raid5: handle register_shrinker failure

register_shrinker() now can fail. When it happens, shrinker.nr_deferred is
null. We use it to determine if unregister_shrinker is required.

Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 08274b4..f94472d 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6372,7 +6372,7 @@ static void free_conf(struct r5conf *conf)
 {
        if (conf->log)
                r5l_exit_log(conf->log);
-       if (conf->shrinker.seeks)
+       if (conf->shrinker.nr_deferred)
                unregister_shrinker(&conf->shrinker);
 
        free_thread_groups(conf);