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
  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	spin_lock(&root->inode_lock);
  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			spin_unlock(&root->inode_lock);
  88			return node;
  89		}
  90
  91		/*
  92		 * It's possible that we're racing into the middle of removing
  93		 * this node from the xarray.  In this case, the refcount
  94		 * was zero and it should never go back to one.  Just return
  95		 * NULL like it was never in the xarray at all; our release
  96		 * function is in the process of removing it.
  97		 *
  98		 * Some implementations of refcount_inc refuse to bump the
  99		 * refcount once it has hit zero.  If we don't do this dance
 100		 * here, refcount_inc() may decide to just WARN_ONCE() instead
 101		 * of actually bumping the refcount.
 102		 *
 103		 * If this node is properly in the xarray, we want to bump the
 104		 * refcount twice, once for the inode and once for this get
 105		 * operation.
 106		 */
 107		if (refcount_inc_not_zero(&node->refs)) {
 108			refcount_inc(&node->refs);
 109			btrfs_inode->delayed_node = node;
 110		} else {
 111			node = NULL;
 112		}
 113
 114		spin_unlock(&root->inode_lock);
 115		return node;
 116	}
 117	spin_unlock(&root->inode_lock);
 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	spin_lock(&root->inode_lock);
 152	ptr = xa_load(&root->delayed_nodes, ino);
 153	if (ptr) {
 154		/* Somebody inserted it, go back and read it. */
 155		spin_unlock(&root->inode_lock);
 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	spin_unlock(&root->inode_lock);
 
 166
 167	return node;
 168}
 169
 170/*
 171 * Call it when holding delayed_node->mutex
 172 *
 173 * If mod = 1, add this node into the prepared list.
 174 */
 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	else
 247		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	else
 272		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		spin_lock(&root->inode_lock);
 279		/*
 280		 * Once our refcount goes to zero, nobody is allowed to bump it
 281		 * back up.  We can delete it now.
 282		 */
 283		ASSERT(refcount_read(&delayed_node->refs) == 0);
 284		xa_erase(&root->delayed_nodes, delayed_node->inode_id);
 
 285		spin_unlock(&root->inode_lock);
 286		kmem_cache_free(delayed_node_cache, delayed_node);
 287	}
 288}
 289
 290static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 291{
 292	__btrfs_release_delayed_node(node, 0);
 293}
 294
 295static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
 296					struct btrfs_delayed_root *delayed_root)
 297{
 298	struct list_head *p;
 299	struct btrfs_delayed_node *node = NULL;
 300
 301	spin_lock(&delayed_root->lock);
 302	if (list_empty(&delayed_root->prepare_list))
 303		goto out;
 304
 305	p = delayed_root->prepare_list.next;
 306	list_del_init(p);
 307	node = list_entry(p, struct btrfs_delayed_node, p_list);
 308	refcount_inc(&node->refs);
 309out:
 310	spin_unlock(&delayed_root->lock);
 311
 312	return node;
 313}
 314
 315static inline void btrfs_release_prepared_delayed_node(
 316					struct btrfs_delayed_node *node)
 317{
 318	__btrfs_release_delayed_node(node, 1);
 319}
 320
 321static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u16 data_len,
 322					   struct btrfs_delayed_node *node,
 323					   enum btrfs_delayed_item_type type)
 324{
 325	struct btrfs_delayed_item *item;
 326
 327	item = kmalloc(struct_size(item, data, data_len), GFP_NOFS);
 328	if (item) {
 329		item->data_len = data_len;
 330		item->type = type;
 331		item->bytes_reserved = 0;
 332		item->delayed_node = node;
 333		RB_CLEAR_NODE(&item->rb_node);
 334		INIT_LIST_HEAD(&item->log_list);
 335		item->logged = false;
 336		refcount_set(&item->refs, 1);
 337	}
 338	return item;
 339}
 340
 341/*
 342 * Look up the delayed item by key.
 343 *
 344 * @delayed_node: pointer to the delayed node
 345 * @index:	  the dir index value to lookup (offset of a dir index key)
 
 
 346 *
 347 * Note: if we don't find the right item, we will return the prev item and
 348 * the next item.
 349 */
 350static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
 351				struct rb_root *root,
 352				u64 index)
 
 
 353{
 354	struct rb_node *node = root->rb_node;
 355	struct btrfs_delayed_item *delayed_item = NULL;
 
 
 
 356
 357	while (node) {
 358		delayed_item = rb_entry(node, struct btrfs_delayed_item,
 359					rb_node);
 360		if (delayed_item->index < index)
 
 
 361			node = node->rb_right;
 362		else if (delayed_item->index > index)
 363			node = node->rb_left;
 364		else
 365			return delayed_item;
 366	}
 367
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 368	return NULL;
 369}
 370
 
 
 
 
 
 
 
 
 371static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 372				    struct btrfs_delayed_item *ins)
 
 373{
 374	struct rb_node **p, *node;
 375	struct rb_node *parent_node = NULL;
 376	struct rb_root_cached *root;
 377	struct btrfs_delayed_item *item;
 
 378	bool leftmost = true;
 379
 380	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM)
 381		root = &delayed_node->ins_root;
 382	else
 383		root = &delayed_node->del_root;
 384
 
 385	p = &root->rb_root.rb_node;
 386	node = &ins->rb_node;
 387
 388	while (*p) {
 389		parent_node = *p;
 390		item = rb_entry(parent_node, struct btrfs_delayed_item,
 391				 rb_node);
 392
 393		if (item->index < ins->index) {
 
 394			p = &(*p)->rb_right;
 395			leftmost = false;
 396		} else if (item->index > ins->index) {
 397			p = &(*p)->rb_left;
 398		} else {
 399			return -EEXIST;
 400		}
 401	}
 402
 403	rb_link_node(node, parent_node, p);
 404	rb_insert_color_cached(node, root, leftmost);
 
 
 405
 406	if (ins->type == BTRFS_DELAYED_INSERTION_ITEM &&
 407	    ins->index >= delayed_node->index_cnt)
 408		delayed_node->index_cnt = ins->index + 1;
 
 409
 410	delayed_node->count++;
 411	atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
 412	return 0;
 413}
 414
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 415static void finish_one_item(struct btrfs_delayed_root *delayed_root)
 416{
 417	int seq = atomic_inc_return(&delayed_root->items_seq);
 418
 419	/* atomic_dec_return implies a barrier */
 420	if ((atomic_dec_return(&delayed_root->items) <
 421	    BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))
 422		cond_wake_up_nomb(&delayed_root->wait);
 423}
 424
 425static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 426{
 427	struct btrfs_delayed_node *delayed_node = delayed_item->delayed_node;
 428	struct rb_root_cached *root;
 429	struct btrfs_delayed_root *delayed_root;
 430
 431	/* Not inserted, ignore it. */
 432	if (RB_EMPTY_NODE(&delayed_item->rb_node))
 433		return;
 
