Re: [PATCH 0/3] NFS regression in 2.6.26?, "task blocked for more than 120 seconds"

Trond Myklebust
2008-12-16T13:00:17Z

On Tue, 2008-12-16 at 13:10 +0100, Kasparek Tomas wrote:
> On Tue, Dec 16, 2008 at 01:05:47PM +0100, Kasparek Tomas wrote:
> > On Sun, Dec 14, 2008 at 02:50:01PM -0500, Trond Myklebust wrote:
> > > On Thu, 2008-12-04 at 11:23 +0100, Kasparek Tomas wrote:
> > > > On Tue, Dec 02, 2008 at 01:10:07PM -0500, Trond Myklebust wrote:
> > > > > On Tue, 2008-12-02 at 17:26 +0100, Kasparek Tomas wrote:
> > > > >
> > > > > > Did tried. The number should be seconds and defaults to 60, These
> > > > > > connections are still there after several hours. Changing it to 10 (sec)
> > > > > > and same behaviour. (BTW The server did not changed in last several months)
> > > > >
> > > > > Are you seeing the same behaviour with 'netstat -t'?
> > > >
> > > > yes:
> > > >
> > > > root@pckasparek: ~# ssh root@pcnlp1 'netstat -pan | grep WAIT' | cut -c-85
> > > > tcp 0 0 147.229.12.146:989 147.229.176.14:2049 FIN_WAIT2
> > > > root@pckasparek: ~# ssh root@pcnlp1 'netstat -t | grep WAIT' | cut -c-85
> > > > tcp 0 0 pcnlp1.fit.vutbr.:ftps-data eva.fit.vutbr.cz:nfs FIN_WAIT2
> > > >
> > > > but it should be the same, did't it? -t just selects TCP connections and
> > > > this is TCP connection so it shows the same
> > >
> > > Right, but the point is that the client is in the state FIN_WAIT2, which
> > > means that it has closed the socket on its end, and is waiting for the
> > > server to close on its end. The fact that the server is failing to do
> > > this is a server bug.
> > >
> > > That said, we can't wait forever for buggy servers. I see now why the
> > > linger2 stuff isn't working. I believe that the appended patch should
> > > help...
> >
> > Hm, not happy to say that but it still does not work after some time. Now
> > the problem is opposite there are no connections to the server according to
> > netstat on client, just time to time there is
> >
> > pcnlp1.fit.vutbr.cz.15234 > kazi.fit.vutbr.cz.nfs: 40 null
> > kazi.fit.vutbr.cz.nfs > pcnlp1.fit.vutbr.cz.15234: reply ok 24 null
> >
> > (kazi is server). Will try to investigate more details.
> >
> > (just to remember the same kernel with reversed
> > e06799f958bf7f9f8fae15f0c6f519953fb0257c works fine - exact patch is
> > included - it was slightly modified to fit 2.6.27.x kernels)
> >
> > Thank you very much for your help so far.
>
> just the forgoten patch promised.

NACK. That takes us right back to the previous broken behaviour.

--
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com