adds new option -g to cgget command

adds new option -g to cgget command
* the option has one argument - controller
* cgget -g devices / returns the values of all variables of controller
devices
* the option could be used multiple times

EXAMLES:

$ ./cgget -n -g cpu -r cpuset.mems /
cpu.rt_period_us=1000000
cpu.rt_runtime_us=950000
cpu.shares=1024
cpuset.mems=0

Signed-off-by: Ivana Hutarova Varekova <varekova@redhat.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>

1 files changed, 152 insertions, 42 deletions

diff --git a/src/tools/cgget.c b/src/tools/cgget.c
index 13b7764..d3c22de 100644
--- a/src/tools/cgget.c
+++ b/src/tools/cgget.c
@@ -19,12 +19,36 @@ void usage(int status, char *program_name)
 			" try %s -h' for more information.\n",
 			program_name);
 	else {
-		printf("Usage: %s [-nv] -r <name> [-r <name>] ... <path> ...\n",
-			program_name);
+		printf("Usage: %s [-nv] [-r <name>] [-g <controller>]..."\
+			"<path> ...\n", program_name);
 	}
 }
 
-int display_values(char **names, int count, const char* group_name,
+int display_one_record(char *name, struct cgroup_controller *group_controller,
+	const char *program_name, int mode)
+{
+	int ret;
+	char *value = NULL;
+
+	ret = cgroup_get_value_string(group_controller, name, &value);
+	if (ret != 0) {
+		fprintf(stderr, "%s: cannot read parameter '%s' "\
+			"from group '%s': %s\n", program_name, name,
+			group_controller->name, cgroup_strerror(ret));
+		return ret;
+	}
+
+	if (mode & MODE_SHOW_NAMES)
+		printf("%s=", name);
+
+	printf("%s\n", value);
+
+	free(value);
+	return ret;
+}
+
+
+int display_name_values(char **names, int count, const char* group_name,
 		const char *program_name, int mode)
 {
 	int i;
@@ -32,10 +56,6 @@ int display_values(char **names, int count, const char* group_name,
 	struct cgroup *group = NULL;
 	int ret = 0;
 	char *controller = NULL, *parameter = NULL;
-	char *value = NULL;
-
-	if (mode & MODE_SHOW_HEADERS)
-		printf("%s:\n", group_name);
 
 	group = cgroup_new_cgroup(group_name);
 	if (group == NULL) {
@@ -79,22 +99,11 @@ int display_values(char **names, int count, const char* group_name,
 			goto err;
 		}
 
-		/*
-		 * Finally read the parameter value.
-		 */
-		ret = cgroup_get_value_string(group_controller, names[i],
-				&value);
-		if (ret != 0) {
-			fprintf(stderr, "%s: cannot read parameter '%s.%s' "\
-					"from group '%s': %s\n", program_name,
-					controller, parameter, group_name,
-					cgroup_strerror(ret));
+		/* Finally read the parameter value.*/
+		ret = display_one_record(names[i], group_controller,
+			program_name, mode);
+		if (ret != 0)
 			goto err;
-		}
-		if (mode & MODE_SHOW_NAMES)
-			printf("%s.%s=", controller, parameter);
-		printf("%s\n", value);
-		free(value);
 	}
 err:
 	if (controller)
@@ -104,14 +113,95 @@ err:
 	return ret;
 }
 
+int display_controller_values(char **controllers, int count,
+		const char *group_name, const char *program_name, int mode)
+{
+	struct cgroup *group = NULL;
+	struct cgroup_controller *group_controller = NULL;
+	char *name;
+	int i, j;
+	int name_count;
+	int ret = 0;
+	int result = 0;
+
+	/* initialize group_name variable */
+	group = cgroup_new_cgroup(group_name);
+	if (group == NULL) {
+		fprintf(stderr, "%s:cannot create group '%s'\n",
+			program_name, group_name);
+		return -1;
+	}
+
+	ret = cgroup_get_cgroup(group);
+	if (ret != 0) {
+		fprintf(stderr, "%s: cannot read group '%s': %s\n",
+			program_name, group_name, cgroup_strerror(ret));
+	}
+
+	/* for all wanted controllers */
+	for (j = 0; j < count; j++) {
+
+		/* read the controller group data */
+		group_controller = cgroup_get_controller(group, controllers[j]);
+		if (group_controller == NULL) {
+			fprintf(stderr, "%s: cannot find controller "\
+				"'%s' in group '%s'\n", program_name,
+				controllers[j], group_name);
+			result = -1;
+		}
+
+		/* for each variable of given group print the statistic */
+		name_count = cgroup_get_value_name_count(group_controller);
+		for (i = 0; i < name_count; i++) {
+			name = cgroup_get_value_name(group_controller, i);
+			if (name != NULL) {
+				ret = display_one_record(name, group_controller,
+					program_name, mode);
+				if (ret)
+					return ret;
+			}
+		}
+	}
+
+	cgroup_free(&group);
+	return result;
+
+}
+
+int add_record_to_buffer(int *p_number,
+	int *p_max, char ***p_records, char *new_rec)
+{
+
+	if (*p_number >= *p_max) {
+		*p_max += CG_NV_MAX;
+		*p_records = (char **) realloc(*p_records,
+			*p_max * sizeof(char *));
+		if (!(*p_records)) {
+			fprintf(stderr, "not enough memory\n");
+			return -1;
+		}
+	}
+
+	(*p_records)[*p_number] = new_rec;
+	(*p_number)++;
+
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
 	int ret = 0;
+	int result = 0;
 	int c, i;
 
