fs/btrfs/delayed-inode.c

   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         512
  26 #define BTRFS_DELAYED_BACKGROUND        128
  27 #define BTRFS_DELAYED_BATCH             16
  28
  29 static struct kmem_cache *delayed_node_cache;
  30
  31 int __init btrfs_delayed_inode_init(void)
  32 {
  33         delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
  34                                         sizeof(struct btrfs_delayed_node),
  35                                         0,
  36                                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
  37                                         NULL);
  38         if (!delayed_node_cache)
  39                 return -ENOMEM;
  40         return 0;
  41 }
  42
  43 void btrfs_delayed_inode_exit(void)
  44 {
  45         if (delayed_node_cache)
  46                 kmem_cache_destroy(delayed_node_cache);
  47 }
  48
  49 static 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->count = 0;
  57         delayed_node->in_list = 0;
  58         delayed_node->inode_dirty = 0;
  59         delayed_node->ins_root = RB_ROOT;
  60         delayed_node->del_root = RB_ROOT;
  61         mutex_init(&delayed_node->mutex);
  62         delayed_node->index_cnt = 0;
  63         INIT_LIST_HEAD(&delayed_node->n_list);
  64         INIT_LIST_HEAD(&delayed_node->p_list);
  65         delayed_node->bytes_reserved = 0;
  66         memset(&delayed_node->inode_item, 0, sizeof(delayed_node->inode_item));
  67 }
  68
  69 static inline int btrfs_is_continuous_delayed_item(
  70                                         struct btrfs_delayed_item *item1,
  71                                         struct btrfs_delayed_item *item2)
  72 {
  73         if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
  74             item1->key.objectid == item2->key.objectid &&
  75             item1->key.type == item2->key.type &&
  76             item1->key.offset + 1 == item2->key.offset)
  77                 return 1;
  78         return 0;
  79 }
  80
  81 static inline struct btrfs_delayed_root *btrfs_get_delayed_root(
  82                                                         struct btrfs_root *root)
  83 {
  84         return root->fs_info->delayed_root;
  85 }
  86
  87 static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
  88 {
  89         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
  90         struct btrfs_root *root = btrfs_inode->root;
  91         u64 ino = btrfs_ino(inode);
  92         struct btrfs_delayed_node *node;
  93
  94         node = ACCESS_ONCE(btrfs_inode->delayed_node);
  95         if (node) {
  96                 atomic_inc(&node->refs);
  97                 return node;
  98         }
  99
 100         spin_lock(&root->inode_lock);
 101         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
 102         if (node) {
 103                 if (btrfs_inode->delayed_node) {
 104                         atomic_inc(&node->refs);        /* can be accessed */
 105                         BUG_ON(btrfs_inode->delayed_node != node);
 106                         spin_unlock(&root->inode_lock);
 107                         return node;
 108                 }
 109                 btrfs_inode->delayed_node = node;
 110                 atomic_inc(&node->refs);        /* can be accessed */
 111                 atomic_inc(&node->refs);        /* cached in the inode */
 112                 spin_unlock(&root->inode_lock);
 113                 return node;
 114         }
 115         spin_unlock(&root->inode_lock);
 116
 117         return NULL;
 118 }
 119
 120 /* Will return either the node or PTR_ERR(-ENOMEM) */
 121 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
 122                                                         struct inode *inode)
 123 {
 124         struct btrfs_delayed_node *node;
 125         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 126         struct btrfs_root *root = btrfs_inode->root;
 127         u64 ino = btrfs_ino(inode);
 128         int ret;
 129
 130 again:
 131         node = btrfs_get_delayed_node(inode);
 132         if (node)
 133                 return node;
 134
 135         node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
 136         if (!node)
 137                 return ERR_PTR(-ENOMEM);
 138         btrfs_init_delayed_node(node, root, ino);
 139
 140         atomic_inc(&node->refs);        /* cached in the btrfs inode */
 141         atomic_inc(&node->refs);        /* can be accessed */
 142
 143         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
 144         if (ret) {
 145                 kmem_cache_free(delayed_node_cache, node);
 146                 return ERR_PTR(ret);
 147         }
 148
 149         spin_lock(&root->inode_lock);
 150         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
 151         if (ret == -EEXIST) {
 152                 kmem_cache_free(delayed_node_cache, node);
 153                 spin_unlock(&root->inode_lock);
 154                 radix_tree_preload_end();
 155                 goto again;
 156         }
 157         btrfs_inode->delayed_node = node;
 158         spin_unlock(&root->inode_lock);
 159         radix_tree_preload_end();
 160
 161         return node;
 162 }
 163
 164 /*
 165  * Call it when holding delayed_node->mutex
 166  *
 167  * If mod = 1, add this node into the prepared list.
 168  */
 169 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
 170                                      struct btrfs_delayed_node *node,
 171                                      int mod)
 172 {
 173         spin_lock(&root->lock);
 174         if (node->in_list) {
 175                 if (!list_empty(&node->p_list))
 176                         list_move_tail(&node->p_list, &root->prepare_list);
 177                 else if (mod)
 178                         list_add_tail(&node->p_list, &root->prepare_list);
 179         } else {
 180                 list_add_tail(&node->n_list, &root->node_list);
 181                 list_add_tail(&node->p_list, &root->prepare_list);
 182                 atomic_inc(&node->refs);        /* inserted into list */
 183                 root->nodes++;
 184                 node->in_list = 1;
 185         }
 186         spin_unlock(&root->lock);
 187 }
 188
 189 /* Call it when holding delayed_node->mutex */
 190 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
 191                                        struct btrfs_delayed_node *node)
 192 {
 193         spin_lock(&root->lock);
 194         if (node->in_list) {
 195                 root->nodes--;
 196                 atomic_dec(&node->refs);        /* not in the list */
 197                 list_del_init(&node->n_list);
 198                 if (!list_empty(&node->p_list))
 199                         list_del_init(&node->p_list);
 200                 node->in_list = 0;
 201         }
 202         spin_unlock(&root->lock);
 203 }
 204
 205 static struct btrfs_delayed_node *btrfs_first_delayed_node(
 206                         struct btrfs_delayed_root *delayed_root)
 207 {
 208         struct list_head *p;
 209         struct btrfs_delayed_node *node = NULL;
 210
 211         spin_lock(&delayed_root->lock);
 212         if (list_empty(&delayed_root->node_list))
 213                 goto out;
 214
 215         p = delayed_root->node_list.next;
 216         node = list_entry(p, struct btrfs_delayed_node, n_list);
 217         atomic_inc(&node->refs);
 218 out:
 219         spin_unlock(&delayed_root->lock);
 220
 221         return node;
 222 }
 223
 224 static struct btrfs_delayed_node *btrfs_next_delayed_node(
 225                                                 struct btrfs_delayed_node *node)
 226 {
 227         struct btrfs_delayed_root *delayed_root;
 228         struct list_head *p;
 229         struct btrfs_delayed_node *next = NULL;
 230
 231         delayed_root = node->root->fs_info->delayed_root;
 232         spin_lock(&delayed_root->lock);
 233         if (!node->in_list) {   /* not in the list */
 234                 if (list_empty(&delayed_root->node_list))
 235                         goto out;
 236                 p = delayed_root->node_list.next;
 237         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
 238                 goto out;
 239         else
 240                 p = node->n_list.next;
 241
 242         next = list_entry(p, struct btrfs_delayed_node, n_list);
 243         atomic_inc(&next->refs);
 244 out:
 245         spin_unlock(&delayed_root->lock);
 246
 247         return next;
 248 }
 249
 250 static void __btrfs_release_delayed_node(
 251                                 struct btrfs_delayed_node *delayed_node,
 252                                 int mod)
 253 {
 254         struct btrfs_delayed_root *delayed_root;
 255
 256         if (!delayed_node)
 257                 return;
 258
 259         delayed_root = delayed_node->root->fs_info->delayed_root;
 260
 261         mutex_lock(&delayed_node->mutex);
 262         if (delayed_node->count)
 263                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
 264         else
 265                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
 266         mutex_unlock(&delayed_node->mutex);
 267
 268         if (atomic_dec_and_test(&delayed_node->refs)) {
 269                 struct btrfs_root *root = delayed_node->root;
 270                 spin_lock(&root->inode_lock);
