From ae2df81ef9b7c8da6a7f8b201e95e01062543953 Mon Sep 17 00:00:00 2001
From: Faiyaz Ahmed <faiyaza@cs.princeton.edu>
Date: Fri, 4 Apr 2008 19:54:58 +0000
Subject: [PATCH] File locking isn't exclusive in the same process across
threads. Switched to regular semaphores. The assumption is
sliver_vs.configure is called before Vserver.start(), which sets
disk_usage_initialized. The disk check should be skipped during start, so
the lock won't carry over. ...I hope.
---
sliver_vs.py | 5 ++++-
tools.py | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/sliver_vs.py b/sliver_vs.py
index 13ff990..3060b9f 100644
--- a/sliver_vs.py
+++ b/sliver_vs.py
@@ -24,6 +24,9 @@ import vserver
import accounts
import logger
import tools
+from threading import BoundedSemaphore
+
+globalsem = BoundedSemaphore()
# special constant that tells vserver to keep its existing settings
KEEP_LIMIT = vserver.VC_LIM_KEEP
@@ -42,7 +45,7 @@ class Sliver_VS(accounts.Account, vserver.VServer):
SHELL = '/bin/vsh'
TYPE = 'sliver.VServer'
- _init_disk_info_sem = tools.NMLock("/var/run/nm-disk-info.lock")
+ _init_disk_info_sem = globalsem
def __init__(self, rec):
logger.verbose ('initing Sliver_VS with name=%s'%rec['name'])
diff --git a/tools.py b/tools.py
index 49441bd..776a8d4 100644
--- a/tools.py
+++ b/tools.py
@@ -94,6 +94,7 @@ def write_temp_file(do_write, mode=None, uidgid=None):
class NMLock:
def __init__(self, file):
+ logger.log("Lock %s initialized." % file, 2)
self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
flags |= fcntl.FD_CLOEXEC
@@ -101,6 +102,8 @@ class NMLock:
def __del__(self):
os.close(self.fd)
def acquire(self):
- fcntl.lockf(self.fd, fcntl.LOCK_EX)
+ logger.log("Lock acquired.", 2)
+ fcntl.lockf(self.fd, fcntl.LOCK_SH)
def release(self):
+ logger.log("Lock released.", 2)
fcntl.lockf(self.fd, fcntl.LOCK_UN)
--
2.47.0