Re: [PATCH 1/1] RDMA/rtrs: Require holding rcu_read_lock explicitly

[Zhu Yanjun <yanjun.zhu@linux.dev>]

在 2023/9/19 15:09, Leon Romanovsky 写道:
> On Mon, Sep 18, 2023 at 11:36:46PM +0800, Zhu Yanjun wrote:
>> From: Zhu Yanjun <yanjun.zhu@linux.dev>
>>
>> No functional change. The function get_next_path_rr needs to hold
>> rcu_read_lock. As such, if no rcu read lock, warnings will pop out.
>>
>> Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
>> ---
>>   drivers/infiniband/ulp/rtrs/rtrs-clt.c | 7 ++++++-
>>   1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
>> index b6ee801fd0ff..bc4b70318bf4 100644
>> --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
>> +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
>> @@ -775,7 +775,7 @@ rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt
>>    * Related to @MP_POLICY_RR
>>    *
>>    * Locks:
>> - *    rcu_read_lock() must be hold.
>> + *    rcu_read_lock() must be held.
>>    */
>>   static struct rtrs_clt_path *get_next_path_rr(struct path_it *it)
>>   {
>> @@ -783,6 +783,11 @@ static struct rtrs_clt_path *get_next_path_rr(struct path_it *it)
>>   	struct rtrs_clt_path *path;
>>   	struct rtrs_clt_sess *clt;
>>   
>> +	/*
>> +	 * Assert that rcu lock must be held
>> +	 */
>> +	WARN_ON_ONCE(!rcu_read_lock_held());
> Let's use RCU_LOCKDEP_WARN(..) macro.

Got it. Will send v2 very soon.

Zhu Yanjun

>
> Thanks
>
>> +
>>   	clt = it->clt;
>>   
>>   	/*
>> -- 
>> 2.40.1
>>