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TOMOYO Linux Cross Reference
Linux/fs/btrfs/delayed-inode.c

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  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 #include "ctree.h"
 25 
 26 #define BTRFS_DELAYED_WRITEBACK         512
 27 #define BTRFS_DELAYED_BACKGROUND        128
 28 #define BTRFS_DELAYED_BATCH             16
 29 
 30 static struct kmem_cache *delayed_node_cache;
 31 
 32 int __init btrfs_delayed_inode_init(void)
 33 {
 34         delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
 35                                         sizeof(struct btrfs_delayed_node),
 36                                         0,
 37                                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
 38                                         NULL);
 39         if (!delayed_node_cache)
 40                 return -ENOMEM;
 41         return 0;
 42 }
 43 
 44 void btrfs_delayed_inode_exit(void)
 45 {
 46         if (delayed_node_cache)
 47                 kmem_cache_destroy(delayed_node_cache);
 48 }
 49 
 50 static inline void btrfs_init_delayed_node(
 51                                 struct btrfs_delayed_node *delayed_node,
 52                                 struct btrfs_root *root, u64 inode_id)
 53 {
 54         delayed_node->root = root;
 55         delayed_node->inode_id = inode_id;
 56         atomic_set(&delayed_node->refs, 0);
 57         delayed_node->count = 0;
 58         delayed_node->flags = 0;
 59         delayed_node->ins_root = RB_ROOT;
 60         delayed_node->del_root = RB_ROOT;
 61         mutex_init(&delayed_node->mutex);
 62         delayed_node->index_cnt = 0;
 63         INIT_LIST_HEAD(&delayed_node->n_list);
 64         INIT_LIST_HEAD(&delayed_node->p_list);
 65         delayed_node->bytes_reserved = 0;
 66         memset(&delayed_node->inode_item, 0, sizeof(delayed_node->inode_item));
 67 }
 68 
 69 static inline int btrfs_is_continuous_delayed_item(
 70                                         struct btrfs_delayed_item *item1,
 71                                         struct btrfs_delayed_item *item2)
 72 {
 73         if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
 74             item1->key.objectid == item2->key.objectid &&
 75             item1->key.type == item2->key.type &&
 76             item1->key.offset + 1 == item2->key.offset)
 77                 return 1;
 78         return 0;
 79 }
 80 
 81 static inline struct btrfs_delayed_root *btrfs_get_delayed_root(
 82                                                         struct btrfs_root *root)
 83 {
 84         return root->fs_info->delayed_root;
 85 }
 86 
 87 static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
 88 {
 89         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 90         struct btrfs_root *root = btrfs_inode->root;
 91         u64 ino = btrfs_ino(inode);
 92         struct btrfs_delayed_node *node;
 93 
 94         node = ACCESS_ONCE(btrfs_inode->delayed_node);
 95         if (node) {
 96                 atomic_inc(&node->refs);
 97                 return node;
 98         }
 99 
100         spin_lock(&root->inode_lock);
101         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
102         if (node) {
103                 if (btrfs_inode->delayed_node) {
104                         atomic_inc(&node->refs);        /* can be accessed */
105                         BUG_ON(btrfs_inode->delayed_node != node);
106                         spin_unlock(&root->inode_lock);
107                         return node;
108                 }
109                 btrfs_inode->delayed_node = node;
110                 /* can be accessed and cached in the inode */
111                 atomic_add(2, &node->refs);
112                 spin_unlock(&root->inode_lock);
113                 return node;
114         }
115         spin_unlock(&root->inode_lock);
116 
117         return NULL;
118 }
119 
120 /* Will return either the node or PTR_ERR(-ENOMEM) */
121 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
122                                                         struct inode *inode)
123 {
124         struct btrfs_delayed_node *node;
125         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
126         struct btrfs_root *root = btrfs_inode->root;
127         u64 ino = btrfs_ino(inode);
128         int ret;
129 
130 again:
131         node = btrfs_get_delayed_node(inode);
132         if (node)
133                 return node;
134 
135         node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
136         if (!node)
137                 return ERR_PTR(-ENOMEM);
138         btrfs_init_delayed_node(node, root, ino);
139 
140         /* cached in the btrfs inode and can be accessed */
141         atomic_add(2, &node->refs);
142 
143         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
144         if (ret) {
145                 kmem_cache_free(delayed_node_cache, node);
146                 return ERR_PTR(ret);
147         }
148 
149         spin_lock(&root->inode_lock);
150         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
151         if (ret == -EEXIST) {
152                 spin_unlock(&root->inode_lock);
153                 kmem_cache_free(delayed_node_cache, node);
154                 radix_tree_preload_end();
155                 goto again;
156         }
157         btrfs_inode->delayed_node = node;
158         spin_unlock(&root->inode_lock);
159         radix_tree_preload_end();
160 
161         return node;
162 }
163 
164 /*
165  * Call it when holding delayed_node->mutex
166  *
167  * If mod = 1, add this node into the prepared list.
168  */
169 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
170                                      struct btrfs_delayed_node *node,
171                                      int mod)
172 {
173         spin_lock(&root->lock);
174         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
175                 if (!list_empty(&node->p_list))
176                         list_move_tail(&node->p_list, &root->prepare_list);
177                 else if (mod)
178                         list_add_tail(&node->p_list, &root->prepare_list);
179         } else {
180                 list_add_tail(&node->n_list, &root->node_list);
181                 list_add_tail(&node->p_list, &root->prepare_list);
182                 atomic_inc(&node->refs);        /* inserted into list */
183                 root->nodes++;
184                 set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
185         }
186         spin_unlock(&root->lock);
187 }
188 
189 /* Call it when holding delayed_node->mutex */
190 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
191                                        struct btrfs_delayed_node *node)
192 {
193         spin_lock(&root->lock);
194         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
195                 root->nodes--;
196                 atomic_dec(&node->refs);        /* not in the list */
197                 list_del_init(&node->n_list);
198                 if (!list_empty(&node->p_list))
199                         list_del_init(&node->p_list);
200                 clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
201         }
202         spin_unlock(&root->lock);
203 }
204 
205 static struct btrfs_delayed_node *btrfs_first_delayed_node(
206                         struct btrfs_delayed_root *delayed_root)
207 {
208         struct list_head *p;
209         struct btrfs_delayed_node *node = NULL;
210 
211         spin_lock(&delayed_root->lock);
212         if (list_empty(&delayed_root->node_list))
213                 goto out;
214 
215         p = delayed_root->node_list.next;
216         node = list_entry(p, struct btrfs_delayed_node, n_list);
217         atomic_inc(&node->refs);
218 out:
219         spin_unlock(&delayed_root->lock);
220 
221         return node;
222 }
223 
224 static struct btrfs_delayed_node *btrfs_next_delayed_node(
225                                                 struct btrfs_delayed_node *node)
226 {
227         struct btrfs_delayed_root *delayed_root;
228         struct list_head *p;
229         struct btrfs_delayed_node *next = NULL;
230 
231         delayed_root = node->root->fs_info->delayed_root;
232         spin_lock(&delayed_root->lock);
233         if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
234                 /* not in the list */
235                 if (list_empty(&delayed_root->node_list))
236                         goto out;
237                 p = delayed_root->node_list.next;
238         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
239                 goto out;
240         else
241                 p = node->n_list.next;
242 
243         next = list_entry(p, struct btrfs_delayed_node, n_list);
244         atomic_inc(&next->refs);
245 out:
246         spin_unlock(&delayed_root->lock);
247 
248         return next;
249 }
250 
251 static void __btrfs_release_delayed_node(
252                                 struct btrfs_delayed_node *delayed_node,
253                                 int mod)
254 {
255         struct btrfs_delayed_root *delayed_root;
256 
257         if (!delayed_node)
258                 return;
259 
260         delayed_root = delayed_node->root->fs_info->delayed_root;
261 
262         mutex_lock(&delayed_node->mutex);
263         if (delayed_node->count)
264                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
265         else
266                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
267         mutex_unlock(&delayed_node->mutex);
268 
269         if (atomic_dec_and_test(&delayed_node->refs)) {
270                 bool free = false;
271                 struct btrfs_root *root = delayed_node->root;
272                 spin_lock(&root->inode_lock);
273                 if (atomic_read(&delayed_node->refs) == 0) {
