[PATCH] nvme-multipath: add iopolicies sysfs attribute

[Christoph Hellwig]

On Sun, Sep 20, 2026 at 12:40:00PM -0400, loberman at redhat.com wrote:
> From: Laurence Oberman <loberman at redhat.com>
> 
> The subsystem iopolicy attribute only shows the active policy, so
> there is no way to see which policies are available. The block layer
> solves this for I/O schedulers by listing all options with the
> active one in brackets in queue/scheduler.
> 
> Changing the output of iopolicy the same way would break existing
> userspace, since nvme-cli compares the value against a bare policy
> name. Leave iopolicy unchanged and add a read-only iopolicies
> attribute that gives equivalent visibility:

Given that we already have a file for the current iopolicy, can we
kill the [ ] notation that makes it hard to machine parse the value?