From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756820Ab3D2Pey (ORCPT ); Mon, 29 Apr 2013 11:34:54 -0400 Received: from smtp2.macqel.be ([194.78.208.39]:16998 "EHLO smtp2.macqel.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752549Ab3D2Pex (ORCPT ); Mon, 29 Apr 2013 11:34:53 -0400 Date: Mon, 29 Apr 2013 17:34:50 +0200 From: Philippe De Muyter To: Karel Zak Cc: linux-kernel@vger.kernel.org, Jens Axboe Subject: Re: [PATCH 2/5] Add aix lvm partitions support files Message-ID: <20130429153450.GA25581@frolo.macqel> References: <1366924229-21569-1-git-send-email-phdm@macqel.be> <1366924229-21569-3-git-send-email-phdm@macqel.be> <20130429093756.GB12317@x2.net.home> <20130429114041.GA10884@frolo.macqel> <20130429123651.GA2400@x2.net.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130429123651.GA2400@x2.net.home> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Karel On Mon, Apr 29, 2013 at 02:36:51PM +0200, Karel Zak wrote: > On Mon, Apr 29, 2013 at 01:40:41PM +0200, Philippe De Muyter wrote: > > > why not memset(pps_found, ....)? I also see magical constant 16 > > > > Actually 16 is the maximum partition count allowed in a disk by linux, > > or should it be 15 ? Is there already a constant for that ? > > The AIX disk I tested with had only :) 11 partitions. > > I don't think it's correct to expect any hardcoded limit. > > The struct parsed_partitions->parts is allocated according to > disk_max_parts() where the limit depends on number of minor numbers or > it's DISK_MAX_PARTS (=256). > > There is no problem to create disk with many partitions: > > # modprobe scsi_debug dev_size_mb=300 > # (echo -e 'g\n'; for i in {1..100}; do echo -e "n\n\n\n+1M"; done; \ > echo -e 'w\nq\n') | fdisk /dev/sdb > > # lsblk -n /dev/sdb | wc -l > 101 how are they named then ? on my system (a 2.6.24 kernel which is the last one that support my powerpc PReP machine because PReP support got removed with the merge of /arch/ppc and /arch/powerpc :( ), I get : root:~# ls -l /dev/sd[ab]* brw-r----- 1 root disk 8, 0 Apr 25 22:22 /dev/sda brw-r----- 1 root disk 8, 10 Apr 25 22:22 /dev/sda10 brw-r----- 1 root disk 8, 11 Apr 25 22:22 /dev/sda11 brw-r----- 1 root disk 8, 3 Apr 25 22:22 /dev/sda3 brw-r----- 1 root disk 8, 4 Apr 25 22:22 /dev/sda4 brw-r----- 1 root disk 8, 5 Apr 25 22:22 /dev/sda5 brw-r----- 1 root disk 8, 6 Apr 25 22:22 /dev/sda6 brw-r----- 1 root disk 8, 7 Apr 25 22:22 /dev/sda7 brw-r----- 1 root disk 8, 8 Apr 25 22:22 /dev/sda8 brw-r----- 1 root disk 8, 9 Apr 25 22:22 /dev/sda9 brw-r----- 1 root disk 8, 16 Apr 25 22:22 /dev/sdb brw-r----- 1 root disk 8, 26 Apr 25 22:22 /dev/sdb10 brw-r----- 1 root disk 8, 27 Apr 25 22:22 /dev/sdb11 brw-r----- 1 root disk 8, 19 Apr 25 22:22 /dev/sdb3 brw-r----- 1 root disk 8, 20 Apr 25 22:22 /dev/sdb4 brw-r----- 1 root disk 8, 21 Apr 25 22:22 /dev/sdb5 brw-r----- 1 root disk 8, 22 Apr 25 22:22 /dev/sdb6 brw-r----- 1 root disk 8, 23 Apr 25 22:22 /dev/sdb7 brw-r----- 1 root disk 8, 24 Apr 25 22:22 /dev/sdb8 brw-r----- 1 root disk 8, 25 Apr 25 22:22 /dev/sdb9 root:~# so sda is 8,0 and sdb is 8,16 and if, while discovering partitions of /dev/sda, I try to make a partition 16 or higher, it is silently discarded by 'put_partition'. Is that changed ? Philippe -- Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles