Re: [PATCH v4] scsi: core: Drop Scsi_Host.default_lock

On 8/17/26 9:53 AM, John Garry wrote:
> From: John Garry <[email protected]>
> 
> Back in the 2.6.xx days, it was possible to for low-level drivers to set
> the shost lock pointer. That is why there is a default lock and a pointer
> to the shost lock.
> 
> However, support for this has long been removed, so drop
> Scsi_Host.default_lock and make Scsi_Host.host_lock as the actual lock.
> 
> Getting the address of embedded host_lock structure just requires adding
> a fixed offset value to the shost pointer. However, getting the value of
> the host_lock pointer requires loading from a fixed offset to the shost
> pointer. The latter should be very slightly slower, which is relevant as
> this lock is used a lot throughout the core code and drivers.
> 
> Signed-off-by: John Garry <[email protected]>
> Acked-by: Damien Le Moal <[email protected]> # ata parts
> Reviewed-by: Bart Van Assche <[email protected]>
> ---
> Difference to v3:
> - Rebase and update some annotations
> 
> Differences to v2:
> - Add tags from Bart and Damien (Thanks!)
> - Update Documentation reference to default_lock (Bart)
> 
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
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