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From:   Li Zhijian <lizhijian@fujitsu.com>
To:     <zyjzyj2000@gmail.com>, <jgg@ziepe.ca>, <leon@kernel.org>,
        <linux-rdma@vger.kernel.org>
CC:     <linux-kernel@vger.kernel.org>, Li Zhijian <lizhijian@fujitsu.com>
Subject: [for-next PATCH v2 1/2] RDMA/rxe: Remove unnecessary mr testing
Date:   Fri, 21 Oct 2022 07:52:43 +0000
Message-ID: <1666338764-2-1-git-send-email-lizhijian@fujitsu.com>
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Before the testing, we already passed it to rxe_mr_copy() where mr could
be dereferenced. so this checking is not exactly correct.

I tried to figure out the details how/when mr could be NULL, but failed
at last. Add a WARN_ON(!mr) to that path to tell us more when it
happends.

Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
---
 drivers/infiniband/sw/rxe/rxe_resp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index ed5a09e86417..218c14fb07c6 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -778,6 +778,7 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 	if (res->state == rdatm_res_state_new) {
 		if (!res->replay) {
 			mr = qp->resp.mr;
+			WARN_ON(!mr);
 			qp->resp.mr = NULL;
 		} else {
 			mr = rxe_recheck_mr(qp, res->read.rkey);
@@ -811,8 +812,7 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 
 	rxe_mr_copy(mr, res->read.va, payload_addr(&ack_pkt),
 		    payload, RXE_FROM_MR_OBJ);
-	if (mr)
-		rxe_put(mr);
+	rxe_put(mr);
 
 	if (bth_pad(&ack_pkt)) {
 		u8 *pad = payload_addr(&ack_pkt) + payload;
-- 
2.31.1