cgfsng: add cgfsng_monitor_create()

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

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index bf8ec4ddb3b097265a82856cafa2b7b577877224..b67655471421e64ee89645dc511b848b42078af7 100644 (file)
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -1193,7 +1193,24 @@ on_error:
        return bret;
 }
 
-static bool create_path_for_hierarchy(struct hierarchy *h, char *cgname)
+static bool monitor_create_path_for_hierarchy(struct hierarchy *h, char *cgname)
+{
+       int ret;
+
+       h->monitor_full_path = must_make_path(h->mountpoint, h->container_base_path, cgname, NULL);
+       if (dir_exists(h->monitor_full_path))
+               return true;
+
+       ret = mkdir_p(h->monitor_full_path, 0755);
+       if (ret < 0) {
+               ERROR("Failed to create cgroup \"%s\"", h->monitor_full_path);
+               return false;
+       }
+
+       return cg_unified_create_cgroup(h, cgname);
+}
+
+static bool container_create_path_for_hierarchy(struct hierarchy *h, char *cgname)
 {
        int ret;
 
@@ -1217,16 +1234,62 @@ static bool create_path_for_hierarchy(struct hierarchy *h, char *cgname)
        return cg_unified_create_cgroup(h, cgname);
 }
 
-static void remove_path_for_hierarchy(struct hierarchy *h, char *cgname)
+static void remove_path_for_hierarchy(struct hierarchy *h, char *cgname, bool monitor)
 {
        int ret;
+       char *full_path;
+
+       if (monitor)
+               full_path = h->monitor_full_path;
+       else
+               full_path = h->container_full_path;
 
-       ret = rmdir(h->container_full_path);
+       ret = rmdir(full_path);
        if (ret < 0)
-               SYSERROR("Failed to rmdir(\"%s\") from failed creation attempt", h->container_full_path);
+               SYSERROR("Failed to rmdir(\"%s\") from failed creation attempt", full_path);
+
+       free(full_path);
+
+       if (monitor)
+               h->monitor_full_path = NULL;
+       else
+               h->container_full_path = NULL;
+}
+
+static inline bool cgfsng_monitor_create(struct cgroup_ops *ops,
+                                        struct lxc_handler *handler)
+{
+       char *monitor_cgroup;
+       bool bret = false;
+       struct lxc_conf *conf = handler->conf;
+
+       if (!conf)
+               return bret;
 
-       free(h->container_full_path);
-       h->container_full_path = NULL;
+       if (conf->cgroup_meta.dir)
+               monitor_cgroup = lxc_string_join("/", (const char *[]){conf->cgroup_meta.dir, ops->monitor_pattern, handler->name, NULL}, false);
+       else
+               monitor_cgroup = must_make_path(ops->monitor_pattern, handler->name, NULL);
+       if (!monitor_cgroup)
+               return bret;
+
+       for (int i = 0; ops->hierarchies[i]; i++) {
+               if (!monitor_create_path_for_hierarchy(ops->hierarchies[i], monitor_cgroup)) {
+                       ERROR("Failed to create cgroup \"%s\"", ops->hierarchies[i]->monitor_full_path);
+                       free(ops->hierarchies[i]->container_full_path);
+                       ops->hierarchies[i]->container_full_path = NULL;
+                       for (int j = 0; j < i; j++)
+                               remove_path_for_hierarchy(ops->hierarchies[j], monitor_cgroup, true);
+                       goto on_error;
+               }
+       }
+
+       bret = true;
+
+on_error:
+       free(monitor_cgroup);
+
+       return bret;
 }
 
 /* Try to create the same cgroup in all hierarchies. Start with cgroup_pattern;
@@ -1286,13 +1349,12 @@ again:
        }
 
        for (i = 0; ops->hierarchies[i]; i++) {
-               if (!create_path_for_hierarchy(ops->hierarchies[i], container_cgroup)) {
-                       int j;
+               if (!container_create_path_for_hierarchy(ops->hierarchies[i], container_cgroup)) {
                        ERROR("Failed to create cgroup \"%s\"", ops->hierarchies[i]->container_full_path);
                        free(ops->hierarchies[i]->container_full_path);
                        ops->hierarchies[i]->container_full_path = NULL;
-                       for (j = 0; j < i; j++)
-                               remove_path_for_hierarchy(ops->hierarchies[j], container_cgroup);
+                       for (int j = 0; j < i; j++)
+                               remove_path_for_hierarchy(ops->hierarchies[j], container_cgroup, false);
                        idx++;
                        goto again;
                }
@@ -2593,6 +2655,7 @@ struct cgroup_ops *cgfsng_ops_init(struct lxc_conf *conf)
 
        cgfsng_ops->data_init = cgfsng_data_init;
        cgfsng_ops->destroy = cgfsng_destroy;
+       cgfsng_ops->monitor_create = cgfsng_monitor_create;
        cgfsng_ops->payload_create = cgfsng_payload_create;
        cgfsng_ops->payload_enter = cgfsng_payload_enter;
        cgfsng_ops->escape = cgfsng_escape;

diff --git a/src/lxc/start.c b/src/lxc/start.c
index 02310635c8c2fc14b9ef664c25f1367b9edd4c97..55eee070f3a208203b28e32f6c320fc66e705eb6 100644 (file)
--- a/src/lxc/start.c
+++ b/src/lxc/start.c
@@ -1949,6 +1949,7 @@ int __lxc_start(const char *name, struct lxc_handler *handler,
 {
        int ret, status;
        struct lxc_conf *conf = handler->conf;
+       struct cgroup_ops *cgroup_ops;
 
        ret = lxc_init(name, handler);
        if (ret < 0) {
@@ -1958,12 +1959,18 @@ int __lxc_start(const char *name, struct lxc_handler *handler,
        handler->ops = ops;
        handler->data = data;
        handler->daemonize = daemonize;
+       cgroup_ops = handler->cgroup_ops;
 
        if (!attach_block_device(handler->conf)) {
                ERROR("Failed to attach block device");
                goto out_fini_nonet;
        }
 
+       if (!cgroup_ops->monitor_create(cgroup_ops, handler)) {
+               ERROR("Failed to create monitor cgroup");
+               goto out_fini_nonet;
+       }
+
        if (geteuid() == 0 && !lxc_list_empty(&conf->id_map)) {
                /* If the backing store is a device, mount it here and now. */
                if (rootfs_is_blockdev(conf)) {