LCOV - code coverage report
Current view: top level - fs/btrfs - delayed-inode.c (source / functions) Hit Total Coverage
Test: fstests of 6.5.0-rc3-djwa @ Mon Jul 31 20:08:17 PDT 2023 Lines: 3 1109 0.3 %
Date: 2023-07-31 20:08:17 Functions: 1 58 1.7 %

          Line data    Source code
       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 "ctree.h"
      10             : #include "fs.h"
      11             : #include "messages.h"
      12             : #include "misc.h"
      13             : #include "delayed-inode.h"
      14             : #include "disk-io.h"
      15             : #include "transaction.h"
      16             : #include "qgroup.h"
      17             : #include "locking.h"
      18             : #include "inode-item.h"
      19             : #include "space-info.h"
      20             : #include "accessors.h"
      21             : #include "file-item.h"
      22             : 
      23             : #define BTRFS_DELAYED_WRITEBACK         512
      24             : #define BTRFS_DELAYED_BACKGROUND        128
      25             : #define BTRFS_DELAYED_BATCH             16
      26             : 
      27             : static struct kmem_cache *delayed_node_cache;
      28             : 
      29           2 : int __init btrfs_delayed_inode_init(void)
      30             : {
      31           2 :         delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
      32             :                                         sizeof(struct btrfs_delayed_node),
      33             :                                         0,
      34             :                                         SLAB_MEM_SPREAD,
      35             :                                         NULL);
      36           2 :         if (!delayed_node_cache)
      37           0 :                 return -ENOMEM;
      38             :         return 0;
      39             : }
      40             : 
      41           0 : void __cold btrfs_delayed_inode_exit(void)
      42             : {
      43           0 :         kmem_cache_destroy(delayed_node_cache);
      44           0 : }
      45             : 
      46           0 : static inline void btrfs_init_delayed_node(
      47             :                                 struct btrfs_delayed_node *delayed_node,
      48             :                                 struct btrfs_root *root, u64 inode_id)
      49             : {
      50           0 :         delayed_node->root = root;
      51           0 :         delayed_node->inode_id = inode_id;
      52           0 :         refcount_set(&delayed_node->refs, 0);
      53           0 :         delayed_node->ins_root = RB_ROOT_CACHED;
      54           0 :         delayed_node->del_root = RB_ROOT_CACHED;
      55           0 :         mutex_init(&delayed_node->mutex);
      56           0 :         INIT_LIST_HEAD(&delayed_node->n_list);
      57           0 :         INIT_LIST_HEAD(&delayed_node->p_list);
      58           0 : }
      59             : 
      60           0 : static struct btrfs_delayed_node *btrfs_get_delayed_node(
      61             :                 struct btrfs_inode *btrfs_inode)
      62             : {
      63           0 :         struct btrfs_root *root = btrfs_inode->root;
      64           0 :         u64 ino = btrfs_ino(btrfs_inode);
      65           0 :         struct btrfs_delayed_node *node;
      66             : 
      67           0 :         node = READ_ONCE(btrfs_inode->delayed_node);
      68           0 :         if (node) {
      69           0 :                 refcount_inc(&node->refs);
      70           0 :                 return node;
      71             :         }
      72             : 
      73           0 :         spin_lock(&root->inode_lock);
      74           0 :         node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
      75             : 
      76           0 :         if (node) {
      77           0 :                 if (btrfs_inode->delayed_node) {
      78           0 :                         refcount_inc(&node->refs);       /* can be accessed */
      79           0 :                         BUG_ON(btrfs_inode->delayed_node != node);
      80           0 :                         spin_unlock(&root->inode_lock);
      81           0 :                         return node;
      82             :                 }
      83             : 
      84             :                 /*
      85             :                  * It's possible that we're racing into the middle of removing
      86             :                  * this node from the radix tree.  In this case, the refcount
      87             :                  * was zero and it should never go back to one.  Just return
      88             :                  * NULL like it was never in the radix at all; our release
      89             :                  * function is in the process of removing it.
      90             :                  *
      91             :                  * Some implementations of refcount_inc refuse to bump the
      92             :                  * refcount once it has hit zero.  If we don't do this dance
      93             :                  * here, refcount_inc() may decide to just WARN_ONCE() instead
      94             :                  * of actually bumping the refcount.
      95             :                  *
      96             :                  * If this node is properly in the radix, we want to bump the
      97             :                  * refcount twice, once for the inode and once for this get
      98             :                  * operation.
      99             :                  */
     100           0 :                 if (refcount_inc_not_zero(&node->refs)) {
     101           0 :                         refcount_inc(&node->refs);
     102           0 :                         btrfs_inode->delayed_node = node;
     103             :                 } else {
     104             :                         node = NULL;
     105             :                 }
     106             : 
     107           0 :                 spin_unlock(&root->inode_lock);
     108           0 :                 return node;
     109             :         }
     110           0 :         spin_unlock(&root->inode_lock);
     111             : 
     112           0 :         return NULL;
     113             : }
     114             : 
     115             : /* Will return either the node or PTR_ERR(-ENOMEM) */
     116           0 : static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
     117             :                 struct btrfs_inode *btrfs_inode)
     118             : {
     119           0 :         struct btrfs_delayed_node *node;
     120           0 :         struct btrfs_root *root = btrfs_inode->root;
     121           0 :         u64 ino = btrfs_ino(btrfs_inode);
     122           0 :         int ret;
     123             : 
     124           0 : again:
     125           0 :         node = btrfs_get_delayed_node(btrfs_inode);
     126           0 :         if (node)
     127           0 :                 return node;
     128             : 
     129           0 :         node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
     130           0 :         if (!node)
     131             :                 return ERR_PTR(-ENOMEM);
     132           0 :         btrfs_init_delayed_node(node, root, ino);
     133             : 
     134             :         /* cached in the btrfs inode and can be accessed */
     135           0 :         refcount_set(&node->refs, 2);
     136             : 
     137           0 :         ret = radix_tree_preload(GFP_NOFS);
     138           0 :         if (ret) {
     139           0 :                 kmem_cache_free(delayed_node_cache, node);
     140           0 :                 return ERR_PTR(ret);
     141             :         }
     142             : 
     143           0 :         spin_lock(&root->inode_lock);
     144           0 :         ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
     145           0 :         if (ret == -EEXIST) {
     146           0 :                 spin_unlock(&root->inode_lock);
     147           0 :                 kmem_cache_free(delayed_node_cache, node);
     148           0 :                 radix_tree_preload_end();
     149           0 :                 goto again;
     150             :         }
     151           0 :         btrfs_inode->delayed_node = node;
     152           0 :         spin_unlock(&root->inode_lock);
     153           0 :         radix_tree_preload_end();
     154             : 
     155           0 :         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           0 : static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
     164             :                                      struct btrfs_delayed_node *node,
     165             :                                      int mod)
     166             : {
     167           0 :         spin_lock(&root->lock);
     168           0 :         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
     169           0 :                 if (!list_empty(&node->p_list))
     170           0 :                         list_move_tail(&node->p_list, &root->prepare_list);
     171           0 :                 else if (mod)
     172           0 :                         list_add_tail(&node->p_list, &root->prepare_list);
     173             :         } else {
     174           0 :                 list_add_tail(&node->n_list, &root->node_list);
     175           0 :                 list_add_tail(&node->p_list, &root->prepare_list);
     176           0 :                 refcount_inc(&node->refs);       /* inserted into list */
     177           0 :                 root->nodes++;
     178           0 :                 set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
     179             :         }
     180           0 :         spin_unlock(&root->lock);
     181           0 : }
     182             : 
     183             : /* Call it when holding delayed_node->mutex */
     184           0 : static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
     185             :                                        struct btrfs_delayed_node *node)
     186             : {
     187           0 :         spin_lock(&root->lock);
     188           0 :         if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
     189           0 :                 root->nodes--;
     190           0 :                 refcount_dec(&node->refs);       /* not in the list */
     191           0 :                 list_del_init(&node->n_list);
     192           0 :                 if (!list_empty(&node->p_list))
     193           0 :                         list_del_init(&node->p_list);
     194           0 :                 clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
     195             :         }
     196           0 :         spin_unlock(&root->lock);
     197           0 : }
     198             : 
     199           0 : static struct btrfs_delayed_node *btrfs_first_delayed_node(
     200             :                         struct btrfs_delayed_root *delayed_root)
     201             : {
     202           0 :         struct list_head *p;
     203           0 :         struct btrfs_delayed_node *node = NULL;
     204             : 
     205           0 :         spin_lock(&delayed_root->lock);
     206           0 :         if (list_empty(&delayed_root->node_list))
     207           0 :                 goto out;
     208             : 
     209           0 :         p = delayed_root->node_list.next;
     210           0 :         node = list_entry(p, struct btrfs_delayed_node, n_list);
     211           0 :         refcount_inc(&node->refs);
     212           0 : out:
     213           0 :         spin_unlock(&delayed_root->lock);
     214             : 
     215           0 :         return node;
     216             : }
     217             : 
     218           0 : static struct btrfs_delayed_node *btrfs_next_delayed_node(
     219             :                                                 struct btrfs_delayed_node *node)
     220             : {
     221           0 :         struct btrfs_delayed_root *delayed_root;
     222           0 :         struct list_head *p;
     223           0 :         struct btrfs_delayed_node *next = NULL;
     224             : 
     225           0 :         delayed_root = node->root->fs_info->delayed_root;
     226           0 :         spin_lock(&delayed_root->lock);
     227           0 :         if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
     228             :                 /* not in the list */
     229           0 :                 if (list_empty(&delayed_root->node_list))
     230           0 :                         goto out;
     231           0 :                 p = delayed_root->node_list.next;
     232           0 :         } else if (list_is_last(&node->n_list, &delayed_root->node_list))
     233           0 :                 goto out;
     234             :         else
     235             :                 p = node->n_list.next;
     236             : 
     237           0 :         next = list_entry(p, struct btrfs_delayed_node, n_list);
     238           0 :         refcount_inc(&next->refs);
     239           0 : out:
     240           0 :         spin_unlock(&delayed_root->lock);
     241             : 
     242           0 :         return next;
     243             : }
     244             : 
     245           0 : static void __btrfs_release_delayed_node(
     246             :                                 struct btrfs_delayed_node *delayed_node,
     247             :                                 int mod)
     248             : {
     249           0 :         struct btrfs_delayed_root *delayed_root;
     250             : 
     251           0 :         if (!delayed_node)
     252             :                 return;
     253             : 
     254           0 :         delayed_root = delayed_node->root->fs_info->delayed_root;
     255             : 
     256           0 :         mutex_lock(&delayed_node->mutex);
     257           0 :         if (delayed_node->count)
     258           0 :                 btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
     259             :         else
     260           0 :                 btrfs_dequeue_delayed_node(delayed_root, delayed_node);
     261           0 :         mutex_unlock(&delayed_node->mutex);
     262             : 
     263           0 :         if (refcount_dec_and_test(&delayed_node->refs)) {
     264           0 :                 struct btrfs_root *root = delayed_node->root;
     265             : 
     266           0 :                 spin_lock(&root->inode_lock);
     267             :                 /*
     268             :                  * Once our refcount goes to zero, nobody is allowed to bump it
     269             :                  * back up.  We can delete it now.
