[PATCH 5.10 101/147] svcrdma: Use svc_rdma_refresh_recvs() in wc_receive

Sasha Levin
2026-02-28T18:18:57Z

From: Chuck Lever <chuck.lever@oracle.com>

[ Upstream commit 7b748c30cc046056a24c459de415844a856ea54b ]

Replace svc_rdma_post_recv() with the new batch receive mechanism.
For the moment it is posting just a single Receive WR at a time,
so no change in behavior is expected.

Since svc_rdma_wc_receive() was the last call site for
svc_rdma_post_recv(), it is removed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Stable-dep-of: afcae7d7b8a2 ("RDMA/core: add rdma_rw_max_sge() helper for SQ sizing")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 43 +++++++------------------
1 file changed, 11 insertions(+), 32 deletions(-)

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 4129a2d5cc715..f2264179d9000 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -293,35 +293,6 @@ static bool svc_rdma_refresh_recvs(struct svcxprt_rdma *rdma,
return false;
}

-static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma,
- struct svc_rdma_recv_ctxt *ctxt)
-{
- int ret;
-
- trace_svcrdma_post_recv(ctxt);
- ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, NULL);
- if (ret)
- goto err_post;
- return 0;
-
-err_post:
- trace_svcrdma_rq_post_err(rdma, ret);
- svc_rdma_recv_ctxt_put(rdma, ctxt);
- return ret;
-}
-
-static int svc_rdma_post_recv(struct svcxprt_rdma *rdma)
-{
- struct svc_rdma_recv_ctxt *ctxt;
-
- if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags))
- return 0;
- ctxt = svc_rdma_recv_ctxt_get(rdma);
- if (!ctxt)
- return -ENOMEM;
- return __svc_rdma_post_recv(rdma, ctxt);
-}
-
/**
* svc_rdma_post_recvs - Post initial set of Recv WRs
* @rdma: fresh svcxprt_rdma
@@ -354,8 +325,17 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
if (wc->status != IB_WC_SUCCESS)
goto flushed;

- if (svc_rdma_post_recv(rdma))
- goto post_err;
+ /* If receive posting fails, the connection is about to be
+ * lost anyway. The server will not be able to send a reply
+ * for this RPC, and the client will retransmit this RPC
+ * anyway when it reconnects.
+ *
+ * Therefore we drop the Receive, even if status was SUCCESS
+ * to reduce the likelihood of replayed requests once the
+ * client reconnects.
+ */
+ if (!svc_rdma_refresh_recvs(rdma, 1, false))
+ goto flushed;

/* All wc fields are now known to be valid */
ctxt->rc_byte_len = wc->byte_len;
@@ -373,7 +353,6 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
return;

flushed:
-post_err:
svc_rdma_recv_ctxt_put(rdma, ctxt);
set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
svc_xprt_enqueue(&rdma->sc_xprt);
--
2.51.0