 271                 if (atomic_read(&delayed_node->refs) == 0) {
 272                         radix_tree_delete(&root->delayed_nodes_tree,
 273                                           delayed_node->inode_id);
 274                         kmem_cache_free(delayed_node_cache, delayed_node);
 275                 }
 276                 spin_unlock(&root->inode_lock);
 277         }
 278 }
 279
 280 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 281 {
 282         __btrfs_release_delayed_node(node, 0);
 283 }
 284
 285 static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
 286                                         struct btrfs_delayed_root *delayed_root)
 287 {
 288         struct list_head *p;
 289         struct btrfs_delayed_node *node = NULL;
 290
 291         spin_lock(&delayed_root->lock);
 292         if (list_empty(&delayed_root->prepare_list))
 293                 goto out;
 294
 295         p = delayed_root->prepare_list.next;
 296         list_del_init(p);
 297         node = list_entry(p, struct btrfs_delayed_node, p_list);
 298         atomic_inc(&node->refs);
 299 out:
 300         spin_unlock(&delayed_root->lock);
 301
 302         return node;
 303 }
 304
 305 static inline void btrfs_release_prepared_delayed_node(
 306                                         struct btrfs_delayed_node *node)
 307 {
 308         __btrfs_release_delayed_node(node, 1);
 309 }
 310
 311 static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
 312 {
 313         struct btrfs_delayed_item *item;
 314         item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
 315         if (item) {
 316                 item->data_len = data_len;
 317                 item->ins_or_del = 0;
 318                 item->bytes_reserved = 0;
 319                 item->delayed_node = NULL;
 320                 atomic_set(&item->refs, 1);
 321         }
 322         return item;
 323 }
 324
 325 /*
 326  * __btrfs_lookup_delayed_item - look up the delayed item by key
 327  * @delayed_node: pointer to the delayed node
 328  * @key:          the key to look up
 329  * @prev:         used to store the prev item if the right item isn't found
 330  * @next:         used to store the next item if the right item isn't found
 331  *
 332  * Note: if we don't find the right item, we will return the prev item and
 333  * the next item.
 334  */
 335 static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
 336                                 struct rb_root *root,
 337                                 struct btrfs_key *key,
 338                                 struct btrfs_delayed_item **prev,
 339                                 struct btrfs_delayed_item **next)
 340 {
 341         struct rb_node *node, *prev_node = NULL;
 342         struct btrfs_delayed_item *delayed_item = NULL;
 343         int ret = 0;
 344
 345         node = root->rb_node;
 346
 347         while (node) {
 348                 delayed_item = rb_entry(node, struct btrfs_delayed_item,
 349                                         rb_node);
 350                 prev_node = node;
 351                 ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
 352                 if (ret < 0)
 353                         node = node->rb_right;
 354                 else if (ret > 0)
 355                         node = node->rb_left;
 356                 else
 357                         return delayed_item;
 358         }
 359
 360         if (prev) {
 361                 if (!prev_node)
 362                         *prev = NULL;
 363                 else if (ret < 0)
 364                         *prev = delayed_item;
 365                 else if ((node = rb_prev(prev_node)) != NULL) {
 366                         *prev = rb_entry(node, struct btrfs_delayed_item,
 367                                          rb_node);
 368                 } else
 369                         *prev = NULL;
 370         }
 371
 372         if (next) {
 373                 if (!prev_node)
 374                         *next = NULL;
 375                 else if (ret > 0)
 376                         *next = delayed_item;
 377                 else if ((node = rb_next(prev_node)) != NULL) {
 378                         *next = rb_entry(node, struct btrfs_delayed_item,
 379                                          rb_node);
 380                 } else
 381                         *next = NULL;
 382         }
 383         return NULL;
 384 }
 385
 386 static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
 387                                         struct btrfs_delayed_node *delayed_node,
 388                                         struct btrfs_key *key)
 389 {
 390         struct btrfs_delayed_item *item;
 391
 392         item = __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
 393                                            NULL, NULL);
 394         return item;
 395 }
 396
 397 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 398                                     struct btrfs_delayed_item *ins,
 399                                     int action)
 400 {
 401         struct rb_node **p, *node;
 402         struct rb_node *parent_node = NULL;
 403         struct rb_root *root;
 404         struct btrfs_delayed_item *item;
 405         int cmp;
 406
 407         if (action == BTRFS_DELAYED_INSERTION_ITEM)
 408                 root = &delayed_node->ins_root;
 409         else if (action == BTRFS_DELAYED_DELETION_ITEM)
 410                 root = &delayed_node->del_root;
 411         else
 412                 BUG();
 413         p = &root->rb_node;
 414         node = &ins->rb_node;
 415
 416         while (*p) {
 417                 parent_node = *p;
 418                 item = rb_entry(parent_node, struct btrfs_delayed_item,
 419                                  rb_node);
 420
 421                 cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
 422                 if (cmp < 0)
 423                         p = &(*p)->rb_right;
 424                 else if (cmp > 0)
 425                         p = &(*p)->rb_left;
 426                 else
 427                         return -EEXIST;
 428         }
 429
 430         rb_link_node(node, parent_node, p);
 431         rb_insert_color(node, root);
 432         ins->delayed_node = delayed_node;
 433         ins->ins_or_del = action;
 434
 435         if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
 436             action == BTRFS_DELAYED_INSERTION_ITEM &&
 437             ins->key.offset >= delayed_node->index_cnt)
 438                         delayed_node->index_cnt = ins->key.offset + 1;
 439
 440         delayed_node->count++;
 441         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
 442         return 0;
 443 }
 444
 445 static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
 446                                               struct btrfs_delayed_item *item)
 447 {
 448         return __btrfs_add_delayed_item(node, item,
 449                                         BTRFS_DELAYED_INSERTION_ITEM);
 450 }
 451
 452 static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
 453                                              struct btrfs_delayed_item *item)
 454 {
 455         return __btrfs_add_delayed_item(node, item,
 456                                         BTRFS_DELAYED_DELETION_ITEM);
 457 }
 458
 459 static void finish_one_item(struct btrfs_delayed_root *delayed_root)
 460 {
 461         int seq = atomic_inc_return(&delayed_root->items_seq);
 462         if ((atomic_dec_return(&delayed_root->items) <
 463             BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0) &&
 464             waitqueue_active(&delayed_root->wait))
 465                 wake_up(&delayed_root->wait);
 466 }
 467
 468 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 469 {
 470         struct rb_root *root;
 471         struct btrfs_delayed_root *delayed_root;
 472
 473         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 474
 475         BUG_ON(!delayed_root);
 476         BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
 477                delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
 478
 479         if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
 480                 root = &delayed_item->delayed_node->ins_root;
 481         else
 482                 root = &delayed_item->delayed_node->del_root;
 483
 484         rb_erase(&delayed_item->rb_node, root);
 485         delayed_item->delayed_node->count--;
 486
 487         finish_one_item(delayed_root);
 488 }
 489
 490 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 491 {
 492         if (item) {
 493                 __btrfs_remove_delayed_item(item);
 494                 if (atomic_dec_and_test(&item->refs))
 495                         kfree(item);
 496         }
 497 }
 498
 499 static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 500                                         struct btrfs_delayed_node *delayed_node)
 501 {
 502         struct rb_node *p;
 503         struct btrfs_delayed_item *item = NULL;
 504
 505         p = rb_first(&delayed_node->ins_root);
 506         if (p)
 507                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 508
 509         return item;
 510 }
 511
 512 static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 513                                         struct btrfs_delayed_node *delayed_node)
 514 {
 515         struct rb_node *p;
