1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Copyright (C) 2011 Fujitsu. All rights reserved.
4	* Written by Miao Xie <miaox@cn.fujitsu.com>
5	*/
6
7	#include <linux/slab.h>
8	#include <linux/iversion.h>
9	#include "ctree.h"
10	#include "fs.h"
11	#include "messages.h"
12	#include "misc.h"
13	#include "delayed-inode.h"
14	#include "disk-io.h"
15	#include "transaction.h"
16	#include "qgroup.h"
17	#include "locking.h"
18	#include "inode-item.h"
19	#include "space-info.h"
20	#include "accessors.h"
21	#include "file-item.h"
22
23	#define BTRFS_DELAYED_WRITEBACK 512
24	#define BTRFS_DELAYED_BACKGROUND 128
25	#define BTRFS_DELAYED_BATCH 16
26
27	static struct kmem_cache *delayed_node_cache;
28
29	int __init btrfs_delayed_inode_init(void)
30	{
31	delayed_node_cache = KMEM_CACHE(btrfs_delayed_node, 0);
32	if (!delayed_node_cache)
33	return -ENOMEM;
34	return 0;
35	}
36
37	void __cold btrfs_delayed_inode_exit(void)
38	{
39	kmem_cache_destroy(s: delayed_node_cache);
40	}
41
42	void btrfs_init_delayed_root(struct btrfs_delayed_root *delayed_root)
43	{
44	atomic_set(v: &delayed_root->items, i: 0);
45	atomic_set(v: &delayed_root->items_seq, i: 0);
46	delayed_root->nodes = 0;
47	spin_lock_init(&delayed_root->lock);
48	init_waitqueue_head(&delayed_root->wait);
49	INIT_LIST_HEAD(list: &delayed_root->node_list);
50	INIT_LIST_HEAD(list: &delayed_root->prepare_list);
51	}
52
53	static inline void btrfs_init_delayed_node(
54	struct btrfs_delayed_node *delayed_node,
55	struct btrfs_root *root, u64 inode_id)
56	{
57	delayed_node->root = root;
58	delayed_node->inode_id = inode_id;
59	refcount_set(r: &delayed_node->refs, n: 0);
60	delayed_node->ins_root = RB_ROOT_CACHED;
61	delayed_node->del_root = RB_ROOT_CACHED;
62	mutex_init(&delayed_node->mutex);
63	INIT_LIST_HEAD(list: &delayed_node->n_list);
64	INIT_LIST_HEAD(list: &delayed_node->p_list);
65	}
66
67	static struct btrfs_delayed_node *btrfs_get_delayed_node(
68	struct btrfs_inode *btrfs_inode)
69	{
70	struct btrfs_root *root = btrfs_inode->root;
71	u64 ino = btrfs_ino(inode: btrfs_inode);
72	struct btrfs_delayed_node *node;
73
74	node = READ_ONCE(btrfs_inode->delayed_node);
75	if (node) {
76	refcount_inc(r: &node->refs);
77	return node;
78	}
79
80	spin_lock(lock: &root->inode_lock);
81	node = xa_load(&root->delayed_nodes, index: ino);
82
83	if (node) {
84	if (btrfs_inode->delayed_node) {
85	refcount_inc(r: &node->refs); /* can be accessed */
86	BUG_ON(btrfs_inode->delayed_node != node);
87	spin_unlock(lock: &root->inode_lock);
88	return node;
89	}
90
91	/*
92	* It's possible that we're racing into the middle of removing
93	* this node from the xarray. In this case, the refcount
94	* was zero and it should never go back to one. Just return
95	* NULL like it was never in the xarray at all; our release
96	* function is in the process of removing it.
97	*
98	* Some implementations of refcount_inc refuse to bump the
99	* refcount once it has hit zero. If we don't do this dance
100	* here, refcount_inc() may decide to just WARN_ONCE() instead
101	* of actually bumping the refcount.
102	*
103	* If this node is properly in the xarray, we want to bump the
104	* refcount twice, once for the inode and once for this get
105	* operation.
106	*/
107	if (refcount_inc_not_zero(r: &node->refs)) {
108	refcount_inc(r: &node->refs);
109	btrfs_inode->delayed_node = node;
110	} else {
111	node = NULL;
112	}
113
114	spin_unlock(lock: &root->inode_lock);
115	return node;
116	}
117	spin_unlock(lock: &root->inode_lock);
118
119	return NULL;
120	}
121
122	/* Will return either the node or PTR_ERR(-ENOMEM) */
123	static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
124	struct btrfs_inode *btrfs_inode)
125	{
126	struct btrfs_delayed_node *node;
127	struct btrfs_root *root = btrfs_inode->root;
128	u64 ino = btrfs_ino(inode: btrfs_inode);
129	int ret;
130	void *ptr;
131
132	again:
133	node = btrfs_get_delayed_node(btrfs_inode);
134	if (node)
135	return node;
136
137	node = kmem_cache_zalloc(k: delayed_node_cache, GFP_NOFS);
138	if (!node)
139	return ERR_PTR(error: -ENOMEM);
140	btrfs_init_delayed_node(delayed_node: node, root, inode_id: ino);
141
142	/* Cached in the inode and can be accessed. */
143	refcount_set(r: &node->refs, n: 2);
144
145	/* Allocate and reserve the slot, from now it can return a NULL from xa_load(). */
146	ret = xa_reserve(xa: &root->delayed_nodes, index: ino, GFP_NOFS);
147	if (ret == -ENOMEM) {
148	kmem_cache_free(s: delayed_node_cache, objp: node);
149	return ERR_PTR(error: -ENOMEM);
150	}
151	spin_lock(lock: &root->inode_lock);
152	ptr = xa_load(&root->delayed_nodes, index: ino);
153	if (ptr) {
154	/* Somebody inserted it, go back and read it. */
155	spin_unlock(lock: &root->inode_lock);
156	kmem_cache_free(s: delayed_node_cache, objp: node);
157	node = NULL;
158	goto again;
159	}
160	ptr = xa_store(&root->delayed_nodes, index: ino, entry: node, GFP_ATOMIC);
161	ASSERT(xa_err(ptr) != -EINVAL);
162	ASSERT(xa_err(ptr) != -ENOMEM);
163	ASSERT(ptr == NULL);
164	btrfs_inode->delayed_node = node;
165	spin_unlock(lock: &root->inode_lock);
166
167	return node;
168	}
169
170	/*
171	* Call it when holding delayed_node->mutex
172	*
173	* If mod = 1, add this node into the prepared list.
174	*/
175	static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
176	struct btrfs_delayed_node *node,
177	int mod)
178	{
179	spin_lock(lock: &root->lock);
180	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
181	if (!list_empty(head: &node->p_list))
182	list_move_tail(list: &node->p_list, head: &root->prepare_list);
183	else if (mod)
184	list_add_tail(new: &node->p_list, head: &root->prepare_list);
185	} else {
186	list_add_tail(new: &node->n_list, head: &root->node_list);
187	list_add_tail(new: &node->p_list, head: &root->prepare_list);
188	refcount_inc(r: &node->refs); /* inserted into list */
189	root->nodes++;
190	set_bit(BTRFS_DELAYED_NODE_IN_LIST, addr: &node->flags);
191	}
192	spin_unlock(lock: &root->lock);
193	}
194
195	/* Call it when holding delayed_node->mutex */
196	static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
197	struct btrfs_delayed_node *node)
198	{
199	spin_lock(lock: &root->lock);
200	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
201	root->nodes--;
202	refcount_dec(r: &node->refs); /* not in the list */
203	list_del_init(entry: &node->n_list);
204	if (!list_empty(head: &node->p_list))
205	list_del_init(entry: &node->p_list);
206	clear_bit(BTRFS_DELAYED_NODE_IN_LIST, addr: &node->flags);
207	}
208	spin_unlock(lock: &root->lock);
209	}
210
211	static struct btrfs_delayed_node *btrfs_first_delayed_node(
212	struct btrfs_delayed_root *delayed_root)
213	{
214	struct list_head *p;
215	struct btrfs_delayed_node *node = NULL;
216
217	spin_lock(lock: &delayed_root->lock);
218	if (list_empty(head: &delayed_root->node_list))
219	goto out;
220
221	p = delayed_root->node_list.next;
222	node = list_entry(p, struct btrfs_delayed_node, n_list);
223	refcount_inc(r: &node->refs);
224	out:
225	spin_unlock(lock: &delayed_root->lock);
226
227	return node;
228	}
229
230	static struct btrfs_delayed_node *btrfs_next_delayed_node(
231	struct btrfs_delayed_node *node)
232	{
233	struct btrfs_delayed_root *delayed_root;
234	struct list_head *p;
235	struct btrfs_delayed_node *next = NULL;
236
237	delayed_root = node->root->fs_info->delayed_root;
238	spin_lock(lock: &delayed_root->lock);
239	if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
240	/* not in the list */
241	if (list_empty(head: &delayed_root->node_list))
242	goto out;
243	p = delayed_root->node_list.next;
244	} else if (list_is_last(list: &node->n_list, head: &delayed_root->node_list))
245	goto out;
246	else
247	p = node->n_list.next;
248
249	next = list_entry(p, struct btrfs_delayed_node, n_list);
250	refcount_inc(r: &next->refs);
251	out:
252	spin_unlock(lock: &delayed_root->lock);
253
254	return next;
255	}
256
257	static void __btrfs_release_delayed_node(
258	struct btrfs_delayed_node *delayed_node,
259	int mod)
260	{
261	struct btrfs_delayed_root *delayed_root;
262
263	if (!delayed_node)
264	return;
265
266	delayed_root = delayed_node->root->fs_info->delayed_root;
267
268	mutex_lock(&delayed_node->mutex);
269	if (delayed_node->count)
270	btrfs_queue_delayed_node(root: delayed_root, node: delayed_node, mod);
271	else
272	btrfs_dequeue_delayed_node(root: delayed_root, node: delayed_node);
273	mutex_unlock(lock: &delayed_node->mutex);
274
275	if (refcount_dec_and_test(r: &delayed_node->refs)) {
276	struct btrfs_root *root = delayed_node->root;
277
278	spin_lock(lock: &root->inode_lock);
279	/*
280	* Once our refcount goes to zero, nobody is allowed to bump it
281	* back up. We can delete it now.
