[net-next 08/21] ixgbe: handle close/suspend race with netif_device_detach/present

[Jeff Kirsher]

From: Emil Tantilov <emil.s.tanti...@intel.com>

When an interface is part of a namespace it is possible that
ixgbe_close() may be called while __ixgbe_shutdown() is running
which ends up in a double free WARN and/or a BUG in free_msi_irqs().

To handle this situation we extend the rtnl_lock() to protect the
call to netif_device_detach() and ixgbe_clear_interrupt_scheme()
in __ixgbe_shutdown() and check for netif_device_present()
to avoid clearing the interrupts second time in ixgbe_close();

Also extend the rtnl lock in ixgbe_resume() to netif_device_attach().

Signed-off-by: Emil Tantilov <emil.s.tanti...@intel.com>
Tested-by: Andrew Bowers <andrewx.bow...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c 
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 6732c90..476f012 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -6200,7 +6200,8 @@ int ixgbe_close(struct net_device *netdev)
 
        ixgbe_ptp_stop(adapter);
 
-       ixgbe_close_suspend(adapter);
+       if (netif_device_present(netdev))
+               ixgbe_close_suspend(adapter);
 
        ixgbe_fdir_filter_exit(adapter);
 
@@ -6245,14 +6246,12 @@ static int ixgbe_resume(struct pci_dev *pdev)
        if (!err && netif_running(netdev))
                err = ixgbe_open(netdev);
 
-       rtnl_unlock();
 
-       if (err)
-               return err;
-
-       netif_device_attach(netdev);
+       if (!err)
+               netif_device_attach(netdev);
+       rtnl_unlock();
 
-       return 0;
+       return err;
 }
 #endif /* CONFIG_PM */
 
@@ -6267,14 +6266,14 @@ static int __ixgbe_shutdown(struct pci_dev *pdev, bool 
*enable_wake)
        int retval = 0;
 #endif
 
+       rtnl_lock();
        netif_device_detach(netdev);
 
-       rtnl_lock();
        if (netif_running(netdev))
                ixgbe_close_suspend(adapter);
-       rtnl_unlock();
 
        ixgbe_clear_interrupt_scheme(adapter);
+       rtnl_unlock();
 
 #ifdef CONFIG_PM
        retval = pci_save_state(pdev);
-- 
2.9.3