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	btrfs_delayed_node_ref_tracker_dir_init(node: delayed_node);
61	delayed_node->ins_root = RB_ROOT_CACHED;
62	delayed_node->del_root = RB_ROOT_CACHED;
63	mutex_init(&delayed_node->mutex);
64	INIT_LIST_HEAD(list: &delayed_node->n_list);
65	INIT_LIST_HEAD(list: &delayed_node->p_list);
66	}
67
68	static struct btrfs_delayed_node *btrfs_get_delayed_node(
69	struct btrfs_inode *btrfs_inode,
70	struct btrfs_ref_tracker *tracker)
71	{
72	struct btrfs_root *root = btrfs_inode->root;
73	u64 ino = btrfs_ino(inode: btrfs_inode);
74	struct btrfs_delayed_node *node;
75
76	node = READ_ONCE(btrfs_inode->delayed_node);
77	if (node) {
78	refcount_inc(r: &node->refs);
79	btrfs_delayed_node_ref_tracker_alloc(node, tracker, GFP_NOFS);
80	return node;
81	}
82
83	xa_lock(&root->delayed_nodes);
84	node = xa_load(&root->delayed_nodes, index: ino);
85
86	if (node) {
87	if (btrfs_inode->delayed_node) {
88	refcount_inc(r: &node->refs); /* can be accessed */
89	btrfs_delayed_node_ref_tracker_alloc(node, tracker, GFP_ATOMIC);
90	BUG_ON(btrfs_inode->delayed_node != node);
91	xa_unlock(&root->delayed_nodes);
92	return node;
93	}
94
95	/*
96	* It's possible that we're racing into the middle of removing
97	* this node from the xarray. In this case, the refcount
98	* was zero and it should never go back to one. Just return
99	* NULL like it was never in the xarray at all; our release
100	* function is in the process of removing it.
101	*
102	* Some implementations of refcount_inc refuse to bump the
103	* refcount once it has hit zero. If we don't do this dance
104	* here, refcount_inc() may decide to just WARN_ONCE() instead
105	* of actually bumping the refcount.
106	*
107	* If this node is properly in the xarray, we want to bump the
108	* refcount twice, once for the inode and once for this get
109	* operation.
110	*/
111	if (refcount_inc_not_zero(r: &node->refs)) {
112	refcount_inc(r: &node->refs);
113	btrfs_delayed_node_ref_tracker_alloc(node, tracker, GFP_ATOMIC);
114	btrfs_delayed_node_ref_tracker_alloc(node, tracker: &node->inode_cache_tracker,
115	GFP_ATOMIC);
116	btrfs_inode->delayed_node = node;
117	} else {
118	node = NULL;
119	}
120
121	xa_unlock(&root->delayed_nodes);
122	return node;
123	}
124	xa_unlock(&root->delayed_nodes);
125
126	return NULL;
127	}
128
129	/*
130	* Look up an existing delayed node associated with @btrfs_inode or create a new
131	* one and insert it to the delayed nodes of the root.
132	*
133	* Return the delayed node, or error pointer on failure.
134	*/
135	static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
136	struct btrfs_inode *btrfs_inode,
137	struct btrfs_ref_tracker *tracker)
138	{
139	struct btrfs_delayed_node *node;
140	struct btrfs_root *root = btrfs_inode->root;
141	u64 ino = btrfs_ino(inode: btrfs_inode);
142	int ret;
143	void *ptr;
144
145	again:
146	node = btrfs_get_delayed_node(btrfs_inode, tracker);
147	if (node)
148	return node;
149
150	node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
151	if (!node)
152	return ERR_PTR(error: -ENOMEM);
153	btrfs_init_delayed_node(delayed_node: node, root, inode_id: ino);
154
155	/* Cached in the inode and can be accessed. */
156	refcount_set(r: &node->refs, n: 2);
157	btrfs_delayed_node_ref_tracker_alloc(node, tracker, GFP_NOFS);
158	btrfs_delayed_node_ref_tracker_alloc(node, tracker: &node->inode_cache_tracker, GFP_NOFS);
159
160	/* Allocate and reserve the slot, from now it can return a NULL from xa_load(). */
161	ret = xa_reserve(xa: &root->delayed_nodes, index: ino, GFP_NOFS);
162	if (ret == -ENOMEM)
163	goto cleanup;
164
165	xa_lock(&root->delayed_nodes);
166	ptr = xa_load(&root->delayed_nodes, index: ino);
167	if (ptr) {
168	/* Somebody inserted it, go back and read it. */
169	xa_unlock(&root->delayed_nodes);
170	goto cleanup;
171	}
172	ptr = __xa_store(&root->delayed_nodes, index: ino, entry: node, GFP_ATOMIC);
173	ASSERT(xa_err(ptr) != -EINVAL);
174	ASSERT(xa_err(ptr) != -ENOMEM);
175	ASSERT(ptr == NULL);
176	btrfs_inode->delayed_node = node;
177	xa_unlock(&root->delayed_nodes);
178
179	return node;
180	cleanup:
181	btrfs_delayed_node_ref_tracker_free(node, tracker);
182	btrfs_delayed_node_ref_tracker_free(node, tracker: &node->inode_cache_tracker);
183	btrfs_delayed_node_ref_tracker_dir_exit(node);
184	kmem_cache_free(s: delayed_node_cache, objp: node);
185	if (ret)
186	return ERR_PTR(error: ret);
187	goto again;
188	}
189
190	/*
191	* Call it when holding delayed_node->mutex
192	*
193	* If mod = 1, add this node into the prepared list.
194	*/
195	static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
196	struct btrfs_delayed_node *node,
197	int mod)
198	{
199	spin_lock(lock: &root->lock);
200	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
201	if (!list_empty(head: &node->p_list))
202	list_move_tail(list: &node->p_list, head: &root->prepare_list);
203	else if (mod)
204	list_add_tail(new: &node->p_list, head: &root->prepare_list);
205	} else {
206	list_add_tail(new: &node->n_list, head: &root->node_list);
207	list_add_tail(new: &node->p_list, head: &root->prepare_list);
208	refcount_inc(r: &node->refs); /* inserted into list */
209	btrfs_delayed_node_ref_tracker_alloc(node, tracker: &node->node_list_tracker,
210	GFP_ATOMIC);
211	root->nodes++;
212	set_bit(BTRFS_DELAYED_NODE_IN_LIST, addr: &node->flags);
213	}
214	spin_unlock(lock: &root->lock);
215	}
216
217	/* Call it when holding delayed_node->mutex */
218	static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
219	struct btrfs_delayed_node *node)
220	{
221	spin_lock(lock: &root->lock);
222	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
223	root->nodes--;
224	btrfs_delayed_node_ref_tracker_free(node, tracker: &node->node_list_tracker);
225	refcount_dec(r: &node->refs); /* not in the list */
226	list_del_init(entry: &node->n_list);
227	if (!list_empty(head: &node->p_list))
228	list_del_init(entry: &node->p_list);
229	clear_bit(BTRFS_DELAYED_NODE_IN_LIST, addr: &node->flags);
230	}
231	spin_unlock(lock: &root->lock);
232	}
233
234	static struct btrfs_delayed_node *btrfs_first_delayed_node(
235	struct btrfs_delayed_root *delayed_root,
236	struct btrfs_ref_tracker *tracker)
237	{
238	struct btrfs_delayed_node *node;
239
240	spin_lock(lock: &delayed_root->lock);
241	node = list_first_entry_or_null(&delayed_root->node_list,
242	struct btrfs_delayed_node, n_list);
243	if (node) {
244	refcount_inc(r: &node->refs);
245	btrfs_delayed_node_ref_tracker_alloc(node, tracker, GFP_ATOMIC);
246	}
247	spin_unlock(lock: &delayed_root->lock);
248
249	return node;
250	}
251
252	static struct btrfs_delayed_node *btrfs_next_delayed_node(
253	struct btrfs_delayed_node *node,
254	struct btrfs_ref_tracker *tracker)
255	{
256	struct btrfs_delayed_root *delayed_root;
257	struct list_head *p;
258	struct btrfs_delayed_node *next = NULL;
259
260	delayed_root = node->root->fs_info->delayed_root;
261	spin_lock(lock: &delayed_root->lock);
262	if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
263	/* not in the list */
264	if (list_empty(head: &delayed_root->node_list))
265	goto out;
266	p = delayed_root->node_list.next;
267	} else if (list_is_last(list: &node->n_list, head: &delayed_root->node_list))
268	goto out;
269	else
270	p = node->n_list.next;
271
272	next = list_entry(p, struct btrfs_delayed_node, n_list);
273	refcount_inc(r: &next->refs);
274	btrfs_delayed_node_ref_tracker_alloc(node: next, tracker, GFP_ATOMIC);
275	out:
276	spin_unlock(lock: &delayed_root->lock);
277
278	return next;
279	}
280
281	static void __btrfs_release_delayed_node(
282	struct btrfs_delayed_node *delayed_node,
283	int mod, struct btrfs_ref_tracker *tracker)
284	{
285	struct btrfs_delayed_root *delayed_root;
286
287	if (!delayed_node)
288	return;
289
290	delayed_root = delayed_node->root->fs_info->delayed_root;
291
292	mutex_lock(&delayed_node->mutex);
293	if (delayed_node->count)
294	btrfs_queue_delayed_node(root: delayed_root, node: delayed_node, mod);
295	else
296	btrfs_dequeue_delayed_node(root: delayed_root, node: delayed_node);
297	mutex_unlock(lock: &delayed_node->mutex);
298
299	btrfs_delayed_node_ref_tracker_free(node: delayed_node, tracker);
300	if (refcount_dec_and_test(r: &delayed_node->refs)) {
301	struct btrfs_root *root = delayed_node->root;
302
303	xa_erase(&root->delayed_nodes, index: delayed_node->inode_id);
304	/*
305	* Once our refcount goes to zero, nobody is allowed to bump it
306	* back up. We can delete it now.