282	*/
283	ASSERT(refcount_read(&delayed_node->refs) == 0);
284	xa_erase(&root->delayed_nodes, index: delayed_node->inode_id);
285	spin_unlock(lock: &root->inode_lock);
286	kmem_cache_free(s: delayed_node_cache, objp: delayed_node);
287	}
288	}
289
290	static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
291	{
292	__btrfs_release_delayed_node(delayed_node: node, mod: 0);
293	}
294
295	static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
296	struct btrfs_delayed_root *delayed_root)
297	{
298	struct list_head *p;
299	struct btrfs_delayed_node *node = NULL;
300
301	spin_lock(lock: &delayed_root->lock);
302	if (list_empty(head: &delayed_root->prepare_list))
303	goto out;
304
305	p = delayed_root->prepare_list.next;
306	list_del_init(entry: p);
307	node = list_entry(p, struct btrfs_delayed_node, p_list);
308	refcount_inc(r: &node->refs);
309	out:
310	spin_unlock(lock: &delayed_root->lock);
311
312	return node;
313	}
314
315	static inline void btrfs_release_prepared_delayed_node(
316	struct btrfs_delayed_node *node)
317	{
318	__btrfs_release_delayed_node(delayed_node: node, mod: 1);
319	}
320
321	static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u16 data_len,
322	struct btrfs_delayed_node *node,
323	enum btrfs_delayed_item_type type)
324	{
325	struct btrfs_delayed_item *item;
326
327	item = kmalloc(struct_size(item, data, data_len), GFP_NOFS);
328	if (item) {
329	item->data_len = data_len;
330	item->type = type;
331	item->bytes_reserved = 0;
332	item->delayed_node = node;
333	RB_CLEAR_NODE(&item->rb_node);
334	INIT_LIST_HEAD(list: &item->log_list);
335	item->logged = false;
336	refcount_set(r: &item->refs, n: 1);
337	}
338	return item;
339	}
340
341	/*
342	* Look up the delayed item by key.
343	*
344	* @delayed_node: pointer to the delayed node
345	* @index: the dir index value to lookup (offset of a dir index key)
346	*
347	* Note: if we don't find the right item, we will return the prev item and
348	* the next item.
349	*/
350	static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
351	struct rb_root *root,
352	u64 index)
353	{
354	struct rb_node *node = root->rb_node;
355	struct btrfs_delayed_item *delayed_item = NULL;
356
357	while (node) {
358	delayed_item = rb_entry(node, struct btrfs_delayed_item,
359	rb_node);
360	if (delayed_item->index < index)
361	node = node->rb_right;
362	else if (delayed_item->index > index)
363	node = node->rb_left;
364	else
365	return delayed_item;
366	}
367
368	return NULL;
369	}
370
371	static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
372	struct btrfs_delayed_item *ins)
373	{
374	struct rb_node **p, *node;
375	struct rb_node *parent_node = NULL;
376	struct rb_root_cached *root;
377	struct btrfs_delayed_item *item;
378	bool leftmost = true;
379
380	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM)
381	root = &delayed_node->ins_root;
382	else
383	root = &delayed_node->del_root;
384
385	p = &root->rb_root.rb_node;
386	node = &ins->rb_node;
387
388	while (*p) {
389	parent_node = *p;
390	item = rb_entry(parent_node, struct btrfs_delayed_item,
391	rb_node);
392
393	if (item->index < ins->index) {
394	p = &(*p)->rb_right;
395	leftmost = false;
396	} else if (item->index > ins->index) {
397	p = &(*p)->rb_left;
398	} else {
399	return -EEXIST;
400	}
401	}
402
403	rb_link_node(node, parent: parent_node, rb_link: p);
404	rb_insert_color_cached(node, root, leftmost);
405
406	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM &&
407	ins->index >= delayed_node->index_cnt)
408	delayed_node->index_cnt = ins->index + 1;
409
410	delayed_node->count++;
411	atomic_inc(v: &delayed_node->root->fs_info->delayed_root->items);
412	return 0;
413	}
414
415	static void finish_one_item(struct btrfs_delayed_root *delayed_root)
416	{
417	int seq = atomic_inc_return(v: &delayed_root->items_seq);
418
419	/* atomic_dec_return implies a barrier */
420	if ((atomic_dec_return(v: &delayed_root->items) <
421	BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))
422	cond_wake_up_nomb(wq: &delayed_root->wait);
423	}
424
425	static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
426	{
427	struct btrfs_delayed_node *delayed_node = delayed_item->delayed_node;
428	struct rb_root_cached *root;
429	struct btrfs_delayed_root *delayed_root;
430
431	/* Not inserted, ignore it. */
432	if (RB_EMPTY_NODE(&delayed_item->rb_node))
433	return;
434
435	/* If it's in a rbtree, then we need to have delayed node locked. */
436	lockdep_assert_held(&delayed_node->mutex);
437
438	delayed_root = delayed_node->root->fs_info->delayed_root;
439
440	if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)
441	root = &delayed_node->ins_root;
442	else
443	root = &delayed_node->del_root;
444
445	rb_erase_cached(node: &delayed_item->rb_node, root);
446	RB_CLEAR_NODE(&delayed_item->rb_node);
447	delayed_node->count--;
448
449	finish_one_item(delayed_root);
450	}
451
452	static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
453	{
454	if (item) {
455	__btrfs_remove_delayed_item(delayed_item: item);
456	if (refcount_dec_and_test(r: &item->refs))
457	kfree(objp: item);
458	}
459	}
460
461	static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
462	struct btrfs_delayed_node *delayed_node)
463	{
464	struct rb_node *p;
465	struct btrfs_delayed_item *item = NULL;
466
467	p = rb_first_cached(&delayed_node->ins_root);
468	if (p)
469	item = rb_entry(p, struct btrfs_delayed_item, rb_node);
470
471	return item;
472	}
473
474	static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
475	struct btrfs_delayed_node *delayed_node)
476	{
477	struct rb_node *p;
478	struct btrfs_delayed_item *item = NULL;
479
480	p = rb_first_cached(&delayed_node->del_root);
481	if (p)
482	item = rb_entry(p, struct btrfs_delayed_item, rb_node);
483
484	return item;
485	}
486
487	static struct btrfs_delayed_item *__btrfs_next_delayed_item(
488	struct btrfs_delayed_item *item)
489	{
490	struct rb_node *p;
491	struct btrfs_delayed_item *next = NULL;
492
493	p = rb_next(&item->rb_node);
494	if (p)
495	next = rb_entry(p, struct btrfs_delayed_item, rb_node);
496
497	return next;
498	}
499
500	static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
501	struct btrfs_delayed_item *item)
502	{
503	struct btrfs_block_rsv *src_rsv;
504	struct btrfs_block_rsv *dst_rsv;
505	struct btrfs_fs_info *fs_info = trans->fs_info;
506	u64 num_bytes;
507	int ret;
508
509	if (!trans->bytes_reserved)
510	return 0;
511
512	src_rsv = trans->block_rsv;
513	dst_rsv = &fs_info->delayed_block_rsv;
514
515	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: 1);
516
517	/*
518	* Here we migrate space rsv from transaction rsv, since have already
519	* reserved space when starting a transaction. So no need to reserve
520	* qgroup space here.
521	*/
522	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, update_size: true);
523	if (!ret) {
524	trace_btrfs_space_reservation(fs_info, type: "delayed_item",
525	val: item->delayed_node->inode_id,
526	bytes: num_bytes, reserve: 1);
527	/*
528	* For insertions we track reserved metadata space by accounting
529	* for the number of leaves that will be used, based on the delayed
530	* node's curr_index_batch_size and index_item_leaves fields.
531	*/
532	if (item->type == BTRFS_DELAYED_DELETION_ITEM)
533	item->bytes_reserved = num_bytes;
534	}
535
536	return ret;
537	}
538
539	static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
540	struct btrfs_delayed_item *item)
541	{
542	struct btrfs_block_rsv *rsv;
543	struct btrfs_fs_info *fs_info = root->fs_info;
544
545	if (!item->bytes_reserved)
546	return;
547
548	rsv = &fs_info->delayed_block_rsv;
549	/*
550	* Check btrfs_delayed_item_reserve_metadata() to see why we don't need
551	* to release/reserve qgroup space.
552	*/
553	trace_btrfs_space_reservation(fs_info, type: "delayed_item",
554	val: item->delayed_node->inode_id,
555	bytes: item->bytes_reserved, reserve: 0);
556	btrfs_block_rsv_release(fs_info, block_rsv: rsv, num_bytes: item->bytes_reserved, NULL);
557	}
558
559	static void btrfs_delayed_item_release_leaves(struct btrfs_delayed_node *node,
560	unsigned int num_leaves)
561	{
562	struct btrfs_fs_info *fs_info = node->root->fs_info;
563	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: num_leaves);
564
565	/* There are no space reservations during log replay, bail out. */
566	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
567	return;
568
569	trace_btrfs_space_reservation(fs_info, type: "delayed_item", val: node->inode_id,
570	bytes, reserve: 0);
571	btrfs_block_rsv_release(fs_info, block_rsv: &fs_info->delayed_block_rsv, num_bytes: bytes, NULL);
572	}
573
574	static int btrfs_delayed_inode_reserve_metadata(
575	struct btrfs_trans_handle *trans,
576	struct btrfs_root *root,
577	struct btrfs_delayed_node *node)
578	{
579	struct btrfs_fs_info *fs_info = root->fs_info;
580	struct btrfs_block_rsv *src_rsv;
581	struct btrfs_block_rsv *dst_rsv;
582	u64 num_bytes;
583	int ret;
584
585	src_rsv = trans->block_rsv;
586	dst_rsv = &fs_info->delayed_block_rsv;
587
588	num_bytes = btrfs_calc_metadata_size(fs_info, num_items: 1);
589
590	/*
591	* btrfs_dirty_inode will update the inode under btrfs_join_transaction
592	* which doesn't reserve space for speed. This is a problem since we
593	* still need to reserve space for this update, so try to reserve the
594	* space.
