xref: /linux/fs/btrfs/delayed-inode.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
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 btrfs_delayed_node *node)
621 {
622 	struct btrfs_block_rsv *src_rsv;
623 	struct btrfs_block_rsv *dst_rsv;
624 	u64 num_bytes;
625 	int ret;
626 
627 	src_rsv = trans->block_rsv;
628 	dst_rsv = &root->fs_info->delayed_block_rsv;
629 
630 	num_bytes = btrfs_calc_trans_metadata_size(root, 1);
631 
632 	/*
633 	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction
634 	 * which doesn't reserve space for speed.  This is a problem since we
635 	 * still need to reserve space for this update, so try to reserve the
636 	 * space.
637 	 *
638 	 * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
639 	 * we're accounted for.
640 	 */
641 	if (!trans->bytes_reserved &&
642 	    src_rsv != &root->fs_info->delalloc_block_rsv) {
643 		ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
644 		/*
645 		 * Since we're under a transaction reserve_metadata_bytes could
646 		 * try to commit the transaction which will make it return
647 		 * EAGAIN to make us stop the transaction we have, so return
648 		 * ENOSPC instead so that btrfs_dirty_inode knows what to do.
649 		 */
650 		if (ret == -EAGAIN)
651 			ret = -ENOSPC;
652 		if (!ret)
653 			node->bytes_reserved = num_bytes;
654 		return ret;
655 	}
656 
657 	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
658 	if (!ret)
659 		node->bytes_reserved = num_bytes;
660 
661 	return ret;
662 }
663 
664 static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
665 						struct btrfs_delayed_node *node)
666 {
667 	struct btrfs_block_rsv *rsv;
668 
669 	if (!node->bytes_reserved)
670 		return;
671 
672 	rsv = &root->fs_info->delayed_block_rsv;
673 	btrfs_block_rsv_release(root, rsv,
674 				node->bytes_reserved);
675 	node->bytes_reserved = 0;
676 }
677 
678 /*
679  * This helper will insert some continuous items into the same leaf according
680  * to the free space of the leaf.
681  */
682 static int btrfs_batch_insert_items(struct btrfs_trans_handle *trans,
683 				struct btrfs_root *root,
684 				struct btrfs_path *path,
685 				struct btrfs_delayed_item *item)
686 {
687 	struct btrfs_delayed_item *curr, *next;
688 	int free_space;
689 	int total_data_size = 0, total_size = 0;
690 	struct extent_buffer *leaf;
691 	char *data_ptr;
692 	struct btrfs_key *keys;
693 	u32 *data_size;
694 	struct list_head head;
695 	int slot;
696 	int nitems;
697 	int i;
698 	int ret = 0;
699 
700 	BUG_ON(!path->nodes[0]);
701 
702 	leaf = path->nodes[0];
703 	free_space = btrfs_leaf_free_space(root, leaf);
704 	INIT_LIST_HEAD(&head);
705 
706 	next = item;
707 	nitems = 0;
708 
709 	/*
710 	 * count the number of the continuous items that we can insert in batch
711 	 */
712 	while (total_size + next->data_len + sizeof(struct btrfs_item) <=
713 	       free_space) {
714 		total_data_size += next->data_len;
715 		total_size += next->data_len + sizeof(struct btrfs_item);
716 		list_add_tail(&next->tree_list, &head);
717 		nitems++;
718 
719 		curr = next;
720 		next = __btrfs_next_delayed_item(curr);
721 		if (!next)
722 			break;
723 
724 		if (!btrfs_is_continuous_delayed_item(curr, next))
725 			break;
726 	}
727 
728 	if (!nitems) {
729 		ret = 0;
730 		goto out;
731 	}
732 
733 	/*
734 	 * we need allocate some memory space, but it might cause the task
735 	 * to sleep, so we set all locked nodes in the path to blocking locks
736 	 * first.
737 	 */
738 	btrfs_set_path_blocking(path);
739 
740 	keys = kmalloc(sizeof(struct btrfs_key) * nitems, GFP_NOFS);
741 	if (!keys) {
742 		ret = -ENOMEM;
743 		goto out;
744 	}
745 
746 	data_size = kmalloc(sizeof(u32) * nitems, GFP_NOFS);
747 	if (!data_size) {
748 		ret = -ENOMEM;
749 		goto error;
750 	}
751 
752 	/* get keys of all the delayed items */
753 	i = 0;
754 	list_for_each_entry(next, &head, tree_list) {
755 		keys[i] = next->key;
756 		data_size[i] = next->data_len;
757 		i++;
758 	}
759 
760 	/* reset all the locked nodes in the patch to spinning locks. */
761 	btrfs_clear_path_blocking(path, NULL, 0);
762 
763 	/* insert the keys of the items */
764 	ret = setup_items_for_insert(trans, root, path, keys, data_size,
765 				     total_data_size, total_size, nitems);
766 	if (ret)
767 		goto error;
768 
769 	/* insert the dir index items */
770 	slot = path->slots[0];
771 	list_for_each_entry_safe(curr, next, &head, tree_list) {
772 		data_ptr = btrfs_item_ptr(leaf, slot, char);
773 		write_extent_buffer(leaf, &curr->data,
774 				    (unsigned long)data_ptr,
775 				    curr->data_len);
776 		slot++;
777 
778 		btrfs_delayed_item_release_metadata(root, curr);
779 
780 		list_del(&curr->tree_list);
781 		btrfs_release_delayed_item(curr);
782 	}
783 
784 error:
785 	kfree(data_size);
786 	kfree(keys);
787 out:
788 	return ret;
789 }
790 
791 /*
792  * This helper can just do simple insertion that needn't extend item for new
793  * data, such as directory name index insertion, inode insertion.