     270             :                  */
     271           0 :                 ASSERT(refcount_read(&delayed_node->refs) == 0);
     272           0 :                 radix_tree_delete(&root->delayed_nodes_tree,
     273           0 :                                   delayed_node->inode_id);
     274           0 :                 spin_unlock(&root->inode_lock);
     275           0 :                 kmem_cache_free(delayed_node_cache, delayed_node);
     276             :         }
     277             : }
     278             : 
     279             : static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
     280             : {
     281           0 :         __btrfs_release_delayed_node(node, 0);
     282           0 : }
     283             : 
     284           0 : static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
     285             :                                         struct btrfs_delayed_root *delayed_root)
     286             : {
     287           0 :         struct list_head *p;
     288           0 :         struct btrfs_delayed_node *node = NULL;
     289             : 
     290           0 :         spin_lock(&delayed_root->lock);
     291           0 :         if (list_empty(&delayed_root->prepare_list))
     292           0 :                 goto out;
     293             : 
     294           0 :         p = delayed_root->prepare_list.next;
     295           0 :         list_del_init(p);
     296           0 :         node = list_entry(p, struct btrfs_delayed_node, p_list);
     297           0 :         refcount_inc(&node->refs);
     298           0 : out:
     299           0 :         spin_unlock(&delayed_root->lock);
     300             : 
     301           0 :         return node;
     302             : }
     303             : 
     304             : static inline void btrfs_release_prepared_delayed_node(
     305             :                                         struct btrfs_delayed_node *node)
     306             : {
     307           0 :         __btrfs_release_delayed_node(node, 1);
     308             : }
     309             : 
     310           0 : static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u16 data_len,
     311             :                                            struct btrfs_delayed_node *node,
     312             :                                            enum btrfs_delayed_item_type type)
     313             : {
     314           0 :         struct btrfs_delayed_item *item;
     315             : 
     316           0 :         item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
     317           0 :         if (item) {
     318           0 :                 item->data_len = data_len;
     319           0 :                 item->type = type;
     320           0 :                 item->bytes_reserved = 0;
     321           0 :                 item->delayed_node = node;
     322           0 :                 RB_CLEAR_NODE(&item->rb_node);
     323           0 :                 INIT_LIST_HEAD(&item->log_list);
     324           0 :                 item->logged = false;
     325           0 :                 refcount_set(&item->refs, 1);
     326             :         }
     327           0 :         return item;
     328             : }
     329             : 
     330             : /*
     331             :  * __btrfs_lookup_delayed_item - look up the delayed item by key
     332             :  * @delayed_node: pointer to the delayed node
     333             :  * @index:        the dir index value to lookup (offset of a dir index key)
     334             :  *
     335             :  * Note: if we don't find the right item, we will return the prev item and
     336             :  * the next item.
     337             :  */
     338             : static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
     339             :                                 struct rb_root *root,
     340             :                                 u64 index)
     341             : {
     342           0 :         struct rb_node *node = root->rb_node;
     343           0 :         struct btrfs_delayed_item *delayed_item = NULL;
     344             : 
     345           0 :         while (node) {
     346           0 :                 delayed_item = rb_entry(node, struct btrfs_delayed_item,
     347             :                                         rb_node);
     348           0 :                 if (delayed_item->index < index)
     349           0 :                         node = node->rb_right;
     350           0 :                 else if (delayed_item->index > index)
     351           0 :                         node = node->rb_left;
     352             :                 else
     353             :                         return delayed_item;
     354             :         }
     355             : 
     356             :         return NULL;
     357             : }
     358             : 
     359           0 : static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
     360             :                                     struct btrfs_delayed_item *ins)
     361             : {
     362           0 :         struct rb_node **p, *node;
     363           0 :         struct rb_node *parent_node = NULL;
     364           0 :         struct rb_root_cached *root;
     365           0 :         struct btrfs_delayed_item *item;
     366           0 :         bool leftmost = true;
     367             : 
     368           0 :         if (ins->type == BTRFS_DELAYED_INSERTION_ITEM)
     369           0 :                 root = &delayed_node->ins_root;
     370             :         else
     371           0 :                 root = &delayed_node->del_root;
     372             : 
     373           0 :         p = &root->rb_root.rb_node;
     374           0 :         node = &ins->rb_node;
     375             : 
     376           0 :         while (*p) {
     377           0 :                 parent_node = *p;
     378           0 :                 item = rb_entry(parent_node, struct btrfs_delayed_item,
     379             :                                  rb_node);
     380             : 
     381           0 :                 if (item->index < ins->index) {
     382           0 :                         p = &(*p)->rb_right;
     383           0 :                         leftmost = false;
     384           0 :                 } else if (item->index > ins->index) {
     385           0 :                         p = &(*p)->rb_left;
     386             :                 } else {
     387             :                         return -EEXIST;
     388             :                 }
     389             :         }
     390             : 
     391           0 :         rb_link_node(node, parent_node, p);
     392           0 :         rb_insert_color_cached(node, root, leftmost);
     393             : 
     394           0 :         if (ins->type == BTRFS_DELAYED_INSERTION_ITEM &&
     395           0 :             ins->index >= delayed_node->index_cnt)
     396           0 :                 delayed_node->index_cnt = ins->index + 1;
     397             : 
     398           0 :         delayed_node->count++;
     399           0 :         atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
     400             :         return 0;
     401             : }
     402             : 
     403           0 : static void finish_one_item(struct btrfs_delayed_root *delayed_root)
     404             : {
     405           0 :         int seq = atomic_inc_return(&delayed_root->items_seq);
     406             : 
     407             :         /* atomic_dec_return implies a barrier */
     408           0 :         if ((atomic_dec_return(&delayed_root->items) <
     409           0 :             BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))
     410           0 :                 cond_wake_up_nomb(&delayed_root->wait);
     411           0 : }
     412             : 
     413           0 : static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
     414             : {
     415           0 :         struct rb_root_cached *root;
     416           0 :         struct btrfs_delayed_root *delayed_root;
     417             : 
     418             :         /* Not inserted, ignore it. */
     419           0 :         if (RB_EMPTY_NODE(&delayed_item->rb_node))
     420             :                 return;
     421             : 
     422           0 :         delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
     423             : 
     424           0 :         BUG_ON(!delayed_root);
     425             : 
     426           0 :         if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)
     427           0 :                 root = &delayed_item->delayed_node->ins_root;
     428             :         else
     429           0 :                 root = &delayed_item->delayed_node->del_root;
     430             : 
     431           0 :         rb_erase_cached(&delayed_item->rb_node, root);
     432           0 :         RB_CLEAR_NODE(&delayed_item->rb_node);
     433           0 :         delayed_item->delayed_node->count--;
     434             : 
     435           0 :         finish_one_item(delayed_root);
     436             : }
     437             : 
     438           0 : static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
     439             : {
     440           0 :         if (item) {
     441           0 :                 __btrfs_remove_delayed_item(item);
     442           0 :                 if (refcount_dec_and_test(&item->refs))
     443           0 :                         kfree(item);
     444             :         }
     445           0 : }
     446             : 
     447             : static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
     448             :                                         struct btrfs_delayed_node *delayed_node)
     449             : {
     450           0 :         struct rb_node *p;
     451           0 :         struct btrfs_delayed_item *item = NULL;
     452             : 
     453           0 :         p = rb_first_cached(&delayed_node->ins_root);
     454           0 :         if (p)
     455           0 :                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
     456             : 
     457           0 :         return item;
     458             : }
     459             : 
     460             : static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
     461             :                                         struct btrfs_delayed_node *delayed_node)
     462             : {
     463           0 :         struct rb_node *p;
     464           0 :         struct btrfs_delayed_item *item = NULL;
     465             : 
     466           0 :         p = rb_first_cached(&delayed_node->del_root);
     467           0 :         if (p)
     468           0 :                 item = rb_entry(p, struct btrfs_delayed_item, rb_node);
     469             : 
     470           0 :         return item;
     471             : }
     472             : 
     473             : static struct btrfs_delayed_item *__btrfs_next_delayed_item(
     474             :                                                 struct btrfs_delayed_item *item)
     475             : {
     476           0 :         struct rb_node *p;
     477           0 :         struct btrfs_delayed_item *next = NULL;
     478             : 
     479           0 :         p = rb_next(&item->rb_node);
     480           0 :         if (p)
     481           0 :                 next = rb_entry(p, struct btrfs_delayed_item, rb_node);
     482             : 
     483           0 :         return next;
     484             : }
     485             : 
     486           0 : static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
     487             :                                                struct btrfs_delayed_item *item)
     488             : {
     489           0 :         struct btrfs_block_rsv *src_rsv;
     490           0 :         struct btrfs_block_rsv *dst_rsv;
     491           0 :         struct btrfs_fs_info *fs_info = trans->fs_info;
     492           0 :         u64 num_bytes;
     493           0 :         int ret;
     494             : 
     495           0 :         if (!trans->bytes_reserved)
     496             :                 return 0;
     497             : 
     498           0 :         src_rsv = trans->block_rsv;
     499           0 :         dst_rsv = &fs_info->delayed_block_rsv;
     500             : 
     501           0 :         num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
     502             : 
     503             :         /*
     504             :          * Here we migrate space rsv from transaction rsv, since have already
     505             :          * reserved space when starting a transaction.  So no need to reserve
     506             :          * qgroup space here.
     507             :          */
     508           0 :         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
     509           0 :         if (!ret) {
     510           0 :                 trace_btrfs_space_reservation(fs_info, "delayed_item",
     511           0 :                                               item->delayed_node->inode_id,
     512             :                                               num_bytes, 1);
     513             :                 /*
     514             :                  * For insertions we track reserved metadata space by accounting
     515             :                  * for the number of leaves that will be used, based on the delayed
     516             :                  * node's index_items_size field.
     517             :                  */
     518           0 :                 if (item->type == BTRFS_DELAYED_DELETION_ITEM)
     519           0 :                         item->bytes_reserved = num_bytes;
     520             :         }
     521             : 
     522             :         return ret;
     523             : }
     524             : 
     525           0 : static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
     526             :                                                 struct btrfs_delayed_item *item)
     527             : {
     528           0 :         struct btrfs_block_rsv *rsv;
     529           0 :         struct btrfs_fs_info *fs_info = root->fs_info;
     530             : 
     531           0 :         if (!item->bytes_reserved)
     532             :                 return;
     533             : 
     534           0 :         rsv = &fs_info->delayed_block_rsv;
     535             :         /*
     536             :          * Check btrfs_delayed_item_reserve_metadata() to see why we don't need
     537             :          * to release/reserve qgroup space.
     538             :          */
     539           0 :         trace_btrfs_space_reservation(fs_info, "delayed_item",
     540           0 :                                       item->delayed_node->inode_id,
     541             :                                       item->bytes_reserved, 0);
     542           0 :         btrfs_block_rsv_release(fs_info, rsv, item->bytes_reserved, NULL);
     543             : }
     544             : 
     545           0 : static void btrfs_delayed_item_release_leaves(struct btrfs_delayed_node *node,
     546             :                                               unsigned int num_leaves)
     547             : {
     548           0 :         struct btrfs_fs_info *fs_info = node->root->fs_info;
     549           0 :         const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_leaves);
     550             : 
     551             :         /* There are no space reservations during log replay, bail out. */
     552           0 :         if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
     553             :                 return;
     554             : 
     555           0 :         trace_btrfs_space_reservation(fs_info, "delayed_item", node->inode_id,
     556             :                                       bytes, 0);
     557           0 :         btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv, bytes, NULL);
     558             : }
     559             : 
     560           0 : static int btrfs_delayed_inode_reserve_metadata(
     561             :                                         struct btrfs_trans_handle *trans,
     562             :                                         struct btrfs_root *root,
     563             :                                         struct btrfs_delayed_node *node)
     564             : {
     565           0 :         struct btrfs_fs_info *fs_info = root->fs_info;
     566           0 :         struct btrfs_block_rsv *src_rsv;
     567           0 :         struct btrfs_block_rsv *dst_rsv;
     568           0 :         u64 num_bytes;
     569           0 :         int ret;
     570             : 
     571           0 :         src_rsv = trans->block_rsv;
     572           0 :         dst_rsv = &fs_info->delayed_block_rsv;
     573             : 
     574           0 :         num_bytes = btrfs_calc_metadata_size(fs_info, 1);
     575             : 
     576             :         /*
     577             :          * btrfs_dirty_inode will update the inode under btrfs_join_transaction
     578             :          * which doesn't reserve space for speed.  This is a problem since we
     579             :          * still need to reserve space for this update, so try to reserve the
     580             :          * space.
