fshalt: wait for fileservers command file to vanish

cwfs and hjfs create ther /srv command files with
ORCLOSE flag, so they get removed once the fileserver
terminates. we can use this to check that the fileserver
has in fact finished halting without making assumtions
about the time it should maximally take for any fileserver
to write out its buffers to disk.

rc/bin/fshalt

@@ -45,6 +45,7 @@ cp /bin/rc /tmp
 cp /bin/sed /tmp
 cp /bin/sleep /tmp
 cp /bin/scram /tmp
+cp /bin/test /tmp
 bind /tmp /rc
 bind /tmp /bin
 
@@ -53,15 +54,12 @@ bind /tmp /bin
 fn x {
 	echo
 	echo -n halting...
-	for (i in $c){
+	for (i in $c $h)
+		echo halt >>$i
+	for (i in $c $h){
 		echo -n $i...
-		echo halt >>$i
-		sleep 2
-	}
-	for(i in $h){
-		echo -n $i
-		echo halt >>$i
-		sleep 2
+		while(test -e $i)
+			sleep 1
 	}
 	echo
 	echo done halting