Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...
[linux-2.6.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("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 }
66
67 static inline int btrfs_is_continuous_delayed_item(
68                                         struct btrfs_delayed_item *item1,
69                                         struct btrfs_delayed_item *item2)
70 {
71         if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
72             item1->key.objectid == item2->key.objectid &&
73             item1->key.type == item2->key.type &&
74             item1->key.offset + 1 == item2->key.offset)
75                 return 1;
76         return 0;
77 }
78
79 static inline struct btrfs_delayed_root *btrfs_get_delayed_root(
80                                                         struct btrfs_root *root)
81 {
82         return root->fs_info->delayed_root;
83 }
84
85 static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
86 {
87         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
88         struct btrfs_root *root = btrfs_inode->root;
89         u64 ino = btrfs_ino(inode);
90         struct btrfs_delayed_node *node;
91
92         node = ACCESS_ONCE(btrfs_inode->delayed_node);
93         if (node) {
94                 atomic_inc(&node->refs);
95                 return node;
96         }
97
98         spin_lock(&root->inode_lock);
99         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
100         if (node) {
101                 if (btrfs_inode->delayed_node) {
102                         atomic_inc(&node->refs);        /* can be accessed */
103                         BUG_ON(btrfs_inode->delayed_node != node);
104                         spin_unlock(&root->inode_lock);
105                         return node;
106                 }
107                 btrfs_inode->delayed_node = node;
108                 atomic_inc(&node->refs);        /* can be accessed */
109                 atomic_inc(&node->refs);        /* cached in the inode */
110                 spin_unlock(&root->inode_lock);
111                 return node;
112         }
113         spin_unlock(&root->inode_lock);
114
115         return NULL;
116 }
117
118 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
119                                                         struct inode *inode)
120 {
121         struct btrfs_delayed_node *node;
122         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
123         struct btrfs_root *root = btrfs_inode->root;
124         u64 ino = btrfs_ino(inode);
125         int ret;
126
127 again:
128         node = btrfs_get_delayed_node(inode);
129         if (node)
130                 return node;
131
132         node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
133         if (!node)
134                 return ERR_PTR(-ENOMEM);
135         btrfs_init_delayed_node(node, root, ino);
136
137         atomic_inc(&node->refs);        /* cached in the btrfs inode */
138         atomic_inc(&node->refs);        /* can be accessed */
139
140         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
141         if (ret) {
142                 kmem_cache_free(delayed_node_cache, node);
143                 return ERR_PTR(ret);
144         }
145
146         spin_lock(&root->inode_lock);
147         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
148         if (ret == -EEXIST) {
149                 kmem_cache_free(delayed_node_cache, node);
150                 spin_unlock(&root->inode_lock);
151                 radix_tree_preload_end();
152                 goto again;
153         }
154         btrfs_inode->delayed_node = node;
155         spin_unlock(&root->inode_lock);
156         radix_tree_preload_end();
157
158         return node;
159 }
160
161 /*
162  * Call it when holding delayed_node->mutex
163  *
164  * If mod = 1, add this node into the prepared list.
165  */
166 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
167                                      struct btrfs_delayed_node *node,
168                                      int mod)
169 {
170         spin_lock(&root->lock);
171         if (node->in_list) {
172                 if (!list_empty(&node->p_list))
173                         list_move_tail(&node->p_list, &root->prepare_list);
174                 else if (mod)
175                         list_add_tail(&node->p_list, &root->prepare_list);
176         } else {
177                 list_add_tail(&node->n_list, &root->node_list);
178                 list_add_tail(&node->p_list, &root->prepare_list);
179                 atomic_inc(&node->refs);        /* inserted into list */
180                 root->nodes++;
181                 node->in_list = 1;
182         }
183         spin_unlock(&root->lock);
184 }
185
186 /* Call it when holding delayed_node->mutex */
187 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
188                                        struct btrfs_delayed_node *node)
189 {
190         spin_lock(&root->lock);
191         if (node->in_list) {
192                 root->nodes--;
193                 atomic_dec(&node->refs);        /* not in the list */
194                 list_del_init(&node->n_list);
195                 if (!list_empty(&node->p_list))
196                         list_del_init(&node->p_list);
197                 node->in_list = 0;
198         }
199         spin_unlock(&root->lock);
200 }
201
202 struct btrfs_delayed_node *btrfs_first_delayed_node(
203                         struct btrfs_delayed_root *delayed_root)
204 {
205         struct list_head *p;
206         struct btrfs_delayed_node *node = NULL;
207
208         spin_lock(&delayed_root->lock);
209         if (list_empty(&delayed_root->node_list))
210                 goto out;
211
212         p = delayed_root->node_list.next;
213         node = list_entry(p, struct btrfs_delayed_node, n_list);
214         atomic_inc(&node->refs);
215 out:
216         spin_unlock(&delayed_root->lock);
217
218         return node;
219 }
220
221 struct btrfs_delayed_node *btrfs_next_delayed_node(
222                                                 struct btrfs_delayed_node *node)
223 {
224         struct btrfs_delayed_root *delayed_root;
225         struct list_head *p;
226         struct btrfs_delayed_node *next = NULL;
227
228         delayed_root = node->root->fs_info->delayed_root;
229         spin_lock(&delayed_root->lock);
230         if (!node->in_list) {   /* not in the list */
231                 if (list_empty(&delayed_root->node_list))
232                         goto out;
233                 p = delayed_root->node_list.next;
234         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
235                 goto out;
236         else
237                 p = node->n_list.next;
238
239         next = list_entry(p, struct btrfs_delayed_node, n_list);
240         atomic_inc(&next->refs);
241 out:
242         spin_unlock(&delayed_root->lock);
243
244         return next;
245 }
246
247 static void __btrfs_release_delayed_node(
248                                 struct btrfs_delayed_node *delayed_node,
249                                 int mod)
250 {
251         struct btrfs_delayed_root *delayed_root;
252
253         if (!delayed_node)
254                 return;
255
256         delayed_root = delayed_node->root->fs_info->delayed_root;
257
258         mutex_lock(&delayed_node->mutex);
259         if (delayed_node->count)
260                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
261         else
262                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
263         mutex_unlock(&delayed_node->mutex);
264
265         if (atomic_dec_and_test(&delayed_node->refs)) {
266                 struct btrfs_root *root = delayed_node->root;
267                 spin_lock(&root->inode_lock);
268                 if (atomic_read(&delayed_node->refs) == 0) {
269                         radix_tree_delete(&root->delayed_nodes_tree,
270                                           delayed_node->inode_id);
271                         kmem_cache_free(delayed_node_cache, delayed_node);
272                 }
273                 spin_unlock(&root->inode_lock);
274         }
275 }
276
277 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
278 {
279         __btrfs_release_delayed_node(node, 0);
280 }
281
282 struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
283                                         struct btrfs_delayed_root *delayed_root)
284 {
285         struct list_head *p;
286         struct btrfs_delayed_node *node = NULL;
287
288         spin_lock(&delayed_root->lock);
289         if (list_empty(&delayed_root->prepare_list))
290                 goto out;
291
292         p = delayed_root->prepare_list.next;
293         list_del_init(p);
294         node = list_entry(p, struct btrfs_delayed_node, p_list);
295         atomic_inc(&node->refs);
296 out:
297         spin_unlock(&delayed_root->lock);
298
299         return node;
300 }
301
302 static inline void btrfs_release_prepared_delayed_node(
303                                         struct btrfs_delayed_node *node)
304 {
305         __btrfs_release_delayed_node(node, 1);
306 }
307
308 struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
309 {
310         struct btrfs_delayed_item *item;
311         item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
312         if (item) {
313                 item->data_len = data_len;
314                 item->ins_or_del = 0;
315                 item->bytes_reserved = 0;
316                 item->delayed_node = NULL;
317                 atomic_set(&item->refs, 1);
318         }
319         return item;
320 }
321
322 /*
323  * __btrfs_lookup_delayed_item - look up the delayed item by key
324  * @delayed_node: pointer to the delayed node
325  * @key:          the key to look up
326  * @prev:         used to store the prev item if the right item isn't found
327  * @next:         used to store the next item if the right item isn't found
328  *
329  * Note: if we don't find the right item, we will return the prev item and
330  * the next item.
