From 3f29c3b274ba79e4413b14697b6253c67cb38481 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 18 Oct 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-10-18

---
 port/cache.c   | 86 +++++++++++++++++++++++++++++++-------------------
 port/chan.c    |  9 ++++--
 port/devproc.c | 27 ++++++++++++++--
 port/portdat.h |  1 -
 4 files changed, 85 insertions(+), 38 deletions(-)

diff --git a/port/cache.c b/port/cache.c
index bca1642f2e541d2185d2ab56fb6c9e022963cf8e..d3dc9f7a4e160adc3144810e213676f00727c858 100644
--- a/port/cache.c
+++ b/port/cache.c
@@ -72,16 +72,29 @@ cinit(void)
 void
 cprint(Chan *c, Mntcache *m, char *s)
 {
+	ulong o;
+	int nb, ct;
 	Extent *e;
 	char buf[128];
-
+return;
 	ptpath(c->path, buf, sizeof(buf));
-	pprint("%s: 0x%lux.0x%lux %d %d %s\n",
-			s, m->path, m->vers, m->type, m->dev, buf);
+	nb = 0;
+	ct = 1;
+	if(m->list)
+		o = m->list->start;
+	for(e = m->list; e; e = e->next) {
+		nb += e->len;
+		if(o != e->start)
+			ct = 0;
+		o = e->start+e->len;
+	}
+	pprint("%s: 0x%lux.0x%lux %d %d %s (%d %c)\n",
+	s, m->path, m->vers, m->type, m->dev, buf, nb, ct ? 'C' : 'N');
 
-	for(e = m->list; e; e = e->next)
-		pprint("\t%4d %5d %4d %lux\n",
+	for(e = m->list; e; e = e->next) {
+		if(0) pprint("\t%4d %5d %4d %lux\n",
 			e->bid, e->start, e->len, e->cache);
+	}
 }
 
 Page*
@@ -130,21 +143,26 @@ ctail(Mntcache *m)
 		cache.tail = m;
 	}
 	else {
-		cache.head = cache.tail = m;
-		m->prev = m->next = 0;
+		cache.head = m;
+		cache.tail = m;
+		m->prev = 0;
+		m->next = 0;
 	}
 }
 
 void
 copen(Chan *c)
 {
+	int h;
+	Extent *e, *next;
 	Mntcache *m, *f, **l;
 
-	if((c->qid.path&CHDIR) || (c->flag&CTEXT))
+	if(c->qid.path&CHDIR)
 		return;
 
+	h = c->qid.path%NHASH;
 	lock(&cache);
-	for(m = cache.hash[c->qid.path%NHASH]; m; m = m->hash) {
+	for(m = cache.hash[h]; m; m = m->hash) {
 		if(m->path == c->qid.path)
 		if(m->dev == c->dev && m->type == c->type) {
 			c->mcp = m;
@@ -153,11 +171,14 @@ copen(Chan *c)
 
 			/* File was updated, invalidate cache */
 			if(m->vers != c->qid.vers) {
+				m->vers = c->qid.vers;
 				qlock(m);
 				cnodata(m);
-				m->vers = c->qid.vers;
 				qunlock(m);
+cprint(c, m, "open mod");
 			}
+else
+cprint(c, m, "open cached");
 			return;
 		}
 	}
@@ -167,25 +188,32 @@ copen(Chan *c)
 	l = &cache.hash[m->path%NHASH];
 	for(f = *l; f; f = f->hash) {
 		if(f == m) {
-			*l = f->hash;
+			*l = m->hash;
 			break;
 		}
 		l = &f->hash;
 	}
-	l = &cache.hash[c->qid.path%NHASH];
-	m->hash = *l;
-	*l = m;
-	ctail(m);
 
 	m->Qid = c->qid;
 	m->dev = c->dev;
 	m->type = c->type;
+
+	l = &cache.hash[h];
+	m->hash = *l;
+	*l = m;
+	ctail(m);
+
 	c->mcp = m;
+	e = m->list;
+	m->list = 0;
 	unlock(&cache);
 
-	qlock(m);
-	cnodata(m);
-	qunlock(m);
+	while(e) {
+		next = e->next;
+		free(e);
+		e = next;
+	}
+cprint(c, m, "open new");
 }
 
 static int
@@ -193,12 +221,12 @@ cdev(Mntcache *m, Chan *c)
 {
 	if(m->path != c->qid.path)
 		return 0;
-	if(m->vers != c->qid.vers)
-		return 0;
 	if(m->dev != c->dev)
 		return 0;
 	if(m->type != c->type)
 		return 0;
+	if(m->vers != c->qid.vers)
+		return 0;
 	return 1;
 }
 
@@ -211,9 +239,6 @@ cread(Chan *c, uchar *buf, int len, ulong offset)
 	Extent *e, **t;
 	int o, l, total;
 
