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1// SPDX-License-Identifier: GPL-2.02/*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		51224#define BTRFS_DELAYED_BACKGROUND	12825#define BTRFS_DELAYED_BATCH		1626 27static struct kmem_cache *delayed_node_cache;28 29int __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 37void __cold btrfs_delayed_inode_exit(void)38{39	kmem_cache_destroy(delayed_node_cache);40}41 42void btrfs_init_delayed_root(struct btrfs_delayed_root *delayed_root)43{44	atomic_set(&delayed_root->items, 0);45	atomic_set(&delayed_root->items_seq, 0);46	delayed_root->nodes = 0;47	spin_lock_init(&delayed_root->lock);48	init_waitqueue_head(&delayed_root->wait);49	INIT_LIST_HEAD(&delayed_root->node_list);50	INIT_LIST_HEAD(&delayed_root->prepare_list);51}52 53static 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(&delayed_node->refs, 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(&delayed_node->n_list);64	INIT_LIST_HEAD(&delayed_node->p_list);65}66 67static 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(btrfs_inode);72	struct btrfs_delayed_node *node;73 74	node = READ_ONCE(btrfs_inode->delayed_node);75	if (node) {76		refcount_inc(&node->refs);77		return node;78	}79 80	xa_lock(&root->delayed_nodes);81	node = xa_load(&root->delayed_nodes, ino);82 83	if (node) {84		if (btrfs_inode->delayed_node) {85			refcount_inc(&node->refs);	/* can be accessed */86			BUG_ON(btrfs_inode->delayed_node != node);87			xa_unlock(&root->delayed_nodes);88			return node;89		}90 91		/*92		 * It's possible that we're racing into the middle of removing93		 * this node from the xarray.  In this case, the refcount94		 * was zero and it should never go back to one.  Just return95		 * NULL like it was never in the xarray at all; our release96		 * function is in the process of removing it.97		 *98		 * Some implementations of refcount_inc refuse to bump the99		 * refcount once it has hit zero.  If we don't do this dance100		 * here, refcount_inc() may decide to just WARN_ONCE() instead101		 * of actually bumping the refcount.102		 *103		 * If this node is properly in the xarray, we want to bump the104		 * refcount twice, once for the inode and once for this get105		 * operation.106		 */107		if (refcount_inc_not_zero(&node->refs)) {108			refcount_inc(&node->refs);109			btrfs_inode->delayed_node = node;110		} else {111			node = NULL;112		}113 114		xa_unlock(&root->delayed_nodes);115		return node;116	}117	xa_unlock(&root->delayed_nodes);118 119	return NULL;120}121 122/* Will return either the node or PTR_ERR(-ENOMEM) */123static 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(btrfs_inode);129	int ret;130	void *ptr;131 132again:133	node = btrfs_get_delayed_node(btrfs_inode);134	if (node)135		return node;136 137	node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);138	if (!node)139		return ERR_PTR(-ENOMEM);140	btrfs_init_delayed_node(node, root, ino);141 142	/* Cached in the inode and can be accessed. */143	refcount_set(&node->refs, 2);144 145	/* Allocate and reserve the slot, from now it can return a NULL from xa_load(). */146	ret = xa_reserve(&root->delayed_nodes, ino, GFP_NOFS);147	if (ret == -ENOMEM) {148		kmem_cache_free(delayed_node_cache, node);149		return ERR_PTR(-ENOMEM);150	}151	xa_lock(&root->delayed_nodes);152	ptr = xa_load(&root->delayed_nodes, ino);153	if (ptr) {154		/* Somebody inserted it, go back and read it. */155		xa_unlock(&root->delayed_nodes);156		kmem_cache_free(delayed_node_cache, node);157		node = NULL;158		goto again;159	}160	ptr = __xa_store(&root->delayed_nodes, ino, 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	xa_unlock(&root->delayed_nodes);166 167	return node;168}169 170/*171 * Call it when holding delayed_node->mutex172 *173 * If mod = 1, add this node into the prepared list.174 */175static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,176				     struct btrfs_delayed_node *node,177				     int mod)178{179	spin_lock(&root->lock);180	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {181		if (!list_empty(&node->p_list))182			list_move_tail(&node->p_list, &root->prepare_list);183		else if (mod)184			list_add_tail(&node->p_list, &root->prepare_list);185	} else {186		list_add_tail(&node->n_list, &root->node_list);187		list_add_tail(&node->p_list, &root->prepare_list);188		refcount_inc(&node->refs);	/* inserted into list */189		root->nodes++;190		set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);191	}192	spin_unlock(&root->lock);193}194 195/* Call it when holding delayed_node->mutex */196static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,197				       struct btrfs_delayed_node *node)198{199	spin_lock(&root->lock);200	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {201		root->nodes--;202		refcount_dec(&node->refs);	/* not in the list */203		list_del_init(&node->n_list);204		if (!list_empty(&node->p_list))205			list_del_init(&node->p_list);206		clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);207	}208	spin_unlock(&root->lock);209}210 211static 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(&delayed_root->lock);218	if (list_empty(&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(&node->refs);224out:225	spin_unlock(&delayed_root->lock);226 227	return node;228}229 230static 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(&delayed_root->lock);239	if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {240		/* not in the list */241		if (list_empty(&delayed_root->node_list))242			goto out;243		p = delayed_root->node_list.next;244	} else if (list_is_last(&node->n_list, &delayed_root->node_list))245		goto out;246	else247		p = node->n_list.next;248 249	next = list_entry(p, struct btrfs_delayed_node, n_list);250	refcount_inc(&next->refs);251out:252	spin_unlock(&delayed_root->lock);253 254	return next;255}256 257static 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(delayed_root, delayed_node, mod);271	else272		btrfs_dequeue_delayed_node(delayed_root, delayed_node);273	mutex_unlock(&delayed_node->mutex);274 275	if (refcount_dec_and_test(&delayed_node->refs)) {276		struct btrfs_root *root = delayed_node->root;277 278		xa_erase(&root->delayed_nodes, delayed_node->inode_id);279		/*280		 * Once our refcount goes to zero, nobody is allowed to bump it281		 * back up.  We can delete it now.282		 */283		ASSERT(refcount_read(&delayed_node->refs) == 0);284		kmem_cache_free(delayed_node_cache, delayed_node);285	}286}287 288static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)289{290	__btrfs_release_delayed_node(node, 0);291}292 293static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(294					struct btrfs_delayed_root *delayed_root)295{296	struct list_head *p;297	struct btrfs_delayed_node *node = NULL;298 299	spin_lock(&delayed_root->lock);300	if (list_empty(&delayed_root->prepare_list))301		goto out;302 303	p = delayed_root->prepare_list.next;304	list_del_init(p);305	node = list_entry(p, struct btrfs_delayed_node, p_list);306	refcount_inc(&node->refs);307out:308	spin_unlock(&delayed_root->lock);309 310	return node;311}312 313static inline void btrfs_release_prepared_delayed_node(314					struct btrfs_delayed_node *node)315{316	__btrfs_release_delayed_node(node, 1);317}318 319static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u16 data_len,320					   struct btrfs_delayed_node *node,321					   enum btrfs_delayed_item_type type)322{323	struct btrfs_delayed_item *item;324 325	item = kmalloc(struct_size(item, data, data_len), GFP_NOFS);326	if (item) {327		item->data_len = data_len;328		item->type = type;329		item->bytes_reserved = 0;330		item->delayed_node = node;331		RB_CLEAR_NODE(&item->rb_node);332		INIT_LIST_HEAD(&item->log_list);333		item->logged = false;334		refcount_set(&item->refs, 1);335	}336	return item;337}338 339/*340 * Look up the delayed item by key.341 *342 * @delayed_node: pointer to the delayed node343 * @index:	  the dir index value to lookup (offset of a dir index key)344 *345 * Note: if we don't find the right item, we will return the prev item and346 * the next item.347 */348static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(349				struct rb_root *root,350				u64 index)351{352	struct rb_node *node = root->rb_node;353	struct btrfs_delayed_item *delayed_item = NULL;354 355	while (node) {356		