bcache: release dc->writeback_lock properly in bch_writeback_thread()

commit 3943b04 upstream. 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 while-loop. Fixes: fadd94e (bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set) Signed-off-by: Shan Hai <[email protected]> Signed-off-by: Coly Li <[email protected]> Tested-by: Shenghui Wang <[email protected]> Cc: [email protected] #4.17+ Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
intel · Sep 9, 2018 · 3ddf06c · 3ddf06c
1 parent 6c6d174
commit 3ddf06c
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
@@ -456,8 +456,10 @@ 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);