On 3/20/19 1:09 PM, Bart Van Assche wrote:
> As explained during the 2018 LSF/MM session about increasing SCSI
> disk probing concurrency, the problems with the current probing
> approach are as follows:
> - The driver core is unaware of asynchronous SCSI LUN probing.
> wait_for_device_probe() waits for all asynchronous probes except
> asynchronous SCSI disk probes.
> - There is unnecessary serialization between sd_probe() and sd_remove().
> This can lead to a deadlock.
>
> Hence this patch that modifies the sd driver such that it uses the
> driver core framework for asynchronous probing. The async domains
> and get_device()/put_device() pairs that became superfluous due to
> this change are removed.
>
> This patch does not affect the time needed for loading the scsi_debug
> kernel module with parameters delay=0 and max_luns=256.
>
> This patch depends on commit ef0ff68351be ("driver core: Probe
> devices asynchronously instead of the driver") that went upstream
> in kernel version v5.1-rc1.
>
> Cc: Lee Duncan <lduncan@xxxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxxx>
> Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> ...
Nice job.
Reviewed-by: Lee Duncan <lduncan@xxxxxxxx>