794  */
795 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
796 				     struct btrfs_root *root,
797 				     struct btrfs_path *path,
798 				     struct btrfs_delayed_item *delayed_item)
799 {
800 	struct extent_buffer *leaf;
801 	struct btrfs_item *item;
802 	char *ptr;
803 	int ret;
804 
805 	ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
806 				      delayed_item->data_len);
807 	if (ret < 0 && ret != -EEXIST)
808 		return ret;
809 
810 	leaf = path->nodes[0];
811 
812 	item = btrfs_item_nr(leaf, path->slots[0]);
813 	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
814 
815 	write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
816 			    delayed_item->data_len);
817 	btrfs_mark_buffer_dirty(leaf);
818 
819 	btrfs_delayed_item_release_metadata(root, delayed_item);
820 	return 0;
821 }
822 
823 /*
824  * we insert an item first, then if there are some continuous items, we try
825  * to insert those items into the same leaf.
826  */
827 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
828 				      struct btrfs_path *path,
829 				      struct btrfs_root *root,
830 				      struct btrfs_delayed_node *node)
831 {
832 	struct btrfs_delayed_item *curr, *prev;
833 	int ret = 0;
834 
835 do_again:
836 	mutex_lock(&node->mutex);
837 	curr = __btrfs_first_delayed_insertion_item(node);
838 	if (!curr)
839 		goto insert_end;
840 
841 	ret = btrfs_insert_delayed_item(trans, root, path, curr);
842 	if (ret < 0) {
843 		btrfs_release_path(path);
844 		goto insert_end;
845 	}
846 
847 	prev = curr;
848 	curr = __btrfs_next_delayed_item(prev);
849 	if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
850 		/* insert the continuous items into the same leaf */
851 		path->slots[0]++;
852 		btrfs_batch_insert_items(trans, root, path, curr);
853 	}
854 	btrfs_release_delayed_item(prev);
855 	btrfs_mark_buffer_dirty(path->nodes[0]);
856 
857 	btrfs_release_path(path);
858 	mutex_unlock(&node->mutex);
859 	goto do_again;
860 
861 insert_end:
862 	mutex_unlock(&node->mutex);
863 	return ret;
864 }
865 
866 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
867 				    struct btrfs_root *root,
868 				    struct btrfs_path *path,
869 				    struct btrfs_delayed_item *item)
870 {
871 	struct btrfs_delayed_item *curr, *next;
872 	struct extent_buffer *leaf;
873 	struct btrfs_key key;
874 	struct list_head head;
875 	int nitems, i, last_item;
876 	int ret = 0;
877 
878 	BUG_ON(!path->nodes[0]);
879 
880 	leaf = path->nodes[0];
881 
882 	i = path->slots[0];
883 	last_item = btrfs_header_nritems(leaf) - 1;
884 	if (i > last_item)
885 		return -ENOENT;	/* FIXME: Is errno suitable? */
886 
887 	next = item;
888 	INIT_LIST_HEAD(&head);
889 	btrfs_item_key_to_cpu(leaf, &key, i);
890 	nitems = 0;
891 	/*
892 	 * count the number of the dir index items that we can delete in batch
893 	 */
894 	while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
895 		list_add_tail(&next->tree_list, &head);
896 		nitems++;
897 
898 		curr = next;
899 		next = __btrfs_next_delayed_item(curr);
900 		if (!next)
901 			break;
902 
903 		if (!btrfs_is_continuous_delayed_item(curr, next))
904 			break;
905 
906 		i++;
907 		if (i > last_item)
908 			break;
909 		btrfs_item_key_to_cpu(leaf, &key, i);
910 	}
911 
912 	if (!nitems)
913 		return 0;
914 
915 	ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
916 	if (ret)
917 		goto out;
918 
919 	list_for_each_entry_safe(curr, next, &head, tree_list) {
920 		btrfs_delayed_item_release_metadata(root, curr);
921 		list_del(&curr->tree_list);
922 		btrfs_release_delayed_item(curr);
923 	}
924 
925 out:
926 	return ret;
927 }
928 
929 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
930 				      struct btrfs_path *path,
931 				      struct btrfs_root *root,
932 				      struct btrfs_delayed_node *node)
933 {
934 	struct btrfs_delayed_item *curr, *prev;
935 	int ret = 0;
936 
937 do_again:
938 	mutex_lock(&node->mutex);
939 	curr = __btrfs_first_delayed_deletion_item(node);
940 	if (!curr)
941 		goto delete_fail;
942 
943 	ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
944 	if (ret < 0)
945 		goto delete_fail;
946 	else if (ret > 0) {
947 		/*
948 		 * can't find the item which the node points to, so this node
949 		 * is invalid, just drop it.