 516         struct btrfs_delayed_item *item = NULL;
 517
 518         p = rb_first(&delayed_node->del_root);
 519         if (p)
 520                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 521
 522         return item;
 523 }
 524
 525 static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 526                                                 struct btrfs_delayed_item *item)
 527 {
 528         struct rb_node *p;
 529         struct btrfs_delayed_item *next = NULL;
 530
 531         p = rb_next(&item->rb_node);
 532         if (p)
 533                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 534
 535         return next;
 536 }
 537
 538 static inline struct btrfs_root *btrfs_get_fs_root(struct btrfs_root *root,
 539                                                    u64 root_id)
 540 {
 541         struct btrfs_key root_key;
 542
 543         if (root->objectid == root_id)
 544                 return root;
 545
 546         root_key.objectid = root_id;
 547         root_key.type = BTRFS_ROOT_ITEM_KEY;
 548         root_key.offset = (u64)-1;
 549         return btrfs_read_fs_root_no_name(root->fs_info, &root_key);
 550 }
 551
 552 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 553                                                struct btrfs_root *root,
 554                                                struct btrfs_delayed_item *item)
 555 {
 556         struct btrfs_block_rsv *src_rsv;
 557         struct btrfs_block_rsv *dst_rsv;
 558         u64 num_bytes;
 559         int ret;
 560
 561         if (!trans->bytes_reserved)
 562                 return 0;
 563
 564         src_rsv = trans->block_rsv;
 565         dst_rsv = &root->fs_info->delayed_block_rsv;
 566
 567         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 568         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
 569         if (!ret) {
 570                 trace_btrfs_space_reservation(root->fs_info, "delayed_item",
 571                                               item->key.objectid,
 572                                               num_bytes, 1);
 573                 item->bytes_reserved = num_bytes;
 574         }
 575
 576         return ret;
 577 }
 578
 579 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
 580                                                 struct btrfs_delayed_item *item)
 581 {
 582         struct btrfs_block_rsv *rsv;
 583
 584         if (!item->bytes_reserved)
 585                 return;
 586
 587         rsv = &root->fs_info->delayed_block_rsv;
 588         trace_btrfs_space_reservation(root->fs_info, "delayed_item",
 589                                       item->key.objectid, item->bytes_reserved,
 590                                       0);
 591         btrfs_block_rsv_release(root, rsv,
 592                                 item->bytes_reserved);
 593 }
 594
 595 static int btrfs_delayed_inode_reserve_metadata(
 596                                         struct btrfs_trans_handle *trans,
 597                                         struct btrfs_root *root,
 598                                         struct inode *inode,
 599                                         struct btrfs_delayed_node *node)
 600 {
 601         struct btrfs_block_rsv *src_rsv;
 602         struct btrfs_block_rsv *dst_rsv;
 603         u64 num_bytes;
 604         int ret;
 605         bool release = false;
 606
 607         src_rsv = trans->block_rsv;
 608         dst_rsv = &root->fs_info->delayed_block_rsv;
 609
 610         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 611
 612         /*
 613          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
 614          * which doesn't reserve space for speed.  This is a problem since we
 615          * still need to reserve space for this update, so try to reserve the
 616          * space.
 617          *
 618          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
 619          * we're accounted for.
 620          */
 621         if (!src_rsv || (!trans->bytes_reserved &&
 622                          src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
 623                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
 624                                           BTRFS_RESERVE_NO_FLUSH);
 625                 /*
 626                  * Since we're under a transaction reserve_metadata_bytes could
 627                  * try to commit the transaction which will make it return
 628                  * EAGAIN to make us stop the transaction we have, so return
 629                  * ENOSPC instead so that btrfs_dirty_inode knows what to do.
 630                  */
 631                 if (ret == -EAGAIN)
 632                         ret = -ENOSPC;
 633                 if (!ret) {
 634                         node->bytes_reserved = num_bytes;
 635                         trace_btrfs_space_reservation(root->fs_info,
 636                                                       "delayed_inode",
 637                                                       btrfs_ino(inode),
 638                                                       num_bytes, 1);
 639                 }
 640                 return ret;
 641         } else if (src_rsv->type == BTRFS_BLOCK_RSV_DELALLOC) {
 642                 spin_lock(&BTRFS_I(inode)->lock);
 643                 if (test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
 644                                        &BTRFS_I(inode)->runtime_flags)) {
 645                         spin_unlock(&BTRFS_I(inode)->lock);
 646                         release = true;
 647                         goto migrate;
 648                 }
 649                 spin_unlock(&BTRFS_I(inode)->lock);
 650
 651                 /* Ok we didn't have space pre-reserved.  This shouldn't happen
 652                  * too often but it can happen if we do delalloc to an existing
 653                  * inode which gets dirtied because of the time update, and then
 654                  * isn't touched again until after the transaction commits and
 655                  * then we try to write out the data.  First try to be nice and
 656                  * reserve something strictly for us.  If not be a pain and try
 657                  * to steal from the delalloc block rsv.
 658                  */
 659                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
 660                                           BTRFS_RESERVE_NO_FLUSH);
 661                 if (!ret)
 662                         goto out;
 663
 664                 ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
 665                 if (!ret)
 666                         goto out;
 667
 668                 /*
 669                  * Ok this is a problem, let's just steal from the global rsv
 670                  * since this really shouldn't happen that often.
 671                  */
 672                 WARN_ON(1);
 673                 ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
 674                                               dst_rsv, num_bytes);
 675                 goto out;
 676         }
 677
 678 migrate:
 679         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
 680
 681 out:
 682         /*
 683          * Migrate only takes a reservation, it doesn't touch the size of the
 684          * block_rsv.  This is to simplify people who don't normally have things
 685          * migrated from their block rsv.  If they go to release their
 686          * reservation, that will decrease the size as well, so if migrate
 687          * reduced size we'd end up with a negative size.  But for the
 688          * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
 689          * but we could in fact do this reserve/migrate dance several times
 690          * between the time we did the original reservation and we'd clean it
 691          * up.  So to take care of this, release the space for the meta
 692          * reservation here.  I think it may be time for a documentation page on
 693          * how block rsvs. work.
 694          */
 695         if (!ret) {
 696                 trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
 697                                               btrfs_ino(inode), num_bytes, 1);
 698                 node->bytes_reserved = num_bytes;
 699         }
 700
 701         if (release) {
 702                 trace_btrfs_space_reservation(root->fs_info, "delalloc",
 703                                               btrfs_ino(inode), num_bytes, 0);
 704                 btrfs_block_rsv_release(root, src_rsv, num_bytes);
 705         }
 706
 707         return ret;
 708 }
 709
 710 static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
 711                                                 struct btrfs_delayed_node *node)
 712 {
 713         struct btrfs_block_rsv *rsv;
 714
 715         if (!node->bytes_reserved)
 716                 return;
 717
 718         rsv = &root->fs_info->delayed_block_rsv;
 719         trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
 720                                       node->inode_id, node->bytes_reserved, 0);
 721         btrfs_block_rsv_release(root, rsv,
 722                                 node->bytes_reserved);
 723         node->bytes_reserved = 0;
 724 }
 725
 726 /*
 727  * This helper will insert some continuous items into the same leaf according
 728  * to the free space of the leaf.
 729  */
 730 static int btrfs_batch_insert_items(struct btrfs_root *root,
 731                                     struct btrfs_path *path,
 732                                     struct btrfs_delayed_item *item)
 733 {
 734         struct btrfs_delayed_item *curr, *next;
 735         int free_space;
 736         int total_data_size = 0, total_size = 0;
 737         struct extent_buffer *leaf;
 738         char *data_ptr;
 739         struct btrfs_key *keys;
 740         u32 *data_size;
 741         struct list_head head;
 742         int slot;
 743         int nitems;
 744         int i;
 745         int ret = 0;
 746
 747         BUG_ON(!path->nodes[0]);
 748
 749         leaf = path->nodes[0];
 750         free_space = btrfs_leaf_free_space(root, leaf);
 751         INIT_LIST_HEAD(&head);
 752
 753         next = item;
 754         nitems = 0;
 755
 756         /*
 757          * count the number of the continuous items that we can insert in batch
 758          */
 759         while (total_size + next->data_len + sizeof(struct btrfs_item) <=
 760                free_space) {
 761                 total_data_size += next->data_len;
 762                 total_size += next->data_len + sizeof(struct btrfs_item);
 763                 list_add_tail(&next->tree_list, &head);
 764                 nitems++;
 765
 766                 curr = next;
 767                 next = __btrfs_next_delayed_item(curr);
 768                 if (!next)
 769                         break;
 770
 771                 if (!btrfs_is_continuous_delayed_item(curr, next))
 772                         break;
 773         }
 774
 775         if (!nitems) {
 776                 ret = 0;
 777                 goto out;
 778         }
 779
 780         /*
 781          * we need allocate some memory space, but it might cause the task
 782          * to sleep, so we set all locked nodes in the path to blocking locks
 783          * first.
 784          */
 785         btrfs_set_path_blocking(path);
 786
 787         keys = kmalloc(sizeof(struct btrfs_key) * nitems, GFP_NOFS);
 788         if (!keys) {
 789                 ret = -ENOMEM;
 790                 goto out;
 791         }
 792
 793         data_size = kmalloc(sizeof(u32) * nitems, GFP_NOFS);
 794         if (!data_size) {
 795                 ret = -ENOMEM;
 796                 goto error;
 797         }
 798
 799         /* get keys of all the delayed items */
 800         i = 0;
 801         list_for_each_entry(next, &head, tree_list) {
 802                 keys[i] = next->key;
 803                 data_size[i] = next->data_len;
 804                 i++;
 805         }
 806
 807         /* reset all the locked nodes in the patch to spinning locks. */
 808         btrfs_clear_path_blocking(path, NULL, 0);
 809
 810         /* insert the keys of the items */
 811         setup_items_for_insert(root, path, keys, data_size,
 812                                total_data_size, total_size, nitems);
 813
 814         /* insert the dir index items */
 815         slot = path->slots[0];
 816         list_for_each_entry_safe(curr, next, &head, tree_list) {
 817                 data_ptr = btrfs_item_ptr(leaf, slot, char);
 818                 write_extent_buffer(leaf, &curr->data,
 819                                     (unsigned long)data_ptr,
 820                                     curr->data_len);
 821                 slot++;
 822
 823                 btrfs_delayed_item_release_metadata(root, curr);
 824
 825                 list_del(&curr->tree_list);
 826                 btrfs_release_delayed_item(curr);
 827         }
 828
 829 error:
 830         kfree(data_size);
 831         kfree(keys);
 832 out:
 833         return ret;
 834 }
 835
 836 /*
 837  * This helper can just do simple insertion that needn't extend item for new
 838  * data, such as directory name index insertion, inode insertion.
 839  */
 840 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 841                                      struct btrfs_root *root,
 842                                      struct btrfs_path *path,
 843                                      struct btrfs_delayed_item *delayed_item)
 844 {
 845         struct extent_buffer *leaf;
 846         char *ptr;
 847         int ret;
 848
 849         ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
 850                                       delayed_item->data_len);
 851         if (ret < 0 && ret != -EEXIST)
 852                 return ret;
 853
 854         leaf = path->nodes[0];
 855
 856         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
 857
 858         write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
 859                             delayed_item->data_len);
 860         btrfs_mark_buffer_dirty(leaf);
 861
 862         btrfs_delayed_item_release_metadata(root, delayed_item);
 863         return 0;
 864 }
 865
 866 /*
 867  * we insert an item first, then if there are some continuous items, we try
 868  * to insert those items into the same leaf.
 869  */
 870 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 871                                       struct btrfs_path *path,
 872                                       struct btrfs_root *root,
 873                                       struct btrfs_delayed_node *node)
 874 {
 875         struct btrfs_delayed_item *curr, *prev;
 876         int ret = 0;
 877
 878 do_again:
 879         mutex_lock(&node->mutex);
 880         curr = __btrfs_first_delayed_insertion_item(node);
 881         if (!curr)
 882                 goto insert_end;
 883
 884         ret = btrfs_insert_delayed_item(trans, root, path, curr);
 885         if (ret < 0) {
 886                 btrfs_release_path(path);
 887                 goto insert_end;
 888         }
 889
 890         prev = curr;
 891         curr = __btrfs_next_delayed_item(prev);
 892         if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
 893                 /* insert the continuous items into the same leaf */
 894                 path->slots[0]++;
 895                 btrfs_batch_insert_items(root, path, curr);
 896         }
 897         btrfs_release_delayed_item(prev);
 898         btrfs_mark_buffer_dirty(path->nodes[0]);
 899
 900         btrfs_release_path(path);
 901         mutex_unlock(&node->mutex);
 902         goto do_again;
 903
 904 insert_end:
 905         mutex_unlock(&node->mutex);
 906         return ret;
 907 }
 908
 909 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
 910                                     struct btrfs_root *root,
 911                                     struct btrfs_path *path,
 912                                     struct btrfs_delayed_item *item)
 913 {
 914         struct btrfs_delayed_item *curr, *next;
 915         struct extent_buffer *leaf;
 916         struct btrfs_key key;
 917         struct list_head head;
 918         int nitems, i, last_item;
 919         int ret = 0;
 920
 921         BUG_ON(!path->nodes[0]);
 922
 923         leaf = path->nodes[0];
 924
 925         i = path->slots[0];
 926         last_item = btrfs_header_nritems(leaf) - 1;
 927         if (i > last_item)
 928                 return -ENOENT; /* FIXME: Is errno suitable? */
 929
 930         next = item;
 931         INIT_LIST_HEAD(&head);
 932         btrfs_item_key_to_cpu(leaf, &key, i);
 933         nitems = 0;
 934         /*
 935          * count the number of the dir index items that we can delete in batch
 936          */
 937         while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
 938                 list_add_tail(&next->tree_list, &head);
 939                 nitems++;
 940
 941                 curr = next;
 942                 next = __btrfs_next_delayed_item(curr);
 943                 if (!next)
 944                         break;
 945
 946                 if (!btrfs_is_continuous_delayed_item(curr, next))
 947                         break;
 948
 949                 i++;
 950                 if (i > last_item)
 951                         break;
 952                 btrfs_item_key_to_cpu(leaf, &key, i);
 953         }
 954
 955         if (!nitems)
 956                 return 0;
 957
 958         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
 959         if (ret)
 960                 goto out;
 961
 962         list_for_each_entry_safe(curr, next, &head, tree_list) {
 963                 btrfs_delayed_item_release_metadata(root, curr);
 964                 list_del(&curr->tree_list);
 965                 btrfs_release_delayed_item(curr);
 966         }
 967
 968 out:
 969         return ret;
 970 }
 971
 972 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
 973                                       struct btrfs_path *path,
 974                                       struct btrfs_root *root,
 975                                       struct btrfs_delayed_node *node)
 976 {
 977         struct btrfs_delayed_item *curr, *prev;
 978         int ret = 0;
 979
 980 do_again:
 981         mutex_lock(&node->mutex);
 982         curr = __btrfs_first_delayed_deletion_item(node);
 983         if (!curr)
 984                 goto delete_fail;
 985
 986         ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
 987         if (ret < 0)
 988                 goto delete_fail;
 989         else if (ret > 0) {
 990                 /*
 991                  * can't find the item which the node points to, so this node
 992                  * is invalid, just drop it.
 993                  */
 994                 prev = curr;
 995                 curr = __btrfs_next_delayed_item(prev);
 996                 btrfs_release_delayed_item(prev);
 997                 ret = 0;
 998                 btrfs_release_path(path);
 999                 if (curr) {
1000                         mutex_unlock(&node->mutex);
1001                         goto do_again;
1002                 } else
1003                         goto delete_fail;
1004         }
1005
1006         btrfs_batch_delete_items(trans, root, path, curr);
1007         btrfs_release_path(path);
1008         mutex_unlock(&node->mutex);
1009         goto do_again;
1010
1011 delete_fail:
1012         btrfs_release_path(path);
1013         mutex_unlock(&node->mutex);
1014         return ret;
1015 }
1016
1017 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
1018 {
1019         struct btrfs_delayed_root *delayed_root;
1020
1021         if (delayed_node && delayed_node->inode_dirty) {
1022                 BUG_ON(!delayed_node->root);
1023                 delayed_node->inode_dirty = 0;
1024                 delayed_node->count--;
1025
1026                 delayed_root = delayed_node->root->fs_info->delayed_root;
1027                 finish_one_item(delayed_root);
1028         }
1029 }
1030
1031 static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1032                                         struct btrfs_root *root,
1033                                         struct btrfs_path *path,
1034                                         struct btrfs_delayed_node *node)
1035 {
1036         struct btrfs_key key;
1037         struct btrfs_inode_item *inode_item;
1038         struct extent_buffer *leaf;
1039         int ret;
1040
1041         key.objectid = node->inode_id;
1042         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
1043         key.offset = 0;
1044
1045         ret = btrfs_lookup_inode(trans, root, path, &key, 1);
1046         if (ret > 0) {
1047                 btrfs_release_path(path);
1048                 return -ENOENT;
1049         } else if (ret < 0) {
1050                 return ret;
1051         }
1052
1053         btrfs_unlock_up_safe(path, 1);
1054         leaf = path->nodes[0];
1055         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1056                                     struct btrfs_inode_item);
1057         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1058                             sizeof(struct btrfs_inode_item));
1059         btrfs_mark_buffer_dirty(leaf);
1060         btrfs_release_path(path);
1061
1062         btrfs_delayed_inode_release_metadata(root, node);
1063         btrfs_release_delayed_inode(node);
1064
1065         return 0;
1066 }
1067
1068 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1069                                              struct btrfs_root *root,
1070                                              struct btrfs_path *path,
1071                                              struct btrfs_delayed_node *node)
1072 {
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         ret = __btrfs_update_delayed_inode(trans, root, path, node);
1082         mutex_unlock(&node->mutex);
1083         return ret;
1084 }
1085
1086 static inline int
1087 __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1088                                    struct btrfs_path *path,
1089                                    struct btrfs_delayed_node *node)
1090 {
1091         int ret;
1092
1093         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1094         if (ret)
1095                 return ret;
1096
1097         ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1098         if (ret)
1099                 return ret;
1100
1101         ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1102         return ret;
1103 }
1104
1105 /*
1106  * Called when committing the transaction.
1107  * Returns 0 on success.
1108  * Returns < 0 on error and returns with an aborted transaction with any
1109  * outstanding delayed items cleaned up.
1110  */
1111 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1112                                      struct btrfs_root *root, int nr)
1113 {
1114         struct btrfs_delayed_root *delayed_root;
1115         struct btrfs_delayed_node *curr_node, *prev_node;
1116         struct btrfs_path *path;
1117         struct btrfs_block_rsv *block_rsv;
1118         int ret = 0;
1119         bool count = (nr > 0);
1120
1121         if (trans->aborted)
1122                 return -EIO;
1123
1124         path = btrfs_alloc_path();
1125         if (!path)
1126                 return -ENOMEM;
1127         path->leave_spinning = 1;
1128
1129         block_rsv = trans->block_rsv;
1130         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1131
1132         delayed_root = btrfs_get_delayed_root(root);
1133
1134         curr_node = btrfs_first_delayed_node(delayed_root);
1135         while (curr_node && (!count || (count && nr--))) {
1136                 ret = __btrfs_commit_inode_delayed_items(trans, path,
1137                                                          curr_node);
1138                 if (ret) {
1139                         btrfs_release_delayed_node(curr_node);
1140                         curr_node = NULL;
1141                         btrfs_abort_transaction(trans, root, ret);
1142                         break;
1143                 }
1144
1145                 prev_node = curr_node;
1146                 curr_node = btrfs_next_delayed_node(curr_node);
1147                 btrfs_release_delayed_node(prev_node);
1148         }
1149
1150         if (curr_node)
1151                 btrfs_release_delayed_node(curr_node);
1152         btrfs_free_path(path);
1153         trans->block_rsv = block_rsv;
1154
1155         return ret;
1156 }
1157
1158 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1159                             struct btrfs_root *root)
1160 {
1161         return __btrfs_run_delayed_items(trans, root, -1);
1162 }
1163
1164 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans,
1165                                struct btrfs_root *root, int nr)
1166 {
1167         return __btrfs_run_delayed_items(trans, root, nr);
1168 }
1169
1170 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1171                                      struct inode *inode)
1172 {
1173         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1174         struct btrfs_path *path;
1175         struct btrfs_block_rsv *block_rsv;
1176         int ret;
1177
1178         if (!delayed_node)
1179                 return 0;
1180
1181         mutex_lock(&delayed_node->mutex);
1182         if (!delayed_node->count) {
1183                 mutex_unlock(&delayed_node->mutex);
1184                 btrfs_release_delayed_node(delayed_node);
1185                 return 0;
1186         }
1187         mutex_unlock(&delayed_node->mutex);
1188
1189         path = btrfs_alloc_path();
1190         if (!path)
1191                 return -ENOMEM;
1192         path->leave_spinning = 1;
1193
1194         block_rsv = trans->block_rsv;
1195         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1196
1197         ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1198
1199         btrfs_release_delayed_node(delayed_node);
1200         btrfs_free_path(path);
1201         trans->block_rsv = block_rsv;
1202
1203         return ret;
1204 }
1205
1206 int btrfs_commit_inode_delayed_inode(struct inode *inode)
1207 {
1208         struct btrfs_trans_handle *trans;
1209         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1210         struct btrfs_path *path;
1211         struct btrfs_block_rsv *block_rsv;
1212         int ret;
1213
1214         if (!delayed_node)
1215                 return 0;
1216
1217         mutex_lock(&delayed_node->mutex);
1218         if (!delayed_node->inode_dirty) {
1219                 mutex_unlock(&delayed_node->mutex);
1220                 btrfs_release_delayed_node(delayed_node);
1221                 return 0;
1222         }
1223         mutex_unlock(&delayed_node->mutex);
1224
1225         trans = btrfs_join_transaction(delayed_node->root);
1226         if (IS_ERR(trans)) {
1227                 ret = PTR_ERR(trans);
1228                 goto out;
1229         }
1230
1231         path = btrfs_alloc_path();
1232         if (!path) {
1233                 ret = -ENOMEM;
1234                 goto trans_out;
1235         }
1236         path->leave_spinning = 1;
1237
1238         block_rsv = trans->block_rsv;
1239         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1240
1241         mutex_lock(&delayed_node->mutex);
1242         if (delayed_node->inode_dirty)
1243                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1244                                                    path, delayed_node);
1245         else
1246                 ret = 0;
1247         mutex_unlock(&delayed_node->mutex);
1248
1249         btrfs_free_path(path);
1250         trans->block_rsv = block_rsv;
1251 trans_out:
1252         btrfs_end_transaction(trans, delayed_node->root);
1253         btrfs_btree_balance_dirty(delayed_node->root);
1254 out:
1255         btrfs_release_delayed_node(delayed_node);
1256
1257         return ret;
1258 }
1259
1260 void btrfs_remove_delayed_node(struct inode *inode)
1261 {
1262         struct btrfs_delayed_node *delayed_node;
1263
1264         delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1265         if (!delayed_node)
1266                 return;
1267
1268         BTRFS_I(inode)->delayed_node = NULL;
1269         btrfs_release_delayed_node(delayed_node);
1270 }
1271
1272 struct btrfs_async_delayed_work {
1273         struct btrfs_delayed_root *delayed_root;
1274         int nr;
1275         struct btrfs_work work;
1276 };
1277
1278 static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1279 {
1280         struct btrfs_async_delayed_work *async_work;
1281         struct btrfs_delayed_root *delayed_root;
1282         struct btrfs_trans_handle *trans;
1283         struct btrfs_path *path;
1284         struct btrfs_delayed_node *delayed_node = NULL;
1285         struct btrfs_root *root;
1286         struct btrfs_block_rsv *block_rsv;
1287         int total_done = 0;
1288
1289         async_work = container_of(work, struct btrfs_async_delayed_work, work);
1290         delayed_root = async_work->delayed_root;
1291
1292         path = btrfs_alloc_path();
1293         if (!path)
1294                 goto out;
1295
1296 again:
1297         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND / 2)
1298                 goto free_path;
1299
1300         delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1301         if (!delayed_node)
1302                 goto free_path;
1303
1304         path->leave_spinning = 1;
1305         root = delayed_node->root;
1306
1307         trans = btrfs_join_transaction(root);
1308         if (IS_ERR(trans))
1309                 goto release_path;
1310
1311         block_rsv = trans->block_rsv;
1312         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1313
1314         __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1315         /*
1316          * Maybe new delayed items have been inserted, so we need requeue
1317          * the work. Besides that, we must dequeue the empty delayed nodes
1318          * to avoid the race between delayed items balance and the worker.
