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 #include "ctree.h"
  25
  26 #define BTRFS_DELAYED_WRITEBACK         512
  27 #define BTRFS_DELAYED_BACKGROUND        128
  28 #define BTRFS_DELAYED_BATCH             16
  29
  30 static struct kmem_cache *delayed_node_cache;
  31
  32 int __init btrfs_delayed_inode_init(void)
  33 {
  34         delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
  35                                         sizeof(struct btrfs_delayed_node),
  36                                         0,
  37                                         SLAB_MEM_SPREAD,
  38                                         NULL);
  39         if (!delayed_node_cache)
  40                 return -ENOMEM;
  41         return 0;
  42 }
  43
  44 void btrfs_delayed_inode_exit(void)
  45 {
  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->ins_root = RB_ROOT;
  57         delayed_node->del_root = RB_ROOT;
  58         mutex_init(&delayed_node->mutex);
  59         INIT_LIST_HEAD(&delayed_node->n_list);
  60         INIT_LIST_HEAD(&delayed_node->p_list);
  61 }
  62
  63 static inline int btrfs_is_continuous_delayed_item(
  64                                         struct btrfs_delayed_item *item1,
  65                                         struct btrfs_delayed_item *item2)
  66 {
  67         if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
  68             item1->key.objectid == item2->key.objectid &&
  69             item1->key.type == item2->key.type &&
  70             item1->key.offset + 1 == item2->key.offset)
  71                 return 1;
  72         return 0;
  73 }
  74
  75 static inline struct btrfs_delayed_root *btrfs_get_delayed_root(
  76                                                         struct btrfs_root *root)
  77 {
  78         return root->fs_info->delayed_root;
  79 }
  80
  81 static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
  82 {
  83         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
  84         struct btrfs_root *root = btrfs_inode->root;
  85         u64 ino = btrfs_ino(inode);
  86         struct btrfs_delayed_node *node;
  87
  88         node = ACCESS_ONCE(btrfs_inode->delayed_node);
  89         if (node) {
  90                 atomic_inc(&node->refs);
  91                 return node;
  92         }
  93
  94         spin_lock(&root->inode_lock);
  95         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
  96         if (node) {
  97                 if (btrfs_inode->delayed_node) {
  98                         atomic_inc(&node->refs);        /* can be accessed */
  99                         BUG_ON(btrfs_inode->delayed_node != node);
 100                         spin_unlock(&root->inode_lock);
 101                         return node;
 102                 }
 103                 btrfs_inode->delayed_node = node;
 104                 /* can be accessed and cached in the inode */
 105                 atomic_add(2, &node->refs);
 106                 spin_unlock(&root->inode_lock);
 107                 return node;
 108         }
 109         spin_unlock(&root->inode_lock);
 110
 111         return NULL;
 112 }
 113
 114 /* Will return either the node or PTR_ERR(-ENOMEM) */
 115 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
 116                                                         struct inode *inode)
 117 {
 118         struct btrfs_delayed_node *node;
 119         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 120         struct btrfs_root *root = btrfs_inode->root;
 121         u64 ino = btrfs_ino(inode);
 122         int ret;
 123
 124 again:
 125         node = btrfs_get_delayed_node(inode);
 126         if (node)
 127                 return node;
 128
 129         node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
 130         if (!node)
 131                 return ERR_PTR(-ENOMEM);
 132         btrfs_init_delayed_node(node, root, ino);
 133
 134         /* cached in the btrfs inode and can be accessed */
 135         atomic_add(2, &node->refs);
 136
 137         ret = radix_tree_preload(GFP_NOFS);
 138         if (ret) {
 139                 kmem_cache_free(delayed_node_cache, node);
 140                 return ERR_PTR(ret);
 141         }
 142
 143         spin_lock(&root->inode_lock);
 144         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
 145         if (ret == -EEXIST) {
 146                 spin_unlock(&root->inode_lock);
 147                 kmem_cache_free(delayed_node_cache, node);
 148                 radix_tree_preload_end();
 149                 goto again;
 150         }
 151         btrfs_inode->delayed_node = node;
 152         spin_unlock(&root->inode_lock);
 153         radix_tree_preload_end();
 154
 155         return node;
 156 }
 157
 158 /*
 159  * Call it when holding delayed_node->mutex
 160  *
 161  * If mod = 1, add this node into the prepared list.
 162  */
 163 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
 164                                      struct btrfs_delayed_node *node,
 165                                      int mod)
 166 {
 167         spin_lock(&root->lock);
 168         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 169                 if (!list_empty(&node->p_list))
 170                         list_move_tail(&node->p_list, &root->prepare_list);
 171                 else if (mod)
 172                         list_add_tail(&node->p_list, &root->prepare_list);
 173         } else {
 174                 list_add_tail(&node->n_list, &root->node_list);
 175                 list_add_tail(&node->p_list, &root->prepare_list);
 176                 atomic_inc(&node->refs);        /* inserted into list */
 177                 root->nodes++;
 178                 set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 179         }
 180         spin_unlock(&root->lock);
 181 }
 182
 183 /* Call it when holding delayed_node->mutex */
 184 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
 185                                        struct btrfs_delayed_node *node)
 186 {
 187         spin_lock(&root->lock);
 188         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 189                 root->nodes--;
 190                 atomic_dec(&node->refs);        /* not in the list */
 191                 list_del_init(&node->n_list);
 192                 if (!list_empty(&node->p_list))
 193                         list_del_init(&node->p_list);
 194                 clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 195         }
 196         spin_unlock(&root->lock);
 197 }
 198
 199 static struct btrfs_delayed_node *btrfs_first_delayed_node(
 200                         struct btrfs_delayed_root *delayed_root)
 201 {
 202         struct list_head *p;
 203         struct btrfs_delayed_node *node = NULL;
 204
 205         spin_lock(&delayed_root->lock);
 206         if (list_empty(&delayed_root->node_list))
 207                 goto out;
 208
 209         p = delayed_root->node_list.next;
 210         node = list_entry(p, struct btrfs_delayed_node, n_list);
 211         atomic_inc(&node->refs);
 212 out:
 213         spin_unlock(&delayed_root->lock);
 214
 215         return node;
 216 }
 217
 218 static struct btrfs_delayed_node *btrfs_next_delayed_node(
 219                                                 struct btrfs_delayed_node *node)
 220 {
 221         struct btrfs_delayed_root *delayed_root;
 222         struct list_head *p;
 223         struct btrfs_delayed_node *next = NULL;
 224
 225         delayed_root = node->root->fs_info->delayed_root;
 226         spin_lock(&delayed_root->lock);
 227         if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 228                 /* not in the list */
 229                 if (list_empty(&delayed_root->node_list))
 230                         goto out;
 231                 p = delayed_root->node_list.next;
 232         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
 233                 goto out;
 234         else
 235                 p = node->n_list.next;
 236
 237         next = list_entry(p, struct btrfs_delayed_node, n_list);
 238         atomic_inc(&next->refs);
 239 out:
 240         spin_unlock(&delayed_root->lock);
 241
 242         return next;
 243 }
 244
 245 static void __btrfs_release_delayed_node(
 246                                 struct btrfs_delayed_node *delayed_node,
 247                                 int mod)
 248 {
 249         struct btrfs_delayed_root *delayed_root;
 250
 251         if (!delayed_node)
 252                 return;
 253
 254         delayed_root = delayed_node->root->fs_info->delayed_root;
 255
 256         mutex_lock(&delayed_node->mutex);
 257         if (delayed_node->count)
 258                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
 259         else
 260                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
 261         mutex_unlock(&delayed_node->mutex);
 262
 263         if (atomic_dec_and_test(&delayed_node->refs)) {
 264                 bool free = false;
 265                 struct btrfs_root *root = delayed_node->root;
 266                 spin_lock(&root->inode_lock);
 267                 if (atomic_read(&delayed_node->refs) == 0) {
 268                         radix_tree_delete(&root->delayed_nodes_tree,
