vircgroup: introduce virCgroupV2DevicesRemoveProg

We need to close our FD that we have for BPF program and map in order
to let kernel remove all resources once the cgroup is removed as well.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/libvirt_private.syms

@@ -1722,6 +1722,7 @@ virCgroupV2DevicesAvailable;
 virCgroupV2DevicesCreateProg;
 virCgroupV2DevicesDetectProg;
 virCgroupV2DevicesPrepareProg;
+virCgroupV2DevicesRemoveProg;
 
 # util/virclosecallbacks.h
 virCloseCallbacksGet;

src/util/vircgroupv2.c

@@ -488,6 +488,9 @@ virCgroupV2Remove(virCgroupPtr group)
     if (virCgroupV2PathOfController(group, controller, "", &grppath) < 0)
         return 0;
 
+    if (virCgroupV2DevicesRemoveProg(group) < 0)
+        return -1;
+
     return virCgroupRemoveRecursively(grppath);
 }
 

src/util/vircgroupv2devices.c

@@ -538,6 +538,25 @@ virCgroupV2DevicesPrepareProg(virCgroupPtr group)
 
     return 0;
 }
+
+
+int
+virCgroupV2DevicesRemoveProg(virCgroupPtr group)
+{
+    if (virCgroupV2DevicesDetectProg(group) < 0)
+        return -1;
+
+    if (group->unified.devices.progfd <= 0 && group->unified.devices.mapfd <= 0)
+        return 0;
+
+    if (group->unified.devices.mapfd >= 0)
+        VIR_FORCE_CLOSE(group->unified.devices.mapfd);
+
+    if (group->unified.devices.progfd >= 0)
+        VIR_FORCE_CLOSE(group->unified.devices.progfd);
+
+    return 0;
+}
 #else /* !HAVE_DECL_BPF_CGROUP_DEVICE */
 bool
 virCgroupV2DevicesAvailable(virCgroupPtr group G_GNUC_UNUSED)
@@ -586,4 +605,11 @@ virCgroupV2DevicesPrepareProg(virCgroupPtr group G_GNUC_UNUSED)
                            "with this kernel"));
     return -1;
 }
+
+
+int
+virCgroupV2DevicesRemoveProg(virCgroupPtr group G_GNUC_UNUSED)
+{
+    return 0;
+}
 #endif /* !HAVE_DECL_BPF_CGROUP_DEVICE */

src/util/vircgroupv2devices.h

@@ -36,3 +36,6 @@ virCgroupV2DevicesCreateProg(virCgroupPtr group);
 
 int
 virCgroupV2DevicesPrepareProg(virCgroupPtr group);
+
+int
+virCgroupV2DevicesRemoveProg(virCgroupPtr group);