595	*
596	* Now if src_rsv == delalloc_block_rsv we'll let it just steal since
597	* we always reserve enough to update the inode item.
598	*/
599	if (!src_rsv || (!trans->bytes_reserved &&
600	src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
601	ret = btrfs_qgroup_reserve_meta(root, num_bytes,
602	type: BTRFS_QGROUP_RSV_META_PREALLOC, enforce: true);
603	if (ret < 0)
604	return ret;
605	ret = btrfs_block_rsv_add(fs_info, block_rsv: dst_rsv, num_bytes,
606	flush: BTRFS_RESERVE_NO_FLUSH);
607	/* NO_FLUSH could only fail with -ENOSPC */
608	ASSERT(ret == 0 || ret == -ENOSPC);
609	if (ret)
610	btrfs_qgroup_free_meta_prealloc(root, num_bytes);
611	} else {
612	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, update_size: true);
613	}
614
615	if (!ret) {
616	trace_btrfs_space_reservation(fs_info, type: "delayed_inode",
617	val: node->inode_id, bytes: num_bytes, reserve: 1);
618	node->bytes_reserved = num_bytes;
619	}
620
621	return ret;
622	}
623
624	static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
625	struct btrfs_delayed_node *node,
626	bool qgroup_free)
627	{
628	struct btrfs_block_rsv *rsv;
629
630	if (!node->bytes_reserved)
631	return;
632
633	rsv = &fs_info->delayed_block_rsv;
634	trace_btrfs_space_reservation(fs_info, type: "delayed_inode",
635	val: node->inode_id, bytes: node->bytes_reserved, reserve: 0);
636	btrfs_block_rsv_release(fs_info, block_rsv: rsv, num_bytes: node->bytes_reserved, NULL);
637	if (qgroup_free)
638	btrfs_qgroup_free_meta_prealloc(root: node->root,
639	num_bytes: node->bytes_reserved);
640	else
641	btrfs_qgroup_convert_reserved_meta(root: node->root,
642	num_bytes: node->bytes_reserved);
643	node->bytes_reserved = 0;
644	}
645
646	/*
647	* Insert a single delayed item or a batch of delayed items, as many as possible
648	* that fit in a leaf. The delayed items (dir index keys) are sorted by their key
649	* in the rbtree, and if there's a gap between two consecutive dir index items,
650	* then it means at some point we had delayed dir indexes to add but they got
651	* removed (by btrfs_delete_delayed_dir_index()) before we attempted to flush them
652	* into the subvolume tree. Dir index keys also have their offsets coming from a
653	* monotonically increasing counter, so we can't get new keys with an offset that
654	* fits within a gap between delayed dir index items.
655	*/
656	static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
657	struct btrfs_root *root,
658	struct btrfs_path *path,
659	struct btrfs_delayed_item *first_item)
660	{
661	struct btrfs_fs_info *fs_info = root->fs_info;
662	struct btrfs_delayed_node *node = first_item->delayed_node;
663	LIST_HEAD(item_list);
664	struct btrfs_delayed_item *curr;
665	struct btrfs_delayed_item *next;
666	const int max_size = BTRFS_LEAF_DATA_SIZE(info: fs_info);
667	struct btrfs_item_batch batch;
668	struct btrfs_key first_key;
669	const u32 first_data_size = first_item->data_len;
670	int total_size;
671	char *ins_data = NULL;
672	int ret;
673	bool continuous_keys_only = false;
674
675	lockdep_assert_held(&node->mutex);
676
677	/*
678	* During normal operation the delayed index offset is continuously
679	* increasing, so we can batch insert all items as there will not be any
680	* overlapping keys in the tree.
681	*
682	* The exception to this is log replay, where we may have interleaved
683	* offsets in the tree, so our batch needs to be continuous keys only in
684	* order to ensure we do not end up with out of order items in our leaf.
685	*/
686	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
687	continuous_keys_only = true;
688
689	/*
690	* For delayed items to insert, we track reserved metadata bytes based
691	* on the number of leaves that we will use.
692	* See btrfs_insert_delayed_dir_index() and
693	* btrfs_delayed_item_reserve_metadata()).
694	*/
695	ASSERT(first_item->bytes_reserved == 0);
696
697	list_add_tail(new: &first_item->tree_list, head: &item_list);
698	batch.total_data_size = first_data_size;
699	batch.nr = 1;
700	total_size = first_data_size + sizeof(struct btrfs_item);
701	curr = first_item;
702
703	while (true) {
704	int next_size;
705
706	next = __btrfs_next_delayed_item(item: curr);
707	if (!next)
708	break;
709
710	/*
711	* We cannot allow gaps in the key space if we're doing log
712	* replay.
713	*/
714	if (continuous_keys_only && (next->index != curr->index + 1))
715	break;
716
717	ASSERT(next->bytes_reserved == 0);
718
719	next_size = next->data_len + sizeof(struct btrfs_item);
720	if (total_size + next_size > max_size)
721	break;
722
723	list_add_tail(new: &next->tree_list, head: &item_list);
724	batch.nr++;
725	total_size += next_size;
726	batch.total_data_size += next->data_len;
727	curr = next;
728	}
729
730	if (batch.nr == 1) {
731	first_key.objectid = node->inode_id;
732	first_key.type = BTRFS_DIR_INDEX_KEY;
733	first_key.offset = first_item->index;
734	batch.keys = &first_key;
735	batch.data_sizes = &first_data_size;
736	} else {
737	struct btrfs_key *ins_keys;
738	u32 *ins_sizes;
739	int i = 0;
740
741	ins_data = kmalloc(size: batch.nr * sizeof(u32) +
742	batch.nr * sizeof(struct btrfs_key), GFP_NOFS);
743	if (!ins_data) {
744	ret = -ENOMEM;
745	goto out;
746	}
747	ins_sizes = (u32 *)ins_data;
748	ins_keys = (struct btrfs_key *)(ins_data + batch.nr * sizeof(u32));
749	batch.keys = ins_keys;
750	batch.data_sizes = ins_sizes;
751	list_for_each_entry(curr, &item_list, tree_list) {
752	ins_keys[i].objectid = node->inode_id;
753	ins_keys[i].type = BTRFS_DIR_INDEX_KEY;
754	ins_keys[i].offset = curr->index;
755	ins_sizes[i] = curr->data_len;
756	i++;
757	}
758	}
759
760	ret = btrfs_insert_empty_items(trans, root, path, batch: &batch);
761	if (ret)
762	goto out;
763
764	list_for_each_entry(curr, &item_list, tree_list) {
765	char *data_ptr;
766
767	data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
768	write_extent_buffer(eb: path->nodes[0], src: &curr->data,
769	start: (unsigned long)data_ptr, len: curr->data_len);
770	path->slots[0]++;
771	}
772
773	/*
774	* Now release our path before releasing the delayed items and their
775	* metadata reservations, so that we don't block other tasks for more
776	* time than needed.
777	*/
778	btrfs_release_path(p: path);
779
780	ASSERT(node->index_item_leaves > 0);
781
782	/*
783	* For normal operations we will batch an entire leaf's worth of delayed
784	* items, so if there are more items to process we can decrement
785	* index_item_leaves by 1 as we inserted 1 leaf's worth of items.
786	*
787	* However for log replay we may not have inserted an entire leaf's
788	* worth of items, we may have not had continuous items, so decrementing
789	* here would mess up the index_item_leaves accounting. For this case
790	* only clean up the accounting when there are no items left.
791	*/
792	if (next && !continuous_keys_only) {
793	/*
794	* We inserted one batch of items into a leaf a there are more
795	* items to flush in a future batch, now release one unit of
796	* metadata space from the delayed block reserve, corresponding
797	* the leaf we just flushed to.
798	*/
799	btrfs_delayed_item_release_leaves(node, num_leaves: 1);
800	node->index_item_leaves--;
801	} else if (!next) {
802	/*
803	* There are no more items to insert. We can have a number of
804	* reserved leaves > 1 here - this happens when many dir index
805	* items are added and then removed before they are flushed (file
806	* names with a very short life, never span a transaction). So
807	* release all remaining leaves.
808	*/
809	btrfs_delayed_item_release_leaves(node, num_leaves: node->index_item_leaves);
810	node->index_item_leaves = 0;
811	}
812
813	list_for_each_entry_safe(curr, next, &item_list, tree_list) {
814	list_del(entry: &curr->tree_list);
815	btrfs_release_delayed_item(item: curr);
816	}
817	out:
818	kfree(objp: ins_data);
819	return ret;
820	}
821
822	static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
823	struct btrfs_path *path,
824	struct btrfs_root *root,
825	struct btrfs_delayed_node *node)
826	{
827	int ret = 0;
828
829	while (ret == 0) {
830	struct btrfs_delayed_item *curr;
831
832	mutex_lock(&node->mutex);
833	curr = __btrfs_first_delayed_insertion_item(delayed_node: node);
834	if (!curr) {
835	mutex_unlock(lock: &node->mutex);
836	break;
837	}
838	ret = btrfs_insert_delayed_item(trans, root, path, first_item: curr);
839	mutex_unlock(lock: &node->mutex);
840	}
841
842	return ret;
843	}
844
845	static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
846	struct btrfs_root *root,
847	struct btrfs_path *path,
848	struct btrfs_delayed_item *item)
849	{
850	const u64 ino = item->delayed_node->inode_id;
851	struct btrfs_fs_info *fs_info = root->fs_info;
852	struct btrfs_delayed_item *curr, *next;
853	struct extent_buffer *leaf = path->nodes[0];
854	LIST_HEAD(batch_list);
855	int nitems, slot, last_slot;
856	int ret;
857	u64 total_reserved_size = item->bytes_reserved;
858
859	ASSERT(leaf != NULL);
860
861	slot = path->slots[0];
862	last_slot = btrfs_header_nritems(eb: leaf) - 1;
863	/*
864	* Our caller always gives us a path pointing to an existing item, so
865	* this can not happen.
