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: Chuck Lever <chuck.lever@oracle.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index f013aed..36396fc 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -189,25 +189,28 @@
}
/*
- * 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)) {
+ 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) {
xprt = svc_find_xprt(serv, "tcp", 0, 0);
if (!xprt)
err = svc_create_xprt(serv, "tcp", nlm_tcpport,
@@ -237,11 +240,8 @@
/*
* 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 @@
goto out;
}
- if ((error = make_socks(serv, proto)) < 0)
+ error = make_socks(serv);
+ if (error < 0)
goto destroy_and_out;
/*
