On Mon, Dec 13, 2021 at 09:04:29PM -0800, Bart Van Assche wrote: > On 12/11/21 02:50, Greg Kroah-Hartman wrote: > > On Fri, Dec 10, 2021 at 09:29:41AM -0800, Bart Van Assche wrote: > > > (b) No other block layer sysfs attribute follows this encoding scheme. > > > > Then follow what they do. Do they have multiple values in a single > > file? If so, they are broken and we should change that. > > Hi Greg, > > The only other block layer sysfs attribute I know of that reports multiple > values is the queue/scheduler attribute. Here is an example of the output > that can be produced by reading that attribute: > > # cat /sys/block/sda/queue/scheduler > [mq-deadline] kyber bfq none That's fine, there is no problem there. That output is the "correct" way to show a list of options and the one that is currently selected in a sysfs file as I thought I said earlier in this thread. > I don't think that changing the behavior of that attribute is an option > because that would break existing user space software, e.g. the > https://github.com/osandov/blktests/ test suite. Very true, do not change this file format. thanks, greg k-h