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From:   "Benjamin Coddington" <bcodding@redhat.com>
To:     "Trond Myklebust" <trondmy@hammerspace.com>
Cc:     anna@kernel.org, linux-nfs@vger.kernel.org, neilb@suse.de
Subject: Re: [PATCH 0/2] NFS: limit use of ACCESS cache for negative responses
Date:   Mon, 19 Sep 2022 15:09:08 -0400
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On 26 Aug 2022, at 20:52, Trond Myklebust wrote:

> Can we please try to solve the real problem first? The real problem is
> not that user permissions change every hour on the server.
>
> POSIX normally only expects changes to happen to your group membership
> when you log in. The problem here is that the NFS server is updating
> its rules concerning your group membership at some random time after
> your log in on the NFS client.
>
> So how about if we just do our best to approximate the POSIX rules, and
> promise to revalidate your cached file access permissions at least once
> after you log in? Then we can let the NFS server do whatever the hell
> it wants to do after that.
> IOW: If the sysadmin changes the group membership for the user, then
> the user can remedy the problem by logging out and then logging back in
> again, just like they do for local filesystems.

This goes a long way toward fixing things up for us, I appreciate it, and
hope to see it merged.  The version on your testing branch (d84b059f) can
have my:

Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>

Ben