(rebase) Add support for /sys/devices/system/node and subfiles

README.md

@@ -17,6 +17,11 @@ such as:
 /proc/uptime
 /proc/slabinfo
 /sys/devices/system/cpu/online
+/sys/devices/system/node
+/sys/devices/system/node/online
+/sys/devices/system/node/has_cpu
+/sys/devices/system/node/has_memory
+/sys/devices/system/node/has_normal_memory
 ```
 
 are container aware such that the values displayed (e.g. in `/proc/uptime`)

src/bindings.h

@@ -69,6 +69,22 @@ enum lxcfs_virt_t {
 
 	LXC_TYPE_SYS_DEVICES_SYSTEM_CPU_ONLINE,
 #define LXC_TYPE_SYS_DEVICES_SYSTEM_CPU_ONLINE_PATH "/sys/devices/system/cpu/online"
+
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE,
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_SUBDIR,
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_SUBFILE,
+
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_ONLINE,
+#define LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_ONLINE_PATH "/sys/devices/system/node/online"
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_HAS_CPU,
+#define LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_HAS_CPU_PATH "/sys/devices/system/node/has_cpu"
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_HAS_MEMORY,
+#define LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_HAS_MEMORY_PATH "/sys/devices/system/node/has_memory"
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_HAS_NORMAL_MEMORY,
+#define LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_HAS_NORMAL_MEMORY_PATH "/sys/devices/system/node/has_normal_memory"
+
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_NODEX_CPULIST,
+	LXC_TYPE_SYS_DEVICES_SYSTEM_NODE_NODEX_CPUMAP,
 	LXC_TYPE_MAX,
 };
 

src/cgroups/cgfsng.c

@@ -683,6 +683,22 @@ static char *readat_cpuset(int cgroup_fd)
 	return NULL;
 }
 
+static char *readat_cpuset_mems(int cgroup_fd)
+{
+	__do_free char *val = NULL;
+
+	val = readat_file(cgroup_fd, "cpuset.mems");
+	if (val && strcmp(val, "") != 0)
+		return move_ptr(val);
+
+	free_disarm(val);
+	val = readat_file(cgroup_fd, "cpuset.mems.effective");
+	if (val && strcmp(val, "") != 0)
+		return move_ptr(val);
+
+	return NULL;
+}
+
 static int cgfsng_get_cpuset_cpus(struct cgroup_ops *ops, const char *cgroup,
 				  char **value)
 {
@@ -736,6 +752,59 @@ static int cgfsng_get_cpuset_cpus(struct cgroup_ops *ops, const char *cgroup,
 	return -1;
 }
 
+static int cgfsng_get_cpuset_mems(struct cgroup_ops *ops, const char *cgroup,
+				  char **value)
+{
+	__do_close int cgroup_fd = -EBADF;
+	__do_free char *path = NULL;
+	char *v;
+	struct hierarchy *h;
+	int ret;
+
+	h = ops->get_hierarchy(ops, "cpuset");
+	if (!h)
+		return -1;
+
+	if (!is_unified_hierarchy(h))
+		ret = CGROUP_SUPER_MAGIC;
+	else
+		ret = CGROUP2_SUPER_MAGIC;
+
+	*value = NULL;
+	path = must_make_path_relative(cgroup, NULL);
+	cgroup_fd = openat_safe(h->fd, path);
+	if (cgroup_fd < 0)
+		return -1;
+
+	v = readat_cpuset_mems(cgroup_fd);
+	if (v) {
+		*value = v;
+		return ret;
+	}
+
+	/*
+	 * cpuset.cpus and cpuset.cpus.effective are empty so we need to look
+	 * the nearest ancestor with a non-empty cpuset.cpus{.effective} file.
+	 */
+	for (;;) {
+		int fd;
+
+		fd = openat_safe(cgroup_fd, "../");
+		if (fd < 0 || !is_cgroup_fd(fd))
+			return -1;
+
+		close_prot_errno_replace(cgroup_fd, fd);
+
+		v = readat_cpuset_mems(fd);
+		if (v) {
+			*value = v;
+			return ret;
+		}
+	}
+
+	return -1;
+}
+
 static int cgfsng_get_io(struct cgroup_ops *ops, const char *cgroup,
 			 const char *file, char **value)
 {
@@ -1023,6 +1092,7 @@ struct cgroup_ops *cgfsng_ops_init(void)
 	/* cpuset */
 	cgfsng_ops->get_cpuset_cpus = cgfsng_get_cpuset_cpus;
 	cgfsng_ops->can_use_cpuview = cgfsng_can_use_cpuview;
+	cgfsng_ops->get_cpuset_mems = cgfsng_get_cpuset_mems;
 
 	/* blkio */
 	cgfsng_ops->get_io_service_bytes	= cgfsng_get_io_service_bytes;

src/cgroups/cgroup.c

@@ -121,3 +121,19 @@ char *get_cpuset(const char *cg)
 
 	return value;
 }
+
+/*
+ * Read the cpuset.mems for cg
+ * Return the answer in a newly allocated string which must be freed
+ */
+char *get_cpuset_mems(const char *cg)
+{
+	char *value = NULL;
+	int ret;
+
+	ret = cgroup_ops->get_cpuset_mems(cgroup_ops, cg, &value);
+	if (ret < 0)
+		return NULL;
+
+	return value;
+}

src/cgroups/cgroup.h

@@ -154,6 +154,8 @@ struct cgroup_ops {
 	int (*get_cpuset_cpus)(struct cgroup_ops *ops, const char *cgroup,
 			       char **value);
 	bool (*can_use_cpuview)(struct cgroup_ops *ops);
+	int (*get_cpuset_mems)(struct cgroup_ops *ops, const char *cgroup,
+			       char **value);
 
 	/* io */
 	int (*get_io_service_bytes)(struct cgroup_ops *ops, const char *cgroup,
@@ -211,5 +213,6 @@ static inline int get_cgroup_fd(const char *controller)
 extern char *get_pid_cgroup(pid_t pid, const char *contrl);
 
 extern char *get_cpuset(const char *cg);
+extern char *get_cpuset_mems(const char *cg);
 
 #endif