From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ram Pai Subject: Re: [PATCH 2/18] cleanups and bug fix in do_loopback() Date: Tue, 08 Nov 2005 00:46:07 -0800 Message-ID: <1131439567.5400.221.camel@localhost> References: Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Al Viro , torvalds@osdl.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Return-path: Received: from e32.co.us.ibm.com ([32.97.110.150]:4762 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S932496AbVKHIqZ (ORCPT ); Tue, 8 Nov 2005 03:46:25 -0500 To: Miklos Szeredi In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Mon, 2005-11-07 at 22:59, Miklos Szeredi wrote: > > - check_mnt() on the source of binding should've been unconditional from > > the very beginning. My fault - as far I could've trace it, that's an > > old thinko made back in 2001. Kudos to Miklos for spotting it... > > Fixed. > > - code cleaned up. > > Can you please explain what purpose does this serve? > > AFAICS check_mnt() was there to ensure that operations are done under > the proper namespace semaphore. > Next in the series the namespace semaphore is made global, which > basically means, that most of the check_mnt() invocations become > useless. > The ones which as a side effect prevent grafting to a detached mount > can be changed to check for (mnt->mnt_namespace == NULL) instead of > check against current->namespace. > > I see no other reason for wanting to prevent binds from detached > mounts or other namespaces. It has been discussed that it would be a > good _controlled_ way to send/receive mounts from other namespace > without adding any complexity. AFAICT, the ability to bind across namespaces defeats the private-ness property of per-process-namespaces. RP