 434
 435	/* If it's in a rbtree, then we need to have delayed node locked. */
 436	lockdep_assert_held(&delayed_node->mutex);
 437
 438	delayed_root = delayed_node->root->fs_info->delayed_root;
 439
 440	if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)
 441		root = &delayed_node->ins_root;
 442	else
 443		root = &delayed_node->del_root;
 444
 445	rb_erase_cached(&delayed_item->rb_node, root);
 446	RB_CLEAR_NODE(&delayed_item->rb_node);
 447	delayed_node->count--;
 448
 449	finish_one_item(delayed_root);
 450}
 451
 452static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 453{
 454	if (item) {
 455		__btrfs_remove_delayed_item(item);
 456		if (refcount_dec_and_test(&item->refs))
 457			kfree(item);
 458	}
 459}
 460
 461static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 462					struct btrfs_delayed_node *delayed_node)
 463{
 464	struct rb_node *p;
 465	struct btrfs_delayed_item *item = NULL;
 466
 467	p = rb_first_cached(&delayed_node->ins_root);
 468	if (p)
 469		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 470
 471	return item;
 472}
 473
 474static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 475					struct btrfs_delayed_node *delayed_node)
 476{
 477	struct rb_node *p;
 478	struct btrfs_delayed_item *item = NULL;
 479
 480	p = rb_first_cached(&delayed_node->del_root);
 481	if (p)
 482		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 483
 484	return item;
 485}
 486
 487static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 488						struct btrfs_delayed_item *item)
 489{
 490	struct rb_node *p;
 491	struct btrfs_delayed_item *next = NULL;
 492
 493	p = rb_next(&item->rb_node);
 494	if (p)
 495		next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 496
 497	return next;
 498}
 499
 500static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 
 501					       struct btrfs_delayed_item *item)
 502{
 503	struct btrfs_block_rsv *src_rsv;
 504	struct btrfs_block_rsv *dst_rsv;
 505	struct btrfs_fs_info *fs_info = trans->fs_info;
 506	u64 num_bytes;
 507	int ret;
 508
 509	if (!trans->bytes_reserved)
 510		return 0;
 511
 512	src_rsv = trans->block_rsv;
 513	dst_rsv = &fs_info->delayed_block_rsv;
 514
 515	num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 516
 517	/*
 518	 * Here we migrate space rsv from transaction rsv, since have already
 519	 * reserved space when starting a transaction.  So no need to reserve
 520	 * qgroup space here.
 521	 */
 522	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 523	if (!ret) {
 524		trace_btrfs_space_reservation(fs_info, "delayed_item",
 525					      item->delayed_node->inode_id,
 526					      num_bytes, 1);
 527		/*
 528		 * For insertions we track reserved metadata space by accounting
 529		 * for the number of leaves that will be used, based on the delayed
 530		 * node's curr_index_batch_size and index_item_leaves fields.
 531		 */
 532		if (item->type == BTRFS_DELAYED_DELETION_ITEM)
 533			item->bytes_reserved = num_bytes;
 534	}
 535
 536	return ret;
 537}
 538
 539static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
 540						struct btrfs_delayed_item *item)
 541{
 542	struct btrfs_block_rsv *rsv;
 543	struct btrfs_fs_info *fs_info = root->fs_info;
 544
 545	if (!item->bytes_reserved)
 546		return;
 547
 548	rsv = &fs_info->delayed_block_rsv;
 549	/*
 550	 * Check btrfs_delayed_item_reserve_metadata() to see why we don't need
 551	 * to release/reserve qgroup space.
 552	 */
 553	trace_btrfs_space_reservation(fs_info, "delayed_item",
 554				      item->delayed_node->inode_id,
 555				      item->bytes_reserved, 0);
 556	btrfs_block_rsv_release(fs_info, rsv, item->bytes_reserved, NULL);
 557}
 558
 559static void btrfs_delayed_item_release_leaves(struct btrfs_delayed_node *node,
 560					      unsigned int num_leaves)
 561{
 562	struct btrfs_fs_info *fs_info = node->root->fs_info;
 563	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_leaves);
 564
 565	/* There are no space reservations during log replay, bail out. */
 566	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
 567		return;
 568
 569	trace_btrfs_space_reservation(fs_info, "delayed_item", node->inode_id,
 570				      bytes, 0);
 571	btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv, bytes, NULL);
 572}
 573
 574static int btrfs_delayed_inode_reserve_metadata(
 575					struct btrfs_trans_handle *trans,
 576					struct btrfs_root *root,
 
 577					struct btrfs_delayed_node *node)
 578{
 579	struct btrfs_fs_info *fs_info = root->fs_info;
 580	struct btrfs_block_rsv *src_rsv;
 581	struct btrfs_block_rsv *dst_rsv;
 582	u64 num_bytes;
 583	int ret;
 584
 585	src_rsv = trans->block_rsv;
 586	dst_rsv = &fs_info->delayed_block_rsv;
 587
 588	num_bytes = btrfs_calc_metadata_size(fs_info, 1);
 589
 590	/*
 591	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction
 592	 * which doesn't reserve space for speed.  This is a problem since we
 593	 * still need to reserve space for this update, so try to reserve the
 594	 * space.
 595	 *
 596	 * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
 597	 * we always reserve enough to update the inode item.
 598	 */
 599	if (!src_rsv || (!trans->bytes_reserved &&
 600			 src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
 601		ret = btrfs_qgroup_reserve_meta(root, num_bytes,
 602					  BTRFS_QGROUP_RSV_META_PREALLOC, true);
 603		if (ret < 0)
 604			return ret;
 605		ret = btrfs_block_rsv_add(fs_info, dst_rsv, num_bytes,
 606					  BTRFS_RESERVE_NO_FLUSH);
 607		/* NO_FLUSH could only fail with -ENOSPC */
 608		ASSERT(ret == 0 || ret == -ENOSPC);
 609		if (ret)
 
 
 
 
 
 610			btrfs_qgroup_free_meta_prealloc(root, num_bytes);
 611	} else {
 612		ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 
 
 
 
 
 
 
 
 
 613	}
 614
 
 615	if (!ret) {
 616		trace_btrfs_space_reservation(fs_info, "delayed_inode",
 617					      node->inode_id, num_bytes, 1);
 618		node->bytes_reserved = num_bytes;
 619	}
 620
 621	return ret;
 622}
 623
 624static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
 625						struct btrfs_delayed_node *node,
 626						bool qgroup_free)
 627{
 628	struct btrfs_block_rsv *rsv;
 629
 630	if (!node->bytes_reserved)
 631		return;
 632
 633	rsv = &fs_info->delayed_block_rsv;
 634	trace_btrfs_space_reservation(fs_info, "delayed_inode",
 635				      node->inode_id, node->bytes_reserved, 0);
 636	btrfs_block_rsv_release(fs_info, rsv, node->bytes_reserved, NULL);
 
 637	if (qgroup_free)
 638		btrfs_qgroup_free_meta_prealloc(node->root,
 639				node->bytes_reserved);
 640	else
 641		btrfs_qgroup_convert_reserved_meta(node->root,
 642				node->bytes_reserved);
 643	node->bytes_reserved = 0;
 644}
 645
 646/*
 647 * Insert a single delayed item or a batch of delayed items, as many as possible
 648 * that fit in a leaf. The delayed items (dir index keys) are sorted by their key
 649 * in the rbtree, and if there's a gap between two consecutive dir index items,
 650 * then it means at some point we had delayed dir indexes to add but they got
 651 * removed (by btrfs_delete_delayed_dir_index()) before we attempted to flush them
 652 * into the subvolume tree. Dir index keys also have their offsets coming from a
 653 * monotonically increasing counter, so we can't get new keys with an offset that
 654 * fits within a gap between delayed dir index items.
 655 */
 656static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 657				     struct btrfs_root *root,
 658				     struct btrfs_path *path,
 659				     struct btrfs_delayed_item *first_item)
 660{
 661	struct btrfs_fs_info *fs_info = root->fs_info;
 662	struct btrfs_delayed_node *node = first_item->delayed_node;
 663	LIST_HEAD(item_list);
 664	struct btrfs_delayed_item *curr;
 665	struct btrfs_delayed_item *next;
 666	const int max_size = BTRFS_LEAF_DATA_SIZE(fs_info);
 667	struct btrfs_item_batch batch;
 668	struct btrfs_key first_key;
 669	const u32 first_data_size = first_item->data_len;
 670	int total_size;
 671	char *ins_data = NULL;
 672	int ret;
 673	bool continuous_keys_only = false;
 674
 675	lockdep_assert_held(&node->mutex);
 676
 677	/*
 678	 * During normal operation the delayed index offset is continuously
 679	 * increasing, so we can batch insert all items as there will not be any
 680	 * overlapping keys in the tree.
 681	 *
 682	 * The exception to this is log replay, where we may have interleaved
 683	 * offsets in the tree, so our batch needs to be continuous keys only in
 684	 * order to ensure we do not end up with out of order items in our leaf.
 685	 */
 686	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
 687		continuous_keys_only = true;
 688
 689	/*
 690	 * For delayed items to insert, we track reserved metadata bytes based
 691	 * on the number of leaves that we will use.
 692	 * See btrfs_insert_delayed_dir_index() and
 693	 * btrfs_delayed_item_reserve_metadata()).
 694	 */
 695	ASSERT(first_item->bytes_reserved == 0);
 696
 697	list_add_tail(&first_item->tree_list, &item_list);
 698	batch.total_data_size = first_data_size;
 699	batch.nr = 1;
 700	total_size = first_data_size + sizeof(struct btrfs_item);
 701	curr = first_item;
 702
 703	while (true) {
 704		int next_size;
 705
 
 706		next = __btrfs_next_delayed_item(curr);
 707		if (!next)
 708			break;
 709
 710		/*
 711		 * We cannot allow gaps in the key space if we're doing log
 712		 * replay.
 713		 */
 714		if (continuous_keys_only && (next->index != curr->index + 1))
 715			break;
 716
 717		ASSERT(next->bytes_reserved == 0);
 718
 719		next_size = next->data_len + sizeof(struct btrfs_item);
 720		if (total_size + next_size > max_size)
 721			break;
 722
 723		list_add_tail(&next->tree_list, &item_list);
 724		batch.nr++;
 725		total_size += next_size;
 726		batch.total_data_size += next->data_len;
 727		curr = next;
 728	}
 729
 730	if (batch.nr == 1) {
 731		first_key.objectid = node->inode_id;
 732		first_key.type = BTRFS_DIR_INDEX_KEY;
 733		first_key.offset = first_item->index;
 734		batch.keys = &first_key;
 735		batch.data_sizes = &first_data_size;
 736	} else {
 737		struct btrfs_key *ins_keys;
 738		u32 *ins_sizes;
 739		int i = 0;
 740
 741		ins_data = kmalloc(batch.nr * sizeof(u32) +
 742				   batch.nr * sizeof(struct btrfs_key), GFP_NOFS);
 743		if (!ins_data) {
 744			ret = -ENOMEM;
 745			goto out;
 746		}
 747		ins_sizes = (u32 *)ins_data;
 748		ins_keys = (struct btrfs_key *)(ins_data + batch.nr * sizeof(u32));
 749		batch.keys = ins_keys;
 750		batch.data_sizes = ins_sizes;
 751		list_for_each_entry(curr, &item_list, tree_list) {
 752			ins_keys[i].objectid = node->inode_id;
 753			ins_keys[i].type = BTRFS_DIR_INDEX_KEY;
 754			ins_keys[i].offset = curr->index;
 755			ins_sizes[i] = curr->data_len;
 756			i++;
 757		}
 758	}
 759
 760	ret = btrfs_insert_empty_items(trans, root, path, &batch);
 761	if (ret)
 
 
 
 
 
 
 
 
 762		goto out;
 
 763
 764	list_for_each_entry(curr, &item_list, tree_list) {
 765		char *data_ptr;
 
 
 
 766
 767		data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
 768		write_extent_buffer(path->nodes[0], &curr->data,
 769				    (unsigned long)data_ptr, 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(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, 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, 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(&curr->tree_list);
 815		btrfs_release_delayed_item(curr);
 816	}
 
 
 
 
 817out:
 818	kfree(ins_data);
 819	return ret;
 820}
 821
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 822static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 823				      struct btrfs_path *path,
 824				      struct btrfs_root *root,
 825				      struct btrfs_delayed_node *node)
 826{
 
 827	int ret = 0;
 828
 829	while (ret == 0) {
 830		struct btrfs_delayed_item *curr;
 
 
 
 831
 832		mutex_lock(&node->mutex);
 833		curr = __btrfs_first_delayed_insertion_item(node);
 834		if (!curr) {
 835			mutex_unlock(&node->mutex);
 836			break;
 837		}
 838		ret = btrfs_insert_delayed_item(trans, root, path, curr);
 839		mutex_unlock(&node->mutex);
 840	}
 841
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 842	return ret;
 843}
 844
 845static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
 846				    struct btrfs_root *root,
 847				    struct btrfs_path *path,
 848				    struct btrfs_delayed_item *item)
 849{
 850	const u64 ino = item->delayed_node->inode_id;
 851	struct btrfs_fs_info *fs_info = root->fs_info;
 852	struct btrfs_delayed_item *curr, *next;
 853	struct extent_buffer *leaf = path->nodes[0];
 854	LIST_HEAD(batch_list);
 855	int nitems, slot, last_slot;
 856	int ret;
 857	u64 total_reserved_size = item->bytes_reserved;
 858
 859	ASSERT(leaf != NULL);
 860
 861	slot = path->slots[0];
 862	last_slot = btrfs_header_nritems(leaf) - 1;
 863	/*
 864	 * Our caller always gives us a path pointing to an existing item, so
 865	 * this can not happen.
 866	 */
 867	ASSERT(slot <= last_slot);
 868	if (WARN_ON(slot > last_slot))
 869		return -ENOENT;
 870
 871	nitems = 1;
 872	curr = item;
 873	list_add_tail(&curr->tree_list, &batch_list);
 874
 
 
 
 
 
 
 
 
 
 875	/*
 876	 * Keep checking if the next delayed item matches the next item in the
 877	 * leaf - if so, we can add it to the batch of items to delete from the
 878	 * leaf.
 879	 */
 880	while (slot < last_slot) {
 881		struct btrfs_key key;
 
 882
 
 883		next = __btrfs_next_delayed_item(curr);
 884		if (!next)
 885			break;
 886
 887		slot++;
 888		btrfs_item_key_to_cpu(leaf, &key, slot);
 889		if (key.objectid != ino ||
 890		    key.type != BTRFS_DIR_INDEX_KEY ||
 891		    key.offset != next->index)
 892			break;
 893		nitems++;
 894		curr = next;
 895		list_add_tail(&curr->tree_list, &batch_list);
 896		total_reserved_size += curr->bytes_reserved;
 
 897	}
 898
 
 
 
 899	ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
 900	if (ret)
 901		return ret;
 902
 903	/* In case of BTRFS_FS_LOG_RECOVERING items won't have reserved space */
 904	if (total_reserved_size > 0) {
 905		/*
 906		 * Check btrfs_delayed_item_reserve_metadata() to see why we
 907		 * don't need to release/reserve qgroup space.
 908		 */
 909		trace_btrfs_space_reservation(fs_info, "delayed_item", ino,
 910					      total_reserved_size, 0);
 911		btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv,
 912					total_reserved_size, NULL);
 913	}
 914
 915	list_for_each_entry_safe(curr, next, &batch_list, tree_list) {
 
 916		list_del(&curr->tree_list);
 917		btrfs_release_delayed_item(curr);
 918	}
 919
 920	return 0;
 
 921}
 922
 923static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
 924				      struct btrfs_path *path,
 925				      struct btrfs_root *root,
 926				      struct btrfs_delayed_node *node)
 927{
 928	struct btrfs_key key;
 929	int ret = 0;
 930
 931	key.objectid = node->inode_id;
 932	key.type = BTRFS_DIR_INDEX_KEY;
 933
 934	while (ret == 0) {
 935		struct btrfs_delayed_item *item;
 936
 937		mutex_lock(&node->mutex);
 938		item = __btrfs_first_delayed_deletion_item(node);
 939		if (!item) {
 940			mutex_unlock(&node->mutex);
 941			break;
 942		}
 943
 944		key.offset = item->index;
 945		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 946		if (ret > 0) {
 947			/*
 948			 * There's no matching item in the leaf. This means we
 949			 * have already deleted this item in a past run of the
 950			 * delayed items. We ignore errors when running delayed
 951			 * items from an async context, through a work queue job
 952			 * running btrfs_async_run_delayed_root(), and don't
 953			 * release delayed items that failed to complete. This
 954			 * is because we will retry later, and at transaction
 955			 * commit time we always run delayed items and will
 956			 * then deal with errors if they fail to run again.
 957			 *
 958			 * So just release delayed items for which we can't find
 959			 * an item in the tree, and move to the next item.
 960			 */
 961			btrfs_release_path(path);
 962			btrfs_release_delayed_item(item);
 963			ret = 0;
 964		} else if (ret == 0) {
 965			ret = btrfs_batch_delete_items(trans, root, path, item);
 966			btrfs_release_path(path);
 967		}
 968
 
 
 
 
 969		/*
 970		 * We unlock and relock on each iteration, this is to prevent
 971		 * blocking other tasks for too long while we are being run from
 972		 * the async context (work queue job). Those tasks are typically
 973		 * running system calls like creat/mkdir/rename/unlink/etc which
 974		 * need to add delayed items to this delayed node.
 975		 */
 976		mutex_unlock(&node->mutex);
 
 
 
 
 
 
 
 
 
 977	}
 978
 
 
 
 
 
 
 