950 		 */
951 		prev = curr;
952 		curr = __btrfs_next_delayed_item(prev);
953 		btrfs_release_delayed_item(prev);
954 		ret = 0;
955 		btrfs_release_path(path);
956 		if (curr)
957 			goto do_again;
958 		else
959 			goto delete_fail;
960 	}
961 
962 	btrfs_batch_delete_items(trans, root, path, curr);
963 	btrfs_release_path(path);
964 	mutex_unlock(&node->mutex);
965 	goto do_again;
966 
967 delete_fail:
968 	btrfs_release_path(path);
969 	mutex_unlock(&node->mutex);
970 	return ret;
971 }
972 
973 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
974 {
975 	struct btrfs_delayed_root *delayed_root;
976 
977 	if (delayed_node && delayed_node->inode_dirty) {
978 		BUG_ON(!delayed_node->root);
979 		delayed_node->inode_dirty = 0;
980 		delayed_node->count--;
981 
982 		delayed_root = delayed_node->root->fs_info->delayed_root;
983 		atomic_dec(&delayed_root->items);
984 		if (atomic_read(&delayed_root->items) <
985 		    BTRFS_DELAYED_BACKGROUND &&
986 		    waitqueue_active(&delayed_root->wait))
987 			wake_up(&delayed_root->wait);
988 	}
989 }
990 
991 static int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
992 				      struct btrfs_root *root,
993 				      struct btrfs_path *path,
994 				      struct btrfs_delayed_node *node)
995 {
996 	struct btrfs_key key;
997 	struct btrfs_inode_item *inode_item;
998 	struct extent_buffer *leaf;
999 	int ret;
1000 
1001 	mutex_lock(&node->mutex);
1002 	if (!node->inode_dirty) {
1003 		mutex_unlock(&node->mutex);
1004 		return 0;
1005 	}
1006 
1007 	key.objectid = node->inode_id;
1008 	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1009 	key.offset = 0;
1010 	ret = btrfs_lookup_inode(trans, root, path, &key, 1);
1011 	if (ret > 0) {
1012 		btrfs_release_path(path);
1013 		mutex_unlock(&node->mutex);
1014 		return -ENOENT;
1015 	} else if (ret < 0) {
1016 		mutex_unlock(&node->mutex);
1017 		return ret;
1018 	}
1019 
1020 	btrfs_unlock_up_safe(path, 1);
1021 	leaf = path->nodes[0];
1022 	inode_item = btrfs_item_ptr(leaf, path->slots[0],
1023 				    struct btrfs_inode_item);
1024 	write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1025 			    sizeof(struct btrfs_inode_item));
1026 	btrfs_mark_buffer_dirty(leaf);
1027 	btrfs_release_path(path);
1028 
1029 	btrfs_delayed_inode_release_metadata(root, node);
1030 	btrfs_release_delayed_inode(node);
1031 	mutex_unlock(&node->mutex);
1032 
1033 	return 0;
1034 }
1035 
1036 /* Called when committing the transaction. */
1037 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1038 			    struct btrfs_root *root)
1039 {
1040 	struct btrfs_delayed_root *delayed_root;
1041 	struct btrfs_delayed_node *curr_node, *prev_node;
1042 	struct btrfs_path *path;
1043 	struct btrfs_block_rsv *block_rsv;
1044 	int ret = 0;
1045 
1046 	path = btrfs_alloc_path();
1047 	if (!path)
1048 		return -ENOMEM;
1049 	path->leave_spinning = 1;
1050 
1051 	block_rsv = trans->block_rsv;
1052 	trans->block_rsv = &root->fs_info->delayed_block_rsv;
1053 
1054 	delayed_root = btrfs_get_delayed_root(root);
1055 
1056 	curr_node = btrfs_first_delayed_node(delayed_root);
1057 	while (curr_node) {
1058 		root = curr_node->root;
1059 		ret = btrfs_insert_delayed_items(trans, path, root,
1060 						 curr_node);
1061 		if (!ret)
1062 			ret = btrfs_delete_delayed_items(trans, path, root,
1063 							 curr_node);
1064 		if (!ret)
1065 			ret = btrfs_update_delayed_inode(trans, root, path,
1066 							 curr_node);
1067 		if (ret) {
1068 			btrfs_release_delayed_node(curr_node);
1069 			break;
1070 		}
1071 
1072 		prev_node = curr_node;
1073 		curr_node = btrfs_next_delayed_node(curr_node);
1074 		btrfs_release_delayed_node(prev_node);
1075 	}
1076 
1077 	btrfs_free_path(path);
1078 	trans->block_rsv = block_rsv;
1079 	return ret;
1080 }
1081 
1082 static int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1083 					      struct btrfs_delayed_node *node)
