[PATCH] bcache: explicitly destory mutex while exiting

[PATCH] bcache: explicitly destory mutex while exiting

[Liang Chen]

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.

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
---
 drivers/md/bcache/super.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 85e3f21..406fe03 100644
--- 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)
@@ -2100,6 +2101,7 @@ static int __init bcache_init(void)
 
 	bcache_major = register_blkdev(0, "bcache");
 	if (bcache_major < 0) {
+		mutex_destroy(&bch_register_lock);
 		unregister_reboot_notifier(&reboot);
 		return bcache_major;
 	}
-- 
1.8.3.1

Re: [PATCH] bcache: explicitly destory mutex while exiting

[Coly Li]

On 2017/5/2 下午4:09, Liang Chen wrote:
> 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.
> 

Hi Liang,

Could you please explain a little bit more about how mutex_destroy()
helps to future proof of the code, and how it helps to mutex debug ?

Forgive me for not catching your point.

Thanks.


> Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
> ---
>  drivers/md/bcache/super.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index 85e3f21..406fe03 100644
> --- 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)
> @@ -2100,6 +2101,7 @@ static int __init bcache_init(void)
>  
>  	bcache_major = register_blkdev(0, "bcache");
>  	if (bcache_major < 0) {
> +		mutex_destroy(&bch_register_lock);
>  		unregister_reboot_notifier(&reboot);
>  		return bcache_major;
>  	}
> 


-- 
Coly Li