866	*/
867	ASSERT(slot <= last_slot);
868	if (WARN_ON(slot > last_slot))
869	return -ENOENT;
870
871	nitems = 1;
872	curr = item;
873	list_add_tail(new: &curr->tree_list, head: &batch_list);
874
875	/*
876	* Keep checking if the next delayed item matches the next item in the
877	* leaf - if so, we can add it to the batch of items to delete from the
878	* leaf.
879	*/
880	while (slot < last_slot) {
881	struct btrfs_key key;
882
883	next = __btrfs_next_delayed_item(item: curr);
884	if (!next)
885	break;
886
887	slot++;
888	btrfs_item_key_to_cpu(eb: leaf, cpu_key: &key, nr: slot);
889	if (key.objectid != ino ||
890	key.type != BTRFS_DIR_INDEX_KEY ||
891	key.offset != next->index)
892	break;
893	nitems++;
894	curr = next;
895	list_add_tail(new: &curr->tree_list, head: &batch_list);
896	total_reserved_size += curr->bytes_reserved;
897	}
898
899	ret = btrfs_del_items(trans, root, path, slot: path->slots[0], nr: nitems);
900	if (ret)
901	return ret;
902
903	/* In case of BTRFS_FS_LOG_RECOVERING items won't have reserved space */
904	if (total_reserved_size > 0) {
905	/*
906	* Check btrfs_delayed_item_reserve_metadata() to see why we
907	* don't need to release/reserve qgroup space.
908	*/
909	trace_btrfs_space_reservation(fs_info, type: "delayed_item", val: ino,
910	bytes: total_reserved_size, reserve: 0);
911	btrfs_block_rsv_release(fs_info, block_rsv: &fs_info->delayed_block_rsv,
912	num_bytes: total_reserved_size, NULL);
913	}
914
915	list_for_each_entry_safe(curr, next, &batch_list, tree_list) {
916	list_del(entry: &curr->tree_list);
917	btrfs_release_delayed_item(item: curr);
918	}
919
920	return 0;
921	}
922
923	static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
924	struct btrfs_path *path,
925	struct btrfs_root *root,
926	struct btrfs_delayed_node *node)
927	{
928	struct btrfs_key key;
929	int ret = 0;
930
931	key.objectid = node->inode_id;
932	key.type = BTRFS_DIR_INDEX_KEY;
933
934	while (ret == 0) {
935	struct btrfs_delayed_item *item;
936
937	mutex_lock(&node->mutex);
938	item = __btrfs_first_delayed_deletion_item(delayed_node: node);
939	if (!item) {
940	mutex_unlock(lock: &node->mutex);
941	break;
942	}
943
944	key.offset = item->index;
945	ret = btrfs_search_slot(trans, root, key: &key, p: path, ins_len: -1, cow: 1);
946	if (ret > 0) {
947	/*
948	* There's no matching item in the leaf. This means we
949	* have already deleted this item in a past run of the
950	* delayed items. We ignore errors when running delayed
951	* items from an async context, through a work queue job
952	* running btrfs_async_run_delayed_root(), and don't
953	* release delayed items that failed to complete. This
954	* is because we will retry later, and at transaction
955	* commit time we always run delayed items and will
956	* then deal with errors if they fail to run again.
957	*
958	* So just release delayed items for which we can't find
959	* an item in the tree, and move to the next item.
960	*/
961	btrfs_release_path(p: path);
962	btrfs_release_delayed_item(item);
963	ret = 0;
964	} else if (ret == 0) {
965	ret = btrfs_batch_delete_items(trans, root, path, item);
966	btrfs_release_path(p: path);
967	}
968
969	/*
970	* We unlock and relock on each iteration, this is to prevent
971	* blocking other tasks for too long while we are being run from
972	* the async context (work queue job). Those tasks are typically
973	* running system calls like creat/mkdir/rename/unlink/etc which
974	* need to add delayed items to this delayed node.
975	*/
976	mutex_unlock(lock: &node->mutex);
977	}
978
979	return ret;
980	}
981
982	static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
983	{
984	struct btrfs_delayed_root *delayed_root;
985
986	if (delayed_node &&
987	test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
988	ASSERT(delayed_node->root);
989	clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, addr: &delayed_node->flags);
990	delayed_node->count--;
991
992	delayed_root = delayed_node->root->fs_info->delayed_root;
993	finish_one_item(delayed_root);
994	}
995	}
996
997	static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
998	{
999
1000	if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, addr: &delayed_node->flags)) {
1001	struct btrfs_delayed_root *delayed_root;
1002
1003	ASSERT(delayed_node->root);
1004	delayed_node->count--;
1005
1006	delayed_root = delayed_node->root->fs_info->delayed_root;
1007	finish_one_item(delayed_root);
1008	}
1009	}
1010
1011	static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1012	struct btrfs_root *root,
1013	struct btrfs_path *path,
1014	struct btrfs_delayed_node *node)
1015	{
1016	struct btrfs_fs_info *fs_info = root->fs_info;
1017	struct btrfs_key key;
1018	struct btrfs_inode_item *inode_item;
1019	struct extent_buffer *leaf;
1020	int mod;
1021	int ret;
1022
1023	key.objectid = node->inode_id;
1024	key.type = BTRFS_INODE_ITEM_KEY;
1025	key.offset = 0;
1026
1027	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1028	mod = -1;
1029	else
1030	mod = 1;
1031
1032	ret = btrfs_lookup_inode(trans, root, path, location: &key, mod);
1033	if (ret > 0)
1034	ret = -ENOENT;
1035	if (ret < 0)
1036	goto out;
1037
1038	leaf = path->nodes[0];
1039	inode_item = btrfs_item_ptr(leaf, path->slots[0],
1040	struct btrfs_inode_item);
1041	write_extent_buffer(eb: leaf, src: &node->inode_item, start: (unsigned long)inode_item,
1042	len: sizeof(struct btrfs_inode_item));
1043	btrfs_mark_buffer_dirty(trans, buf: leaf);
1044
1045	if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1046	goto out;
1047
1048	/*
1049	* Now we're going to delete the INODE_REF/EXTREF, which should be the
1050	* only one ref left. Check if the next item is an INODE_REF/EXTREF.
1051	*
1052	* But if we're the last item already, release and search for the last
1053	* INODE_REF/EXTREF.
1054	*/
1055	if (path->slots[0] + 1 >= btrfs_header_nritems(eb: leaf)) {
1056	key.objectid = node->inode_id;
1057	key.type = BTRFS_INODE_EXTREF_KEY;
1058	key.offset = (u64)-1;
1059
1060	btrfs_release_path(p: path);
1061	ret = btrfs_search_slot(trans, root, key: &key, p: path, ins_len: -1, cow: 1);
1062	if (ret < 0)
1063	goto err_out;
1064	ASSERT(ret > 0);
1065	ASSERT(path->slots[0] > 0);
1066	ret = 0;
1067	path->slots[0]--;
1068	leaf = path->nodes[0];
1069	} else {
1070	path->slots[0]++;
1071	}
1072	btrfs_item_key_to_cpu(eb: leaf, cpu_key: &key, nr: path->slots[0]);
1073	if (key.objectid != node->inode_id)
1074	goto out;
1075	if (key.type != BTRFS_INODE_REF_KEY &&
1076	key.type != BTRFS_INODE_EXTREF_KEY)
1077	goto out;
1078
1079	/*
1080	* Delayed iref deletion is for the inode who has only one link,
1081	* so there is only one iref. The case that several irefs are
1082	* in the same item doesn't exist.
1083	*/
1084	ret = btrfs_del_item(trans, root, path);
1085	out:
1086	btrfs_release_delayed_iref(delayed_node: node);
1087	btrfs_release_path(p: path);
1088	err_out:
1089	btrfs_delayed_inode_release_metadata(fs_info, node, qgroup_free: (ret < 0));
1090	btrfs_release_delayed_inode(delayed_node: node);
1091
1092	/*
1093	* If we fail to update the delayed inode we need to abort the
1094	* transaction, because we could leave the inode with the improper
1095	* counts behind.
1096	*/
1097	if (ret && ret != -ENOENT)
1098	btrfs_abort_transaction(trans, ret);
1099
1100	return ret;
1101	}
1102
1103	static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1104	struct btrfs_root *root,
1105	struct btrfs_path *path,
1106	struct btrfs_delayed_node *node)
1107	{
1108	int ret;
1109
1110	mutex_lock(&node->mutex);
1111	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1112	mutex_unlock(lock: &node->mutex);
1113	return 0;
1114	}
1115
1116	ret = __btrfs_update_delayed_inode(trans, root, path, node);
1117	mutex_unlock(lock: &node->mutex);
1118	return ret;
1119	}
1120
1121	static inline int
1122	__btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1123	struct btrfs_path *path,
1124	struct btrfs_delayed_node *node)
1125	{
1126	int ret;
1127
1128	ret = btrfs_insert_delayed_items(trans, path, root: node->root, node);
1129	if (ret)
1130	return ret;
1131
1132	ret = btrfs_delete_delayed_items(trans, path, root: node->root, node);
1133	if (ret)
1134	return ret;
1135
1136	ret = btrfs_record_root_in_trans(trans, root: node->root);
1137	if (ret)
1138	return ret;
1139	ret = btrfs_update_delayed_inode(trans, root: node->root, path, node);
1140	return ret;
1141	}
1142
1143	/*
1144	* Called when committing the transaction.