     581             :          *
     582             :          * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
     583             :          * we always reserve enough to update the inode item.
     584             :          */
     585           0 :         if (!src_rsv || (!trans->bytes_reserved &&
     586           0 :                          src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
     587           0 :                 ret = btrfs_qgroup_reserve_meta(root, num_bytes,
     588             :                                           BTRFS_QGROUP_RSV_META_PREALLOC, true);
     589           0 :                 if (ret < 0)
     590             :                         return ret;
     591           0 :                 ret = btrfs_block_rsv_add(fs_info, dst_rsv, num_bytes,
     592             :                                           BTRFS_RESERVE_NO_FLUSH);
     593             :                 /* NO_FLUSH could only fail with -ENOSPC */
     594           0 :                 ASSERT(ret == 0 || ret == -ENOSPC);
     595           0 :                 if (ret)
     596           0 :                         btrfs_qgroup_free_meta_prealloc(root, num_bytes);
     597             :         } else {
     598           0 :                 ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
     599             :         }
     600             : 
     601           0 :         if (!ret) {
     602           0 :                 trace_btrfs_space_reservation(fs_info, "delayed_inode",
     603             :                                               node->inode_id, num_bytes, 1);
     604           0 :                 node->bytes_reserved = num_bytes;
     605             :         }
     606             : 
     607             :         return ret;
     608             : }
     609             : 
     610           0 : static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
     611             :                                                 struct btrfs_delayed_node *node,
     612             :                                                 bool qgroup_free)
     613             : {
     614           0 :         struct btrfs_block_rsv *rsv;
     615             : 
     616           0 :         if (!node->bytes_reserved)
     617             :                 return;
     618             : 
     619           0 :         rsv = &fs_info->delayed_block_rsv;
     620           0 :         trace_btrfs_space_reservation(fs_info, "delayed_inode",
     621             :                                       node->inode_id, node->bytes_reserved, 0);
     622           0 :         btrfs_block_rsv_release(fs_info, rsv, node->bytes_reserved, NULL);
     623           0 :         if (qgroup_free)
     624           0 :                 btrfs_qgroup_free_meta_prealloc(node->root,
     625           0 :                                 node->bytes_reserved);
     626             :         else
     627           0 :                 btrfs_qgroup_convert_reserved_meta(node->root,
     628           0 :                                 node->bytes_reserved);
     629           0 :         node->bytes_reserved = 0;
     630             : }
     631             : 
     632             : /*
     633             :  * Insert a single delayed item or a batch of delayed items, as many as possible
     634             :  * that fit in a leaf. The delayed items (dir index keys) are sorted by their key
     635             :  * in the rbtree, and if there's a gap between two consecutive dir index items,
     636             :  * then it means at some point we had delayed dir indexes to add but they got
     637             :  * removed (by btrfs_delete_delayed_dir_index()) before we attempted to flush them
     638             :  * into the subvolume tree. Dir index keys also have their offsets coming from a
     639             :  * monotonically increasing counter, so we can't get new keys with an offset that
     640             :  * fits within a gap between delayed dir index items.
     641             :  */
     642           0 : static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
     643             :                                      struct btrfs_root *root,
     644             :                                      struct btrfs_path *path,
     645             :                                      struct btrfs_delayed_item *first_item)
     646             : {
     647           0 :         struct btrfs_fs_info *fs_info = root->fs_info;
     648           0 :         struct btrfs_delayed_node *node = first_item->delayed_node;
     649           0 :         LIST_HEAD(item_list);
     650           0 :         struct btrfs_delayed_item *curr;
     651           0 :         struct btrfs_delayed_item *next;
     652           0 :         const int max_size = BTRFS_LEAF_DATA_SIZE(fs_info);
     653           0 :         struct btrfs_item_batch batch;
     654           0 :         struct btrfs_key first_key;
     655           0 :         const u32 first_data_size = first_item->data_len;
     656           0 :         int total_size;
     657           0 :         char *ins_data = NULL;
     658           0 :         int ret;
     659           0 :         bool continuous_keys_only = false;
     660             : 
     661           0 :         lockdep_assert_held(&node->mutex);
     662             : 
     663             :         /*
     664             :          * During normal operation the delayed index offset is continuously
     665             :          * increasing, so we can batch insert all items as there will not be any
     666             :          * overlapping keys in the tree.
     667             :          *
     668             :          * The exception to this is log replay, where we may have interleaved
     669             :          * offsets in the tree, so our batch needs to be continuous keys only in
     670             :          * order to ensure we do not end up with out of order items in our leaf.
     671             :          */
     672           0 :         if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
     673           0 :                 continuous_keys_only = true;
     674             : 
     675             :         /*
     676             :          * For delayed items to insert, we track reserved metadata bytes based
     677             :          * on the number of leaves that we will use.
     678             :          * See btrfs_insert_delayed_dir_index() and
     679             :          * btrfs_delayed_item_reserve_metadata()).
     680             :          */
     681           0 :         ASSERT(first_item->bytes_reserved == 0);
     682             : 
     683           0 :         list_add_tail(&first_item->tree_list, &item_list);
     684           0 :         batch.total_data_size = first_data_size;
     685           0 :         batch.nr = 1;
     686           0 :         total_size = first_data_size + sizeof(struct btrfs_item);
     687           0 :         curr = first_item;
     688             : 
     689           0 :         while (true) {
     690           0 :                 int next_size;
     691             : 
     692           0 :                 next = __btrfs_next_delayed_item(curr);
     693           0 :                 if (!next)
     694             :                         break;
     695             : 
     696             :                 /*
     697             :                  * We cannot allow gaps in the key space if we're doing log
     698             :                  * replay.
     699             :                  */
     700           0 :                 if (continuous_keys_only && (next->index != curr->index + 1))
     701             :                         break;
     702             : 
     703           0 :                 ASSERT(next->bytes_reserved == 0);
     704             : 
     705           0 :                 next_size = next->data_len + sizeof(struct btrfs_item);
     706           0 :                 if (total_size + next_size > max_size)
     707             :                         break;
     708             : 
     709           0 :                 list_add_tail(&next->tree_list, &item_list);
     710           0 :                 batch.nr++;
     711           0 :                 total_size += next_size;
     712           0 :                 batch.total_data_size += next->data_len;
     713           0 :                 curr = next;
     714             :         }
     715             : 
     716           0 :         if (batch.nr == 1) {
     717           0 :                 first_key.objectid = node->inode_id;
     718           0 :                 first_key.type = BTRFS_DIR_INDEX_KEY;
     719           0 :                 first_key.offset = first_item->index;
     720           0 :                 batch.keys = &first_key;
     721           0 :                 batch.data_sizes = &first_data_size;
     722             :         } else {
     723           0 :                 struct btrfs_key *ins_keys;
     724           0 :                 u32 *ins_sizes;
     725           0 :                 int i = 0;
     726             : 
     727           0 :                 ins_data = kmalloc(batch.nr * sizeof(u32) +
     728             :                                    batch.nr * sizeof(struct btrfs_key), GFP_NOFS);
     729           0 :                 if (!ins_data) {
     730           0 :                         ret = -ENOMEM;
     731           0 :                         goto out;
     732             :                 }
     733           0 :                 ins_sizes = (u32 *)ins_data;
     734           0 :                 ins_keys = (struct btrfs_key *)(ins_data + batch.nr * sizeof(u32));
     735           0 :                 batch.keys = ins_keys;
     736           0 :                 batch.data_sizes = ins_sizes;
     737           0 :                 list_for_each_entry(curr, &item_list, tree_list) {
     738           0 :                         ins_keys[i].objectid = node->inode_id;
     739           0 :                         ins_keys[i].type = BTRFS_DIR_INDEX_KEY;
     740           0 :                         ins_keys[i].offset = curr->index;
     741           0 :                         ins_sizes[i] = curr->data_len;
     742           0 :                         i++;
     743             :                 }
     744             :         }
     745             : 
     746           0 :         ret = btrfs_insert_empty_items(trans, root, path, &batch);
     747           0 :         if (ret)
     748           0 :                 goto out;
     749             : 
     750           0 :         list_for_each_entry(curr, &item_list, tree_list) {
     751           0 :                 char *data_ptr;
     752             : 
     753           0 :                 data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
     754           0 :                 write_extent_buffer(path->nodes[0], &curr->data,
     755           0 :                                     (unsigned long)data_ptr, curr->data_len);
     756           0 :                 path->slots[0]++;
     757             :         }
     758             : 
     759             :         /*
     760             :          * Now release our path before releasing the delayed items and their
     761             :          * metadata reservations, so that we don't block other tasks for more
     762             :          * time than needed.
     763             :          */
     764           0 :         btrfs_release_path(path);
     765             : 
     766           0 :         ASSERT(node->index_item_leaves > 0);
     767             : 
     768             :         /*
     769             :          * For normal operations we will batch an entire leaf's worth of delayed
     770             :          * items, so if there are more items to process we can decrement
     771             :          * index_item_leaves by 1 as we inserted 1 leaf's worth of items.
     772             :          *
     773             :          * However for log replay we may not have inserted an entire leaf's
     774             :          * worth of items, we may have not had continuous items, so decrementing
     775             :          * here would mess up the index_item_leaves accounting.  For this case
     776             :          * only clean up the accounting when there are no items left.
     777             :          */
     778           0 :         if (next && !continuous_keys_only) {
     779             :                 /*
     780             :                  * We inserted one batch of items into a leaf a there are more
     781             :                  * items to flush in a future batch, now release one unit of
     782             :                  * metadata space from the delayed block reserve, corresponding
     783             :                  * the leaf we just flushed to.
     784             :                  */
     785           0 :                 btrfs_delayed_item_release_leaves(node, 1);
     786           0 :                 node->index_item_leaves--;
     787           0 :         } else if (!next) {
     788             :                 /*
     789             :                  * There are no more items to insert. We can have a number of
     790             :                  * reserved leaves > 1 here - this happens when many dir index
     791             :                  * items are added and then removed before they are flushed (file
     792             :                  * names with a very short life, never span a transaction). So
     793             :                  * release all remaining leaves.
     794             :                  */
     795           0 :                 btrfs_delayed_item_release_leaves(node, node->index_item_leaves);
     796           0 :                 node->index_item_leaves = 0;
     797             :         }
     798             : 
     799           0 :         list_for_each_entry_safe(curr, next, &item_list, tree_list) {
     800           0 :                 list_del(&curr->tree_list);
     801           0 :                 btrfs_release_delayed_item(curr);
     802             :         }
     803           0 : out:
     804           0 :         kfree(ins_data);
     805           0 :         return ret;
     806             : }
     807             : 
     808           0 : static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
     809             :                                       struct btrfs_path *path,
     810             :                                       struct btrfs_root *root,
     811             :                                       struct btrfs_delayed_node *node)
     812             : {
     813           0 :         int ret = 0;
     814             : 
     815           0 :         while (ret == 0) {
     816           0 :                 struct btrfs_delayed_item *curr;
     817             : 
     818           0 :                 mutex_lock(&node->mutex);
     819           0 :                 curr = __btrfs_first_delayed_insertion_item(node);
     820           0 :                 if (!curr) {
     821           0 :                         mutex_unlock(&node->mutex);
     822           0 :                         break;
     823             :                 }
     824           0 :                 ret = btrfs_insert_delayed_item(trans, root, path, curr);
     825           0 :                 mutex_unlock(&node->mutex);
     826             :         }
     827             : 
     828           0 :         return ret;
     829             : }
     830             : 
     831           0 : static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
     832             :                                     struct btrfs_root *root,
     833             :                                     struct btrfs_path *path,
     834             :                                     struct btrfs_delayed_item *item)
     835             : {
     836           0 :         const u64 ino = item->delayed_node->inode_id;
     837           0 :         struct btrfs_fs_info *fs_info = root->fs_info;
     838           0 :         struct btrfs_delayed_item *curr, *next;
     839           0 :         struct extent_buffer *leaf = path->nodes[0];
     840           0 :         LIST_HEAD(batch_list);
     841           0 :         int nitems, slot, last_slot;
     842           0 :         int ret;
     843           0 :         u64 total_reserved_size = item->bytes_reserved;
     844             : 
     845           0 :         ASSERT(leaf != NULL);
     846             : 
     847           0 :         slot = path->slots[0];
     848           0 :         last_slot = btrfs_header_nritems(leaf) - 1;
     849             :         /*
     850             :          * Our caller always gives us a path pointing to an existing item, so
     851             :          * this can not happen.
