fs/btrfs/delayed-inode.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2011 Fujitsu.  All rights reserved.
   4  * Written by Miao Xie <miaox@cn.fujitsu.com>
   5  */
   6
   7 #include <linux/slab.h>
   8 #include <linux/iversion.h>
   9 #include <linux/sched/mm.h>
  10 #include "misc.h"
  11 #include "delayed-inode.h"
  12 #include "disk-io.h"
  13 #include "transaction.h"
  14 #include "ctree.h"
  15 #include "qgroup.h"
  16
  17 #define BTRFS_DELAYED_WRITEBACK         512
  18 #define BTRFS_DELAYED_BACKGROUND        128
  19 #define BTRFS_DELAYED_BATCH             16
  20
  21 static struct kmem_cache *delayed_node_cache;
  22
  23 int __init btrfs_delayed_inode_init(void)
  24 {
  25         delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
  26                                         sizeof(struct btrfs_delayed_node),
  27                                         0,
  28                                         SLAB_MEM_SPREAD,
  29                                         NULL);
  30         if (!delayed_node_cache)
  31                 return -ENOMEM;
  32         return 0;
  33 }
  34
  35 void __cold btrfs_delayed_inode_exit(void)
  36 {
  37         kmem_cache_destroy(delayed_node_cache);
  38 }
  39
  40 static inline void btrfs_init_delayed_node(
  41                                 struct btrfs_delayed_node *delayed_node,
  42                                 struct btrfs_root *root, u64 inode_id)
  43 {
  44         delayed_node->root = root;
  45         delayed_node->inode_id = inode_id;
  46         refcount_set(&delayed_node->refs, 0);
  47         delayed_node->ins_root = RB_ROOT_CACHED;
  48         delayed_node->del_root = RB_ROOT_CACHED;
  49         mutex_init(&delayed_node->mutex);
  50         INIT_LIST_HEAD(&delayed_node->n_list);
  51         INIT_LIST_HEAD(&delayed_node->p_list);
  52 }
  53
  54 static inline int btrfs_is_continuous_delayed_item(
  55                                         struct btrfs_delayed_item *item1,
  56                                         struct btrfs_delayed_item *item2)
  57 {
  58         if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
  59             item1->key.objectid == item2->key.objectid &&
  60             item1->key.type == item2->key.type &&
  61             item1->key.offset + 1 == item2->key.offset)
  62                 return 1;
  63         return 0;
  64 }
  65
  66 static struct btrfs_delayed_node *btrfs_get_delayed_node(
  67                 struct btrfs_inode *btrfs_inode)
  68 {
  69         struct btrfs_root *root = btrfs_inode->root;
  70         u64 ino = btrfs_ino(btrfs_inode);
  71         struct btrfs_delayed_node *node;
  72
  73         node = READ_ONCE(btrfs_inode->delayed_node);
  74         if (node) {
  75                 refcount_inc(&node->refs);
  76                 return node;
  77         }
  78
  79         spin_lock(&root->inode_lock);
  80         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
  81
  82         if (node) {
  83                 if (btrfs_inode->delayed_node) {
  84                         refcount_inc(&node->refs);      /* can be accessed */
  85                         BUG_ON(btrfs_inode->delayed_node != node);
  86                         spin_unlock(&root->inode_lock);
  87                         return node;
  88                 }
  89
  90                 /*
  91                  * It's possible that we're racing into the middle of removing
  92                  * this node from the radix tree.  In this case, the refcount
  93                  * was zero and it should never go back to one.  Just return
  94                  * NULL like it was never in the radix at all; our release
  95                  * function is in the process of removing it.
  96                  *
  97                  * Some implementations of refcount_inc refuse to bump the
  98                  * refcount once it has hit zero.  If we don't do this dance
  99                  * here, refcount_inc() may decide to just WARN_ONCE() instead
 100                  * of actually bumping the refcount.
 101                  *
 102                  * If this node is properly in the radix, we want to bump the
 103                  * refcount twice, once for the inode and once for this get
 104                  * operation.
 105                  */
 106                 if (refcount_inc_not_zero(&node->refs)) {
 107                         refcount_inc(&node->refs);
 108                         btrfs_inode->delayed_node = node;
 109                 } else {
 110                         node = NULL;
 111                 }
 112
 113                 spin_unlock(&root->inode_lock);
 114                 return node;
 115         }
 116         spin_unlock(&root->inode_lock);
 117
 118         return NULL;
 119 }
 120
 121 /* Will return either the node or PTR_ERR(-ENOMEM) */
 122 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
 123                 struct btrfs_inode *btrfs_inode)
 124 {
 125         struct btrfs_delayed_node *node;
 126         struct btrfs_root *root = btrfs_inode->root;
 127         u64 ino = btrfs_ino(btrfs_inode);
 128         int ret;
 129
 130 again:
 131         node = btrfs_get_delayed_node(btrfs_inode);
 132         if (node)
 133                 return node;
 134
 135         node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
 136         if (!node)
 137                 return ERR_PTR(-ENOMEM);
 138         btrfs_init_delayed_node(node, root, ino);
 139
 140         /* cached in the btrfs inode and can be accessed */
 141         refcount_set(&node->refs, 2);
 142
 143         ret = radix_tree_preload(GFP_NOFS);
 144         if (ret) {
 145                 kmem_cache_free(delayed_node_cache, node);
 146                 return ERR_PTR(ret);
 147         }
 148
 149         spin_lock(&root->inode_lock);
 150         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
 151         if (ret == -EEXIST) {
 152                 spin_unlock(&root->inode_lock);
 153                 kmem_cache_free(delayed_node_cache, node);
 154                 radix_tree_preload_end();
 155                 goto again;
 156         }
 157         btrfs_inode->delayed_node = node;
 158         spin_unlock(&root->inode_lock);
 159         radix_tree_preload_end();
 160
 161         return node;
 162 }
 163
 164 /*
 165  * Call it when holding delayed_node->mutex
 166  *
 167  * If mod = 1, add this node into the prepared list.
 168  */
 169 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
 170                                      struct btrfs_delayed_node *node,
 171                                      int mod)
 172 {
 173         spin_lock(&root->lock);
 174         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 175                 if (!list_empty(&node->p_list))
 176                         list_move_tail(&node->p_list, &root->prepare_list);
 177                 else if (mod)
 178                         list_add_tail(&node->p_list, &root->prepare_list);
 179         } else {
 180                 list_add_tail(&node->n_list, &root->node_list);
 181                 list_add_tail(&node->p_list, &root->prepare_list);
 182                 refcount_inc(&node->refs);      /* inserted into list */
 183                 root->nodes++;
 184                 set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 185         }
 186         spin_unlock(&root->lock);
 187 }
 188
 189 /* Call it when holding delayed_node->mutex */
 190 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
 191                                        struct btrfs_delayed_node *node)
 192 {
 193         spin_lock(&root->lock);
 194         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 195                 root->nodes--;
 196                 refcount_dec(&node->refs);      /* not in the list */
 197                 list_del_init(&node->n_list);
 198                 if (!list_empty(&node->p_list))
 199                         list_del_init(&node->p_list);
 200                 clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 201         }
 202         spin_unlock(&root->lock);
 203 }
 204
 205 static struct btrfs_delayed_node *btrfs_first_delayed_node(
 206                         struct btrfs_delayed_root *delayed_root)
 207 {
 208         struct list_head *p;
 209         struct btrfs_delayed_node *node = NULL;
 210
 211         spin_lock(&delayed_root->lock);
 212         if (list_empty(&delayed_root->node_list))
 213                 goto out;
 214
 215         p = delayed_root->node_list.next;
 216         node = list_entry(p, struct btrfs_delayed_node, n_list);
 217         refcount_inc(&node->refs);
 218 out:
 219         spin_unlock(&delayed_root->lock);
 220
 221         return node;
 222 }
 223
 224 static struct btrfs_delayed_node *btrfs_next_delayed_node(
 225                                                 struct btrfs_delayed_node *node)
 226 {
 227         struct btrfs_delayed_root *delayed_root;
 228         struct list_head *p;
 229         struct btrfs_delayed_node *next = NULL;
 230
 231         delayed_root = node->root->fs_info->delayed_root;
 232         spin_lock(&delayed_root->lock);
 233         if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 234                 /* not in the list */
 235                 if (list_empty(&delayed_root->node_list))
 236                         goto out;
 237                 p = delayed_root->node_list.next;
 238         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
 239                 goto out;
 240         else
 241                 p = node->n_list.next;
 242
 243         next = list_entry(p, struct btrfs_delayed_node, n_list);
 244         refcount_inc(&next->refs);
 245 out:
 246         spin_unlock(&delayed_root->lock);
 247
 248         return next;
 249 }
 250
 251 static void __btrfs_release_delayed_node(
 252                                 struct btrfs_delayed_node *delayed_node,
 253                                 int mod)
 254 {
 255         struct btrfs_delayed_root *delayed_root;
 256
 257         if (!delayed_node)
 258                 return;
 259
 260         delayed_root = delayed_node->root->fs_info->delayed_root;
 261
 262         mutex_lock(&delayed_node->mutex);
 263         if (delayed_node->count)
 264                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
 265         else
 266                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
 267         mutex_unlock(&delayed_node->mutex);
 268
 269         if (refcount_dec_and_test(&delayed_node->refs)) {
 270                 struct btrfs_root *root = delayed_node->root;
 271
 272                 spin_lock(&root->inode_lock);
 273                 /*
 274                  * Once our refcount goes to zero, nobody is allowed to bump it
 275                  * back up.  We can delete it now.
 276                  */
 277                 ASSERT(refcount_read(&delayed_node->refs) == 0);
 278                 radix_tree_delete(&root->delayed_nodes_tree,
 279                                   delayed_node->inode_id);
 280                 spin_unlock(&root->inode_lock);
 281                 kmem_cache_free(delayed_node_cache, delayed_node);
 282         }
 283 }
 284
 285 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 286 {
 287         __btrfs_release_delayed_node(node, 0);
 288 }
 289
 290 static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
 291                                         struct btrfs_delayed_root *delayed_root)
 292 {
 293         struct list_head *p;
 294         struct btrfs_delayed_node *node = NULL;
 295
 296         spin_lock(&delayed_root->lock);
 297         if (list_empty(&delayed_root->prepare_list))
 298                 goto out;
 299
 300         p = delayed_root->prepare_list.next;
 301         list_del_init(p);
 302         node = list_entry(p, struct btrfs_delayed_node, p_list);
 303         refcount_inc(&node->refs);
 304 out:
 305         spin_unlock(&delayed_root->lock);
 306
 307         return node;
 308 }
 309
 310 static inline void btrfs_release_prepared_delayed_node(
 311                                         struct btrfs_delayed_node *node)
 312 {
 313         __btrfs_release_delayed_node(node, 1);
 314 }
 315
 316 static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
 317 {
 318         struct btrfs_delayed_item *item;
 319         item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
 320         if (item) {
 321                 item->data_len = data_len;
 322                 item->ins_or_del = 0;
 323                 item->bytes_reserved = 0;
 324                 item->delayed_node = NULL;
 325                 refcount_set(&item->refs, 1);
 326         }
 327         return item;
 328 }
 329
 330 /*
 331  * __btrfs_lookup_delayed_item - look up the delayed item by key
 332  * @delayed_node: pointer to the delayed node
 333  * @key:          the key to look up
 334  * @prev:         used to store the prev item if the right item isn't found
 335  * @next:         used to store the next item if the right item isn't found
 336  *
 337  * Note: if we don't find the right item, we will return the prev item and
 338  * the next item.
 339  */
 340 static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
 341                                 struct rb_root *root,
 342                                 struct btrfs_key *key,
 343                                 struct btrfs_delayed_item **prev,
 344                                 struct btrfs_delayed_item **next)
 345 {
 346         struct rb_node *node, *prev_node = NULL;
 347         struct btrfs_delayed_item *delayed_item = NULL;
 348         int ret = 0;
 349
 350         node = root->rb_node;
 351
 352         while (node) {
 353                 delayed_item = rb_entry(node, struct btrfs_delayed_item,
 354                                         rb_node);
 355                 prev_node = node;
 356                 ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
 357                 if (ret < 0)
 358                         node = node->rb_right;
 359                 else if (ret > 0)
 360                         node = node->rb_left;
 361                 else
 362                         return delayed_item;
 363         }
 364
 365         if (prev) {
 366                 if (!prev_node)
 367                         *prev = NULL;
 368                 else if (ret < 0)
 369                         *prev = delayed_item;
 370                 else if ((node = rb_prev(prev_node)) != NULL) {
 371                         *prev = rb_entry(node, struct btrfs_delayed_item,
 372                                          rb_node);
 373                 } else
 374                         *prev = NULL;
 375         }
 376
 377         if (next) {
 378                 if (!prev_node)
 379                         *next = NULL;
 380                 else if (ret > 0)
 381                         *next = delayed_item;
 382                 else if ((node = rb_next(prev_node)) != NULL) {
 383                         *next = rb_entry(node, struct btrfs_delayed_item,
 384                                          rb_node);
 385                 } else
 386                         *next = NULL;
 387         }
 388         return NULL;
 389 }
 390
 391 static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
 392                                         struct btrfs_delayed_node *delayed_node,
 393                                         struct btrfs_key *key)
 394 {
 395         return __btrfs_lookup_delayed_item(&delayed_node->ins_root.rb_root, key,
 396                                            NULL, NULL);
 397 }
 398
 399 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 400                                     struct btrfs_delayed_item *ins,
 401                                     int action)
 402 {
 403         struct rb_node **p, *node;
 404         struct rb_node *parent_node = NULL;
 405         struct rb_root_cached *root;
 406         struct btrfs_delayed_item *item;
 407         int cmp;
 408         bool leftmost = true;
 409
 410         if (action == BTRFS_DELAYED_INSERTION_ITEM)
 411                 root = &delayed_node->ins_root;
 412         else if (action == BTRFS_DELAYED_DELETION_ITEM)
 413                 root = &delayed_node->del_root;
 414         else
 415                 BUG();
 416         p = &root->rb_root.rb_node;
 417         node = &ins->rb_node;
 418
 419         while (*p) {
 420                 parent_node = *p;
 421                 item = rb_entry(parent_node, struct btrfs_delayed_item,
 422                                  rb_node);
 423
 424                 cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
 425                 if (cmp < 0) {
 426                         p = &(*p)->rb_right;
 427                         leftmost = false;
 428                 } else if (cmp > 0) {
 429                         p = &(*p)->rb_left;
 430                 } else {
 431                         return -EEXIST;
 432                 }
 433         }
 434
 435         rb_link_node(node, parent_node, p);
 436         rb_insert_color_cached(node, root, leftmost);
 437         ins->delayed_node = delayed_node;
 438         ins->ins_or_del = action;
 439
 440         if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
 441             action == BTRFS_DELAYED_INSERTION_ITEM &&
 442             ins->key.offset >= delayed_node->index_cnt)
 443                         delayed_node->index_cnt = ins->key.offset + 1;
 444
 445         delayed_node->count++;
 446         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
 447         return 0;
 448 }
 449
 450 static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
 451                                               struct btrfs_delayed_item *item)
 452 {
 453         return __btrfs_add_delayed_item(node, item,
 454                                         BTRFS_DELAYED_INSERTION_ITEM);
 455 }
 456
 457 static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
 458                                              struct btrfs_delayed_item *item)
 459 {
 460         return __btrfs_add_delayed_item(node, item,
 461                                         BTRFS_DELAYED_DELETION_ITEM);
 462 }
 463
 464 static void finish_one_item(struct btrfs_delayed_root *delayed_root)
 465 {
 466         int seq = atomic_inc_return(&delayed_root->items_seq);
 467
 468         /* atomic_dec_return implies a barrier */
 469         if ((atomic_dec_return(&delayed_root->items) <
 470             BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))
 471                 cond_wake_up_nomb(&delayed_root->wait);
 472 }
 473
 474 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 475 {
 476         struct rb_root_cached *root;
 477         struct btrfs_delayed_root *delayed_root;
 478
 479         /* Not associated with any delayed_node */
 480         if (!delayed_item->delayed_node)
 481                 return;
 482         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 483
 484         BUG_ON(!delayed_root);
 485         BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
 486                delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
 487
 488         if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
 489                 root = &delayed_item->delayed_node->ins_root;
 490         else
 491                 root = &delayed_item->delayed_node->del_root;
 492
 493         rb_erase_cached(&delayed_item->rb_node, root);
 494         delayed_item->delayed_node->count--;
 495
 496         finish_one_item(delayed_root);
 497 }
 498
 499 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 500 {
 501         if (item) {
 502                 __btrfs_remove_delayed_item(item);
 503                 if (refcount_dec_and_test(&item->refs))
 504                         kfree(item);
 505         }
 506 }
 507
 508 static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 509                                         struct btrfs_delayed_node *delayed_node)
 510 {
 511         struct rb_node *p;
 512         struct btrfs_delayed_item *item = NULL;
 513
 514         p = rb_first_cached(&delayed_node->ins_root);
 515         if (p)
 516                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 517
 518         return item;
 519 }
 520
 521 static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 522                                         struct btrfs_delayed_node *delayed_node)
 523 {
 524         struct rb_node *p;
 525         struct btrfs_delayed_item *item = NULL;
 526
 527         p = rb_first_cached(&delayed_node->del_root);
 528         if (p)
 529                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 530
 531         return item;
 532 }
 533
 534 static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 535                                                 struct btrfs_delayed_item *item)
 536 {
 537         struct rb_node *p;
 538         struct btrfs_delayed_item *next = NULL;
 539
 540         p = rb_next(&item->rb_node);
 541         if (p)
 542                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 543
 544         return next;
 545 }
 546
 547 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 548                                                struct btrfs_root *root,
 549                                                struct btrfs_delayed_item *item)
 550 {
 551         struct btrfs_block_rsv *src_rsv;
 552         struct btrfs_block_rsv *dst_rsv;
 553         struct btrfs_fs_info *fs_info = root->fs_info;
 554         u64 num_bytes;
 555         int ret;
 556
 557         if (!trans->bytes_reserved)
 558                 return 0;
 559
 560         src_rsv = trans->block_rsv;
 561         dst_rsv = &fs_info->delayed_block_rsv;
 562
 563         num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 564
 565         /*
 566          * Here we migrate space rsv from transaction rsv, since have already
 567          * reserved space when starting a transaction.  So no need to reserve
 568          * qgroup space here.
 569          */
 570         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 571         if (!ret) {
 572                 trace_btrfs_space_reservation(fs_info, "delayed_item",
 573                                               item->key.objectid,
 574                                               num_bytes, 1);
 575                 item->bytes_reserved = num_bytes;
 576         }
 577
 578         return ret;
 579 }
 580
 581 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
 582                                                 struct btrfs_delayed_item *item)
 583 {
 584         struct btrfs_block_rsv *rsv;
 585         struct btrfs_fs_info *fs_info = root->fs_info;
 586
 587         if (!item->bytes_reserved)
 588                 return;
 589
 590         rsv = &fs_info->delayed_block_rsv;
 591         /*
 592          * Check btrfs_delayed_item_reserve_metadata() to see why we don't need
 593          * to release/reserve qgroup space.
 594          */
 595         trace_btrfs_space_reservation(fs_info, "delayed_item",
 596                                       item->key.objectid, item->bytes_reserved,
 597                                       0);
 598         btrfs_block_rsv_release(fs_info, rsv,
 599                                 item->bytes_reserved);
 600 }
 601
 602 static int btrfs_delayed_inode_reserve_metadata(
 603                                         struct btrfs_trans_handle *trans,
 604                                         struct btrfs_root *root,
 605                                         struct btrfs_inode *inode,
 606                                         struct btrfs_delayed_node *node)
 607 {
 608         struct btrfs_fs_info *fs_info = root->fs_info;
 609         struct btrfs_block_rsv *src_rsv;
 610         struct btrfs_block_rsv *dst_rsv;
 611         u64 num_bytes;
 612         int ret;
 613
 614         src_rsv = trans->block_rsv;
 615         dst_rsv = &fs_info->delayed_block_rsv;
 616
 617         num_bytes = btrfs_calc_metadata_size(fs_info, 1);
 618
 619         /*
 620          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
 621          * which doesn't reserve space for speed.  This is a problem since we
 622          * still need to reserve space for this update, so try to reserve the
 623          * space.
 624          *
 625          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
 626          * we always reserve enough to update the inode item.
 627          */
 628         if (!src_rsv || (!trans->bytes_reserved &&
 629                          src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
 630                 ret = btrfs_qgroup_reserve_meta(root, num_bytes,
 631                                           BTRFS_QGROUP_RSV_META_PREALLOC, true);
 632                 if (ret < 0)
 633                         return ret;
 634                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
 635                                           BTRFS_RESERVE_NO_FLUSH);
 636                 /*
 637                  * Since we're under a transaction reserve_metadata_bytes could
 638                  * try to commit the transaction which will make it return
 639                  * EAGAIN to make us stop the transaction we have, so return
 640                  * ENOSPC instead so that btrfs_dirty_inode knows what to do.
 641                  */
 642                 if (ret == -EAGAIN) {
 643                         ret = -ENOSPC;
 644                         btrfs_qgroup_free_meta_prealloc(root, num_bytes);
 645                 }
 646                 if (!ret) {
 647                         node->bytes_reserved = num_bytes;
 648                         trace_btrfs_space_reservation(fs_info,
 649                                                       "delayed_inode",
 650                                                       btrfs_ino(inode),
 651                                                       num_bytes, 1);
 652                 } else {
 653                         btrfs_qgroup_free_meta_prealloc(root, num_bytes);
 654                 }
 655                 return ret;
 656         }
 657
 658         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 659         if (!ret) {
 660                 trace_btrfs_space_reservation(fs_info, "delayed_inode",
 661                                               btrfs_ino(inode), num_bytes, 1);
 662                 node->bytes_reserved = num_bytes;
 663         }
 664
 665         return ret;
 666 }
 667
 668 static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
 669                                                 struct btrfs_delayed_node *node,
 670                                                 bool qgroup_free)
 671 {
 672         struct btrfs_block_rsv *rsv;
 673
 674         if (!node->bytes_reserved)
 675                 return;
 676
 677         rsv = &fs_info->delayed_block_rsv;
 678         trace_btrfs_space_reservation(fs_info, "delayed_inode",
 679                                       node->inode_id, node->bytes_reserved, 0);
 680         btrfs_block_rsv_release(fs_info, rsv,
 681                                 node->bytes_reserved);
 682         if (qgroup_free)
 683                 btrfs_qgroup_free_meta_prealloc(node->root,
 684                                 node->bytes_reserved);
 685         else
 686                 btrfs_qgroup_convert_reserved_meta(node->root,
 687                                 node->bytes_reserved);
 688         node->bytes_reserved = 0;
 689 }
 690
 691 /*
 692  * This helper will insert some continuous items into the same leaf according
 693  * to the free space of the leaf.
 694  */
 695 static int btrfs_batch_insert_items(struct btrfs_root *root,
 696                                     struct btrfs_path *path,
 697                                     struct btrfs_delayed_item *item)
 698 {
 699         struct btrfs_delayed_item *curr, *next;
 700         int free_space;
 701         int total_data_size = 0, total_size = 0;
 702         struct extent_buffer *leaf;
 703         char *data_ptr;
 704         struct btrfs_key *keys;
 705         u32 *data_size;
 706         struct list_head head;
 707         int slot;
 708         int nitems;
 709         int i;
 710         int ret = 0;
 711
 712         BUG_ON(!path->nodes[0]);
 713
 714         leaf = path->nodes[0];
 715         free_space = btrfs_leaf_free_space(leaf);
 716         INIT_LIST_HEAD(&head);
 717
 718         next = item;
 719         nitems = 0;
 720
 721         /*
 722          * count the number of the continuous items that we can insert in batch
 723          */
 724         while (total_size + next->data_len + sizeof(struct btrfs_item) <=
 725                free_space) {
 726                 total_data_size += next->data_len;
 727                 total_size += next->data_len + sizeof(struct btrfs_item);
 728                 list_add_tail(&next->tree_list, &head);
 729                 nitems++;
 730
 731                 curr = next;
 732                 next = __btrfs_next_delayed_item(curr);
 733                 if (!next)
 734                         break;
 735
 736                 if (!btrfs_is_continuous_delayed_item(curr, next))
 737                         break;
 738         }
 739
 740         if (!nitems) {
 741                 ret = 0;
 742                 goto out;
 743         }
 744
 745         /*
 746          * we need allocate some memory space, but it might cause the task
 747          * to sleep, so we set all locked nodes in the path to blocking locks
 748          * first.
