Re: [LSF/MM TOPIC] update on discard support & testing with vendors

Matthew Wilcox
2011-01-18T00:37:36Z

On Mon, Jan 17, 2011 at 06:38:54PM -0500, Martin K. Petersen wrote:
> Yeah, many vendors stick to reporting compliance with really old
> revisions to prevent legacy operating systems from blowing up.

That sounds like a heuristic ... :-)

> However, the SCSI folks are vehemently against having heuristics in the
> first place (guess how many USB-ATA bridge vendors actively participate
> in T10).

It's an odd situation where 99.9% of the marketshare don't participate
in the standards committee.

> T10's official policy is that the device can fail any command
> with any (valid) arguments at any time. And that the OS stack should
> always retry with less data, try a different command variant, etc. That
> might be another good topic for discussion, actually. Because while we
> do have some hacks in place (use_10, etc.) things will soon get more
> complex.

I'd love to live in their world where the device won't fall over and
refuse to respond to any further commands without a power cycle.

--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."