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         return ret;
1080
1081 search:
1082         btrfs_release_path(path);
1083
1084         key.type = BTRFS_INODE_EXTREF_KEY;
1085         key.offset = -1;
1086         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1087         if (ret < 0)
1088                 goto err_out;
1089         ASSERT(ret);
1090
1091         ret = 0;
1092         leaf = path->nodes[0];
1093         path->slots[0]--;
1094         goto again;
1095 }
1096
1097 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1098                                              struct btrfs_root *root,
1099                                              struct btrfs_path *path,
1100                                              struct btrfs_delayed_node *node)
1101 {
1102         int ret;
1103
1104         mutex_lock(&node->mutex);
1105         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1106                 mutex_unlock(&node->mutex);
1107                 return 0;
1108         }
1109
1110         ret = __btrfs_update_delayed_inode(trans, root, path, node);
1111         mutex_unlock(&node->mutex);
1112         return ret;
1113 }
1114
1115 static inline int
1116 __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1117                                    struct btrfs_path *path,
1118                                    struct btrfs_delayed_node *node)
1119 {
1120         int ret;
1121
1122         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1123         if (ret)
1124                 return ret;
1125
1126         ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1127         if (ret)
1128                 return ret;
1129
1130         ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1131         return ret;
1132 }
1133
1134 /*
1135  * Called when committing the transaction.
1136  * Returns 0 on success.
1137  * Returns < 0 on error and returns with an aborted transaction with any
1138  * outstanding delayed items cleaned up.
1139  */
1140 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1141                                      struct btrfs_root *root, int nr)
1142 {
1143         struct btrfs_delayed_root *delayed_root;
1144         struct btrfs_delayed_node *curr_node, *prev_node;
1145         struct btrfs_path *path;
1146         struct btrfs_block_rsv *block_rsv;
1147         int ret = 0;
1148         bool count = (nr > 0);
1149
1150         if (trans->aborted)
1151                 return -EIO;
1152
1153         path = btrfs_alloc_path();
1154         if (!path)
1155                 return -ENOMEM;
1156         path->leave_spinning = 1;
1157
1158         block_rsv = trans->block_rsv;
1159         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1160
1161         delayed_root = btrfs_get_delayed_root(root);
1162
1163         curr_node = btrfs_first_delayed_node(delayed_root);
1164         while (curr_node && (!count || (count && nr--))) {
1165                 ret = __btrfs_commit_inode_delayed_items(trans, path,
1166                                                          curr_node);
1167                 if (ret) {
1168                         btrfs_release_delayed_node(curr_node);
1169                         curr_node = NULL;
1170                         btrfs_abort_transaction(trans, ret);
1171                         break;
1172                 }
1173
1174                 prev_node = curr_node;
1175                 curr_node = btrfs_next_delayed_node(curr_node);
1176                 btrfs_release_delayed_node(prev_node);
1177         }
1178
1179         if (curr_node)
1180                 btrfs_release_delayed_node(curr_node);
1181         btrfs_free_path(path);
1182         trans->block_rsv = block_rsv;
1183
1184         return ret;
1185 }
1186
1187 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans,
1188                             struct btrfs_root *root)
1189 {
1190         return __btrfs_run_delayed_items(trans, root, -1);
1191 }
1192
1193 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans,
1194                                struct btrfs_root *root, int nr)
1195 {
1196         return __btrfs_run_delayed_items(trans, root, nr);
1197 }
1198
1199 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1200                                      struct inode *inode)
1201 {
1202         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1203         struct btrfs_path *path;
1204         struct btrfs_block_rsv *block_rsv;
1205         int ret;
1206
1207         if (!delayed_node)
1208                 return 0;
1209
1210         mutex_lock(&delayed_node->mutex);
1211         if (!delayed_node->count) {
1212                 mutex_unlock(&delayed_node->mutex);
1213                 btrfs_release_delayed_node(delayed_node);
1214                 return 0;
1215         }
1216         mutex_unlock(&delayed_node->mutex);
1217
