From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: Why does stat() return invalid st_dev field for btrfs ?? Date: Mon, 17 Aug 2009 22:01:26 -0400 Message-ID: <4A8A0B76.1030800@rtr.ca> References: <4A89C1DA.6040601@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Cc: linux-btrfs@vger.kernel.org, Chris Mason , Linux Kernel To: Kay Sievers Return-path: In-Reply-To: List-ID: 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.