iavf: Fix race between iavf_close and iavf_reset_task

During stress tests with adding VF to namespace and changing vf's
trust there was a race between iavf_reset_task and iavf_close.
Sometimes when IAVF_FLAG_AQ_DISABLE_QUEUES from iavf_close was sent
to PF after reset and before IAVF_AQ_GET_CONFIG was sent then PF
returns error IAVF_NOT_SUPPORTED to disable queues request and
following requests. There is need to get_config before other
aq_required will be send but iavf_close clears all flags, if
get_config was not sent before iavf_close, then it will not be send
at all.

In case when IAVF_FLAG_AQ_GET_OFFLOAD_VLAN_V2_CAPS was sent before
IAVF_FLAG_AQ_DISABLE_QUEUES then there was rtnl_lock deadlock
between iavf_close and iavf_adminq_task until iavf_close timeouts
and disable queues was sent after iavf_close ends.

There was also a problem with sending delete/add filters.
Sometimes when filters was not yet added to PF and in
iavf_close all filters was set to remove there might be a try
to remove nonexistent filters on PF.

Add aq_required_tmp to save aq_required flags and send them after
disable_queues will be handled. Clear flags given to iavf_down
different than IAVF_FLAG_AQ_GET_CONFIG as this flag is necessary
to sent other aq_required. Remove some flags that we don't
want to send as we are in iavf_close and we want to disable
interface. Remove filters which was not yet sent and send del
filters flags only when there are filters to remove.

Signed-off-by: Michal Jaron <michalx.jaron@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index f39440a..b62bf4e 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -1270,66 +1270,138 @@ static void iavf_up_complete(struct iavf_adapter *adapter)
 }
 
 /**
- * iavf_down - Shutdown the connection processing
+ * iavf_clear_mac_vlan_filters - Remove mac and vlan filters not sent to PF
+ * yet and mark other to be removed.
  * @adapter: board private structure
- *
- * Expects to be called while holding the __IAVF_IN_CRITICAL_TASK bit lock.
  **/
-void iavf_down(struct iavf_adapter *adapter)
+static void iavf_clear_mac_vlan_filters(struct iavf_adapter *adapter)
 {
-       struct net_device *netdev = adapter->netdev;
-       struct iavf_vlan_filter *vlf;
-       struct iavf_cloud_filter *cf;
-       struct iavf_fdir_fltr *fdir;
-       struct iavf_mac_filter *f;
-       struct iavf_adv_rss *rss;
-
-       if (adapter->state <= __IAVF_DOWN_PENDING)
-               return;
-
-       netif_carrier_off(netdev);
-       netif_tx_disable(netdev);
-       adapter->link_up = false;
-       iavf_napi_disable_all(adapter);
-       iavf_irq_disable(adapter);
+       struct iavf_vlan_filter *vlf, *vlftmp;
+       struct iavf_mac_filter *f, *ftmp;
 
        spin_lock_bh(&adapter->mac_vlan_list_lock);
-
        /* clear the sync flag on all filters */
        __dev_uc_unsync(adapter->netdev, NULL);
        __dev_mc_unsync(adapter->netdev, NULL);
 
        /* remove all MAC filters */
-       list_for_each_entry(f, &adapter->mac_filter_list, list) {
-               f->remove = true;
+       list_for_each_entry_safe(f, ftmp, &adapter->mac_filter_list,
+                                list) {
+               if (f->add) {
+                       list_del(&f->list);
+                       kfree(f);
+               } else {
+                       f->remove = true;
+               }
        }
 
        /* remove all VLAN filters */
-       list_for_each_entry(vlf, &adapter->vlan_filter_list, list) {
-               vlf->remove = true;
+       list_for_each_entry_safe(vlf, vlftmp, &adapter->vlan_filter_list,
+                                list) {
+               if (vlf->add) {
+                       list_del(&vlf->list);
+                       kfree(vlf);
+               } else {
+                       vlf->remove = true;
+               }
        }
-
        spin_unlock_bh(&adapter->mac_vlan_list_lock);
+}
+
+/**
+ * iavf_clear_cloud_filters - Remove cloud filters not sent to PF yet and
+ * mark other to be removed.
+ * @adapter: board private structure
+ **/
+static void iavf_clear_cloud_filters(struct iavf_adapter *adapter)
+{
+       struct iavf_cloud_filter *cf, *cftmp;
 
        /* remove all cloud filters */
        spin_lock_bh(&adapter->cloud_filter_list_lock);
-       list_for_each_entry(cf, &adapter->cloud_filter_list, list) {
-               cf->del = true;
+       list_for_each_entry_safe(cf, cftmp, &adapter->cloud_filter_list,
+                                list) {
+               if (cf->add) {
+                       list_del(&cf->list);
+                       kfree(cf);
+                       adapter->num_cloud_filters--;
+               } else {
+                       cf->del = true;
+               }
        }
        spin_unlock_bh(&adapter->cloud_filter_list_lock);
+}
+
+/**
+ * iavf_clear_fdir_filters - Remove fdir filters not sent to PF yet and mark
+ * other to be removed.
+ * @adapter: board private structure
+ **/
+static void iavf_clear_fdir_filters(struct iavf_adapter *adapter)
+{
+       struct iavf_fdir_fltr *fdir, *fdirtmp;
 
        /* remove all Flow Director filters */
        spin_lock_bh(&adapter->fdir_fltr_lock);
-       list_for_each_entry(fdir, &adapter->fdir_list_head, list) {
-               fdir->state = IAVF_FDIR_FLTR_DEL_REQUEST;
+       list_for_each_entry_safe(fdir, fdirtmp, &adapter->fdir_list_head,
+                                list) {
+               if (fdir->state == IAVF_FDIR_FLTR_ADD_REQUEST) {
+                       list_del(&fdir->list);
+                       kfree(fdir);
+                       adapter->fdir_active_fltr--;
+               } else {
+                       fdir->state = IAVF_FDIR_FLTR_DEL_REQUEST;
+               }
        }
        spin_unlock_bh(&adapter->fdir_fltr_lock);
+}
+
+/**
+ * iavf_clear_adv_rss_conf - Remove adv rss conf not sent to PF yet and mark
+ * other to be removed.
+ * @adapter: board private structure
+ **/
+static void iavf_clear_adv_rss_conf(struct iavf_adapter *adapter)
+{
+       struct iavf_adv_rss *rss, *rsstmp;
 
        /* remove all advance RSS configuration */
        spin_lock_bh(&adapter->adv_rss_lock);
-       list_for_each_entry(rss, &adapter->adv_rss_list_head, list)
-               rss->state = IAVF_ADV_RSS_DEL_REQUEST;
+       list_for_each_entry_safe(rss, rsstmp, &adapter->adv_rss_list_head,
+                                list) {
+               if (rss->state == IAVF_ADV_RSS_ADD_REQUEST) {
+                       list_del(&rss->list);
+                       kfree(rss);
+               } else {
+                       rss->state = IAVF_ADV_RSS_DEL_REQUEST;
+               }
+       }
        spin_unlock_bh(&adapter->adv_rss_lock);
+}
+
+/**
+ * iavf_down - Shutdown the connection processing
+ * @adapter: board private structure
+ *
+ * Expects to be called while holding the __IAVF_IN_CRITICAL_TASK bit lock.
+ **/
+void iavf_down(struct iavf_adapter *adapter)
+{
+       struct net_device *netdev = adapter->netdev;
+
+       if (adapter->state <= __IAVF_DOWN_PENDING)
+               return;
+
+       netif_carrier_off(netdev);
+       netif_tx_disable(netdev);
+       adapter->link_up = false;
+       iavf_napi_disable_all(adapter);
+       iavf_irq_disable(adapter);
+
+       iavf_clear_mac_vlan_filters(adapter);
+       iavf_clear_cloud_filters(adapter);
+       iavf_clear_fdir_filters(adapter);
+       iavf_clear_adv_rss_conf(adapter);
 
