1/*
   2 * Copyright (C) 2011 Fujitsu.  All rights reserved.
   3 * Written by Miao Xie <miaox@cn.fujitsu.com>
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public
   7 * License v2 as published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 * General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public
  15 * License along with this program; if not, write to the
  16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17 * Boston, MA 021110-1307, USA.
  18 */
  19
  20#include <linux/slab.h>
 
 
 
  21#include "delayed-inode.h"
  22#include "disk-io.h"
  23#include "transaction.h"
  24#include "ctree.h"
 
 
  25
  26#define BTRFS_DELAYED_WRITEBACK		512
  27#define BTRFS_DELAYED_BACKGROUND	128
  28#define BTRFS_DELAYED_BATCH		16
  29
  30static struct kmem_cache *delayed_node_cache;
  31
  32int __init btrfs_delayed_inode_init(void)
  33{
  34	delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
  35					sizeof(struct btrfs_delayed_node),
  36					0,
  37					SLAB_MEM_SPREAD,
  38					NULL);
  39	if (!delayed_node_cache)
  40		return -ENOMEM;
  41	return 0;
  42}
  43
  44void btrfs_delayed_inode_exit(void)
  45{
  46	kmem_cache_destroy(delayed_node_cache);
  47}
  48
  49static inline void btrfs_init_delayed_node(
  50				struct btrfs_delayed_node *delayed_node,
  51				struct btrfs_root *root, u64 inode_id)
  52{
  53	delayed_node->root = root;
  54	delayed_node->inode_id = inode_id;
  55	atomic_set(&delayed_node->refs, 0);
  56	delayed_node->ins_root = RB_ROOT;
  57	delayed_node->del_root = RB_ROOT;
  58	mutex_init(&delayed_node->mutex);
  59	INIT_LIST_HEAD(&delayed_node->n_list);
  60	INIT_LIST_HEAD(&delayed_node->p_list);
  61}
  62
  63static inline int btrfs_is_continuous_delayed_item(
  64					struct btrfs_delayed_item *item1,
  65					struct btrfs_delayed_item *item2)
  66{
  67	if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
  68	    item1->key.objectid == item2->key.objectid &&
  69	    item1->key.type == item2->key.type &&
  70	    item1->key.offset + 1 == item2->key.offset)
  71		return 1;
  72	return 0;
  73}
  74
  75static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
 
  76{
  77	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
  78	struct btrfs_root *root = btrfs_inode->root;
  79	u64 ino = btrfs_ino(inode);
  80	struct btrfs_delayed_node *node;
  81
  82	node = ACCESS_ONCE(btrfs_inode->delayed_node);
  83	if (node) {
  84		atomic_inc(&node->refs);
  85		return node;
  86	}
  87
  88	spin_lock(&root->inode_lock);
  89	node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
 
  90	if (node) {
  91		if (btrfs_inode->delayed_node) {
  92			atomic_inc(&node->refs);	/* can be accessed */
  93			BUG_ON(btrfs_inode->delayed_node != node);
  94			spin_unlock(&root->inode_lock);
  95			return node;
  96		}
  97		btrfs_inode->delayed_node = node;
  98		/* can be accessed and cached in the inode */
  99		atomic_add(2, &node->refs);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 100		spin_unlock(&root->inode_lock);
 101		return node;
 102	}
 103	spin_unlock(&root->inode_lock);
 104
 105	return NULL;
 106}
 107
 108/* Will return either the node or PTR_ERR(-ENOMEM) */
 109static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
 110							struct inode *inode)
 111{
 112	struct btrfs_delayed_node *node;
 113	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 114	struct btrfs_root *root = btrfs_inode->root;
 115	u64 ino = btrfs_ino(inode);
 116	int ret;
 117
 118again:
 119	node = btrfs_get_delayed_node(inode);
 120	if (node)
 121		return node;
 122
 123	node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
 124	if (!node)
 125		return ERR_PTR(-ENOMEM);
 126	btrfs_init_delayed_node(node, root, ino);
 127
 128	/* cached in the btrfs inode and can be accessed */
 129	atomic_add(2, &node->refs);
 130
 131	ret = radix_tree_preload(GFP_NOFS);
 132	if (ret) {
 133		kmem_cache_free(delayed_node_cache, node);
 134		return ERR_PTR(ret);
 135	}
 136
 137	spin_lock(&root->inode_lock);
 138	ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
 139	if (ret == -EEXIST) {
 140		spin_unlock(&root->inode_lock);
 141		kmem_cache_free(delayed_node_cache, node);
 142		radix_tree_preload_end();
 143		goto again;
 144	}
 145	btrfs_inode->delayed_node = node;
 146	spin_unlock(&root->inode_lock);
 147	radix_tree_preload_end();
 148
 149	return node;
 150}
 151
 152/*
 153 * Call it when holding delayed_node->mutex
 154 *
 155 * If mod = 1, add this node into the prepared list.
 156 */
 157static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
 158				     struct btrfs_delayed_node *node,
 159				     int mod)
 160{
 161	spin_lock(&root->lock);
 162	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 163		if (!list_empty(&node->p_list))
 164			list_move_tail(&node->p_list, &root->prepare_list);
 165		else if (mod)
 166			list_add_tail(&node->p_list, &root->prepare_list);
 167	} else {
 168		list_add_tail(&node->n_list, &root->node_list);
 169		list_add_tail(&node->p_list, &root->prepare_list);
 170		atomic_inc(&node->refs);	/* inserted into list */
 171		root->nodes++;
 172		set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 173	}
 174	spin_unlock(&root->lock);
 175}
 176
 177/* Call it when holding delayed_node->mutex */
 178static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
 179				       struct btrfs_delayed_node *node)
 180{
 181	spin_lock(&root->lock);
 182	if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 183		root->nodes--;
 184		atomic_dec(&node->refs);	/* not in the list */
 185		list_del_init(&node->n_list);
 186		if (!list_empty(&node->p_list))
 187			list_del_init(&node->p_list);
 188		clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 189	}
 190	spin_unlock(&root->lock);
 191}
 192
 193static struct btrfs_delayed_node *btrfs_first_delayed_node(
 194			struct btrfs_delayed_root *delayed_root)
 195{
 196	struct list_head *p;
 197	struct btrfs_delayed_node *node = NULL;
 198
 199	spin_lock(&delayed_root->lock);
 200	if (list_empty(&delayed_root->node_list))
 201		goto out;
 202
 203	p = delayed_root->node_list.next;
 204	node = list_entry(p, struct btrfs_delayed_node, n_list);
 205	atomic_inc(&node->refs);
 206out:
 207	spin_unlock(&delayed_root->lock);
 208
 209	return node;
 210}
 211
 212static struct btrfs_delayed_node *btrfs_next_delayed_node(
 213						struct btrfs_delayed_node *node)
 214{
 215	struct btrfs_delayed_root *delayed_root;
 216	struct list_head *p;
 217	struct btrfs_delayed_node *next = NULL;
 218
 219	delayed_root = node->root->fs_info->delayed_root;
 220	spin_lock(&delayed_root->lock);
 221	if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 222		/* not in the list */
 223		if (list_empty(&delayed_root->node_list))
 224			goto out;
 225		p = delayed_root->node_list.next;
 226	} else if (list_is_last(&node->n_list, &delayed_root->node_list))
 227		goto out;
 228	else
 229		p = node->n_list.next;
 230
 231	next = list_entry(p, struct btrfs_delayed_node, n_list);
 232	atomic_inc(&next->refs);
 233out:
 234	spin_unlock(&delayed_root->lock);
 235
 236	return next;
 237}
 238
 239static void __btrfs_release_delayed_node(
 240				struct btrfs_delayed_node *delayed_node,
 241				int mod)
 242{
 243	struct btrfs_delayed_root *delayed_root;
 244
 245	if (!delayed_node)
 246		return;
 247
 248	delayed_root = delayed_node->root->fs_info->delayed_root;
 249
 250	mutex_lock(&delayed_node->mutex);
 251	if (delayed_node->count)
 252		btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
 253	else
 254		btrfs_dequeue_delayed_node(delayed_root, delayed_node);
 255	mutex_unlock(&delayed_node->mutex);
 256
 257	if (atomic_dec_and_test(&delayed_node->refs)) {
 258		bool free = false;
 259		struct btrfs_root *root = delayed_node->root;
 
