Re: 2.6.19-rc3 system freezes when ripping with cdparanoia at ioctl(SG_IO)

From: Douglas Gilbert
Date: Sat Nov 11 2006 - 11:40:16 EST


Christoph Hellwig wrote:
> On Fri, Nov 10, 2006 at 12:08:15PM -0800, Luben Tuikov wrote:
>> P.S. I'd love to see SG_DXFER_TO_FROM_DEV completely ripped out
>> of sg.c, for obvious reasons. Can you not duplicate the resid "fix"
>> it provides into "FROM_DEV" -- do apps really rely on it?
>
> At the beginning of this thread it was mentioned cdparanio uses it.
> But in general we can't just rip out userland interfaces, we pretend
> to have a stable userspace abi (and except for the big sysfs mess that
> actually comes very close to the truth).
>
> What we should do is to document very well what SG_DXFER_TO_FROM_DEV
> is doing and that odd name that's been chosen for it. I'll prepare
> a patch for that.

Christoph,
It is documented and has been from day one. See scsi/sg.h
and http://sg.torque.net/sg/p/sg_v3_ho.html

Naming it is a challenge and at the time there
were no bidirectional transfers to/from a device
to worry about.

A more appropriate but impractical name might be:
SG_DXFER_TO_KERNEL_BUFFER_THEN_READ_FROM_DEV_VIA_KERNEL_BUFFER


Doug Gilbert

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/