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 #include "locking.h"
  17
  18 #define BTRFS_DELAYED_WRITEBACK         512
  19 #define BTRFS_DELAYED_BACKGROUND        128
  20 #define BTRFS_DELAYED_BATCH             16
  21
  22 static struct kmem_cache *delayed_node_cache;
  23
  24 int __init btrfs_delayed_inode_init(void)
  25 {
  26         delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
  27                                         sizeof(struct btrfs_delayed_node),
  28                                         0,
  29                                         SLAB_MEM_SPREAD,
  30                                         NULL);
  31         if (!delayed_node_cache)
  32                 return -ENOMEM;
  33         return 0;
  34 }
  35
  36 void __cold btrfs_delayed_inode_exit(void)
  37 {
  38         kmem_cache_destroy(delayed_node_cache);
  39 }
  40
  41 static inline void btrfs_init_delayed_node(
  42                                 struct btrfs_delayed_node *delayed_node,
  43                                 struct btrfs_root *root, u64 inode_id)
  44 {
  45         delayed_node->root = root;
  46         delayed_node->inode_id = inode_id;
  47         refcount_set(&delayed_node->refs, 0);
  48         delayed_node->ins_root = RB_ROOT_CACHED;
  49         delayed_node->del_root = RB_ROOT_CACHED;
  50         mutex_init(&delayed_node->mutex);
  51         INIT_LIST_HEAD(&delayed_node->n_list);
  52         INIT_LIST_HEAD(&delayed_node->p_list);
  53 }
  54
  55 static inline int btrfs_is_continuous_delayed_item(
  56                                         struct btrfs_delayed_item *item1,
  57                                         struct btrfs_delayed_item *item2)
  58 {
  59         if (item1->key.type == BTRFS_DIR_INDEX_KEY &&
  60             item1->key.objectid == item2->key.objectid &&
  61             item1->key.type == item2->key.type &&
  62             item1->key.offset + 1 == item2->key.offset)
  63                 return 1;
  64         return 0;
  65 }
  66
  67 static struct btrfs_delayed_node *btrfs_get_delayed_node(
  68                 struct btrfs_inode *btrfs_inode)
  69 {
  70         struct btrfs_root *root = btrfs_inode->root;
  71         u64 ino = btrfs_ino(btrfs_inode);
  72         struct btrfs_delayed_node *node;
  73
  74         node = READ_ONCE(btrfs_inode->delayed_node);
  75         if (node) {
  76                 refcount_inc(&node->refs);
  77                 return node;
  78         }
  79
  80         spin_lock(&root->inode_lock);
  81         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
  82
  83         if (node) {
  84                 if (btrfs_inode->delayed_node) {
  85                         refcount_inc(&node->refs);      /* can be accessed */
  86                         BUG_ON(btrfs_inode->delayed_node != node);
  87                         spin_unlock(&root->inode_lock);
  88                         return node;
  89                 }
  90
  91                 /*
  92                  * It's possible that we're racing into the middle of removing
  93                  * this node from the radix tree.  In this case, the refcount
  94                  * was zero and it should never go back to one.  Just return
  95                  * NULL like it was never in the radix at all; our release
  96                  * function is in the process of removing it.
  97                  *
  98                  * Some implementations of refcount_inc refuse to bump the
  99                  * refcount once it has hit zero.  If we don't do this dance
 100                  * here, refcount_inc() may decide to just WARN_ONCE() instead
 101                  * of actually bumping the refcount.
 102                  *
 103                  * If this node is properly in the radix, we want to bump the
 104                  * refcount twice, once for the inode and once for this get
 105                  * operation.
 106                  */
 107                 if (refcount_inc_not_zero(&node->refs)) {
 108                         refcount_inc(&node->refs);
 109                         btrfs_inode->delayed_node = node;
 110                 } else {
 111                         node = NULL;
 112                 }
 113
 114                 spin_unlock(&root->inode_lock);
 115                 return node;
 116         }
 117         spin_unlock(&root->inode_lock);
 118
 119         return NULL;
 120 }
 121
 122 /* Will return either the node or PTR_ERR(-ENOMEM) */
 123 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
 124                 struct btrfs_inode *btrfs_inode)
 125 {
 126         struct btrfs_delayed_node *node;
 127         struct btrfs_root *root = btrfs_inode->root;
 128         u64 ino = btrfs_ino(btrfs_inode);
 129         int ret;
 130
 131 again:
 132         node = btrfs_get_delayed_node(btrfs_inode);
 133         if (node)
 134                 return node;
 135
 136         node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
 137         if (!node)
 138                 return ERR_PTR(-ENOMEM);
 139         btrfs_init_delayed_node(node, root, ino);
 140
 141         /* cached in the btrfs inode and can be accessed */
 142         refcount_set(&node->refs, 2);
 143
 144         ret = radix_tree_preload(GFP_NOFS);
 145         if (ret) {
 146                 kmem_cache_free(delayed_node_cache, node);
 147                 return ERR_PTR(ret);
 148         }
 149
 150         spin_lock(&root->inode_lock);
 151         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
 152         if (ret == -EEXIST) {
 153                 spin_unlock(&root->inode_lock);
 154                 kmem_cache_free(delayed_node_cache, node);
 155                 radix_tree_preload_end();
 156                 goto again;
 157         }
 158         btrfs_inode->delayed_node = node;
 159         spin_unlock(&root->inode_lock);
 160         radix_tree_preload_end();
 161
 162         return node;
 163 }
 164
 165 /*
 166  * Call it when holding delayed_node->mutex
 167  *
 168  * If mod = 1, add this node into the prepared list.
 169  */
 170 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
 171                                      struct btrfs_delayed_node *node,
 172                                      int mod)
 173 {
 174         spin_lock(&root->lock);
 175         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 176                 if (!list_empty(&node->p_list))
 177                         list_move_tail(&node->p_list, &root->prepare_list);
 178                 else if (mod)
 179                         list_add_tail(&node->p_list, &root->prepare_list);
 180         } else {
 181                 list_add_tail(&node->n_list, &root->node_list);
 182                 list_add_tail(&node->p_list, &root->prepare_list);
 183                 refcount_inc(&node->refs);      /* inserted into list */
 184                 root->nodes++;
 185                 set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 186         }
 187         spin_unlock(&root->lock);
 188 }
 189
 190 /* Call it when holding delayed_node->mutex */
 191 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
 192                                        struct btrfs_delayed_node *node)
 193 {
 194         spin_lock(&root->lock);
 195         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 196                 root->nodes--;
 197                 refcount_dec(&node->refs);      /* not in the list */
 198                 list_del_init(&node->n_list);
 199                 if (!list_empty(&node->p_list))
 200                         list_del_init(&node->p_list);
 201                 clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
 202         }
 203         spin_unlock(&root->lock);
 204 }
 205
 206 static struct btrfs_delayed_node *btrfs_first_delayed_node(
 207                         struct btrfs_delayed_root *delayed_root)
 208 {
 209         struct list_head *p;
 210         struct btrfs_delayed_node *node = NULL;
 211
 212         spin_lock(&delayed_root->lock);
 213         if (list_empty(&delayed_root->node_list))
 214                 goto out;
 215
 216         p = delayed_root->node_list.next;
 217         node = list_entry(p, struct btrfs_delayed_node, n_list);
 218         refcount_inc(&node->refs);
 219 out:
 220         spin_unlock(&delayed_root->lock);
 221
 222         return node;
 223 }
 224
 225 static struct btrfs_delayed_node *btrfs_next_delayed_node(
 226                                                 struct btrfs_delayed_node *node)
 227 {
 228         struct btrfs_delayed_root *delayed_root;
 229         struct list_head *p;
 230         struct btrfs_delayed_node *next = NULL;
 231
 232         delayed_root = node->root->fs_info->delayed_root;
 233         spin_lock(&delayed_root->lock);
 234         if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
 235                 /* not in the list */
 236                 if (list_empty(&delayed_root->node_list))
 237                         goto out;
 238                 p = delayed_root->node_list.next;
 239         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
 240                 goto out;
 241         else
 242                 p = node->n_list.next;
 243
 244         next = list_entry(p, struct btrfs_delayed_node, n_list);
 245         refcount_inc(&next->refs);
 246 out:
 247         spin_unlock(&delayed_root->lock);
 248
 249         return next;
 250 }
 251
 252 static void __btrfs_release_delayed_node(
 253                                 struct btrfs_delayed_node *delayed_node,
 254                                 int mod)
 255 {
 256         struct btrfs_delayed_root *delayed_root;
 257
 258         if (!delayed_node)
 259                 return;
 260
 261         delayed_root = delayed_node->root->fs_info->delayed_root;
 262
 263         mutex_lock(&delayed_node->mutex);
 264         if (delayed_node->count)
 265                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
 266         else
 267                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
 268         mutex_unlock(&delayed_node->mutex);
 269
 270         if (refcount_dec_and_test(&delayed_node->refs)) {
 271                 struct btrfs_root *root = delayed_node->root;
 272
 273                 spin_lock(&root->inode_lock);
 274                 /*
 275                  * Once our refcount goes to zero, nobody is allowed to bump it
 276                  * back up.  We can delete it now.
