ehea: fix race condition

When ehea_stop is called the function
cancel_work_sync(&port->reset_task) is used to ensure
that the reset task is not running anymore. We need an
additional flag to ensure that it can not be scheduled
after this call again for a certain time.

Signed-off-by: Jan-Bernd Themann <themann@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

2 files changed, 16 insertions, 7 deletions

diff --git a/drivers/net/ehea/ehea.h b/drivers/net/ehea/ehea.h
index bf57e1532f5e..e01926b7b5b7 100644
--- a/drivers/net/ehea/ehea.h
+++ b/drivers/net/ehea/ehea.h
@@ -40,7 +40,7 @@
 #include <asm/io.h>
 
 #define DRV_NAME        "ehea"
-#define DRV_VERSION     "EHEA_0091"
+#define DRV_VERSION     "EHEA_0092"
 
 /* eHEA capability flags */
 #define DLPAR_PORT_ADD_REM 1
@@ -478,6 +478,7 @@ struct ehea_port {
         int num_add_tx_qps;
         int num_mcs;
         int resets;
+        u64 flags;
         u64 mac_addr;
         u32 logical_port_id;
         u32 port_speed;
@@ -501,7 +502,8 @@ struct port_res_cfg {
 };
 
 enum ehea_flag_bits {
-        __EHEA_STOP_XFER
+        __EHEA_STOP_XFER,
+        __EHEA_DISABLE_PORT_RESET
 };
 
 void ehea_set_ethtool_ops(struct net_device *netdev);
diff --git a/drivers/net/ehea/ehea_main.c b/drivers/net/ehea/ehea_main.c
index 6ebcb221cd5e..49ba6a9a7b06 100644
--- a/drivers/net/ehea/ehea_main.c
+++ b/drivers/net/ehea/ehea_main.c
@@ -138,6 +138,12 @@ void ehea_dump(void *adr, int len, char *msg)
         }
 }
 
+void ehea_schedule_port_reset(struct ehea_port *port)
+{
+        if (!test_bit(__EHEA_DISABLE_PORT_RESET, &port->flags))
+                schedule_work(&port->reset_task);
+}
+
 static void ehea_update_firmware_handles(void)
 {
         struct ehea_fw_handle_entry *arr = NULL;
@@ -588,7 +594,7 @@ static int ehea_treat_poll_error(struct ehea_port_res *pr, int rq,
                                    "Resetting port.", pr->qp->init_attr.qp_nr);
                         ehea_dump(cqe, sizeof(*cqe), "CQE");
                 }
-                schedule_work(&pr->port->reset_task);
+                ehea_schedule_port_reset(pr->port);
                 return 1;
         }
 
@@ -766,7 +772,7 @@ static struct ehea_cqe *ehea_proc_cqes(struct ehea_port_res *pr, int my_quota)
                         ehea_error("Send Completion Error: Resetting port");
                         if (netif_msg_tx_err(pr->port))
                                 ehea_dump(cqe, sizeof(*cqe), "Send CQE");
-                        schedule_work(&pr->port->reset_task);
+                        ehea_schedule_port_reset(pr->port);
                         break;
                 }
 
@@ -886,7 +892,7 @@ static irqreturn_t ehea_qp_aff_irq_handler(int irq, void *param)
                 eqe = ehea_poll_eq(port->qp_eq);
         }
 
-        schedule_work(&port->reset_task);
+        ehea_schedule_port_reset(port);
 
         return IRQ_HANDLED;
 }
@@ -2606,13 +2612,14 @@ static int ehea_stop(struct net_device *dev)
         if (netif_msg_ifdown(port))
                 ehea_info("disabling port %s", dev->name);
 
+        set_bit(__EHEA_DISABLE_PORT_RESET, &port->flags);
         cancel_work_sync(&port->reset_task);
-
         mutex_lock(&port->port_lock);
         netif_stop_queue(dev);
         port_napi_disable(port);
         ret = ehea_down(dev);
         mutex_unlock(&port->port_lock);
+        clear_bit(__EHEA_DISABLE_PORT_RESET, &port->flags);
         return ret;
 }
 
@@ -2942,7 +2949,7 @@ static void ehea_tx_watchdog(struct net_device *dev)
 
         if (netif_carrier_ok(dev) &&
             !test_bit(__EHEA_STOP_XFER, &ehea_driver_flags))
-                schedule_work(&port->reset_task);
+                ehea_schedule_port_reset(port);
 }
 
 int ehea_sense_adapter_attr(struct ehea_adapter *adapter)