 260		spin_lock(&root->inode_lock);
 261		if (atomic_read(&delayed_node->refs) == 0) {
 262			radix_tree_delete(&root->delayed_nodes_tree,
 263					  delayed_node->inode_id);
 264			free = true;
 265		}
 
 
 266		spin_unlock(&root->inode_lock);
 267		if (free)
 268			kmem_cache_free(delayed_node_cache, delayed_node);
 269	}
 270}
 271
 272static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 273{
 274	__btrfs_release_delayed_node(node, 0);
 275}
 276
 277static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
 278					struct btrfs_delayed_root *delayed_root)
 279{
 280	struct list_head *p;
 281	struct btrfs_delayed_node *node = NULL;
 282
 283	spin_lock(&delayed_root->lock);
 284	if (list_empty(&delayed_root->prepare_list))
 285		goto out;
 286
 287	p = delayed_root->prepare_list.next;
 288	list_del_init(p);
 289	node = list_entry(p, struct btrfs_delayed_node, p_list);
 290	atomic_inc(&node->refs);
 291out:
 292	spin_unlock(&delayed_root->lock);
 293
 294	return node;
 295}
 296
 297static inline void btrfs_release_prepared_delayed_node(
 298					struct btrfs_delayed_node *node)
 299{
 300	__btrfs_release_delayed_node(node, 1);
 301}
 302
 303static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
 304{
 305	struct btrfs_delayed_item *item;
 306	item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
 307	if (item) {
 308		item->data_len = data_len;
 309		item->ins_or_del = 0;
 310		item->bytes_reserved = 0;
 311		item->delayed_node = NULL;
 312		atomic_set(&item->refs, 1);
 313	}
 314	return item;
 315}
 316
 317/*
 318 * __btrfs_lookup_delayed_item - look up the delayed item by key
 319 * @delayed_node: pointer to the delayed node
 320 * @key:	  the key to look up
 321 * @prev:	  used to store the prev item if the right item isn't found
 322 * @next:	  used to store the next item if the right item isn't found
 323 *
 324 * Note: if we don't find the right item, we will return the prev item and
 325 * the next item.
 326 */
 327static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
 328				struct rb_root *root,
 329				struct btrfs_key *key,
 330				struct btrfs_delayed_item **prev,
 331				struct btrfs_delayed_item **next)
 332{
 333	struct rb_node *node, *prev_node = NULL;
 334	struct btrfs_delayed_item *delayed_item = NULL;
 335	int ret = 0;
 336
 337	node = root->rb_node;
 338
 339	while (node) {
 340		delayed_item = rb_entry(node, struct btrfs_delayed_item,
 341					rb_node);
 342		prev_node = node;
 343		ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
 344		if (ret < 0)
 345			node = node->rb_right;
 346		else if (ret > 0)
 347			node = node->rb_left;
 348		else
 349			return delayed_item;
 350	}
 351
 352	if (prev) {
 353		if (!prev_node)
 354			*prev = NULL;
 355		else if (ret < 0)
 356			*prev = delayed_item;
 357		else if ((node = rb_prev(prev_node)) != NULL) {
 358			*prev = rb_entry(node, struct btrfs_delayed_item,
 359					 rb_node);
 360		} else
 361			*prev = NULL;
 362	}
 363
 364	if (next) {
 365		if (!prev_node)
 366			*next = NULL;
 367		else if (ret > 0)
 368			*next = delayed_item;
 369		else if ((node = rb_next(prev_node)) != NULL) {
 370			*next = rb_entry(node, struct btrfs_delayed_item,
 371					 rb_node);
 372		} else
 373			*next = NULL;
 374	}
 375	return NULL;
 376}
 377
 378static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
 379					struct btrfs_delayed_node *delayed_node,
 380					struct btrfs_key *key)
 381{
 382	return __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
 383					   NULL, NULL);
 384}
 385
 386static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 387				    struct btrfs_delayed_item *ins,
 388				    int action)
 389{
 390	struct rb_node **p, *node;
 391	struct rb_node *parent_node = NULL;
 392	struct rb_root *root;
 393	struct btrfs_delayed_item *item;
 394	int cmp;
 
 395
 396	if (action == BTRFS_DELAYED_INSERTION_ITEM)
 397		root = &delayed_node->ins_root;
 398	else if (action == BTRFS_DELAYED_DELETION_ITEM)
 399		root = &delayed_node->del_root;
 400	else
 401		BUG();
 402	p = &root->rb_node;
 403	node = &ins->rb_node;
 404
 405	while (*p) {
 406		parent_node = *p;
 407		item = rb_entry(parent_node, struct btrfs_delayed_item,
 408				 rb_node);
 409
 410		cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
 411		if (cmp < 0)
 412			p = &(*p)->rb_right;
 413		else if (cmp > 0)
 
 414			p = &(*p)->rb_left;
 415		else
 416			return -EEXIST;
 
 417	}
 418
 419	rb_link_node(node, parent_node, p);
 420	rb_insert_color(node, root);
 421	ins->delayed_node = delayed_node;
 422	ins->ins_or_del = action;
 423
 424	if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
 425	    action == BTRFS_DELAYED_INSERTION_ITEM &&
 426	    ins->key.offset >= delayed_node->index_cnt)
 427			delayed_node->index_cnt = ins->key.offset + 1;
 428
 429	delayed_node->count++;
 430	atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
 431	return 0;
 432}
 433
 434static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
 435					      struct btrfs_delayed_item *item)
 436{
 437	return __btrfs_add_delayed_item(node, item,
 438					BTRFS_DELAYED_INSERTION_ITEM);
 439}
 440
 441static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
 442					     struct btrfs_delayed_item *item)
 443{
 444	return __btrfs_add_delayed_item(node, item,
 445					BTRFS_DELAYED_DELETION_ITEM);
 446}
 447
 448static void finish_one_item(struct btrfs_delayed_root *delayed_root)
 449{
 450	int seq = atomic_inc_return(&delayed_root->items_seq);
 451
 452	/*
 453	 * atomic_dec_return implies a barrier for waitqueue_active
 454	 */
 455	if ((atomic_dec_return(&delayed_root->items) <
 456	    BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0) &&
 457	    waitqueue_active(&delayed_root->wait))
 458		wake_up(&delayed_root->wait);
 459}
 460
 461static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 462{
 463	struct rb_root *root;
 464	struct btrfs_delayed_root *delayed_root;
 465
 
 
 
 466	delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 467
 468	BUG_ON(!delayed_root);
 469	BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
 470	       delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
 471
 472	if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
 473		root = &delayed_item->delayed_node->ins_root;
 474	else
 475		root = &delayed_item->delayed_node->del_root;
 476
 477	rb_erase(&delayed_item->rb_node, root);
 478	delayed_item->delayed_node->count--;
 479
 480	finish_one_item(delayed_root);
 481}
 482
 483static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 484{
 485	if (item) {
 486		__btrfs_remove_delayed_item(item);
 487		if (atomic_dec_and_test(&item->refs))
 488			kfree(item);
 489	}
 490}
 491
 492static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 493					struct btrfs_delayed_node *delayed_node)
 494{
 495	struct rb_node *p;
 496	struct btrfs_delayed_item *item = NULL;
 497
 498	p = rb_first(&delayed_node->ins_root);
 499	if (p)
 500		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 501
 502	return item;
 503}
 504
 505static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 506					struct btrfs_delayed_node *delayed_node)
 507{
 508	struct rb_node *p;
 509	struct btrfs_delayed_item *item = NULL;
 510
 511	p = rb_first(&delayed_node->del_root);
 512	if (p)
 513		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 514
 515	return item;
 516}
 517
 518static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 519						struct btrfs_delayed_item *item)
 520{
 521	struct rb_node *p;
 522	struct btrfs_delayed_item *next = NULL;
 523
 524	p = rb_next(&item->rb_node);
 525	if (p)
 526		next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 527
 528	return next;
 529}
 530
 531static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 532					       struct btrfs_fs_info *fs_info,
 533					       struct btrfs_delayed_item *item)
 534{
 535	struct btrfs_block_rsv *src_rsv;
 536	struct btrfs_block_rsv *dst_rsv;
 
