smb: smbdirect: add SMBDIRECT_RECV_IO_MAX_SGE

This will allow the client and server specific defines to be
replaced.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: metze-samba

fs/smb/common/smbdirect/smbdirect_socket.h

@@ -92,6 +92,13 @@ struct smbdirect_socket {
 struct smbdirect_recv_io {
 	struct smbdirect_socket *socket;
 	struct ib_cqe cqe;
+
+	/*
+	 * For now we only use a single SGE
+	 * as we have just one large buffer
+	 * per posted recv.
+	 */
+#define SMBDIRECT_RECV_IO_MAX_SGE 1
 	struct ib_sge sge;
 
 	/* Link to free or reassembly list */