Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751820AbWCRAYa (ORCPT ); Fri, 17 Mar 2006 19:24:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751803AbWCRAYa (ORCPT ); Fri, 17 Mar 2006 19:24:30 -0500 Received: from smtp009.mail.ukl.yahoo.com ([217.12.11.63]:7317 "HELO smtp009.mail.ukl.yahoo.com") by vger.kernel.org with SMTP id S1751820AbWCRAY3 (ORCPT ); Fri, 17 Mar 2006 19:24:29 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.it; h=Received:From:To:Subject:Date:User-Agent:Cc:References:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id; b=V+zPcwONlNJg+uqwEfuFWGPPE62WHx1/t7Qv4+xnziMIfxTESnW3mRNjfpvKOnCMghzUt62Ta9x2TJq1RQCFTmgLygHyiZqMNr9KSEwzYvEhapCQFcKsUmc5o3szp2zEP8fLs891O4e5Am+s86NGuqgEFj0Q4SFHMZUIfLg4TMc= ; From: Blaisorblade To: user-mode-linux-devel@lists.sourceforge.net Subject: Re: [uml-devel] kernel BUG at drivers/block/loop.c:621 Date: Sat, 18 Mar 2006 01:24:18 +0100 User-Agent: KMail/1.8.3 Cc: Rob Landley , linux-kernel@vger.kernel.org References: <200603171912.12082.rob@landley.net> In-Reply-To: <200603171912.12082.rob@landley.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200603180124.19077.blaisorblade@yahoo.it> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2539 Lines: 61 On Saturday 18 March 2006 01:12, Rob Landley wrote: > I can reproduce the following in 2.6.16-rc5, User Mode Linux: > > kernel BUG at drivers/block/loop.c:621! > Kernel panic - not syncing: BUG! > > EIP: 0073:[] CPU: 0 Not tainted ESP: 007b:b7de1f9c EFLAGS: > 00200246 Not tainted > EAX: 00000000 EBX: 000018be ECX: 00000013 EDX: 000018be > ESI: 000018bb EDI: 00000011 EBP: b7de1fb8 DS: 007b ES: 007b > 09b87bb4: [<0806c762>] show_regs+0x102/0x110 > 09b87bd0: [<0805b6fc>] panic_exit+0x2c/0x50 > 09b87be0: [<0807ff7d>] notifier_call_chain+0x2d/0x50 > 09b87c00: [<08071095>] panic+0x75/0x120 > 09b87c20: [<0812e181>] loop_thread+0x151/0x160 > 09b87c4c: [<08065297>] run_kernel_thread+0x37/0x60 > 09b87cfc: [<0805bbd1>] new_thread_handler+0x91/0xc0 The below is strange - GCC is putting disks in the .text section or kallsyms has some bug. > 09b87d20: [] disks+0xf7e7ec84/0x4 > The reproduction sequence is a bit involved (my mount regression test and > the current svn snapshot of busybox are involved), and running the > following sequence of commands: > > mount; mount -a; mount; mount /dev/loop1 /images/vfat.dir ; > losetup /dev/loop1; ls; vi /etc/fstab; cat /etc/fstab; losetup /dev/loop0; > mount /images/vfat.img /images/vfat.dir -o ro > > The current busybox mount is still broken in a couple of known places > (hence the testing; I'm fixing it). But it probably shouldn't panic the > kernel... *) Is this reproducible on host? *) I don't understand yet what UML may be doing wrong. *) look at: that spin_lock (SMP kernel? SPINLOCK_DEBUG? Try enabling the latter and see what happens). (a bio is a block I/O request) *) given what the code says, on that line bio is NULL, i.e. loop_get_bio returned NULL, i.e. (I guess) wait_for_completion_interruptible returned, because someone else (loop_make_request) did "complete" on its param, but incorrectly as the "someone else" hadn't filled the lo->lo_bio. -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Messenger with Voice: chiama da PC a telefono a tariffe esclusive http://it.messenger.yahoo.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/