[PATCH 0/2] smb:client/server/smbdirect: correct value for max_fragmented_recv_size

[Namjae Jeon]

On Fri, Feb 6, 2026 at 1:14 AM Stefan Metzmacher <metze at samba.org> wrote:
>
> Hi,
>
> here is one additional fix for the credit problems
> in the client, it most likely happens when using
> signing on rdma: 'rdma,sec=ntlmsspi' as mount options.
>
> The problem is that we announce a large
> max_fragmented_recv_size to the server, while we
> don't have enough recv buffers to hold
> the largest possible fragmented message.
>
> For now we use the same logic as we are
> currently using in the server:
>
> max_fragmented_recv_size = (recv_credit_max * max_recv_size) / 2
>
> There's a lot to improve here, but this makes sure
> we're able talk to a peer without running out of credits
> while transferring a message that uses the full
> max_fragmented_recv_size.
>
> The server patch is basically just cosmetic
> explaining the logic we're are using.
> Note the value of smb_direct_max_fragmented_recv_size
> is never really used as smb_direct_prepare
> recalculates max_fragmented_recv_size.
>
> This applies on top of ksmbd-for-next
>
> Stefan Metzmacher (2):
>   smb: client: correct value for smbd_max_fragmented_recv_size
>   smb: server: correct value for smb_direct_max_fragmented_recv_size
Acked-by: Namjae Jeon <linkinjeon at kernel.org>

Thanks!