Re: [patch] add dentry revalidate to follow mount.

[Andreas Dilger <adilger@sun.com>]

On Jun 08, 2009  21:17 +0100, Al Viro wrote:
> On Tue, Jun 09, 2009 at 01:53:56AM +0530, pravin shelar wrote:
> > Al Viro wrote:
> >> On Mon, Jun 08, 2009 at 07:14:15PM +0530, pravin shelar wrote:
> >>> Hi
> >>>          i have seen error in lustre while setting permission on fs root
> >>> from a client. problem is permission are not getting propagated to
> >>> other clients.
> >>>
> >>> this is because of do_lookup() call path which does not revalidate
> >>> fs root dentry in follow_mount()
> >>>
> >>> attached patch adds revalidation call in follow_mount.
> >>
> >> ... and makes umount() of such thing impossible.  NAK.  That's not a solution.
> >
> > i am not sure how this patch could cause problem for umount. i have 
> > tested patch with nfs and it worked fine.
> > can u elaborate what is problem?
> 
> Think what happens if revalidate fails and keeps failing.  Would do
> wonders to pathname resolution in umount(2)...

Would having a limit on the number of revalidations be a suitable
compromise?

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.