[PATCH 4.19 188/271] bcache: destroy dc->writeback_write_wq if failed to create dc->writeback_thread

[Greg Kroah-Hartman]

From: Coly Li <col...@suse.de>

commit f54d801dda14942dbefa00541d10603015b7859c upstream.

Commit 9baf30972b55 ("bcache: fix for gc and write-back race") added a
new work queue dc->writeback_write_wq, but forgot to destroy it in the
error condition when creating dc->writeback_thread failed.

This patch destroys dc->writeback_write_wq if kthread_create() returns
error pointer to dc->writeback_thread, then a memory leak is avoided.

Fixes: 9baf30972b55 ("bcache: fix for gc and write-back race")
Signed-off-by: Coly Li <col...@suse.de>
Cc: sta...@vger.kernel.org
Signed-off-by: Jens Axboe <ax...@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/md/bcache/writeback.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -807,6 +807,7 @@ int bch_cached_dev_writeback_start(struc
                                              "bcache_writeback");
        if (IS_ERR(dc->writeback_thread)) {
                cached_dev_put(dc);
+               destroy_workqueue(dc->writeback_write_wq);
                return PTR_ERR(dc->writeback_thread);
        }