     852             :          */
     853           0 :         ASSERT(slot <= last_slot);
     854           0 :         if (WARN_ON(slot > last_slot))
     855             :                 return -ENOENT;
     856             : 
     857           0 :         nitems = 1;
     858           0 :         curr = item;
     859           0 :         list_add_tail(&curr->tree_list, &batch_list);
     860             : 
     861             :         /*
     862             :          * Keep checking if the next delayed item matches the next item in the
     863             :          * leaf - if so, we can add it to the batch of items to delete from the
     864             :          * leaf.
     865             :          */
     866           0 :         while (slot < last_slot) {
     867           0 :                 struct btrfs_key key;
     868             : 
     869           0 :                 next = __btrfs_next_delayed_item(curr);
     870           0 :                 if (!next)
     871             :                         break;
     872             : 
     873           0 :                 slot++;
     874           0 :                 btrfs_item_key_to_cpu(leaf, &key, slot);
     875           0 :                 if (key.objectid != ino ||
     876           0 :                     key.type != BTRFS_DIR_INDEX_KEY ||
     877           0 :                     key.offset != next->index)
     878             :                         break;
     879           0 :                 nitems++;
     880           0 :                 curr = next;
     881           0 :                 list_add_tail(&curr->tree_list, &batch_list);
     882           0 :                 total_reserved_size += curr->bytes_reserved;
     883             :         }
     884             : 
     885           0 :         ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
     886           0 :         if (ret)
     887             :                 return ret;
     888             : 
     889             :         /* In case of BTRFS_FS_LOG_RECOVERING items won't have reserved space */
     890           0 :         if (total_reserved_size > 0) {
     891             :                 /*
     892             :                  * Check btrfs_delayed_item_reserve_metadata() to see why we
     893             :                  * don't need to release/reserve qgroup space.
     894             :                  */
     895           0 :                 trace_btrfs_space_reservation(fs_info, "delayed_item", ino,
     896             :                                               total_reserved_size, 0);
     897           0 :                 btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv,
     898             :                                         total_reserved_size, NULL);
     899             :         }
     900             : 
     901           0 :         list_for_each_entry_safe(curr, next, &batch_list, tree_list) {
     902           0 :                 list_del(&curr->tree_list);
     903           0 :                 btrfs_release_delayed_item(curr);
     904             :         }
     905             : 
     906             :         return 0;
     907             : }
     908             : 
     909           0 : static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
     910             :                                       struct btrfs_path *path,
     911             :                                       struct btrfs_root *root,
     912             :                                       struct btrfs_delayed_node *node)
     913             : {
     914           0 :         struct btrfs_key key;
     915           0 :         int ret = 0;
     916             : 
     917           0 :         key.objectid = node->inode_id;
     918           0 :         key.type = BTRFS_DIR_INDEX_KEY;
     919             : 
     920           0 :         while (ret == 0) {
     921           0 :                 struct btrfs_delayed_item *item;
     922             : 
     923           0 :                 mutex_lock(&node->mutex);
     924           0 :                 item = __btrfs_first_delayed_deletion_item(node);
     925           0 :                 if (!item) {
     926           0 :                         mutex_unlock(&node->mutex);
     927           0 :                         break;
     928             :                 }
     929             : 
     930           0 :                 key.offset = item->index;
     931           0 :                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
     932           0 :                 if (ret > 0) {
     933             :                         /*
     934             :                          * There's no matching item in the leaf. This means we
     935             :                          * have already deleted this item in a past run of the
     936             :                          * delayed items. We ignore errors when running delayed
     937             :                          * items from an async context, through a work queue job
     938             :                          * running btrfs_async_run_delayed_root(), and don't
     939             :                          * release delayed items that failed to complete. This
     940             :                          * is because we will retry later, and at transaction
     941             :                          * commit time we always run delayed items and will
     942             :                          * then deal with errors if they fail to run again.
     943             :                          *
     944             :                          * So just release delayed items for which we can't find
     945             :                          * an item in the tree, and move to the next item.
     946             :                          */
     947           0 :                         btrfs_release_path(path);
     948           0 :                         btrfs_release_delayed_item(item);
     949           0 :                         ret = 0;
     950           0 :                 } else if (ret == 0) {
     951           0 :                         ret = btrfs_batch_delete_items(trans, root, path, item);
     952           0 :                         btrfs_release_path(path);
     953             :                 }
     954             : 
     955             :                 /*
     956             :                  * We unlock and relock on each iteration, this is to prevent
     957             :                  * blocking other tasks for too long while we are being run from
     958             :                  * the async context (work queue job). Those tasks are typically
     959             :                  * running system calls like creat/mkdir/rename/unlink/etc which
     960             :                  * need to add delayed items to this delayed node.
     961             :                  */
     962           0 :                 mutex_unlock(&node->mutex);
     963             :         }
     964             : 
     965           0 :         return ret;
     966             : }
     967             : 
     968           0 : static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
     969             : {
     970           0 :         struct btrfs_delayed_root *delayed_root;
     971             : 
     972           0 :         if (delayed_node &&
     973           0 :             test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
     974           0 :                 BUG_ON(!delayed_node->root);
     975           0 :                 clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
     976           0 :                 delayed_node->count--;
     977             : 
     978           0 :                 delayed_root = delayed_node->root->fs_info->delayed_root;
     979           0 :                 finish_one_item(delayed_root);
     980             :         }
     981           0 : }
     982             : 
     983           0 : static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
     984             : {
     985             : 
     986           0 :         if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags)) {
     987           0 :                 struct btrfs_delayed_root *delayed_root;
     988             : 
     989           0 :                 ASSERT(delayed_node->root);
     990           0 :                 delayed_node->count--;
     991             : 
     992           0 :                 delayed_root = delayed_node->root->fs_info->delayed_root;
     993           0 :                 finish_one_item(delayed_root);
     994             :         }
     995           0 : }
     996             : 
     997           0 : static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
     998             :                                         struct btrfs_root *root,
     999             :                                         struct btrfs_path *path,
    1000             :                                         struct btrfs_delayed_node *node)
    1001             : {
    1002           0 :         struct btrfs_fs_info *fs_info = root->fs_info;
    1003           0 :         struct btrfs_key key;
    1004           0 :         struct btrfs_inode_item *inode_item;
    1005           0 :         struct extent_buffer *leaf;
    1006           0 :         int mod;
    1007           0 :         int ret;
    1008             : 
    1009           0 :         key.objectid = node->inode_id;
    1010           0 :         key.type = BTRFS_INODE_ITEM_KEY;
    1011           0 :         key.offset = 0;
    1012             : 
    1013           0 :         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
    1014             :                 mod = -1;
    1015             :         else
    1016           0 :                 mod = 1;
    1017             : 
    1018           0 :         ret = btrfs_lookup_inode(trans, root, path, &key, mod);
    1019           0 :         if (ret > 0)
    1020             :                 ret = -ENOENT;
    1021           0 :         if (ret < 0)
    1022           0 :                 goto out;
    1023             : 
    1024           0 :         leaf = path->nodes[0];
    1025           0 :         inode_item = btrfs_item_ptr(leaf, path->slots[0],
    1026             :                                     struct btrfs_inode_item);
    1027           0 :         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
    1028             :                             sizeof(struct btrfs_inode_item));
    1029           0 :         btrfs_mark_buffer_dirty(leaf);
    1030             : 
    1031           0 :         if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
    1032           0 :                 goto out;
    1033             : 
    1034           0 :         path->slots[0]++;
    1035           0 :         if (path->slots[0] >= btrfs_header_nritems(leaf))
    1036           0 :                 goto search;
    1037           0 : again:
    1038           0 :         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
    1039           0 :         if (key.objectid != node->inode_id)
    1040           0 :                 goto out;
    1041             : 
    1042           0 :         if (key.type != BTRFS_INODE_REF_KEY &&
    1043             :             key.type != BTRFS_INODE_EXTREF_KEY)
    1044           0 :                 goto out;
    1045             : 
    1046             :         /*
    1047             :          * Delayed iref deletion is for the inode who has only one link,
    1048             :          * so there is only one iref. The case that several irefs are
    1049             :          * in the same item doesn't exist.
    1050             :          */
    1051           0 :         ret = btrfs_del_item(trans, root, path);
    1052           0 : out:
    1053           0 :         btrfs_release_delayed_iref(node);
    1054           0 :         btrfs_release_path(path);
    1055           0 : err_out:
    1056           0 :         btrfs_delayed_inode_release_metadata(fs_info, node, (ret < 0));
    1057           0 :         btrfs_release_delayed_inode(node);
    1058             : 
    1059             :         /*
    1060             :          * If we fail to update the delayed inode we need to abort the
    1061             :          * transaction, because we could leave the inode with the improper
    1062             :          * counts behind.
    1063             :          */
    1064           0 :         if (ret && ret != -ENOENT)
    1065           0 :                 btrfs_abort_transaction(trans, ret);
    1066             : 
    1067           0 :         return ret;
    1068             : 
    1069             : search:
    1070           0 :         btrfs_release_path(path);
    1071             : 
    1072           0 :         key.type = BTRFS_INODE_EXTREF_KEY;
    1073           0 :         key.offset = -1;
    1074             : 
    1075           0 :         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
    1076           0 :         if (ret < 0)
    1077           0 :                 goto err_out;
    1078           0 :         ASSERT(ret);
    1079             : 
    1080           0 :         ret = 0;
    1081           0 :         leaf = path->nodes[0];
    1082           0 :         path->slots[0]--;
    1083           0 :         goto again;
    1084             : }
    1085             : 
    1086           0 : static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
    1087             :                                              struct btrfs_root *root,
    1088             :                                              struct btrfs_path *path,
    1089             :                                              struct btrfs_delayed_node *node)
    1090             : {
    1091           0 :         int ret;
    1092             : 
    1093           0 :         mutex_lock(&node->mutex);
    1094           0 :         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
    1095           0 :                 mutex_unlock(&node->mutex);
    1096           0 :                 return 0;
    1097             :         }
    1098             : 
    1099           0 :         ret = __btrfs_update_delayed_inode(trans, root, path, node);
    1100           0 :         mutex_unlock(&node->mutex);
    1101           0 :         return ret;
    1102             : }
    1103             : 
    1104             : static inline int
    1105           0 : __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
    1106             :                                    struct btrfs_path *path,
    1107             :                                    struct btrfs_delayed_node *node)
    1108             : {
    1109           0 :         int ret;
    1110             : 
    1111           0 :         ret = btrfs_insert_delayed_items(trans, path, node->root, node);
    1112           0 :         if (ret)
    1113             :                 return ret;
    1114             : 
    1115           0 :         ret = btrfs_delete_delayed_items(trans, path, node->root, node);
    1116           0 :         if (ret)
    1117             :                 return ret;
    1118             : 
    1119           0 :         ret = btrfs_update_delayed_inode(trans, node->root, path, node);
    1120           0 :         return ret;
    1121             : }
    1122             : 
    1123             : /*
    1124             :  * Called when committing the transaction.
