NFSD: Keep existing listeners on portlist error

[ Upstream commit c20106944eb679fa3ab7e686fe5f6ba30fbc51e5 ]

If nfsd has existing listening sockets without any processes, then an error
returned from svc_create_xprt() for an additional transport will remove
those existing listeners.  We're seeing this in practice when userspace
attempts to create rpcrdma transports without having the rpcrdma modules
present before creating nfsd kernel processes.  Fix this by checking for
existing sockets before calling nfsd_destroy().

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 0cd57db5c5af5e689c16cc3354f1a067a2ed00f2..dfd1949b31eac354cc2f74147e16294772a23f7d 100644 (file)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -768,7 +768,10 @@ out_close:
                svc_xprt_put(xprt);
        }
 out_err:
-       nfsd_destroy(net);
+       if (!list_empty(&nn->nfsd_serv->sv_permsocks))
+               nn->nfsd_serv->sv_nrthreads--;
+        else
+               nfsd_destroy(net);
        return err;
 }