From d1a265da7b2983e3201988f1a8202e749e2d4352 Mon Sep 17 00:00:00 2001 From: Shan Hai Date: Thu, 23 Aug 2018 02:02:56 +0800 Subject: [PATCH] bcache: release dc->writeback_lock properly in bch_writeback_thread() commit 3943b040f11ed0cc6d4585fd286a623ca8634547 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: fadd94e05c02 (bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set) Signed-off-by: Shan Hai Signed-off-by: Coly Li Tested-by: Shenghui Wang Cc: stable@vger.kernel.org #4.17+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- 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 930b00f6a3a2..5adb0c850b6c 100644 --- 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);