Patch "xprtrdma: Remap Receive buffers after a reconnect" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    xprtrdma: Remap Receive buffers after a reconnect

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xprtrdma-remap-receive-buffers-after-a-reconnect.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 556598ba9c18382448b3e77eb8ce8e2b5f1ce9d7
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date:   Mon Jul 3 14:18:29 2023 -0400

    xprtrdma: Remap Receive buffers after a reconnect
    
    [ Upstream commit 895cedc1791916e8a98864f12b656702fad0bb67 ]
    
    On server-initiated disconnect, rpcrdma_xprt_disconnect() was DMA-
    unmapping the Receive buffers, but rpcrdma_post_recvs() neglected
    to remap them after a new connection had been established. The
    result was immediate failure of the new connection with the Receives
    flushing with LOCAL_PROT_ERR.
    
    Fixes: 671c450b6fe0 ("xprtrdma: Fix oops in Receive handler after device removal")
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 338b06de86d16..d015576f3081a 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -972,9 +972,6 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
 	if (!rep->rr_rdmabuf)
 		goto out_free;
 
-	if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf))
-		goto out_free_regbuf;
-
 	xdr_buf_init(&rep->rr_hdrbuf, rdmab_data(rep->rr_rdmabuf),
 		     rdmab_length(rep->rr_rdmabuf));
 	rep->rr_cqe.done = rpcrdma_wc_receive;
@@ -987,8 +984,6 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
 	list_add(&rep->rr_all, &r_xprt->rx_buf.rb_all_reps);
 	return rep;
 
-out_free_regbuf:
-	rpcrdma_regbuf_free(rep->rr_rdmabuf);
 out_free:
 	kfree(rep);
 out:
@@ -1425,6 +1420,10 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp)
 			rep = rpcrdma_rep_create(r_xprt, temp);
 		if (!rep)
 			break;
+		if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf)) {
+			rpcrdma_rep_put(buf, rep);
+			break;
+		}
 
 		trace_xprtrdma_post_recv(rep);
 		rep->rr_recv_wr.next = wr;