 749          */
 750         btrfs_set_path_blocking(path);
 751
 752         keys = kmalloc_array(nitems, sizeof(struct btrfs_key), GFP_NOFS);
 753         if (!keys) {
 754                 ret = -ENOMEM;
 755                 goto out;
 756         }
 757
 758         data_size = kmalloc_array(nitems, sizeof(u32), GFP_NOFS);
 759         if (!data_size) {
 760                 ret = -ENOMEM;
 761                 goto error;
 762         }
 763
 764         /* get keys of all the delayed items */
 765         i = 0;
 766         list_for_each_entry(next, &head, tree_list) {
 767                 keys[i] = next->key;
 768                 data_size[i] = next->data_len;
 769                 i++;
 770         }
 771
 772         /* insert the keys of the items */
 773         setup_items_for_insert(root, path, keys, data_size,
 774                                total_data_size, total_size, nitems);
 775
 776         /* insert the dir index items */
 777         slot = path->slots[0];
 778         list_for_each_entry_safe(curr, next, &head, tree_list) {
 779                 data_ptr = btrfs_item_ptr(leaf, slot, char);
 780                 write_extent_buffer(leaf, &curr->data,
 781                                     (unsigned long)data_ptr,
 782                                     curr->data_len);
 783                 slot++;
 784
 785                 btrfs_delayed_item_release_metadata(root, curr);
 786
 787                 list_del(&curr->tree_list);
 788                 btrfs_release_delayed_item(curr);
 789         }
 790
 791 error:
 792         kfree(data_size);
 793         kfree(keys);
 794 out:
 795         return ret;
 796 }
 797
 798 /*
 799  * This helper can just do simple insertion that needn't extend item for new
 800  * data, such as directory name index insertion, inode insertion.
 801  */
 802 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 803                                      struct btrfs_root *root,
 804                                      struct btrfs_path *path,
 805                                      struct btrfs_delayed_item *delayed_item)
 806 {
 807         struct extent_buffer *leaf;
 808         unsigned int nofs_flag;
 809         char *ptr;
 810         int ret;
 811
 812         nofs_flag = memalloc_nofs_save();
 813         ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
 814                                       delayed_item->data_len);
 815         memalloc_nofs_restore(nofs_flag);
 816         if (ret < 0 && ret != -EEXIST)
 817                 return ret;
 818
 819         leaf = path->nodes[0];
 820
 821         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
 822
 823         write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
 824                             delayed_item->data_len);
 825         btrfs_mark_buffer_dirty(leaf);
 826
 827         btrfs_delayed_item_release_metadata(root, delayed_item);
 828         return 0;
 829 }
 830
 831 /*
 832  * we insert an item first, then if there are some continuous items, we try
 833  * to insert those items into the same leaf.
 834  */
 835 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 836                                       struct btrfs_path *path,
 837                                       struct btrfs_root *root,
 838                                       struct btrfs_delayed_node *node)
 839 {
 840         struct btrfs_delayed_item *curr, *prev;
 841         int ret = 0;
 842
 843 do_again:
 844         mutex_lock(&node->mutex);
 845         curr = __btrfs_first_delayed_insertion_item(node);
 846         if (!curr)
 847                 goto insert_end;
 848
 849         ret = btrfs_insert_delayed_item(trans, root, path, curr);
 850         if (ret < 0) {
 851                 btrfs_release_path(path);
 852                 goto insert_end;
 853         }
 854
 855         prev = curr;
 856         curr = __btrfs_next_delayed_item(prev);
 857         if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
 858                 /* insert the continuous items into the same leaf */
 859                 path->slots[0]++;
 860                 btrfs_batch_insert_items(root, path, curr);
 861         }
 862         btrfs_release_delayed_item(prev);
 863         btrfs_mark_buffer_dirty(path->nodes[0]);
 864
 865         btrfs_release_path(path);
 866         mutex_unlock(&node->mutex);
 867         goto do_again;
 868
 869 insert_end:
 870         mutex_unlock(&node->mutex);
 871         return ret;
 872 }
 873
 874 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
 875                                     struct btrfs_root *root,
 876                                     struct btrfs_path *path,
 877                                     struct btrfs_delayed_item *item)
 878 {
 879         struct btrfs_delayed_item *curr, *next;
 880         struct extent_buffer *leaf;
 881         struct btrfs_key key;
 882         struct list_head head;
 883         int nitems, i, last_item;
 884         int ret = 0;
 885
 886         BUG_ON(!path->nodes[0]);
 887
 888         leaf = path->nodes[0];
 889
 890         i = path->slots[0];
 891         last_item = btrfs_header_nritems(leaf) - 1;
 892         if (i > last_item)
 893                 return -ENOENT; /* FIXME: Is errno suitable? */
 894
 895         next = item;
 896         INIT_LIST_HEAD(&head);
 897         btrfs_item_key_to_cpu(leaf, &key, i);
 898         nitems = 0;
 899         /*
 900          * count the number of the dir index items that we can delete in batch
 901          */
 902         while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
 903                 list_add_tail(&next->tree_list, &head);
 904                 nitems++;
 905
 906                 curr = next;
 907                 next = __btrfs_next_delayed_item(curr);
 908                 if (!next)
 909                         break;
 910
 911                 if (!btrfs_is_continuous_delayed_item(curr, next))
 912                         break;
 913
 914                 i++;
 915                 if (i > last_item)
 916                         break;
 917                 btrfs_item_key_to_cpu(leaf, &key, i);
 918         }
 919
 920         if (!nitems)
 921                 return 0;
 922
 923         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
 924         if (ret)
 925                 goto out;
 926
 927         list_for_each_entry_safe(curr, next, &head, tree_list) {
 928                 btrfs_delayed_item_release_metadata(root, curr);
 929                 list_del(&curr->tree_list);
 930                 btrfs_release_delayed_item(curr);
 931         }
 932
 933 out:
 934         return ret;
 935 }
 936
 937 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
 938                                       struct btrfs_path *path,
 939                                       struct btrfs_root *root,
 940                                       struct btrfs_delayed_node *node)
 941 {
 942         struct btrfs_delayed_item *curr, *prev;
 943         unsigned int nofs_flag;
 944         int ret = 0;
 945
 946 do_again:
 947         mutex_lock(&node->mutex);
 948         curr = __btrfs_first_delayed_deletion_item(node);
 949         if (!curr)
 950                 goto delete_fail;
 951
 952         nofs_flag = memalloc_nofs_save();
 953         ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
 954         memalloc_nofs_restore(nofs_flag);
 955         if (ret < 0)
 956                 goto delete_fail;
 957         else if (ret > 0) {
 958                 /*
 959                  * can't find the item which the node points to, so this node
 960                  * is invalid, just drop it.