274                         radix_tree_delete(&root->delayed_nodes_tree,
275                                           delayed_node->inode_id);
276                         free = true;
277                 }
278                 spin_unlock(&root->inode_lock);
279                 if (free)
280                         kmem_cache_free(delayed_node_cache, delayed_node);
281         }
282 }
283 
284 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
285 {
286         __btrfs_release_delayed_node(node, 0);
287 }
288 
289 static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
290                                         struct btrfs_delayed_root *delayed_root)
291 {
292         struct list_head *p;
293         struct btrfs_delayed_node *node = NULL;
294 
295         spin_lock(&delayed_root->lock);
296         if (list_empty(&delayed_root->prepare_list))
297                 goto out;
298 
299         p = delayed_root->prepare_list.next;
300         list_del_init(p);
301         node = list_entry(p, struct btrfs_delayed_node, p_list);
302         atomic_inc(&node->refs);
303 out:
304         spin_unlock(&delayed_root->lock);
305 
306         return node;
307 }
308 
309 static inline void btrfs_release_prepared_delayed_node(
310                                         struct btrfs_delayed_node *node)
311 {
312         __btrfs_release_delayed_node(node, 1);
313 }
314 
315 static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
316 {
317         struct btrfs_delayed_item *item;
318         item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
319         if (item) {
320                 item->data_len = data_len;
321                 item->ins_or_del = 0;
322                 item->bytes_reserved = 0;
323                 item->delayed_node = NULL;
324                 atomic_set(&item->refs, 1);
325         }
326         return item;
327 }
328 
329 /*
330  * __btrfs_lookup_delayed_item - look up the delayed item by key
331  * @delayed_node: pointer to the delayed node
332  * @key:          the key to look up
333  * @prev:         used to store the prev item if the right item isn't found
334  * @next:         used to store the next item if the right item isn't found
335  *
336  * Note: if we don't find the right item, we will return the prev item and
337  * the next item.
338  */
339 static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
340                                 struct rb_root *root,
341                                 struct btrfs_key *key,
342                                 struct btrfs_delayed_item **prev,
343                                 struct btrfs_delayed_item **next)
344 {
345         struct rb_node *node, *prev_node = NULL;
346         struct btrfs_delayed_item *delayed_item = NULL;
347         int ret = 0;
348 
349         node = root->rb_node;
350 
351         while (node) {
352                 delayed_item = rb_entry(node, struct btrfs_delayed_item,
353                                         rb_node);
354                 prev_node = node;
355                 ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
356                 if (ret < 0)
357                         node = node->rb_right;
358                 else if (ret > 0)
359                         node = node->rb_left;
360                 else
361                         return delayed_item;
362         }
363 
364         if (prev) {
365                 if (!prev_node)
366                         *prev = NULL;
367                 else if (ret < 0)
368                         *prev = delayed_item;
369                 else if ((node = rb_prev(prev_node)) != NULL) {
370                         *prev = rb_entry(node, struct btrfs_delayed_item,
371                                          rb_node);
372                 } else
373                         *prev = NULL;
374         }
375 
376         if (next) {
377                 if (!prev_node)
378                         *next = NULL;
379                 else if (ret > 0)
380                         *next = delayed_item;
381                 else if ((node = rb_next(prev_node)) != NULL) {
382                         *next = rb_entry(node, struct btrfs_delayed_item,
383                                          rb_node);
384                 } else
385                         *next = NULL;
386         }
387         return NULL;
388 }
389 
390 static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
391                                         struct btrfs_delayed_node *delayed_node,
392                                         struct btrfs_key *key)
393 {
394         struct btrfs_delayed_item *item;
395 
396         item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
397                                            NULL, NULL);
398         return item;
399 }
400 
401 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
402                                     struct btrfs_delayed_item *ins,
403                                     int action)
404 {
405         struct rb_node **p, *node;
406         struct rb_node *parent_node = NULL;
407         struct rb_root *root;
408         struct btrfs_delayed_item *item;
409         int cmp;
410 
411         if (action == BTRFS_DELAYED_INSERTION_ITEM)
412                 root = &delayed_node->ins_root;
413         else if (action == BTRFS_DELAYED_DELETION_ITEM)
414                 root = &delayed_node->del_root;
415         else
416                 BUG();
417         p = &root->rb_node;
418         node = &ins->rb_node;
419 
420         while (*p) {
421                 parent_node = *p;
422                 item = rb_entry(parent_node, struct btrfs_delayed_item,
423                                  rb_node);
424 
425                 cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
426                 if (cmp < 0)
427                         p = &(*p)->rb_right;
428                 else if (cmp > 0)
429                         p = &(*p)->rb_left;
430                 else
431                         return -EEXIST;
432         }
433 
434         rb_link_node(node, parent_node, p);
435         rb_insert_color(node, root);
436         ins->delayed_node = delayed_node;
437         ins->ins_or_del = action;
438 
439         if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
440             action == BTRFS_DELAYED_INSERTION_ITEM &&
441             ins->key.offset >= delayed_node->index_cnt)
442                         delayed_node->index_cnt = ins->key.offset + 1;
443 
444         delayed_node->count++;
445         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
446         return 0;
447 }
448 
449 static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
450                                               struct btrfs_delayed_item *item)
451 {
452         return __btrfs_add_delayed_item(node, item,
453                                         BTRFS_DELAYED_INSERTION_ITEM);
454 }
455 
456 static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
457                                              struct btrfs_delayed_item *item)
458 {
459         return __btrfs_add_delayed_item(node, item,
460                                         BTRFS_DELAYED_DELETION_ITEM);
461 }
462 
463 static void finish_one_item(struct btrfs_delayed_root *delayed_root)
464 {
465         int seq = atomic_inc_return(&delayed_root->items_seq);
466         if ((atomic_dec_return(&delayed_root->items) <
467             BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0) &&
468             waitqueue_active(&delayed_root->wait))
469                 wake_up(&delayed_root->wait);
470 }
471 
472 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
473 {
474         struct rb_root *root;
475         struct btrfs_delayed_root *delayed_root;
476 
477         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
478 
479         BUG_ON(!delayed_root);
480         BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
481                delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
482 
483         if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
484                 root = &delayed_item->delayed_node->ins_root;
485         else
486                 root = &delayed_item->delayed_node->del_root;
487 
488         rb_erase(&delayed_item->rb_node, root);
489         delayed_item->delayed_node->count--;
490 
491         finish_one_item(delayed_root);
492 }
493 
494 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
495 {
496         if (item) {
497                 __btrfs_remove_delayed_item(item);
498                 if (atomic_dec_and_test(&item->refs))
499                         kfree(item);
500         }
501 }
502 
503 static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
504                                         struct btrfs_delayed_node *delayed_node)
505 {
506         struct rb_node *p;
507         struct btrfs_delayed_item *item = NULL;
508 
509         p = rb_first(&delayed_node->ins_root);
510         if (p)
511                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
512 
513         return item;
514 }
515 
516 static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
517                                         struct btrfs_delayed_node *delayed_node)
518 {
519         struct rb_node *p;
520         struct btrfs_delayed_item *item = NULL;
521 
522         p = rb_first(&delayed_node->del_root);
523         if (p)
524                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
525 
526         return item;
527 }
528 
529 static struct btrfs_delayed_item *__btrfs_next_delayed_item(
530                                                 struct btrfs_delayed_item *item)
531 {
532         struct rb_node *p;
533         struct btrfs_delayed_item *next = NULL;
534 
535         p = rb_next(&item->rb_node);
536         if (p)
537                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
538 
539         return next;
540 }
541 
542 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
