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author | Stefan Bader <stefan.bader@canonical.com> | 2015-11-30 05:44:49 +0300 |
---|---|---|
committer | Sasha Levin <sasha.levin@oracle.com> | 2016-02-10 06:56:17 +0300 |
commit | fa362f255a283516f852b5405ba30462da7b6f5e (patch) | |
tree | dc1ff344adde0c47fef792beff85831356a0b3cf /drivers/md | |
parent | e321fdfb1a07ad716265a24346dbe0814b102c09 (diff) | |
download | linux-fa362f255a283516f852b5405ba30462da7b6f5e.tar.xz |
bcache: prevent crash on changing writeback_running
[ Upstream commit 8d16ce540c94c9d366eb36fc91b7154d92d6397b ]
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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers/md')
-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) |