1218         path = btrfs_alloc_path();
1219         if (!path) {
1220                 btrfs_release_delayed_node(delayed_node);
1221                 return -ENOMEM;
1222         }
1223         path->leave_spinning = 1;
1224
1225         block_rsv = trans->block_rsv;
1226         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1227
1228         ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1229
1230         btrfs_release_delayed_node(delayed_node);
1231         btrfs_free_path(path);
1232         trans->block_rsv = block_rsv;
1233
1234         return ret;
1235 }
1236
1237 int btrfs_commit_inode_delayed_inode(struct inode *inode)
1238 {
1239         struct btrfs_trans_handle *trans;
1240         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1241         struct btrfs_path *path;
1242         struct btrfs_block_rsv *block_rsv;
1243         int ret;
1244
1245         if (!delayed_node)
1246                 return 0;
1247
1248         mutex_lock(&delayed_node->mutex);
1249         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1250                 mutex_unlock(&delayed_node->mutex);
1251                 btrfs_release_delayed_node(delayed_node);
1252                 return 0;
1253         }
1254         mutex_unlock(&delayed_node->mutex);
1255
1256         trans = btrfs_join_transaction(delayed_node->root);
1257         if (IS_ERR(trans)) {
1258                 ret = PTR_ERR(trans);
1259                 goto out;
1260         }
1261
1262         path = btrfs_alloc_path();
1263         if (!path) {
1264                 ret = -ENOMEM;
1265                 goto trans_out;
1266         }
1267         path->leave_spinning = 1;
1268
1269         block_rsv = trans->block_rsv;
1270         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1271
1272         mutex_lock(&delayed_node->mutex);
1273         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1274                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1275                                                    path, delayed_node);
1276         else
1277                 ret = 0;
1278         mutex_unlock(&delayed_node->mutex);
1279
1280         btrfs_free_path(path);
1281         trans->block_rsv = block_rsv;
1282 trans_out:
1283         btrfs_end_transaction(trans, delayed_node->root);
1284         btrfs_btree_balance_dirty(delayed_node->root);
1285 out:
1286         btrfs_release_delayed_node(delayed_node);
1287
1288         return ret;
1289 }
1290
1291 void btrfs_remove_delayed_node(struct inode *inode)
1292 {
1293         struct btrfs_delayed_node *delayed_node;
1294
1295         delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
1296         if (!delayed_node)
1297                 return;
1298
1299         BTRFS_I(inode)->delayed_node = NULL;
1300         btrfs_release_delayed_node(delayed_node);
1301 }
1302
1303 struct btrfs_async_delayed_work {
1304         struct btrfs_delayed_root *delayed_root;
1305         int nr;
1306         struct btrfs_work work;
1307 };
1308
1309 static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1310 {
1311         struct btrfs_async_delayed_work *async_work;
1312         struct btrfs_delayed_root *delayed_root;
1313         struct btrfs_trans_handle *trans;
1314         struct btrfs_path *path;
1315         struct btrfs_delayed_node *delayed_node = NULL;
1316         struct btrfs_root *root;
1317         struct btrfs_block_rsv *block_rsv;
1318         int total_done = 0;
1319
1320         async_work = container_of(work, struct btrfs_async_delayed_work, work);
1321         delayed_root = async_work->delayed_root;
1322
1323         path = btrfs_alloc_path();
1324         if (!path)
1325                 goto out;
1326
1327 again:
1328         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND / 2)
1329                 goto free_path;
1330
1331         delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1332         if (!delayed_node)
1333                 goto free_path;
1334
1335         path->leave_spinning = 1;
1336         root = delayed_node->root;
1337
1338         trans = btrfs_join_transaction(root);
1339         if (IS_ERR(trans))
1340                 goto release_path;
1341
1342         block_rsv = trans->block_rsv;
1343         trans->block_rsv = &root->fs_info->delayed_block_rsv;
1344
1345         __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1346
1347         trans->block_rsv = block_rsv;
1348         btrfs_end_transaction(trans, root);
1349         btrfs_btree_balance_dirty_nodelay(root);
1350
1351 release_path:
1352         btrfs_release_path(path);
1353         total_done++;
1354
1355         btrfs_release_prepared_delayed_node(delayed_node);
1356         if (async_work->nr == 0 || total_done < async_work->nr)
1357                 goto again;
1358
1359 free_path:
1360         btrfs_free_path(path);
1361 out:
1362         wake_up(&delayed_root->wait);
