From owner-freebsd-hackers Wed Dec 12 11:31:33 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 1F72037B417 for ; Wed, 12 Dec 2001 11:31:27 -0800 (PST) Received: (from dillon@localhost) by apollo.backplane.com (8.11.6/8.9.1) id fBCJVPp79265; Wed, 12 Dec 2001 11:31:25 -0800 (PST) (envelope-from dillon) Date: Wed, 12 Dec 2001 11:31:25 -0800 (PST) From: Matthew Dillon Message-Id: <200112121931.fBCJVPp79265@apollo.backplane.com> To: Jordan Hubbard Cc: hackers@FreeBSD.ORG Subject: Re: NFS: How to make FreeBSD fall on its face in one easy step References: <200112121623.fBCGNuY52543@winston.freebsd.org> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Oooh. Very cool! I'll start messing with it (oops, that's going to make both Paul and Alfred annoyed with me!) -Matt :It came up in a meeting today at Apple just how fragile the BSD NFS :implementation was before significant work was put in to stabilizing it, :and in that discussion came up a little test tool written originally by :Avie Tevanian and subsequently improved by one of the folks here. : :This tool basically tries to do everything it can (legally) to confuse an :NFS server. It seeks around, does I/O to and truncates/changes the size :of a test file, all while doing everything it can to detect data corruption :or other signs of misbehavior which might result from out-of-order replies :or any other previously-observed NFS pathology. Very few NFS implementations :apparently survive this test and FreeBSD's is no exception. The sources are :provided below, courtesy of Avie, for the education and enjoyment(?) of :anyone who's motivated to play with (or even pretends to understand) NFS. : :Usage: : cc fsx.c -o fsx : ./fsx /some/nfs/mounted/scratchfile : [ ** kaboom! ** ] : :I'm also trying to determine which of the fixes Apple has made to NFS might :be adapted to FreeBSD, something which is made more difficult by the fact :that much of the code was taken straight from 4.4 Lite some time back and :both operating systems have diverged significantly since then. Anyone :really keen on investigating this further themselves on it can also go to :http://www.opensource.apple.com/projects/darwin and register themselves :online (it's easy) to access the Darwin CVS repository, the module in :question being "xnu" (the Darwin kernel). Thanks. : :- Jordan : :... To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message