diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Metadata.py | 35 |
1 files changed, 27 insertions, 8 deletions
diff --git a/src/lib/Bcfg2/Server/Plugins/Metadata.py b/src/lib/Bcfg2/Server/Plugins/Metadata.py index 932c35545..ae268d8b7 100644 --- a/src/lib/Bcfg2/Server/Plugins/Metadata.py +++ b/src/lib/Bcfg2/Server/Plugins/Metadata.py @@ -6,6 +6,7 @@ import os import sys import time import copy +import errno import fcntl import socket import logging @@ -159,18 +160,36 @@ class XMLMetadataConfig(Bcfg2.Server.Plugin.XMLFileBacked): def write_xml(self, fname, xmltree): """Write changes to xml back to disk.""" tmpfile = "%s.new" % fname - try: - datafile = open(tmpfile, 'w') - except IOError: - msg = "Failed to write %s: %s" % (tmpfile, sys.exc_info()[1]) - self.logger.error(msg) - raise Bcfg2.Server.Plugin.MetadataRuntimeError(msg) + datafile = None + fd = None + i = 0 # counter to avoid flooding logs with lock messages + while datafile is None: + try: + fd = os.open(tmpfile, os.O_CREAT | os.O_EXCL | os.O_WRONLY) + datafile = os.fdopen(fd, 'w') + except OSError: + err = sys.exc_info()[1] + if err.errno == errno.EEXIST: + # note: not a real lock. this is here to avoid + # the scenario where two threads write to the file + # at the same-ish time, and one writes to + # foo.xml.new, then the other one writes to it + # (losing the first thread's changes), then the + # first renames it, then the second tries to + # rename it and borks. + if (i % 10) == 0: + self.logger.info("%s is locked, waiting" % fname) + i += 1 + time.sleep(0.1) + else: + msg = "Failed to write %s: %s" % (tmpfile, err) + self.logger.error(msg) + raise Bcfg2.Server.Plugin.MetadataRuntimeError(msg) # prep data dataroot = xmltree.getroot() newcontents = lxml.etree.tostring(dataroot, xml_declaration=False, pretty_print=True).decode('UTF-8') - fd = datafile.fileno() while locked(fd) == True: pass try: @@ -383,7 +402,7 @@ class Metadata(Bcfg2.Server.Plugin.Metadata, self.groups_xml = self._handle_file("groups.xml") if (self._use_db and os.path.exists(os.path.join(self.data, "clients.xml"))): - self.logger.warning("Metadata: database enabled but clients.xml" + self.logger.warning("Metadata: database enabled but clients.xml " "found, parsing in compatibility mode") self.clients_xml = self._handle_file("clients.xml") elif not self._use_db: |