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