 537	u64 num_bytes;
 538	int ret;
 539
 540	if (!trans->bytes_reserved)
 541		return 0;
 542
 543	src_rsv = trans->block_rsv;
 544	dst_rsv = &fs_info->delayed_block_rsv;
 545
 546	num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
 547	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
 
 
 
 
 
 
 548	if (!ret) {
 549		trace_btrfs_space_reservation(fs_info, "delayed_item",
 550					      item->key.objectid,
 551					      num_bytes, 1);
 552		item->bytes_reserved = num_bytes;
 553	}
 554
 555	return ret;
 556}
 557
 558static void btrfs_delayed_item_release_metadata(struct btrfs_fs_info *fs_info,
 559						struct btrfs_delayed_item *item)
 560{
 561	struct btrfs_block_rsv *rsv;
 
 562
 563	if (!item->bytes_reserved)
 564		return;
 565
 566	rsv = &fs_info->delayed_block_rsv;
 
 
 
 
 567	trace_btrfs_space_reservation(fs_info, "delayed_item",
 568				      item->key.objectid, item->bytes_reserved,
 569				      0);
 570	btrfs_block_rsv_release(fs_info, rsv,
 571				item->bytes_reserved);
 572}
 573
 574static int btrfs_delayed_inode_reserve_metadata(
 575					struct btrfs_trans_handle *trans,
 576					struct btrfs_root *root,
 577					struct inode *inode,
 578					struct btrfs_delayed_node *node)
 579{
 580	struct btrfs_fs_info *fs_info = root->fs_info;
 581	struct btrfs_block_rsv *src_rsv;
 582	struct btrfs_block_rsv *dst_rsv;
 583	u64 num_bytes;
 584	int ret;
 585	bool release = false;
 586
 587	src_rsv = trans->block_rsv;
 588	dst_rsv = &fs_info->delayed_block_rsv;
 589
 590	num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
 591
 592	/*
 593	 * If our block_rsv is the delalloc block reserve then check and see if
 594	 * we have our extra reservation for updating the inode.  If not fall
 595	 * through and try to reserve space quickly.
 596	 *
 597	 * We used to try and steal from the delalloc block rsv or the global
 598	 * reserve, but we'd steal a full reservation, which isn't kind.  We are
 599	 * here through delalloc which means we've likely just cowed down close
 600	 * to the leaf that contains the inode, so we would steal less just
 601	 * doing the fallback inode update, so if we do end up having to steal
 602	 * from the global block rsv we hopefully only steal one or two blocks
 603	 * worth which is less likely to hurt us.
 604	 */
 605	if (src_rsv && src_rsv->type == BTRFS_BLOCK_RSV_DELALLOC) {
 606		spin_lock(&BTRFS_I(inode)->lock);
 607		if (test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
 608				       &BTRFS_I(inode)->runtime_flags))
 609			release = true;
 610		else
 611			src_rsv = NULL;
 612		spin_unlock(&BTRFS_I(inode)->lock);
 613	}
 614
 615	/*
 616	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction
 617	 * which doesn't reserve space for speed.  This is a problem since we
 618	 * still need to reserve space for this update, so try to reserve the
 619	 * space.
 620	 *
 621	 * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
 622	 * we're accounted for.
 623	 */
 624	if (!src_rsv || (!trans->bytes_reserved &&
 625			 src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
 
 
 
 
 626		ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
 627					  BTRFS_RESERVE_NO_FLUSH);
 628		/*
 629		 * Since we're under a transaction reserve_metadata_bytes could
 630		 * try to commit the transaction which will make it return
 631		 * EAGAIN to make us stop the transaction we have, so return
 632		 * ENOSPC instead so that btrfs_dirty_inode knows what to do.
 633		 */
 634		if (ret == -EAGAIN)
 635			ret = -ENOSPC;
 
 
 636		if (!ret) {
 637			node->bytes_reserved = num_bytes;
 638			trace_btrfs_space_reservation(fs_info,
 639						      "delayed_inode",
 640						      btrfs_ino(inode),
 641						      num_bytes, 1);
 
 
 642		}
 643		return ret;
 644	}
 645
 646	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
 647
 648	/*
 649	 * Migrate only takes a reservation, it doesn't touch the size of the
 650	 * block_rsv.  This is to simplify people who don't normally have things
 651	 * migrated from their block rsv.  If they go to release their
 652	 * reservation, that will decrease the size as well, so if migrate
 653	 * reduced size we'd end up with a negative size.  But for the
 654	 * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
 655	 * but we could in fact do this reserve/migrate dance several times
 656	 * between the time we did the original reservation and we'd clean it
 657	 * up.  So to take care of this, release the space for the meta
 658	 * reservation here.  I think it may be time for a documentation page on
 659	 * how block rsvs. work.
 660	 */
 661	if (!ret) {
 662		trace_btrfs_space_reservation(fs_info, "delayed_inode",
 663					      btrfs_ino(inode), num_bytes, 1);
 664		node->bytes_reserved = num_bytes;
 665	}
 666
 667	if (release) {
 668		trace_btrfs_space_reservation(fs_info, "delalloc",
 669					      btrfs_ino(inode), num_bytes, 0);
 670		btrfs_block_rsv_release(fs_info, src_rsv, num_bytes);
 671	}
 672
 673	return ret;
 674}
 675
 676static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
 677						struct btrfs_delayed_node *node)
 
 678{
 679	struct btrfs_block_rsv *rsv;
 680
 681	if (!node->bytes_reserved)
 682		return;
 683
 684	rsv = &fs_info->delayed_block_rsv;
 685	trace_btrfs_space_reservation(fs_info, "delayed_inode",
 686				      node->inode_id, node->bytes_reserved, 0);
 687	btrfs_block_rsv_release(fs_info, rsv,
 
 
 
 
 