delayed_item = rb_entry(node, struct btrfs_delayed_item,357					rb_node);358		if (delayed_item->index < index)359			node = node->rb_right;360		else if (delayed_item->index > index)361			node = node->rb_left;362		else363			return delayed_item;364	}365 366	return NULL;367}368 369static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,370				    struct btrfs_delayed_item *ins)371{372	struct rb_node **p, *node;373	struct rb_node *parent_node = NULL;374	struct rb_root_cached *root;375	struct btrfs_delayed_item *item;376	bool leftmost = true;377 378	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM)379		root = &delayed_node->ins_root;380	else381		root = &delayed_node->del_root;382 383	p = &root->rb_root.rb_node;384	node = &ins->rb_node;385 386	while (*p) {387		parent_node = *p;388		item = rb_entry(parent_node, struct btrfs_delayed_item,389				 rb_node);390 391		if (item->index < ins->index) {392			p = &(*p)->rb_right;393			leftmost = false;394		} else if (item->index > ins->index) {395			p = &(*p)->rb_left;396		} else {397			return -EEXIST;398		}399	}400 401	rb_link_node(node, parent_node, p);402	rb_insert_color_cached(node, root, leftmost);403 404	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM &&405	    ins->index >= delayed_node->index_cnt)406		delayed_node->index_cnt = ins->index + 1;407 408	delayed_node->count++;409	atomic_inc(&delayed_node->root->fs_info->delayed_root->items);410	return 0;411}412 413static void finish_one_item(struct btrfs_delayed_root *delayed_root)414{415	int seq = atomic_inc_return(&delayed_root->items_seq);416 417	/* atomic_dec_return implies a barrier */418	if ((atomic_dec_return(&delayed_root->items) <419	    BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))420		cond_wake_up_nomb(&delayed_root->wait);421}422 423static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)424{425	struct btrfs_delayed_node *delayed_node = delayed_item->delayed_node;426	struct rb_root_cached *root;427	struct btrfs_delayed_root *delayed_root;428 429	/* Not inserted, ignore it. */430	if (RB_EMPTY_NODE(&delayed_item->rb_node))431		return;432 433	/* If it's in a rbtree, then we need to have delayed node locked. */434	lockdep_assert_held(&delayed_node->mutex);435 436	delayed_root = delayed_node->root->fs_info->delayed_root;437 438	if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)439		root = &delayed_node->ins_root;440	else441		root = &delayed_node->del_root;442 443	rb_erase_cached(&delayed_item->rb_node, root);444	RB_CLEAR_NODE(&delayed_item->rb_node);445	delayed_node->count--;446 447	finish_one_item(delayed_root);448}449 450static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)451{452	if (item) {453		__btrfs_remove_delayed_item(item);454		if (refcount_dec_and_test(&item->refs))455			kfree(item);456	}457}458 459static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(460					struct btrfs_delayed_node *delayed_node)461{462	struct rb_node *p;463	struct btrfs_delayed_item *item = NULL;464 465	p = rb_first_cached(&delayed_node->ins_root);466	if (p)467		item = rb_entry(p, struct btrfs_delayed_item, rb_node);468 469	return item;470}471 472static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(473					struct btrfs_delayed_node *delayed_node)474{475	struct rb_node *p;476	struct btrfs_delayed_item *item = NULL;477 478	p = rb_first_cached(&delayed_node->del_root);479	if (p)480		item = rb_entry(p, struct btrfs_delayed_item, rb_node);481 482	return item;483}484 485static struct btrfs_delayed_item *__btrfs_next_delayed_item(486						struct btrfs_delayed_item *item)487{488	struct rb_node *p;489	struct btrfs_delayed_item *next = NULL;490 491	p = rb_next(&item->rb_node);492	if (p)493		next = rb_entry(p, struct btrfs_delayed_item, rb_node);494 495	return next;496}497 498static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,499					       struct btrfs_delayed_item *item)500{501	struct btrfs_block_rsv *src_rsv;502	struct btrfs_block_rsv *dst_rsv;503	struct btrfs_fs_info *fs_info = trans->fs_info;504	u64 num_bytes;505	int ret;506 507	if (!trans->bytes_reserved)508		return 0;509 510	src_rsv = trans->block_rsv;511	dst_rsv = &fs_info->delayed_block_rsv;512 513	num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);514 515	/*516	 * Here we migrate space rsv from transaction rsv, since have already517	 * reserved space when starting a transaction.  So no need to reserve518	 * qgroup space here.519	 */520	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);521	if (!ret) {522		trace_btrfs_space_reservation(fs_info, "delayed_item",523					      item->delayed_node->inode_id,524					      num_bytes, 1);525		/*526		 * For insertions we track reserved metadata space by accounting527		 * for the number of leaves that will be used, based on the delayed528		 * node's curr_index_batch_size and index_item_leaves fields.529		 */530		if (item->type == BTRFS_DELAYED_DELETION_ITEM)531			item->bytes_reserved = num_bytes;532	}533 534	return ret;535}536 537static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,538						struct btrfs_delayed_item *item)539{540	struct btrfs_block_rsv *rsv;541	struct btrfs_fs_info *fs_info = root->fs_info;542 543	if (!item->bytes_reserved)544		return;545 546	rsv = &fs_info->delayed_block_rsv;547	/*548	 * Check btrfs_delayed_item_reserve_metadata() to see why we don't need549	 * to release/reserve qgroup space.550	 */551	trace_btrfs_space_reservation(fs_info, "delayed_item",552				      item->delayed_node->inode_id,553				      item->bytes_reserved, 0);554	btrfs_block_rsv_release(fs_info, rsv, item->bytes_reserved, NULL);555}556 557static void btrfs_delayed_item_release_leaves(struct btrfs_delayed_node *node,558					      unsigned int num_leaves)559{560	struct btrfs_fs_info *fs_info = node->root->fs_info;561	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_leaves);562 563	/* There are no space reservations during log replay, bail out. */564	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))565		return;566 567	trace_btrfs_space_reservation(fs_info, "delayed_item", node->inode_id,568				      bytes, 0);569	btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv, bytes, NULL);570}571 572static int btrfs_delayed_inode_reserve_metadata(573					struct btrfs_trans_handle *trans,574					struct btrfs_root *root,575					struct btrfs_delayed_node *node)576{577	struct btrfs_fs_info *fs_info = root->fs_info;578	struct btrfs_block_rsv *src_rsv;579	struct btrfs_block_rsv *dst_rsv;580	u64 num_bytes;581	int ret;582 583	src_rsv = trans->block_rsv;584	dst_rsv = &fs_info->delayed_block_rsv;585 586	num_bytes = btrfs_calc_metadata_size(fs_info, 1);587 588	/*589	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction590	 * which doesn't reserve space for speed.  This is a problem since we591	 * still need to reserve space for this update, so try to reserve the592	 * space.593	 *594	 * Now if src_rsv == delalloc_block_rsv we'll let it just steal since595	 * we always reserve enough to update the inode item.596	 */597	if (!src_rsv || (!trans->bytes_reserved &&598			 src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {599		ret = btrfs_qgroup_reserve_meta(root, num_bytes,600					  BTRFS_QGROUP_RSV_META_PREALLOC, true);601		if (ret < 0)602			return ret;603		ret = btrfs_block_rsv_add(fs_info, dst_rsv, num_bytes,604					  BTRFS_RESERVE_NO_FLUSH);605		/* NO_FLUSH could only fail with -ENOSPC */606		ASSERT(ret == 0 || ret == -ENOSPC);607		if (ret)608			btrfs_qgroup_free_meta_prealloc(root, num_bytes);609	} else {610		ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);611	}612 613	if (!ret) {614		trace_btrfs_space_reservation(fs_info, "delayed_inode",615					      node->inode_id, num_bytes, 1);616		node->bytes_reserved = num_bytes;617	}618 619	return ret;620}621 622static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,623						struct btrfs_delayed_node *node,624						bool qgroup_free)625{626	struct btrfs_block_rsv *rsv;627 628	if (!node->bytes_reserved)629		return;630 631	rsv = &fs_info->delayed_block_rsv;632	trace_btrfs_space_reservation(fs_info, "delayed_inode",633				      node->inode_id, node->bytes_reserved, 0);634	btrfs_block_rsv_release(fs_info, rsv, node->bytes_reserved, NULL);635	if (qgroup_free)636		btrfs_qgroup_free_meta_prealloc(node->root,637				node->bytes_reserved);638	else639		