From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [patch] add dentry revalidate to follow mount.
Date: Mon, 8 Jun 2009 21:17:45 +0100
Message-ID: <20090608201745.GO8633@ZenIV.linux.org.uk>
References: <4A2D15AF.8090000@sun.com> <20090608141317.GJ8633@ZenIV.linux.org.uk> <4A2D735C.8090703@sun.com>
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To: pravin shelar <Pravin.Shelar@Sun.COM>
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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)...