From 1a320dc9be592763fb30fa23e61c56ce57051c64 Mon Sep 17 00:00:00 2001
From: christos <christos@NetBSD.org>
Date: Mon, 14 Nov 1994 06:01:16 +0000
Subject: [PATCH] added extra argument in vn_open and VOP_OPEN to allow cloning
 devices

---
 sys/kern/kern_acct.c    |  4 ++--
 sys/kern/kern_ktrace.c  |  4 ++--
 sys/kern/kern_sig.c     |  4 ++--
 sys/kern/vfs_syscalls.c | 20 ++++++++++++++++++--
 sys/kern/vfs_vnops.c    |  7 ++++---
 sys/kern/vnode_if.src   |  3 ++-
 6 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/sys/kern/kern_acct.c b/sys/kern/kern_acct.c
index 5136abf14954..153707e09a27 100644
--- a/sys/kern/kern_acct.c
+++ b/sys/kern/kern_acct.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_acct.c,v 1.33 1994/10/20 04:22:39 cgd Exp $	*/
+/*	$NetBSD: kern_acct.c,v 1.34 1994/11/14 06:01:16 christos Exp $	*/
 
 /*-
  * Copyright (c) 1994 Christopher G. Demetriou
@@ -115,7 +115,7 @@ acct(p, uap, retval)
 	if (SCARG(uap, path) != NULL) {
 		NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path),
 		    p);
-		if (error = vn_open(&nd, FWRITE, 0))
+		if (error = vn_open(&nd, FWRITE, 0, NULL))
 			return (error);
 		VOP_UNLOCK(nd.ni_vp);
 		if (nd.ni_vp->v_type != VREG) {
diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index 74233504616e..6a73ec6896c8 100644
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_ktrace.c,v 1.13 1994/10/20 04:22:49 cgd Exp $	*/
+/*	$NetBSD: kern_ktrace.c,v 1.14 1994/11/14 06:01:18 christos Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -249,7 +249,7 @@ ktrace(curp, uap, retval)
 		 */
 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, fname),
 		    curp);
-		if (error = vn_open(&nd, FREAD|FWRITE, 0)) {
+		if (error = vn_open(&nd, FREAD|FWRITE, 0, NULL)) {
 			curp->p_traceflag &= ~KTRFAC_ACTIVE;
 			return (error);
 		}
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 301999593ad4..54e2ba2f093c 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_sig.c,v 1.34 1994/11/06 20:39:50 mycroft Exp $	*/
+/*	$NetBSD: kern_sig.c,v 1.35 1994/11/14 06:01:20 christos Exp $	*/
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -1172,7 +1172,7 @@ coredump(p)
 	sprintf(name, "%s.core", p->p_comm);
 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, name, p);
 	if (error = vn_open(&nd,
-	    O_CREAT | FWRITE, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))
+	    O_CREAT | FWRITE, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH, NULL))
 		return (error);
 	vp = nd.ni_vp;
 
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index 813c5988eb90..c8dc602e43b5 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: vfs_syscalls.c,v 1.36 1994/10/30 21:48:14 cgd Exp $	*/
+/*	$NetBSD: vfs_syscalls.c,v 1.37 1994/11/14 06:01:22 christos Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -617,7 +617,8 @@ open(p, uap, retval)
 	cmode = ((SCARG(uap, mode) &~ fdp->fd_cmask) & ALLPERMS) &~ S_ISTXT;
 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
 	p->p_dupfd = -indx - 1;			/* XXX check for fdopen */
-	if (error = vn_open(&nd, flags, cmode)) {
+	fp->f_data = (caddr_t) NULL;
+	if (error = vn_open(&nd, flags, cmode, fp)) {
 		ffree(fp);
 		if ((error == ENODEV || error == ENXIO) &&
 		    p->p_dupfd >= 0 &&			/* XXX from fdopen */
@@ -631,8 +632,23 @@ open(p, uap, retval)
 		fdp->fd_ofiles[indx] = NULL;
 		return (error);
 	}
+
 	p->p_dupfd = 0;
 	vp = nd.ni_vp;
+
+	if (fp->f_data != (caddr_t) NULL) {
+		/* 
+		 * The fp data was changed, so it is a cloning operation
+		 * Cleanup and return
+		 */
+		VOP_UNLOCK(vp);
+		if (flags & FWRITE)
+			vp->v_writecount--;
+		vput(vp);
+		*retval = indx;
+		return (0);
+	}
+
 	fp->f_flag = flags & FMASK;
 	fp->f_type = DTYPE_VNODE;
 	fp->f_ops = &vnops;
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index a46caa790f7b..f0e6f4fd621c 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: vfs_vnops.c,v 1.15 1994/10/30 21:48:16 cgd Exp $	*/
+/*	$NetBSD: vfs_vnops.c,v 1.16 1994/11/14 06:01:24 christos Exp $	*/
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -62,9 +62,10 @@ struct 	fileops vnops =
  * Common code for vnode open operations.
  * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
  */
-vn_open(ndp, fmode, cmode)
+vn_open(ndp, fmode, cmode, fp)
 	register struct nameidata *ndp;
 	int fmode, cmode;
+	struct file *fp;
 {
 	register struct vnode *vp;
 	register struct proc *p = ndp->ni_cnd.cn_proc;
@@ -139,7 +140,7 @@ vn_open(ndp, fmode, cmode)
 		if (error = VOP_SETATTR(vp, vap, cred, p))
 			goto bad;
 	}
-	if (error = VOP_OPEN(vp, fmode, cred, p))
+	if (error = VOP_OPEN(vp, fmode, cred, p, fp))
 		goto bad;
 	if (fmode & FWRITE)
 		vp->v_writecount++;
diff --git a/sys/kern/vnode_if.src b/sys/kern/vnode_if.src
index 82cd36eed9d3..29e85a9b90ab 100644
--- a/sys/kern/vnode_if.src
+++ b/sys/kern/vnode_if.src
@@ -1,4 +1,4 @@
-#	$NetBSD: vnode_if.src,v 1.4 1994/10/30 21:48:17 cgd Exp $
+#	$NetBSD: vnode_if.src,v 1.5 1994/11/14 06:01:25 christos Exp $
 #
 # Copyright (c) 1992, 1993
 #	The Regents of the University of California.  All rights reserved.
@@ -58,6 +58,7 @@ vop_open {
 	IN int mode;
 	IN struct ucred *cred;
 	IN struct proc *p;
+	INOUT struct file *fp;
 };
 
 vop_close {