1084 {
1085 	struct btrfs_path *path;
1086 	struct btrfs_block_rsv *block_rsv;
1087 	int ret;
1088 
1089 	path = btrfs_alloc_path();
1090 	if (!path)
1091 		return -ENOMEM;
1092 	path->leave_spinning = 1;
1093 
1094 	block_rsv = trans->block_rsv;
1095 	trans->block_rsv = &node->root->fs_info->delayed_block_rsv;
1096 
1097 	ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1098 	if (!ret)
1099 		ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1100 	if (!ret)
1101 		ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1102 	btrfs_free_path(path);
1103 
1104 	trans->block_rsv = block_rsv;
1105 	return ret;
1106 }
1107 
1108 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1109 				     struct inode *inode)
1110 {
1111 	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1112 	int ret;
1113 
1114 	if (!delayed_node)
1115 		return 0;
1116 
1117 	mutex_lock(&delayed_node->mutex);
1118 	if (!delayed_node->count) {
1119 		mutex_unlock(&delayed_node->mutex);
1120 		btrfs_release_delayed_node(delayed_node);
1121 		return 0;
1122 	}
1123 	mutex_unlock(&delayed_node->mutex);
1124 
1125 	ret = __btrfs_commit_inode_delayed_items(trans, delayed_node);
1126 	btrfs_release_delayed_node(delayed_node);
1127 	return ret;
1128 }
1129 
1130 void btrfs_remove_delayed_node(struct inode *inode)
1131 {
1132 	struct btrfs_delayed_node *delayed_node;
1133 
1134 	delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1135 	if (!delayed_node)
1136 		return;
1137 
1138 	BTRFS_I(inode)->delayed_node = NULL;
1139 	btrfs_release_delayed_node(delayed_node);
1140 }
1141 
1142 struct btrfs_async_delayed_node {
1143 	struct btrfs_root *root;
1144 	struct btrfs_delayed_node *delayed_node;
1145 	struct btrfs_work work;
1146 };
1147 
1148 static void btrfs_async_run_delayed_node_done(struct btrfs_work *work)
1149 {
1150 	struct btrfs_async_delayed_node *async_node;
1151 	struct btrfs_trans_handle *trans;
1152 	struct btrfs_path *path;
1153 	struct btrfs_delayed_node *delayed_node = NULL;
1154 	struct btrfs_root *root;
1155 	struct btrfs_block_rsv *block_rsv;
1156 	unsigned long nr = 0;
1157 	int need_requeue = 0;
1158 	int ret;
1159 
1160 	async_node = container_of(work, struct btrfs_async_delayed_node, work);
1161 
1162 	path = btrfs_alloc_path();
1163 	if (!path)
1164 		goto out;
1165 	path->leave_spinning = 1;
1166 
1167 	delayed_node = async_node->delayed_node;
1168 	root = delayed_node->root;
1169 
1170 	trans = btrfs_join_transaction(root);
1171 	if (IS_ERR(trans))
1172 		goto free_path;
1173 
1174 	block_rsv = trans->block_rsv;
1175 	trans->block_rsv = &root->fs_info->delayed_block_rsv;
1176 
1177 	ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
1178 	if (!ret)
1179 		ret = btrfs_delete_delayed_items(trans, path, root,
1180 						 delayed_node);
1181 
1182 	if (!ret)
1183 		btrfs_update_delayed_inode(trans, root, path, delayed_node);
1184 
1185 	/*
1186 	 * Maybe new delayed items have been inserted, so we need requeue
1187 	 * the work. Besides that, we must dequeue the empty delayed nodes
1188 	 * to avoid the race between delayed items balance and the worker.
1189 	 * The race like this:
1190 	 * 	Task1				Worker thread
1191 	 * 					count == 0, needn't requeue
1192 	 * 					  also needn't insert the
1193 	 * 					  delayed node into prepare
1194 	 * 					  list again.
1195 	 * 	add lots of delayed items
1196 	 * 	queue the delayed node
1197 	 * 	  already in the list,
1198 	 * 	  and not in the prepare
1199 	 * 	  list, it means the delayed
1200 	 * 	  node is being dealt with
1201 	 * 	  by the worker.
1202 	 * 	do delayed items balance
1203 	 * 	  the delayed node is being
1204 	 * 	  dealt with by the worker
1205 	 * 	  now, just wait.
1206 	 * 	  				the worker goto idle.
1207 	 * Task1 will sleep until the transaction is commited.
