mainline inclusion from mainline-5.2-rc1 commit eb8cbb6df38f6e5124a3d5f1f8a3dbf519537c60 category: backport This patch tries to release mutex bch_register_lock early, to give chance to stop cache set and bcache device early. This patch also expends time out of stopping all bcache device from 2 seconds to 10 seconds, because stopping writeback rate update worker may delay for 5 seconds, 2 seconds is not enough. After this patch applied, stopping bcache devices during system reboot or shutdown is very hard to be observed any more. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> --- drivers/md/bcache/super.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 6010881c706e..e5b29aa7e18a 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -2385,10 +2385,19 @@ static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x) list_for_each_entry_safe(dc, tdc, &uncached_devices, list) bcache_device_stop(&dc->disk); + mutex_unlock(&bch_register_lock); + + /* + * Give an early chance for other kthreads and + * kworkers to stop themselves + */ + schedule(); + /* What's a condition variable? */ while (1) { - long timeout = start + 2 * HZ - jiffies; + long timeout = start + 10 * HZ - jiffies; + mutex_lock(&bch_register_lock); stopped = list_empty(&bch_cache_sets) && list_empty(&uncached_devices); @@ -2400,7 +2409,6 @@ static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x) mutex_unlock(&bch_register_lock); schedule_timeout(timeout); - mutex_lock(&bch_register_lock); } finish_wait(&unregister_wait, &wait); -- 2.16.4