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 f704f90db36cd93dcd0872f82cb030ae3d921398..2418b9d829ae1542f8cc7faf0341715b8ffdad80 100644 (file)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -765,7 +765,10 @@ 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;
 }