[22/37] bcache: stop writeback kthread and kworker when bch_cached_dev_run() failed

Commit Message

Coly Li June 28, 2019, 11:59 a.m. UTC

In bch_cached_dev_attach() after bch_cached_dev_writeback_start()
called, the wrireback kthread and writeback rate update kworker of the
cached device are created, if the following bch_cached_dev_run()
failed, bch_cached_dev_attach() will return with -ENOMEM without
stopping the writeback related kthread and kworker.

This patch stops writeback kthread and writeback rate update kworker
before returning -ENOMEM if bch_cached_dev_run() returns error.

Signed-off-by: Coly Li <[e-mail]>
---
 drivers/md/bcache/super.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index c4c4b2d99dc2..791cb930b353 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1189,6 +1189,14 @@  int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	ret = bch_cached_dev_run(dc);
 	if (ret && (ret != -EBUSY)) {
 		up_write(&dc->writeback_lock);
+		/*
+		 * bch_register_lock is held, bcache_device_stop() is not
+		 * able to be directly called. The kthread and kworker
+		 * created previously in bch_cached_dev_writeback_start()
+		 * have to be stopped manually here.
+		 */
+		kthread_stop(dc->writeback_thread);
+		cancel_writeback_rate_update_dwork(dc);
 		pr_err("Couldn't run cached device %s",
 		       dc->backing_dev_name);
 		return ret;