 269                                           delayed_node->inode_id);
 270                         free = true;
 271                 }
 272                 spin_unlock(&root->inode_lock);
 273                 if (free)
 274                         kmem_cache_free(delayed_node_cache, delayed_node);
 275         }
 276 }
 277
 278 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 279 {
 280         __btrfs_release_delayed_node(node, 0);
 281 }
 282
 283 static struct 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);
 297 out:
 298         spin_unlock(&delayed_root->lock);
 299
 300         return node;
 301 }
 302
 303 static inline void btrfs_release_prepared_delayed_node(
 304                                         struct btrfs_delayed_node *node)
 305 {
 306         __btrfs_release_delayed_node(node, 1);
 307 }
 308
 309 static struct 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  */
 333 static 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
 384 static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
 385                                         struct btrfs_delayed_node *delayed_node,
 386                                         struct btrfs_key *key)
 387 {
 388         return __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
 389                                            NULL, NULL);
 390 }
 391
 392 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 393                                     struct btrfs_delayed_item *ins,
 394                                     int action)
 395 {
 396         struct rb_node **p, *node;
 397         struct rb_node *parent_node = NULL;
 398         struct rb_root *root;
 399         struct btrfs_delayed_item *item;
 400         int cmp;
 401
 402         if (action == BTRFS_DELAYED_INSERTION_ITEM)
 403                 root = &delayed_node->ins_root;
 404         else if (action == BTRFS_DELAYED_DELETION_ITEM)
 405                 root = &delayed_node->del_root;
 406         else
 407                 BUG();
 408         p = &root->rb_node;
 409         node = &ins->rb_node;
 410
 411         while (*p) {
 412                 parent_node = *p;
 413                 item = rb_entry(parent_node, struct btrfs_delayed_item,
 414                                  rb_node);
 415
 416                 cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
 417                 if (cmp < 0)
 418                         p = &(*p)->rb_right;
 419                 else if (cmp > 0)
 420                         p = &(*p)->rb_left;
 421                 else
 422                         return -EEXIST;
 423         }
 424
 425         rb_link_node(node, parent_node, p);
 426         rb_insert_color(node, root);
 427         ins->delayed_node = delayed_node;
 428         ins->ins_or_del = action;
 429
 430         if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
 431             action == BTRFS_DELAYED_INSERTION_ITEM &&
 432             ins->key.offset >= delayed_node->index_cnt)
 433                         delayed_node->index_cnt = ins->key.offset + 1;
 434
 435         delayed_node->count++;
 436         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
 437         return 0;
 438 }
 439
 440 static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
 441                                               struct btrfs_delayed_item *item)
 442 {
 443         return __btrfs_add_delayed_item(node, item,
 444                                         BTRFS_DELAYED_INSERTION_ITEM);
 445 }
 446
 447 static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
 448                                              struct btrfs_delayed_item *item)
 449 {
 450         return __btrfs_add_delayed_item(node, item,
 451                                         BTRFS_DELAYED_DELETION_ITEM);
 452 }
 453
 454 static void finish_one_item(struct btrfs_delayed_root *delayed_root)
 455 {
 456         int seq = atomic_inc_return(&delayed_root->items_seq);
 457
 458         /*
 459          * atomic_dec_return implies a barrier for waitqueue_active
 460          */
 461         if ((atomic_dec_return(&delayed_root->items) <
 462             BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0) &&
 463             waitqueue_active(&delayed_root->wait))
 464                 wake_up(&delayed_root->wait);
 465 }
 466
 467 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 468 {
 469         struct rb_root *root;
 470         struct btrfs_delayed_root *delayed_root;
 471
 472         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 473
 474         BUG_ON(!delayed_root);
 475         BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
 476                delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
 477
 478         if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
 479                 root = &delayed_item->delayed_node->ins_root;
 480         else
 481                 root = &delayed_item->delayed_node->del_root;
 482
 483         rb_erase(&delayed_item->rb_node, root);
 484         delayed_item->delayed_node->count--;
 485
 486         finish_one_item(delayed_root);
 487 }
 488
 489 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 490 {
 491         if (item) {
 492                 __btrfs_remove_delayed_item(item);
 493                 if (atomic_dec_and_test(&item->refs))
 494                         kfree(item);
 495         }
 496 }
 497
 498 static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 499                                         struct btrfs_delayed_node *delayed_node)
 500 {
 501         struct rb_node *p;
 502         struct btrfs_delayed_item *item = NULL;
 503
 504         p = rb_first(&delayed_node->ins_root);
 505         if (p)
 506                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 507
 508         return item;
 509 }
 510
 511 static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 512                                         struct btrfs_delayed_node *delayed_node)
 513 {
 514         struct rb_node *p;
 515         struct btrfs_delayed_item *item = NULL;
 516
 517         p = rb_first(&delayed_node->del_root);
 518         if (p)
 519                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 520
 521         return item;
 522 }
 523
 524 static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 525                                                 struct btrfs_delayed_item *item)
 526 {
 527         struct rb_node *p;
 528         struct btrfs_delayed_item *next = NULL;
 529
 530         p = rb_next(&item->rb_node);
 531         if (p)
 532                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 533
 534         return next;
 535 }
 536
 537 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 538                                                struct btrfs_root *root,
 539                                                struct btrfs_delayed_item *item)
 540 {
 541         struct btrfs_block_rsv *src_rsv;
 542         struct btrfs_block_rsv *dst_rsv;
 543         u64 num_bytes;
 544         int ret;
 545
 546         if (!trans->bytes_reserved)
 547                 return 0;
 548
 549         src_rsv = trans->block_rsv;
 550         dst_rsv = &root->fs_info->delayed_block_rsv;
 551
 552         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 553         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
 554         if (!ret) {
 555                 trace_btrfs_space_reservation(root->fs_info, "delayed_item",
 556                                               item->key.objectid,
 557                                               num_bytes, 1);
 558                 item->bytes_reserved = num_bytes;
 559         }
 560
 561         return ret;
 562 }
 563
 564 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
 565                                                 struct btrfs_delayed_item *item)
 566 {
 567         struct btrfs_block_rsv *rsv;
 568
 569         if (!item->bytes_reserved)
 570                 return;
 571
 572         rsv = &root->fs_info->delayed_block_rsv;
 573         trace_btrfs_space_reservation(root->fs_info, "delayed_item",
 574                                       item->key.objectid, item->bytes_reserved,
 575                                       0);
 576         btrfs_block_rsv_release(root, rsv,
 577                                 item->bytes_reserved);
 578 }
 579
 580 static int btrfs_delayed_inode_reserve_metadata(
 581                                         struct btrfs_trans_handle *trans,
 582                                         struct btrfs_root *root,
 583                                         struct inode *inode,
 584                                         struct btrfs_delayed_node *node)
 585 {
 586         struct btrfs_block_rsv *src_rsv;
 587         struct btrfs_block_rsv *dst_rsv;
 588         u64 num_bytes;
 589         int ret;
 590         bool release = false;
 591
 592         src_rsv = trans->block_rsv;
 593         dst_rsv = &root->fs_info->delayed_block_rsv;
 594
 595         num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 596
 597         /*
 598          * If our block_rsv is the delalloc block reserve then check and see if
 599          * we have our extra reservation for updating the inode.  If not fall
 600          * through and try to reserve space quickly.