1208 	 */
1209 	mutex_lock(&delayed_node->mutex);
1210 	if (delayed_node->count)
1211 		need_requeue = 1;
1212 	else
1213 		btrfs_dequeue_delayed_node(root->fs_info->delayed_root,
1214 					   delayed_node);
1215 	mutex_unlock(&delayed_node->mutex);
1216 
1217 	nr = trans->blocks_used;
1218 
1219 	trans->block_rsv = block_rsv;
1220 	btrfs_end_transaction_dmeta(trans, root);
1221 	__btrfs_btree_balance_dirty(root, nr);
1222 free_path:
1223 	btrfs_free_path(path);
1224 out:
1225 	if (need_requeue)
1226 		btrfs_requeue_work(&async_node->work);
1227 	else {
1228 		btrfs_release_prepared_delayed_node(delayed_node);
1229 		kfree(async_node);
1230 	}
1231 }
1232 
1233 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1234 				     struct btrfs_root *root, int all)
1235 {
1236 	struct btrfs_async_delayed_node *async_node;
1237 	struct btrfs_delayed_node *curr;
1238 	int count = 0;
1239 
1240 again:
1241 	curr = btrfs_first_prepared_delayed_node(delayed_root);
1242 	if (!curr)
1243 		return 0;
1244 
1245 	async_node = kmalloc(sizeof(*async_node), GFP_NOFS);
1246 	if (!async_node) {
1247 		btrfs_release_prepared_delayed_node(curr);
1248 		return -ENOMEM;
1249 	}
1250 
1251 	async_node->root = root;
1252 	async_node->delayed_node = curr;
1253 
1254 	async_node->work.func = btrfs_async_run_delayed_node_done;
1255 	async_node->work.flags = 0;
1256 
1257 	btrfs_queue_worker(&root->fs_info->delayed_workers, &async_node->work);
1258 	count++;
1259 
1260 	if (all || count < 4)
1261 		goto again;
1262 
1263 	return 0;
1264 }
1265 
1266 void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1267 {
1268 	struct btrfs_delayed_root *delayed_root;
1269 	delayed_root = btrfs_get_delayed_root(root);
1270 	WARN_ON(btrfs_first_delayed_node(delayed_root));
1271 }
1272 
1273 void btrfs_balance_delayed_items(struct btrfs_root *root)
1274 {
1275 	struct btrfs_delayed_root *delayed_root;
1276 
1277 	delayed_root = btrfs_get_delayed_root(root);
1278 
1279 	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1280 		return;
1281 
1282 	if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1283 		int ret;
1284 		ret = btrfs_wq_run_delayed_node(delayed_root, root, 1);
1285 		if (ret)
1286 			return;
1287 
1288 		wait_event_interruptible_timeout(
1289 				delayed_root->wait,
1290 				(atomic_read(&delayed_root->items) <
1291 				 BTRFS_DELAYED_BACKGROUND),
1292 				HZ);
1293 		return;
1294 	}
1295 
1296 	btrfs_wq_run_delayed_node(delayed_root, root, 0);
1297 }
1298 
1299 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1300 				   struct btrfs_root *root, const char *name,
1301 				   int name_len, struct inode *dir,
1302 				   struct btrfs_disk_key *disk_key, u8 type,
1303 				   u64 index)
1304 {
1305 	struct btrfs_delayed_node *delayed_node;
1306 	struct btrfs_delayed_item *delayed_item;
1307 	struct btrfs_dir_item *dir_item;
1308 	int ret;
1309 
1310 	delayed_node = btrfs_get_or_create_delayed_node(dir);
1311 	if (IS_ERR(delayed_node))
1312 		return PTR_ERR(delayed_node);
1313 
1314 	delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1315 	if (!delayed_item) {
1316 		ret = -ENOMEM;
1317 		goto release_node;
1318 	}
1319 
1320 	ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1321 	/*
1322 	 * we have reserved enough space when we start a new transaction,
1323 	 * so reserving metadata failure is impossible
1324 	 */
1325 	BUG_ON(ret);
1326 
1327 	delayed_item->key.objectid = btrfs_ino(dir);
1328 	btrfs_set_key_type(&delayed_item->key, BTRFS_DIR_INDEX_KEY);
1329 	delayed_item->key.offset = index;
1330 
1331 	dir_item = (struct btrfs_dir_item *)delayed_item->data;
1332 	dir_item->location = *disk_key;
1333 	dir_item->transid = cpu_to_le64(trans->transid);
1334 	dir_item->data_len = 0;
1335 	dir_item->name_len = cpu_to_le16(name_len);
1336 	dir_item->type = type;
1337 	memcpy((char *)(dir_item + 1), name, name_len);
1338 
1339 	mutex_lock(&delayed_node->mutex);
1340 	ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1341 	if (unlikely(ret)) {
1342 		printk(KERN_ERR "err add delayed dir index item(name: %s) into "
1343 				"the insertion tree of the delayed node"
1344 				"(root id: %llu, inode id: %llu, errno: %d)\n",
1345 				name,
1346 				(unsigned long long)delayed_node->root->objectid,
1347 				(unsigned long long)delayed_node->inode_id,
1348 				ret);
1349 		BUG();
1350 	}
1351 	mutex_unlock(&delayed_node->mutex);
1352 
1353 release_node:
1354 	btrfs_release_delayed_node(delayed_node);
1355 	return ret;
1356 }
1357 
1358 static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1359 					       struct btrfs_delayed_node *node,
1360 					       struct btrfs_key *key)
1361 {
1362 	struct btrfs_delayed_item *item;
1363 
1364 	mutex_lock(&node->mutex);
1365 	item = __btrfs_lookup_delayed_insertion_item(node, key);
1366 	if (!item) {
1367 		mutex_unlock(&node->mutex);
1368 		return 1;
1369 	}
1370 
1371 	btrfs_delayed_item_release_metadata(root, item);
1372 	btrfs_release_delayed_item(item);
1373 	mutex_unlock(&node->mutex);
1374 	return 0;
1375 }
1376 
1377 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1378 				   struct btrfs_root *root, struct inode *dir,
1379 				   u64 index)
1380 {
1381 	struct btrfs_delayed_node *node;
1382 	struct btrfs_delayed_item *item;
1383 	struct btrfs_key item_key;
1384 	int ret;
1385 
1386 	node = btrfs_get_or_create_delayed_node(dir);
1387 	if (IS_ERR(node))
1388 		return PTR_ERR(node);
1389 
1390 	item_key.objectid = btrfs_ino(dir);
1391 	btrfs_set_key_type(&item_key, BTRFS_DIR_INDEX_KEY);
1392 	item_key.offset = index;
1393 
1394 	ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1395 	if (!ret)
1396 		goto end;
1397 
1398 	item = btrfs_alloc_delayed_item(0);
1399 	if (!item) {
1400 		ret = -ENOMEM;
1401 		goto end;
1402 	}
1403 
1404 	item->key = item_key;
1405 
1406 	ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1407 	/*
1408 	 * we have reserved enough space when we start a new transaction,
1409 	 * so reserving metadata failure is impossible.
