[Cluster-devel] [BUG] fs: dlm: possible ABBA deadlock
Jia-Ju Bai
baijiaju1990 at gmail.com
Fri Aug 20 08:16:02 UTC 2021
On 2021/8/19 23:55, David Teigland wrote:
> On Thu, Aug 19, 2021 at 04:54:57PM +0800, Jia-Ju Bai wrote:
>> Hello,
>>
>> My static analysis tool reports a possible ABBA deadlock in the dlm
>> filesystem in Linux 5.10:
>>
>> dlm_recover_waiters_pre()
>> mutex_lock(&ls->ls_waiters_mutex); --> line 5130
>> recover_convert_waiter()
>> _receive_convert_reply()
>> lock_rsb()
>> mutex_lock(&r->res_mutex); --> line 69
>>
>> dlm_recover_waiters_post()
>> lock_rsb()
>> mutex_lock(&r->res_mutex); --> line 69
>> mutex_lock(&ls->ls_waiters_mutex); --> line 5307
>>
>> When dlm_recover_waiters_pre() and dlm_recover_waiters_post() are
>> concurrently executed, the deadlock can occur.
>>
>> I am not quite sure whether this possible deadlock is real and how to fix it
>> if it is real.
>> Any feedback would be appreciated, thanks :)
> They won't be concurrent, "pre" runs before recovery, and "post" is after.
Okay, thanks for your reply :)
Best wishes,
Jia-Ju Bai
More information about the Cluster-devel
mailing list