Patch "bcache: explicitly destroy mutex while exiting" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

bcache: explicitly destroy mutex while exiting

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
bcache-explicitly-destroy-mutex-while-exiting.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Liang Chen <[email protected]>
Date: Mon, 30 Oct 2017 14:46:35 -0700
Subject: bcache: explicitly destroy mutex while exiting

From: Liang Chen <[email protected]>

[ 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.

---
 drivers/md/bcache/super.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

@@ -2085,6 +2085,7 @@ 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)

@@ -2103,14 +2104,15 @@ 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 = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0)) ||
 	    !(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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/bcache-explicitly-destroy-mutex-while-exiting.patch