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
  25#define BTRFS_DELAYED_WRITEBACK		400
  26#define BTRFS_DELAYED_BACKGROUND	100
 
  27
  28static struct kmem_cache *delayed_node_cache;
  29
  30int __init btrfs_delayed_inode_init(void)
  31{
  32	delayed_node_cache = kmem_cache_create("delayed_node",
  33					sizeof(struct btrfs_delayed_node),
  34					0,
  35					SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
  36					NULL);
  37	if (!delayed_node_cache)
  38		return -ENOMEM;
  39	return 0;
  40}
  41
  42void btrfs_delayed_inode_exit(void)
  43{
  44	if (delayed_node_cache)
  45		kmem_cache_destroy(delayed_node_cache);
  46}
  47
  48static inline void btrfs_init_delayed_node(
  49				struct btrfs_delayed_node *delayed_node,
  50				struct btrfs_root *root, u64 inode_id)
  51{
  52	delayed_node->root = root;
  53	delayed_node->inode_id = inode_id;
  54	atomic_set(&delayed_node->refs, 0);
  55	delayed_node->count = 0;
  56	delayed_node->in_list = 0;
  57	delayed_node->inode_dirty = 0;
  58	delayed_node->ins_root = RB_ROOT;
  59	delayed_node->del_root = RB_ROOT;
  60	mutex_init(&delayed_node->mutex);
  61	delayed_node->index_cnt = 0;
  62	INIT_LIST_HEAD(&delayed_node->n_list);
  63	INIT_LIST_HEAD(&delayed_node->p_list);
  64	delayed_node->bytes_reserved = 0;
  65}
  66
  67static inline int btrfs_is_continuous_delayed_item(
  68					struct btrfs_delayed_item *item1,
  69					struct btrfs_delayed_item *item2)
  70{
  71	if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
  72	    item1->key.objectid == item2->key.objectid &&
  73	    item1->key.type == item2->key.type &&
  74	    item1->key.offset + 1 == item2->key.offset)
  75		return 1;
  76	return 0;
  77}
  78
  79static inline struct btrfs_delayed_root *btrfs_get_delayed_root(
  80							struct btrfs_root *root)
  81{
  82	return root->fs_info->delayed_root;
  83}
  84
  85static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
  86{
  87	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
  88	struct btrfs_root *root = btrfs_inode->root;
  89	u64 ino = btrfs_ino(inode);
  90	struct btrfs_delayed_node *node;
  91
  92	node = ACCESS_ONCE(btrfs_inode->delayed_node);
  93	if (node) {
  94		atomic_inc(&node->refs);
  95		return node;
  96	}
  97
  98	spin_lock(&root->inode_lock);
  99	node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
 100	if (node) {
 101		if (btrfs_inode->delayed_node) {
 102			atomic_inc(&node->refs);	/* can be accessed */
 103			BUG_ON(btrfs_inode->delayed_node != node);
 104			spin_unlock(&root->inode_lock);
 105			return node;
 106		}
 107		btrfs_inode->delayed_node = node;
 108		atomic_inc(&node->refs);	/* can be accessed */
 109		atomic_inc(&node->refs);	/* cached in the inode */
 110		spin_unlock(&root->inode_lock);
 111		return node;
 112	}
 113	spin_unlock(&root->inode_lock);
 114
 115	return NULL;
 116}
 117
 118/* Will return either the node or PTR_ERR(-ENOMEM) */
 119static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
 120							struct inode *inode)
 121{
 122	struct btrfs_delayed_node *node;
 123	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 124	struct btrfs_root *root = btrfs_inode->root;
 125	u64 ino = btrfs_ino(inode);
 126	int ret;
 127
 128again:
 129	node = btrfs_get_delayed_node(inode);
 130	if (node)
 131		return node;
 132
 133	node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
 134	if (!node)
 135		return ERR_PTR(-ENOMEM);
 136	btrfs_init_delayed_node(node, root, ino);
 137
 138	atomic_inc(&node->refs);	/* cached in the btrfs inode */
 139	atomic_inc(&node->refs);	/* can be accessed */
 140
 141	ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
 142	if (ret) {
 143		kmem_cache_free(delayed_node_cache, node);
 144		return ERR_PTR(ret);
 145	}
 146
 147	spin_lock(&root->inode_lock);
 148	ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
 149	if (ret == -EEXIST) {
 150		kmem_cache_free(delayed_node_cache, node);
 151		spin_unlock(&root->inode_lock);
 
 152		radix_tree_preload_end();
 153		goto again;
 154	}
 155	btrfs_inode->delayed_node = node;
 156	spin_unlock(&root->inode_lock);
 157	radix_tree_preload_end();
 158
 159	return node;
 160}
 161
 162/*
 163 * Call it when holding delayed_node->mutex
 164 *
 165 * If mod = 1, add this node into the prepared list.
 166 */
 167static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
 168				     struct btrfs_delayed_node *node,
 169				     int mod)
 170{
 171	spin_lock(&root->lock);
 172	if (node->in_list) {
 173		if (!list_empty(&node->p_list))
 174			list_move_tail(&node->p_list, &root->prepare_list);
 175		else if (mod)
 176			list_add_tail(&node->p_list, &root->prepare_list);
 177	} else {
 178		list_add_tail(&node->n_list, &root->node_list);
 179		list_add_tail(&node->p_list, &root->prepare_list);
 180		atomic_inc(&node->refs);	/* inserted into list */
 181		root->nodes++;
 182		node->in_list = 1;
 183	}
 184	spin_unlock(&root->lock);
 185}
 186
 187/* Call it when holding delayed_node->mutex */
 188static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
 189				       struct btrfs_delayed_node *node)
 190{
 191	spin_lock(&root->lock);
 192	if (node->in_list) {
 193		root->nodes--;
 194		atomic_dec(&node->refs);	/* not in the list */
 195		list_del_init(&node->n_list);
 196		if (!list_empty(&node->p_list))
 197			list_del_init(&node->p_list);
 198		node->in_list = 0;
 199	}
 200	spin_unlock(&root->lock);
 201}
 202
 203struct btrfs_delayed_node *btrfs_first_delayed_node(
 204			struct btrfs_delayed_root *delayed_root)
 205{
 206	struct list_head *p;
 207	struct btrfs_delayed_node *node = NULL;
 208
 209	spin_lock(&delayed_root->lock);
 210	if (list_empty(&delayed_root->node_list))
 211		goto out;
 212
 213	p = delayed_root->node_list.next;
 214	node = list_entry(p, struct btrfs_delayed_node, n_list);
 215	atomic_inc(&node->refs);
 216out:
 217	spin_unlock(&delayed_root->lock);
 218
 219	return node;
 220}
 221
 222struct btrfs_delayed_node *btrfs_next_delayed_node(
 223						struct btrfs_delayed_node *node)
 224{
 225	struct btrfs_delayed_root *delayed_root;
 226	struct list_head *p;
 227	struct btrfs_delayed_node *next = NULL;
 228
 229	delayed_root = node->root->fs_info->delayed_root;
 230	spin_lock(&delayed_root->lock);
 231	if (!node->in_list) {	/* not in the list */
 
 232		if (list_empty(&delayed_root->node_list))
 233			goto out;
 234		p = delayed_root->node_list.next;
 235	} else if (list_is_last(&node->n_list, &delayed_root->node_list))
 236		goto out;
 237	else
 238		p = node->n_list.next;
 239
 240	next = list_entry(p, struct btrfs_delayed_node, n_list);
 241	atomic_inc(&next->refs);
 242out:
 243	spin_unlock(&delayed_root->lock);
 244
 245	return next;
 246}
 247
 248static void __btrfs_release_delayed_node(
 249				struct btrfs_delayed_node *delayed_node,
 250				int mod)
 251{
 252	struct btrfs_delayed_root *delayed_root;
 253
 254	if (!delayed_node)
 255		return;
 256
 257	delayed_root = delayed_node->root->fs_info->delayed_root;
 258
 259	mutex_lock(&delayed_node->mutex);
 260	if (delayed_node->count)
 261		btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
 262	else
 263		btrfs_dequeue_delayed_node(delayed_root, delayed_node);
 264	mutex_unlock(&delayed_node->mutex);
 265
 266	if (atomic_dec_and_test(&delayed_node->refs)) {
 