307	*/
308	ASSERT(refcount_read(&delayed_node->refs) == 0);
309	btrfs_delayed_node_ref_tracker_dir_exit(node: delayed_node);
310	kmem_cache_free(s: delayed_node_cache, objp: delayed_node);
311	}
312	}
313
314	static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node,
315	struct btrfs_ref_tracker *tracker)
316	{
317	__btrfs_release_delayed_node(delayed_node: node, mod: 0, tracker);
318	}
319
320	static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
321	struct btrfs_delayed_root *delayed_root,
322	struct btrfs_ref_tracker *tracker)
323	{
324	struct btrfs_delayed_node *node;
325
326	spin_lock(lock: &delayed_root->lock);
327	node = list_first_entry_or_null(&delayed_root->prepare_list,
328	struct btrfs_delayed_node, p_list);
329	if (node) {
330	list_del_init(entry: &node->p_list);
331	refcount_inc(r: &node->refs);
332	btrfs_delayed_node_ref_tracker_alloc(node, tracker, GFP_ATOMIC);
333	}
334	spin_unlock(lock: &delayed_root->lock);
335
336	return node;
337	}
338
339	static inline void btrfs_release_prepared_delayed_node(
340	struct btrfs_delayed_node *node,
341	struct btrfs_ref_tracker *tracker)
342	{
343	__btrfs_release_delayed_node(delayed_node: node, mod: 1, tracker);
344	}
345
346	static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u16 data_len,
347	struct btrfs_delayed_node *node,
348	enum btrfs_delayed_item_type type)
349	{
350	struct btrfs_delayed_item *item;
351
352	item = kmalloc(struct_size(item, data, data_len), GFP_NOFS);
353	if (item) {
354	item->data_len = data_len;
355	item->type = type;
356	item->bytes_reserved = 0;
357	item->delayed_node = node;
358	RB_CLEAR_NODE(&item->rb_node);
359	INIT_LIST_HEAD(list: &item->log_list);
360	item->logged = false;
361	refcount_set(r: &item->refs, n: 1);
362	}
363	return item;
364	}
365
366	static int delayed_item_index_cmp(const void *key, const struct rb_node *node)
367	{
368	const u64 *index = key;
369	const struct btrfs_delayed_item *delayed_item = rb_entry(node,
370	struct btrfs_delayed_item, rb_node);
371
372	if (delayed_item->index < *index)
373	return 1;
374	else if (delayed_item->index > *index)
375	return -1;
376
377	return 0;
378	}
379
380	/*
381	* Look up the delayed item by key.
382	*
383	* @delayed_node: pointer to the delayed node
384	* @index: the dir index value to lookup (offset of a dir index key)
385	*
386	* Note: if we don't find the right item, we will return the prev item and
387	* the next item.
388	*/
389	static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
390	struct rb_root *root,
391	u64 index)
392	{
393	struct rb_node *node;
394
395	node = rb_find(key: &index, tree: root, cmp: delayed_item_index_cmp);
396	return rb_entry_safe(node, struct btrfs_delayed_item, rb_node);
397	}
398
399	static int btrfs_delayed_item_cmp(const struct rb_node *new,
400	const struct rb_node *exist)
401	{
402	const struct btrfs_delayed_item *new_item =
403	rb_entry(new, struct btrfs_delayed_item, rb_node);
404
405	return delayed_item_index_cmp(key: &new_item->index, node: exist);
406	}
407
408	static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
409	struct btrfs_delayed_item *ins)
410	{
411	struct rb_root_cached *root;
412	struct rb_node *exist;
413
414	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM)
415	root = &delayed_node->ins_root;
416	else
417	root = &delayed_node->del_root;
418
419	exist = rb_find_add_cached(node: &ins->rb_node, tree: root, cmp: btrfs_delayed_item_cmp);
420	if (exist)
421	return -EEXIST;
422
423	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM &&
424	ins->index >= delayed_node->index_cnt)
425	delayed_node->index_cnt = ins->index + 1;
426
427	delayed_node->count++;
428	atomic_inc(v: &delayed_node->root->fs_info->delayed_root->items);
429	return 0;
430	}
431
432	static void finish_one_item(struct btrfs_delayed_root *delayed_root)
433	{
434	int seq = atomic_inc_return(v: &delayed_root->items_seq);
435
436	/* atomic_dec_return implies a barrier */
437	if ((atomic_dec_return(v: &delayed_root->items) <
438	BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))
439	cond_wake_up_nomb(wq: &delayed_root->wait);
440	}
441
442	static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
443	{
444	struct btrfs_delayed_node *delayed_node = delayed_item->delayed_node;
445	struct rb_root_cached *root;
446	struct btrfs_delayed_root *delayed_root;
447
448	/* Not inserted, ignore it. */
449	if (RB_EMPTY_NODE(&delayed_item->rb_node))
450	return;
451
452	/* If it's in a rbtree, then we need to have delayed node locked. */
453	lockdep_assert_held(&delayed_node->mutex);
454
455	delayed_root = delayed_node->root->fs_info->delayed_root;
456
457	if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)
458	root = &delayed_node->ins_root;
459	else
460	root = &delayed_node->del_root;
461
462	rb_erase_cached(node: &delayed_item->rb_node, root);
463	RB_CLEAR_NODE(&delayed_item->rb_node);
464	delayed_node->count--;
465
466	finish_one_item(delayed_root);
467	}
468
469	static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
470	{
471	if (item) {
472	__btrfs_remove_delayed_item(delayed_item: item);
473	if (refcount_dec_and_test(r: &item->refs))
474	kfree(objp: item);
475	}
476	}
477
478	static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
479	struct btrfs_delayed_node *delayed_node)
480	{
481	struct rb_node *p = rb_first_cached(&delayed_node->ins_root);
482
483	return rb_entry_safe(p, struct btrfs_delayed_item, rb_node);
484	}
485
486	static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
487	struct btrfs_delayed_node *delayed_node)
488	{
489	struct rb_node *p = rb_first_cached(&delayed_node->del_root);
490
491	return rb_entry_safe(p, struct btrfs_delayed_item, rb_node);
492	}
493
494	static struct btrfs_delayed_item *__btrfs_next_delayed_item(
495	struct btrfs_delayed_item *item)
496	{
497	struct rb_node *p = rb_next(&item->rb_node);
498
499	return rb_entry_safe(p, struct btrfs_delayed_item, rb_node);
500	}
501
502	static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
503	struct btrfs_delayed_item *item)
504	{
505	struct btrfs_block_rsv *src_rsv;
506	struct btrfs_block_rsv *dst_rsv;
507	struct btrfs_fs_info *fs_info = trans->fs_info;
508	u64 num_bytes;
509	int ret;
510
511	if (!trans->bytes_reserved)
512	return 0;
513
514	src_rsv = trans->block_rsv;
515	dst_rsv = &fs_info->delayed_block_rsv;
516
517	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: 1);
518
519	/*
520	* Here we migrate space rsv from transaction rsv, since have already
521	* reserved space when starting a transaction. So no need to reserve
522	* qgroup space here.
523	*/
524	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, update_size: true);
525	if (!ret) {
526	trace_btrfs_space_reservation(fs_info, type: "delayed_item",
527	val: item->delayed_node->inode_id,
528	bytes: num_bytes, reserve: 1);
529	/*
530	* For insertions we track reserved metadata space by accounting
531	* for the number of leaves that will be used, based on the delayed
532	* node's curr_index_batch_size and index_item_leaves fields.
533	*/
534	if (item->type == BTRFS_DELAYED_DELETION_ITEM)
535	item->bytes_reserved = num_bytes;
536	}
537
538	return ret;
539	}
540
541	static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
542	struct btrfs_delayed_item *item)
543	{
544	struct btrfs_block_rsv *rsv;
545	struct btrfs_fs_info *fs_info = root->fs_info;
546
547	if (!item->bytes_reserved)
548	return;
549
550	rsv = &fs_info->delayed_block_rsv;
551	/*
552	* Check btrfs_delayed_item_reserve_metadata() to see why we don't need
553	* to release/reserve qgroup space.
554	*/
555	trace_btrfs_space_reservation(fs_info, type: "delayed_item",
556	val: item->delayed_node->inode_id,
557	bytes: item->bytes_reserved, reserve: 0);
558	btrfs_block_rsv_release(fs_info, block_rsv: rsv, num_bytes: item->bytes_reserved, NULL);
559	}
560
561	static void btrfs_delayed_item_release_leaves(struct btrfs_delayed_node *node,
562	unsigned int num_leaves)
563	{
564	struct btrfs_fs_info *fs_info = node->root->fs_info;
565	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: num_leaves);
566
567	/* There are no space reservations during log replay, bail out. */
568	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
569	return;
570
571	trace_btrfs_space_reservation(fs_info, type: "delayed_item", val: node->inode_id,
572	bytes, reserve: 0);
573	btrfs_block_rsv_release(fs_info, block_rsv: &fs_info->delayed_block_rsv, num_bytes: bytes, NULL);
574	}
575
576	static int btrfs_delayed_inode_reserve_metadata(
577	struct btrfs_trans_handle *trans,
578	struct btrfs_root *root,
579	struct btrfs_delayed_node *node)
580	{
581	struct btrfs_fs_info *fs_info = root->fs_info;
582	struct btrfs_block_rsv *src_rsv;
583	struct btrfs_block_rsv *dst_rsv;
584	u64 num_bytes;
585	int ret;
586
587	src_rsv = trans->block_rsv;
588	dst_rsv = &fs_info->delayed_block_rsv;
589
590	num_bytes = btrfs_calc_metadata_size(fs_info, num_items: 1);
591
592	/*
593	* btrfs_dirty_inode will update the inode under btrfs_join_transaction
594	* which doesn't reserve space for speed. This is a problem since we
595	* still need to reserve space for this update, so try to reserve the
596	* space.
597	*
598	* Now if src_rsv == delalloc_block_rsv we'll let it just steal since
599	* we always reserve enough to update the inode item.
