From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx11.extmail.prod.ext.phx2.redhat.com [10.5.110.16]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p6B1OSel023058 for ; Sun, 10 Jul 2011 21:24:28 -0400 Received: from Ishtar.tlinx.org (ishtar.tlinx.org [173.164.175.65]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p6B1ORWK002976 for ; Sun, 10 Jul 2011 21:24:27 -0400 Received: from [192.168.3.140] (Athenae2 [192.168.3.140]) by Ishtar.tlinx.org (8.14.4/8.14.4/SuSE Linux 0.8) with ESMTP id p6B1ONcp009040 for ; Sun, 10 Jul 2011 18:24:25 -0700 Message-ID: <4E1A50C7.5090006@tlinx.org> Date: Sun, 10 Jul 2011 18:24:23 -0700 From: "Linda A. Walsh" MIME-Version: 1.0 References: <4E19E3FD.9000805@tlinx.org> <20110710220815.GB7857@agk-dp.fab.redhat.com> In-Reply-To: <20110710220815.GB7857@agk-dp.fab.redhat.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] Bug! lvs shouldn't need 'root' access Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: LVM general discussion and development Alasdair G Kergon wrote: > On Sun, Jul 10, 2011 at 10:40:13AM -0700, Linda A. Walsh wrote: > >> I could write to the darn things!, but all I NEED is read (hmmm >> > > I thought so too when we first began work on LVM, but - surprising > to me - there's been hardly any demand expressed for this feature. > > The proposed method of handling this was to accept dm ioctls on > the actual devices themselves controlled by normal ioctl permissions. > > Currently, you need CAP_SYS_ADMIN (and access to /dev/mapper/control). > ---- Why is CAP_SYS_ADMIN needed to access a disk device when device permissions are already present for this? I can put myself for view purposes in a group disk and give an read-only access to the disks as well as /dev/mapper/control. Being able to get status information out of the system shouldn't require CAP_SYS_ADMIN NOR write access -- ability t0 'read' should allow reading of status. with control by group. CAP_SYS_ADMIN is poor control, since how do I set CAP_SYS_ADMIN on my login and *only* have it allow reading ??? I don't. Might as well run as root all the time. Can this be revisited and a justification made why running "top" shouldn't require sys_admin as well?