smb: smbdirect: introduce struct smbdirect_mr_io

This will be used by the client in order to maintain
memory registrations.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Acked-by: 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

@@ -334,6 +334,32 @@ struct smbdirect_recv_io {
 	u8 packet[];
 };
 
+enum smbdirect_mr_state {
+	SMBDIRECT_MR_READY,
+	SMBDIRECT_MR_REGISTERED,
+	SMBDIRECT_MR_INVALIDATED,
+	SMBDIRECT_MR_ERROR
+};
+
+struct smbdirect_mr_io {
+	struct smbdirect_socket *socket;
+	struct ib_cqe cqe;
+
+	struct list_head list;
+
+	enum smbdirect_mr_state state;
+	struct ib_mr *mr;
+	struct sg_table sgt;
+	enum dma_data_direction dir;
+	union {
+		struct ib_reg_wr wr;
+		struct ib_send_wr inv_wr;
+	};
+
+	bool need_invalidate;
+	struct completion invalidate_done;
+};
+
 struct smbdirect_rw_io {
 	struct smbdirect_socket *socket;
 	struct ib_cqe cqe;