 601          *
 602          * We used to try and steal from the delalloc block rsv or the global
 603          * reserve, but we'd steal a full reservation, which isn't kind.  We are
 604          * here through delalloc which means we've likely just cowed down close
 605          * to the leaf that contains the inode, so we would steal less just
 606          * doing the fallback inode update, so if we do end up having to steal
 607          * from the global block rsv we hopefully only steal one or two blocks
 608          * worth which is less likely to hurt us.
 609          */
 610         if (src_rsv && src_rsv->type == BTRFS_BLOCK_RSV_DELALLOC) {
 611                 spin_lock(&BTRFS_I(inode)->lock);
 612                 if (test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
 613                                        &BTRFS_I(inode)->runtime_flags))
 614                         release = true;
 615                 else
 616                         src_rsv = NULL;
 617                 spin_unlock(&BTRFS_I(inode)->lock);
 618         }
 619
 620         /*
 621          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
 622          * which doesn't reserve space for speed.  This is a problem since we
 623          * still need to reserve space for this update, so try to reserve the
 624          * space.
 625          *
 626          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
 627          * we're accounted for.
 628          */
 629         if (!src_rsv || (!trans->bytes_reserved &&
 630                          src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
 631                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
 632                                           BTRFS_RESERVE_NO_FLUSH);
 633                 /*
 634                  * Since we're under a transaction reserve_metadata_bytes could
 635                  * try to commit the transaction which will make it return
 636                  * EAGAIN to make us stop the transaction we have, so return
 637                  * ENOSPC instead so that btrfs_dirty_inode knows what to do.
 638                  */
 639                 if (ret == -EAGAIN)
 640                         ret = -ENOSPC;
 641                 if (!ret) {
 642                         node->bytes_reserved = num_bytes;
 643                         trace_btrfs_space_reservation(root->fs_info,
 644                                                       "delayed_inode",
 645                                                       btrfs_ino(inode),
 646                                                       num_bytes, 1);
 647                 }
 648                 return ret;
 649         }
 650
 651         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
 652
 653         /*
 654          * Migrate only takes a reservation, it doesn't touch the size of the
 655          * block_rsv.  This is to simplify people who don't normally have things
 656          * migrated from their block rsv.  If they go to release their
 657          * reservation, that will decrease the size as well, so if migrate
 658          * reduced size we'd end up with a negative size.  But for the
 659          * delalloc_meta_reserved stuff we will only know to drop 1 reservation,
 660          * but we could in fact do this reserve/migrate dance several times
 661          * between the time we did the original reservation and we'd clean it
 662          * up.  So to take care of this, release the space for the meta
 663          * reservation here.  I think it may be time for a documentation page on
 664          * how block rsvs. work.
 665          */
 666         if (!ret) {
 667                 trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
 668                                               btrfs_ino(inode), num_bytes, 1);
 669                 node->bytes_reserved = num_bytes;
 670         }
 671
 672         if (release) {
 673                 trace_btrfs_space_reservation(root->fs_info, "delalloc",
 674                                               btrfs_ino(inode), num_bytes, 0);
 675                 btrfs_block_rsv_release(root, src_rsv, num_bytes);
 676         }
 677
 678         return ret;
 679 }
 680
 681 static void btrfs_delayed_inode_release_metadata(struct btrfs_root *root,
 682                                                 struct btrfs_delayed_node *node)
 683 {
 684         struct btrfs_block_rsv *rsv;
 685
 686         if (!node->bytes_reserved)
 687                 return;
 688
 689         rsv = &root->fs_info->delayed_block_rsv;
 690         trace_btrfs_space_reservation(root->fs_info, "delayed_inode",
 691                                       node->inode_id, node->bytes_reserved, 0);
 692         btrfs_block_rsv_release(root, rsv,
 693                                 node->bytes_reserved);
 694         node->bytes_reserved = 0;
 695 }
 696
 697 /*
 698  * This helper will insert some continuous items into the same leaf according
 699  * to the free space of the leaf.
 700  */
 701 static int btrfs_batch_insert_items(struct btrfs_root *root,
 702                                     struct btrfs_path *path,
 703                                     struct btrfs_delayed_item *item)
 704 {
 705         struct btrfs_delayed_item *curr, *next;
 706         int free_space;
 707         int total_data_size = 0, total_size = 0;
 708         struct extent_buffer *leaf;
 709         char *data_ptr;
 710         struct btrfs_key *keys;
 711         u32 *data_size;
 712         struct list_head head;
 713         int slot;
 714         int nitems;
 715         int i;
 716         int ret = 0;
 717
 718         BUG_ON(!path->nodes[0]);
 719
 720         leaf = path->nodes[0];
 721         free_space = btrfs_leaf_free_space(root, leaf);
 722         INIT_LIST_HEAD(&head);
 723
 724         next = item;
 725         nitems = 0;
 726
 727         /*
 728          * count the number of the continuous items that we can insert in batch
 729          */
 730         while (total_size + next->data_len + sizeof(struct btrfs_item) <=
 731                free_space) {
 732                 total_data_size += next->data_len;
 733                 total_size += next->data_len + sizeof(struct btrfs_item);
 734                 list_add_tail(&next->tree_list, &head);
 735                 nitems++;
 736
 737                 curr = next;
 738                 next = __btrfs_next_delayed_item(curr);
 739                 if (!next)
 740                         break;
 741
 742                 if (!btrfs_is_continuous_delayed_item(curr, next))
 743                         break;
 744         }
 745
 746         if (!nitems) {
 747                 ret = 0;
 748                 goto out;
 749         }
 750
 751         /*
 752          * we need allocate some memory space, but it might cause the task
 753          * to sleep, so we set all locked nodes in the path to blocking locks
 754          * first.
 755          */
 756         btrfs_set_path_blocking(path);
 757
 758         keys = kmalloc_array(nitems, sizeof(struct btrfs_key), GFP_NOFS);
 759         if (!keys) {
 760                 ret = -ENOMEM;
 761                 goto out;
 762         }
 763
 764         data_size = kmalloc_array(nitems, sizeof(u32), GFP_NOFS);
 765         if (!data_size) {
 766                 ret = -ENOMEM;
 767                 goto error;
 768         }
 769
 770         /* get keys of all the delayed items */
 771         i = 0;
 772         list_for_each_entry(next, &head, tree_list) {
 773                 keys[i] = next->key;
 774                 data_size[i] = next->data_len;
 775                 i++;
 776         }
 777
 778         /* reset all the locked nodes in the patch to spinning locks. */
 779         btrfs_clear_path_blocking(path, NULL, 0);
 780
 781         /* insert the keys of the items */
 782         setup_items_for_insert(root, path, keys, data_size,
 783                                total_data_size, total_size, nitems);
 784
 785         /* insert the dir index items */
 786         slot = path->slots[0];
 787         list_for_each_entry_safe(curr, next, &head, tree_list) {
 788                 data_ptr = btrfs_item_ptr(leaf, slot, char);
 789                 write_extent_buffer(leaf, &curr->data,
 790                                     (unsigned long)data_ptr,
 791                                     curr->data_len);
 792                 slot++;
 793
 794                 btrfs_delayed_item_release_metadata(root, curr);
 795
 796                 list_del(&curr->tree_list);
 797                 btrfs_release_delayed_item(curr);
 798         }
 799
 800 error:
 801         kfree(data_size);
 802         kfree(keys);
 803 out:
 804         return ret;
 805 }
 806
 807 /*
 808  * This helper can just do simple insertion that needn't extend item for new
 809  * data, such as directory name index insertion, inode insertion.
