Add storage device WWN to facts for Linux (#16640)

World Wide Name (WWN) is unique identifier of device.
This patch adds this identifier to facts for Linux.

lib/ansible/module_utils/facts.py

@@ -1435,6 +1435,20 @@ class LinuxHardware(Hardware):
         except OSError:
             return
 
+        devs_wwn = {}
+        try:
+            devs_by_id = os.listdir("/dev/disk/by-id")
+        except OSError:
+            pass
+        else:
+            for link_name in devs_by_id:
+                if link_name.startswith("wwn-"):
+                    try:
+                        wwn_link = os.readlink(os.path.join("/dev/disk/by-id", link_name))
+                    except OSError:
+                        continue
+                    devs_wwn[os.path.basename(wwn_link)] = link_name[4:]
+
         for block in block_devs:
             virtual = 1
             sysfs_no_links = 0
@@ -1467,6 +1481,9 @@ class LinuxHardware(Hardware):
                               ]:
                 d[key] = get_file_content(sysdir + test)
 
+            if diskname in devs_wwn:
+                d['wwn'] = devs_wwn[diskname]
+
             d['partitions'] = {}
             for folder in os.listdir(sysdir):
                 m = re.search("(" + diskname + "\d+)", folder)