exit gracefully on echo exit>/proc/pid/ctl
remove old code

Notes:
Tue Mar 14 08:14:45 EST 2006 rsc
    I put the cleanups in, but I left the exit behavior
    as it is.  It's true that the bind wasn't doing anything,
    but that might be for the best -- it seems antisocial
    to me to reconstruct /proc.  Exiting will deaden the
    mount anyway, leaving whatever was there before.
    Also, sending nil to rchan may not work, especially
    if the remote machine is acting up.  I'm more 
    comfortable with postnote.
    


Reference: /n/sources/patch/applied/rdbfs-exit
Date: Mon Mar 13 23:46:49 CET 2006
Reviewed-by: rsc

--- /sys/src/cmd/rdbfs.c	Mon Mar 13 23:45:04 2006
+++ /sys/src/cmd/rdbfs.c	Mon Mar 13 23:44:59 2006
@@ -132,16 +132,12 @@
 };
 
 int	textfd;
-int	srvfd;
 int	rfd;
 Biobuf	rfb;
 char*	portname = "/dev/eia0";
 char*	textfile = "/386/9pc";
 char*	procname = "1";
 Channel* rchan;
-char*	Eexist = "file does not exist";
-
-char*	progname = "rdbfs";
 
 void
 usage(void)
@@ -150,22 +146,6 @@
 	exits("usage");
 }
 
-int
-forkproc(void (*fn)(void))
-{
-	int pid;
-	switch(pid=rfork(RFNAMEG|RFMEM|RFPROC)){
-	case -1:
-		sysfatal("fork: %r");
-	case 0:
-		fn();
-		_exits(0);
-	default:
-		return pid;
-	}
-	return -1;	/* not reached */
-}
-
 void
 noalarm(void*, char *msg)
 {
@@ -248,6 +228,7 @@
 		}
 	Break2:;
 	}
+	bind("#p", "/proc", MREPL);
 }
 
 void
@@ -341,9 +322,7 @@
 		if(strncmp(r->ifcall.data, "kill", 4) == 0 ||
 		   strncmp(r->ifcall.data, "exit", 4) == 0) {
 			respond(r, nil);
-			bind("#p", "/proc", MREPL);
-			postnote(PNGROUP, getpid(), "umount");
-			exits(nil);
+			sendp(rchan, 0);
 		}else if(strncmp(r->ifcall.data, "refresh", 7) == 0){
 			flushcache();
 			respond(r, nil);
@@ -388,17 +367,10 @@
 	"status",	Xstatus,	0444,
 };
 
-void
-killall(Srv*)
-{
-	postnote(PNGROUP, getpid(), "kill");
-}
-
 Srv fs = {
 .open=	fsopen,
 .read=	fsread,
 .write=	fswrite,
-.end=	killall,
 };
 
 void
@@ -441,7 +413,6 @@
 		sysfatal("pipe: %r");
 
 	fmtinstall('F', fcallfmt);
-	srvfd = p[1];
 	proccreate(eiaread, nil, 8192);
 
 	fs.tree = alloctree("rdbfs", "rdbfs", DMDIR|0555, nil);