4.4-stable review patch. If anyone has any objections, please let me know.
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From: Liang Chen liangchen.linux@gmail.com
[ 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@gmail.com Reviewed-by: Michael Lyle mlyle@lyle.org Reviewed-by: Coly Li colyli@suse.de Reviewed-by: Eric Wheeler bcache@linux.ewheeler.net Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/bcache/super.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -2083,6 +2083,7 @@ 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) @@ -2101,14 +2102,15 @@ 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;