 267		struct btrfs_root *root = delayed_node->root;
 268		spin_lock(&root->inode_lock);
 269		if (atomic_read(&delayed_node->refs) == 0) {
 270			radix_tree_delete(&root->delayed_nodes_tree,
 271					  delayed_node->inode_id);
 272			kmem_cache_free(delayed_node_cache, delayed_node);
 273		}
 274		spin_unlock(&root->inode_lock);
 
 
 275	}
 276}
 277
 278static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 279{
 280	__btrfs_release_delayed_node(node, 0);
 281}
 282
 283struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
 284					struct btrfs_delayed_root *delayed_root)
 285{
 286	struct list_head *p;
 287	struct btrfs_delayed_node *node = NULL;
 288
 289	spin_lock(&delayed_root->lock);
 290	if (list_empty(&delayed_root->prepare_list))
 291		goto out;
 292
 293	p = delayed_root->prepare_list.next;
 294	list_del_init(p);
 295	node = list_entry(p, struct btrfs_delayed_node, p_list);
 296	atomic_inc(&node->refs);
 297out:
 298	spin_unlock(&delayed_root->lock);
 299
 300	return node;
 301}
 302
 303static inline void btrfs_release_prepared_delayed_node(
 304					struct btrfs_delayed_node *node)
 305{
 306	__btrfs_release_delayed_node(node, 1);
 307}
 308
 309struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
 310{
 311	struct btrfs_delayed_item *item;
 312	item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
 313	if (item) {
 314		item->data_len = data_len;
 315		item->ins_or_del = 0;
 316		item->bytes_reserved = 0;
 317		item->delayed_node = NULL;
 318		atomic_set(&item->refs, 1);
 319	}
 320	return item;
 321}
 322
 323/*
 324 * __btrfs_lookup_delayed_item - look up the delayed item by key
 325 * @delayed_node: pointer to the delayed node
 326 * @key:	  the key to look up
 327 * @prev:	  used to store the prev item if the right item isn't found
 328 * @next:	  used to store the next item if the right item isn't found
 329 *
 330 * Note: if we don't find the right item, we will return the prev item and
 331 * the next item.
 332 */
 333static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
 334				struct rb_root *root,
 335				struct btrfs_key *key,
 336				struct btrfs_delayed_item **prev,
 337				struct btrfs_delayed_item **next)
 338{
 339	struct rb_node *node, *prev_node = NULL;
 340	struct btrfs_delayed_item *delayed_item = NULL;
 341	int ret = 0;
 342
 343	node = root->rb_node;
 344
 345	while (node) {
 346		delayed_item = rb_entry(node, struct btrfs_delayed_item,
 347					rb_node);
 348		prev_node = node;
 349		ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
 350		if (ret < 0)
 351			node = node->rb_right;
 352		else if (ret > 0)
 353			node = node->rb_left;
 354		else
 355			return delayed_item;
 356	}
 357
 358	if (prev) {
 359		if (!prev_node)
 360			*prev = NULL;
 361		else if (ret < 0)
 362			*prev = delayed_item;
 363		else if ((node = rb_prev(prev_node)) != NULL) {
 364			*prev = rb_entry(node, struct btrfs_delayed_item,
 365					 rb_node);
 366		} else
 367			*prev = NULL;
 368	}
 369
 370	if (next) {
 371		if (!prev_node)
 372			*next = NULL;
 373		else if (ret > 0)
 374			*next = delayed_item;
 375		else if ((node = rb_next(prev_node)) != NULL) {
 376			*next = rb_entry(node, struct btrfs_delayed_item,
 377					 rb_node);
 378		} else
 379			*next = NULL;
 380	}
 381	return NULL;
 382}
 383
 384struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
 385					struct btrfs_delayed_node *delayed_node,
 386					struct btrfs_key *key)
 387{
 388	struct btrfs_delayed_item *item;
 389
 390	item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
 391					   NULL, NULL);
 392	return item;
 393}
 394
 395struct btrfs_delayed_item *__btrfs_lookup_delayed_deletion_item(
 396					struct btrfs_delayed_node *delayed_node,
 397					struct btrfs_key *key)
 398{
 399	struct btrfs_delayed_item *item;
 400
 401	item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
 402					   NULL, NULL);
 403	return item;
 404}
 405
 406struct btrfs_delayed_item *__btrfs_search_delayed_insertion_item(
 407					struct btrfs_delayed_node *delayed_node,
 408					struct btrfs_key *key)
 409{
 410	struct btrfs_delayed_item *item, *next;
 411
 412	item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
 413					   NULL, &next);
 414	if (!item)
 415		item = next;
 416
 417	return item;
 418}
 419
 420struct btrfs_delayed_item *__btrfs_search_delayed_deletion_item(
 421					struct btrfs_delayed_node *delayed_node,
 422					struct btrfs_key *key)
 423{
 424	struct btrfs_delayed_item *item, *next;
 425
 426	item = __btrfs_lookup_delayed_item(&delayed_node->del_root, key,
 427					   NULL, &next);
 428	if (!item)
 429		item = next;
 430
 431	return item;
 432}
 433
 434static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 435				    struct btrfs_delayed_item *ins,
 436				    int action)
 437{
 438	struct rb_node **p, *node;
 439	struct rb_node *parent_node = NULL;
 440	struct rb_root *root;
 441	struct btrfs_delayed_item *item;
 442	int cmp;
 443
 444	if (action == BTRFS_DELAYED_INSERTION_ITEM)
 445		root = &delayed_node->ins_root;
 446	else if (action == BTRFS_DELAYED_DELETION_ITEM)
 447		root = &delayed_node->del_root;
 448	else
 449		BUG();
 450	p = &root->rb_node;
 451	node = &ins->rb_node;
 452
 453	while (*p) {
 454		parent_node = *p;
 455		item = rb_entry(parent_node, struct btrfs_delayed_item,
 456				 rb_node);
 457
 458		cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
 459		if (cmp < 0)
 460			p = &(*p)->rb_right;
 461		else if (cmp > 0)
 462			p = &(*p)->rb_left;
 463		else
 464			return -EEXIST;
 465	}
 466
 467	rb_link_node(node, parent_node, p);
 468	rb_insert_color(node, root);
 469	ins->delayed_node = delayed_node;
 470	ins->ins_or_del = action;
 471
 472	if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
 473	    action == BTRFS_DELAYED_INSERTION_ITEM &&
 474	    ins->key.offset >= delayed_node->index_cnt)
 475			delayed_node->index_cnt = ins->key.offset + 1;
 476
 477	delayed_node->count++;
 478	atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
 479	return 0;
 480}
 481
 482static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
 483					      struct btrfs_delayed_item *item)
 484{
 485	return __btrfs_add_delayed_item(node, item,
 486					BTRFS_DELAYED_INSERTION_ITEM);
 487}
 488
 489static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
 490					     struct btrfs_delayed_item *item)
 491{
 492	return __btrfs_add_delayed_item(node, item,
 493					BTRFS_DELAYED_DELETION_ITEM);
 494}
 495
 
 
 
 
 
 
 
 
 
 
 
 
 
