Re: flock LOCK_EX hangs

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, May 16, 2007 at 03:12:53PM +0200, Baurzhan Ismagulov wrote:
> I'm experiencing problems with the kernel NFS server. The client hangs
> on the flock call. This is Debian etch, Linux 2.6.16-1-686-smp, the
> server and the client is the same machine. The directory is exported
> with rw, no mount options. The lockd kernel thread is present, rpcinfo
> -p reports nlockmgr registered, the firewall passes all the traffic
> through.
> 
> I've googled and searched the list archive, the postings are usually
> quite old (only two were from 2006 and referred to Linux 2.6), and I
> couldn't see how I could further analyze the problem. I've also tried
> mounting with nolock, but this apparently makes flock / fcntl to fail,
> since the tools I use (automake and debootstrap, although I checked this
> only with the latter) exited with an error code, and I rely upon it.

Might be fun to watch the network traffic as this is happening.  I'd
probably do something like

	wireshark -Slk -ilo

then try to get a lock, and try to understand what's happening on the
"network": is the client sending requests that the server doesn't
answer?  Or are there errors coming back?  Etc.

Or you could run

	tcpdump -s0 -ilo -wtmp.pcap

and mail a copy of tmp.pcap and somebody could take a look.

There's also been a lot fixed since 2.6.16, so it might be worth trying
something newer.

--b.

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
NFS maillist  -  NFS@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs