> 在 2018年3月2日，下午2:34，tang.junhui@xxxxxxxxxx 写道：
>
> From: Tang Junhui <tang.junhui@xxxxxxxxxx>
>
> Hello Chengguang
>
>> When unloading bcache module there is lack of removing
>> operation for closure debug file, so it will cause
>> creating error when trying to reload module.
>>
>
> Yes, This issue is true.
> Actually, the original code try to remove closure debug file
> by bch_debug_exit(), which remove all the debug file in
> bcache directory, and closure debug file is expected to be
> one debug file in bcache debug directory.
>
> But currently code, closure_debug_init() is called to create
> closure debug file before the bcache debug crated in
> bch_debug_init(), so closure debug file created outside
> the bcache directory, then when bch_debug_exit() being called,
> bcache diretory removed, but closure debug file didn't removed.
>
> So the best way to resolve this issue is not remove the
> closure debug file again, but to take the closure debug file
> under the bcache directory in debug sysfs.
Yes, that looks better, I’ll modify as your suggestion in v2. Thanks for your review.
>
>> This fix introduces closure_debug_exit to handle removing
>> operation properly.
>>
>> Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxx>
>> ---
>> drivers/md/bcache/closure.c | 5 +++++
>> drivers/md/bcache/closure.h | 2 ++
>> drivers/md/bcache/super.c | 2 ++
>> 3 files changed, 9 insertions(+)
>>
>> diff --git a/drivers/md/bcache/closure.c b/drivers/md/bcache/closure.c
>> index 7f12920..8fcd737 100644
>> --- a/drivers/md/bcache/closure.c
>> +++ b/drivers/md/bcache/closure.c
>> @@ -204,6 +204,11 @@ void __init closure_debug_init(void)
>> debug = debugfs_create_file("closures", 0400, NULL, NULL, &debug_ops);
>> }
>>
>> +void closure_debug_exit(void)
>> +{
>> + debugfs_remove(debug);
>> +}
>> +
>> #endif
>>
>> MODULE_AUTHOR("Kent Overstreet <koverstreet@xxxxxxxxxx>");
>> diff --git a/drivers/md/bcache/closure.h b/drivers/md/bcache/closure.h
>> index 3b9dfc9..1aa0f7e 100644
>> --- a/drivers/md/bcache/closure.h
>> +++ b/drivers/md/bcache/closure.h
>> @@ -186,12 +186,14 @@ static inline void closure_sync(struct closure *cl)
>> #ifdef CONFIG_BCACHE_CLOSURES_DEBUG
>>
>> void closure_debug_init(void);
>> +void closure_debug_exit(void);
>> void closure_debug_create(struct closure *cl);
>> void closure_debug_destroy(struct closure *cl);
>>
>> #else
>>
>> static inline void closure_debug_init(void) {}
>> +static inline void closure_debug_exit(void) {}
>> static inline void closure_debug_create(struct closure *cl) {}
>> static inline void closure_debug_destroy(struct closure *cl) {}
>>
>> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
>> index 1a9fdab..38e2e21 100644
>> --- a/drivers/md/bcache/super.c
>> +++ b/drivers/md/bcache/super.c
>> @@ -2118,6 +2118,7 @@ static void bcache_exit(void)
>> destroy_workqueue(bcache_wq);
>> if (bcache_major)
>> unregister_blkdev(bcache_major, "bcache");
>> + closure_debug_exit();
>> unregister_reboot_notifier(&reboot);
>> mutex_destroy(&bch_register_lock);
>> }
>> @@ -2137,6 +2138,7 @@ static int __init bcache_init(void)
>>
>> bcache_major = register_blkdev(0, "bcache");
>> if (bcache_major < 0) {
>> + closure_debug_exit();
>> unregister_reboot_notifier(&reboot);
>> mutex_destroy(&bch_register_lock);
>> return bcache_major;
>> --
>> 1.8.3.1
>
> Thanks
> Tang Junhui
