Re: [PATCH][next] scsi: scsi_debug: remove a redundant assignment to variable ret

[John Garry]

On 16/10/2024 08:16, John Garry wrote:
> > > scsi_debug.c
> > > @@ -3686,14 +3686,12 @@ static int do_device_access(struct 
> > > sdeb_store_info *sip, struct scsi_cmnd *scp,
> > >           sdeb_data_sector_lock(sip, do_write);
> > >           ret = sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
> > You would think there would be a:
> >
> >     total += ret;
> >
> > here.
> >
> > >              fsp + (block * sdebug_sector_size),
> > >              sdebug_sector_size, sg_skip, do_write);T
> > >           sdeb_data_sector_unlock(sip, do_write);
> > > -        if (ret != sdebug_sector_size) {
> > > -            ret += (i * sdebug_sector_size);
> > > +        if (ret != sdebug_sector_size)
> > >               break;
> > > -        }
> > >           sg_skip += sdebug_sector_size;
> > >           if (++block >= sdebug_store_sectors)
> > >               block = 0;
> > >       }
> > >       ret = num * sdebug_sector_size;
> >          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > And that this would be a "return total;"
>
> Right, the function is currently a little messy as there is no variable 
> for "total", and we re-assign ret per loop.
>
> So I think that we can either:
> a. introduce a variable to hold "total"
> b. this change:
>
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index af5e3a7f47a9..39218ffc6a31 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -3690,13 +3690,14 @@ static int do_device_access(struct
> sdeb_store_info *sip, struct scsi_cmnd *scp,
>                 sdeb_data_sector_unlock(sip, do_write);
>                 if (ret != sdebug_sector_size) {
>                         ret += (i * sdebug_sector_size);
> -                       break;
> +                       goto out_unlock;
>                 }
>                 sg_skip += sdebug_sector_size;
>                 if (++block >= sdebug_store_sectors)
>                         block = 0;
>         }
>         ret = num * sdebug_sector_size;
> +out_unlock:
>         sdeb_data_unlock(sip, atomic);
>
>
> Maybe a. is better, as b. is maintaining some messiness.

BTW, let me know if you are happy for me to send a patch to fix this.

Thanks!