From d22521e4b671a9dfa6bc9fffb3fd6dd3b0079cda Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 14 Apr 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-04-14

---
 gnot/fns.h    |  1 +
 port/chan.c   | 26 +++++++++++++++-----------
 port/dev.c    | 17 ++++++++++++++---
 port/devmnt.c | 27 +++++++++++++++++++++++++++
 port/fcall.c  | 14 ++++++++++++++
 power/fns.h   |  1 +
 ss/fns.h      |  1 +
 7 files changed, 73 insertions(+), 14 deletions(-)

diff --git a/gnot/fns.h b/gnot/fns.h
index 78e5a1999741368465d5d906d40c097954260ca1..35d2189d8d3f7fce3a7629b7af150724cda0867a 100644
--- a/gnot/fns.h
+++ b/gnot/fns.h
@@ -70,6 +70,7 @@ void	fprestore(FPsave*);
 void	fpregrestore(char*);
 void	freeb(Block*);
 int	freebroken(void);
+void	freechan(Chan*);
 void	freenextmod(PTE*);
 void	freepage(Orig*, int);
 void	freepte(Orig*);
diff --git a/port/chan.c b/port/chan.c
index 9dcf9d8fdf4efc18debf05416e35a9e14197a51a..da75c143c617164238d82606aa9a6f6782bd2e3f 100644
--- a/port/chan.c
+++ b/port/chan.c
@@ -101,11 +101,13 @@ loop:
 void
 freechan(Chan *c)
 {
-	c->flag = CFREE;
-	lock(&chanalloc);
-	c->next = chanalloc.free;
-	chanalloc.free = c;
-	unlock(&chanalloc);
+	if(decref(c) == 0){
+		c->flag = CFREE;
+		lock(&chanalloc);
+		c->next = chanalloc.free;
+		chanalloc.free = c;
+		unlock(&chanalloc);
+	}
 }
 
 void
@@ -114,13 +116,15 @@ close(Chan *c)
 	if(c->flag & CFREE)
 		panic("close");
 	if(decref(c) == 0){
-		if(waserror()) {
-			freechan(c);
-			nexterror();
+		if(!waserror()) {
+			(*devtab[c->type].close)(c);
+			poperror();
 		}
-		(*devtab[c->type].close)(c);
-		freechan(c);
-		poperror();
+		c->flag = CFREE;
+		lock(&chanalloc);
+		c->next = chanalloc.free;
+		chanalloc.free = c;
+		unlock(&chanalloc);
 	}
 }
 
diff --git a/port/dev.c b/port/dev.c
index 0d38f024a64e36aa6837e34c487fb98a07e5afce..cdd1b32ddea9b4e0c33baeeffc264dacf191fb3a 100644
--- a/port/dev.c
+++ b/port/dev.c
@@ -107,10 +107,21 @@ devwalk(Chan *c, char *name, Dirtab *tab, int ntab, Devgen *gen)
 		}
 }
 
-int devclwalk(Chan *c, Chan *nc, char *name, Dirtab *tab, int ntab, Devgen *gen)
+Chan*
+devclwalk(Chan *c, char *name)
 {
-	c = devclone(c, nc);
-	return devwalk(c, name, tab, ntab, gen);
+	Chan *nc;
+
+	nc = 0;
+	if(waserror()){
+		if(nc)
+			close(nc);
+		return 0;
+	}
+	nc = (*devtab[c->type].clone)(c, 0);
+	(*devtab[nc->type].walk)(nc, name);
+	poperror();
+	return nc;
 }
 
 void
diff --git a/port/devmnt.c b/port/devmnt.c
index 4de1ed4011cd34711e02e25dd62d9fb1941ef1ff..8424228573397901ef7153e880763153484804b6 100644
--- a/port/devmnt.c
+++ b/port/devmnt.c
@@ -388,6 +388,33 @@ mntwalk(Chan *c, char *name)
 	return found;
 }
 
+Chan *
+mntclwalk(Chan *c, char *name)
+{
+	Mnt *m;
+	Mnthdr *mh;
+	Chan *nc;
+
+	nc = newchan();
+	m = mntdev(c->dev, 0);
+	mh = mhalloc();
+	mh->thdr.type = Tclwalk;
+	mh->thdr.fid = c->fid;
+	mh->thdr.newfid = nc->fid;
+	strcpy(mh->thdr.name, name);
+	if(waserror()){	/* BUG: can check type of error? */
+		freechan(nc);
+		nc = 0;
+		goto Out;
+	}
+	mntxmit(m, mh);
+	nc->qid = mh->rhdr.qid;
+	poperror();
+    Out:
+	mhfree(mh);
+	return nc;
+}
+
 void	 
 mntstat(Chan *c, char *dp)
 {
diff --git a/port/fcall.c b/port/fcall.c
index 64d0195a664fd4c30f05da2a3e9a3a7ff3b1d707..be3e842f9432aa0cf0db476515bf23c37dcfe209 100644
--- a/port/fcall.c
+++ b/port/fcall.c
@@ -92,6 +92,12 @@ convS2M(Fcall *f, char *ap)
 		SHORT(fid);
 		STRING(stat, sizeof(f->stat));
 		break;
+
+	case Tclwalk:
+		SHORT(fid);
+		SHORT(newfid);
+		STRING(name, sizeof(f->name));
+		break;
 /*
  */
 	case Rnop:
@@ -117,6 +123,7 @@ convS2M(Fcall *f, char *ap)
 		SHORT(fid);
 		break;
 
+	case Rclwalk:
 	case Rwalk:
 		SHORT(fid);
 		LONG(qid.path);
@@ -284,6 +291,12 @@ convM2S(char *ap, Fcall *f, int n)
 		SHORT(fid);
 		STRING(stat, sizeof(f->stat));
 		break;
+
+	case Tclwalk:
+		SHORT(fid);
+		SHORT(newfid);
+		STRING(name, sizeof(f->name));
+		break;
 /*
  */
 	case Rnop:
@@ -310,6 +323,7 @@ convM2S(char *ap, Fcall *f, int n)
 		break;
 
 	case Rwalk:
+	case Rclwalk:
 		SHORT(fid);
 		LONG(qid.path);
 		LONG(qid.vers);
diff --git a/power/fns.h b/power/fns.h
index b6d453cc7fe581d77733139c5bc9c38ba962cda2..29ed30e011f9533408a904c2b57ed0b595f3f497 100644
--- a/power/fns.h
+++ b/power/fns.h
@@ -70,6 +70,7 @@ void	flushmmu(void);
 void	forkmod(Seg*, Seg*, Proc*);
 void	freeb(Block*);
 int	freebroken(void);
+void	freechan(Chan*);
 void	freepage(Orig*, int);
 void	freepte(Orig*);
 void	freesegs(int);
diff --git a/ss/fns.h b/ss/fns.h
index 45d0f23c59b5b8a231c4211cb8c15327df771d5b..466e9b7dbde56d4df9a15095b769948fb776dfed 100644
--- a/ss/fns.h
+++ b/ss/fns.h
@@ -77,6 +77,7 @@ void	fprestore(FPsave*);
 void	fpregrestore(char*);
 void	freeb(Block*);
 int	freebroken(void);
+void	freechan(Chan*);
 void	freenextmod(PTE*);
 void	freepage(Orig*, int);
 void	freepte(Orig*);