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From:   Olga Kornievskaia <aglo@umich.edu>
Date:   Mon, 28 Jun 2021 16:23:47 -0400
Message-ID: <CAN-5tyEuB5C9u+xZ5L47fSQ9cwZnsbhJuBs+gybU2A-jzAkfog@mail.gmail.com>
Subject: client's caching of server-side capabilities
To:     linux-nfs <linux-nfs@vger.kernel.org>
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Hi folks,

I have a general question of why the client doesn't throw away the
cached server's capabilities on server reboot. Say a client mounted a
server when the server didn't support security_labels, then the server
was rebooted and support was enabled. Client re-establishes its
clientid/session, recovers state, but assumes all the old capabilities
apply. A remount is required to clear old/find new capabilities. The
opposite is true that a capability could be removed (but I'm assuming
that's a less practical example).

I'm curious what are the problems of clearing server capabilities and
rediscovering them on reboot? Is it because a local filesystem could
never have its attributes changed and thus a network file system can't
either?

Thank you.