fix(tapdisk-pause): ensure LINSTOR VHD chain is available

Signed-off-by: Ronan Abhamon <ronan.abhamon@vates.fr>

drivers/LinstorSR.py

@@ -1830,7 +1830,7 @@ def attach(self, sr_uuid, vdi_uuid):
             return self._attach_using_http_nbd()
 
         # Ensure we have a path...
-        self._create_chain_paths(self.uuid)
+        self.sr._vhdutil.create_chain_paths(self.uuid)
 
         self.attached = True
         return VDI.VDI.attach(self, self.sr.uuid, self.uuid)
@@ -2357,7 +2357,7 @@ def _snapshot(self, snap_type, cbtlog=None, cbt_consistency=None):
             raise xs_errors.XenError('SnapshotChainTooLong')
 
         # Ensure we have a valid path if we don't have a local diskful.
-        self._create_chain_paths(self.uuid)
+        self.sr._vhdutil.create_chain_paths(self.uuid)
 
         volume_path = self.path
         if not util.pathexists(volume_path):
@@ -2820,37 +2820,6 @@ def _detach_using_http_nbd(self):
         self._kill_persistent_nbd_server(volume_name)
         self._kill_persistent_http_server(volume_name)
 
-    def _create_chain_paths(self, vdi_uuid):
-        # OPTIMIZE: Add a limit_to_first_allocated_block param to limit vhdutil calls.
-        # Useful for the snapshot code algorithm.
-
-        while vdi_uuid:
-            path = self._linstor.get_device_path(vdi_uuid)
-            if not util.pathexists(path):
-                raise xs_errors.XenError(
-                    'VDIUnavailable', opterr='Could not find: {}'.format(path)
-                )
-
-            # Diskless path can be created on the fly, ensure we can open it.
-            def check_volume_usable():
-                while True:
-                    try:
-                        with open(path, 'r+'):
-                            pass
-                    except IOError as e:
-                        if e.errno == errno.ENODATA:
-                            time.sleep(2)
-                            continue
-                        if e.errno == errno.EROFS:
-                            util.SMlog('Volume not attachable because RO. Openers: {}'.format(
-                                self.sr._linstor.get_volume_openers(vdi_uuid)
-                            ))
-                        raise
-                    break
-            util.retry(check_volume_usable, 15, 2)
-
-            vdi_uuid = self.sr._vhdutil.get_vhd_info(vdi_uuid).parentUuid
-
 # ------------------------------------------------------------------------------
 
 

drivers/linstorvhdutil.py

@@ -21,6 +21,7 @@
 import errno
 import json
 import socket
+import time
 import util
 import vhdutil
 import xs_errors
@@ -141,6 +142,43 @@ def __init__(self, session, linstor):
         self._session = session
         self._linstor = linstor
 
+    def create_chain_paths(self, vdi_uuid):
+        # OPTIMIZE: Add a limit_to_first_allocated_block param to limit vhdutil calls.
+        # Useful for the snapshot code algorithm.
+
+        leaf_vdi_path = self._linstor.get_device_path(vdi_uuid)
+        path = leaf_vdi_path
+        while True:
+            if not util.pathexists(path):
+                raise xs_errors.XenError(
+                    'VDIUnavailable', opterr='Could not find: {}'.format(path)
+                )
+
+            # Diskless path can be created on the fly, ensure we can open it.
+            def check_volume_usable():
+                while True:
+                    try:
+                        with open(path, 'r+'):
+                            pass
+                    except IOError as e:
+                        if e.errno == errno.ENODATA:
+                            time.sleep(2)
+                            continue
+                        if e.errno == errno.EROFS:
+                            util.SMlog('Volume not attachable because RO. Openers: {}'.format(
+                                self._linstor.get_volume_openers(vdi_uuid)
+                            ))
+                        raise
+                    break
+            util.retry(check_volume_usable, 15, 2)
+
+            vdi_uuid = self.get_vhd_info(vdi_uuid).parentUuid
+            if not vdi_uuid:
+                break
+            path = self._linstor.get_device_path(vdi_uuid)
+
+        return leaf_vdi_path
+
     # --------------------------------------------------------------------------
     # Getters: read locally and try on another host in case of failure.
     # --------------------------------------------------------------------------

drivers/tapdisk-pause

@@ -30,6 +30,7 @@ import vhdutil
 import lvmcache
 
 try:
+    from linstorvhdutil import LinstorVhdUtil
     from linstorvolumemanager import get_controller_uri, LinstorVolumeManager
     LINSTOR_AVAILABLE = True
 except ImportError:
@@ -162,11 +163,12 @@ class Tapdisk:
             dconf = session.xenapi.PBD.get_device_config(pbd)
             group_name = dconf['group-name']
 
-            device_path = LinstorVolumeManager(
+            linstor = LinstorVolumeManager(
                 get_controller_uri(),
                 group_name,
                 logger=util.SMlog
-            ).get_device_path(self.vdi_uuid)
+            )
+            device_path = LinstorVhdUtil(session, linstor).create_chain_paths(self.vdi_uuid)
 
             if realpath != device_path:
                 util.SMlog(