600	*/
601	if (!src_rsv || (!trans->bytes_reserved &&
602	src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
603	ret = btrfs_qgroup_reserve_meta(root, num_bytes,
604	type: BTRFS_QGROUP_RSV_META_PREALLOC, enforce: true);
605	if (ret < 0)
606	return ret;
607	ret = btrfs_block_rsv_add(fs_info, block_rsv: dst_rsv, num_bytes,
608	flush: BTRFS_RESERVE_NO_FLUSH);
609	/* NO_FLUSH could only fail with -ENOSPC */
610	ASSERT(ret == 0 || ret == -ENOSPC);
611	if (ret)
612	btrfs_qgroup_free_meta_prealloc(root, num_bytes);
613	} else {
614	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, update_size: true);
615	}
616
617	if (!ret) {
618	trace_btrfs_space_reservation(fs_info, type: "delayed_inode",
619	val: node->inode_id, bytes: num_bytes, reserve: 1);
620	node->bytes_reserved = num_bytes;
621	}
622
623	return ret;
624	}
625
626	static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
627	struct btrfs_delayed_node *node,
628	bool qgroup_free)
629	{
630	struct btrfs_block_rsv *rsv;
631
632	if (!node->bytes_reserved)
633	return;
634
635	rsv = &fs_info->delayed_block_rsv;
636	trace_btrfs_space_reservation(fs_info, type: "delayed_inode",
637	val: node->inode_id, bytes: node->bytes_reserved, reserve: 0);
638	btrfs_block_rsv_release(fs_info, block_rsv: rsv, num_bytes: node->bytes_reserved, NULL);
639	if (qgroup_free)
640	btrfs_qgroup_free_meta_prealloc(root: node->root,
641	num_bytes: node->bytes_reserved);
642	else
643	btrfs_qgroup_convert_reserved_meta(root: node->root,
644	num_bytes: node->bytes_reserved);
645	node->bytes_reserved = 0;
646	}
647
648	/*
649	* Insert a single delayed item or a batch of delayed items, as many as possible
650	* that fit in a leaf. The delayed items (dir index keys) are sorted by their key
651	* in the rbtree, and if there's a gap between two consecutive dir index items,
652	* then it means at some point we had delayed dir indexes to add but they got
653	* removed (by btrfs_delete_delayed_dir_index()) before we attempted to flush them
654	* into the subvolume tree. Dir index keys also have their offsets coming from a
655	* monotonically increasing counter, so we can't get new keys with an offset that
656	* fits within a gap between delayed dir index items.
657	*/
658	static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
659	struct btrfs_root *root,
660	struct btrfs_path *path,
661	struct btrfs_delayed_item *first_item)
662	{
663	struct btrfs_fs_info *fs_info = root->fs_info;
664	struct btrfs_delayed_node *node = first_item->delayed_node;
665	LIST_HEAD(item_list);
666	struct btrfs_delayed_item *curr;
667	struct btrfs_delayed_item *next;
668	const int max_size = BTRFS_LEAF_DATA_SIZE(info: fs_info);
669	struct btrfs_item_batch batch;
670	struct btrfs_key first_key;
671	const u32 first_data_size = first_item->data_len;
672	int total_size;
673	char AUTO_KFREE(ins_data);
674	int ret;
675	bool continuous_keys_only = false;
676
677	lockdep_assert_held(&node->mutex);
678
679	/*
680	* During normal operation the delayed index offset is continuously
681	* increasing, so we can batch insert all items as there will not be any
682	* overlapping keys in the tree.
683	*
684	* The exception to this is log replay, where we may have interleaved
685	* offsets in the tree, so our batch needs to be continuous keys only in
686	* order to ensure we do not end up with out of order items in our leaf.
687	*/
688	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
689	continuous_keys_only = true;
690
691	/*
692	* For delayed items to insert, we track reserved metadata bytes based
693	* on the number of leaves that we will use.
694	* See btrfs_insert_delayed_dir_index() and
695	* btrfs_delayed_item_reserve_metadata()).
696	*/
697	ASSERT(first_item->bytes_reserved == 0);
698
699	list_add_tail(new: &first_item->tree_list, head: &item_list);
700	batch.total_data_size = first_data_size;
701	batch.nr = 1;
702	total_size = first_data_size + sizeof(struct btrfs_item);
703	curr = first_item;
704
705	while (true) {
706	int next_size;
707
708	next = __btrfs_next_delayed_item(item: curr);
709	if (!next)
710	break;
711
712	/*
713	* We cannot allow gaps in the key space if we're doing log
714	* replay.
715	*/
716	if (continuous_keys_only && (next->index != curr->index + 1))
717	break;
718
719	ASSERT(next->bytes_reserved == 0);
720
721	next_size = next->data_len + sizeof(struct btrfs_item);
722	if (total_size + next_size > max_size)
723	break;
724
725	list_add_tail(new: &next->tree_list, head: &item_list);
726	batch.nr++;
727	total_size += next_size;
728	batch.total_data_size += next->data_len;
729	curr = next;
730	}
731
732	if (batch.nr == 1) {
733	first_key.objectid = node->inode_id;
734	first_key.type = BTRFS_DIR_INDEX_KEY;
735	first_key.offset = first_item->index;
736	batch.keys = &first_key;
737	batch.data_sizes = &first_data_size;
738	} else {
739	struct btrfs_key *ins_keys;
740	u32 *ins_sizes;
741	int i = 0;
742
743	ins_data = kmalloc_array(batch.nr,
744	sizeof(u32) + sizeof(struct btrfs_key), GFP_NOFS);
745	if (!ins_data)
746	return -ENOMEM;
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	return ret;
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
818	return 0;
819	}
820
821	static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
822	struct btrfs_path *path,
823	struct btrfs_root *root,
824	struct btrfs_delayed_node *node)
825	{
826	int ret = 0;
827
828	while (ret == 0) {
829	struct btrfs_delayed_item *curr;
830
831	mutex_lock(&node->mutex);
832	curr = __btrfs_first_delayed_insertion_item(delayed_node: node);
833	if (!curr) {
834	mutex_unlock(lock: &node->mutex);
835	break;
836	}
837	ret = btrfs_insert_delayed_item(trans, root, path, first_item: curr);
838	mutex_unlock(lock: &node->mutex);
839	}
840
841	return ret;
842	}
843
844	static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
845	struct btrfs_root *root,
846	struct btrfs_path *path,
847	struct btrfs_delayed_item *item)
848	{
849	const u64 ino = item->delayed_node->inode_id;
850	struct btrfs_fs_info *fs_info = root->fs_info;
851	struct btrfs_delayed_item *curr, *next;
852	struct extent_buffer *leaf = path->nodes[0];
853	LIST_HEAD(batch_list);
854	int nitems, slot, last_slot;
855	int ret;
856	u64 total_reserved_size = item->bytes_reserved;
857
858	ASSERT(leaf != NULL);
859
860	slot = path->slots[0];
861	last_slot = btrfs_header_nritems(eb: leaf) - 1;
862	/*
863	* Our caller always gives us a path pointing to an existing item, so
864	* this can not happen.
865	*/
866	ASSERT(slot <= last_slot);
867	if (WARN_ON(slot > last_slot))
868	return -ENOENT;
869
870	nitems = 1;
871	curr = item;
872	list_add_tail(new: &curr->tree_list, head: &batch_list);
873
874	/*
875	* Keep checking if the next delayed item matches the next item in the
876	* leaf - if so, we can add it to the batch of items to delete from the
877	* leaf.
878	*/
879	while (slot < last_slot) {
880	struct btrfs_key key;
881
882	next = __btrfs_next_delayed_item(item: curr);
883	if (!next)
884	break;
885
886	slot++;
887	btrfs_item_key_to_cpu(eb: leaf, cpu_key: &key, nr: slot);
888	if (key.objectid != ino ||
889	key.type != BTRFS_DIR_INDEX_KEY ||
890	key.offset != next->index)
891	break;
892	nitems++;
893	curr = next;
894	list_add_tail(new: &curr->tree_list, head: &batch_list);
895	total_reserved_size += curr->bytes_reserved;
896	}
897
898	ret = btrfs_del_items(trans, root, path, slot: path->slots[0], nr: nitems);
899	if (ret)
900	return ret;
901
902	/* In case of BTRFS_FS_LOG_RECOVERING items won't have reserved space */
903	if (total_reserved_size > 0) {
904	/*
905	* Check btrfs_delayed_item_reserve_metadata() to see why we
906	* don't need to release/reserve qgroup space.
907	*/
908	trace_btrfs_space_reservation(fs_info, type: "delayed_item", val: ino,
909	bytes: total_reserved_size, reserve: 0);
910	btrfs_block_rsv_release(fs_info, block_rsv: &fs_info->delayed_block_rsv,
911	num_bytes: total_reserved_size, NULL);
912	}
913
914	list_for_each_entry_safe(curr, next, &batch_list, tree_list) {
915	list_del(entry: &curr->tree_list);
916	btrfs_release_delayed_item(item: curr);
917	}
918
919	return 0;
920	}
921
922	static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
923	struct btrfs_path *path,
924	struct btrfs_root *root,
925	struct btrfs_delayed_node *node)
926	{
927	struct btrfs_key key;
928	int ret = 0;
929
930	key.objectid = node->inode_id;
931	key.type = BTRFS_DIR_INDEX_KEY;
932
933	while (ret == 0) {
934	struct btrfs_delayed_item *item;
935
936	mutex_lock(&node->mutex);
937	item = __btrfs_first_delayed_deletion_item(delayed_node: node);
938	if (!item) {
939	mutex_unlock(lock: &node->mutex);
940	break;
941	}
942
943	key.offset = item->index;
944	ret = btrfs_search_slot(trans, root, key: &key, p: path, ins_len: -1, cow: 1);
945	if (ret > 0) {
946	/*
947	* There's no matching item in the leaf. This means we
948	* have already deleted this item in a past run of the
949	* delayed items. We ignore errors when running delayed
950	* items from an async context, through a work queue job
951	* running btrfs_async_run_delayed_root(), and don't
952	* release delayed items that failed to complete. This
953	* is because we will retry later, and at transaction
954	* commit time we always run delayed items and will
955	* then deal with errors if they fail to run again.
