device-dax: Fix error path in dax_driver_register
The static variable match_always_count is supposed to track if there is
a driver registered that has .match_always set. If driver_register()
fails, the previous increment must be undone.
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210205222842.34896-4-uwe@kleine-koenig.org
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index ef53da4..d2419e8 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1420,7 +1420,15 @@ int __dax_driver_register(struct dax_device_driver *dax_drv,
mutex_unlock(&dax_bus_lock);
if (rc)
return rc;
- return driver_register(drv);
+
+ rc = driver_register(drv);
+ if (rc && dax_drv->match_always) {
+ mutex_lock(&dax_bus_lock);
+ match_always_count -= dax_drv->match_always;
+ mutex_unlock(&dax_bus_lock);
+ }
+
+ return rc;
}
EXPORT_SYMBOL_GPL(__dax_driver_register);