From 5d0efa621fff90f4252108dacb8155f222145c96 Mon Sep 17 00:00:00 2001
From: Kouya Shimura <kouya@jp.fujitsu.com>
Date: Wed, 15 Dec 2010 16:49:06 +0000
Subject: [PATCH] tools/hotplug/Linux: force release lock if holder process is
 gone (fix)

22508:57907b28e51a was unsafe for mutual exclusion.  There is a case
that the owner file doesn't exist yet when an atomic mkdir operation
fails.

Signed-off-by: Kouya Shimura <kouya@jp.fujitsu.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
 tools/hotplug/Linux/locking.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/hotplug/Linux/locking.sh b/tools/hotplug/Linux/locking.sh
index 8748d95454..e233c4763a 100644
--- a/tools/hotplug/Linux/locking.sh
+++ b/tools/hotplug/Linux/locking.sh
@@ -63,7 +63,7 @@ _claim_lock()
       retries=0
     else
       local pid=$(echo $owner | cut -d : -f 1)
-      if [ ! -f "/proc/$pid/status" ]
+      if [ -n "$pid" -a "$pid" != "unknown" -a ! -f "/proc/$pid/status" ]
       then
         _release_lock $lockdir
       fi
-- 
2.30.2