Move check for cgroup devices ACL upfront in LXC hotplug

The check for whether the cgroup devices ACL is available is
done quite late during LXC hotplug - in fact after the device
node is already created in the container in some cases. Better
to do it upfront so we fail immediately.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/lxc/lxc_driver.c

@@ -3675,6 +3675,12 @@ lxcDomainAttachDeviceDiskLive(virLXCDriverPtr driver,
         goto cleanup;
     }
 
+    if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES)) {
+        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                       _("devices cgroup isn't mounted"));
+        goto cleanup;
+    }
+
     if (def->type != VIR_DOMAIN_DISK_TYPE_BLOCK) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                        _("Can't setup disk for non-block device"));
@@ -3742,12 +3748,6 @@ lxcDomainAttachDeviceDiskLive(virLXCDriverPtr driver,
                                         vm->def, def) < 0)
         goto cleanup;
 
-    if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES)) {
-        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
-                       _("devices cgroup isn't mounted"));
-        goto cleanup;
-    }
-
     if (virCgroupAllowDevicePath(priv->cgroup, def->src,
                                  (def->readonly ?
                                   VIR_CGROUP_DEVICE_READ :
@@ -3944,12 +3944,6 @@ lxcDomainAttachDeviceHostdevSubsysUSBLive(virLXCDriverPtr driver,
                     def->source.subsys.u.usb.device) < 0)
         goto cleanup;
 
-    if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES)) {
-        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
-                       _("devices cgroup isn't mounted"));
-        goto cleanup;
-    }
-
     if (!(usb = virUSBDeviceNew(def->source.subsys.u.usb.bus,
                                 def->source.subsys.u.usb.device, vroot)))
         goto cleanup;
@@ -4097,12 +4091,6 @@ lxcDomainAttachDeviceHostdevStorageLive(virLXCDriverPtr driver,
                                           vm->def, def, vroot) < 0)
         goto cleanup;
 
-    if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES)) {
-        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
-                       _("devices cgroup isn't mounted"));
-        goto cleanup;
-    }
-
     if (virCgroupAllowDevicePath(priv->cgroup, def->source.caps.u.storage.block,
                                  VIR_CGROUP_DEVICE_RW |
                                  VIR_CGROUP_DEVICE_MKNOD) != 0) {
@@ -4205,12 +4193,6 @@ lxcDomainAttachDeviceHostdevMiscLive(virLXCDriverPtr driver,
                                           vm->def, def, vroot) < 0)
         goto cleanup;
 
-    if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES)) {
-        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
-                       _("devices cgroup isn't mounted"));
-        goto cleanup;
-    }
-
     if (virCgroupAllowDevicePath(priv->cgroup, def->source.caps.u.misc.chardev,
                                  VIR_CGROUP_DEVICE_RW |
                                  VIR_CGROUP_DEVICE_MKNOD) != 0) {
@@ -4286,6 +4268,12 @@ lxcDomainAttachDeviceHostdevLive(virLXCDriverPtr driver,
         return -1;
     }
 
+    if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES)) {
+        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                       _("devices cgroup isn't mounted"));
+        return -1;
+    }
+
     switch (dev->data.hostdev->mode) {
     case VIR_DOMAIN_HOSTDEV_MODE_SUBSYS:
         return lxcDomainAttachDeviceHostdevSubsysLive(driver, vm, dev);