On Fri, Oct 29, 2010 at 05:32:16PM +0800, Lai Jiangshan wrote:

When wen mount any cgroup without "-o devices", we will fail to start vms:

# virsh start vm1 error: Failed to start domain vm1 error: Unable to deny all devices for vm1: No such file or directory

When wen mount any cgroup without "-o cpu", we will fail to get schedinfo: # virsh schedinfo vm1 Scheduler : posix error: unable to get cpu shares tunable: No such file or directory

We should only use the cgroup controllers which are mounted on host. So I add virCgroupMounted() for qemuCgroupControllerActive()

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 3b127d6..5885ad8 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -61,6 +61,7 @@ virConfWriteMem; # cgroup.h virCgroupForDomain; virCgroupForDriver; +virCgroupMounted; virCgroupRemove; virCgroupFree; virCgroupAddTask; diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 16f34f7..f09d029 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -724,6 +724,8 @@ static int qemuCgroupControllerActive(struct qemud_driver *driver, { if (driver->cgroup == NULL) return 0; + if (!virCgroupMounted(driver->cgroup, controller)) + return 0; if (driver->cgroupControllers & (1 << controller)) return 1; return 0; diff --git a/src/util/cgroup.c b/src/util/cgroup.c index 7e887dc..8fac389 100644 --- a/src/util/cgroup.c +++ b/src/util/cgroup.c @@ -71,6 +71,17 @@ void virCgroupFree(virCgroupPtr *group) VIR_FREE(*group); }

+/** + * virCgroupMounted: query whether a cgroup subsystem is mounted or not + * + * @cgroup: The group structure to be queried + * @controller: cgroup subsystem id + */ +bool virCgroupMounted(virCgroupPtr cgroup, int controller) +{ + return !!cgroup->controllers[controller].mountPoint; +}

IMHO its slightly clearer to read with mountPoint != NULL, rather than !!

+ #if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R /* * Process /proc/mounts figuring out what controllers are diff --git a/src/util/cgroup.h b/src/util/cgroup.h index b8f2d08..9e1c61f 100644 --- a/src/util/cgroup.h +++ b/src/util/cgroup.h @@ -83,5 +83,6 @@ int virCgroupGetFreezerState(virCgroupPtr group, char **state); int virCgroupRemove(virCgroupPtr group);

void virCgroupFree(virCgroupPtr *group); +bool virCgroupMounted(virCgroupPtr cgroup, int controller);

ACK aside from that minor point. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|