1319          * The race like this:
1320          *      Task1                           Worker thread
1321          *                                      count == 0, needn't requeue
1322          *                                        also needn't insert the
1323          *                                        delayed node into prepare
1324          *                                        list again.
1325          *      add lots of delayed items
1326          *      queue the delayed node
1327          *        already in the list,
1328          *        and not in the prepare
1329          *        list, it means the delayed
1330          *        node is being dealt with
1331          *        by the worker.
1332          *      do delayed items balance
1333          *        the delayed node is being
1334          *        dealt with by the worker
1335          *        now, just wait.
1336          *                                      the worker goto idle.
1337          * Task1 will sleep until the transaction is commited.
1338          */
1339         mutex_lock(&delayed_node->mutex);
1340         btrfs_dequeue_delayed_node(root->fs_info->delayed_root, delayed_node);
1341         mutex_unlock(&delayed_node->mutex);
1342
1343         trans->block_rsv = block_rsv;
1344         btrfs_end_transaction_dmeta(trans, root);
1345         btrfs_btree_balance_dirty_nodelay(root);
1346
1347 release_path:
1348         btrfs_release_path(path);
1349         total_done++;
1350
1351         btrfs_release_prepared_delayed_node(delayed_node);
1352         if (async_work->nr == 0 || total_done < async_work->nr)
1353                 goto again;
1354
1355 free_path:
1356         btrfs_free_path(path);
1357 out:
1358         wake_up(&delayed_root->wait);
1359         kfree(async_work);
1360 }
1361
1362
1363 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1364                                      struct btrfs_root *root, int nr)
1365 {
1366         struct btrfs_async_delayed_work *async_work;
1367
1368         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1369                 return 0;
1370
1371         async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1372         if (!async_work)
1373                 return -ENOMEM;
1374
1375         async_work->delayed_root = delayed_root;
1376         async_work->work.func = btrfs_async_run_delayed_root;
1377         async_work->work.flags = 0;
1378         async_work->nr = nr;
1379
1380         btrfs_queue_worker(&root->fs_info->delayed_workers, &async_work->work);
1381         return 0;
1382 }
1383
1384 void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1385 {
1386         struct btrfs_delayed_root *delayed_root;
1387         delayed_root = btrfs_get_delayed_root(root);
1388         WARN_ON(btrfs_first_delayed_node(delayed_root));
1389 }
1390
1391 static int refs_newer(struct btrfs_delayed_root *delayed_root,
1392                       int seq, int count)
1393 {
1394         int val = atomic_read(&delayed_root->items_seq);
1395
1396         if (val < seq || val >= seq + count)
1397                 return 1;
1398         return 0;
1399 }
1400
1401 void btrfs_balance_delayed_items(struct btrfs_root *root)
1402 {
1403         struct btrfs_delayed_root *delayed_root;
1404         int seq;
1405
1406         delayed_root = btrfs_get_delayed_root(root);
1407
1408         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1409                 return;
1410
1411         seq = atomic_read(&delayed_root->items_seq);
1412
1413         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1414                 int ret;
1415                 DEFINE_WAIT(__wait);
1416
1417                 ret = btrfs_wq_run_delayed_node(delayed_root, root, 0);
1418                 if (ret)
1419                         return;
1420
1421                 while (1) {
1422                         prepare_to_wait(&delayed_root->wait, &__wait,
1423                                         TASK_INTERRUPTIBLE);
1424
1425                         if (refs_newer(delayed_root, seq,
1426                                        BTRFS_DELAYED_BATCH) ||
1427                             atomic_read(&delayed_root->items) <
1428                             BTRFS_DELAYED_BACKGROUND) {
1429                                 break;
1430                         }
1431                         if (!signal_pending(current))
1432                                 schedule();
1433                         else
1434                                 break;
1435                 }
1436                 finish_wait(&delayed_root->wait, &__wait);
1437         }
1438
1439         btrfs_wq_run_delayed_node(delayed_root, root, BTRFS_DELAYED_BATCH);
1440 }
1441
1442 /* Will return 0 or -ENOMEM */
1443 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1444                                    struct btrfs_root *root, const char *name,
1445                                    int name_len, struct inode *dir,
1446                                    struct btrfs_disk_key *disk_key, u8 type,
1447                                    u64 index)
1448 {
1449         struct btrfs_delayed_node *delayed_node;
1450         struct btrfs_delayed_item *delayed_item;
1451         struct btrfs_dir_item *dir_item;
1452         int ret;
1453
1454         delayed_node = btrfs_get_or_create_delayed_node(dir);
1455         if (IS_ERR(delayed_node))
1456                 return PTR_ERR(delayed_node);
1457
1458         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1459         if (!delayed_item) {
1460                 ret = -ENOMEM;
1461                 goto release_node;
1462         }
1463
1464         delayed_item->key.objectid = btrfs_ino(dir);
1465         btrfs_set_key_type(&delayed_item->key, BTRFS_DIR_INDEX_KEY);
1466         delayed_item->key.offset = index;
1467
1468         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1469         dir_item->location = *disk_key;
1470         dir_item->transid = cpu_to_le64(trans->transid);
1471         dir_item->data_len = 0;
1472         dir_item->name_len = cpu_to_le16(name_len);
1473         dir_item->type = type;
1474         memcpy((char *)(dir_item + 1), name, name_len);
1475
1476         ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1477         /*
1478          * we have reserved enough space when we start a new transaction,
1479          * so reserving metadata failure is impossible
1480          */
1481         BUG_ON(ret);
1482
1483
1484         mutex_lock(&delayed_node->mutex);
1485         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1486         if (unlikely(ret)) {
1487                 printk(KERN_ERR "err add delayed dir index item(name: %s) into "
1488                                 "the insertion tree of the delayed node"
1489                                 "(root id: %llu, inode id: %llu, errno: %d)\n",
1490                                 name,
1491                                 (unsigned long long)delayed_node->root->objectid,
1492                                 (unsigned long long)delayed_node->inode_id,
1493                                 ret);
1494                 BUG();
1495         }
1496         mutex_unlock(&delayed_node->mutex);
1497
1498 release_node:
1499         btrfs_release_delayed_node(delayed_node);
1500         return ret;
1501 }
1502
1503 static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1504                                                struct btrfs_delayed_node *node,
1505                                                struct btrfs_key *key)
1506 {
1507         struct btrfs_delayed_item *item;
1508
1509         mutex_lock(&node->mutex);
1510         item = __btrfs_lookup_delayed_insertion_item(node, key);
1511         if (!item) {
1512                 mutex_unlock(&node->mutex);
1513                 return 1;
1514         }
1515
1516         btrfs_delayed_item_release_metadata(root, item);
1517         btrfs_release_delayed_item(item);
1518         mutex_unlock(&node->mutex);
1519         return 0;
1520 }
1521
1522 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1523                                    struct btrfs_root *root, struct inode *dir,
1524                                    u64 index)
1525 {
1526         struct btrfs_delayed_node *node;
1527         struct btrfs_delayed_item *item;
1528         struct btrfs_key item_key;
1529         int ret;
1530
1531         node = btrfs_get_or_create_delayed_node(dir);
1532         if (IS_ERR(node))
1533                 return PTR_ERR(node);
1534
1535         item_key.objectid = btrfs_ino(dir);
1536         btrfs_set_key_type(&item_key, BTRFS_DIR_INDEX_KEY);
1537         item_key.offset = index;
1538
1539         ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1540         if (!ret)
1541                 goto end;
1542
1543         item = btrfs_alloc_delayed_item(0);
1544         if (!item) {
1545                 ret = -ENOMEM;
1546                 goto end;
1547         }
1548
1549         item->key = item_key;
1550
1551         ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1552         /*
1553          * we have reserved enough space when we start a new transaction,
1554          * so reserving metadata failure is impossible.