1363         kfree(async_work);
1364 }
1365
1366
1367 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1368                                      struct btrfs_fs_info *fs_info, int nr)
1369 {
1370         struct btrfs_async_delayed_work *async_work;
1371
1372         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1373                 return 0;
1374
1375         async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1376         if (!async_work)
1377                 return -ENOMEM;
1378
1379         async_work->delayed_root = delayed_root;
1380         btrfs_init_work(&async_work->work, btrfs_delayed_meta_helper,
1381                         btrfs_async_run_delayed_root, NULL, NULL);
1382         async_work->nr = nr;
1383
1384         btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
1385         return 0;
1386 }
1387
1388 void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
1389 {
1390         struct btrfs_delayed_root *delayed_root;
1391         delayed_root = btrfs_get_delayed_root(root);
1392         WARN_ON(btrfs_first_delayed_node(delayed_root));
1393 }
1394
1395 static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1396 {
1397         int val = atomic_read(&delayed_root->items_seq);
1398
1399         if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1400                 return 1;
1401
1402         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1403                 return 1;
1404
1405         return 0;
1406 }
1407
1408 void btrfs_balance_delayed_items(struct btrfs_root *root)
1409 {
1410         struct btrfs_delayed_root *delayed_root;
1411         struct btrfs_fs_info *fs_info = root->fs_info;
1412
1413         delayed_root = btrfs_get_delayed_root(root);
1414
1415         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1416                 return;
1417
1418         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1419                 int seq;
1420                 int ret;
1421
1422                 seq = atomic_read(&delayed_root->items_seq);
1423
1424                 ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
1425                 if (ret)
1426                         return;
1427
1428                 wait_event_interruptible(delayed_root->wait,
1429                                          could_end_wait(delayed_root, seq));
1430                 return;
1431         }
1432
1433         btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1434 }
1435
1436 /* Will return 0 or -ENOMEM */
1437 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1438                                    struct btrfs_root *root, const char *name,
1439                                    int name_len, struct inode *dir,
1440                                    struct btrfs_disk_key *disk_key, u8 type,
1441                                    u64 index)
1442 {
1443         struct btrfs_delayed_node *delayed_node;
1444         struct btrfs_delayed_item *delayed_item;
1445         struct btrfs_dir_item *dir_item;
1446         int ret;
1447
1448         delayed_node = btrfs_get_or_create_delayed_node(dir);
1449         if (IS_ERR(delayed_node))
1450                 return PTR_ERR(delayed_node);
1451
1452         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1453         if (!delayed_item) {
1454                 ret = -ENOMEM;
1455                 goto release_node;
1456         }
1457
1458         delayed_item->key.objectid = btrfs_ino(dir);
1459         delayed_item->key.type = BTRFS_DIR_INDEX_KEY;
1460         delayed_item->key.offset = index;
1461
1462         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1463         dir_item->location = *disk_key;
1464         btrfs_set_stack_dir_transid(dir_item, trans->transid);
1465         btrfs_set_stack_dir_data_len(dir_item, 0);
1466         btrfs_set_stack_dir_name_len(dir_item, name_len);
1467         btrfs_set_stack_dir_type(dir_item, type);
1468         memcpy((char *)(dir_item + 1), name, name_len);
1469
1470         ret = btrfs_delayed_item_reserve_metadata(trans, root, delayed_item);
1471         /*
1472          * we have reserved enough space when we start a new transaction,
1473          * so reserving metadata failure is impossible
1474          */
1475         BUG_ON(ret);
1476
1477
1478         mutex_lock(&delayed_node->mutex);
1479         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1480         if (unlikely(ret)) {
1481                 btrfs_err(root->fs_info,
1482                           "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1483                           name_len, name, delayed_node->root->objectid,
1484                           delayed_node->inode_id, ret);
1485                 BUG();
1486         }
1487         mutex_unlock(&delayed_node->mutex);
1488
1489 release_node:
1490         btrfs_release_delayed_node(delayed_node);
1491         return ret;