1410 	 */
1411 	BUG_ON(ret);
1412 
1413 	mutex_lock(&node->mutex);
1414 	ret = __btrfs_add_delayed_deletion_item(node, item);
1415 	if (unlikely(ret)) {
1416 		printk(KERN_ERR "err add delayed dir index item(index: %llu) "
1417 				"into the deletion tree of the delayed node"
1418 				"(root id: %llu, inode id: %llu, errno: %d)\n",
1419 				(unsigned long long)index,
1420 				(unsigned long long)node->root->objectid,
1421 				(unsigned long long)node->inode_id,
1422 				ret);
1423 		BUG();
1424 	}
1425 	mutex_unlock(&node->mutex);
1426 end:
1427 	btrfs_release_delayed_node(node);
1428 	return ret;
1429 }
1430 
1431 int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1432 {
1433 	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1434 
1435 	if (!delayed_node)
1436 		return -ENOENT;
1437 
1438 	/*
1439 	 * Since we have held i_mutex of this directory, it is impossible that
1440 	 * a new directory index is added into the delayed node and index_cnt
1441 	 * is updated now. So we needn't lock the delayed node.
1442 	 */
1443 	if (!delayed_node->index_cnt) {
1444 		btrfs_release_delayed_node(delayed_node);
1445 		return -EINVAL;
1446 	}
1447 
1448 	BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1449 	btrfs_release_delayed_node(delayed_node);
1450 	return 0;
1451 }
1452 
1453 void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
1454 			     struct list_head *del_list)
1455 {
1456 	struct btrfs_delayed_node *delayed_node;
1457 	struct btrfs_delayed_item *item;
1458 
1459 	delayed_node = btrfs_get_delayed_node(inode);
1460 	if (!delayed_node)
1461 		return;
1462 
1463 	mutex_lock(&delayed_node->mutex);
1464 	item = __btrfs_first_delayed_insertion_item(delayed_node);
1465 	while (item) {
1466 		atomic_inc(&item->refs);
1467 		list_add_tail(&item->readdir_list, ins_list);
1468 		item = __btrfs_next_delayed_item(item);
1469 	}
1470 
1471 	item = __btrfs_first_delayed_deletion_item(delayed_node);
1472 	while (item) {
1473 		atomic_inc(&item->refs);
1474 		list_add_tail(&item->readdir_list, del_list);
1475 		item = __btrfs_next_delayed_item(item);
1476 	}
1477 	mutex_unlock(&delayed_node->mutex);
1478 	/*
1479 	 * This delayed node is still cached in the btrfs inode, so refs
1480 	 * must be > 1 now, and we needn't check it is going to be freed
1481 	 * or not.
1482 	 *
1483 	 * Besides that, this function is used to read dir, we do not
1484 	 * insert/delete delayed items in this period. So we also needn't
1485 	 * requeue or dequeue this delayed node.
1486 	 */
1487 	atomic_dec(&delayed_node->refs);
1488 }
1489 
1490 void btrfs_put_delayed_items(struct list_head *ins_list,
1491 			     struct list_head *del_list)
1492 {
1493 	struct btrfs_delayed_item *curr, *next;
1494 
1495 	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1496 		list_del(&curr->readdir_list);
1497 		if (atomic_dec_and_test(&curr->refs))
1498 			kfree(curr);
1499 	}
1500 
1501 	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1502 		list_del(&curr->readdir_list);
1503 		if (atomic_dec_and_test(&curr->refs))
1504 			kfree(curr);
1505 	}
1506 }
1507 
1508 int btrfs_should_delete_dir_index(struct list_head *del_list,
1509 				  u64 index)
1510 {
1511 	struct btrfs_delayed_item *curr, *next;
1512 	int ret;
1513 
1514 	if (list_empty(del_list))
1515 		return 0;
1516 
1517 	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1518 		if (curr->key.offset > index)
1519 			break;
1520 
1521 		list_del(&curr->readdir_list);
1522 		ret = (curr->key.offset == index);
1523 
1524 		if (atomic_dec_and_test(&curr->refs))
1525 			kfree(curr);
1526 
1527 		if (ret)
1528 			return 1;
1529 		else
1530 			continue;
1531 	}
1532 	return 0;
1533 }
1534 
1535 /*
1536  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1537  *
1538  */
1539 int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
1540 				    filldir_t filldir,
1541 				    struct list_head *ins_list)
1542 {
1543 	struct btrfs_dir_item *di;
1544 	struct btrfs_delayed_item *curr, *next;
1545 	struct btrfs_key location;
1546 	char *name;
1547 	int name_len;
1548 	int over = 0;
1549 	unsigned char d_type;
1550 
1551 	if (list_empty(ins_list))
1552 		return 0;
1553 
1554 	/*
1555 	 * Changing the data of the delayed item is impossible. So
1556 	 * we needn't lock them. And we have held i_mutex of the
1557 	 * directory, nobody can delete any directory indexes now.
