From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964944AbWFHTHg (ORCPT ); Thu, 8 Jun 2006 15:07:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964945AbWFHTHf (ORCPT ); Thu, 8 Jun 2006 15:07:35 -0400 Received: from smtp3-g19.free.fr ([212.27.42.29]:34481 "EHLO smtp3-g19.free.fr") by vger.kernel.org with ESMTP id S964944AbWFHTHf (ORCPT ); Thu, 8 Jun 2006 15:07:35 -0400 Message-ID: <448875D1.5080905@free.fr> Date: Thu, 08 Jun 2006 21:09:05 +0200 From: Laurent Riffard User-Agent: Mozilla/5.0 (X11; U; Linux i686; fr-FR; rv:1.8.0.1) Gecko/20060130 SeaMonkey/1.0 MIME-Version: 1.0 To: Kernel development list Subject: 2.6.17-rc6-mm1/pktcdvd - BUG: possible circular locking X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, This BUG happened while pktcdvd service was starting. Basically, the 2 following commands were issued: - modprobe ptkcdvd - pktsetup dvd /dev/dvd cdrom: This disc doesn't have any tracks I recognize! pktcdvd: writer pktcdvd0 mapped to hdc ===================================================== [ BUG: possible circular locking deadlock detected! ] ----------------------------------------------------- vol_id/2298 is trying to acquire lock: (&ctl_mutex){....}, at: [] mutex_lock+0x21/0x24 but task is already holding lock: (&bdev->bd_mutex){....}, at: [] do_open+0x68/0x38b which lock already depends on the new lock, which could lead to circular deadlocks! the existing dependency chain (in reverse order) is: -> #1 (&bdev->bd_mutex){....}: [] lock_acquire+0x43/0x5c [] mutex_lock_nested+0xb3/0x1db [] do_open+0x68/0x38b [] blkdev_get+0x6e/0x79 [] pkt_ctl_ioctl+0x20f/0x586 [pktcdvd] [] do_ioctl+0x3c/0x4f [] vfs_ioctl+0x203/0x21a [] sys_ioctl+0x2c/0x47 [] sysenter_past_esp+0x56/0x79 -> #0 (&ctl_mutex){....}: [] lock_acquire+0x43/0x5c [] __mutex_lock_slowpath+0x9b/0x1c3 [] mutex_lock+0x21/0x24 [] pkt_open+0x1e/0xbef [pktcdvd] [] do_open+0x9a/0x38b [] blkdev_open+0x1f/0x48 [] __dentry_open+0xb8/0x186 [] nameidata_to_filp+0x1c/0x2e [] do_filp_open+0x2e/0x35 [] do_sys_open+0x40/0xbb [] sys_open+0x16/0x18 [] sysenter_past_esp+0x56/0x79 other info that might help us debug this: 1 lock held by vol_id/2298: #0: (&bdev->bd_mutex){....}, at: [] do_open+0x68/0x38b stack backtrace: [] show_trace+0xd/0x10 [] dump_stack+0x19/0x1b [] print_circular_bug_tail+0x59/0x64 [] __lock_acquire+0x5a9/0x6cf [] lock_acquire+0x43/0x5c [] __mutex_lock_slowpath+0x9b/0x1c3 [] mutex_lock+0x21/0x24 [] pkt_open+0x1e/0xbef [pktcdvd] [] do_open+0x9a/0x38b [] blkdev_open+0x1f/0x48 [] __dentry_open+0xb8/0x186 [] nameidata_to_filp+0x1c/0x2e [] do_filp_open+0x2e/0x35 [] do_sys_open+0x40/0xbb [] sys_open+0x16/0x18 [] sysenter_past_esp+0x56/0x79