From 123b9a72f9791f9d29d76ef10918a03cf0533e29 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 16 Nov 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-11-16

---
 pc/clock.c     |  2 ++
 port/devcons.c | 16 ++++++++--------
 port/devdk.c   | 44 ++++++++++++++++++++++++++++++--------------
 port/devproc.c |  2 +-
 port/net.c     |  4 ++--
 5 files changed, 43 insertions(+), 25 deletions(-)

diff --git a/pc/clock.c b/pc/clock.c
index 9813a1fa87583fab19728a79dd736ab35e5b68ee..376f3f59189443b6d1467df15416c92e23c9ee60 100644
--- a/pc/clock.c
+++ b/pc/clock.c
@@ -87,10 +87,12 @@ clock(Ureg *ur)
 			else
 				sched();
 		}
+#ifdef asdf
 		if((ur->cs&0xffff) == UESEL){
 			spllo();		/* in case we fault */
 			(*(ulong*)(USTKTOP-BY2WD)) += TK2MS(1);	/* profiling clock */
 			splhi();
 		}
+#endif asdf
 	}
 }
diff --git a/port/devcons.c b/port/devcons.c
index 5624e45539bb350455306d9d962c1820549c4477..8c5858dd0bdc8e0912d045ed7ca2f48d8fcf4562 100644
--- a/port/devcons.c
+++ b/port/devcons.c
@@ -679,7 +679,7 @@ conswrite(Chan *c, void *va, long n, ulong offset)
 {
 	char cbuf[64];
 	char buf[256];
-	long l, m;
+	long l, bp;
 	char *a = va;
 	Mach *mp;
 	int id, fd;
@@ -693,13 +693,13 @@ conswrite(Chan *c, void *va, long n, ulong offset)
 		 */
 		l = n;
 		while(l > 0){
-			m = l;
-			if(m > sizeof buf)
-				m = sizeof buf;
-			memmove(buf, a, m);
-			putstrn(a, m);
-			a += m;
-			l -= m;
+			bp = l;
+			if(bp > sizeof buf)
+				bp = sizeof buf;
+			memmove(buf, a, bp);
+			putstrn(a, bp);
+			a += bp;
+			l -= bp;
 		}
 		break;
 
diff --git a/port/devdk.c b/port/devdk.c
index d2c4c9c997dd248a14cc4e793733154da9d62c53..1dcee34dc97271a420e701431985b14f409b8ed9 100644
--- a/port/devdk.c
+++ b/port/devdk.c
@@ -106,14 +106,17 @@ struct Line {
  *  dkmux line discipline is pushed onto.
  */
 struct Dk {
+	QLock;
+	Chan	*csc;
+
 	Lock;
 	int	opened;
+
 	char	name[64];	/* dk name */
 	Queue	*wq;		/* dk output queue */
 	Stream	*s;
-	int	lines;		/* number of lines */
 	int	ncsc;		/* csc line number */
-	Chan	*csc;
+	int	lines;		/* number of lines */
 	Line	**linep;
 	int	restart;
 	int	urpwindow;
@@ -123,7 +126,7 @@ struct Dk {
 	Network	net;
 	Netprot *prot;
 
-	Block	*alloc;
+	Block	*alloc;		/* blocks containing Line structs */
 };
 static Dk *dk;
 static Lock dklock;
@@ -179,6 +182,7 @@ extern Qinfo urpinfo;
 Chan*		dkattach(char*);
 static void	dkmuxconfig(Queue*, Block*);
 static Chan*	dkopenline(Dk*, int);
+static Chan*	dkopencsc(Dk*);
 static int	dkmesg(Chan*, int, int, int, int);
 static void	dkcsckproc(void*);
 static void	dkanswer(Chan*, int, int);
@@ -504,7 +508,7 @@ dkstclose(Queue *q)
 			close(c);
 		goto out;
 	}	
-	c = dkopenline(dp, dp->ncsc);
+	c = dkopencsc(dp);
 
 	/*
 	 *  shake hands with dk
@@ -536,8 +540,11 @@ dkstclose(Queue *q)
 out:
 	qlock(lp);
 	lp->rq = 0;
-	netdisown(&dp->net, lp->lineno);
 	qunlock(lp);
+
+	if(lp->lineno == dp->ncsc)
+		dp->csc = 0;
+	netdisown(&dp->net, lp->lineno);
 }
 
 /*
@@ -672,7 +679,7 @@ dkmuxconfig(Queue *q, Block *bp)
 	 *  all fighting for it at once.
 	 */
 	dp->closeall = 0;
-	dp->csc = dkopenline(dp, dp->ncsc);
+	dkopencsc(dp);
 
 	/*
 	 *  start a process to listen to csc messages
@@ -873,9 +880,6 @@ dkcloneline(Chan *c)
 	error(Enodev);
 }
 
-/*
- *  open the common signalling channel
- */
 static Chan*
 dkopenline(Dk *dp, int line)
 {
@@ -895,6 +899,21 @@ dkopenline(Dk *dp, int line)
 	return c;
 }
 
+/*
+ *  open the common signalling channel
+ */
+static Chan*
+dkopencsc(Dk *dp)
+{
+	qlock(dp);
+	if(dp->csc == 0)
+		dp->csc = dkopenline(dp, dp->ncsc);
+	else
+		incref(dp->csc);
+	qunlock(dp);
+	return dp->csc;
+}
+
 /*
  *  return the contents of the info files
  */
@@ -1037,7 +1056,7 @@ dkcall(int type, Chan *c, char *addr, char *nuser, char *machine)
 	 *  tell the controller we want to make a call
 	 */
 	DPRINT("dialout\n");
-	csc = dkopenline(dp, dp->ncsc);
+	csc = dkopencsc(dp);
 	if(waserror()){
 		close(csc);
 		nexterror();
@@ -1610,10 +1629,7 @@ dktimer(void *a)
 		return;
 	}
 
-	/*
-	 *  open csc
-	 */
-	c = dkopenline(dp, dp->ncsc);
+	c = dkopencsc(dp);
 
 	for(;;){
 		if(dp->opened==0)
diff --git a/port/devproc.c b/port/devproc.c
index 598bcf754dd4a85be59731ab4f21ff3c80252641..15a3bd882a8cd684355d885299d58f7fee63d2d4 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -426,7 +426,7 @@ procwrite(Chan *c, void *va, long n, ulong offset)
 
 	case Qnote:
 		if(p->kp)
-			errors("can' t note kproc");
+			errors("can't note kproc");
 		k = kmap(p->upage);
 		up = (User*)VA(k);
 		if(up->p != p){
diff --git a/port/net.c b/port/net.c
index 97dc6287d837cd799b8066e0017f10a12dbfbd79..c9dc4bad0259bde979debd1cfb32503bc4afd20b 100644
--- a/port/net.c
+++ b/port/net.c
@@ -180,8 +180,6 @@ netopen(Chan *c, int omode, Network *np)
 		case Sdataqid:
 		case Sctlqid:
 			id = STREAMID(c->qid.path);
-			if(netown(np, id, u->p->user, omode&7) < 0)
-				error(Eperm);
 			break;
 		case Qlisten:
 			streamopen(c, np->devp);
@@ -203,6 +201,8 @@ netopen(Chan *c, int omode, Network *np)
 			streamopen(c, np->devp);
 			if(np->protop && c->stream->devq->next->info != np->protop)
 				pushq(c->stream, np->protop);
+			if(netown(np, id, u->p->user, omode&7) < 0)
+				error(Eperm);
 			break;
 		}
 	}