 961                  */
 962                 prev = curr;
 963                 curr = __btrfs_next_delayed_item(prev);
 964                 btrfs_release_delayed_item(prev);
 965                 ret = 0;
 966                 btrfs_release_path(path);
 967                 if (curr) {
 968                         mutex_unlock(&node->mutex);
 969                         goto do_again;
 970                 } else
 971                         goto delete_fail;
 972         }
 973
 974         btrfs_batch_delete_items(trans, root, path, curr);
 975         btrfs_release_path(path);
 976         mutex_unlock(&node->mutex);
 977         goto do_again;
 978
 979 delete_fail:
 980         btrfs_release_path(path);
 981         mutex_unlock(&node->mutex);
 982         return ret;
 983 }
 984
 985 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
 986 {
 987         struct btrfs_delayed_root *delayed_root;
 988
 989         if (delayed_node &&
 990             test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
 991                 BUG_ON(!delayed_node->root);
 992                 clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
 993                 delayed_node->count--;
 994
 995                 delayed_root = delayed_node->root->fs_info->delayed_root;
 996                 finish_one_item(delayed_root);
 997         }
 998 }
 999
1000 static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
1001 {
1002         struct btrfs_delayed_root *delayed_root;
1003
1004         ASSERT(delayed_node->root);
1005         clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1006         delayed_node->count--;
1007
1008         delayed_root = delayed_node->root->fs_info->delayed_root;
1009         finish_one_item(delayed_root);
1010 }
1011
1012 static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1013                                         struct btrfs_root *root,
1014                                         struct btrfs_path *path,
1015                                         struct btrfs_delayed_node *node)
1016 {
1017         struct btrfs_fs_info *fs_info = root->fs_info;
1018         struct btrfs_key key;
1019         struct btrfs_inode_item *inode_item;
1020         struct extent_buffer *leaf;
1021         unsigned int nofs_flag;
1022         int mod;
1023         int ret;
1024
1025         key.objectid = node->inode_id;
1026         key.type = BTRFS_INODE_ITEM_KEY;
1027         key.offset = 0;
1028
1029         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1030                 mod = -1;
1031         else
1032                 mod = 1;
1033
1034         nofs_flag = memalloc_nofs_save();
1035         ret = btrfs_lookup_inode(trans, root, path, &key, mod);
1036         memalloc_nofs_restore(nofs_flag);
1037         if (ret > 0)
1038                 ret = -ENOENT;
1039         if (ret < 0)
1040                 goto out;
1041
1042         leaf = path->nodes[0];
1043         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1044                                     struct btrfs_inode_item);
1045         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1046                             sizeof(struct btrfs_inode_item));
1047         btrfs_mark_buffer_dirty(leaf);
1048
1049         if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1050                 goto no_iref;
1051
1052         path->slots[0]++;
1053         if (path->slots[0] >= btrfs_header_nritems(leaf))
1054                 goto search;
1055 again:
1056         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1057         if (key.objectid != node->inode_id)
1058                 goto out;
1059
1060         if (key.type != BTRFS_INODE_REF_KEY &&
1061             key.type != BTRFS_INODE_EXTREF_KEY)
1062                 goto out;
1063
1064         /*
1065          * Delayed iref deletion is for the inode who has only one link,
1066          * so there is only one iref. The case that several irefs are
1067          * in the same item doesn't exist.
1068          */
1069         btrfs_del_item(trans, root, path);
1070 out:
1071         btrfs_release_delayed_iref(node);
1072 no_iref:
1073         btrfs_release_path(path);
1074 err_out:
1075         btrfs_delayed_inode_release_metadata(fs_info, node, (ret < 0));
1076         btrfs_release_delayed_inode(node);
1077
1078         /*
1079          * If we fail to update the delayed inode we need to abort the
1080          * transaction, because we could leave the inode with the improper
1081          * counts behind.
1082          */
1083         if (ret && ret != -ENOENT)
1084                 btrfs_abort_transaction(trans, ret);
1085
1086         return ret;
1087
1088 search:
1089         btrfs_release_path(path);
1090
1091         key.type = BTRFS_INODE_EXTREF_KEY;
1092         key.offset = -1;
1093
1094         nofs_flag = memalloc_nofs_save();
1095         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1096         memalloc_nofs_restore(nofs_flag);
1097         if (ret < 0)
1098                 goto err_out;
1099         ASSERT(ret);
1100
1101         ret = 0;
1102         leaf = path->nodes[0];
1103         path->slots[0]--;
1104         goto again;
1105 }
1106
1107 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1108                                              struct btrfs_root *root,
1109                                              struct btrfs_path *path,
1110                                              struct btrfs_delayed_node *node)
1111 {
1112         int ret;
1113
1114         mutex_lock(&node->mutex);
1115         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1116                 mutex_unlock(&node->mutex);
1117                 return 0;
1118         }
1119
1120         ret = __btrfs_update_delayed_inode(trans, root, path, node);
1121         mutex_unlock(&node->mutex);
1122         return ret;
1123 }
1124
1125 static inline int
1126 __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1127                                    struct btrfs_path *path,
1128                                    struct btrfs_delayed_node *node)
1129 {
1130         int ret;
1131
1132         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1133         if (ret)
1134                 return ret;
1135
1136         ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1137         if (ret)
1138                 return ret;
1139
1140         ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1141         return ret;
1142 }
1143
1144 /*
1145  * Called when committing the transaction.
1146  * Returns 0 on success.
1147  * Returns < 0 on error and returns with an aborted transaction with any
1148  * outstanding delayed items cleaned up.
1149  */
1150 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
1151 {
1152         struct btrfs_fs_info *fs_info = trans->fs_info;
1153         struct btrfs_delayed_root *delayed_root;
1154         struct btrfs_delayed_node *curr_node, *prev_node;
1155         struct btrfs_path *path;
1156         struct btrfs_block_rsv *block_rsv;
1157         int ret = 0;
1158         bool count = (nr > 0);
1159
1160         if (TRANS_ABORTED(trans))
1161                 return -EIO;
1162
1163         path = btrfs_alloc_path();
1164         if (!path)
1165                 return -ENOMEM;
1166         path->leave_spinning = 1;
1167
1168         block_rsv = trans->block_rsv;
1169         trans->block_rsv = &fs_info->delayed_block_rsv;
1170
1171         delayed_root = fs_info->delayed_root;
1172
1173         curr_node = btrfs_first_delayed_node(delayed_root);
1174         while (curr_node && (!count || (count && nr--))) {
1175                 ret = __btrfs_commit_inode_delayed_items(trans, path,
1176                                                          curr_node);
1177                 if (ret) {
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                 /*
1185                  * See the comment below about releasing path before releasing
1186                  * node. If the commit of delayed items was successful the path
1187                  * should always be released, but in case of an error, it may
1188                  * point to locked extent buffers (a leaf at the very least).
1189                  */
1190                 ASSERT(path->nodes[0] == NULL);
1191                 btrfs_release_delayed_node(prev_node);
1192         }
1193
1194         /*
1195          * Release the path to avoid a potential deadlock and lockdep splat when
1196          * releasing the delayed node, as that requires taking the delayed node's
1197          * mutex. If another task starts running delayed items before we take
1198          * the mutex, it will first lock the mutex and then it may try to lock
1199          * the same btree path (leaf).