btrfs_qgroup_convert_reserved_meta(node->root,640				node->bytes_reserved);641	node->bytes_reserved = 0;642}643 644/*645 * Insert a single delayed item or a batch of delayed items, as many as possible646 * that fit in a leaf. The delayed items (dir index keys) are sorted by their key647 * in the rbtree, and if there's a gap between two consecutive dir index items,648 * then it means at some point we had delayed dir indexes to add but they got649 * removed (by btrfs_delete_delayed_dir_index()) before we attempted to flush them650 * into the subvolume tree. Dir index keys also have their offsets coming from a651 * monotonically increasing counter, so we can't get new keys with an offset that652 * fits within a gap between delayed dir index items.653 */654static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,655				     struct btrfs_root *root,656				     struct btrfs_path *path,657				     struct btrfs_delayed_item *first_item)658{659	struct btrfs_fs_info *fs_info = root->fs_info;660	struct btrfs_delayed_node *node = first_item->delayed_node;661	LIST_HEAD(item_list);662	struct btrfs_delayed_item *curr;663	struct btrfs_delayed_item *next;664	const int max_size = BTRFS_LEAF_DATA_SIZE(fs_info);665	struct btrfs_item_batch batch;666	struct btrfs_key first_key;667	const u32 first_data_size = first_item->data_len;668	int total_size;669	char *ins_data = NULL;670	int ret;671	bool continuous_keys_only = false;672 673	lockdep_assert_held(&node->mutex);674 675	/*676	 * During normal operation the delayed index offset is continuously677	 * increasing, so we can batch insert all items as there will not be any678	 * overlapping keys in the tree.679	 *680	 * The exception to this is log replay, where we may have interleaved681	 * offsets in the tree, so our batch needs to be continuous keys only in682	 * order to ensure we do not end up with out of order items in our leaf.683	 */684	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))685		continuous_keys_only = true;686 687	/*688	 * For delayed items to insert, we track reserved metadata bytes based689	 * on the number of leaves that we will use.690	 * See btrfs_insert_delayed_dir_index() and691	 * btrfs_delayed_item_reserve_metadata()).692	 */693	ASSERT(first_item->bytes_reserved == 0);694 695	list_add_tail(&first_item->tree_list, &item_list);696	batch.total_data_size = first_data_size;697	batch.nr = 1;698	total_size = first_data_size + sizeof(struct btrfs_item);699	curr = first_item;700 701	while (true) {702		int next_size;703 704		next = __btrfs_next_delayed_item(curr);705		if (!next)706			break;707 708		/*709		 * We cannot allow gaps in the key space if we're doing log710		 * replay.711		 */712		if (continuous_keys_only && (next->index != curr->index + 1))713			break;714 715		ASSERT(next->bytes_reserved == 0);716 717		next_size = next->data_len + sizeof(struct btrfs_item);718		if (total_size + next_size > max_size)719			break;720 721		list_add_tail(&next->tree_list, &item_list);722		batch.nr++;723		total_size += next_size;724		batch.total_data_size += next->data_len;725		curr = next;726	}727 728	if (batch.nr == 1) {729		first_key.objectid = node->inode_id;730		first_key.type = BTRFS_DIR_INDEX_KEY;731		first_key.offset = first_item->index;732		batch.keys = &first_key;733		batch.data_sizes = &first_data_size;734	} else {735		struct btrfs_key *ins_keys;736		u32 *ins_sizes;737		int i = 0;738 739		ins_data = kmalloc(batch.nr * sizeof(u32) +740				   batch.nr * sizeof(struct btrfs_key), GFP_NOFS);741		if (!ins_data) {742			ret = -ENOMEM;743			goto out;744		}745		ins_sizes = (u32 *)ins_data;746		ins_keys = (struct btrfs_key *)(ins_data + batch.nr * sizeof(u32));747		batch.keys = ins_keys;748		batch.data_sizes = ins_sizes;749		list_for_each_entry(curr, &item_list, tree_list) {750			ins_keys[i].objectid = node->inode_id;751			ins_keys[i].type = BTRFS_DIR_INDEX_KEY;752			ins_keys[i].offset = curr->index;753			ins_sizes[i] = curr->data_len;754			i++;755		}756	}757 758	ret = btrfs_insert_empty_items(trans, root, path, &batch);759	if (ret)760		goto out;761 762	list_for_each_entry(curr, &item_list, tree_list) {763		char *data_ptr;764 765		data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);766		write_extent_buffer(path->nodes[0], &curr->data,767				    (unsigned long)data_ptr, curr->data_len);768		path->slots[0]++;769	}770 771	/*772	 * Now release our path before releasing the delayed items and their773	 * metadata reservations, so that we don't block other tasks for more774	 * time than needed.775	 */776	btrfs_release_path(path);777 778	ASSERT(node->index_item_leaves > 0);779 780	/*781	 * For normal operations we will batch an entire leaf's worth of delayed782	 * items, so if there are more items to process we can decrement783	 * index_item_leaves by 1 as we inserted 1 leaf's worth of items.784	 *785	 * However for log replay we may not have inserted an entire leaf's786	 * worth of items, we may have not had continuous items, so decrementing787	 * here would mess up the index_item_leaves accounting.  For this case788	 * only clean up the accounting when there are no items left.789	 */790	if (next && !continuous_keys_only) {791		/*792		 * We inserted one batch of items into a leaf a there are more793		 * items to flush in a future batch, now release one unit of794		 * metadata space from the delayed block reserve, corresponding795		 * the leaf we just flushed to.796		 */797		btrfs_delayed_item_release_leaves(node, 1);798		node->index_item_leaves--;799	} else if (!next) {800		/*801		 * There are no more items to insert. We can have a number of802		 * reserved leaves > 1 here - this happens when many dir index803		 * items are added and then removed before they are flushed (file804		 * names with a very short life, never span a transaction). So805		 * release all remaining leaves.806		 */807		btrfs_delayed_item_release_leaves(node, node->index_item_leaves);808		node->index_item_leaves = 0;809	}810 811	list_for_each_entry_safe(curr, next, &item_list, tree_list) {812		list_del(&curr->tree_list);813		btrfs_release_delayed_item(curr);814	}815out:816	kfree(ins_data);817	return ret;818}819 820static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,821				      struct btrfs_path *path,822				      struct btrfs_root *root,823				      struct btrfs_delayed_node *node)824{825	int ret = 0;826 827	while (ret == 0) {828		struct btrfs_delayed_item *curr;829 830		mutex_lock(&node->mutex);831		curr = __btrfs_first_delayed_insertion_item(node);832		if (!curr) {833			mutex_unlock(&node->mutex);834			break;835		}836		ret = btrfs_insert_delayed_item(trans, root, path, curr);837		mutex_unlock(&node->mutex);838	}839 840	return ret;841}842 843static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,844				    struct btrfs_root *root,845				    struct btrfs_path *path,846				    struct btrfs_delayed_item *item)847{848	const u64 ino = item->delayed_node->inode_id;849	struct btrfs_fs_info *fs_info = root->fs_info;850	struct btrfs_delayed_item *curr, *next;851	struct extent_buffer *leaf = path->nodes[0];852	LIST_HEAD(batch_list);853	int nitems, slot, last_slot;854	int ret;855	u64 total_reserved_size = item->bytes_reserved;856 857	ASSERT(leaf != NULL);858 859	slot = path->slots[0];860	last_slot = btrfs_header_nritems(leaf) - 1;861	/*862	 * Our caller always gives us a path pointing to an existing item, so863	 * this can not happen.864	 */865	ASSERT(slot <= last_slot);866	if (WARN_ON(slot > last_slot))867		return -ENOENT;868 869	nitems = 1;870	curr = item;871	list_add_tail(&curr->tree_list, &batch_list);872 873	/*874	 * Keep checking if the next delayed item matches the next item in the875	 * leaf - if so, we can add it to the batch of items to delete from the876	 * leaf.877	 */878	while (slot < last_slot) {879		struct btrfs_key key;880 881		next = __btrfs_next_delayed_item(curr);882		if (!next)883			break;884 885		slot++;886		btrfs_item_key_to_cpu(leaf, &key, slot);887		if (key.objectid != ino ||888		    key.type != BTRFS_DIR_INDEX_KEY ||889		    key.offset != next->index)890			break;891		nitems++;892		curr = next;893		list_add_tail(&curr->tree_list, &batch_list);894		total_reserved_size += curr->bytes_reserved;895	}896 897	ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);898	if (ret)899		return ret;900 