 496static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 497{
 498	struct rb_root *root;
 499	struct btrfs_delayed_root *delayed_root;
 500
 501	delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 502
 503	BUG_ON(!delayed_root);
 504	BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
 505	       delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
 506
 507	if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
 508		root = &delayed_item->delayed_node->ins_root;
 509	else
 510		root = &delayed_item->delayed_node->del_root;
 511
 512	rb_erase(&delayed_item->rb_node, root);
 513	delayed_item->delayed_node->count--;
 514	atomic_dec(&delayed_root->items);
 515	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND &&
 516	    waitqueue_active(&delayed_root->wait))
 517		wake_up(&delayed_root->wait);
 518}
 519
 520static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 521{
 522	if (item) {
 523		__btrfs_remove_delayed_item(item);
 524		if (atomic_dec_and_test(&item->refs))
 525			kfree(item);
 526	}
 527}
 528
 529struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 530					struct btrfs_delayed_node *delayed_node)
 531{
 532	struct rb_node *p;
 533	struct btrfs_delayed_item *item = NULL;
 534
 535	p = rb_first(&delayed_node->ins_root);
 536	if (p)
 537		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 538
 539	return item;
 540}
 541
 542struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 543					struct btrfs_delayed_node *delayed_node)
 544{
 545	struct rb_node *p;
 546	struct btrfs_delayed_item *item = NULL;
 547
 548	p = rb_first(&delayed_node->del_root);
 549	if (p)
 550		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 551
 552	return item;
 553}
 554
 555struct btrfs_delayed_item *__btrfs_next_delayed_item(
 556						struct btrfs_delayed_item *item)
 557{
 558	struct rb_node *p;
 559	struct btrfs_delayed_item *next = NULL;
 560
 561	p = rb_next(&item->rb_node);
 562	if (p)
 563		next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 564
 565	return next;
 566}
 567
 568static inline struct btrfs_root *btrfs_get_fs_root(struct btrfs_root *root,
 569						   u64 root_id)
 570{
 571	struct btrfs_key root_key;
 572
 573	if (root->objectid == root_id)
 574		return root;
 575
 576	root_key.objectid = root_id;
 577	root_key.type = BTRFS_ROOT_ITEM_KEY;
 578	root_key.offset = (u64)-1;
 579	return btrfs_read_fs_root_no_name(root->fs_info, &root_key);
 580}
 581
 582static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 583					       struct btrfs_root *root,
 584					       struct btrfs_delayed_item *item)
 585{
 586	struct btrfs_block_rsv *src_rsv;
 587	struct btrfs_block_rsv *dst_rsv;
 588	u64 num_bytes;
 589	int ret;
 590
 591	if (!trans->bytes_reserved)
 592		return 0;
 593
 594	src_rsv = trans->block_rsv;
 595	dst_rsv = &root->fs_info->delayed_block_rsv;
 596
 597	num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 598	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
 599	if (!ret) {
 600		trace_btrfs_space_reservation(root->fs_info, "delayed_item",
 601					      item->key.objectid,
 602					      num_bytes, 1);
 603		item->bytes_reserved = num_bytes;
 604	}
 605
 606	return ret;
 607}
 608
 609static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
 610						struct btrfs_delayed_item *item)
 611{
 612	struct btrfs_block_rsv *rsv;
 613
 614	if (!item->bytes_reserved)
 615		return;
 616
 617	rsv = &root->fs_info->delayed_block_rsv;
 618	trace_btrfs_space_reservation(root->fs_info, "delayed_item",
 619				      item->key.objectid, item->bytes_reserved,
 620				      0);
 621	btrfs_block_rsv_release(root, rsv,
 622				item->bytes_reserved);
 623}
 624
 625static int btrfs_delayed_inode_reserve_metadata(
 626					struct btrfs_trans_handle *trans,
 627					struct btrfs_root *root,
 628					struct inode *inode,
 629					struct btrfs_delayed_node *node)
 630{
 631	struct btrfs_block_rsv *src_rsv;
 632	struct btrfs_block_rsv *dst_rsv;
 633	u64 num_bytes;
 634	int ret;
 635	bool release = false;
 636
 637	src_rsv = trans->block_rsv;
 638	dst_rsv = &root->fs_info->delayed_block_rsv;
 639
 640	num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 641
 642	/*
 643	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction
 644	 * which doesn't reserve space for speed.  This is a problem since we
 645	 * still need to reserve space for this update, so try to reserve the
 646	 * space.
 647	 *
 648	 * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
 649	 * we're accounted for.
 650	 */
 651	if (!src_rsv || (!trans->bytes_reserved &&
 652	    src_rsv != &root->fs_info->delalloc_block_rsv)) {
 653		ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
 
 654		/*
 655		 * Since we're under a transaction reserve_metadata_bytes could
 656		 * try to commit the transaction which will make it return
 657		 * EAGAIN to make us stop the transaction we have, so return
 658		 * ENOSPC instead so that btrfs_dirty_inode knows what to do.
 659		 */
 660		if (ret == -EAGAIN)
 661			ret = -ENOSPC;
 662		if (!ret) {
 663			node->bytes_reserved = num_bytes;
 664			trace_btrfs_space_reservation(root->fs_info,
 665						      "delayed_inode",
 666						      btrfs_ino(inode),
 667						      num_bytes, 1);
 668		}
 669		return ret;
 670	} else if (src_rsv == &root->fs_info->delalloc_block_rsv) {
 671		spin_lock(&BTRFS_I(inode)->lock);
 672		if (test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
 673				       &BTRFS_I(inode)->runtime_flags)) {
 674			spin_unlock(&BTRFS_I(inode)->lock);
 675			release = true;
 676			goto migrate;
 677		}
 678		spin_unlock(&BTRFS_I(inode)->lock);
 679
 680		/* Ok we didn't have space pre-reserved.  This shouldn't happen
 681		 * too often but it can happen if we do delalloc to an existing
 682		 * inode which gets dirtied because of the time update, and then
 683		 * isn't touched again until after the transaction commits and
 684		 * then we try to write out the data.  First try to be nice and
 685		 * reserve something strictly for us.  If not be a pain and try
 686		 * to steal from the delalloc block rsv.
 687		 */
 688		ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
 
 689		if (!ret)
 690			goto out;
 691
 692		ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
 693		if (!ret)
 694			goto out;
 695
 
 
 
 
 
