OSCL-LXR linux-6.0.1/​fs/​btrfs/​delayed-inode.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2011 Fujitsu.  All rights reserved.
  * Written by Miao Xie <miaox@cn.fujitsu.com>
  */
 
 #include <linux/slab.h>
 #include <linux/iversion.h>
 #include "misc.h"
 #include "delayed-inode.h"
 #include "disk-io.h"
 #include "transaction.h"
 #include "ctree.h"
 #include "qgroup.h"
 #include "locking.h"
 #include "inode-item.h"
 
 #define BTRFS_DELAYED_WRITEBACK     512
 #define BTRFS_DELAYED_BACKGROUND    128
 #define BTRFS_DELAYED_BATCH     16
 
 static struct kmem_cache *delayed_node_cache;
 
 int __init btrfs_delayed_inode_init(void)
 {
     delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
                     sizeof(struct btrfs_delayed_node),
                     0,
                     SLAB_MEM_SPREAD,
                     NULL);
     if (!delayed_node_cache)
         return -ENOMEM;
     return 0;
 }
 
 void __cold btrfs_delayed_inode_exit(void)
 {
     kmem_cache_destroy(delayed_node_cache);
 }
 
 static inline void btrfs_init_delayed_node(
                 struct btrfs_delayed_node *delayed_node,
                 struct btrfs_root *root, u64 inode_id)
 {
     delayed_node->root = root;
     delayed_node->inode_id = inode_id;
     refcount_set(&delayed_node->refs, 0);
     delayed_node->ins_root = RB_ROOT_CACHED;
     delayed_node->del_root = RB_ROOT_CACHED;
     mutex_init(&delayed_node->mutex);
     INIT_LIST_HEAD(&delayed_node->n_list);
     INIT_LIST_HEAD(&delayed_node->p_list);
 }
 
 static struct btrfs_delayed_node *btrfs_get_delayed_node(
         struct btrfs_inode *btrfs_inode)
 {
     struct btrfs_root *root = btrfs_inode->root;
     u64 ino = btrfs_ino(btrfs_inode);
     struct btrfs_delayed_node *node;
 
     node = READ_ONCE(btrfs_inode->delayed_node);
     if (node) {
         refcount_inc(&node->refs);
         return node;
     }
 
     spin_lock(&root->inode_lock);
     node = radix_tree_lookup(&root->delayed_nodes_tree, ino);
 
     if (node) {
         if (btrfs_inode->delayed_node) {
             refcount_inc(&node->refs);  /* can be accessed */
             BUG_ON(btrfs_inode->delayed_node != node);
             spin_unlock(&root->inode_lock);
             return node;
         }
 
         /*
          * It's possible that we're racing into the middle of removing
          * this node from the radix tree.  In this case, the refcount
          * was zero and it should never go back to one.  Just return
          * NULL like it was never in the radix at all; our release
          * function is in the process of removing it.
          *
          * Some implementations of refcount_inc refuse to bump the
          * refcount once it has hit zero.  If we don't do this dance
          * here, refcount_inc() may decide to just WARN_ONCE() instead
          * of actually bumping the refcount.
          *
          * If this node is properly in the radix, we want to bump the
          * refcount twice, once for the inode and once for this get
          * operation.
          */
         if (refcount_inc_not_zero(&node->refs)) {
             refcount_inc(&node->refs);
             btrfs_inode->delayed_node = node;
         } else {
             node = NULL;
         }
 
         spin_unlock(&root->inode_lock);
         return node;
     }
     spin_unlock(&root->inode_lock);
 
     return NULL;
 }
 
 /* Will return either the node or PTR_ERR(-ENOMEM) */
 static struct btrfs_delayed_node *btrfs_get_or_create_delayed_node(
         struct btrfs_inode *btrfs_inode)
 {
     struct btrfs_delayed_node *node;
     struct btrfs_root *root = btrfs_inode->root;
     u64 ino = btrfs_ino(btrfs_inode);
     int ret;
 
 again:
     node = btrfs_get_delayed_node(btrfs_inode);
     if (node)
         return node;
 
     node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
     if (!node)
         return ERR_PTR(-ENOMEM);
     btrfs_init_delayed_node(node, root, ino);
 
     /* cached in the btrfs inode and can be accessed */
     refcount_set(&node->refs, 2);
 
     ret = radix_tree_preload(GFP_NOFS);
     if (ret) {
         kmem_cache_free(delayed_node_cache, node);
         return ERR_PTR(ret);
     }
 
     spin_lock(&root->inode_lock);
     ret = radix_tree_insert(&root->delayed_nodes_tree, ino, node);
     if (ret == -EEXIST) {
         spin_unlock(&root->inode_lock);
         kmem_cache_free(delayed_node_cache, node);
         radix_tree_preload_end();
         goto again;
     }
     btrfs_inode->delayed_node = node;
     spin_unlock(&root->inode_lock);
     radix_tree_preload_end();
 
     return node;
 }
 
 /*
  * Call it when holding delayed_node->mutex
  *
  * If mod = 1, add this node into the prepared list.
  */
 static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
                      struct btrfs_delayed_node *node,
                      int mod)
 {
     spin_lock(&root->lock);
     if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
         if (!list_empty(&node->p_list))
             list_move_tail(&node->p_list, &root->prepare_list);
         else if (mod)
             list_add_tail(&node->p_list, &root->prepare_list);
     } else {
         list_add_tail(&node->n_list, &root->node_list);
         list_add_tail(&node->p_list, &root->prepare_list);
         refcount_inc(&node->refs);  /* inserted into list */
         root->nodes++;
         set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
     }
     spin_unlock(&root->lock);
 }
 
 /* Call it when holding delayed_node->mutex */
 static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
                        struct btrfs_delayed_node *node)
 {
     spin_lock(&root->lock);
     if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
         root->nodes--;
         refcount_dec(&node->refs);  /* not in the list */
         list_del_init(&node->n_list);
         if (!list_empty(&node->p_list))
             list_del_init(&node->p_list);
         clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
     }
     spin_unlock(&root->lock);
 }
 
 static struct btrfs_delayed_node *btrfs_first_delayed_node(
             struct btrfs_delayed_root *delayed_root)
 {
     struct list_head *p;
     struct btrfs_delayed_node *node = NULL;
 
     spin_lock(&delayed_root->lock);
     if (list_empty(&delayed_root->node_list))
         goto out;
 
     p = delayed_root->node_list.next;
     node = list_entry(p, struct btrfs_delayed_node, n_list);
     refcount_inc(&node->refs);
 out:
     spin_unlock(&delayed_root->lock);
 
     return node;
 }
 
 static struct btrfs_delayed_node *btrfs_next_delayed_node(
                         struct btrfs_delayed_node *node)
 {
     struct btrfs_delayed_root *delayed_root;
     struct list_head *p;
     struct btrfs_delayed_node *next = NULL;
 
     delayed_root = node->root->fs_info->delayed_root;
     spin_lock(&delayed_root->lock);
     if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
         /* not in the list */
         if (list_empty(&delayed_root->node_list))
             goto out;
         p = delayed_root->node_list.next;
     } else if (list_is_last(&node->n_list, &delayed_root->node_list))
         goto out;
     else
         p = node->n_list.next;
 
     next = list_entry(p, struct btrfs_delayed_node, n_list);
     refcount_inc(&next->refs);
 out:
     spin_unlock(&delayed_root->lock);
 
     return next;
 }
 
 static void __btrfs_release_delayed_node(
                 struct btrfs_delayed_node *delayed_node,
                 int mod)
 {
     struct btrfs_delayed_root *delayed_root;
 
     if (!delayed_node)
         return;
 
     delayed_root = delayed_node->root->fs_info->delayed_root;
 
     mutex_lock(&delayed_node->mutex);
     if (delayed_node->count)
         btrfs_queue_delayed_node(delayed_root, delayed_node, mod);
     else
         btrfs_dequeue_delayed_node(delayed_root, delayed_node);
     mutex_unlock(&delayed_node->mutex);
 
