Do dmsetup remove device in rollback

Without this change, the final unmount will timeout after the
rollbacks are called when the partitioning fails due to a user error.

dmsetup remove is called both for partition and LVM volume devices.

Change-Id: I99679ea00338d4018a95d4da9b21685161cd5049

diskimage_builder/block_device/level1/lvm.py

@@ -20,6 +20,7 @@ from diskimage_builder.block_device.plugin import NodeBase
 from diskimage_builder.block_device.plugin import PluginBase
 from diskimage_builder.block_device.utils import exec_sudo
 from diskimage_builder.block_device.utils import parse_abs_size_spec
+from diskimage_builder.block_device.utils import remove_device
 
 PHYSICAL_EXTENT_BYTES = parse_abs_size_spec('4MiB')
 
@@ -211,13 +212,15 @@ class LvsNode(NodeBase):
         exec_sudo(cmd)
 
         # save state
+        device_name = '%s-%s' % (self.base, self.name)
         self.state['blockdev'][self.name] = {
             'vgs': self.base,
             'size': self.size,
             'extents': self.extents,
             'opts': self.options,
-            'device': '/dev/mapper/%s-%s' % (self.base, self.name)
+            'device': '/dev/mapper/%s' % device_name
         }
+        self.add_rollback(remove_device, device_name)
 
     def _umount(self):
         exec_sudo(['lvchange', '-an',

diskimage_builder/block_device/level1/partitioning.py

@@ -23,6 +23,7 @@ from diskimage_builder.block_device.plugin import PluginBase
 from diskimage_builder.block_device.utils import exec_sudo
 from diskimage_builder.block_device.utils import parse_abs_size_spec
 from diskimage_builder.block_device.utils import parse_rel_size_spec
+from diskimage_builder.block_device.utils import remove_device
 
 
 logger = logging.getLogger(__name__)
@@ -117,10 +118,11 @@ class Partitioning(PluginBase):
                 # below once we're done.  So the device this partition
                 # will be seen at becomes "/dev/mapper/loop0pX"
                 assert self.device_path[:5] == "/dev/"
-                partition_device_name = "/dev/mapper/%sp%d" % \
+                device_name = "%sp%d" % (self.device_path[5:], part_no)
-                                        (self.device_path[5:], part_no)
+                device_path = "/dev/mapper/%s" % device_name
                 self.state['blockdev'][part_name] \
-                    = {'device': partition_device_name}
+                    = {'device': device_path}
+                part_cfg.add_rollback(remove_device, device_name)
 
     def _create_gpt(self):
         """Create partitions with GPT"""
@@ -158,14 +160,16 @@ class Partitioning(PluginBase):
             # below once we're done.  So the device this partition
             # will be seen at becomes "/dev/mapper/loop0pX"
             assert self.device_path[:5] == "/dev/"
-            device_name = "/dev/mapper/%sp%d" % (self.device_path[5:], pnum)
+            device_name = "%sp%d" % (self.device_path[5:], pnum)
+            device_path = "/dev/mapper/%s" % device_name
             self.state['blockdev'][p.get_name()] \
-                = {'device': device_name}
+                = {'device': device_path}
 
             disk_free = disk_free - size
             pnum = pnum + 1
             logger.debug("Partition %s added, %s remaining in disk",
                          pnum, disk_free)
+            p.add_rollback(remove_device, device_name)
 
         logger.debug("cmd: %s", ' '.join(cmd))
         exec_sudo(cmd)

diskimage_builder/block_device/utils.py

@@ -143,3 +143,20 @@ def exec_sudo(cmd):
         raise e
 
     return out
+
+
+def remove_device(device_name):
+    """Attempt to remove a device-mapper device
+
+    Convenience rollback function to attempt to delete a device,
+    logging a warning if the delete fails.
+
+    :param device_name: Name of device to run dmsetup remove on
+    """
+    logger.debug('Removing device %s', device_name)
+    try:
+        exec_sudo(["dmsetup", "remove", device_name])
+    except BlockDeviceSetupException as e:
+        # Do not raise an error - maybe other cleanup methods
+        # can at least do some more work.
+        logger.warning("Removing device failed (%s)", e.returncode)