1200          */
1201         btrfs_free_path(path);
1202
1203         if (curr_node)
1204                 btrfs_release_delayed_node(curr_node);
1205         trans->block_rsv = block_rsv;
1206
1207         return ret;
1208 }
1209
1210 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)
1211 {
1212         return __btrfs_run_delayed_items(trans, -1);
1213 }
1214
1215 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)
1216 {
1217         return __btrfs_run_delayed_items(trans, nr);
1218 }
1219
1220 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1221                                      struct btrfs_inode *inode)
1222 {
1223         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1224         struct btrfs_path *path;
1225         struct btrfs_block_rsv *block_rsv;
1226         int ret;
1227
1228         if (!delayed_node)
1229                 return 0;
1230
1231         mutex_lock(&delayed_node->mutex);
1232         if (!delayed_node->count) {
1233                 mutex_unlock(&delayed_node->mutex);
1234                 btrfs_release_delayed_node(delayed_node);
1235                 return 0;
1236         }
1237         mutex_unlock(&delayed_node->mutex);
1238
1239         path = btrfs_alloc_path();
1240         if (!path) {
1241                 btrfs_release_delayed_node(delayed_node);
1242                 return -ENOMEM;
1243         }
1244         path->leave_spinning = 1;
1245
1246         block_rsv = trans->block_rsv;
1247         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1248
1249         ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1250
1251         btrfs_release_delayed_node(delayed_node);
1252         btrfs_free_path(path);
1253         trans->block_rsv = block_rsv;
1254
1255         return ret;
1256 }
1257
1258 int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
1259 {
1260         struct btrfs_fs_info *fs_info = inode->root->fs_info;
1261         struct btrfs_trans_handle *trans;
1262         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1263         struct btrfs_path *path;
1264         struct btrfs_block_rsv *block_rsv;
1265         int ret;
1266
1267         if (!delayed_node)
1268                 return 0;
1269
1270         mutex_lock(&delayed_node->mutex);
1271         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1272                 mutex_unlock(&delayed_node->mutex);
1273                 btrfs_release_delayed_node(delayed_node);
1274                 return 0;
1275         }
1276         mutex_unlock(&delayed_node->mutex);
1277
1278         trans = btrfs_join_transaction(delayed_node->root);
1279         if (IS_ERR(trans)) {
1280                 ret = PTR_ERR(trans);
1281                 goto out;
1282         }
1283
1284         path = btrfs_alloc_path();
1285         if (!path) {
1286                 ret = -ENOMEM;
1287                 goto trans_out;
1288         }
1289         path->leave_spinning = 1;
1290
1291         block_rsv = trans->block_rsv;
1292         trans->block_rsv = &fs_info->delayed_block_rsv;
1293
1294         mutex_lock(&delayed_node->mutex);
1295         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1296                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1297                                                    path, delayed_node);
1298         else
1299                 ret = 0;
1300         mutex_unlock(&delayed_node->mutex);
1301
1302         btrfs_free_path(path);
1303         trans->block_rsv = block_rsv;
1304 trans_out:
1305         btrfs_end_transaction(trans);
1306         btrfs_btree_balance_dirty(fs_info);
1307 out:
1308         btrfs_release_delayed_node(delayed_node);
1309
1310         return ret;
1311 }
1312
1313 void btrfs_remove_delayed_node(struct btrfs_inode *inode)
1314 {
1315         struct btrfs_delayed_node *delayed_node;
1316
1317         delayed_node = READ_ONCE(inode->delayed_node);
1318         if (!delayed_node)
1319                 return;
1320
1321         inode->delayed_node = NULL;
1322         btrfs_release_delayed_node(delayed_node);
1323 }
1324
1325 struct btrfs_async_delayed_work {
1326         struct btrfs_delayed_root *delayed_root;
1327         int nr;
1328         struct btrfs_work work;
1329 };
1330
1331 static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1332 {
1333         struct btrfs_async_delayed_work *async_work;
1334         struct btrfs_delayed_root *delayed_root;
1335         struct btrfs_trans_handle *trans;
1336         struct btrfs_path *path;
1337         struct btrfs_delayed_node *delayed_node = NULL;
1338         struct btrfs_root *root;
1339         struct btrfs_block_rsv *block_rsv;
1340         int total_done = 0;
1341
1342         async_work = container_of(work, struct btrfs_async_delayed_work, work);
1343         delayed_root = async_work->delayed_root;
1344
1345         path = btrfs_alloc_path();
1346         if (!path)
1347                 goto out;
1348
1349         do {
1350                 if (atomic_read(&delayed_root->items) <
1351                     BTRFS_DELAYED_BACKGROUND / 2)
1352                         break;
1353
1354                 delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1355                 if (!delayed_node)
1356                         break;
1357
1358                 path->leave_spinning = 1;
1359                 root = delayed_node->root;
1360
1361                 trans = btrfs_join_transaction(root);
1362                 if (IS_ERR(trans)) {
1363                         btrfs_release_path(path);
1364                         btrfs_release_prepared_delayed_node(delayed_node);
1365                         total_done++;
1366                         continue;
1367                 }
1368
1369                 block_rsv = trans->block_rsv;
1370                 trans->block_rsv = &root->fs_info->delayed_block_rsv;
1371
1372                 __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1373
1374                 trans->block_rsv = block_rsv;
1375                 btrfs_end_transaction(trans);
1376                 btrfs_btree_balance_dirty_nodelay(root->fs_info);
1377
1378                 btrfs_release_path(path);
1379                 btrfs_release_prepared_delayed_node(delayed_node);
1380                 total_done++;
1381
1382         } while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
1383                  || total_done < async_work->nr);
1384
1385         btrfs_free_path(path);
1386 out:
1387         wake_up(&delayed_root->wait);
1388         kfree(async_work);
1389 }
1390
1391
1392 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1393                                      struct btrfs_fs_info *fs_info, int nr)
1394 {
1395         struct btrfs_async_delayed_work *async_work;
1396
1397         async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1398         if (!async_work)
1399                 return -ENOMEM;
1400
1401         async_work->delayed_root = delayed_root;
1402         btrfs_init_work(&async_work->work, btrfs_async_run_delayed_root, NULL,
1403                         NULL);
1404         async_work->nr = nr;
1405
1406         btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
1407         return 0;
1408 }
1409
1410 void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
1411 {
1412         WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));
1413 }
1414
1415 static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1416 {
1417         int val = atomic_read(&delayed_root->items_seq);
1418
1419         if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1420                 return 1;
1421
1422         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1423                 return 1;
1424
1425         return 0;
1426 }
1427
1428 void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
1429 {
1430         struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
1431
1432         if ((atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
1433                 btrfs_workqueue_normal_congested(fs_info->delayed_workers))
1434                 return;
1435
1436         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1437                 int seq;
1438                 int ret;
1439
1440                 seq = atomic_read(&delayed_root->items_seq);
1441
1442                 ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
1443                 if (ret)
1444                         return;
1445
1446                 wait_event_interruptible(delayed_root->wait,
1447                                          could_end_wait(delayed_root, seq));
1448                 return;
1449         }
1450
1451         btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1452 }
1453
1454 /* Will return 0 or -ENOMEM */
1455 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1456                                    const char *name, int name_len,
1457                                    struct btrfs_inode *dir,
1458                                    struct btrfs_disk_key *disk_key, u8 type,
1459                                    u64 index)
1460 {
1461         struct btrfs_delayed_node *delayed_node;
1462         struct btrfs_delayed_item *delayed_item;
1463         struct btrfs_dir_item *dir_item;
1464         int ret;
1465
1466         delayed_node = btrfs_get_or_create_delayed_node(dir);
1467         if (IS_ERR(delayed_node))
1468                 return PTR_ERR(delayed_node);
1469
1470         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1471         if (!delayed_item) {
1472                 ret = -ENOMEM;
1473                 goto release_node;
1474         }
1475
1476         delayed_item->key.objectid = btrfs_ino(dir);
1477         delayed_item->key.type = BTRFS_DIR_INDEX_KEY;
1478         delayed_item->key.offset = index;
1479
1480         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1481         dir_item->location = *disk_key;
1482         btrfs_set_stack_dir_transid(dir_item, trans->transid);
1483         btrfs_set_stack_dir_data_len(dir_item, 0);
1484         btrfs_set_stack_dir_name_len(dir_item, name_len);
1485         btrfs_set_stack_dir_type(dir_item, type);
1486         memcpy((char *)(dir_item + 1), name, name_len);
1487
1488         ret = btrfs_delayed_item_reserve_metadata(trans, dir->root, delayed_item);
1489         /*
1490          * we have reserved enough space when we start a new transaction,
1491          * so reserving metadata failure is impossible
1492          */
1493         BUG_ON(ret);
1494
1495         mutex_lock(&delayed_node->mutex);
1496         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1497         if (unlikely(ret)) {
1498                 btrfs_err(trans->fs_info,
1499                           "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1500                           name_len, name, delayed_node->root->root_key.objectid,
1501                           delayed_node->inode_id, ret);
1502                 BUG();
1503         }
1504         mutex_unlock(&delayed_node->mutex);
1505
1506 release_node:
1507         btrfs_release_delayed_node(delayed_node);
1508         return ret;
1509 }
1510
1511 static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,
1512                                                struct btrfs_delayed_node *node,
1513                                                struct btrfs_key *key)
1514 {
1515         struct btrfs_delayed_item *item;
1516
1517         mutex_lock(&node->mutex);
1518         item = __btrfs_lookup_delayed_insertion_item(node, key);
1519         if (!item) {
1520                 mutex_unlock(&node->mutex);
1521                 return 1;
1522         }
1523
1524         btrfs_delayed_item_release_metadata(node->root, item);
1525         btrfs_release_delayed_item(item);
1526         mutex_unlock(&node->mutex);
1527         return 0;
1528 }
1529
1530 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1531                                    struct btrfs_inode *dir, u64 index)
1532 {
1533         struct btrfs_delayed_node *node;
1534         struct btrfs_delayed_item *item;
1535         struct btrfs_key item_key;
1536         int ret;
1537
1538         node = btrfs_get_or_create_delayed_node(dir);
1539         if (IS_ERR(node))
1540                 return PTR_ERR(node);
1541
1542         item_key.objectid = btrfs_ino(dir);
1543         item_key.type = BTRFS_DIR_INDEX_KEY;
1544         item_key.offset = index;
1545
1546         ret = btrfs_delete_delayed_insertion_item(trans->fs_info, node,
1547                                                   &item_key);
1548         if (!ret)
1549                 goto end;
1550
1551         item = btrfs_alloc_delayed_item(0);
1552         if (!item) {
1553                 ret = -ENOMEM;
1554                 goto end;
1555         }
1556
1557         item->key = item_key;
1558
1559         ret = btrfs_delayed_item_reserve_metadata(trans, dir->root, item);
1560         /*
1561          * we have reserved enough space when we start a new transaction,
1562          * so reserving metadata failure is impossible.