 277                  */
 278                 ASSERT(refcount_read(&delayed_node->refs) == 0);
 279                 radix_tree_delete(&root->delayed_nodes_tree,
 280                                   delayed_node->inode_id);
 281                 spin_unlock(&root->inode_lock);
 282                 kmem_cache_free(delayed_node_cache, delayed_node);
 283         }
 284 }
 285
 286 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 287 {
 288         __btrfs_release_delayed_node(node, 0);
 289 }
 290
 291 static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
 292                                         struct btrfs_delayed_root *delayed_root)
 293 {
 294         struct list_head *p;
 295         struct btrfs_delayed_node *node = NULL;
 296
 297         spin_lock(&delayed_root->lock);
 298         if (list_empty(&delayed_root->prepare_list))
 299                 goto out;
 300
 301         p = delayed_root->prepare_list.next;
 302         list_del_init(p);
 303         node = list_entry(p, struct btrfs_delayed_node, p_list);
 304         refcount_inc(&node->refs);
 305 out:
 306         spin_unlock(&delayed_root->lock);
 307
 308         return node;
 309 }
 310
 311 static inline void btrfs_release_prepared_delayed_node(
 312                                         struct btrfs_delayed_node *node)
 313 {
 314         __btrfs_release_delayed_node(node, 1);
 315 }
 316
 317 static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
 318 {
 319         struct btrfs_delayed_item *item;
 320         item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
 321         if (item) {
 322                 item->data_len = data_len;
 323                 item->ins_or_del = 0;
 324                 item->bytes_reserved = 0;
 325                 item->delayed_node = NULL;
 326                 refcount_set(&item->refs, 1);
 327         }
 328         return item;
 329 }
 330
 331 /*
 332  * __btrfs_lookup_delayed_item - look up the delayed item by key
 333  * @delayed_node: pointer to the delayed node
 334  * @key:          the key to look up
 335  * @prev:         used to store the prev item if the right item isn't found
 336  * @next:         used to store the next item if the right item isn't found
 337  *
 338  * Note: if we don't find the right item, we will return the prev item and
 339  * the next item.
 340  */
 341 static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
 342                                 struct rb_root *root,
 343                                 struct btrfs_key *key,
 344                                 struct btrfs_delayed_item **prev,
 345                                 struct btrfs_delayed_item **next)
 346 {
 347         struct rb_node *node, *prev_node = NULL;
 348         struct btrfs_delayed_item *delayed_item = NULL;
 349         int ret = 0;
 350
 351         node = root->rb_node;
 352
 353         while (node) {
 354                 delayed_item = rb_entry(node, struct btrfs_delayed_item,
 355                                         rb_node);
 356                 prev_node = node;
 357                 ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
 358                 if (ret < 0)
 359                         node = node->rb_right;
 360                 else if (ret > 0)
 361                         node = node->rb_left;
 362                 else
 363                         return delayed_item;
 364         }
 365
 366         if (prev) {
 367                 if (!prev_node)
 368                         *prev = NULL;
 369                 else if (ret < 0)
 370                         *prev = delayed_item;
 371                 else if ((node = rb_prev(prev_node)) != NULL) {
 372                         *prev = rb_entry(node, struct btrfs_delayed_item,
 373                                          rb_node);
 374                 } else
 375                         *prev = NULL;
 376         }
 377
 378         if (next) {
 379                 if (!prev_node)
 380                         *next = NULL;
 381                 else if (ret > 0)
 382                         *next = delayed_item;
 383                 else if ((node = rb_next(prev_node)) != NULL) {
 384                         *next = rb_entry(node, struct btrfs_delayed_item,
 385                                          rb_node);
 386                 } else
 387                         *next = NULL;
 388         }
 389         return NULL;
 390 }
 391
 392 static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
 393                                         struct btrfs_delayed_node *delayed_node,
 394                                         struct btrfs_key *key)
 395 {
 396         return __btrfs_lookup_delayed_item(&delayed_node->ins_root.rb_root, key,
 397                                            NULL, NULL);
 398 }
 399
 400 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 401                                     struct btrfs_delayed_item *ins,
 402                                     int action)
 403 {
 404         struct rb_node **p, *node;
 405         struct rb_node *parent_node = NULL;
 406         struct rb_root_cached *root;
 407         struct btrfs_delayed_item *item;
 408         int cmp;
 409         bool leftmost = true;
 410
 411         if (action == BTRFS_DELAYED_INSERTION_ITEM)
 412                 root = &delayed_node->ins_root;
 413         else if (action == BTRFS_DELAYED_DELETION_ITEM)
 414                 root = &delayed_node->del_root;
 415         else
 416                 BUG();
 417         p = &root->rb_root.rb_node;
 418         node = &ins->rb_node;
 419
 420         while (*p) {
 421                 parent_node = *p;
 422                 item = rb_entry(parent_node, struct btrfs_delayed_item,
 423                                  rb_node);
 424
 425                 cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
 426                 if (cmp < 0) {
 427                         p = &(*p)->rb_right;
 428                         leftmost = false;
 429                 } else if (cmp > 0) {
 430                         p = &(*p)->rb_left;
 431                 } else {
 432                         return -EEXIST;
 433                 }
 434         }
 435
 436         rb_link_node(node, parent_node, p);
 437         rb_insert_color_cached(node, root, leftmost);
 438         ins->delayed_node = delayed_node;
 439         ins->ins_or_del = action;
 440
 441         if (ins->key.type == BTRFS_DIR_INDEX_KEY &&
 442             action == BTRFS_DELAYED_INSERTION_ITEM &&
 443             ins->key.offset >= delayed_node->index_cnt)
 444                         delayed_node->index_cnt = ins->key.offset + 1;
 445
 446         delayed_node->count++;
 447         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
 448         return 0;
 449 }
 450
 451 static int __btrfs_add_delayed_insertion_item(struct btrfs_delayed_node *node,
 452                                               struct btrfs_delayed_item *item)
 453 {
 454         return __btrfs_add_delayed_item(node, item,
 455                                         BTRFS_DELAYED_INSERTION_ITEM);
 456 }
 457
 458 static int __btrfs_add_delayed_deletion_item(struct btrfs_delayed_node *node,
 459                                              struct btrfs_delayed_item *item)
 460 {
 461         return __btrfs_add_delayed_item(node, item,
 462                                         BTRFS_DELAYED_DELETION_ITEM);
 463 }
 464
 465 static void finish_one_item(struct btrfs_delayed_root *delayed_root)
 466 {
 467         int seq = atomic_inc_return(&delayed_root->items_seq);
 468
 469         /* atomic_dec_return implies a barrier */
 470         if ((atomic_dec_return(&delayed_root->items) <
 471             BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))
 472                 cond_wake_up_nomb(&delayed_root->wait);
 473 }
 474
 475 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 476 {
 477         struct rb_root_cached *root;
 478         struct btrfs_delayed_root *delayed_root;
 479
 480         /* Not associated with any delayed_node */
 481         if (!delayed_item->delayed_node)
 482                 return;
 483         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 484
 485         BUG_ON(!delayed_root);
 486         BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
 487                delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
 488
 489         if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
 490                 root = &delayed_item->delayed_node->ins_root;
 491         else
 492                 root = &delayed_item->delayed_node->del_root;
 493
 494         rb_erase_cached(&delayed_item->rb_node, root);
 495         delayed_item->delayed_node->count--;
 496
 497         finish_one_item(delayed_root);
 498 }
 499
 500 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 501 {
 502         if (item) {
 503                 __btrfs_remove_delayed_item(item);
 504                 if (refcount_dec_and_test(&item->refs))
 505                         kfree(item);
 506         }
 507 }
 508
 509 static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 510                                         struct btrfs_delayed_node *delayed_node)
 511 {
 512         struct rb_node *p;
 513         struct btrfs_delayed_item *item = NULL;
 514
 515         p = rb_first_cached(&delayed_node->ins_root);
 516         if (p)
 517                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 518
 519         return item;
 520 }
 521
 522 static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 523                                         struct btrfs_delayed_node *delayed_node)
 524 {
 525         struct rb_node *p;
 526         struct btrfs_delayed_item *item = NULL;
 527
 528         p = rb_first_cached(&delayed_node->del_root);
 529         if (p)
 530                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 531
 532         return item;
 533 }
 534
 535 static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 536                                                 struct btrfs_delayed_item *item)
 537 {
 538         struct rb_node *p;
 539         struct btrfs_delayed_item *next = NULL;
 540
 541         p = rb_next(&item->rb_node);
 542         if (p)
 543                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 544
 545         return next;
 546 }
 547
 548 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 549                                                struct btrfs_root *root,
 550                                                struct btrfs_delayed_item *item)
 551 {
 552         struct btrfs_block_rsv *src_rsv;
 553         struct btrfs_block_rsv *dst_rsv;
 554         struct btrfs_fs_info *fs_info = root->fs_info;
 555         u64 num_bytes;
 556         int ret;
 557
 558         if (!trans->bytes_reserved)
 559                 return 0;
 560
 561         src_rsv = trans->block_rsv;
 562         dst_rsv = &fs_info->delayed_block_rsv;
 563
 564         num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 565
 566         /*
 567          * Here we migrate space rsv from transaction rsv, since have already
 568          * reserved space when starting a transaction.  So no need to reserve
 569          * qgroup space here.
