Hi Dan,
Dan Carpenter <dan.carpenter@xxxxxxxxxx> 于2021年4月21日周三 上午11:09写道：
>
> Hello Gioh Kim,
>
> The patch fa607fcb87f6: "block/rnbd-clt: Support polling mode for IO
> latency optimization" from Apr 19, 2021, leads to the following
> static checker warning:
>
> drivers/infiniband/ulp/rtrs/rtrs-clt.c:2998 rtrs_clt_rdma_cq_direct()
> error: uninitialized symbol 'cnt'.
>
> drivers/infiniband/ulp/rtrs/rtrs-clt.c
> 2977 int rtrs_clt_rdma_cq_direct(struct rtrs_clt *clt, unsigned int index)
> 2978 {
> 2979 int cnt;
>
> What about if no sessions are connected?
This indeed a bug, will fix it soon. cnt should be init to 0.
>
> 2980 struct rtrs_con *con;
> 2981 struct rtrs_clt_sess *sess;
> 2982 struct path_it it;
> 2983
> 2984 rcu_read_lock();
> 2985 for (path_it_init(&it, clt);
> 2986 (sess = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
> 2987 if (READ_ONCE(sess->state) != RTRS_CLT_CONNECTED)
> 2988 continue;
> 2989
> 2990 con = sess->s.con[index + 1];
> 2991 cnt = ib_process_cq_direct(con->cq, -1);
> 2992 if (cnt)
> 2993 break;
>
> I don't know any of this code but I would have expect use to add up
> cnt for the whole loop... Something like:
>
> ret = ib_process_cq_direct(con->cq, -1);
ib_process_cq_direct does not return negative value AFAIK.
The idea is as we give -1 which means ib_process_cq_direct will poll
all pending cq.
when it returns positive value, we are done.
> if (ret < 0)
> break;
> cnt += ret;
>
> 2994 }
> 2995 path_it_deinit(&it);
> 2996 rcu_read_unlock();
> 2997
> 2998 return cnt;
>
> if (ret < 0)
> return ret;
>
> return cnt;
>
> 2999 }
>
> regards,
> dan carpenter
Thanks for the reporting.
Regards!