 688				node->bytes_reserved);
 689	node->bytes_reserved = 0;
 690}
 691
 692/*
 693 * This helper will insert some continuous items into the same leaf according
 694 * to the free space of the leaf.
 695 */
 696static int btrfs_batch_insert_items(struct btrfs_root *root,
 697				    struct btrfs_path *path,
 698				    struct btrfs_delayed_item *item)
 699{
 700	struct btrfs_fs_info *fs_info = root->fs_info;
 701	struct btrfs_delayed_item *curr, *next;
 702	int free_space;
 703	int total_data_size = 0, total_size = 0;
 704	struct extent_buffer *leaf;
 705	char *data_ptr;
 706	struct btrfs_key *keys;
 707	u32 *data_size;
 708	struct list_head head;
 709	int slot;
 710	int nitems;
 711	int i;
 712	int ret = 0;
 713
 714	BUG_ON(!path->nodes[0]);
 715
 716	leaf = path->nodes[0];
 717	free_space = btrfs_leaf_free_space(fs_info, leaf);
 718	INIT_LIST_HEAD(&head);
 719
 720	next = item;
 721	nitems = 0;
 722
 723	/*
 724	 * count the number of the continuous items that we can insert in batch
 725	 */
 726	while (total_size + next->data_len + sizeof(struct btrfs_item) <=
 727	       free_space) {
 728		total_data_size += next->data_len;
 729		total_size += next->data_len + sizeof(struct btrfs_item);
 730		list_add_tail(&next->tree_list, &head);
 731		nitems++;
 732
 733		curr = next;
 734		next = __btrfs_next_delayed_item(curr);
 735		if (!next)
 736			break;
 737
 738		if (!btrfs_is_continuous_delayed_item(curr, next))
 739			break;
 740	}
 741
 742	if (!nitems) {
 743		ret = 0;
 744		goto out;
 745	}
 746
 747	/*
 748	 * we need allocate some memory space, but it might cause the task
 749	 * to sleep, so we set all locked nodes in the path to blocking locks
 750	 * first.
 751	 */
 752	btrfs_set_path_blocking(path);
 753
 754	keys = kmalloc_array(nitems, sizeof(struct btrfs_key), GFP_NOFS);
 755	if (!keys) {
 756		ret = -ENOMEM;
 757		goto out;
 758	}
 759
 760	data_size = kmalloc_array(nitems, sizeof(u32), GFP_NOFS);
 761	if (!data_size) {
 762		ret = -ENOMEM;
 763		goto error;
 764	}
 765
 766	/* get keys of all the delayed items */
 767	i = 0;
 768	list_for_each_entry(next, &head, tree_list) {
 769		keys[i] = next->key;
 770		data_size[i] = next->data_len;
 771		i++;
 772	}
 773
 774	/* reset all the locked nodes in the patch to spinning locks. */
 775	btrfs_clear_path_blocking(path, NULL, 0);
 776
 777	/* insert the keys of the items */
 778	setup_items_for_insert(root, path, keys, data_size,
 779			       total_data_size, total_size, nitems);
 780
 781	/* insert the dir index items */
 782	slot = path->slots[0];
 783	list_for_each_entry_safe(curr, next, &head, tree_list) {
 784		data_ptr = btrfs_item_ptr(leaf, slot, char);
 785		write_extent_buffer(leaf, &curr->data,
 786				    (unsigned long)data_ptr,
 787				    curr->data_len);
 788		slot++;
 789
 790		btrfs_delayed_item_release_metadata(fs_info, curr);
 791
 792		list_del(&curr->tree_list);
 793		btrfs_release_delayed_item(curr);
 794	}
 795
 796error:
 797	kfree(data_size);
 798	kfree(keys);
 799out:
 800	return ret;
 801}
 802
 803/*
 804 * This helper can just do simple insertion that needn't extend item for new
 805 * data, such as directory name index insertion, inode insertion.
 806 */
 807static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 808				     struct btrfs_root *root,
 809				     struct btrfs_path *path,
 810				     struct btrfs_delayed_item *delayed_item)
 811{
 812	struct btrfs_fs_info *fs_info = root->fs_info;
 813	struct extent_buffer *leaf;
 
 814	char *ptr;
 815	int ret;
 816
 
 817	ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
 818				      delayed_item->data_len);
 
 819	if (ret < 0 && ret != -EEXIST)
 820		return ret;
 821
 822	leaf = path->nodes[0];
 823
 824	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
 825
 826	write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
 827			    delayed_item->data_len);
 828	btrfs_mark_buffer_dirty(leaf);
 829
 830	btrfs_delayed_item_release_metadata(fs_info, delayed_item);
 831	return 0;
 832}
 833
 834/*
 835 * we insert an item first, then if there are some continuous items, we try
 836 * to insert those items into the same leaf.
 837 */
 838static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 839				      struct btrfs_path *path,
 840				      struct btrfs_root *root,
 841				      struct btrfs_delayed_node *node)
 842{
 843	struct btrfs_delayed_item *curr, *prev;
 844	int ret = 0;
 845
 846do_again:
 847	mutex_lock(&node->mutex);
 848	curr = __btrfs_first_delayed_insertion_item(node);
 849	if (!curr)
 850		goto insert_end;
 851
 852	ret = btrfs_insert_delayed_item(trans, root, path, curr);
 853	if (ret < 0) {
 854		btrfs_release_path(path);
 855		goto insert_end;
 856	}
 857
 858	prev = curr;
 859	curr = __btrfs_next_delayed_item(prev);
 860	if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
 861		/* insert the continuous items into the same leaf */
 862		path->slots[0]++;
 863		btrfs_batch_insert_items(root, path, curr);
 864	}
 865	btrfs_release_delayed_item(prev);
 866	btrfs_mark_buffer_dirty(path->nodes[0]);
 867
 868	btrfs_release_path(path);
 869	mutex_unlock(&node->mutex);
 870	goto do_again;
 871
 872insert_end:
 873	mutex_unlock(&node->mutex);
 874	return ret;
 875}
 876
 877static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
 878				    struct btrfs_root *root,
 879				    struct btrfs_path *path,
 880				    struct btrfs_delayed_item *item)
 881{
 882	struct btrfs_fs_info *fs_info = root->fs_info;
 883	struct btrfs_delayed_item *curr, *next;
 884	struct extent_buffer *leaf;
 885	struct btrfs_key key;
 886	struct list_head head;
 887	int nitems, i, last_item;
 888	int ret = 0;
 889
 890	BUG_ON(!path->nodes[0]);
 891
 892	leaf = path->nodes[0];
 893
 894	i = path->slots[0];
 895	last_item = btrfs_header_nritems(leaf) - 1;
 896	if (i > last_item)
 897		return -ENOENT;	/* FIXME: Is errno suitable? */
 898
 899	next = item;
 900	INIT_LIST_HEAD(&head);
 901	btrfs_item_key_to_cpu(leaf, &key, i);
 902	nitems = 0;
 903	/*
 904	 * count the number of the dir index items that we can delete in batch
 905	 */
 906	while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
 907		list_add_tail(&next->tree_list, &head);
 908		nitems++;
 909
 910		curr = next;
 911		next = __btrfs_next_delayed_item(curr);
 912		if (!next)
 913			break;
 914
 915		if (!btrfs_is_continuous_delayed_item(curr, next))
 916			break;
 917
 918		i++;
 919		if (i > last_item)
 920			break;
 921		btrfs_item_key_to_cpu(leaf, &key, i);
 922	}
 923
 924	if (!nitems)
 925		return 0;
 926
 927	ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
 928	if (ret)
 929		goto out;
 930
 931	list_for_each_entry_safe(curr, next, &head, tree_list) {
 932		btrfs_delayed_item_release_metadata(fs_info, curr);
 933		list_del(&curr->tree_list);
 934		btrfs_release_delayed_item(curr);
 935	}
 936
 937out:
 938	return ret;
 939}
 940
 941static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
 942				      struct btrfs_path *path,
 943				      struct btrfs_root *root,
 944				      struct btrfs_delayed_node *node)
 945{
 946	struct btrfs_delayed_item *curr, *prev;
 
 947	int ret = 0;
 948
 949do_again:
 950	mutex_lock(&node->mutex);
 951	curr = __btrfs_first_delayed_deletion_item(node);
 952	if (!curr)
 953		goto delete_fail;
 954
 