543                                                struct btrfs_root *root,
544                                                struct btrfs_delayed_item *item)
545 {
546         struct btrfs_block_rsv *src_rsv;
547         struct btrfs_block_rsv *dst_rsv;
548         u64 num_bytes;
549         int ret;
550 
551         if (!trans->bytes_reserved)
552                 return 0;
553 
554         src_rsv = trans->block_rsv;
555         dst_rsv = &root->fs_info->delayed_block_rsv;
556 
557         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
558         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
559         if (!ret) {
560                 trace_btrfs_space_reservation(root->fs_info, "delayed_item",
561                                               item->key.objectid,
562                                               num_bytes, 1);
563                 item->bytes_reserved = num_bytes;
564         }
565 
566         return ret;
567 }
568 
569 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
570                                                 struct btrfs_delayed_item *item)
571 {
572         struct btrfs_block_rsv *rsv;
573 
574         if (!item->bytes_reserved)
575                 return;
576 
577         rsv = &root->fs_info->delayed_block_rsv;
578         trace_btrfs_space_reservation(root->fs_info, "delayed_item",
579                                       item->key.objectid, item->bytes_reserved,
580                                       0);
581         btrfs_block_rsv_release(root, rsv,
582                                 item->bytes_reserved);
583 }
584 
585 static int btrfs_delayed_inode_reserve_metadata(
586                                         struct btrfs_trans_handle *trans,
587                                         struct btrfs_root *root,
588                                         struct inode *inode,
589                                         struct btrfs_delayed_node *node)
590 {
591         struct btrfs_block_rsv *src_rsv;
592         struct btrfs_block_rsv *dst_rsv;
593         u64 num_bytes;
594         int ret;
595         bool release = false;
596 
597         src_rsv = trans->block_rsv;
598         dst_rsv = &root->fs_info->delayed_block_rsv;
599 
600         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
601 
602         /*
603          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
604          * which doesn't reserve space for speed.  This is a problem since we
605          * still need to reserve space for this update, so try to reserve the
606          * space.
607          *
608          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
609          * we're accounted for.
610          */
611         if (!src_rsv || (!trans->bytes_reserved &&
612                          src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
613                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
614                                           BTRFS_RESERVE_NO_FLUSH);
615                 /*
616                  * Since we're under a transaction reserve_metadata_bytes could
617                  * try to commit the transaction which will make it return
618                  * EAGAIN to make us stop the transaction we have, so return
619                  * ENOSPC instead so that btrfs_dirty_inode knows what to do.
620                  */
621                 if (ret == -EAGAIN)
622                         ret = -ENOSPC;
623                 if (!ret) {
624                         node->bytes_reserved = num_bytes;
625                         trace_btrfs_space_reservation(root->fs_info,
626                                                       "delayed_inode",
627                                                       btrfs_ino(inode),
628                                                       num_bytes, 1);
629                 }
630                 return ret;
631         } else if (src_rsv->type == BTRFS_BLOCK_RSV_DELALLOC) {
632                 spin_lock(&BTRFS_I(inode)->lock);
633                 if (test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
634                                        &BTRFS_I(inode)->runtime_flags)) {
635                         spin_unlock(&BTRFS_I(inode)->lock);
636                         release = true;
637                         goto migrate;
638                 }
639                 spin_unlock(&BTRFS_I(inode)->lock);
640 
641                 /* Ok we didn't have space pre-reserved.  This shouldn't happen
642                  * too often but it can happen if we do delalloc to an existing
643                  * inode which gets dirtied because of the time update, and then
644                  * isn't touched again until after the transaction commits and
645                  * then we try to write out the data.  First try to be nice and
646                  * reserve something strictly for us.  If not be a pain and try
647                  * to steal from the delalloc block rsv.
648                  */
649                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
650                                           BTRFS_RESERVE_NO_FLUSH);
651                 if (!ret)
652                         goto out;
653 
654                 ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
655                 if (!WARN_ON(ret))
656                         goto out;
657 
658                 /*
659                  * Ok this is a problem, let's just steal from the global rsv
660                  * since this really shouldn't happen that often.
661                  */
662                 ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
663                                               dst_rsv, num_bytes);
664                 goto out;
665         }
666 
667 migrate:
668         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
669 
670 out:
671         /*
672          * Migrate only takes a reservation, it doesn't touch the size of the
673          * block_rsv.  This is to simplify people who don't normally have things
674          * migrated from their block rsv.  If they go to release their
675          * reservation, that will decrease the size as well, so if migrate
676          * reduced size we'd end up with a negative size.  But for the
677          * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
678          * but we could in fact do this reserve/migrate dance several times
679          * between the time we did the original reservation and we'd clean it
680          * up.  So to take care of this, release the space for the meta
681          * reservation here.  I think it may be time for a documentation page on
682          * how block rsvs. work.
683          */
684         if (!ret) {
685                 trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
686                                               btrfs_ino(inode), num_bytes, 1);
687                 node->bytes_reserved = num_bytes;
688         }
689 
690         if (release) {
691                 trace_btrfs_space_reservation(root->fs_info, "delalloc",
692                                               btrfs_ino(inode), num_bytes, 0);
693                 btrfs_block_rsv_release(root, src_rsv, num_bytes);
694         }
695 
696         return ret;
697 }
698 
699 static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
700                                                 struct btrfs_delayed_node *node)
701 {
702         struct btrfs_block_rsv *rsv;
703 
704         if (!node->bytes_reserved)
705                 return;
706 
707         rsv = &root->fs_info->delayed_block_rsv;
708         trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
709                                       node->inode_id, node->bytes_reserved, 0);
710         btrfs_block_rsv_release(root, rsv,
711                                 node->bytes_reserved);
712         node->bytes_reserved = 0;
713 }
714 
715 /*
716  * This helper will insert some continuous items into the same leaf according
717  * to the free space of the leaf.
718  */
719 static int btrfs_batch_insert_items(struct btrfs_root *root,
720                                     struct btrfs_path *path,
721                                     struct btrfs_delayed_item *item)
722 {
723         struct btrfs_delayed_item *curr, *next;
724         int free_space;
725         int total_data_size = 0, total_size = 0;
726         struct extent_buffer *leaf;
727         char *data_ptr;
728         struct btrfs_key *keys;
729         u32 *data_size;
730         struct list_head head;
731         int slot;
732         int nitems;
733         int i;
734         int ret = 0;
735 
736         BUG_ON(!path->nodes[0]);
737 
738         leaf = path->nodes[0];
739         free_space = btrfs_leaf_free_space(root, leaf);
740         INIT_LIST_HEAD(&head);
741 
742         next = item;
743         nitems = 0;
744 
745         /*
746          * count the number of the continuous items that we can insert in batch
747          */
748         while (total_size + next->data_len + sizeof(struct btrfs_item) <=
749                free_space) {
750                 total_data_size += next->data_len;
751                 total_size += next->data_len + sizeof(struct btrfs_item);
752                 list_add_tail(&next->tree_list, &head);
753                 nitems++;
754 
755                 curr = next;
756                 next = __btrfs_next_delayed_item(curr);
757                 if (!next)
758                         break;
759 
760                 if (!btrfs_is_continuous_delayed_item(curr, next))
761                         break;
762         }
763 
764         if (!nitems) {
765                 ret = 0;
766                 goto out;
767         }
768 
769         /*
770          * we need allocate some memory space, but it might cause the task
771          * to sleep, so we set all locked nodes in the path to blocking locks
772          * first.
