On Tue, Sep 17, 2024 at 02:32:58PM +0900, Damien Le Moal wrote:
> Commit 734e1a860312 ("block: Prevent deadlocks when switching
> elevators") introduced the function elv_iosched_load_module() to allow
> loading an elevator module outside of elv_iosched_store() with the
> target device queue not frozen, to avoid deadlocks. However, the "none"
> scheduler does not have a module and as a result,
> elv_iosched_load_module() always returns an error when trying to switch
> to this valid scheduler.
>
> Fix this by checking that the requested scheduler is "none" and doing
> nothing in that case.
The old code before this commit simply ignored the request_module,
just as most callers of it do. I think that's the right approach
here as well.
