[PATCH RESEND] ubifs: Introduce a mount option of force_atime.

[Dongsheng Yang]

On 06/23/2015 06:44 PM, Artem Bityutskiy wrote:
> On Tue, 2015-06-23 at 17:55 +0800, Dongsheng Yang wrote:
>> In short, I think force_atime to ubifs is the choice from my opinion.
>
> So will we end up with this:
>
> -o - no atime support
> -o atime - no atime support
> -o noatime - same, no atime support
> -o force_atime - full atime support
> -o relatime - relative atime support
> -o lazyatime - lazy atime support
>
> IOW, atime/noatime mount options have no effect on UBIFS. To have full
> atime support - people have to use "force_atime". And then the rest of
> the standard options are supported.
>
> So if you are the user, would not you find this confusing and
> inconsistent? I would.
>
>
> How about this alternative: we preserve current behavior, but we
> introduce a compile-time configuration option which enables atime
> support _and_ changes the default behavior to match the behavior of the
> mainstream file-systems.
>
> Or to put it differently.
>
> 1. We introduce the UBIFS_ATIME_SUPPORT configuration option. This
> option will be off by default.
>
> 3. If UBIFS_ATIME_SUPPORT is off, users get the current (legacy)
> behavior. Atime is not supported. The atime/noatime/relatime/lazyatime
> mount options are ignored.
>
> 4. If UBIFS_ATIME_SUPPORT is on, UBIFS supports atime by default. I.e.:
>
> -o - full atime support
> -o atime - full atime support
> -o noatime - no atime support
>
> We may also print a fat big warning from the mount function about the
> fact that atime support is enabled. Just in case a legacy user enabled
> this option.
>
> How does this sound to you?

Great!! good idea to me.

And we can also do the other changes to match mainstream
file-systems, if necessary, in similar way in future.

Yang
>
> Artem.
>
> .
>