773          */
774         btrfs_set_path_blocking(path);
775 
776         keys = kmalloc_array(nitems, sizeof(struct btrfs_key), GFP_NOFS);
777         if (!keys) {
778                 ret = -ENOMEM;
779                 goto out;
780         }
781 
782         data_size = kmalloc_array(nitems, sizeof(u32), GFP_NOFS);
783         if (!data_size) {
784                 ret = -ENOMEM;
785                 goto error;
786         }
787 
788         /* get keys of all the delayed items */
789         i = 0;
790         list_for_each_entry(next, &head, tree_list) {
791                 keys[i] = next->key;
792                 data_size[i] = next->data_len;
793                 i++;
794         }
795 
796         /* reset all the locked nodes in the patch to spinning locks. */
797         btrfs_clear_path_blocking(path, NULL, 0);
798 
799         /* insert the keys of the items */
800         setup_items_for_insert(root, path, keys, data_size,
801                                total_data_size, total_size, nitems);
802 
803         /* insert the dir index items */
804         slot = path->slots[0];
805         list_for_each_entry_safe(curr, next, &head, tree_list) {
806                 data_ptr = btrfs_item_ptr(leaf, slot, char);
807                 write_extent_buffer(leaf, &curr->data,
808                                     (unsigned long)data_ptr,
809                                     curr->data_len);
810                 slot++;
811 
812                 btrfs_delayed_item_release_metadata(root, curr);
813 
814                 list_del(&curr->tree_list);
815                 btrfs_release_delayed_item(curr);
816         }
817 
818 error:
819         kfree(data_size);
820         kfree(keys);
821 out:
822         return ret;
823 }
824 
825 /*
826  * This helper can just do simple insertion that needn't extend item for new
827  * data, such as directory name index insertion, inode insertion.
828  */
829 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
830                                      struct btrfs_root *root,
831                                      struct btrfs_path *path,
832                                      struct btrfs_delayed_item *delayed_item)
833 {
834         struct extent_buffer *leaf;
835         char *ptr;
836         int ret;
837 
838         ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
839                                       delayed_item->data_len);
840         if (ret < 0 && ret != -EEXIST)
841                 return ret;
842 
843         leaf = path->nodes[0];
844 
845         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
846 
847         write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
848                             delayed_item->data_len);
849         btrfs_mark_buffer_dirty(leaf);
850 
851         btrfs_delayed_item_release_metadata(root, delayed_item);
852         return 0;
853 }
854 
855 /*
856  * we insert an item first, then if there are some continuous items, we try
857  * to insert those items into the same leaf.
858  */
859 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
860                                       struct btrfs_path *path,
861                                       struct btrfs_root *root,
862                                       struct btrfs_delayed_node *node)
863 {
864         struct btrfs_delayed_item *curr, *prev;
865         int ret = 0;
866 
867 do_again:
868         mutex_lock(&node->mutex);
869         curr = __btrfs_first_delayed_insertion_item(node);
870         if (!curr)
871                 goto insert_end;
872 
873         ret = btrfs_insert_delayed_item(trans, root, path, curr);
874         if (ret < 0) {
875                 btrfs_release_path(path);
876                 goto insert_end;
877         }
878 
879         prev = curr;
880         curr = __btrfs_next_delayed_item(prev);
881         if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
882                 /* insert the continuous items into the same leaf */
883                 path->slots[0]++;
884                 btrfs_batch_insert_items(root, path, curr);
885         }
886         btrfs_release_delayed_item(prev);
887         btrfs_mark_buffer_dirty(path->nodes[0]);
888 
889         btrfs_release_path(path);
890         mutex_unlock(&node->mutex);
891         goto do_again;
892 
893 insert_end:
894         mutex_unlock(&node->mutex);
895         return ret;
896 }
897 
898 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
899                                     struct btrfs_root *root,
900                                     struct btrfs_path *path,
901                                     struct btrfs_delayed_item *item)
902 {
903         struct btrfs_delayed_item *curr, *next;
904         struct extent_buffer *leaf;
905         struct btrfs_key key;
906         struct list_head head;
907         int nitems, i, last_item;
908         int ret = 0;
909 
910         BUG_ON(!path->nodes[0]);
911 
912         leaf = path->nodes[0];
913 
914         i = path->slots[0];
915         last_item = btrfs_header_nritems(leaf) - 1;
916         if (i > last_item)
917                 return -ENOENT; /* FIXME: Is errno suitable? */
918 
919         next = item;
920         INIT_LIST_HEAD(&head);
921         btrfs_item_key_to_cpu(leaf, &key, i);
922         nitems = 0;
923         /*
924          * count the number of the dir index items that we can delete in batch
925          */
926         while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
927                 list_add_tail(&next->tree_list, &head);
928                 nitems++;
929 
930                 curr = next;
931                 next = __btrfs_next_delayed_item(curr);
932                 if (!next)
933                         break;
934 
935                 if (!btrfs_is_continuous_delayed_item(curr, next))
936                         break;
937 
938                 i++;
939                 if (i > last_item)
940                         break;
941                 btrfs_item_key_to_cpu(leaf, &key, i);
942         }
943 
944         if (!nitems)
945                 return 0;
946 
947         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
948         if (ret)
949                 goto out;
950 
951         list_for_each_entry_safe(curr, next, &head, tree_list) {
952                 btrfs_delayed_item_release_metadata(root, curr);
953                 list_del(&curr->tree_list);
954                 btrfs_release_delayed_item(curr);
955         }
956 
957 out:
958         return ret;
959 }
960 
961 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
962                                       struct btrfs_path *path,
963                                       struct btrfs_root *root,
964                                       struct btrfs_delayed_node *node)
965 {
966         struct btrfs_delayed_item *curr, *prev;
967         int ret = 0;
968 
969 do_again:
970         mutex_lock(&node->mutex);
971         curr = __btrfs_first_delayed_deletion_item(node);
972         if (!curr)
973                 goto delete_fail;
974 
975         ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
976         if (ret < 0)
977                 goto delete_fail;
978         else if (ret > 0) {
979                 /*
980                  * can't find the item which the node points to, so this node
981                  * is invalid, just drop it.
982                  */
983                 prev = curr;
984                 curr = __btrfs_next_delayed_item(prev);
985                 btrfs_release_delayed_item(prev);
986                 ret = 0;
987                 btrfs_release_path(path);
988                 if (curr) {
989                         mutex_unlock(&node->mutex);
990                         goto do_again;
991                 } else
992                         goto delete_fail;
993         }
994 
995         btrfs_batch_delete_items(trans, root, path, curr);
996         btrfs_release_path(path);
997         mutex_unlock(&node->mutex);
998         goto do_again;
999 
1000 delete_fail:
1001         btrfs_release_path(path);
1002         mutex_unlock(&node->mutex);
1003         return ret;
1004 }
1005 
1006 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
1007 {
1008         struct btrfs_delayed_root *delayed_root;
1009 
1010         if (delayed_node &&
1011             test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1012                 BUG_ON(!delayed_node->root);
1013                 clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1014                 delayed_node->count--;
1015 
1016                 delayed_root = delayed_node->root->fs_info->delayed_root;
1017                 finish_one_item(delayed_root);
1018         }
1019 }
1020 
1021 static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
1022 {
1023         struct btrfs_delayed_root *delayed_root;
1024 
1025         ASSERT(delayed_node->root);
1026         clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1027         delayed_node->count--;
1028 
1029         delayed_root = delayed_node->root->fs_info->delayed_root;
1030         finish_one_item(delayed_root);
1031 }
1032 
1033 static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1034                                         struct btrfs_root *root,
1035                                         struct btrfs_path *path,
1036                                         struct btrfs_delayed_node *node)
1037 {
1038         struct btrfs_key key;
1039         struct btrfs_inode_item *inode_item;
1040         struct extent_buffer *leaf;
1041         int mod;
1042         int ret;
1043 
1044         key.objectid = node->inode_id;
1045         key.type = BTRFS_INODE_ITEM_KEY;
1046         key.offset = 0;
1047 
1048         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1049                 mod = -1;
1050         else
1051                 mod = 1;
1052 
1053         ret = btrfs_lookup_inode(trans, root, path, &key, mod);
1054         if (ret > 0) {
1055                 btrfs_release_path(path);
1056                 return -ENOENT;
1057         } else if (ret < 0) {
1058                 return ret;
1059         }
1060 
1061         leaf = path->nodes[0];
1062         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1063                                     struct btrfs_inode_item);
1064         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1065                             sizeof(struct btrfs_inode_item));
1066         btrfs_mark_buffer_dirty(leaf);
1067 
1068         if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1069                 goto no_iref;
1070 
1071         path->slots[0]++;
1072         if (path->slots[0] >= btrfs_header_nritems(leaf))
1073                 goto search;
1074 again:
1075         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1076         if (key.objectid != node->inode_id)
1077                 goto out;
1078 
1079         if (key.type != BTRFS_INODE_REF_KEY &&
1080             key.type != BTRFS_INODE_EXTREF_KEY)
1081                 goto out;
1082 
1083         /*
1084          * Delayed iref deletion is for the inode who has only one link,
1085          * so there is only one iref. The case that several irefs are
1086          * in the same item doesn't exist.
1087          */
1088         btrfs_del_item(trans, root, path);
1089 out:
1090         btrfs_release_delayed_iref(node);
1091 no_iref:
1092         btrfs_release_path(path);
1093 err_out:
1094         btrfs_delayed_inode_release_metadata(root, node);
1095         btrfs_release_delayed_inode(node);
1096 
1097         return ret;
1098 
1099 search:
1100         btrfs_release_path(path);
1101 
1102         key.type = BTRFS_INODE_EXTREF_KEY;
1103         key.offset = -1;
1104         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1105         if (ret < 0)
1106                 goto err_out;
1107         ASSERT(ret);
1108 
1109         ret = 0;
1110         leaf = path->nodes[0];
1111         path->slots[0]--;
1112         goto again;
1113 }
1114 
1115 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1116                                              struct btrfs_root *root,
1117                                              struct btrfs_path *path,
1118                                              struct btrfs_delayed_node *node)
1119 {
1120         int ret;
1121 
1122         mutex_lock(&node->mutex);
1123         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1124                 mutex_unlock(&node->mutex);
1125                 return 0;
1126         }
1127 
1128         ret = __btrfs_update_delayed_inode(trans, root, path, node);
1129         mutex_unlock(&node->mutex);
1130         return ret;
1131 }
1132 
1133 static inline int
1134 __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1135                                    struct btrfs_path *path,
1136                                    struct btrfs_delayed_node *node)
1137 {
1138         int ret;
1139 
1140         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1141         if (ret)
1142                 return ret;
1143 
1144         ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1145         if (ret)
1146                 return ret;
1147 
1148         ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1149         return ret;
1150 }
1151 
1152 /*
1153  * Called when committing the transaction.
1154  * Returns 0 on success.
1155  * Returns < 0 on error and returns with an aborted transaction with any
1156  * outstanding delayed items cleaned up.
1157  */
1158 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1159                                      struct btrfs_root *root, int nr)
1160 {
1161         struct btrfs_delayed_root *delayed_root;
1162         struct btrfs_delayed_node *curr_node, *prev_node;
1163         struct btrfs_path *path;
1164         struct btrfs_block_rsv *block_rsv;
1165         int ret = 0;
1166         bool count = (nr > 0);
1167 
1168         if (trans->aborted)
1169                 return -EIO;
1170 
1171         path = btrfs_alloc_path();
1172         if (!path)
1173                 return -ENOMEM;
1174         path->leave_spinning = 1;
1175 
1176         block_rsv = trans->block_rsv;
1177         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1178 
1179         delayed_root = btrfs_get_delayed_root(root);
1180 
1181         curr_node = btrfs_first_delayed_node(delayed_root);
1182         while (curr_node && (!count || (count && nr--))) {
1183                 ret = __btrfs_commit_inode_delayed_items(trans, path,
1184                                                          curr_node);
1185                 if (ret) {
1186                         btrfs_release_delayed_node(curr_node);
1187                         curr_node = NULL;
1188                         btrfs_abort_transaction(trans, root, ret);
1189                         break;
1190                 }
1191 
1192                 prev_node = curr_node;
1193                 curr_node = btrfs_next_delayed_node(curr_node);
1194                 btrfs_release_delayed_node(prev_node);
1195         }
1196 
1197         if (curr_node)
1198                 btrfs_release_delayed_node(curr_node);
1199         btrfs_free_path(path);
1200         trans->block_rsv = block_rsv;
1201 
1202         return ret;
1203 }
1204 
1205 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1206                             struct btrfs_root *root)
1207 {
1208         return __btrfs_run_delayed_items(trans, root, -1);
1209 }
1210 
1211 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans,
1212                                struct btrfs_root *root, int nr)
1213 {
1214         return __btrfs_run_delayed_items(trans, root, nr);
1215 }
1216 
1217 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1218                                      struct inode *inode)
1219 {
1220         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1221         struct btrfs_path *path;
1222         struct btrfs_block_rsv *block_rsv;
1223         int ret;
1224 
1225         if (!delayed_node)
1226                 return 0;
1227 
1228         mutex_lock(&delayed_node->mutex);
1229         if (!delayed_node->count) {
1230                 mutex_unlock(&delayed_node->mutex);
1231                 btrfs_release_delayed_node(delayed_node);
1232                 return 0;
1233         }
1234         mutex_unlock(&delayed_node->mutex);
1235 
1236         path = btrfs_alloc_path();
1237         if (!path) {
1238                 btrfs_release_delayed_node(delayed_node);
1239                 return -ENOMEM;
1240         }
1241         path->leave_spinning = 1;
1242 
1243         block_rsv = trans->block_rsv;
1244         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1245 
1246         ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1247 
1248         btrfs_release_delayed_node(delayed_node);
1249         btrfs_free_path(path);
1250         trans->block_rsv = block_rsv;
1251 
1252         return ret;
1253 }
1254 
1255 int btrfs_commit_inode_delayed_inode(struct inode *inode)
1256 {
1257         struct btrfs_trans_handle *trans;
1258         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1259         struct btrfs_path *path;
1260         struct btrfs_block_rsv *block_rsv;
1261         int ret;
1262 
1263         if (!delayed_node)
1264                 return 0;
1265 
1266         mutex_lock(&delayed_node->mutex);
1267         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1268                 mutex_unlock(&delayed_node->mutex);
1269                 btrfs_release_delayed_node(delayed_node);
1270                 return 0;
1271         }
1272         mutex_unlock(&delayed_node->mutex);
1273 
1274         trans = btrfs_join_transaction(delayed_node->root);
1275         if (IS_ERR(trans)) {
1276                 ret = PTR_ERR(trans);
1277                 goto out;
1278         }
1279 