1563          */
1564         if (ret < 0) {
1565                 btrfs_err(trans->fs_info,
1566 "metadata reservation failed for delayed dir item deltiona, should have been reserved");
1567                 btrfs_release_delayed_item(item);
1568                 goto end;
1569         }
1570
1571         mutex_lock(&node->mutex);
1572         ret = __btrfs_add_delayed_deletion_item(node, item);
1573         if (unlikely(ret)) {
1574                 btrfs_err(trans->fs_info,
1575                           "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1576                           index, node->root->root_key.objectid,
1577                           node->inode_id, ret);
1578                 btrfs_delayed_item_release_metadata(dir->root, item);
1579                 btrfs_release_delayed_item(item);
1580         }
1581         mutex_unlock(&node->mutex);
1582 end:
1583         btrfs_release_delayed_node(node);
1584         return ret;
1585 }
1586
1587 int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)
1588 {
1589         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1590
1591         if (!delayed_node)
1592                 return -ENOENT;
1593
1594         /*
1595          * Since we have held i_mutex of this directory, it is impossible that
1596          * a new directory index is added into the delayed node and index_cnt
1597          * is updated now. So we needn't lock the delayed node.
1598          */
1599         if (!delayed_node->index_cnt) {
1600                 btrfs_release_delayed_node(delayed_node);
1601                 return -EINVAL;
1602         }
1603
1604         inode->index_cnt = delayed_node->index_cnt;
1605         btrfs_release_delayed_node(delayed_node);
1606         return 0;
1607 }
1608
1609 bool btrfs_readdir_get_delayed_items(struct inode *inode,
1610                                      struct list_head *ins_list,
1611                                      struct list_head *del_list)
1612 {
1613         struct btrfs_delayed_node *delayed_node;
1614         struct btrfs_delayed_item *item;
1615
1616         delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
1617         if (!delayed_node)
1618                 return false;
1619
1620         /*
1621          * We can only do one readdir with delayed items at a time because of
1622          * item->readdir_list.
1623          */
1624         inode_unlock_shared(inode);
1625         inode_lock(inode);
1626
1627         mutex_lock(&delayed_node->mutex);
1628         item = __btrfs_first_delayed_insertion_item(delayed_node);
1629         while (item) {
1630                 refcount_inc(&item->refs);
1631                 list_add_tail(&item->readdir_list, ins_list);
1632                 item = __btrfs_next_delayed_item(item);
1633         }
1634
1635         item = __btrfs_first_delayed_deletion_item(delayed_node);
1636         while (item) {
1637                 refcount_inc(&item->refs);
1638                 list_add_tail(&item->readdir_list, del_list);
1639                 item = __btrfs_next_delayed_item(item);
1640         }
1641         mutex_unlock(&delayed_node->mutex);
1642         /*
1643          * This delayed node is still cached in the btrfs inode, so refs
1644          * must be > 1 now, and we needn't check it is going to be freed
1645          * or not.
1646          *
1647          * Besides that, this function is used to read dir, we do not
1648          * insert/delete delayed items in this period. So we also needn't
1649          * requeue or dequeue this delayed node.
1650          */
1651         refcount_dec(&delayed_node->refs);
1652
1653         return true;
1654 }
1655
1656 void btrfs_readdir_put_delayed_items(struct inode *inode,
1657                                      struct list_head *ins_list,
1658                                      struct list_head *del_list)
1659 {
1660         struct btrfs_delayed_item *curr, *next;
1661
1662         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1663                 list_del(&curr->readdir_list);
1664                 if (refcount_dec_and_test(&curr->refs))
1665                         kfree(curr);
1666         }
1667
1668         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1669                 list_del(&curr->readdir_list);
1670                 if (refcount_dec_and_test(&curr->refs))
1671                         kfree(curr);
1672         }
1673
1674         /*
1675          * The VFS is going to do up_read(), so we need to downgrade back to a
1676          * read lock.
1677          */
1678         downgrade_write(&inode->i_rwsem);
1679 }
1680
1681 int btrfs_should_delete_dir_index(struct list_head *del_list,
1682                                   u64 index)
1683 {
1684         struct btrfs_delayed_item *curr;
1685         int ret = 0;
1686
1687         list_for_each_entry(curr, del_list, readdir_list) {
1688                 if (curr->key.offset > index)
1689                         break;
1690                 if (curr->key.offset == index) {
1691                         ret = 1;
1692                         break;
1693                 }
1694         }
1695         return ret;
1696 }
1697
1698 /*
1699  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1700  *
1701  */
1702 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1703                                     struct list_head *ins_list)
1704 {
1705         struct btrfs_dir_item *di;
1706         struct btrfs_delayed_item *curr, *next;
1707         struct btrfs_key location;
1708         char *name;
1709         int name_len;
1710         int over = 0;
1711         unsigned char d_type;
1712
1713         if (list_empty(ins_list))
1714                 return 0;
1715
1716         /*
1717          * Changing the data of the delayed item is impossible. So
1718          * we needn't lock them. And we have held i_mutex of the
1719          * directory, nobody can delete any directory indexes now.
