Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758562AbZAQOEA (ORCPT ); Sat, 17 Jan 2009 09:04:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753203AbZAQODs (ORCPT ); Sat, 17 Jan 2009 09:03:48 -0500 Received: from mail-in-14.arcor-online.net ([151.189.21.54]:46428 "EHLO mail-in-14.arcor-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751014AbZAQODr (ORCPT ); Sat, 17 Jan 2009 09:03:47 -0500 From: Bodo Eggert <7eggert@gmx.de> Subject: Re: [PATCH] Allow SysRq emergency sync to thaw frozen filesystems To: Eric Sandeen , Valdis.Kletnieks@vt.edu, Eric Sandeen , Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, t-sato@yk.jp.nec.com Reply-To: 7eggert@gmx.de Date: Sat, 17 Jan 2009 15:03:39 +0100 References: User-Agent: KNode/0.10.4 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit Message-Id: X-be10.7eggert.dyndns.org-MailScanner-Information: See www.mailscanner.info for information X-be10.7eggert.dyndns.org-MailScanner: Found to be clean X-be10.7eggert.dyndns.org-MailScanner-From: 7eggert@gmx.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1107 Lines: 21 Eric Sandeen wrote: > Valdis.Kletnieks@vt.edu wrote: >> On Thu, 15 Jan 2009 21:59:10 CST, Eric Sandeen said: >>> Oh, actually, I'd think not. If the freeze was done properly by the >>> filesystem, all data was flushed, the fs was quiesced, and new IO was >>> blocked. pdflush should never be visiting these... >> >> Yes, but a lot of 'if's - and usually you're reaching for sysrq-S precisely >> *because* you suspect that stuff wasn't happening properly on its own... > > Actually, only one if - if the fs implemented freeze properly. > > Well, the use case I envision here is something like: > > # freeze /my/mount/point/to/fs/to/snapshot > > except oops, that wasn't mounted, and you just froze your root fs. Maybe freeze should protect against that by requiring to specify the exact mountpount, unless you say freeze --subdir? -- 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/