From owner-freebsd-current Sat Nov 6 20: 8:54 1999 Delivered-To: freebsd-current@freebsd.org Received: from frmug.org (frmug-gw.frmug.org [193.56.58.252]) by hub.freebsd.org (Postfix) with ESMTP id 0B9DB14DBF for ; Sat, 6 Nov 1999 20:08:51 -0800 (PST) (envelope-from roberto@keltia.freenix.fr) Received: (from uucp@localhost) by frmug.org (8.9.3/frmug-2.5/nospam) with UUCP id FAA26460 for current@freebsd.org; Sun, 7 Nov 1999 05:08:47 +0100 (CET) (envelope-from roberto@keltia.freenix.fr) Received: by keltia.freenix.fr (Postfix, from userid 101) id EFE5F8711; Sun, 7 Nov 1999 02:01:02 +0100 (CET) Date: Sun, 7 Nov 1999 02:01:02 +0100 From: Ollivier Robert To: current@freebsd.org Subject: Re: Serious locking problem in CURRENT Message-ID: <19991107020102.A9992@keltia.freenix.fr> Mail-Followup-To: current@freebsd.org References: <199911061929.NAA26145@free.pcs> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii User-Agent: Mutt/1.0pre2i In-Reply-To: <199911061929.NAA26145@free.pcs> X-Operating-System: FreeBSD 4.0-CURRENT/ELF AMD-K6/200 & 2x PPro/200 SMP Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG According to Jonathan Lemon: > NOTES > Locks are on files, not file descriptors. That is, file descriptors > du- plicated through dup(2) or fork(2) do not result in multiple > instances of a lock, but rather multiple references to a single lock. > If a process holding a lock on a file forks and the child explicitly > unlocks the file, the parent will lose its lock. Right but in Postfix case this is not the case. The "master" process run to check whether Postfix is running or not is definitely NOT a child of the real "master" process. We just have a case where a lock on a given file is not seen at all by another process, thus defeating the whole idea. Locking is broken. -- Ollivier ROBERT -=- FreeBSD: The Power to Serve! -=- roberto@keltia.freenix.fr FreeBSD keltia.freenix.fr 4.0-CURRENT #75: Tue Nov 2 21:03:12 CET 1999 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message