 
 979	return ret;
 980}
 981
 982static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
 983{
 984	struct btrfs_delayed_root *delayed_root;
 985
 986	if (delayed_node &&
 987	    test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
 988		ASSERT(delayed_node->root);
 989		clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
 990		delayed_node->count--;
 991
 992		delayed_root = delayed_node->root->fs_info->delayed_root;
 993		finish_one_item(delayed_root);
 994	}
 995}
 996
 997static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
 998{
 
 999
1000	if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags)) {
1001		struct btrfs_delayed_root *delayed_root;
1002
1003		ASSERT(delayed_node->root);
1004		delayed_node->count--;
1005
1006		delayed_root = delayed_node->root->fs_info->delayed_root;
1007		finish_one_item(delayed_root);
1008	}
1009}
1010
1011static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1012					struct btrfs_root *root,
1013					struct btrfs_path *path,
1014					struct btrfs_delayed_node *node)
1015{
1016	struct btrfs_fs_info *fs_info = root->fs_info;
1017	struct btrfs_key key;
1018	struct btrfs_inode_item *inode_item;
1019	struct extent_buffer *leaf;
1020	int mod;
1021	int ret;
1022
1023	key.objectid = node->inode_id;
1024	key.type = BTRFS_INODE_ITEM_KEY;
1025	key.offset = 0;
1026
1027	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1028		mod = -1;
1029	else
1030		mod = 1;
1031
1032	ret = btrfs_lookup_inode(trans, root, path, &key, mod);
1033	if (ret > 0)
1034		ret = -ENOENT;
1035	if (ret < 0)
1036		goto out;
 
 
1037
1038	leaf = path->nodes[0];
1039	inode_item = btrfs_item_ptr(leaf, path->slots[0],
1040				    struct btrfs_inode_item);
1041	write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1042			    sizeof(struct btrfs_inode_item));
1043	btrfs_mark_buffer_dirty(trans, leaf);
1044
1045	if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1046		goto out;
1047
1048	/*
1049	 * Now we're going to delete the INODE_REF/EXTREF, which should be the
1050	 * only one ref left.  Check if the next item is an INODE_REF/EXTREF.
1051	 *
1052	 * But if we're the last item already, release and search for the last
1053	 * INODE_REF/EXTREF.
1054	 */
1055	if (path->slots[0] + 1 >= btrfs_header_nritems(leaf)) {
1056		key.objectid = node->inode_id;
1057		key.type = BTRFS_INODE_EXTREF_KEY;
1058		key.offset = (u64)-1;
1059
1060		btrfs_release_path(path);
1061		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1062		if (ret < 0)
1063			goto err_out;
1064		ASSERT(ret > 0);
1065		ASSERT(path->slots[0] > 0);
1066		ret = 0;
1067		path->slots[0]--;
1068		leaf = path->nodes[0];
1069	} else {
1070		path->slots[0]++;
1071	}
1072	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1073	if (key.objectid != node->inode_id)
1074		goto out;
 
1075	if (key.type != BTRFS_INODE_REF_KEY &&
1076	    key.type != BTRFS_INODE_EXTREF_KEY)
1077		goto out;
1078
1079	/*
1080	 * Delayed iref deletion is for the inode who has only one link,
1081	 * so there is only one iref. The case that several irefs are
1082	 * in the same item doesn't exist.
1083	 */
1084	ret = btrfs_del_item(trans, root, path);
1085out:
1086	btrfs_release_delayed_iref(node);
 
1087	btrfs_release_path(path);
1088err_out:
1089	btrfs_delayed_inode_release_metadata(fs_info, node, (ret < 0));
1090	btrfs_release_delayed_inode(node);
1091
1092	/*
1093	 * If we fail to update the delayed inode we need to abort the
1094	 * transaction, because we could leave the inode with the improper
1095	 * counts behind.
1096	 */
1097	if (ret && ret != -ENOENT)
1098		btrfs_abort_transaction(trans, ret);
1099
1100	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1101}
1102
1103static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1104					     struct btrfs_root *root,
1105					     struct btrfs_path *path,
1106					     struct btrfs_delayed_node *node)
1107{
1108	int ret;
1109
1110	mutex_lock(&node->mutex);
1111	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1112		mutex_unlock(&node->mutex);
1113		return 0;
1114	}
1115
1116	ret = __btrfs_update_delayed_inode(trans, root, path, node);
1117	mutex_unlock(&node->mutex);
1118	return ret;
1119}
1120
1121static inline int
1122__btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1123				   struct btrfs_path *path,
1124				   struct btrfs_delayed_node *node)
1125{
1126	int ret;
1127
1128	ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1129	if (ret)
1130		return ret;
1131
1132	ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1133	if (ret)
1134		return ret;
1135
1136	ret = btrfs_record_root_in_trans(trans, node->root);
1137	if (ret)
1138		return ret;
1139	ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1140	return ret;
1141}
1142
1143/*
1144 * Called when committing the transaction.
1145 * Returns 0 on success.
1146 * Returns < 0 on error and returns with an aborted transaction with any
1147 * outstanding delayed items cleaned up.
1148 */
1149static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
1150{
1151	struct btrfs_fs_info *fs_info = trans->fs_info;
1152	struct btrfs_delayed_root *delayed_root;
1153	struct btrfs_delayed_node *curr_node, *prev_node;
1154	struct btrfs_path *path;
1155	struct btrfs_block_rsv *block_rsv;
1156	int ret = 0;
1157	bool count = (nr > 0);
1158
1159	if (TRANS_ABORTED(trans))
1160		return -EIO;
1161
1162	path = btrfs_alloc_path();
1163	if (!path)
1164		return -ENOMEM;
 
1165
1166	block_rsv = trans->block_rsv;
1167	trans->block_rsv = &fs_info->delayed_block_rsv;
1168
1169	delayed_root = fs_info->delayed_root;
1170
1171	curr_node = btrfs_first_delayed_node(delayed_root);
1172	while (curr_node && (!count || nr--)) {
1173		ret = __btrfs_commit_inode_delayed_items(trans, path,
1174							 curr_node);
1175		if (ret) {
 
 
1176			btrfs_abort_transaction(trans, ret);
1177			break;
1178		}
1179
1180		prev_node = curr_node;
1181		curr_node = btrfs_next_delayed_node(curr_node);
1182		/*
1183		 * See the comment below about releasing path before releasing
1184		 * node. If the commit of delayed items was successful the path
1185		 * should always be released, but in case of an error, it may
1186		 * point to locked extent buffers (a leaf at the very least).
1187		 */
1188		ASSERT(path->nodes[0] == NULL);
1189		btrfs_release_delayed_node(prev_node);
1190	}
1191
1192	/*
1193	 * Release the path to avoid a potential deadlock and lockdep splat when
1194	 * releasing the delayed node, as that requires taking the delayed node's
1195	 * mutex. If another task starts running delayed items before we take
1196	 * the mutex, it will first lock the mutex and then it may try to lock
1197	 * the same btree path (leaf).
1198	 */
1199	btrfs_free_path(path);
1200
1201	if (curr_node)
1202		btrfs_release_delayed_node(curr_node);
 
1203	trans->block_rsv = block_rsv;
1204
1205	return ret;
1206}
1207
1208int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)
1209{
1210	return __btrfs_run_delayed_items(trans, -1);
1211}
1212
1213int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)
1214{
1215	return __btrfs_run_delayed_items(trans, nr);
1216}
1217
1218int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1219				     struct btrfs_inode *inode)
1220{
1221	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1222	struct btrfs_path *path;
1223	struct btrfs_block_rsv *block_rsv;
1224	int ret;
1225
1226	if (!delayed_node)
1227		return 0;
1228
1229	mutex_lock(&delayed_node->mutex);
1230	if (!delayed_node->count) {
1231		mutex_unlock(&delayed_node->mutex);
1232		btrfs_release_delayed_node(delayed_node);
1233		return 0;
1234	}
1235	mutex_unlock(&delayed_node->mutex);
1236
1237	path = btrfs_alloc_path();
1238	if (!path) {
1239		btrfs_release_delayed_node(delayed_node);
1240		return -ENOMEM;
1241	}
 
