diff mbox

[rdma-rc,V1,2/4] IB/rxe: Fix duplicate atomic request handling

Message ID 1473246247-16536-3-git-send-email-leon@kernel.org (mailing list archive)
State Accepted
Headers show

Commit Message

Leon Romanovsky Sept. 7, 2016, 11:04 a.m. UTC 
From: Yonatan Cohen <yonatanc@mellanox.com>

When handling ack for atomic opcodes like "fetch&add"
or "cmp&swp", the method send_atomic_ack() saves the ack
before sending it, in case it gets lost and never reach the
requester. In which case the method duplicate_request()
will need to find it using the duplicated request.psn.
But send_atomic_ack() used a wrong psn value and thus
the above ack was never found.
This fix uses the ack.psn to locate the ack in case
its needed.
This fix also copies the ack packet to the skb's control buffer
since duplicate_request() will need it when calling rxe_xmit_packet()

Fixes: 8700e3e7c485 ("Soft RoCE driver")
Signed-off-by: Yonatan Cohen <yonatanc@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
---
 drivers/infiniband/sw/rxe/rxe_resp.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

--
2.7.4

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Comments

Or Gerlitz Sept. 7, 2016, 11:16 a.m. UTC | #1 
On Wed, Sep 7, 2016 at 2:04 PM, Leon Romanovsky <leon@kernel.org> wrote:
> From: Yonatan Cohen <yonatanc@mellanox.com>
>
> When handling ack for atomic opcodes like "fetch&add"
> or "cmp&swp", the method send_atomic_ack() saves the ack
> before sending it, in case it gets lost and never reach the
> requester. In which case the method duplicate_request()
> will need to find it using the duplicated request.psn.
> But send_atomic_ack() used a wrong psn value and thus
> the above ack was never found.
> This fix uses the ack.psn to locate the ack in case
> its needed.
> This fix also copies the ack packet to the skb's control buffer
> since duplicate_request() will need it when calling rxe_xmit_packet()

Are you using tiny screen? any special  reason to limit the change-log lines
to be ~55 chars long and not 70 or 80?
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diff mbox

Patch

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index ebb03b4..3e0f0f2 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -972,11 +972,13 @@  static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
 	free_rd_atomic_resource(qp, res);
 	rxe_advance_resp_resource(qp);

+	memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(skb->cb));
+
 	res->type = RXE_ATOMIC_MASK;
 	res->atomic.skb = skb;
-	res->first_psn = qp->resp.psn;
-	res->last_psn = qp->resp.psn;
-	res->cur_psn = qp->resp.psn;
+	res->first_psn = ack_pkt.psn;
+	res->last_psn  = ack_pkt.psn;
+	res->cur_psn   = ack_pkt.psn;

 	rc = rxe_xmit_packet(rxe, qp, &ack_pkt, skb_copy);
 	if (rc) {
@@ -1116,8 +1118,7 @@  static enum resp_states duplicate_request(struct rxe_qp *qp,
 				rc = RESPST_CLEANUP;
 				goto out;
 			}
-			bth_set_psn(SKB_TO_PKT(skb_copy),
-				    qp->resp.psn - 1);
+
 			/* Resend the result. */
 			rc = rxe_xmit_packet(to_rdev(qp->ibqp.device), qp,
 					     pkt, skb_copy);