xenapi: Add cleanup_sm_locks script

XenServer 5.6 and 6.0 don't appear to be cleaning up sm locks when using
a FileSR. When enough locks accumulate, this causes image related
operations to fail.

This cleanup script is a stop-gap solution that can be run against all
of the dom0's in the cluster to prevent too many locks from
accumulating.

We can remove this script when the root-cause is fixed upstream.

References 1103158

Change-Id: I798bcfeb727a59003910b82d331fdbe031c4a2b4

1 files changed, 123 insertions, 0 deletions

diff --git a/tools/xenserver/cleanup_sm_locks.py b/tools/xenserver/cleanup_sm_locks.py
new file mode 100755
index 000000000..de455b076
--- /dev/null
+++ b/tools/xenserver/cleanup_sm_locks.py
@@ -0,0 +1,123 @@
+#!/usr/bin/env python
+
+# Copyright 2013 OpenStack, LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+Script to cleanup old XenServer /var/lock/sm locks.
+
+XenServer 5.6 and 6.0 do not appear to always cleanup locks when using a
+FileSR. ext3 has a limit of 32K inode links, so when we have 32K-2 (31998)
+locks laying around, builds will begin to fail because we can't create any
+additional locks.  This cleanup script is something we can run periodically as
+a stop-gap measure until this is fixed upstream.
+
+This script should be run on the dom0 of the affected machine.
+"""
+import errno
+import optparse
+import os
+import sys
+import time
+
+BASE = '/var/lock/sm'
+
+
+def _get_age_days(secs):
+    return float(time.time() - secs) / 86400
+
+
+def _parse_args():
+    parser = optparse.OptionParser()
+    parser.add_option("-d", "--dry-run",
+                      action="store_true", dest="dry_run", default=False,
+                      help="don't actually remove locks")
+    parser.add_option("-l", "--limit",
+                      action="store", type='int', dest="limit",
+                      default=sys.maxint,
+                      help="max number of locks to delete (default: no limit)")
+    parser.add_option("-v", "--verbose",
+                      action="store_true", dest="verbose", default=False,
+                      help="don't print status messages to stdout")
+
+    options, args = parser.parse_args()
+
+    try:
+        days_old = int(args[0])
+    except (IndexError, ValueError):
+        parser.print_help()
+        sys.exit(1)
+
+    return options, days_old
+
+
+def main():
+    options, days_old = _parse_args()
+
+    if not os.path.exists(BASE):
+        print >> sys.stderr, "error: '%s' doesn't exist. Make sure you're"\
+                             " running this on the dom0." % BASE
+        sys.exit(1)
+
+    lockpaths_removed = 0
+    nspaths_removed = 0
+
+    for nsname in os.listdir(BASE)[:options.limit]:
+        nspath = os.path.join(BASE, nsname)
+
+        if not os.path.isdir(nspath):
+            continue
+
+        # Remove old lockfiles
+        removed = 0
+        locknames = os.listdir(nspath)
+        for lockname in locknames:
+            lockpath = os.path.join(nspath, lockname)
+            lock_age_days = _get_age_days(os.path.getmtime(lockpath))
+            if lock_age_days > days_old:
+                lockpaths_removed += 1
+                removed += 1
+
+                if options.verbose:
+                    print 'Removing old lock: %03d %s' % (lock_age_days,
+                                                          lockpath)
+
+                if not options.dry_run:
+                    os.unlink(lockpath)
+
+        # Remove empty namespace paths
+        if len(locknames) == removed:
+            nspaths_removed += 1
+
+            if options.verbose:
+                print 'Removing empty namespace: %s' % nspath
+
+            if not options.dry_run:
+                try:
+                    os.rmdir(nspath)
+                except OSError, e:
+                    if e.errno == errno.ENOTEMPTY:
+                        print >> sys.stderr, "warning: directory '%s'"\
+                                             " not empty" % nspath
+                    else:
+                        raise
+
+    if options.dry_run:
+        print "** Dry Run **"
+
+    print "Total locks removed: ", lockpaths_removed
+    print "Total namespaces removed: ", nspaths_removed
+
+
+if __name__ == '__main__':
+    main()