1242
1243	block_rsv = trans->block_rsv;
1244	trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1245
1246	ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1247
1248	btrfs_release_delayed_node(delayed_node);
1249	btrfs_free_path(path);
1250	trans->block_rsv = block_rsv;
1251
1252	return ret;
1253}
1254
1255int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
1256{
1257	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1258	struct btrfs_trans_handle *trans;
1259	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1260	struct btrfs_path *path;
1261	struct btrfs_block_rsv *block_rsv;
1262	int ret;
1263
1264	if (!delayed_node)
1265		return 0;
1266
1267	mutex_lock(&delayed_node->mutex);
1268	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1269		mutex_unlock(&delayed_node->mutex);
1270		btrfs_release_delayed_node(delayed_node);
1271		return 0;
1272	}
1273	mutex_unlock(&delayed_node->mutex);
1274
1275	trans = btrfs_join_transaction(delayed_node->root);
1276	if (IS_ERR(trans)) {
1277		ret = PTR_ERR(trans);
1278		goto out;
1279	}
1280
1281	path = btrfs_alloc_path();
1282	if (!path) {
1283		ret = -ENOMEM;
1284		goto trans_out;
1285	}
 
1286
1287	block_rsv = trans->block_rsv;
1288	trans->block_rsv = &fs_info->delayed_block_rsv;
1289
1290	mutex_lock(&delayed_node->mutex);
1291	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1292		ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1293						   path, delayed_node);
1294	else
1295		ret = 0;
1296	mutex_unlock(&delayed_node->mutex);
1297
1298	btrfs_free_path(path);
1299	trans->block_rsv = block_rsv;
1300trans_out:
1301	btrfs_end_transaction(trans);
1302	btrfs_btree_balance_dirty(fs_info);
1303out:
1304	btrfs_release_delayed_node(delayed_node);
1305
1306	return ret;
1307}
1308
1309void btrfs_remove_delayed_node(struct btrfs_inode *inode)
1310{
1311	struct btrfs_delayed_node *delayed_node;
1312
1313	delayed_node = READ_ONCE(inode->delayed_node);
1314	if (!delayed_node)
1315		return;
1316
1317	inode->delayed_node = NULL;
1318	btrfs_release_delayed_node(delayed_node);
1319}
1320
1321struct btrfs_async_delayed_work {
1322	struct btrfs_delayed_root *delayed_root;
1323	int nr;
1324	struct btrfs_work work;
1325};
1326
1327static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1328{
1329	struct btrfs_async_delayed_work *async_work;
1330	struct btrfs_delayed_root *delayed_root;
1331	struct btrfs_trans_handle *trans;
1332	struct btrfs_path *path;
1333	struct btrfs_delayed_node *delayed_node = NULL;
1334	struct btrfs_root *root;
1335	struct btrfs_block_rsv *block_rsv;
1336	int total_done = 0;
1337
1338	async_work = container_of(work, struct btrfs_async_delayed_work, work);
1339	delayed_root = async_work->delayed_root;
1340
1341	path = btrfs_alloc_path();
1342	if (!path)
1343		goto out;
1344
1345	do {
1346		if (atomic_read(&delayed_root->items) <
1347		    BTRFS_DELAYED_BACKGROUND / 2)
1348			break;
1349
1350		delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1351		if (!delayed_node)
1352			break;
1353
 
1354		root = delayed_node->root;
1355
1356		trans = btrfs_join_transaction(root);
1357		if (IS_ERR(trans)) {
1358			btrfs_release_path(path);
1359			btrfs_release_prepared_delayed_node(delayed_node);
1360			total_done++;
1361			continue;
1362		}
1363
1364		block_rsv = trans->block_rsv;
1365		trans->block_rsv = &root->fs_info->delayed_block_rsv;
1366
1367		__btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1368
1369		trans->block_rsv = block_rsv;
1370		btrfs_end_transaction(trans);
1371		btrfs_btree_balance_dirty_nodelay(root->fs_info);
1372
1373		btrfs_release_path(path);
1374		btrfs_release_prepared_delayed_node(delayed_node);
1375		total_done++;
1376
1377	} while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
1378		 || total_done < async_work->nr);
1379
1380	btrfs_free_path(path);
1381out:
1382	wake_up(&delayed_root->wait);
1383	kfree(async_work);
1384}
1385
1386
1387static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1388				     struct btrfs_fs_info *fs_info, int nr)
1389{
1390	struct btrfs_async_delayed_work *async_work;
1391
1392	async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1393	if (!async_work)
1394		return -ENOMEM;
1395
1396	async_work->delayed_root = delayed_root;
1397	btrfs_init_work(&async_work->work, btrfs_async_run_delayed_root, NULL);
 
1398	async_work->nr = nr;
1399
1400	btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
1401	return 0;
1402}
1403
1404void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
1405{
1406	WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));
1407}
1408
1409static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1410{
1411	int val = atomic_read(&delayed_root->items_seq);
1412
1413	if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1414		return 1;
1415
1416	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1417		return 1;
1418
1419	return 0;
1420}
1421
1422void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
1423{
1424	struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
1425
1426	if ((atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
1427		btrfs_workqueue_normal_congested(fs_info->delayed_workers))
1428		return;
1429
1430	if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1431		int seq;
1432		int ret;
1433
1434		seq = atomic_read(&delayed_root->items_seq);
1435
1436		ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
1437		if (ret)
1438			return;
1439
1440		wait_event_interruptible(delayed_root->wait,
1441					 could_end_wait(delayed_root, seq));
1442		return;
1443	}
1444
1445	btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1446}
1447
1448static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans)
1449{
1450	struct btrfs_fs_info *fs_info = trans->fs_info;
1451	const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
1452
1453	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1454		return;
1455
1456	/*
1457	 * Adding the new dir index item does not require touching another
1458	 * leaf, so we can release 1 unit of metadata that was previously
1459	 * reserved when starting the transaction. This applies only to
1460	 * the case where we had a transaction start and excludes the
1461	 * transaction join case (when replaying log trees).
1462	 */
1463	trace_btrfs_space_reservation(fs_info, "transaction",
1464				      trans->transid, bytes, 0);
1465	btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
1466	ASSERT(trans->bytes_reserved >= bytes);
1467	trans->bytes_reserved -= bytes;
1468}
1469
1470/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */
1471int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1472				   const char *name, int name_len,
1473				   struct btrfs_inode *dir,
1474				   struct btrfs_disk_key *disk_key, u8 flags,
1475				   u64 index)
1476{
1477	struct btrfs_fs_info *fs_info = trans->fs_info;
1478	const unsigned int leaf_data_size = BTRFS_LEAF_DATA_SIZE(fs_info);
1479	struct btrfs_delayed_node *delayed_node;
1480	struct btrfs_delayed_item *delayed_item;
1481	struct btrfs_dir_item *dir_item;
1482	bool reserve_leaf_space;
1483	u32 data_len;
1484	int ret;
1485
1486	delayed_node = btrfs_get_or_create_delayed_node(dir);
1487	if (IS_ERR(delayed_node))
1488		return PTR_ERR(delayed_node);
1489
1490	delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len,
1491						delayed_node,
1492						BTRFS_DELAYED_INSERTION_ITEM);
1493	if (!delayed_item) {
1494		ret = -ENOMEM;
1495		goto release_node;
1496	}
1497
1498	delayed_item->index = index;
 
 
1499
1500	dir_item = (struct btrfs_dir_item *)delayed_item->data;
1501	dir_item->location = *disk_key;
1502	btrfs_set_stack_dir_transid(dir_item, trans->transid);
1503	btrfs_set_stack_dir_data_len(dir_item, 0);
1504	btrfs_set_stack_dir_name_len(dir_item, name_len);
1505	btrfs_set_stack_dir_flags(dir_item, flags);
1506	memcpy((char *)(dir_item + 1), name, name_len);
1507
1508	data_len = delayed_item->data_len + sizeof(struct btrfs_item);
1509
1510	mutex_lock(&delayed_node->mutex);
1511
1512	/*
1513	 * First attempt to insert the delayed item. This is to make the error
1514	 * handling path simpler in case we fail (-EEXIST). There's no risk of
1515	 * any other task coming in and running the delayed item before we do
1516	 * the metadata space reservation below, because we are holding the
1517	 * delayed node's mutex and that mutex must also be locked before the
1518	 * node's delayed items can be run.
1519	 */
1520	ret = __btrfs_add_delayed_item(delayed_node, delayed_item);
 
 
 
