[PVFS2-developers] Re: smallio server death with old kernel

[Sam Lang]

Thanks for looking into this Murali.  I'm back from vacation today so  
I'll look at these patches and try to get them committed ASAP.

-sam

On Jan 5, 2006, at 3:43 PM, Murali Vilayannur wrote:

> Hi Pete,
> Attached patch fixes the size computation bug (I hope!). Also  
> attached the
> one liner change to accomodate encode related print statements  
> appear in
> the logs.
>
> However, RobL pointed out to me that pvfs2-cp still has data  
> corruption
> issues, which unfortunately don't get triggered thru the VFS as  
> easily.
> So I am going to dig that a little bit and see  if I can spot  
> something
> obvious.
> Thanks for your comments/fixes on the encoding issues!
> Murali
>
> On Thu, 5 Jan 2006, Pete Wyckoff wrote:
>
>> vilayann at mcs.anl.gov wrote on Wed, 04 Jan 2006 21:26 -0600:
>>> Could you try the attached patch and let me know if it fixes the  
>>> crash?
>>> (There are still some other bugs like the size of the file  
>>> reported is
>>> off-by-one, but I haven't dug deep into the SMALL_IO code just  
>>> yet..)
>>
>> Yes, that fixes the crash, thanks!  But it is indeed off-by-one:
>>
>>     piv001$ tar tvfz tarball.tgz
>>     drwxr-xr-x pw/oscsys         0 2005-12-23 17:15:49 ./
>>     -rw-r--r-- pw/oscsys    180224 2005-12-23 17:15:40 ./data
>>     piv001$ tar xfzvC tarball.tgz /pvfs
>>     ./
>>     ./data
>>     piv001$ pvfs2-ls -la /pvfs
>>     drwxrwxrwx    1 pw       oscsys          4096 2006-01-05 10:05 .
>>     drwxrwxrwx    1 pw       oscsys          4096 2006-01-05  
>> 10:05 .. (faked)
>>     -rw-r--r--    1 pw       oscsys        180223 2005-12-23 17:15  
>> data
>>     drwxrwxrwx    1 pw       oscsys          4096 2006-01-05 10:04  
>> lost+found
>>
>> But I don't see your debugging statements in the logs when I turn on
>> verbose on the client; weird.  Server logs attached too just in  
>> case those
>> are interesting.
>>
>>> Also, could you look over and see if the encode_skip4 that I  
>>> added will
>>> fix those pesky alignment warnings on 64 bit machines or if they are
>>> unnecessary?
>>
>> Yours looks fine, but a bit more direct would be to remove the  
>> existing
>> skip4 and let the fs_id and enum nestle together in a single 64-bit
>> word.  It didn't break anything on ia64 (modified patch attached.)
>> There are other unrelated unaligned problems that have cropped up in
>> the past few months that I'll take a look at, though.
>>
>>> Sam wrote the SMALL_IO protocol and he knows it best. I am pretty  
>>> sure
>>> this is an ugly fix if at all it works :)
>>> I don't know how/if Rob/Sam want SMALL_IO protocol to be disabled  
>>> since
>>> we need people to use the CVS head version and find the last  
>>> remaining
>>> bugs (hopefully!). We could make an environment variable/mount- 
>>> time option
>>> that would disable small i/o changes temporarily but I think that  
>>> decision is upto
>>> them..
>>
>> Agree, it should be fixed.  I was just under pressure here to get
>> past some old bugs and was hoping to do so by moving up to the CVS
>> head where I know at least one has been addressed (append bug).
>>
>> 		-- Pete
>> <smallio2.patch>
> _______________________________________________
> PVFS2-developers mailing list
> PVFS2-developers at beowulf-underground.org
> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers