From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.saout.de ([127.0.0.1]) by localhost (mail.saout.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hiXvUpgTYP3y for ; Fri, 30 Aug 2013 08:23:24 +0200 (CEST) Received: from mail-ee0-x230.google.com (mail-ee0-x230.google.com [IPv6:2a00:1450:4013:c00::230]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mail.saout.de (Postfix) with ESMTPS for ; Fri, 30 Aug 2013 08:23:24 +0200 (CEST) Received: by mail-ee0-f48.google.com with SMTP id l10so687683eei.35 for ; Thu, 29 Aug 2013 23:23:23 -0700 (PDT) Message-ID: <52203A57.6060606@gmail.com> Date: Fri, 30 Aug 2013 08:23:19 +0200 From: Milan Broz MIME-Version: 1.0 References: <1377358818.1313.21.camel@ryx.lan> <20130826082310.GA10172@citd.de> <521EE10F.4040602@gmail.com> <20130829231605.GA25013@citd.de> <52202DD1.4040808@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [dm-crypt] u?mount (8) helper script for luks encrypted disks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "dm-crypt@saout.de" On 30.8.2013 7:58, .. ink .. wrote: > > On 30.8.2013 1:56, .. ink .. wrote: > > On unmounting. > 1. Look at the path to be unmounted,if it starts with "/dev/mapper/" > then it could an mdraid path or a cryptsetup mapper path or > something else.Its easy to check which one is it. > > > Nope. > > You have /dev/VG/LV or /dev/mpath/NAME (aka friendly mpath names) etc. > These are symlinks, or on non-udev system directly device nodes. > > If you want to check for dm device, you should check for major > number of device. Ditto for MD (note md can be some fake > raid as well as replacement for dmraid.) > > > checking for major:minor number does not work on devices with btrfs[1] Yes. But I thought you want to check if underlying device is DM device, then major is DM major number always. > > What i do in my project to identify lvm path is to check if the path exists in both "/dev/abc/def" and "/dev/mapper/abd-def".formats. That will _usually_ work but the cost of duplicating lvm/mpath naming logic in your program (I think multipath has this configurable also). > > mdraid paths are usually in "/dev/mdX" or "/dev/md/X" format. Yes. But once this will change, you will have to update all programs which have this logic hardcoded. But again, it it works for you, that's fine but maintaining such script upstream means thinking about generic solution. > [1] http://article.gmane.org/gmane.comp.file-systems.btrfs/2851 Yes, I know about it, util-linux maintainer complained several times about it as well. Milan