901	/* In case of BTRFS_FS_LOG_RECOVERING items won't have reserved space */902	if (total_reserved_size > 0) {903		/*904		 * Check btrfs_delayed_item_reserve_metadata() to see why we905		 * don't need to release/reserve qgroup space.906		 */907		trace_btrfs_space_reservation(fs_info, "delayed_item", ino,908					      total_reserved_size, 0);909		btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv,910					total_reserved_size, NULL);911	}912 913	list_for_each_entry_safe(curr, next, &batch_list, tree_list) {914		list_del(&curr->tree_list);915		btrfs_release_delayed_item(curr);916	}917 918	return 0;919}920 921static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,922				      struct btrfs_path *path,923				      struct btrfs_root *root,924				      struct btrfs_delayed_node *node)925{926	struct btrfs_key key;927	int ret = 0;928 929	key.objectid = node->inode_id;930	key.type = BTRFS_DIR_INDEX_KEY;931 932	while (ret == 0) {933		struct btrfs_delayed_item *item;934 935		mutex_lock(&node->mutex);936		item = __btrfs_first_delayed_deletion_item(node);937		if (!item) {938			mutex_unlock(&node->mutex);939			break;940		}941 942		key.offset = item->index;943		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);944		if (ret > 0) {945			/*946			 * There's no matching item in the leaf. This means we947			 * have already deleted this item in a past run of the948			 * delayed items. We ignore errors when running delayed949			 * items from an async context, through a work queue job950			 * running btrfs_async_run_delayed_root(), and don't951			 * release delayed items that failed to complete. This952			 * is because we will retry later, and at transaction953			 * commit time we always run delayed items and will954			 * then deal with errors if they fail to run again.955			 *956			 * So just release delayed items for which we can't find957			 * an item in the tree, and move to the next item.958			 */959			btrfs_release_path(path);960			btrfs_release_delayed_item(item);961			ret = 0;962		} else if (ret == 0) {963			ret = btrfs_batch_delete_items(trans, root, path, item);964			btrfs_release_path(path);965		}966 967		/*968		 * We unlock and relock on each iteration, this is to prevent969		 * blocking other tasks for too long while we are being run from970		 * the async context (work queue job). Those tasks are typically971		 * running system calls like creat/mkdir/rename/unlink/etc which972		 * need to add delayed items to this delayed node.973		 */974		mutex_unlock(&node->mutex);975	}976 977	return ret;978}979 980static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)981{982	struct btrfs_delayed_root *delayed_root;983 984	if (delayed_node &&985	    test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {986		ASSERT(delayed_node->root);987		clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);988		delayed_node->count--;989 990		delayed_root = delayed_node->root->fs_info->delayed_root;991		finish_one_item(delayed_root);992	}993}994 995static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)996{997 998	if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags)) {999		struct btrfs_delayed_root *delayed_root;1000 1001		ASSERT(delayed_node->root);1002		delayed_node->count--;1003 1004		delayed_root = delayed_node->root->fs_info->delayed_root;1005		finish_one_item(delayed_root);1006	}1007}1008 1009static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,1010					struct btrfs_root *root,1011					struct btrfs_path *path,1012					struct btrfs_delayed_node *node)1013{1014	struct btrfs_fs_info *fs_info = root->fs_info;1015	struct btrfs_key key;1016	struct btrfs_inode_item *inode_item;1017	struct extent_buffer *leaf;1018	int mod;1019	int ret;1020 1021	key.objectid = node->inode_id;1022	key.type = BTRFS_INODE_ITEM_KEY;1023	key.offset = 0;1024 1025	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))1026		mod = -1;1027	else1028		mod = 1;1029 1030	ret = btrfs_lookup_inode(trans, root, path, &key, mod);1031	if (ret > 0)1032		ret = -ENOENT;1033	if (ret < 0)1034		goto out;1035 1036	leaf = path->nodes[0];1037	inode_item = btrfs_item_ptr(leaf, path->slots[0],1038				    struct btrfs_inode_item);1039	write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,1040			    sizeof(struct btrfs_inode_item));1041	btrfs_mark_buffer_dirty(trans, leaf);1042 1043	if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))1044		goto out;1045 1046	/*1047	 * Now we're going to delete the INODE_REF/EXTREF, which should be the1048	 * only one ref left.  Check if the next item is an INODE_REF/EXTREF.1049	 *1050	 * But if we're the last item already, release and search for the last1051	 * INODE_REF/EXTREF.1052	 */1053	if (path->slots[0] + 1 >= btrfs_header_nritems(leaf)) {1054		key.objectid = node->inode_id;1055		key.type = BTRFS_INODE_EXTREF_KEY;1056		key.offset = (u64)-1;1057 1058		btrfs_release_path(path);1059		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);1060		if (ret < 0)1061			goto err_out;1062		ASSERT(ret > 0);1063		ASSERT(path->slots[0] > 0);1064		ret = 0;1065		path->slots[0]--;1066		leaf = path->nodes[0];1067	} else {1068		path->slots[0]++;1069	}1070	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);1071	if (key.objectid != node->inode_id)1072		goto out;1073	if (key.type != BTRFS_INODE_REF_KEY &&1074	    key.type != BTRFS_INODE_EXTREF_KEY)1075		goto out;1076 1077	/*1078	 * Delayed iref deletion is for the inode who has only one link,1079	 * so there is only one iref. The case that several irefs are1080	 * in the same item doesn't exist.1081	 */1082	ret = btrfs_del_item(trans, root, path);1083out:1084	btrfs_release_delayed_iref(node);1085	btrfs_release_path(path);1086err_out:1087	btrfs_delayed_inode_release_metadata(fs_info, node, (ret < 0));1088	btrfs_release_delayed_inode(node);1089 1090	/*1091	 * If we fail to update the delayed inode we need to abort the1092	 * transaction, because we could leave the inode with the improper1093	 * counts behind.1094	 */1095	if (ret && ret != -ENOENT)1096		btrfs_abort_transaction(trans, ret);1097 1098	return ret;1099}1100 1101static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,1102					     struct btrfs_root *root,1103					     struct btrfs_path *path,1104					     struct btrfs_delayed_node *node)1105{1106	int ret;1107 1108	mutex_lock(&node->mutex);1109	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {1110		mutex_unlock(&node->mutex);1111		return 0;1112	}1113 1114	ret = __btrfs_update_delayed_inode(trans, root, path, node);1115	mutex_unlock(&node->mutex);1116	return ret;1117}1118 1119static inline int1120__btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,1121				   struct btrfs_path *path,1122				   struct btrfs_delayed_node *node)1123{1124	int ret;1125 1126	ret = btrfs_insert_delayed_items(trans, path, node->root, node);1127	if (ret)1128		return ret;1129 1130	ret = btrfs_delete_delayed_items(trans, path, node->root, node);1131	if (ret)1132		return ret;1133 1134	ret = btrfs_record_root_in_trans(trans, node->root);1135	if (ret)1136		return ret;1137	ret = btrfs_update_delayed_inode(trans, node->root, path, node);1138	return ret;1139}1140 1141/*1142 * Called when committing the transaction.1143 * Returns 0 on success.1144 * Returns < 0 on error and returns with an aborted transaction with any1145 * outstanding delayed items cleaned up.1146 */1147static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)1148{1149	struct btrfs_fs_info *fs_info = trans->fs_info;1150	struct btrfs_delayed_root *delayed_root;1151	struct btrfs_delayed_node *curr_node, *prev_node;1152	struct btrfs_path *path;1153	struct btrfs_block_rsv *block_rsv;1154	int ret = 0;1155	bool count = (nr > 0);1156 1157	if (TRANS_ABORTED(trans))1158		return -EIO;1159 1160	path = btrfs_alloc_path();1161	if (!path)1162		return -ENOMEM;1163 1164	block_rsv = trans->block_rsv;1165	trans->block_rsv = &fs_info->delayed_block_rsv;1166 1167	delayed_root = fs_info->delayed_root;1168 1169	curr_node = btrfs_first_delayed_node(delayed_root);1170	while (curr_node && (!count || nr--)) {1171		ret = __btrfs_commit_inode_delayed_items(trans, path,1172							 curr_node);1173		if (ret) {1174			btrfs_abort_transaction(trans, ret);1175			break;1176		}1177 1178		prev_node = curr_node;1179		curr_node = btrfs_next_delayed_node(curr_node);1180		/*1181		 * See the comment below about releasing path before releasing1182		 * node. If the commit of delayed items was successful the path1183		 * should always be released, but in case of an error, it may1184		 * point to locked extent buffers (a leaf at the very least).1185		 */1186		ASSERT(path->nodes[0] == NULL);1187		btrfs_release_delayed_node(prev_node);1188	}1189 1190	/*1191	 * Release the path to avoid a potential deadlock and lockdep splat when1192	 * releasing the delayed node, as that requires taking the delayed node's1193	 * mutex. If another task starts running delayed items before we take1194	 * the mutex, it will first lock the mutex and then it may try to lock1195	 * the same btree path (leaf).1196	 */1197	btrfs_free_path(path);1198 1199	if (curr_node)1200		btrfs_release_delayed_node(curr_node);1201	trans->block_rsv = block_rsv;1202 1203	return ret;1204}1205 1206int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)1207{1208	return __btrfs_run_delayed_items(trans, -1);1209}1210 1211int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)1212{1213	return __btrfs_run_delayed_items(trans, nr);1214}1215 1216int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,1217				     struct btrfs_inode *inode)1218{1219	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);1220	struct btrfs_path *path;1221	struct btrfs_block_rsv *block_rsv;1222	int ret;1223 1224	if (!delayed_node)1225		return 0;1226 1227	mutex_lock(&delayed_node->mutex);1228	if (!delayed_node->count) {1229		mutex_unlock(&delayed_node->mutex);1230		btrfs_release_delayed_node(delayed_node);1231		return 0;1232	}1233	mutex_unlock(&delayed_node->mutex);1234 1235	path = btrfs_alloc_path();1236	if (!path) {1237		btrfs_release_delayed_node(delayed_node);1238		return -ENOMEM;1239	}1240 1241	block_rsv = trans->block_rsv;1242	trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;1243 1244	ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);1245 1246	btrfs_release_delayed_node(delayed_node);1247	btrfs_free_path(path);1248	trans->block_rsv = block_rsv;1249 1250	return ret;1251}1252 1253int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)1254{1255	struct btrfs_fs_info *fs_info = inode->root->fs_info;1256	struct btrfs_trans_handle *trans;1257	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);1258	struct btrfs_path *path;1259	struct btrfs_block_rsv *block_rsv;1260	int ret;1261 1262	if (!delayed_node)1263		return 0;1264 1265	mutex_lock(&delayed_node->mutex);1266	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {1267		mutex_unlock(&delayed_node->mutex);1268		btrfs_release_delayed_node(delayed_node);1269		return 0;1270	}1271	mutex_unlock(&delayed_node->mutex);1272 1273	trans = btrfs_join_transaction(delayed_node->root);1274	if (IS_ERR(trans)) {1275		ret = PTR_ERR(trans);1276		goto out;1277	}1278 1279	path = btrfs_alloc_path();1280	if (!path) {1281		ret = -ENOMEM;1282		goto trans_out;1283	}1284 1285	block_rsv = trans->block_rsv;1286	trans->block_rsv = &fs_info->delayed_block_rsv;1287 1288	mutex_lock(&delayed_node->mutex);1289	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))1290		ret = __btrfs_update_delayed_inode(trans, delayed_node->root,1291						   path, delayed_node);1292	else1293		ret = 0;1294	mutex_unlock(&delayed_node->mutex);1295 1296	btrfs_free_path(path);1297	trans->block_rsv = block_rsv;1298trans_out:1299	btrfs_end_transaction(trans);1300	btrfs_btree_balance_dirty(fs_info);1301out:1302	btrfs_release_delayed_node(delayed_node);1303 1304	return ret;1305}1306 1307void btrfs_remove_delayed_node(struct btrfs_inode *inode)1308{1309	struct btrfs_delayed_node *delayed_node;1310 1311	delayed_node = READ_ONCE(inode->delayed_node);1312	if (!delayed_node)1313		return;1314 1315	inode->delayed_node = NULL;1316	btrfs_release_delayed_node(delayed_node);1317}1318 1319struct btrfs_async_delayed_work {1320	struct btrfs_delayed_root *delayed_root;1321	int nr;1322	struct btrfs_work work;1323};1324 1325static void btrfs_async_run_delayed_root(struct btrfs_work *work)1326{1327	struct btrfs_async_delayed_work *async_work;1328	struct btrfs_delayed_root *delayed_root;1329	struct btrfs_trans_handle *trans;1330	struct btrfs_path *path;1331	struct btrfs_delayed_node *delayed_node = NULL;1332	struct btrfs_root *root;1333	struct btrfs_block_rsv *block_rsv;1334	int total_done = 0;1335 1336	async_work = container_of(work, struct btrfs_async_delayed_work, work);1337	delayed_root = async_work->delayed_root;1338 1339	path = btrfs_alloc_path();1340	if (!path)1341		goto out;1342 1343	do {1344		if (atomic_read(&delayed_root->items) <1345		    BTRFS_DELAYED_BACKGROUND / 2)1346			break;1347 1348		delayed_node = btrfs_first_prepared_delayed_node(delayed_root);1349		if (!delayed_node)1350			break;1351 1352		root = delayed_node->root;1353 1354		trans = btrfs_join_transaction(root);1355		if (IS_ERR(trans)) {1356			btrfs_release_path(path);1357			btrfs_release_prepared_delayed_node(delayed_node);1358			total_done++;1359			continue;1360		}1361 1362		block_rsv = trans->block_rsv;1363		trans->block_rsv = &root->fs_info->delayed_block_rsv;1364 1365		__btrfs_commit_inode_delayed_items(trans, path, delayed_node);1366 1367		trans->block_rsv = block_rsv;1368		btrfs_end_transaction(trans);1369		btrfs_btree_balance_dirty_nodelay(root->fs_info);1370 1371		btrfs_release_path(path);1372		btrfs_release_prepared_delayed_node(delayed_node);1373		total_done++;1374 1375	} while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)1376		 || total_done < async_work->nr);1377 1378	btrfs_free_path(path);1379out:1380	wake_up(&delayed_root->wait);1381	kfree(async_work);1382}1383 1384 1385static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,1386				     struct btrfs_fs_info *fs_info, int nr)1387{1388	struct btrfs_async_delayed_work *async_work;1389 1390	async_work = kmalloc(sizeof(*async_work), GFP_NOFS);1391	if (!async_work)1392		return -ENOMEM;1393 1394	async_work->delayed_root = delayed_root;1395	btrfs_init_work(&async_work->work, btrfs_async_run_delayed_root, NULL);1396	async_work->nr = nr;1397 1398	btrfs_queue_work(fs_info->delayed_workers, &async_work->work);1399	return 0;1400}1401 1402void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)1403{1404	WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));1405}1406 1407static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)1408{1409	int val = atomic_read(&delayed_root->items_seq);1410 1411	if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)1412		return 1;1413 1414	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)1415		return 1;1416 1417	return 0;1418}1419 1420void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)1421{1422	struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;1423 1424	if ((atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||1425		btrfs_workqueue_normal_congested(fs_info->delayed_workers))1426		return;1427 1428	if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {1429		int seq;1430		int ret;1431 1432		seq = atomic_read(&delayed_root->items_seq);1433 1434		ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);1435		if (ret)1436			return;1437 1438		wait_event_interruptible(delayed_root->wait,1439					 could_end_wait(delayed_root, seq));1440		return;1441	}1442 1443	btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);1444}1445 1446static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans)1447{1448	struct btrfs_fs_info *fs_info = trans->fs_info;1449	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);1450 1451	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))1452		return;1453 1454	/*1455	 * Adding the new dir index item does not require touching another1456	 * leaf, so we can release 1 unit of metadata that was previously1457	 * reserved when starting the transaction. This applies only to1458	 * the case where we had a transaction start and excludes the1459	 * transaction join case (when replaying log trees).1460	 */1461	trace_btrfs_space_reservation(fs_info, "transaction",1462				      trans->transid, bytes, 0);1463	btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);1464	ASSERT(trans->bytes_reserved >= bytes);1465	trans->bytes_reserved -= bytes;1466}1467 1468/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */1469int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,1470				   