 570          */
 571         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 572         if (!ret) {
 573                 trace_btrfs_space_reservation(fs_info, "delayed_item",
 574                                               item->key.objectid,
 575                                               num_bytes, 1);
 576                 item->bytes_reserved = num_bytes;
 577         }
 578
 579         return ret;
 580 }
 581
 582 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
 583                                                 struct btrfs_delayed_item *item)
 584 {
 585         struct btrfs_block_rsv *rsv;
 586         struct btrfs_fs_info *fs_info = root->fs_info;
 587
 588         if (!item->bytes_reserved)
 589                 return;
 590
 591         rsv = &fs_info->delayed_block_rsv;
 592         /*
 593          * Check btrfs_delayed_item_reserve_metadata() to see why we don't need
 594          * to release/reserve qgroup space.
 595          */
 596         trace_btrfs_space_reservation(fs_info, "delayed_item",
 597                                       item->key.objectid, item->bytes_reserved,
 598                                       0);
 599         btrfs_block_rsv_release(fs_info, rsv, item->bytes_reserved, NULL);
 600 }
 601
 602 static int btrfs_delayed_inode_reserve_metadata(
 603                                         struct btrfs_trans_handle *trans,
 604                                         struct btrfs_root *root,
 605                                         struct btrfs_delayed_node *node)
 606 {
 607         struct btrfs_fs_info *fs_info = root->fs_info;
 608         struct btrfs_block_rsv *src_rsv;
 609         struct btrfs_block_rsv *dst_rsv;
 610         u64 num_bytes;
 611         int ret;
 612
 613         src_rsv = trans->block_rsv;
 614         dst_rsv = &fs_info->delayed_block_rsv;
 615
 616         num_bytes = btrfs_calc_metadata_size(fs_info, 1);
 617
 618         /*
 619          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
 620          * which doesn't reserve space for speed.  This is a problem since we
 621          * still need to reserve space for this update, so try to reserve the
 622          * space.
 623          *
 624          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
 625          * we always reserve enough to update the inode item.
 626          */
 627         if (!src_rsv || (!trans->bytes_reserved &&
 628                          src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
 629                 ret = btrfs_qgroup_reserve_meta(root, num_bytes,
 630                                           BTRFS_QGROUP_RSV_META_PREALLOC, true);
 631                 if (ret < 0)
 632                         return ret;
 633                 ret = btrfs_block_rsv_add(root, dst_rsv, num_bytes,
 634                                           BTRFS_RESERVE_NO_FLUSH);
 635                 /* NO_FLUSH could only fail with -ENOSPC */
 636                 ASSERT(ret == 0 || ret == -ENOSPC);
 637                 if (ret)
 638                         btrfs_qgroup_free_meta_prealloc(root, num_bytes);
 639         } else {
 640                 ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 641         }
 642
 643         if (!ret) {
 644                 trace_btrfs_space_reservation(fs_info, "delayed_inode",
 645                                               node->inode_id, num_bytes, 1);
 646                 node->bytes_reserved = num_bytes;
 647         }
 648
 649         return ret;
 650 }
 651
 652 static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
 653                                                 struct btrfs_delayed_node *node,
 654                                                 bool qgroup_free)
 655 {
 656         struct btrfs_block_rsv *rsv;
 657
 658         if (!node->bytes_reserved)
 659                 return;
 660
 661         rsv = &fs_info->delayed_block_rsv;
 662         trace_btrfs_space_reservation(fs_info, "delayed_inode",
 663                                       node->inode_id, node->bytes_reserved, 0);
 664         btrfs_block_rsv_release(fs_info, rsv, node->bytes_reserved, NULL);
 665         if (qgroup_free)
 666                 btrfs_qgroup_free_meta_prealloc(node->root,
 667                                 node->bytes_reserved);
 668         else
 669                 btrfs_qgroup_convert_reserved_meta(node->root,
 670                                 node->bytes_reserved);
 671         node->bytes_reserved = 0;
 672 }
 673
 674 /*
 675  * This helper will insert some continuous items into the same leaf according
 676  * to the free space of the leaf.
 677  */
 678 static int btrfs_batch_insert_items(struct btrfs_root *root,
 679                                     struct btrfs_path *path,
 680                                     struct btrfs_delayed_item *item)
 681 {
 682         struct btrfs_delayed_item *curr, *next;
 683         int free_space;
 684         int total_size = 0;
 685         struct extent_buffer *leaf;
 686         char *data_ptr;
 687         struct btrfs_key *keys;
 688         u32 *data_size;
 689         struct list_head head;
 690         int slot;
 691         int nitems;
 692         int i;
 693         int ret = 0;
 694
 695         BUG_ON(!path->nodes[0]);
 696
 697         leaf = path->nodes[0];
 698         free_space = btrfs_leaf_free_space(leaf);
 699         INIT_LIST_HEAD(&head);
 700
 701         next = item;
 702         nitems = 0;
 703
 704         /*
 705          * count the number of the continuous items that we can insert in batch
 706          */
 707         while (total_size + next->data_len + sizeof(struct btrfs_item) <=
 708                free_space) {
 709                 total_size += next->data_len + sizeof(struct btrfs_item);
 710                 list_add_tail(&next->tree_list, &head);
 711                 nitems++;
 712
 713                 curr = next;
 714                 next = __btrfs_next_delayed_item(curr);
 715                 if (!next)
 716                         break;
 717
 718                 if (!btrfs_is_continuous_delayed_item(curr, next))
 719                         break;
 720         }
 721
 722         if (!nitems) {
 723                 ret = 0;
 724                 goto out;
 725         }
 726
 727         keys = kmalloc_array(nitems, sizeof(struct btrfs_key), GFP_NOFS);
 728         if (!keys) {
 729                 ret = -ENOMEM;
 730                 goto out;
 731         }
 732
 733         data_size = kmalloc_array(nitems, sizeof(u32), GFP_NOFS);
 734         if (!data_size) {
 735                 ret = -ENOMEM;
 736                 goto error;
 737         }
 738
 739         /* get keys of all the delayed items */
 740         i = 0;
 741         list_for_each_entry(next, &head, tree_list) {
 742                 keys[i] = next->key;
 743                 data_size[i] = next->data_len;
 744                 i++;
 745         }
 746
 747         /* insert the keys of the items */
 748         setup_items_for_insert(root, path, keys, data_size, nitems);
 749
 750         /* insert the dir index items */
 751         slot = path->slots[0];
 752         list_for_each_entry_safe(curr, next, &head, tree_list) {
 753                 data_ptr = btrfs_item_ptr(leaf, slot, char);
 754                 write_extent_buffer(leaf, &curr->data,
 755                                     (unsigned long)data_ptr,
 756                                     curr->data_len);
 757                 slot++;
 758
 759                 btrfs_delayed_item_release_metadata(root, curr);
 760
 761                 list_del(&curr->tree_list);
 762                 btrfs_release_delayed_item(curr);
 763         }
 764
 765 error:
 766         kfree(data_size);
 767         kfree(keys);
 768 out:
 769         return ret;
 770 }
 771
 772 /*
 773  * This helper can just do simple insertion that needn't extend item for new
 774  * data, such as directory name index insertion, inode insertion.
