[PATCH] hotplug: update xencommons script to run only when needed

[PATCH] hotplug: update xencommons script to run only when needed

[Olaf Hering]

# HG changeset patch
# User Olaf Hering <olaf@aepfle.de>
# Date 1313133097 -7200
# Node ID 0e95f2c754bf526a89bb8a097959e6c970e9b5b7
# Parent  1f08b380d4386cdd6714786a9163e5f51aecab5d
hotplug: update xencommons script to run only when needed

Currently xencommons prints an error if /proc/xen/capabilities does not
exist when started on a non-xen kernel.

Update the xencommons script to run only when needed:
- do not run if /proc/xen does not exist
- check if /proc/xen/capabilities exists before doing the grep for dom0
- use variable for /proc/xen/capabilities
- use grep -q instead of stdout redirection when looking for xenfs,
  its already used later

Signed-off-by: Olaf Hering <olaf@aepfle.de>

diff -r 1f08b380d438 -r 0e95f2c754bf tools/hotplug/Linux/init.d/xencommons
--- a/tools/hotplug/Linux/init.d/xencommons
+++ b/tools/hotplug/Linux/init.d/xencommons
@@ -27,17 +27,29 @@ fi
 test -f $xencommons_config/xencommons && . $xencommons_config/xencommons
 
 XENCONSOLED_PIDFILE=/var/run/xenconsoled.pid
+XEN_CAPABILITIES=/proc/xen/capabilities
 shopt -s extglob
 
+# not running in Xen dom0 or domU
+if ! test -d /proc/xen ; then
+	exit 0
+fi
+
+# mount xenfs in dom0 or domU with a pv_ops kernel
 if test "x$1" = xstart && \
-     test -d /proc/xen && \
-   ! test -f /proc/xen/capabilities && \
-   ! grep '^xenfs ' /proc/mounts >/dev/null;
+   ! test -f $XEN_CAPABILITIES && \
+   ! grep -q '^xenfs ' /proc/mounts ;
 then
 	mount -t xenfs xenfs /proc/xen
 fi
 
-if ! grep -q "control_d" /proc/xen/capabilities ; then
+# run this script only in dom0:
+# no capabilities file in xenlinux kernel
+if ! test -f $XEN_CAPABILITIES ; then
+	exit 0
+fi
+# empty capabilities file in pv_ops kernel
+if ! grep -q "control_d" $XEN_CAPABILITIES ; then
 	exit 0
 fi

Re: [PATCH] hotplug: update xencommons script to run only when needed

[Ian Jackson]

Olaf Hering writes ("[Xen-devel] [PATCH] hotplug: update xencommons script to run only when needed"):
> Update the xencommons script to run only when needed:

Thanks.  I like most of this.  But:

> - use variable for /proc/xen/capabilities

Why ?  Is this going to move ?  I think if it moves we have other
problems, since it's part of the published /proc interface from
Xen-enabled kernels.

Ian.

Re: [PATCH] hotplug: update xencommons script to run only when needed

[Olaf Hering]

On Thu, Aug 25, Ian Jackson wrote:

> Olaf Hering writes ("[Xen-devel] [PATCH] hotplug: update xencommons script to run only when needed"):
> > Update the xencommons script to run only when needed:
> 
> Thanks.  I like most of this.  But:
> 
> > - use variable for /proc/xen/capabilities
> 
> Why ?  Is this going to move ?  I think if it moves we have other
> problems, since it's part of the published /proc interface from
> Xen-enabled kernels.

There is no special reason for the variable.
Do you want me to send a patch without the new variable?

Olaf

Re: [PATCH] hotplug: update xencommons script to run only when needed

[Ian Jackson]

Olaf Hering writes ("Re: [Xen-devel] [PATCH] hotplug: update xencommons script to run only when needed"):
> There is no special reason for the variable.

Right.

> Do you want me to send a patch without the new variable?

If you like, or I can just take it out myself.

Ian.

[PATCH] hotplug: update xencommons script to run only when needed

[Olaf Hering]

# HG changeset patch
# User Olaf Hering <olaf@aepfle.de>
# Date 1315479698 -7200
# Node ID 7829ad83ee66fbec0653ccb53ce5b8502657a71f
# Parent  7b55f33f29cd7aaa0057485b8cae53722bac8741
hotplug: update xencommons script to run only when needed

Currently xencommons prints an error if /proc/xen/capabilities does not
exist when started on a non-xen kernel.

Update the xencommons script to run only when needed:
- do not run if /proc/xen does not exist
- check if /proc/xen/capabilities exists before doing the grep for dom0

Signed-off-by: Olaf Hering <olaf@aepfle.de>

diff -r 7b55f33f29cd -r 7829ad83ee66 tools/hotplug/Linux/init.d/xencommons
--- a/tools/hotplug/Linux/init.d/xencommons
+++ b/tools/hotplug/Linux/init.d/xencommons
@@ -29,15 +29,24 @@ test -f $xencommons_config/xencommons &&
 XENCONSOLED_PIDFILE=/var/run/xenconsoled.pid
 shopt -s extglob
 
+# not running in Xen dom0 or domU
+if ! test -d /proc/xen ; then
+	exit 0
+fi
+
+# mount xenfs in dom0 or domU with a pv_ops kernel
 if test "x$1" = xstart && \
-     test -d /proc/xen && \
    ! test -f /proc/xen/capabilities && \
    ! grep '^xenfs ' /proc/mounts >/dev/null;
 then
 	mount -t xenfs xenfs /proc/xen
 fi
 
-if ! grep -q "control_d" /proc/xen/capabilities ; then
+# run this script only in dom0:
+# no capabilities file in xenlinux domU kernel
+# empty capabilities file in pv_ops domU kernel
+if test -f /proc/xen/capabilities && \
+   ! grep -q "control_d" /proc/xen/capabilities ; then
 	exit 0
 fi