1521	if (unlikely(ret)) {
1522		btrfs_err(trans->fs_info,
1523"error adding delayed dir index item, name: %.*s, index: %llu, root: %llu, dir: %llu, dir->index_cnt: %llu, delayed_node->index_cnt: %llu, error: %d",
1524			  name_len, name, index, btrfs_root_id(delayed_node->root),
1525			  delayed_node->inode_id, dir->index_cnt,
1526			  delayed_node->index_cnt, ret);
1527		btrfs_release_delayed_item(delayed_item);
1528		btrfs_release_dir_index_item_space(trans);
1529		mutex_unlock(&delayed_node->mutex);
1530		goto release_node;
1531	}
1532
1533	if (delayed_node->index_item_leaves == 0 ||
1534	    delayed_node->curr_index_batch_size + data_len > leaf_data_size) {
1535		delayed_node->curr_index_batch_size = data_len;
1536		reserve_leaf_space = true;
1537	} else {
1538		delayed_node->curr_index_batch_size += data_len;
1539		reserve_leaf_space = false;
1540	}
1541
1542	if (reserve_leaf_space) {
1543		ret = btrfs_delayed_item_reserve_metadata(trans, delayed_item);
1544		/*
1545		 * Space was reserved for a dir index item insertion when we
1546		 * started the transaction, so getting a failure here should be
1547		 * impossible.
1548		 */
1549		if (WARN_ON(ret)) {
1550			btrfs_release_delayed_item(delayed_item);
1551			mutex_unlock(&delayed_node->mutex);
1552			goto release_node;
1553		}
1554
1555		delayed_node->index_item_leaves++;
1556	} else {
1557		btrfs_release_dir_index_item_space(trans);
1558	}
1559	mutex_unlock(&delayed_node->mutex);
1560
1561release_node:
1562	btrfs_release_delayed_node(delayed_node);
1563	return ret;
1564}
1565
1566static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,
1567					       struct btrfs_delayed_node *node,
1568					       u64 index)
1569{
1570	struct btrfs_delayed_item *item;
1571
1572	mutex_lock(&node->mutex);
1573	item = __btrfs_lookup_delayed_item(&node->ins_root.rb_root, index);
1574	if (!item) {
1575		mutex_unlock(&node->mutex);
1576		return 1;
1577	}
1578
1579	/*
1580	 * For delayed items to insert, we track reserved metadata bytes based
1581	 * on the number of leaves that we will use.
1582	 * See btrfs_insert_delayed_dir_index() and
1583	 * btrfs_delayed_item_reserve_metadata()).
1584	 */
1585	ASSERT(item->bytes_reserved == 0);
1586	ASSERT(node->index_item_leaves > 0);
1587
1588	/*
1589	 * If there's only one leaf reserved, we can decrement this item from the
1590	 * current batch, otherwise we can not because we don't know which leaf
1591	 * it belongs to. With the current limit on delayed items, we rarely
1592	 * accumulate enough dir index items to fill more than one leaf (even
1593	 * when using a leaf size of 4K).
1594	 */
1595	if (node->index_item_leaves == 1) {
1596		const u32 data_len = item->data_len + sizeof(struct btrfs_item);
1597
1598		ASSERT(node->curr_index_batch_size >= data_len);
1599		node->curr_index_batch_size -= data_len;
1600	}
1601
1602	btrfs_release_delayed_item(item);
1603
1604	/* If we now have no more dir index items, we can release all leaves. */
1605	if (RB_EMPTY_ROOT(&node->ins_root.rb_root)) {
1606		btrfs_delayed_item_release_leaves(node, node->index_item_leaves);
1607		node->index_item_leaves = 0;
1608	}
1609
1610	mutex_unlock(&node->mutex);
1611	return 0;
1612}
1613
1614int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1615				   struct btrfs_inode *dir, u64 index)
1616{
1617	struct btrfs_delayed_node *node;
1618	struct btrfs_delayed_item *item;
 
1619	int ret;
1620
1621	node = btrfs_get_or_create_delayed_node(dir);
1622	if (IS_ERR(node))
1623		return PTR_ERR(node);
1624
1625	ret = btrfs_delete_delayed_insertion_item(trans->fs_info, node, index);
 
 
 
 
 
1626	if (!ret)
1627		goto end;
1628
1629	item = btrfs_alloc_delayed_item(0, node, BTRFS_DELAYED_DELETION_ITEM);
1630	if (!item) {
1631		ret = -ENOMEM;
1632		goto end;
1633	}
1634
1635	item->index = index;
1636
1637	ret = btrfs_delayed_item_reserve_metadata(trans, item);
1638	/*
1639	 * we have reserved enough space when we start a new transaction,
1640	 * so reserving metadata failure is impossible.
1641	 */
1642	if (ret < 0) {
1643		btrfs_err(trans->fs_info,
1644"metadata reservation failed for delayed dir item deltiona, should have been reserved");
1645		btrfs_release_delayed_item(item);
1646		goto end;
1647	}
1648
1649	mutex_lock(&node->mutex);
1650	ret = __btrfs_add_delayed_item(node, item);
1651	if (unlikely(ret)) {
1652		btrfs_err(trans->fs_info,
1653			  "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1654			  index, node->root->root_key.objectid,
1655			  node->inode_id, ret);
1656		btrfs_delayed_item_release_metadata(dir->root, item);
1657		btrfs_release_delayed_item(item);
1658	}
1659	mutex_unlock(&node->mutex);
1660end:
1661	btrfs_release_delayed_node(node);
1662	return ret;
1663}
1664
1665int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)
1666{
1667	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1668
1669	if (!delayed_node)
1670		return -ENOENT;
1671
1672	/*
1673	 * Since we have held i_mutex of this directory, it is impossible that
1674	 * a new directory index is added into the delayed node and index_cnt
1675	 * is updated now. So we needn't lock the delayed node.
1676	 */
1677	if (!delayed_node->index_cnt) {
1678		btrfs_release_delayed_node(delayed_node);
1679		return -EINVAL;
1680	}
1681
1682	inode->index_cnt = delayed_node->index_cnt;
1683	btrfs_release_delayed_node(delayed_node);
1684	return 0;
1685}
1686
1687bool btrfs_readdir_get_delayed_items(struct inode *inode,
1688				     u64 last_index,
1689				     struct list_head *ins_list,
1690				     struct list_head *del_list)
1691{
1692	struct btrfs_delayed_node *delayed_node;
1693	struct btrfs_delayed_item *item;
1694
1695	delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
1696	if (!delayed_node)
1697		return false;
1698
1699	/*
1700	 * We can only do one readdir with delayed items at a time because of
1701	 * item->readdir_list.
1702	 */
1703	btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_SHARED);
1704	btrfs_inode_lock(BTRFS_I(inode), 0);
1705
1706	mutex_lock(&delayed_node->mutex);
1707	item = __btrfs_first_delayed_insertion_item(delayed_node);
1708	while (item && item->index <= last_index) {
1709		refcount_inc(&item->refs);
1710		list_add_tail(&item->readdir_list, ins_list);
1711		item = __btrfs_next_delayed_item(item);
1712	}
1713
1714	item = __btrfs_first_delayed_deletion_item(delayed_node);
1715	while (item && item->index <= last_index) {
1716		refcount_inc(&item->refs);
1717		list_add_tail(&item->readdir_list, del_list);
1718		item = __btrfs_next_delayed_item(item);
1719	}
1720	mutex_unlock(&delayed_node->mutex);
1721	/*
1722	 * This delayed node is still cached in the btrfs inode, so refs
1723	 * must be > 1 now, and we needn't check it is going to be freed
1724	 * or not.
1725	 *
1726	 * Besides that, this function is used to read dir, we do not
1727	 * insert/delete delayed items in this period. So we also needn't
1728	 * requeue or dequeue this delayed node.
1729	 */
1730	refcount_dec(&delayed_node->refs);
1731
1732	return true;
1733}
1734
1735void btrfs_readdir_put_delayed_items(struct inode *inode,
1736				     struct list_head *ins_list,
1737				     struct list_head *del_list)
1738{
1739	struct btrfs_delayed_item *curr, *next;
1740
1741	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1742		list_del(&curr->readdir_list);
1743		if (refcount_dec_and_test(&curr->refs))
1744			kfree(curr);
1745	}
1746
1747	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1748		list_del(&curr->readdir_list);
1749		if (refcount_dec_and_test(&curr->refs))
1750			kfree(curr);
1751	}
1752
1753	/*
1754	 * The VFS is going to do up_read(), so we need to downgrade back to a
1755	 * read lock.
1756	 */
1757	downgrade_write(&inode->i_rwsem);
1758}
1759
1760int btrfs_should_delete_dir_index(struct list_head *del_list,
1761				  u64 index)
1762{
1763	struct btrfs_delayed_item *curr;
1764	int ret = 0;
1765
1766	list_for_each_entry(curr, del_list, readdir_list) {
1767		if (curr->index > index)
1768			break;
1769		if (curr->index == index) {
1770			ret = 1;
1771			break;
1772		}
1773	}
1774	return ret;
1775}
1776
1777/*
1778 * Read dir info stored in the delayed tree.
 
