[Libcg-devel] [PATCH] cgcreate: use "*" character as a meta character for all mounted controllers

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

    This patch adds the possibility to use meta character "*" as a shortcut for all mounted controllers. This meta character can be used in "-g" option.
    For example:
    $ cgcreate -g *:first  -g cpu:second
    $ lssubsys
    cpuset:/
    cpuset:/first
    cpu,cpuacct:/
    cpu,cpuacct:/first
    cpu,cpuacct:/second
    memory:/
    memory:/first
    devices:/
    devices:/first
    freezer:/
    freezer:/first
    net_cls,net_prio:/
    net_cls,net_prio:/first
    blkio:/
    blkio:/first
    perf_event:/
    perf_event:/first
    hugetlb:/
    hugetlb:/first


Signed-off-by: Ivana Hutarova Varekova <var...@re...>
---
 doc/man/cgcreate.1   |    3 +-
 src/tools/cgcreate.c |   82 +++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 75 insertions(+), 10 deletions(-)

diff --git a/doc/man/cgcreate.1 b/doc/man/cgcreate.1
index 7068073..557b5ae 100644
--- a/doc/man/cgcreate.1
+++ b/doc/man/cgcreate.1
@@ -38,7 +38,8 @@ others permissions to the owners permissions).
 .TP
 .B -g <controllers>:<path>
 defines control groups to be added.
-\fBcontrollers\fR is a list of controllers and
+\fBcontrollers\fR is a list of controllers. Character "*" can be used
+as a shortcut for "all mounted controllers".
 \fBpath\fR is the relative path to control groups
 in the given controllers list. This option can be specified
 multiple times.
diff --git a/src/tools/cgcreate.c b/src/tools/cgcreate.c
index 73abd91..b9c9b9d 100644
--- a/src/tools/cgcreate.c
+++ b/src/tools/cgcreate.c
@@ -54,6 +54,57 @@ static void usage(int status, const char *program_name)
 	printf("  -t <tuid>:<tgid>		Owner of the tasks file\n");
 }
 
+/* add all controllers to control cgroup structure */
+int cgcreate_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;
+}
+
 
 int main(int argc, char *argv[])
 {
@@ -195,16 +246,29 @@ int main(int argc, char *argv[])
 		/* add controllers to the new cgroup */
 		j = 0;
 		while (cgroup_list[i]->controllers[j]) {
-			cgc = cgroup_add_controller(cgroup,
-				cgroup_list[i]->controllers[j]);
-			if (!cgc) {
-				ret = ECGINVAL;
-				fprintf(stderr, "%s: "
-					"controller %s can't be add\n",
-					argv[0],
+			if (strcmp(cgroup_list[i]->controllers[j], "*") == 0) {
+				/* itis meta character -> add all controllers */
+				ret = cgcreate_add_all_controllers(cgroup);
+				if (ret != 0) {
+					ret = ECGINVAL;
+					fprintf(stderr, "%s: can't add ",
+						argv[0]);
+					fprintf(stderr, "all controllers\n");
+					cgroup_free(&cgroup);
+					goto err;
+				}
+			} else {
+				cgc = cgroup_add_controller(cgroup,
 					cgroup_list[i]->controllers[j]);
-				cgroup_free(&cgroup);
-				goto err;
+				if (!cgc) {
+					ret = ECGINVAL;
+					fprintf(stderr, "%s: ", argv[0]);
+					fprintf(stderr, "controller %s",
+						cgroup_list[i]->controllers[j]);
+					fprintf(stderr, "can't be add\n");
+					cgroup_free(&cgroup);
+					goto err;
+				}
 			}
 			j++;
 		}