From: Liang Chen <liangchen.linux@xxxxxxxxx> This patch has been added to the stable tree. If you have any objections, please let us know. =============== [ Upstream commit 330a4db89d39a6b43f36da16824eaa7a7509d34d ] mutex_destroy does nothing most of time, but it's better to call it to make the code future proof and it also has some meaning for like mutex debug. As Coly pointed out in a previous review, bcache_exit() may not be able to handle all the references properly if userspace registers cache and backing devices right before bch_debug_init runs and bch_debug_init failes later. So not exposing userspace interface until everything is ready to avoid that issue. Signed-off-by: Liang Chen <liangchen.linux@xxxxxxxxx> Reviewed-by: Michael Lyle <mlyle@xxxxxxxx> Reviewed-by: Coly Li <colyli@xxxxxxx> Reviewed-by: Eric Wheeler <bcache@xxxxxxxxxxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/md/bcache/super.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index b911a7d7a06b..6f7bc8a8674b 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -2122,6 +2122,7 @@ static void bcache_exit(void) if (bcache_major) unregister_blkdev(bcache_major, "bcache"); unregister_reboot_notifier(&reboot); + mutex_destroy(&bch_register_lock); } static int __init bcache_init(void) @@ -2140,14 +2141,15 @@ static int __init bcache_init(void) bcache_major = register_blkdev(0, "bcache"); if (bcache_major < 0) { unregister_reboot_notifier(&reboot); + mutex_destroy(&bch_register_lock); return bcache_major; } if (!(bcache_wq = create_workqueue("bcache")) || !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) || - sysfs_create_files(bcache_kobj, files) || bch_request_init() || - bch_debug_init(bcache_kobj)) + bch_debug_init(bcache_kobj) || + sysfs_create_files(bcache_kobj, files)) goto err; return 0; -- 2.11.0