diff options
| author | Shlomo Pongratz <shlomop@mellanox.com> | 2012-08-29 15:14:34 +0000 |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2012-09-12 09:21:45 -0700 |
| commit | b5120a6e11e90d98d8a752545ac60bfa1ea95f1a (patch) | |
| tree | f376dd84bf679fb2b3ed5ae18af967455a75a958 /drivers/infiniband/ulp/ipoib/ipoib_multicast.c | |
| parent | 66172c09938bfc4efdcf9b5e0246a85b9b76dd54 (diff) | |
IPoIB: Fix AB-BA deadlock when deleting neighbours
Lockdep points out a circular locking dependency betwwen the ipoib
device priv spinlock (priv->lock) and the neighbour table rwlock
(ntbl->rwlock).
In the normal path, ie neigbour garbage collection task, the neigh
table rwlock is taken first and then if the neighbour needs to be
deleted, priv->lock is taken.
However in some error paths, such as in ipoib_cm_handle_tx_wc(),
priv->lock is taken first and then ipoib_neigh_free routine is called
which in turn takes the neighbour table ntbl->rwlock.
The solution is to get rid the neigh table rwlock completely and use
only priv->lock.
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband/ulp/ipoib/ipoib_multicast.c')
| -rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index 13f4aa7593c8..75367249f447 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -707,9 +707,7 @@ out: neigh = ipoib_neigh_get(dev, daddr); spin_lock_irqsave(&priv->lock, flags); if (!neigh) { - spin_unlock_irqrestore(&priv->lock, flags); neigh = ipoib_neigh_alloc(daddr, dev); - spin_lock_irqsave(&priv->lock, flags); if (neigh) { kref_get(&mcast->ah->ref); neigh->ah = mcast->ah; |