[Intel-wired-lan] [PATCH net v1 2/2] iavf: Fix race condition between iavf_shutdown and iavf_remove

[Mateusz Palczewski <mateusz.palczewski@intel.com>]

From: SlawomirX Laba <slawomirx.laba@intel.com>

Fix a deadlock introduced by commit
974578017fc1 ("iavf: Add waiting so the port is initialized in remove")
due to race condition between iavf_shutdown and iavf_remove, where
iavf_remove stucks forever in while loop since iavf_shutdown already
set __IAVF_REMOVE adapter state.

Fix this by checking if the __IAVF_IN_REMOVE_TASK has already been
set and return if so.

Fixes: 974578017fc1 ("iavf: Add waiting so the port is initialized in remove")
Signed-off-by: Slawomir Laba <slawomirx.laba@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
---
 drivers/net/ethernet/intel/iavf/iavf_main.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 74be5e3a09df..d0889fe24b9e 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -4744,23 +4744,24 @@ static int __maybe_unused iavf_resume(struct device *dev_d)
 static void iavf_remove(struct pci_dev *pdev)
 {
 	struct iavf_adapter *adapter = iavf_pdev_to_adapter(pdev);
-	struct net_device *netdev = adapter->netdev;
 	struct iavf_fdir_fltr *fdir, *fdirtmp;
 	struct iavf_vlan_filter *vlf, *vlftmp;
+	struct iavf_cloud_filter *cf, *cftmp;
 	struct iavf_adv_rss *rss, *rsstmp;
 	struct iavf_mac_filter *f, *ftmp;
-	struct iavf_cloud_filter *cf, *cftmp;
-	struct iavf_hw *hw = &adapter->hw;
+	struct net_device *netdev;
+	struct iavf_hw *hw;
 	int err;
 
-	/* When reboot/shutdown is in progress no need to do anything
-	 * as the adapter is already REMOVE state that was set during
-	 * iavf_shutdown() callback.
-	 */
-	if (adapter->state == __IAVF_REMOVE)
+	if (!adapter)
+		return;
+
+	netdev = adapter->netdev;
+	hw = &adapter->hw;
+
+	if (test_and_set_bit(__IAVF_IN_REMOVE_TASK, &adapter->crit_section))
 		return;
 
-	set_bit(__IAVF_IN_REMOVE_TASK, &adapter->crit_section);
 	/* Wait until port initialization is complete.
 	 * There are flows where register/unregister netdev may race.
 	 */
-- 
2.27.0

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