From: Christoph Hellwig Subject: Re: [PATCH 1/2] fs: Do not dispatch FITRIM through separate super_operation Date: Fri, 19 Nov 2010 09:06:39 -0500 Message-ID: <20101119140639.GA25488@infradead.org> References: <1290100750.3041.72.camel@mulgrave.site> <1290102098.3041.77.camel@mulgrave.site> <4CE59E57.2090009@teksavvy.com> <4CE5C616.7070706@teksavvy.com> <20101119115516.GA1152@infradead.org> <4CE6831E.4020606@teksavvy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Greg Freemyer , "Martin K. Petersen" , James Bottomley , Jeff Moyer , Matthew Wilcox , Josef Bacik , Lukas Czerner , tytso@mit.edu, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, sandeen@redhat.com To: Mark Lord Return-path: Content-Disposition: inline In-Reply-To: <4CE6831E.4020606@teksavvy.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Fri, Nov 19, 2010 at 09:01:02AM -0500, Mark Lord wrote: > That is my intent already, thanks. Just needs time, perhaps this winter. This wasn't addressed at you, but a snide remark at Greg, who is just contantly bickering without actually beeing any help. > I think a reasonable approach would be to modify the existing interfaces > so that the LLD can report a "max discard ranges per command" back up > the stack. > > This way, libata could report a max of say, 64 ranges per "discard" (trim), > and DM/RAID could simply (for now) report a max of one range per discard. That's certainly the easy way out. You'll need a good way to actually transport the ranges as we can't simply sote them in bi_sector/bi_size and adapt the whole block layer to deal with the two types of different discards. Not saying it's impossible, but when I tried it before it wasn't pretty.