When creating a cgroup, detect whether cgroup.clone_children
exists.  If not, then manually copy the parent's cpuset.cpus
and cpuset.mems values.

Signed-off-by: Serge Hallyn <[email protected]>
---
 src/lxc/cgroup.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/src/lxc/cgroup.c b/src/lxc/cgroup.c
index 4482b32..49f1ba1 100644
--- a/src/lxc/cgroup.c
+++ b/src/lxc/cgroup.c
@@ -74,6 +74,7 @@ static int do_setup_cgroup_limits(struct lxc_handler *h, 
struct lxc_list *cgroup
 static int cgroup_recursive_task_count(const char *cgroup_path);
 static int count_lines(const char *fn);
 static int handle_cgroup_settings(struct cgroup_mount_point *mp, char 
*cgroup_path);
+static void setup_cpuset_if_needed(char **subsystems, char *path);
 
 static struct cgroup_ops cgfs_ops;
 struct cgroup_ops *active_cg_ops = &cgfs_ops;
@@ -723,6 +724,71 @@ static char *cgroup_rename_nsgroup(const char *mountpath, 
const char *oldname, p
        return newname;
 }
 
+static long get_value(const char *dir, const char *file)
+{
+       FILE *f;
+       char path[MAXPATHLEN];
+       int ret, retv;
+
+       retv = snprintf(path, MAXPATHLEN, "%s/%s", dir, file);
+       if (retv < 0 || retv >= MAXPATHLEN)
+               return 0;
+       f = fopen(path, "r");
+       ret = fscanf(f, "%d", &retv);
+       fclose(f);
+       if (ret != 1)
+               return 0;
+       return retv;
+}
+
+static void set_value(const char *dir, const char *file, long v)
+{
+       FILE *f;
+       char path[MAXPATHLEN];
+       int retv;
+
+       retv = snprintf(path, MAXPATHLEN, "%s/%s", dir, file);
+       if (retv < 0 || retv >= MAXPATHLEN)
+               return;
+       f = fopen(path, "w");
+       fprintf(f, "%ld\n", v);
+       fclose(f);
+}
+
+static bool file_exists(const char *dir, const char *file)
+{
+       char path[MAXPATHLEN];
+       struct stat sb;
+       int ret;
+
+       ret = snprintf(path, MAXPATHLEN, "%s/%s", dir, file);
+       if (ret < 0 || ret >= MAXPATHLEN)
+               return true;
+       ret = stat(path, &sb);
+       return ret == 0;
+}
+
+static void setup_cpuset_if_needed(char **subsystems, char *path)
+{
+       char *parentpath, *p;
+       long v;
+       
+       if (!lxc_string_in_array("cpuset", (const char **) subsystems))
+               return;
+       if (file_exists(path, "cgroup.clone_children"))
+               return;
+       parentpath = strdup(path);
+       if (!parentpath)
+               return;
+       if ((p = rindex(parentpath, '/')))
+               *p = '\0';
+       v = get_value(parentpath, "cpuset.mems");
+       set_value(path, "cpuset.mems", v);
+       v = get_value(parentpath, "cpuset.cpus");
+       set_value(path, "cpuset.cpus", v);
+       free(parentpath);
+}
+
 /* create a new cgroup */
 struct cgroup_process_info *lxc_cgroupfs_create(const char *name, const char 
*path_pattern, struct cgroup_meta_data *meta_data, const char *sub_pattern)
 {
@@ -898,6 +964,8 @@ struct cgroup_process_info *lxc_cgroupfs_create(const char 
*name, const char *pa
                                if (r < 0)
                                        goto cleanup_from_error;
                                
info_ptr->created_paths[info_ptr->created_paths_count++] = current_entire_path;
+                               
setup_cpuset_if_needed(info_ptr->hierarchy->subsystems,
+                                               current_entire_path);
                        } else {
                                /* if we didn't create the cgroup, then we have 
to make sure that
                                 * further cgroups will be created properly
@@ -2039,8 +2107,12 @@ static int handle_cgroup_settings(struct 
cgroup_mount_point *mp,
         */
        if (lxc_string_in_array("cpuset", (const char 
**)mp->hierarchy->subsystems)) {
                char *cc_path = cgroup_to_absolute_path(mp, cgroup_path, 
"/cgroup.clone_children");
+               struct stat sb;
+
                if (!cc_path)
                        return -1;
+               if (stat(cc_path, &sb) != 0 && errno == ENOENT)
+                       return 0;
                r = lxc_read_from_file(cc_path, buf, 1);
                if (r == 1 && buf[0] == '1') {
                        free(cc_path);
-- 
1.8.5.3

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