Re: [PATCH v3 06/26] scsi_debug: Set .alloc_pseudo_sdev

[John Garry <john.g.garry@oracle.com>]

On 04/09/2025 20:44, Bart Van Assche wrote:
>> for scsi_debug, maybe we can add reserved command handling as part of 
>> the driver abort handling, e.g. eh_abort_handler -> scsi_debug_abort 
>> should send a reserved command to "abort" a scmd, and the reserved 
>> command handler does the same as scsi_debug_abort currently does.
> 
> Another possibility for getting rid of .alloc_pseudo_sdev is to allocate
> a pseudo SCSI device if either .nr_reserved_cmds 
> or .queue_reserved_command has been set in the SCSI host template. A dummy
> .queue_reserved_command method could be defined as follows in the SCSI
> debug driver:
> 
> +/*
> + * The only purpose of this function is to make the SCSI core allocate a
> + * pseudo SCSI device.
> + */
> +static int scsi_debug_queue_reserved_command(struct Scsi_Host *shost,
> +                         struct scsi_cmnd *scp)
> +{
> +    WARN_ON_ONCE(true);
> +    scp->result = DID_ERROR << 16;
> +    scsi_done(scp);
> +    return 0;
> +}

Sure, but it would be nice if this was not a stub, but rather actually 
did some work, like "aborting" a task (as I mentioned above). Then 
people like me who don't have UFS HW can actually test this 
functionality. I do appreciate that it is more work to implement this.

Thanks,
John