const char *name, int name_len,1471				   struct btrfs_inode *dir,1472				   const struct btrfs_disk_key *disk_key, u8 flags,1473				   u64 index)1474{1475	struct btrfs_fs_info *fs_info = trans->fs_info;1476	const unsigned int leaf_data_size = BTRFS_LEAF_DATA_SIZE(fs_info);1477	struct btrfs_delayed_node *delayed_node;1478	struct btrfs_delayed_item *delayed_item;1479	struct btrfs_dir_item *dir_item;1480	bool reserve_leaf_space;1481	u32 data_len;1482	int ret;1483 1484	delayed_node = btrfs_get_or_create_delayed_node(dir);1485	if (IS_ERR(delayed_node))1486		return PTR_ERR(delayed_node);1487 1488	delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len,1489						delayed_node,1490						BTRFS_DELAYED_INSERTION_ITEM);1491	if (!delayed_item) {1492		ret = -ENOMEM;1493		goto release_node;1494	}1495 1496	delayed_item->index = index;1497 1498	dir_item = (struct btrfs_dir_item *)delayed_item->data;1499	dir_item->location = *disk_key;1500	btrfs_set_stack_dir_transid(dir_item, trans->transid);1501	btrfs_set_stack_dir_data_len(dir_item, 0);1502	btrfs_set_stack_dir_name_len(dir_item, name_len);1503	btrfs_set_stack_dir_flags(dir_item, flags);1504	memcpy((char *)(dir_item + 1), name, name_len);1505 1506	data_len = delayed_item->data_len + sizeof(struct btrfs_item);1507 1508	mutex_lock(&delayed_node->mutex);1509 1510	/*1511	 * First attempt to insert the delayed item. This is to make the error1512	 * handling path simpler in case we fail (-EEXIST). There's no risk of1513	 * any other task coming in and running the delayed item before we do1514	 * the metadata space reservation below, because we are holding the1515	 * delayed node's mutex and that mutex must also be locked before the1516	 * node's delayed items can be run.1517	 */1518	ret = __btrfs_add_delayed_item(delayed_node, delayed_item);1519	if (unlikely(ret)) {1520		btrfs_err(trans->fs_info,1521"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",1522			  name_len, name, index, btrfs_root_id(delayed_node->root),1523			  delayed_node->inode_id, dir->index_cnt,1524			  delayed_node->index_cnt, ret);1525		btrfs_release_delayed_item(delayed_item);1526		btrfs_release_dir_index_item_space(trans);1527		mutex_unlock(&delayed_node->mutex);1528		goto release_node;1529	}1530 1531	if (delayed_node->index_item_leaves == 0 ||1532	    delayed_node->curr_index_batch_size + data_len > leaf_data_size) {1533		delayed_node->curr_index_batch_size = data_len;1534		reserve_leaf_space = true;1535	} else {1536		delayed_node->curr_index_batch_size += data_len;1537		reserve_leaf_space = false;1538	}1539 1540	if (reserve_leaf_space) {1541		ret = btrfs_delayed_item_reserve_metadata(trans, delayed_item);1542		/*1543		 * Space was reserved for a dir index item insertion when we1544		 * started the transaction, so getting a failure here should be1545		 * impossible.1546		 */1547		if (WARN_ON(ret)) {1548			btrfs_release_delayed_item(delayed_item);1549			mutex_unlock(&delayed_node->mutex);1550			goto release_node;1551		}1552 1553		delayed_node->index_item_leaves++;1554	} else {1555		btrfs_release_dir_index_item_space(trans);1556	}1557	mutex_unlock(&delayed_node->mutex);1558 1559release_node:1560	btrfs_release_delayed_node(delayed_node);1561	return ret;1562}1563 1564static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,1565					       struct btrfs_delayed_node *node,1566					       u64 index)1567{1568	struct btrfs_delayed_item *item;1569 1570	mutex_lock(&node->mutex);1571	item = __btrfs_lookup_delayed_item(&node->ins_root.rb_root, index);1572	if (!item) {1573		mutex_unlock(&node->mutex);1574		return 1;1575	}1576 1577	/*1578	 * For delayed items to insert, we track reserved metadata bytes based1579	 * on the number of leaves that we will use.1580	 * See btrfs_insert_delayed_dir_index() and1581	 * btrfs_delayed_item_reserve_metadata()).1582	 */1583	ASSERT(item->bytes_reserved == 0);1584	ASSERT(node->index_item_leaves > 0);1585 1586	/*1587	 * If there's only one leaf reserved, we can decrement this item from the1588	 * current batch, otherwise we can not because we don't know which leaf1589	 * it belongs to. With the current limit on delayed items, we rarely1590	 * accumulate enough dir index items to fill more than one leaf (even1591	 * when using a leaf size of 4K).1592	 */1593	if (node->index_item_leaves == 1) {1594		const u32 data_len = item->data_len + sizeof(struct btrfs_item);1595 1596		ASSERT(node->curr_index_batch_size >= data_len);1597		node->curr_index_batch_size -= data_len;1598	}1599 1600	btrfs_release_delayed_item(item);1601 1602	/* If we now have no more dir index items, we can release all leaves. */1603	if (RB_EMPTY_ROOT(&node->ins_root.rb_root)) {1604		btrfs_delayed_item_release_leaves(node, node->index_item_leaves);1605		node->index_item_leaves = 0;1606	}1607 1608	mutex_unlock(&node->mutex);1609	return 0;1610}1611 1612int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,1613				   struct btrfs_inode *dir, u64 index)1614{1615	struct btrfs_delayed_node *node;1616	struct btrfs_delayed_item *item;1617	int ret;1618 1619	node = btrfs_get_or_create_delayed_node(dir);1620	if (IS_ERR(node))1621		return PTR_ERR(node);1622 1623	ret = btrfs_delete_delayed_insertion_item(trans->fs_info, node, index);1624	if (!ret)1625		goto end;1626 1627	item = btrfs_alloc_delayed_item(0, node, BTRFS_DELAYED_DELETION_ITEM);1628	if (!item) {1629		ret = -ENOMEM;1630		goto end;1631	}1632 1633	item->index = index;1634 1635	ret = btrfs_delayed_item_reserve_metadata(trans, item);1636	/*1637	 * we have reserved enough space when we start a new transaction,1638	 * so reserving metadata failure is impossible.1639	 */1640	if (ret < 0) {1641		btrfs_err(trans->fs_info,1642"metadata reservation failed for delayed dir item deltiona, should have been reserved");1643		btrfs_release_delayed_item(item);1644		goto end;1645	}1646 1647	mutex_lock(&node->mutex);1648	ret = __btrfs_add_delayed_item(node, item);1649	if (unlikely(ret)) {1650		btrfs_err(trans->fs_info,1651			  "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",1652			  index, btrfs_root_id(node->root),1653			  node->inode_id, ret);1654		btrfs_delayed_item_release_metadata(dir->root, item);1655		btrfs_release_delayed_item(item);1656	}1657	mutex_unlock(&node->mutex);1658end:1659	btrfs_release_delayed_node(node);1660	return ret;1661}1662 1663int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)1664{1665	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);1666 1667	if (!delayed_node)1668		return -ENOENT;1669 1670	/*1671	 * Since we have held i_mutex of this directory, it is impossible that1672	 * a new directory index is added into the delayed node and index_cnt1673	 * is updated now. So we needn't lock the delayed node.1674	 */1675	if (!delayed_node->index_cnt) {1676		btrfs_release_delayed_node(delayed_node);1677		return -EINVAL;1678	}1679 1680	inode->index_cnt = delayed_node->index_cnt;1681	btrfs_release_delayed_node(delayed_node);1682	return 0;1683}1684 1685bool btrfs_readdir_get_delayed_items(struct btrfs_inode *inode,1686				     u64 last_index,1687				     struct list_head *ins_list,1688				     struct list_head *del_list)1689{1690	struct btrfs_delayed_node *delayed_node;1691	struct btrfs_delayed_item *item;1692 1693	delayed_node = btrfs_get_delayed_node(inode);1694	if (!delayed_node)1695		return false;1696 1697	/*1698	 * We can only do one readdir with delayed items at a time because of1699	 * item->readdir_list.1700	 */1701	btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);1702	btrfs_inode_lock(inode, 0);1703 1704	mutex_lock(&delayed_node->mutex);1705	item = __btrfs_first_delayed_insertion_item(delayed_node);1706	while (item && item->index <= last_index) {1707		refcount_inc(&item->refs);1708		list_add_tail(&item->readdir_list, ins_list);1709		item = __btrfs_next_delayed_item(item);1710	}1711 1712	item = __btrfs_first_delayed_deletion_item(delayed_node);1713	while (item && item->index <= last_index) {1714		refcount_inc(&item->refs);1715		list_add_tail(&item->readdir_list, del_list);1716		item = __btrfs_next_delayed_item(item);1717	}1718	mutex_unlock(&delayed_node->mutex);1719	/*1720	 * This delayed node is still cached in the btrfs inode, so refs1721	 * must be > 1 now, and we needn't check it is going to be freed1722	 * or not.1723	 *1724	 * Besides that, this