    1125             :  * Returns 0 on success.
    1126             :  * Returns < 0 on error and returns with an aborted transaction with any
    1127             :  * outstanding delayed items cleaned up.
    1128             :  */
    1129           0 : static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
    1130             : {
    1131           0 :         struct btrfs_fs_info *fs_info = trans->fs_info;
    1132           0 :         struct btrfs_delayed_root *delayed_root;
    1133           0 :         struct btrfs_delayed_node *curr_node, *prev_node;
    1134           0 :         struct btrfs_path *path;
    1135           0 :         struct btrfs_block_rsv *block_rsv;
    1136           0 :         int ret = 0;
    1137           0 :         bool count = (nr > 0);
    1138             : 
    1139           0 :         if (TRANS_ABORTED(trans))
    1140             :                 return -EIO;
    1141             : 
    1142           0 :         path = btrfs_alloc_path();
    1143           0 :         if (!path)
    1144             :                 return -ENOMEM;
    1145             : 
    1146           0 :         block_rsv = trans->block_rsv;
    1147           0 :         trans->block_rsv = &fs_info->delayed_block_rsv;
    1148             : 
    1149           0 :         delayed_root = fs_info->delayed_root;
    1150             : 
    1151           0 :         curr_node = btrfs_first_delayed_node(delayed_root);
    1152           0 :         while (curr_node && (!count || nr--)) {
    1153           0 :                 ret = __btrfs_commit_inode_delayed_items(trans, path,
    1154             :                                                          curr_node);
    1155           0 :                 if (ret) {
    1156           0 :                         btrfs_release_delayed_node(curr_node);
    1157           0 :                         curr_node = NULL;
    1158           0 :                         btrfs_abort_transaction(trans, ret);
    1159           0 :                         break;
    1160             :                 }
    1161             : 
    1162           0 :                 prev_node = curr_node;
    1163           0 :                 curr_node = btrfs_next_delayed_node(curr_node);
    1164           0 :                 btrfs_release_delayed_node(prev_node);
    1165             :         }
    1166             : 
    1167           0 :         if (curr_node)
    1168           0 :                 btrfs_release_delayed_node(curr_node);
    1169           0 :         btrfs_free_path(path);
    1170           0 :         trans->block_rsv = block_rsv;
    1171             : 
    1172           0 :         return ret;
    1173             : }
    1174             : 
    1175           0 : int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)
    1176             : {
    1177           0 :         return __btrfs_run_delayed_items(trans, -1);
    1178             : }
    1179             : 
    1180           0 : int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)
    1181             : {
    1182           0 :         return __btrfs_run_delayed_items(trans, nr);
    1183             : }
    1184             : 
    1185           0 : int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
    1186             :                                      struct btrfs_inode *inode)
    1187             : {
    1188           0 :         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
    1189           0 :         struct btrfs_path *path;
    1190           0 :         struct btrfs_block_rsv *block_rsv;
    1191           0 :         int ret;
    1192             : 
    1193           0 :         if (!delayed_node)
    1194             :                 return 0;
    1195             : 
    1196           0 :         mutex_lock(&delayed_node->mutex);
    1197           0 :         if (!delayed_node->count) {
    1198           0 :                 mutex_unlock(&delayed_node->mutex);
    1199           0 :                 btrfs_release_delayed_node(delayed_node);
    1200           0 :                 return 0;
    1201             :         }
    1202           0 :         mutex_unlock(&delayed_node->mutex);
    1203             : 
    1204           0 :         path = btrfs_alloc_path();
    1205           0 :         if (!path) {
    1206           0 :                 btrfs_release_delayed_node(delayed_node);
    1207           0 :                 return -ENOMEM;
    1208             :         }
    1209             : 
    1210           0 :         block_rsv = trans->block_rsv;
    1211           0 :         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
    1212             : 
    1213           0 :         ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
    1214             : 
    1215           0 :         btrfs_release_delayed_node(delayed_node);
    1216           0 :         btrfs_free_path(path);
    1217           0 :         trans->block_rsv = block_rsv;
    1218             : 
    1219           0 :         return ret;
    1220             : }
    1221             : 
    1222           0 : int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
    1223             : {
    1224           0 :         struct btrfs_fs_info *fs_info = inode->root->fs_info;
    1225           0 :         struct btrfs_trans_handle *trans;
    1226           0 :         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
    1227           0 :         struct btrfs_path *path;
    1228           0 :         struct btrfs_block_rsv *block_rsv;
    1229           0 :         int ret;
    1230             : 
    1231           0 :         if (!delayed_node)
    1232             :                 return 0;
    1233             : 
    1234           0 :         mutex_lock(&delayed_node->mutex);
    1235           0 :         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
    1236           0 :                 mutex_unlock(&delayed_node->mutex);
    1237           0 :                 btrfs_release_delayed_node(delayed_node);
    1238           0 :                 return 0;
    1239             :         }
    1240           0 :         mutex_unlock(&delayed_node->mutex);
    1241             : 
    1242           0 :         trans = btrfs_join_transaction(delayed_node->root);
    1243           0 :         if (IS_ERR(trans)) {
    1244           0 :                 ret = PTR_ERR(trans);
    1245           0 :                 goto out;
    1246             :         }
    1247             : 
    1248           0 :         path = btrfs_alloc_path();
    1249           0 :         if (!path) {
    1250           0 :                 ret = -ENOMEM;
    1251           0 :                 goto trans_out;
    1252             :         }
    1253             : 
    1254           0 :         block_rsv = trans->block_rsv;
    1255           0 :         trans->block_rsv = &fs_info->delayed_block_rsv;
    1256             : 
    1257           0 :         mutex_lock(&delayed_node->mutex);
    1258           0 :         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
    1259           0 :                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
    1260             :                                                    path, delayed_node);
    1261             :         else
    1262             :                 ret = 0;
    1263           0 :         mutex_unlock(&delayed_node->mutex);
    1264             : 
    1265           0 :         btrfs_free_path(path);
    1266           0 :         trans->block_rsv = block_rsv;
    1267           0 : trans_out:
    1268           0 :         btrfs_end_transaction(trans);
    1269           0 :         btrfs_btree_balance_dirty(fs_info);
    1270           0 : out:
    1271           0 :         btrfs_release_delayed_node(delayed_node);
    1272             : 
    1273           0 :         return ret;
    1274             : }
    1275             : 
    1276           0 : void btrfs_remove_delayed_node(struct btrfs_inode *inode)
    1277             : {
    1278           0 :         struct btrfs_delayed_node *delayed_node;
    1279             : 
    1280           0 :         delayed_node = READ_ONCE(inode->delayed_node);
    1281           0 :         if (!delayed_node)
    1282             :                 return;
    1283             : 
    1284           0 :         inode->delayed_node = NULL;
    1285           0 :         btrfs_release_delayed_node(delayed_node);
    1286             : }
    1287             : 
    1288             : struct btrfs_async_delayed_work {
    1289             :         struct btrfs_delayed_root *delayed_root;
    1290             :         int nr;
    1291             :         struct btrfs_work work;
    1292             : };
    1293             : 
    1294           0 : static void btrfs_async_run_delayed_root(struct btrfs_work *work)
    1295             : {
    1296           0 :         struct btrfs_async_delayed_work *async_work;
    1297           0 :         struct btrfs_delayed_root *delayed_root;
    1298           0 :         struct btrfs_trans_handle *trans;
    1299           0 :         struct btrfs_path *path;
    1300           0 :         struct btrfs_delayed_node *delayed_node = NULL;
    1301           0 :         struct btrfs_root *root;
    1302           0 :         struct btrfs_block_rsv *block_rsv;
    1303           0 :         int total_done = 0;
    1304             : 
    1305           0 :         async_work = container_of(work, struct btrfs_async_delayed_work, work);
    1306           0 :         delayed_root = async_work->delayed_root;
    1307             : 
    1308           0 :         path = btrfs_alloc_path();
    1309           0 :         if (!path)
    1310           0 :                 goto out;
    1311             : 
    1312           0 :         do {
    1313           0 :                 if (atomic_read(&delayed_root->items) <
    1314             :                     BTRFS_DELAYED_BACKGROUND / 2)
    1315             :                         break;
    1316             : 
    1317           0 :                 delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
    1318           0 :                 if (!delayed_node)
    1319             :                         break;
    1320             : 
    1321           0 :                 root = delayed_node->root;
    1322             : 
    1323           0 :                 trans = btrfs_join_transaction(root);
    1324           0 :                 if (IS_ERR(trans)) {
    1325           0 :                         btrfs_release_path(path);
    1326           0 :                         btrfs_release_prepared_delayed_node(delayed_node);
    1327           0 :                         total_done++;
    1328           0 :                         continue;
    1329             :                 }
    1330             : 
    1331           0 :                 block_rsv = trans->block_rsv;
    1332           0 :                 trans->block_rsv = &root->fs_info->delayed_block_rsv;
    1333             : 
    1334           0 :                 __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
    1335             : 
    1336           0 :                 trans->block_rsv = block_rsv;
    1337           0 :                 btrfs_end_transaction(trans);
    1338           0 :                 btrfs_btree_balance_dirty_nodelay(root->fs_info);
    1339             : 
    1340           0 :                 btrfs_release_path(path);
    1341           0 :                 btrfs_release_prepared_delayed_node(delayed_node);
    1342           0 :                 total_done++;
    1343             : 
    1344           0 :         } while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
    1345           0 :                  || total_done < async_work->nr);
    1346             : 
    1347           0 :         btrfs_free_path(path);
    1348           0 : out:
    1349           0 :         wake_up(&delayed_root->wait);
    1350           0 :         kfree(async_work);
    1351           0 : }
    1352             : 
    1353             : 
    1354           0 : static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
    1355             :                                      struct btrfs_fs_info *fs_info, int nr)
    1356             : {
    1357           0 :         struct btrfs_async_delayed_work *async_work;
    1358             : 
    1359           0 :         async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
    1360           0 :         if (!async_work)
    1361             :                 return -ENOMEM;
    1362             : 
    1363           0 :         async_work->delayed_root = delayed_root;
    1364           0 :         btrfs_init_work(&async_work->work, btrfs_async_run_delayed_root, NULL,
    1365             :                         NULL);
    1366           0 :         async_work->nr = nr;
    1367             : 
    1368           0 :         btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
    1369           0 :         return 0;
    1370             : }
    1371             : 
    1372           0 : void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
    1373             : {
    1374           0 :         WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));
    1375           0 : }
    1376             : 
    1377             : static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
    1378             : {
    1379           0 :         int val = atomic_read(&delayed_root->items_seq);
    1380             : 
    1381           0 :         if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
    1382             :                 return 1;
    1383             : 
    1384           0 :         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
    1385             :                 return 1;
    1386             : 
    1387             :         return 0;
    1388             : }
    1389             : 
    1390           0 : void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
    1391             : {
    1392           0 :         struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
    1393             : 
    1394           0 :         if ((atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
    1395           0 :                 btrfs_workqueue_normal_congested(fs_info->delayed_workers))
    1396           0 :                 return;
    1397             : 
    1398           0 :         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
    1399           0 :                 int seq;
    1400           0 :                 int ret;
    1401             : 
    1402           0 :                 seq = atomic_read(&delayed_root->items_seq);
    1403             : 
    1404           0 :                 ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
    1405           0 :                 if (ret)
    1406             :                         return;
    1407             : 
    1408           0 :                 wait_event_interruptible(delayed_root->wait,
    1409             :                                          could_end_wait(delayed_root, seq));
    1410           0 :                 return;
    1411             :         }
    1412             : 
    1413           0 :         btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
    1414             : }
    1415             : 
    1416             : /* Will return 0 or -ENOMEM */
    1417           0 : int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
    1418             :                                    const char *name, int name_len,
    1419             :                                    struct btrfs_inode *dir,
    1420             :                                    struct btrfs_disk_key *disk_key, u8 flags,
    1421             :                                    u64 index)
    1422             : {
    1423           0 :         struct btrfs_fs_info *fs_info = trans->fs_info;
    1424           0 :         const unsigned int leaf_data_size = BTRFS_LEAF_DATA_SIZE(fs_info);
    1425           0 :         struct btrfs_delayed_node *delayed_node;
    1426           0 :         struct btrfs_delayed_item *delayed_item;
    1427           0 :         struct btrfs_dir_item *dir_item;
    1428           0 :         bool reserve_leaf_space;
    1429           0 :         u32 data_len;
    1430           0 :         int ret;
    1431             : 
    1432           0 :         delayed_node = btrfs_get_or_create_delayed_node(dir);
    1433           0 :         if (IS_ERR(delayed_node))
    1434           0 :                 return PTR_ERR(delayed_node);
    1435             : 
    1436           0 :         delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len,
    1437             :                                                 delayed_node,
    1438             :                                                 BTRFS_DELAYED_INSERTION_ITEM);
    1439           0 :         if (!delayed_item) {
    1440           0 :                 ret = -ENOMEM;
    1441           0 :                 goto release_node;
    1442             :         }
    1443             : 
    1444           0 :         delayed_item->index = index;
    1445             : 
    1446           0 :         dir_item = (struct btrfs_dir_item *)delayed_item->data;
    1447           0 :         dir_item->location = *disk_key;
    1448           0 :         btrfs_set_stack_dir_transid(dir_item, trans->transid);
    1449           0 :         btrfs_set_stack_dir_data_len(dir_item, 0);
    1450           0 :         btrfs_set_stack_dir_name_len(dir_item, name_len);
    1451           0 :         btrfs_set_stack_dir_flags(dir_item, flags);
    1452           0 :         memcpy((char *)(dir_item + 1), name, name_len);
    1453             : 
    1454           0 :         data_len = delayed_item->data_len + sizeof(struct btrfs_item);
    1455             : 
    1456           0 :         mutex_lock(&delayed_node->mutex);
    1457             : 
    1458           0 :         if (delayed_node->index_item_leaves == 0 ||
    1459           0 :             delayed_node->curr_index_batch_size + data_len > leaf_data_size) {
    1460           0 :                 delayed_node->curr_index_batch_size = data_len;
    1461           0 :                 reserve_leaf_space = true;
    1462             :         } else {
    1463           0 :                 delayed_node->curr_index_batch_size += data_len;
    1464           0 :                 reserve_leaf_space = false;
    1465             :         }
    1466             : 
    1467           0 :         if (reserve_leaf_space) {
    1468           0 :                 ret = btrfs_delayed_item_reserve_metadata(trans, delayed_item);
    1469             :                 /*
    1470             :                  * Space was reserved for a dir index item insertion when we
    1471             :                  * started the transaction, so getting a failure here should be
    1472             :                  * impossible.