 810  */
 811 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 812                                      struct btrfs_root *root,
 813                                      struct btrfs_path *path,
 814                                      struct btrfs_delayed_item *delayed_item)
 815 {
 816         struct extent_buffer *leaf;
 817         char *ptr;
 818         int ret;
 819
 820         ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
 821                                       delayed_item->data_len);
 822         if (ret < 0 && ret != -EEXIST)
 823                 return ret;
 824
 825         leaf = path->nodes[0];
 826
 827         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
 828
 829         write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
 830                             delayed_item->data_len);
 831         btrfs_mark_buffer_dirty(leaf);
 832
 833         btrfs_delayed_item_release_metadata(root, delayed_item);
 834         return 0;
 835 }
 836
 837 /*
 838  * we insert an item first, then if there are some continuous items, we try
 839  * to insert those items into the same leaf.
 840  */
 841 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 842                                       struct btrfs_path *path,
 843                                       struct btrfs_root *root,
 844                                       struct btrfs_delayed_node *node)
 845 {
 846         struct btrfs_delayed_item *curr, *prev;
 847         int ret = 0;
 848
 849 do_again:
 850         mutex_lock(&node->mutex);
 851         curr = __btrfs_first_delayed_insertion_item(node);
 852         if (!curr)
 853                 goto insert_end;
 854
 855         ret = btrfs_insert_delayed_item(trans, root, path, curr);
 856         if (ret < 0) {
 857                 btrfs_release_path(path);
 858                 goto insert_end;
 859         }
 860
 861         prev = curr;
 862         curr = __btrfs_next_delayed_item(prev);
 863         if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
 864                 /* insert the continuous items into the same leaf */
 865                 path->slots[0]++;
 866                 btrfs_batch_insert_items(root, path, curr);
 867         }
 868         btrfs_release_delayed_item(prev);
 869         btrfs_mark_buffer_dirty(path->nodes[0]);
 870
 871         btrfs_release_path(path);
 872         mutex_unlock(&node->mutex);
 873         goto do_again;
 874
 875 insert_end:
 876         mutex_unlock(&node->mutex);
 877         return ret;
 878 }
 879
 880 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
 881                                     struct btrfs_root *root,
 882                                     struct btrfs_path *path,
 883                                     struct btrfs_delayed_item *item)
 884 {
 885         struct btrfs_delayed_item *curr, *next;
 886         struct extent_buffer *leaf;
 887         struct btrfs_key key;
 888         struct list_head head;
 889         int nitems, i, last_item;
 890         int ret = 0;
 891
 892         BUG_ON(!path->nodes[0]);
 893
 894         leaf = path->nodes[0];
 895
 896         i = path->slots[0];
 897         last_item = btrfs_header_nritems(leaf) - 1;
 898         if (i > last_item)
 899                 return -ENOENT; /* FIXME: Is errno suitable? */
 900
 901         next = item;
 902         INIT_LIST_HEAD(&head);
 903         btrfs_item_key_to_cpu(leaf, &key, i);
 904         nitems = 0;
 905         /*
 906          * count the number of the dir index items that we can delete in batch
 907          */
 908         while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
 909                 list_add_tail(&next->tree_list, &head);
 910                 nitems++;
 911
 912                 curr = next;
 913                 next = __btrfs_next_delayed_item(curr);
 914                 if (!next)
 915                         break;
 916
 917                 if (!btrfs_is_continuous_delayed_item(curr, next))
 918                         break;
 919
 920                 i++;
 921                 if (i > last_item)
 922                         break;
 923                 btrfs_item_key_to_cpu(leaf, &key, i);
 924         }
 925
 926         if (!nitems)
 927                 return 0;
 928
 929         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
 930         if (ret)
 931                 goto out;
 932
 933         list_for_each_entry_safe(curr, next, &head, tree_list) {
 934                 btrfs_delayed_item_release_metadata(root, curr);
 935                 list_del(&curr->tree_list);
 936                 btrfs_release_delayed_item(curr);
 937         }
 938
 939 out:
 940         return ret;
 941 }
 942
 943 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
 944                                       struct btrfs_path *path,
 945                                       struct btrfs_root *root,
 946                                       struct btrfs_delayed_node *node)
 947 {
 948         struct btrfs_delayed_item *curr, *prev;
 949         int ret = 0;
 950
 951 do_again:
 952         mutex_lock(&node->mutex);
 953         curr = __btrfs_first_delayed_deletion_item(node);
 954         if (!curr)
 955                 goto delete_fail;
 956
 957         ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
 958         if (ret < 0)
 959                 goto delete_fail;
 960         else if (ret > 0) {
 961                 /*
 962                  * can't find the item which the node points to, so this node
 963                  * is invalid, just drop it.
 964                  */
 965                 prev = curr;
 966                 curr = __btrfs_next_delayed_item(prev);
 967                 btrfs_release_delayed_item(prev);
 968                 ret = 0;
 969                 btrfs_release_path(path);
 970                 if (curr) {
 971                         mutex_unlock(&node->mutex);
 972                         goto do_again;
 973                 } else
 974                         goto delete_fail;
 975         }
 976
 977         btrfs_batch_delete_items(trans, root, path, curr);
 978         btrfs_release_path(path);
 979         mutex_unlock(&node->mutex);
 980         goto do_again;
 981
 982 delete_fail:
 983         btrfs_release_path(path);
 984         mutex_unlock(&node->mutex);
 985         return ret;
 986 }
 987
 988 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
 989 {
 990         struct btrfs_delayed_root *delayed_root;
 991
 992         if (delayed_node &&
 993             test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
 994                 BUG_ON(!delayed_node->root);
 995                 clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
 996                 delayed_node->count--;
 997
 998                 delayed_root = delayed_node->root->fs_info->delayed_root;
 999                 finish_one_item(delayed_root);
1000         }
1001 }
1002
1003 static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
1004 {
1005         struct btrfs_delayed_root *delayed_root;
1006
1007         ASSERT(delayed_node->root);
1008         clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1009         delayed_node->count--;
1010
1011         delayed_root = delayed_node->root->fs_info->delayed_root;
1012         finish_one_item(delayed_root);
1013 }
1014
1015 static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1016                                         struct btrfs_root *root,
1017                                         struct btrfs_path *path,
1018                                         struct btrfs_delayed_node *node)
1019 {
1020         struct btrfs_key key;
1021         struct btrfs_inode_item *inode_item;
1022         struct extent_buffer *leaf;
1023         int mod;
1024         int ret;
1025
1026         key.objectid = node->inode_id;
1027         key.type = BTRFS_INODE_ITEM_KEY;
1028         key.offset = 0;
1029
1030         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1031                 mod = -1;
1032         else
1033                 mod = 1;
1034
1035         ret = btrfs_lookup_inode(trans, root, path, &key, mod);
1036         if (ret > 0) {
1037                 btrfs_release_path(path);
1038                 return -ENOENT;
1039         } else if (ret < 0) {
1040                 return ret;
1041         }
1042
1043         leaf = path->nodes[0];
1044         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1045                                     struct btrfs_inode_item);
1046         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1047                             sizeof(struct btrfs_inode_item));
1048         btrfs_mark_buffer_dirty(leaf);
1049
1050         if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1051                 goto no_iref;
1052
1053         path->slots[0]++;
1054         if (path->slots[0] >= btrfs_header_nritems(leaf))
1055                 goto search;
1056 again:
1057         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1058         if (key.objectid != node->inode_id)
1059                 goto out;
1060
1061         if (key.type != BTRFS_INODE_REF_KEY &&
1062             key.type != BTRFS_INODE_EXTREF_KEY)
1063                 goto out;
1064
1065         /*
1066          * Delayed iref deletion is for the inode who has only one link,
1067          * so there is only one iref. The case that several irefs are
1068          * in the same item doesn't exist.