 	char **names = NULL;
 	int n_number = 0;
 	int n_max = 0;
+
+	char **controllers = NULL;
+	int c_number = 0;
+	int c_max = 0;
+
 	int mode = MODE_SHOW_NAMES | MODE_SHOW_HEADERS;
 
 	/* No parameter on input? */
@@ -121,11 +211,11 @@ int main(int argc, char *argv[])
 	}
 
 	/* Parse arguments. */
-	while ((c = getopt(argc, argv, "r:hnv")) != -1) {
+	while ((c = getopt(argc, argv, "r:hnvg:")) != -1) {
 		switch (c) {
 		case 'h':
 			usage(0, argv[0]);
-			ret = 0;
+			result = 0;
 			goto err;
 			break;
 
@@ -141,24 +231,25 @@ int main(int argc, char *argv[])
 
 		case 'r':
 			/* Add name to buffer. */
-			if (n_number >= n_max) {
-				n_max += CG_NV_MAX;
-				names = (char **) realloc(names,
-					n_max * sizeof(char *));
-				if (!names) {
-					fprintf(stderr, "%s: "
-						"not enough memory\n", argv[0]);
-					ret = -1;
-					goto err;
-				}
+			ret = add_record_to_buffer(
+				&n_number, &n_max, &names, optarg);
+			if (ret) {
+				result = ret;
+				goto err;
+			}
+			break;
+		case 'g':
+			/* for each controller add all variables to list */
+			ret = add_record_to_buffer(&c_number,
+				&c_max, &controllers, optarg);
+			if (ret) {
+				result = ret;
+				goto err;
 			}
-
-			names[n_number] = optarg;
-			n_number++;
 			break;
 		default:
 			usage(1, argv[0]);
-			ret = 1;
+			result = -1;
 			goto err;
 			break;
 		}
@@ -166,7 +257,7 @@ int main(int argc, char *argv[])
 
 	if (!argv[optind]) {
 		fprintf(stderr, "%s: no cgroup specified\n", argv[0]);
-		ret = -1;
+		result = -1;
 		goto err;
 	}
 
@@ -175,14 +266,33 @@ int main(int argc, char *argv[])
 	if (ret) {
 		fprintf(stderr, "%s: libcgroup initialization failed: %s\n",
 			argv[0], cgroup_strerror(ret));
+		result = ret;
+		goto err;
+	}
+
+	if (!argv[optind]) {
+		fprintf(stderr, "%s: no cgroup specified\n", argv[0]);
+		result = -1;
 		goto err;
 	}
 
 	/* Parse control groups and print them .*/
 	for (i = optind; i < argc; i++) {
-		ret = display_values(names, n_number, argv[i], argv[0], mode);
+
+		/* display the directory if needed */
+		if (mode & MODE_SHOW_HEADERS)
+			printf("%s:\n", argv[i]);
+
+		ret = display_name_values(names,
+			n_number, argv[i], argv[0], mode);
 		if (ret)
-			goto err;
+			result = ret;
+
+		ret = display_controller_values(controllers,
+			c_number, argv[i], argv[0], mode);
+		if (ret)
+			result = ret;
+
 		/* Separate each group with empty line. */
 		if (mode & MODE_SHOW_HEADERS && i != argc-1)
 			printf("\n");
@@ -190,5 +300,5 @@ int main(int argc, char *argv[])
 
 err:
 	free(names);
-	return ret;
+	return result;
 }