Re: [PATCH 02/42] scsi_ioctl: return error code when blk_rq_map_kern() fails

[Bart Van Assche <bvanassche@acm.org>]

On 4/21/21 10:47 AM, Hannes Reinecke wrote:
> The callers of sg_scsi_ioctl() already check for negative
> return values, so we can drop the usage of DRIVER_ERROR
> and return the error from blk_rq_map_kern() instead.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>   block/scsi_ioctl.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
> index 6599bac0a78c..99d58786e0d5 100644
> --- a/block/scsi_ioctl.c
> +++ b/block/scsi_ioctl.c
> @@ -488,9 +488,10 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
>   		break;
>   	}
>   
> -	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, GFP_NOIO)) {
> -		err = DRIVER_ERROR << 24;
> -		goto error;
> +	if (bytes) {
> +		err = blk_rq_map_kern(q, rq, buffer, bytes, GFP_NOIO);
> +		if (err)
> +			goto error;
>   	}
>   
>   	blk_execute_rq(disk, rq, 0);

Is this perhaps a backwards-incompatible user space ABI change since the 
sg_scsi_ioctl() return value is reported to user space?

Thanks,

Bart.