    1473             :                  */
    1474           0 :                 if (WARN_ON(ret)) {
    1475           0 :                         mutex_unlock(&delayed_node->mutex);
    1476           0 :                         btrfs_release_delayed_item(delayed_item);
    1477           0 :                         goto release_node;
    1478             :                 }
    1479             : 
    1480           0 :                 delayed_node->index_item_leaves++;
    1481           0 :         } else if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
    1482           0 :                 const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
    1483             : 
    1484             :                 /*
    1485             :                  * Adding the new dir index item does not require touching another
    1486             :                  * leaf, so we can release 1 unit of metadata that was previously
    1487             :                  * reserved when starting the transaction. This applies only to
    1488             :                  * the case where we had a transaction start and excludes the
    1489             :                  * transaction join case (when replaying log trees).
    1490             :                  */
    1491           0 :                 trace_btrfs_space_reservation(fs_info, "transaction",
    1492             :                                               trans->transid, bytes, 0);
    1493           0 :                 btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
    1494           0 :                 ASSERT(trans->bytes_reserved >= bytes);
    1495           0 :                 trans->bytes_reserved -= bytes;
    1496             :         }
    1497             : 
    1498           0 :         ret = __btrfs_add_delayed_item(delayed_node, delayed_item);
    1499           0 :         if (unlikely(ret)) {
    1500           0 :                 btrfs_err(trans->fs_info,
    1501             :                           "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
    1502             :                           name_len, name, delayed_node->root->root_key.objectid,
    1503             :                           delayed_node->inode_id, ret);
    1504           0 :                 BUG();
    1505             :         }
    1506           0 :         mutex_unlock(&delayed_node->mutex);
    1507             : 
    1508           0 : release_node:
    1509           0 :         btrfs_release_delayed_node(delayed_node);
    1510           0 :         return ret;
    1511             : }
    1512             : 
    1513           0 : static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,
    1514             :                                                struct btrfs_delayed_node *node,
    1515             :                                                u64 index)
    1516             : {
    1517           0 :         struct btrfs_delayed_item *item;
    1518             : 
    1519           0 :         mutex_lock(&node->mutex);
    1520           0 :         item = __btrfs_lookup_delayed_item(&node->ins_root.rb_root, index);
    1521           0 :         if (!item) {
    1522           0 :                 mutex_unlock(&node->mutex);
    1523           0 :                 return 1;
    1524             :         }
    1525             : 
    1526             :         /*
    1527             :          * For delayed items to insert, we track reserved metadata bytes based
    1528             :          * on the number of leaves that we will use.
    1529             :          * See btrfs_insert_delayed_dir_index() and
    1530             :          * btrfs_delayed_item_reserve_metadata()).
    1531             :          */
    1532           0 :         ASSERT(item->bytes_reserved == 0);
    1533           0 :         ASSERT(node->index_item_leaves > 0);
    1534             : 
    1535             :         /*
    1536             :          * If there's only one leaf reserved, we can decrement this item from the
    1537             :          * current batch, otherwise we can not because we don't know which leaf
    1538             :          * it belongs to. With the current limit on delayed items, we rarely
    1539             :          * accumulate enough dir index items to fill more than one leaf (even
    1540             :          * when using a leaf size of 4K).
    1541             :          */
    1542           0 :         if (node->index_item_leaves == 1) {
    1543           0 :                 const u32 data_len = item->data_len + sizeof(struct btrfs_item);
    1544             : 
    1545           0 :                 ASSERT(node->curr_index_batch_size >= data_len);
    1546           0 :                 node->curr_index_batch_size -= data_len;
    1547             :         }
    1548             : 
    1549           0 :         btrfs_release_delayed_item(item);
    1550             : 
    1551             :         /* If we now have no more dir index items, we can release all leaves. */
    1552           0 :         if (RB_EMPTY_ROOT(&node->ins_root.rb_root)) {
    1553           0 :                 btrfs_delayed_item_release_leaves(node, node->index_item_leaves);
    1554           0 :                 node->index_item_leaves = 0;
    1555             :         }
    1556             : 
    1557           0 :         mutex_unlock(&node->mutex);
    1558           0 :         return 0;
    1559             : }
    1560             : 
    1561           0 : int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
    1562             :                                    struct btrfs_inode *dir, u64 index)
    1563             : {
    1564           0 :         struct btrfs_delayed_node *node;
    1565           0 :         struct btrfs_delayed_item *item;
    1566           0 :         int ret;
    1567             : 
    1568           0 :         node = btrfs_get_or_create_delayed_node(dir);
    1569           0 :         if (IS_ERR(node))
    1570           0 :                 return PTR_ERR(node);
    1571             : 
    1572           0 :         ret = btrfs_delete_delayed_insertion_item(trans->fs_info, node, index);
    1573           0 :         if (!ret)
    1574           0 :                 goto end;
    1575             : 
    1576           0 :         item = btrfs_alloc_delayed_item(0, node, BTRFS_DELAYED_DELETION_ITEM);
    1577           0 :         if (!item) {
    1578           0 :                 ret = -ENOMEM;
    1579           0 :                 goto end;
    1580             :         }
    1581             : 
    1582           0 :         item->index = index;
    1583             : 
    1584           0 :         ret = btrfs_delayed_item_reserve_metadata(trans, item);
    1585             :         /*
    1586             :          * we have reserved enough space when we start a new transaction,
    1587             :          * so reserving metadata failure is impossible.
    1588             :          */
    1589           0 :         if (ret < 0) {
    1590           0 :                 btrfs_err(trans->fs_info,
    1591             : "metadata reservation failed for delayed dir item deltiona, should have been reserved");
    1592           0 :                 btrfs_release_delayed_item(item);
    1593           0 :                 goto end;
    1594             :         }
    1595             : 
    1596           0 :         mutex_lock(&node->mutex);
    1597           0 :         ret = __btrfs_add_delayed_item(node, item);
    1598           0 :         if (unlikely(ret)) {
    1599           0 :                 btrfs_err(trans->fs_info,
    1600             :                           "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
    1601             :                           index, node->root->root_key.objectid,
    1602             :                           node->inode_id, ret);
    1603           0 :                 btrfs_delayed_item_release_metadata(dir->root, item);
    1604           0 :                 btrfs_release_delayed_item(item);
    1605             :         }
    1606           0 :         mutex_unlock(&node->mutex);
    1607           0 : end:
    1608           0 :         btrfs_release_delayed_node(node);
    1609           0 :         return ret;
    1610             : }
    1611             : 
    1612           0 : int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)
    1613             : {
    1614           0 :         struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
    1615             : 
    1616           0 :         if (!delayed_node)
    1617             :                 return -ENOENT;
    1618             : 
    1619             :         /*
    1620             :          * Since we have held i_mutex of this directory, it is impossible that
    1621             :          * a new directory index is added into the delayed node and index_cnt
    1622             :          * is updated now. So we needn't lock the delayed node.
    1623             :          */
    1624           0 :         if (!delayed_node->index_cnt) {
    1625           0 :                 btrfs_release_delayed_node(delayed_node);
    1626           0 :                 return -EINVAL;
    1627             :         }
    1628             : 
    1629           0 :         inode->index_cnt = delayed_node->index_cnt;
    1630           0 :         btrfs_release_delayed_node(delayed_node);
    1631           0 :         return 0;
    1632             : }
    1633             : 
    1634           0 : bool btrfs_readdir_get_delayed_items(struct inode *inode,
    1635             :                                      struct list_head *ins_list,
    1636             :                                      struct list_head *del_list)
    1637             : {
    1638           0 :         struct btrfs_delayed_node *delayed_node;
    1639           0 :         struct btrfs_delayed_item *item;
    1640             : 
    1641           0 :         delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
    1642           0 :         if (!delayed_node)
    1643             :                 return false;
    1644             : 
    1645             :         /*
    1646             :          * We can only do one readdir with delayed items at a time because of
    1647             :          * item->readdir_list.
