Re: [PATCH] bcache: prevent crash on changing writeback_running
From: Slava Pestov <hidden>
Date: 2014-08-19 18:03:14
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Thanks, this is now in our development branch. On Tue, Aug 19, 2014 at 6:01 AM, Stefan Bader [off-list ref] wrote:
quoted hunk ↗ jump to hunk
commit a664d0f05a2ec02c8f042db536d84d15d6e19e81 bcache: fix crash on shutdown in passthrough mode 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 <redacted> --- drivers/md/bcache/writeback.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h index 0a9dab1..073a042 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) --1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html