From: Matthew Wilcox Subject: Re: [PATCH 1/2] fs: Do not dispatch FITRIM through separate super_operation Date: Thu, 18 Nov 2010 07:19:58 -0700 Message-ID: <20101118141957.GK6178@parisc-linux.org> References: <1290065809-3976-1-git-send-email-lczerner@redhat.com> <20101118130630.GJ6178@parisc-linux.org> <20101118134804.GN5618@dhcp231-156.rdu.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Lukas Czerner , tytso@mit.edu, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, hch@infradead.org, sandeen@redhat.com To: Josef Bacik Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:60977 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752190Ab0KROT7 (ORCPT ); Thu, 18 Nov 2010 09:19:59 -0500 Content-Disposition: inline In-Reply-To: <20101118134804.GN5618@dhcp231-156.rdu.redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Nov 18, 2010 at 08:48:04AM -0500, Josef Bacik wrote: > On Thu, Nov 18, 2010 at 06:06:30AM -0700, Matthew Wilcox wrote: > > On Thu, Nov 18, 2010 at 08:36:48AM +0100, Lukas Czerner wrote: > > > There was concern that FITRIM ioctl is not common enough to be included > > > in core vfs ioctl, as Christoph Hellwig pointed out there's no real point > > > in dispatching this out to a separate vector instead of just through > > > ->ioctl. > > > > Um, are you and Josef working independently of each other? You don't > > seem to be cc'ing each other on your patches, and you're basically doing > > the same thing. > > > > I guess they are the same thing in that we're both dealing with free'ing up > space, but thats about where the similarities end. Lukas' work is in TRIM'ing > already free'd space, mine is in creating free'd space. Plus I don't know > anything nor wish to ever know anything about TRIM ;). Thanks, I guess I was assuming that, on receiving a FALLOC_FL_PUNCH_HOLE, a filesystem that was TRIM-aware would pass that information down to the block device that it's mounted on. I strongly feel that we shouldn't have two interfaces to do essentially the same thing. I guess I'm saying that you're going to have to learn about TRIM :-) -- 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."