diff mbox

[06/19] bcache: explicitly destory mutex while exiting

Message ID 1498855388-16990-6-git-send-email-bcache@lists.ewheeler.net (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Wheeler June 30, 2017, 8:42 p.m. UTC 
From: Liang Chen <liangchen.linux@gmail.com>

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>
Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net>
Cc: stable@vger.kernel.org
---
 drivers/md/bcache/super.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Christoph Hellwig July 5, 2017, 6:27 p.m. UTC | #1 
On Fri, Jun 30, 2017 at 01:42:55PM -0700, bcache@lists.ewheeler.net wrote:
> From: Liang Chen <liangchen.linux@gmail.com>
> 
> 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.

It shouldn't really - we should get the destroy behavior for free
when doing a slab free of the area.

What issue are you trying to solve?
Liang Chen July 6, 2017, 1:56 a.m. UTC | #2 
mutex_destroy does nothing normally (may not be true in the future), but
when debug mutex is turned on it helps with debugging - mutex_destroy
in mutex-debug.c.
It's not about freeing of the memory. It's more about consistency of the
use of mutex and making the code future proof.

Thanks,
Linag

On Thu, Jul 6, 2017 at 2:27 AM, Christoph Hellwig <hch@infradead.org> wrote:
> On Fri, Jun 30, 2017 at 01:42:55PM -0700, bcache@lists.ewheeler.net wrote:
>> From: Liang Chen <liangchen.linux@gmail.com>
>>
>> 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.
>
> It shouldn't really - we should get the destroy behavior for free
> when doing a slab free of the area.
>
> What issue are you trying to solve?
diff mbox

Patch

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 48b8c20..1f84791 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2089,6 +2089,7 @@  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)
@@ -2106,6 +2107,7 @@  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;
 	}