From owner-cvs-src@FreeBSD.ORG Mon Jan 22 16:02:45 2007 Return-Path: X-Original-To: cvs-src@freebsd.org Delivered-To: cvs-src@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 2BFF216A413 for ; Mon, 22 Jan 2007 16:02:45 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.185]) by mx1.freebsd.org (Postfix) with ESMTP id 8AC2513C459 for ; Mon, 22 Jan 2007 16:02:44 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: by nf-out-0910.google.com with SMTP id m19so511936nfc for ; Mon, 22 Jan 2007 08:02:43 -0800 (PST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=ED9uaUnHe7obY+4e2Z3iDX0OVcAbxYeNx1FopKmKhd7ajW+QW81atnxj0lCoYVoRHN8VhSD+QBy3ne50ucdcjvJ3zYw5eK9lGgwCFeHLp3yGZ3I0/1kBfe+2dFpobaxP1DWsTYo2joch2kFhHHj5ekAn7qrKuVBRHpVuvGkySl8= Received: by 10.49.41.18 with SMTP id t18mr6813500nfj.1169480208402; Mon, 22 Jan 2007 07:36:48 -0800 (PST) Received: by 10.48.238.14 with HTTP; Mon, 22 Jan 2007 07:36:48 -0800 (PST) Message-ID: <3bbf2fe10701220736l729c2915v58f25cc1908d923a@mail.gmail.com> Date: Mon, 22 Jan 2007 16:36:48 +0100 From: "Attilio Rao" Sender: asmrookie@gmail.com To: "Kostik Belousov" In-Reply-To: <20070122122509.GB71333@deviant.kiev.zoral.com.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200701221125.l0MBPMS4041567@repoman.freebsd.org> <20070122115230.J82671@maildrop.int.zabbadoz.net> <20070122122509.GB71333@deviant.kiev.zoral.com.ua> X-Google-Sender-Auth: ebb2f79f6da71905 Cc: bzeeb-lists@lists.zabbadoz.net, src-committers@freebsd.org, cvs-all@freebsd.org, cvs-src@freebsd.org Subject: Re: cvs commit: src/sys/fs/deadfs dead_vnops.c src/sys/kern vfs_lookup.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Jan 2007 16:02:45 -0000 2007/1/22, Kostik Belousov : > On Mon, Jan 22, 2007 at 11:53:50AM +0000, Bjoern A. Zeeb wrote: > > On Mon, 22 Jan 2007, Konstantin Belousov wrote: > > > > >kib 2007-01-22 11:25:22 UTC > > > > > > FreeBSD src repository > > > > > > Modified files: > > > sys/fs/deadfs dead_vnops.c > > > sys/kern vfs_lookup.c > > > Log: > > > Below is slightly edited description of the LOR by Tor Egge: > > > > > > -------------------------- > > > [Deadlock] is caused by a lock order reversal in vfs_lookup(), where > > > [some] process is trying to lock a directory vnode, that is the parent > > > directory of covered vnode) while holding an exclusive vnode lock on > > > covering vnode. > > >.... > > > To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp > > > is actually not used by the callers of namei. Thus, placeholder deadfs > > > vnode vp_crossmp is introduced that is filled into ni_dvp. > > > > which of the LOR #s on "The LOR page" can be marked "patched" with > > this commit? > > > > http://sources.zabbadoz.net/freebsd/lor.html > > None, your page lists only LORs that are detectable by WITNESS. This one is > between lockmgr lock and vfs_busy(), both of them are invisible to WITNESS. FYI, I tried to add WITNESS support to lockmgr but kernel hangs on a vfs lockmgr. This is a very strange bug and it suggests their implementation is very fragile (from this the necessity to rewrite them: //depot/user/attilio/attilio_lockmgr/... on perforce). -- Peace can only be achieved by understanding - A. Einstein