From e64cbebf99fab42662b0e72a44f3a5bdef69bf8d Mon Sep 17 00:00:00 2001
Message-Id: <e64cbebf99fab42662b0e72a44f3a5bdef69bf8d@dist-git>
From: Martin Kletzander <mkletzan@redhat.com>
Date: Thu, 15 Jan 2015 15:03:44 +0100
Subject: [PATCH] util: Add function virCgroupHasEmptyTasks

https://bugzilla.redhat.com/show_bug.cgi?id=1161540

That function helps checking whether there's a task in that cgroup.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
(cherry picked from commit 1a80b97ddfb096a21af60d63a42d1af280fb6886)
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/util/vircgroup.c     | 23 +++++++++++++++++++++++
 src/util/vircgroup.h     |  4 +++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index cf3c842..62f4f08 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1087,6 +1087,7 @@ virCgroupGetMemSwapHardLimit;
 virCgroupGetMemSwapUsage;
 virCgroupGetPercpuStats;
 virCgroupHasController;
+virCgroupHasEmptyTasks;
 virCgroupIsolateMount;
 virCgroupKill;
 virCgroupKillPainfully;
diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
index 152ef96..dbe7ee7 100644
--- a/src/util/vircgroup.c
+++ b/src/util/vircgroup.c
@@ -3915,6 +3915,20 @@ virCgroupSupportsCpuBW(virCgroupPtr cgroup)
     return ret;
 }
 
+int
+virCgroupHasEmptyTasks(virCgroupPtr cgroup, int controller)
+{
+    int ret = -1;
+    char *content = NULL;
+
+    ret = virCgroupGetValueStr(cgroup, controller, "tasks", &content);
+
+    if (ret == 0 && content[0] == '\0')
+        ret = 1;
+
+    VIR_FREE(content);
+    return ret;
+}
 
 #else /* !VIR_CGROUP_SUPPORTED */
 
@@ -4633,4 +4647,13 @@ virCgroupSetOwner(virCgroupPtr cgroup ATTRIBUTE_UNUSED,
     return -1;
 }
 
+int
+virCgroupHasEmptyTasks(virCgroupPtr cgroup ATTRIBUTE_UNUSED,
+                       int controller ATTRIBUTE_UNUSED)
+{
+    virReportSystemError(ENOSYS, "%s",
+                         _("Control groups not supported on this platform"));
+    return -1;
+}
+
 #endif /* !VIR_CGROUP_SUPPORTED */
diff --git a/src/util/vircgroup.h b/src/util/vircgroup.h
index 19e82d1..3dbae12 100644
--- a/src/util/vircgroup.h
+++ b/src/util/vircgroup.h
@@ -1,7 +1,7 @@
 /*
  * vircgroup.h: methods for managing control cgroups
  *
- * Copyright (C) 2011-2013 Red Hat, Inc.
+ * Copyright (C) 2011-2014 Red Hat, Inc.
  * Copyright IBM Corp. 2008
  *
  * This library is free software; you can redistribute it and/or
@@ -265,4 +265,6 @@ int virCgroupSetOwner(virCgroupPtr cgroup,
                       gid_t gid,
                       int controllers);
 
+int virCgroupHasEmptyTasks(virCgroupPtr cgroup, int controller);
+
 #endif /* __VIR_CGROUP_H__ */
-- 
2.2.1