1280         path = btrfs_alloc_path();
1281         if (!path) {
1282                 ret = -ENOMEM;
1283                 goto trans_out;
1284         }
1285         path->leave_spinning = 1;
1286 
1287         block_rsv = trans->block_rsv;
1288         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1289 
1290         mutex_lock(&delayed_node->mutex);
1291         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1292                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1293                                                    path, delayed_node);
1294         else
1295                 ret = 0;
1296         mutex_unlock(&delayed_node->mutex);
1297 
1298         btrfs_free_path(path);
1299         trans->block_rsv = block_rsv;
1300 trans_out:
1301         btrfs_end_transaction(trans, delayed_node->root);
1302         btrfs_btree_balance_dirty(delayed_node->root);
1303 out:
1304         btrfs_release_delayed_node(delayed_node);
1305 
1306         return ret;
1307 }
1308 
1309 void btrfs_remove_delayed_node(struct inode *inode)
1310 {
1311         struct btrfs_delayed_node *delayed_node;
1312 
1313         delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1314         if (!delayed_node)
1315                 return;
1316 
1317         BTRFS_I(inode)->delayed_node = NULL;
1318         btrfs_release_delayed_node(delayed_node);
1319 }
1320 
1321 struct btrfs_async_delayed_work {
1322         struct btrfs_delayed_root *delayed_root;
1323         int nr;
1324         struct btrfs_work work;
1325 };
1326 
1327 static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1328 {
1329         struct btrfs_async_delayed_work *async_work;
1330         struct btrfs_delayed_root *delayed_root;
1331         struct btrfs_trans_handle *trans;
1332         struct btrfs_path *path;
1333         struct btrfs_delayed_node *delayed_node = NULL;
1334         struct btrfs_root *root;
1335         struct btrfs_block_rsv *block_rsv;
1336         int total_done = 0;
1337 
1338         async_work = container_of(work, struct btrfs_async_delayed_work, work);
1339         delayed_root = async_work->delayed_root;
1340 
1341         path = btrfs_alloc_path();
1342         if (!path)
1343                 goto out;
1344 
1345 again:
1346         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND / 2)
1347                 goto free_path;
1348 
1349         delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1350         if (!delayed_node)
1351                 goto free_path;
1352 
1353         path->leave_spinning = 1;
1354         root = delayed_node->root;
1355 
1356         trans = btrfs_join_transaction(root);
1357         if (IS_ERR(trans))
1358                 goto release_path;
1359 
1360         block_rsv = trans->block_rsv;
1361         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1362 
1363         __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1364 
1365         trans->block_rsv = block_rsv;
1366         btrfs_end_transaction(trans, root);
1367         btrfs_btree_balance_dirty_nodelay(root);
1368 
1369 release_path:
1370         btrfs_release_path(path);
1371         total_done++;
1372 
1373         btrfs_release_prepared_delayed_node(delayed_node);
1374         if ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK) ||
1375             total_done < async_work->nr)
1376                 goto again;
1377 
1378 free_path:
1379         btrfs_free_path(path);
1380 out:
1381         wake_up(&delayed_root->wait);
1382         kfree(async_work);
1383 }
1384 
1385 
1386 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1387                                      struct btrfs_fs_info *fs_info, int nr)
1388 {
1389         struct btrfs_async_delayed_work *async_work;
1390 
1391         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND ||
1392             btrfs_workqueue_normal_congested(fs_info->delayed_workers))
1393                 return 0;
1394 
1395         async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1396         if (!async_work)
1397                 return -ENOMEM;
1398 
1399         async_work->delayed_root = delayed_root;
1400         btrfs_init_work(&async_work->work, btrfs_delayed_meta_helper,
1401                         btrfs_async_run_delayed_root, NULL, NULL);
1402         async_work->nr = nr;
1403 
1404         btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
1405         return 0;
1406 }
1407 
1408 void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1409 {
1410         struct btrfs_delayed_root *delayed_root;
1411         delayed_root = btrfs_get_delayed_root(root);
1412         WARN_ON(btrfs_first_delayed_node(delayed_root));
1413 }
1414 
1415 static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1416 {
1417         int val = atomic_read(&delayed_root->items_seq);
1418 
1419         if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1420                 return 1;
1421 
1422         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1423                 return 1;
1424 
1425         return 0;
1426 }
1427 
1428 void btrfs_balance_delayed_items(struct btrfs_root *root)
1429 {
1430         struct btrfs_delayed_root *delayed_root;
1431         struct btrfs_fs_info *fs_info = root->fs_info;
1432 
1433         delayed_root = btrfs_get_delayed_root(root);
1434 
1435         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1436                 return;
1437 
1438         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1439                 int seq;
1440                 int ret;
1441 
1442                 seq = atomic_read(&delayed_root->items_seq);
1443 
1444                 ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
1445                 if (ret)
1446                         return;
1447 
1448                 wait_event_interruptible(delayed_root->wait,
1449                                          could_end_wait(delayed_root, seq));
1450                 return;
1451         }
1452 
1453         btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1454 }
1455 
1456 /* Will return 0 or -ENOMEM */
1457 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1458                                    struct btrfs_root *root, const char *name,
1459                                    int name_len, struct inode *dir,
1460                                    struct btrfs_disk_key *disk_key, u8 type,
1461                                    u64 index)
1462 {
1463         struct btrfs_delayed_node *delayed_node;
1464         struct btrfs_delayed_item *delayed_item;
1465         struct btrfs_dir_item *dir_item;
1466         int ret;
1467 
1468         delayed_node = btrfs_get_or_create_delayed_node(dir);
1469         if (IS_ERR(delayed_node))
1470                 return PTR_ERR(delayed_node);
1471 
1472         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1473         if (!delayed_item) {
1474                 ret = -ENOMEM;
1475                 goto release_node;
1476         }
1477 
1478         delayed_item->key.objectid = btrfs_ino(dir);
1479         delayed_item->key.type = BTRFS_DIR_INDEX_KEY;
1480         delayed_item->key.offset = index;
1481 
1482         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1483         dir_item->location = *disk_key;
1484         btrfs_set_stack_dir_transid(dir_item, trans->transid);
1485         btrfs_set_stack_dir_data_len(dir_item, 0);
1486         btrfs_set_stack_dir_name_len(dir_item, name_len);
1487         btrfs_set_stack_dir_type(dir_item, type);
1488         memcpy((char *)(dir_item + 1), name, name_len);
1489 
1490         ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1491         /*
1492          * we have reserved enough space when we start a new transaction,
1493          * so reserving metadata failure is impossible
1494          */
1495         BUG_ON(ret);
1496 
1497 
1498         mutex_lock(&delayed_node->mutex);
1499         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1500         if (unlikely(ret)) {
1501                 btrfs_err(root->fs_info, "err add delayed dir index item(name: %.*s) "
1502                                 "into the insertion tree of the delayed node"
1503                                 "(root id: %llu, inode id: %llu, errno: %d)",
1504                                 name_len, name, delayed_node->root->objectid,
1505                                 delayed_node->inode_id, ret);
1506                 BUG();
1507         }
1508         mutex_unlock(&delayed_node->mutex);
1509 
1510 release_node:
1511         btrfs_release_delayed_node(delayed_node);
1512         return ret;
1513 }
1514 
1515 static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1516                                                struct btrfs_delayed_node *node,
1517                                                struct btrfs_key *key)
1518 {
1519         struct btrfs_delayed_item *item;
1520 
1521         mutex_lock(&node->mutex);
1522         item = __btrfs_lookup_delayed_insertion_item(node, key);
1523         if (!item) {
1524                 mutex_unlock(&node->mutex);
1525                 return 1;
1526         }
1527 
1528         btrfs_delayed_item_release_metadata(root, item);
1529         btrfs_release_delayed_item(item);
1530         mutex_unlock(&node->mutex);
1531         return 0;
1532 }
1533 
1534 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1535                                    struct btrfs_root *root, struct inode *dir,
1536                                    u64 index)
1537 {
1538         struct btrfs_delayed_node *node;
1539         struct btrfs_delayed_item *item;
1540         struct btrfs_key item_key;
1541         int ret;
1542 
1543         node = btrfs_get_or_create_delayed_node(dir);
1544         if (IS_ERR(node))
1545                 return PTR_ERR(node);
1546 
1547         item_key.objectid = btrfs_ino(dir);
1548         item_key.type = BTRFS_DIR_INDEX_KEY;
1549         item_key.offset = index;
1550 
1551         ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1552         if (!ret)
1553                 goto end;
1554 
1555         item = btrfs_alloc_delayed_item(0);
1556         if (!item) {
1557                 ret = -ENOMEM;
1558                 goto end;
1559         }
1560 
1561         item->key = item_key;
1562 
1563         ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1564         /*
1565          * we have reserved enough space when we start a new transaction,
1566          * so reserving metadata failure is impossible.