956	*
957	* So just release delayed items for which we can't find
958	* an item in the tree, and move to the next item.
959	*/
960	btrfs_release_path(p: path);
961	btrfs_release_delayed_item(item);
962	ret = 0;
963	} else if (ret == 0) {
964	ret = btrfs_batch_delete_items(trans, root, path, item);
965	btrfs_release_path(p: path);
966	}
967
968	/*
969	* We unlock and relock on each iteration, this is to prevent
970	* blocking other tasks for too long while we are being run from
971	* the async context (work queue job). Those tasks are typically
972	* running system calls like creat/mkdir/rename/unlink/etc which
973	* need to add delayed items to this delayed node.
974	*/
975	mutex_unlock(lock: &node->mutex);
976	}
977
978	return ret;
979	}
980
981	static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
982	{
983	struct btrfs_delayed_root *delayed_root;
984
985	if (delayed_node &&
986	test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
987	ASSERT(delayed_node->root);
988	clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, addr: &delayed_node->flags);
989	delayed_node->count--;
990
991	delayed_root = delayed_node->root->fs_info->delayed_root;
992	finish_one_item(delayed_root);
993	}
994	}
995
996	static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
997	{
998
999	if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, addr: &delayed_node->flags)) {
1000	struct btrfs_delayed_root *delayed_root;
1001
1002	ASSERT(delayed_node->root);
1003	delayed_node->count--;
1004
1005	delayed_root = delayed_node->root->fs_info->delayed_root;
1006	finish_one_item(delayed_root);
1007	}
1008	}
1009
1010	static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1011	struct btrfs_root *root,
1012	struct btrfs_path *path,
1013	struct btrfs_delayed_node *node)
1014	{
1015	struct btrfs_fs_info *fs_info = root->fs_info;
1016	struct btrfs_key key;
1017	struct btrfs_inode_item *inode_item;
1018	struct extent_buffer *leaf;
1019	int mod;
1020	int ret;
1021
1022	key.objectid = node->inode_id;
1023	key.type = BTRFS_INODE_ITEM_KEY;
1024	key.offset = 0;
1025
1026	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1027	mod = -1;
1028	else
1029	mod = 1;
1030
1031	ret = btrfs_lookup_inode(trans, root, path, location: &key, mod);
1032	if (ret > 0)
1033	ret = -ENOENT;
1034	if (ret < 0) {
1035	/*
1036	* If we fail to update the delayed inode we need to abort the
1037	* transaction, because we could leave the inode with the
1038	* improper counts behind.
1039	*/
1040	if (unlikely(ret != -ENOENT))
1041	btrfs_abort_transaction(trans, ret);
1042	goto out;
1043	}
1044
1045	leaf = path->nodes[0];
1046	inode_item = btrfs_item_ptr(leaf, path->slots[0],
1047	struct btrfs_inode_item);
1048	write_extent_buffer(eb: leaf, src: &node->inode_item, start: (unsigned long)inode_item,
1049	len: sizeof(struct btrfs_inode_item));
1050
1051	if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1052	goto out;
1053
1054	/*
1055	* Now we're going to delete the INODE_REF/EXTREF, which should be the
1056	* only one ref left. Check if the next item is an INODE_REF/EXTREF.
1057	*
1058	* But if we're the last item already, release and search for the last
1059	* INODE_REF/EXTREF.
1060	*/
1061	if (path->slots[0] + 1 >= btrfs_header_nritems(eb: leaf)) {
1062	key.objectid = node->inode_id;
1063	key.type = BTRFS_INODE_EXTREF_KEY;
1064	key.offset = (u64)-1;
1065
1066	btrfs_release_path(p: path);
1067	ret = btrfs_search_slot(trans, root, key: &key, p: path, ins_len: -1, cow: 1);
1068	if (unlikely(ret < 0)) {
1069	btrfs_abort_transaction(trans, ret);
1070	goto err_out;
1071	}
1072	ASSERT(ret > 0);
1073	ASSERT(path->slots[0] > 0);
1074	ret = 0;
1075	path->slots[0]--;
1076	leaf = path->nodes[0];
1077	} else {
1078	path->slots[0]++;
1079	}
1080	btrfs_item_key_to_cpu(eb: leaf, cpu_key: &key, nr: path->slots[0]);
1081	if (key.objectid != node->inode_id)
1082	goto out;
1083	if (key.type != BTRFS_INODE_REF_KEY &&
1084	key.type != BTRFS_INODE_EXTREF_KEY)
1085	goto out;
1086
1087	/*
1088	* Delayed iref deletion is for the inode who has only one link,
1089	* so there is only one iref. The case that several irefs are
1090	* in the same item doesn't exist.
1091	*/
1092	ret = btrfs_del_item(trans, root, path);
1093	if (ret < 0)
1094	btrfs_abort_transaction(trans, ret);
1095	out:
1096	btrfs_release_delayed_iref(delayed_node: node);
1097	btrfs_release_path(p: path);
1098	err_out:
1099	btrfs_delayed_inode_release_metadata(fs_info, node, qgroup_free: (ret < 0));
1100	btrfs_release_delayed_inode(delayed_node: node);
1101	return ret;
1102	}
1103
1104	static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1105	struct btrfs_root *root,
1106	struct btrfs_path *path,
1107	struct btrfs_delayed_node *node)
1108	{
1109	int ret;
1110
1111	mutex_lock(&node->mutex);
1112	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1113	mutex_unlock(lock: &node->mutex);
1114	return 0;
1115	}
1116
1117	ret = __btrfs_update_delayed_inode(trans, root, path, node);
1118	mutex_unlock(lock: &node->mutex);
1119	return ret;
1120	}
1121
1122	static inline int
1123	__btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1124	struct btrfs_path *path,
1125	struct btrfs_delayed_node *node)
1126	{
1127	int ret;
1128
1129	ret = btrfs_insert_delayed_items(trans, path, root: node->root, node);
1130	if (ret)
1131	return ret;
1132
1133	ret = btrfs_delete_delayed_items(trans, path, root: node->root, node);
1134	if (ret)
1135	return ret;
1136
1137	ret = btrfs_record_root_in_trans(trans, root: node->root);
1138	if (ret)
1139	return ret;
1140	ret = btrfs_update_delayed_inode(trans, root: node->root, path, node);
1141	return ret;
1142	}
1143
1144	/*
1145	* Called when committing the transaction.
1146	* Returns 0 on success.
1147	* Returns < 0 on error and returns with an aborted transaction with any
1148	* outstanding delayed items cleaned up.
1149	*/
1150	static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
1151	{
1152	struct btrfs_fs_info *fs_info = trans->fs_info;
1153	struct btrfs_delayed_root *delayed_root;
1154	struct btrfs_delayed_node *curr_node, *prev_node;
1155	struct btrfs_ref_tracker curr_delayed_node_tracker, prev_delayed_node_tracker;
1156	struct btrfs_path *path;
1157	struct btrfs_block_rsv *block_rsv;
1158	int ret = 0;
1159	bool count = (nr > 0);
1160
1161	if (TRANS_ABORTED(trans))
1162	return -EIO;
1163
1164	path = btrfs_alloc_path();
1165	if (!path)
1166	return -ENOMEM;
1167
1168	block_rsv = trans->block_rsv;
1169	trans->block_rsv = &fs_info->delayed_block_rsv;
1170
1171	delayed_root = fs_info->delayed_root;
1172
1173	curr_node = btrfs_first_delayed_node(delayed_root, tracker: &curr_delayed_node_tracker);
1174	while (curr_node && (!count || nr--)) {
1175	ret = __btrfs_commit_inode_delayed_items(trans, path,
1176	node: curr_node);
1177	if (unlikely(ret)) {
1178	btrfs_abort_transaction(trans, ret);
1179	break;
1180	}
1181
1182	prev_node = curr_node;
1183	prev_delayed_node_tracker = curr_delayed_node_tracker;
1184	curr_node = btrfs_next_delayed_node(node: curr_node, tracker: &curr_delayed_node_tracker);
1185	/*
1186	* See the comment below about releasing path before releasing
1187	* node. If the commit of delayed items was successful the path
1188	* should always be released, but in case of an error, it may
1189	* point to locked extent buffers (a leaf at the very least).
1190	*/
1191	ASSERT(path->nodes[0] == NULL);
1192	btrfs_release_delayed_node(node: prev_node, tracker: &prev_delayed_node_tracker);
1193	}
1194
1195	/*
1196	* Release the path to avoid a potential deadlock and lockdep splat when
1197	* releasing the delayed node, as that requires taking the delayed node's
1198	* mutex. If another task starts running delayed items before we take
1199	* the mutex, it will first lock the mutex and then it may try to lock
1200	* the same btree path (leaf).
