From: Feras Daoud <fera...@mellanox.com>
[ Upstream commit 1c3098cdb05207e740715857df7b0998e372f527 ]
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 <fera...@mellanox.com>
Signed-off-by: Erez Shitrit <ere...@mellanox.com>
Reviewed-by: Alex Vesker <va...@mellanox.com>
Signed-off-by: Leon Romanovsky <l...@kernel.org>
Signed-off-by: Doug Ledford <dledf...@redhat.com>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
---
drivers/infiniband/ulp/ipoib/ipoib_vlan.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
index 57a34f87dedf..3a647fd50f09 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
@@ -185,7 +185,6 @@ int ipoib_vlan_delete(struct net_device *pdev, unsigned
short pkey)
list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
if (priv->pkey == pkey &&
priv->child_type == IPOIB_LEGACY_CHILD) {
- unregister_netdevice(priv->dev);
list_del(&priv->list);
dev = priv->dev;
break;
@@ -193,6 +192,11 @@ int ipoib_vlan_delete(struct net_device *pdev, unsigned
short pkey)
}
up_write(&ppriv->vlan_rwsem);
+ if (dev) {
+ ipoib_dbg(ppriv, "delete child vlan %s\n", dev->name);
+ unregister_netdevice(dev);
+ }
+
rtnl_unlock();
if (dev) {
--
2.11.0
