These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / net / ipv4 / inet_timewait_sock.c

diff --git a/kernel/net/ipv4/inet_timewait_sock.c b/kernel/net/ipv4/inet_timewait_sock.c
index 00ec8d5..c67f9bd 100644 (file)
--- a/kernel/net/ipv4/inet_timewait_sock.c
+++ b/kernel/net/ipv4/inet_timewait_sock.c
@@ -17,28 +17,6 @@
 #include <net/ip.h>
 
 
-/**
- *     inet_twsk_unhash - unhash a timewait socket from established hash
- *     @tw: timewait socket
- *
- *     unhash a timewait socket from established hash, if hashed.
- *     ehash lock must be held by caller.
- *     Returns 1 if caller should call inet_twsk_put() after lock release.
- */
-int inet_twsk_unhash(struct inet_timewait_sock *tw)
-{
-       if (hlist_nulls_unhashed(&tw->tw_node))
-               return 0;
-
-       hlist_nulls_del_rcu(&tw->tw_node);
-       sk_nulls_node_init(&tw->tw_node);
-       /*
-        * We cannot call inet_twsk_put() ourself under lock,
-        * caller must call it for us.
-        */
-       return 1;
-}
-
 /**
  *     inet_twsk_bind_unhash - unhash a timewait socket from bind hash
  *     @tw: timewait socket
@@ -48,35 +26,29 @@ int inet_twsk_unhash(struct inet_timewait_sock *tw)
  *     bind hash lock must be held by caller.
  *     Returns 1 if caller should call inet_twsk_put() after lock release.
  */
-int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
+void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
                          struct inet_hashinfo *hashinfo)
 {
        struct inet_bind_bucket *tb = tw->tw_tb;
 
        if (!tb)
-               return 0;
+               return;
 
        __hlist_del(&tw->tw_bind_node);
        tw->tw_tb = NULL;
        inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
-       /*
-        * We cannot call inet_twsk_put() ourself under lock,
-        * caller must call it for us.
-        */
-       return 1;
+       __sock_put((struct sock *)tw);
 }
 
 /* Must be called with locally disabled BHs. */
 static void inet_twsk_kill(struct inet_timewait_sock *tw)
 {
        struct inet_hashinfo *hashinfo = tw->tw_dr->hashinfo;
-       struct inet_bind_hashbucket *bhead;
-       int refcnt;
-       /* Unlink from established hashes. */
        spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash);
+       struct inet_bind_hashbucket *bhead;
 
        spin_lock(lock);
-       refcnt = inet_twsk_unhash(tw);
+       sk_nulls_del_node_init_rcu((struct sock *)tw);
        spin_unlock(lock);
 
        /* Disassociate with bind bucket. */
@@ -84,11 +56,9 @@ static void inet_twsk_kill(struct inet_timewait_sock *tw)
                        hashinfo->bhash_size)];
 
        spin_lock(&bhead->lock);
-       refcnt += inet_twsk_bind_unhash(tw, hashinfo);
+       inet_twsk_bind_unhash(tw, hashinfo);
        spin_unlock(&bhead->lock);
 
-       BUG_ON(refcnt >= atomic_read(&tw->tw_refcnt));
-       atomic_sub(refcnt, &tw->tw_refcnt);
        atomic_dec(&tw->tw_dr->tw_count);
        inet_twsk_put(tw);
 }
@@ -153,13 +123,15 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
        /*
         * Step 2: Hash TW into tcp ehash chain.
         * Notes :
-        * - tw_refcnt is set to 3 because :
+        * - tw_refcnt is set to 4 because :
         * - We have one reference from bhash chain.
         * - We have one reference from ehash chain.
+        * - We have one reference from timer.
+        * - One reference for ourself (our caller will release it).
         * We can use atomic_set() because prior spin_lock()/spin_unlock()
         * committed into memory all tw fields.
         */
-       atomic_set(&tw->tw_refcnt, 1 + 1 + 1);
+       atomic_set(&tw->tw_refcnt, 4);
        inet_twsk_add_node_rcu(tw, &ehead->chain);
 
        /* Step 3: Remove SK from hash chain */
@@ -170,7 +142,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
 }
 EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
 
-void tw_timer_handler(unsigned long data)
+static void tw_timer_handler(unsigned long data)
 {
        struct inet_timewait_sock *tw = (struct inet_timewait_sock *)data;
 
@@ -235,15 +207,19 @@ EXPORT_SYMBOL_GPL(inet_twsk_alloc);
  * tcp_input.c to verify this.
  */
 
-/* This is for handling early-kills of TIME_WAIT sockets. */
-void inet_twsk_deschedule(struct inet_timewait_sock *tw)
+/* This is for handling early-kills of TIME_WAIT sockets.
+ * Warning : consume reference.
+ * Caller should not access tw anymore.
+ */
+void inet_twsk_deschedule_put(struct inet_timewait_sock *tw)
 {
        if (del_timer_sync(&tw->tw_timer))
                inet_twsk_kill(tw);
+       inet_twsk_put(tw);
 }
-EXPORT_SYMBOL(inet_twsk_deschedule);
+EXPORT_SYMBOL(inet_twsk_deschedule_put);
 
-void inet_twsk_schedule(struct inet_timewait_sock *tw, const int timeo)
+void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo, bool rearm)
 {
        /* timeout := RTO * 3.5
         *
@@ -271,12 +247,14 @@ void inet_twsk_schedule(struct inet_timewait_sock *tw, const int timeo)
         */
 
        tw->tw_kill = timeo <= 4*HZ;
-       if (!mod_timer_pinned(&tw->tw_timer, jiffies + timeo)) {
-               atomic_inc(&tw->tw_refcnt);
+       if (!rearm) {
+               BUG_ON(mod_timer_pinned(&tw->tw_timer, jiffies + timeo));
                atomic_inc(&tw->tw_dr->tw_count);
+       } else {
+               mod_timer_pending(&tw->tw_timer, jiffies + timeo);
        }
 }
-EXPORT_SYMBOL_GPL(inet_twsk_schedule);
+EXPORT_SYMBOL_GPL(__inet_twsk_schedule);
 
 void inet_twsk_purge(struct inet_hashinfo *hashinfo,
                     struct inet_timewait_death_row *twdr, int family)
@@ -311,9 +289,8 @@ restart:
 
                        rcu_read_unlock();
                        local_bh_disable();
-                       inet_twsk_deschedule(tw);
+                       inet_twsk_deschedule_put(tw);
                        local_bh_enable();
-                       inet_twsk_put(tw);
                        goto restart_rcu;
                }
                /* If the nulls value we got at the end of this lookup is