1201	*/
1202	btrfs_free_path(p: path);
1203
1204	if (curr_node)
1205	btrfs_release_delayed_node(node: curr_node, tracker: &curr_delayed_node_tracker);
1206	trans->block_rsv = block_rsv;
1207
1208	return ret;
1209	}
1210
1211	int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)
1212	{
1213	return __btrfs_run_delayed_items(trans, nr: -1);
1214	}
1215
1216	int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)
1217	{
1218	return __btrfs_run_delayed_items(trans, nr);
1219	}
1220
1221	int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1222	struct btrfs_inode *inode)
1223	{
1224	struct btrfs_ref_tracker delayed_node_tracker;
1225	struct btrfs_delayed_node *delayed_node =
1226	btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
1227	BTRFS_PATH_AUTO_FREE(path);
1228	struct btrfs_block_rsv *block_rsv;
1229	int ret;
1230
1231	if (!delayed_node)
1232	return 0;
1233
1234	mutex_lock(&delayed_node->mutex);
1235	if (!delayed_node->count) {
1236	mutex_unlock(lock: &delayed_node->mutex);
1237	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1238	return 0;
1239	}
1240	mutex_unlock(lock: &delayed_node->mutex);
1241
1242	path = btrfs_alloc_path();
1243	if (!path) {
1244	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1245	return -ENOMEM;
1246	}
1247
1248	block_rsv = trans->block_rsv;
1249	trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1250
1251	ret = __btrfs_commit_inode_delayed_items(trans, path, node: delayed_node);
1252
1253	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1254	trans->block_rsv = block_rsv;
1255
1256	return ret;
1257	}
1258
1259	int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
1260	{
1261	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1262	struct btrfs_trans_handle *trans;
1263	struct btrfs_ref_tracker delayed_node_tracker;
1264	struct btrfs_delayed_node *delayed_node;
1265	struct btrfs_path *path;
1266	struct btrfs_block_rsv *block_rsv;
1267	int ret;
1268
1269	delayed_node = btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
1270	if (!delayed_node)
1271	return 0;
1272
1273	mutex_lock(&delayed_node->mutex);
1274	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1275	mutex_unlock(lock: &delayed_node->mutex);
1276	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1277	return 0;
1278	}
1279	mutex_unlock(lock: &delayed_node->mutex);
1280
1281	trans = btrfs_join_transaction(root: delayed_node->root);
1282	if (IS_ERR(ptr: trans)) {
1283	ret = PTR_ERR(ptr: trans);
1284	goto out;
1285	}
1286
1287	path = btrfs_alloc_path();
1288	if (!path) {
1289	ret = -ENOMEM;
1290	goto trans_out;
1291	}
1292
1293	block_rsv = trans->block_rsv;
1294	trans->block_rsv = &fs_info->delayed_block_rsv;
1295
1296	mutex_lock(&delayed_node->mutex);
1297	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1298	ret = __btrfs_update_delayed_inode(trans, root: delayed_node->root,
1299	path, node: delayed_node);
1300	else
1301	ret = 0;
1302	mutex_unlock(lock: &delayed_node->mutex);
1303
1304	btrfs_free_path(p: path);
1305	trans->block_rsv = block_rsv;
1306	trans_out:
1307	btrfs_end_transaction(trans);
1308	btrfs_btree_balance_dirty(fs_info);
1309	out:
1310	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1311
1312	return ret;
1313	}
1314
1315	void btrfs_remove_delayed_node(struct btrfs_inode *inode)
1316	{
1317	struct btrfs_delayed_node *delayed_node;
1318
1319	delayed_node = READ_ONCE(inode->delayed_node);
1320	if (!delayed_node)
1321	return;
1322
1323	inode->delayed_node = NULL;
1324
1325	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node->inode_cache_tracker);
1326	}
1327
1328	struct btrfs_async_delayed_work {
1329	struct btrfs_delayed_root *delayed_root;
1330	int nr;
1331	struct btrfs_work work;
1332	};
1333
1334	static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1335	{
1336	struct btrfs_async_delayed_work *async_work;
1337	struct btrfs_delayed_root *delayed_root;
1338	struct btrfs_trans_handle *trans;
1339	struct btrfs_path *path;
1340	struct btrfs_delayed_node *delayed_node = NULL;
1341	struct btrfs_ref_tracker delayed_node_tracker;
1342	struct btrfs_root *root;
1343	struct btrfs_block_rsv *block_rsv;
1344	int total_done = 0;
1345
1346	async_work = container_of(work, struct btrfs_async_delayed_work, work);
1347	delayed_root = async_work->delayed_root;
1348
1349	path = btrfs_alloc_path();
1350	if (!path)
1351	goto out;
1352
1353	do {
1354	if (atomic_read(v: &delayed_root->items) <
1355	BTRFS_DELAYED_BACKGROUND / 2)
1356	break;
1357
1358	delayed_node = btrfs_first_prepared_delayed_node(delayed_root,
1359	tracker: &delayed_node_tracker);
1360	if (!delayed_node)
1361	break;
1362
1363	root = delayed_node->root;
1364
1365	trans = btrfs_join_transaction(root);
1366	if (IS_ERR(ptr: trans)) {
1367	btrfs_release_path(p: path);
1368	btrfs_release_prepared_delayed_node(node: delayed_node,
1369	tracker: &delayed_node_tracker);
1370	total_done++;
1371	continue;
1372	}
1373
1374	block_rsv = trans->block_rsv;
1375	trans->block_rsv = &root->fs_info->delayed_block_rsv;
1376
1377	__btrfs_commit_inode_delayed_items(trans, path, node: delayed_node);
1378
1379	trans->block_rsv = block_rsv;
1380	btrfs_end_transaction(trans);
1381	btrfs_btree_balance_dirty_nodelay(fs_info: root->fs_info);
1382
1383	btrfs_release_path(p: path);
1384	btrfs_release_prepared_delayed_node(node: delayed_node,
1385	tracker: &delayed_node_tracker);
1386	total_done++;
1387
1388	} while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
1389	|| total_done < async_work->nr);
1390
1391	btrfs_free_path(p: path);
1392	out:
1393	wake_up(&delayed_root->wait);
1394	kfree(objp: async_work);
1395	}
1396
1397
1398	static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1399	struct btrfs_fs_info *fs_info, int nr)
1400	{
1401	struct btrfs_async_delayed_work *async_work;
1402
1403	async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1404	if (!async_work)
1405	return -ENOMEM;
1406
1407	async_work->delayed_root = delayed_root;
1408	btrfs_init_work(work: &async_work->work, func: btrfs_async_run_delayed_root, NULL);
1409	async_work->nr = nr;
1410
1411	btrfs_queue_work(wq: fs_info->delayed_workers, work: &async_work->work);
1412	return 0;
1413	}
1414
1415	void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
1416	{
1417	struct btrfs_ref_tracker delayed_node_tracker;
1418	struct btrfs_delayed_node *node;
1419
1420	node = btrfs_first_delayed_node( delayed_root: fs_info->delayed_root, tracker: &delayed_node_tracker);
1421	if (WARN_ON(node)) {
1422	btrfs_delayed_node_ref_tracker_free(node,
1423	tracker: &delayed_node_tracker);
1424	refcount_dec(r: &node->refs);
1425	}
1426	}
1427
1428	static bool could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1429	{
1430	int val = atomic_read(v: &delayed_root->items_seq);
1431
1432	if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1433	return true;
1434
1435	if (atomic_read(v: &delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1436	return true;
1437
1438	return false;
1439	}
1440
1441	void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
1442	{
1443	struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
1444
1445	if ((atomic_read(v: &delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
1446	btrfs_workqueue_normal_congested(wq: fs_info->delayed_workers))
1447	return;
1448
1449	if (atomic_read(v: &delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1450	int seq;
1451	int ret;
1452
1453	seq = atomic_read(v: &delayed_root->items_seq);
1454
1455	ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, nr: 0);
1456	if (ret)
1457	return;
1458
1459	wait_event_interruptible(delayed_root->wait,
1460	could_end_wait(delayed_root, seq));
1461	return;
1462	}
1463
1464	btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1465	}
1466
1467	static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans)
1468	{
1469	struct btrfs_fs_info *fs_info = trans->fs_info;
1470	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: 1);
1471
1472	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1473	return;
1474
1475	/*
1476	* Adding the new dir index item does not require touching another
1477	* leaf, so we can release 1 unit of metadata that was previously
1478	* reserved when starting the transaction. This applies only to
1479	* the case where we had a transaction start and excludes the
1480	* transaction join case (when replaying log trees).
1481	*/
1482	trace_btrfs_space_reservation(fs_info, type: "transaction",
1483	val: trans->transid, bytes, reserve: 0);
1484	btrfs_block_rsv_release(fs_info, block_rsv: trans->block_rsv, num_bytes: bytes, NULL);
1485	ASSERT(trans->bytes_reserved >= bytes);
1486	trans->bytes_reserved -= bytes;
1487	}
1488
1489	/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */
1490	int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1491	const char *name, int name_len,
1492	struct btrfs_inode *dir,
1493	const struct btrfs_disk_key *disk_key, u8 flags,
1494	u64 index)
1495	{
1496	struct btrfs_fs_info *fs_info = trans->fs_info;
1497	const unsigned int leaf_data_size = BTRFS_LEAF_DATA_SIZE(info: fs_info);
1498	struct btrfs_delayed_node *delayed_node;
1499	struct btrfs_ref_tracker delayed_node_tracker;
1500	struct btrfs_delayed_item *delayed_item;
1501	struct btrfs_dir_item *dir_item;
1502	bool reserve_leaf_space;
1503	u32 data_len;
1504	int ret;
1505
1506	delayed_node = btrfs_get_or_create_delayed_node(btrfs_inode: dir, tracker: &delayed_node_tracker);
1507	if (IS_ERR(ptr: delayed_node))
1508	return PTR_ERR(ptr: delayed_node);
1509
1510	delayed_item = btrfs_alloc_delayed_item(data_len: sizeof(*dir_item) + name_len,
1511	node: delayed_node,
1512	type: BTRFS_DELAYED_INSERTION_ITEM);
1513	if (!delayed_item) {
1514	ret = -ENOMEM;
1515	goto release_node;
1516	}
1517
1518	delayed_item->index = index;
1519
1520	dir_item = (struct btrfs_dir_item *)delayed_item->data;
1521	dir_item->location = *disk_key;
1522	btrfs_set_stack_dir_transid(s: dir_item, val: trans->transid);
1523	btrfs_set_stack_dir_data_len(s: dir_item, val: 0);
1524	btrfs_set_stack_dir_name_len(s: dir_item, val: name_len);
1525	btrfs_set_stack_dir_flags(s: dir_item, val: flags);
1526	memcpy((char *)(dir_item + 1), name, name_len);
1527
1528	data_len = delayed_item->data_len + sizeof(struct btrfs_item);
1529
1530	mutex_lock(&delayed_node->mutex);
1531
1532	/*
1533	* First attempt to insert the delayed item. This is to make the error
1534	* handling path simpler in case we fail (-EEXIST). There's no risk of
1535	* any other task coming in and running the delayed item before we do
1536	* the metadata space reservation below, because we are holding the
1537	* delayed node's mutex and that mutex must also be locked before the
1538	* node's delayed items can be run.
