Switch to mapper device name if pvs returns the wrong one.

library/system/lvg

@@ -67,7 +67,7 @@ EXAMPLES = '''
 # Create a volume group on top of /dev/sda1 with physical extent size = 32MB.
 - lvg:  vg=vg.services pvs=/dev/sda1 pesize=32
 
-# Create or resize a volume group on top of /dev/sdb1 and /dev/sdc5. 
+# Create or resize a volume group on top of /dev/sdb1 and /dev/sdc5.
 # If, for example, we already have VG vg.services on top of /dev/sdb1,
 # this VG will be extended by /dev/sdc5.  Or if vg.services was created on
 # top of /dev/sda5, we first extend it with /dev/sdb1 and /dev/sdc5,
@@ -89,10 +89,22 @@ def parse_vgs(data):
         })
     return vgs
 
-def parse_pvs(data):
+def find_mapper_device_name(module, dm_device):
+        dmsetup_cmd = module.get_bin_path('dmsetup', True)
+        mapper_prefix = '/dev/mapper/'
+        rc, dm_name, err = module.run_command("%s info -C --noheadings -o name %s" % (dmsetup_cmd, dm_device))
+        if rc != 0:
+            module.fail_json(msg="Failed executing dmsetup command.", rc=rc, err=err)
+        mapper_device = mapper_prefix + dm_name.rstrip()
+        return mapper_device
+
+def parse_pvs(module, data):
     pvs = []
+    dm_prefix = '/dev/dm-'
     for line in data.splitlines():
         parts = line.strip().split(';')
+        if parts[0].startswith(dm_prefix):
+            parts[0] = find_mapper_device_name(module, parts[0])
         pvs.append({
             'name': parts[0],
             'vg_name': parts[1],
@@ -125,7 +137,7 @@ def main():
         module.fail_json(msg="No physical volumes given.")
 
 
-    
+
     if state=='present':
         ### check given devices
         for test_dev in dev_list:
@@ -139,7 +151,7 @@ def main():
             module.fail_json(msg="Failed executing pvs command.",rc=rc, err=err)
 
         ### check pv for devices
-        pvs = parse_pvs(current_pvs)
+        pvs = parse_pvs(module, current_pvs)
         used_pvs = [ pv for pv in pvs if pv['name'] in dev_list and pv['vg_name'] and pv['vg_name'] != vg ]
         if used_pvs:
             module.fail_json(msg="Device %s is already in %s volume group."%(used_pvs[0]['name'],used_pvs[0]['vg_name']))