IPoIB: Fix race in detaching from mcast group before attaching

There's a race between ipoib_mcast_leave() and ipoib_mcast_join_finish()
where we can try to detach from a multicast group before we've
attached to it.  Fix this by reordering the code in ipoib_mcast_leave
to free the multicast group first, which waits for the multicast
callback thread (which calls ipoib_mcast_join_finish()) to complete
before detaching from the group.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Sean Hefty 2007-03-19 14:31:36 -08:00 committed by Roland Dreier
parent 60a596dab7
commit e07832b662

View file

@ -644,6 +644,9 @@ static int ipoib_mcast_leave(struct net_device *dev, struct ipoib_mcast *mcast)
struct ipoib_dev_priv *priv = netdev_priv(dev);
int ret = 0;
if (test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags))
ib_sa_free_multicast(mcast->mc);
if (test_and_clear_bit(IPOIB_MCAST_FLAG_ATTACHED, &mcast->flags)) {
ipoib_dbg_mcast(priv, "leaving MGID " IPOIB_GID_FMT "\n",
IPOIB_GID_ARG(mcast->mcmember.mgid));
@ -655,9 +658,6 @@ static int ipoib_mcast_leave(struct net_device *dev, struct ipoib_mcast *mcast)
ipoib_warn(priv, "ipoib_mcast_detach failed (result = %d)\n", ret);
}
if (test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags))
ib_sa_free_multicast(mcast->mc);
return 0;
}