1492 }
1493
1494 static int btrfs_delete_delayed_insertion_item(struct btrfs_root *root,
1495                                                struct btrfs_delayed_node *node,
1496                                                struct btrfs_key *key)
1497 {
1498         struct btrfs_delayed_item *item;
1499
1500         mutex_lock(&node->mutex);
1501         item = __btrfs_lookup_delayed_insertion_item(node, key);
1502         if (!item) {
1503                 mutex_unlock(&node->mutex);
1504                 return 1;
1505         }
1506
1507         btrfs_delayed_item_release_metadata(root, item);
1508         btrfs_release_delayed_item(item);
1509         mutex_unlock(&node->mutex);
1510         return 0;
1511 }
1512
1513 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1514                                    struct btrfs_root *root, struct inode *dir,
1515                                    u64 index)
1516 {
1517         struct btrfs_delayed_node *node;
1518         struct btrfs_delayed_item *item;
1519         struct btrfs_key item_key;
1520         int ret;
1521
1522         node = btrfs_get_or_create_delayed_node(dir);
1523         if (IS_ERR(node))
1524                 return PTR_ERR(node);
1525
1526         item_key.objectid = btrfs_ino(dir);
1527         item_key.type = BTRFS_DIR_INDEX_KEY;
1528         item_key.offset = index;
1529
1530         ret = btrfs_delete_delayed_insertion_item(root, node, &item_key);
1531         if (!ret)
1532                 goto end;
1533
1534         item = btrfs_alloc_delayed_item(0);
1535         if (!item) {
1536                 ret = -ENOMEM;
1537                 goto end;
1538         }
1539
1540         item->key = item_key;
1541
1542         ret = btrfs_delayed_item_reserve_metadata(trans, root, item);
1543         /*
1544          * we have reserved enough space when we start a new transaction,
1545          * so reserving metadata failure is impossible.
1546          */
1547         BUG_ON(ret);
1548
1549         mutex_lock(&node->mutex);
1550         ret = __btrfs_add_delayed_deletion_item(node, item);
1551         if (unlikely(ret)) {
1552                 btrfs_err(root->fs_info,
1553                           "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1554                           index, node->root->objectid, node->inode_id, ret);
1555                 BUG();
1556         }
1557         mutex_unlock(&node->mutex);
1558 end:
1559         btrfs_release_delayed_node(node);
1560         return ret;
1561 }
1562
1563 int btrfs_inode_delayed_dir_index_count(struct inode *inode)
1564 {
1565         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1566
1567         if (!delayed_node)
1568                 return -ENOENT;
1569
1570         /*
1571          * Since we have held i_mutex of this directory, it is impossible that
1572          * a new directory index is added into the delayed node and index_cnt
1573          * is updated now. So we needn't lock the delayed node.
1574          */
1575         if (!delayed_node->index_cnt) {
1576                 btrfs_release_delayed_node(delayed_node);
1577                 return -EINVAL;
1578         }
1579
1580         BTRFS_I(inode)->index_cnt = delayed_node->index_cnt;
1581         btrfs_release_delayed_node(delayed_node);
1582         return 0;
1583 }
1584
1585 bool btrfs_readdir_get_delayed_items(struct inode *inode,
1586                                      struct list_head *ins_list,
1587                                      struct list_head *del_list)
1588 {
1589         struct btrfs_delayed_node *delayed_node;
1590         struct btrfs_delayed_item *item;
1591
1592         delayed_node = btrfs_get_delayed_node(inode);
1593         if (!delayed_node)
1594                 return false;
1595
1596         /*
1597          * We can only do one readdir with delayed items at a time because of
1598          * item->readdir_list.
1599          */
1600         inode_unlock_shared(inode);
1601         inode_lock(inode);
1602
1603         mutex_lock(&delayed_node->mutex);
1604         item = __btrfs_first_delayed_insertion_item(delayed_node);
1605         while (item) {
1606                 atomic_inc(&item->refs);
1607                 list_add_tail(&item->readdir_list, ins_list);
1608                 item = __btrfs_next_delayed_item(item);
1609         }
1610
1611         item = __btrfs_first_delayed_deletion_item(delayed_node);
1612         while (item) {
1613                 atomic_inc(&item->refs);
1614                 list_add_tail(&item->readdir_list, del_list);
1615                 item = __btrfs_next_delayed_item(item);
1616         }
1617         mutex_unlock(&delayed_node->mutex);
1618         /*
1619          * This delayed node is still cached in the btrfs inode, so refs
1620          * must be > 1 now, and we needn't check it is going to be freed
1621          * or not.
