summaryrefslogtreecommitdiffstats
path: root/drivers/md/bcache
diff options
context:
space:
mode:
authorStefan Bader <stefan.bader@canonical.com>2015-11-30 03:44:49 +0100
committerJens Axboe <axboe@fb.com>2015-12-31 04:23:14 +0100
commit8d16ce540c94c9d366eb36fc91b7154d92d6397b (patch)
tree0fae348076b0dcd745a2ee2cadaba965bd0587e4 /drivers/md/bcache
parentbcache: allows use of register in udev to avoid "device_busy" error. (diff)
downloadlinux-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>
Diffstat (limited to 'drivers/md/bcache')
-rw-r--r--drivers/md/bcache/writeback.h3
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)