1779 */
1780int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1781				    struct list_head *ins_list)
1782{
1783	struct btrfs_dir_item *di;
1784	struct btrfs_delayed_item *curr, *next;
1785	struct btrfs_key location;
1786	char *name;
1787	int name_len;
1788	int over = 0;
1789	unsigned char d_type;
1790
 
 
 
1791	/*
1792	 * Changing the data of the delayed item is impossible. So
1793	 * we needn't lock them. And we have held i_mutex of the
1794	 * directory, nobody can delete any directory indexes now.
1795	 */
1796	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1797		list_del(&curr->readdir_list);
1798
1799		if (curr->index < ctx->pos) {
1800			if (refcount_dec_and_test(&curr->refs))
1801				kfree(curr);
1802			continue;
1803		}
1804
1805		ctx->pos = curr->index;
1806
1807		di = (struct btrfs_dir_item *)curr->data;
1808		name = (char *)(di + 1);
1809		name_len = btrfs_stack_dir_name_len(di);
1810
1811		d_type = fs_ftype_to_dtype(btrfs_dir_flags_to_ftype(di->type));
1812		btrfs_disk_key_to_cpu(&location, &di->location);
1813
1814		over = !dir_emit(ctx, name, name_len,
1815			       location.objectid, d_type);
1816
1817		if (refcount_dec_and_test(&curr->refs))
1818			kfree(curr);
1819
1820		if (over)
1821			return 1;
1822		ctx->pos++;
1823	}
1824	return 0;
1825}
1826
1827static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1828				  struct btrfs_inode_item *inode_item,
1829				  struct inode *inode)
1830{
1831	u64 flags;
1832
1833	btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1834	btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1835	btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1836	btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1837	btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1838	btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1839	btrfs_set_stack_inode_generation(inode_item,
1840					 BTRFS_I(inode)->generation);
1841	btrfs_set_stack_inode_sequence(inode_item,
1842				       inode_peek_iversion(inode));
1843	btrfs_set_stack_inode_transid(inode_item, trans->transid);
1844	btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1845	flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
1846					  BTRFS_I(inode)->ro_flags);
1847	btrfs_set_stack_inode_flags(inode_item, flags);
1848	btrfs_set_stack_inode_block_group(inode_item, 0);
1849
1850	btrfs_set_stack_timespec_sec(&inode_item->atime,
1851				     inode_get_atime_sec(inode));
1852	btrfs_set_stack_timespec_nsec(&inode_item->atime,
1853				      inode_get_atime_nsec(inode));
1854
1855	btrfs_set_stack_timespec_sec(&inode_item->mtime,
1856				     inode_get_mtime_sec(inode));
1857	btrfs_set_stack_timespec_nsec(&inode_item->mtime,
1858				      inode_get_mtime_nsec(inode));
1859
1860	btrfs_set_stack_timespec_sec(&inode_item->ctime,
1861				     inode_get_ctime_sec(inode));
1862	btrfs_set_stack_timespec_nsec(&inode_item->ctime,
1863				      inode_get_ctime_nsec(inode));
1864
1865	btrfs_set_stack_timespec_sec(&inode_item->otime, BTRFS_I(inode)->i_otime_sec);
1866	btrfs_set_stack_timespec_nsec(&inode_item->otime, BTRFS_I(inode)->i_otime_nsec);
 
 
1867}
1868
1869int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1870{
1871	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1872	struct btrfs_delayed_node *delayed_node;
1873	struct btrfs_inode_item *inode_item;
1874
1875	delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
1876	if (!delayed_node)
1877		return -ENOENT;
1878
1879	mutex_lock(&delayed_node->mutex);
1880	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1881		mutex_unlock(&delayed_node->mutex);
1882		btrfs_release_delayed_node(delayed_node);
1883		return -ENOENT;
1884	}
1885
1886	inode_item = &delayed_node->inode_item;
1887
1888	i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1889	i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1890	btrfs_i_size_write(BTRFS_I(inode), btrfs_stack_inode_size(inode_item));
1891	btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
1892			round_up(i_size_read(inode), fs_info->sectorsize));
1893	inode->i_mode = btrfs_stack_inode_mode(inode_item);
1894	set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1895	inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1896	BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1897        BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
1898
1899	inode_set_iversion_queried(inode,
1900				   btrfs_stack_inode_sequence(inode_item));
1901	inode->i_rdev = 0;
1902	*rdev = btrfs_stack_inode_rdev(inode_item);
1903	btrfs_inode_split_flags(btrfs_stack_inode_flags(inode_item),
1904				&BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
1905
1906	inode_set_atime(inode, btrfs_stack_timespec_sec(&inode_item->atime),
1907			btrfs_stack_timespec_nsec(&inode_item->atime));
1908
1909	inode_set_mtime(inode, btrfs_stack_timespec_sec(&inode_item->mtime),
1910			btrfs_stack_timespec_nsec(&inode_item->mtime));
1911
1912	inode_set_ctime(inode, btrfs_stack_timespec_sec(&inode_item->ctime),
1913			btrfs_stack_timespec_nsec(&inode_item->ctime));
1914
1915	BTRFS_I(inode)->i_otime_sec = btrfs_stack_timespec_sec(&inode_item->otime);
1916	BTRFS_I(inode)->i_otime_nsec = btrfs_stack_timespec_nsec(&inode_item->otime);
 
 
1917
1918	inode->i_generation = BTRFS_I(inode)->generation;
1919	BTRFS_I(inode)->index_cnt = (u64)-1;
1920
1921	mutex_unlock(&delayed_node->mutex);
1922	btrfs_release_delayed_node(delayed_node);
1923	return 0;
1924}
1925
1926int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1927			       struct btrfs_inode *inode)
1928{
1929	struct btrfs_root *root = inode->root;
1930	struct btrfs_delayed_node *delayed_node;
1931	int ret = 0;
1932
1933	delayed_node = btrfs_get_or_create_delayed_node(inode);
1934	if (IS_ERR(delayed_node))
1935		return PTR_ERR(delayed_node);
1936
1937	mutex_lock(&delayed_node->mutex);
1938	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1939		fill_stack_inode_item(trans, &delayed_node->inode_item,
1940				      &inode->vfs_inode);
1941		goto release_node;
1942	}
1943
1944	ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
 
1945	if (ret)
1946		goto release_node;
1947
1948	fill_stack_inode_item(trans, &delayed_node->inode_item, &inode->vfs_inode);
1949	set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1950	delayed_node->count++;
1951	atomic_inc(&root->fs_info->delayed_root->items);
1952release_node:
1953	mutex_unlock(&delayed_node->mutex);
1954	btrfs_release_delayed_node(delayed_node);
1955	return ret;
1956}
1957
1958int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)
1959{
1960	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1961	struct btrfs_delayed_node *delayed_node;
1962
1963	/*
1964	 * we don't do delayed inode updates during log recovery because it
1965	 * leads to enospc problems.  This means we also can't do
1966	 * delayed inode refs
1967	 */
1968	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1969		return -EAGAIN;
1970
1971	delayed_node = btrfs_get_or_create_delayed_node(inode);
1972	if (IS_ERR(delayed_node))
1973		return PTR_ERR(delayed_node);
1974
1975	/*
1976	 * We don't reserve space for inode ref deletion is because:
1977	 * - We ONLY do async inode ref deletion for the inode who has only
1978	 *   one link(i_nlink == 1), it means there is only one inode ref.
1979	 *   And in most case, the inode ref and the inode item are in the
1980	 *   same leaf, and we will deal with them at the same time.
1981	 *   Since we are sure we will reserve the space for the inode item,
1982	 *   it is unnecessary to reserve space for inode ref deletion.
1983	 * - If the inode ref and the inode item are not in the same leaf,
1984	 *   We also needn't worry about enospc problem, because we reserve
1985	 *   much more space for the inode update than it needs.
1986	 * - At the worst, we can steal some space from the global reservation.
1987	 *   It is very rare.
1988	 */
1989	mutex_lock(&delayed_node->mutex);
1990	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1991		goto release_node;
1992
1993	set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1994	delayed_node->count++;
1995	atomic_inc(&fs_info->delayed_root->items);
1996release_node:
1997	mutex_unlock(&delayed_node->mutex);
1998	btrfs_release_delayed_node(delayed_node);
1999	return 0;
2000}
2001
2002static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
2003{
2004	struct btrfs_root *root = delayed_node->root;
2005	struct btrfs_fs_info *fs_info = root->fs_info;
2006	struct btrfs_delayed_item *curr_item, *prev_item;
2007
2008	mutex_lock(&delayed_node->mutex);
2009	curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
2010	while (curr_item) {
 
2011		prev_item = curr_item;
2012		curr_item = __btrfs_next_delayed_item(prev_item);
2013		btrfs_release_delayed_item(prev_item);
2014	}
2015
2016	if (delayed_node->index_item_leaves > 0) {
2017		btrfs_delayed_item_release_leaves(delayed_node,
2018					  delayed_node->index_item_leaves);
2019		delayed_node->index_item_leaves = 0;
2020	}
2021
2022	curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
2023	while (curr_item) {
2024		btrfs_delayed_item_release_metadata(root, curr_item);
2025		prev_item = curr_item;
2026		curr_item = __btrfs_next_delayed_item(prev_item);
2027		btrfs_release_delayed_item(prev_item);
2028	}
2029
2030	btrfs_release_delayed_iref(delayed_node);
 
2031
2032	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
2033		btrfs_delayed_inode_release_metadata(fs_info, delayed_node, false);
2034		btrfs_release_delayed_inode(delayed_node);
2035	}
2036	mutex_unlock(&delayed_node->mutex);
2037}
2038
2039void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)
2040{
2041	struct btrfs_delayed_node *delayed_node;
2042
2043	delayed_node = btrfs_get_delayed_node(inode);
2044	if (!delayed_node)
2045		return;
2046
2047	__btrfs_kill_delayed_node(delayed_node);
2048	btrfs_release_delayed_node(delayed_node);
2049}
2050
2051void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
2052{
2053	unsigned long index = 0;
2054	struct btrfs_delayed_node *delayed_nodes[8];
 
2055
2056	while (1) {
2057		struct btrfs_delayed_node *node;
2058		int count;
2059
2060		spin_lock(&root->inode_lock);
2061		if (xa_empty(&root->delayed_nodes)) {
 
 
 
2062			spin_unlock(&root->inode_lock);
2063			return;
2064		}
2065
2066		count = 0;
2067		xa_for_each_start(&root->delayed_nodes, index, node, index) {
2068			/*
2069			 * Don't increase refs in case the node is dead and
2070			 * about to be removed from the tree in the loop below
2071			 */
2072			if (refcount_inc_not_zero(&node->refs)) {
2073				delayed_nodes[count] = node;
2074				count++;
2075			}
2076			if (count >= ARRAY_SIZE(delayed_nodes))
2077				break;
2078		}
2079		spin_unlock(&root->inode_lock);
2080		index++;
2081
2082		for (int i = 0; i < count; i++) {
2083			__btrfs_kill_delayed_node(delayed_nodes[i]);
2084			btrfs_release_delayed_node(delayed_nodes[i]);
2085		}
2086	}
2087}
2088
2089void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
2090{
2091	struct btrfs_delayed_node *curr_node, *prev_node;
2092
2093	curr_node = btrfs_first_delayed_node(fs_info->delayed_root);
2094	while (curr_node) {
2095		__btrfs_kill_delayed_node(curr_node);
2096
2097		prev_node = curr_node;
2098		curr_node = btrfs_next_delayed_node(curr_node);
2099		btrfs_release_delayed_node(prev_node);
2100	}
2101}
2102
2103void btrfs_log_get_delayed_items(struct btrfs_inode *inode,
2104				 struct list_head *ins_list,
2105				 struct list_head *del_list)
2106{
2107	struct btrfs_delayed_node *node;
2108	struct btrfs_delayed_item *item;
2109
2110	node = btrfs_get_delayed_node(inode);
2111	if (!node)
2112		return;
2113
2114	mutex_lock(&node->mutex);
2115	item = __btrfs_first_delayed_insertion_item(node);
2116	while (item) {
2117		/*
2118		 * It's possible that the item is already in a log list. This
2119		 * can happen in case two tasks are trying to log the same
2120		 * directory. For example if we have tasks A and task B:
2121		 *
2122		 * Task A collected the delayed items into a log list while
2123		 * under the inode's log_mutex (at btrfs_log_inode()), but it
2124		 * only releases the items after logging the inodes they point
2125		 * to (if they are new inodes), which happens after unlocking
2126		 * the log mutex;
2127		 *
2128		 * Task B enters btrfs_log_inode() and acquires the log_mutex
2129		 * of the same directory inode, before task B releases the
2130		 * delayed items. This can happen for example when logging some
2131		 * inode we need to trigger logging of its parent directory, so
2132		 * logging two files that have the same parent directory can
2133		 * lead to this.
2134		 *
2135		 * If this happens, just ignore delayed items already in a log
2136		 * list. All the tasks logging the directory are under a log
2137		 * transaction and whichever finishes first can not sync the log
2138		 * before the other completes and leaves the log transaction.
2139		 */
2140		if (!item->logged && list_empty(&item->log_list)) {
2141			refcount_inc(&item->refs);
2142			list_add_tail(&item->log_list, ins_list);
2143		}
2144		item = __btrfs_next_delayed_item(item);
2145	}
2146
2147	item = __btrfs_first_delayed_deletion_item(node);
2148	while (item) {
2149		/* It may be non-empty, for the same reason mentioned above. */
2150		if (!item->logged && list_empty(&item->log_list)) {
2151			refcount_inc(&item->refs);
2152			list_add_tail(&item->log_list, del_list);
2153		}
2154		item = __btrfs_next_delayed_item(item);
2155	}
2156	mutex_unlock(&node->mutex);
2157
2158	/*
2159	 * We are called during inode logging, which means the inode is in use
2160	 * and can not be evicted before we finish logging the inode. So we never
2161	 * have the last reference on the delayed inode.
2162	 * Also, we don't use btrfs_release_delayed_node() because that would
2163	 * requeue the delayed inode (change its order in the list of prepared
2164	 * nodes) and we don't want to do such change because we don't create or
2165	 * delete delayed items.
2166	 */
2167	ASSERT(refcount_read(&node->refs) > 1);
2168	refcount_dec(&node->refs);
2169}
2170
2171void btrfs_log_put_delayed_items(struct btrfs_inode *inode,
2172				 struct list_head *ins_list,
2173				 struct list_head *del_list)
2174{
2175	struct btrfs_delayed_node *node;
2176	struct btrfs_delayed_item *item;
2177	struct btrfs_delayed_item *next;
2178
2179	node = btrfs_get_delayed_node(inode);
2180	if (!node)
2181		return;
2182
2183	mutex_lock(&node->mutex);
2184
2185	list_for_each_entry_safe(item, next, ins_list, log_list) {
2186		item->logged = true;
2187		list_del_init(&item->log_list);
2188		if (refcount_dec_and_test(&item->refs))
2189			kfree(item);
2190	}
2191
2192	list_for_each_entry_safe(item, next, del_list, log_list) {
2193		item->logged = true;
2194		list_del_init(&item->log_list);
2195		if (refcount_dec_and_test(&item->refs))
2196			kfree(item);
2197	}
2198
2199	mutex_unlock(&node->mutex);
2200
2201	/*
2202	 * We are called during inode logging, which means the inode is in use
2203	 * and can not be evicted before we finish logging the inode. So we never
2204	 * have the last reference on the delayed inode.
2205	 * Also, we don't use btrfs_release_delayed_node() because that would
2206	 * requeue the delayed inode (change its order in the list of prepared
2207	 * nodes) and we don't want to do such change because we don't create or
2208	 * delete delayed items.
2209	 */
2210	ASSERT(refcount_read(&node->refs) > 1);
2211	refcount_dec(&node->refs);
2212}