331  */
332 static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
333                                 struct rb_root *root,
334                                 struct btrfs_key *key,
335                                 struct btrfs_delayed_item **prev,
336                                 struct btrfs_delayed_item **next)
337 {
338         struct rb_node *node, *prev_node = NULL;
339         struct btrfs_delayed_item *delayed_item = NULL;
340         int ret = 0;
341
342         node = root->rb_node;
343
344         while (node) {
345                 delayed_item = rb_entry(node, struct btrfs_delayed_item,
346                                         rb_node);
347                 prev_node = node;
348                 ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
349                 if (ret < 0)
350                         node = node->rb_right;
351                 else if (ret > 0)
352                         node = node->rb_left;
353                 else
354                         return delayed_item;
355         }
356
357         if (prev) {
358                 if (!prev_node)
359                         *prev = NULL;
360                 else if (ret < 0)
361                         *prev = delayed_item;
362                 else if ((node = rb_prev(prev_node)) != NULL) {
363                         *prev = rb_entry(node, struct btrfs_delayed_item,
364                                          rb_node);
365                 } else
366                         *prev = NULL;
367         }
368
369         if (next) {
370                 if (!prev_node)
371                         *next = NULL;
372                 else if (ret > 0)
373                         *next = delayed_item;
374                 else if ((node = rb_next(prev_node)) != NULL) {
375                         *next = rb_entry(node, struct btrfs_delayed_item,
376                                          rb_node);
377                 } else
378                         *next = NULL;
379         }
380         return NULL;
381 }
382
383 struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
384                                         struct btrfs_delayed_node *delayed_node,
385                                         struct btrfs_key *key)
386 {
387         struct btrfs_delayed_item *item;
388
389         item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
390                                            NULL, NULL);
391         return item;
392 }
393
394 struct btrfs_delayed_item *__btrfs_lookup_delayed_deletion_item(
395                                         struct btrfs_delayed_node *delayed_node,
396                                         struct btrfs_key *key)
397 {
398         struct btrfs_delayed_item *item;
399
400         item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
401                                            NULL, NULL);
402         return item;
403 }
404
405 struct btrfs_delayed_item *__btrfs_search_delayed_insertion_item(
406                                         struct btrfs_delayed_node *delayed_node,
407                                         struct btrfs_key *key)
408 {
409         struct btrfs_delayed_item *item, *next;
410
411         item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
412                                            NULL, &next);
413         if (!item)
414                 item = next;
415
416         return item;
417 }
418
419 struct btrfs_delayed_item *__btrfs_search_delayed_deletion_item(
420                                         struct btrfs_delayed_node *delayed_node,
421                                         struct btrfs_key *key)
422 {
423         struct btrfs_delayed_item *item, *next;
424
425         item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
426                                            NULL, &next);
427         if (!item)
428                 item = next;
429
430         return item;
431 }
432
433 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
434                                     struct btrfs_delayed_item *ins,
435                                     int action)
436 {
437         struct rb_node **p, *node;
438         struct rb_node *parent_node = NULL;
439         struct rb_root *root;
440         struct btrfs_delayed_item *item;
441         int cmp;
442
443         if (action == BTRFS_DELAYED_INSERTION_ITEM)
444                 root = &delayed_node->ins_root;
445         else if (action == BTRFS_DELAYED_DELETION_ITEM)
446                 root = &delayed_node->del_root;
447         else
448                 BUG();
449         p = &root->rb_node;
450         node = &ins->rb_node;
451
452         while (*p) {
453                 parent_node = *p;
454                 item = rb_entry(parent_node, struct btrfs_delayed_item,
455                                  rb_node);
456
457                 cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
458                 if (cmp < 0)
459                         p = &(*p)->rb_right;
460                 else if (cmp > 0)
461                         p = &(*p)->rb_left;
462                 else
463                         return -EEXIST;
464         }
465
466         rb_link_node(node, parent_node, p);
467         rb_insert_color(node, root);
468         ins->delayed_node = delayed_node;
469         ins->ins_or_del = action;
470
471         if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
472             action == BTRFS_DELAYED_INSERTION_ITEM &&
473             ins->key.offset >= delayed_node->index_cnt)
474                         delayed_node->index_cnt = ins->key.offset + 1;
475
476         delayed_node->count++;
477         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
478         return 0;
479 }
480
481 static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
482                                               struct btrfs_delayed_item *item)
483 {
484         return __btrfs_add_delayed_item(node, item,
485                                         BTRFS_DELAYED_INSERTION_ITEM);
486 }
487
488 static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
489                                              struct btrfs_delayed_item *item)
490 {
491         return __btrfs_add_delayed_item(node, item,
492                                         BTRFS_DELAYED_DELETION_ITEM);
493 }
494
495 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
496 {
497         struct rb_root *root;
498         struct btrfs_delayed_root *delayed_root;
499
500         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
501
502         BUG_ON(!delayed_root);
503         BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
504                delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
505
506         if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
507                 root = &delayed_item->delayed_node->ins_root;
508         else
509                 root = &delayed_item->delayed_node->del_root;
510
511         rb_erase(&delayed_item->rb_node, root);
512         delayed_item->delayed_node->count--;
513         atomic_dec(&delayed_root->items);
514         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND &&
515             waitqueue_active(&delayed_root->wait))
516                 wake_up(&delayed_root->wait);
517 }
518
519 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
520 {
521         if (item) {
522                 __btrfs_remove_delayed_item(item);
523                 if (atomic_dec_and_test(&item->refs))
524                         kfree(item);
525         }
526 }
527
528 struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
529                                         struct btrfs_delayed_node *delayed_node)
530 {
531         struct rb_node *p;
532         struct btrfs_delayed_item *item = NULL;
533
534         p = rb_first(&delayed_node->ins_root);
535         if (p)
536                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
537
538         return item;
539 }
540
541 struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
542                                         struct btrfs_delayed_node *delayed_node)
543 {
544         struct rb_node *p;
545         struct btrfs_delayed_item *item = NULL;
546
547         p = rb_first(&delayed_node->del_root);
548         if (p)
549                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
550
551         return item;
552 }
553
554 struct btrfs_delayed_item *__btrfs_next_delayed_item(
555                                                 struct btrfs_delayed_item *item)
556 {
557         struct rb_node *p;
558         struct btrfs_delayed_item *next = NULL;
559
560         p = rb_next(&item->rb_node);
561         if (p)
562                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
563
564         return next;
565 }
566
567 static inline struct btrfs_root *btrfs_get_fs_root(struct btrfs_root *root,
568                                                    u64 root_id)