        if (!(adapter->flags & IAVF_FLAG_PF_COMMS_FAILED)) {
                /* cancel any current operation */
@@ -1338,11 +1410,16 @@ void iavf_down(struct iavf_adapter *adapter)
                 * here for this to complete. The watchdog is still running
                 * and it will take care of this.
                 */
-               adapter->aq_required = IAVF_FLAG_AQ_DEL_MAC_FILTER;
-               adapter->aq_required |= IAVF_FLAG_AQ_DEL_VLAN_FILTER;
-               adapter->aq_required |= IAVF_FLAG_AQ_DEL_CLOUD_FILTER;
-               adapter->aq_required |= IAVF_FLAG_AQ_DEL_FDIR_FILTER;
-               adapter->aq_required |= IAVF_FLAG_AQ_DEL_ADV_RSS_CFG;
+               if (!list_empty(&adapter->mac_filter_list))
+                       adapter->aq_required |= IAVF_FLAG_AQ_DEL_MAC_FILTER;
+               if (!list_empty(&adapter->vlan_filter_list))
+                       adapter->aq_required |= IAVF_FLAG_AQ_DEL_VLAN_FILTER;
+               if (!list_empty(&adapter->cloud_filter_list))
+                       adapter->aq_required |= IAVF_FLAG_AQ_DEL_CLOUD_FILTER;
+               if (!list_empty(&adapter->fdir_list_head))
+                       adapter->aq_required |= IAVF_FLAG_AQ_DEL_FDIR_FILTER;
+               if (!list_empty(&adapter->adv_rss_list_head))
+                       adapter->aq_required |= IAVF_FLAG_AQ_DEL_ADV_RSS_CFG;
                adapter->aq_required |= IAVF_FLAG_AQ_DISABLE_QUEUES;
        }
 
@@ -4173,6 +4250,7 @@ err_unlock:
 static int iavf_close(struct net_device *netdev)
 {
        struct iavf_adapter *adapter = netdev_priv(netdev);
+       u64 aq_to_restore;
        int status;
 
        mutex_lock(&adapter->crit_lock);
@@ -4185,6 +4263,29 @@ static int iavf_close(struct net_device *netdev)
        set_bit(__IAVF_VSI_DOWN, adapter->vsi.state);
        if (CLIENT_ENABLED(adapter))
                adapter->flags |= IAVF_FLAG_CLIENT_NEEDS_CLOSE;
+       /* We cannot send IAVF_FLAG_AQ_GET_OFFLOAD_VLAN_V2_CAPS before
+        * IAVF_FLAG_AQ_DISABLE_QUEUES because in such case there is rtnl
+        * deadlock with adminq_task() until iavf_close timeouts. We must send
+        * IAVF_FLAG_AQ_GET_CONFIG before IAVF_FLAG_AQ_DISABLE_QUEUES to make
+        * disable queues possible for vf. Give only necessary flags to
+        * iavf_down and save other to set them right before iavf_close()
+        * returns, when IAVF_FLAG_AQ_DISABLE_QUEUES will be already sent and
+        * iavf will be in DOWN state.
+        */
+       aq_to_restore = adapter->aq_required;
+       adapter->aq_required &= IAVF_FLAG_AQ_GET_CONFIG;
+
+       /* Remove flags which we do not want to send after close or we want to
+        * send before disable queues.
+        */
+       aq_to_restore &= ~(IAVF_FLAG_AQ_GET_CONFIG              |
+                          IAVF_FLAG_AQ_ENABLE_QUEUES           |
+                          IAVF_FLAG_AQ_CONFIGURE_QUEUES        |
+                          IAVF_FLAG_AQ_ADD_VLAN_FILTER         |
+                          IAVF_FLAG_AQ_ADD_MAC_FILTER          |
+                          IAVF_FLAG_AQ_ADD_CLOUD_FILTER        |
+                          IAVF_FLAG_AQ_ADD_FDIR_FILTER         |
+                          IAVF_FLAG_AQ_ADD_ADV_RSS_CFG);
 
        iavf_down(adapter);
        iavf_change_state(adapter, __IAVF_DOWN_PENDING);
@@ -4208,6 +4309,10 @@ static int iavf_close(struct net_device *netdev)
                                    msecs_to_jiffies(500));
        if (!status)
                netdev_warn(netdev, "Device resources not yet released\n");
+
+       mutex_lock(&adapter->crit_lock);
+       adapter->aq_required |= aq_to_restore;
+       mutex_unlock(&adapter->crit_lock);
        return 0;
 }