 955	ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
 
 956	if (ret < 0)
 957		goto delete_fail;
 958	else if (ret > 0) {
 959		/*
 960		 * can't find the item which the node points to, so this node
 961		 * is invalid, just drop it.
 962		 */
 963		prev = curr;
 964		curr = __btrfs_next_delayed_item(prev);
 965		btrfs_release_delayed_item(prev);
 966		ret = 0;
 967		btrfs_release_path(path);
 968		if (curr) {
 969			mutex_unlock(&node->mutex);
 970			goto do_again;
 971		} else
 972			goto delete_fail;
 973	}
 974
 975	btrfs_batch_delete_items(trans, root, path, curr);
 976	btrfs_release_path(path);
 977	mutex_unlock(&node->mutex);
 978	goto do_again;
 979
 980delete_fail:
 981	btrfs_release_path(path);
 982	mutex_unlock(&node->mutex);
 983	return ret;
 984}
 985
 986static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
 987{
 988	struct btrfs_delayed_root *delayed_root;
 989
 990	if (delayed_node &&
 991	    test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
 992		BUG_ON(!delayed_node->root);
 993		clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
 994		delayed_node->count--;
 995
 996		delayed_root = delayed_node->root->fs_info->delayed_root;
 997		finish_one_item(delayed_root);
 998	}
 999}
1000
1001static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
1002{
1003	struct btrfs_delayed_root *delayed_root;
1004
1005	ASSERT(delayed_node->root);
1006	clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1007	delayed_node->count--;
1008
1009	delayed_root = delayed_node->root->fs_info->delayed_root;
1010	finish_one_item(delayed_root);
1011}
1012
1013static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1014					struct btrfs_root *root,
1015					struct btrfs_path *path,
1016					struct btrfs_delayed_node *node)
1017{
1018	struct btrfs_fs_info *fs_info = root->fs_info;
1019	struct btrfs_key key;
1020	struct btrfs_inode_item *inode_item;
1021	struct extent_buffer *leaf;
 
1022	int mod;
1023	int ret;
1024
1025	key.objectid = node->inode_id;
1026	key.type = BTRFS_INODE_ITEM_KEY;
1027	key.offset = 0;
1028
1029	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1030		mod = -1;
1031	else
1032		mod = 1;
1033
 
1034	ret = btrfs_lookup_inode(trans, root, path, &key, mod);
 
1035	if (ret > 0) {
1036		btrfs_release_path(path);
1037		return -ENOENT;
1038	} else if (ret < 0) {
1039		return ret;
1040	}
1041
1042	leaf = path->nodes[0];
1043	inode_item = btrfs_item_ptr(leaf, path->slots[0],
1044				    struct btrfs_inode_item);
1045	write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1046			    sizeof(struct btrfs_inode_item));
1047	btrfs_mark_buffer_dirty(leaf);
1048
1049	if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1050		goto no_iref;
1051
1052	path->slots[0]++;
1053	if (path->slots[0] >= btrfs_header_nritems(leaf))
1054		goto search;
1055again:
1056	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1057	if (key.objectid != node->inode_id)
1058		goto out;
1059
1060	if (key.type != BTRFS_INODE_REF_KEY &&
1061	    key.type != BTRFS_INODE_EXTREF_KEY)
1062		goto out;
1063
1064	/*
1065	 * Delayed iref deletion is for the inode who has only one link,
1066	 * so there is only one iref. The case that several irefs are
1067	 * in the same item doesn't exist.
1068	 */
1069	btrfs_del_item(trans, root, path);
1070out:
1071	btrfs_release_delayed_iref(node);
1072no_iref:
1073	btrfs_release_path(path);
1074err_out:
1075	btrfs_delayed_inode_release_metadata(fs_info, node);
1076	btrfs_release_delayed_inode(node);
1077
1078	return ret;
1079
1080search:
1081	btrfs_release_path(path);
1082
1083	key.type = BTRFS_INODE_EXTREF_KEY;
1084	key.offset = -1;
 
 
1085	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 
1086	if (ret < 0)
1087		goto err_out;
1088	ASSERT(ret);
1089
1090	ret = 0;
1091	leaf = path->nodes[0];
1092	path->slots[0]--;
1093	goto again;
1094}
1095
1096static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1097					     struct btrfs_root *root,
1098					     struct btrfs_path *path,
1099					     struct btrfs_delayed_node *node)
1100{
1101	int ret;
1102
1103	mutex_lock(&node->mutex);
1104	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1105		mutex_unlock(&node->mutex);
1106		return 0;
1107	}
1108
1109	ret = __btrfs_update_delayed_inode(trans, root, path, node);
1110	mutex_unlock(&node->mutex);
1111	return ret;
1112}
1113
1114static inline int
1115__btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1116				   struct btrfs_path *path,
1117				   struct btrfs_delayed_node *node)
1118{
1119	int ret;
1120
1121	ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1122	if (ret)
1123		return ret;
1124
1125	ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1126	if (ret)
1127		return ret;
1128
1129	ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1130	return ret;
1131}
1132
1133/*
1134 * Called when committing the transaction.
1135 * Returns 0 on success.
1136 * Returns < 0 on error and returns with an aborted transaction with any
1137 * outstanding delayed items cleaned up.
1138 */
1139static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1140				     struct btrfs_fs_info *fs_info, int nr)
1141{
 
1142	struct btrfs_delayed_root *delayed_root;
1143	struct btrfs_delayed_node *curr_node, *prev_node;
1144	struct btrfs_path *path;
1145	struct btrfs_block_rsv *block_rsv;
1146	int ret = 0;
1147	bool count = (nr > 0);
1148
1149	if (trans->aborted)
1150		return -EIO;
1151
1152	path = btrfs_alloc_path();
1153	if (!path)
1154		return -ENOMEM;
1155	path->leave_spinning = 1;
1156
1157	block_rsv = trans->block_rsv;
1158	trans->block_rsv = &fs_info->delayed_block_rsv;
1159
1160	delayed_root = fs_info->delayed_root;
1161
1162	curr_node = btrfs_first_delayed_node(delayed_root);
1163	while (curr_node && (!count || (count && nr--))) {
1164		ret = __btrfs_commit_inode_delayed_items(trans, path,
1165							 curr_node);
1166		if (ret) {
1167			btrfs_release_delayed_node(curr_node);
1168			curr_node = NULL;
1169			btrfs_abort_transaction(trans, ret);
1170			break;
1171		}
1172
1173		prev_node = curr_node;
1174		curr_node = btrfs_next_delayed_node(curr_node);
1175		btrfs_release_delayed_node(prev_node);
1176	}
1177
1178	if (curr_node)
1179		btrfs_release_delayed_node(curr_node);
1180	btrfs_free_path(path);
1181	trans->block_rsv = block_rsv;
1182
1183	return ret;
1184}
1185
1186int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1187			    struct btrfs_fs_info *fs_info)
1188{
1189	return __btrfs_run_delayed_items(trans, fs_info, -1);
1190}
1191
1192int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans,
1193			       struct btrfs_fs_info *fs_info, int nr)
1194{
1195	return __btrfs_run_delayed_items(trans, fs_info, nr);
1196}
1197
1198int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1199				     struct inode *inode)
1200{
1201	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1202	struct btrfs_path *path;
1203	struct btrfs_block_rsv *block_rsv;
1204	int ret;
1205
1206	if (!delayed_node)
1207		return 0;
1208
1209	mutex_lock(&delayed_node->mutex);
1210	if (!delayed_node->count) {
1211		mutex_unlock(&delayed_node->mutex);
1212		btrfs_release_delayed_node(delayed_node);
1213		return 0;
1214	}
1215	mutex_unlock(&delayed_node->mutex);
1216
1217	path = btrfs_alloc_path();
1218	if (!path) {
1219		btrfs_release_delayed_node(delayed_node);
1220		return -ENOMEM;
1221	}
1222	path->leave_spinning = 1;
1223
1224	block_rsv = trans->block_rsv;
1225	trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1226
1227	ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1228
1229	btrfs_release_delayed_node(delayed_node);
1230	btrfs_free_path(path);
1231	trans->block_rsv = block_rsv;
1232
1233	return ret;
1234}
1235
1236int btrfs_commit_inode_delayed_inode(struct inode *inode)
1237{
1238	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1239	struct btrfs_trans_handle *trans;
1240	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1241	struct btrfs_path *path;
1242	struct btrfs_block_rsv *block_rsv;
1243	int ret;
1244
1245	if (!delayed_node)
1246		return 0;
1247
1248	mutex_lock(&delayed_node->mutex);
1249	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1250		mutex_unlock(&delayed_node->mutex);
1251		btrfs_release_delayed_node(delayed_node);
1252		return 0;
1253	}
1254	mutex_unlock(&delayed_node->mutex);
1255
1256	trans = btrfs_join_transaction(delayed_node->root);
1257	if (IS_ERR(trans)) {
1258		ret = PTR_ERR(trans);
1259		goto out;
1260	}
1261
1262	path = btrfs_alloc_path();
1263	if (!path) {
1264		ret = -ENOMEM;
1265		goto trans_out;
1266	}
1267	path->leave_spinning = 1;
1268
1269	block_rsv = trans->block_rsv;
1270	trans->block_rsv = &fs_info->delayed_block_rsv;
1271
1272	mutex_lock(&delayed_node->mutex);
1273	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1274		ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1275						   path, delayed_node);
1276	else
1277		ret = 0;
1278	mutex_unlock(&delayed_node->mutex);
1279
1280	btrfs_free_path(path);
1281	trans->block_rsv = block_rsv;
1282trans_out:
1283	btrfs_end_transaction(trans);
1284	btrfs_btree_balance_dirty(fs_info);
1285out:
1286	btrfs_release_delayed_node(delayed_node);
1287
1288	return ret;
1289}
1290
1291void btrfs_remove_delayed_node(struct inode *inode)
1292{
1293	struct btrfs_delayed_node *delayed_node;
1294
1295	delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1296	if (!delayed_node)
1297		return;
1298
1299	BTRFS_I(inode)->delayed_node = NULL;
1300	btrfs_release_delayed_node(delayed_node);
1301}
1302
1303struct btrfs_async_delayed_work {
1304	struct btrfs_delayed_root *delayed_root;
1305	int nr;
1306	struct btrfs_work work;
1307};
1308
1309static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1310{
1311	struct btrfs_async_delayed_work *async_work;
1312	struct btrfs_delayed_root *delayed_root;
1313	struct btrfs_trans_handle *trans;
1314	struct btrfs_path *path;
1315	struct btrfs_delayed_node *delayed_node = NULL;
1316	struct btrfs_root *root;
1317	struct btrfs_block_rsv *block_rsv;
1318	int total_done = 0;
1319
1320	async_work = container_of(work, struct btrfs_async_delayed_work, work);
1321	delayed_root = async_work->delayed_root;
1322
1323	path = btrfs_alloc_path();
1324	if (!path)
1325		goto out;
1326
1327again:
1328	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND / 2)
1329		goto free_path;
 
