Re: [NLM] 2.6.27.14 breakage when grace period expires

[Frank van Maarseveen <frankvm@frankvm.com>]

On Thu, Feb 12, 2009 at 01:17:27PM -0500, Trond Myklebust wrote:
> On Thu, 2009-02-12 at 16:36 +0100, Frank van Maarseveen wrote:
> > A little theorizing:
> > If the unlock of a yet unrecovered lock has failed up to that point then
> > the client sure must remember the lock somehow. That might explain the
> > secondary error when a conflicting lock is granted by the server.
> 
> Sorry, but that doesn't hold water. The client will release the VFS
> 'mirror' of the lock before it attempts to unlock. Otherwise, you could
> have some nasty races between the unlock thread and the recovery
> thread...
> Besides, the granted callback handler on the client only checks the list
> of blocked locks for a match.

ok, then we have more than one NLM bug to resolve.

> 
> Oh, bugger, I know what this is... It's the same thing that happened to
> the NFSv4 callback server. If you compile with CONFIG_IPV6 or
> CONFIG_IPV6_MODULE enabled, and also set CONFIG_SUNRPC_REGISTER_V4, then
> the NLM server will listen on an IPv6 socket, and so the RPC request
> come in with their IPv4 address mapped into the IPv6 namespace.

Nope:

	$ zgrep IPV6 /proc/config.gz 
	# CONFIG_IPV6 is not set
	$ zgrep SUNRPC /proc/config.gz 
	CONFIG_SUNRPC=y
	CONFIG_SUNRPC_GSS=y
	# CONFIG_SUNRPC_BIND34 is not set


And remember this is not a recent regression.

-- 
Frank