 696		/*
 697		 * Ok this is a problem, let's just steal from the global rsv
 698		 * since this really shouldn't happen that often.
 699		 */
 700		WARN_ON(1);
 701		ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
 702					      dst_rsv, num_bytes);
 703		goto out;
 704	}
 705
 706migrate:
 707	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
 708
 709out:
 710	/*
 711	 * Migrate only takes a reservation, it doesn't touch the size of the
 712	 * block_rsv.  This is to simplify people who don't normally have things
 713	 * migrated from their block rsv.  If they go to release their
 714	 * reservation, that will decrease the size as well, so if migrate
 715	 * reduced size we'd end up with a negative size.  But for the
 716	 * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
 717	 * but we could in fact do this reserve/migrate dance several times
 718	 * between the time we did the original reservation and we'd clean it
 719	 * up.  So to take care of this, release the space for the meta
 720	 * reservation here.  I think it may be time for a documentation page on
 721	 * how block rsvs. work.
 722	 */
 723	if (!ret) {
 724		trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
 725					      btrfs_ino(inode), num_bytes, 1);
 726		node->bytes_reserved = num_bytes;
 727	}
 728
 729	if (release) {
 730		trace_btrfs_space_reservation(root->fs_info, "delalloc",
 731					      btrfs_ino(inode), num_bytes, 0);
 732		btrfs_block_rsv_release(root, src_rsv, num_bytes);
 733	}
 734
 735	return ret;
 736}
 737
 738static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
 739						struct btrfs_delayed_node *node)
 740{
 741	struct btrfs_block_rsv *rsv;
 742
 743	if (!node->bytes_reserved)
 744		return;
 745
 746	rsv = &root->fs_info->delayed_block_rsv;
 747	trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
 748				      node->inode_id, node->bytes_reserved, 0);
 749	btrfs_block_rsv_release(root, rsv,
 750				node->bytes_reserved);
 751	node->bytes_reserved = 0;
 752}
 753
 754/*
 755 * This helper will insert some continuous items into the same leaf according
 756 * to the free space of the leaf.
 757 */
 758static int btrfs_batch_insert_items(struct btrfs_trans_handle *trans,
 759				struct btrfs_root *root,
 760				struct btrfs_path *path,
 761				struct btrfs_delayed_item *item)
 762{
 763	struct btrfs_delayed_item *curr, *next;
 764	int free_space;
 765	int total_data_size = 0, total_size = 0;
 766	struct extent_buffer *leaf;
 767	char *data_ptr;
 768	struct btrfs_key *keys;
 769	u32 *data_size;
 770	struct list_head head;
 771	int slot;
 772	int nitems;
 773	int i;
 774	int ret = 0;
 775
 776	BUG_ON(!path->nodes[0]);
 777
 778	leaf = path->nodes[0];
 779	free_space = btrfs_leaf_free_space(root, leaf);
 780	INIT_LIST_HEAD(&head);
 781
 782	next = item;
 783	nitems = 0;
 784
 785	/*
 786	 * count the number of the continuous items that we can insert in batch
 787	 */
 788	while (total_size + next->data_len + sizeof(struct btrfs_item) <=
 789	       free_space) {
 790		total_data_size += next->data_len;
 791		total_size += next->data_len + sizeof(struct btrfs_item);
 792		list_add_tail(&next->tree_list, &head);
 793		nitems++;
 794
 795		curr = next;
 796		next = __btrfs_next_delayed_item(curr);
 797		if (!next)
 798			break;
 799
 800		if (!btrfs_is_continuous_delayed_item(curr, next))
 801			break;
 802	}
 803
 804	if (!nitems) {
 805		ret = 0;
 806		goto out;
 807	}
 808
 809	/*
 810	 * we need allocate some memory space, but it might cause the task
 811	 * to sleep, so we set all locked nodes in the path to blocking locks
 812	 * first.
 813	 */
 814	btrfs_set_path_blocking(path);
 815
 816	keys = kmalloc(sizeof(struct btrfs_key) * nitems, GFP_NOFS);
 817	if (!keys) {
 818		ret = -ENOMEM;
 819		goto out;
 820	}
 821
 822	data_size = kmalloc(sizeof(u32) * nitems, GFP_NOFS);
 823	if (!data_size) {
 824		ret = -ENOMEM;
 825		goto error;
 826	}
 827
 828	/* get keys of all the delayed items */
 829	i = 0;
 830	list_for_each_entry(next, &head, tree_list) {
 831		keys[i] = next->key;
 832		data_size[i] = next->data_len;
 833		i++;
 834	}
 835
 836	/* reset all the locked nodes in the patch to spinning locks. */
 837	btrfs_clear_path_blocking(path, NULL, 0);
 838
 839	/* insert the keys of the items */
 840	setup_items_for_insert(trans, root, path, keys, data_size,
 841			       total_data_size, total_size, nitems);
 842
 843	/* insert the dir index items */
 844	slot = path->slots[0];
 845	list_for_each_entry_safe(curr, next, &head, tree_list) {
 846		data_ptr = btrfs_item_ptr(leaf, slot, char);
 847		write_extent_buffer(leaf, &curr->data,
 848				    (unsigned long)data_ptr,
 849				    curr->data_len);
 850		slot++;
 851
 852		btrfs_delayed_item_release_metadata(root, curr);
 853
 854		list_del(&curr->tree_list);
 855		btrfs_release_delayed_item(curr);
 856	}
 857
 858error:
 859	kfree(data_size);
 860	kfree(keys);
 861out:
 862	return ret;
 863}
 864
 865/*
 866 * This helper can just do simple insertion that needn't extend item for new
 867 * data, such as directory name index insertion, inode insertion.
 868 */
 869static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 870				     struct btrfs_root *root,
 871				     struct btrfs_path *path,
 872				     struct btrfs_delayed_item *delayed_item)
 873{
 874	struct extent_buffer *leaf;
 875	struct btrfs_item *item;
 876	char *ptr;
 877	int ret;
 878
 879	ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
 880				      delayed_item->data_len);
 881	if (ret < 0 && ret != -EEXIST)
 882		return ret;
 883
 884	leaf = path->nodes[0];
 885
 886	item = btrfs_item_nr(leaf, path->slots[0]);
 887	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
 888
 889	write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
 890			    delayed_item->data_len);
 891	btrfs_mark_buffer_dirty(leaf);
 892
 893	btrfs_delayed_item_release_metadata(root, delayed_item);
 894	return 0;
 895}
 896
 897/*
 898 * we insert an item first, then if there are some continuous items, we try
 899 * to insert those items into the same leaf.
 900 */
 901static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 902				      struct btrfs_path *path,
 903				      struct btrfs_root *root,
 904				      struct btrfs_delayed_node *node)
 905{
 906	struct btrfs_delayed_item *curr, *prev;
 907	int ret = 0;
 908
 909do_again:
 910	mutex_lock(&node->mutex);
 911	curr = __btrfs_first_delayed_insertion_item(node);
 912	if (!curr)
 913		goto insert_end;
 914
 915	ret = btrfs_insert_delayed_item(trans, root, path, curr);
 916	if (ret < 0) {
 917		btrfs_release_path(path);
 918		goto insert_end;
 919	}
 920
 921	prev = curr;
 922	curr = __btrfs_next_delayed_item(prev);
 923	if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
 924		/* insert the continuous items into the same leaf */
 925		path->slots[0]++;
 926		btrfs_batch_insert_items(trans, root, path, curr);
 927	}
 928	btrfs_release_delayed_item(prev);
 929	btrfs_mark_buffer_dirty(path->nodes[0]);
 930
 931	btrfs_release_path(path);
 932	mutex_unlock(&node->mutex);
 933	goto do_again;
 934
 935insert_end:
 936	mutex_unlock(&node->mutex);
 937	return ret;
 938}
 939
 940static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
 941				    struct btrfs_root *root,
 942				    struct btrfs_path *path,
 943				    struct btrfs_delayed_item *item)
 944{
 945	struct btrfs_delayed_item *curr, *next;
 946	struct extent_buffer *leaf;
 947	struct btrfs_key key;
 948	struct list_head head;
 949	int nitems, i, last_item;
 950	int ret = 0;
 951
 952	BUG_ON(!path->nodes[0]);
 953
 954	leaf = path->nodes[0];
 955
 956	i = path->slots[0];
 957	last_item = btrfs_header_nritems(leaf) - 1;
 958	if (i > last_item)
 959		return -ENOENT;	/* FIXME: Is errno suitable? */
 960
 961	next = item;
 962	INIT_LIST_HEAD(&head);
 963	btrfs_item_key_to_cpu(leaf, &key, i);
 964	nitems = 0;
 965	/*
 966	 * count the number of the dir index items that we can delete in batch
 967	 */
 968	while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
 969		list_add_tail(&next->tree_list, &head);
 970		nitems++;
 971
 972		curr = next;
 973		next = __btrfs_next_delayed_item(curr);
 974		if (!next)
 975			break;
 976
 977		if (!btrfs_is_continuous_delayed_item(curr, next))
 978			break;
 979
 980		i++;
 981		if (i > last_item)
 982			break;
 983		btrfs_item_key_to_cpu(leaf, &key, i);
 984	}
 985
 986	if (!nitems)
 987		return 0;
 988
 989	ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
 990	if (ret)
 991		goto out;
 992
 993	list_for_each_entry_safe(curr, next, &head, tree_list) {
 994		btrfs_delayed_item_release_metadata(root, curr);
 995		list_del(&curr->tree_list);
 996		btrfs_release_delayed_item(curr);
 997	}
 998
 999out:
1000	return ret;
1001}
1002
1003static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
1004				      struct btrfs_path *path,
1005				      struct btrfs_root *root,
1006				      struct btrfs_delayed_node *node)
1007{
1008	struct btrfs_delayed_item *curr, *prev;
1009	int ret = 0;
1010
1011do_again:
1012	mutex_lock(&node->mutex);
1013	curr = __btrfs_first_delayed_deletion_item(node);
1014	if (!curr)
1015		goto delete_fail;
1016
1017	ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
1018	if (ret < 0)
1019		goto delete_fail;
1020	else if (ret > 0) {
1021		/*
1022		 * can't find the item which the node points to, so this node
1023		 * is invalid, just drop it.
1024		 */
1025		prev = curr;
1026		curr = __btrfs_next_delayed_item(prev);
1027		btrfs_release_delayed_item(prev);
1028		ret = 0;
1029		btrfs_release_path(path);
1030		if (curr)
 
1031			goto do_again;
1032		else
1033			goto delete_fail;
1034	}
1035
1036	btrfs_batch_delete_items(trans, root, path, curr);
1037	btrfs_release_path(path);
1038	mutex_unlock(&node->mutex);
1039	goto do_again;
1040
1041delete_fail:
1042	btrfs_release_path(path);
1043	mutex_unlock(&node->mutex);
1044	return ret;
1045}
1046
1047static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
1048{
1049	struct btrfs_delayed_root *delayed_root;
1050
1051	if (delayed_node && delayed_node->inode_dirty) {
 
1052		BUG_ON(!delayed_node->root);
1053		delayed_node->inode_dirty = 0;
1054		delayed_node->count--;
1055
1056		delayed_root = delayed_node->root->fs_info->delayed_root;
1057		atomic_dec(&delayed_root->items);
1058		if (atomic_read(&delayed_root->items) <
1059		    BTRFS_DELAYED_BACKGROUND &&
1060		    waitqueue_active(&delayed_root->wait))
1061			wake_up(&delayed_root->wait);
1062	}
1063}
1064
1065static int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1066				      struct btrfs_root *root,
1067				      struct btrfs_path *path,
1068				      struct btrfs_delayed_node *node)
 
 
 
 
 
 
 
 
 
 
 
 
1069{
1070	struct btrfs_key key;
1071	struct btrfs_inode_item *inode_item;
1072	struct extent_buffer *leaf;
 
1073	int ret;
1074
1075	mutex_lock(&node->mutex);
1076	if (!node->inode_dirty) {
1077		mutex_unlock(&node->mutex);
1078		return 0;
1079	}
1080
1081	key.objectid = node->inode_id;
1082	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1083	key.offset = 0;
1084	ret = btrfs_lookup_inode(trans, root, path, &key, 1);
 
 
 
 
 
 
1085	if (ret > 0) {
1086		btrfs_release_path(path);
1087		mutex_unlock(&node->mutex);
1088		return -ENOENT;
1089	} else if (ret < 0) {
1090		mutex_unlock(&node->mutex);
1091		return ret;
1092	}
1093
1094	btrfs_unlock_up_safe(path, 1);
1095	leaf = path->nodes[0];
1096	inode_item = btrfs_item_ptr(leaf, path->slots[0],
1097				    struct btrfs_inode_item);
1098	write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1099			    sizeof(struct btrfs_inode_item));
1100	btrfs_mark_buffer_dirty(leaf);
1101	btrfs_release_path(path);
1102
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1103	btrfs_delayed_inode_release_metadata(root, node);
1104	btrfs_release_delayed_inode(node);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1105	mutex_unlock(&node->mutex);
 
 
1106
1107	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1108}
1109
1110/*
1111 * Called when committing the transaction.
1112 * Returns 0 on success.
1113 * Returns < 0 on error and returns with an aborted transaction with any
1114 * outstanding delayed items cleaned up.
1115 */
1116int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1117			    struct btrfs_root *root)
1118{
1119	struct btrfs_root *curr_root = root;
1120	struct btrfs_delayed_root *delayed_root;
1121	struct btrfs_delayed_node *curr_node, *prev_node;
1122	struct btrfs_path *path;
1123	struct btrfs_block_rsv *block_rsv;
1124	int ret = 0;
 
1125
1126	if (trans->aborted)
1127		return -EIO;
1128
1129	path = btrfs_alloc_path();
1130	if (!path)
1131		return -ENOMEM;
1132	path->leave_spinning = 1;
1133
1134	block_rsv = trans->block_rsv;
1135	trans->block_rsv = &root->fs_info->delayed_block_rsv;
1136
1137	delayed_root = btrfs_get_delayed_root(root);
1138
1139	curr_node = btrfs_first_delayed_node(delayed_root);
1140	while (curr_node) {
1141		curr_root = curr_node->root;
1142		ret = btrfs_insert_delayed_items(trans, path, curr_root,
1143						 curr_node);
1144		if (!ret)
1145			ret = btrfs_delete_delayed_items(trans, path,
1146						curr_root, curr_node);
1147		if (!ret)
1148			ret = btrfs_update_delayed_inode(trans, curr_root,
1149						path, curr_node);
1150		if (ret) {
1151			btrfs_release_delayed_node(curr_node);
 
1152			btrfs_abort_transaction(trans, root, ret);
1153			break;
1154		}
1155
1156		prev_node = curr_node;
1157		curr_node = btrfs_next_delayed_node(curr_node);
1158		btrfs_release_delayed_node(prev_node);
1159	}
1160
 
 
1161	btrfs_free_path(path);
1162	trans->block_rsv = block_rsv;
1163
1164	return ret;
1165}
1166
1167static int __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1168					      struct btrfs_delayed_node *node)
 
 
 
 
 
 
 
 
 
 
 
 
1169{
 
1170	struct btrfs_path *path;
1171	struct btrfs_block_rsv *block_rsv;
1172	int ret;
1173
 
 
 
 
 
 
 
 
 
 
 
1174	path = btrfs_alloc_path();
1175	if (!path)
 
1176		return -ENOMEM;
 
1177	path->leave_spinning = 1;
1178
1179	block_rsv = trans->block_rsv;
1180	trans->block_rsv = &node->root->fs_info->delayed_block_rsv;
1181
1182	ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1183	if (!ret)
1184		ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1185	if (!ret)
1186		ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1187	btrfs_free_path(path);
1188
 
 
1189	trans->block_rsv = block_rsv;
 
1190	return ret;
1191}
1192
1193int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1194				     struct inode *inode)
1195{
 
1196	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
 
 
1197	int ret;
1198
1199	if (!delayed_node)
1200		return 0;
1201
1202	mutex_lock(&delayed_node->mutex);
1203	if (!delayed_node->count) {
1204		mutex_unlock(&delayed_node->mutex);
1205		btrfs_release_delayed_node(delayed_node);
1206		return 0;
1207	}
1208	mutex_unlock(&delayed_node->mutex);
1209
1210	ret = __btrfs_commit_inode_delayed_items(trans, delayed_node);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1211	btrfs_release_delayed_node(delayed_node);
 
