Re: 2.6.38: Quota over NFS4

[Adam Lackorzynski <adam@os.inf.tu-dresden.de>]

On Thu Mar 17, 2011 at 19:03:15 -0400, J. Bruce Fields wrote:
> On Thu, Mar 17, 2011 at 11:59:08PM +0100, Adam Lackorzynski wrote:
> > 
> > On Thu Mar 17, 2011 at 18:27:32 -0400, J. Bruce Fields wrote:
> > > On Thu, Mar 17, 2011 at 10:33:03PM +0100, Adam Lackorzynski wrote:
> > > > 
> > > > On Thu Mar 17, 2011 at 13:38:05 -0400, J. Bruce Fields wrote:
> > > > > On Thu, Mar 17, 2011 at 02:32:47PM +0100, Adam Lackorzynski wrote:
> > > > > > Hello,
> > > > > > 
> > > > > > I'm seeing a problem with quotas in a system where the server running
> > > > > > 2.6.38 exports an XFS filesystem via NFS4 to a client. The client kernel
> > > > > > version does not seem to play a role, checked with 2.6.38, 2.6.37 and
> > > > > > 2.6.36. The following script and output show the problem:
> > > > > > 
> > > > > > #! /bin/sh
> > > > > > 
> > > > > > quota | grep home
> > > > > > du
> > > > > > cp /bin/ls x1
> > > > > > du
> > > > > > cat x1 > /dev/null
> > > > > > rm x1
> > > > > > du
> > > > > > quota | grep home
> > > > > > 
> > > > > > Output:
> > > > > > 
> > > > > >    homes:/home/ 8194720  9072000 9174400          403670  500000  550000        
> > > > > > 0       .
> > > > > > 96      .
> > > > > > 0       .
> > > > > >    homes:/home/ 8194816  9072000 9174400          403671  500000  550000        
> > > > > > 
> > > > > > 
> > > > > > As can be seen the 96 kb are still accounted on the quota of the user.
> > > > > > Removing the 'cat' command from the script makes the quota be ok again
> > > > > > (original value). Also mounting via nfs3 does not exhibit it, same for running
> > > > > > the script on the nfs-server directly.
> > > > > 
> > > > > Does "df" show the same problem?
> > > > 
> > > > With '/bin/ls' it does not change at all, so I took a bigger binary
> > > > which yields to:
> > > > 
> > > >    homes:/home/ 8203780  9072000 9174400          403688  500000  550000        
> > > > 0       .
> > > > Filesystem           1K-blocks      Used Available Use% Mounted on
> > > >   homes:/home        513671168 335251456 178419712  66% /tmp/xx
> > > > 4592    .
> > > > Filesystem           1K-blocks      Used Available Use% Mounted on
> > > >   homes:/home        513671168 335256576 178414592  66% /tmp/xx
> > > > 0       .
> > > > Filesystem           1K-blocks      Used Available Use% Mounted on
> > > >   homes:/home        513671168 335256576 178414592  66% /tmp/xx
> > > >    homes:/home/ 8208372  9072000 9174400          403689  500000  550000        
> > > > 
> > > > So yes, it seems to be there as well.
> > > 
> > > It might be easier to see with "df -i" (assuming we're leaking an
> > > inode).
> > 
> > Result is as expected, inode goes one up and not down again.
> 
> Is this something special about binaries?  If you copy something other
> than a binary, do you not see the bug?

No change when using a plain text file instead of a binary.


Adam
-- 
Adam                 adam@os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/