     if (refcount_dec_and_test(&delayed_node->refs)) {
         struct btrfs_root *root = delayed_node->root;
 
         spin_lock(&root->inode_lock);
         /*
          * Once our refcount goes to zero, nobody is allowed to bump it
          * back up.  We can delete it now.
          */
         ASSERT(refcount_read(&delayed_node->refs) == 0);
         radix_tree_delete(&root->delayed_nodes_tree,
                   delayed_node->inode_id);
         spin_unlock(&root->inode_lock);
         kmem_cache_free(delayed_node_cache, delayed_node);
     }
 }
 
 static inline void btrfs_release_delayed_node(struct btrfs_delayed_node *node)
 {
     __btrfs_release_delayed_node(node, 0);
 }
 
 static struct btrfs_delayed_node *btrfs_first_prepared_delayed_node(
                     struct btrfs_delayed_root *delayed_root)
 {
     struct list_head *p;
     struct btrfs_delayed_node *node = NULL;
 
     spin_lock(&delayed_root->lock);
     if (list_empty(&delayed_root->prepare_list))
         goto out;
 
     p = delayed_root->prepare_list.next;
     list_del_init(p);
     node = list_entry(p, struct btrfs_delayed_node, p_list);
     refcount_inc(&node->refs);
 out:
     spin_unlock(&delayed_root->lock);
 
     return node;
 }
 
 static inline void btrfs_release_prepared_delayed_node(
                     struct btrfs_delayed_node *node)
 {
     __btrfs_release_delayed_node(node, 1);
 }
 
 static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u32 data_len)
 {
     struct btrfs_delayed_item *item;
     item = kmalloc(sizeof(*item) + data_len, GFP_NOFS);
     if (item) {
         item->data_len = data_len;
         item->ins_or_del = 0;
         item->bytes_reserved = 0;
         item->delayed_node = NULL;
         refcount_set(&item->refs, 1);
     }
     return item;
 }
 
 /*
  * __btrfs_lookup_delayed_item - look up the delayed item by key
  * @delayed_node: pointer to the delayed node
  * @key:      the key to look up
  * @prev:     used to store the prev item if the right item isn't found
  * @next:     used to store the next item if the right item isn't found
  *
  * Note: if we don't find the right item, we will return the prev item and
  * the next item.
  */
 static struct btrfs_delayed_item *__btrfs_lookup_delayed_item(
                 struct rb_root *root,
                 struct btrfs_key *key,
                 struct btrfs_delayed_item **prev,
                 struct btrfs_delayed_item **next)
 {
     struct rb_node *node, *prev_node = NULL;
     struct btrfs_delayed_item *delayed_item = NULL;
     int ret = 0;
 
     node = root->rb_node;
 
     while (node) {
         delayed_item = rb_entry(node, struct btrfs_delayed_item,
                     rb_node);
         prev_node = node;
         ret = btrfs_comp_cpu_keys(&delayed_item->key, key);
         if (ret < 0)
             node = node->rb_right;
         else if (ret > 0)
             node = node->rb_left;
         else
             return delayed_item;
     }
 
     if (prev) {
         if (!prev_node)
             *prev = NULL;
         else if (ret < 0)
             *prev = delayed_item;
         else if ((node = rb_prev(prev_node)) != NULL) {
             *prev = rb_entry(node, struct btrfs_delayed_item,
                      rb_node);
         } else
             *prev = NULL;
     }
 
     if (next) {
         if (!prev_node)
             *next = NULL;
         else if (ret > 0)
             *next = delayed_item;
         else if ((node = rb_next(prev_node)) != NULL) {
             *next = rb_entry(node, struct btrfs_delayed_item,
                      rb_node);
         } else
             *next = NULL;
     }
     return NULL;
 }
 
 static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
                     struct btrfs_delayed_node *delayed_node,
                     struct btrfs_key *key)
 {
     return __btrfs_lookup_delayed_item(&delayed_node->ins_root.rb_root, key,
                        NULL, NULL);
 }
 
 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
                     struct btrfs_delayed_item *ins)
 {
     struct rb_node **p, *node;
     struct rb_node *parent_node = NULL;
     struct rb_root_cached *root;
     struct btrfs_delayed_item *item;
     int cmp;
     bool leftmost = true;
 
     if (ins->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
         root = &delayed_node->ins_root;
     else if (ins->ins_or_del == BTRFS_DELAYED_DELETION_ITEM)
         root = &delayed_node->del_root;
     else
         BUG();
     p = &root->rb_root.rb_node;
     node = &ins->rb_node;
 
     while (*p) {
         parent_node = *p;
         item = rb_entry(parent_node, struct btrfs_delayed_item,
                  rb_node);
 
         cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
         if (cmp < 0) {
             p = &(*p)->rb_right;
             leftmost = false;
         } else if (cmp > 0) {
             p = &(*p)->rb_left;
         } else {
             return -EEXIST;
         }
     }
 
     rb_link_node(node, parent_node, p);
     rb_insert_color_cached(node, root, leftmost);
     ins->delayed_node = delayed_node;
 
     /* Delayed items are always for dir index items. */
     ASSERT(ins->key.type == BTRFS_DIR_INDEX_KEY);
 
     if (ins->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM &&
         ins->key.offset >= delayed_node->index_cnt)
         delayed_node->index_cnt = ins->key.offset + 1;
 
     delayed_node->count++;
     atomic_inc(&delayed_node->root->fs_info->delayed_root->items);
     return 0;
 }
 
 static void finish_one_item(struct btrfs_delayed_root *delayed_root)
 {
     int seq = atomic_inc_return(&delayed_root->items_seq);
 
     /* atomic_dec_return implies a barrier */
     if ((atomic_dec_return(&delayed_root->items) <
         BTRFS_DELAYED_BACKGROUND || seq % BTRFS_DELAYED_BATCH == 0))
         cond_wake_up_nomb(&delayed_root->wait);
 }
 
 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 {
     struct rb_root_cached *root;
     struct btrfs_delayed_root *delayed_root;
 
     /* Not associated with any delayed_node */
     if (!delayed_item->delayed_node)
         return;
     delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 
     BUG_ON(!delayed_root);
     BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
            delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
 
     if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
         root = &delayed_item->delayed_node->ins_root;
     else
         root = &delayed_item->delayed_node->del_root;
 
     rb_erase_cached(&delayed_item->rb_node, root);
     delayed_item->delayed_node->count--;
 
     finish_one_item(delayed_root);
 }
 
 static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 {
     if (item) {
         __btrfs_remove_delayed_item(item);
         if (refcount_dec_and_test(&item->refs))
             kfree(item);
     }
 }
 
 static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
                     struct btrfs_delayed_node *delayed_node)
 {
     struct rb_node *p;
     struct btrfs_delayed_item *item = NULL;
 
     p = rb_first_cached(&delayed_node->ins_root);
     if (p)
         item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 
     return item;
 }
 
 static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
                     struct btrfs_delayed_node *delayed_node)
 {
     struct rb_node *p;
     struct btrfs_delayed_item *item = NULL;
 
     p = rb_first_cached(&delayed_node->del_root);
     if (p)
         item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 
     return item;
 }
 
 static struct btrfs_delayed_item *__btrfs_next_delayed_item(
                         struct btrfs_delayed_item *item)
 {
     struct rb_node *p;
     struct btrfs_delayed_item *next = NULL;
 
     p = rb_next(&item->rb_node);
     if (p)
         next = rb_entry(p, struct btrfs_delayed_item, rb_node);
 
     return next;
 }
 
 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            struct btrfs_delayed_item *item)
 {
     struct btrfs_block_rsv *src_rsv;
     struct btrfs_block_rsv *dst_rsv;
     struct btrfs_fs_info *fs_info = root->fs_info;
     u64 num_bytes;
     int ret;
 
     if (!trans->bytes_reserved)
         return 0;
 
     src_rsv = trans->block_rsv;
     dst_rsv = &fs_info->delayed_block_rsv;
 
     num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 
     /*
      * Here we migrate space rsv from transaction rsv, since have already
      * reserved space when starting a transaction.  So no need to reserve
      * qgroup space here.
      */
     ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
     if (!ret) {
         trace_btrfs_space_reservation(fs_info, "delayed_item",
                           item->key.objectid,
                           num_bytes, 1);
         /*
          * For insertions we track reserved metadata space by accounting
          * for the number of leaves that will be used, based on the delayed
          * node's index_items_size field.
          */
         if (item->ins_or_del == BTRFS_DELAYED_DELETION_ITEM)
             item->bytes_reserved = num_bytes;
     }
 
     return ret;
 }
 
 static void btrfs_delayed_item_release_metadata(struct btrfs_root *root,
                         struct btrfs_delayed_item *item)
 {
     struct btrfs_block_rsv *rsv;
     struct btrfs_fs_info *fs_info = root->fs_info;
 
     if (!item->bytes_reserved)
         return;
 
     rsv = &fs_info->delayed_block_rsv;
     /*
      * Check btrfs_delayed_item_reserve_metadata() to see why we don't need
      * to release/reserve qgroup space.
      */
     trace_btrfs_space_reservation(fs_info, "delayed_item",
                       item->key.objectid, item->bytes_reserved,
                       0);
     btrfs_block_rsv_release(fs_info, rsv, item->bytes_reserved, NULL);
 }
 
 static void btrfs_delayed_item_release_leaves(struct btrfs_delayed_node *node,
                           unsigned int num_leaves)
 {
     struct btrfs_fs_info *fs_info = node->root->fs_info;
     const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, num_leaves);
 
     /* There are no space reservations during log replay, bail out. */
     if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
         return;
 
     trace_btrfs_space_reservation(fs_info, "delayed_item", node->inode_id,
                       bytes, 0);
     btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv, bytes, NULL);
 }
 
 static int btrfs_delayed_inode_reserve_metadata(
                     struct btrfs_trans_handle *trans,
                     struct btrfs_root *root,
                     struct btrfs_delayed_node *node)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_block_rsv *src_rsv;
     struct btrfs_block_rsv *dst_rsv;
     u64 num_bytes;
     int ret;
 
     src_rsv = trans->block_rsv;
     dst_rsv = &fs_info->delayed_block_rsv;
 
     num_bytes = btrfs_calc_metadata_size(fs_info, 1);
 
     /*
      * btrfs_dirty_inode will update the inode under btrfs_join_transaction
      * which doesn't reserve space for speed.  This is a problem since we
      * still need to reserve space for this update, so try to reserve the
      * space.
      *
      * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
      * we always reserve enough to update the inode item.
      */
     if (!src_rsv || (!trans->bytes_reserved &&
              src_rsv->type != BTRFS_BLOCK_RSV_DELALLOC)) {
         ret = btrfs_qgroup_reserve_meta(root, num_bytes,
                       BTRFS_QGROUP_RSV_META_PREALLOC, true);
         if (ret < 0)
             return ret;
         ret = btrfs_block_rsv_add(fs_info, dst_rsv, num_bytes,
                       BTRFS_RESERVE_NO_FLUSH);
         /* NO_FLUSH could only fail with -ENOSPC */
         ASSERT(ret == 0 || ret == -ENOSPC);
         if (ret)
             btrfs_qgroup_free_meta_prealloc(root, num_bytes);
     } else {
         ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
     }
 
     if (!ret) {
         trace_btrfs_space_reservation(fs_info, "delayed_inode",
                           node->inode_id, num_bytes, 1);
         node->bytes_reserved = num_bytes;
     }
 
     return ret;
 }
 
 static void btrfs_delayed_inode_release_metadata(struct btrfs_fs_info *fs_info,
                         struct btrfs_delayed_node *node,
                         bool qgroup_free)
 {
     struct btrfs_block_rsv *rsv;
 
     if (!node->bytes_reserved)
         return;
 
     rsv = &fs_info->delayed_block_rsv;
     trace_btrfs_space_reservation(fs_info, "delayed_inode",
                       node->inode_id, node->bytes_reserved, 0);
     btrfs_block_rsv_release(fs_info, rsv, node->bytes_reserved, NULL);
     if (qgroup_free)
         btrfs_qgroup_free_meta_prealloc(node->root,
                 node->bytes_reserved);
     else
         btrfs_qgroup_convert_reserved_meta(node->root,
                 node->bytes_reserved);
     node->bytes_reserved = 0;
 }
 
 /*
  * Insert a single delayed item or a batch of delayed items, as many as possible
  * that fit in a leaf. The delayed items (dir index keys) are sorted by their key
  * in the rbtree, and if there's a gap between two consecutive dir index items,
  * then it means at some point we had delayed dir indexes to add but they got
  * removed (by btrfs_delete_delayed_dir_index()) before we attempted to flush them
  * into the subvolume tree. Dir index keys also have their offsets coming from a
  * monotonically increasing counter, so we can't get new keys with an offset that
  * fits within a gap between delayed dir index items.
  */
 static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root,
                      struct btrfs_path *path,
                      struct btrfs_delayed_item *first_item)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_delayed_node *node = first_item->delayed_node;
     LIST_HEAD(item_list);
     struct btrfs_delayed_item *curr;
     struct btrfs_delayed_item *next;
     const int max_size = BTRFS_LEAF_DATA_SIZE(fs_info);
     struct btrfs_item_batch batch;
     int total_size;
     char *ins_data = NULL;
     int ret;
     bool continuous_keys_only = false;
 
     lockdep_assert_held(&node->mutex);
 
     /*
      * During normal operation the delayed index offset is continuously
      * increasing, so we can batch insert all items as there will not be any
      * overlapping keys in the tree.
      *
      * The exception to this is log replay, where we may have interleaved
      * offsets in the tree, so our batch needs to be continuous keys only in
      * order to ensure we do not end up with out of order items in our leaf.
      */
     if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
         continuous_keys_only = true;
 
     /*
      * For delayed items to insert, we track reserved metadata bytes based
      * on the number of leaves that we will use.
      * See btrfs_insert_delayed_dir_index() and
      * btrfs_delayed_item_reserve_metadata()).
      */
     ASSERT(first_item->bytes_reserved == 0);
 
     list_add_tail(&first_item->tree_list, &item_list);
     batch.total_data_size = first_item->data_len;
     batch.nr = 1;
     total_size = first_item->data_len + sizeof(struct btrfs_item);
     curr = first_item;
 
     while (true) {
         int next_size;
 
         next = __btrfs_next_delayed_item(curr);
         if (!next)
             break;
 
         /*
          * We cannot allow gaps in the key space if we're doing log
          * replay.
          */
         if (continuous_keys_only &&
             (next->key.offset != curr->key.offset + 1))
             break;
 
         ASSERT(next->bytes_reserved == 0);
 
         next_size = next->data_len + sizeof(struct btrfs_item);
         if (total_size + next_size > max_size)
             break;
 
         list_add_tail(&next->tree_list, &item_list);
         batch.nr++;
         total_size += next_size;
         batch.total_data_size += next->data_len;
         curr = next;
     }
 
     if (batch.nr == 1) {
         batch.keys = &first_item->key;
         batch.data_sizes = &first_item->data_len;
     } else {
         struct btrfs_key *ins_keys;
         u32 *ins_sizes;
         int i = 0;
 
         ins_data = kmalloc(batch.nr * sizeof(u32) +
                    batch.nr * sizeof(struct btrfs_key), GFP_NOFS);
         if (!ins_data) {
             ret = -ENOMEM;
             goto out;
         }
         ins_sizes = (u32 *)ins_data;
         ins_keys = (struct btrfs_key *)(ins_data + batch.nr * sizeof(u32));
         batch.keys = ins_keys;
         batch.data_sizes = ins_sizes;
         list_for_each_entry(curr, &item_list, tree_list) {
             ins_keys[i] = curr->key;
             ins_sizes[i] = curr->data_len;
             i++;
         }
     }
 
     ret = btrfs_insert_empty_items(trans, root, path, &batch);
     if (ret)
         goto out;
 
     list_for_each_entry(curr, &item_list, tree_list) {
         char *data_ptr;
 
         data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
         write_extent_buffer(path->nodes[0], &curr->data,
                     (unsigned long)data_ptr, curr->data_len);
         path->slots[0]++;
     }
 
