From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932739AbZHRCB2 (ORCPT ); Mon, 17 Aug 2009 22:01:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932530AbZHRCB1 (ORCPT ); Mon, 17 Aug 2009 22:01:27 -0400 Received: from rtr.ca ([76.10.145.34]:46966 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753278AbZHRCB0 (ORCPT ); Mon, 17 Aug 2009 22:01:26 -0400 Message-ID: <4A8A0B76.1030800@rtr.ca> Date: Mon, 17 Aug 2009 22:01:26 -0400 From: Mark Lord Organization: Real-Time Remedies Inc. User-Agent: Thunderbird 2.0.0.22 (X11/20090608) MIME-Version: 1.0 To: Kay Sievers Cc: linux-btrfs@vger.kernel.org, Chris Mason , Linux Kernel Subject: Re: Why does stat() return invalid st_dev field for btrfs ?? References: <4A89C1DA.6040601@rtr.ca> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Kay Sievers wrote: > On Mon, Aug 17, 2009 at 22:47, Mark Lord wrote: >> Chris / list, >> >> stat(2) seems to return invalid major/minor device info >> for btrfs filesystems. >> >> Why? Is this a bug? > > This is not invalid and not a bug. It's a superblock without a device, > and expected behavior. > > There is no one-to-one relation from a btrfs mountpoint to a device, > it's a tree, and therefore therefore there can not be a single > major/minor. .. Sure there is for the most common case. When there is only a single device, stat() should return that device. When there are several, it should do something different. But really, it should be using DM/LVM when there are multiple devices.