Re: [RESEND PATCH v3 0/4] configfs: implement committable items and add sample code

From: Linus Walleij
Date: Tue Jan 05 2021 - 10:13:29 EST


On Tue, Dec 29, 2020 at 11:22 AM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:

Committable items in configfs are well defined and documented but unfortunately
> so far never implemented.
>
> The use-case we have over at the GPIO subsystem is using configfs in
> conjunction with sysfs to replace our current gpio-mockup testing module
> with one that will be much more flexible and will allow complete coverage
> of the GPIO uAPI.
>
> The current gpio-mockup module is controlled using module parameters which
> forces the user to reload it everytime they need to change the chip
> configuration or layout and makes it difficult to extend its functionality.
>
> Testing module based on configfs would allow fine-grained control over dummy
> GPIO chips but since GPIO devices must be configured before they are
> instantiated, we need committable items.
>
> This implements them and adds code examples to configfs_sample module. The
> first two patches are just cosmetic.
>
> v1 -> v2:
> - fix a 'set but not used' build warning reported by kernel test robot
>
> v2 -> v3:
> - use (1UL << bit) instead of BIT() in patch 2/4
> - extend configfs_dump_one() to make it print the new flags
> - clear the CONFIGFS_USET_DIR bit on the live group dirent
>
> Rebased on top of v5.11-rc1.

This patch set makes a lot of sense to me.
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij