xencommons: Attempt to load blktap2 driver

Older kernels, such as those found in Debian Squeeze:
* Have bugs in handling of AIO into foreign pages
* Have blktap modules, which will cause qemu not to use AIO, but
  which are not loaded on boot.

Attempt to load blktap in xencommons, to make sure modern qemu's which
use AIO will work properly on those kernels.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Prefer to load blktap2 if it exists. This is the name of the driver in
classic-Xen ports, while in mainline kernels the driver is called just
blktap.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/tools/hotplug/Linux/init.d/xencommons b/tools/hotplug/Linux/init.d/xencommons
index 25e0e2d8eb2f96272b49e4b145d3d5c118865617..cc8177e6ea558d72a5b516747ac13057f2c76310 100644 (file)
--- a/tools/hotplug/Linux/init.d/xencommons
+++ b/tools/hotplug/Linux/init.d/xencommons
@@ -68,6 +68,7 @@ do_start () {
        modprobe usbbk 2>/dev/null
        modprobe pciback 2>/dev/null
        modprobe xen-acpi-processor 2>/dev/null
+       modprobe blktap2 2>/dev/null || modprobe blktap 2>/dev/null
        mkdir -p /var/run/xen
 
        if ! `xenstore-read -s / >/dev/null 2>&1`