This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-devel] [PATCH, resend] Linux udev rules adjustment

To: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] [PATCH, resend] Linux udev rules adjustment
From: "Jan Beulich" <JBeulich@xxxxxxxxxx>
Date: Mon, 20 Sep 2010 14:26:11 +0100
Delivery-date: Mon, 20 Sep 2010 06:29:13 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
While earlier this year some work was done to eliminate libxc's
creation of nodes under /dev (as in some cases it actually got
things wrong), I just found that tapdisk2 does exactly the same.
While I'm not currently aiming at removing this code, I want to
at least suggest some adjustments to the provided rules file.

First of all, the present rule

KERNEL=="blktap[0-9]*", NAME="xen/%k"

matches both blktap1's devices and blktap2's ring devices,
resulting in whoever comes last replacing what was there
before (e.g. a tap2:aio: attach will replace bltap1's
/dev/blktap0 [i.e. the main control device] with the ring device
of the new virtual disk). Therefore we should add a subsystem
qualifier there.

Second, at some udev versions default to using 0660 as the
permissions on nodes it creates. The kernel (with devtmpfs)
defaults to 0600, and hence I'd suggest to also make this
explicit in the rules.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

--- 2010-08-12.orig/tools/hotplug/Linux/xen-backend.rules       2010-08-12 
08:17:22.000000000 +0200
+++ 2010-08-12/tools/hotplug/Linux/xen-backend.rules    2010-09-09 
15:58:15.000000000 +0200
@@ -7,6 +7,10 @@ SUBSYSTEM=="xen-backend", KERNEL=="vif-*
 SUBSYSTEM=="xen-backend", KERNEL=="vscsi*", RUN+="/etc/xen/scripts/vscsi 
 SUBSYSTEM=="xen-backend", ACTION=="remove", 
 KERNEL=="evtchn", NAME="xen/%k"
-KERNEL=="blktap[0-9]*", NAME="xen/%k"
-KERNEL=="pci_iomul", NAME="xen/%k"
+SUBSYSTEM=="xen", KERNEL=="blktap[0-9]*", NAME="xen/%k", MODE="0600"
+SUBSYSTEM=="blktap2", KERNEL=="blktap[0-9]*", NAME="xen/blktap-2/%k", 
+KERNEL=="blktap-control", NAME="xen/blktap-2/control", MODE="0600"
+KERNEL=="gntdev", NAME="xen/%k", MODE="0600"
+KERNEL=="pci_iomul", NAME="xen/%k", MODE="0600"
+KERNEL=="tapdev[a-z]*", NAME="xen/blktap-2/tapdev%m", MODE="0600"
 SUBSYSTEM=="net", KERNEL=="tap*", ACTION=="add", 
RUN+="/etc/xen/scripts/vif-setup $env{ACTION} type_if=tap"

Attachment: udev-rules.patch
Description: Text document

Xen-devel mailing list
<Prev in Thread] Current Thread [Next in Thread>