 775  */
 776 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 777                                      struct btrfs_root *root,
 778                                      struct btrfs_path *path,
 779                                      struct btrfs_delayed_item *delayed_item)
 780 {
 781         struct extent_buffer *leaf;
 782         unsigned int nofs_flag;
 783         char *ptr;
 784         int ret;
 785
 786         nofs_flag = memalloc_nofs_save();
 787         ret = btrfs_insert_empty_item(trans, root, path, &delayed_item->key,
 788                                       delayed_item->data_len);
 789         memalloc_nofs_restore(nofs_flag);
 790         if (ret < 0 && ret != -EEXIST)
 791                 return ret;
 792
 793         leaf = path->nodes[0];
 794
 795         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
 796
 797         write_extent_buffer(leaf, delayed_item->data, (unsigned long)ptr,
 798                             delayed_item->data_len);
 799         btrfs_mark_buffer_dirty(leaf);
 800
 801         btrfs_delayed_item_release_metadata(root, delayed_item);
 802         return 0;
 803 }
 804
 805 /*
 806  * we insert an item first, then if there are some continuous items, we try
 807  * to insert those items into the same leaf.
 808  */
 809 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
 810                                       struct btrfs_path *path,
 811                                       struct btrfs_root *root,
 812                                       struct btrfs_delayed_node *node)
 813 {
 814         struct btrfs_delayed_item *curr, *prev;
 815         int ret = 0;
 816
 817 do_again:
 818         mutex_lock(&node->mutex);
 819         curr = __btrfs_first_delayed_insertion_item(node);
 820         if (!curr)
 821                 goto insert_end;
 822
 823         ret = btrfs_insert_delayed_item(trans, root, path, curr);
 824         if (ret < 0) {
 825                 btrfs_release_path(path);
 826                 goto insert_end;
 827         }
 828
 829         prev = curr;
 830         curr = __btrfs_next_delayed_item(prev);
 831         if (curr && btrfs_is_continuous_delayed_item(prev, curr)) {
 832                 /* insert the continuous items into the same leaf */
 833                 path->slots[0]++;
 834                 btrfs_batch_insert_items(root, path, curr);
 835         }
 836         btrfs_release_delayed_item(prev);
 837         btrfs_mark_buffer_dirty(path->nodes[0]);
 838
 839         btrfs_release_path(path);
 840         mutex_unlock(&node->mutex);
 841         goto do_again;
 842
 843 insert_end:
 844         mutex_unlock(&node->mutex);
 845         return ret;
 846 }
 847
 848 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
 849                                     struct btrfs_root *root,
 850                                     struct btrfs_path *path,
 851                                     struct btrfs_delayed_item *item)
 852 {
 853         struct btrfs_delayed_item *curr, *next;
 854         struct extent_buffer *leaf;
 855         struct btrfs_key key;
 856         struct list_head head;
 857         int nitems, i, last_item;
 858         int ret = 0;
 859
 860         BUG_ON(!path->nodes[0]);
 861
 862         leaf = path->nodes[0];
 863
 864         i = path->slots[0];
 865         last_item = btrfs_header_nritems(leaf) - 1;
 866         if (i > last_item)
 867                 return -ENOENT; /* FIXME: Is errno suitable? */
 868
 869         next = item;
 870         INIT_LIST_HEAD(&head);
 871         btrfs_item_key_to_cpu(leaf, &key, i);
 872         nitems = 0;
 873         /*
 874          * count the number of the dir index items that we can delete in batch
 875          */
 876         while (btrfs_comp_cpu_keys(&next->key, &key) == 0) {
 877                 list_add_tail(&next->tree_list, &head);
 878                 nitems++;
 879
 880                 curr = next;
 881                 next = __btrfs_next_delayed_item(curr);
 882                 if (!next)
 883                         break;
 884
 885                 if (!btrfs_is_continuous_delayed_item(curr, next))
 886                         break;
 887
 888                 i++;
 889                 if (i > last_item)
 890                         break;
 891                 btrfs_item_key_to_cpu(leaf, &key, i);
 892         }
 893
 894         if (!nitems)
 895                 return 0;
 896
 897         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
 898         if (ret)
 899                 goto out;
 900
 901         list_for_each_entry_safe(curr, next, &head, tree_list) {
 902                 btrfs_delayed_item_release_metadata(root, curr);
 903                 list_del(&curr->tree_list);
 904                 btrfs_release_delayed_item(curr);
 905         }
 906
 907 out:
 908         return ret;
 909 }
 910
 911 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
 912                                       struct btrfs_path *path,
 913                                       struct btrfs_root *root,
 914                                       struct btrfs_delayed_node *node)
 915 {
 916         struct btrfs_delayed_item *curr, *prev;
 917         unsigned int nofs_flag;
 918         int ret = 0;
 919
 920 do_again:
 921         mutex_lock(&node->mutex);
 922         curr = __btrfs_first_delayed_deletion_item(node);
 923         if (!curr)
 924                 goto delete_fail;
 925
 926         nofs_flag = memalloc_nofs_save();
 927         ret = btrfs_search_slot(trans, root, &curr->key, path, -1, 1);
 928         memalloc_nofs_restore(nofs_flag);
 929         if (ret < 0)
 930                 goto delete_fail;
 931         else if (ret > 0) {
 932                 /*
 933                  * can't find the item which the node points to, so this node
 934                  * is invalid, just drop it.
