From e8224e4b804b4fd26723191c1891101a5959bb8a Mon Sep 17 00:00:00 2001 From: Yossi Etigin Date: Tue, 16 Sep 2008 11:57:45 -0700 Subject: IPoIB: Fix deadlock on RTNL between bcast join comp and ipoib_stop() Taking rtnl_lock in ipoib_mcast_join_complete() causes a deadlock with ipoib_stop(). We avoid it by scheduling the piece of code that takes the lock on ipoib_workqueue instead of executing it directly. This works because we only flush the ipoib_workqueue with the RTNL not held. The deadlock happens because ipoib_stop() calls ipoib_ib_dev_down() which calls ipoib_mcast_dev_flush(), which calls ipoib_mcast_free(), which calls ipoib_mcast_leave(). The latter calls ib_sa_free_multicast(), and this waits until the multicast completion handler finishes. This handler is ipoib_mcast_join_complete(), which waits for the rtnl_lock(), which was already taken by ipoib_stop(). This bug was introduced in commit a77a57a1 ("IPoIB: Fix deadlock on RTNL in ipoib_stop()"). Signed-off-by: Yossi Etigin Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/ipoib/ipoib_main.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/infiniband/ulp/ipoib/ipoib_main.c') diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c index 7e9e218738f..1b1df5cc411 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c @@ -1075,6 +1075,7 @@ static void ipoib_setup(struct net_device *dev) INIT_DELAYED_WORK(&priv->pkey_poll_task, ipoib_pkey_poll); INIT_DELAYED_WORK(&priv->mcast_task, ipoib_mcast_join_task); + INIT_WORK(&priv->carrier_on_task, ipoib_mcast_carrier_on_task); INIT_WORK(&priv->flush_light, ipoib_ib_dev_flush_light); INIT_WORK(&priv->flush_normal, ipoib_ib_dev_flush_normal); INIT_WORK(&priv->flush_heavy, ipoib_ib_dev_flush_heavy); -- cgit v1.2.3-18-g5258