1558 	 */
1559 	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1560 		list_del(&curr->readdir_list);
1561 
1562 		if (curr->key.offset < filp->f_pos) {
1563 			if (atomic_dec_and_test(&curr->refs))
1564 				kfree(curr);
1565 			continue;
1566 		}
1567 
1568 		filp->f_pos = curr->key.offset;
1569 
1570 		di = (struct btrfs_dir_item *)curr->data;
1571 		name = (char *)(di + 1);
1572 		name_len = le16_to_cpu(di->name_len);
1573 
1574 		d_type = btrfs_filetype_table[di->type];
1575 		btrfs_disk_key_to_cpu(&location, &di->location);
1576 
1577 		over = filldir(dirent, name, name_len, curr->key.offset,
1578 			       location.objectid, d_type);
1579 
1580 		if (atomic_dec_and_test(&curr->refs))
1581 			kfree(curr);
1582 
1583 		if (over)
1584 			return 1;
1585 	}
1586 	return 0;
1587 }
1588 
1589 BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item,
1590 			 generation, 64);
1591 BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item,
1592 			 sequence, 64);
1593 BTRFS_SETGET_STACK_FUNCS(stack_inode_transid, struct btrfs_inode_item,
1594 			 transid, 64);
1595 BTRFS_SETGET_STACK_FUNCS(stack_inode_size, struct btrfs_inode_item, size, 64);
1596 BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes, struct btrfs_inode_item,
1597 			 nbytes, 64);
1598 BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group, struct btrfs_inode_item,
1599 			 block_group, 64);
1600 BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink, struct btrfs_inode_item, nlink, 32);
1601 BTRFS_SETGET_STACK_FUNCS(stack_inode_uid, struct btrfs_inode_item, uid, 32);
1602 BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32);
1603 BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32);
1604 BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64);
1605 BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64);
1606 
1607 BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
1608 BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
1609 
1610 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1611 				  struct btrfs_inode_item *inode_item,
1612 				  struct inode *inode)
1613 {
1614 	btrfs_set_stack_inode_uid(inode_item, inode->i_uid);
1615 	btrfs_set_stack_inode_gid(inode_item, inode->i_gid);
1616 	btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1617 	btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1618 	btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1619 	btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1620 	btrfs_set_stack_inode_generation(inode_item,
1621 					 BTRFS_I(inode)->generation);
1622 	btrfs_set_stack_inode_sequence(inode_item, BTRFS_I(inode)->sequence);
1623 	btrfs_set_stack_inode_transid(inode_item, trans->transid);
1624 	btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1625 	btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1626 	btrfs_set_stack_inode_block_group(inode_item, 0);
1627 
1628 	btrfs_set_stack_timespec_sec(btrfs_inode_atime(inode_item),
1629 				     inode->i_atime.tv_sec);
1630 	btrfs_set_stack_timespec_nsec(btrfs_inode_atime(inode_item),
1631 				      inode->i_atime.tv_nsec);
1632 
1633 	btrfs_set_stack_timespec_sec(btrfs_inode_mtime(inode_item),
1634 				     inode->i_mtime.tv_sec);
1635 	btrfs_set_stack_timespec_nsec(btrfs_inode_mtime(inode_item),
1636 				      inode->i_mtime.tv_nsec);
1637 
1638 	btrfs_set_stack_timespec_sec(btrfs_inode_ctime(inode_item),
1639 				     inode->i_ctime.tv_sec);
1640 	btrfs_set_stack_timespec_nsec(btrfs_inode_ctime(inode_item),
1641 				      inode->i_ctime.tv_nsec);
1642 }
1643 
1644 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1645 {
1646 	struct btrfs_delayed_node *delayed_node;
1647 	struct btrfs_inode_item *inode_item;
1648 	struct btrfs_timespec *tspec;
1649 
1650 	delayed_node = btrfs_get_delayed_node(inode);
1651 	if (!delayed_node)
1652 		return -ENOENT;
1653 
1654 	mutex_lock(&delayed_node->mutex);
1655 	if (!delayed_node->inode_dirty) {
1656 		mutex_unlock(&delayed_node->mutex);
1657 		btrfs_release_delayed_node(delayed_node);
1658 		return -ENOENT;
1659 	}
1660 
1661 	inode_item = &delayed_node->inode_item;
1662 
1663 	inode->i_uid = btrfs_stack_inode_uid(inode_item);
1664 	inode->i_gid = btrfs_stack_inode_gid(inode_item);
1665 	btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1666 	inode->i_mode = btrfs_stack_inode_mode(inode_item);
