[NETPOLL]: Fixups for 'fix soft lockup when removing module'

>From my recent patch:

> >    #1
> >    Until kernel ver. 2.6.21 (including) cancel_rearming_delayed_work()
> >    required a work function should always (unconditionally) rearm with
> >    delay > 0 - otherwise it would endlessly loop. This patch replaces
> >    this function with cancel_delayed_work(). Later kernel versions don't
> >    require this, so here it's only for uniformity.

But Oleg Nesterov <oleg@tv-sign.ru> found:

> But 2.6.22 doesn't need this change, why it was merged?
>
> In fact, I suspect this change adds a race,
...

His description was right (thanks), so this patch reverts #1.

Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index cf40ff91ac01da94912ed4ed67ce6b80649bdfbf..a0efdd7a6b375951546319eb9717167edd301972 100644 (file)
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -72,8 +72,7 @@ static void queue_process(struct work_struct *work)
                        netif_tx_unlock(dev);
                        local_irq_restore(flags);
 
-                       if (atomic_read(&npinfo->refcnt))
-                               schedule_delayed_work(&npinfo->tx_work, HZ/10);
+                       schedule_delayed_work(&npinfo->tx_work, HZ/10);
                        return;
                }
                netif_tx_unlock(dev);
@@ -786,8 +785,7 @@ void netpoll_cleanup(struct netpoll *np)
                        if (atomic_dec_and_test(&npinfo->refcnt)) {
                                skb_queue_purge(&npinfo->arp_tx);
                                skb_queue_purge(&npinfo->txq);
-                               cancel_delayed_work(&npinfo->tx_work);
-                               flush_scheduled_work();
+                               cancel_rearming_delayed_work(&npinfo->tx_work);
 
                                /* clean after last, unfinished work */
                                if (!skb_queue_empty(&npinfo->txq)) {