Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758001Ab3CNNf7 (ORCPT ); Thu, 14 Mar 2013 09:35:59 -0400 Received: from mail-la0-f44.google.com ([209.85.215.44]:42853 "EHLO mail-la0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757678Ab3CNNf5 (ORCPT ); Thu, 14 Mar 2013 09:35:57 -0400 MIME-Version: 1.0 X-Originating-IP: [188.6.195.195] In-Reply-To: <20130313160623.52ec76cd5239c791b59828b8@linux-foundation.org> References: <1363184193-1796-1-git-send-email-miklos@szeredi.hu> <1363184193-1796-9-git-send-email-miklos@szeredi.hu> <20130313160623.52ec76cd5239c791b59828b8@linux-foundation.org> Date: Thu, 14 Mar 2013 14:35:54 +0100 Message-ID: Subject: Re: [PATCH 8/9] overlay: overlay filesystem documentation From: Miklos Szeredi To: Andrew Morton Cc: viro@zeniv.linux.org.uk, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, apw@canonical.com, nbd@openwrt.org, neilb@suse.de, jordipujolp@gmail.com, ezk@fsl.cs.sunysb.edu, dhowells@redhat.com, sedat.dilek@googlemail.com, hooanon05@yahoo.co.jp, mszeredi@suse.cz Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1246 Lines: 34 On Thu, Mar 14, 2013 at 12:06 AM, Andrew Morton wrote: > On Wed, 13 Mar 2013 15:16:32 +0100 Miklos Szeredi wrote: > >> From: Neil Brown >> >> Document the overlay filesystem. >> > > Damn, I did it again. This is good, thanks. > >> +Changes to the underlying filesystems while part of a mounted overlay >> +filesystem are not allowed. If the underlying filesystem is changed, >> +the behavior of the overlay is undefined, though it will not result in >> +a crash or deadlock. > > ah-hah, there it is. I was wondering how this can-o-worms would be > handled ;) > > Is there anything in place to enforce this at runtime? Checks for > read-onlyness, code to prevent rw remounts, etc? No, currently it is not enforced. I didn't think this was important enough, and there was no complaint about this from users. I think most people are going to be careful, especially if lots of warnings are given in the documentation. Thanks, Miklos -- 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/