Re: 2.6.38: Quota over NFS4

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

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.

> And does unmounting/remounting on the
> client clear the problem?

No.

> (Or that, in combination with stopping the
> server, unmounting the xfs export, remounting it, and restarting?)

I rebooted once, got a recovery and then the quotas were ok again (and
supposedly the used blocks as well). I assume a unmount/mount would show
the same behaviour but requires a bit of preparation to try out.

> Was there an earlier server version that didn't exhibit this problem?

Had 2.6.37 on the server before and that was fine regarding this.

> > Client mount options are:
> > homes:/home/ /home nfs4 rw,nosuid,nodev,relatime,vers=4,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=1.2.3.3,minorversion=0,local_lock=none,addr=1.2.3.4 0 0
> > 
> > Server mount options are:
> > /dev/mapper/vg-homefs /home xfs rw,nosuid,nodev,relatime,attr2,usrquota 0 0

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