1212	return ret;
1213}
1214
1215void btrfs_remove_delayed_node(struct inode *inode)
1216{
1217	struct btrfs_delayed_node *delayed_node;
1218
1219	delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1220	if (!delayed_node)
1221		return;
1222
1223	BTRFS_I(inode)->delayed_node = NULL;
1224	btrfs_release_delayed_node(delayed_node);
1225}
1226
1227struct btrfs_async_delayed_node {
1228	struct btrfs_root *root;
1229	struct btrfs_delayed_node *delayed_node;
1230	struct btrfs_work work;
1231};
1232
1233static void btrfs_async_run_delayed_node_done(struct btrfs_work *work)
1234{
1235	struct btrfs_async_delayed_node *async_node;
 
1236	struct btrfs_trans_handle *trans;
1237	struct btrfs_path *path;
1238	struct btrfs_delayed_node *delayed_node = NULL;
1239	struct btrfs_root *root;
1240	struct btrfs_block_rsv *block_rsv;
1241	unsigned long nr = 0;
1242	int need_requeue = 0;
1243	int ret;
1244
1245	async_node = container_of(work, struct btrfs_async_delayed_node, work);
 
1246
1247	path = btrfs_alloc_path();
1248	if (!path)
1249		goto out;
1250	path->leave_spinning = 1;
1251
1252	delayed_node = async_node->delayed_node;
 
 
 
 
 
 
 
 
1253	root = delayed_node->root;
1254
1255	trans = btrfs_join_transaction(root);
1256	if (IS_ERR(trans))
1257		goto free_path;
1258
1259	block_rsv = trans->block_rsv;
1260	trans->block_rsv = &root->fs_info->delayed_block_rsv;
1261
1262	ret = btrfs_insert_delayed_items(trans, path, root, delayed_node);
1263	if (!ret)
1264		ret = btrfs_delete_delayed_items(trans, path, root,
1265						 delayed_node);
1266
1267	if (!ret)
1268		btrfs_update_delayed_inode(trans, root, path, delayed_node);
 
1269
1270	/*
1271	 * Maybe new delayed items have been inserted, so we need requeue
1272	 * the work. Besides that, we must dequeue the empty delayed nodes
1273	 * to avoid the race between delayed items balance and the worker.
1274	 * The race like this:
1275	 * 	Task1				Worker thread
1276	 * 					count == 0, needn't requeue
1277	 * 					  also needn't insert the
1278	 * 					  delayed node into prepare
1279	 * 					  list again.
1280	 * 	add lots of delayed items
1281	 * 	queue the delayed node
1282	 * 	  already in the list,
1283	 * 	  and not in the prepare
1284	 * 	  list, it means the delayed
1285	 * 	  node is being dealt with
1286	 * 	  by the worker.
1287	 * 	do delayed items balance
1288	 * 	  the delayed node is being
1289	 * 	  dealt with by the worker
1290	 * 	  now, just wait.
1291	 * 	  				the worker goto idle.
1292	 * Task1 will sleep until the transaction is commited.
1293	 */
1294	mutex_lock(&delayed_node->mutex);
1295	if (delayed_node->count)
1296		need_requeue = 1;
1297	else
1298		btrfs_dequeue_delayed_node(root->fs_info->delayed_root,
1299					   delayed_node);
1300	mutex_unlock(&delayed_node->mutex);
1301
1302	nr = trans->blocks_used;
 
 
1303
1304	trans->block_rsv = block_rsv;
1305	btrfs_end_transaction_dmeta(trans, root);
1306	__btrfs_btree_balance_dirty(root, nr);
1307free_path:
1308	btrfs_free_path(path);
1309out:
1310	if (need_requeue)
1311		btrfs_requeue_work(&async_node->work);
1312	else {
1313		btrfs_release_prepared_delayed_node(delayed_node);
1314		kfree(async_node);
1315	}
1316}
1317
 
1318static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1319				     struct btrfs_root *root, int all)
1320{
1321	struct btrfs_async_delayed_node *async_node;
1322	struct btrfs_delayed_node *curr;
1323	int count = 0;
1324
1325again:
1326	curr = btrfs_first_prepared_delayed_node(delayed_root);
1327	if (!curr)
1328		return 0;
1329
1330	async_node = kmalloc(sizeof(*async_node), GFP_NOFS);
1331	if (!async_node) {
1332		btrfs_release_prepared_delayed_node(curr);
1333		return -ENOMEM;
1334	}
1335
1336	async_node->root = root;
1337	async_node->delayed_node = curr;
1338
1339	async_node->work.func = btrfs_async_run_delayed_node_done;
1340	async_node->work.flags = 0;
1341
1342	btrfs_queue_worker(&root->fs_info->delayed_workers, &async_node->work);
1343	count++;
1344
1345	if (all || count < 4)
1346		goto again;
 
 
1347
 
1348	return 0;
1349}
1350
1351void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1352{
1353	struct btrfs_delayed_root *delayed_root;
1354	delayed_root = btrfs_get_delayed_root(root);
1355	WARN_ON(btrfs_first_delayed_node(delayed_root));
1356}
1357
 
 
 
 
 
 
 
 
 
 
 
 
 
1358void btrfs_balance_delayed_items(struct btrfs_root *root)
1359{
1360	struct btrfs_delayed_root *delayed_root;
 
1361
1362	delayed_root = btrfs_get_delayed_root(root);
1363
1364	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1365		return;
1366
1367	if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
 
1368		int ret;
1369		ret = btrfs_wq_run_delayed_node(delayed_root, root, 1);
 
 
 
1370		if (ret)
1371			return;
1372
1373		wait_event_interruptible_timeout(
1374				delayed_root->wait,
1375				(atomic_read(&delayed_root->items) <
1376				 BTRFS_DELAYED_BACKGROUND),
1377				HZ);
1378		return;
1379	}
1380
1381	btrfs_wq_run_delayed_node(delayed_root, root, 0);
1382}
1383
1384/* Will return 0 or -ENOMEM */
1385int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1386				   struct btrfs_root *root, const char *name,
1387				   int name_len, struct inode *dir,
1388				   struct btrfs_disk_key *disk_key, u8 type,
1389				   u64 index)
1390{
1391	struct btrfs_delayed_node *delayed_node;
1392	struct btrfs_delayed_item *delayed_item;
1393	struct btrfs_dir_item *dir_item;
1394	int ret;
1395
1396	delayed_node = btrfs_get_or_create_delayed_node(dir);
1397	if (IS_ERR(delayed_node))
1398		return PTR_ERR(delayed_node);
1399
1400	delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1401	if (!delayed_item) {
1402		ret = -ENOMEM;
1403		goto release_node;
1404	}
1405
1406	delayed_item->key.objectid = btrfs_ino(dir);
1407	btrfs_set_key_type(&delayed_item->key, BTRFS_DIR_INDEX_KEY);
1408	delayed_item->key.offset = index;
1409
1410	dir_item = (struct btrfs_dir_item *)delayed_item->data;
1411	dir_item->location = *disk_key;
1412	dir_item->transid = cpu_to_le64(trans->transid);
1413	dir_item->data_len = 0;
1414	dir_item->name_len = cpu_to_le16(name_len);
1415	dir_item->type = type;
1416	memcpy((char *)(dir_item + 1), name, name_len);
1417
1418	ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1419	/*
1420	 * we have reserved enough space when we start a new transaction,
1421	 * so reserving metadata failure is impossible
1422	 */
1423	BUG_ON(ret);
1424
1425
1426	mutex_lock(&delayed_node->mutex);
1427	ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1428	if (unlikely(ret)) {
1429		printk(KERN_ERR "err add delayed dir index item(name: %s) into "
1430				"the insertion tree of the delayed node"
1431				"(root id: %llu, inode id: %llu, errno: %d)\n",
1432				name,
1433				(unsigned long long)delayed_node->root->objectid,
1434				(unsigned long long)delayed_node->inode_id,
1435				ret);
1436		BUG();
1437	}
1438	mutex_unlock(&delayed_node->mutex);
1439
1440release_node:
1441	btrfs_release_delayed_node(delayed_node);
1442	return ret;
1443}
1444
1445static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1446					       struct btrfs_delayed_node *node,
1447					       struct btrfs_key *key)
1448{
1449	struct btrfs_delayed_item *item;
1450
1451	mutex_lock(&node->mutex);
1452	item = __btrfs_lookup_delayed_insertion_item(node, key);
1453	if (!item) {
1454		mutex_unlock(&node->mutex);
1455		return 1;
1456	}
1457
1458	btrfs_delayed_item_release_metadata(root, item);
1459	btrfs_release_delayed_item(item);
1460	mutex_unlock(&node->mutex);
1461	return 0;
1462}
1463
1464int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1465				   struct btrfs_root *root, struct inode *dir,
1466				   u64 index)
1467{
1468	struct btrfs_delayed_node *node;
1469	struct btrfs_delayed_item *item;
1470	struct btrfs_key item_key;
1471	int ret;
1472
1473	node = btrfs_get_or_create_delayed_node(dir);
1474	if (IS_ERR(node))
1475		return PTR_ERR(node);
1476
1477	item_key.objectid = btrfs_ino(dir);
1478	btrfs_set_key_type(&item_key, BTRFS_DIR_INDEX_KEY);
1479	item_key.offset = index;
1480
1481	ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1482	if (!ret)
1483		goto end;
1484
1485	item = btrfs_alloc_delayed_item(0);
1486	if (!item) {
1487		ret = -ENOMEM;
1488		goto end;
1489	}
1490
1491	item->key = item_key;
1492
1493	ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1494	/*
1495	 * we have reserved enough space when we start a new transaction,
1496	 * so reserving metadata failure is impossible.
1497	 */
1498	BUG_ON(ret);
1499
1500	mutex_lock(&node->mutex);
1501	ret = __btrfs_add_delayed_deletion_item(node, item);
1502	if (unlikely(ret)) {
1503		printk(KERN_ERR "err add delayed dir index item(index: %llu) "
1504				"into the deletion tree of the delayed node"
1505				"(root id: %llu, inode id: %llu, errno: %d)\n",
1506				(unsigned long long)index,
1507				(unsigned long long)node->root->objectid,
1508				(unsigned long long)node->inode_id,
1509				ret);
1510		BUG();
1511	}
1512	mutex_unlock(&node->mutex);
1513end:
1514	btrfs_release_delayed_node(node);
1515	return ret;
1516}
1517
1518int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1519{
1520	struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1521
1522	if (!delayed_node)
1523		return -ENOENT;
1524
1525	/*
1526	 * Since we have held i_mutex of this directory, it is impossible that
1527	 * a new directory index is added into the delayed node and index_cnt
1528	 * is updated now. So we needn't lock the delayed node.
1529	 */
1530	if (!delayed_node->index_cnt) {
1531		btrfs_release_delayed_node(delayed_node);
1532		return -EINVAL;
1533	}
1534
1535	BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1536	btrfs_release_delayed_node(delayed_node);
1537	return 0;
1538}
1539
1540void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
1541			     struct list_head *del_list)
1542{
1543	struct btrfs_delayed_node *delayed_node;
1544	struct btrfs_delayed_item *item;
1545
1546	delayed_node = btrfs_get_delayed_node(inode);
1547	if (!delayed_node)
1548		return;
1549
1550	mutex_lock(&delayed_node->mutex);
1551	item = __btrfs_first_delayed_insertion_item(delayed_node);
1552	while (item) {
1553		atomic_inc(&item->refs);
1554		list_add_tail(&item->readdir_list, ins_list);
1555		item = __btrfs_next_delayed_item(item);
1556	}
1557
1558	item = __btrfs_first_delayed_deletion_item(delayed_node);
1559	while (item) {
1560		atomic_inc(&item->refs);
1561		list_add_tail(&item->readdir_list, del_list);
1562		item = __btrfs_next_delayed_item(item);
1563	}
1564	mutex_unlock(&delayed_node->mutex);
1565	/*
1566	 * This delayed node is still cached in the btrfs inode, so refs
1567	 * must be > 1 now, and we needn't check it is going to be freed
1568	 * or not.
1569	 *
1570	 * Besides that, this function is used to read dir, we do not
1571	 * insert/delete delayed items in this period. So we also needn't
1572	 * requeue or dequeue this delayed node.
1573	 */
1574	atomic_dec(&delayed_node->refs);
1575}
1576
1577void btrfs_put_delayed_items(struct list_head *ins_list,
1578			     struct list_head *del_list)
1579{
1580	struct btrfs_delayed_item *curr, *next;
1581
1582	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1583		list_del(&curr->readdir_list);
1584		if (atomic_dec_and_test(&curr->refs))
1585			kfree(curr);
1586	}
1587
1588	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1589		list_del(&curr->readdir_list);
1590		if (atomic_dec_and_test(&curr->refs))
1591			kfree(curr);
1592	}
1593}
1594
1595int btrfs_should_delete_dir_index(struct list_head *del_list,
1596				  u64 index)
1597{
1598	struct btrfs_delayed_item *curr, *next;
1599	int ret;
1600
1601	if (list_empty(del_list))
1602		return 0;
1603
1604	list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1605		if (curr->key.offset > index)
1606			break;
1607
1608		list_del(&curr->readdir_list);
1609		ret = (curr->key.offset == index);
1610
1611		if (atomic_dec_and_test(&curr->refs))
1612			kfree(curr);
1613
1614		if (ret)
1615			return 1;
1616		else
1617			continue;
1618	}
1619	return 0;
1620}
1621
1622/*
1623 * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1624 *
1625 */
1626int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
1627				    filldir_t filldir,
1628				    struct list_head *ins_list)
1629{
1630	struct btrfs_dir_item *di;
1631	struct btrfs_delayed_item *curr, *next;
1632	struct btrfs_key location;
1633	char *name;
1634	int name_len;
1635	int over = 0;
1636	unsigned char d_type;
1637
1638	if (list_empty(ins_list))
1639		return 0;
1640
1641	/*
1642	 * Changing the data of the delayed item is impossible. So
1643	 * we needn't lock them. And we have held i_mutex of the
1644	 * directory, nobody can delete any directory indexes now.
1645	 */
1646	list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1647		list_del(&curr->readdir_list);
1648
1649		if (curr->key.offset < filp->f_pos) {
1650			if (atomic_dec_and_test(&curr->refs))
1651				kfree(curr);
1652			continue;
1653		}
1654
1655		filp->f_pos = curr->key.offset;
1656
1657		di = (struct btrfs_dir_item *)curr->data;
1658		name = (char *)(di + 1);
1659		name_len = le16_to_cpu(di->name_len);
1660
1661		d_type = btrfs_filetype_table[di->type];
1662		btrfs_disk_key_to_cpu(&location, &di->location);
1663
1664		over = filldir(dirent, name, name_len, curr->key.offset,
1665			       location.objectid, d_type);
1666
1667		if (atomic_dec_and_test(&curr->refs))
1668			kfree(curr);
1669
1670		if (over)
1671			return 1;
 