569 {
570         struct btrfs_key root_key;
571
572         if (root->objectid == root_id)
573                 return root;
574
575         root_key.objectid = root_id;
576         root_key.type = BTRFS_ROOT_ITEM_KEY;
577         root_key.offset = (u64)-1;
578         return btrfs_read_fs_root_no_name(root->fs_info, &root_key);
579 }
580
581 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
582                                                struct btrfs_root *root,
583                                                struct btrfs_delayed_item *item)
584 {
585         struct btrfs_block_rsv *src_rsv;
586         struct btrfs_block_rsv *dst_rsv;
587         u64 num_bytes;
588         int ret;
589
590         if (!trans->bytes_reserved)
591                 return 0;
592
593         src_rsv = trans->block_rsv;
594         dst_rsv = &root->fs_info->delayed_block_rsv;
595
596         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
597         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
598         if (!ret)
599                 item->bytes_reserved = num_bytes;
600
601         return ret;
602 }
603
604 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
605                                                 struct btrfs_delayed_item *item)
606 {
607         struct btrfs_block_rsv *rsv;
608
609         if (!item->bytes_reserved)
610                 return;
611
612         rsv = &root->fs_info->delayed_block_rsv;
613         btrfs_block_rsv_release(root, rsv,
614                                 item->bytes_reserved);
615 }
616
617 static int btrfs_delayed_inode_reserve_metadata(
618                                         struct btrfs_trans_handle *trans,
619                                         struct btrfs_root *root,
620                                         struct inode *inode,
621                                         struct btrfs_delayed_node *node)
622 {
623         struct btrfs_block_rsv *src_rsv;
624         struct btrfs_block_rsv *dst_rsv;
625         u64 num_bytes;
626         int ret;
627         int release = false;
628
629         src_rsv = trans->block_rsv;
630         dst_rsv = &root->fs_info->delayed_block_rsv;
631
632         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
633
634         /*
635          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
636          * which doesn't reserve space for speed.  This is a problem since we
637          * still need to reserve space for this update, so try to reserve the
638          * space.
639          *
640          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
641          * we're accounted for.
642          */
643         if (!trans->bytes_reserved &&
644             src_rsv != &root->fs_info->delalloc_block_rsv) {
645                 ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
646                 /*
647                  * Since we're under a transaction reserve_metadata_bytes could
648                  * try to commit the transaction which will make it return
649                  * EAGAIN to make us stop the transaction we have, so return
650                  * ENOSPC instead so that btrfs_dirty_inode knows what to do.
651                  */
652                 if (ret == -EAGAIN)
653                         ret = -ENOSPC;
654                 if (!ret)
655                         node->bytes_reserved = num_bytes;
656                 return ret;
657         } else if (src_rsv == &root->fs_info->delalloc_block_rsv) {
658                 spin_lock(&BTRFS_I(inode)->lock);
659                 if (BTRFS_I(inode)->delalloc_meta_reserved) {
660                         BTRFS_I(inode)->delalloc_meta_reserved = 0;
661                         spin_unlock(&BTRFS_I(inode)->lock);
662                         release = true;
663                         goto migrate;
664                 }
665                 spin_unlock(&BTRFS_I(inode)->lock);
666
667                 /* Ok we didn't have space pre-reserved.  This shouldn't happen
668                  * too often but it can happen if we do delalloc to an existing
669                  * inode which gets dirtied because of the time update, and then
670                  * isn't touched again until after the transaction commits and
671                  * then we try to write out the data.  First try to be nice and
672                  * reserve something strictly for us.  If not be a pain and try
673                  * to steal from the delalloc block rsv.
674                  */
675                 ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
676                 if (!ret)
677                         goto out;
678
679                 ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
680                 if (!ret)
681                         goto out;
682
683                 /*
684                  * Ok this is a problem, let's just steal from the global rsv
685                  * since this really shouldn't happen that often.
686                  */
687                 WARN_ON(1);
688                 ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
689                                               dst_rsv, num_bytes);
690                 goto out;
691         }
692
693 migrate:
694         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
695
696 out:
697         /*
698          * Migrate only takes a reservation, it doesn't touch the size of the
699          * block_rsv.  This is to simplify people who don't normally have things
700          * migrated from their block rsv.  If they go to release their
701          * reservation, that will decrease the size as well, so if migrate
702          * reduced size we'd end up with a negative size.  But for the
703          * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
704          * but we could in fact do this reserve/migrate dance several times
705          * between the time we did the original reservation and we'd clean it
706          * up.  So to take care of this, release the space for the meta
707          * reservation here.  I think it may be time for a documentation page on
708          * how block rsvs. work.
709          */
710         if (!ret)
711                 node->bytes_reserved = num_bytes;
712
713         if (release)
714                 btrfs_block_rsv_release(root, src_rsv, num_bytes);
715
716         return ret;
717 }
718
719 static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
720                                                 struct btrfs_delayed_node *node)
721 {
722         struct btrfs_block_rsv *rsv;
723
724         if (!node->bytes_reserved)
725                 return;
726
727         rsv = &root->fs_info->delayed_block_rsv;
728         btrfs_block_rsv_release(root, rsv,
729                                 node->bytes_reserved);
730         node->bytes_reserved = 0;
731 }
732
733 /*
734  * This helper will insert some continuous items into the same leaf according
735  * to the free space of the leaf.
736  */
737 static int btrfs_batch_insert_items(struct btrfs_trans_handle *trans,
738                                 struct btrfs_root *root,
739                                 struct btrfs_path *path,
740                                 struct btrfs_delayed_item *item)
741 {
742         struct btrfs_delayed_item *curr, *next;
743         int free_space;
744         int total_data_size = 0, total_size = 0;
745         struct extent_buffer *leaf;
746         char *data_ptr;
747         struct btrfs_key *keys;
748         u32 *data_size;
749         struct list_head head;
750         int slot;
751         int nitems;
752         int i;
753         int ret = 0;
754
755         BUG_ON(!path->nodes[0]);
756
757         leaf = path->nodes[0];
758         free_space = btrfs_leaf_free_space(root, leaf);
759         INIT_LIST_HEAD(&head);
760
761         next = item;
762         nitems = 0;
763
764         /*
765          * count the number of the continuous items that we can insert in batch
766          */
767         while (total_size + next->data_len + sizeof(struct btrfs_item) <=
768                free_space) {
769                 total_data_size += next->data_len;
770                 total_size += next->data_len + sizeof(struct btrfs_item);
771                 list_add_tail(&next->tree_list, &head);
772                 nitems++;
773
774                 curr = next;
775                 next = __btrfs_next_delayed_item(curr);
776                 if (!next)
777                         break;
778
779                 if (!btrfs_is_continuous_delayed_item(curr, next))
780                         break;
781         }
782
783         if (!nitems) {
784                 ret = 0;
785                 goto out;
786         }
787
788         /*
789          * we need allocate some memory space, but it might cause the task
790          * to sleep, so we set all locked nodes in the path to blocking locks
791          * first.