-	if(c->qid.path & CHDIR)
-		return 0;
-
 	m = c->mcp;
 	if(m == 0)
 		return 0;
@@ -226,7 +251,7 @@ cread(Chan *c, uchar *buf, int len, ulong offset)
 
 	t = &m->list;
 	for(e = *t; e; e = e->next) {
-		if(offset > e->start && offset < e->start+e->len)
+		if(offset >= e->start && offset < e->start+e->len)
 			break;
 		t = &e->next;
 	}
@@ -274,7 +299,7 @@ cread(Chan *c, uchar *buf, int len, ulong offset)
 		if(e == 0 || e->start != offset)
 			break;
 	}
-if(len) print("P"); else print("F");
+
 	qunlock(m);
 	return total;
 }
@@ -307,10 +332,12 @@ cchain(uchar *buf, ulong offset, int len, Extent **tail)
 		e->cache = p;
 		e->start = offset;
 		e->len = l;
+
 		lock(&cache);
 		e->bid = cache.pgno;
 		cache.pgno += BY2PG;
 		unlock(&cache);
+
 		p->daddr = e->bid;
 		k = kmap(p);
 		memmove((void*)VA(k), buf, l);
@@ -350,7 +377,7 @@ cpgmove(Extent *e, uchar *buf, int boff, int len)
 }
 
 void
-cxupdate(Chan *c, uchar *buf, int len, ulong offset)
+cupdate(Chan *c, uchar *buf, int len, ulong offset)
 {
 	Mntcache *m;
 	Extent *tail;
@@ -457,12 +484,6 @@ cxupdate(Chan *c, uchar *buf, int len, ulong offset)
 	qunlock(m);
 }
 
-void
-cupdate(Chan *c, uchar *buf, int len, ulong offset)
-{
-	cxupdate(c, buf, len, offset);
-}
-
 void
 cwrite(Chan* c, uchar *buf, int len, ulong offset)
 {
@@ -502,6 +523,7 @@ cwrite(Chan* c, uchar *buf, int len, ulong offset)
 			if(p->len == 0)
 				panic("del empty extent");
 		}
+		/* Pack sequential write if there is space */
 		if(ee == offset && p->len < BY2PG) {
 			o = len;
 			if(o > BY2PG - p->len)
diff --git a/port/chan.c b/port/chan.c
index 643e408862b9ce2a6a9994477a6bf7dde09c726f..68a90de40adbb27e467b86130a3ac3511da3a132 100644
--- a/port/chan.c
+++ b/port/chan.c
@@ -613,10 +613,13 @@ namec(char *name, int amode, int omode, ulong perm)
 		}
 	Open:
 		/* else error() in open has wrong value of c saved */
-		saveregisters();	
-		c = (*devtab[c->type].open)(c, omode);
+		saveregisters();
+
 		if(omode == OEXEC)
-			c->flag |= CTEXT;
+			c->flag &= ~CCACHE;
+	
+		c = (*devtab[c->type].open)(c, omode);
+
 		if(omode & OCEXEC)
 			c->flag |= CCEXEC;
 		if(omode & ORCLOSE)
diff --git a/port/devproc.c b/port/devproc.c
index e5b58f323b81b4a3c71d1b8a85683c8f2284a665..33a52def7f1fc362c922c869ae9c3e9e60e81b31 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -16,6 +16,7 @@ enum
 	Qkregs,
 	Qmem,
 	Qnote,
+	Qnoteid,
 	Qnotepg,
 	Qns,
 	Qproc,
@@ -34,6 +35,7 @@ Dirtab procdir[] =
 	"kregs",	{Qkregs},	sizeof(Ureg),		0000,
 	"mem",		{Qmem},		0,			0000,
 	"note",		{Qnote},	0,			0000,
+	"noteid",	{Qnoteid},	0,			0666,
 	"notepg",	{Qnotepg},	0,			0000,
 	"ns",		{Qns},		0,			0400,
 	"proc",		{Qproc},	0,			0400,
@@ -188,6 +190,7 @@ procopen(Chan *c, int omode)
 
 	case Qctl:
 	case Qnote:
+	case Qnoteid:
 	case Qmem:
 	case Qstatus:
 	case Qwait:
@@ -470,6 +473,8 @@ procread(Chan *c, void *va, long n, ulong offset)
 		}
 		a += ptpath(mw->cm->to->path, a, n);
 		return a - (char*)va;
+	case Qnoteid:
+		return readnum(offset, va, n, p->noteid, NUMSIZE);
 	}
 	error(Egreg);
 	return 0;		/* not reached */
@@ -516,7 +521,8 @@ mntscan(Mntwalk *mw)
 long
 procwrite(Chan *c, void *va, long n, ulong offset)
 {
-	Proc *p;
+	int id;
+	Proc *p, *t, *et;
 	char buf[ERRLEN];
 
 	if(c->qid.path & CHDIR)
@@ -578,7 +584,24 @@ procwrite(Chan *c, void *va, long n, ulong offset)
 		if(!postnote(p, 0, buf, NUser))
 			error("note not posted");
 		break;
-
+	case Qnoteid:
+		id = atoi((char*)va);
+		if(id == p->pid) {
+			p->noteid = id;
+			break;
+		}
+		t = proctab(0);
+		for(et = t+conf.nproc; t < et; t++) {
+			if(id == t->noteid) {
+				if(strcmp(p->user, t->user) != 0)
+					error(Eperm);
+				p->noteid = id;
+				break;
+			}
+		}
+		if(p->noteid != id)
+			error(Ebadarg);
+		break;
 	default:
 		pprint("unknown qid in procwrite\n");
 		error(Egreg);
diff --git a/port/portdat.h b/port/portdat.h
index 74ec747b916ac84d03551c86bef9169204c15b76..32f2352eceec531d894f53ccb9c9d7e22084f879 100644
--- a/port/portdat.h
+++ b/port/portdat.h
@@ -110,7 +110,6 @@ enum
 	CRCLOSE	= 0x0020,		/* remove on close */
 	CRECOV	= 0x0040,		/* requires recovery */
 	CCACHE	= 0x0080,		/* client cache */
-	CTEXT	= 0x0100,		/* text file */
 };
 
 struct Path