1622          *
1623          * Besides that, this function is used to read dir, we do not
1624          * insert/delete delayed items in this period. So we also needn't
1625          * requeue or dequeue this delayed node.
1626          */
1627         atomic_dec(&delayed_node->refs);
1628
1629         return true;
1630 }
1631
1632 void btrfs_readdir_put_delayed_items(struct inode *inode,
1633                                      struct list_head *ins_list,
1634                                      struct list_head *del_list)
1635 {
1636         struct btrfs_delayed_item *curr, *next;
1637
1638         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1639                 list_del(&curr->readdir_list);
1640                 if (atomic_dec_and_test(&curr->refs))
1641                         kfree(curr);
1642         }
1643
1644         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1645                 list_del(&curr->readdir_list);
1646                 if (atomic_dec_and_test(&curr->refs))
1647                         kfree(curr);
1648         }
1649
1650         /*
1651          * The VFS is going to do up_read(), so we need to downgrade back to a
1652          * read lock.
1653          */
1654         downgrade_write(&inode->i_rwsem);
1655 }
1656
1657 int btrfs_should_delete_dir_index(struct list_head *del_list,
1658                                   u64 index)
1659 {
1660         struct btrfs_delayed_item *curr, *next;
1661         int ret;
1662
1663         if (list_empty(del_list))
1664                 return 0;
1665
1666         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1667                 if (curr->key.offset > index)
1668                         break;
1669
1670                 list_del(&curr->readdir_list);
1671                 ret = (curr->key.offset == index);
1672
1673                 if (atomic_dec_and_test(&curr->refs))
1674                         kfree(curr);
1675
1676                 if (ret)
1677                         return 1;
1678                 else
1679                         continue;
1680         }
1681         return 0;
1682 }
1683
1684 /*
1685  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1686  *
1687  */
1688 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1689                                     struct list_head *ins_list, bool *emitted)
1690 {
1691         struct btrfs_dir_item *di;
1692         struct btrfs_delayed_item *curr, *next;
1693         struct btrfs_key location;
1694         char *name;
1695         int name_len;
1696         int over = 0;
1697         unsigned char d_type;
1698
1699         if (list_empty(ins_list))
1700                 return 0;
1701
1702         /*
1703          * Changing the data of the delayed item is impossible. So
1704          * we needn't lock them. And we have held i_mutex of the
1705          * directory, nobody can delete any directory indexes now.
1706          */
1707         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1708                 list_del(&curr->readdir_list);
1709
1710                 if (curr->key.offset < ctx->pos) {
1711                         if (atomic_dec_and_test(&curr->refs))
1712                                 kfree(curr);
1713                         continue;
1714                 }
1715
1716                 ctx->pos = curr->key.offset;
1717
1718                 di = (struct btrfs_dir_item *)curr->data;
1719                 name = (char *)(di + 1);
1720                 name_len = btrfs_stack_dir_name_len(di);
1721
1722                 d_type = btrfs_filetype_table[di->type];
1723                 btrfs_disk_key_to_cpu(&location, &di->location);
1724
1725                 over = !dir_emit(ctx, name, name_len,
1726                                location.objectid, d_type);
1727
1728                 if (atomic_dec_and_test(&curr->refs))
1729                         kfree(curr);
1730
1731                 if (over)
1732                         return 1;
1733                 *emitted = true;
1734         }
1735         return 0;
1736 }
1737
1738 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1739                                   struct btrfs_inode_item *inode_item,
1740                                   struct inode *inode)
1741 {
1742         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1743         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1744         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1745         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1746         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1747         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1748         btrfs_set_stack_inode_generation(inode_item,
1749                                          BTRFS_I(inode)->generation);
1750         btrfs_set_stack_inode_sequence(inode_item, inode->i_version);
1751         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1752         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1753         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1754         btrfs_set_stack_inode_block_group(inode_item, 0);
1755
1756         btrfs_set_stack_timespec_sec(&inode_item->atime,
1757                                      inode->i_atime.tv_sec);
1758         btrfs_set_stack_timespec_nsec(&inode_item->atime,
1759                                       inode->i_atime.tv_nsec);