792          */
793         btrfs_set_path_blocking(path);
794
795         keys = kmalloc(sizeof(struct btrfs_key) * nitems, GFP_NOFS);
796         if (!keys) {
797                 ret = -ENOMEM;
798                 goto out;
799         }
800
801         data_size = kmalloc(sizeof(u32) * nitems, GFP_NOFS);
802         if (!data_size) {
803                 ret = -ENOMEM;
804                 goto error;
805         }
806
807         /* get keys of all the delayed items */
808         i = 0;
809         list_for_each_entry(next, &head, tree_list) {
810                 keys[i] = next->key;
811                 data_size[i] = next->data_len;
812                 i++;
813         }
814
815         /* reset all the locked nodes in the patch to spinning locks. */
816         btrfs_clear_path_blocking(path, NULL, 0);
817
818         /* insert the keys of the items */
819         ret = setup_items_for_insert(trans, root, path, keys, data_size,
820                                      total_data_size, total_size, nitems);
821         if (ret)
822                 goto error;
823
824         /* insert the dir index items */
825         slot = path->slots[0];
826         list_for_each_entry_safe(curr, next, &head, tree_list) {
827                 data_ptr = btrfs_item_ptr(leaf, slot, char);
828                 write_extent_buffer(leaf, &curr->data,
829                                     (unsigned long)data_ptr,
830                                     curr->data_len);
831                 slot++;
832
833                 btrfs_delayed_item_release_metadata(root, curr);
834
835                 list_del(&curr->tree_list);
836                 btrfs_release_delayed_item(curr);
837         }
838
839 error:
840         kfree(data_size);
841         kfree(keys);
842 out:
843         return ret;
844 }
845
846 /*
847  * This helper can just do simple insertion that needn't extend item for new
848  * data, such as directory name index insertion, inode insertion.
849  */
850 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
851                                      struct btrfs_root *root,
852                                      struct btrfs_path *path,
853                                      struct btrfs_delayed_item *delayed_item)
854 {
855         struct extent_buffer *leaf;
856         struct btrfs_item *item;
857         char *ptr;
858         int ret;
859
860         ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
861                                       delayed_item->data_len);
862         if (ret < 0 && ret != -EEXIST)
863                 return ret;
864
865         leaf = path->nodes[0];
866
867         item = btrfs_item_nr(leaf, path->slots[0]);
868         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
869
870         write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
871                             delayed_item->data_len);
872         btrfs_mark_buffer_dirty(leaf);
873
874         btrfs_delayed_item_release_metadata(root, delayed_item);
875         return 0;
876 }
877
878 /*
879  * we insert an item first, then if there are some continuous items, we try
880  * to insert those items into the same leaf.
881  */
882 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
883                                       struct btrfs_path *path,
884                                       struct btrfs_root *root,
885                                       struct btrfs_delayed_node *node)
886 {
887         struct btrfs_delayed_item *curr, *prev;
888         int ret = 0;
889
890 do_again:
891         mutex_lock(&node->mutex);
892         curr = __btrfs_first_delayed_insertion_item(node);
893         if (!curr)
894                 goto insert_end;
895
896         ret = btrfs_insert_delayed_item(trans, root, path, curr);
897         if (ret < 0) {
898                 btrfs_release_path(path);
899                 goto insert_end;
900         }
901
902         prev = curr;
903         curr = __btrfs_next_delayed_item(prev);
904         if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
905                 /* insert the continuous items into the same leaf */
906                 path->slots[0]++;
907                 btrfs_batch_insert_items(trans, root, path, curr);
908         }
909         btrfs_release_delayed_item(prev);
910         btrfs_mark_buffer_dirty(path->nodes[0]);
911
912         btrfs_release_path(path);
913         mutex_unlock(&node->mutex);
914         goto do_again;
915
916 insert_end:
917         mutex_unlock(&node->mutex);
918         return ret;
919 }
920
921 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
922                                     struct btrfs_root *root,
923                                     struct btrfs_path *path,
924                                     struct btrfs_delayed_item *item)
925 {
926         struct btrfs_delayed_item *curr, *next;
927         struct extent_buffer *leaf;
928         struct btrfs_key key;
929         struct list_head head;
930         int nitems, i, last_item;
931         int ret = 0;
932
933         BUG_ON(!path->nodes[0]);
934
935         leaf = path->nodes[0];
936
937         i = path->slots[0];
938         last_item = btrfs_header_nritems(leaf) - 1;
939         if (i > last_item)
940                 return -ENOENT; /* FIXME: Is errno suitable? */
941
942         next = item;
943         INIT_LIST_HEAD(&head);
944         btrfs_item_key_to_cpu(leaf, &key, i);
945         nitems = 0;
946         /*
947          * count the number of the dir index items that we can delete in batch
948          */
949         while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
950                 list_add_tail(&next->tree_list, &head);
951                 nitems++;
952
953                 curr = next;
954                 next = __btrfs_next_delayed_item(curr);
955                 if (!next)
956                         break;
957
958                 if (!btrfs_is_continuous_delayed_item(curr, next))
959                         break;
960
961                 i++;
962                 if (i > last_item)
963                         break;
964                 btrfs_item_key_to_cpu(leaf, &key, i);
965         }
966
967         if (!nitems)
968                 return 0;
969
970         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
971         if (ret)
972                 goto out;
973
974         list_for_each_entry_safe(curr, next, &head, tree_list) {
975                 btrfs_delayed_item_release_metadata(root, curr);
976                 list_del(&curr->tree_list);
977                 btrfs_release_delayed_item(curr);
978         }
979
980 out:
981         return ret;
982 }
983
984 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
985                                       struct btrfs_path *path,
986                                       struct btrfs_root *root,
987                                       struct btrfs_delayed_node *node)
988 {
989         struct btrfs_delayed_item *curr, *prev;
990         int ret = 0;
991
992 do_again:
993         mutex_lock(&node->mutex);
994         curr = __btrfs_first_delayed_deletion_item(node);
995         if (!curr)
996                 goto delete_fail;
997
998         ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
999         if (ret < 0)
1000                 goto delete_fail;
1001         else if (ret > 0) {
1002                 /*
1003                  * can't find the item which the node points to, so this node
1004                  * is invalid, just drop it.
