From: Yu Kuai <yukuai3@xxxxxxxxxx> This reverts commit b13015af94cf405f73ff64ce0797269554020c37. Because this will cause that r5c_disable_writeback_async() to wait forever, since caller hold reconfig_mutex and conf->log is not NULL: wait_event conf->log == NULL || (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) && (locked = mddev_trylock(mddev))) This problem is found by code review, and the null-ptr-deref this patch fixed will be fixed by another approch in the next patch. Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> --- drivers/md/raid5-cache.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 47ba7d9e81e1..083288e36949 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -3168,13 +3168,12 @@ void r5l_exit_log(struct r5conf *conf) { struct r5l_log *log = conf->log; + conf->log = NULL; + /* Ensure disable_writeback_work wakes up and exits */ wake_up(&conf->mddev->sb_wait); flush_work(&log->disable_writeback_work); md_unregister_thread(&log->reclaim_thread); - - conf->log = NULL; - mempool_exit(&log->meta_pool); bioset_exit(&log->bs); mempool_exit(&log->io_pool); -- 2.39.2