ocfs2: Fix refcnt leak on ocfs2_fast_follow_link() error path

If ->follow_link handler returns an error, it should decrement
nd->path refcnt. But ocfs2_fast_follow_link() doesn't decrement.

This patch fixes the problem by using nd_set_link() style error handling
instead of playing with nd->path.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/symlink.c

@@ -137,20 +137,20 @@ static void *ocfs2_fast_follow_link(struct dentry *dentry,
 	}
 
 	memcpy(link, target, len);
-	nd_set_link(nd, link);
 
 bail:
+	nd_set_link(nd, status ? ERR_PTR(status) : link);
 	brelse(bh);
 
 	mlog_exit(status);
-	return status ? ERR_PTR(status) : link;
+	return NULL;
 }
 
 static void ocfs2_fast_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
 {
-	char *link = cookie;
-
-	kfree(link);
+	char *link = nd_get_link(nd);
+	if (!IS_ERR(link))
+		kfree(link);
 }
 
 const struct inode_operations ocfs2_symlink_inode_operations = {