Re: [RFC PATCH 1/8] docs: Add block device LED trigger documentation

From: Greg KH
Date: Fri Jul 30 2021 - 01:22:22 EST


On Thu, Jul 29, 2021 at 10:52:06AM -0500, Ian Pilcher wrote:
> On 7/28/21 10:09 PM, Valdis Klētnieks wrote:
> > > + # cat /sys/class/block/led_trigger_list
> > > + baz: 0
> > > + bar: 0
> > > + foo: 0
> >
> > This looks like an abuse of the "one entry one value" rule for sysfs.
> > Perhaps this should be a directory /sys/class/block/defined_triggers/
> > and separate files under that for foo, bar, and baz? That would probably
> > make reference counting a lot easier as well....
>
> Indeed it is.
>
> Funny that you should mention using a subdirectory. I originally wanted
> to put all of the trigger-related stuff into
> /sys/class/block/led_triggers/, but I couldn't find any API to create a
> subdirectory for *class* attributes (only for device attributes), nor do
> I see any such subdirectories on my system.

Add a name to your attribute group and sysfs creates the subdirectory
automagically for you.

thanks,

greg k-h