[PATCH 1/1] bcache: release the lock before stopping the writeback thread

[Shan Hai <shan.hai@xxxxxxxxxx>]

The writeback thread would exit with a lock held when the cache device is
detached via sysfs interface, fix it by releasing the held lock before exiting
the thread.

Signed-off-by: Shan Hai <shan.hai@xxxxxxxxxx>
---
 drivers/md/bcache/writeback.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 481d4cf..adc583f 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -679,8 +679,10 @@ static int bch_writeback_thread(void *arg)
 			 * data on cache. BCACHE_DEV_DETACHING flag is set in
 			 * bch_cached_dev_detach().
 			 */
-			if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags))
+			if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) {
+				up_write(&dc->writeback_lock);
 				break;
+			}
 		}
 
 		up_write(&dc->writeback_lock);
-- 
2.7.4