ceph: use pathlen values returned by set_request_path_attr

We make copies of the dentry name in set_request_path_attr, but then
create_request_message re-fetches the lengths out of the dentry. While
we don't currently set the *_drop fields unless the parents are locked,
it's still better not to rely on that sort of implicit assumption.

Use the pathlen values that set_request_path_attr returned instead, as
they will always be correct for the returned paths themselves.
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Reviewed-by: N"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

fs/ceph/mds_client.c

@@ -2288,9 +2288,9 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
 		(!!req->r_inode_drop + !!req->r_dentry_drop +
 		 !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
 	if (req->r_dentry_drop)
-		len += req->r_dentry->d_name.len;
+		len += pathlen1;
 	if (req->r_old_dentry_drop)
-		len += req->r_old_dentry->d_name.len;
+		len += pathlen2;
 
 	msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
 	if (!msg) {