From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc MERLIN Subject: Re: make-bcache bug? Date: Mon, 15 May 2017 17:58:48 -0700 Message-ID: <20170516005848.GO29894@merlins.org> References: <20170514175840.s3l6p4zjxnf2brm6@merlins.org> <20170514220055.2d06210e@jupiter.sol.kaishome.de> <20170514201940.76bu7rz764jeplnd@merlins.org> <20170514232816.79c2530e@jupiter.sol.kaishome.de> <8737c6th8m.fsf@esperi.org.uk> <20170515203745.4fc14030@jupiter.sol.kaishome.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from magic.merlins.org ([209.81.13.136]:37174 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751295AbdEPA6t (ORCPT ); Mon, 15 May 2017 20:58:49 -0400 Content-Disposition: inline In-Reply-To: <20170515203745.4fc14030@jupiter.sol.kaishome.de> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Kai Krakow Cc: linux-bcache@vger.kernel.org On Mon, May 15, 2017 at 08:37:45PM +0200, Kai Krakow wrote: > Am Mon, 15 May 2017 13:52:09 +0100 > schrieb Nix : > > > On 14 May 2017, Kai Krakow said: > > > I had done this previously, too, and had no such message. But I had > > > to use wipefs anyway because otherwise udev came and triggered the > > > device for reasons I couldn't really follow. > > > > udev does a blkid to see how the block device needs to be activated: > > this relies on precisely the information wipefs removes. Avoiding this > > problem is why wipefs *exists*. :) > > Yes, but something triggered udev when it shouldn't... > > This ends up in unregistering/stopping the bcache, then wipefs the > cdev, then look if udev was triggered and eventually stop it again. > > I guess everytime I ran "fdisk -l" to double-check the devices, or > "lsblk", or "blkid", udev was triggered and re-enabled the bcache. This > is a race you cannot win. ;-) Note that this is orthogonal to the problem I reported. It tells me Already a bcache device on /dev/sde2, overwrite with --wipe-bcache when it fact this does not work, apparently ever. So either the message gets changed, or make-bcache --wipe-bcache -C /dev/sde2 Device /dev/sde2 already has a non-bcache superblock, remove it using wipefs and wipefs -a does not happen. there was no non-bcache superblock. Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/