     /*
      * Now release our path before releasing the delayed items and their
      * metadata reservations, so that we don't block other tasks for more
      * time than needed.
      */
     btrfs_release_path(path);
 
     ASSERT(node->index_item_leaves > 0);
 
     /*
      * For normal operations we will batch an entire leaf's worth of delayed
      * items, so if there are more items to process we can decrement
      * index_item_leaves by 1 as we inserted 1 leaf's worth of items.
      *
      * However for log replay we may not have inserted an entire leaf's
      * worth of items, we may have not had continuous items, so decrementing
      * here would mess up the index_item_leaves accounting.  For this case
      * only clean up the accounting when there are no items left.
      */
     if (next && !continuous_keys_only) {
         /*
          * We inserted one batch of items into a leaf a there are more
          * items to flush in a future batch, now release one unit of
          * metadata space from the delayed block reserve, corresponding
          * the leaf we just flushed to.
          */
         btrfs_delayed_item_release_leaves(node, 1);
         node->index_item_leaves--;
     } else if (!next) {
         /*
          * There are no more items to insert. We can have a number of
          * reserved leaves > 1 here - this happens when many dir index
          * items are added and then removed before they are flushed (file
          * names with a very short life, never span a transaction). So
          * release all remaining leaves.
          */
         btrfs_delayed_item_release_leaves(node, node->index_item_leaves);
         node->index_item_leaves = 0;
     }
 
     list_for_each_entry_safe(curr, next, &item_list, tree_list) {
         list_del(&curr->tree_list);
         btrfs_release_delayed_item(curr);
     }
 out:
     kfree(ins_data);
     return ret;
 }
 
 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,
                       struct btrfs_path *path,
                       struct btrfs_root *root,
                       struct btrfs_delayed_node *node)
 {
     int ret = 0;
 
     while (ret == 0) {
         struct btrfs_delayed_item *curr;
 
         mutex_lock(&node->mutex);
         curr = __btrfs_first_delayed_insertion_item(node);
         if (!curr) {
             mutex_unlock(&node->mutex);
             break;
         }
         ret = btrfs_insert_delayed_item(trans, root, path, curr);
         mutex_unlock(&node->mutex);
     }
 
     return ret;
 }
 
 static int btrfs_batch_delete_items(struct btrfs_trans_handle *trans,
                     struct btrfs_root *root,
                     struct btrfs_path *path,
                     struct btrfs_delayed_item *item)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_delayed_item *curr, *next;
     struct extent_buffer *leaf = path->nodes[0];
     LIST_HEAD(batch_list);
     int nitems, slot, last_slot;
     int ret;
     u64 total_reserved_size = item->bytes_reserved;
 
     ASSERT(leaf != NULL);
 
     slot = path->slots[0];
     last_slot = btrfs_header_nritems(leaf) - 1;
     /*
      * Our caller always gives us a path pointing to an existing item, so
      * this can not happen.
      */
     ASSERT(slot <= last_slot);
     if (WARN_ON(slot > last_slot))
         return -ENOENT;
 
     nitems = 1;
     curr = item;
     list_add_tail(&curr->tree_list, &batch_list);
 
     /*
      * Keep checking if the next delayed item matches the next item in the
      * leaf - if so, we can add it to the batch of items to delete from the
      * leaf.
      */
     while (slot < last_slot) {
         struct btrfs_key key;
 
         next = __btrfs_next_delayed_item(curr);
         if (!next)
             break;
 
         slot++;
         btrfs_item_key_to_cpu(leaf, &key, slot);
         if (btrfs_comp_cpu_keys(&next->key, &key) != 0)
             break;
         nitems++;
         curr = next;
         list_add_tail(&curr->tree_list, &batch_list);
         total_reserved_size += curr->bytes_reserved;
     }
 
     ret = btrfs_del_items(trans, root, path, path->slots[0], nitems);
     if (ret)
         return ret;
 
     /* In case of BTRFS_FS_LOG_RECOVERING items won't have reserved space */
     if (total_reserved_size > 0) {
         /*
          * Check btrfs_delayed_item_reserve_metadata() to see why we
          * don't need to release/reserve qgroup space.
          */
         trace_btrfs_space_reservation(fs_info, "delayed_item",
                           item->key.objectid, total_reserved_size,
                           0);
         btrfs_block_rsv_release(fs_info, &fs_info->delayed_block_rsv,
                     total_reserved_size, NULL);
     }
 
     list_for_each_entry_safe(curr, next, &batch_list, tree_list) {
         list_del(&curr->tree_list);
         btrfs_release_delayed_item(curr);
     }
 
     return 0;
 }
 
 static int btrfs_delete_delayed_items(struct btrfs_trans_handle *trans,
                       struct btrfs_path *path,
                       struct btrfs_root *root,
                       struct btrfs_delayed_node *node)
 {
     int ret = 0;
 
     while (ret == 0) {
         struct btrfs_delayed_item *item;
 
         mutex_lock(&node->mutex);
         item = __btrfs_first_delayed_deletion_item(node);
         if (!item) {
             mutex_unlock(&node->mutex);
             break;
         }
 
         ret = btrfs_search_slot(trans, root, &item->key, path, -1, 1);
         if (ret > 0) {
             /*
              * There's no matching item in the leaf. This means we
              * have already deleted this item in a past run of the
              * delayed items. We ignore errors when running delayed
              * items from an async context, through a work queue job
              * running btrfs_async_run_delayed_root(), and don't
              * release delayed items that failed to complete. This
              * is because we will retry later, and at transaction
              * commit time we always run delayed items and will
              * then deal with errors if they fail to run again.
              *
              * So just release delayed items for which we can't find
              * an item in the tree, and move to the next item.
              */
             btrfs_release_path(path);
             btrfs_release_delayed_item(item);
             ret = 0;
         } else if (ret == 0) {
             ret = btrfs_batch_delete_items(trans, root, path, item);
             btrfs_release_path(path);
         }
 
         /*
          * We unlock and relock on each iteration, this is to prevent
          * blocking other tasks for too long while we are being run from
          * the async context (work queue job). Those tasks are typically
          * running system calls like creat/mkdir/rename/unlink/etc which
          * need to add delayed items to this delayed node.
          */
         mutex_unlock(&node->mutex);
     }
 
     return ret;
 }
 
 static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
 {
     struct btrfs_delayed_root *delayed_root;
 
     if (delayed_node &&
         test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
         BUG_ON(!delayed_node->root);
         clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
         delayed_node->count--;
 
         delayed_root = delayed_node->root->fs_info->delayed_root;
         finish_one_item(delayed_root);
     }
 }
 
 static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
 {
 
     if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags)) {
         struct btrfs_delayed_root *delayed_root;
 
         ASSERT(delayed_node->root);
         delayed_node->count--;
 
         delayed_root = delayed_node->root->fs_info->delayed_root;
         finish_one_item(delayed_root);
     }
 }
 
 static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
                     struct btrfs_root *root,
                     struct btrfs_path *path,
                     struct btrfs_delayed_node *node)
 {
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_key key;
     struct btrfs_inode_item *inode_item;
     struct extent_buffer *leaf;
     int mod;
     int ret;
 
     key.objectid = node->inode_id;
     key.type = BTRFS_INODE_ITEM_KEY;
     key.offset = 0;
 
     if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
         mod = -1;
     else
         mod = 1;
 
     ret = btrfs_lookup_inode(trans, root, path, &key, mod);
     if (ret > 0)
         ret = -ENOENT;
     if (ret < 0)
         goto out;
 
     leaf = path->nodes[0];
     inode_item = btrfs_item_ptr(leaf, path->slots[0],
                     struct btrfs_inode_item);
     write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
                 sizeof(struct btrfs_inode_item));
     btrfs_mark_buffer_dirty(leaf);
 
     if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
         goto out;
 
     path->slots[0]++;
     if (path->slots[0] >= btrfs_header_nritems(leaf))
         goto search;
 again:
     btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
     if (key.objectid != node->inode_id)
         goto out;
 
     if (key.type != BTRFS_INODE_REF_KEY &&
         key.type != BTRFS_INODE_EXTREF_KEY)
         goto out;
 