1667 	set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1668 	inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1669 	BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1670 	BTRFS_I(inode)->sequence = btrfs_stack_inode_sequence(inode_item);
1671 	inode->i_rdev = 0;
1672 	*rdev = btrfs_stack_inode_rdev(inode_item);
1673 	BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1674 
1675 	tspec = btrfs_inode_atime(inode_item);
1676 	inode->i_atime.tv_sec = btrfs_stack_timespec_sec(tspec);
1677 	inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1678 
1679 	tspec = btrfs_inode_mtime(inode_item);
1680 	inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(tspec);
1681 	inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1682 
1683 	tspec = btrfs_inode_ctime(inode_item);
1684 	inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(tspec);
1685 	inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1686 
1687 	inode->i_generation = BTRFS_I(inode)->generation;
1688 	BTRFS_I(inode)->index_cnt = (u64)-1;
1689 
1690 	mutex_unlock(&delayed_node->mutex);
1691 	btrfs_release_delayed_node(delayed_node);
1692 	return 0;
1693 }
1694 
1695 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1696 			       struct btrfs_root *root, struct inode *inode)
1697 {
1698 	struct btrfs_delayed_node *delayed_node;
1699 	int ret = 0;
1700 
1701 	delayed_node = btrfs_get_or_create_delayed_node(inode);
1702 	if (IS_ERR(delayed_node))
1703 		return PTR_ERR(delayed_node);
1704 
1705 	mutex_lock(&delayed_node->mutex);
1706 	if (delayed_node->inode_dirty) {
1707 		fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1708 		goto release_node;
1709 	}
1710 
1711 	ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
1712 	if (ret)
1713 		goto release_node;
1714 
1715 	fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1716 	delayed_node->inode_dirty = 1;
1717 	delayed_node->count++;
1718 	atomic_inc(&root->fs_info->delayed_root->items);
1719 release_node:
1720 	mutex_unlock(&delayed_node->mutex);
1721 	btrfs_release_delayed_node(delayed_node);
1722 	return ret;
1723 }
1724 
1725 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1726 {
1727 	struct btrfs_root *root = delayed_node->root;
1728 	struct btrfs_delayed_item *curr_item, *prev_item;
1729 
1730 	mutex_lock(&delayed_node->mutex);
1731 	curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1732 	while (curr_item) {
1733 		btrfs_delayed_item_release_metadata(root, curr_item);
1734 		prev_item = curr_item;
1735 		curr_item = __btrfs_next_delayed_item(prev_item);
1736 		btrfs_release_delayed_item(prev_item);
1737 	}
1738 
1739 	curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1740 	while (curr_item) {
1741 		btrfs_delayed_item_release_metadata(root, curr_item);
1742 		prev_item = curr_item;
1743 		curr_item = __btrfs_next_delayed_item(prev_item);
1744 		btrfs_release_delayed_item(prev_item);
1745 	}
1746 
1747 	if (delayed_node->inode_dirty) {
1748 		btrfs_delayed_inode_release_metadata(root, delayed_node);
1749 		btrfs_release_delayed_inode(delayed_node);
1750 	}
1751 	mutex_unlock(&delayed_node->mutex);
1752 }
1753 
1754 void btrfs_kill_delayed_inode_items(struct inode *inode)
1755 {
1756 	struct btrfs_delayed_node *delayed_node;
1757 
1758 	delayed_node = btrfs_get_delayed_node(inode);
1759 	if (!delayed_node)
1760 		return;
1761 
1762 	__btrfs_kill_delayed_node(delayed_node);
1763 	btrfs_release_delayed_node(delayed_node);
1764 }
1765 
1766 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1767 {
1768 	u64 inode_id = 0;
1769 	struct btrfs_delayed_node *delayed_nodes[8];
1770 	int i, n;
1771 
1772 	while (1) {
1773 		spin_lock(&root->inode_lock);
1774 		n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1775 					   (void **)delayed_nodes, inode_id,
1776 					   ARRAY_SIZE(delayed_nodes));
1777 		if (!n) {
1778 			spin_unlock(&root->inode_lock);
1779 			break;
1780 		}
1781 
1782 		inode_id = delayed_nodes[n - 1]->inode_id + 1;
1783 
1784 		for (i = 0; i < n; i++)
1785 			atomic_inc(&delayed_nodes[i]->refs);
1786 		spin_unlock(&root->inode_lock);
1787 
1788 		for (i = 0; i < n; i++) {
1789 			__btrfs_kill_delayed_node(delayed_nodes[i]);
1790 			btrfs_release_delayed_node(delayed_nodes[i]);
1791 		}
1792 	}
1793 }
1794