From owner-freebsd-current Sun Nov 23 15:24:46 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id PAA10119 for current-outgoing; Sun, 23 Nov 1997 15:24:46 -0800 (PST) (envelope-from owner-freebsd-current) Received: from wall.jhs.no_domain (vector.muc.ditec.de [194.120.126.35]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id PAA10099 for ; Sun, 23 Nov 1997 15:24:34 -0800 (PST) (envelope-from jhs@freebsd.org) Received: (from jhs@localhost) by desk.jhs.no_domain (8.8.5/8.8.5) id XAA19956; Thu, 20 Nov 1997 23:20:48 +0100 (MET) Date: Thu, 20 Nov 1997 23:20:48 +0100 (MET) Message-Id: <199711202220.XAA19956@desk.jhs.no_domain> To: current@freebsd.org Subject: nfs remote mount of busy cd crashes client kernel From: "Julian H. Stacey" Reply-To: "Julian H. Stacey" X-Address: Holz Strasse 27d, 80469 Munich, Germany X-Web: http://www.freebsd.org/~jhs/ (Has PGP Key) X-Tel: +49.89.268616 X-Fax: +49.89.2608126 X-Data: +49.89.26023276 X-Company: Vector Systems Ltd, Unix & Internet Consultants. X-Mailer: EXMH-1.6.9 + FreeBSD-2.2.2 (Unix) Content-type: text/plain; charset=us-ascii Sender: owner-freebsd-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk For kernel / nfs folk only I guess: I noticed this on 2 networked 2.2.2 systems, (but I'm about to upgrade so I'm mentioning it in case it's still around on 2.2.5 or current, & for those who like to try for kernel crashes. I had a 486/16M/66MHz/ reading it's scsi cd (freebsd.2.2.5 disc #2) on to a scsi disk by a local (within host) tar cf- . | (cd ....blah ; tar xf -), It had been running maybe 15 mins so cdrom was probably fully queued up. My new 586/64/200 then booted, & 'df' as a normal user caused trap 12, page fault in kernel mode I did this 4 times with fscks inbetween, so repeatable. I then did a umount -a -t nfs ; df it didnt crash. BTW: -r-xr-sr-x 1 bin operator 49152 Jun 24 18:49 /bin/df & the 2 systems are 10M co-ax ethernet linked on a quiet (home) ether. There's an earlier pre crash symprom to watch for: I have in fstab: desk:/cdrom /net/desk/cdrom nfs ro,intr,soft,bg 0 0 but I get this: % pwd /net/desk % ls ls: cdrom: Input/output error dos/ root/ usr/ usr1/ usr2/ usr3/ usr4/ var/ yet mount thinks it's there % mount .... desk:/cdrom on /net/desk/cdrom (read-only) Even after the 486 has finised the copy, the 586 will still crash on df, even after the 486 cd is no longer busy, & the 586 has rebooted. PS the 486 kernel might be a stable of some vintage, & not a 2.2.2, but it's the 2.2.2 release kernel that crashes. I know nfs is flakey, & don't mind it failing, but it seems a shame that when it dies it takes the 2.2.2 kernel with it. No doubt I'll be trying a similar scenario on 2.2.5 & current soon, by accident or design, but kernel people might want to try something similar. Julian -- Julian H. Stacey http://www.freebsd.org/~jhs/ Tel. +49 89 268616