From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Woodhouse Subject: Re: [PATCH 1/5] [BLOCK] Add 'discard' request handling Date: Fri, 08 Aug 2008 15:27:29 +0100 Message-ID: <1218205649.12232.175.camel@pmac.infradead.org> References: <20080726130200.f541e604.akpm@linux-foundation.org> <1217900716.3454.667.camel@pmac.infradead.org> <20080805114210.GW20055@kernel.dk> <1217953741.3454.784.camel@pmac.infradead.org> <1217957140.3454.800.camel@pmac.infradead.org> <1218014703.5111.35.camel@pmac.infradead.org> <20080807184155.GE20055@kernel.dk> <1218187995.12232.95.camel@pmac.infradead.org> <20080808103041.GM20055@kernel.dk> <1218192731.12232.110.camel@pmac.infradead.org> <20080808142232.GD8618@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Jens Axboe , Andrew Morton , Ric Wheeler , linux-fsdevel@vger.kernel.org, gilad@codefidence.com To: Matthew Wilcox Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:35629 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750771AbYHHO1u (ORCPT ); Fri, 8 Aug 2008 10:27:50 -0400 In-Reply-To: <20080808142232.GD8618@parisc-linux.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, 2008-08-08 at 08:22 -0600, Matthew Wilcox wrote: > If the current T10 and T13 proposals stand unmodified, it'll be a bit of a > pain to implement fully. PUNCH currently requires creating a data buffer > and attaching it to the command. When we get down into libata, we then > want to throw that data buffer away again because TRIM doesn't need a > data buffer (indeed to translate PUNCH to TRIM, we need to send a series > of commands because PUNCH allows you to specify a set of ranges whereas > TRIM only lets you send one range at a time). > > Let's hope T10 agrees that only one range is necessary at a time. Weird. Does it really make sense for us to be 'translating' from generic requests to SCSI and then from those to ATA? I hadn't realised our code was that baroque... -- David Woodhouse Open Source Technology Centre David.Woodhouse@intel.com Intel Corporation