Re: Bug report: PXE blocksize

["Vladimir 'φ-coder/phcoder' Serbinenko" <phcoder@gmail.com>]

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On 08/30/2010 04:52 PM, Turner, Ian wrote:
>> I don't see where you mean. The only reference to pxe_blksize I see in
>> pxefs_read is following:
>>       o.packet_size = grub_pxe_blksize;
>>       grub_pxe_call (GRUB_PXENV_TFTP_OPEN, &o);
>> Which is called only when reopening file. Could you retry pulling? Now
>> newreloc is merged into mainline so you can just pull mainline.
>>     
> You're right. The problem is more complex that I thought originally. I think it's something more like this:
>
> 1. Start loading a file 'grub.cfg' with blksize=512
> 2. File contains a directive to change blocksize to something else (e.g., 1024). This updates grub_pxe_blksize but doesn't change the parameters of the grub.cfg session.
> 3. File also contains a directive that causes grub to load some other file (say, an insmod or source command). This causes pxe.c to close grub.cfg for now, but the grub_pxe_data object sticks around.
> 4. Upon resuming read of grub.cfg, pxe opens with the new blocksize but reads with the old one.
>
> I still think the solution is what I proposed originally (patch follows), which maintains the same PXE blocksize for a given file until it is finally closed by the requestor, no matter how many times PXE itself needs to open/close the TFTP session.
>   
There are 2 problems with changing blocksize in the middle of the stream:
1) pn isn't recomputed. Easy to fix
2) bufio doesn't change the size. Difficult and ugly to fix.
So I applied your patch. Thanks
> --- pxe-broken.c        2010-08-30 10:52:03.717580213 -0400
> +++ pxe-fixed.c 2010-08-30 10:52:49.370957060 -0400
> @@ -281,7 +281,7 @@
>        o.gateway_ip = disk_data->gateway_ip;
>        grub_strcpy ((char *)&o.filename[0], data->filename);
>        o.tftp_port = grub_cpu_to_be16 (GRUB_PXE_TFTP_PORT);
> -      o.packet_size = grub_pxe_blksize;
> +      o.packet_size = data->block_size;
>        grub_pxe_call (GRUB_PXENV_TFTP_OPEN, &o);
>        if (o.status)
>         {
>
> Cheers,
>
> --Ian
>
>   
>
>
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>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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