[PATCHv9 3/7] block: allow ability to limit partition write hints

[Keith Busch]

On Mon, Oct 28, 2024 at 11:27:33AM -0700, Bart Van Assche wrote:
> On 10/25/24 2:36 PM, Keith Busch wrote:
> > When multiple partitions are used, you may want to enforce different
> > subsets of the available write hints for each partition. Provide a
> > bitmap attribute of the available write hints, and allow an admin to
> > write a different mask to set the partition's allowed write hints.
> 
> After /proc/irq/*/smp_affinity was introduced (a bitmask),
> /proc/irq/*/smp_affinity_list (set of ranges) was introduced as a more
> user-friendly alternative. Is the same expected to happen with the
> write_hint_mask? If so, shouldn't we skip the bitmask user space
> interface and directly introduce the more user friendly interface (set
> of ranges)?

I don't much of have an opinion either way. One thing I like for the
bitmask representation is you write 0 to turn it off vs. the list type
writes a null string. Writing 0 to disable just feels more natural to
me, but not a big deal.