Re: System CPU increasing on idle 2.6.36

[Trond Myklebust <Trond.Myklebust@netapp.com>]

On Wed, 2010-12-15 at 13:08 -0500, J. Bruce Fields wrote:
> On Tue, Dec 14, 2010 at 05:56:09PM -0800, Simon Kirby wrote:
> > On Tue, Dec 14, 2010 at 05:10:21PM -0800, Simon Kirby wrote:
> > 
> > > On Tue, Dec 14, 2010 at 03:38:43PM -0800, Simon Kirby wrote:
> > > 
> > > > I'm just about to try
> > > > 2.6.37-rc5-git3 on there plus your NFS fixes (which Linus seems to have
> > > > half-merged and uploaded as -git3 but not pushed to his public git) 
> > > 
> > > Ignore this; I was just confusing myself by having the leak fixes already
> > > applied.  Otoh, I got this Oops while trying NFSv4.  I'll check my
> > > merging again.
> > > 
> > > Do you have a git branch exposed with the "Allow the admin to turn off
> > > NFSv4 uid/gid mapping" patches applied?
> > 
> > Hm, the fixes were merged for -git4, and it seems to work fine there.
> > 
> > As for the nfs4 uid/gid mapping patch, it seems the server side support
> > for this is still neded?
> 
> I'm not convinced that this behavior should depend on the security
> flavor, so I'm assuming that something like steved's libnfsidmap patches
> should do the job.

Don't assume.

Those patches do not fix the problem that if uid(name@server) !=
uid(name@client), then the client will be creating files with the 'wrong
username' on the server.

In that case, everything from setuid applications through open(O_CREAT)
to 'chown' will be broken because your authentication and authorisation
models do not match up.

Trond
-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com