Commit d2806d96 authored by Marcin Szycik's avatar Marcin Szycik Committed by Tony Nguyen
Browse files

Revert "iavf: Detach device during reset task" 



This reverts commit aa626da9.

Detaching device during reset was not fully fixing the rtnl locking issue,
as there could be a situation where callback was already in progress before
detaching netdev.

Furthermore, detaching netdevice causes TX timeouts if traffic is running.
To reproduce:

ip netns exec ns1 iperf3 -c $PEER_IP -t 600 --logfile /dev/null &
while :; do
        for i in 200 7000 400 5000 300 3000 ; do
		ip netns exec ns1 ip link set $VF1 mtu $i
                sleep 2
        done
        sleep 10
done

Currently, callbacks such as iavf_change_mtu() wait for the reset.
If the reset fails to acquire the rtnl_lock, they schedule the netdev
update for later while continuing the reset flow. Operations like MTU
changes are performed under the rtnl_lock. Therefore, when the operation
finishes, another callback that uses rtnl_lock can start.

Signed-off-by: default avatarDawid Wesierski <dawidx.wesierski@intel.com>
Signed-off-by: default avatarMarcin Szycik <marcin.szycik@linux.intel.com>
Signed-off-by: default avatarMateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: default avatarRafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent c2ed2403

drivers/net/ethernet/intel/iavf/iavf_main.c

+2 −11
Original line number Diff line number Diff line
@@ -2977,11 +2977,6 @@ static void iavf_reset_task(struct work_struct *work) 
	int i = 0, err;

	bool running;



	/* Detach interface to avoid subsequent NDO callbacks */

	rtnl_lock();

	netif_device_detach(netdev);

	rtnl_unlock();



	/* When device is being removed it doesn't make sense to run the reset

	 * task, just return in such a case.

	 */
@@ -2989,7 +2984,7 @@ static void iavf_reset_task(struct work_struct *work) 
		if (adapter->state != __IAVF_REMOVE)

			queue_work(adapter->wq, &adapter->reset_task);



		goto reset_finish;

		return;

	}



	while (!mutex_trylock(&adapter->client_lock))
@@ -3192,7 +3187,7 @@ static void iavf_reset_task(struct work_struct *work) 
	mutex_unlock(&adapter->client_lock);

	mutex_unlock(&adapter->crit_lock);



	goto reset_finish;

	return;

reset_err:

	if (running) {

		set_bit(__IAVF_VSI_DOWN, adapter->vsi.state);
@@ -3213,10 +3208,6 @@ static void iavf_reset_task(struct work_struct *work) 
	}



	dev_err(&adapter->pdev->dev, "failed to allocate resources during reinit\n");

reset_finish:

	rtnl_lock();

	netif_device_attach(netdev);

	rtnl_unlock();

}



/**