diff options
| author | Stefan Bader <stefan.bader@canonical.com> | 2015-11-30 03:44:49 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-12-31 04:23:14 +0100 |
| commit | 8d16ce540c94c9d366eb36fc91b7154d92d6397b (patch) | |
| tree | 0fae348076b0dcd745a2ee2cadaba965bd0587e4 | |
| parent | bcache: allows use of register in udev to avoid "device_busy" error. (diff) | |
| download | linux-8d16ce540c94c9d366eb36fc91b7154d92d6397b.tar.xz linux-8d16ce540c94c9d366eb36fc91b7154d92d6397b.zip | |
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>
| -rw-r--r-- | drivers/md/bcache/writeback.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h index 0a9dab187b79..073a042aed24 100644 --- a/drivers/md/bcache/writeback.h +++ b/drivers/md/bcache/writeback.h @@ -63,7 +63,8 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio, static inline void bch_writeback_queue(struct cached_dev *dc) { - wake_up_process(dc->writeback_thread); + if (!IS_ERR_OR_NULL(dc->writeback_thread)) + wake_up_process(dc->writeback_thread); } static inline void bch_writeback_add(struct cached_dev *dc) |