Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...

[mirror_ubuntu-zesty-kernel.git] / drivers / target / target_core_hba.c

diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c
index d746a3a4a623c306a533bed561a4ec07dd072141..9522960c7fddacf70c682326a38586f8562c4487 100644 (file)
--- a/drivers/target/target_core_hba.c
+++ b/drivers/target/target_core_hba.c
@@ -84,8 +84,16 @@ void target_backend_unregister(const struct target_backend_ops *ops)
        list_for_each_entry(tb, &backend_list, list) {
                if (tb->ops == ops) {
                        list_del(&tb->list);
+                       mutex_unlock(&backend_mutex);
+                       /*
+                        * Wait for any outstanding backend driver ->rcu_head
+                        * callbacks to complete post TBO->free_device() ->
+                        * call_rcu(), before allowing backend driver module
+                        * unload of target_backend_ops->owner to proceed.
+                        */
+                       rcu_barrier();
                        kfree(tb);
-                       break;
+                       return;
                }
        }
        mutex_unlock(&backend_mutex);