From: Andrew Morton <akpm@linux-foundation.org>
To: Ed Cashin <ecashin@coraid.com>
Cc: <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] aoe: adjust ref of head for compound page tails
Date: Wed, 7 Aug 2013 14:26:47 -0700 [thread overview]
Message-ID: <20130807142647.6614d3ec88a7af12cba4505a@linux-foundation.org> (raw)
In-Reply-To: <EB4C2185-3868-42A3-A88D-F9642962D336@coraid.com>
On Wed, 7 Aug 2013 17:21:32 -0400 Ed Cashin <ecashin@coraid.com> wrote:
> > What are the end-user-visible effects of the problem which is being
> > fixed? Please always include this info when fixing bugs so that others
> > can work out what kernel version(s) need the patch.
>
>
> Sorry. I tried to cover that but maybe should have separated it more clearly from the running text.
>
> The patch changes the current behavior encountered with direct I/O and aoe:
>
> aoe can BUG when direct I/O used
>
> ... to a new behavior:
>
> aoe does not BUG when direct I/O is used
>
> And the user will never know that instead aoe is manipulating the _count of the head page, even though that's what's happening with this patch applied.
>
> (The user-visible effects that motivated the older patch that added the BUG to aoe when page tails are used for block I/O was a VM_BUG_ON that occurred when the aoe driver manipulated the _count of a compound page tail.)
OK, I added "Fix a BUG which can trigger when direct-IO is used with
AOE". Which kernel versions are affected?
next prev parent reply other threads:[~2013-08-07 21:26 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-02 1:29 [PATCH] aoe: respect compound page reference tracking expectations Ed Cashin
2013-08-02 1:29 ` [PATCH] aoe: adjust ref of head for compound page tails Ed Cashin
2013-08-07 20:58 ` Andrew Morton
2013-08-07 21:12 ` Ed Cashin
2013-08-07 21:18 ` Andrew Morton
2013-08-07 21:27 ` Andrew Morton
2013-08-07 23:41 ` Ed Cashin
2013-08-07 23:48 ` Ed Cashin
2013-08-07 23:51 ` Andrew Morton
2013-08-07 21:00 ` Andrew Morton
2013-08-07 21:21 ` Ed Cashin
2013-08-07 21:26 ` Andrew Morton [this message]
2013-08-07 23:27 ` Ed Cashin
2013-08-07 23:35 ` Andrew Morton
2013-08-07 23:54 ` Ed Cashin
2013-08-08 0:05 ` Andrew Morton
2013-08-08 0:50 ` Ed Cashin
2013-08-08 19:56 ` Andrew Morton
2013-08-08 21:02 ` Ed Cashin
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