Btrfs: introduce the delayed inode ref deletion for the single link inode

The inode reference item is close to inode item, so we insert it simultaneously
with the inode item insertion when we create a file/directory.. In fact, we also
can handle the inode reference deletion by the same way. So we made this patch to
introduce the delayed inode reference deletion for the single link inode(At most
case, the file doesn't has hard link, so we don't take the hard link into account).

This function is based on the delayed inode mechanism. After applying this patch,
we can reduce the time of the file/directory deletion by ~10%.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
index a6a13f7e014d..f70119f25421 100644
--- a/fs/btrfs/delayed-inode.h
+++ b/fs/btrfs/delayed-inode.h
@@ -50,6 +50,7 @@ struct btrfs_delayed_root {
 
 #define BTRFS_DELAYED_NODE_IN_LIST	0
 #define BTRFS_DELAYED_NODE_INODE_DIRTY	1
+#define BTRFS_DELAYED_NODE_DEL_IREF	2
 
 struct btrfs_delayed_node {
 	u64 inode_id;
@@ -127,6 +128,7 @@ int btrfs_commit_inode_delayed_inode(struct inode *inode);
 int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root, struct inode *inode);
 int btrfs_fill_inode(struct inode *inode, u32 *rdev);
+int btrfs_delayed_delete_inode_ref(struct inode *inode);
 
 /* Used for drop dead root */
 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root);