1330
1331	delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1332	if (!delayed_node)
1333		goto free_path;
1334
1335	path->leave_spinning = 1;
1336	root = delayed_node->root;
1337
1338	trans = btrfs_join_transaction(root);
1339	if (IS_ERR(trans))
1340		goto release_path;
 
 
 
 
1341
1342	block_rsv = trans->block_rsv;
1343	trans->block_rsv = &root->fs_info->delayed_block_rsv;
1344
1345	__btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1346
1347	trans->block_rsv = block_rsv;
1348	btrfs_end_transaction(trans);
1349	btrfs_btree_balance_dirty_nodelay(root->fs_info);
1350
1351release_path:
1352	btrfs_release_path(path);
1353	total_done++;
1354
1355	btrfs_release_prepared_delayed_node(delayed_node);
1356	if ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK) ||
1357	    total_done < async_work->nr)
1358		goto again;
1359
1360free_path:
1361	btrfs_free_path(path);
1362out:
1363	wake_up(&delayed_root->wait);
1364	kfree(async_work);
1365}
1366
1367
1368static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1369				     struct btrfs_fs_info *fs_info, int nr)
1370{
1371	struct btrfs_async_delayed_work *async_work;
1372
1373	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND ||
1374	    btrfs_workqueue_normal_congested(fs_info->delayed_workers))
1375		return 0;
1376
1377	async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1378	if (!async_work)
1379		return -ENOMEM;
1380
1381	async_work->delayed_root = delayed_root;
1382	btrfs_init_work(&async_work->work, btrfs_delayed_meta_helper,
1383			btrfs_async_run_delayed_root, NULL, NULL);
1384	async_work->nr = nr;
1385
1386	btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
1387	return 0;
1388}
1389
1390void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
1391{
1392	WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));
1393}
1394
1395static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1396{
1397	int val = atomic_read(&delayed_root->items_seq);
1398
1399	if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1400		return 1;
1401
1402	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1403		return 1;
1404
1405	return 0;
1406}
1407
1408void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
1409{
1410	struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
1411
1412	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
 
1413		return;
1414
1415	if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1416		int seq;
1417		int ret;
1418
1419		seq = atomic_read(&delayed_root->items_seq);
1420
1421		ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
1422		if (ret)
1423			return;
1424
1425		wait_event_interruptible(delayed_root->wait,
1426					 could_end_wait(delayed_root, seq));
1427		return;
1428	}
1429
1430	btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1431}
1432
1433/* Will return 0 or -ENOMEM */
1434int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1435				   struct btrfs_fs_info *fs_info,
1436				   const char *name, int name_len,
1437				   struct inode *dir,
1438				   struct btrfs_disk_key *disk_key, u8 type,
1439				   u64 index)
1440{
1441	struct btrfs_delayed_node *delayed_node;
1442	struct btrfs_delayed_item *delayed_item;
1443	struct btrfs_dir_item *dir_item;
1444	int ret;
1445
1446	delayed_node = btrfs_get_or_create_delayed_node(dir);
1447	if (IS_ERR(delayed_node))
1448		return PTR_ERR(delayed_node);
1449
1450	delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1451	if (!delayed_item) {
1452		ret = -ENOMEM;
1453		goto release_node;
1454	}
1455
1456	delayed_item->key.objectid = btrfs_ino(dir);
1457	delayed_item->key.type = BTRFS_DIR_INDEX_KEY;
1458	delayed_item->key.offset = index;
1459
1460	dir_item = (struct btrfs_dir_item *)delayed_item->data;
1461	dir_item->location = *disk_key;
1462	btrfs_set_stack_dir_transid(dir_item, trans->transid);
1463	btrfs_set_stack_dir_data_len(dir_item, 0);
1464	btrfs_set_stack_dir_name_len(dir_item, name_len);
1465	btrfs_set_stack_dir_type(dir_item, type);
1466	memcpy((char *)(dir_item + 1), name, name_len);
1467
1468	ret = btrfs_delayed_item_reserve_metadata(trans, fs_info, delayed_item);
1469	/*
1470	 * we have reserved enough space when we start a new transaction,
1471	 * so reserving metadata failure is impossible
1472	 */
1473	BUG_ON(ret);
1474
1475
1476	mutex_lock(&delayed_node->mutex);
1477	ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1478	if (unlikely(ret)) {
1479		btrfs_err(fs_info,
1480			  "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1481			  name_len, name, delayed_node->root->objectid,
1482			  delayed_node->inode_id, ret);
1483		BUG();
1484	}
1485	mutex_unlock(&delayed_node->mutex);
1486
1487release_node:
1488	btrfs_release_delayed_node(delayed_node);
1489	return ret;
1490}
1491
1492static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,
1493					       struct btrfs_delayed_node *node,
1494					       struct btrfs_key *key)
1495{
1496	struct btrfs_delayed_item *item;
1497
1498	mutex_lock(&node->mutex);
1499	item = __btrfs_lookup_delayed_insertion_item(node, key);
1500	if (!item) {
1501		mutex_unlock(&node->mutex);
1502		return 1;
1503	}
1504
1505	btrfs_delayed_item_release_metadata(fs_info, item);
1506	btrfs_release_delayed_item(item);
1507	mutex_unlock(&node->mutex);
1508	return 0;
1509}
1510
1511int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1512				   struct btrfs_fs_info *fs_info,
1513				   struct inode *dir, u64 index)
1514{
1515	struct btrfs_delayed_node *node;
1516	struct btrfs_delayed_item *item;
1517	struct btrfs_key item_key;
1518	int ret;
1519
1520	node = btrfs_get_or_create_delayed_node(dir);
1521	if (IS_ERR(node))
1522		return PTR_ERR(node);
1523
1524	item_key.objectid = btrfs_ino(dir);
1525	item_key.type = BTRFS_DIR_INDEX_KEY;
1526	item_key.offset = index;
1527
1528	ret = btrfs_delete_delayed_insertion_item(fs_info, node, &item_key);
 