1555          */
1556         BUG_ON(ret);
1557
1558         mutex_lock(&node->mutex);
1559         ret = __btrfs_add_delayed_deletion_item(node, item);
1560         if (unlikely(ret)) {
1561                 printk(KERN_ERR "err add delayed dir index item(index: %llu) "
1562                                 "into the deletion tree of the delayed node"
1563                                 "(root id: %llu, inode id: %llu, errno: %d)\n",
1564                                 (unsigned long long)index,
1565                                 (unsigned long long)node->root->objectid,
1566                                 (unsigned long long)node->inode_id,
1567                                 ret);
1568                 BUG();
1569         }
1570         mutex_unlock(&node->mutex);
1571 end:
1572         btrfs_release_delayed_node(node);
1573         return ret;
1574 }
1575
1576 int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1577 {
1578         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1579
1580         if (!delayed_node)
1581                 return -ENOENT;
1582
1583         /*
1584          * Since we have held i_mutex of this directory, it is impossible that
1585          * a new directory index is added into the delayed node and index_cnt
1586          * is updated now. So we needn't lock the delayed node.
1587          */
1588         if (!delayed_node->index_cnt) {
1589                 btrfs_release_delayed_node(delayed_node);
1590                 return -EINVAL;
1591         }
1592
1593         BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1594         btrfs_release_delayed_node(delayed_node);
1595         return 0;
1596 }
1597
1598 void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
1599                              struct list_head *del_list)
1600 {
1601         struct btrfs_delayed_node *delayed_node;
1602         struct btrfs_delayed_item *item;
1603
1604         delayed_node = btrfs_get_delayed_node(inode);
1605         if (!delayed_node)
1606                 return;
1607
1608         mutex_lock(&delayed_node->mutex);
1609         item = __btrfs_first_delayed_insertion_item(delayed_node);
1610         while (item) {
1611                 atomic_inc(&item->refs);
1612                 list_add_tail(&item->readdir_list, ins_list);
1613                 item = __btrfs_next_delayed_item(item);
1614         }
1615
1616         item = __btrfs_first_delayed_deletion_item(delayed_node);
1617         while (item) {
1618                 atomic_inc(&item->refs);
1619                 list_add_tail(&item->readdir_list, del_list);
1620                 item = __btrfs_next_delayed_item(item);
1621         }
1622         mutex_unlock(&delayed_node->mutex);
1623         /*
1624          * This delayed node is still cached in the btrfs inode, so refs
1625          * must be > 1 now, and we needn't check it is going to be freed
1626          * or not.
1627          *
1628          * Besides that, this function is used to read dir, we do not
1629          * insert/delete delayed items in this period. So we also needn't
1630          * requeue or dequeue this delayed node.
1631          */
1632         atomic_dec(&delayed_node->refs);
1633 }
1634
1635 void btrfs_put_delayed_items(struct list_head *ins_list,
1636                              struct list_head *del_list)
1637 {
1638         struct btrfs_delayed_item *curr, *next;
1639
1640         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1641                 list_del(&curr->readdir_list);
1642                 if (atomic_dec_and_test(&curr->refs))
1643                         kfree(curr);
1644         }
1645
1646         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1647                 list_del(&curr->readdir_list);
1648                 if (atomic_dec_and_test(&curr->refs))
1649                         kfree(curr);
1650         }
1651 }
1652
1653 int btrfs_should_delete_dir_index(struct list_head *del_list,
1654                                   u64 index)
1655 {
1656         struct btrfs_delayed_item *curr, *next;
1657         int ret;
1658
1659         if (list_empty(del_list))
1660                 return 0;
1661
1662         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1663                 if (curr->key.offset > index)
1664                         break;
1665
1666                 list_del(&curr->readdir_list);
1667                 ret = (curr->key.offset == index);
1668
1669                 if (atomic_dec_and_test(&curr->refs))
1670                         kfree(curr);
1671
1672                 if (ret)
1673                         return 1;
1674                 else
1675                         continue;
1676         }
1677         return 0;
1678 }
1679
1680 /*
1681  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1682  *
1683  */
1684 int btrfs_readdir_delayed_dir_index(struct file *filp, void *dirent,
1685                                     filldir_t filldir,
1686                                     struct list_head *ins_list)
1687 {
1688         struct btrfs_dir_item *di;
1689         struct btrfs_delayed_item *curr, *next;
1690         struct btrfs_key location;
1691         char *name;
1692         int name_len;
1693         int over = 0;
1694         unsigned char d_type;
1695
1696         if (list_empty(ins_list))
1697                 return 0;
1698
1699         /*
1700          * Changing the data of the delayed item is impossible. So
1701          * we needn't lock them. And we have held i_mutex of the
1702          * directory, nobody can delete any directory indexes now.