1539	*/
1540	ret = __btrfs_add_delayed_item(delayed_node, ins: delayed_item);
1541	if (unlikely(ret)) {
1542	btrfs_err(trans->fs_info,
1543	"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",
1544	name_len, name, index, btrfs_root_id(delayed_node->root),
1545	delayed_node->inode_id, dir->index_cnt,
1546	delayed_node->index_cnt, ret);
1547	btrfs_release_delayed_item(item: delayed_item);
1548	btrfs_release_dir_index_item_space(trans);
1549	mutex_unlock(lock: &delayed_node->mutex);
1550	goto release_node;
1551	}
1552
1553	if (delayed_node->index_item_leaves == 0 ||
1554	delayed_node->curr_index_batch_size + data_len > leaf_data_size) {
1555	delayed_node->curr_index_batch_size = data_len;
1556	reserve_leaf_space = true;
1557	} else {
1558	delayed_node->curr_index_batch_size += data_len;
1559	reserve_leaf_space = false;
1560	}
1561
1562	if (reserve_leaf_space) {
1563	ret = btrfs_delayed_item_reserve_metadata(trans, item: delayed_item);
1564	/*
1565	* Space was reserved for a dir index item insertion when we
1566	* started the transaction, so getting a failure here should be
1567	* impossible.
1568	*/
1569	if (WARN_ON(ret)) {
1570	btrfs_release_delayed_item(item: delayed_item);
1571	mutex_unlock(lock: &delayed_node->mutex);
1572	goto release_node;
1573	}
1574
1575	delayed_node->index_item_leaves++;
1576	} else {
1577	btrfs_release_dir_index_item_space(trans);
1578	}
1579	mutex_unlock(lock: &delayed_node->mutex);
1580
1581	release_node:
1582	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1583	return ret;
1584	}
1585
1586	static bool btrfs_delete_delayed_insertion_item(struct btrfs_delayed_node *node,
1587	u64 index)
1588	{
1589	struct btrfs_delayed_item *item;
1590
1591	mutex_lock(&node->mutex);
1592	item = __btrfs_lookup_delayed_item(root: &node->ins_root.rb_root, index);
1593	if (!item) {
1594	mutex_unlock(lock: &node->mutex);
1595	return false;
1596	}
1597
1598	/*
1599	* For delayed items to insert, we track reserved metadata bytes based
1600	* on the number of leaves that we will use.
1601	* See btrfs_insert_delayed_dir_index() and
1602	* btrfs_delayed_item_reserve_metadata()).
1603	*/
1604	ASSERT(item->bytes_reserved == 0);
1605	ASSERT(node->index_item_leaves > 0);
1606
1607	/*
1608	* If there's only one leaf reserved, we can decrement this item from the
1609	* current batch, otherwise we can not because we don't know which leaf
1610	* it belongs to. With the current limit on delayed items, we rarely
1611	* accumulate enough dir index items to fill more than one leaf (even
1612	* when using a leaf size of 4K).
1613	*/
1614	if (node->index_item_leaves == 1) {
1615	const u32 data_len = item->data_len + sizeof(struct btrfs_item);
1616
1617	ASSERT(node->curr_index_batch_size >= data_len);
1618	node->curr_index_batch_size -= data_len;
1619	}
1620
1621	btrfs_release_delayed_item(item);
1622
1623	/* If we now have no more dir index items, we can release all leaves. */
1624	if (RB_EMPTY_ROOT(&node->ins_root.rb_root)) {
1625	btrfs_delayed_item_release_leaves(node, num_leaves: node->index_item_leaves);
1626	node->index_item_leaves = 0;
1627	}
1628
1629	mutex_unlock(lock: &node->mutex);
1630	return true;
1631	}
1632
1633	int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1634	struct btrfs_inode *dir, u64 index)
1635	{
1636	struct btrfs_delayed_node *node;
1637	struct btrfs_ref_tracker delayed_node_tracker;
1638	struct btrfs_delayed_item *item;
1639	int ret;
1640
1641	node = btrfs_get_or_create_delayed_node(btrfs_inode: dir, tracker: &delayed_node_tracker);
1642	if (IS_ERR(ptr: node))
1643	return PTR_ERR(ptr: node);
1644
1645	if (btrfs_delete_delayed_insertion_item(node, index)) {
1646	ret = 0;
1647	goto end;
1648	}
1649
1650	item = btrfs_alloc_delayed_item(data_len: 0, node, type: BTRFS_DELAYED_DELETION_ITEM);
1651	if (!item) {
1652	ret = -ENOMEM;
1653	goto end;
1654	}
1655
1656	item->index = index;
1657
1658	ret = btrfs_delayed_item_reserve_metadata(trans, item);
1659	/*
1660	* we have reserved enough space when we start a new transaction,
1661	* so reserving metadata failure is impossible.
1662	*/
1663	if (ret < 0) {
1664	btrfs_err(trans->fs_info,
1665	"metadata reservation failed for delayed dir item deletion, index: %llu, root: %llu, inode: %llu, error: %d",
1666	index, btrfs_root_id(node->root), node->inode_id, ret);
1667	btrfs_release_delayed_item(item);
1668	goto end;
1669	}
1670
1671	mutex_lock(&node->mutex);
1672	ret = __btrfs_add_delayed_item(delayed_node: node, ins: item);
1673	if (unlikely(ret)) {
1674	btrfs_err(trans->fs_info,
1675	"failed to add delayed dir index item, root: %llu, inode: %llu, index: %llu, error: %d",
1676	index, btrfs_root_id(node->root), node->inode_id, ret);
1677	btrfs_delayed_item_release_metadata(root: dir->root, item);
1678	btrfs_release_delayed_item(item);
1679	}
1680	mutex_unlock(lock: &node->mutex);
1681	end:
1682	btrfs_release_delayed_node(node, tracker: &delayed_node_tracker);
1683	return ret;
1684	}
1685
1686	int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)
1687	{
1688	struct btrfs_ref_tracker delayed_node_tracker;
1689	struct btrfs_delayed_node *delayed_node;
1690
1691	delayed_node = btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
1692	if (!delayed_node)
1693	return -ENOENT;
1694
1695	/*
1696	* Since we have held i_mutex of this directory, it is impossible that
1697	* a new directory index is added into the delayed node and index_cnt
1698	* is updated now. So we needn't lock the delayed node.
1699	*/
1700	if (!delayed_node->index_cnt) {
1701	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1702	return -EINVAL;
1703	}
1704
1705	inode->index_cnt = delayed_node->index_cnt;
1706	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1707	return 0;
1708	}
1709
1710	bool btrfs_readdir_get_delayed_items(struct btrfs_inode *inode,
1711	u64 last_index,
1712	struct list_head *ins_list,
1713	struct list_head *del_list)
1714	{
1715	struct btrfs_delayed_node *delayed_node;
1716	struct btrfs_delayed_item *item;
1717	struct btrfs_ref_tracker delayed_node_tracker;
1718
1719	delayed_node = btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
1720	if (!delayed_node)
1721	return false;
1722
1723	/*
1724	* We can only do one readdir with delayed items at a time because of
1725	* item->readdir_list.
1726	*/
1727	btrfs_inode_unlock(inode, ilock_flags: BTRFS_ILOCK_SHARED);
1728	btrfs_inode_lock(inode, ilock_flags: 0);
1729
1730	mutex_lock(&delayed_node->mutex);
1731	item = __btrfs_first_delayed_insertion_item(delayed_node);
1732	while (item && item->index <= last_index) {
1733	refcount_inc(r: &item->refs);
1734	list_add_tail(new: &item->readdir_list, head: ins_list);
1735	item = __btrfs_next_delayed_item(item);
1736	}
1737
1738	item = __btrfs_first_delayed_deletion_item(delayed_node);
1739	while (item && item->index <= last_index) {
1740	refcount_inc(r: &item->refs);
1741	list_add_tail(new: &item->readdir_list, head: del_list);
1742	item = __btrfs_next_delayed_item(item);
1743	}
1744	mutex_unlock(lock: &delayed_node->mutex);
1745	/*
1746	* This delayed node is still cached in the btrfs inode, so refs
1747	* must be > 1 now, and we needn't check it is going to be freed
1748	* or not.
1749	*
1750	* Besides that, this function is used to read dir, we do not
1751	* insert/delete delayed items in this period. So we also needn't
1752	* requeue or dequeue this delayed node.
1753	*/
1754	btrfs_delayed_node_ref_tracker_free(node: delayed_node, tracker: &delayed_node_tracker);
1755	refcount_dec(r: &delayed_node->refs);
1756
1757	return true;
1758	}
1759
1760	void btrfs_readdir_put_delayed_items(struct btrfs_inode *inode,
1761	struct list_head *ins_list,
1762	struct list_head *del_list)
1763	{
1764	struct btrfs_delayed_item *curr, *next;
1765
1766	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1767	list_del(entry: &curr->readdir_list);
1768	if (refcount_dec_and_test(r: &curr->refs))
1769	kfree(objp: curr);
1770	}
1771
1772	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1773	list_del(entry: &curr->readdir_list);
1774	if (refcount_dec_and_test(r: &curr->refs))
1775	kfree(objp: curr);
1776	}
1777
1778	/*
1779	* The VFS is going to do up_read(), so we need to downgrade back to a
1780	* read lock.
