Re: [PATCH v2 2/2] ublk: introduce and use ublk_set_canceling helper

[Ming Lei]

On Thu, Jul 03, 2025 at 11:41:08PM -0600, Uday Shankar wrote:
> For performance reasons (minimizing the number of cache lines accessed
> in the hot path), we store the "canceling" state redundantly - there is
> one flag in the device, which can be considered the source of truth, and
> per-queue copies of that flag. This redundancy can cause confusion, and
> opens the door to bugs where the state is set inconsistently. Try to
> guard against these bugs by introducing a ublk_set_canceling helper
> which is the sole mutator of both the per-device and per-queue canceling
> state. This helper always sets the state consistently. Use the helper in
> all places where we need to modify the canceling state.
> 
> No functional changes are expected.
> 
> Signed-off-by: Uday Shankar <ushankar@xxxxxxxxxxxxxxx>

Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>

thanks,
Ming