porting: Add fixes to support kernel 4.15.x

This patch enables OVS kernel module to run on kernel 4.15.x.
Two conntrack-related tests failed:
 - conntrack - multiple zones, local
 - conntrack - multi-stage pipeline, local
This might be due to conntrack policy changes for packets coming
from local ports on kernel 4.15. More survey will be done later.

Signed-off-by: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: Yifeng Sun <pkusunyifeng@gmail.com>
Co-authored-by: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
Tested-by: Gregory Rose <gvrose8192@gmail.com>
Reviewed-by: Gregory Rose <gvrose8192@gmail.com>

.travis.yml

@@ -35,11 +35,11 @@ env:
   - BUILD_ENV="-m32" OPTS="--disable-ssl"
   - KERNEL=3.16.54 DPDK=1
   - KERNEL=3.16.54 DPDK=1 OPTS="--enable-shared"
-  - KERNEL=4.14.47
-  - KERNEL=4.9.105
-  - KERNEL=4.4.135
-  - KERNEL=4.1.52
-  - KERNEL=3.16.56
+  - KERNEL=4.15.18
+  - KERNEL=4.14.63
+  - KERNEL=4.9.120
+  - KERNEL=4.4.148
+  - KERNEL=3.16.57
   - TESTSUITE=1 LIBS=-ljemalloc
 
 matrix:

Documentation/faq/releases.rst

@@ -67,7 +67,7 @@ Q: What Linux kernel versions does each Open vSwitch release work with?
     2.7.x        3.10 to 4.9
     2.8.x        3.10 to 4.12
     2.9.x        3.10 to 4.13
-    2.10.x       3.10 to 4.14
+    2.10.x       3.10 to 4.15
     ============ ==============
 
     Open vSwitch userspace should also work with the Linux kernel module built

acinclude.m4

@@ -151,10 +151,10 @@ AC_DEFUN([OVS_CHECK_LINUX], [
     AC_MSG_RESULT([$kversion])
 
     if test "$version" -ge 4; then
-       if test "$version" = 4 && test "$patchlevel" -le 14; then
+       if test "$version" = 4 && test "$patchlevel" -le 15; then
           : # Linux 4.x
        else
-          AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version newer than 4.14.x is not supported (please refer to the FAQ for advice)])
+          AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version newer than 4.15.x is not supported (please refer to the FAQ for advice)])
        fi
     elif test "$version" = 3 && test "$patchlevel" -ge 10; then
        : # Linux 3.x
@@ -882,6 +882,8 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h],
                   [void.*ndo_get_stats64],
                   [OVS_DEFINE([HAVE_VOID_NDO_GET_STATS64])])
+  OVS_GREP_IFELSE([$KSRC/include/linux/timer.h], [init_timer_deferrable],
+                  [OVS_DEFINE([HAVE_INIT_TIMER_DEFERRABLE])])
 
   if cmp -s datapath/linux/kcompat.h.new \
             datapath/linux/kcompat.h >/dev/null 2>&1; then

datapath/linux/compat/vxlan.c

@@ -1245,9 +1245,15 @@ netdev_tx_t rpl_vxlan_xmit(struct sk_buff *skb)
 EXPORT_SYMBOL_GPL(rpl_vxlan_xmit);
 
 /* Walk the forwarding table and purge stale entries */
+#ifdef HAVE_INIT_TIMER_DEFERRABLE
 static void vxlan_cleanup(unsigned long arg)
 {
 	struct vxlan_dev *vxlan = (struct vxlan_dev *) arg;
+#else
+static void vxlan_cleanup(struct timer_list *t)
+{
+       struct vxlan_dev *vxlan = from_timer(vxlan, t, age_timer);
+#endif
 	unsigned long next_timer = jiffies + FDB_AGE_INTERVAL;
 	unsigned int h;
 
@@ -1582,9 +1588,13 @@ static void vxlan_setup(struct net_device *dev)
 	INIT_LIST_HEAD(&vxlan->next);
 	spin_lock_init(&vxlan->hash_lock);
 
+#ifdef HAVE_INIT_TIMER_DEFERRABLE
 	init_timer_deferrable(&vxlan->age_timer);
 	vxlan->age_timer.function = vxlan_cleanup;
 	vxlan->age_timer.data = (unsigned long) vxlan;
+#else
+	timer_setup(&vxlan->age_timer, vxlan_cleanup, TIMER_DEFERRABLE);
+#endif
 
 	vxlan->cfg.dst_port = htons(vxlan_port);