Re: [PATCH 2/2] ksmbd: smbd: change the default maximum read/write, receive size

[Hyunchul Lee <hyc.lee@gmail.com>]

2022년 1월 9일 (일) 오후 9:56, Namjae Jeon <linkinjeon@kernel.org>님이 작성:
>
> 2022-01-09 15:44 GMT+09:00, Steve French <smfrench@gmail.com>:
> > Do you have more detail on what the negotiated readsize/writesize
> > would be for Windows clients with this size? for Linux clients?
> Hyunchul, Please answer.
>

For a Linux client, if connected using smb-direct,
the size will be 1048512. But connected with multichannel,
the size will be 4MB instead of 1048512. And this causes
problems because the read/write size is bigger than 1048512.
It looks like a bug. I have to limit the ksmbd's SMB2 maximum
read/write size for a test.

For Windows clients, the actual read/write size is less than
1048512.

> >
> > It looked like it would still be 4MB at first glance (although in
> > theory some Windows could do 8MB) ... I may have missed something
> I understood that multiple-buffer descriptor support was required to
> set a read/write size of 1MB or more. As I know, Hyunchul is currently
> working on it.
> It seems to be set to the smaller of max read/write size in smb-direct
> negotiate and max read/write size in smb2 negotiate.
>
> Hyunchul, I have one question more, How did you get 1048512 setting value ?
> >

I remember when the size was 1MB, Windows clients requested read/write with
1048512 and 64.

> > On Sat, Jan 8, 2022 at 8:43 PM Namjae Jeon <linkinjeon@kernel.org> wrote:
> >>
> >> 2022-01-07 14:45 GMT+09:00, Hyunchul Lee <hyc.lee@gmail.com>:
> >> > 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.
> >> >
> >> > Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
> >> Acked-by: Namjae Jeon <linkinjeon@kernel.org>
> >
> >
> >
> > --
> > Thanks,
> >
> > Steve
> >



--
Thanks,
Hyunchul