vircgroup: rework virCgroupNewSelf

With the introduction of `libvirt` sub-directory to the cgroup topology
some of the cgroup configuration was moved into that sub-directory
together with the VM processes.

LXC uses virCgroupNewSelf() in the container process to detect cgroups
in order to report various data from cgroups inside the container.

We need to properly detect the new `libvirt` sub-directory here
otherwise LXC will report incorrect data.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/util/vircgroup.c

@@ -1024,7 +1024,20 @@ virCgroupNewNested(virCgroup *parent,
 int
 virCgroupNewSelf(virCgroup **group)
 {
-    return virCgroupNewDetect(-1, -1, group);
+    g_autoptr(virCgroup) newGroup = NULL;
+    g_autoptr(virCgroup) nested = NULL;
+
+    if (virCgroupNewDetect(-1, -1, &newGroup) < 0)
+        return -1;
+
+    if (virCgroupNewNested(newGroup, -1, false, -1, &nested) < 0)
+        return -1;
+
+    if (virCgroupExists(nested))
+        newGroup->nested = g_steal_pointer(&nested);
+
+    *group = g_steal_pointer(&newGroup);
+    return 0;
 }
 
 

tests/vircgrouptest.c

@@ -1019,7 +1019,9 @@ mymain(void)
     DETECT_MOUNTS("cgroups1");
     DETECT_MOUNTS("cgroups2");
     DETECT_MOUNTS("cgroups3");
+    fakerootdir = initFakeFS(NULL, "all-in-one");
     DETECT_MOUNTS("all-in-one");
+    cleanupFakeFS(fakerootdir);
     DETECT_MOUNTS_FAIL("no-cgroups");
     DETECT_MOUNTS("kubevirt");
     fakerootdir = initFakeFS("unified", NULL);