1781	*/
1782	downgrade_write(sem: &inode->vfs_inode.i_rwsem);
1783	}
1784
1785	bool btrfs_should_delete_dir_index(const struct list_head *del_list, u64 index)
1786	{
1787	struct btrfs_delayed_item *curr;
1788	bool ret = false;
1789
1790	list_for_each_entry(curr, del_list, readdir_list) {
1791	if (curr->index > index)
1792	break;
1793	if (curr->index == index) {
1794	ret = true;
1795	break;
1796	}
1797	}
1798	return ret;
1799	}
1800
1801	/*
1802	* Read dir info stored in the delayed tree.
1803	*/
1804	bool btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1805	const struct list_head *ins_list)
1806	{
1807	struct btrfs_dir_item *di;
1808	struct btrfs_delayed_item *curr, *next;
1809	struct btrfs_key location;
1810	char *name;
1811	int name_len;
1812	unsigned char d_type;
1813
1814	/*
1815	* Changing the data of the delayed item is impossible. So
1816	* we needn't lock them. And we have held i_mutex of the
1817	* directory, nobody can delete any directory indexes now.
1818	*/
1819	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1820	bool over;
1821
1822	list_del(entry: &curr->readdir_list);
1823
1824	if (curr->index < ctx->pos) {
1825	if (refcount_dec_and_test(r: &curr->refs))
1826	kfree(objp: curr);
1827	continue;
1828	}
1829
1830	ctx->pos = curr->index;
1831
1832	di = (struct btrfs_dir_item *)curr->data;
1833	name = (char *)(di + 1);
1834	name_len = btrfs_stack_dir_name_len(s: di);
1835
1836	d_type = fs_ftype_to_dtype(filetype: btrfs_dir_flags_to_ftype(flags: di->type));
1837	btrfs_disk_key_to_cpu(cpu_key: &location, disk_key: &di->location);
1838
1839	over = !dir_emit(ctx, name, namelen: name_len, ino: location.objectid, type: d_type);
1840
1841	if (refcount_dec_and_test(r: &curr->refs))
1842	kfree(objp: curr);
1843
1844	if (over)
1845	return true;
1846	ctx->pos++;
1847	}
1848	return false;
1849	}
1850
1851	static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1852	struct btrfs_inode_item *inode_item,
1853	struct btrfs_inode *inode)
1854	{
1855	struct inode *vfs_inode = &inode->vfs_inode;
1856	u64 flags;
1857
1858	btrfs_set_stack_inode_uid(s: inode_item, val: i_uid_read(inode: vfs_inode));
1859	btrfs_set_stack_inode_gid(s: inode_item, val: i_gid_read(inode: vfs_inode));
1860	btrfs_set_stack_inode_size(s: inode_item, val: inode->disk_i_size);
1861	btrfs_set_stack_inode_mode(s: inode_item, val: vfs_inode->i_mode);
1862	btrfs_set_stack_inode_nlink(s: inode_item, val: vfs_inode->i_nlink);
1863	btrfs_set_stack_inode_nbytes(s: inode_item, val: inode_get_bytes(inode: vfs_inode));
1864	btrfs_set_stack_inode_generation(s: inode_item, val: inode->generation);
1865	btrfs_set_stack_inode_sequence(s: inode_item,
1866	val: inode_peek_iversion(inode: vfs_inode));
1867	btrfs_set_stack_inode_transid(s: inode_item, val: trans->transid);
1868	btrfs_set_stack_inode_rdev(s: inode_item, val: vfs_inode->i_rdev);
1869	flags = btrfs_inode_combine_flags(flags: inode->flags, ro_flags: inode->ro_flags);
1870	btrfs_set_stack_inode_flags(s: inode_item, val: flags);
1871	btrfs_set_stack_inode_block_group(s: inode_item, val: 0);
1872
1873	btrfs_set_stack_timespec_sec(s: &inode_item->atime,
1874	val: inode_get_atime_sec(inode: vfs_inode));
1875	btrfs_set_stack_timespec_nsec(s: &inode_item->atime,
1876	val: inode_get_atime_nsec(inode: vfs_inode));
1877
1878	btrfs_set_stack_timespec_sec(s: &inode_item->mtime,
1879	val: inode_get_mtime_sec(inode: vfs_inode));
1880	btrfs_set_stack_timespec_nsec(s: &inode_item->mtime,
1881	val: inode_get_mtime_nsec(inode: vfs_inode));
1882
1883	btrfs_set_stack_timespec_sec(s: &inode_item->ctime,
1884	val: inode_get_ctime_sec(inode: vfs_inode));
1885	btrfs_set_stack_timespec_nsec(s: &inode_item->ctime,
1886	val: inode_get_ctime_nsec(inode: vfs_inode));
1887
1888	btrfs_set_stack_timespec_sec(s: &inode_item->otime, val: inode->i_otime_sec);
1889	btrfs_set_stack_timespec_nsec(s: &inode_item->otime, val: inode->i_otime_nsec);
1890	}
1891
1892	int btrfs_fill_inode(struct btrfs_inode *inode, u32 *rdev)
1893	{
1894	struct btrfs_delayed_node *delayed_node;
1895	struct btrfs_ref_tracker delayed_node_tracker;
1896	struct btrfs_inode_item *inode_item;
1897	struct inode *vfs_inode = &inode->vfs_inode;
1898
1899	delayed_node = btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
1900	if (!delayed_node)
1901	return -ENOENT;
1902
1903	mutex_lock(&delayed_node->mutex);
1904	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1905	mutex_unlock(lock: &delayed_node->mutex);
1906	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1907	return -ENOENT;
1908	}
1909
1910	inode_item = &delayed_node->inode_item;
1911
1912	i_uid_write(inode: vfs_inode, uid: btrfs_stack_inode_uid(s: inode_item));
1913	i_gid_write(inode: vfs_inode, gid: btrfs_stack_inode_gid(s: inode_item));
1914	btrfs_i_size_write(inode, size: btrfs_stack_inode_size(s: inode_item));
1915	vfs_inode->i_mode = btrfs_stack_inode_mode(s: inode_item);
1916	set_nlink(inode: vfs_inode, nlink: btrfs_stack_inode_nlink(s: inode_item));
1917	inode_set_bytes(inode: vfs_inode, bytes: btrfs_stack_inode_nbytes(s: inode_item));
1918	inode->generation = btrfs_stack_inode_generation(s: inode_item);
1919	inode->last_trans = btrfs_stack_inode_transid(s: inode_item);
1920
1921	inode_set_iversion_queried(inode: vfs_inode, val: btrfs_stack_inode_sequence(s: inode_item));
1922	vfs_inode->i_rdev = 0;
1923	*rdev = btrfs_stack_inode_rdev(s: inode_item);
1924	btrfs_inode_split_flags(inode_item_flags: btrfs_stack_inode_flags(s: inode_item),
1925	flags: &inode->flags, ro_flags: &inode->ro_flags);
1926
1927	inode_set_atime(inode: vfs_inode, sec: btrfs_stack_timespec_sec(s: &inode_item->atime),
1928	nsec: btrfs_stack_timespec_nsec(s: &inode_item->atime));
1929
1930	inode_set_mtime(inode: vfs_inode, sec: btrfs_stack_timespec_sec(s: &inode_item->mtime),
1931	nsec: btrfs_stack_timespec_nsec(s: &inode_item->mtime));
1932
1933	inode_set_ctime(inode: vfs_inode, sec: btrfs_stack_timespec_sec(s: &inode_item->ctime),
1934	nsec: btrfs_stack_timespec_nsec(s: &inode_item->ctime));
1935
1936	inode->i_otime_sec = btrfs_stack_timespec_sec(s: &inode_item->otime);
1937	inode->i_otime_nsec = btrfs_stack_timespec_nsec(s: &inode_item->otime);
1938
1939	vfs_inode->i_generation = inode->generation;
1940	if (S_ISDIR(vfs_inode->i_mode))
1941	inode->index_cnt = (u64)-1;
1942
1943	mutex_unlock(lock: &delayed_node->mutex);
1944	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1945	return 0;
1946	}
1947
1948	int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1949	struct btrfs_inode *inode)
1950	{
1951	struct btrfs_root *root = inode->root;
1952	struct btrfs_delayed_node *delayed_node;
1953	struct btrfs_ref_tracker delayed_node_tracker;
1954	int ret = 0;
1955
1956	delayed_node = btrfs_get_or_create_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
1957	if (IS_ERR(ptr: delayed_node))
1958	return PTR_ERR(ptr: delayed_node);
1959
1960	mutex_lock(&delayed_node->mutex);
1961	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1962	fill_stack_inode_item(trans, inode_item: &delayed_node->inode_item, inode);
1963	goto release_node;
1964	}
1965
1966	ret = btrfs_delayed_inode_reserve_metadata(trans, root, node: delayed_node);
1967	if (ret)
1968	goto release_node;
1969
1970	fill_stack_inode_item(trans, inode_item: &delayed_node->inode_item, inode);
1971	set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, addr: &delayed_node->flags);
1972	delayed_node->count++;
1973	atomic_inc(v: &root->fs_info->delayed_root->items);
1974	release_node:
1975	mutex_unlock(lock: &delayed_node->mutex);
1976	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
1977	return ret;
1978	}
1979
1980	int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)
1981	{
1982	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1983	struct btrfs_delayed_node *delayed_node;
1984	struct btrfs_ref_tracker delayed_node_tracker;
1985
1986	/*
1987	* we don't do delayed inode updates during log recovery because it
1988	* leads to enospc problems. This means we also can't do
1989	* delayed inode refs
1990	*/
1991	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1992	return -EAGAIN;
1993
1994	delayed_node = btrfs_get_or_create_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
1995	if (IS_ERR(ptr: delayed_node))
1996	return PTR_ERR(ptr: delayed_node);
1997
1998	/*
1999	* We don't reserve space for inode ref deletion is because:
2000	* - We ONLY do async inode ref deletion for the inode who has only
2001	* one link(i_nlink == 1), it means there is only one inode ref.