1145	* Returns 0 on success.
1146	* Returns < 0 on error and returns with an aborted transaction with any
1147	* outstanding delayed items cleaned up.
1148	*/
1149	static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
1150	{
1151	struct btrfs_fs_info *fs_info = trans->fs_info;
1152	struct btrfs_delayed_root *delayed_root;
1153	struct btrfs_delayed_node *curr_node, *prev_node;
1154	struct btrfs_path *path;
1155	struct btrfs_block_rsv *block_rsv;
1156	int ret = 0;
1157	bool count = (nr > 0);
1158
1159	if (TRANS_ABORTED(trans))
1160	return -EIO;
1161
1162	path = btrfs_alloc_path();
1163	if (!path)
1164	return -ENOMEM;
1165
1166	block_rsv = trans->block_rsv;
1167	trans->block_rsv = &fs_info->delayed_block_rsv;
1168
1169	delayed_root = fs_info->delayed_root;
1170
1171	curr_node = btrfs_first_delayed_node(delayed_root);
1172	while (curr_node && (!count || nr--)) {
1173	ret = __btrfs_commit_inode_delayed_items(trans, path,
1174	node: curr_node);
1175	if (ret) {
1176	btrfs_abort_transaction(trans, ret);
1177	break;
1178	}
1179
1180	prev_node = curr_node;
1181	curr_node = btrfs_next_delayed_node(node: curr_node);
1182	/*
1183	* See the comment below about releasing path before releasing
1184	* node. If the commit of delayed items was successful the path
1185	* should always be released, but in case of an error, it may
1186	* point to locked extent buffers (a leaf at the very least).
1187	*/
1188	ASSERT(path->nodes[0] == NULL);
1189	btrfs_release_delayed_node(node: prev_node);
1190	}
1191
1192	/*
1193	* Release the path to avoid a potential deadlock and lockdep splat when
1194	* releasing the delayed node, as that requires taking the delayed node's
1195	* mutex. If another task starts running delayed items before we take
1196	* the mutex, it will first lock the mutex and then it may try to lock
1197	* the same btree path (leaf).
1198	*/
1199	btrfs_free_path(p: path);
1200
1201	if (curr_node)
1202	btrfs_release_delayed_node(node: curr_node);
1203	trans->block_rsv = block_rsv;
1204
1205	return ret;
1206	}
1207
1208	int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)
1209	{
1210	return __btrfs_run_delayed_items(trans, nr: -1);
1211	}
1212
1213	int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)
1214	{
1215	return __btrfs_run_delayed_items(trans, nr);
1216	}
1217
1218	int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1219	struct btrfs_inode *inode)
1220	{
1221	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(btrfs_inode: inode);
1222	struct btrfs_path *path;
1223	struct btrfs_block_rsv *block_rsv;
1224	int ret;
1225
1226	if (!delayed_node)
1227	return 0;
1228
1229	mutex_lock(&delayed_node->mutex);
1230	if (!delayed_node->count) {
1231	mutex_unlock(lock: &delayed_node->mutex);
1232	btrfs_release_delayed_node(node: delayed_node);
1233	return 0;
1234	}
1235	mutex_unlock(lock: &delayed_node->mutex);
1236
1237	path = btrfs_alloc_path();
1238	if (!path) {
1239	btrfs_release_delayed_node(node: delayed_node);
1240	return -ENOMEM;
1241	}
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, node: delayed_node);
1247
1248	btrfs_release_delayed_node(node: delayed_node);
1249	btrfs_free_path(p: path);
1250	trans->block_rsv = block_rsv;
1251
1252	return ret;
1253	}
1254
1255	int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
1256	{
1257	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1258	struct btrfs_trans_handle *trans;
1259	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(btrfs_inode: inode);
1260	struct btrfs_path *path;
1261	struct btrfs_block_rsv *block_rsv;
1262	int ret;
1263
1264	if (!delayed_node)
1265	return 0;
1266
1267	mutex_lock(&delayed_node->mutex);
1268	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1269	mutex_unlock(lock: &delayed_node->mutex);
1270	btrfs_release_delayed_node(node: delayed_node);
1271	return 0;
1272	}
1273	mutex_unlock(lock: &delayed_node->mutex);
1274
1275	trans = btrfs_join_transaction(root: delayed_node->root);
1276	if (IS_ERR(ptr: trans)) {
1277	ret = PTR_ERR(ptr: trans);
1278	goto out;
1279	}
1280
1281	path = btrfs_alloc_path();
1282	if (!path) {
1283	ret = -ENOMEM;
1284	goto trans_out;
1285	}
1286
1287	block_rsv = trans->block_rsv;
1288	trans->block_rsv = &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, root: delayed_node->root,
1293	path, node: delayed_node);
1294	else
1295	ret = 0;
1296	mutex_unlock(lock: &delayed_node->mutex);
1297
1298	btrfs_free_path(p: path);
1299	trans->block_rsv = block_rsv;
1300	trans_out:
1301	btrfs_end_transaction(trans);
1302	btrfs_btree_balance_dirty(fs_info);
1303	out:
1304	btrfs_release_delayed_node(node: delayed_node);
1305
1306	return ret;
1307	}
1308
1309	void btrfs_remove_delayed_node(struct btrfs_inode *inode)
1310	{
1311	struct btrfs_delayed_node *delayed_node;
1312
1313	delayed_node = READ_ONCE(inode->delayed_node);
1314	if (!delayed_node)
1315	return;
1316
1317	inode->delayed_node = NULL;
1318	btrfs_release_delayed_node(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	do {
1346	if (atomic_read(v: &delayed_root->items) <
1347	BTRFS_DELAYED_BACKGROUND / 2)
1348	break;
1349
1350	delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1351	if (!delayed_node)
1352	break;
1353
1354	root = delayed_node->root;
1355
1356	trans = btrfs_join_transaction(root);
1357	if (IS_ERR(ptr: trans)) {
1358	btrfs_release_path(p: path);
1359	btrfs_release_prepared_delayed_node(node: delayed_node);
1360	total_done++;
1361	continue;
1362	}
1363
1364	block_rsv = trans->block_rsv;
1365	trans->block_rsv = &root->fs_info->delayed_block_rsv;
1366
1367	__btrfs_commit_inode_delayed_items(trans, path, node: delayed_node);
1368
1369	trans->block_rsv = block_rsv;
1370	btrfs_end_transaction(trans);
1371	btrfs_btree_balance_dirty_nodelay(fs_info: root->fs_info);
1372
1373	btrfs_release_path(p: path);
1374	btrfs_release_prepared_delayed_node(node: delayed_node);
1375	total_done++;
1376
1377	} while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
1378	|| total_done < async_work->nr);
1379
1380	btrfs_free_path(p: path);
1381	out:
1382	wake_up(&delayed_root->wait);
1383	kfree(objp: async_work);
1384	}
1385
1386
1387	static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1388	struct btrfs_fs_info *fs_info, int nr)
1389	{
1390	struct btrfs_async_delayed_work *async_work;
1391
1392	async_work = kmalloc(size: sizeof(*async_work), GFP_NOFS);
1393	if (!async_work)
1394	return -ENOMEM;
1395
1396	async_work->delayed_root = delayed_root;
1397	btrfs_init_work(work: &async_work->work, func: btrfs_async_run_delayed_root, NULL);
1398	async_work->nr = nr;
1399
1400	btrfs_queue_work(wq: fs_info->delayed_workers, work: &async_work->work);
1401	return 0;
1402	}
1403
1404	void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
1405	{
1406	WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));
1407	}
1408
1409	static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1410	{
1411	int val = atomic_read(v: &delayed_root->items_seq);
1412
1413	if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1414	return 1;
1415
1416	if (atomic_read(v: &delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1417	return 1;
1418
1419	return 0;
1420	}
1421
1422	void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
1423	{
1424	struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
1425
1426	if ((atomic_read(v: &delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
1427	btrfs_workqueue_normal_congested(wq: fs_info->delayed_workers))
1428	return;
1429
1430	if (atomic_read(v: &delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1431	int seq;
1432	int ret;
1433
1434	seq = atomic_read(v: &delayed_root->items_seq);
1435
1436	ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, nr: 0);
1437	if (ret)
1438	return;
1439
1440	wait_event_interruptible(delayed_root->wait,
1441	could_end_wait(delayed_root, seq));
1442	return;
1443	}
1444
1445	btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1446	}
1447
1448	static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans)
1449	{
1450	struct btrfs_fs_info *fs_info = trans->fs_info;
1451	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: 1);
1452
1453	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1454	return;
1455
1456	/*
1457	* Adding the new dir index item does not require touching another
1458	* leaf, so we can release 1 unit of metadata that was previously
1459	* reserved when starting the transaction. This applies only to
1460	* the case where we had a transaction start and excludes the
1461	* transaction join case (when replaying log trees).
1462	*/
1463	trace_btrfs_space_reservation(fs_info, type: "transaction",
1464	val: trans->transid, bytes, reserve: 0);
1465	btrfs_block_rsv_release(fs_info, block_rsv: trans->block_rsv, num_bytes: bytes, NULL);
1466	ASSERT(trans->bytes_reserved >= bytes);
1467	trans->bytes_reserved -= bytes;
1468	}
1469
1470	/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */
1471	int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1472	const char *name, int name_len,
1473	struct btrfs_inode *dir,
1474	struct btrfs_disk_key *disk_key, u8 flags,
1475	u64 index)
1476	{
1477	struct btrfs_fs_info *fs_info = trans->fs_info;
1478	const unsigned int leaf_data_size = BTRFS_LEAF_DATA_SIZE(info: fs_info);
1479	struct btrfs_delayed_node *delayed_node;
1480	struct btrfs_delayed_item *delayed_item;
1481	struct btrfs_dir_item *dir_item;
1482	bool reserve_leaf_space;
1483	u32 data_len;
1484	int ret;
1485
1486	delayed_node = btrfs_get_or_create_delayed_node(btrfs_inode: dir);
1487	if (IS_ERR(ptr: delayed_node))
1488	return PTR_ERR(ptr: delayed_node);
1489
1490	delayed_item = btrfs_alloc_delayed_item(data_len: sizeof(*dir_item) + name_len,
1491	node: delayed_node,
1492	type: BTRFS_DELAYED_INSERTION_ITEM);
1493	if (!delayed_item) {
1494	ret = -ENOMEM;
1495	goto release_node;
1496	}
1497
1498	delayed_item->index = index;
1499
1500	dir_item = (struct btrfs_dir_item *)delayed_item->data;
1501	dir_item->location = *disk_key;
1502	btrfs_set_stack_dir_transid(s: dir_item, val: trans->transid);
1503	btrfs_set_stack_dir_data_len(s: dir_item, val: 0);
1504	btrfs_set_stack_dir_name_len(s: dir_item, val: name_len);
1505	btrfs_set_stack_dir_flags(s: dir_item, val: flags);
1506	memcpy((char *)(dir_item + 1), name, name_len);
1507
1508	data_len = delayed_item->data_len + sizeof(struct btrfs_item);
1509
1510	mutex_lock(&delayed_node->mutex);
1511
1512	/*
1513	* First attempt to insert the delayed item. This is to make the error
1514	* handling path simpler in case we fail (-EEXIST). There's no risk of
1515	* any other task coming in and running the delayed item before we do
1516	* the metadata space reservation below, because we are holding the
1517	* delayed node's mutex and that mutex must also be locked before the
1518	* node's delayed items can be run.
1519	*/
1520	ret = __btrfs_add_delayed_item(delayed_node, ins: delayed_item);
1521	if (unlikely(ret)) {
1522	btrfs_err(trans->fs_info,
1523	"error adding delayed dir index item, name: %.*s, index: %llu, root: %llu, dir: %llu, dir->index_cnt: %llu, delayed_node->index_cnt: %llu, error: %d",
1524	name_len, name, index, btrfs_root_id(delayed_node->root),
1525	delayed_node->inode_id, dir->index_cnt,
1526	delayed_node->index_cnt, ret);
1527	btrfs_release_delayed_item(item: delayed_item);
1528	btrfs_release_dir_index_item_space(trans);
1529	mutex_unlock(lock: &delayed_node->mutex);
1530	goto release_node;
1531	}
1532
1533	if (delayed_node->index_item_leaves == 0 ||
1534	delayed_node->curr_index_batch_size + data_len > leaf_data_size) {
1535	delayed_node->curr_index_batch_size = data_len;
1536	reserve_leaf_space = true;
1537	} else {
1538	delayed_node->curr_index_batch_size += data_len;
1539	reserve_leaf_space = false;
1540	}
1541
1542	if (reserve_leaf_space) {
1543	ret = btrfs_delayed_item_reserve_metadata(trans, item: delayed_item);
1544	/*
1545	* Space was reserved for a dir index item insertion when we
1546	* started the transaction, so getting a failure here should be
1547	* impossible.
1548	*/
1549	if (WARN_ON(ret)) {
1550	btrfs_release_delayed_item(item: delayed_item);
1551	mutex_unlock(lock: &delayed_node->mutex);
1552	goto release_node;
1553	}
1554
1555	delayed_node->index_item_leaves++;
1556	} else {
1557	btrfs_release_dir_index_item_space(trans);
1558	}
1559	mutex_unlock(lock: &delayed_node->mutex);
1560
1561	release_node:
1562	btrfs_release_delayed_node(node: delayed_node);
1563	return ret;
1564	}
1565
1566	static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,
1567	struct btrfs_delayed_node *node,
1568	u64 index)
1569	{
1570	struct btrfs_delayed_item *item;
1571
1572	mutex_lock(&node->mutex);
1573	item = __btrfs_lookup_delayed_item(root: &node->ins_root.rb_root, index);
1574	if (!item) {
1575	mutex_unlock(lock: &node->mutex);
1576	return 1;
1577	}
1578
1579	/*
1580	* For delayed items to insert, we track reserved metadata bytes based
1581	* on the number of leaves that we will use.
1582	* See btrfs_insert_delayed_dir_index() and
1583	* btrfs_delayed_item_reserve_metadata()).
1584	*/
1585	ASSERT(item->bytes_reserved == 0);
1586	ASSERT(node->index_item_leaves > 0);
1587
1588	/*
1589	* If there's only one leaf reserved, we can decrement this item from the
1590	* current batch, otherwise we can not because we don't know which leaf
1591	* it belongs to. With the current limit on delayed items, we rarely
1592	* accumulate enough dir index items to fill more than one leaf (even
1593	* when using a leaf size of 4K).
1594	*/
1595	if (node->index_item_leaves == 1) {
1596	const u32 data_len = item->data_len + sizeof(struct btrfs_item);
1597
1598	ASSERT(node->curr_index_batch_size >= data_len);
1599	node->curr_index_batch_size -= data_len;
1600	}
1601
1602	btrfs_release_delayed_item(item);
1603
1604	/* If we now have no more dir index items, we can release all leaves. */
1605	if (RB_EMPTY_ROOT(&node->ins_root.rb_root)) {
1606	btrfs_delayed_item_release_leaves(node, num_leaves: node->index_item_leaves);
1607	node->index_item_leaves = 0;
1608	}
1609
1610	mutex_unlock(lock: &node->mutex);
1611	return 0;
1612	}
1613
1614	int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1615	struct btrfs_inode *dir, u64 index)
1616	{
1617	struct btrfs_delayed_node *node;
1618	struct btrfs_delayed_item *item;
1619	int ret;
1620
1621	node = btrfs_get_or_create_delayed_node(btrfs_inode: dir);
1622	if (IS_ERR(ptr: node))
1623	return PTR_ERR(ptr: node);
1624
1625	ret = btrfs_delete_delayed_insertion_item(fs_info: trans->fs_info, node, index);
1626	if (!ret)
1627	goto end;
1628
1629	item = btrfs_alloc_delayed_item(data_len: 0, node, type: BTRFS_DELAYED_DELETION_ITEM);
1630	if (!item) {
1631	ret = -ENOMEM;
1632	goto end;
1633	}
1634
1635	item->index = index;
1636
1637	ret = btrfs_delayed_item_reserve_metadata(trans, item);
1638	/*
1639	* we have reserved enough space when we start a new transaction,
1640	* so reserving metadata failure is impossible.
1641	*/
1642	if (ret < 0) {
1643	btrfs_err(trans->fs_info,
1644	"metadata reservation failed for delayed dir item deltiona, should have been reserved");
1645	btrfs_release_delayed_item(item);
1646	goto end;
1647	}
1648
1649	mutex_lock(&node->mutex);
1650	ret = __btrfs_add_delayed_item(delayed_node: node, ins: item);
1651	if (unlikely(ret)) {
1652	btrfs_err(trans->fs_info,
1653	"err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1654	index, node->root->root_key.objectid,
1655	node->inode_id, ret);
1656	btrfs_delayed_item_release_metadata(root: dir->root, item);
1657	btrfs_release_delayed_item(item);
1658	}
1659	mutex_unlock(lock: &node->mutex);
1660	end:
1661	btrfs_release_delayed_node(node);
1662	return ret;
1663	}
1664
1665	int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)
1666	{
1667	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(btrfs_inode: inode);
1668
1669	if (!delayed_node)
1670	return -ENOENT;
1671
1672	/*
1673	* Since we have held i_mutex of this directory, it is impossible that
1674	* a new directory index is added into the delayed node and index_cnt
1675	* is updated now. So we needn't lock the delayed node.
1676	*/
1677	if (!delayed_node->index_cnt) {
1678	btrfs_release_delayed_node(node: delayed_node);
1679	return -EINVAL;
1680	}
1681
1682	inode->index_cnt = delayed_node->index_cnt;
1683	btrfs_release_delayed_node(node: delayed_node);
1684	return 0;
1685	}
1686
1687	bool btrfs_readdir_get_delayed_items(struct inode *inode,
1688	u64 last_index,
1689	struct list_head *ins_list,
1690	struct list_head *del_list)
1691	{
1692	struct btrfs_delayed_node *delayed_node;
1693	struct btrfs_delayed_item *item;
1694
1695	delayed_node = btrfs_get_delayed_node(btrfs_inode: BTRFS_I(inode));
1696	if (!delayed_node)
1697	return false;
1698
1699	/*
1700	* We can only do one readdir with delayed items at a time because of
1701	* item->readdir_list.
1702	*/
1703	btrfs_inode_unlock(inode: BTRFS_I(inode), ilock_flags: BTRFS_ILOCK_SHARED);
1704	btrfs_inode_lock(inode: BTRFS_I(inode), ilock_flags: 0);
1705
1706	mutex_lock(&delayed_node->mutex);
1707	item = __btrfs_first_delayed_insertion_item(delayed_node);
1708	while (item && item->index <= last_index) {
1709	refcount_inc(r: &item->refs);
1710	list_add_tail(new: &item->readdir_list, head: ins_list);
1711	item = __btrfs_next_delayed_item(item);
1712	}
1713
1714	item = __btrfs_first_delayed_deletion_item(delayed_node);
1715	while (item && item->index <= last_index) {
1716	refcount_inc(r: &item->refs);
1717	list_add_tail(new: &item->readdir_list, head: del_list);
1718	item = __btrfs_next_delayed_item(item);
1719	}
1720	mutex_unlock(lock: &delayed_node->mutex);
1721	/*
1722	* This delayed node is still cached in the btrfs inode, so refs
1723	* must be > 1 now, and we needn't check it is going to be freed
1724	* or not.
1725	*
1726	* Besides that, this function is used to read dir, we do not
1727	* insert/delete delayed items in this period. So we also needn't
1728	* requeue or dequeue this delayed node.
