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Commit 8c3916f4 authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields
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NLM: Always start both UDP and TCP listeners 



Commit 24e36663, which first appeared in 2.6.19, changed lockd so that
the client side starts a UDP listener only if there is a UDP NFSv2/v3
mount.  Its description notes:

    This... means that lockd will *not* listen on UDP if the only
    mounts are TCP mount (and nfsd hasn't started).

    The latter is the only one that concerns me at all - I don't know
    if this might be a problem with some servers.

Unfortunately it is a problem for Linux itself.  The rpc.statd daemon
on Linux uses UDP for contacting the local lockd, no matter which
protocol is used for NFS mounts.  Without a local lockd UDP listener,
NFSv2/v3 lock recovery from Linux NFS clients always fails.

Revert parts of commit 24e36663 so lockd_up() always starts both
listeners.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 9a38a838

fs/lockd/svc.c

+19 −18
Original line number Diff line number Diff line
@@ -189,25 +189,28 @@ lockd(void *vrqstp) 
}



/*

 * Make any sockets that are needed but not present.

 * If nlm_udpport or nlm_tcpport were set as module

 * options, make those sockets unconditionally

 * Ensure there are active UDP and TCP listeners for lockd.

 *

 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some

 * local services (such as rpc.statd) still require UDP, and

 * some NFS servers do not yet support NLM over TCP.

 *

 * Returns zero if all listeners are available; otherwise a

 * negative errno value is returned.

 */

static int make_socks(struct svc_serv *serv, int proto)

static int make_socks(struct svc_serv *serv)

{

	static int warned;

	struct svc_xprt *xprt;

	int err = 0;



	if (proto == IPPROTO_UDP || nlm_udpport) {

	xprt = svc_find_xprt(serv, "udp", 0, 0);

	if (!xprt)

		err = svc_create_xprt(serv, "udp", nlm_udpport,

				      SVC_SOCK_DEFAULTS);

	else

		svc_xprt_put(xprt);

	}

	if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {

	if (err >= 0) {

		xprt = svc_find_xprt(serv, "tcp", 0, 0);

		if (!xprt)

			err = svc_create_xprt(serv, "tcp", nlm_tcpport,
@@ -237,11 +240,8 @@ lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ 
	/*

	 * Check whether we're already up and running.

	 */

	if (nlmsvc_rqst) {

		if (proto)

			error = make_socks(nlmsvc_rqst->rq_server, proto);

	if (nlmsvc_rqst)

		goto out;

	}



	/*

	 * Sanity check: if there's no pid,
@@ -258,7 +258,8 @@ lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ 
		goto out;

	}



	if ((error = make_socks(serv, proto)) < 0)

	error = make_socks(serv);

	if (error < 0)

		goto destroy_and_out;



	/*