[openib-general] [PATCH series] ipoib: fix multicast related issues

[Michael S. Tsirkin]

Multicast handling was susceptible to several race conditions, where
different sources would try to start/stop multicast thread
and create/destroy multicast groups in parallel.

The following two patches (sent separately) solve these races by
1. Forcing all entries into ipoib_multicast.c to go through
   the single-threaded ipoib workqueue.
2. Protecting each access to mcast->queue, priv->broadcast
   and priv->mcast_list by priv->lock.

With these two patches applied (and with the mthca patch that I've
sent previously), I've been running the up/down test for more than 24 hours
without failures now.

-- 
MST