IB/ipoib: Fix deadlock over vlan_mutex
authorFeras Daoud <ferasda@mellanox.com>
Wed, 28 Dec 2016 12:47:22 +0000 (14:47 +0200)
committerDoug Ledford <dledford@redhat.com>
Thu, 12 Jan 2017 19:01:02 +0000 (14:01 -0500)
commit1c3098cdb05207e740715857df7b0998e372f527
tree509e47da55579a63c00c710a2105f5fdc522c253
parent80b5b35aba62232521b31440f0a3cf6caa033849
IB/ipoib: Fix deadlock over vlan_mutex

This patch fixes Deadlock while executing ipoib_vlan_delete.

The function takes the vlan_rwsem semaphore and calls
unregister_netdevice. The later function calls
ipoib_mcast_stop_thread that cause workqueue flush.

When the queue has one of the ipoib_ib_dev_flush_xxx events,
a deadlock occur because these events also tries to catch the
same vlan_rwsem semaphore.

To fix, unregister_netdevice should be called after releasing
the semaphore.

Fixes: cbbe1efa4972 ("IPoIB: Fix deadlock between ipoib_open() and child interface create")
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
drivers/infiniband/ulp/ipoib/ipoib_vlan.c