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Date:   Mon, 8 Oct 2018 17:55:45 +0100
From:   Al Viro <viro@ZenIV.linux.org.uk>
To:     Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        David Howells <dhowells@redhat.com>,
        Florian Westphal <fw@strlen.de>, linux-kernel@vger.kernel.org,
        kernel@pengutronix.de
Subject: Re: [PATCH RFC] proc: Don't retain negative dentries
Message-ID: <20181008165545.GE32577@ZenIV.linux.org.uk>
References: <20181008165009.21890-1-a.fatoum@pengutronix.de>
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On Mon, Oct 08, 2018 at 06:50:10PM +0200, Ahmad Fatoum wrote:
> The referenced commit 1da4d377f94 ("proc: revalidate misc dentries")
> caused following userspace code to access a stale /proc/net/dev
> after the network namespace was changed:

> Despite switching the network namespace, the read access from the
> newly opened file gave back what the very first read in the default
> network namespace returned.

What the hell does that have to do with negative dentries anywhere???

NAK.  Rationale makes no sense _and_ the patch has nothing to do
with claimed rationale.