xfrm: Remove ancient sleeping when the SA is in acquire state

We now queue packets to the policy if the states are not yet resolved,
this replaces the ancient sleeping code. Also the sleeping can cause
indefinite task hangs if the needed state does not get resolved.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

3 files changed, 5 insertions, 42 deletions

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 9a039acf37e8..5beabd8ba772 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1380,10 +1380,9 @@ static int pfkey_acquire(struct sock *sk, struct sk_buff *skb, const struct sadb
                 return 0;
 
         spin_lock_bh(&x->lock);
-        if (x->km.state == XFRM_STATE_ACQ) {
+        if (x->km.state == XFRM_STATE_ACQ)
                 x->km.state = XFRM_STATE_ERROR;
-                wake_up(&net->xfrm.km_waitq);
-        }
+
         spin_unlock_bh(&x->lock);
         xfrm_state_put(x);
         return 0;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 73b04d3df44e..a7487f34e813 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1901,8 +1901,7 @@ static struct xfrm_dst *xfrm_create_dummy_bundle(struct net *net,
         if (IS_ERR(xdst))
                 return xdst;
 
-        if (net->xfrm.sysctl_larval_drop || num_xfrms <= 0 ||
-            (fl->flowi_flags & FLOWI_FLAG_CAN_SLEEP))
+        if (net->xfrm.sysctl_larval_drop || num_xfrms <= 0)
                 return xdst;
 
         dst1 = &xdst->u.dst;
@@ -2077,7 +2076,6 @@ struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
         u8 dir = policy_to_flow_dir(XFRM_POLICY_OUT);
         int i, err, num_pols, num_xfrms = 0, drop_pols = 0;
 
-restart:
         dst = NULL;
         xdst = NULL;
         route = NULL;
@@ -2157,23 +2155,8 @@ restart:
 
                         return make_blackhole(net, family, dst_orig);
                 }
-                if (fl->flowi_flags & FLOWI_FLAG_CAN_SLEEP) {
-                        DECLARE_WAITQUEUE(wait, current);
 
-                        add_wait_queue(&net->xfrm.km_waitq, &wait);
-                        set_current_state(TASK_INTERRUPTIBLE);
-                        schedule();
-                        set_current_state(TASK_RUNNING);
-                        remove_wait_queue(&net->xfrm.km_waitq, &wait);
-
-                        if (!signal_pending(current)) {
-                                dst_release(dst);
-                                goto restart;
-                        }
-
-                        err = -ERESTART;
-                } else
-                        err = -EAGAIN;
+                err = -EAGAIN;
 
                 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTNOSTATES);
                 goto error;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 290479d0746d..e845066547c4 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -372,8 +372,6 @@ static void xfrm_state_gc_task(struct work_struct *work)
 
         hlist_for_each_entry_safe(x, tmp, &gc_list, gclist)
                 xfrm_state_gc_destroy(x);
-
-        wake_up(&net->xfrm.km_waitq);
 }
 
 static inline unsigned long make_jiffies(long secs)
@@ -388,7 +386,6 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer * me)
 {
         struct tasklet_hrtimer *thr = container_of(me, struct tasklet_hrtimer, timer);
         struct xfrm_state *x = container_of(thr, struct xfrm_state, mtimer);
-        struct net *net = xs_net(x);
         unsigned long now = get_seconds();
         long next = LONG_MAX;
         int warn = 0;
@@ -458,12 +455,8 @@ resched:
         goto out;
 
 expired:
-        if (x->km.state == XFRM_STATE_ACQ && x->id.spi == 0) {
+        if (x->km.state == XFRM_STATE_ACQ && x->id.spi == 0)
                 x->km.state = XFRM_STATE_EXPIRED;
-                wake_up(&net->xfrm.km_waitq);
-                next = 2;
-                goto resched;
-        }
 
         err = __xfrm_state_delete(x);
         if (!err)
@@ -635,7 +628,6 @@ restart:
 
 out:
         spin_unlock_bh(&net->xfrm.xfrm_state_lock);
-        wake_up(&net->xfrm.km_waitq);
         return err;
 }
 EXPORT_SYMBOL(xfrm_state_flush);
@@ -948,8 +940,6 @@ static void __xfrm_state_insert(struct xfrm_state *x)
         if (x->replay_maxage)
                 mod_timer(&x->rtimer, jiffies + x->replay_maxage);
 
-        wake_up(&net->xfrm.km_waitq);
-
         net->xfrm.state_num++;
 
         xfrm_hash_grow_check(net, x->bydst.next != NULL);
@@ -1658,16 +1648,12 @@ EXPORT_SYMBOL(km_state_notify);
 
 void km_state_expired(struct xfrm_state *x, int hard, u32 portid)
 {
-        struct net *net = xs_net(x);
         struct km_event c;
 
         c.data.hard = hard;
         c.portid = portid;
         c.event = XFRM_MSG_EXPIRE;
         km_state_notify(x, &c);
-
-        if (hard)
-                wake_up(&net->xfrm.km_waitq);
 }
 
 EXPORT_SYMBOL(km_state_expired);
@@ -1710,16 +1696,12 @@ EXPORT_SYMBOL(km_new_mapping);
 
 void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 portid)
 {
-        struct net *net = xp_net(pol);
         struct km_event c;
 
         c.data.hard = hard;
         c.portid = portid;
         c.event = XFRM_MSG_POLEXPIRE;
         km_policy_notify(pol, dir, &c);
-
-        if (hard)
-                wake_up(&net->xfrm.km_waitq);
 }
 EXPORT_SYMBOL(km_policy_expired);
 
@@ -2028,7 +2010,6 @@ int __net_init xfrm_state_init(struct net *net)
         INIT_WORK(&net->xfrm.state_hash_work, xfrm_hash_resize);
         INIT_HLIST_HEAD(&net->xfrm.state_gc_list);
         INIT_WORK(&net->xfrm.state_gc_work, xfrm_state_gc_task);
-        init_waitqueue_head(&net->xfrm.km_waitq);
         spin_lock_init(&net->xfrm.xfrm_state_lock);
         return 0;