Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935275Ab3E2WDt (ORCPT ); Wed, 29 May 2013 18:03:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50732 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935228Ab3E2WDo (ORCPT ); Wed, 29 May 2013 18:03:44 -0400 Date: Wed, 29 May 2013 15:03:42 -0700 From: Andrew Morton To: "Stephen M. Cameron" Cc: axboe@kernel.dk, stephenmcameron@gmail.com, mikem@beardog.cce.hp.com, linux-kernel@vger.kernel.org, thenzl@redhat.com Subject: Re: [PATCH] cciss: fix broken mutex usage in ioctl Message-Id: <20130529150342.7f16e4402c82227604931984@linux-foundation.org> In-Reply-To: <20130524192841.21256.51523.stgit@beardog.cce.hp.com> References: <20130524192841.21256.51523.stgit@beardog.cce.hp.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 738 Lines: 16 On Fri, 24 May 2013 14:28:41 -0500 "Stephen M. Cameron" wrote: > If a new logical drive is added and the CCISS_REGNEWD ioctl is invoked > (as is normal with the Array Configuration Utility) the process > will hang as below. It attempts to acquire the same mutex twice, once > in do_ioctl() and once in cciss_unlocked_open(). The BKL was recursive, > the mutex isn't. huh, now that's a really old-school deadlock. I wonder why lockdep didn't shout about it. -- 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/