function is used to read dir, we do not1725	 * insert/delete delayed items in this period. So we also needn't1726	 * requeue or dequeue this delayed node.1727	 */1728	refcount_dec(&delayed_node->refs);1729 1730	return true;1731}1732 1733void btrfs_readdir_put_delayed_items(struct btrfs_inode *inode,1734				     struct list_head *ins_list,1735				     struct list_head *del_list)1736{1737	struct btrfs_delayed_item *curr, *next;1738 1739	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {1740		list_del(&curr->readdir_list);1741		if (refcount_dec_and_test(&curr->refs))1742			kfree(curr);1743	}1744 1745	list_for_each_entry_safe(curr, next, del_list, readdir_list) {1746		list_del(&curr->readdir_list);1747		if (refcount_dec_and_test(&curr->refs))1748			kfree(curr);1749	}1750 1751	/*1752	 * The VFS is going to do up_read(), so we need to downgrade back to a1753	 * read lock.1754	 */1755	downgrade_write(&inode->vfs_inode.i_rwsem);1756}1757 1758int btrfs_should_delete_dir_index(const struct list_head *del_list,1759				  u64 index)1760{1761	struct btrfs_delayed_item *curr;1762	int ret = 0;1763 1764	list_for_each_entry(curr, del_list, readdir_list) {1765		if (curr->index > index)1766			break;1767		if (curr->index == index) {1768			ret = 1;1769			break;1770		}1771	}1772	return ret;1773}1774 1775/*1776 * Read dir info stored in the delayed tree.1777 */1778int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,1779				    const struct list_head *ins_list)1780{1781	struct btrfs_dir_item *di;1782	struct btrfs_delayed_item *curr, *next;1783	struct btrfs_key location;1784	char *name;1785	int name_len;1786	int over = 0;1787	unsigned char d_type;1788 1789	/*1790	 * Changing the data of the delayed item is impossible. So1791	 * we needn't lock them. And we have held i_mutex of the1792	 * directory, nobody can delete any directory indexes now.1793	 */1794	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {1795		list_del(&curr->readdir_list);1796 1797		if (curr->index < ctx->pos) {1798			if (refcount_dec_and_test(&curr->refs))1799				kfree(curr);1800			continue;1801		}1802 1803		ctx->pos = curr->index;1804 1805		di = (struct btrfs_dir_item *)curr->data;1806		name = (char *)(di + 1);1807		name_len = btrfs_stack_dir_name_len(di);1808 1809		d_type = fs_ftype_to_dtype(btrfs_dir_flags_to_ftype(di->type));1810		btrfs_disk_key_to_cpu(&location, &di->location);1811 1812		over = !dir_emit(ctx, name, name_len,1813			       location.objectid, d_type);1814 1815		if (refcount_dec_and_test(&curr->refs))1816			kfree(curr);1817 1818		if (over)1819			return 1;1820		ctx->pos++;1821	}1822	return 0;1823}1824 1825static void fill_stack_inode_item(struct btrfs_trans_handle *trans,1826				  struct btrfs_inode_item *inode_item,1827				  struct inode *inode)1828{1829	u64 flags;1830 1831	btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));1832	btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));1833	btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);1834	btrfs_set_stack_inode_mode(inode_item, inode->i_mode);1835	btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);1836	btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));1837	btrfs_set_stack_inode_generation(inode_item,1838					 BTRFS_I(inode)->generation);1839	btrfs_set_stack_inode_sequence(inode_item,1840				       inode_peek_iversion(inode));1841	btrfs_set_stack_inode_transid(inode_item, trans->transid);1842	btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);1843	flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,1844					  BTRFS_I(inode)->ro_flags);1845	btrfs_set_stack_inode_flags(inode_item, flags);1846	btrfs_set_stack_inode_block_group(inode_item, 0);1847 1848	btrfs_set_stack_timespec_sec(&inode_item->atime,1849				     inode_get_atime_sec(inode));1850	btrfs_set_stack_timespec_nsec(&inode_item->atime,1851				      inode_get_atime_nsec(inode));1852 1853	btrfs_set_stack_timespec_sec(&inode_item->mtime,1854				     inode_get_mtime_sec(inode));1855	btrfs_set_stack_timespec_nsec(&inode_item->mtime,1856				      inode_get_mtime_nsec(inode));1857 1858	btrfs_set_stack_timespec_sec(&inode_item->ctime,1859				     inode_get_ctime_sec(inode));1860	btrfs_set_stack_timespec_nsec(&inode_item->ctime,1861				      inode_get_ctime_nsec(inode));1862 1863	btrfs_set_stack_timespec_sec(&inode_item->otime, BTRFS_I(inode)->i_otime_sec);1864	btrfs_set_stack_timespec_nsec(&inode_item->otime, BTRFS_I(inode)->i_otime_nsec);1865}1866 1867int btrfs_fill_inode(struct inode *inode, u32 *rdev)1868{1869	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;1870	struct btrfs_delayed_node *delayed_node;1871	struct btrfs_inode_item *inode_item;1872 1873	delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));1874	if (!delayed_node)1875		return -ENOENT;1876 1877	mutex_lock(&delayed_node->mutex);1878	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {1879		mutex_unlock(&delayed_node->mutex);1880		btrfs_release_delayed_node(delayed_node);1881		return -ENOENT;1882	}1883 1884	inode_item = &delayed_node->inode_item;1885 1886	i_uid_write(inode, btrfs_stack_inode_uid(inode_item));1887	i_gid_write(inode, btrfs_stack_inode_gid(inode_item));1888	btrfs_i_size_write(BTRFS_I(inode), btrfs_stack_inode_size(inode_item));1889	btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,1890			round_up(i_size_read(inode), fs_info->sectorsize));1891	inode->i_mode = btrfs_stack_inode_mode(inode_item);1892	set_nlink(inode, btrfs_stack_inode_nlink(inode_item));1893	inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));1894	BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);1895        BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);1896 1897	inode_set_iversion_queried(inode,1898				   btrfs_stack_inode_sequence(inode_item));1899	inode->i_rdev = 0;1900	*rdev = btrfs_stack_inode_rdev(inode_item);1901	btrfs_inode_split_flags(btrfs_stack_inode_flags(inode_item),1902				&BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);1903 1904	inode_set_atime(inode, btrfs_stack_timespec_sec(&inode_item->atime),1905			btrfs_stack_timespec_nsec(&inode_item->atime));1906 1907	inode_set_mtime(inode, btrfs_stack_timespec_sec(&inode_item->mtime),1908			btrfs_stack_timespec_nsec(&inode_item->mtime));1909 1910	inode_set_ctime(inode, btrfs_stack_timespec_sec(&inode_item->ctime),1911			btrfs_stack_timespec_nsec(&inode_item->ctime));1912 1913	BTRFS_I(inode)->i_otime_sec = btrfs_stack_timespec_sec(&inode_item->otime);1914	BTRFS_I(inode)->i_otime_nsec = btrfs_stack_timespec_nsec(&inode_item->otime);1915 1916	inode->i_generation = BTRFS_I(inode)->generation;1917	if (S_ISDIR(inode->i_mode))1918		BTRFS_I(inode)->index_cnt = (u64)-1;1919 1920	mutex_unlock(&delayed_node->mutex);1921	btrfs_release_delayed_node(delayed_node);1922	return 0;1923}1924 1925int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,1926			       struct btrfs_inode *inode)1927{1928	struct btrfs_root *root = inode->root;1929	struct btrfs_delayed_node *delayed_node;1930	int ret = 0;1931 1932	delayed_node = btrfs_get_or_create_delayed_node(inode);1933	if (IS_ERR(delayed_node))1934		return PTR_ERR(delayed_node);1935 1936	mutex_lock(&delayed_node->mutex);1937	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {1938		fill_stack_inode_item(trans, &delayed_node->inode_item,1939				      &inode->vfs_inode);1940		goto release_node;1941	}1942 1943	ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);1944	if (ret)1945		goto release_node;1946 1947	fill_stack_inode_item(trans, &delayed_node->inode_item, &inode->vfs_inode);1948	set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);1949	delayed_node->count++;1950	atomic_inc(&root->fs_info->delayed_root->items);1951release_node:1952	mutex_unlock(&delayed_node->mutex);1953	btrfs_release_delayed_node(delayed_node);1954	return ret;1955}1956 1957int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)1958{1959	struct btrfs_fs_info *fs_info = inode->root->fs_info;1960	struct btrfs_delayed_node *delayed_node;1961 1962	/*1963	 * we don't do delayed inode updates during log recovery because it1964	 * leads to enospc problems.  