address review

README.rst

@@ -117,6 +117,10 @@ Several methods have been added which are not present in psutil, but will provid
   - VirtualizationSystem  (ex: "LXC")
   - VirtualizationRole    (ex: "guest"/"host")
 
+- IOCounters
+
+  - Label (linux only)    The registered [device mapper name](https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-block-dm)
+
 - cpu/CPUInfo()  (linux, freebsd)
 
   - CPU          (ex: 0, 1, ...)

disk/disk_linux.go

@@ -415,7 +415,7 @@ func GetDiskSerialNumberWithContext(ctx context.Context, name string) string {
 // See https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-block-dm
 func GetLabel(name string) string {
 	// Try label based on devicemapper name
-	dmname_filename := fmt.Sprintf("/sys/block/%s/dm/name", name)
+	dmname_filename := common.HostSys(fmt.Sprintf("block/%s/dm/name", name))
 
 	if !common.PathExists(dmname_filename) {
 		return ""