1567          */
1568         BUG_ON(ret);
1569 
1570         mutex_lock(&node->mutex);
1571         ret = __btrfs_add_delayed_deletion_item(node, item);
1572         if (unlikely(ret)) {
1573                 btrfs_err(root->fs_info, "err add delayed dir index item(index: %llu) "
1574                                 "into the deletion tree of the delayed node"
1575                                 "(root id: %llu, inode id: %llu, errno: %d)",
1576                                 index, node->root->objectid, node->inode_id,
1577                                 ret);
1578                 BUG();
1579         }
1580         mutex_unlock(&node->mutex);
1581 end:
1582         btrfs_release_delayed_node(node);
1583         return ret;
1584 }
1585 
1586 int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1587 {
1588         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1589 
1590         if (!delayed_node)
1591                 return -ENOENT;
1592 
1593         /*
1594          * Since we have held i_mutex of this directory, it is impossible that
1595          * a new directory index is added into the delayed node and index_cnt
1596          * is updated now. So we needn't lock the delayed node.
1597          */
1598         if (!delayed_node->index_cnt) {
1599                 btrfs_release_delayed_node(delayed_node);
1600                 return -EINVAL;
1601         }
1602 
1603         BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1604         btrfs_release_delayed_node(delayed_node);
1605         return 0;
1606 }
1607 
1608 void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
1609                              struct list_head *del_list)
1610 {
1611         struct btrfs_delayed_node *delayed_node;
1612         struct btrfs_delayed_item *item;
1613 
1614         delayed_node = btrfs_get_delayed_node(inode);
1615         if (!delayed_node)
1616                 return;
1617 
1618         mutex_lock(&delayed_node->mutex);
1619         item = __btrfs_first_delayed_insertion_item(delayed_node);
1620         while (item) {
1621                 atomic_inc(&item->refs);
1622                 list_add_tail(&item->readdir_list, ins_list);
1623                 item = __btrfs_next_delayed_item(item);
1624         }
1625 
1626         item = __btrfs_first_delayed_deletion_item(delayed_node);
1627         while (item) {
1628                 atomic_inc(&item->refs);
1629                 list_add_tail(&item->readdir_list, del_list);
1630                 item = __btrfs_next_delayed_item(item);
1631         }
1632         mutex_unlock(&delayed_node->mutex);
1633         /*
1634          * This delayed node is still cached in the btrfs inode, so refs
1635          * must be > 1 now, and we needn't check it is going to be freed
1636          * or not.
1637          *
1638          * Besides that, this function is used to read dir, we do not
1639          * insert/delete delayed items in this period. So we also needn't
1640          * requeue or dequeue this delayed node.
1641          */
1642         atomic_dec(&delayed_node->refs);
1643 }
1644 
1645 void btrfs_put_delayed_items(struct list_head *ins_list,
1646                              struct list_head *del_list)
1647 {
1648         struct btrfs_delayed_item *curr, *next;
1649 
1650         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1651                 list_del(&curr->readdir_list);
1652                 if (atomic_dec_and_test(&curr->refs))
1653                         kfree(curr);
1654         }
1655 
1656         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1657                 list_del(&curr->readdir_list);
1658                 if (atomic_dec_and_test(&curr->refs))
1659                         kfree(curr);
1660         }
1661 }
1662 
1663 int btrfs_should_delete_dir_index(struct list_head *del_list,
1664                                   u64 index)
1665 {
1666         struct btrfs_delayed_item *curr, *next;
1667         int ret;
1668 
1669         if (list_empty(del_list))
1670                 return 0;
1671 
1672         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1673                 if (curr->key.offset > index)
1674                         break;
1675 
1676                 list_del(&curr->readdir_list);
1677                 ret = (curr->key.offset == index);
1678 
1679                 if (atomic_dec_and_test(&curr->refs))
1680                         kfree(curr);
1681 
1682                 if (ret)
1683                         return 1;
1684                 else
1685                         continue;
1686         }
1687         return 0;
1688 }
1689 
1690 /*
1691  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1692  *
1693  */
1694 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1695                                     struct list_head *ins_list, bool *emitted)
1696 {
1697         struct btrfs_dir_item *di;
1698         struct btrfs_delayed_item *curr, *next;
1699         struct btrfs_key location;
1700         char *name;
1701         int name_len;
1702         int over = 0;
1703         unsigned char d_type;
1704 
1705         if (list_empty(ins_list))
1706                 return 0;
1707 
1708         /*
1709          * Changing the data of the delayed item is impossible. So
1710          * we needn't lock them. And we have held i_mutex of the
1711          * directory, nobody can delete any directory indexes now.
