Date: Fri, 18 May 2012 17:43:19 +0100
From: Alasdair G Kergon <agk@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: koverstreet@google.com, axboe@kernel.dk, dm-devel@redhat.com,
        linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, agk@redhat.com,
        Junichi Nomura <j-nomura@ce.jp.nec.com>,
        Mikulas Patocka <mpatocka@redhat.com>
Subject: Re: [dm-devel] [PATCH 02/13] dm: kill dm_rq_bio_destructor
Message-ID: <20120518164319.GJ29330@agk-dp.fab.redhat.com>
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	agk@redhat.com, Junichi Nomura <j-nomura@ce.jp.nec.com>,
	Mikulas Patocka <mpatocka@redhat.com>
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On Fri, May 18, 2012 at 08:57:29AM -0700, Tejun Heo wrote:
> Please explain why this is done and how it's safe.  Alasdair / dm
> folks, can you please ack this?
 
I think it's relying on there being never more than one reference on those 
bios so that that endio fn, called exactly once, always frees it and there
are no dm_puts elsewhere.

Alasdair

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