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

Kasparek Tomas
2008-12-16T12:05:52Z

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.

--

Tomas Kasparek, PhD student E-mail: kasparek@fit.vutbr.cz
CVT FIT VUT Brno, L127 Web: http://www.fit.vutbr.cz/~kasparek
Bozetechova 1, 612 66 Fax: +420 54114-1270
Brno, Czech Republic Phone: +420 54114-1220

jabber: tomas.kasparek-2ASvDZBniIelVyrhU4qvOw@public.gmane.org
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