From: Sean Hefty Date: Mon, 19 Mar 2007 22:31:36 +0000 (-0800) Subject: IPoIB: Fix race in detaching from mcast group before attaching X-Git-Tag: v2.6.21-rc5~46^2~5 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e07832b66285124038a96b25a2056e91a55d8b1e;p=linux-2.6 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 Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index 56c87a81bb..54fbead4de 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -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; }