Re: [PATCH] loop: Fix lost writes caused by missing flag

[Dan Williams]

On Tue, Feb 13, 2018 at 11:22 AM, Ross Zwisler
<ross.zwisler@xxxxxxxxxxxxxxx> wrote:
> On Tue, Feb 13, 2018 at 03:54:04PM +0100, Christoph Hellwig wrote:
>> Looks good:
>>
>> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
>>
>> 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.