From 750037aa0a9f28d84df3dcf319a28423d69092fd Mon Sep 17 00:00:00 2001
From: Olga Kornievskaia <okorniev@redhat.com>
Date: Thu, 6 Feb 2025 13:15:34 -0500
Subject: [PATCH] svcrdma: do not unregister device for listeners
On an rdma-capable machine, a start/stop/start and then on a stop of
a knfsd server would lead kref underflow warning because svc_rdma_free
would indiscriminately unregister the rdma device but a listening
transport never calls the rdma_rn_register() thus leading to kref
going down to 0 on the 1st stop of the server and on the 2nd stop
it leads to a problem.
Suggested-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: c4de97f7c454 ("svcrdma: Handle device removal outside of the CM event handler")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/xprtrdma/svc_rdma_transport.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index c3fbf0779d4ab..aca8bdf65d729 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -621,7 +621,8 @@ static void __svc_rdma_free(struct work_struct *work)
/* Destroy the CM ID */
rdma_destroy_id(rdma->sc_cm_id);
- rpcrdma_rn_unregister(device, &rdma->sc_rn);
+ if (!test_bit(XPT_LISTENER, &rdma->sc_xprt.xpt_flags))
+ rpcrdma_rn_unregister(device, &rdma->sc_rn);
kfree(rdma);
}