From: Bartosz Golaszewski <bgolaszew...@baylibre.com> 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. Bartosz Golaszewski (4): configfs: increase the item name length configfs: use BIT() for internal flags configfs: implement committable items samples: configfs: add a committable group Documentation/filesystems/configfs.rst | 6 +- fs/configfs/configfs_internal.h | 22 +-- fs/configfs/dir.c | 239 ++++++++++++++++++++++++- fs/configfs/file.c | 8 + include/linux/configfs.h | 3 +- samples/configfs/configfs_sample.c | 150 ++++++++++++++++ 6 files changed, 408 insertions(+), 20 deletions(-) -- 2.29.1
