Re: [PATCH] xfstests: test for atime-related mount options

[Eric Sandeen <sandeen@redhat.com>]

On 2/14/14, 4:24 PM, Dave Chinner wrote:
> On Fri, Feb 14, 2014 at 10:41:16AM -0600, Eric Sandeen wrote:
>> On 2/14/14, 10:39 AM, David Sterba wrote:
>>> On Thu, Feb 13, 2014 at 10:42:55AM -0600, Eric Sandeen wrote:
>>>>> +cat /proc/mounts | grep "$SCRATCH_MNT" | grep relatime >> $seqres.full
>>>>> +[ $? -ne 0 ] && echo "The relatime mount option should be the default."
>>>>
>>>> Ok, I guess "relatime" in /proc/mounts is from core vfs code and
>>>> should be there for the foreseeable future, so seems ok.
>>>>
>>>> But - relatime was added in v2.6.20, and made default in 2.6.30.  So
>>>> testing older kernels may not go as expected; it'd probably be best to
>>>> catch situations where relatime isn't available (< 2.6.20) or not
>>>> default (< 2.6.30), by explicitly mounting with relatime, and skipping
>>>> relatime/strictatime tests if that fails?
>>>
>>> Is there some consensus what's the lowest kernel version to be supported
>>> by xfstests? 2.6.32 is the lowest base for kernels in use today, so
>>> worrying about anything older does not seem necessary.
>>>
>>
>> I don't know that it's been discussed - selfishly, I know our QE uses
>> xfstests on RHEL5, which is 2.6.18-based.
> 
> Sure, but they can just add the test to a "rhel5-expunged" file and
> they don't have to care about tests that won't work on RHEL 5 or
> other older kernels. Or to send patches to add "_requires_relatime"
> so that it automatically does the right thing for older kernels.

sure but some of this test is still valid on a kernel w/o relatime.
And since it's the default, "relatime" might disappear from /proc/mounts
some day anyway, so explicitly mounting with the option & failing
if that fails might be good future-proofind in any case.

*shrug*

It was just a request, not a demand.  :)  Koen, you can do with
it whatever you like.  Reviews aren't ultimatums.  :)

If xfstests upstream is only targeted at the current kernel, that's
fine, but maye we should make that a little more explicit.

-Eric

> Ultimately, upstream developers can't do all the work necessary to
> support distros - that's why the distros have their own engineers
> and QE to make sure the upstream code works correctly when they
> backport it. xfstests is no different. ;)
> 
> IOWs, if someone wants to run a modern test suite on a 7 year old
> distro, then they need to make sure that the test suite does the
> right thing for their distro. We'll take the patches that make it
> work, but we can't expect upstream developers to know what old
> distros require, let alone test and make stuff work on them...
> 
> Just my 2c worth.
> 
> Cheers,
> 
> Dave.
>