cgroups: add unified_cgroup_fd() helper

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
lxc · Feb 26, 2021 · 6870cd2 · 6870cd2
1 parent 579a0d4
commit 6870cd2
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diff --git a/src/lxc/cgroups/cgroup_utils.c b/src/lxc/cgroups/cgroup_utils.c
@@ -98,3 +98,16 @@ int unified_cgroup_hierarchy(void)
 
 	return 0;
 }
+
+int unified_cgroup_fd(int fd)
+{
+
+	int ret;
+	struct statfs fs;
+
+	ret = fstatfs(fd, &fs);
+	if (!ret && is_fs_type(&fs, CGROUP2_SUPER_MAGIC))
+		return true;
+
+	return false;
+}
diff --git a/src/lxc/cgroups/cgroup_utils.h b/src/lxc/cgroups/cgroup_utils.h
@@ -30,4 +30,6 @@ __hidden extern bool test_writeable_v2(char *mountpoint, char *path);
 
 __hidden extern int unified_cgroup_hierarchy(void);
 
+__hidden extern int unified_cgroup_fd(int fd);
+
 #endif /* __LXC_CGROUP_UTILS_H */