1 files changed, 40 insertions, 2 deletions

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index ac481ad112ad..704b8e034946 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -57,6 +57,9 @@ MODULE_PARM_DESC(ddp_min, "Minimum I/O size in bytes for "	\
 
 DEFINE_MUTEX(fcoe_config_mutex);
 
+/* fcoe_percpu_clean completion.  Waiter protected by fcoe_create_mutex */
+static DECLARE_COMPLETION(fcoe_flush_completion);
+
 /* fcoe host list */
 /* must only by accessed under the RTNL mutex */
 LIST_HEAD(fcoe_hostlist);
@@ -827,7 +830,7 @@ static void fcoe_percpu_thread_create(unsigned int cpu)
         thread = kthread_create(fcoe_percpu_receive_thread,
                                 (void *)p, "fcoethread/%d", cpu);
 
-        if (likely(!IS_ERR(p->thread))) {
+        if (likely(!IS_ERR(thread))) {
                 kthread_bind(thread, cpu);
                 wake_up_process(thread);
 
@@ -1300,6 +1303,15 @@ int fcoe_xmit(struct fc_lport *lp, struct fc_frame *fp)
 }
 
 /**
+ * fcoe_percpu_flush_done() - Indicate percpu queue flush completion.
+ * @skb: the skb being completed.
+ */
+static void fcoe_percpu_flush_done(struct sk_buff *skb)
+{
+        complete(&fcoe_flush_completion);
+}
+
+/**
  * fcoe_percpu_receive_thread() - recv thread per cpu
  * @arg: ptr to the fcoe per cpu struct
  *
@@ -1338,7 +1350,8 @@ int fcoe_percpu_receive_thread(void *arg)
                 fr = fcoe_dev_from_skb(skb);
                 lp = fr->fr_dev;
                 if (unlikely(lp == NULL)) {
-                        FCOE_NETDEV_DBG(skb->dev, "Invalid HBA Structure");
+                        if (skb->destructor != fcoe_percpu_flush_done)
+                                FCOE_NETDEV_DBG(skb->dev, "NULL lport in skb");
                         kfree_skb(skb);
                         continue;
                 }
@@ -1799,6 +1812,13 @@ int fcoe_link_ok(struct fc_lport *lp)
 /**
  * fcoe_percpu_clean() - Clear the pending skbs for an lport
  * @lp: the fc_lport
+ *
+ * Must be called with fcoe_create_mutex held to single-thread completion.
+ *
+ * This flushes the pending skbs by adding a new skb to each queue and
+ * waiting until they are all freed.  This assures us that not only are
+ * there no packets that will be handled by the lport, but also that any
+ * threads already handling packet have returned.
  */
 void fcoe_percpu_clean(struct fc_lport *lp)
 {
@@ -1823,7 +1843,25 @@ void fcoe_percpu_clean(struct fc_lport *lp)
                                 kfree_skb(skb);
                         }
                 }
+
+                if (!pp->thread || !cpu_online(cpu)) {
+                        spin_unlock_bh(&pp->fcoe_rx_list.lock);
+                        continue;
+                }
+
+                skb = dev_alloc_skb(0);
+                if (!skb) {
+                        spin_unlock_bh(&pp->fcoe_rx_list.lock);
+                        continue;
+                }
+                skb->destructor = fcoe_percpu_flush_done;
+
+                __skb_queue_tail(&pp->fcoe_rx_list, skb);
+                if (pp->fcoe_rx_list.qlen == 1)
+                        wake_up_process(pp->thread);
                 spin_unlock_bh(&pp->fcoe_rx_list.lock);
+
+                wait_for_completion(&fcoe_flush_completion);
         }
 }