[PATCH 4.4 114/115] IB/ipoib: Grab rtnl lock on heavy flush when calling ndo_open/stop

Greg Kroah-Hartman
2017-12-18T15:57:38Z

From: Alex Vesker <valex@mellanox.com>

[ Upstream commit b4b678b06f6eef18bff44a338c01870234db0bc9 ]

When ndo_open and ndo_stop are called RTNL lock should be held.
In this specific case ipoib_ib_dev_open calls the offloaded ndo_open
which re-sets the number of TX queue assuming RTNL lock is held.
Since RTNL lock is not held, RTNL assert will fail.

Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/infiniband/ulp/ipoib/ipoib_ib.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -1044,10 +1044,15 @@ static void __ipoib_ib_dev_flush(struct
ipoib_ib_dev_down(dev);

if (level == IPOIB_FLUSH_HEAVY) {
+ rtnl_lock();
if (test_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
ipoib_ib_dev_stop(dev);
- if (ipoib_ib_dev_open(dev) != 0)
+
+ result = ipoib_ib_dev_open(dev);
+ rtnl_unlock();
+ if (result)
return;
+
if (netif_queue_stopped(dev))
netif_start_queue(dev);
}