1672	}
1673	return 0;
1674}
1675
1676BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item,
1677			 generation, 64);
1678BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item,
1679			 sequence, 64);
1680BTRFS_SETGET_STACK_FUNCS(stack_inode_transid, struct btrfs_inode_item,
1681			 transid, 64);
1682BTRFS_SETGET_STACK_FUNCS(stack_inode_size, struct btrfs_inode_item, size, 64);
1683BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes, struct btrfs_inode_item,
1684			 nbytes, 64);
1685BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group, struct btrfs_inode_item,
1686			 block_group, 64);
1687BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink, struct btrfs_inode_item, nlink, 32);
1688BTRFS_SETGET_STACK_FUNCS(stack_inode_uid, struct btrfs_inode_item, uid, 32);
1689BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32);
1690BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32);
1691BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64);
1692BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64);
1693
1694BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
1695BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
1696
1697static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1698				  struct btrfs_inode_item *inode_item,
1699				  struct inode *inode)
1700{
1701	btrfs_set_stack_inode_uid(inode_item, inode->i_uid);
1702	btrfs_set_stack_inode_gid(inode_item, inode->i_gid);
1703	btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1704	btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1705	btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1706	btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1707	btrfs_set_stack_inode_generation(inode_item,
1708					 BTRFS_I(inode)->generation);
1709	btrfs_set_stack_inode_sequence(inode_item, inode->i_version);
1710	btrfs_set_stack_inode_transid(inode_item, trans->transid);
1711	btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1712	btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1713	btrfs_set_stack_inode_block_group(inode_item, 0);
1714
1715	btrfs_set_stack_timespec_sec(btrfs_inode_atime(inode_item),
1716				     inode->i_atime.tv_sec);
1717	btrfs_set_stack_timespec_nsec(btrfs_inode_atime(inode_item),
1718				      inode->i_atime.tv_nsec);
1719
1720	btrfs_set_stack_timespec_sec(btrfs_inode_mtime(inode_item),
1721				     inode->i_mtime.tv_sec);
1722	btrfs_set_stack_timespec_nsec(btrfs_inode_mtime(inode_item),
1723				      inode->i_mtime.tv_nsec);
1724
1725	btrfs_set_stack_timespec_sec(btrfs_inode_ctime(inode_item),
1726				     inode->i_ctime.tv_sec);
1727	btrfs_set_stack_timespec_nsec(btrfs_inode_ctime(inode_item),
1728				      inode->i_ctime.tv_nsec);
 
 
 
 
 
1729}
1730
1731int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1732{
1733	struct btrfs_delayed_node *delayed_node;
1734	struct btrfs_inode_item *inode_item;
1735	struct btrfs_timespec *tspec;
1736
1737	delayed_node = btrfs_get_delayed_node(inode);
1738	if (!delayed_node)
1739		return -ENOENT;
1740
1741	mutex_lock(&delayed_node->mutex);
1742	if (!delayed_node->inode_dirty) {
1743		mutex_unlock(&delayed_node->mutex);
1744		btrfs_release_delayed_node(delayed_node);
1745		return -ENOENT;
1746	}
1747
1748	inode_item = &delayed_node->inode_item;
1749
1750	inode->i_uid = btrfs_stack_inode_uid(inode_item);
1751	inode->i_gid = btrfs_stack_inode_gid(inode_item);
1752	btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1753	inode->i_mode = btrfs_stack_inode_mode(inode_item);
1754	set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1755	inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1756	BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
 
 
1757	inode->i_version = btrfs_stack_inode_sequence(inode_item);
1758	inode->i_rdev = 0;
1759	*rdev = btrfs_stack_inode_rdev(inode_item);
1760	BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1761
1762	tspec = btrfs_inode_atime(inode_item);
1763	inode->i_atime.tv_sec = btrfs_stack_timespec_sec(tspec);
1764	inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1765
1766	tspec = btrfs_inode_mtime(inode_item);
1767	inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(tspec);
1768	inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1769
1770	tspec = btrfs_inode_ctime(inode_item);
1771	inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(tspec);
1772	inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
 
 
1773
1774	inode->i_generation = BTRFS_I(inode)->generation;
1775	BTRFS_I(inode)->index_cnt = (u64)-1;
1776
1777	mutex_unlock(&delayed_node->mutex);
1778	btrfs_release_delayed_node(delayed_node);
1779	return 0;
1780}
1781
1782int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1783			       struct btrfs_root *root, struct inode *inode)
1784{
1785	struct btrfs_delayed_node *delayed_node;
1786	int ret = 0;
1787
1788	delayed_node = btrfs_get_or_create_delayed_node(inode);
1789	if (IS_ERR(delayed_node))
1790		return PTR_ERR(delayed_node);
1791
1792	mutex_lock(&delayed_node->mutex);
1793	if (delayed_node->inode_dirty) {
1794		fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1795		goto release_node;
1796	}
1797
1798	ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1799						   delayed_node);
1800	if (ret)
1801		goto release_node;
1802
1803	fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1804	delayed_node->inode_dirty = 1;
1805	delayed_node->count++;
1806	atomic_inc(&root->fs_info->delayed_root->items);
1807release_node:
1808	mutex_unlock(&delayed_node->mutex);
1809	btrfs_release_delayed_node(delayed_node);
1810	return ret;
1811}
1812
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1813static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1814{
1815	struct btrfs_root *root = delayed_node->root;
1816	struct btrfs_delayed_item *curr_item, *prev_item;
1817
1818	mutex_lock(&delayed_node->mutex);
1819	curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1820	while (curr_item) {
1821		btrfs_delayed_item_release_metadata(root, curr_item);
1822		prev_item = curr_item;
1823		curr_item = __btrfs_next_delayed_item(prev_item);
1824		btrfs_release_delayed_item(prev_item);
1825	}
1826
1827	curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1828	while (curr_item) {
1829		btrfs_delayed_item_release_metadata(root, curr_item);
1830		prev_item = curr_item;
1831		curr_item = __btrfs_next_delayed_item(prev_item);
1832		btrfs_release_delayed_item(prev_item);
1833	}
1834
1835	if (delayed_node->inode_dirty) {
 
 
 
1836		btrfs_delayed_inode_release_metadata(root, delayed_node);
1837		btrfs_release_delayed_inode(delayed_node);
1838	}
1839	mutex_unlock(&delayed_node->mutex);
1840}
1841
1842void btrfs_kill_delayed_inode_items(struct inode *inode)
1843{
1844	struct btrfs_delayed_node *delayed_node;
1845
1846	delayed_node = btrfs_get_delayed_node(inode);
1847	if (!delayed_node)
1848		return;
1849
1850	__btrfs_kill_delayed_node(delayed_node);
1851	btrfs_release_delayed_node(delayed_node);
1852}
1853
1854void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1855{
1856	u64 inode_id = 0;
1857	struct btrfs_delayed_node *delayed_nodes[8];
1858	int i, n;
1859
1860	while (1) {
1861		spin_lock(&root->inode_lock);
1862		n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1863					   (void **)delayed_nodes, inode_id,
1864					   ARRAY_SIZE(delayed_nodes));
1865		if (!n) {
1866			spin_unlock(&root->inode_lock);
1867			break;
1868		}
1869
1870		inode_id = delayed_nodes[n - 1]->inode_id + 1;
1871
1872		for (i = 0; i < n; i++)
1873			atomic_inc(&delayed_nodes[i]->refs);
1874		spin_unlock(&root->inode_lock);
1875
1876		for (i = 0; i < n; i++) {
1877			__btrfs_kill_delayed_node(delayed_nodes[i]);
1878			btrfs_release_delayed_node(delayed_nodes[i]);
1879		}
1880	}
1881}
1882
1883void btrfs_destroy_delayed_inodes(struct btrfs_root *root)
1884{
1885	struct btrfs_delayed_root *delayed_root;
1886	struct btrfs_delayed_node *curr_node, *prev_node;
1887
1888	delayed_root = btrfs_get_delayed_root(root);
1889
1890	curr_node = btrfs_first_delayed_node(delayed_root);
1891	while (curr_node) {
1892		__btrfs_kill_delayed_node(curr_node);
1893
1894		prev_node = curr_node;
1895		curr_node = btrfs_next_delayed_node(curr_node);
1896		btrfs_release_delayed_node(prev_node);
1897	}
1898}
1899