1069          */
1070         btrfs_del_item(trans, root, path);
1071 out:
1072         btrfs_release_delayed_iref(node);
1073 no_iref:
1074         btrfs_release_path(path);
1075 err_out:
1076         btrfs_delayed_inode_release_metadata(root, node);
1077         btrfs_release_delayed_inode(node);
1078
1079         /*
1080          * If we fail to update the delayed inode we need to abort the
1081          * transaction, because we could leave the inode with the improper
1082          * counts behind.
1083          */
1084         if (ret && ret != -ENOENT)
1085                 btrfs_abort_transaction(trans, ret);
1086
1087         return ret;
1088
1089 search:
1090         btrfs_release_path(path);
1091
1092         key.type = BTRFS_INODE_EXTREF_KEY;
1093         key.offset = -1;
1094         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1095         if (ret < 0)
1096                 goto err_out;
1097         ASSERT(ret);
1098
1099         ret = 0;
1100         leaf = path->nodes[0];
1101         path->slots[0]--;
1102         goto again;
1103 }
1104
1105 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1106                                              struct btrfs_root *root,
1107                                              struct btrfs_path *path,
1108                                              struct btrfs_delayed_node *node)
1109 {
1110         int ret;
1111
1112         mutex_lock(&node->mutex);
1113         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1114                 mutex_unlock(&node->mutex);
1115                 return 0;
1116         }
1117
1118         ret = __btrfs_update_delayed_inode(trans, root, path, node);
1119         mutex_unlock(&node->mutex);
1120         return ret;
1121 }
1122
1123 static inline int
1124 __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1125                                    struct btrfs_path *path,
1126                                    struct btrfs_delayed_node *node)
1127 {
1128         int ret;
1129
1130         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1131         if (ret)
1132                 return ret;
1133
1134         ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1135         if (ret)
1136                 return ret;
1137
1138         ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1139         return ret;
1140 }
1141
1142 /*
1143  * Called when committing the transaction.
1144  * Returns 0 on success.
1145  * Returns < 0 on error and returns with an aborted transaction with any
1146  * outstanding delayed items cleaned up.
1147  */
1148 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1149                                      struct btrfs_root *root, int nr)
1150 {
1151         struct btrfs_delayed_root *delayed_root;
1152         struct btrfs_delayed_node *curr_node, *prev_node;
1153         struct btrfs_path *path;
1154         struct btrfs_block_rsv *block_rsv;
1155         int ret = 0;
1156         bool count = (nr > 0);
1157
1158         if (trans->aborted)
1159                 return -EIO;
1160
1161         path = btrfs_alloc_path();
1162         if (!path)
1163                 return -ENOMEM;
1164         path->leave_spinning = 1;
1165
1166         block_rsv = trans->block_rsv;
1167         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1168
1169         delayed_root = btrfs_get_delayed_root(root);
1170
1171         curr_node = btrfs_first_delayed_node(delayed_root);
1172         while (curr_node && (!count || (count && nr--))) {
1173                 ret = __btrfs_commit_inode_delayed_items(trans, path,
1174                                                          curr_node);
1175                 if (ret) {
1176                         btrfs_release_delayed_node(curr_node);
1177                         curr_node = NULL;
1178                         btrfs_abort_transaction(trans, ret);
1179                         break;
1180                 }
1181
1182                 prev_node = curr_node;
1183                 curr_node = btrfs_next_delayed_node(curr_node);
1184                 btrfs_release_delayed_node(prev_node);
1185         }
1186
1187         if (curr_node)
1188                 btrfs_release_delayed_node(curr_node);
1189         btrfs_free_path(path);
1190         trans->block_rsv = block_rsv;
1191
1192         return ret;
1193 }
1194
1195 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1196                             struct btrfs_root *root)
1197 {
1198         return __btrfs_run_delayed_items(trans, root, -1);
1199 }
1200
1201 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans,
1202                                struct btrfs_root *root, int nr)
1203 {
1204         return __btrfs_run_delayed_items(trans, root, nr);
1205 }
1206
1207 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1208                                      struct inode *inode)
1209 {
1210         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1211         struct btrfs_path *path;
1212         struct btrfs_block_rsv *block_rsv;
1213         int ret;
1214
1215         if (!delayed_node)
1216                 return 0;
1217
1218         mutex_lock(&delayed_node->mutex);
1219         if (!delayed_node->count) {
1220                 mutex_unlock(&delayed_node->mutex);
1221                 btrfs_release_delayed_node(delayed_node);
1222                 return 0;
1223         }
1224         mutex_unlock(&delayed_node->mutex);
1225
1226         path = btrfs_alloc_path();
1227         if (!path) {
1228                 btrfs_release_delayed_node(delayed_node);
1229                 return -ENOMEM;
1230         }
1231         path->leave_spinning = 1;
1232
1233         block_rsv = trans->block_rsv;
1234         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1235
1236         ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1237
1238         btrfs_release_delayed_node(delayed_node);
1239         btrfs_free_path(path);
1240         trans->block_rsv = block_rsv;
1241
1242         return ret;
1243 }
1244
1245 int btrfs_commit_inode_delayed_inode(struct inode *inode)
1246 {
1247         struct btrfs_trans_handle *trans;
1248         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1249         struct btrfs_path *path;
1250         struct btrfs_block_rsv *block_rsv;
1251         int ret;
1252
1253         if (!delayed_node)
1254                 return 0;
1255
1256         mutex_lock(&delayed_node->mutex);
1257         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1258                 mutex_unlock(&delayed_node->mutex);
1259                 btrfs_release_delayed_node(delayed_node);
1260                 return 0;
1261         }
1262         mutex_unlock(&delayed_node->mutex);
1263
1264         trans = btrfs_join_transaction(delayed_node->root);
1265         if (IS_ERR(trans)) {
1266                 ret = PTR_ERR(trans);
1267                 goto out;
1268         }
1269
1270         path = btrfs_alloc_path();
1271         if (!path) {
1272                 ret = -ENOMEM;
1273                 goto trans_out;
1274         }
1275         path->leave_spinning = 1;
1276
1277         block_rsv = trans->block_rsv;
1278         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1279
1280         mutex_lock(&delayed_node->mutex);
1281         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1282                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1283                                                    path, delayed_node);
1284         else
1285                 ret = 0;
1286         mutex_unlock(&delayed_node->mutex);
1287
1288         btrfs_free_path(path);
1289         trans->block_rsv = block_rsv;
1290 trans_out:
1291         btrfs_end_transaction(trans, delayed_node->root);
1292         btrfs_btree_balance_dirty(delayed_node->root);
1293 out:
1294         btrfs_release_delayed_node(delayed_node);
1295
1296         return ret;
1297 }
1298
1299 void btrfs_remove_delayed_node(struct inode *inode)
1300 {
1301         struct btrfs_delayed_node *delayed_node;
1302
1303         delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1304         if (!delayed_node)
1305                 return;
1306
1307         BTRFS_I(inode)->delayed_node = NULL;
1308         btrfs_release_delayed_node(delayed_node);
1309 }
1310
1311 struct btrfs_async_delayed_work {
1312         struct btrfs_delayed_root *delayed_root;
1313         int nr;
1314         struct btrfs_work work;
1315 };
1316
1317 static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1318 {
1319         struct btrfs_async_delayed_work *async_work;
1320         struct btrfs_delayed_root *delayed_root;
