From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268085AbUBRU7Y (ORCPT ); Wed, 18 Feb 2004 15:59:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268086AbUBRU7Y (ORCPT ); Wed, 18 Feb 2004 15:59:24 -0500 Received: from fw.osdl.org ([65.172.181.6]:59018 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S268085AbUBRU7L (ORCPT ); Wed, 18 Feb 2004 15:59:11 -0500 Date: Wed, 18 Feb 2004 13:00:23 -0800 From: Andrew Morton To: Brandon Low Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6.3-mm1 Message-Id: <20040218130023.7cd2fdcb.akpm@osdl.org> In-Reply-To: <20040218205206.GD449@lostlogicx.com> References: <20040217232130.61667965.akpm@osdl.org> <40338FE8.60809@tmr.com> <20040218200439.GB449@lostlogicx.com> <20040218122216.62bb9e82.akpm@osdl.org> <20040218203325.GC449@lostlogicx.com> <20040218125227.0bf7dc2f.akpm@osdl.org> <20040218205206.GD449@lostlogicx.com> X-Mailer: Sylpheed version 0.9.4 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Brandon Low wrote: > > I am just reading up on dm now, but correct me if I am wrong, I will > need to do losetup, dmcreate, mount in that order in order to use > dmcrypt on loop where with cryptoloop, I could just do "mount"... there > must be an easier way to handle this! See Bert's email from eariler today: Date: Wed, 18 Feb 2004 13:14:16 +0100 From: bert hubert > People need to test and use this please. There is documentation at > http://www.saout.de/misc/dm-crypt/. Works amazingly well. Starting from stock 2.6.3 I applied 'dm*' from the broken out 2.6.3-mm1, no fuzz or offset, and ran make on the kernel I had built this morning. I then turned on the device mapper and its crypto support and loaded the modules, without rebooting. Downloaded ftp://ftp.sistina.com/pub/LVM2/device-mapper/device-mapper-latest.tgz ./configure && make && sudo make install sudo ./scripts/devmap_mknod.sh (to create /dev/mapper) Downloaded http://www.stwing.org/~sluskyb/util-linux/hashalot-0.2.0.tar.gz ./configure && make && sudo make install Downloaded http://www.saout.de/misc/cryptsetup ran: cryptsetup -h plain create crypted /dev/hdb1 (the -h plain isn't necessary, I didn't have hashalot earlier, and even with -h plain it wants hashalot) entered a passphrase (already forgotten though) e2fsck /dev/mapper/crypted mount /dev/mapper/crypted /mnt mke2fs proved to be a significant CPU load (all sy) and took a minute or two to run, which could be forgiven, it had to mke2fs 200G. I then copied the entire Linux build tree to /mnt, ran make clean, make, and 12 minutes later I had a new kernel. System load was below <10% at all times, mostly <5%. Then I did the whole thing again but then with ext3, which worked too. System load appeared slightly higher, the build however took 12 minutes as well. Kudos! Suggestions ----------- 1) Add a reference to the hashalot location to http://www.saout.de/misc/dm-crypt/ and add some units to 'cryptsetup', something like this (probably tab/space damaged): --- cryptsetup 2003-12-26 21:27:08.000000000 +0100 +++ cryptsetup.ahu 2004-02-18 12:46:18.000000000 +0100 @@ -229,10 +229,10 @@ gettable "$NAME" echo "$DMPATH$NAME is active:" echo " cipher: $CIPHER" - echo " keysize: $[${#KEY}/2]" + echo " keysize: $[${#KEY}/2] bytes" echo " device: $DEVICE" echo " offset: $SKIPPED" - echo " size: $SIZE" + echo " size: $SIZE sectors" [ $SKIPPED -gt 0 ] && echo " skipped: $SKIPPED" unset KEY else The output can be mighty confusing otherwise. 2) Remove dependence on hashalot for -h plain 3) Add pointer to hashalot on the main page 4) make make install of the device mapper userspace run the mknod script > filesystems. ie: ext3 on cryptoloop will no longer be crash-proof. (...) > After that we should remove cryptoloop altogether. Big fat warnings might be wise in the meantime. I sincerely hope that dm-crypt can be merged sooner rather than later. It feels good and it Just Works.