NFSD: move lockd_up() before svc_addsock()

Clean up.

A couple of years ago, a series of commits, finishing with commit
5680c446, swapped the order of the lockd_up() and svc_addsock() calls
in __write_ports().  At that time lockd_up() needed to know the
transport protocol of the passed-in socket to start a listener on the
same transport protocol.

These days, lockd_up() doesn't take a protocol argument; it always
starts both a UDP and TCP listener.  It's now more straightforward to
try the lockd_up() first, then do a lockd_down() if the svc_addsock()
fails.

Careful review of this code shows that the svc_sock_names() call is
used only to close the just-opened socket in case lockd_up() fails.
So it is no longer needed if lockd_up() is done first.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfsctl.c

@@ -939,17 +939,18 @@ static ssize_t __write_ports_addfd(char *buf)
 	if (err != 0)
 		return err;
 
-	err = svc_addsock(nfsd_serv, fd, buf);
-	if (err >= 0) {
-		err = lockd_up();
-		if (err < 0)
-			svc_sock_names(buf + strlen(buf) + 1, nfsd_serv, buf);
+	err = lockd_up();
+	if (err != 0)
+		goto out;
 
-		/* Decrease the count, but don't shut down the service */
-		nfsd_serv->sv_nrthreads--;
-	}
+	err = svc_addsock(nfsd_serv, fd, buf);
+	if (err < 0)
+		lockd_down();
 
-	return err < 0 ? err : 0;
+out:
+	/* Decrease the count, but don't shut down the service */
+	nfsd_serv->sv_nrthreads--;
+	return err;
 }
 
 /*