1321         struct btrfs_trans_handle *trans;
1322         struct btrfs_path *path;
1323         struct btrfs_delayed_node *delayed_node = NULL;
1324         struct btrfs_root *root;
1325         struct btrfs_block_rsv *block_rsv;
1326         int total_done = 0;
1327
1328         async_work = container_of(work, struct btrfs_async_delayed_work, work);
1329         delayed_root = async_work->delayed_root;
1330
1331         path = btrfs_alloc_path();
1332         if (!path)
1333                 goto out;
1334
1335 again:
1336         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND / 2)
1337                 goto free_path;
1338
1339         delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1340         if (!delayed_node)
1341                 goto free_path;
1342
1343         path->leave_spinning = 1;
1344         root = delayed_node->root;
1345
1346         trans = btrfs_join_transaction(root);
1347         if (IS_ERR(trans))
1348                 goto release_path;
1349
1350         block_rsv = trans->block_rsv;
1351         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1352
1353         __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1354
1355         trans->block_rsv = block_rsv;
1356         btrfs_end_transaction(trans, root);
1357         btrfs_btree_balance_dirty_nodelay(root);
1358
1359 release_path:
1360         btrfs_release_path(path);
1361         total_done++;
1362
1363         btrfs_release_prepared_delayed_node(delayed_node);
1364         if ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK) ||
1365             total_done < async_work->nr)
1366                 goto again;
1367
1368 free_path:
1369         btrfs_free_path(path);
1370 out:
1371         wake_up(&delayed_root->wait);
1372         kfree(async_work);
1373 }
1374
1375
1376 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1377                                      struct btrfs_fs_info *fs_info, int nr)
1378 {
1379         struct btrfs_async_delayed_work *async_work;
1380
1381         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND ||
1382             btrfs_workqueue_normal_congested(fs_info->delayed_workers))
1383                 return 0;
1384
1385         async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1386         if (!async_work)
1387                 return -ENOMEM;
1388
1389         async_work->delayed_root = delayed_root;
1390         btrfs_init_work(&async_work->work, btrfs_delayed_meta_helper,
1391                         btrfs_async_run_delayed_root, NULL, NULL);
1392         async_work->nr = nr;
1393
1394         btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
1395         return 0;
1396 }
1397
1398 void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1399 {
1400         struct btrfs_delayed_root *delayed_root;
1401         delayed_root = btrfs_get_delayed_root(root);
1402         WARN_ON(btrfs_first_delayed_node(delayed_root));
1403 }
1404
1405 static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1406 {
1407         int val = atomic_read(&delayed_root->items_seq);
1408
1409         if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1410                 return 1;
1411
1412         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1413                 return 1;
1414
1415         return 0;
1416 }
1417
1418 void btrfs_balance_delayed_items(struct btrfs_root *root)
1419 {
1420         struct btrfs_delayed_root *delayed_root;
1421         struct btrfs_fs_info *fs_info = root->fs_info;
1422
1423         delayed_root = btrfs_get_delayed_root(root);
1424
1425         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1426                 return;
1427
1428         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1429                 int seq;
1430                 int ret;
1431
1432                 seq = atomic_read(&delayed_root->items_seq);
1433
1434                 ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
1435                 if (ret)
1436                         return;
1437
1438                 wait_event_interruptible(delayed_root->wait,
1439                                          could_end_wait(delayed_root, seq));
1440                 return;
1441         }
1442
1443         btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1444 }
1445
1446 /* Will return 0 or -ENOMEM */
1447 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1448                                    struct btrfs_root *root, const char *name,
1449                                    int name_len, struct inode *dir,
1450                                    struct btrfs_disk_key *disk_key, u8 type,
1451                                    u64 index)
1452 {
1453         struct btrfs_delayed_node *delayed_node;
1454         struct btrfs_delayed_item *delayed_item;
1455         struct btrfs_dir_item *dir_item;
1456         int ret;
1457
1458         delayed_node = btrfs_get_or_create_delayed_node(dir);
1459         if (IS_ERR(delayed_node))
1460                 return PTR_ERR(delayed_node);
1461
1462         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1463         if (!delayed_item) {
1464                 ret = -ENOMEM;
1465                 goto release_node;
1466         }
1467
1468         delayed_item->key.objectid = btrfs_ino(dir);
1469         delayed_item->key.type = BTRFS_DIR_INDEX_KEY;
1470         delayed_item->key.offset = index;
1471
1472         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1473         dir_item->location = *disk_key;
1474         btrfs_set_stack_dir_transid(dir_item, trans->transid);
1475         btrfs_set_stack_dir_data_len(dir_item, 0);
1476         btrfs_set_stack_dir_name_len(dir_item, name_len);
1477         btrfs_set_stack_dir_type(dir_item, type);
1478         memcpy((char *)(dir_item + 1), name, name_len);
1479
1480         ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1481         /*
1482          * we have reserved enough space when we start a new transaction,
1483          * so reserving metadata failure is impossible
1484          */
1485         BUG_ON(ret);
1486
1487
1488         mutex_lock(&delayed_node->mutex);
1489         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1490         if (unlikely(ret)) {
1491                 btrfs_err(root->fs_info,
1492                           "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1493                           name_len, name, delayed_node->root->objectid,
1494                           delayed_node->inode_id, ret);
1495                 BUG();
1496         }
1497         mutex_unlock(&delayed_node->mutex);
1498
1499 release_node:
1500         btrfs_release_delayed_node(delayed_node);
1501         return ret;
1502 }
1503
1504 static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1505                                                struct btrfs_delayed_node *node,
1506                                                struct btrfs_key *key)
1507 {
1508         struct btrfs_delayed_item *item;
1509
1510         mutex_lock(&node->mutex);
1511         item = __btrfs_lookup_delayed_insertion_item(node, key);
1512         if (!item) {
1513                 mutex_unlock(&node->mutex);
1514                 return 1;
1515         }
1516
1517         btrfs_delayed_item_release_metadata(root, item);
1518         btrfs_release_delayed_item(item);
1519         mutex_unlock(&node->mutex);
1520         return 0;
1521 }
1522
1523 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1524                                    struct btrfs_root *root, struct inode *dir,
1525                                    u64 index)
1526 {
1527         struct btrfs_delayed_node *node;
1528         struct btrfs_delayed_item *item;
1529         struct btrfs_key item_key;
1530         int ret;
1531
1532         node = btrfs_get_or_create_delayed_node(dir);
1533         if (IS_ERR(node))
1534                 return PTR_ERR(node);
1535
1536         item_key.objectid = btrfs_ino(dir);
1537         item_key.type = BTRFS_DIR_INDEX_KEY;
1538         item_key.offset = index;
1539
1540         ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1541         if (!ret)
1542                 goto end;
1543
1544         item = btrfs_alloc_delayed_item(0);
1545         if (!item) {
1546                 ret = -ENOMEM;
1547                 goto end;
1548         }
1549
1550         item->key = item_key;
1551
1552         ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1553         /*
1554          * we have reserved enough space when we start a new transaction,
1555          * so reserving metadata failure is impossible.