1760
1761         btrfs_set_stack_timespec_sec(&inode_item->mtime,
1762                                      inode->i_mtime.tv_sec);
1763         btrfs_set_stack_timespec_nsec(&inode_item->mtime,
1764                                       inode->i_mtime.tv_nsec);
1765
1766         btrfs_set_stack_timespec_sec(&inode_item->ctime,
1767                                      inode->i_ctime.tv_sec);
1768         btrfs_set_stack_timespec_nsec(&inode_item->ctime,
1769                                       inode->i_ctime.tv_nsec);
1770
1771         btrfs_set_stack_timespec_sec(&inode_item->otime,
1772                                      BTRFS_I(inode)->i_otime.tv_sec);
1773         btrfs_set_stack_timespec_nsec(&inode_item->otime,
1774                                      BTRFS_I(inode)->i_otime.tv_nsec);
1775 }
1776
1777 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1778 {
1779         struct btrfs_delayed_node *delayed_node;
1780         struct btrfs_inode_item *inode_item;
1781
1782         delayed_node = btrfs_get_delayed_node(inode);
1783         if (!delayed_node)
1784                 return -ENOENT;
1785
1786         mutex_lock(&delayed_node->mutex);
1787         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1788                 mutex_unlock(&delayed_node->mutex);
1789                 btrfs_release_delayed_node(delayed_node);
1790                 return -ENOENT;
1791         }
1792
1793         inode_item = &delayed_node->inode_item;
1794
1795         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1796         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1797         btrfs_i_size_write(inode, btrfs_stack_inode_size(inode_item));
1798         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1799         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1800         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1801         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1802         BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
1803
1804         inode->i_version = btrfs_stack_inode_sequence(inode_item);
1805         inode->i_rdev = 0;
1806         *rdev = btrfs_stack_inode_rdev(inode_item);
1807         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1808
1809         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
1810         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
1811
1812         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
1813         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
1814
1815         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
1816         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
1817
1818         BTRFS_I(inode)->i_otime.tv_sec =
1819                 btrfs_stack_timespec_sec(&inode_item->otime);
1820         BTRFS_I(inode)->i_otime.tv_nsec =
1821                 btrfs_stack_timespec_nsec(&inode_item->otime);
1822
1823         inode->i_generation = BTRFS_I(inode)->generation;
1824         BTRFS_I(inode)->index_cnt = (u64)-1;
1825
1826         mutex_unlock(&delayed_node->mutex);
1827         btrfs_release_delayed_node(delayed_node);
1828         return 0;
1829 }
1830
1831 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1832                                struct btrfs_root *root, struct inode *inode)
1833 {
1834         struct btrfs_delayed_node *delayed_node;
1835         int ret = 0;
1836
1837         delayed_node = btrfs_get_or_create_delayed_node(inode);
1838         if (IS_ERR(delayed_node))
1839                 return PTR_ERR(delayed_node);
1840
1841         mutex_lock(&delayed_node->mutex);
1842         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1843                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1844                 goto release_node;
1845         }
1846
1847         ret = btrfs_delayed_inode_reserve_metadata(trans, root, inode,
1848                                                    delayed_node);
1849         if (ret)
1850                 goto release_node;
1851
1852         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1853         set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1854         delayed_node->count++;
1855         atomic_inc(&root->fs_info->delayed_root->items);
1856 release_node:
1857         mutex_unlock(&delayed_node->mutex);
1858         btrfs_release_delayed_node(delayed_node);
1859         return ret;
1860 }
1861
1862 int btrfs_delayed_delete_inode_ref(struct inode *inode)
1863 {
1864         struct btrfs_delayed_node *delayed_node;
1865
1866         /*
1867          * we don't do delayed inode updates during log recovery because it
1868          * leads to enospc problems.  This means we also can't do
1869          * delayed inode refs
1870          */
1871         if (test_bit(BTRFS_FS_LOG_RECOVERING,
1872                      &BTRFS_I(inode)->root->fs_info->flags))
1873                 return -EAGAIN;
1874
1875         delayed_node = btrfs_get_or_create_delayed_node(inode);
1876         if (IS_ERR(delayed_node))
1877                 return PTR_ERR(delayed_node);
1878
1879         /*
1880          * We don't reserve space for inode ref deletion is because:
1881          * - We ONLY do async inode ref deletion for the inode who has only
1882          *   one link(i_nlink == 1), it means there is only one inode ref.