    1648             :          */
    1649           0 :         btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_SHARED);
    1650           0 :         btrfs_inode_lock(BTRFS_I(inode), 0);
    1651             : 
    1652           0 :         mutex_lock(&delayed_node->mutex);
    1653           0 :         item = __btrfs_first_delayed_insertion_item(delayed_node);
    1654           0 :         while (item) {
    1655           0 :                 refcount_inc(&item->refs);
    1656           0 :                 list_add_tail(&item->readdir_list, ins_list);
    1657           0 :                 item = __btrfs_next_delayed_item(item);
    1658             :         }
    1659             : 
    1660           0 :         item = __btrfs_first_delayed_deletion_item(delayed_node);
    1661           0 :         while (item) {
    1662           0 :                 refcount_inc(&item->refs);
    1663           0 :                 list_add_tail(&item->readdir_list, del_list);
    1664           0 :                 item = __btrfs_next_delayed_item(item);
    1665             :         }
    1666           0 :         mutex_unlock(&delayed_node->mutex);
    1667             :         /*
    1668             :          * This delayed node is still cached in the btrfs inode, so refs
    1669             :          * must be > 1 now, and we needn't check it is going to be freed
    1670             :          * or not.
    1671             :          *
    1672             :          * Besides that, this function is used to read dir, we do not
    1673             :          * insert/delete delayed items in this period. So we also needn't
    1674             :          * requeue or dequeue this delayed node.
    1675             :          */
    1676           0 :         refcount_dec(&delayed_node->refs);
    1677             : 
    1678           0 :         return true;
    1679             : }
    1680             : 
    1681           0 : void btrfs_readdir_put_delayed_items(struct inode *inode,
    1682             :                                      struct list_head *ins_list,
    1683             :                                      struct list_head *del_list)
    1684             : {
    1685           0 :         struct btrfs_delayed_item *curr, *next;
    1686             : 
    1687           0 :         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
    1688           0 :                 list_del(&curr->readdir_list);
    1689           0 :                 if (refcount_dec_and_test(&curr->refs))
    1690           0 :                         kfree(curr);
    1691             :         }
    1692             : 
    1693           0 :         list_for_each_entry_safe(curr, next, del_list, readdir_list) {
    1694           0 :                 list_del(&curr->readdir_list);
    1695           0 :                 if (refcount_dec_and_test(&curr->refs))
    1696           0 :                         kfree(curr);
    1697             :         }
    1698             : 
    1699             :         /*
    1700             :          * The VFS is going to do up_read(), so we need to downgrade back to a
    1701             :          * read lock.
    1702             :          */
    1703           0 :         downgrade_write(&inode->i_rwsem);
    1704           0 : }
    1705             : 
    1706           0 : int btrfs_should_delete_dir_index(struct list_head *del_list,
    1707             :                                   u64 index)
    1708             : {
    1709           0 :         struct btrfs_delayed_item *curr;
    1710           0 :         int ret = 0;
    1711             : 
    1712           0 :         list_for_each_entry(curr, del_list, readdir_list) {
    1713           0 :                 if (curr->index > index)
    1714             :                         break;
    1715           0 :                 if (curr->index == index) {
    1716             :                         ret = 1;
    1717             :                         break;
    1718             :                 }
    1719             :         }
    1720           0 :         return ret;
    1721             : }
    1722             : 
    1723             : /*
    1724             :  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
    1725             :  *
    1726             :  */
    1727           0 : int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
    1728             :                                     struct list_head *ins_list)
    1729             : {
    1730           0 :         struct btrfs_dir_item *di;
    1731           0 :         struct btrfs_delayed_item *curr, *next;
    1732           0 :         struct btrfs_key location;
    1733           0 :         char *name;
    1734           0 :         int name_len;
    1735           0 :         int over = 0;
    1736           0 :         unsigned char d_type;
    1737             : 
    1738           0 :         if (list_empty(ins_list))
    1739             :                 return 0;
    1740             : 
    1741             :         /*
    1742             :          * Changing the data of the delayed item is impossible. So
    1743             :          * we needn't lock them. And we have held i_mutex of the
    1744             :          * directory, nobody can delete any directory indexes now.
    1745             :          */
    1746           0 :         list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
    1747           0 :                 list_del(&curr->readdir_list);
    1748             : 
    1749           0 :                 if (curr->index < ctx->pos) {
    1750           0 :                         if (refcount_dec_and_test(&curr->refs))
    1751           0 :                                 kfree(curr);
    1752           0 :                         continue;
    1753             :                 }
    1754             : 
    1755           0 :                 ctx->pos = curr->index;
    1756             : 
    1757           0 :                 di = (struct btrfs_dir_item *)curr->data;
    1758           0 :                 name = (char *)(di + 1);
    1759           0 :                 name_len = btrfs_stack_dir_name_len(di);
    1760             : 
    1761           0 :                 d_type = fs_ftype_to_dtype(btrfs_dir_flags_to_ftype(di->type));
    1762           0 :                 btrfs_disk_key_to_cpu(&location, &di->location);
    1763             : 
    1764           0 :                 over = !dir_emit(ctx, name, name_len,
    1765             :                                location.objectid, d_type);
    1766             : 
    1767           0 :                 if (refcount_dec_and_test(&curr->refs))
    1768           0 :                         kfree(curr);
    1769             : 
    1770           0 :                 if (over)
    1771             :                         return 1;
    1772           0 :                 ctx->pos++;
    1773             :         }
    1774             :         return 0;
    1775             : }
    1776             : 
    1777           0 : static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
    1778             :                                   struct btrfs_inode_item *inode_item,
    1779             :                                   struct inode *inode)
    1780             : {
    1781           0 :         u64 flags;
    1782             : 
    1783           0 :         btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
    1784           0 :         btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
    1785           0 :         btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
    1786           0 :         btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
    1787           0 :         btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
    1788           0 :         btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
    1789           0 :         btrfs_set_stack_inode_generation(inode_item,
    1790             :                                          BTRFS_I(inode)->generation);
    1791           0 :         btrfs_set_stack_inode_sequence(inode_item,
    1792             :                                        inode_peek_iversion(inode));
    1793           0 :         btrfs_set_stack_inode_transid(inode_item, trans->transid);
    1794           0 :         btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
    1795           0 :         flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
    1796             :                                           BTRFS_I(inode)->ro_flags);
    1797           0 :         btrfs_set_stack_inode_flags(inode_item, flags);
    1798           0 :         btrfs_set_stack_inode_block_group(inode_item, 0);
    1799             : 
    1800           0 :         btrfs_set_stack_timespec_sec(&inode_item->atime,
    1801           0 :                                      inode->i_atime.tv_sec);
    1802           0 :         btrfs_set_stack_timespec_nsec(&inode_item->atime,
    1803           0 :                                       inode->i_atime.tv_nsec);
    1804             : 
    1805           0 :         btrfs_set_stack_timespec_sec(&inode_item->mtime,
    1806           0 :                                      inode->i_mtime.tv_sec);
    1807           0 :         btrfs_set_stack_timespec_nsec(&inode_item->mtime,
    1808           0 :                                       inode->i_mtime.tv_nsec);
    1809             : 
    1810           0 :         btrfs_set_stack_timespec_sec(&inode_item->ctime,
    1811           0 :                                      inode->i_ctime.tv_sec);
    1812           0 :         btrfs_set_stack_timespec_nsec(&inode_item->ctime,
    1813           0 :                                       inode->i_ctime.tv_nsec);
    1814             : 
    1815           0 :         btrfs_set_stack_timespec_sec(&inode_item->otime,
    1816           0 :                                      BTRFS_I(inode)->i_otime.tv_sec);
    1817           0 :         btrfs_set_stack_timespec_nsec(&inode_item->otime,
    1818           0 :                                      BTRFS_I(inode)->i_otime.tv_nsec);
    1819           0 : }
    1820             : 
    1821           0 : int btrfs_fill_inode(struct inode *inode, u32 *rdev)
    1822             : {
    1823           0 :         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
    1824           0 :         struct btrfs_delayed_node *delayed_node;
    1825           0 :         struct btrfs_inode_item *inode_item;
    1826             : 
    1827           0 :         delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
    1828           0 :         if (!delayed_node)
    1829             :                 return -ENOENT;
    1830             : 
    1831           0 :         mutex_lock(&delayed_node->mutex);
    1832           0 :         if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
    1833           0 :                 mutex_unlock(&delayed_node->mutex);
    1834           0 :                 btrfs_release_delayed_node(delayed_node);
    1835           0 :                 return -ENOENT;
    1836             :         }
    1837             : 
    1838           0 :         inode_item = &delayed_node->inode_item;
    1839             : 
    1840           0 :         i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
    1841           0 :         i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
    1842           0 :         btrfs_i_size_write(BTRFS_I(inode), btrfs_stack_inode_size(inode_item));
    1843           0 :         btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
    1844           0 :                         round_up(i_size_read(inode), fs_info->sectorsize));
    1845           0 :         inode->i_mode = btrfs_stack_inode_mode(inode_item);
    1846           0 :         set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
    1847           0 :         inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
    1848           0 :         BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
    1849           0 :         BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
    1850             : 
    1851           0 :         inode_set_iversion_queried(inode,
    1852             :                                    btrfs_stack_inode_sequence(inode_item));
    1853           0 :         inode->i_rdev = 0;
    1854           0 :         *rdev = btrfs_stack_inode_rdev(inode_item);
    1855           0 :         btrfs_inode_split_flags(btrfs_stack_inode_flags(inode_item),
    1856             :                                 &BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
    1857             : 
    1858           0 :         inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
    1859           0 :         inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
    1860             : 
    1861           0 :         inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
    1862           0 :         inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
    1863             : 
    1864           0 :         inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
    1865           0 :         inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
    1866             : 
    1867           0 :         BTRFS_I(inode)->i_otime.tv_sec =
    1868           0 :                 btrfs_stack_timespec_sec(&inode_item->otime);
    1869           0 :         BTRFS_I(inode)->i_otime.tv_nsec =
    1870           0 :                 btrfs_stack_timespec_nsec(&inode_item->otime);
    1871             : 
    1872           0 :         inode->i_generation = BTRFS_I(inode)->generation;
    1873           0 :         BTRFS_I(inode)->index_cnt = (u64)-1;
    1874             : 
    1875           0 :         mutex_unlock(&delayed_node->mutex);
    1876           0 :         btrfs_release_delayed_node(delayed_node);
    1877           0 :         return 0;
    1878             : }
    1879             : 
    1880           0 : int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
    1881             :                                struct btrfs_root *root,
    1882             :                                struct btrfs_inode *inode)
    1883             : {
    1884           0 :         struct btrfs_delayed_node *delayed_node;
    1885           0 :         int ret = 0;
    1886             : 
    1887           0 :         delayed_node = btrfs_get_or_create_delayed_node(inode);
    1888           0 :         if (IS_ERR(delayed_node))
    1889           0 :                 return PTR_ERR(delayed_node);
    1890             : 
    1891           0 :         mutex_lock(&delayed_node->mutex);
    1892           0 :         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
    1893           0 :                 fill_stack_inode_item(trans, &delayed_node->inode_item,
    1894             :                                       &inode->vfs_inode);
    1895           0 :                 goto release_node;
    1896             :         }
    1897             : 
    1898           0 :         ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
    1899           0 :         if (ret)
    1900           0 :                 goto release_node;
    1901             : 
    1902           0 :         fill_stack_inode_item(trans, &delayed_node->inode_item, &inode->vfs_inode);
    1903           0 :         set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
    1904           0 :         delayed_node->count++;
    1905           0 :         atomic_inc(&root->fs_info->delayed_root->items);
    1906           0 : release_node:
    1907           0 :         mutex_unlock(&delayed_node->mutex);
    1908           0 :         btrfs_release_delayed_node(delayed_node);
    1909           0 :         return ret;
    1910             : }
    1911             : 
    1912           0 : int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)
    1913             : {
    1914           0 :         struct btrfs_fs_info *fs_info = inode->root->fs_info;
    1915           0 :         struct btrfs_delayed_node *delayed_node;
    1916             : 
    1917             :         /*
    1918             :          * we don't do delayed inode updates during log recovery because it
    1919             :          * leads to enospc problems.  This means we also can't do
    1920             :          * delayed inode refs
    1921             :          */
    1922           0 :         if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
    1923             :                 return -EAGAIN;
    1924             : 
    1925           0 :         delayed_node = btrfs_get_or_create_delayed_node(inode);
    1926           0 :         if (IS_ERR(delayed_node))
    1927           0 :                 return PTR_ERR(delayed_node);
    1928             : 
    1929             :         /*
    1930             :          * We don't reserve space for inode ref deletion is because:
    1931             :          * - We ONLY do async inode ref deletion for the inode who has only
    1932             :          *   one link(i_nlink == 1), it means there is only one inode ref.