1556          */
1557         BUG_ON(ret);
1558
1559         mutex_lock(&node->mutex);
1560         ret = __btrfs_add_delayed_deletion_item(node, item);
1561         if (unlikely(ret)) {
1562                 btrfs_err(root->fs_info,
1563                           "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1564                           index, node->root->objectid, node->inode_id, ret);
1565                 BUG();
1566         }
1567         mutex_unlock(&node->mutex);
1568 end:
1569         btrfs_release_delayed_node(node);
1570         return ret;
1571 }
1572
1573 int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1574 {
1575         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1576
1577         if (!delayed_node)
1578                 return -ENOENT;
1579
1580         /*
1581          * Since we have held i_mutex of this directory, it is impossible that
1582          * a new directory index is added into the delayed node and index_cnt
1583          * is updated now. So we needn't lock the delayed node.
1584          */
1585         if (!delayed_node->index_cnt) {
1586                 btrfs_release_delayed_node(delayed_node);
1587                 return -EINVAL;
1588         }
1589
1590         BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1591         btrfs_release_delayed_node(delayed_node);
1592         return 0;
1593 }
1594
1595 bool btrfs_readdir_get_delayed_items(struct inode *inode,
1596                                      struct list_head *ins_list,
1597                                      struct list_head *del_list)
1598 {
1599         struct btrfs_delayed_node *delayed_node;
1600         struct btrfs_delayed_item *item;
1601
1602         delayed_node = btrfs_get_delayed_node(inode);
1603         if (!delayed_node)
1604                 return false;
1605
1606         /*
1607          * We can only do one readdir with delayed items at a time because of
1608          * item->readdir_list.
1609          */
1610         inode_unlock_shared(inode);
1611         inode_lock(inode);
1612
1613         mutex_lock(&delayed_node->mutex);
1614         item = __btrfs_first_delayed_insertion_item(delayed_node);
1615         while (item) {
1616                 atomic_inc(&item->refs);
1617                 list_add_tail(&item->readdir_list, ins_list);
1618                 item = __btrfs_next_delayed_item(item);
1619         }
1620
1621         item = __btrfs_first_delayed_deletion_item(delayed_node);
1622         while (item) {
1623                 atomic_inc(&item->refs);
1624                 list_add_tail(&item->readdir_list, del_list);
1625                 item = __btrfs_next_delayed_item(item);
1626         }
1627         mutex_unlock(&delayed_node->mutex);
1628         /*
1629          * This delayed node is still cached in the btrfs inode, so refs
1630          * must be > 1 now, and we needn't check it is going to be freed
1631          * or not.
1632          *
1633          * Besides that, this function is used to read dir, we do not
1634          * insert/delete delayed items in this period. So we also needn't
1635          * requeue or dequeue this delayed node.
1636          */
1637         atomic_dec(&delayed_node->refs);
1638
1639         return true;
1640 }
1641
1642 void btrfs_readdir_put_delayed_items(struct inode *inode,
1643                                      struct list_head *ins_list,
1644                                      struct list_head *del_list)
1645 {
1646         struct btrfs_delayed_item *curr, *next;
1647
1648         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1649                 list_del(&curr->readdir_list);
1650                 if (atomic_dec_and_test(&curr->refs))
1651                         kfree(curr);
1652         }
1653
1654         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1655                 list_del(&curr->readdir_list);
1656                 if (atomic_dec_and_test(&curr->refs))
1657                         kfree(curr);
1658         }
1659
1660         /*
1661          * The VFS is going to do up_read(), so we need to downgrade back to a
1662          * read lock.
1663          */
1664         downgrade_write(&inode->i_rwsem);
1665 }
1666
1667 int btrfs_should_delete_dir_index(struct list_head *del_list,
1668                                   u64 index)
1669 {
1670         struct btrfs_delayed_item *curr, *next;
1671         int ret;
1672
1673         if (list_empty(del_list))
1674                 return 0;
1675
1676         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1677                 if (curr->key.offset > index)
1678                         break;
1679
1680                 list_del(&curr->readdir_list);
1681                 ret = (curr->key.offset == index);
1682
1683                 if (atomic_dec_and_test(&curr->refs))
1684                         kfree(curr);
1685
1686                 if (ret)
1687                         return 1;
1688                 else
1689                         continue;
1690         }
1691         return 0;
1692 }
1693
1694 /*
1695  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1696  *
1697  */
1698 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1699                                     struct list_head *ins_list, bool *emitted)
1700 {
1701         struct btrfs_dir_item *di;
1702         struct btrfs_delayed_item *curr, *next;
1703         struct btrfs_key location;
1704         char *name;
1705         int name_len;
1706         int over = 0;
1707         unsigned char d_type;
1708
1709         if (list_empty(ins_list))
1710                 return 0;
1711
1712         /*
1713          * Changing the data of the delayed item is impossible. So
1714          * we needn't lock them. And we have held i_mutex of the
1715          * directory, nobody can delete any directory indexes now.
1716          */
1717         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1718                 list_del(&curr->readdir_list);
1719
1720                 if (curr->key.offset < ctx->pos) {
1721                         if (atomic_dec_and_test(&curr->refs))
1722                                 kfree(curr);
1723                         continue;
1724                 }
1725
1726                 ctx->pos = curr->key.offset;
1727
1728                 di = (struct btrfs_dir_item *)curr->data;
1729                 name = (char *)(di + 1);
1730                 name_len = btrfs_stack_dir_name_len(di);
1731
1732                 d_type = btrfs_filetype_table[di->type];
1733                 btrfs_disk_key_to_cpu(&location, &di->location);
1734
1735                 over = !dir_emit(ctx, name, name_len,
1736                                location.objectid, d_type);
1737
1738                 if (atomic_dec_and_test(&curr->refs))
1739                         kfree(curr);
1740
1741                 if (over)
1742                         return 1;
1743                 *emitted = true;
1744         }
1745         return 0;
1746 }
1747
1748 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1749                                   struct btrfs_inode_item *inode_item,
1750                                   struct inode *inode)
1751 {
1752         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1753         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1754         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1755         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1756         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1757         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1758         btrfs_set_stack_inode_generation(inode_item,
1759                                          BTRFS_I(inode)->generation);
1760         btrfs_set_stack_inode_sequence(inode_item, inode->i_version);
1761         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1762         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1763         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1764         btrfs_set_stack_inode_block_group(inode_item, 0);
1765
1766         btrfs_set_stack_timespec_sec(&inode_item->atime,
1767                                      inode->i_atime.tv_sec);
1768         btrfs_set_stack_timespec_nsec(&inode_item->atime,
1769                                       inode->i_atime.tv_nsec);
1770
1771         btrfs_set_stack_timespec_sec(&inode_item->mtime,
1772                                      inode->i_mtime.tv_sec);
1773         btrfs_set_stack_timespec_nsec(&inode_item->mtime,
1774                                       inode->i_mtime.tv_nsec);
1775
1776         btrfs_set_stack_timespec_sec(&inode_item->ctime,
1777                                      inode->i_ctime.tv_sec);
1778         btrfs_set_stack_timespec_nsec(&inode_item->ctime,
1779                                       inode->i_ctime.tv_nsec);
1780
1781         btrfs_set_stack_timespec_sec(&inode_item->otime,
1782                                      BTRFS_I(inode)->i_otime.tv_sec);
1783         btrfs_set_stack_timespec_nsec(&inode_item->otime,
1784                                      BTRFS_I(inode)->i_otime.tv_nsec);
1785 }
1786
