Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758037AbZCZBoS (ORCPT ); Wed, 25 Mar 2009 21:44:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755114AbZCZBoG (ORCPT ); Wed, 25 Mar 2009 21:44:06 -0400 Received: from mx2.redhat.com ([66.187.237.31]:52801 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753285AbZCZBoD (ORCPT ); Wed, 25 Mar 2009 21:44:03 -0400 Message-ID: <49CADCCC.4000902@redhat.com> Date: Wed, 25 Mar 2009 21:39:24 -0400 From: Ric Wheeler User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Jeff Garzik CC: Eric Sandeen , Linus Torvalds , Theodore Tso , Ingo Molnar , Alan Cox , Arjan van de Ven , Andrew Morton , Peter Zijlstra , Nick Piggin , David Rees , Jesper Krogh , Linux Kernel Mailing List Subject: Re: [PATCH] issue storage device flush via sync_blockdev() (was Re: Linux 2.6.29) References: <20090324132032.GK5814@mit.edu> <20090324184549.GE32307@mit.edu> <49C93AB0.6070300@garzik.org> <20090325093913.GJ27476@kernel.dk> <49CA86BD.6060205@garzik.org> <20090325194341.GB27476@kernel.dk> <49CA9346.6040108@garzik.org> <20090325212923.GA5620@havoc.gtf.org> <49CAA88B.1080102@sandeen.net> <49CAD343.5070009@redhat.com> <49CAD9B3.1010208@garzik.org> <49CADB55.8050400@garzik.org> In-Reply-To: <49CADB55.8050400@garzik.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1366 Lines: 39 Jeff Garzik wrote: > Jeff Garzik wrote: >> Ric Wheeler wrote: >> What do you think sync_blockdev() does? What is its purpose? > >> Twofold: >> (1) guarantee all user data is flushed out before a major event >> (unmount, journal close, unplug, poweroff, explosion, ...) > >> (2) As a sledgehammer hack for simple or legacy filesystems that do >> not wish or need the complexity of transactional protection. >> sync_blockdev() is intentionally used in lieu of complexity for the >> following filesystems: HFS, HFS+, ADFS, AFFS, FAT, bfs, UFS, NTFS, qnx4. > >> My patch adds needed guarantees, only for the above filesystems, >> where none were present before. > > To be specific, I was referring to fsync(2) guarantees being added to > HFS, HFS+, ADFS, AFFS, FAT, bfs, UFS, NTFS, and qnx4. > > Other filesystems, besides those in the list, gain the > flush-on-unmount action (a rare but useful addition) with my patch. > > Jeff > > > Sorry for misunderstanding the scope of this before - this is certainly a net win for the file systems that don't have proper barrier support baked in already. Thanks! Ric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/