 935                  */
 936                 prev = curr;
 937                 curr = __btrfs_next_delayed_item(prev);
 938                 btrfs_release_delayed_item(prev);
 939                 ret = 0;
 940                 btrfs_release_path(path);
 941                 if (curr) {
 942                         mutex_unlock(&node->mutex);
 943                         goto do_again;
 944                 } else
 945                         goto delete_fail;
 946         }
 947
 948         btrfs_batch_delete_items(trans, root, path, curr);
 949         btrfs_release_path(path);
 950         mutex_unlock(&node->mutex);
 951         goto do_again;
 952
 953 delete_fail:
 954         btrfs_release_path(path);
 955         mutex_unlock(&node->mutex);
 956         return ret;
 957 }
 958
 959 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
 960 {
 961         struct btrfs_delayed_root *delayed_root;
 962
 963         if (delayed_node &&
 964             test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
 965                 BUG_ON(!delayed_node->root);
 966                 clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
 967                 delayed_node->count--;
 968
 969                 delayed_root = delayed_node->root->fs_info->delayed_root;
 970                 finish_one_item(delayed_root);
 971         }
 972 }
 973
 974 static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
 975 {
 976
 977         if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags)) {
 978                 struct btrfs_delayed_root *delayed_root;
 979
 980                 ASSERT(delayed_node->root);
 981                 delayed_node->count--;
 982
 983                 delayed_root = delayed_node->root->fs_info->delayed_root;
 984                 finish_one_item(delayed_root);
 985         }
 986 }
 987
 988 static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
 989                                         struct btrfs_root *root,
 990                                         struct btrfs_path *path,
 991                                         struct btrfs_delayed_node *node)
 992 {
 993         struct btrfs_fs_info *fs_info = root->fs_info;
 994         struct btrfs_key key;
 995         struct btrfs_inode_item *inode_item;
 996         struct extent_buffer *leaf;
 997         unsigned int nofs_flag;
 998         int mod;
 999         int ret;
1000
1001         key.objectid = node->inode_id;
1002         key.type = BTRFS_INODE_ITEM_KEY;
1003         key.offset = 0;
1004
1005         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1006                 mod = -1;
1007         else
1008                 mod = 1;
1009
1010         nofs_flag = memalloc_nofs_save();
1011         ret = btrfs_lookup_inode(trans, root, path, &key, mod);
1012         memalloc_nofs_restore(nofs_flag);
1013         if (ret > 0)
1014                 ret = -ENOENT;
1015         if (ret < 0)
1016                 goto out;
1017
1018         leaf = path->nodes[0];
1019         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1020                                     struct btrfs_inode_item);
1021         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
1022                             sizeof(struct btrfs_inode_item));
1023         btrfs_mark_buffer_dirty(leaf);
1024
1025         if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
1026                 goto out;
1027
1028         path->slots[0]++;
1029         if (path->slots[0] >= btrfs_header_nritems(leaf))
1030                 goto search;
1031 again:
1032         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1033         if (key.objectid != node->inode_id)
1034                 goto out;
1035
1036         if (key.type != BTRFS_INODE_REF_KEY &&
1037             key.type != BTRFS_INODE_EXTREF_KEY)
1038                 goto out;
1039
1040         /*
1041          * Delayed iref deletion is for the inode who has only one link,
1042          * so there is only one iref. The case that several irefs are
1043          * in the same item doesn't exist.
1044          */
1045         btrfs_del_item(trans, root, path);
1046 out:
1047         btrfs_release_delayed_iref(node);
1048         btrfs_release_path(path);
1049 err_out:
1050         btrfs_delayed_inode_release_metadata(fs_info, node, (ret < 0));
1051         btrfs_release_delayed_inode(node);
1052
1053         /*
1054          * If we fail to update the delayed inode we need to abort the
1055          * transaction, because we could leave the inode with the improper
1056          * counts behind.
1057          */
1058         if (ret && ret != -ENOENT)
1059                 btrfs_abort_transaction(trans, ret);
1060
1061         return ret;
1062
1063 search:
1064         btrfs_release_path(path);
1065
1066         key.type = BTRFS_INODE_EXTREF_KEY;
1067         key.offset = -1;
1068
1069         nofs_flag = memalloc_nofs_save();
1070         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1071         memalloc_nofs_restore(nofs_flag);
1072         if (ret < 0)
1073                 goto err_out;
1074         ASSERT(ret);
1075
1076         ret = 0;
1077         leaf = path->nodes[0];
1078         path->slots[0]--;
1079         goto again;
1080 }
1081
1082 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
1083                                              struct btrfs_root *root,
1084                                              struct btrfs_path *path,
1085                                              struct btrfs_delayed_node *node)
1086 {
1087         int ret;
1088
1089         mutex_lock(&node->mutex);
1090         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
1091                 mutex_unlock(&node->mutex);
1092                 return 0;
1093         }
1094
1095         ret = __btrfs_update_delayed_inode(trans, root, path, node);
1096         mutex_unlock(&node->mutex);
1097         return ret;
1098 }
1099
1100 static inline int
1101 __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1102                                    struct btrfs_path *path,
1103                                    struct btrfs_delayed_node *node)
1104 {
1105         int ret;
1106
1107         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
1108         if (ret)
1109                 return ret;
1110
1111         ret = btrfs_delete_delayed_items(trans, path, node->root, node);
1112         if (ret)
1113                 return ret;
1114
1115         ret = btrfs_update_delayed_inode(trans, node->root, path, node);
1116         return ret;
1117 }
1118
1119 /*
1120  * Called when committing the transaction.
1121  * Returns 0 on success.
1122  * Returns < 0 on error and returns with an aborted transaction with any
1123  * outstanding delayed items cleaned up.
1124  */
1125 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
1126 {
1127         struct btrfs_fs_info *fs_info = trans->fs_info;
1128         struct btrfs_delayed_root *delayed_root;
1129         struct btrfs_delayed_node *curr_node, *prev_node;
1130         struct btrfs_path *path;
1131         struct btrfs_block_rsv *block_rsv;
1132         int ret = 0;
1133         bool count = (nr > 0);
1134
1135         if (TRANS_ABORTED(trans))
1136                 return -EIO;
1137
1138         path = btrfs_alloc_path();
1139         if (!path)
1140                 return -ENOMEM;
1141
1142         block_rsv = trans->block_rsv;
1143         trans->block_rsv = &fs_info->delayed_block_rsv;
1144
1145         delayed_root = fs_info->delayed_root;
1146
1147         curr_node = btrfs_first_delayed_node(delayed_root);
1148         while (curr_node && (!count || nr--)) {
1149                 ret = __btrfs_commit_inode_delayed_items(trans, path,
1150                                                          curr_node);
1151                 if (ret) {
1152                         btrfs_release_delayed_node(curr_node);
1153                         curr_node = NULL;
1154                         btrfs_abort_transaction(trans, ret);
1155                         break;
1156                 }
1157
1158                 prev_node = curr_node;
1159                 curr_node = btrfs_next_delayed_node(curr_node);
1160                 btrfs_release_delayed_node(prev_node);
1161         }
1162
1163         if (curr_node)
1164                 btrfs_release_delayed_node(curr_node);
1165         btrfs_free_path(path);
1166         trans->block_rsv = block_rsv;
1167
1168         return ret;
1169 }
1170
1171 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)
1172 {
1173         return __btrfs_run_delayed_items(trans, -1);
1174 }
1175
1176 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)
1177 {
1178         return __btrfs_run_delayed_items(trans, nr);
1179 }
1180
1181 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
1182                                      struct btrfs_inode *inode)
1183 {
1184         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1185         struct btrfs_path *path;
1186         struct btrfs_block_rsv *block_rsv;
1187         int ret;
1188
1189         if (!delayed_node)
1190                 return 0;
1191
1192         mutex_lock(&delayed_node->mutex);
1193         if (!delayed_node->count) {
1194                 mutex_unlock(&delayed_node->mutex);
1195                 btrfs_release_delayed_node(delayed_node);
1196                 return 0;
1197         }
1198         mutex_unlock(&delayed_node->mutex);
1199
1200         path = btrfs_alloc_path();
1201         if (!path) {
1202                 btrfs_release_delayed_node(delayed_node);
1203                 return -ENOMEM;
1204         }
1205
1206         block_rsv = trans->block_rsv;
1207         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
1208
1209         ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1210
1211         btrfs_release_delayed_node(delayed_node);
1212         btrfs_free_path(path);
1213         trans->block_rsv = block_rsv;
1214
1215         return ret;
1216 }
1217
1218 int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
1219 {
1220         struct btrfs_fs_info *fs_info = inode->root->fs_info;
1221         struct btrfs_trans_handle *trans;
1222         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1223         struct btrfs_path *path;
1224         struct btrfs_block_rsv *block_rsv;
1225         int ret;
1226
1227         if (!delayed_node)
1228                 return 0;
1229
1230         mutex_lock(&delayed_node->mutex);
1231         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1232                 mutex_unlock(&delayed_node->mutex);
1233                 btrfs_release_delayed_node(delayed_node);
1234                 return 0;
1235         }
1236         mutex_unlock(&delayed_node->mutex);
1237
1238         trans = btrfs_join_transaction(delayed_node->root);
1239         if (IS_ERR(trans)) {
1240                 ret = PTR_ERR(trans);
1241                 goto out;
1242         }
1243
1244         path = btrfs_alloc_path();
1245         if (!path) {
1246                 ret = -ENOMEM;
1247                 goto trans_out;
1248         }
1249
1250         block_rsv = trans->block_rsv;
1251         trans->block_rsv = &fs_info->delayed_block_rsv;
1252
1253         mutex_lock(&delayed_node->mutex);
1254         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
1255                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
1256                                                    path, delayed_node);
1257         else
1258                 ret = 0;
1259         mutex_unlock(&delayed_node->mutex);
1260
1261         btrfs_free_path(path);
1262         trans->block_rsv = block_rsv;
1263 trans_out:
1264         btrfs_end_transaction(trans);
1265         btrfs_btree_balance_dirty(fs_info);
1266 out:
1267         btrfs_release_delayed_node(delayed_node);
1268
1269         return ret;
1270 }
1271
1272 void btrfs_remove_delayed_node(struct btrfs_inode *inode)
1273 {
1274         struct btrfs_delayed_node *delayed_node;
1275
1276         delayed_node = READ_ONCE(inode->delayed_node);
1277         if (!delayed_node)
1278                 return;
1279
1280         inode->delayed_node = NULL;
1281         btrfs_release_delayed_node(delayed_node);
1282 }
1283
1284 struct btrfs_async_delayed_work {
1285         struct btrfs_delayed_root *delayed_root;
1286         int nr;
1287         struct btrfs_work work;
1288 };
1289
1290 static void btrfs_async_run_delayed_root(struct btrfs_work *work)
1291 {
1292         struct btrfs_async_delayed_work *async_work;
1293         struct btrfs_delayed_root *delayed_root;
1294         struct btrfs_trans_handle *trans;
1295         struct btrfs_path *path;
1296         struct btrfs_delayed_node *delayed_node = NULL;
1297         struct btrfs_root *root;
1298         struct btrfs_block_rsv *block_rsv;
1299         int total_done = 0;
1300
1301         async_work = container_of(work, struct btrfs_async_delayed_work, work);
1302         delayed_root = async_work->delayed_root;
1303
1304         path = btrfs_alloc_path();
1305         if (!path)
1306                 goto out;
1307
1308         do {
1309                 if (atomic_read(&delayed_root->items) <
1310                     BTRFS_DELAYED_BACKGROUND / 2)
1311                         break;
1312
1313                 delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
1314                 if (!delayed_node)
1315                         break;
1316
1317                 root = delayed_node->root;
1318
1319                 trans = btrfs_join_transaction(root);
1320                 if (IS_ERR(trans)) {
1321                         btrfs_release_path(path);
1322                         btrfs_release_prepared_delayed_node(delayed_node);
1323                         total_done++;
1324                         continue;
1325                 }
1326
1327                 block_rsv = trans->block_rsv;
1328                 trans->block_rsv = &root->fs_info->delayed_block_rsv;
1329
1330                 __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
1331
1332                 trans->block_rsv = block_rsv;
1333                 btrfs_end_transaction(trans);
1334                 btrfs_btree_balance_dirty_nodelay(root->fs_info);
1335
1336                 btrfs_release_path(path);
1337                 btrfs_release_prepared_delayed_node(delayed_node);
1338                 total_done++;
1339
1340         } while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
1341                  || total_done < async_work->nr);
1342
1343         btrfs_free_path(path);
1344 out:
1345         wake_up(&delayed_root->wait);
1346         kfree(async_work);
1347 }
1348
1349
1350 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
1351                                      struct btrfs_fs_info *fs_info, int nr)
1352 {
1353         struct btrfs_async_delayed_work *async_work;
1354
1355         async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
1356         if (!async_work)
1357                 return -ENOMEM;
1358
1359         async_work->delayed_root = delayed_root;
1360         btrfs_init_work(&async_work->work, btrfs_async_run_delayed_root, NULL,
1361                         NULL);
1362         async_work->nr = nr;
1363
1364         btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
1365         return 0;
1366 }
1367
1368 void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
1369 {
1370         WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));
1371 }
1372
1373 static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
1374 {
1375         int val = atomic_read(&delayed_root->items_seq);
1376
1377         if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
1378                 return 1;
1379
1380         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
1381                 return 1;
1382
1383         return 0;
1384 }
1385
1386 void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
1387 {
1388         struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
1389
1390         if ((atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
1391                 btrfs_workqueue_normal_congested(fs_info->delayed_workers))
1392                 return;
1393
1394         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
1395                 int seq;
1396                 int ret;
1397
1398                 seq = atomic_read(&delayed_root->items_seq);
1399
1400                 ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
1401                 if (ret)
1402                         return;
1403
1404                 wait_event_interruptible(delayed_root->wait,
1405                                          could_end_wait(delayed_root, seq));
1406                 return;
1407         }
1408
1409         btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
1410 }
1411
1412 /* Will return 0 or -ENOMEM */
1413 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
1414                                    const char *name, int name_len,
1415                                    struct btrfs_inode *dir,
1416                                    struct btrfs_disk_key *disk_key, u8 type,
1417                                    u64 index)
1418 {
1419         struct btrfs_delayed_node *delayed_node;
1420         struct btrfs_delayed_item *delayed_item;
1421         struct btrfs_dir_item *dir_item;
1422         int ret;
1423
1424         delayed_node = btrfs_get_or_create_delayed_node(dir);
1425         if (IS_ERR(delayed_node))
1426                 return PTR_ERR(delayed_node);
1427
1428         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
1429         if (!delayed_item) {
1430                 ret = -ENOMEM;
1431                 goto release_node;
1432         }
1433
1434         delayed_item->key.objectid = btrfs_ino(dir);
1435         delayed_item->key.type = BTRFS_DIR_INDEX_KEY;
1436         delayed_item->key.offset = index;
1437
1438         dir_item = (struct btrfs_dir_item *)delayed_item->data;
1439         dir_item->location = *disk_key;
1440         btrfs_set_stack_dir_transid(dir_item, trans->transid);
1441         btrfs_set_stack_dir_data_len(dir_item, 0);
1442         btrfs_set_stack_dir_name_len(dir_item, name_len);
1443         btrfs_set_stack_dir_type(dir_item, type);
1444         memcpy((char *)(dir_item + 1), name, name_len);
1445
1446         ret = btrfs_delayed_item_reserve_metadata(trans, dir->root, delayed_item);
1447         /*
1448          * we have reserved enough space when we start a new transaction,
1449          * so reserving metadata failure is impossible
1450          */
1451         BUG_ON(ret);
1452
1453         mutex_lock(&delayed_node->mutex);
1454         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
1455         if (unlikely(ret)) {
1456                 btrfs_err(trans->fs_info,
1457                           "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1458                           name_len, name, delayed_node->root->root_key.objectid,
1459                           delayed_node->inode_id, ret);
1460                 BUG();
1461         }
1462         mutex_unlock(&delayed_node->mutex);
1463
1464 release_node:
1465         btrfs_release_delayed_node(delayed_node);
1466         return ret;
1467 }
1468
1469 static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,
1470                                                struct btrfs_delayed_node *node,
1471                                                struct btrfs_key *key)
1472 {
1473         struct btrfs_delayed_item *item;
1474
1475         mutex_lock(&node->mutex);
1476         item = __btrfs_lookup_delayed_insertion_item(node, key);
1477         if (!item) {
1478                 mutex_unlock(&node->mutex);
1479                 return 1;
1480         }
1481
1482         btrfs_delayed_item_release_metadata(node->root, item);
1483         btrfs_release_delayed_item(item);
1484         mutex_unlock(&node->mutex);
1485         return 0;
1486 }
1487
1488 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
1489                                    struct btrfs_inode *dir, u64 index)
1490 {
1491         struct btrfs_delayed_node *node;
1492         struct btrfs_delayed_item *item;
1493         struct btrfs_key item_key;
1494         int ret;
1495
1496         node = btrfs_get_or_create_delayed_node(dir);
1497         if (IS_ERR(node))
1498                 return PTR_ERR(node);
1499
1500         item_key.objectid = btrfs_ino(dir);
1501         item_key.type = BTRFS_DIR_INDEX_KEY;
1502         item_key.offset = index;
1503
1504         ret = btrfs_delete_delayed_insertion_item(trans->fs_info, node,
1505                                                   &item_key);
1506         if (!ret)
1507                 goto end;
1508
1509         item = btrfs_alloc_delayed_item(0);
1510         if (!item) {
1511                 ret = -ENOMEM;
1512                 goto end;
1513         }
1514
1515         item->key = item_key;
1516
1517         ret = btrfs_delayed_item_reserve_metadata(trans, dir->root, item);
1518         /*
1519          * we have reserved enough space when we start a new transaction,
1520          * so reserving metadata failure is impossible.