1712          */
1713         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1714                 list_del(&curr->readdir_list);
1715 
1716                 if (curr->key.offset < ctx->pos) {
1717                         if (atomic_dec_and_test(&curr->refs))
1718                                 kfree(curr);
1719                         continue;
1720                 }
1721 
1722                 ctx->pos = curr->key.offset;
1723 
1724                 di = (struct btrfs_dir_item *)curr->data;
1725                 name = (char *)(di + 1);
1726                 name_len = btrfs_stack_dir_name_len(di);
1727 
1728                 d_type = btrfs_filetype_table[di->type];
1729                 btrfs_disk_key_to_cpu(&location, &di->location);
1730 
1731                 over = !dir_emit(ctx, name, name_len,
1732                                location.objectid, d_type);
1733 
1734                 if (atomic_dec_and_test(&curr->refs))
1735                         kfree(curr);
1736 
1737                 if (over)
1738                         return 1;
1739                 *emitted = true;
1740         }
1741         return 0;
1742 }
1743 
1744 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1745                                   struct btrfs_inode_item *inode_item,
1746                                   struct inode *inode)
1747 {
1748         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1749         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1750         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1751         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1752         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1753         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1754         btrfs_set_stack_inode_generation(inode_item,
1755                                          BTRFS_I(inode)->generation);
1756         btrfs_set_stack_inode_sequence(inode_item, inode->i_version);
1757         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1758         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1759         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1760         btrfs_set_stack_inode_block_group(inode_item, 0);
1761 
1762         btrfs_set_stack_timespec_sec(&inode_item->atime,
1763                                      inode->i_atime.tv_sec);
1764         btrfs_set_stack_timespec_nsec(&inode_item->atime,
1765                                       inode->i_atime.tv_nsec);
1766 
1767         btrfs_set_stack_timespec_sec(&inode_item->mtime,
1768                                      inode->i_mtime.tv_sec);
1769         btrfs_set_stack_timespec_nsec(&inode_item->mtime,
1770                                       inode->i_mtime.tv_nsec);
1771 
1772         btrfs_set_stack_timespec_sec(&inode_item->ctime,
1773                                      inode->i_ctime.tv_sec);
1774         btrfs_set_stack_timespec_nsec(&inode_item->ctime,
1775                                       inode->i_ctime.tv_nsec);
1776 
1777         btrfs_set_stack_timespec_sec(&inode_item->otime,
1778                                      BTRFS_I(inode)->i_otime.tv_sec);
1779         btrfs_set_stack_timespec_nsec(&inode_item->otime,
1780                                      BTRFS_I(inode)->i_otime.tv_nsec);
1781 }
1782 
1783 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1784 {
1785         struct btrfs_delayed_node *delayed_node;
1786         struct btrfs_inode_item *inode_item;
1787 
1788         delayed_node = btrfs_get_delayed_node(inode);
1789         if (!delayed_node)
1790                 return -ENOENT;
1791 
1792         mutex_lock(&delayed_node->mutex);
1793         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1794                 mutex_unlock(&delayed_node->mutex);
1795                 btrfs_release_delayed_node(delayed_node);
1796                 return -ENOENT;
1797         }
1798 
1799         inode_item = &delayed_node->inode_item;
1800 
1801         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1802         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1803         btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1804         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1805         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1806         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1807         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1808         BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
1809 
1810         inode->i_version = btrfs_stack_inode_sequence(inode_item);
1811         inode->i_rdev = 0;
1812         *rdev = btrfs_stack_inode_rdev(inode_item);
1813         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1814 
1815         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
1816         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
1817 
1818         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
1819         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
1820 
1821         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
1822         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
1823 
1824         BTRFS_I(inode)->i_otime.tv_sec =
1825                 btrfs_stack_timespec_sec(&inode_item->otime);
1826         BTRFS_I(inode)->i_otime.tv_nsec =
1827                 btrfs_stack_timespec_nsec(&inode_item->otime);
1828 
1829         inode->i_generation = BTRFS_I(inode)->generation;
1830         BTRFS_I(inode)->index_cnt = (u64)-1;
1831 
1832         mutex_unlock(&delayed_node->mutex);
1833         btrfs_release_delayed_node(delayed_node);
1834         return 0;
1835 }
1836 
1837 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1838                                struct btrfs_root *root, struct inode *inode)
1839 {
1840         struct btrfs_delayed_node *delayed_node;
1841         int ret = 0;
1842 
1843         delayed_node = btrfs_get_or_create_delayed_node(inode);
1844         if (IS_ERR(delayed_node))
1845                 return PTR_ERR(delayed_node);
1846 
1847         mutex_lock(&delayed_node->mutex);
1848         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1849                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1850                 goto release_node;
1851         }
1852 
1853         ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1854                                                    delayed_node);
1855         if (ret)
1856                 goto release_node;
1857 
1858         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1859         set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1860         delayed_node->count++;
1861         atomic_inc(&root->fs_info->delayed_root->items);
1862 release_node:
1863         mutex_unlock(&delayed_node->mutex);
1864         btrfs_release_delayed_node(delayed_node);
1865         return ret;
1866 }
1867 
1868 int btrfs_delayed_delete_inode_ref(struct inode *inode)
1869 {
1870         struct btrfs_delayed_node *delayed_node;
1871 
1872         /*
1873          * we don't do delayed inode updates during log recovery because it
1874          * leads to enospc problems.  This means we also can't do
1875          * delayed inode refs
1876          */
1877         if (BTRFS_I(inode)->root->fs_info->log_root_recovering)
1878                 return -EAGAIN;
1879 
1880         delayed_node = btrfs_get_or_create_delayed_node(inode);
1881         if (IS_ERR(delayed_node))
1882                 return PTR_ERR(delayed_node);
1883 
1884         /*
1885          * We don't reserve space for inode ref deletion is because:
1886          * - We ONLY do async inode ref deletion for the inode who has only
1887          *   one link(i_nlink == 1), it means there is only one inode ref.
1888          *   And in most case, the inode ref and the inode item are in the
1889          *   same leaf, and we will deal with them at the same time.
1890          *   Since we are sure we will reserve the space for the inode item,
1891          *   it is unnecessary to reserve space for inode ref deletion.
1892          * - If the inode ref and the inode item are not in the same leaf,
1893          *   We also needn't worry about enospc problem, because we reserve
1894          *   much more space for the inode update than it needs.
1895          * - At the worst, we can steal some space from the global reservation.
1896          *   It is very rare.
1897          */
1898         mutex_lock(&delayed_node->mutex);
1899         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1900                 goto release_node;
1901 
1902         set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1903         delayed_node->count++;
1904         atomic_inc(&BTRFS_I(inode)->root->fs_info->delayed_root->items);
1905 release_node:
1906         mutex_unlock(&delayed_node->mutex);
1907         btrfs_release_delayed_node(delayed_node);
1908         return 0;
1909 }
1910 
1911 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1912 {
1913         struct btrfs_root *root = delayed_node->root;
1914         struct btrfs_delayed_item *curr_item, *prev_item;
1915 
1916         mutex_lock(&delayed_node->mutex);
1917         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1918         while (curr_item) {
1919                 btrfs_delayed_item_release_metadata(root, curr_item);
1920                 prev_item = curr_item;
1921                 curr_item = __btrfs_next_delayed_item(prev_item);
1922                 btrfs_release_delayed_item(prev_item);
1923         }
1924 
1925         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1926         while (curr_item) {
1927                 btrfs_delayed_item_release_metadata(root, curr_item);
1928                 prev_item = curr_item;
1929                 curr_item = __btrfs_next_delayed_item(prev_item);
1930                 btrfs_release_delayed_item(prev_item);
1931         }
1932 
1933         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1934                 btrfs_release_delayed_iref(delayed_node);
1935 
1936         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1937                 btrfs_delayed_inode_release_metadata(root, delayed_node);
1938                 btrfs_release_delayed_inode(delayed_node);
1939         }
1940         mutex_unlock(&delayed_node->mutex);
1941 }
1942 
1943 void btrfs_kill_delayed_inode_items(struct inode *inode)
1944 {
1945         struct btrfs_delayed_node *delayed_node;
1946 
1947         delayed_node = btrfs_get_delayed_node(inode);
1948         if (!delayed_node)
1949                 return;
1950 
1951         __btrfs_kill_delayed_node(delayed_node);
1952         btrfs_release_delayed_node(delayed_node);
1953 }
1954 
1955 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1956 {
1957         u64 inode_id = 0;
1958         struct btrfs_delayed_node *delayed_nodes[8];
1959         int i, n;
1960 
1961         while (1) {
1962                 spin_lock(&root->inode_lock);
1963                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1964                                            (void **)delayed_nodes, inode_id,
1965                                            ARRAY_SIZE(delayed_nodes));
1966                 if (!n) {
1967                         spin_unlock(&root->inode_lock);
1968                         break;
1969                 }
1970 
1971                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1972 
1973                 for (i = 0; i < n; i++)
1974                         atomic_inc(&delayed_nodes[i]->refs);
1975                 spin_unlock(&root->inode_lock);
1976 
1977                 for (i = 0; i < n; i++) {
1978                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1979                         btrfs_release_delayed_node(delayed_nodes[i]);
1980                 }
1981         }
1982 }
1983 
1984 void btrfs_destroy_delayed_inodes(struct btrfs_root *root)
1985 {
1986         struct btrfs_delayed_root *delayed_root;
1987         struct btrfs_delayed_node *curr_node, *prev_node;
1988 
1989         delayed_root = btrfs_get_delayed_root(root);
1990 
1991         curr_node = btrfs_first_delayed_node(delayed_root);
1992         while (curr_node) {
1993                 __btrfs_kill_delayed_node(curr_node);
1994 
1995                 prev_node = curr_node;
1996                 curr_node = btrfs_next_delayed_node(curr_node);
1997                 btrfs_release_delayed_node(prev_node);
1998         }
1999 }
2000 
2001 

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