From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:35037 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751410AbdJPORV (ORCPT ); Mon, 16 Oct 2017 10:17:21 -0400 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1e46CM-0007xR-HO for linux-btrfs@vger.kernel.org; Mon, 16 Oct 2017 16:16:54 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: [PATCH v2 3/3] btrfs-progs: device: add remove missing-all Date: Mon, 16 Oct 2017 14:16:47 +0000 (UTC) Message-ID: References: <649452a3-908d-670d-8bfd-b0e248b32b32@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Misono, Tomohiro posted on Mon, 16 Oct 2017 13:35:08 +0900 as excerpted: > On 2017/10/16 12:30, Anand Jain wrote: >> >> >> On 10/13/2017 01:27 PM, Duncan wrote: >>> Misono, Tomohiro posted on Wed, 11 Oct 2017 11:18:50 +0900 as >>> excerpted: >>> >>>> Add 'btrfs remove missing-all' to remove all the missing devices at >>>> once for improving usability. >>>> >>>> Example: >>>> sudo mkfs.btrfs -f -d raid1 /dev/sdb1 /dev/sdb2 /dev/sdb3 /dev/sdb4 >>>> sudo wipefs -a /dev/sdb1 /dev/sdb3 sudo mount -o degraded /dev/sdb2 >>>> /mnt <-- >> >> >> I agree with Duncan here. This step itself will fail even with RO >> option. Do you have any patch that is not in the ML which will make >> this step a success in the first place ? >> >> Thanks, Anand >> >> > commit 21634a19f646 ("btrfs: Introduce a function to check if all chunks > a OK for degraded rw mount") allow this from 4.14 (I checked on > 4.14-rc4). That's why I said recent patches allow it in corner-cases. However, I think those corner-cases would I think be difficult to document concisely in the manpage, and without that, I believe the option would be more confusing than helpful, since people would expect it to actually work when it won't, for them. > But I will withdraw this patch as Duncan suggests. If someone comes up with a satisfactory way to explain at a manpage level the corner-cases in which removing more than one missing device at a time can work... -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman