cgroups: handle limits on the unified hierarchy

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/cgroups/cgfs.c

@@ -2525,14 +2525,14 @@ static bool cgfs_unfreeze(void *hdata)
 	return ret == 0;
 }
 
-static bool cgroupfs_setup_limits(void *hdata, struct lxc_list *cgroup_conf,
+static bool cgroupfs_setup_limits(void *hdata, struct lxc_conf *conf,
 				  bool with_devices)
 {
 	struct cgfs_data *d = hdata;
 
 	if (!d)
 		return false;
-	return do_setup_cgroup_limits(d, cgroup_conf, with_devices) == 0;
+	return do_setup_cgroup_limits(d, &conf->cgroup, with_devices) == 0;
 }
 
 static bool lxc_cgroupfs_attach(const char *name, const char *lxcpath, pid_t pid)

src/lxc/cgroups/cgfsng.c

@@ -2161,6 +2161,7 @@ static bool cgfsng_escape()
 	return true;
 }
 
+/* TODO: handle the unified cgroup hierarchy */
 static int cgfsng_num_hierarchies(void)
 {
 	int i;
@@ -2171,15 +2172,15 @@ static int cgfsng_num_hierarchies(void)
 	return i;
 }
 
+/* TODO: handle the unified cgroup hierarchy */
 static bool cgfsng_get_hierarchies(int n, char ***out)
 {
 	int i;
 
 	/* sanity check n */
-	for (i = 0; i < n; i++) {
+	for (i = 0; i < n; i++)
 		if (!hierarchies[i])
 			return false;
-	}
 
 	*out = hierarchies[i]->controllers;
 
@@ -2541,8 +2542,9 @@ static int lxc_cgroup_set_data(const char *filename, const char *value, struct c
 	return ret;
 }
 
-static bool cgfsng_setup_limits(void *hdata, struct lxc_list *cgroup_settings,
+static bool __cgfsng_setup_limits_legacy(void *hdata,
-				  bool do_devices)
+					 struct lxc_list *cgroup_settings,
+					 bool do_devices)
 {
 	struct cgfsng_handler_data *d = hdata;
 	struct lxc_list *iterator, *sorted_cgroup_settings, *next;
@@ -2553,9 +2555,8 @@ static bool cgfsng_setup_limits(void *hdata, struct lxc_list *cgroup_settings,
 		return true;
 
 	sorted_cgroup_settings = sort_cgroup_settings(cgroup_settings);
-	if (!sorted_cgroup_settings) {
+	if (!sorted_cgroup_settings)
 		return false;
-	}
 
 	lxc_list_for_each(iterator, sorted_cgroup_settings) {
 		cg = iterator->elem;
@@ -2576,7 +2577,7 @@ static bool cgfsng_setup_limits(void *hdata, struct lxc_list *cgroup_settings,
 	}
 
 	ret = true;
-	INFO("cgroup has been setup");
+	INFO("Limits for the legacy cgroup hierarchies have been setup");
 out:
 	lxc_list_for_each_safe(iterator, sorted_cgroup_settings, next) {
 		lxc_list_del(iterator);
@@ -2586,6 +2587,49 @@ out:
 	return ret;
 }
 
+static bool __cgfsng_setup_limits_unified(void *hdata,
+					  struct lxc_list *cgroup_settings)
+{
+	struct lxc_list *iterator;
+	struct hierarchy *h = unified;
+
+	if (lxc_list_empty(cgroup_settings))
+		return true;
+
+	if (!h)
+		return false;
+
+	lxc_list_for_each(iterator, cgroup_settings) {
+		int ret;
+		char *fullpath;
+		struct lxc_cgroup *cg = iterator->elem;
+
+		fullpath = must_make_path(h->fullcgpath, cg->subsystem, NULL);
+		ret = lxc_write_to_file(fullpath, cg->value, strlen(cg->value), false);
+		free(fullpath);
+		if (ret < 0) {
+			SYSERROR("Failed to set \"%s\" to \"%s\"", cg->subsystem, cg->value);
+			return false;
+		}
+		TRACE("Set \"%s\" to \"%s\"", cg->subsystem, cg->value);
+	}
+
+	INFO("Limits for the unified cgroup hierarchy have been setup");
+	return true;
+}
+
+static bool cgfsng_setup_limits(void *hdata, struct lxc_conf *conf,
+				bool do_devices)
+{
+	bool bret;
+
+	bret = __cgfsng_setup_limits_legacy(hdata, &conf->cgroup, do_devices);
+	if (!bret)
+		return false;
+
+	return __cgfsng_setup_limits_unified(hdata, &conf->cgroup2);
+}
+
 static struct cgroup_ops cgfsng_ops = {
 	.init = cgfsng_init,
 	.destroy = cgfsng_destroy,

src/lxc/cgroups/cgmanager.c

@@ -1479,11 +1479,12 @@ static bool cgm_unfreeze(void *hdata)
 	return ret;
 }
 
-static bool cgm_setup_limits(void *hdata, struct lxc_list *cgroup_settings, bool do_devices)
+static bool cgm_setup_limits(void *hdata, struct lxc_conf *conf, bool do_devices)
 {
 	struct cgm_data *d = hdata;
 	struct lxc_list *iterator, *sorted_cgroup_settings, *next;
 	struct lxc_cgroup *cg;
+	struct lxc_list *cgroup_settings = &conf->cgroup;
 	bool ret = false;
 
 	if (lxc_list_empty(cgroup_settings))

src/lxc/cgroups/cgroup.c

@@ -150,7 +150,7 @@ bool cgroup_setup_limits(struct lxc_handler *handler, bool with_devices)
 {
 	if (ops)
 		return ops->setup_limits(handler->cgroup_data,
-					 &handler->conf->cgroup, with_devices);
+					 handler->conf, with_devices);
 
 	return false;
 }

src/lxc/cgroups/cgroup.h

@@ -60,7 +60,7 @@ struct cgroup_ops {
 	int (*set)(const char *filename, const char *value, const char *name, const char *lxcpath);
 	int (*get)(const char *filename, char *value, size_t len, const char *name, const char *lxcpath);
 	bool (*unfreeze)(void *hdata);
-	bool (*setup_limits)(void *hdata, struct lxc_list *cgroup_conf, bool with_devices);
+	bool (*setup_limits)(void *hdata, struct lxc_conf *conf, bool with_devices);
 	bool (*chown)(void *hdata, struct lxc_conf *conf);
 	bool (*attach)(const char *name, const char *lxcpath, pid_t pid);
 	bool (*mount_cgroup)(void *hdata, const char *root, int type);
@@ -80,7 +80,8 @@ extern bool cgroup_enter(struct lxc_handler *handler);
 extern void cgroup_cleanup(struct lxc_handler *handler);
 extern bool cgroup_create_legacy(struct lxc_handler *handler);
 extern int cgroup_nrtasks(struct lxc_handler *handler);
-extern const char *cgroup_get_cgroup(struct lxc_handler *handler, const char *subsystem);
+extern const char *cgroup_get_cgroup(struct lxc_handler *handler,
+				     const char *subsystem);
 extern bool cgroup_escape();
 extern int cgroup_num_hierarchies();
 extern bool cgroup_get_hierarchies(int i, char ***out);