3.16.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Slava Pestov <sp@xxxxxxxxxxxxx> commit a664d0f05a2ec02c8f042db536d84d15d6e19e81 upstream. We never started the writeback thread in this case, so don't stop it. Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/md/bcache/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1073,7 +1073,8 @@ static void cached_dev_free(struct closu struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl); cancel_delayed_work_sync(&dc->writeback_rate_update); - kthread_stop(dc->writeback_thread); + if (!IS_ERR_OR_NULL(dc->writeback_thread)) + kthread_stop(dc->writeback_thread); mutex_lock(&bch_register_lock);