Commit 8d16ce54 authored Nov 29, 2015 by Stefan Bader Committed by Jens Axboe Dec 30, 2015

bcache: prevent crash on changing writeback_running

Added a safeguard in the shutdown case. At least while not being
attached it is also possible to trigger a kernel bug by writing into
writeback_running. This change  adds the same check before trying to
wake up the thread for that case.

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>

parent d7076f21

drivers/md/bcache/writeback.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -63,6 +63,7 @@ static inline bool should_writeback(struct cached_dev dc, struct bio bio,

		static inline void bch_writeback_queue(struct cached_dev *dc)
		{
		if (!IS_ERR_OR_NULL(dc->writeback_thread))
		wake_up_process(dc->writeback_thread);
		}