Large SMBwriteX testing.

Steve French smfrench at gmail.com
Wed Nov 7 22:56:32 GMT 2007


I have verified that it works for the case in which "min receivefile
size" is under 128K.  When I set it to 250000 and tried to read 148000
there were two or three problems (reply_write_and_X in Samba is
calling smb_len instead of smb_len_large and it is looking for
"req->unread_bytes" incorrectly in a few places in reply.c and
fileio.c

On Nov 2, 2007 6:43 PM, Jeremy Allison <jra at samba.org> wrote:
> Hi Steve,
>
>         I've finished adding the ability for smbd to support up to
> 16MB writeX calls in the latest git 3.2 tree.
>
> To enable, set the parameter :
>
> min receivefile size = XXX
>
> where XXX is the smallest writeX you want to handle with recvfile.
>
> The linux kernel doesn't yet support zerocopy from network to
> file (ie. splice only works one way currently) so it's emulated
> in userspace (with a 128k staging buffer) for now.
>
> Also it must be an unsigned connection (for obvious reasons).
>
> Once you've set this param smbd will start reporting
> CIFS_UNIX_LARGE_WRITE_CAP on a SMB_QUERY_CIFS_UNIX_INFO:
> call and you should be good to go. You'll need to use
> a writeX call identical to Windows (14 wct with a 1 byte
> pad field) in order to trigger the new code.
>
> Let me know if you get the chance to test it and if
> it makes a speed difference for CIFSFS.
>
> Cheers,
>
>         Jeremy.
>



-- 
Thanks,

Steve


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