     /*
      * Delayed iref deletion is for the inode who has only one link,
      * so there is only one iref. The case that several irefs are
      * in the same item doesn't exist.
      */
     btrfs_del_item(trans, root, path);
 out:
     btrfs_release_delayed_iref(node);
     btrfs_release_path(path);
 err_out:
     btrfs_delayed_inode_release_metadata(fs_info, node, (ret < 0));
     btrfs_release_delayed_inode(node);
 
     /*
      * If we fail to update the delayed inode we need to abort the
      * transaction, because we could leave the inode with the improper
      * counts behind.
      */
     if (ret && ret != -ENOENT)
         btrfs_abort_transaction(trans, ret);
 
     return ret;
 
 search:
     btrfs_release_path(path);
 
     key.type = BTRFS_INODE_EXTREF_KEY;
     key.offset = -1;
 
     ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
     if (ret < 0)
         goto err_out;
     ASSERT(ret);
 
     ret = 0;
     leaf = path->nodes[0];
     path->slots[0]--;
     goto again;
 }
 
 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root,
                          struct btrfs_path *path,
                          struct btrfs_delayed_node *node)
 {
     int ret;
 
     mutex_lock(&node->mutex);
     if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
         mutex_unlock(&node->mutex);
         return 0;
     }
 
     ret = __btrfs_update_delayed_inode(trans, root, path, node);
     mutex_unlock(&node->mutex);
     return ret;
 }
 
 static inline int
 __btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
                    struct btrfs_path *path,
                    struct btrfs_delayed_node *node)
 {
     int ret;
 
     ret = btrfs_insert_delayed_items(trans, path, node->root, node);
     if (ret)
         return ret;
 
     ret = btrfs_delete_delayed_items(trans, path, node->root, node);
     if (ret)
         return ret;
 
     ret = btrfs_update_delayed_inode(trans, node->root, path, node);
     return ret;
 }
 
 /*
  * Called when committing the transaction.
  * Returns 0 on success.
  * Returns < 0 on error and returns with an aborted transaction with any
  * outstanding delayed items cleaned up.
  */
 static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
 {
     struct btrfs_fs_info *fs_info = trans->fs_info;
     struct btrfs_delayed_root *delayed_root;
     struct btrfs_delayed_node *curr_node, *prev_node;
     struct btrfs_path *path;
     struct btrfs_block_rsv *block_rsv;
     int ret = 0;
     bool count = (nr > 0);
 
     if (TRANS_ABORTED(trans))
         return -EIO;
 
     path = btrfs_alloc_path();
     if (!path)
         return -ENOMEM;
 
     block_rsv = trans->block_rsv;
     trans->block_rsv = &fs_info->delayed_block_rsv;
 
     delayed_root = fs_info->delayed_root;
 
     curr_node = btrfs_first_delayed_node(delayed_root);
     while (curr_node && (!count || nr--)) {
         ret = __btrfs_commit_inode_delayed_items(trans, path,
                              curr_node);
         if (ret) {
             btrfs_release_delayed_node(curr_node);
             curr_node = NULL;
             btrfs_abort_transaction(trans, ret);
             break;
         }
 
         prev_node = curr_node;
         curr_node = btrfs_next_delayed_node(curr_node);
         btrfs_release_delayed_node(prev_node);
     }
 
     if (curr_node)
         btrfs_release_delayed_node(curr_node);
     btrfs_free_path(path);
     trans->block_rsv = block_rsv;
 
     return ret;
 }
 
 int btrfs_run_delayed_items(struct btrfs_trans_handle *trans)
 {
     return __btrfs_run_delayed_items(trans, -1);
 }
 
 int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, int nr)
 {
     return __btrfs_run_delayed_items(trans, nr);
 }
 
 int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans,
                      struct btrfs_inode *inode)
 {
     struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
     struct btrfs_path *path;
     struct btrfs_block_rsv *block_rsv;
     int ret;
 
     if (!delayed_node)
         return 0;
 
     mutex_lock(&delayed_node->mutex);
     if (!delayed_node->count) {
         mutex_unlock(&delayed_node->mutex);
         btrfs_release_delayed_node(delayed_node);
         return 0;
     }
     mutex_unlock(&delayed_node->mutex);
 
     path = btrfs_alloc_path();
     if (!path) {
         btrfs_release_delayed_node(delayed_node);
         return -ENOMEM;
     }
 
     block_rsv = trans->block_rsv;
     trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
 
     ret = __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
 
     btrfs_release_delayed_node(delayed_node);
     btrfs_free_path(path);
     trans->block_rsv = block_rsv;
 
     return ret;
 }
 
 int btrfs_commit_inode_delayed_inode(struct btrfs_inode *inode)
 {
     struct btrfs_fs_info *fs_info = inode->root->fs_info;
     struct btrfs_trans_handle *trans;
     struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
     struct btrfs_path *path;
     struct btrfs_block_rsv *block_rsv;
     int ret;
 
     if (!delayed_node)
         return 0;
 
     mutex_lock(&delayed_node->mutex);
     if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
         mutex_unlock(&delayed_node->mutex);
         btrfs_release_delayed_node(delayed_node);
         return 0;
     }
     mutex_unlock(&delayed_node->mutex);
 
     trans = btrfs_join_transaction(delayed_node->root);
     if (IS_ERR(trans)) {
         ret = PTR_ERR(trans);
         goto out;
     }
 
     path = btrfs_alloc_path();
     if (!path) {
         ret = -ENOMEM;
         goto trans_out;
     }
 
     block_rsv = trans->block_rsv;
     trans->block_rsv = &fs_info->delayed_block_rsv;
 
     mutex_lock(&delayed_node->mutex);
     if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
         ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
                            path, delayed_node);
     else
         ret = 0;
     mutex_unlock(&delayed_node->mutex);
 
     btrfs_free_path(path);
     trans->block_rsv = block_rsv;
 trans_out:
     btrfs_end_transaction(trans);
     btrfs_btree_balance_dirty(fs_info);
 out:
     btrfs_release_delayed_node(delayed_node);
 
     return ret;
 }
 
 void btrfs_remove_delayed_node(struct btrfs_inode *inode)
 {
     struct btrfs_delayed_node *delayed_node;
 
     delayed_node = READ_ONCE(inode->delayed_node);
     if (!delayed_node)
         return;
 
     inode->delayed_node = NULL;
     btrfs_release_delayed_node(delayed_node);
 }
 
 struct btrfs_async_delayed_work {
     struct btrfs_delayed_root *delayed_root;
     int nr;
     struct btrfs_work work;
 };
 
 static void btrfs_async_run_delayed_root(struct btrfs_work *work)
 {
     struct btrfs_async_delayed_work *async_work;
     struct btrfs_delayed_root *delayed_root;
     struct btrfs_trans_handle *trans;
     struct btrfs_path *path;
     struct btrfs_delayed_node *delayed_node = NULL;
     struct btrfs_root *root;
     struct btrfs_block_rsv *block_rsv;
     int total_done = 0;
 
     async_work = container_of(work, struct btrfs_async_delayed_work, work);
     delayed_root = async_work->delayed_root;
 
     path = btrfs_alloc_path();
     if (!path)
         goto out;
 
     do {
         if (atomic_read(&delayed_root->items) <
             BTRFS_DELAYED_BACKGROUND / 2)
             break;
 
         delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
         if (!delayed_node)
             break;
 
         root = delayed_node->root;
 
         trans = btrfs_join_transaction(root);
         if (IS_ERR(trans)) {
             btrfs_release_path(path);
             btrfs_release_prepared_delayed_node(delayed_node);
             total_done++;
             continue;
         }
 
         block_rsv = trans->block_rsv;
         trans->block_rsv = &root->fs_info->delayed_block_rsv;
 