1529	if (!ret)
1530		goto end;
1531
1532	item = btrfs_alloc_delayed_item(0);
1533	if (!item) {
1534		ret = -ENOMEM;
1535		goto end;
1536	}
1537
1538	item->key = item_key;
1539
1540	ret = btrfs_delayed_item_reserve_metadata(trans, fs_info, item);
1541	/*
1542	 * we have reserved enough space when we start a new transaction,
1543	 * so reserving metadata failure is impossible.
1544	 */
1545	BUG_ON(ret);
 
 
 
 
 
1546
1547	mutex_lock(&node->mutex);
1548	ret = __btrfs_add_delayed_deletion_item(node, item);
1549	if (unlikely(ret)) {
1550		btrfs_err(fs_info,
1551			  "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1552			  index, node->root->objectid, node->inode_id, ret);
1553		BUG();
 
 
1554	}
1555	mutex_unlock(&node->mutex);
1556end:
1557	btrfs_release_delayed_node(node);
1558	return ret;
1559}
1560
1561int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1562{
1563	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1564
1565	if (!delayed_node)
1566		return -ENOENT;
1567
1568	/*
1569	 * Since we have held i_mutex of this directory, it is impossible that
1570	 * a new directory index is added into the delayed node and index_cnt
1571	 * is updated now. So we needn't lock the delayed node.
1572	 */
1573	if (!delayed_node->index_cnt) {
1574		btrfs_release_delayed_node(delayed_node);
1575		return -EINVAL;
1576	}
1577
1578	BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1579	btrfs_release_delayed_node(delayed_node);
1580	return 0;
1581}
1582
1583bool btrfs_readdir_get_delayed_items(struct inode *inode,
1584				     struct list_head *ins_list,
1585				     struct list_head *del_list)
1586{
1587	struct btrfs_delayed_node *delayed_node;
1588	struct btrfs_delayed_item *item;
1589
1590	delayed_node = btrfs_get_delayed_node(inode);
1591	if (!delayed_node)
1592		return false;
1593
1594	/*
1595	 * We can only do one readdir with delayed items at a time because of
1596	 * item->readdir_list.
1597	 */
1598	inode_unlock_shared(inode);
1599	inode_lock(inode);
1600
1601	mutex_lock(&delayed_node->mutex);
1602	item = __btrfs_first_delayed_insertion_item(delayed_node);
1603	while (item) {
1604		atomic_inc(&item->refs);
1605		list_add_tail(&item->readdir_list, ins_list);
1606		item = __btrfs_next_delayed_item(item);
1607	}
1608
1609	item = __btrfs_first_delayed_deletion_item(delayed_node);
1610	while (item) {
1611		atomic_inc(&item->refs);
1612		list_add_tail(&item->readdir_list, del_list);
1613		item = __btrfs_next_delayed_item(item);
1614	}
1615	mutex_unlock(&delayed_node->mutex);
1616	/*
1617	 * This delayed node is still cached in the btrfs inode, so refs
1618	 * must be > 1 now, and we needn't check it is going to be freed
1619	 * or not.
1620	 *
1621	 * Besides that, this function is used to read dir, we do not
1622	 * insert/delete delayed items in this period. So we also needn't
1623	 * requeue or dequeue this delayed node.
1624	 */
1625	atomic_dec(&delayed_node->refs);
1626
1627	return true;
1628}
1629
1630void btrfs_readdir_put_delayed_items(struct inode *inode,
1631				     struct list_head *ins_list,
1632				     struct list_head *del_list)
1633{
1634	struct btrfs_delayed_item *curr, *next;
1635
1636	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1637		list_del(&curr->readdir_list);
1638		if (atomic_dec_and_test(&curr->refs))
1639			kfree(curr);
1640	}
1641
1642	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1643		list_del(&curr->readdir_list);
1644		if (atomic_dec_and_test(&curr->refs))
1645			kfree(curr);
1646	}
1647
1648	/*
1649	 * The VFS is going to do up_read(), so we need to downgrade back to a
1650	 * read lock.
1651	 */
1652	downgrade_write(&inode->i_rwsem);
1653}
1654
1655int btrfs_should_delete_dir_index(struct list_head *del_list,
1656				  u64 index)
1657{
1658	struct btrfs_delayed_item *curr, *next;
1659	int ret;
1660
1661	if (list_empty(del_list))
1662		return 0;
1663
1664	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1665		if (curr->key.offset > index)
1666			break;
1667
1668		list_del(&curr->readdir_list);
1669		ret = (curr->key.offset == index);
1670
1671		if (atomic_dec_and_test(&curr->refs))
1672			kfree(curr);
1673
1674		if (ret)
1675			return 1;
1676		else
1677			continue;
1678	}
1679	return 0;
1680}
1681
1682/*
1683 * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1684 *
1685 */
1686int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1687				    struct list_head *ins_list)
1688{
1689	struct btrfs_dir_item *di;
1690	struct btrfs_delayed_item *curr, *next;
1691	struct btrfs_key location;
1692	char *name;
1693	int name_len;
1694	int over = 0;
1695	unsigned char d_type;
1696
1697	if (list_empty(ins_list))
1698		return 0;
1699
1700	/*
1701	 * Changing the data of the delayed item is impossible. So
1702	 * we needn't lock them. And we have held i_mutex of the
1703	 * directory, nobody can delete any directory indexes now.
1704	 */
1705	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1706		list_del(&curr->readdir_list);
1707
1708		if (curr->key.offset < ctx->pos) {
1709			if (atomic_dec_and_test(&curr->refs))
1710				kfree(curr);
1711			continue;
1712		}
1713
1714		ctx->pos = curr->key.offset;
1715
1716		di = (struct btrfs_dir_item *)curr->data;
1717		name = (char *)(di + 1);
1718		name_len = btrfs_stack_dir_name_len(di);
1719
1720		d_type = btrfs_filetype_table[di->type];
1721		btrfs_disk_key_to_cpu(&location, &di->location);
1722
1723		over = !dir_emit(ctx, name, name_len,
1724			       location.objectid, d_type);
1725
1726		if (atomic_dec_and_test(&curr->refs))
1727			kfree(curr);
1728
1729		if (over)
1730			return 1;
 
1731	}
1732	return 0;
1733}
1734
1735static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1736				  struct btrfs_inode_item *inode_item,
1737				  struct inode *inode)
1738{
1739	btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1740	btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1741	btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1742	btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1743	btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1744	btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1745	btrfs_set_stack_inode_generation(inode_item,
1746					 BTRFS_I(inode)->generation);
1747	btrfs_set_stack_inode_sequence(inode_item, inode->i_version);
 
1748	btrfs_set_stack_inode_transid(inode_item, trans->transid);
1749	btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1750	btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1751	btrfs_set_stack_inode_block_group(inode_item, 0);
1752
1753	btrfs_set_stack_timespec_sec(&inode_item->atime,
1754				     inode->i_atime.tv_sec);
1755	btrfs_set_stack_timespec_nsec(&inode_item->atime,
1756				      inode->i_atime.tv_nsec);
1757
1758	btrfs_set_stack_timespec_sec(&inode_item->mtime,
1759				     inode->i_mtime.tv_sec);
1760	btrfs_set_stack_timespec_nsec(&inode_item->mtime,
1761				      inode->i_mtime.tv_nsec);
1762
1763	btrfs_set_stack_timespec_sec(&inode_item->ctime,
1764				     inode->i_ctime.tv_sec);
1765	btrfs_set_stack_timespec_nsec(&inode_item->ctime,
1766				      inode->i_ctime.tv_nsec);
1767
1768	btrfs_set_stack_timespec_sec(&inode_item->otime,
1769				     BTRFS_I(inode)->i_otime.tv_sec);
1770	btrfs_set_stack_timespec_nsec(&inode_item->otime,
1771				     BTRFS_I(inode)->i_otime.tv_nsec);
1772}
1773
1774int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1775{
 
1776	struct btrfs_delayed_node *delayed_node;
1777	struct btrfs_inode_item *inode_item;
1778
1779	delayed_node = btrfs_get_delayed_node(inode);
1780	if (!delayed_node)
1781		return -ENOENT;
1782
1783	mutex_lock(&delayed_node->mutex);
1784	if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1785		mutex_unlock(&delayed_node->mutex);
1786		btrfs_release_delayed_node(delayed_node);
1787		return -ENOENT;
1788	}
1789
1790	inode_item = &delayed_node->inode_item;
1791
1792	i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1793	i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1794	btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
 
 
1795	inode->i_mode = btrfs_stack_inode_mode(inode_item);
1796	set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1797	inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1798	BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1799        BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
1800
1801	inode->i_version = btrfs_stack_inode_sequence(inode_item);
 
1802	inode->i_rdev = 0;
1803	*rdev = btrfs_stack_inode_rdev(inode_item);
1804	BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1805
1806	inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
1807	inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
1808
1809	inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
1810	inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
1811
1812	inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
1813	inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
1814
1815	BTRFS_I(inode)->i_otime.tv_sec =
1816		btrfs_stack_timespec_sec(&inode_item->otime);
1817	BTRFS_I(inode)->i_otime.tv_nsec =
1818		btrfs_stack_timespec_nsec(&inode_item->otime);
1819
1820	inode->i_generation = BTRFS_I(inode)->generation;
1821	BTRFS_I(inode)->index_cnt = (u64)-1;
1822
1823	mutex_unlock(&delayed_node->mutex);
1824	btrfs_release_delayed_node(delayed_node);
1825	return 0;
1826}
1827
1828int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1829			       struct btrfs_root *root, struct inode *inode)
1830{
1831	struct btrfs_delayed_node *delayed_node;
1832	int ret = 0;
1833
1834	delayed_node = btrfs_get_or_create_delayed_node(inode);
1835	if (IS_ERR(delayed_node))
1836		return PTR_ERR(delayed_node);
1837
1838	mutex_lock(&delayed_node->mutex);
1839	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1840		fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1841		goto release_node;
1842	}
1843
1844	ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1845						   delayed_node);
1846	if (ret)
1847		goto release_node;
1848
1849	fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1850	set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1851	delayed_node->count++;
1852	atomic_inc(&root->fs_info->delayed_root->items);
1853release_node:
1854	mutex_unlock(&delayed_node->mutex);
1855	btrfs_release_delayed_node(delayed_node);
1856	return ret;
1857}
1858
1859int btrfs_delayed_delete_inode_ref(struct inode *inode)
1860{
1861	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1862	struct btrfs_delayed_node *delayed_node;
1863
1864	/*
1865	 * we don't do delayed inode updates during log recovery because it
1866	 * leads to enospc problems.  This means we also can't do
1867	 * delayed inode refs
1868	 */
1869	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1870		return -EAGAIN;
1871
1872	delayed_node = btrfs_get_or_create_delayed_node(inode);
1873	if (IS_ERR(delayed_node))
1874		return PTR_ERR(delayed_node);
1875
1876	/*
1877	 * We don't reserve space for inode ref deletion is because:
1878	 * - We ONLY do async inode ref deletion for the inode who has only
1879	 *   one link(i_nlink == 1), it means there is only one inode ref.
1880	 *   And in most case, the inode ref and the inode item are in the
1881	 *   same leaf, and we will deal with them at the same time.
1882	 *   Since we are sure we will reserve the space for the inode item,
1883	 *   it is unnecessary to reserve space for inode ref deletion.
1884	 * - If the inode ref and the inode item are not in the same leaf,
1885	 *   We also needn't worry about enospc problem, because we reserve
1886	 *   much more space for the inode update than it needs.
1887	 * - At the worst, we can steal some space from the global reservation.
1888	 *   It is very rare.
1889	 */
1890	mutex_lock(&delayed_node->mutex);
1891	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1892		goto release_node;
1893
1894	set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1895	delayed_node->count++;
1896	atomic_inc(&fs_info->delayed_root->items);
1897release_node:
1898	mutex_unlock(&delayed_node->mutex);
1899	btrfs_release_delayed_node(delayed_node);
1900	return 0;
1901}
1902
1903static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1904{
1905	struct btrfs_root *root = delayed_node->root;
1906	struct btrfs_fs_info *fs_info = root->fs_info;
1907	struct btrfs_delayed_item *curr_item, *prev_item;
1908
1909	mutex_lock(&delayed_node->mutex);
1910	curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1911	while (curr_item) {
1912		btrfs_delayed_item_release_metadata(fs_info, curr_item);
1913		prev_item = curr_item;
1914		curr_item = __btrfs_next_delayed_item(prev_item);
1915		btrfs_release_delayed_item(prev_item);
1916	}
1917
1918	curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1919	while (curr_item) {
1920		btrfs_delayed_item_release_metadata(fs_info, curr_item);
1921		prev_item = curr_item;
1922		curr_item = __btrfs_next_delayed_item(prev_item);
1923		btrfs_release_delayed_item(prev_item);
1924	}
1925
1926	if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1927		btrfs_release_delayed_iref(delayed_node);
1928
1929	if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1930		btrfs_delayed_inode_release_metadata(fs_info, delayed_node);
1931		btrfs_release_delayed_inode(delayed_node);
1932	}
1933	mutex_unlock(&delayed_node->mutex);
1934}
1935
1936void btrfs_kill_delayed_inode_items(struct inode *inode)
1937{
1938	struct btrfs_delayed_node *delayed_node;
1939
1940	delayed_node = btrfs_get_delayed_node(inode);
1941	if (!delayed_node)
1942		return;
1943
1944	__btrfs_kill_delayed_node(delayed_node);
1945	btrfs_release_delayed_node(delayed_node);
1946}
1947
1948void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1949{
1950	u64 inode_id = 0;
1951	struct btrfs_delayed_node *delayed_nodes[8];
1952	int i, n;
1953
1954	while (1) {
1955		spin_lock(&root->inode_lock);
1956		n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1957					   (void **)delayed_nodes, inode_id,
1958					   ARRAY_SIZE(delayed_nodes));
1959		if (!n) {
1960			spin_unlock(&root->inode_lock);
1961			break;
1962		}
1963
1964		inode_id = delayed_nodes[n - 1]->inode_id + 1;
1965
1966		for (i = 0; i < n; i++)
1967			atomic_inc(&delayed_nodes[i]->refs);
 
 
 
 
 
1968		spin_unlock(&root->inode_lock);
1969
1970		for (i = 0; i < n; i++) {
 
 
1971			__btrfs_kill_delayed_node(delayed_nodes[i]);
1972			btrfs_release_delayed_node(delayed_nodes[i]);
1973		}
1974	}
1975}
1976
1977void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
1978{
1979	struct btrfs_delayed_node *curr_node, *prev_node;
1980
1981	curr_node = btrfs_first_delayed_node(fs_info->delayed_root);
1982	while (curr_node) {
1983		__btrfs_kill_delayed_node(curr_node);
1984
1985		prev_node = curr_node;
1986		curr_node = btrfs_next_delayed_node(curr_node);
1987		btrfs_release_delayed_node(prev_node);
1988	}
1989}
1990