IB/srpt: Fix a race condition related to wait list processing

Wait list processing only occurs if the channel state >= CH_LIVE. Hence
set the channel state to CH_LIVE before triggering wait list processing
asynchronously.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 6278c44..372f1eb 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2355,18 +2355,20 @@ static void srpt_cm_rtu_recv(struct srpt_rdma_ch *ch)
                return;
        }
 
-       /* Trigger wait list processing. */
-       ret = srpt_zerolength_write(ch);
-       WARN_ONCE(ret < 0, "%d\n", ret);
-
        /*
         * Note: calling srpt_close_ch() if the transition to the LIVE state
         * fails is not necessary since that means that that function has
         * already been invoked from another thread.
         */
-       if (!srpt_set_ch_state(ch, CH_LIVE))
+       if (!srpt_set_ch_state(ch, CH_LIVE)) {
                pr_err("%s-%d: channel transition to LIVE state failed\n",
                       ch->sess_name, ch->qp->qp_num);
+               return;
+       }
+
+       /* Trigger wait list processing. */
+       ret = srpt_zerolength_write(ch);
+       WARN_ONCE(ret < 0, "%d\n", ret);
 }
 
 /**