         __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
 
         trans->block_rsv = block_rsv;
         btrfs_end_transaction(trans);
         btrfs_btree_balance_dirty_nodelay(root->fs_info);
 
         btrfs_release_path(path);
         btrfs_release_prepared_delayed_node(delayed_node);
         total_done++;
 
     } while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
          || total_done < async_work->nr);
 
     btrfs_free_path(path);
 out:
     wake_up(&delayed_root->wait);
     kfree(async_work);
 }
 
 
 static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
                      struct btrfs_fs_info *fs_info, int nr)
 {
     struct btrfs_async_delayed_work *async_work;
 
     async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
     if (!async_work)
         return -ENOMEM;
 
     async_work->delayed_root = delayed_root;
     btrfs_init_work(&async_work->work, btrfs_async_run_delayed_root, NULL,
             NULL);
     async_work->nr = nr;
 
     btrfs_queue_work(fs_info->delayed_workers, &async_work->work);
     return 0;
 }
 
 void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info)
 {
     WARN_ON(btrfs_first_delayed_node(fs_info->delayed_root));
 }
 
 static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
 {
     int val = atomic_read(&delayed_root->items_seq);
 
     if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
         return 1;
 
     if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
         return 1;
 
     return 0;
 }
 
 void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
 {
     struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
 
     if ((atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
         btrfs_workqueue_normal_congested(fs_info->delayed_workers))
         return;
 
     if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
         int seq;
         int ret;
 
         seq = atomic_read(&delayed_root->items_seq);
 
         ret = btrfs_wq_run_delayed_node(delayed_root, fs_info, 0);
         if (ret)
             return;
 
         wait_event_interruptible(delayed_root->wait,
                      could_end_wait(delayed_root, seq));
         return;
     }
 
     btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
 }
 
 /* Will return 0 or -ENOMEM */
 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
                    const char *name, int name_len,
                    struct btrfs_inode *dir,
                    struct btrfs_disk_key *disk_key, u8 type,
                    u64 index)
 {
     struct btrfs_fs_info *fs_info = trans->fs_info;
     const unsigned int leaf_data_size = BTRFS_LEAF_DATA_SIZE(fs_info);
     struct btrfs_delayed_node *delayed_node;
     struct btrfs_delayed_item *delayed_item;
     struct btrfs_dir_item *dir_item;
     bool reserve_leaf_space;
     u32 data_len;
     int ret;
 
     delayed_node = btrfs_get_or_create_delayed_node(dir);
     if (IS_ERR(delayed_node))
         return PTR_ERR(delayed_node);
 
     delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len);
     if (!delayed_item) {
         ret = -ENOMEM;
         goto release_node;
     }
 
     delayed_item->key.objectid = btrfs_ino(dir);
     delayed_item->key.type = BTRFS_DIR_INDEX_KEY;
     delayed_item->key.offset = index;
     delayed_item->ins_or_del = BTRFS_DELAYED_INSERTION_ITEM;
 
     dir_item = (struct btrfs_dir_item *)delayed_item->data;
     dir_item->location = *disk_key;
     btrfs_set_stack_dir_transid(dir_item, trans->transid);
     btrfs_set_stack_dir_data_len(dir_item, 0);
     btrfs_set_stack_dir_name_len(dir_item, name_len);
     btrfs_set_stack_dir_type(dir_item, type);
     memcpy((char *)(dir_item + 1), name, name_len);
 
     data_len = delayed_item->data_len + sizeof(struct btrfs_item);
 
     mutex_lock(&delayed_node->mutex);
 
     if (delayed_node->index_item_leaves == 0 ||
         delayed_node->curr_index_batch_size + data_len > leaf_data_size) {
         delayed_node->curr_index_batch_size = data_len;
         reserve_leaf_space = true;
     } else {
         delayed_node->curr_index_batch_size += data_len;
         reserve_leaf_space = false;
     }
 
     if (reserve_leaf_space) {
         ret = btrfs_delayed_item_reserve_metadata(trans, dir->root,
                               delayed_item);
         /*
          * Space was reserved for a dir index item insertion when we
          * started the transaction, so getting a failure here should be
          * impossible.
          */
         if (WARN_ON(ret)) {
             mutex_unlock(&delayed_node->mutex);
             btrfs_release_delayed_item(delayed_item);
             goto release_node;
         }
 
         delayed_node->index_item_leaves++;
     } else if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
         const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 
         /*
          * Adding the new dir index item does not require touching another
          * leaf, so we can release 1 unit of metadata that was previously
          * reserved when starting the transaction. This applies only to
          * the case where we had a transaction start and excludes the
          * transaction join case (when replaying log trees).
          */
         trace_btrfs_space_reservation(fs_info, "transaction",
                           trans->transid, bytes, 0);
         btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
         ASSERT(trans->bytes_reserved >= bytes);
         trans->bytes_reserved -= bytes;
     }
 
     ret = __btrfs_add_delayed_item(delayed_node, delayed_item);
     if (unlikely(ret)) {
         btrfs_err(trans->fs_info,
               "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
               name_len, name, delayed_node->root->root_key.objectid,
               delayed_node->inode_id, ret);
         BUG();
     }
     mutex_unlock(&delayed_node->mutex);
 
 release_node:
     btrfs_release_delayed_node(delayed_node);
     return ret;
 }
 
 static int btrfs_delete_delayed_insertion_item(struct btrfs_fs_info *fs_info,
                            struct btrfs_delayed_node *node,
                            struct btrfs_key *key)
 {
     struct btrfs_delayed_item *item;
 
     mutex_lock(&node->mutex);
     item = __btrfs_lookup_delayed_insertion_item(node, key);
     if (!item) {
         mutex_unlock(&node->mutex);
         return 1;
     }
 
     /*
      * For delayed items to insert, we track reserved metadata bytes based
      * on the number of leaves that we will use.
      * See btrfs_insert_delayed_dir_index() and
      * btrfs_delayed_item_reserve_metadata()).
      */
     ASSERT(item->bytes_reserved == 0);
     ASSERT(node->index_item_leaves > 0);
 
     /*
      * If there's only one leaf reserved, we can decrement this item from the
      * current batch, otherwise we can not because we don't know which leaf
      * it belongs to. With the current limit on delayed items, we rarely
      * accumulate enough dir index items to fill more than one leaf (even
      * when using a leaf size of 4K).
      */
     if (node->index_item_leaves == 1) {
         const u32 data_len = item->data_len + sizeof(struct btrfs_item);
 
         ASSERT(node->curr_index_batch_size >= data_len);
         node->curr_index_batch_size -= data_len;
     }
 
     btrfs_release_delayed_item(item);
 
     /* If we now have no more dir index items, we can release all leaves. */
     if (RB_EMPTY_ROOT(&node->ins_root.rb_root)) {
         btrfs_delayed_item_release_leaves(node, node->index_item_leaves);
         node->index_item_leaves = 0;
     }
 
     mutex_unlock(&node->mutex);
     return 0;
 }
 
 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
                    struct btrfs_inode *dir, u64 index)
 {
     struct btrfs_delayed_node *node;
     struct btrfs_delayed_item *item;
     struct btrfs_key item_key;
     int ret;
 
     node = btrfs_get_or_create_delayed_node(dir);
     if (IS_ERR(node))
         return PTR_ERR(node);
 
     item_key.objectid = btrfs_ino(dir);
     item_key.type = BTRFS_DIR_INDEX_KEY;
     item_key.offset = index;
 
     ret = btrfs_delete_delayed_insertion_item(trans->fs_info, node,
                           &item_key);
     if (!ret)
         goto end;
 
     item = btrfs_alloc_delayed_item(0);
     if (!item) {
         ret = -ENOMEM;
         goto end;
     }
 
     item->key = item_key;
     item->ins_or_del = BTRFS_DELAYED_DELETION_ITEM;
 
     ret = btrfs_delayed_item_reserve_metadata(trans, dir->root, item);
     /*
      * we have reserved enough space when we start a new transaction,
      * so reserving metadata failure is impossible.
      */
     if (ret < 0) {
         btrfs_err(trans->fs_info,
 "metadata reservation failed for delayed dir item deltiona, should have been reserved");
         btrfs_release_delayed_item(item);
         goto end;
     }
 
     mutex_lock(&node->mutex);
     ret = __btrfs_add_delayed_item(node, item);
     if (unlikely(ret)) {
         btrfs_err(trans->fs_info,
               "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
               index, node->root->root_key.objectid,
               node->inode_id, ret);
         btrfs_delayed_item_release_metadata(dir->root, item);
         btrfs_release_delayed_item(item);
     }
     mutex_unlock(&node->mutex);
 end:
     btrfs_release_delayed_node(node);
     return ret;
 }
 
 int btrfs_inode_delayed_dir_index_count(struct btrfs_inode *inode)
 {
     struct btrfs_delayed_node *delayed_node = btrfs_get_delayed_node(inode);
 
     if (!delayed_node)
         return -ENOENT;
 