1005                  */
1006                 prev = curr;
1007                 curr = __btrfs_next_delayed_item(prev);
1008                 btrfs_release_delayed_item(prev);
1009                 ret = 0;
1010                 btrfs_release_path(path);
1011                 if (curr)
1012                         goto do_again;
1013                 else
1014                         goto delete_fail;
1015         }
1016
1017         btrfs_batch_delete_items(trans, root, path, curr);
1018         btrfs_release_path(path);
1019         mutex_unlock(&node->mutex);
1020         goto do_again;
1021
1022 delete_fail:
1023         btrfs_release_path(path);
1024         mutex_unlock(&node->mutex);
1025         return ret;
1026 }
1027
1028 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
1029 {
1030         struct btrfs_delayed_root *delayed_root;
1031
1032         if (delayed_node && delayed_node->inode_dirty) {
1033                 BUG_ON(!delayed_node->root);
1034                 delayed_node->inode_dirty = 0;
1035                 delayed_node->count--;
1036
1037                 delayed_root = delayed_node->root->fs_info->delayed_root;
1038                 atomic_dec(&delayed_root->items);
1039                 if (atomic_read(&delayed_root->items) <
1040                     BTRFS_DELAYED_BACKGROUND &&
1041                     waitqueue_active(&delayed_root->wait))
1042                         wake_up(&delayed_root->wait);
1043         }
1044 }
1045
1046 static int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1047                                       struct btrfs_root *root,
1048                                       struct btrfs_path *path,
1049                                       struct btrfs_delayed_node *node)
1050 {
1051         struct btrfs_key key;
1052         struct btrfs_inode_item *inode_item;
1053         struct extent_buffer *leaf;
1054         int ret;
1055
1056         mutex_lock(&node->mutex);
1057         if (!node->inode_dirty) {
1058                 mutex_unlock(&node->mutex);
1059                 return 0;
1060         }
1061
1062         key.objectid = node->inode_id;
1063         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1064         key.offset = 0;
1065         ret = btrfs_lookup_inode(trans, root, path, &key, 1);
1066         if (ret > 0) {
1067                 btrfs_release_path(path);
1068                 mutex_unlock(&node->mutex);
1069                 return -ENOENT;
1070         } else if (ret < 0) {
1071                 mutex_unlock(&node->mutex);
1072                 return ret;
1073         }
1074
1075         btrfs_unlock_up_safe(path, 1);
1076         leaf = path->nodes[0];
1077         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1078                                     struct btrfs_inode_item);
1079         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1080                             sizeof(struct btrfs_inode_item));
1081         btrfs_mark_buffer_dirty(leaf);
1082         btrfs_release_path(path);
1083
1084         btrfs_delayed_inode_release_metadata(root, node);
1085         btrfs_release_delayed_inode(node);
1086         mutex_unlock(&node->mutex);
1087
1088         return 0;
1089 }
1090
1091 /* Called when committing the transaction. */
1092 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1093                             struct btrfs_root *root)
1094 {
1095         struct btrfs_delayed_root *delayed_root;
1096         struct btrfs_delayed_node *curr_node, *prev_node;
1097         struct btrfs_path *path;
1098         struct btrfs_block_rsv *block_rsv;
1099         int ret = 0;
1100
1101         path = btrfs_alloc_path();
1102         if (!path)
1103                 return -ENOMEM;
1104         path->leave_spinning = 1;
1105
1106         block_rsv = trans->block_rsv;
1107         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1108
1109         delayed_root = btrfs_get_delayed_root(root);
1110
1111         curr_node = btrfs_first_delayed_node(delayed_root);
1112         while (curr_node) {
1113                 root = curr_node->root;
1114                 ret = btrfs_insert_delayed_items(trans, path, root,
1115                                                  curr_node);
1116                 if (!ret)
1117                         ret = btrfs_delete_delayed_items(trans, path, root,
1118                                                          curr_node);
1119                 if (!ret)
1120                         ret = btrfs_update_delayed_inode(trans, root, path,
1121                                                          curr_node);
1122                 if (ret) {
1123                         btrfs_release_delayed_node(curr_node);
1124                         break;
1125                 }
1126
1127                 prev_node = curr_node;
1128                 curr_node = btrfs_next_delayed_node(curr_node);
1129                 btrfs_release_delayed_node(prev_node);
1130         }
1131
1132         btrfs_free_path(path);
1133         trans->block_rsv = block_rsv;
1134         return ret;
1135 }
1136
1137 static int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1138                                               struct btrfs_delayed_node *node)
1139 {
1140         struct btrfs_path *path;
1141         struct btrfs_block_rsv *block_rsv;
1142         int ret;
1143
1144         path = btrfs_alloc_path();
1145         if (!path)
1146                 return -ENOMEM;
1147         path->leave_spinning = 1;
1148
1149         block_rsv = trans->block_rsv;
1150         trans->block_rsv = &node->root->fs_info->delayed_block_rsv;
1151
1152         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1153         if (!ret)
1154                 ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1155         if (!ret)
1156                 ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1157         btrfs_free_path(path);
1158
1159         trans->block_rsv = block_rsv;
1160         return ret;
1161 }
1162
1163 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1164                                      struct inode *inode)
1165 {
1166         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1167         int ret;
1168
1169         if (!delayed_node)
1170                 return 0;
1171
1172         mutex_lock(&delayed_node->mutex);
1173         if (!delayed_node->count) {
1174                 mutex_unlock(&delayed_node->mutex);
1175                 btrfs_release_delayed_node(delayed_node);
1176                 return 0;
1177         }
1178         mutex_unlock(&delayed_node->mutex);
1179
1180         ret = __btrfs_commit_inode_delayed_items(trans, delayed_node);
1181         btrfs_release_delayed_node(delayed_node);
1182         return ret;
1183 }
1184
1185 void btrfs_remove_delayed_node(struct inode *inode)
1186 {
1187         struct btrfs_delayed_node *delayed_node;
1188
1189         delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1190         if (!delayed_node)
1191                 return;
1192
1193         BTRFS_I(inode)->delayed_node = NULL;
1194         btrfs_release_delayed_node(delayed_node);
1195 }
1196
1197 struct btrfs_async_delayed_node {
1198         struct btrfs_root *root;
1199         struct btrfs_delayed_node *delayed_node;
1200         struct btrfs_work work;
1201 };
1202
1203 static void btrfs_async_run_delayed_node_done(struct btrfs_work *work)
1204 {
1205         struct btrfs_async_delayed_node *async_node;
1206         struct btrfs_trans_handle *trans;
1207         struct btrfs_path *path;
1208         struct btrfs_delayed_node *delayed_node = NULL;
1209         struct btrfs_root *root;
1210         struct btrfs_block_rsv *block_rsv;
1211         unsigned long nr = 0;
1212         int need_requeue = 0;
1213         int ret;
1214
1215         async_node = container_of(work, struct btrfs_async_delayed_node, work);
1216
1217         path = btrfs_alloc_path();
1218         if (!path)
1219                 goto out;
1220         path->leave_spinning = 1;
1221
1222         delayed_node = async_node->delayed_node;
1223         root = delayed_node->root;
1224
1225         trans = btrfs_join_transaction(root);
1226         if (IS_ERR(trans))
1227                 goto free_path;
1228
1229         block_rsv = trans->block_rsv;
1230         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1231
1232         ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
1233         if (!ret)
1234                 ret = btrfs_delete_delayed_items(trans, path, root,
1235                                                  delayed_node);
1236
1237         if (!ret)
1238                 btrfs_update_delayed_inode(trans, root, path, delayed_node);
1239
1240         /*
1241          * Maybe new delayed items have been inserted, so we need requeue
1242          * the work. Besides that, we must dequeue the empty delayed nodes
1243          * to avoid the race between delayed items balance and the worker.