This means we also can't do1965	 * delayed inode refs1966	 */1967	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))1968		return -EAGAIN;1969 1970	delayed_node = btrfs_get_or_create_delayed_node(inode);1971	if (IS_ERR(delayed_node))1972		return PTR_ERR(delayed_node);1973 1974	/*1975	 * We don't reserve space for inode ref deletion is because:1976	 * - We ONLY do async inode ref deletion for the inode who has only1977	 *   one link(i_nlink == 1), it means there is only one inode ref.1978	 *   And in most case, the inode ref and the inode item are in the1979	 *   same leaf, and we will deal with them at the same time.1980	 *   Since we are sure we will reserve the space for the inode item,1981	 *   it is unnecessary to reserve space for inode ref deletion.1982	 * - If the inode ref and the inode item are not in the same leaf,1983	 *   We also needn't worry about enospc problem, because we reserve1984	 *   much more space for the inode update than it needs.1985	 * - At the worst, we can steal some space from the global reservation.1986	 *   It is very rare.1987	 */1988	mutex_lock(&delayed_node->mutex);1989	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))1990		goto release_node;1991 1992	set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);1993	delayed_node->count++;1994	atomic_inc(&fs_info->delayed_root->items);1995release_node:1996	mutex_unlock(&delayed_node->mutex);1997	btrfs_release_delayed_node(delayed_node);1998	return 0;1999}2000 2001static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)2002{2003	struct btrfs_root *root = delayed_node->root;2004	struct btrfs_fs_info *fs_info = root->fs_info;2005	struct btrfs_delayed_item *curr_item, *prev_item;2006 2007	mutex_lock(&delayed_node->mutex);2008	curr_item = __btrfs_first_delayed_insertion_item(delayed_node);2009	while (curr_item) {2010		prev_item = curr_item;2011		curr_item = __btrfs_next_delayed_item(prev_item);2012		btrfs_release_delayed_item(prev_item);2013	}2014 2015	if (delayed_node->index_item_leaves > 0) {2016		btrfs_delayed_item_release_leaves(delayed_node,2017					  delayed_node->index_item_leaves);2018		delayed_node->index_item_leaves = 0;2019	}2020 2021	curr_item = __btrfs_first_delayed_deletion_item(delayed_node);2022	while (curr_item) {2023		btrfs_delayed_item_release_metadata(root, curr_item);2024		prev_item = curr_item;2025		curr_item = __btrfs_next_delayed_item(prev_item);2026		btrfs_release_delayed_item(prev_item);2027	}2028 2029	btrfs_release_delayed_iref(delayed_node);2030 2031	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {2032		btrfs_delayed_inode_release_metadata(fs_info, delayed_node, false);2033		btrfs_release_delayed_inode(delayed_node);2034	}2035	mutex_unlock(&delayed_node->mutex);2036}2037 2038void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)2039{2040	struct btrfs_delayed_node *delayed_node;2041 2042	delayed_node = btrfs_get_delayed_node(inode);2043	if (!delayed_node)2044		return;2045 2046	__btrfs_kill_delayed_node(delayed_node);2047	btrfs_release_delayed_node(delayed_node);2048}2049 2050void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)2051{2052	unsigned long index = 0;2053	struct btrfs_delayed_node *delayed_nodes[8];2054 2055	while (1) {2056		struct btrfs_delayed_node *node;2057		int count;2058 2059		xa_lock(&root->delayed_nodes);2060		if (xa_empty(&root->delayed_nodes)) {2061			xa_unlock(&root->delayed_nodes);2062			return;2063		}2064 2065		count = 0;2066		xa_for_each_start(&root->delayed_nodes, index, node, index) {2067			/*2068			 * Don't increase refs in case the node is dead and2069			 * about to be removed from the tree in the loop below2070			 */2071			if (refcount_inc_not_zero(&node->refs)) {2072				delayed_nodes[count] = node;2073				count++;2074			}2075			if (count >= ARRAY_SIZE(delayed_nodes))2076				break;2077		}2078		xa_unlock(&root->delayed_nodes);2079		index++;2080 2081		for (int i = 0; i < count; i++) {2082			__btrfs_kill_delayed_node(delayed_nodes[i]);2083			btrfs_release_delayed_node(delayed_nodes[i]);2084		}2085	}2086}2087 2088void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)2089{2090	struct btrfs_delayed_node *curr_node, *prev_node;2091 2092	curr_node = btrfs_first_delayed_node(fs_info->delayed_root);2093	while (curr_node) {2094		__btrfs_kill_delayed_node(curr_node);2095 2096		prev_node = curr_node;2097		curr_node = btrfs_next_delayed_node(curr_node);2098		btrfs_release_delayed_node(prev_node);2099	}2100}2101 2102void btrfs_log_get_delayed_items(struct btrfs_inode *inode,2103				 struct list_head *ins_list,2104				 struct list_head *del_list)2105{2106	struct btrfs_delayed_node *node;2107	struct btrfs_delayed_item *item;2108 2109	node = btrfs_get_delayed_node(inode);2110	if (!node)2111		return;2112 2113	mutex_lock(&node->mutex);2114	item = __btrfs_first_delayed_insertion_item(node);2115	while (item) {2116		/*2117		 * It's possible that the item is already in a log list. This2118		 * can happen in case two tasks are trying to log the same2119		 * directory. For example if we have tasks A and task B:2120		 *2121		 * Task A collected the delayed items into a log list while2122		 * under the inode's log_mutex (at btrfs_log_inode()), but it2123		 * only releases the items after logging the inodes they point2124		 * to (if they are new inodes), which happens after unlocking2125		 * the log mutex;2126		 *2127		 * Task B enters btrfs_log_inode() and acquires the log_mutex2128		 * of the same directory inode, before task B releases the2129		 * delayed items. This can happen for example when logging some2130		 * inode we need to trigger logging of its parent directory, so2131		 * logging two files that have the same parent directory can2132		 * lead to this.2133		 *2134		 * If this happens, just ignore delayed items already in a log2135		 * list. All the tasks logging the directory are under a log2136		 * transaction and whichever finishes first can not sync the log2137		 * before the other completes and leaves the log transaction.2138		 */2139		if (!item->logged && list_empty(&item->log_list)) {2140			refcount_inc(&item->refs);2141			list_add_tail(&item->log_list, ins_list);2142		}2143		item = __btrfs_next_delayed_item(item);2144	}2145 2146	item = __btrfs_first_delayed_deletion_item(node);2147	while (item) {2148		/* It may be non-empty, for the same reason mentioned above. */2149		if (!item->logged && list_empty(&item->log_list)) {2150			refcount_inc(&item->refs);2151			list_add_tail(&item->log_list, del_list);2152		}2153		item = __btrfs_next_delayed_item(item);2154	}2155	mutex_unlock(&node->mutex);2156 2157	/*2158	 * We are called during inode logging, which means the inode is in use2159	 * and can not be evicted before we finish logging the inode. So we never2160	 * have the last reference on the delayed inode.2161	 * Also, we don't use btrfs_release_delayed_node() because that would2162	 * requeue the delayed inode (change its order in the list of prepared2163	 * nodes) and we don't want to do such change because we don't create or2164	 * delete delayed items.2165	 */2166	ASSERT(refcount_read(&node->refs) > 1);2167	refcount_dec(&node->refs);2168}2169 2170void btrfs_log_put_delayed_items(struct btrfs_inode *inode,2171				 struct list_head *ins_list,2172				 struct list_head *del_list)2173{2174	struct btrfs_delayed_node *node;2175	struct btrfs_delayed_item *item;2176	struct btrfs_delayed_item *next;2177 2178	node = btrfs_get_delayed_node(inode);2179	if (!node)2180		return;2181 2182	mutex_lock(&node->mutex);2183 2184	list_for_each_entry_safe(item, next, ins_list, log_list) {2185		item->logged = true;2186		list_del_init(&item->log_list);2187		if (refcount_dec_and_test(&item->refs))2188			kfree(item);2189	}2190 2191	list_for_each_entry_safe(item, next, del_list, log_list) {2192		item->logged = true;2193		list_del_init(&item->log_list);2194		if (refcount_dec_and_test(&item->refs))2195			kfree(item);2196	}2197 2198	mutex_unlock(&node->mutex);2199 2200	/*2201	 * We are called during inode logging, which means the inode is in use2202	 * and can not be evicted before we finish logging the inode. So we never2203	 * have the last reference on the delayed inode.2204	 * Also, we don't use btrfs_release_delayed_node() because that would2205	 * requeue the delayed inode (change its order in the list of prepared2206	 * nodes) and we don't want to do such change because we don't create or2207	 * delete delayed items.2208	 */2209	ASSERT(refcount_read(&node->refs) > 1);2210	refcount_dec(&node->refs);2211}2212