From: Bodo Eggert <7eggert@gmx.de>
Subject: Re: no way to swapoff a deleted swap file?
To: David Newall <davidn@davidnewall.com>, Hugh Dickins <hugh@veritas.com>,
       Peter Zijlstra <peterz@infradead.org>, Peter Cordes <peter@cordes.ca>,
       linux-kernel@vger.kernel.org, Christoph Hellwig <hch@infradead.org>,
       linux-mm <linux-mm@kvack.org>
Reply-To: 7eggert@gmx.de
Date: Fri, 17 Oct 2008 10:20:22 +0200
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David Newall <davidn@davidnewall.com> wrote:
> Hugh Dickins wrote:
>> On Thu, 16 Oct 2008, Peter Zijlstra wrote:

>>> On Wed, 2008-10-15 at 17:21 -0300, Peter Cordes wrote:
>>>     
>>>> I unlinked a swapfile without realizing I was still swapping on it.

[...]

> Me too.  The kernel shouldn't protect the administrator against all
> possible mistakes; and this mistake is one of them.  Besides, who's to
> say it's always a mistake?  Somebody might want their swap file to have
> zero links.

Somebody might want their swapfiles to have zero links, _and_ the possibility
of doing swapoff. If you can do it by keeping some fds open to let
/proc/pid/fd point to the files, I think it's OK.

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