[Libcg-devel] [PATCH 1/2] api.c: add cgroup_add_all_controllers function

[Ivana H. V. <var...@re...>]

cgroup_add_all_controllers function attach all mounted controllers to a given cgroup. This function just modifies internal libcgroup structure, not the kernel control group.
 input parameter: cgroup
 output parameter: zero or error number


Signed-off-by: Ivana Hutarova Varekova <var...@re...>
---
 include/libcgroup/groups.h |   10 +++++++++
 src/libcgroup.map          |    7 ++++++
 src/wrapper.c              |   50 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)

diff --git a/include/libcgroup/groups.h b/include/libcgroup/groups.h
index d5c87aa..201558f 100644
--- a/include/libcgroup/groups.h
+++ b/include/libcgroup/groups.h
@@ -150,6 +150,16 @@ struct cgroup_controller *cgroup_add_controller(struct cgroup *cgroup,
 						const char *name);
 
 /**
+ * Attach all mounted controllers to given cgroup. This function just modifies
+ * internal libcgroup structure, not the kernel control group.
+ *
+ * @param cgroup
+ * @return zero or error number
+ */
+int cgroup_add_all_controllers(struct cgroup *cgroup);
+
+
+/**
  * Return appropriate controller from given group.
  * The controller must be added before using cgroup_add_controller() or loaded
  * from kernel using cgroup_get_cgroup().
diff --git a/src/libcgroup.map b/src/libcgroup.map
index f8b0fb9..8fe1990 100644
--- a/src/libcgroup.map
+++ b/src/libcgroup.map
@@ -122,3 +122,10 @@ CGROUP_0.40 {
 	cgroup_templates_cache_set_source_files;
 	cgroup_load_templates_cache_from_files;
 } CGROUP_0.39;
+
+CGROUP_0.41 {
+} CGROUP_0.40;
+
+CGROUP_0.42 {
+	cgroup_add_all_controllers;
+} CGROUP_0.41;
diff --git a/src/wrapper.c b/src/wrapper.c
index c03472a..3a9331f 100644
--- a/src/wrapper.c
+++ b/src/wrapper.c
@@ -92,6 +92,56 @@ struct cgroup_controller *cgroup_add_controller(struct cgroup *cgroup,
 	return controller;
 }
 
+int cgroup_add_all_controllers(struct cgroup *cgroup)
+{
+	int ret;
+	void *handle;
+	struct controller_data info;
+	struct cgroup_controller *cgc;
+
+	/* go through the controller list */
+	ret = cgroup_get_all_controller_begin(&handle, &info);
+	if ((ret != 0) && (ret != ECGEOF)) {
+		fprintf(stderr, "cannot read controller data: %s\n",
+			cgroup_strerror(ret));
+		return ret;
+	}
+
+	while (ret == 0) {
+		if (info.hierarchy == 0) {
+			/* the controller is not attached to any hierarchy
+			   skip it */
+			goto next;
+		}
+
+		/* add mounted controller to cgroup structure */
+		cgc = cgroup_add_controller(cgroup, info.name);
+		if (!cgc) {
+			ret = ECGINVAL;
+			fprintf(stderr, "controller %s can't be add\n",
+				info.name);
+		}
+
+next:
+		ret = cgroup_get_all_controller_next(&handle, &info);
+		if (ret && ret != ECGEOF)
+			goto end;
+	}
+
+end:
+	cgroup_get_all_controller_end(&handle);
+
+	if (ret == ECGEOF)
+		ret = 0;
+
+	if (ret)
+		fprintf(stderr,
+			"cgroup_get_controller_begin/next failed (%s)\n",
+			cgroup_strerror(ret));
+
+	return ret;
+}
+
 void cgroup_free_controllers(struct cgroup *cgroup)
 {
 	int i, j;