1521          */
1522         if (ret < 0) {
1523                 btrfs_err(trans->fs_info,
1524 "metadata reservation failed for delayed dir item deltiona, should have been reserved");
1525                 btrfs_release_delayed_item(item);
1526                 goto end;
1527         }
1528
1529         mutex_lock(&node->mutex);
1530         ret = __btrfs_add_delayed_deletion_item(node, item);
1531         if (unlikely(ret)) {
1532                 btrfs_err(trans->fs_info,
1533                           "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
1534                           index, node->root->root_key.objectid,
1535                           node->inode_id, ret);
1536                 btrfs_delayed_item_release_metadata(dir->root, item);
1537                 btrfs_release_delayed_item(item);
1538         }
1539         mutex_unlock(&node->mutex);
1540 end:
1541         btrfs_release_delayed_node(node);
1542         return ret;
1543 }
1544
1545 int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)
1546 {
1547         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
1548
1549         if (!delayed_node)
1550                 return -ENOENT;
1551
1552         /*
1553          * Since we have held i_mutex of this directory, it is impossible that
1554          * a new directory index is added into the delayed node and index_cnt
1555          * is updated now. So we needn't lock the delayed node.
1556          */
1557         if (!delayed_node->index_cnt) {
1558                 btrfs_release_delayed_node(delayed_node);
1559                 return -EINVAL;
1560         }
1561
1562         inode->index_cnt = delayed_node->index_cnt;
1563         btrfs_release_delayed_node(delayed_node);
1564         return 0;
1565 }
1566
1567 bool btrfs_readdir_get_delayed_items(struct inode *inode,
1568                                      struct list_head *ins_list,
1569                                      struct list_head *del_list)
1570 {
1571         struct btrfs_delayed_node *delayed_node;
1572         struct btrfs_delayed_item *item;
1573
1574         delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
1575         if (!delayed_node)
1576                 return false;
1577
1578         /*
1579          * We can only do one readdir with delayed items at a time because of
1580          * item->readdir_list.
1581          */
1582         btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
1583         btrfs_inode_lock(inode, 0);
1584
1585         mutex_lock(&delayed_node->mutex);
1586         item = __btrfs_first_delayed_insertion_item(delayed_node);
1587         while (item) {
1588                 refcount_inc(&item->refs);
1589                 list_add_tail(&item->readdir_list, ins_list);
1590                 item = __btrfs_next_delayed_item(item);
1591         }
1592
1593         item = __btrfs_first_delayed_deletion_item(delayed_node);
1594         while (item) {
1595                 refcount_inc(&item->refs);
1596                 list_add_tail(&item->readdir_list, del_list);
1597                 item = __btrfs_next_delayed_item(item);
1598         }
1599         mutex_unlock(&delayed_node->mutex);
1600         /*
1601          * This delayed node is still cached in the btrfs inode, so refs
1602          * must be > 1 now, and we needn't check it is going to be freed
1603          * or not.
1604          *
1605          * Besides that, this function is used to read dir, we do not
1606          * insert/delete delayed items in this period. So we also needn't
1607          * requeue or dequeue this delayed node.
1608          */
1609         refcount_dec(&delayed_node->refs);
1610
1611         return true;
1612 }
1613
1614 void btrfs_readdir_put_delayed_items(struct inode *inode,
1615                                      struct list_head *ins_list,
1616                                      struct list_head *del_list)
1617 {
1618         struct btrfs_delayed_item *curr, *next;
1619
1620         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1621                 list_del(&curr->readdir_list);
1622                 if (refcount_dec_and_test(&curr->refs))
1623                         kfree(curr);
1624         }
1625
1626         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
1627                 list_del(&curr->readdir_list);
1628                 if (refcount_dec_and_test(&curr->refs))
1629                         kfree(curr);
1630         }
1631
1632         /*
1633          * The VFS is going to do up_read(), so we need to downgrade back to a
1634          * read lock.
1635          */
1636         downgrade_write(&inode->i_rwsem);
1637 }
1638
1639 int btrfs_should_delete_dir_index(struct list_head *del_list,
1640                                   u64 index)
1641 {
1642         struct btrfs_delayed_item *curr;
1643         int ret = 0;
1644
1645         list_for_each_entry(curr, del_list, readdir_list) {
1646                 if (curr->key.offset > index)
1647                         break;
1648                 if (curr->key.offset == index) {
1649                         ret = 1;
1650                         break;
1651                 }
1652         }
1653         return ret;
1654 }
1655
1656 /*
1657  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
1658  *
1659  */
1660 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
1661                                     struct list_head *ins_list)
1662 {
1663         struct btrfs_dir_item *di;
1664         struct btrfs_delayed_item *curr, *next;
1665         struct btrfs_key location;
1666         char *name;
1667         int name_len;
1668         int over = 0;
1669         unsigned char d_type;
1670
1671         if (list_empty(ins_list))
1672                 return 0;
1673
1674         /*
1675          * Changing the data of the delayed item is impossible. So
1676          * we needn't lock them. And we have held i_mutex of the
1677          * directory, nobody can delete any directory indexes now.
1678          */
1679         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
1680                 list_del(&curr->readdir_list);
1681
1682                 if (curr->key.offset < ctx->pos) {
1683                         if (refcount_dec_and_test(&curr->refs))
1684                                 kfree(curr);
1685                         continue;
1686                 }
1687
1688                 ctx->pos = curr->key.offset;
1689
1690                 di = (struct btrfs_dir_item *)curr->data;
1691                 name = (char *)(di + 1);
1692                 name_len = btrfs_stack_dir_name_len(di);
1693
1694                 d_type = fs_ftype_to_dtype(di->type);
1695                 btrfs_disk_key_to_cpu(&location, &di->location);
1696
1697                 over = !dir_emit(ctx, name, name_len,
1698                                location.objectid, d_type);
1699
1700                 if (refcount_dec_and_test(&curr->refs))
1701                         kfree(curr);
1702
1703                 if (over)
1704                         return 1;
1705                 ctx->pos++;
1706         }
1707         return 0;
1708 }
1709
1710 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
1711                                   struct btrfs_inode_item *inode_item,
1712                                   struct inode *inode)
1713 {
1714         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
1715         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
1716         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
1717         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
1718         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
1719         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
1720         btrfs_set_stack_inode_generation(inode_item,
1721                                          BTRFS_I(inode)->generation);
1722         btrfs_set_stack_inode_sequence(inode_item,
1723                                        inode_peek_iversion(inode));
1724         btrfs_set_stack_inode_transid(inode_item, trans->transid);
1725         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
1726         btrfs_set_stack_inode_flags(inode_item, BTRFS_I(inode)->flags);
1727         btrfs_set_stack_inode_block_group(inode_item, 0);
1728
1729         btrfs_set_stack_timespec_sec(&inode_item->atime,
1730                                      inode->i_atime.tv_sec);
1731         btrfs_set_stack_timespec_nsec(&inode_item->atime,
1732                                       inode->i_atime.tv_nsec);
1733
1734         btrfs_set_stack_timespec_sec(&inode_item->mtime,
1735                                      inode->i_mtime.tv_sec);
1736         btrfs_set_stack_timespec_nsec(&inode_item->mtime,
1737                                       inode->i_mtime.tv_nsec);
1738
1739         btrfs_set_stack_timespec_sec(&inode_item->ctime,
1740                                      inode->i_ctime.tv_sec);
1741         btrfs_set_stack_timespec_nsec(&inode_item->ctime,
1742                                       inode->i_ctime.tv_nsec);
1743
1744         btrfs_set_stack_timespec_sec(&inode_item->otime,
1745                                      BTRFS_I(inode)->i_otime.tv_sec);
1746         btrfs_set_stack_timespec_nsec(&inode_item->otime,
1747                                      BTRFS_I(inode)->i_otime.tv_nsec);
1748 }
1749
1750 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
1751 {
1752         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1753         struct btrfs_delayed_node *delayed_node;
1754         struct btrfs_inode_item *inode_item;
1755
