diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index a1cd0da72c94..ef724a5fc30e 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -189,6 +189,8 @@ static inline void drop_delayed_ref(struct btrfs_trans_handle *trans, } else { assert_spin_locked(&head->lock); list_del(&ref->list); + if (!list_empty(&ref->add_list)) + list_del(&ref->add_list); } ref->in_tree = 0; btrfs_put_delayed_ref(ref); @@ -431,6 +433,15 @@ add_delayed_ref_tail_merge(struct btrfs_trans_handle *trans, exist->action = ref->action; mod = -exist->ref_mod; exist->ref_mod = ref->ref_mod; + if (ref->action == BTRFS_ADD_DELAYED_REF) + list_add_tail(&exist->add_list, + &href->ref_add_list); + else if (ref->action == BTRFS_DROP_DELAYED_REF) { + ASSERT(!list_empty(&exist->add_list)); + list_del(&exist->add_list); + } else { + ASSERT(0); + } } else mod = -ref->ref_mod; } @@ -444,6 +455,8 @@ add_delayed_ref_tail_merge(struct btrfs_trans_handle *trans, add_tail: list_add_tail(&ref->list, &href->ref_list); + if (ref->action == BTRFS_ADD_DELAYED_REF) + list_add_tail(&ref->add_list, &href->ref_add_list); atomic_inc(&root->num_entries); trans->delayed_ref_updates++; spin_unlock(&href->lock); @@ -590,6 +603,7 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, head_ref->must_insert_reserved = must_insert_reserved; head_ref->is_data = is_data; INIT_LIST_HEAD(&head_ref->ref_list); + INIT_LIST_HEAD(&head_ref->ref_add_list); head_ref->processing = 0; head_ref->total_ref_mod = count_mod; head_ref->qgroup_reserved = 0; @@ -671,6 +685,8 @@ add_delayed_tree_ref(struct btrfs_fs_info *fs_info, ref->is_head = 0; ref->in_tree = 1; ref->seq = seq; + INIT_LIST_HEAD(&ref->list); + INIT_LIST_HEAD(&ref->add_list); full_ref = btrfs_delayed_node_to_tree_ref(ref); full_ref->parent = parent; @@ -726,6 +742,8 @@ add_delayed_data_ref(struct btrfs_fs_info *fs_info, ref->is_head = 0; ref->in_tree = 1; ref->seq = seq; + INIT_LIST_HEAD(&ref->list); + INIT_LIST_HEAD(&ref->add_list); full_ref = btrfs_delayed_node_to_data_ref(ref); full_ref->parent = parent; diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h index 43f3629760e9..dba97842b47a 100644 --- a/fs/btrfs/delayed-ref.h +++ b/fs/btrfs/delayed-ref.h @@ -42,6 +42,12 @@ struct btrfs_delayed_ref_node { /*data/tree ref use list, stored in ref_head->ref_list. */ struct list_head list; + /* + * If action is BTRFS_ADD_DELAYED_REF, also link this node to + * ref_head->ref_add_list, then we do not need to iterate the + * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes. + */ + struct list_head add_list; /* the starting bytenr of the extent */ u64 bytenr; @@ -99,6 +105,8 @@ struct btrfs_delayed_ref_head { spinlock_t lock; struct list_head ref_list; + /* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */ + struct list_head ref_add_list; struct rb_node href_node; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 8677d29efade..811662cce977 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4344,6 +4344,8 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, list) { ref->in_tree = 0; list_del(&ref->list); + if (!list_empty(&ref->add_list)) + list_del(&ref->add_list); atomic_dec(&delayed_refs->num_entries); btrfs_put_delayed_ref(ref); } diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index af0bcbd8302f..0d80136206b1 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2454,13 +2454,14 @@ select_delayed_ref(struct btrfs_delayed_ref_head *head) * the extent item from the extent tree, when there still are references * to add, which would fail because they would not find the extent item. */ - list_for_each_entry(ref, &head->ref_list, list) { - if (ref->action == BTRFS_ADD_DELAYED_REF) - return ref; - } + if (!list_empty(&head->ref_add_list)) + return list_first_entry(&head->ref_add_list, + struct btrfs_delayed_ref_node, add_list); - return list_entry(head->ref_list.next, struct btrfs_delayed_ref_node, - list); + ref = list_first_entry(&head->ref_list, struct btrfs_delayed_ref_node, + list); + ASSERT(list_empty(&ref->add_list)); + return ref; } /* @@ -2620,6 +2621,8 @@ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, actual_count++; ref->in_tree = 0; list_del(&ref->list); + if (!list_empty(&ref->add_list)) + list_del(&ref->add_list); } atomic_dec(&delayed_refs->num_entries);