From owner-freebsd-stable Thu Feb 5 17:46:35 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id RAA18691 for stable-outgoing; Thu, 5 Feb 1998 17:46:35 -0800 (PST) (envelope-from owner-freebsd-stable@FreeBSD.ORG) Received: from passer.osg.gov.bc.ca (passer.osg.gov.bc.ca [142.32.110.29]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id RAA18612 for ; Thu, 5 Feb 1998 17:46:07 -0800 (PST) (envelope-from cy@cschuber.net.gov.bc.ca) Received: (from uucp@localhost) by passer.osg.gov.bc.ca (8.8.8/8.6.10) id RAA03147; Thu, 5 Feb 1998 17:39:19 -0800 (PST) Received: from cschuber.net.gov.bc.ca(142.31.240.113), claiming to be "cwsys.cwsent.com" via SMTP by passer.osg.gov.bc.ca, id smtpdaaabta; Thu Feb 5 17:39:16 1998 Received: (from uucp@localhost) by cwsys.cwsent.com (8.8.8/8.6.10) id RAA08385; Thu, 5 Feb 1998 17:39:13 -0800 (PST) Message-Id: <199802060139.RAA08385@cwsys.cwsent.com> Received: from localhost.cwsent.com(127.0.0.1), claiming to be "cwsys" via SMTP by localhost.cwsent.com, id smtpd008377; Fri Feb 6 01:38:29 1998 X-Mailer: exmh version 2.0.1 12/23/97 Reply-to: Cy Schubert - ITSD Open Systems Group From: Cy Schubert - ITSD Open Systems Group X-Sender: cy To: "Evan Champion" cc: "Cy Schubert - ITSD Open Systems Group" , freebsd-stable@FreeBSD.ORG Subject: Re: Instant trap on make installworld In-reply-to: Your message of "Thu, 05 Feb 1998 16:48:09 EST." <00b501bd327f$bfe170a0$2844c00a@cello.synapse.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 05 Feb 1998 17:38:26 -0800 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-To-Unsubscribe: mail to majordomo@FreeBSD.org "unsubscribe stable" > >There is a bug in nullfs/umapfs or VM (depending on your point of view) > >which causes the panic you're describing when the mmap() system call is > >used. I put together a patch (kludge) and submitted it as a PR. This > >has caused a fair bit of discussion among various develpers and members > >of the Core Team. > > > ... and of course, as soon as make installworld resets the libpaths, mmap() > gets involved on the nullfs... > > Ok, given that this bug exists, is there a way I can use links to simulate > what I wanted to accomplish with nullfs? The basic problem is that on the > client, the tree is mounted as /usr/src and /usr/obj, but on the server it > is under /exports. > > If I try to link /usr/src to /exports/src etc. on the server, make > installworld fails because it tries to find the objects then under > /exports/obj/exports/src (or something similar) instead of > /exports/obj/usr/src, where they would have been written by the client. > > Obviously, I can hand-link to fix the problem, but are there a set of make > options that will allow me to build without tinkering? > > Evan This patch will fix the nullfs/umapfs divide-by-zero panic. vnode_pager.c is probably not the best place to fix this problem, however the patch suffices until a better fix can be found. --- src/sys/vm/vnode_pager.c.orig2 Sun Dec 7 13:11:03 1997 +++ src/sys/vm/vnode_pager.c Fri Dec 19 06:30:27 1997 @@ -231,10 +231,12 @@ blocksperpage = 0; if (pagesperblock > 0) { reqblock = pindex / pagesperblock; - } else { + } else if (bsize > 0) { blocksperpage = (PAGE_SIZE / bsize); reqblock = pindex * blocksperpage; - } + } else + return FALSE; + err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, after, before); if (err) Regards, Phone: (250)387-8437 Cy Schubert Fax: (250)387-5766 UNIX Support OV/VM: BCSC02(CSCHUBER) ITSD BITNET: CSCHUBER@BCSC02.BITNET Government of BC Internet: cschuber@uumail.gov.bc.ca Cy.Schubert@gems8.gov.bc.ca