fix a race and prevent unlinking of a file locked by another process in portage_locks...

svn path=/main/trunk/; revision=2714

diff --git a/pym/portage_locks.py b/pym/portage_locks.py
index a6e1afe57d41cee165615ff2455d2f4c1f5aa77d..7a9b55674a2ac39b630b9c252baac2a451f3f591 100644 (file)
--- a/pym/portage_locks.py
+++ b/pym/portage_locks.py
@@ -147,10 +147,9 @@ def unlockfile(mytuple):
                unhardlink_lockfile(lockfilename)
                return True
        
-       if type(lockfilename) == types.StringType and not os.path.exists(lockfilename):
+       if type(lockfilename) == types.StringType and os.fstat(myfd).st_nlink != 1:
                portage_util.writemsg("lockfile does not exist '%s'\n" % lockfilename,1)
-               if (myfd != None) and type(lockfilename) == types.StringType:
-                       os.close(myfd)
+               os.close(myfd)
                return False
 
        try:
@@ -178,9 +177,14 @@ def unlockfile(mytuple):
                        # We can safely delete the file.
                        portage_util.writemsg("Got the lockfile...\n",1)
                        #portage_util.writemsg("Unlinking...\n")
-                       os.unlink(lockfilename)
-                       portage_util.writemsg("Unlinked lockfile...\n",1)
-                       locking_method(myfd,fcntl.LOCK_UN)
+                       if os.fstat(myfd).st_nlink == 1:
+                               os.unlink(lockfilename)
+                               portage_util.writemsg("Unlinked lockfile...\n",1)
+                               locking_method(myfd,fcntl.LOCK_UN)
+                       else:
+                               portage_util.writemsg("lockfile does not exist '%s'\n" % lockfilename,1)
+                               os.close(myfd)
+                               return False
        except SystemExit, e:
                raise
        except Exception, e: