smb: smbdirect: introduce struct smbdirect_send_io

This will be used in client and server soon
in order to replace smbd_request/smb_direct_sendmsg.

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

@@ -89,6 +89,30 @@ struct smbdirect_socket {
 	} recv_io;
 };
 
+struct smbdirect_send_io {
+	struct smbdirect_socket *socket;
+	struct ib_cqe cqe;
+
+	/*
+	 * The SGE entries for this work request
+	 *
+	 * The first points to the packet header
+	 */
+#define SMBDIRECT_SEND_IO_MAX_SGE 6
+	size_t num_sge;
+	struct ib_sge sge[SMBDIRECT_SEND_IO_MAX_SGE];
+
+	/*
+	 * Link to the list of sibling smbdirect_send_io
+	 * messages.
+	 */
+	struct list_head sibling_list;
+	struct ib_send_wr wr;
+
+	/* SMBD packet header follows this structure */
+	u8 packet[];
+};
+
 struct smbdirect_recv_io {
 	struct smbdirect_socket *socket;
 	struct ib_cqe cqe;