         delayed_node = btrfs_get_or_create_delayed_node(inode);
1805         if (IS_ERR(delayed_node))
1806                 return PTR_ERR(delayed_node);
1807
1808         mutex_lock(&delayed_node->mutex);
1809         if (delayed_node->inode_dirty) {
1810                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1811                 goto release_node;
1812         }
1813
1814         ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1815                                                    delayed_node);
1816         if (ret)
1817                 goto release_node;
1818
1819         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1820         delayed_node->inode_dirty = 1;
1821         delayed_node->count++;
1822         atomic_inc(&root->fs_info->delayed_root->items);
1823 release_node:
1824         mutex_unlock(&delayed_node->mutex);
1825         btrfs_release_delayed_node(delayed_node);
1826         return ret;
1827 }
1828
1829 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1830 {
1831         struct btrfs_root *root = delayed_node->root;
1832         struct btrfs_delayed_item *curr_item, *prev_item;
1833
1834         mutex_lock(&delayed_node->mutex);
1835         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1836         while (curr_item) {
1837                 btrfs_delayed_item_release_metadata(root, curr_item);
1838                 prev_item = curr_item;
1839                 curr_item = __btrfs_next_delayed_item(prev_item);
1840                 btrfs_release_delayed_item(prev_item);
1841         }
1842
1843         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1844         while (curr_item) {
1845                 btrfs_delayed_item_release_metadata(root, curr_item);
1846                 prev_item = curr_item;
1847                 curr_item = __btrfs_next_delayed_item(prev_item);
1848                 btrfs_release_delayed_item(prev_item);
1849         }
1850
1851         if (delayed_node->inode_dirty) {
1852                 btrfs_delayed_inode_release_metadata(root, delayed_node);
1853                 btrfs_release_delayed_inode(delayed_node);
1854         }
1855         mutex_unlock(&delayed_node->mutex);
1856 }
1857
1858 void btrfs_kill_delayed_inode_items(struct inode *inode)
1859 {
1860         struct btrfs_delayed_node *delayed_node;
1861
1862         delayed_node = btrfs_get_delayed_node(inode);
1863         if (!delayed_node)
1864                 return;
1865
1866         __btrfs_kill_delayed_node(delayed_node);
1867         btrfs_release_delayed_node(delayed_node);
1868 }
1869
1870 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1871 {
1872         u64 inode_id = 0;
1873         struct btrfs_delayed_node *delayed_nodes[8];
1874         int i, n;
1875
1876         while (1) {
1877                 spin_lock(&root->inode_lock);
1878                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1879                                            (void **)delayed_nodes, inode_id,
1880                                            ARRAY_SIZE(delayed_nodes));
1881                 if (!n) {
1882                         spin_unlock(&root->inode_lock);
1883                         break;
1884                 }
1885
1886                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1887
1888                 for (i = 0; i < n; i++)
1889                         atomic_inc(&delayed_nodes[i]->refs);
1890                 spin_unlock(&root->inode_lock);
1891
1892                 for (i = 0; i < n; i++) {
1893                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1894                         btrfs_release_delayed_node(delayed_nodes[i]);
1895                 }
1896         }
1897 }
1898
1899 void btrfs_destroy_delayed_inodes(struct btrfs_root *root)
1900 {
1901         struct btrfs_delayed_root *delayed_root;
1902         struct btrfs_delayed_node *curr_node, *prev_node;
1903
1904         delayed_root = btrfs_get_delayed_root(root);
1905
1906         curr_node = btrfs_first_delayed_node(delayed_root);
1907         while (curr_node) {
1908                 __btrfs_kill_delayed_node(curr_node);
1909
1910                 prev_node = curr_node;
1911                 curr_node = btrfs_next_delayed_node(curr_node);
1912                 btrfs_release_delayed_node(prev_node);
1913         }
1914 }
1915