From owner-freebsd-current@FreeBSD.ORG Fri Jul 31 12:27:51 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 82AE71065686; Fri, 31 Jul 2009 12:27:51 +0000 (UTC) (envelope-from serenity@exscape.org) Received: from ch-smtp01.sth.basefarm.net (ch-smtp01.sth.basefarm.net [80.76.149.212]) by mx1.freebsd.org (Postfix) with ESMTP id 001FA8FC16; Fri, 31 Jul 2009 12:27:50 +0000 (UTC) (envelope-from serenity@exscape.org) Received: from c83-253-252-234.bredband.comhem.se ([83.253.252.234]:43667 helo=mx.exscape.org) by ch-smtp01.sth.basefarm.net with esmtp (Exim 4.68) (envelope-from ) id 1MWrCi-0004oB-47; Fri, 31 Jul 2009 14:27:22 +0200 Received: from [192.168.1.5] (macbookpro [192.168.1.5]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mx.exscape.org (Postfix) with ESMTPSA id 7866A3611B; Fri, 31 Jul 2009 14:27:17 +0200 (CEST) Message-Id: <76338BEC-9B85-4AD1-B04B-850486866F3B@exscape.org> From: Thomas Backman To: James R. Van Artsdalen In-Reply-To: <4A72D946.4090401@jrv.org> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v935.3) Date: Fri, 31 Jul 2009 14:27:15 +0200 References: <20090727072503.GA52309@jpru.ffm.jpru.de> <4A6EC9E2.5070200@icyb.net.ua> <20090729084723.GD1586@garage.freebsd.pl> <4A7030B6.8010205@icyb.net.ua> <97D5950F-4E4D-4446-AC22-92679135868D@exscape.org> <4A7048A9.4020507@icyb.net.ua> <52AA86CB-6C06-4370-BA73-CE19175467D0@exscape.org> <4A705299.8060504@icyb.net.ua> <4A7054E1.5060402@icyb.net.ua> <5918824D-A67C-43E6-8685-7B72A52B9CAE@exscape.org> <4A705E50.8070307@icyb.net.ua> <4A70728C.7020004@freebsd.org> <6D47A34B-0753-4CED-BF3D-C505B37748FC@exscape.org> <4A708455.5070304@freebsd.org> <86983A55-E5C4-4C04-A4C7-0AE9A9EE37A3@exscape.org> <4A718E03.6030909@freebsd.org> <71A038EC-02B1-4606-96C2-5E84BE80F005@exscape.org> <4A719CA4.4060400@freebsd.org> <19347561-3CE6-40B3-930A-EB9925D3AFD1@exscape.org> <4A71AD29.10705@freebsd.org> <7544AED1-1216-4A24-B287-F54117641F76@exscape.org> <4A71B2DA.9060902@freebsd.org> <4A72D946.4090 401@jrv.org> X-Mailer: Apple Mail (2.935.3) X-Originating-IP: 83.253.252.234 X-Scan-Result: No virus found in message 1MWrCi-0004oB-47. X-Scan-Signature: ch-smtp01.sth.basefarm.net 1MWrCi-0004oB-47 67b2a4853640d5ae6f4cd19fe5a4945e Cc: freebsd-fs@freebsd.org, FreeBSD current , Pawel Jakub Dawidek , Andriy Gapon Subject: Re: zfs: Fatal trap 12: page fault while in kernel mode X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Jul 2009 12:27:52 -0000 On Jul 31, 2009, at 13:45, James R. Van Artsdalen wrote: > Andriy Gapon wrote: >> on 30/07/2009 17:39 Thomas Backman said the following: >> >>> Or, in patch form (I think the intendation screws the patch up as >>> linked >>> there): >>> http://exscape.org/temp/libzfs_sendrecv.patch >>> >> >> One comment on the patch - I personally don't like bit-wise xor in >> a logical >> expression. But if otherwise the expression would be huge and ugly, >> then OK. >> > > If you're going to code an XOR, use an XOR. > Don' make the reader untangle code to figure out that that some other > code is really just an XOR. > > However I think I was trying to handle two cases that can't happen: > the > top filesystem cannot be renamed to somewhere else in the pool, and no > other filesystem can be renamed to the root. So the new version of > the > patch below needs no XOR. > > Without this or something like it you can't replicate an entire > pool, i.e. > > zfs send -R -I @yesterday pool@today | ssh backup zfs recv -vF -d > pool > > dumps core from the strccmp(0, 0) in the original code below. > > > Index: cddl/contrib/opensolaris/lib/libzfs/common/libzfs_sendrecv.c > =================================================================== > ... Nice job, thanks :) Just wanted to chime in and say that your new patch seems to work just as well as the previous one. I hope you don't mind me hosting this too (I had to apply it manually thanks to spacing... I think it's my mail client not being very nice at retaining tabs/spaces)... Straight from svn diff: http://exscape.org/temp/libzfs_sendrecv.new.patch BTW (maybe not on topic for this mail, but for this thread), I've created a test case to reproduce the new panic (every time). It happens with -DDEBUG=1, after destroying a filesystem and then doing an incremental backup. Currently recompiling world/kernel on a second box to reproduce before I post that. Regards, Thomas