     /*
      * Since we have held i_mutex of this directory, it is impossible that
      * a new directory index is added into the delayed node and index_cnt
      * is updated now. So we needn't lock the delayed node.
      */
     if (!delayed_node->index_cnt) {
         btrfs_release_delayed_node(delayed_node);
         return -EINVAL;
     }
 
     inode->index_cnt = delayed_node->index_cnt;
     btrfs_release_delayed_node(delayed_node);
     return 0;
 }
 
 bool btrfs_readdir_get_delayed_items(struct inode *inode,
                      struct list_head *ins_list,
                      struct list_head *del_list)
 {
     struct btrfs_delayed_node *delayed_node;
     struct btrfs_delayed_item *item;
 
     delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
     if (!delayed_node)
         return false;
 
     /*
      * We can only do one readdir with delayed items at a time because of
      * item->readdir_list.
      */
     btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
     btrfs_inode_lock(inode, 0);
 
     mutex_lock(&delayed_node->mutex);
     item = __btrfs_first_delayed_insertion_item(delayed_node);
     while (item) {
         refcount_inc(&item->refs);
         list_add_tail(&item->readdir_list, ins_list);
         item = __btrfs_next_delayed_item(item);
     }
 
     item = __btrfs_first_delayed_deletion_item(delayed_node);
     while (item) {
         refcount_inc(&item->refs);
         list_add_tail(&item->readdir_list, del_list);
         item = __btrfs_next_delayed_item(item);
     }
     mutex_unlock(&delayed_node->mutex);
     /*
      * This delayed node is still cached in the btrfs inode, so refs
      * must be > 1 now, and we needn't check it is going to be freed
      * or not.
      *
      * Besides that, this function is used to read dir, we do not
      * insert/delete delayed items in this period. So we also needn't
      * requeue or dequeue this delayed node.
      */
     refcount_dec(&delayed_node->refs);
 
     return true;
 }
 
 void btrfs_readdir_put_delayed_items(struct inode *inode,
                      struct list_head *ins_list,
                      struct list_head *del_list)
 {
     struct btrfs_delayed_item *curr, *next;
 
     list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
         list_del(&curr->readdir_list);
         if (refcount_dec_and_test(&curr->refs))
             kfree(curr);
     }
 
     list_for_each_entry_safe(curr, next, del_list, readdir_list) {
         list_del(&curr->readdir_list);
         if (refcount_dec_and_test(&curr->refs))
             kfree(curr);
     }
 
     /*
      * The VFS is going to do up_read(), so we need to downgrade back to a
      * read lock.
      */
     downgrade_write(&inode->i_rwsem);
 }
 
 int btrfs_should_delete_dir_index(struct list_head *del_list,
                   u64 index)
 {
     struct btrfs_delayed_item *curr;
     int ret = 0;
 
     list_for_each_entry(curr, del_list, readdir_list) {
         if (curr->key.offset > index)
             break;
         if (curr->key.offset == index) {
             ret = 1;
             break;
         }
     }
     return ret;
 }
 
 /*
  * btrfs_readdir_delayed_dir_index - read dir info stored in the delayed tree
  *
  */
 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
                     struct list_head *ins_list)
 {
     struct btrfs_dir_item *di;
     struct btrfs_delayed_item *curr, *next;
     struct btrfs_key location;
     char *name;
     int name_len;
     int over = 0;
     unsigned char d_type;
 
     if (list_empty(ins_list))
         return 0;
 
     /*
      * Changing the data of the delayed item is impossible. So
      * we needn't lock them. And we have held i_mutex of the
      * directory, nobody can delete any directory indexes now.
      */
     list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
         list_del(&curr->readdir_list);
 
         if (curr->key.offset < ctx->pos) {
             if (refcount_dec_and_test(&curr->refs))
                 kfree(curr);
             continue;
         }
 
         ctx->pos = curr->key.offset;
 
         di = (struct btrfs_dir_item *)curr->data;
         name = (char *)(di + 1);
         name_len = btrfs_stack_dir_name_len(di);
 
         d_type = fs_ftype_to_dtype(di->type);
         btrfs_disk_key_to_cpu(&location, &di->location);
 
         over = !dir_emit(ctx, name, name_len,
                    location.objectid, d_type);
 
         if (refcount_dec_and_test(&curr->refs))
             kfree(curr);
 
         if (over)
             return 1;
         ctx->pos++;
     }
     return 0;
 }
 
 static void fill_stack_inode_item(struct btrfs_trans_handle *trans,
                   struct btrfs_inode_item *inode_item,
                   struct inode *inode)
 {
     u64 flags;
 
     btrfs_set_stack_inode_uid(inode_item, i_uid_read(inode));
     btrfs_set_stack_inode_gid(inode_item, i_gid_read(inode));
     btrfs_set_stack_inode_size(inode_item, BTRFS_I(inode)->disk_i_size);
     btrfs_set_stack_inode_mode(inode_item, inode->i_mode);
     btrfs_set_stack_inode_nlink(inode_item, inode->i_nlink);
     btrfs_set_stack_inode_nbytes(inode_item, inode_get_bytes(inode));
     btrfs_set_stack_inode_generation(inode_item,
                      BTRFS_I(inode)->generation);
     btrfs_set_stack_inode_sequence(inode_item,
                        inode_peek_iversion(inode));
     btrfs_set_stack_inode_transid(inode_item, trans->transid);
     btrfs_set_stack_inode_rdev(inode_item, inode->i_rdev);
     flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
                       BTRFS_I(inode)->ro_flags);
     btrfs_set_stack_inode_flags(inode_item, flags);
     btrfs_set_stack_inode_block_group(inode_item, 0);
 
     btrfs_set_stack_timespec_sec(&inode_item->atime,
                      inode->i_atime.tv_sec);
     btrfs_set_stack_timespec_nsec(&inode_item->atime,
                       inode->i_atime.tv_nsec);
 
     btrfs_set_stack_timespec_sec(&inode_item->mtime,
                      inode->i_mtime.tv_sec);
     btrfs_set_stack_timespec_nsec(&inode_item->mtime,
                       inode->i_mtime.tv_nsec);
 
     btrfs_set_stack_timespec_sec(&inode_item->ctime,
                      inode->i_ctime.tv_sec);
     btrfs_set_stack_timespec_nsec(&inode_item->ctime,
                       inode->i_ctime.tv_nsec);
 
     btrfs_set_stack_timespec_sec(&inode_item->otime,
                      BTRFS_I(inode)->i_otime.tv_sec);
     btrfs_set_stack_timespec_nsec(&inode_item->otime,
                      BTRFS_I(inode)->i_otime.tv_nsec);
 }
 
 int btrfs_fill_inode(struct inode *inode, u32 *rdev)
 {
     struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
     struct btrfs_delayed_node *delayed_node;
     struct btrfs_inode_item *inode_item;
 
     delayed_node = btrfs_get_delayed_node(BTRFS_I(inode));
     if (!delayed_node)
         return -ENOENT;
 
     mutex_lock(&delayed_node->mutex);
     if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
         mutex_unlock(&delayed_node->mutex);
         btrfs_release_delayed_node(delayed_node);
         return -ENOENT;
     }
 
