[PATCH] knfsd: be more selective in which sockets lockd listens on

Currently lockd listens on UDP always, and TCP if CONFIG_NFSD_TCP is set.

However as lockd performs services of the client as well, this is a problem.
If CONFIG_NfSD_TCP is not set, and a tcp mount is used, the server will not be
able to call back to lockd.

So:
 - add an option to lockd_up saying which protocol is needed
 - Always open sockets for which an explicit port was given, otherwise
   only open a socket of the type required
 - Change nfsd to do one lockd_up per socket rather than one per thread.

This
 - removes the dependancy on CONFIG_NFSD_TCP
 - means that lockd may open sockets other than at startup
 - 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.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 41 insertions, 8 deletions

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index f95cc3f3c42d..6abb465b650f 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -202,7 +202,7 @@ reclaimer(void *ptr)
         /* This one ensures that our parent doesn't terminate while the
          * reclaim is in progress */
         lock_kernel();
-        lockd_up();
+        lockd_up(0);
 
         nlmclnt_prepare_reclaim(host);
         /* First, reclaim all locks that have been marked. */
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 13feba45030e..8d19de6a14dc 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -31,6 +31,7 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/svc.h>
 #include <linux/sunrpc/svcsock.h>
+#include <net/ip.h>
 #include <linux/lockd/lockd.h>
 #include <linux/nfs.h>
 
@@ -46,6 +47,7 @@ EXPORT_SYMBOL(nlmsvc_ops);
 static DEFINE_MUTEX(nlmsvc_mutex);
 static unsigned int             nlmsvc_users;
 static pid_t                    nlmsvc_pid;
+static struct svc_serv          *nlmsvc_serv;
 int                             nlmsvc_grace_period;
 unsigned long                   nlmsvc_timeout;
 
@@ -112,6 +114,7 @@ lockd(struct svc_rqst *rqstp)
          * Let our maker know we're running.
          */
         nlmsvc_pid = current->pid;
+        nlmsvc_serv = serv;
         complete(&lockd_start_done);
 
         daemonize("lockd");
@@ -189,6 +192,7 @@ lockd(struct svc_rqst *rqstp)
                         nlmsvc_invalidate_all();
                 nlm_shutdown_hosts();
                 nlmsvc_pid = 0;
+                nlmsvc_serv = NULL;
         } else
                 printk(KERN_DEBUG
                         "lockd: new process, skipping host shutdown\n");
@@ -205,11 +209,42 @@ lockd(struct svc_rqst *rqstp)
         module_put_and_exit(0);
 }
 
+
+static int find_socket(struct svc_serv *serv, int proto)
+{
+        struct svc_sock *svsk;
+        int found = 0;
+        list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
+                if (svsk->sk_sk->sk_protocol == proto) {
+                        found = 1;
+                        break;
+                }
+        return found;
+}
+
+static int make_socks(struct svc_serv *serv, int proto)
+{
+        /* Make any sockets that are needed but not present.
+         * If nlm_udpport or nlm_tcpport were set as module
+         * options, make those sockets unconditionally
+         */
+        int err = 0;
+        if (proto == IPPROTO_UDP || nlm_udpport)
+                if (!find_socket(serv, IPPROTO_UDP))
+                        err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport);
+        if (err)
+                return err;
+        if (proto == IPPROTO_TCP || nlm_tcpport)
+                if (!find_socket(serv, IPPROTO_TCP))
+                        err= svc_makesock(serv, IPPROTO_TCP, nlm_tcpport);
+        return err;
+}
+
 /*
  * Bring up the lockd process if it's not already up.
  */
 int
-lockd_up(void)
+lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 {
         static int              warned;
         struct svc_serv *       serv;
@@ -224,8 +259,10 @@ lockd_up(void)
         /*
          * Check whether we're already up and running.
          */
-        if (nlmsvc_pid)
+        if (nlmsvc_pid) {
+                error = make_socks(nlmsvc_serv, proto);
                 goto out;
+        }
 
         /*
          * Sanity check: if there's no pid,
@@ -242,11 +279,7 @@ lockd_up(void)
                 goto out;
         }
 
-        if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0 
-#ifdef CONFIG_NFSD_TCP
-         || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0
-#endif
-                ) {
+        if ((error = make_socks(serv, proto)) < 0) {
                 if (warned++ == 0) 
                         printk(KERN_WARNING
                                 "lockd_up: makesock failed, error=%d\n", error);