[PATCHv10 9/9] scsi: set permanent stream count in block limits

[Christoph Hellwig]

On Tue, Oct 29, 2024 at 08:19:22AM -0700, Keith Busch wrote:
> From: Keith Busch <kbusch at kernel.org>
> 
> The block limits exports the number of write hints, so set this limit if
> the device reports support for the lifetime hints. Not only does this
> inform the user of which hints are possible, it also allows scsi devices
> supporting the feature to utilize the full range through raw block
> device direct-io.
> 
> Reviewed-by: Bart Van Assche <bvanassche at acm.org>
> Reviewed-by: Hannes Reinecke <hare at suse.de>
> Signed-off-by: Keith Busch <kbusch at kernel.org>

Despite the reviews this is still incorrect.  The permanent streams have
a relative data temperature associated with them as pointed out last
round and are not arbitrary write stream contexts despite (ab)using
the SBC streams facilities.

Bart, btw: I think the current sd implementation is buggy as well, as
it assumes the permanent streams are ordered by their data temperature
in the IO Advise hints mode page, but I can't find anything in the
spec that requires a particular ordering.