bcache: release dc->writeback_lock properly in bch_writeback_thread()
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 <shan.hai@oracle.com>
Signed-off-by: Coly Li <colyli@suse.de>
Tested-by: Shenghui Wang <shhuiw@foxmail.com>
Cc: stable@vger.kernel.org #4.17+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 6be05bd..08c3a9f 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -685,8 +685,10 @@ 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);
