IB/ipoib: No longer use flush as a parameter

Various places in the IPoIB code had a deadlock related to flushing
the ipoib workqueue.  Now that we have per device workqueues and a
specific flush workqueue, there is no longer a deadlock issue with
flushing the device specific workqueues and we can do so unilaterally.

Signed-off-by: Doug Ledford <dledford@redhat.com>

4 files changed, 39 insertions, 30 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index e940cd9f8471..9ef432ae72e8 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -478,10 +478,10 @@ void ipoib_ib_dev_flush_heavy(struct work_struct *work);
 void ipoib_pkey_event(struct work_struct *work);
 void ipoib_ib_dev_cleanup(struct net_device *dev);
 
-int ipoib_ib_dev_open(struct net_device *dev, int flush);
+int ipoib_ib_dev_open(struct net_device *dev);
 int ipoib_ib_dev_up(struct net_device *dev);
-int ipoib_ib_dev_down(struct net_device *dev, int flush);
-int ipoib_ib_dev_stop(struct net_device *dev, int flush);
+int ipoib_ib_dev_down(struct net_device *dev);
+int ipoib_ib_dev_stop(struct net_device *dev);
 void ipoib_pkey_dev_check_presence(struct net_device *dev);
 
 int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port);
@@ -493,7 +493,7 @@ void ipoib_mcast_send(struct net_device *dev, u8 *daddr, struct sk_buff *skb);
 
 void ipoib_mcast_restart_task(struct work_struct *work);
 int ipoib_mcast_start_thread(struct net_device *dev);
-int ipoib_mcast_stop_thread(struct net_device *dev, int flush);
+int ipoib_mcast_stop_thread(struct net_device *dev);
 
 void ipoib_mcast_dev_down(struct net_device *dev);
 void ipoib_mcast_dev_flush(struct net_device *dev);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index 2a56b7a11a92..e144d07d53cc 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -659,22 +659,21 @@ void ipoib_reap_ah(struct work_struct *work)
                                    round_jiffies_relative(HZ));
 }
 
-static void ipoib_flush_ah(struct net_device *dev, int flush)
+static void ipoib_flush_ah(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
         cancel_delayed_work(&priv->ah_reap_task);
-        if (flush)
-                flush_workqueue(priv->wq);
+        flush_workqueue(priv->wq);
         ipoib_reap_ah(&priv->ah_reap_task.work);
 }
 
-static void ipoib_stop_ah(struct net_device *dev, int flush)
+static void ipoib_stop_ah(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
         set_bit(IPOIB_STOP_REAPER, &priv->flags);
-        ipoib_flush_ah(dev, flush);
+        ipoib_flush_ah(dev);
 }
 
 static void ipoib_ib_tx_timer_func(unsigned long ctx)
@@ -682,7 +681,7 @@ static void ipoib_ib_tx_timer_func(unsigned long ctx)
         drain_tx_cq((struct net_device *)ctx);
 }
 
-int ipoib_ib_dev_open(struct net_device *dev, int flush)
+int ipoib_ib_dev_open(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
         int ret;
@@ -724,7 +723,7 @@ int ipoib_ib_dev_open(struct net_device *dev, int flush)
 dev_stop:
         if (!test_and_set_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
                 napi_enable(&priv->napi);
-        ipoib_ib_dev_stop(dev, flush);
+        ipoib_ib_dev_stop(dev);
         return -1;
 }
 
@@ -756,7 +755,7 @@ int ipoib_ib_dev_up(struct net_device *dev)
         return ipoib_mcast_start_thread(dev);
 }
 
-int ipoib_ib_dev_down(struct net_device *dev, int flush)
+int ipoib_ib_dev_down(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
@@ -765,7 +764,7 @@ int ipoib_ib_dev_down(struct net_device *dev, int flush)
         clear_bit(IPOIB_FLAG_OPER_UP, &priv->flags);
         netif_carrier_off(dev);
 
-        ipoib_mcast_stop_thread(dev, flush);
+        ipoib_mcast_stop_thread(dev);
         ipoib_mcast_dev_flush(dev);
 
         ipoib_flush_paths(dev);
@@ -825,7 +824,7 @@ void ipoib_drain_cq(struct net_device *dev)
         local_bh_enable();
 }
 
-int ipoib_ib_dev_stop(struct net_device *dev, int flush)
+int ipoib_ib_dev_stop(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
         struct ib_qp_attr qp_attr;
@@ -895,7 +894,7 @@ timeout:
         if (ib_modify_qp(priv->qp, &qp_attr, IB_QP_STATE))
                 ipoib_warn(priv, "Failed to modify QP to RESET state\n");
 
-        ipoib_flush_ah(dev, flush);
+        ipoib_flush_ah(dev);
 
         ib_req_notify_cq(priv->recv_cq, IB_CQ_NEXT_COMP);
 
