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Subject: [PATCH v1 3/8] xprtrdma: Put flushed Receives on free list instead of
 destroying them
From:   Chuck Lever <chuck.lever@oracle.com>
To:     linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org
Date:   Wed, 31 Mar 2021 15:36:17 -0400
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Defer destruction of an rpcrdma_rep until transport tear-down to
avoid races between Receive completion and rpcrdma_reps_unmap().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/verbs.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 1d88685badbe..92af272f9cc9 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -80,6 +80,8 @@ static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt,
 				       struct rpcrdma_sendctx *sc);
 static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt);
 static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt);
+static void rpcrdma_rep_put(struct rpcrdma_buffer *buf,
+			    struct rpcrdma_rep *rep);
 static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep);
 static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt);
 static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
@@ -205,7 +207,7 @@ static void rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
 
 out_flushed:
 	rpcrdma_flush_disconnect(r_xprt, wc);
-	rpcrdma_rep_destroy(rep);
+	rpcrdma_rep_put(&r_xprt->rx_buf, rep);
 }
 
 static void rpcrdma_update_cm_private(struct rpcrdma_ep *ep,