Revert "Adjust lock acquiring logic"

This reverts commit cbb9121a28.

Reason for revert: reverting as this caused issues in DC upgrade

Change-Id: Ie665b9c4e4d1280d7c8a0821cb7995c9374ce02f

sysinv/sysinv/sysinv/sysinv/agent/manager.py

@@ -34,6 +34,7 @@ Commands (from conductors) are received via RPC calls.
 """
 
 from __future__ import print_function
+import errno
 from eventlet.green import subprocess
 import fcntl
 import fileinput
@@ -582,7 +583,25 @@ class AgentManager(service.PeriodicService):
         """
         lock_file_fd = os.open(
             constants.NETWORK_CONFIG_LOCK_FILE, os.O_CREAT | os.O_RDONLY)
-        return utils.acquire_file_lock(lock_file_fd)
+        count = 1
+        delay = 5
+        max_count = 5
+        while count <= max_count:
+            try:
+                fcntl.flock(lock_file_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+                return lock_file_fd
+            except IOError as e:
+                # raise on unrelated IOErrors
+                if e.errno != errno.EAGAIN:
+                    raise
+                else:
+                    LOG.info("Could not acquire lock({}): {} ({}/{}), "
+                             "will retry".format(lock_file_fd, str(e),
+                                                 count, max_count))
+                    time.sleep(delay)
+                    count += 1
+        LOG.error("Failed to acquire lock (fd={})".format(lock_file_fd))
+        return 0
 
     def _release_network_config_lock(self, lockfd):
         """ Release the lock guarding apply_network_config.sh """

sysinv/sysinv/sysinv/sysinv/common/utils.py

@@ -1372,34 +1372,6 @@ def _get_cinder_device_info(dbapi, forihostid):
     return cinder_device, cinder_size_gib
 
 
-def acquire_file_lock(lockfd, max_retry=5, wait_interval=5):
-    """
-    This method is to acquire a lock for the given file descriptor to
-    avoid conflict with other processes trying accessing the same file.
-
-    :returns: fd of the lock, if successful. 0 on error.
-    """
-    count = 1
-    while count <= max_retry:
-        try:
-            fcntl.flock(lockfd, fcntl.LOCK_EX | fcntl.LOCK_NB)
-            LOG.debug("Successfully acquired lock (fd={})".format(lockfd))
-            return lockfd
-        except IOError as e:
-            # raise on unrelated IOErrors
-            if e.errno != errno.EAGAIN:
-                raise
-            else:
-                LOG.info("Could not acquire lock({}): {} ({}/{}), "
-                         "will retry".format(lockfd, str(e),
-                                             count, max_retry))
-                time.sleep(wait_interval)
-                count += 1
-
-    LOG.error("Failed to acquire lock (fd={}). Stop trying...".format(lockfd))
-    return 0
-
-
 def skip_udev_partition_probe(function):
     def wrapper(*args, **kwargs):
         """Decorator to skip partition rescanning in udev
@@ -1427,7 +1399,7 @@ def skip_udev_partition_probe(function):
         device_node = kwargs.get('device_node', None)
         if device_node:
             with open(device_node, 'r') as f:
-                acquire_file_lock(f)
+                fcntl.flock(f, fcntl.LOCK_SH | fcntl.LOCK_NB)
                 try:
                     return function(*args, **kwargs)
                 finally: