From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753937AbaIEXS2 (ORCPT ); Fri, 5 Sep 2014 19:18:28 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:33310 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753807AbaIEXS0 (ORCPT ); Fri, 5 Sep 2014 19:18:26 -0400 Date: Fri, 5 Sep 2014 16:18:22 -0700 From: Dmitry Torokhov To: Arjan van de Ven Cc: Tejun Heo , "Luis R. Rodriguez" , Greg Kroah-Hartman , Wu Zhangjin , Takashi Iwai , "linux-kernel@vger.kernel.org" , Oleg Nesterov , hare@suse.com, Andrew Morton , Tetsuo Handa , Joseph Salisbury , Benjamin Poirier , Santosh Rastapur , Kay Sievers , One Thousand Gnomes , Tim Gardner , Pierre Fersing , Nagalakshmi Nandigama , Praveen Krishnamoorthy , Sreekanth Reddy , Abhijit Mahajan , Casey Leedom , Hariprasad S , MPT-FusionLinux.pdl@avagotech.com, Linux SCSI List , "netdev@vger.kernel.org" Subject: Re: [RFC v2 3/6] kthread: warn on kill signal if not OOM Message-ID: <20140905231821.GD35667@core.coreip.homeip.net> References: <1409899047-13045-1-git-send-email-mcgrof@do-not-panic.com> <20140905141241.GC10455@mtj.dyndns.org> <20140905164405.GA28964@core.coreip.homeip.net> <20140905174925.GA12991@mtj.dyndns.org> <20140905181003.GA29003@core.coreip.homeip.net> <20140905222956.GA15723@mtj.dyndns.org> <540A3CF4.5070508@linux.intel.com> <20140905225248.GC35667@core.coreip.homeip.net> <540A41BA.4010105@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <540A41BA.4010105@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 05, 2014 at 04:05:30PM -0700, Arjan van de Ven wrote: > On 9/5/2014 3:52 PM, Dmitry Torokhov wrote: > >On Fri, Sep 05, 2014 at 03:45:08PM -0700, Arjan van de Ven wrote: > >>On 9/5/2014 3:29 PM, Tejun Heo wrote: > >>>Hello, Dmitry. > >>> > >>>On Fri, Sep 05, 2014 at 11:10:03AM -0700, Dmitry Torokhov wrote: > >>>>I do not agree that it is actually user-visible change: generally speaking you > >>>>do not really know if device is there or not. They come and go. Like I said, > >>>>consider all permutations, with hot-pluggable buses, deferred probing, etc, > >>> > >>>It is for storage devices which always have guaranteed synchronous > >>>probing on module load and well-defined probing order. Sure, modern > >>>setups are a lot more dynamic but I'm quite certain that there are > >>>setups in the wild which depend on storage driver loading being > >>>synchronous. We can't simply declare one day that such behavior is > >>>broken and break, most likely, their boots. > >> > >>we even depend on this in the mount-by-label cases > >> > >>many setups assume that the internal storage prevails over the USB stick in the case of conflicts. > >>it's a security issue; you don't want the built in secure bootloader that has a kernel root argument > >>by label/uuid. > >>the security there tends to assume that built-in wins over USB > > > >Ahem... and they sure it works reliably with large storage arrays? With > >SCSI doing probing asynchronously already? > > you tend to trust your large storage array > you tend to not trust the walk up USB stick. If you allow physical access it does not matter really. -- Dmitry