1883          *   And in most case, the inode ref and the inode item are in the
1884          *   same leaf, and we will deal with them at the same time.
1885          *   Since we are sure we will reserve the space for the inode item,
1886          *   it is unnecessary to reserve space for inode ref deletion.
1887          * - If the inode ref and the inode item are not in the same leaf,
1888          *   We also needn't worry about enospc problem, because we reserve
1889          *   much more space for the inode update than it needs.
1890          * - At the worst, we can steal some space from the global reservation.
1891          *   It is very rare.
1892          */
1893         mutex_lock(&delayed_node->mutex);
1894         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1895                 goto release_node;
1896
1897         set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1898         delayed_node->count++;
1899         atomic_inc(&BTRFS_I(inode)->root->fs_info->delayed_root->items);
1900 release_node:
1901         mutex_unlock(&delayed_node->mutex);
1902         btrfs_release_delayed_node(delayed_node);
1903         return 0;
1904 }
1905
1906 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1907 {
1908         struct btrfs_root *root = delayed_node->root;
1909         struct btrfs_delayed_item *curr_item, *prev_item;
1910
1911         mutex_lock(&delayed_node->mutex);
1912         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1913         while (curr_item) {
1914                 btrfs_delayed_item_release_metadata(root, curr_item);
1915                 prev_item = curr_item;
1916                 curr_item = __btrfs_next_delayed_item(prev_item);
1917                 btrfs_release_delayed_item(prev_item);
1918         }
1919
1920         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1921         while (curr_item) {
1922                 btrfs_delayed_item_release_metadata(root, curr_item);
1923                 prev_item = curr_item;
1924                 curr_item = __btrfs_next_delayed_item(prev_item);
1925                 btrfs_release_delayed_item(prev_item);
1926         }
1927
1928         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1929                 btrfs_release_delayed_iref(delayed_node);
1930
1931         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1932                 btrfs_delayed_inode_release_metadata(root, delayed_node);
1933                 btrfs_release_delayed_inode(delayed_node);
1934         }
1935         mutex_unlock(&delayed_node->mutex);
1936 }
1937
1938 void btrfs_kill_delayed_inode_items(struct inode *inode)
1939 {
1940         struct btrfs_delayed_node *delayed_node;
1941
1942         delayed_node = btrfs_get_delayed_node(inode);
1943         if (!delayed_node)
1944                 return;
1945
1946         __btrfs_kill_delayed_node(delayed_node);
1947         btrfs_release_delayed_node(delayed_node);
1948 }
1949
1950 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1951 {
1952         u64 inode_id = 0;
1953         struct btrfs_delayed_node *delayed_nodes[8];
1954         int i, n;
1955
1956         while (1) {
1957                 spin_lock(&root->inode_lock);
1958                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1959                                            (void **)delayed_nodes, inode_id,
1960                                            ARRAY_SIZE(delayed_nodes));
1961                 if (!n) {
1962                         spin_unlock(&root->inode_lock);
1963                         break;
1964                 }
1965
1966                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1967
1968                 for (i = 0; i < n; i++)
1969                         atomic_inc(&delayed_nodes[i]->refs);
1970                 spin_unlock(&root->inode_lock);
1971
1972                 for (i = 0; i < n; i++) {
1973                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1974                         btrfs_release_delayed_node(delayed_nodes[i]);
1975                 }
1976         }
1977 }
1978
1979 void btrfs_destroy_delayed_inodes(struct btrfs_root *root)
1980 {
1981         struct btrfs_delayed_root *delayed_root;
1982         struct btrfs_delayed_node *curr_node, *prev_node;
1983
1984         delayed_root = btrfs_get_delayed_root(root);
1985
1986         curr_node = btrfs_first_delayed_node(delayed_root);
1987         while (curr_node) {
1988                 __btrfs_kill_delayed_node(curr_node);
1989
1990                 prev_node = curr_node;
1991                 curr_node = btrfs_next_delayed_node(curr_node);
1992                 btrfs_release_delayed_node(prev_node);
1993         }
1994 }
1995