From: Joe Stringer <joe@ovn.org>
Date: Thu, 24 Dec 2015 18:41:35 +0000 (-0800)
Subject: compat: Detect and use inet_frag_queue->list_evictor.
X-Git-Url: http://git.cascardo.eti.br/?p=cascardo%2Fovs.git;a=commitdiff_plain;h=e0d45da35ec70f2224826a5a62ce66e505ee1962

compat: Detect and use inet_frag_queue->list_evictor.

Kernels 3.17 to 4.2 have a work queue to evict old fragments, but do not
track these fragments in an eviction list. On these kernels, we detect
the absence of the list_evictor and provide one. This commit fixes the
reliance on kernel versions in the case that this functionality is
backported.

Signed-off-by: Joe Stringer <joe@ovn.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
---

diff --git a/acinclude.m4 b/acinclude.m4
index 7ed464c14..e99420e5f 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -355,10 +355,13 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
                   [OVS_DEFINE([HAVE_INET_FRAGS_CONST])])
   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [last_in],
                   [OVS_DEFINE([HAVE_INET_FRAGS_LAST_IN])])
+  OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_evicting])
   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
                         [frags_work])
   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
                         [rwlock])
+  OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_queue],
+                        [list_evictor])
   OVS_GREP_IFELSE([$KSRC/include/net/inetpeer.h], [vif],
                   [OVS_DEFINE([HAVE_INETPEER_VIF_SUPPORT])])
 
diff --git a/datapath/linux/compat/include/net/inet_frag.h b/datapath/linux/compat/include/net/inet_frag.h
index 2708cddf2..64edffa2b 100644
--- a/datapath/linux/compat/include/net/inet_frag.h
+++ b/datapath/linux/compat/include/net/inet_frag.h
@@ -22,6 +22,7 @@
 #define qp_flags(qp) (qp->q.flags)
 #endif
 
+#ifndef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
 /**
  * struct ovs_inet_frag_queue - fragment queue
  *
@@ -44,6 +45,15 @@ static inline bool rpl_inet_frag_evicting(struct inet_frag_queue *q)
 #endif
 }
 #define inet_frag_evicting rpl_inet_frag_evicting
+#else /* HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR */
+#ifndef HAVE_INET_FRAG_EVICTING
+static inline bool rpl_inet_frag_evicting(struct inet_frag_queue *q)
+{
+	return !hlist_unhashed(&q->list_evictor);
+}
+#define inet_frag_evicting rpl_inet_frag_evicting
+#endif
+#endif
 
 static unsigned int rpl_frag_percpu_counter_batch = 130000;
 #define frag_percpu_counter_batch rpl_frag_percpu_counter_batch
diff --git a/datapath/linux/compat/inet_fragment.c b/datapath/linux/compat/inet_fragment.c
index 741a05554..0b9b9515e 100644
--- a/datapath/linux/compat/inet_fragment.c
+++ b/datapath/linux/compat/inet_fragment.c
@@ -130,7 +130,7 @@ static bool inet_fragq_should_evict(const struct inet_frag_queue *q)
 static unsigned int
 inet_evict_bucket(struct inet_frags *f, struct inet_frag_bucket *hb)
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
+#ifndef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
 	struct ovs_inet_frag_queue *ofq;
 #endif
 	struct inet_frag_queue *fq;
@@ -147,23 +147,23 @@ inet_evict_bucket(struct inet_frags *f, struct inet_frag_bucket *hb)
 		if (!del_timer(&fq->timer))
 			continue;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
+#ifdef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
+		hlist_add_head(&fq->list_evictor, &expired);
+#else
 		ofq = (struct ovs_inet_frag_queue *)fq;
 		hlist_add_head(&ofq->list_evictor, &expired);
-#else
-		hlist_add_head(&fq->list_evictor, &expired);
 #endif
 		++evicted;
 	}
 
 	spin_unlock(&hb->chain_lock);
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
-	hlist_for_each_entry_safe(ofq, n, &expired, list_evictor)
-		f->frag_expire((unsigned long) &ofq->fq);
-#else
+#ifdef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
 	hlist_for_each_entry_safe(fq, n, &expired, list_evictor)
 		f->frag_expire((unsigned long) fq);
+#else
+	hlist_for_each_entry_safe(ofq, n, &expired, list_evictor)
+		f->frag_expire((unsigned long) &ofq->fq);
 #endif
 
 	return evicted;
diff --git a/datapath/linux/compat/ip_fragment.c b/datapath/linux/compat/ip_fragment.c
index 1841c49b9..4fa50193b 100644
--- a/datapath/linux/compat/ip_fragment.c
+++ b/datapath/linux/compat/ip_fragment.c
@@ -78,7 +78,7 @@ struct ipfrag_skb_cb
 struct ipq {
 	union {
 		struct inet_frag_queue q;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
+#ifndef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
 		struct ovs_inet_frag_queue oq;
 #endif
 	};