From ebacb31fb5619bfe405107c53b9e27dc9724c29a Mon Sep 17 00:00:00 2001
From: Stefan Berger <stefanb@us.ibm.com>
Date: Fri, 30 Apr 2010 08:10:12 -0400
Subject: [PATCH] Syncronize the teardown of rules with the thread

Introduce a function to notify the IP address learning
thread to terminate and thus release the lock on the interface.
Notify the thread before grabbing the lock on the interface
and tearing down the rules. This prevents a 'virsh destroy' to
tear down the rules that the IP address learning thread has
applied.
---
 src/nwfilter/nwfilter_gentech_driver.c |  8 ++++++++
 src/nwfilter/nwfilter_learnipaddr.c    | 27 +++++++++++++++++++++++++-
 src/nwfilter/nwfilter_learnipaddr.h    |  1 +
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/nwfilter/nwfilter_gentech_driver.c b/src/nwfilter/nwfilter_gentech_driver.c
index 095dc92931..9fede3b673 100644
--- a/src/nwfilter/nwfilter_gentech_driver.c
+++ b/src/nwfilter/nwfilter_gentech_driver.c
@@ -937,10 +937,18 @@ _virNWFilterTeardownFilter(const char *ifname)
                                drvname);
         return 1;
     }
+
+    virNWFilterTerminateLearnReq(ifname);
+
+    if (virNWFilterLockIface(ifname))
+       return 1;
+
     techdriver->allTeardown(ifname);
 
     virNWFilterDelIpAddrForIfname(ifname);
 
+    virNWFilterUnlockIface(ifname);
+
     return 0;
 }
 
diff --git a/src/nwfilter/nwfilter_learnipaddr.c b/src/nwfilter/nwfilter_learnipaddr.c
index 2bb777bad0..71dc240b4f 100644
--- a/src/nwfilter/nwfilter_learnipaddr.c
+++ b/src/nwfilter/nwfilter_learnipaddr.c
@@ -243,8 +243,33 @@ virNWFilterRegisterLearnReq(virNWFilterIPAddrLearnReqPtr req) {
     return res;
 }
 
+
 #endif
 
+int
+virNWFilterTerminateLearnReq(const char *ifname) {
+    int rc = 1;
+    int ifindex;
+    virNWFilterIPAddrLearnReqPtr req;
+
+    if (ifaceGetIndex(false, ifname, &ifindex) == 0) {
+
+        IFINDEX2STR(ifindex_str, ifindex);
+
+        virMutexLock(&pendingLearnReqLock);
+
+        req = virHashLookup(pendingLearnReq, ifindex_str);
+        if (req) {
+            rc = 0;
+            req->terminate = true;
+        }
+
+        virMutexUnlock(&pendingLearnReqLock);
+    }
+
+    return rc;
+}
+
 
 virNWFilterIPAddrLearnReqPtr
 virNWFilterLookupLearnReq(int ifindex) {
@@ -472,7 +497,7 @@ learnIPAddressThread(void *arg)
 
         if (!packet) {
 
-            if (threadsTerminate) {
+            if (threadsTerminate || req->terminate) {
                 req->status = ECANCELED;
                 showError = false;
                 break;
diff --git a/src/nwfilter/nwfilter_learnipaddr.h b/src/nwfilter/nwfilter_learnipaddr.h
index 6f3cb7f201..ebe65c2c9e 100644
--- a/src/nwfilter/nwfilter_learnipaddr.h
+++ b/src/nwfilter/nwfilter_learnipaddr.h
@@ -46,6 +46,7 @@ struct _virNWFilterIPAddrLearnReq {
 
     int status;
     pthread_t thread;
+    volatile bool terminate;
 };
 
 int virNWFilterLearnIPAddress(virNWFilterTechDriverPtr techdriver,