From owner-freebsd-hackers Sat Oct 19 22:12:51 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9247737B404; Sat, 19 Oct 2002 22:12:50 -0700 (PDT) Received: from HAL9000.homeunix.com (12-232-220-15.client.attbi.com [12.232.220.15]) by mx1.FreeBSD.org (Postfix) with ESMTP id D6B1543E9E; Sat, 19 Oct 2002 22:12:49 -0700 (PDT) (envelope-from dschultz@uclink.Berkeley.EDU) Received: from HAL9000.homeunix.com (localhost [127.0.0.1]) by HAL9000.homeunix.com (8.12.6/8.12.5) with ESMTP id g9K5Cfjf024325; Sat, 19 Oct 2002 22:12:41 -0700 (PDT) (envelope-from dschultz@uclink.Berkeley.EDU) Received: (from das@localhost) by HAL9000.homeunix.com (8.12.6/8.12.5/Submit) id g9K5CfxB024324; Sat, 19 Oct 2002 22:12:41 -0700 (PDT) (envelope-from dschultz@uclink.Berkeley.EDU) Date: Sat, 19 Oct 2002 22:12:41 -0700 From: David Schultz To: Matthew Dillon Cc: Poul-Henning Kamp , Maxim Sobolev , hackers@FreeBSD.ORG Subject: Re: Patch to allow a driver to report unrecoverable write errors to the buf layer Message-ID: <20021020051241.GA24293@HAL9000.homeunix.com> Mail-Followup-To: Matthew Dillon , Poul-Henning Kamp , Maxim Sobolev , hackers@FreeBSD.ORG References: <3DB048B5.21097613@FreeBSD.org> <28472.1035014051@critter.freebsd.dk> <20021020043706.GA23972@HAL9000.homeunix.com> <200210200457.g9K4vbAE030661@apollo.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200210200457.g9K4vbAE030661@apollo.backplane.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Thus spake Matthew Dillon : > Extremely difficult, which is why this is all fantasy and no action. > By the time the filesystem layer gets the notification there is > insufficient information to unwind the original operation(s) without > a huge amount of work. A bitmap write failed? Great! Find the > file that the related bitmap blocks are related to. Good luck! And > that is just one case out of dozens that would require a sophisticated > solution. It might be possible via softupdates, but I shudder at the > level of complexity of code required to support such a beast. Not to > mention the fact that pulling a floppy out a bad time could destroy > far more data then whatever pending write operations might have failed. > It's a waste of time. Then how about trying to solve a slightly easier problem? When the filesystem is forcibly unmounted, would it be possible to seek out and destroy all busy buffers associated with it that couldn't be written? This isn't quite as nice a solution as getting the system to automatically give up, but it's better than necessitating a reboot to work around the problem. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message