cgroups/cgfsng: rework cgfsng_monitor_destroy()

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

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index 8a6d6cba5b63c32522d8a3c8434b7ec5373a0375..2549ca628e2d166470452c714b9a0e539cf8dfe0 100644 (file)
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -1124,12 +1124,23 @@ __cgfsng_ops static void cgfsng_monitor_destroy(struct cgroup_ops *ops,
                                                struct lxc_handler *handler)
 {
        int len;
-       struct lxc_conf *conf = handler->conf;
        char pidstr[INTTYPE_TO_STRLEN(pid_t)];
+       struct lxc_conf *conf;
+
+       if (!ops)
+               log_error_errno(return, ENOENT, "Called with uninitialized cgroup operations");
 
        if (!ops->hierarchies)
                return;
 
+       if (!handler)
+               log_error_errno(return, EINVAL, "Called with uninitialized handler");
+
+       if (!handler->conf)
+               log_error_errno(return, EINVAL, "Called with uninitialized conf");
+
+       conf = handler->conf;
+
        len = snprintf(pidstr, sizeof(pidstr), "%d", handler->monitor_pid);
        if (len < 0 || (size_t)len >= sizeof(pidstr))
                return;
@@ -1164,16 +1175,15 @@ __cgfsng_ops static void cgfsng_monitor_destroy(struct cgroup_ops *ops,
                 * Make sure not to pass in the ro string literal PIVOT_CGROUP
                 * here.
                 */
-               if (!cg_legacy_handle_cpuset_hierarchy(h, pivot_cgroup)) {
-                       WARN("Failed to handle legacy cpuset controller");
-                       continue;
-               }
+               if (!cg_legacy_handle_cpuset_hierarchy(h, pivot_cgroup))
+                       log_warn_errno(continue,
+                                      errno, "Failed to handle legacy cpuset controller");
 
                ret = mkdir_p(pivot_path, 0755);
-               if (ret < 0 && errno != EEXIST) {
-                       SYSWARN("Failed to create cgroup \"%s\"\n", pivot_path);
-                       continue;
-               }
+               if (ret < 0 && errno != EEXIST)
+                       log_warn_errno(continue, errno,
+                                      "Failed to create cgroup \"%s\"\n",
+                                      pivot_path);
 
                if (chop)
                        *chop = '/';
@@ -1182,10 +1192,10 @@ __cgfsng_ops static void cgfsng_monitor_destroy(struct cgroup_ops *ops,
                 * cgroup.
                 */
                ret = lxc_write_to_file(pivot_path, pidstr, len, false, 0666);
-               if (ret != 0) {
-                       SYSWARN("Failed to move monitor %s to \"%s\"\n", pidstr, pivot_path);
-                       continue;
-               }
+               if (ret != 0)
+                       log_warn_errno(continue, errno,
+                                      "Failed to move monitor %s to \"%s\"\n",
+                                      pidstr, pivot_path);
 
                ret = recursive_destroy(h->monitor_full_path);
                if (ret < 0)