Rename virCgroupMounted to virCgroupHasController & make it more robust

The virCgroupMounted method is badly named, since a controller can be
mounted, but disabled in the current object. Rename the method to be
virCgroupHasController. Also make it tolerant to a  NULL virCgroupPtr
and out-of-range controller index, to avoid duplication of these
checks in all callers

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 786d25a98ab179c85ca41f75a618bc48aa6d0b50..3a297ec1fd1846d821b316cb49de7358ea8cdc28 100644 (file)
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1117,10 +1117,10 @@ virCgroupGetMemorySoftLimit;
 virCgroupGetMemoryUsage;
 virCgroupGetMemSwapHardLimit;
 virCgroupGetMemSwapUsage;
+virCgroupHasController;
 virCgroupKill;
 virCgroupKillPainfully;
 virCgroupKillRecursive;
-virCgroupMounted;
 virCgroupMoveTask;
 virCgroupPathOfController;
 virCgroupRemove;

diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index 00cfd81442e0e836d138775761d5b1db424f9153..2b47f18b2c50e76c863856656375aac3cc5300eb 100644 (file)
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -1642,17 +1642,7 @@ cleanup:
 static bool lxcCgroupControllerActive(virLXCDriverPtr driver,
                                       int controller)
 {
-    if (driver->cgroup == NULL)
-        return false;
-    if (controller < 0 || controller >= VIR_CGROUP_CONTROLLER_LAST)
-        return false;
-    if (!virCgroupMounted(driver->cgroup, controller))
-        return false;
-#if 0
-    if (driver->cgroupControllers & (1 << controller))
-        return true;
-#endif
-    return true;
+    return virCgroupHasController(driver->cgroup, controller);
 }
 
 

diff --git a/src/lxc/lxc_process.c b/src/lxc/lxc_process.c
index 06090c6bc037a0a5bb209273f419a1f9824eaa44..b51c880d2e76ba518af349e89044277124baa2fd 100644 (file)
--- a/src/lxc/lxc_process.c
+++ b/src/lxc/lxc_process.c
@@ -1053,20 +1053,20 @@ int virLXCProcessStart(virConnectPtr conn,
         return -1;
     }
 
-    if (!virCgroupMounted(lxc_driver->cgroup,
+    if (!virCgroupHasController(lxc_driver->cgroup,
                           VIR_CGROUP_CONTROLLER_CPUACCT)) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("Unable to find 'cpuacct' cgroups controller mount"));
         return -1;
     }
-    if (!virCgroupMounted(lxc_driver->cgroup,
-                          VIR_CGROUP_CONTROLLER_DEVICES)) {
+    if (!virCgroupHasController(lxc_driver->cgroup,
+                                VIR_CGROUP_CONTROLLER_DEVICES)) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("Unable to find 'devices' cgroups controller mount"));
         return -1;
     }
-    if (!virCgroupMounted(lxc_driver->cgroup,
-                          VIR_CGROUP_CONTROLLER_MEMORY)) {
+    if (!virCgroupHasController(lxc_driver->cgroup,
+                                VIR_CGROUP_CONTROLLER_MEMORY)) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("Unable to find 'memory' cgroups controller mount"));
         return -1;

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index 2cdc2b7073162de36dbe7e7b48713fdf13315150..5aa94168edad6dfb2882df54ea3ded7780a97747 100644 (file)
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -48,19 +48,7 @@ static const char *const defaultDeviceACL[] = {
 bool qemuCgroupControllerActive(virQEMUDriverPtr driver,
                                 int controller)
 {
-    virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
-    bool ret = false;
-
-    if (driver->cgroup == NULL)
-        goto cleanup;
-    if (controller < 0 || controller >= VIR_CGROUP_CONTROLLER_LAST)
-        goto cleanup;
-    if (!virCgroupMounted(driver->cgroup, controller))
-        goto cleanup;
-
-cleanup:
-    virObjectUnref(cfg);
-    return ret;
+    return virCgroupHasController(driver->cgroup, controller);
 }
 
 static int

diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
index 085421ec00f9fee23e2b0ca6b473888de7a0bd10..dc2b4313d9b76236a46b0a7645b4fe6ac08e4515 100644 (file)
--- a/src/util/vircgroup.c
+++ b/src/util/vircgroup.c
@@ -94,15 +94,20 @@ void virCgroupFree(virCgroupPtr *group)
 }
 
 /**
- * virCgroupMounted: query whether a cgroup subsystem is mounted or not
+ * virCgroupHasController: query whether a cgroup controller is present
  *
- * @cgroup: The group structure to be queried
+ * @cgroup: The group structure to be queried, or NULL
  * @controller: cgroup subsystem id
  *
- * Returns true if a cgroup is subsystem is mounted.
+ * Returns true if a cgroup controller is mounted and is associated
+ * with this cgroup object.
  */
-bool virCgroupMounted(virCgroupPtr cgroup, int controller)
+bool virCgroupHasController(virCgroupPtr cgroup, int controller)
 {
+    if (!cgroup)
+        return false;
+    if (controller < 0 || controller >= VIR_CGROUP_CONTROLLER_LAST)
+        return false;
     return cgroup->controllers[controller].mountPoint != NULL;
 }
 

diff --git a/src/util/vircgroup.h b/src/util/vircgroup.h
index 725d2d050c4e5a953474cbec2ee25cf7ef0ef311..4c1134dc8bac94d552e6887ad71eaeeaaaef188a 100644 (file)
--- a/src/util/vircgroup.h
+++ b/src/util/vircgroup.h
@@ -161,7 +161,7 @@ int virCgroupRemoveRecursively(char *grppath);
 int virCgroupRemove(virCgroupPtr group);
 
 void virCgroupFree(virCgroupPtr *group);
-bool virCgroupMounted(virCgroupPtr cgroup, int controller);
+bool virCgroupHasController(virCgroupPtr cgroup, int controller);
 
 int virCgroupKill(virCgroupPtr group, int signum);
 int virCgroupKillRecursive(virCgroupPtr group, int signum);