From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:58301 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752232AbbAZNiX (ORCPT ); Mon, 26 Jan 2015 08:38:23 -0500 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YFjrs-0000ss-PI for linux-btrfs@vger.kernel.org; Mon, 26 Jan 2015 14:38:16 +0100 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 26 Jan 2015 14:38:16 +0100 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 26 Jan 2015 14:38:16 +0100 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: Bug Report Data Rescue: btrfs send ... btrfs set prop on linux 3.18-2 on Arch Linux Date: Mon, 26 Jan 2015 13:38:09 +0000 (UTC) Message-ID: References: <54C63021.8000502@automatix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Juergen Sauer posted on Mon, 26 Jan 2015 13:16:33 +0100 as excerpted: > I think this is an Bug in btrfs send, not to check if an btrfs > filesystem is mounted ro for refusing working. > > It may be much more easier to recover damaged systems, if such annoying > thngs would not occour. That has been noted before, and is indeed considered a bug. The problem is that in normal circumstances, a read-only mount wasn't considered secure enough, because the user could make it writable while the send was underway, causing the send to fail. But at minimum, there needs to be a way to do a send from a forced-read- only filesystem, you are correct, thus the bug. I don't know whether they plan to relax the requirement and live with the chance of a user making it writable (admin responsibility, admin breaks the send, admin gets to keep the pieces), or if they plan to add an attribute to force-read-only so it can be distinguished from user-mounted- read-only, in which case forced-read-only could be considered sufficient for a send. But indeed, the current situation is acknowledged to be "less than ideal" by the devs, which will probably do something about it at some point, based on comments. I don't know how soon that "some point" might be, however... -- 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