[libvirt] [PATCH] nwfilter: fix learning address thread shutdown

[Nikolay Shirokovskiy]

If learning thread is configured to learn on all ethernet frames (which is
hardcoded) then chances are big that there is packet on every iteration of
inspecting frames loop. As result we will hang on shutdown because we don't
check threadsTerminate if there is packet.

Let's just check termination conditions on every iteration.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
---
 src/nwfilter/nwfilter_learnipaddr.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/src/nwfilter/nwfilter_learnipaddr.c b/src/nwfilter/nwfilter_learnipaddr.c
index 008c24b..e6cb996 100644
--- a/src/nwfilter/nwfilter_learnipaddr.c
+++ b/src/nwfilter/nwfilter_learnipaddr.c
@@ -483,6 +483,12 @@ learnIPAddressThread(void *arg)
     while (req->status == 0 && vmaddr == 0) {
         int n = poll(fds, ARRAY_CARDINALITY(fds), PKT_TIMEOUT_MS);
 
+        if (threadsTerminate || req->terminate) {
+            req->status = ECANCELED;
+            showError = false;
+            break;
+        }
+
         if (n < 0) {
             if (errno == EAGAIN || errno == EINTR)
                 continue;
@@ -492,15 +498,8 @@ learnIPAddressThread(void *arg)
             break;
         }
 
-        if (n == 0) {
-            if (threadsTerminate || req->terminate) {
-                VIR_DEBUG("Terminate request seen, cancelling pcap");
-                req->status = ECANCELED;
-                showError = false;
-                break;
-            }
+        if (n == 0)
             continue;
-        }
 
         if (fds[0].revents & (POLLHUP | POLLERR)) {
             VIR_DEBUG("Error from FD probably dev deleted");
@@ -512,13 +511,6 @@ learnIPAddressThread(void *arg)
         packet = pcap_next(handle, &header);
 
         if (!packet) {
-            /* Already handled with poll, but lets be sure */
-            if (threadsTerminate || req->terminate) {
-                req->status = ECANCELED;
-                showError = false;
-                break;
-            }
-
             /* Again, already handled above, but lets be sure */
             if (virNetDevValidateConfig(req->binding->portdevname, NULL, req->ifindex) <= 0) {
                 virResetLastError();
-- 
1.8.3.1