1244          * The race like this:
1245          *      Task1                           Worker thread
1246          *                                      count == 0, needn't requeue
1247          *                                        also needn't insert the
1248          *                                        delayed node into prepare
1249          *                                        list again.
1250          *      add lots of delayed items
1251          *      queue the delayed node
1252          *        already in the list,
1253          *        and not in the prepare
1254          *        list, it means the delayed
1255          *        node is being dealt with
1256          *        by the worker.
1257          *      do delayed items balance
1258          *        the delayed node is being
1259          *        dealt with by the worker
1260          *        now, just wait.
1261          *                                      the worker goto idle.
1262          * Task1 will sleep until the transaction is commited.
1263          */
1264         mutex_lock(&delayed_node->mutex);
1265         if (delayed_node->count)
1266                 need_requeue = 1;
1267         else
1268                 btrfs_dequeue_delayed_node(root->fs_info->delayed_root,
1269                                            delayed_node);
1270         mutex_unlock(&delayed_node->mutex);
1271
1272         nr = trans->blocks_used;
1273
1274         trans->block_rsv = block_rsv;
1275         btrfs_end_transaction_dmeta(trans, root);
1276         __btrfs_btree_balance_dirty(root, nr);
1277 free_path:
1278         btrfs_free_path(path);
1279 out:
1280         if (need_requeue)
1281                 btrfs_requeue_work(&async_node->work);
1282         else {
1283                 btrfs_release_prepared_delayed_node(delayed_node);
1284                 kfree(async_node);
1285         }
1286 }
1287
1288 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1289                                      struct btrfs_root *root, int all)
1290 {
1291         struct btrfs_async_delayed_node *async_node;
1292         struct btrfs_delayed_node *curr;
1293         int count = 0;
1294
1295 again:
1296         curr = btrfs_first_prepared_delayed_node(delayed_root);
1297         if (!curr)
1298                 return 0;
1299
1300         async_node = kmalloc(sizeof(*async_node), GFP_NOFS);
1301         if (!async_node) {
1302                 btrfs_release_prepared_delayed_node(curr);
1303                 return -ENOMEM;
1304         }
1305
1306         async_node->root = root;
1307         async_node->delayed_node = curr;
1308
1309         async_node->work.func = btrfs_async_run_delayed_node_done;
1310         async_node->work.flags = 0;
1311
1312         btrfs_queue_worker(&root->fs_info->delayed_workers, &async_node->work);
1313         count++;
1314
1315         if (all || count < 4)
1316                 goto again;
1317
1318         return 0;
1319 }
1320
1321 void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1322 {
1323         struct btrfs_delayed_root *delayed_root;
1324         delayed_root = btrfs_get_delayed_root(root);
1325         WARN_ON(btrfs_first_delayed_node(delayed_root));
1326 }
1327
1328 void btrfs_balance_delayed_items(struct btrfs_root *root)
1329 {
1330         struct btrfs_delayed_root *delayed_root;
1331
1332         delayed_root = btrfs_get_delayed_root(root);
1333
1334         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1335                 return;
1336
1337         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1338                 int ret;
1339                 ret = btrfs_wq_run_delayed_node(delayed_root, root, 1);
1340                 if (ret)
1341                         return;
1342
1343                 wait_event_interruptible_timeout(
1344                                 delayed_root->wait,
1345                                 (atomic_read(&delayed_root->items) <
1346                                  BTRFS_DELAYED_BACKGROUND),
1347                                 HZ);
1348                 return;
1349         }
1350
1351         btrfs_wq_run_delayed_node(delayed_root, root, 0);
1352 }
1353
1354 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1355                                    struct btrfs_root *root, const char *name,
1356                                    int name_len, struct inode *dir,
1357                                    struct btrfs_disk_key *disk_key, u8 type,
1358                                    u64 index)
1359 {
1360         struct btrfs_delayed_node *delayed_node;
1361         struct btrfs_delayed_item *delayed_item;
1362         struct btrfs_dir_item *dir_item;
1363         int ret;
1364
1365         delayed_node = btrfs_get_or_create_delayed_node(dir);
1366         if (IS_ERR(delayed_node))
1367                 return PTR_ERR(delayed_node);
1368
1369         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1370         if (!delayed_item) {
1371                 ret = -ENOMEM;
1372                 goto release_node;
1373         }
1374
1375         ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1376         /*
1377          * we have reserved enough space when we start a new transaction,
1378          * so reserving metadata failure is impossible
1379          */
1380         BUG_ON(ret);
1381
1382         delayed_item->key.objectid = btrfs_ino(dir);
1383         btrfs_set_key_type(&delayed_item->key, BTRFS_DIR_INDEX_KEY);
1384         delayed_item->key.offset = index;
1385
1386         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1387         dir_item->location = *disk_key;
1388         dir_item->transid = cpu_to_le64(trans->transid);
1389         dir_item->data_len = 0;
1390         dir_item->name_len = cpu_to_le16(name_len);
1391         dir_item->type = type;
1392         memcpy((char *)(dir_item + 1), name, name_len);
1393
1394         mutex_lock(&delayed_node->mutex);
1395         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1396         if (unlikely(ret)) {
1397                 printk(KERN_ERR "err add delayed dir index item(name: %s) into "
1398                                 "the insertion tree of the delayed node"
1399                                 "(root id: %llu, inode id: %llu, errno: %d)\n",
1400                                 name,
1401                                 (unsigned long long)delayed_node->root->objectid,
1402                                 (unsigned long long)delayed_node->inode_id,
1403                                 ret);
1404                 BUG();
1405         }
1406         mutex_unlock(&delayed_node->mutex);
1407
1408 release_node:
1409         btrfs_release_delayed_node(delayed_node);
1410         return ret;
1411 }
1412
1413 static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1414                                                struct btrfs_delayed_node *node,
1415                                                struct btrfs_key *key)
1416 {
1417         struct btrfs_delayed_item *item;
1418
1419         mutex_lock(&node->mutex);
1420         item = __btrfs_lookup_delayed_insertion_item(node, key);
1421         if (!item) {
1422                 mutex_unlock(&node->mutex);
1423                 return 1;
1424         }
1425
1426         btrfs_delayed_item_release_metadata(root, item);
1427         btrfs_release_delayed_item(item);
1428         mutex_unlock(&node->mutex);
1429         return 0;
1430 }
1431
1432 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1433                                    struct btrfs_root *root, struct inode *dir,
1434                                    u64 index)
1435 {
1436         struct btrfs_delayed_node *node;
1437         struct btrfs_delayed_item *item;
1438         struct btrfs_key item_key;
1439         int ret;
1440
1441         node = btrfs_get_or_create_delayed_node(dir);
1442         if (IS_ERR(node))
1443                 return PTR_ERR(node);
1444
1445         item_key.objectid = btrfs_ino(dir);
1446         btrfs_set_key_type(&item_key, BTRFS_DIR_INDEX_KEY);
1447         item_key.offset = index;
1448
1449         ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1450         if (!ret)
1451                 goto end;
1452
1453         item = btrfs_alloc_delayed_item(0);
1454         if (!item) {
1455                 ret = -ENOMEM;
1456                 goto end;
1457         }
1458
1459         item->key = item_key;
1460
1461         ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1462         /*
1463          * we have reserved enough space when we start a new transaction,
1464          * so reserving metadata failure is impossible.
1465          */
1466         BUG_ON(ret);
1467
1468         mutex_lock(&node->mutex);
1469         ret = __btrfs_add_delayed_deletion_item(node, item);
1470         if (unlikely(ret)) {
1471                 printk(KERN_ERR "err add delayed dir index item(index: %llu) "
1472                                 "into the deletion tree of the delayed node"
1473                                 "(root id: %llu, inode id: %llu, errno: %d)\n",
1474                                 (unsigned long long)index,
1475                                 (unsigned long long)node->root->objectid,
1476                                 (unsigned long long)node->inode_id,
1477                                 ret);
1478                 BUG();
1479         }
1480         mutex_unlock(&node->mutex);
1481 end:
1482         btrfs_release_delayed_node(node);
1483         return ret;
1484 }
1485
1486 int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1487 {
1488         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1489
1490         if (!delayed_node)
1491                 return -ENOENT;
1492
1493         /*
1494          * Since we have held i_mutex of this directory, it is impossible that
1495          * a new directory index is added into the delayed node and index_cnt
1496          * is updated now. So we needn't lock the delayed node.
1497          */
1498         if (!delayed_node->index_cnt) {
1499                 btrfs_release_delayed_node(delayed_node);
1500                 return -EINVAL;
1501         }
1502
1503         BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1504         btrfs_release_delayed_node(delayed_node);
1505         return 0;
1506 }
1507
1508 void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
1509                              struct list_head *del_list)
1510 {
1511         struct btrfs_delayed_node *delayed_node;
1512         struct btrfs_delayed_item *item;
1513
1514         delayed_node = btrfs_get_delayed_node(inode);
1515         if (!delayed_node)
1516                 return;
1517
1518         mutex_lock(&delayed_node->mutex);
1519         item = __btrfs_first_delayed_insertion_item(delayed_node);
1520         while (item) {
1521                 atomic_inc(&item->refs);
1522                 list_add_tail(&item->readdir_list, ins_list);
1523                 item = __btrfs_next_delayed_item(item);
1524         }
1525
1526         item = __btrfs_first_delayed_deletion_item(delayed_node);
1527         while (item) {
1528                 atomic_inc(&item->refs);
1529                 list_add_tail(&item->readdir_list, del_list);
1530                 item = __btrfs_next_delayed_item(item);
1531         }
1532         mutex_unlock(&delayed_node->mutex);
1533         /*
1534          * This delayed node is still cached in the btrfs inode, so refs
1535          * must be > 1 now, and we needn't check it is going to be freed
1536          * or not.
1537          *
1538          * Besides that, this function is used to read dir, we do not
1539          * insert/delete delayed items in this period. So we also needn't
1540          * requeue or dequeue this delayed node.
1541          */
1542         atomic_dec(&delayed_node->refs);
1543 }
1544
1545 void btrfs_put_delayed_items(struct list_head *ins_list,
1546                              struct list_head *del_list)
1547 {
1548         struct btrfs_delayed_item *curr, *next;
1549
1550         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1551                 list_del(&curr->readdir_list);
1552                 if (atomic_dec_and_test(&curr->refs))
1553                         kfree(curr);
1554         }
1555
1556         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1557                 list_del(&curr->readdir_list);
1558                 if (atomic_dec_and_test(&curr->refs))
1559                         kfree(curr);
1560         }
1561 }
1562
1563 int btrfs_should_delete_dir_index(struct list_head *del_list,
1564                                   u64 index)
1565 {
1566         struct btrfs_delayed_item *curr, *next;
1567         int ret;
1568
1569         if (list_empty(del_list))
1570                 return 0;
1571
1572         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1573                 if (curr->key.offset > index)
1574                         break;
1575
1576                 list_del(&curr->readdir_list);
1577                 ret = (curr->key.offset == index);
1578
1579                 if (atomic_dec_and_test(&curr->refs))
1580                         kfree(curr);
1581
1582                 if (ret)
1583                         return 1;
1584                 else
1585                         continue;
1586         }
1587         return 0;
1588 }
1589
1590 /*
1591  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1592  *
1593  */
1594 int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
1595                                     filldir_t filldir,
1596                                     struct list_head *ins_list)
1597 {
1598         struct btrfs_dir_item *di;
1599         struct btrfs_delayed_item *curr, *next;
1600         struct btrfs_key location;
1601         char *name;
1602         int name_len;
1603         int over = 0;
1604         unsigned char d_type;
1605
1606         if (list_empty(ins_list))
1607                 return 0;
1608
1609         /*
1610          * Changing the data of the delayed item is impossible. So
1611          * we needn't lock them. And we have held i_mutex of the
1612          * directory, nobody can delete any directory indexes now.
