From: Kien Truong <duckientruong@gmail.com>
Date: Sun, 5 Apr 2015 23:46:22 +0000 (+0000)
Subject: Sort the cgroup memory settings before applying.
X-Git-Tag: lxc-1.0.8~64
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=16d90770c7a661a4164cd646792e66dbc824133d;p=thirdparty%2Flxc.git

Sort the cgroup memory settings before applying.

Add a function to sort the cgroup settings before applying.
Currently, the function will put memory.memsw.limit_in_bytes after
memory.limit_in_bytes setting so the container will start
regardless of the order specified in the input. Fix #453

Signed-off-by: Kien Truong <duckientruong@gmail.com>
---

diff --git a/src/lxc/cgfs.c b/src/lxc/cgfs.c
index a3adc37f6..8aedfe4ec 100644
--- a/src/lxc/cgfs.c
+++ b/src/lxc/cgfs.c
@@ -1888,12 +1888,15 @@ static int do_setup_cgroup_limits(struct cgfs_data *d,
 {
 	struct lxc_list *iterator;
 	struct lxc_cgroup *cg;
+	struct lxc_list *sorted_cgroup_settings;
 	int ret = -1;
 
 	if (lxc_list_empty(cgroup_settings))
 		return 0;
 
-	lxc_list_for_each(iterator, cgroup_settings) {
+	sorted_cgroup_settings = sort_cgroup_settings(cgroup_settings);
+
+	lxc_list_for_each(iterator, sorted_cgroup_settings) {
 		cg = iterator->elem;
 
 		if (do_devices == !strncmp("devices", cg->subsystem, 7)) {
@@ -1916,6 +1919,10 @@ static int do_setup_cgroup_limits(struct cgfs_data *d,
 	ret = 0;
 	INFO("cgroup has been setup");
 out:
+	lxc_list_for_each(iterator, sorted_cgroup_settings) {
+		lxc_list_del(iterator);
+		free(iterator);
+	}
 	return ret;
 }
 
diff --git a/src/lxc/cgmanager.c b/src/lxc/cgmanager.c
index ffbcae364..0d1b73f36 100644
--- a/src/lxc/cgmanager.c
+++ b/src/lxc/cgmanager.c
@@ -1335,6 +1335,7 @@ static bool cgm_setup_limits(void *hdata, struct lxc_list *cgroup_settings, bool
 	struct lxc_list *iterator;
 	struct lxc_cgroup *cg;
 	bool ret = false;
+	struct lxc_list *sorted_cgroup_settings;
 
 	if (lxc_list_empty(cgroup_settings))
 		return true;
@@ -1347,7 +1348,9 @@ static bool cgm_setup_limits(void *hdata, struct lxc_list *cgroup_settings, bool
 		return false;
 	}
 
-	lxc_list_for_each(iterator, cgroup_settings) {
+	sorted_cgroup_settings = sort_cgroup_settings(cgroup_settings);
+
+	lxc_list_for_each(iterator, sorted_cgroup_settings) {
 		char controller[100], *p;
 		cg = iterator->elem;
 		if (do_devices != !strncmp("devices", cg->subsystem, 7))
@@ -1375,6 +1378,10 @@ static bool cgm_setup_limits(void *hdata, struct lxc_list *cgroup_settings, bool
 	ret = true;
 	INFO("cgroup limits have been setup");
 out:
+	lxc_list_for_each(iterator, sorted_cgroup_settings) {
+		lxc_list_del(iterator);
+		free(iterator);
+	}
 	cgm_dbus_disconnect();
 	return ret;
 }
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 38473f66d..39756a536 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -4829,3 +4829,38 @@ void suggest_default_idmap(void)
 	free(gname);
 	free(uname);
 }
+
+/*
+ * Return the list of cgroup_settings sorted according to the following rules
+ * 1. Put memory.limit_in_bytes before memory.memsw.limit_in_bytes
+ */
+struct lxc_list *sort_cgroup_settings(struct lxc_list* cgroup_settings)
+{
+	struct lxc_list *result;
+	struct lxc_list *memsw_limit = NULL;
+	struct lxc_list *it = NULL;
+	struct lxc_cgroup *cg = NULL;
+	struct lxc_list *item = NULL;
+
+	result = malloc(sizeof(*result));
+	lxc_list_init(result);
+
+	/*Iterate over the cgroup settings and copy them to the output list*/
+	lxc_list_for_each(it, cgroup_settings) {
+		item = malloc(sizeof(*item));
+		item->elem = it->elem;
+		cg = it->elem;
+		if (strcmp(cg->subsystem, "memory.memsw.limit_in_bytes") == 0) {
+			/* Store the memsw_limit location */
+			memsw_limit = item;
+		} else if (strcmp(cg->subsystem, "memory.limit_in_bytes") == 0 && memsw_limit != NULL) {
+			/* lxc.cgroup.memory.memsw.limit_in_bytes is found before 
+			 * lxc.cgroup.memory.limit_in_bytes, swap these two items */
+			item->elem = memsw_limit->elem;
+			memsw_limit->elem = it->elem;
+		}
+		lxc_list_add_tail(result, item);
+	}
+
+	return result;
+}
diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index 341612437..ac2b58ca8 100644
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -401,4 +401,5 @@ extern int parse_mntopts(const char *mntopts, unsigned long *mntflags,
 extern void tmp_proc_unmount(struct lxc_conf *lxc_conf);
 void remount_all_slave(void);
 extern void suggest_default_idmap(void);
+struct lxc_list *sort_cgroup_settings(struct lxc_list* cgroup_settings);
 #endif