ceph: have ceph_mdsc_do_request call ceph_mdsc_submit_request

Nothing calls ceph_mdsc_submit_request today, but in later patches we'll
need to be able to call this separately.

Have the helper return an int so we can check the r_err under the mutex,
and have the caller just check the error code from the submit. Also move
the acquisition of CEPH_CAP_PIN references into the same function.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index ebcad5af..a83f28b 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -465,8 +465,9 @@ extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 					   struct inode *dir);
 extern struct ceph_mds_request *
 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
-extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
-				     struct ceph_mds_request *req);
+extern int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
+				    struct inode *dir,
+				    struct ceph_mds_request *req);
 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 				struct inode *dir,
 				struct ceph_mds_request *req);