From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: util-linux-owner@vger.kernel.org Received: from mail-bk0-f50.google.com ([209.85.214.50]:44446 "EHLO mail-bk0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932148Ab3AIRsM (ORCPT ); Wed, 9 Jan 2013 12:48:12 -0500 Message-ID: <50EDAD6C.4050901@gmail.com> Date: Wed, 09 Jan 2013 18:48:28 +0100 From: Goffredo Baroncelli Reply-To: kreijack@inwind.it MIME-Version: 1.0 To: Karel Zak CC: Goffredo Baroncelli , util-linux@vger.kernel.org, linux-btrfs , Chris Mason , Chris Murphy Subject: Re: Btrfs: wipe all the superblock [redhat bugzilla 889888] References: <50E9C267.3050302@inwind.it> <20130108164314.GA9177@x2.net.home> In-Reply-To: <20130108164314.GA9177@x2.net.home> Content-Type: text/plain; charset=ISO-8859-1 Sender: util-linux-owner@vger.kernel.org List-ID: Hi Karel, > > You can specify more than one magic strings for the same filesystem, > the .magics = { } is array. thanks for you suggestion. However this seems to me not applicable. I tried to change the code, and what I got to me seems inconsistently: Whit this change 1) if I do "wipefs ", I got the offset of the first superblock (good enough) 2) if I do "wipefs -a ", I clean-up *all three* superblocks (very good) 3) if I do "wipefs -o ", I clean-up only the superblock located at (very bad) If the user doesn't know enough btrfs, trying 1) and 3) could think that the disk is cleaned-up. Instead the 2nd and the 3rd super-blocks still exist. > see for example libblkid/src/superblocks/reiserfs.c I think that this is a different case: the reiser superblocks are *alternative*; instead in the btrfs case, *all the three superblocks* exist at the same time. > Karel Ciao Goffredo -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5