1729	*/
1730	refcount_dec(r: &delayed_node->refs);
1731
1732	return true;
1733	}
1734
1735	void btrfs_readdir_put_delayed_items(struct inode *inode,
1736	struct list_head *ins_list,
1737	struct list_head *del_list)
1738	{
1739	struct btrfs_delayed_item *curr, *next;
1740
1741	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1742	list_del(entry: &curr->readdir_list);
1743	if (refcount_dec_and_test(r: &curr->refs))
1744	kfree(objp: curr);
1745	}
1746
1747	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1748	list_del(entry: &curr->readdir_list);
1749	if (refcount_dec_and_test(r: &curr->refs))
1750	kfree(objp: curr);
1751	}
1752
1753	/*
1754	* The VFS is going to do up_read(), so we need to downgrade back to a
1755	* read lock.
1756	*/
1757	downgrade_write(sem: &inode->i_rwsem);
1758	}
1759
1760	int btrfs_should_delete_dir_index(struct list_head *del_list,
1761	u64 index)
1762	{
1763	struct btrfs_delayed_item *curr;
1764	int ret = 0;
1765
1766	list_for_each_entry(curr, del_list, readdir_list) {
1767	if (curr->index > index)
1768	break;
1769	if (curr->index == index) {
1770	ret = 1;
1771	break;
1772	}
1773	}
1774	return ret;
1775	}
1776
1777	/*
1778	* Read dir info stored in the delayed tree.
1779	*/
1780	int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1781	struct list_head *ins_list)
1782	{
1783	struct btrfs_dir_item *di;
1784	struct btrfs_delayed_item *curr, *next;
1785	struct btrfs_key location;
1786	char *name;
1787	int name_len;
1788	int over = 0;
1789	unsigned char d_type;
1790
1791	/*
1792	* Changing the data of the delayed item is impossible. So
1793	* we needn't lock them. And we have held i_mutex of the
1794	* directory, nobody can delete any directory indexes now.
1795	*/
1796	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1797	list_del(entry: &curr->readdir_list);
1798
1799	if (curr->index < ctx->pos) {
1800	if (refcount_dec_and_test(r: &curr->refs))
1801	kfree(objp: curr);
1802	continue;
1803	}
1804
1805	ctx->pos = curr->index;
1806
1807	di = (struct btrfs_dir_item *)curr->data;
1808	name = (char *)(di + 1);
1809	name_len = btrfs_stack_dir_name_len(s: di);
1810
1811	d_type = fs_ftype_to_dtype(filetype: btrfs_dir_flags_to_ftype(flags: di->type));
1812	btrfs_disk_key_to_cpu(cpu_key: &location, disk_key: &di->location);
1813
1814	over = !dir_emit(ctx, name, namelen: name_len,
1815	ino: location.objectid, type: d_type);
1816
1817	if (refcount_dec_and_test(r: &curr->refs))
1818	kfree(objp: curr);
1819
1820	if (over)
1821	return 1;
1822	ctx->pos++;
1823	}
1824	return 0;
1825	}
1826
1827	static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1828	struct btrfs_inode_item *inode_item,
1829	struct inode *inode)
1830	{
1831	u64 flags;
1832
1833	btrfs_set_stack_inode_uid(s: inode_item, val: i_uid_read(inode));
1834	btrfs_set_stack_inode_gid(s: inode_item, val: i_gid_read(inode));
1835	btrfs_set_stack_inode_size(s: inode_item, val: BTRFS_I(inode)->disk_i_size);
1836	btrfs_set_stack_inode_mode(s: inode_item, val: inode->i_mode);
1837	btrfs_set_stack_inode_nlink(s: inode_item, val: inode->i_nlink);
1838	btrfs_set_stack_inode_nbytes(s: inode_item, val: inode_get_bytes(inode));
1839	btrfs_set_stack_inode_generation(s: inode_item,
1840	val: BTRFS_I(inode)->generation);
1841	btrfs_set_stack_inode_sequence(s: inode_item,
1842	val: inode_peek_iversion(inode));
1843	btrfs_set_stack_inode_transid(s: inode_item, val: trans->transid);
1844	btrfs_set_stack_inode_rdev(s: inode_item, val: inode->i_rdev);
1845	flags = btrfs_inode_combine_flags(flags: BTRFS_I(inode)->flags,
1846	ro_flags: BTRFS_I(inode)->ro_flags);
1847	btrfs_set_stack_inode_flags(s: inode_item, val: flags);
1848	btrfs_set_stack_inode_block_group(s: inode_item, val: 0);
1849
1850	btrfs_set_stack_timespec_sec(s: &inode_item->atime,
1851	val: inode_get_atime_sec(inode));
1852	btrfs_set_stack_timespec_nsec(s: &inode_item->atime,
1853	val: inode_get_atime_nsec(inode));
1854
1855	btrfs_set_stack_timespec_sec(s: &inode_item->mtime,
1856	val: inode_get_mtime_sec(inode));
1857	btrfs_set_stack_timespec_nsec(s: &inode_item->mtime,
1858	val: inode_get_mtime_nsec(inode));
1859
1860	btrfs_set_stack_timespec_sec(s: &inode_item->ctime,
1861	val: inode_get_ctime_sec(inode));
1862	btrfs_set_stack_timespec_nsec(s: &inode_item->ctime,
1863	val: inode_get_ctime_nsec(inode));
1864
1865	btrfs_set_stack_timespec_sec(s: &inode_item->otime, val: BTRFS_I(inode)->i_otime_sec);
1866	btrfs_set_stack_timespec_nsec(s: &inode_item->otime, val: BTRFS_I(inode)->i_otime_nsec);
1867	}
1868
1869	int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1870	{
1871	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1872	struct btrfs_delayed_node *delayed_node;
1873	struct btrfs_inode_item *inode_item;
1874
1875	delayed_node = btrfs_get_delayed_node(btrfs_inode: BTRFS_I(inode));
1876	if (!delayed_node)
1877	return -ENOENT;
1878
1879	mutex_lock(&delayed_node->mutex);
1880	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1881	mutex_unlock(lock: &delayed_node->mutex);
1882	btrfs_release_delayed_node(node: delayed_node);
1883	return -ENOENT;
1884	}
1885
1886	inode_item = &delayed_node->inode_item;
1887
1888	i_uid_write(inode, uid: btrfs_stack_inode_uid(s: inode_item));
1889	i_gid_write(inode, gid: btrfs_stack_inode_gid(s: inode_item));
1890	btrfs_i_size_write(inode: BTRFS_I(inode), size: btrfs_stack_inode_size(s: inode_item));
1891	btrfs_inode_set_file_extent_range(inode: BTRFS_I(inode), start: 0,
1892	round_up(i_size_read(inode), fs_info->sectorsize));
1893	inode->i_mode = btrfs_stack_inode_mode(s: inode_item);
1894	set_nlink(inode, nlink: btrfs_stack_inode_nlink(s: inode_item));
1895	inode_set_bytes(inode, bytes: btrfs_stack_inode_nbytes(s: inode_item));
1896	BTRFS_I(inode)->generation = btrfs_stack_inode_generation(s: inode_item);
1897	BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(s: inode_item);
1898
1899	inode_set_iversion_queried(inode,
1900	val: btrfs_stack_inode_sequence(s: inode_item));
1901	inode->i_rdev = 0;
1902	*rdev = btrfs_stack_inode_rdev(s: inode_item);
1903	btrfs_inode_split_flags(inode_item_flags: btrfs_stack_inode_flags(s: inode_item),
1904	flags: &BTRFS_I(inode)->flags, ro_flags: &BTRFS_I(inode)->ro_flags);
1905
1906	inode_set_atime(inode, sec: btrfs_stack_timespec_sec(s: &inode_item->atime),
1907	nsec: btrfs_stack_timespec_nsec(s: &inode_item->atime));
1908
1909	inode_set_mtime(inode, sec: btrfs_stack_timespec_sec(s: &inode_item->mtime),
1910	nsec: btrfs_stack_timespec_nsec(s: &inode_item->mtime));
1911
1912	inode_set_ctime(inode, sec: btrfs_stack_timespec_sec(s: &inode_item->ctime),
1913	nsec: btrfs_stack_timespec_nsec(s: &inode_item->ctime));
1914
1915	BTRFS_I(inode)->i_otime_sec = btrfs_stack_timespec_sec(s: &inode_item->otime);
1916	BTRFS_I(inode)->i_otime_nsec = btrfs_stack_timespec_nsec(s: &inode_item->otime);
1917
1918	inode->i_generation = BTRFS_I(inode)->generation;
1919	BTRFS_I(inode)->index_cnt = (u64)-1;
1920
1921	mutex_unlock(lock: &delayed_node->mutex);
1922	btrfs_release_delayed_node(node: delayed_node);
1923	return 0;
1924	}
1925
1926	int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1927	struct btrfs_inode *inode)
1928	{
1929	struct btrfs_root *root = inode->root;
1930	struct btrfs_delayed_node *delayed_node;
1931	int ret = 0;
1932
1933	delayed_node = btrfs_get_or_create_delayed_node(btrfs_inode: inode);
1934	if (IS_ERR(ptr: delayed_node))
1935	return PTR_ERR(ptr: delayed_node);
1936
1937	mutex_lock(&delayed_node->mutex);
1938	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1939	fill_stack_inode_item(trans, inode_item: &delayed_node->inode_item,
1940	inode: &inode->vfs_inode);
1941	goto release_node;
1942	}
1943
1944	ret = btrfs_delayed_inode_reserve_metadata(trans, root, node: delayed_node);
1945	if (ret)
1946	goto release_node;
1947
1948	fill_stack_inode_item(trans, inode_item: &delayed_node->inode_item, inode: &inode->vfs_inode);
1949	set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, addr: &delayed_node->flags);
1950	delayed_node->count++;
1951	atomic_inc(v: &root->fs_info->delayed_root->items);
1952	release_node:
1953	mutex_unlock(lock: &delayed_node->mutex);
1954	btrfs_release_delayed_node(node: delayed_node);
1955	return ret;
1956	}
1957
1958	int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)
1959	{
1960	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1961	struct btrfs_delayed_node *delayed_node;
1962
1963	/*
1964	* we don't do delayed inode updates during log recovery because it
1965	* leads to enospc problems. This means we also can't do
1966	* delayed inode refs
1967	*/
1968	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1969	return -EAGAIN;
1970
1971	delayed_node = btrfs_get_or_create_delayed_node(btrfs_inode: inode);
1972	if (IS_ERR(ptr: delayed_node))
1973	return PTR_ERR(ptr: delayed_node);
1974
1975	/*
1976	* We don't reserve space for inode ref deletion is because:
1977	* - We ONLY do async inode ref deletion for the inode who has only
1978	* one link(i_nlink == 1), it means there is only one inode ref.
