From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756907Ab2LGVna (ORCPT ); Fri, 7 Dec 2012 16:43:30 -0500 Received: from mx1.fusionio.com ([66.114.96.30]:51439 "EHLO mx1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755149Ab2LGVn2 (ORCPT ); Fri, 7 Dec 2012 16:43:28 -0500 X-ASG-Debug-ID: 1354916607-03d6a508b81ae310001-xx1T2L X-Barracuda-Envelope-From: clmason@fusionio.com Date: Fri, 7 Dec 2012 16:43:25 -0500 From: Chris Mason To: "Theodore Ts'o" CC: Chris Mason , Linus Torvalds , Ric Wheeler , Ingo Molnar , Christoph Hellwig , Martin Steigerwald , Linux Kernel Mailing List , Dave Chinner , linux-fsdevel Subject: Re: [PATCH, 3.7-rc7, RESEND] fs: revert commit bbdd6808 to fallocate UAPI Message-ID: <20121207214325.GB25713@shiny> X-ASG-Orig-Subj: Re: [PATCH, 3.7-rc7, RESEND] fs: revert commit bbdd6808 to fallocate UAPI Mail-Followup-To: Chris Mason , Theodore Ts'o , Chris Mason , Linus Torvalds , Ric Wheeler , Ingo Molnar , Christoph Hellwig , Martin Steigerwald , Linux Kernel Mailing List , Dave Chinner , linux-fsdevel References: <201212051148.28039.Martin@lichtvoll.de> <20121206120532.GA14100@infradead.org> <20121207011628.GB16373@gmail.com> <50C22923.90102@redhat.com> <20121207190306.GB14972@shiny> <20121207204325.GC29435@thunk.org> <20121207210932.GA25713@shiny> <20121207212743.GE29435@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20121207212743.GE29435@thunk.org> User-Agent: Mutt/1.5.21 (2011-07-01) X-Barracuda-Connect: mail1.int.fusionio.com[10.101.1.21] X-Barracuda-Start-Time: 1354916607 X-Barracuda-Encrypted: AES128-SHA X-Barracuda-URL: http://10.101.1.180:8000/cgi-mod/mark.cgi X-Barracuda-Bayes: INNOCENT GLOBAL 0.0065 1.0000 -1.9788 X-Barracuda-Spam-Score: -1.38 X-Barracuda-Spam-Status: No, SCORE=-1.38 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests=COMMA_SUBJECT X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.116375 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- 0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject' Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 07, 2012 at 02:27:43PM -0700, Theodore Ts'o wrote: > On Fri, Dec 07, 2012 at 04:09:32PM -0500, Chris Mason wrote: > > Persistent trim is what I had in mind, but there are other ideas that do > > imply a change in behavior as well. Can we safely assume this feature > > won't matter on spinning media? New features like persistent > > trim do make it much easier to solve securely, and using a bit for it > > means we can toss back an error to the app if the underlying storage > > isn't safe. > > We originally implemented no hide stale for spinning media. Some > folks have claimed that for XFS their superior technology means that > no hide stale doesn't buy them anything for HDD's. I'm not entirely > sure I buy this, since if you need to update metadata, it means at > least one extra seek for each random write into 4k preallocated space, > and 7200 RPM disks only have about 200 seeks per second. True, 7200 RPM disks are slow, but even allowing them to expose stale data just makes them a little less slow. I know it's against the rules to pretend that disks don't matter. But really, once you're doing random IO into a spindle you've given up on performance anyway. -chris