ceph: fix inode reference leakage in ceph_get_snapdir()

The ceph_get_inode() will search for or insert a new inode into the
hash for the given vino, and return a reference to it. If new is
non-NULL, its reference is consumed.

We should release the reference when in error handing cases.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/inode.c

@@ -87,13 +87,13 @@ struct inode *ceph_get_snapdir(struct inode *parent)
 	if (!S_ISDIR(parent->i_mode)) {
 		pr_warn_once("bad snapdir parent type (mode=0%o)\n",
 			     parent->i_mode);
-		return ERR_PTR(-ENOTDIR);
+		goto err;
 	}
 
 	if (!(inode->i_state & I_NEW) && !S_ISDIR(inode->i_mode)) {
 		pr_warn_once("bad snapdir inode type (mode=0%o)\n",
 			     inode->i_mode);
-		return ERR_PTR(-ENOTDIR);
+		goto err;
 	}
 
 	inode->i_mode = parent->i_mode;
@@ -113,6 +113,12 @@ struct inode *ceph_get_snapdir(struct inode *parent)
 	}
 
 	return inode;
+err:
+	if ((inode->i_state & I_NEW))
+		discard_new_inode(inode);
+	else
+		iput(inode);
+	return ERR_PTR(-ENOTDIR);
 }
 
 const struct inode_operations ceph_file_iops = {