1979	* And in most case, the inode ref and the inode item are in the
1980	* same leaf, and we will deal with them at the same time.
1981	* Since we are sure we will reserve the space for the inode item,
1982	* it is unnecessary to reserve space for inode ref deletion.
1983	* - If the inode ref and the inode item are not in the same leaf,
1984	* We also needn't worry about enospc problem, because we reserve
1985	* much more space for the inode update than it needs.
1986	* - At the worst, we can steal some space from the global reservation.
1987	* It is very rare.
1988	*/
1989	mutex_lock(&delayed_node->mutex);
1990	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1991	goto release_node;
1992
1993	set_bit(BTRFS_DELAYED_NODE_DEL_IREF, addr: &delayed_node->flags);
1994	delayed_node->count++;
1995	atomic_inc(v: &fs_info->delayed_root->items);
1996	release_node:
1997	mutex_unlock(lock: &delayed_node->mutex);
1998	btrfs_release_delayed_node(node: delayed_node);
1999	return 0;
2000	}
2001
2002	static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
2003	{
2004	struct btrfs_root *root = delayed_node->root;
2005	struct btrfs_fs_info *fs_info = root->fs_info;
2006	struct btrfs_delayed_item *curr_item, *prev_item;
2007
2008	mutex_lock(&delayed_node->mutex);
2009	curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
2010	while (curr_item) {
2011	prev_item = curr_item;
2012	curr_item = __btrfs_next_delayed_item(item: prev_item);
2013	btrfs_release_delayed_item(item: prev_item);
2014	}
2015
2016	if (delayed_node->index_item_leaves > 0) {
2017	btrfs_delayed_item_release_leaves(node: delayed_node,
2018	num_leaves: delayed_node->index_item_leaves);
2019	delayed_node->index_item_leaves = 0;
2020	}
2021
2022	curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
2023	while (curr_item) {
2024	btrfs_delayed_item_release_metadata(root, item: curr_item);
2025	prev_item = curr_item;
2026	curr_item = __btrfs_next_delayed_item(item: prev_item);
2027	btrfs_release_delayed_item(item: prev_item);
2028	}
2029
2030	btrfs_release_delayed_iref(delayed_node);
2031
2032	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
2033	btrfs_delayed_inode_release_metadata(fs_info, node: delayed_node, qgroup_free: false);
2034	btrfs_release_delayed_inode(delayed_node);
2035	}
2036	mutex_unlock(lock: &delayed_node->mutex);
2037	}
2038
2039	void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)
2040	{
2041	struct btrfs_delayed_node *delayed_node;
2042
2043	delayed_node = btrfs_get_delayed_node(btrfs_inode: inode);
2044	if (!delayed_node)
2045	return;
2046
2047	__btrfs_kill_delayed_node(delayed_node);
2048	btrfs_release_delayed_node(node: delayed_node);
2049	}
2050
2051	void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
2052	{
2053	unsigned long index = 0;
2054	struct btrfs_delayed_node *delayed_nodes[8];
2055
2056	while (1) {
2057	struct btrfs_delayed_node *node;
2058	int count;
2059
2060	spin_lock(lock: &root->inode_lock);
2061	if (xa_empty(xa: &root->delayed_nodes)) {
2062	spin_unlock(lock: &root->inode_lock);
2063	return;
2064	}
2065
2066	count = 0;
2067	xa_for_each_start(&root->delayed_nodes, index, node, index) {
2068	/*
2069	* Don't increase refs in case the node is dead and
2070	* about to be removed from the tree in the loop below
2071	*/
2072	if (refcount_inc_not_zero(r: &node->refs)) {
2073	delayed_nodes[count] = node;
2074	count++;
2075	}
2076	if (count >= ARRAY_SIZE(delayed_nodes))
2077	break;
2078	}
2079	spin_unlock(lock: &root->inode_lock);
2080	index++;
2081
2082	for (int i = 0; i < count; i++) {
2083	__btrfs_kill_delayed_node(delayed_node: delayed_nodes[i]);
2084	btrfs_release_delayed_node(node: delayed_nodes[i]);
2085	}
2086	}
2087	}
2088
2089	void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
2090	{
2091	struct btrfs_delayed_node *curr_node, *prev_node;
2092
2093	curr_node = btrfs_first_delayed_node(delayed_root: fs_info->delayed_root);
2094	while (curr_node) {
2095	__btrfs_kill_delayed_node(delayed_node: curr_node);
2096
2097	prev_node = curr_node;
2098	curr_node = btrfs_next_delayed_node(node: curr_node);
2099	btrfs_release_delayed_node(node: prev_node);
2100	}
2101	}
2102
2103	void btrfs_log_get_delayed_items(struct btrfs_inode *inode,
2104	struct list_head *ins_list,
2105	struct list_head *del_list)
2106	{
2107	struct btrfs_delayed_node *node;
2108	struct btrfs_delayed_item *item;
2109
2110	node = btrfs_get_delayed_node(btrfs_inode: inode);
2111	if (!node)
2112	return;
2113
2114	mutex_lock(&node->mutex);
2115	item = __btrfs_first_delayed_insertion_item(delayed_node: node);
2116	while (item) {
2117	/*
2118	* It's possible that the item is already in a log list. This
2119	* can happen in case two tasks are trying to log the same
2120	* directory. For example if we have tasks A and task B:
2121	*
2122	* Task A collected the delayed items into a log list while
2123	* under the inode's log_mutex (at btrfs_log_inode()), but it
2124	* only releases the items after logging the inodes they point
2125	* to (if they are new inodes), which happens after unlocking
2126	* the log mutex;
2127	*
2128	* Task B enters btrfs_log_inode() and acquires the log_mutex
2129	* of the same directory inode, before task B releases the
2130	* delayed items. This can happen for example when logging some
2131	* inode we need to trigger logging of its parent directory, so
2132	* logging two files that have the same parent directory can
2133	* lead to this.
2134	*
2135	* If this happens, just ignore delayed items already in a log
2136	* list. All the tasks logging the directory are under a log
2137	* transaction and whichever finishes first can not sync the log
2138	* before the other completes and leaves the log transaction.
2139	*/
2140	if (!item->logged && list_empty(head: &item->log_list)) {
2141	refcount_inc(r: &item->refs);
2142	list_add_tail(new: &item->log_list, head: ins_list);
2143	}
2144	item = __btrfs_next_delayed_item(item);
2145	}
2146
2147	item = __btrfs_first_delayed_deletion_item(delayed_node: node);
2148	while (item) {
2149	/* It may be non-empty, for the same reason mentioned above. */
2150	if (!item->logged && list_empty(head: &item->log_list)) {
2151	refcount_inc(r: &item->refs);
2152	list_add_tail(new: &item->log_list, head: del_list);
2153	}
2154	item = __btrfs_next_delayed_item(item);
2155	}
2156	mutex_unlock(lock: &node->mutex);
2157
2158	/*
2159	* We are called during inode logging, which means the inode is in use
2160	* and can not be evicted before we finish logging the inode. So we never
2161	* have the last reference on the delayed inode.
2162	* Also, we don't use btrfs_release_delayed_node() because that would
2163	* requeue the delayed inode (change its order in the list of prepared
2164	* nodes) and we don't want to do such change because we don't create or
2165	* delete delayed items.
2166	*/
2167	ASSERT(refcount_read(&node->refs) > 1);
2168	refcount_dec(r: &node->refs);
2169	}
2170
2171	void btrfs_log_put_delayed_items(struct btrfs_inode *inode,
2172	struct list_head *ins_list,
2173	struct list_head *del_list)
2174	{
2175	struct btrfs_delayed_node *node;
2176	struct btrfs_delayed_item *item;
2177	struct btrfs_delayed_item *next;
2178
2179	node = btrfs_get_delayed_node(btrfs_inode: inode);
2180	if (!node)
2181	return;
2182
2183	mutex_lock(&node->mutex);
2184
2185	list_for_each_entry_safe(item, next, ins_list, log_list) {
2186	item->logged = true;
2187	list_del_init(entry: &item->log_list);
2188	if (refcount_dec_and_test(r: &item->refs))
2189	kfree(objp: item);
2190	}
2191
2192	list_for_each_entry_safe(item, next, del_list, log_list) {
2193	item->logged = true;
2194	list_del_init(entry: &item->log_list);
2195	if (refcount_dec_and_test(r: &item->refs))
2196	kfree(objp: item);
2197	}
2198
2199	mutex_unlock(lock: &node->mutex);
2200
2201	/*
2202	* We are called during inode logging, which means the inode is in use
2203	* and can not be evicted before we finish logging the inode. So we never
2204	* have the last reference on the delayed inode.
2205	* Also, we don't use btrfs_release_delayed_node() because that would
2206	* requeue the delayed inode (change its order in the list of prepared
2207	* nodes) and we don't want to do such change because we don't create or
2208	* delete delayed items.
2209	*/
2210	ASSERT(refcount_read(&node->refs) > 1);
2211	refcount_dec(r: &node->refs);
2212	}
2213