ksmbd: smbd: change the default maximum read/write, receive size

Due to restriction that cannot handle multiple
buffer descriptor structures, decrease the maximum
read/write size for Windows clients.

And set the maximum fragmented receive size
in consideration of the receive queue size.
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/transport_rdma.c

@@ -80,7 +80,7 @@ static int smb_direct_max_fragmented_recv_size = 1024 * 1024;
 /*  The maximum single-message size which can be received */
 static int smb_direct_max_receive_size = 8192;
 
-static int smb_direct_max_read_write_size = 1024 * 1024;
+static int smb_direct_max_read_write_size = 1048512;
 
 static int smb_direct_max_outstanding_rw_ops = 8;
 
@@ -1908,7 +1908,9 @@ static int smb_direct_prepare(struct ksmbd_transport *t)
 	st->max_send_size = min_t(int, st->max_send_size,
 				  le32_to_cpu(req->max_receive_size));
 	st->max_fragmented_send_size =
-			le32_to_cpu(req->max_fragmented_size);
+		le32_to_cpu(req->max_fragmented_size);
+	st->max_fragmented_recv_size =
+		(st->recv_credit_max * st->max_recv_size) / 2;
 
 	ret = smb_direct_send_negotiate_response(st, ret);
 out: