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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Tue, 13 Feb 2018 12:52:22 -0800
Message-ID: <CAPcyv4jgc0yhZ6mX4az4HJf79q=t0dNy5h=rXHyJYFWhR8Zatg@mail.gmail.com>
Subject: Re: [PATCH] loop: Fix lost writes caused by missing flag
To:     Ross Zwisler <ross.zwisler@linux.intel.com>
Cc:     Christoph Hellwig <hch@lst.de>, stable@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Al Viro <viro@zeniv.linux.org.uk>, linux-nvdimm@lists.01.org
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On Tue, Feb 13, 2018 at 11:22 AM, Ross Zwisler
<ross.zwisler@linux.intel.com> wrote:
> On Tue, Feb 13, 2018 at 03:54:04PM +0100, Christoph Hellwig wrote:
>> Looks good:
>>
>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>
>> Can you wire up your test cases for blktests?
>
> Is blktests really the right place for this test?  This failure is highly
> dependent on the configuration of the filesystem that is holding the file that
> we are using for the loopback device.  It doesn't seem like blktests has
> support for mount options (dax), etc?
>
> Because of the interaction with the underlying filesystem this seems like a
> better fit with xfstests to me, but I don't know if we need to add tests there
> because we already have pretty good coverage of loopback device failures.
> That's how we found this - this bug causes all these tests to fail:
> xfs/074 xfs/078 xfs/216 xfs/217 xfs/250

The problem is that those tests don't configure the device in 4K
sector mode, so we're still missing a regression test. That seems to
be where blktests can come into play.