Re: [GIT PULL] SCSI fixes for 4.18-rc3

From: Christoph Hellwig
Date: Wed Jul 11 2018 - 02:45:49 EST


On Tue, Jul 10, 2018 at 05:53:18PM -0400, Tony Battersby wrote:
> At my job (https://www.cybernetics.com/), I use the write()/read()
> interface to the SCSI generic driver for access to tape drives and tape
> medium changers.  For example, the write()/read() interface is useful
> for implementing RAID-like functionality for tape drives since a single
> thread can send commands to multiple tape drives at once and poll() for
> command completion.  We have a lot of code invested in this interface,
> so it would be a huge pain for us if it were removed.  But in our case,
> everything runs as root (as the firmware of an embedded storage
> appliance), so extra permission checks should be OK.

Do you just use read/write on /dev/sg or also on /dev/bsg? Because
I started a discussion to kill the read/write support for the latter
even before Linus brought it up here.. (and we have the same fix
pending for /dev/bsg)