From owner-freebsd-hackers Tue Feb 6 12:35:37 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from fw.wintelcom.net (ns1.wintelcom.net [209.1.153.20]) by hub.freebsd.org (Postfix) with ESMTP id 310BF37B503 for ; Tue, 6 Feb 2001 12:35:16 -0800 (PST) Received: (from bright@localhost) by fw.wintelcom.net (8.10.0/8.10.0) id f16KX0h23272; Tue, 6 Feb 2001 12:33:00 -0800 (PST) Date: Tue, 6 Feb 2001 12:33:00 -0800 From: Alfred Perlstein To: Andre Oppermann Cc: Rik van Riel , Matt Dillon , Mike Silbersack , Poul-Henning Kamp , Charles Randall , Dan Phoenix , Jos Backus , freebsd-hackers@FreeBSD.ORG Subject: Re: soft updates and qmail (RE: qmail IO problems) Message-ID: <20010206123259.U26076@fw.wintelcom.net> References: <3A805E94.8FF4F103@monzoon.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3A805E94.8FF4F103@monzoon.net>; from oppermann@monzoon.net on Tue, Feb 06, 2001 at 09:29:08PM +0100 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG * Andre Oppermann [010206 12:30] wrote: > Rik van Riel wrote: > > > > On Tue, 6 Feb 2001, Andre Oppermann wrote: > > > > > But please answer me one question: Is the link() call atomically > > > in FFS/UFS w or w/o softupdates? Meaning when the call returns > > > the meta- data is written to stable storage like with fsync()? > > > > Since when does `atomic' equal `synchronous' ? > > Because otherwise it would not be atomically, would it? Softupdates does it atomically but not synchronously. :) Basically, the in-memory view of the filesystem != the on-disk version. The update happens atomically with respect to locking in memory, so running processes never see a non-atomic snapshot of the directory, but if a crash occurs the disk may be several steps behind the memory at the time of the crash. -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] "I have the heart of a child; I keep it in a jar on my desk." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message