1787 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1788 {
1789         struct btrfs_delayed_node *delayed_node;
1790         struct btrfs_inode_item *inode_item;
1791
1792         delayed_node = btrfs_get_delayed_node(inode);
1793         if (!delayed_node)
1794                 return -ENOENT;
1795
1796         mutex_lock(&delayed_node->mutex);
1797         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1798                 mutex_unlock(&delayed_node->mutex);
1799                 btrfs_release_delayed_node(delayed_node);
1800                 return -ENOENT;
1801         }
1802
1803         inode_item = &delayed_node->inode_item;
1804
1805         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1806         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1807         btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1808         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1809         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1810         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1811         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1812         BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
1813
1814         inode->i_version = btrfs_stack_inode_sequence(inode_item);
1815         inode->i_rdev = 0;
1816         *rdev = btrfs_stack_inode_rdev(inode_item);
1817         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1818
1819         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
1820         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
1821
1822         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
1823         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
1824
1825         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
1826         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
1827
1828         BTRFS_I(inode)->i_otime.tv_sec =
1829                 btrfs_stack_timespec_sec(&inode_item->otime);
1830         BTRFS_I(inode)->i_otime.tv_nsec =
1831                 btrfs_stack_timespec_nsec(&inode_item->otime);
1832
1833         inode->i_generation = BTRFS_I(inode)->generation;
1834         BTRFS_I(inode)->index_cnt = (u64)-1;
1835
1836         mutex_unlock(&delayed_node->mutex);
1837         btrfs_release_delayed_node(delayed_node);
1838         return 0;
1839 }
1840
1841 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1842                                struct btrfs_root *root, struct inode *inode)
1843 {
1844         struct btrfs_delayed_node *delayed_node;
1845         int ret = 0;
1846
1847         delayed_node = btrfs_get_or_create_delayed_node(inode);
1848         if (IS_ERR(delayed_node))
1849                 return PTR_ERR(delayed_node);
1850
1851         mutex_lock(&delayed_node->mutex);
1852         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1853                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1854                 goto release_node;
1855         }
1856
1857         ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1858                                                    delayed_node);
1859         if (ret)
1860                 goto release_node;
1861
1862         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1863         set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1864         delayed_node->count++;
1865         atomic_inc(&root->fs_info->delayed_root->items);
1866 release_node:
1867         mutex_unlock(&delayed_node->mutex);
1868         btrfs_release_delayed_node(delayed_node);
1869         return ret;
1870 }
1871
1872 int btrfs_delayed_delete_inode_ref(struct inode *inode)
1873 {
1874         struct btrfs_delayed_node *delayed_node;
1875
1876         /*
1877          * we don't do delayed inode updates during log recovery because it
1878          * leads to enospc problems.  This means we also can't do
1879          * delayed inode refs
1880          */
1881         if (test_bit(BTRFS_FS_LOG_RECOVERING,
1882                      &BTRFS_I(inode)->root->fs_info->flags))
1883                 return -EAGAIN;
1884
1885         delayed_node = btrfs_get_or_create_delayed_node(inode);
1886         if (IS_ERR(delayed_node))
1887                 return PTR_ERR(delayed_node);
1888
1889         /*
1890          * We don't reserve space for inode ref deletion is because:
1891          * - We ONLY do async inode ref deletion for the inode who has only
1892          *   one link(i_nlink == 1), it means there is only one inode ref.
1893          *   And in most case, the inode ref and the inode item are in the
1894          *   same leaf, and we will deal with them at the same time.
1895          *   Since we are sure we will reserve the space for the inode item,
1896          *   it is unnecessary to reserve space for inode ref deletion.
1897          * - If the inode ref and the inode item are not in the same leaf,
1898          *   We also needn't worry about enospc problem, because we reserve
1899          *   much more space for the inode update than it needs.
1900          * - At the worst, we can steal some space from the global reservation.
1901          *   It is very rare.
1902          */
1903         mutex_lock(&delayed_node->mutex);
1904         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1905                 goto release_node;
1906
1907         set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1908         delayed_node->count++;
1909         atomic_inc(&BTRFS_I(inode)->root->fs_info->delayed_root->items);
1910 release_node:
1911         mutex_unlock(&delayed_node->mutex);
1912         btrfs_release_delayed_node(delayed_node);
1913         return 0;
1914 }
1915
1916 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1917 {
1918         struct btrfs_root *root = delayed_node->root;
1919         struct btrfs_delayed_item *curr_item, *prev_item;
1920
1921         mutex_lock(&delayed_node->mutex);
1922         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1923         while (curr_item) {
1924                 btrfs_delayed_item_release_metadata(root, curr_item);
1925                 prev_item = curr_item;
1926                 curr_item = __btrfs_next_delayed_item(prev_item);
1927                 btrfs_release_delayed_item(prev_item);
1928         }
1929
1930         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1931         while (curr_item) {
1932                 btrfs_delayed_item_release_metadata(root, curr_item);
1933                 prev_item = curr_item;
1934                 curr_item = __btrfs_next_delayed_item(prev_item);
1935                 btrfs_release_delayed_item(prev_item);
1936         }
1937
1938         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1939                 btrfs_release_delayed_iref(delayed_node);
1940
1941         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1942                 btrfs_delayed_inode_release_metadata(root, delayed_node);
1943                 btrfs_release_delayed_inode(delayed_node);
1944         }
1945         mutex_unlock(&delayed_node->mutex);
1946 }
1947
1948 void btrfs_kill_delayed_inode_items(struct inode *inode)
1949 {
1950         struct btrfs_delayed_node *delayed_node;
1951
1952         delayed_node = btrfs_get_delayed_node(inode);
1953         if (!delayed_node)
1954                 return;
1955
1956         __btrfs_kill_delayed_node(delayed_node);
1957         btrfs_release_delayed_node(delayed_node);
1958 }
1959
1960 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1961 {
1962         u64 inode_id = 0;
1963         struct btrfs_delayed_node *delayed_nodes[8];
1964         int i, n;
1965
1966         while (1) {
1967                 spin_lock(&root->inode_lock);
1968                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1969                                            (void **)delayed_nodes, inode_id,
1970                                            ARRAY_SIZE(delayed_nodes));
1971                 if (!n) {
1972                         spin_unlock(&root->inode_lock);
1973                         break;
1974                 }
1975
1976                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1977
1978                 for (i = 0; i < n; i++)
1979                         atomic_inc(&delayed_nodes[i]->refs);
1980                 spin_unlock(&root->inode_lock);
1981
1982                 for (i = 0; i < n; i++) {
1983                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1984                         btrfs_release_delayed_node(delayed_nodes[i]);
1985                 }
1986         }
1987 }
1988
1989 void btrfs_destroy_delayed_inodes(struct btrfs_root *root)
1990 {
1991         struct btrfs_delayed_root *delayed_root;
1992         struct btrfs_delayed_node *curr_node, *prev_node;
1993
1994         delayed_root = btrfs_get_delayed_root(root);
1995
1996         curr_node = btrfs_first_delayed_node(delayed_root);
1997         while (curr_node) {
1998                 __btrfs_kill_delayed_node(curr_node);
1999
2000                 prev_node = curr_node;
2001                 curr_node = btrfs_next_delayed_node(curr_node);
2002                 btrfs_release_delayed_node(prev_node);
2003         }
2004 }
2005