From 86fb3a730ac6c3ce58ff031e3e11865829afba60 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 2 Apr 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-04-02

---
 port/devmnt.c  | 30 +++++++++++++++++++++++-------
 port/portfns.h |  1 +
 port/sysfile.c | 31 +++++++++++++++++++++++++++++++
 port/systab.h  |  6 ++++++
 4 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/port/devmnt.c b/port/devmnt.c
index f65d184caa4cad6d54bae3a1fa6c29106d48d045..df2867fc71908a5971f6591cce1ed9a6a7fb17f5 100644
--- a/port/devmnt.c
+++ b/port/devmnt.c
@@ -44,7 +44,7 @@ void	mntgate(Mnt*);
 void	mntpntfree(Mnt*);
 void	mntqrm(Mnt*, Mntrpc*);
 Mntrpc*	mntralloc(Chan*);
-long	mntrdwr(int , Chan*, void*,long , ulong);
+long	mntrdwr(int , Chan*, void*,long , ulong, int);
 void	mntrpcread(Mnt*, Mntrpc*);
 void	mountio(Mnt*, Mntrpc*);
 void	mountmux(Mnt*, Mntrpc*);
@@ -168,6 +168,7 @@ mntattach(char *muxattach)
 	mattach(m, c, bogus.spec);
 	poperror();
 
+#ifdef STUPIDHACK
 	/* Work out how deep we are nested and reduce the blocksize
 	 * accordingly
 	 */
@@ -182,6 +183,7 @@ mntattach(char *muxattach)
 		mc = mc->mntptr->c;
 	}
 	m->blocksize -= nest * 32;
+#endif STUPIDHACK
 
 	/*
 	 * Detect a recursive mount for a mount point served by exportfs.
@@ -513,7 +515,7 @@ mntread(Chan *c, void *buf, long n, ulong offset)
 		}
 	}
 
-	n = mntrdwr(Tread, c, buf, n, offset);
+	n = mntrdwr(Tread, c, buf, n, offset, 0);
 	if(c->qid.path & CHDIR) {
 		for(p = (uchar*)buf, e = &p[n]; p < e; p += DIRLEN)
 			mntdirfix(p, c);
@@ -526,14 +528,20 @@ mntread(Chan *c, void *buf, long n, ulong offset)
 	return n;
 }
 
+long	 
+mntwrite9p(Chan *c, void *buf, long n, ulong offset)
+{
+	return mntrdwr(Twrite, c, buf, n, offset, 1);
+}
+
 long	 
 mntwrite(Chan *c, void *buf, long n, ulong offset)
 {
-	return mntrdwr(Twrite, c, buf, n, offset);
+	return mntrdwr(Twrite, c, buf, n, offset, 0);
 }
 
 long
-mntrdwr(int type, Chan *c, void *buf, long n, ulong offset)
+mntrdwr(int type, Chan *c, void *buf, long n, ulong offset, int p9msg)
 {
 	Mnt *m;
  	Mntrpc *r;
@@ -555,7 +563,10 @@ mntrdwr(int type, Chan *c, void *buf, long n, ulong offset)
 		r->request.fid = c->fid;
 		r->request.offset = offset;
 		r->request.data = uba;
-		r->request.count = limit(n, m->blocksize);
+		if(p9msg)
+			r->request.count = limit(n, m->blocksize + MAXMSG - 20);
+		else
+			r->request.count = limit(n, m->blocksize);
 		mountrpc(m, r);
 		nr = r->reply.count;
 		if(nr > r->request.count)
@@ -629,8 +640,13 @@ mountio(Mnt *m, Mntrpc *r)
 			nexterror();
 	}
 	else {
-		if((*devtab[m->c->type].write)(m->c, r->rpc, n, 0) != n)
-			error(Emountrpc);
+		if(devchar[m->c->type] == L'M'){
+			if(mntwrite9p(m->c, r->rpc, n, 0) != n)
+				error(Emountrpc);
+		}else{
+			if((*devtab[m->c->type].write)(m->c, r->rpc, n, 0) != n)
+				error(Emountrpc);
+		}
 		poperror();
 	}
 	if(m->mux) {
diff --git a/port/portfns.h b/port/portfns.h
index d25887481b75ed21d635ef987001e02fe98f67d6..16d959c996ea2791c0f9dcd010dc7ae5dac44285 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -262,6 +262,7 @@ void*		vmemchr(void*, int, int);
 void		wakeup(Rendez*);
 Chan*		walk(Chan*, char*, int);
 void		wlock(RWlock*);
+long		mntwrite9p(Chan*, void*, long, ulong);
 void		wunlock(RWlock*);
 #define		xalloc(s)	xallocz(s, 1)
 void*		xallocz(ulong, int);
diff --git a/port/sysfile.c b/port/sysfile.c
index 3658e0236084681aa0f86b2c5aa08991fed562cc..3333f5f245b4c8f77b687b118cff1dc8f6d49778 100644
--- a/port/sysfile.c
+++ b/port/sysfile.c
@@ -325,6 +325,37 @@ sysread(ulong *arg)
 	return n;
 }
 
+long
+syswrite9p(ulong *arg)
+{
+	Chan *c;
+	long n;
+
+	validaddr(arg[1], arg[2], 0);
+	c = fdtochan(arg[0], OWRITE, 1, 1);
+	if(waserror()) {
+		close(c);
+		nexterror();
+	}
+
+	if(c->qid.path & CHDIR)
+		error(Eisdir);
+
+	if(devchar[c->type] != L'M')
+		n = (*devtab[c->type].write)(c, (void*)arg[1], arg[2], c->offset);
+	else
+		n = mntwrite9p(c, (void*)arg[1], arg[2], c->offset);
+
+	lock(c);
+	c->offset += n;
+	unlock(c);
+
+	poperror();
+	close(c);
+
+	return n;
+}
+
 long
 syswrite(ulong *arg)
 {
diff --git a/port/systab.h b/port/systab.h
index dd8abb0217e1e9bc6e73db9d76c1aa5a37df1624..a8c967f1ef503e50ccb8cf5722637d7d067538ae 100644
--- a/port/systab.h
+++ b/port/systab.h
@@ -40,6 +40,8 @@ Syscall syssegflush;
 Syscall sysrendezvous;
 Syscall sysunmount;
 Syscall syswait;
+Syscall syswrite9p;
+Syscall ;
 Syscall ;
 Syscall	sysdeath;
 
@@ -81,6 +83,8 @@ Syscall *systab[]={
 	[RENDEZVOUS]	sysrendezvous,
 	[UNMOUNT]	sysunmount,
 	[WAIT]		syswait,
+	[WRITE9P]	syswrite9p,
+
 
 };
 
@@ -122,5 +126,7 @@ char *sysctab[]={
 	[RENDEZVOUS]	"Rendez",
 	[UNMOUNT]	"Unmount",
 	[WAIT]		"Wait",
+	[WRITE9P]	"Write9p",
+
 
 };