1720          */
1721         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1722                 list_del(&curr->readdir_list);
1723
1724                 if (curr->key.offset < ctx->pos) {
1725                         if (refcount_dec_and_test(&curr->refs))
1726                                 kfree(curr);
1727                         continue;
1728                 }
1729
1730                 ctx->pos = curr->key.offset;
1731
1732                 di = (struct btrfs_dir_item *)curr->data;
1733                 name = (char *)(di + 1);
1734                 name_len = btrfs_stack_dir_name_len(di);
1735
1736                 d_type = fs_ftype_to_dtype(di->type);
1737                 btrfs_disk_key_to_cpu(&location, &di->location);
1738
1739                 over = !dir_emit(ctx, name, name_len,
1740                                location.objectid, d_type);
1741
1742                 if (refcount_dec_and_test(&curr->refs))
1743                         kfree(curr);
1744
1745                 if (over)
1746                         return 1;
1747                 ctx->pos++;
1748         }
1749         return 0;
1750 }
1751
1752 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1753                                   struct btrfs_inode_item *inode_item,
1754                                   struct inode *inode)
1755 {
1756         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1757         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1758         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1759         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1760         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1761         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1762         btrfs_set_stack_inode_generation(inode_item,
1763                                          BTRFS_I(inode)->generation);
1764         btrfs_set_stack_inode_sequence(inode_item,
1765                                        inode_peek_iversion(inode));
1766         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1767         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1768         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1769         btrfs_set_stack_inode_block_group(inode_item, 0);
1770
1771         btrfs_set_stack_timespec_sec(&inode_item->atime,
1772                                      inode->i_atime.tv_sec);
1773         btrfs_set_stack_timespec_nsec(&inode_item->atime,
1774                                       inode->i_atime.tv_nsec);
1775
1776         btrfs_set_stack_timespec_sec(&inode_item->mtime,
1777                                      inode->i_mtime.tv_sec);
1778         btrfs_set_stack_timespec_nsec(&inode_item->mtime,
1779                                       inode->i_mtime.tv_nsec);
1780
1781         btrfs_set_stack_timespec_sec(&inode_item->ctime,
1782                                      inode->i_ctime.tv_sec);
1783         btrfs_set_stack_timespec_nsec(&inode_item->ctime,
1784                                       inode->i_ctime.tv_nsec);
1785
1786         btrfs_set_stack_timespec_sec(&inode_item->otime,
1787                                      BTRFS_I(inode)->i_otime.tv_sec);
1788         btrfs_set_stack_timespec_nsec(&inode_item->otime,
1789                                      BTRFS_I(inode)->i_otime.tv_nsec);
1790 }
1791
1792 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1793 {
1794         struct btrfs_delayed_node *delayed_node;
1795         struct btrfs_inode_item *inode_item;
1796
1797         delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
1798         if (!delayed_node)
1799                 return -ENOENT;
1800
1801         mutex_lock(&delayed_node->mutex);
1802         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1803                 mutex_unlock(&delayed_node->mutex);
1804                 btrfs_release_delayed_node(delayed_node);
1805                 return -ENOENT;
1806         }
1807
1808         inode_item = &delayed_node->inode_item;
1809
1810         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1811         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1812         btrfs_i_size_write(BTRFS_I(inode), btrfs_stack_inode_size(inode_item));
1813         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1814         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1815         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1816         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1817         BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
1818
1819         inode_set_iversion_queried(inode,
1820                                    btrfs_stack_inode_sequence(inode_item));
1821         inode->i_rdev = 0;
1822         *rdev = btrfs_stack_inode_rdev(inode_item);
1823         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1824
1825         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
1826         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
1827
1828         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
1829         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
1830
1831         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
1832         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
1833
1834         BTRFS_I(inode)->i_otime.tv_sec =
1835                 btrfs_stack_timespec_sec(&inode_item->otime);
1836         BTRFS_I(inode)->i_otime.tv_nsec =
1837                 btrfs_stack_timespec_nsec(&inode_item->otime);
1838
1839         inode->i_generation = BTRFS_I(inode)->generation;
1840         BTRFS_I(inode)->index_cnt = (u64)-1;
1841
1842         mutex_unlock(&delayed_node->mutex);
1843         btrfs_release_delayed_node(delayed_node);
1844         return 0;
1845 }
1846
1847 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1848                                struct btrfs_root *root, struct inode *inode)
1849 {
1850         struct btrfs_delayed_node *delayed_node;
1851         int ret = 0;
1852
1853         delayed_node = btrfs_get_or_create_delayed_node(BTRFS_I(inode));
1854         if (IS_ERR(delayed_node))
1855                 return PTR_ERR(delayed_node);
1856
1857         mutex_lock(&delayed_node->mutex);
1858         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1859                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1860                 goto release_node;
1861         }
1862
1863         ret = btrfs_delayed_inode_reserve_metadata(trans, root, BTRFS_I(inode),
1864                                                    delayed_node);
1865         if (ret)
1866                 goto release_node;
1867
1868         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
1869         set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1870         delayed_node->count++;
1871         atomic_inc(&root->fs_info->delayed_root->items);
1872 release_node:
1873         mutex_unlock(&delayed_node->mutex);
1874         btrfs_release_delayed_node(delayed_node);
1875         return ret;
1876 }
1877
1878 int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)
1879 {
1880         struct btrfs_fs_info *fs_info = inode->root->fs_info;
1881         struct btrfs_delayed_node *delayed_node;
1882
1883         /*
1884          * we don't do delayed inode updates during log recovery because it
1885          * leads to enospc problems.  This means we also can't do
1886          * delayed inode refs
1887          */
1888         if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1889                 return -EAGAIN;
1890
1891         delayed_node = btrfs_get_or_create_delayed_node(inode);
1892         if (IS_ERR(delayed_node))
1893                 return PTR_ERR(delayed_node);
1894
1895         /*
1896          * We don't reserve space for inode ref deletion is because:
1897          * - We ONLY do async inode ref deletion for the inode who has only
1898          *   one link(i_nlink == 1), it means there is only one inode ref.
1899          *   And in most case, the inode ref and the inode item are in the
1900          *   same leaf, and we will deal with them at the same time.
1901          *   Since we are sure we will reserve the space for the inode item,
1902          *   it is unnecessary to reserve space for inode ref deletion.
1903          * - If the inode ref and the inode item are not in the same leaf,
1904          *   We also needn't worry about enospc problem, because we reserve
1905          *   much more space for the inode update than it needs.
1906          * - At the worst, we can steal some space from the global reservation.
1907          *   It is very rare.
1908          */
1909         mutex_lock(&delayed_node->mutex);
1910         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1911                 goto release_node;
1912
1913         set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1914         delayed_node->count++;
1915         atomic_inc(&fs_info->delayed_root->items);
1916 release_node:
1917         mutex_unlock(&delayed_node->mutex);
1918         btrfs_release_delayed_node(delayed_node);
1919         return 0;
1920 }
1921
1922 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1923 {
1924         struct btrfs_root *root = delayed_node->root;
1925         struct btrfs_fs_info *fs_info = root->fs_info;
1926         struct btrfs_delayed_item *curr_item, *prev_item;
1927
1928         mutex_lock(&delayed_node->mutex);
1929         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1930         while (curr_item) {
1931                 btrfs_delayed_item_release_metadata(root, curr_item);
1932                 prev_item = curr_item;
1933                 curr_item = __btrfs_next_delayed_item(prev_item);
1934                 btrfs_release_delayed_item(prev_item);
1935         }
1936
1937         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1938         while (curr_item) {
1939                 btrfs_delayed_item_release_metadata(root, curr_item);
1940                 prev_item = curr_item;
1941                 curr_item = __btrfs_next_delayed_item(prev_item);
1942                 btrfs_release_delayed_item(prev_item);
1943         }
1944
1945         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1946                 btrfs_release_delayed_iref(delayed_node);
1947
1948         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1949                 btrfs_delayed_inode_release_metadata(fs_info, delayed_node, false);
1950                 btrfs_release_delayed_inode(delayed_node);
1951         }
1952         mutex_unlock(&delayed_node->mutex);
1953 }
1954
1955 void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)
1956 {
1957         struct btrfs_delayed_node *delayed_node;
1958
1959         delayed_node = btrfs_get_delayed_node(inode);
1960         if (!delayed_node)
1961                 return;
1962
1963         __btrfs_kill_delayed_node(delayed_node);
1964         btrfs_release_delayed_node(delayed_node);
1965 }
1966
1967 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1968 {
1969         u64 inode_id = 0;
1970         struct btrfs_delayed_node *delayed_nodes[8];
1971         int i, n;
1972
1973         while (1) {
1974                 spin_lock(&root->inode_lock);
1975                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1976                                            (void **)delayed_nodes, inode_id,
1977                                            ARRAY_SIZE(delayed_nodes));
1978                 if (!n) {
1979                         spin_unlock(&root->inode_lock);
1980                         break;
1981                 }
1982
1983                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1984                 for (i = 0; i < n; i++) {
1985                         /*
1986                          * Don't increase refs in case the node is dead and
1987                          * about to be removed from the tree in the loop below
1988                          */
1989                         if (!refcount_inc_not_zero(&delayed_nodes[i]->refs))
1990                                 delayed_nodes[i] = NULL;
1991                 }
1992                 spin_unlock(&root->inode_lock);
1993
1994                 for (i = 0; i < n; i++) {
1995                         if (!delayed_nodes[i])
1996                                 continue;
1997                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1998                         btrfs_release_delayed_node(delayed_nodes[i]);
1999                 }
2000         }
2001 }
2002
2003 void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
2004 {
2005         struct btrfs_delayed_node *curr_node, *prev_node;
2006
2007         curr_node = btrfs_first_delayed_node(fs_info->delayed_root);
2008         while (curr_node) {
2009                 __btrfs_kill_delayed_node(curr_node);
2010
2011                 prev_node = curr_node;
2012                 curr_node = btrfs_next_delayed_node(curr_node);
2013                 btrfs_release_delayed_node(prev_node);
2014         }
2015 }
2016