@@ -919,7 +918,7 @@ int ipoib_ib_dev_init(struct net_device *dev, struct ib_device *ca, int port)
                     (unsigned long) dev);
 
         if (dev->flags & IFF_UP) {
-                if (ipoib_ib_dev_open(dev, 1)) {
+                if (ipoib_ib_dev_open(dev)) {
                         ipoib_transport_dev_cleanup(dev);
                         return -ENODEV;
                 }
@@ -1038,16 +1037,16 @@ static void __ipoib_ib_dev_flush(struct ipoib_dev_priv *priv,
         if (level == IPOIB_FLUSH_LIGHT) {
                 ipoib_mark_paths_invalid(dev);
                 ipoib_mcast_dev_flush(dev);
-                ipoib_flush_ah(dev, 0);
+                ipoib_flush_ah(dev);
         }
 
         if (level >= IPOIB_FLUSH_NORMAL)
-                ipoib_ib_dev_down(dev, 0);
+                ipoib_ib_dev_down(dev);
 
         if (level == IPOIB_FLUSH_HEAVY) {
                 if (test_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
-                        ipoib_ib_dev_stop(dev, 0);
-                if (ipoib_ib_dev_open(dev, 0) != 0)
+                        ipoib_ib_dev_stop(dev);
+                if (ipoib_ib_dev_open(dev) != 0)
                         return;
                 if (netif_queue_stopped(dev))
                         netif_start_queue(dev);
@@ -1099,7 +1098,7 @@ void ipoib_ib_dev_cleanup(struct net_device *dev)
          */
         ipoib_flush_paths(dev);
 
-        ipoib_mcast_stop_thread(dev, 1);
+        ipoib_mcast_stop_thread(dev);
         ipoib_mcast_dev_flush(dev);
 
         /*
@@ -1108,7 +1107,7 @@ void ipoib_ib_dev_cleanup(struct net_device *dev)
          * the neighbor garbage collection is stopped and reaped.
          * That should all be done now, so make a final ah flush.
          */
-        ipoib_stop_ah(dev, 1);
+        ipoib_stop_ah(dev);
 
         ipoib_transport_dev_cleanup(dev);
 }
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 4be80bec93ca..176b3dfb49c3 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -108,7 +108,7 @@ int ipoib_open(struct net_device *dev)
 
         set_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);
 
-        if (ipoib_ib_dev_open(dev, 1)) {
+        if (ipoib_ib_dev_open(dev)) {
                 if (!test_bit(IPOIB_PKEY_ASSIGNED, &priv->flags))
                         return 0;
                 goto err_disable;
@@ -139,7 +139,7 @@ int ipoib_open(struct net_device *dev)
         return 0;
 
 err_stop:
-        ipoib_ib_dev_stop(dev, 1);
+        ipoib_ib_dev_stop(dev);
 
 err_disable:
         clear_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);
@@ -157,8 +157,8 @@ static int ipoib_stop(struct net_device *dev)
 
         netif_stop_queue(dev);
 
-        ipoib_ib_dev_down(dev, 1);
-        ipoib_ib_dev_stop(dev, 0);
+        ipoib_ib_dev_down(dev);
+        ipoib_ib_dev_stop(dev);
 
         if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
                 struct ipoib_dev_priv *cpriv;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 9d3c1ed576ea..bb1b69904f96 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -613,7 +613,7 @@ int ipoib_mcast_start_thread(struct net_device *dev)
         return 0;
 }
 
-int ipoib_mcast_stop_thread(struct net_device *dev, int flush)
+int ipoib_mcast_stop_thread(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
@@ -624,8 +624,7 @@ int ipoib_mcast_stop_thread(struct net_device *dev, int flush)
         cancel_delayed_work(&priv->mcast_task);
         mutex_unlock(&mcast_mutex);
 
-        if (flush)
-                flush_workqueue(priv->wq);
+        flush_workqueue(priv->wq);
 
         return 0;
 }
@@ -797,7 +796,18 @@ void ipoib_mcast_restart_task(struct work_struct *work)
 
         ipoib_dbg_mcast(priv, "restarting multicast task\n");
 
-        ipoib_mcast_stop_thread(dev, 0);
+        /*
+         * We're running on the priv->wq right now, so we can't call
+         * mcast_stop_thread as it wants to flush the wq and that
+         * will deadlock.  We don't actually *need* to stop the
+         * thread here anyway, so just clear the run flag, cancel
+         * any delayed work, do our work, remove the old entries,
+         * then restart the thread.
+         */
+        mutex_lock(&mcast_mutex);
+        clear_bit(IPOIB_MCAST_RUN, &priv->flags);
+        cancel_delayed_work(&priv->mcast_task);
+        mutex_unlock(&mcast_mutex);
 
         local_irq_save(flags);
         netif_addr_lock(dev);