2002	* And in most case, the inode ref and the inode item are in the
2003	* same leaf, and we will deal with them at the same time.
2004	* Since we are sure we will reserve the space for the inode item,
2005	* it is unnecessary to reserve space for inode ref deletion.
2006	* - If the inode ref and the inode item are not in the same leaf,
2007	* We also needn't worry about enospc problem, because we reserve
2008	* much more space for the inode update than it needs.
2009	* - At the worst, we can steal some space from the global reservation.
2010	* It is very rare.
2011	*/
2012	mutex_lock(&delayed_node->mutex);
2013	if (!test_and_set_bit(BTRFS_DELAYED_NODE_DEL_IREF, addr: &delayed_node->flags)) {
2014	delayed_node->count++;
2015	atomic_inc(v: &fs_info->delayed_root->items);
2016	}
2017	mutex_unlock(lock: &delayed_node->mutex);
2018	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
2019	return 0;
2020	}
2021
2022	static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
2023	{
2024	struct btrfs_root *root = delayed_node->root;
2025	struct btrfs_fs_info *fs_info = root->fs_info;
2026	struct btrfs_delayed_item *curr_item, *prev_item;
2027
2028	mutex_lock(&delayed_node->mutex);
2029	curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
2030	while (curr_item) {
2031	prev_item = curr_item;
2032	curr_item = __btrfs_next_delayed_item(item: prev_item);
2033	btrfs_release_delayed_item(item: prev_item);
2034	}
2035
2036	if (delayed_node->index_item_leaves > 0) {
2037	btrfs_delayed_item_release_leaves(node: delayed_node,
2038	num_leaves: delayed_node->index_item_leaves);
2039	delayed_node->index_item_leaves = 0;
2040	}
2041
2042	curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
2043	while (curr_item) {
2044	btrfs_delayed_item_release_metadata(root, item: curr_item);
2045	prev_item = curr_item;
2046	curr_item = __btrfs_next_delayed_item(item: prev_item);
2047	btrfs_release_delayed_item(item: prev_item);
2048	}
2049
2050	btrfs_release_delayed_iref(delayed_node);
2051
2052	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
2053	btrfs_delayed_inode_release_metadata(fs_info, node: delayed_node, qgroup_free: false);
2054	btrfs_release_delayed_inode(delayed_node);
2055	}
2056	mutex_unlock(lock: &delayed_node->mutex);
2057	}
2058
2059	void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)
2060	{
2061	struct btrfs_delayed_node *delayed_node;
2062	struct btrfs_ref_tracker delayed_node_tracker;
2063
2064	delayed_node = btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
2065	if (!delayed_node)
2066	return;
2067
2068	__btrfs_kill_delayed_node(delayed_node);
2069	btrfs_release_delayed_node(node: delayed_node, tracker: &delayed_node_tracker);
2070	}
2071
2072	void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
2073	{
2074	unsigned long index = 0;
2075	struct btrfs_delayed_node *delayed_nodes[8];
2076	struct btrfs_ref_tracker delayed_node_trackers[8];
2077
2078	while (1) {
2079	struct btrfs_delayed_node *node;
2080	int count;
2081
2082	xa_lock(&root->delayed_nodes);
2083	if (xa_empty(xa: &root->delayed_nodes)) {
2084	xa_unlock(&root->delayed_nodes);
2085	return;
2086	}
2087
2088	count = 0;
2089	xa_for_each_start(&root->delayed_nodes, index, node, index) {
2090	/*
2091	* Don't increase refs in case the node is dead and
2092	* about to be removed from the tree in the loop below
2093	*/
2094	if (refcount_inc_not_zero(r: &node->refs)) {
2095	btrfs_delayed_node_ref_tracker_alloc(node,
2096	tracker: &delayed_node_trackers[count],
2097	GFP_ATOMIC);
2098	delayed_nodes[count] = node;
2099	count++;
2100	}
2101	if (count >= ARRAY_SIZE(delayed_nodes))
2102	break;
2103	}
2104	xa_unlock(&root->delayed_nodes);
2105	index++;
2106
2107	for (int i = 0; i < count; i++) {
2108	__btrfs_kill_delayed_node(delayed_node: delayed_nodes[i]);
2109	btrfs_delayed_node_ref_tracker_dir_print(node: delayed_nodes[i]);
2110	btrfs_release_delayed_node(node: delayed_nodes[i],
2111	tracker: &delayed_node_trackers[i]);
2112	}
2113	}
2114	}
2115
2116	void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
2117	{
2118	struct btrfs_delayed_node *curr_node, *prev_node;
2119	struct btrfs_ref_tracker curr_delayed_node_tracker, prev_delayed_node_tracker;
2120
2121	curr_node = btrfs_first_delayed_node(delayed_root: fs_info->delayed_root,
2122	tracker: &curr_delayed_node_tracker);
2123	while (curr_node) {
2124	__btrfs_kill_delayed_node(delayed_node: curr_node);
2125
2126	prev_node = curr_node;
2127	prev_delayed_node_tracker = curr_delayed_node_tracker;
2128	curr_node = btrfs_next_delayed_node(node: curr_node, tracker: &curr_delayed_node_tracker);
2129	btrfs_release_delayed_node(node: prev_node, tracker: &prev_delayed_node_tracker);
2130	}
2131	}
2132
2133	void btrfs_log_get_delayed_items(struct btrfs_inode *inode,
2134	struct list_head *ins_list,
2135	struct list_head *del_list)
2136	{
2137	struct btrfs_delayed_node *node;
2138	struct btrfs_delayed_item *item;
2139	struct btrfs_ref_tracker delayed_node_tracker;
2140
2141	node = btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
2142	if (!node)
2143	return;
2144
2145	mutex_lock(&node->mutex);
2146	item = __btrfs_first_delayed_insertion_item(delayed_node: node);
2147	while (item) {
2148	/*
2149	* It's possible that the item is already in a log list. This
2150	* can happen in case two tasks are trying to log the same
2151	* directory. For example if we have tasks A and task B:
2152	*
2153	* Task A collected the delayed items into a log list while
2154	* under the inode's log_mutex (at btrfs_log_inode()), but it
2155	* only releases the items after logging the inodes they point
2156	* to (if they are new inodes), which happens after unlocking
2157	* the log mutex;
2158	*
2159	* Task B enters btrfs_log_inode() and acquires the log_mutex
2160	* of the same directory inode, before task B releases the
2161	* delayed items. This can happen for example when logging some
2162	* inode we need to trigger logging of its parent directory, so
2163	* logging two files that have the same parent directory can
2164	* lead to this.
2165	*
2166	* If this happens, just ignore delayed items already in a log
2167	* list. All the tasks logging the directory are under a log
2168	* transaction and whichever finishes first can not sync the log
2169	* before the other completes and leaves the log transaction.
2170	*/
2171	if (!item->logged && list_empty(head: &item->log_list)) {
2172	refcount_inc(r: &item->refs);
2173	list_add_tail(new: &item->log_list, head: ins_list);
2174	}
2175	item = __btrfs_next_delayed_item(item);
2176	}
2177
2178	item = __btrfs_first_delayed_deletion_item(delayed_node: node);
2179	while (item) {
2180	/* It may be non-empty, for the same reason mentioned above. */
2181	if (!item->logged && list_empty(head: &item->log_list)) {
2182	refcount_inc(r: &item->refs);
2183	list_add_tail(new: &item->log_list, head: del_list);
2184	}
2185	item = __btrfs_next_delayed_item(item);
2186	}
2187	mutex_unlock(lock: &node->mutex);
2188
2189	/*
2190	* We are called during inode logging, which means the inode is in use
2191	* and can not be evicted before we finish logging the inode. So we never
2192	* have the last reference on the delayed inode.
2193	* Also, we don't use btrfs_release_delayed_node() because that would
2194	* requeue the delayed inode (change its order in the list of prepared
2195	* nodes) and we don't want to do such change because we don't create or
2196	* delete delayed items.
2197	*/
2198	ASSERT(refcount_read(&node->refs) > 1);
2199	btrfs_delayed_node_ref_tracker_free(node, tracker: &delayed_node_tracker);
2200	refcount_dec(r: &node->refs);
2201	}
2202
2203	void btrfs_log_put_delayed_items(struct btrfs_inode *inode,
2204	struct list_head *ins_list,
2205	struct list_head *del_list)
2206	{
2207	struct btrfs_delayed_node *node;
2208	struct btrfs_delayed_item *item;
2209	struct btrfs_delayed_item *next;
2210	struct btrfs_ref_tracker delayed_node_tracker;
2211
2212	node = btrfs_get_delayed_node(btrfs_inode: inode, tracker: &delayed_node_tracker);
2213	if (!node)
2214	return;
2215
2216	mutex_lock(&node->mutex);
2217
2218	list_for_each_entry_safe(item, next, ins_list, log_list) {
2219	item->logged = true;
2220	list_del_init(entry: &item->log_list);
2221	if (refcount_dec_and_test(r: &item->refs))
2222	kfree(objp: item);
2223	}
2224
2225	list_for_each_entry_safe(item, next, del_list, log_list) {
2226	item->logged = true;
2227	list_del_init(entry: &item->log_list);
2228	if (refcount_dec_and_test(r: &item->refs))
2229	kfree(objp: item);
2230	}
2231
2232	mutex_unlock(lock: &node->mutex);
2233
2234	/*
2235	* We are called during inode logging, which means the inode is in use
2236	* and can not be evicted before we finish logging the inode. So we never
2237	* have the last reference on the delayed inode.
2238	* Also, we don't use btrfs_release_delayed_node() because that would
2239	* requeue the delayed inode (change its order in the list of prepared
2240	* nodes) and we don't want to do such change because we don't create or
2241	* delete delayed items.
2242	*/
2243	ASSERT(refcount_read(&node->refs) > 1);
2244	btrfs_delayed_node_ref_tracker_free(node, tracker: &delayed_node_tracker);
2245	refcount_dec(r: &node->refs);
2246	}
2247