From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [LSF/MM TOPIC] update on discard support & testing with vendors Date: Mon, 17 Jan 2011 17:37:34 -0700 Message-ID: <20110118003734.GE6262@parisc-linux.org> References: <4D345637.6000207@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Mike Snitzer , Ric Wheeler , lsf-pc@lists.linuxfoundation.org, linux-fsdevel@vger.kernel.org, "linux-scsi@vger.kernel.org" To: "Martin K. Petersen" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org 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."