1703          */
1704         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1705                 list_del(&curr->readdir_list);
1706
1707                 if (curr->key.offset < filp->f_pos) {
1708                         if (atomic_dec_and_test(&curr->refs))
1709                                 kfree(curr);
1710                         continue;
1711                 }
1712
1713                 filp->f_pos = curr->key.offset;
1714
1715                 di = (struct btrfs_dir_item *)curr->data;
1716                 name = (char *)(di + 1);
1717                 name_len = le16_to_cpu(di->name_len);
1718
1719                 d_type = btrfs_filetype_table[di->type];
1720                 btrfs_disk_key_to_cpu(&location, &di->location);
1721
1722                 over = filldir(dirent, name, name_len, curr->key.offset,
1723                                location.objectid, d_type);
1724
1725                 if (atomic_dec_and_test(&curr->refs))
1726                         kfree(curr);
1727
1728                 if (over)
1729                         return 1;
1730         }
1731         return 0;
1732 }
1733
1734 BTRFS_SETGET_STACK_FUNCS(stack_inode_generation, struct btrfs_inode_item,
1735                          generation, 64);
1736 BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence, struct btrfs_inode_item,
1737                          sequence, 64);
1738 BTRFS_SETGET_STACK_FUNCS(stack_inode_transid, struct btrfs_inode_item,
1739                          transid, 64);
1740 BTRFS_SETGET_STACK_FUNCS(stack_inode_size, struct btrfs_inode_item, size, 64);
1741 BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes, struct btrfs_inode_item,
1742                          nbytes, 64);
1743 BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group, struct btrfs_inode_item,
1744                          block_group, 64);
1745 BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink, struct btrfs_inode_item, nlink, 32);
1746 BTRFS_SETGET_STACK_FUNCS(stack_inode_uid, struct btrfs_inode_item, uid, 32);
1747 BTRFS_SETGET_STACK_FUNCS(stack_inode_gid, struct btrfs_inode_item, gid, 32);
1748 BTRFS_SETGET_STACK_FUNCS(stack_inode_mode, struct btrfs_inode_item, mode, 32);
1749 BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev, struct btrfs_inode_item, rdev, 64);
1750 BTRFS_SETGET_STACK_FUNCS(stack_inode_flags, struct btrfs_inode_item, flags, 64);
1751
1752 BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
1753 BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);
1754
1755 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1756                                   struct btrfs_inode_item *inode_item,
1757                                   struct inode *inode)
1758 {
1759         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1760         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1761         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1762         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1763         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1764         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1765         btrfs_set_stack_inode_generation(inode_item,
1766                                          BTRFS_I(inode)->generation);
1767         btrfs_set_stack_inode_sequence(inode_item, inode->i_version);
1768         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1769         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1770         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1771         btrfs_set_stack_inode_block_group(inode_item, 0);
1772
1773         btrfs_set_stack_timespec_sec(btrfs_inode_atime(inode_item),
1774                                      inode->i_atime.tv_sec);
1775         btrfs_set_stack_timespec_nsec(btrfs_inode_atime(inode_item),
1776                                       inode->i_atime.tv_nsec);
1777
1778         btrfs_set_stack_timespec_sec(btrfs_inode_mtime(inode_item),
1779                                      inode->i_mtime.tv_sec);
1780         btrfs_set_stack_timespec_nsec(btrfs_inode_mtime(inode_item),
1781                                       inode->i_mtime.tv_nsec);
1782
1783         btrfs_set_stack_timespec_sec(btrfs_inode_ctime(inode_item),
1784                                      inode->i_ctime.tv_sec);
1785         btrfs_set_stack_timespec_nsec(btrfs_inode_ctime(inode_item),
1786                                       inode->i_ctime.tv_nsec);
1787 }
1788
1789 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1790 {
1791         struct btrfs_delayed_node *delayed_node;
1792         struct btrfs_inode_item *inode_item;
1793         struct btrfs_timespec *tspec;
1794
1795         delayed_node = btrfs_get_delayed_node(inode);
1796         if (!delayed_node)
1797                 return -ENOENT;
1798
1799         mutex_lock(&delayed_node->mutex);
1800         if (!delayed_node->inode_dirty) {
1801                 mutex_unlock(&delayed_node->mutex);
1802                 btrfs_release_delayed_node(delayed_node);
1803                 return -ENOENT;
1804         }
1805
1806         inode_item = &delayed_node->inode_item;
1807
1808         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1809         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1810         btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1811         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1812         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1813         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1814         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1815         inode->i_version = btrfs_stack_inode_sequence(inode_item);
1816         inode->i_rdev = 0;
1817         *rdev = btrfs_stack_inode_rdev(inode_item);
1818         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1819
1820         tspec = btrfs_inode_atime(inode_item);
1821         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(tspec);
1822         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1823
1824         tspec = btrfs_inode_mtime(inode_item);
1825         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(tspec);
1826         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1827
1828         tspec = btrfs_inode_ctime(inode_item);
1829         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(tspec);
1830         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(tspec);
1831
1832         inode->i_generation = BTRFS_I(inode)->generation;
1833         BTRFS_I(inode)->index_cnt = (u64)-1;
1834
1835         mutex_unlock(&delayed_node->mutex);
1836         btrfs_release_delayed_node(delayed_node);
1837         return 0;
1838 }
1839
1840 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1841                                struct btrfs_root *root, struct inode *inode)
1842 {
1843         struct btrfs_delayed_node *delayed_node;
1844         int ret = 0;
1845
1846         /*
1847          * we don't do delayed inode updates during log recovery because it
1848          * leads to enospc problems.  This means we also can't do
1849          * delayed inode refs
1850          */
1851         if (BTRFS_I(inode)->root->fs_info->log_root_recovering)
1852                 return -EAGAIN;
1853
1854         delayed_node = btrfs_get_or_create_delayed_node(inode);
1855         if (IS_ERR(delayed_node))
1856                 return PTR_ERR(delayed_node);
1857
1858         mutex_lock(&delayed_node->mutex);
1859         if (delayed_node->inode_dirty) {
1860                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1861                 goto release_node;
1862         }
1863
1864         ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1865                                                    delayed_node);
1866         if (ret)
1867                 goto release_node;
1868
1869         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1870         delayed_node->inode_dirty = 1;
1871         delayed_node->count++;
1872         atomic_inc(&root->fs_info->delayed_root->items);
1873 release_node:
1874         mutex_unlock(&delayed_node->mutex);
1875         btrfs_release_delayed_node(delayed_node);
1876         return ret;
1877 }
1878
1879 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1880 {
1881         struct btrfs_root *root = delayed_node->root;
1882         struct btrfs_delayed_item *curr_item, *prev_item;
1883
1884         mutex_lock(&delayed_node->mutex);
1885         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1886         while (curr_item) {
1887                 btrfs_delayed_item_release_metadata(root, curr_item);
1888                 prev_item = curr_item;
1889                 curr_item = __btrfs_next_delayed_item(prev_item);
1890                 btrfs_release_delayed_item(prev_item);
1891         }
1892
1893         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1894         while (curr_item) {
1895                 btrfs_delayed_item_release_metadata(root, curr_item);
1896                 prev_item = curr_item;
1897                 curr_item = __btrfs_next_delayed_item(prev_item);
1898                 btrfs_release_delayed_item(prev_item);
1899         }
1900
1901         if (delayed_node->inode_dirty) {
1902                 btrfs_delayed_inode_release_metadata(root, delayed_node);
1903                 btrfs_release_delayed_inode(delayed_node);
1904         }
1905         mutex_unlock(&delayed_node->mutex);
1906 }
1907
1908 void btrfs_kill_delayed_inode_items(struct inode *inode)
1909 {
1910         struct btrfs_delayed_node *delayed_node;
1911
1912         delayed_node = btrfs_get_delayed_node(inode);
1913         if (!delayed_node)
1914                 return;
1915
1916         __btrfs_kill_delayed_node(delayed_node);
1917         btrfs_release_delayed_node(delayed_node);
1918 }
1919
1920 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1921 {
1922         u64 inode_id = 0;
1923         struct btrfs_delayed_node *delayed_nodes[8];
1924         int i, n;
1925
1926         while (1) {
1927                 spin_lock(&root->inode_lock);
1928                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1929                                            (void **)delayed_nodes, inode_id,
1930                                            ARRAY_SIZE(delayed_nodes));
1931                 if (!n) {
1932                         spin_unlock(&root->inode_lock);
1933                         break;
1934                 }
1935
1936                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1937
1938                 for (i = 0; i < n; i++)
1939                         atomic_inc(&delayed_nodes[i]->refs);
1940                 spin_unlock(&root->inode_lock);
1941
1942                 for (i = 0; i < n; i++) {
1943                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1944                         btrfs_release_delayed_node(delayed_nodes[i]);
1945                 }
1946         }
1947 }
1948
1949 void btrfs_destroy_delayed_inodes(struct btrfs_root *root)
1950 {
1951         struct btrfs_delayed_root *delayed_root;
1952         struct btrfs_delayed_node *curr_node, *prev_node;
1953
1954         delayed_root = btrfs_get_delayed_root(root);
1955
1956         curr_node = btrfs_first_delayed_node(delayed_root);
1957         while (curr_node) {
1958                 __btrfs_kill_delayed_node(curr_node);
1959
1960                 prev_node = curr_node;
1961                 curr_node = btrfs_next_delayed_node(curr_node);
1962                 btrfs_release_delayed_node(prev_node);
1963         }
1964 }
1965