[PATCH 26/28] IB/srpt: Fix a race condition related to wait list processing

Bart Van Assche
2018-01-03T21:39:36Z

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-Sjgp3cTcYWE@public.gmane.org>
---
drivers/infiniband/ulp/srpt/ib_srpt.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index e222794ec1aa..a509e0d0df0b 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2300,18 +2300,20 @@ 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);
}

/*