IB/ipath: fix race with exposing reset file

[pandora-kernel.git] / drivers / infiniband / hw / ipath / ipath_sysfs.c

diff --git a/drivers/infiniband/hw/ipath/ipath_sysfs.c b/drivers/infiniband/hw/ipath/ipath_sysfs.c
index 32acd80..f323791 100644 (file)
--- a/drivers/infiniband/hw/ipath/ipath_sysfs.c
+++ b/drivers/infiniband/hw/ipath/ipath_sysfs.c
@@ -711,10 +711,22 @@ static struct attribute_group dev_attr_group = {
  * enters diag mode.  A device reset is quite likely to crash the
  * machine entirely, so we don't want to normally make it
  * available.
+ *
+ * Called with ipath_mutex held.
  */
 int ipath_expose_reset(struct device *dev)
 {
-       return device_create_file(dev, &dev_attr_reset);
+       static int exposed;
+       int ret;
+
+       if (!exposed) {
+               ret = device_create_file(dev, &dev_attr_reset);
+               exposed = 1;
+       }
+       else
+               ret = 0;
+
+       return ret;
 }
 
 int ipath_driver_create_group(struct device_driver *drv)