     inode_item = &delayed_node->inode_item;
 
     i_uid_write(inode, btrfs_stack_inode_uid(inode_item));
     i_gid_write(inode, btrfs_stack_inode_gid(inode_item));
     btrfs_i_size_write(BTRFS_I(inode), btrfs_stack_inode_size(inode_item));
     btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
             round_up(i_size_read(inode), fs_info->sectorsize));
     inode->i_mode = btrfs_stack_inode_mode(inode_item);
     set_nlink(inode, btrfs_stack_inode_nlink(inode_item));
     inode_set_bytes(inode, btrfs_stack_inode_nbytes(inode_item));
     BTRFS_I(inode)->generation = btrfs_stack_inode_generation(inode_item);
         BTRFS_I(inode)->last_trans = btrfs_stack_inode_transid(inode_item);
 
     inode_set_iversion_queried(inode,
                    btrfs_stack_inode_sequence(inode_item));
     inode->i_rdev = 0;
     *rdev = btrfs_stack_inode_rdev(inode_item);
     btrfs_inode_split_flags(btrfs_stack_inode_flags(inode_item),
                 &BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
 
     inode->i_atime.tv_sec = btrfs_stack_timespec_sec(&inode_item->atime);
     inode->i_atime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->atime);
 
     inode->i_mtime.tv_sec = btrfs_stack_timespec_sec(&inode_item->mtime);
     inode->i_mtime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->mtime);
 
     inode->i_ctime.tv_sec = btrfs_stack_timespec_sec(&inode_item->ctime);
     inode->i_ctime.tv_nsec = btrfs_stack_timespec_nsec(&inode_item->ctime);
 
     BTRFS_I(inode)->i_otime.tv_sec =
         btrfs_stack_timespec_sec(&inode_item->otime);
     BTRFS_I(inode)->i_otime.tv_nsec =
         btrfs_stack_timespec_nsec(&inode_item->otime);
 
     inode->i_generation = BTRFS_I(inode)->generation;
     BTRFS_I(inode)->index_cnt = (u64)-1;
 
     mutex_unlock(&delayed_node->mutex);
     btrfs_release_delayed_node(delayed_node);
     return 0;
 }
 
 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
                    struct btrfs_root *root,
                    struct btrfs_inode *inode)
 {
     struct btrfs_delayed_node *delayed_node;
     int ret = 0;
 
     delayed_node = btrfs_get_or_create_delayed_node(inode);
     if (IS_ERR(delayed_node))
         return PTR_ERR(delayed_node);
 
     mutex_lock(&delayed_node->mutex);
     if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
         fill_stack_inode_item(trans, &delayed_node->inode_item,
                       &inode->vfs_inode);
         goto release_node;
     }
 
     ret = btrfs_delayed_inode_reserve_metadata(trans, root, delayed_node);
     if (ret)
         goto release_node;
 
     fill_stack_inode_item(trans, &delayed_node->inode_item, &inode->vfs_inode);
     set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
     delayed_node->count++;
     atomic_inc(&root->fs_info->delayed_root->items);
 release_node:
     mutex_unlock(&delayed_node->mutex);
     btrfs_release_delayed_node(delayed_node);
     return ret;
 }
 
 int btrfs_delayed_delete_inode_ref(struct btrfs_inode *inode)
 {
     struct btrfs_fs_info *fs_info = inode->root->fs_info;
     struct btrfs_delayed_node *delayed_node;
 
     /*
      * we don't do delayed inode updates during log recovery because it
      * leads to enospc problems.  This means we also can't do
      * delayed inode refs
      */
     if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
         return -EAGAIN;
 
     delayed_node = btrfs_get_or_create_delayed_node(inode);
     if (IS_ERR(delayed_node))
         return PTR_ERR(delayed_node);
 
     /*
      * We don't reserve space for inode ref deletion is because:
      * - We ONLY do async inode ref deletion for the inode who has only
      *   one link(i_nlink == 1), it means there is only one inode ref.
      *   And in most case, the inode ref and the inode item are in the
      *   same leaf, and we will deal with them at the same time.
      *   Since we are sure we will reserve the space for the inode item,
      *   it is unnecessary to reserve space for inode ref deletion.
      * - If the inode ref and the inode item are not in the same leaf,
      *   We also needn't worry about enospc problem, because we reserve
      *   much more space for the inode update than it needs.
      * - At the worst, we can steal some space from the global reservation.
      *   It is very rare.
      */
     mutex_lock(&delayed_node->mutex);
     if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
         goto release_node;
 
     set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
     delayed_node->count++;
     atomic_inc(&fs_info->delayed_root->items);
 release_node:
     mutex_unlock(&delayed_node->mutex);
     btrfs_release_delayed_node(delayed_node);
     return 0;
 }
 
 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
 {
     struct btrfs_root *root = delayed_node->root;
     struct btrfs_fs_info *fs_info = root->fs_info;
     struct btrfs_delayed_item *curr_item, *prev_item;
 
     mutex_lock(&delayed_node->mutex);
     curr_item = __btrfs_first_delayed_insertion_item(delayed_node);
     while (curr_item) {
         prev_item = curr_item;
         curr_item = __btrfs_next_delayed_item(prev_item);
         btrfs_release_delayed_item(prev_item);
     }
 
     if (delayed_node->index_item_leaves > 0) {
         btrfs_delayed_item_release_leaves(delayed_node,
                       delayed_node->index_item_leaves);
         delayed_node->index_item_leaves = 0;
     }
 
     curr_item = __btrfs_first_delayed_deletion_item(delayed_node);
     while (curr_item) {
         btrfs_delayed_item_release_metadata(root, curr_item);
         prev_item = curr_item;
         curr_item = __btrfs_next_delayed_item(prev_item);
         btrfs_release_delayed_item(prev_item);
     }
 
     btrfs_release_delayed_iref(delayed_node);
 
     if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
         btrfs_delayed_inode_release_metadata(fs_info, delayed_node, false);
         btrfs_release_delayed_inode(delayed_node);
     }
     mutex_unlock(&delayed_node->mutex);
 }
 
 void btrfs_kill_delayed_inode_items(struct btrfs_inode *inode)
 {
     struct btrfs_delayed_node *delayed_node;
 
     delayed_node = btrfs_get_delayed_node(inode);
     if (!delayed_node)
         return;
 
     __btrfs_kill_delayed_node(delayed_node);
     btrfs_release_delayed_node(delayed_node);
 }
 
 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
 {
     u64 inode_id = 0;
     struct btrfs_delayed_node *delayed_nodes[8];
     int i, n;
 
     while (1) {
         spin_lock(&root->inode_lock);
         n = radix_tree_gang_lookup(&root->delayed_nodes_tree,
                        (void **)delayed_nodes, inode_id,
                        ARRAY_SIZE(delayed_nodes));
         if (!n) {
             spin_unlock(&root->inode_lock);
             break;
         }
 
         inode_id = delayed_nodes[n - 1]->inode_id + 1;
         for (i = 0; i < n; i++) {
             /*
              * Don't increase refs in case the node is dead and
              * about to be removed from the tree in the loop below
              */
             if (!refcount_inc_not_zero(&delayed_nodes[i]->refs))
                 delayed_nodes[i] = NULL;
         }
         spin_unlock(&root->inode_lock);
 
         for (i = 0; i < n; i++) {
             if (!delayed_nodes[i])
                 continue;
             __btrfs_kill_delayed_node(delayed_nodes[i]);
             btrfs_release_delayed_node(delayed_nodes[i]);
         }
     }
 }
 
 void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info)
 {
     struct btrfs_delayed_node *curr_node, *prev_node;
 
     curr_node = btrfs_first_delayed_node(fs_info->delayed_root);
     while (curr_node) {
         __btrfs_kill_delayed_node(curr_node);
 
         prev_node = curr_node;
         curr_node = btrfs_next_delayed_node(curr_node);
         btrfs_release_delayed_node(prev_node);
     }
 }
 

This page was automatically generated by the 2.1.0 LXR engine. The LXR team