1613          */
1614         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1615                 list_del(&curr->readdir_list);
1616
1617                 if (curr->key.offset < filp->f_pos) {
1618                         if (atomic_dec_and_test(&curr->refs))
1619                                 kfree(curr);
1620                         continue;
1621                 }
1622
1623                 filp->f_pos = curr->key.offset;
1624
1625                 di = (struct btrfs_dir_item *)curr->data;
1626                 name = (char *)(di + 1);
1627                 name_len = le16_to_cpu(di->name_len);
1628
1629                 d_type = btrfs_filetype_table[di->type];
1630                 btrfs_disk_key_to_cpu(&location, &di->location);
1631
1632                 over = filldir(dirent, name, name_len, curr->key.offset,
1633                                location.objectid, d_type);
1634
1635                 if (atomic_dec_and_test(&curr->refs))
1636                         kfree(curr);
1637
1638                 if (over)
1639                         return 1;
1640         }
1641         return 0;
1642 }
1643
1644 BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item,
1645                          generation, 64);
1646 BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item,
1647                          sequence, 64);
1648 BTRFS_SETGET_STACK_FUNCS(stack_inode_transid, struct btrfs_inode_item,
1649                          transid, 64);
1650 BTRFS_SETGET_STACK_FUNCS(stack_inode_size, struct btrfs_inode_item, size, 64);
1651 BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes, struct btrfs_inode_item,
1652                          nbytes, 64);
1653 BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group, struct btrfs_inode_item,
1654                          block_group, 64);
1655 BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink, struct btrfs_inode_item, nlink, 32);
1656 BTRFS_SETGET_STACK_FUNCS(stack_inode_uid, struct btrfs_inode_item, uid, 32);
1657 BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32);
1658 BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32);
1659 BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64);
1660 BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64);
1661
1662 BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
1663 BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
1664
1665 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1666                                   struct btrfs_inode_item *inode_item,
1667                                   struct inode *inode)
1668 {
1669         btrfs_set_stack_inode_uid(inode_item, inode->i_uid);
1670         btrfs_set_stack_inode_gid(inode_item, inode->i_gid);
1671         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1672         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1673         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1674         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1675         btrfs_set_stack_inode_generation(inode_item,
1676                                          BTRFS_I(inode)->generation);
1677         btrfs_set_stack_inode_sequence(inode_item, BTRFS_I(inode)->sequence);
1678         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1679         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1680         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1681         btrfs_set_stack_inode_block_group(inode_item, 0);
1682
1683         btrfs_set_stack_timespec_sec(btrfs_inode_atime(inode_item),
1684                                      inode->i_atime.tv_sec);
1685         btrfs_set_stack_timespec_nsec(btrfs_inode_atime(inode_item),
1686                                       inode->i_atime.tv_nsec);
1687
1688         btrfs_set_stack_timespec_sec(btrfs_inode_mtime(inode_item),
1689                                      inode->i_mtime.tv_sec);
1690         btrfs_set_stack_timespec_nsec(btrfs_inode_mtime(inode_item),
1691                                       inode->i_mtime.tv_nsec);
1692
1693         btrfs_set_stack_timespec_sec(btrfs_inode_ctime(inode_item),
1694                                      inode->i_ctime.tv_sec);
1695         btrfs_set_stack_timespec_nsec(btrfs_inode_ctime(inode_item),
1696                                       inode->i_ctime.tv_nsec);
1697 }
1698
1699 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1700 {
1701         struct btrfs_delayed_node *delayed_node;
1702         struct btrfs_inode_item *inode_item;
1703         struct btrfs_timespec *tspec;
1704
1705         delayed_node = btrfs_get_delayed_node(inode);
1706         if (!delayed_node)
1707                 return -ENOENT;
1708
1709         mutex_lock(&delayed_node->mutex);
1710         if (!delayed_node->inode_dirty) {
1711                 mutex_unlock(&delayed_node->mutex);
1712                 btrfs_release_delayed_node(delayed_node);
1713                 return -ENOENT;
1714         }
1715
1716         inode_item = &delayed_node->inode_item;
1717
1718         inode->i_uid = btrfs_stack_inode_uid(inode_item);
1719         inode->i_gid = btrfs_stack_inode_gid(inode_item);
1720         btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1721         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1722         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1723         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1724         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1725         BTRFS_I(inode)->sequence = btrfs_stack_inode_sequence(inode_item);
1726         inode->i_rdev = 0;
1727         *rdev = btrfs_stack_inode_rdev(inode_item);
1728         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1729
1730         tspec = btrfs_inode_atime(inode_item);
1731         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(tspec);
1732         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1733
1734         tspec = btrfs_inode_mtime(inode_item);
1735         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(tspec);
1736         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1737
1738         tspec = btrfs_inode_ctime(inode_item);
1739         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(tspec);
1740         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1741
1742         inode->i_generation = BTRFS_I(inode)->generation;
1743         BTRFS_I(inode)->index_cnt = (u64)-1;
1744
1745         mutex_unlock(&delayed_node->mutex);
1746         btrfs_release_delayed_node(delayed_node);
1747         return 0;
1748 }
1749
1750 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1751                                struct btrfs_root *root, struct inode *inode)
1752 {
1753         struct btrfs_delayed_node *delayed_node;
1754         int ret = 0;
1755
1756         delayed_node = btrfs_get_or_create_delayed_node(inode);
1757         if (IS_ERR(delayed_node))
1758                 return PTR_ERR(delayed_node);
1759
1760         mutex_lock(&delayed_node->mutex);
1761         if (delayed_node->inode_dirty) {
1762                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1763                 goto release_node;
1764         }
1765
1766         ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1767                                                    delayed_node);
1768         if (ret)
1769                 goto release_node;
1770
1771         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1772         delayed_node->inode_dirty = 1;
1773         delayed_node->count++;
1774         atomic_inc(&root->fs_info->delayed_root->items);
1775 release_node:
1776         mutex_unlock(&delayed_node->mutex);
1777         btrfs_release_delayed_node(delayed_node);
1778         return ret;
1779 }
1780
1781 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1782 {
1783         struct btrfs_root *root = delayed_node->root;
1784         struct btrfs_delayed_item *curr_item, *prev_item;
1785
1786         mutex_lock(&delayed_node->mutex);
1787         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1788         while (curr_item) {
1789                 btrfs_delayed_item_release_metadata(root, curr_item);
1790                 prev_item = curr_item;
1791                 curr_item = __btrfs_next_delayed_item(prev_item);
1792                 btrfs_release_delayed_item(prev_item);
1793         }
1794
1795         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1796         while (curr_item) {
1797                 btrfs_delayed_item_release_metadata(root, curr_item);
1798                 prev_item = curr_item;
1799                 curr_item = __btrfs_next_delayed_item(prev_item);
1800                 btrfs_release_delayed_item(prev_item);
1801         }
1802
1803         if (delayed_node->inode_dirty) {
1804                 btrfs_delayed_inode_release_metadata(root, delayed_node);
1805                 btrfs_release_delayed_inode(delayed_node);
1806         }
1807         mutex_unlock(&delayed_node->mutex);
1808 }
1809
1810 void btrfs_kill_delayed_inode_items(struct inode *inode)
1811 {
1812         struct btrfs_delayed_node *delayed_node;
1813
1814         delayed_node = btrfs_get_delayed_node(inode);
1815         if (!delayed_node)
1816                 return;
1817
1818         __btrfs_kill_delayed_node(delayed_node);
1819         btrfs_release_delayed_node(delayed_node);
1820 }
1821
1822 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1823 {
1824         u64 inode_id = 0;
1825         struct btrfs_delayed_node *delayed_nodes[8];
1826         int i, n;
1827
1828         while (1) {
1829                 spin_lock(&root->inode_lock);
1830                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1831                                            (void **)delayed_nodes, inode_id,
1832                                            ARRAY_SIZE(delayed_nodes));
1833                 if (!n) {
1834                         spin_unlock(&root->inode_lock);
1835                         break;
1836                 }
1837
1838                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1839
1840                 for (i = 0; i < n; i++)
1841                         atomic_inc(&delayed_nodes[i]->refs);
1842                 spin_unlock(&root->inode_lock);
1843
1844                 for (i = 0; i < n; i++) {
1845                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1846                         btrfs_release_delayed_node(delayed_nodes[i]);
1847                 }
1848         }
1849 }