[CRIU] [PATCH p.haul] p.haul: fix error handling after successfull restore at target host

[Nikita Spiridonov]

Since we can't fail migration after htype was restored (or started for
restart migration mode) at target host need to catch all exceptions
in source part of phaul during final cleanup. Phaul can ruin running
container without such exceptions handling.

Signed-off-by: Nikita Spiridonov <nspiridonov at virtuozzo.com>
---
 phaul/iters.py |   41 ++++++++++++++++++++++++-----------------
 1 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/phaul/iters.py b/phaul/iters.py
index b8b06cf..301c04e 100644
--- a/phaul/iters.py
+++ b/phaul/iters.py
@@ -220,31 +220,35 @@ class phaul_iter_worker:
 			# Handle final FS and images sync on frozen htype
 			logging.info("Final FS and images sync")
 			fsstats = self.fs.stop_migration()
-
 			self.img.sync_imgs_to_target(self.target_host, self.htype,
 				self.connection.mem_sk)
 
 			# Restore htype on target
 			logging.info("Asking target host to restore")
 			self.target_host.restore_from_images()
-			logging.info("Restored on target host")
+
 		except:
 			self.htype.migration_fail(self.fs)
 			raise
 
-		# Ack previous dump request to terminate all frozen tasks
-		resp = self.criu_connection.ack_notify()
-		if not resp.success:
-			logging.warning("Bad notification from target host")
+		# Restored on target, can't fail starting from this point
+		try:
+			# Ack previous dump request to terminate all frozen tasks
+			resp = self.criu_connection.ack_notify()
+			if not resp.success:
+				logging.warning("Bad notification from target host")
 
-		dstats = criu_api.criu_get_dstats(self.img)
-		migration_stats.handle_iteration(dstats, fsstats)
+			dstats = criu_api.criu_get_dstats(self.img)
+			migration_stats.handle_iteration(dstats, fsstats)
 
-		logging.info("Migration succeeded")
-		self.htype.migration_complete(self.fs, self.target_host)
-		migration_stats.handle_stop(self)
-		self.img.close()
-		self.criu_connection.close()
+			logging.info("Migration succeeded")
+			self.htype.migration_complete(self.fs, self.target_host)
+			migration_stats.handle_stop(self)
+			self.img.close()
+			self.criu_connection.close()
+
+		except Exception as e:
+			logging.warning("Exception during final cleanup: %s", e)
 
 	def __start_restart_migration(self):
 		"""
@@ -292,16 +296,19 @@ class phaul_iter_worker:
 			# Start htype on target
 			logging.info("Asking target host to start")
 			self.target_host.start_htype()
-			logging.info("Started on target host")
 
 		except:
 			self.htype.migration_fail(self.fs)
 			self.htype.start()
 			raise
 
-		logging.info("Migration succeeded")
-		self.htype.migration_complete(self.fs, self.target_host)
-		migration_stats.handle_stop()
+		# Started on target, can't fail starting from this point
+		try:
+			logging.info("Migration succeeded")
+			self.htype.migration_complete(self.fs, self.target_host)
+			migration_stats.handle_stop()
+		except Exception as e:
+			logging.warning("Exception during final cleanup: %s", e)
 
 	def __check_live_iter_progress(self, index, dstats, prev_dstats):
 
-- 
1.7.1