1756         delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
1757         if (!delayed_node)
1758                 return -ENOENT;
1759
1760         mutex_lock(&delayed_node->mutex);
1761         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1762                 mutex_unlock(&delayed_node->mutex);
1763                 btrfs_release_delayed_node(delayed_node);
1764                 return -ENOENT;
1765         }
1766
1767         inode_item = &delayed_node->inode_item;
1768
1769         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
1770         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
1771         btrfs_i_size_write(BTRFS_I(inode), btrfs_stack_inode_size(inode_item));
1772         btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
1773                         round_up(i_size_read(inode), fs_info->sectorsize));
1774         inode->i_mode = btrfs_stack_inode_mode(inode_item);
1775         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
1776         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
1777         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
1778         BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
1779
1780         inode_set_iversion_queried(inode,
1781                                    btrfs_stack_inode_sequence(inode_item));
1782         inode->i_rdev = 0;
1783         *rdev = btrfs_stack_inode_rdev(inode_item);
1784         BTRFS_I(inode)->flags = btrfs_stack_inode_flags(inode_item);
1785
1786         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
1787         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
1788
1789         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
1790         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
1791
1792         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
1793         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
1794
1795         BTRFS_I(inode)->i_otime.tv_sec =
1796                 btrfs_stack_timespec_sec(&inode_item->otime);
1797         BTRFS_I(inode)->i_otime.tv_nsec =
1798                 btrfs_stack_timespec_nsec(&inode_item->otime);
1799
1800         inode->i_generation = BTRFS_I(inode)->generation;
1801         BTRFS_I(inode)->index_cnt = (u64)-1;
1802
1803         mutex_unlock(&delayed_node->mutex);
1804         btrfs_release_delayed_node(delayed_node);
1805         return 0;
1806 }
1807
1808 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
1809                                struct btrfs_root *root,
1810                                struct btrfs_inode *inode)
1811 {
1812         struct btrfs_delayed_node *delayed_node;
1813         int ret = 0;
1814
1815         delayed_node = btrfs_get_or_create_delayed_node(inode);
1816         if (IS_ERR(delayed_node))
1817                 return PTR_ERR(delayed_node);
1818
1819         mutex_lock(&delayed_node->mutex);
1820         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1821                 fill_stack_inode_item(trans, &delayed_node->inode_item,
1822                                       &inode->vfs_inode);
1823                 goto release_node;
1824         }
1825
1826         ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
1827         if (ret)
1828                 goto release_node;
1829
1830         fill_stack_inode_item(trans, &delayed_node->inode_item, &inode->vfs_inode);
1831         set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
1832         delayed_node->count++;
1833         atomic_inc(&root->fs_info->delayed_root->items);
1834 release_node:
1835         mutex_unlock(&delayed_node->mutex);
1836         btrfs_release_delayed_node(delayed_node);
1837         return ret;
1838 }
1839
1840 int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)
1841 {
1842         struct btrfs_fs_info *fs_info = inode->root->fs_info;
1843         struct btrfs_delayed_node *delayed_node;
1844
1845         /*
1846          * we don't do delayed inode updates during log recovery because it
1847          * leads to enospc problems.  This means we also can't do
1848          * delayed inode refs
1849          */
1850         if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
1851                 return -EAGAIN;
1852
1853         delayed_node = btrfs_get_or_create_delayed_node(inode);
1854         if (IS_ERR(delayed_node))
1855                 return PTR_ERR(delayed_node);
1856
1857         /*
1858          * We don't reserve space for inode ref deletion is because:
1859          * - We ONLY do async inode ref deletion for the inode who has only
1860          *   one link(i_nlink == 1), it means there is only one inode ref.
1861          *   And in most case, the inode ref and the inode item are in the
1862          *   same leaf, and we will deal with them at the same time.
1863          *   Since we are sure we will reserve the space for the inode item,
1864          *   it is unnecessary to reserve space for inode ref deletion.
1865          * - If the inode ref and the inode item are not in the same leaf,
1866          *   We also needn't worry about enospc problem, because we reserve
1867          *   much more space for the inode update than it needs.
1868          * - At the worst, we can steal some space from the global reservation.
1869          *   It is very rare.
1870          */
1871         mutex_lock(&delayed_node->mutex);
1872         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
1873                 goto release_node;
1874
1875         set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
1876         delayed_node->count++;
1877         atomic_inc(&fs_info->delayed_root->items);
1878 release_node:
1879         mutex_unlock(&delayed_node->mutex);
1880         btrfs_release_delayed_node(delayed_node);
1881         return 0;
1882 }
1883
1884 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
1885 {
1886         struct btrfs_root *root = delayed_node->root;
1887         struct btrfs_fs_info *fs_info = root->fs_info;
1888         struct btrfs_delayed_item *curr_item, *prev_item;
1889
1890         mutex_lock(&delayed_node->mutex);
1891         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
1892         while (curr_item) {
1893                 btrfs_delayed_item_release_metadata(root, curr_item);
1894                 prev_item = curr_item;
1895                 curr_item = __btrfs_next_delayed_item(prev_item);
1896                 btrfs_release_delayed_item(prev_item);
1897         }
1898
1899         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
1900         while (curr_item) {
1901                 btrfs_delayed_item_release_metadata(root, curr_item);
1902                 prev_item = curr_item;
1903                 curr_item = __btrfs_next_delayed_item(prev_item);
1904                 btrfs_release_delayed_item(prev_item);
1905         }
1906
1907         btrfs_release_delayed_iref(delayed_node);
1908
1909         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
1910                 btrfs_delayed_inode_release_metadata(fs_info, delayed_node, false);
1911                 btrfs_release_delayed_inode(delayed_node);
1912         }
1913         mutex_unlock(&delayed_node->mutex);
1914 }
1915
1916 void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)
1917 {
1918         struct btrfs_delayed_node *delayed_node;
1919
1920         delayed_node = btrfs_get_delayed_node(inode);
1921         if (!delayed_node)
1922                 return;
1923
1924         __btrfs_kill_delayed_node(delayed_node);
1925         btrfs_release_delayed_node(delayed_node);
1926 }
1927
1928 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
1929 {
1930         u64 inode_id = 0;
1931         struct btrfs_delayed_node *delayed_nodes[8];
1932         int i, n;
1933
1934         while (1) {
1935                 spin_lock(&root->inode_lock);
1936                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
1937                                            (void **)delayed_nodes, inode_id,
1938                                            ARRAY_SIZE(delayed_nodes));
1939                 if (!n) {
1940                         spin_unlock(&root->inode_lock);
1941                         break;
1942                 }
1943
1944                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
1945                 for (i = 0; i < n; i++) {
1946                         /*
1947                          * Don't increase refs in case the node is dead and
1948                          * about to be removed from the tree in the loop below
1949                          */
1950                         if (!refcount_inc_not_zero(&delayed_nodes[i]->refs))
1951                                 delayed_nodes[i] = NULL;
1952                 }
1953                 spin_unlock(&root->inode_lock);
1954
1955                 for (i = 0; i < n; i++) {
1956                         if (!delayed_nodes[i])
1957                                 continue;
1958                         __btrfs_kill_delayed_node(delayed_nodes[i]);
1959                         btrfs_release_delayed_node(delayed_nodes[i]);
1960                 }
1961         }
1962 }
1963
1964 void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
1965 {
1966         struct btrfs_delayed_node *curr_node, *prev_node;
1967
1968         curr_node = btrfs_first_delayed_node(fs_info->delayed_root);
1969         while (curr_node) {
1970                 __btrfs_kill_delayed_node(curr_node);
1971
1972                 prev_node = curr_node;
1973                 curr_node = btrfs_next_delayed_node(curr_node);
1974                 btrfs_release_delayed_node(prev_node);
1975         }
1976 }
1977