    1933             :          *   And in most case, the inode ref and the inode item are in the
    1934             :          *   same leaf, and we will deal with them at the same time.
    1935             :          *   Since we are sure we will reserve the space for the inode item,
    1936             :          *   it is unnecessary to reserve space for inode ref deletion.
    1937             :          * - If the inode ref and the inode item are not in the same leaf,
    1938             :          *   We also needn't worry about enospc problem, because we reserve
    1939             :          *   much more space for the inode update than it needs.
    1940             :          * - At the worst, we can steal some space from the global reservation.
    1941             :          *   It is very rare.
    1942             :          */
    1943           0 :         mutex_lock(&delayed_node->mutex);
    1944           0 :         if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
    1945           0 :                 goto release_node;
    1946             : 
    1947           0 :         set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
    1948           0 :         delayed_node->count++;
    1949           0 :         atomic_inc(&fs_info->delayed_root->items);
    1950           0 : release_node:
    1951           0 :         mutex_unlock(&delayed_node->mutex);
    1952           0 :         btrfs_release_delayed_node(delayed_node);
    1953           0 :         return 0;
    1954             : }
    1955             : 
    1956           0 : static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
    1957             : {
    1958           0 :         struct btrfs_root *root = delayed_node->root;
    1959           0 :         struct btrfs_fs_info *fs_info = root->fs_info;
    1960           0 :         struct btrfs_delayed_item *curr_item, *prev_item;
    1961             : 
    1962           0 :         mutex_lock(&delayed_node->mutex);
    1963           0 :         curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
    1964           0 :         while (curr_item) {
    1965           0 :                 prev_item = curr_item;
    1966           0 :                 curr_item = __btrfs_next_delayed_item(prev_item);
    1967           0 :                 btrfs_release_delayed_item(prev_item);
    1968             :         }
    1969             : 
    1970           0 :         if (delayed_node->index_item_leaves > 0) {
    1971           0 :                 btrfs_delayed_item_release_leaves(delayed_node,
    1972             :                                           delayed_node->index_item_leaves);
    1973           0 :                 delayed_node->index_item_leaves = 0;
    1974             :         }
    1975             : 
    1976           0 :         curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
    1977           0 :         while (curr_item) {
    1978           0 :                 btrfs_delayed_item_release_metadata(root, curr_item);
    1979           0 :                 prev_item = curr_item;
    1980           0 :                 curr_item = __btrfs_next_delayed_item(prev_item);
    1981           0 :                 btrfs_release_delayed_item(prev_item);
    1982             :         }
    1983             : 
    1984           0 :         btrfs_release_delayed_iref(delayed_node);
    1985             : 
    1986           0 :         if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
    1987           0 :                 btrfs_delayed_inode_release_metadata(fs_info, delayed_node, false);
    1988           0 :                 btrfs_release_delayed_inode(delayed_node);
    1989             :         }
    1990           0 :         mutex_unlock(&delayed_node->mutex);
    1991           0 : }
    1992             : 
    1993           0 : void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)
    1994             : {
    1995           0 :         struct btrfs_delayed_node *delayed_node;
    1996             : 
    1997           0 :         delayed_node = btrfs_get_delayed_node(inode);
    1998           0 :         if (!delayed_node)
    1999             :                 return;
    2000             : 
    2001           0 :         __btrfs_kill_delayed_node(delayed_node);
    2002           0 :         btrfs_release_delayed_node(delayed_node);
    2003             : }
    2004             : 
    2005           0 : void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
    2006             : {
    2007           0 :         u64 inode_id = 0;
    2008           0 :         struct btrfs_delayed_node *delayed_nodes[8];
    2009           0 :         int i, n;
    2010             : 
    2011           0 :         while (1) {
    2012           0 :                 spin_lock(&root->inode_lock);
    2013           0 :                 n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
    2014             :                                            (void **)delayed_nodes, inode_id,
    2015             :                                            ARRAY_SIZE(delayed_nodes));
    2016           0 :                 if (!n) {
    2017           0 :                         spin_unlock(&root->inode_lock);
    2018           0 :                         break;
    2019             :                 }
    2020             : 
    2021           0 :                 inode_id = delayed_nodes[n - 1]->inode_id + 1;
    2022           0 :                 for (i = 0; i < n; i++) {
    2023             :                         /*
    2024             :                          * Don't increase refs in case the node is dead and
    2025             :                          * about to be removed from the tree in the loop below
    2026             :                          */
    2027           0 :                         if (!refcount_inc_not_zero(&delayed_nodes[i]->refs))
    2028           0 :                                 delayed_nodes[i] = NULL;
    2029             :                 }
    2030           0 :                 spin_unlock(&root->inode_lock);
    2031             : 
    2032           0 :                 for (i = 0; i < n; i++) {
    2033           0 :                         if (!delayed_nodes[i])
    2034           0 :                                 continue;
    2035           0 :                         __btrfs_kill_delayed_node(delayed_nodes[i]);
    2036           0 :                         btrfs_release_delayed_node(delayed_nodes[i]);
    2037             :                 }
    2038             :         }
    2039           0 : }
    2040             : 
    2041           0 : void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
    2042             : {
    2043           0 :         struct btrfs_delayed_node *curr_node, *prev_node;
    2044             : 
    2045           0 :         curr_node = btrfs_first_delayed_node(fs_info->delayed_root);
    2046           0 :         while (curr_node) {
    2047           0 :                 __btrfs_kill_delayed_node(curr_node);
    2048             : 
    2049           0 :                 prev_node = curr_node;
    2050           0 :                 curr_node = btrfs_next_delayed_node(curr_node);
    2051           0 :                 btrfs_release_delayed_node(prev_node);
    2052             :         }
    2053           0 : }
    2054             : 
    2055           0 : void btrfs_log_get_delayed_items(struct btrfs_inode *inode,
    2056             :                                  struct list_head *ins_list,
    2057             :                                  struct list_head *del_list)
    2058             : {
    2059           0 :         struct btrfs_delayed_node *node;
    2060           0 :         struct btrfs_delayed_item *item;
    2061             : 
    2062           0 :         node = btrfs_get_delayed_node(inode);
    2063           0 :         if (!node)
    2064             :                 return;
    2065             : 
    2066           0 :         mutex_lock(&node->mutex);
    2067           0 :         item = __btrfs_first_delayed_insertion_item(node);
    2068           0 :         while (item) {
    2069             :                 /*
    2070             :                  * It's possible that the item is already in a log list. This
    2071             :                  * can happen in case two tasks are trying to log the same
    2072             :                  * directory. For example if we have tasks A and task B:
    2073             :                  *
    2074             :                  * Task A collected the delayed items into a log list while
    2075             :                  * under the inode's log_mutex (at btrfs_log_inode()), but it
    2076             :                  * only releases the items after logging the inodes they point
    2077             :                  * to (if they are new inodes), which happens after unlocking
    2078             :                  * the log mutex;
    2079             :                  *
    2080             :                  * Task B enters btrfs_log_inode() and acquires the log_mutex
    2081             :                  * of the same directory inode, before task B releases the
    2082             :                  * delayed items. This can happen for example when logging some
    2083             :                  * inode we need to trigger logging of its parent directory, so
    2084             :                  * logging two files that have the same parent directory can
    2085             :                  * lead to this.
    2086             :                  *
    2087             :                  * If this happens, just ignore delayed items already in a log
    2088             :                  * list. All the tasks logging the directory are under a log
    2089             :                  * transaction and whichever finishes first can not sync the log
    2090             :                  * before the other completes and leaves the log transaction.
    2091             :                  */
    2092           0 :                 if (!item->logged && list_empty(&item->log_list)) {
    2093           0 :                         refcount_inc(&item->refs);
    2094           0 :                         list_add_tail(&item->log_list, ins_list);
    2095             :                 }
    2096           0 :                 item = __btrfs_next_delayed_item(item);
    2097             :         }
    2098             : 
    2099           0 :         item = __btrfs_first_delayed_deletion_item(node);
    2100           0 :         while (item) {
    2101             :                 /* It may be non-empty, for the same reason mentioned above. */
    2102           0 :                 if (!item->logged && list_empty(&item->log_list)) {
    2103           0 :                         refcount_inc(&item->refs);
    2104           0 :                         list_add_tail(&item->log_list, del_list);
    2105             :                 }
    2106           0 :                 item = __btrfs_next_delayed_item(item);
    2107             :         }
    2108           0 :         mutex_unlock(&node->mutex);
    2109             : 
    2110             :         /*
    2111             :          * We are called during inode logging, which means the inode is in use
    2112             :          * and can not be evicted before we finish logging the inode. So we never
    2113             :          * have the last reference on the delayed inode.
    2114             :          * Also, we don't use btrfs_release_delayed_node() because that would
    2115             :          * requeue the delayed inode (change its order in the list of prepared
    2116             :          * nodes) and we don't want to do such change because we don't create or
    2117             :          * delete delayed items.
    2118             :          */
    2119           0 :         ASSERT(refcount_read(&node->refs) > 1);
    2120           0 :         refcount_dec(&node->refs);
    2121             : }
    2122             : 
    2123           0 : void btrfs_log_put_delayed_items(struct btrfs_inode *inode,
    2124             :                                  struct list_head *ins_list,
    2125             :                                  struct list_head *del_list)
    2126             : {
    2127           0 :         struct btrfs_delayed_node *node;
    2128           0 :         struct btrfs_delayed_item *item;
    2129           0 :         struct btrfs_delayed_item *next;
    2130             : 
    2131           0 :         node = btrfs_get_delayed_node(inode);
    2132           0 :         if (!node)
    2133             :                 return;
    2134             : 
    2135           0 :         mutex_lock(&node->mutex);
    2136             : 
    2137           0 :         list_for_each_entry_safe(item, next, ins_list, log_list) {
    2138           0 :                 item->logged = true;
    2139           0 :                 list_del_init(&item->log_list);
    2140           0 :                 if (refcount_dec_and_test(&item->refs))
    2141           0 :                         kfree(item);
    2142             :         }
    2143             : 
    2144           0 :         list_for_each_entry_safe(item, next, del_list, log_list) {
    2145           0 :                 item->logged = true;
    2146           0 :                 list_del_init(&item->log_list);
    2147           0 :                 if (refcount_dec_and_test(&item->refs))
    2148           0 :                         kfree(item);
    2149             :         }
    2150             : 
    2151           0 :         mutex_unlock(&node->mutex);
    2152             : 
    2153             :         /*
    2154             :          * We are called during inode logging, which means the inode is in use
    2155             :          * and can not be evicted before we finish logging the inode. So we never
    2156             :          * have the last reference on the delayed inode.
    2157             :          * Also, we don't use btrfs_release_delayed_node() because that would
    2158             :          * requeue the delayed inode (change its order in the list of prepared
    2159             :          * nodes) and we don't want to do such change because we don't create or
    2160             :          * delete delayed items.
    2161             :          */
    2162           0 :         ASSERT(refcount_read(&node->refs) > 1);
    2163           0 :         refcount_dec(&node->refs);
    2164             : }

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