From c770c5a23ae92b3b4de79c9c7b87716f7881c07b Mon Sep 17 00:00:00 2001
From: kn <kn@openbsd.org>
Date: Fri, 19 Aug 2022 08:27:48 +0000
Subject: [PATCH] Split -p into own synopsis

Platform-dependent preparation of the filesystem required by the boot loader
only ever creates a new fileystem without instaling using any bootstrap files.

To reflect reality, turn
	# installboot -nvp vnd0
	Using / as root
	would install bootstrap on /dev/rvnd0c
	using first-stage /usr/mdec/biosboot, second-stage /usr/mdec/boot
	would newfs 545c9bdf92aa18f9.i

into
	# ./obj/installboot -nvp vnd0
	would newfs 4db2c0e89e0d3268.i

and error out if -p is combined with -r or stages:
	$ man -hl./installboot.8
	installboot [-nv] [-r root] disk [stage1 [stage2]]
	installboot [-nv] -p disk

Feedback OK millert
---
 usr.sbin/installboot/installboot.8 | 12 ++++++----
 usr.sbin/installboot/installboot.c | 37 +++++++++++++++---------------
 2 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/usr.sbin/installboot/installboot.8 b/usr.sbin/installboot/installboot.8
index 3429ffcfbf9..a9a7f44a9cb 100644
--- a/usr.sbin/installboot/installboot.8
+++ b/usr.sbin/installboot/installboot.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: installboot.8,v 1.5 2021/07/20 14:51:56 kettenis Exp $
+.\"	$OpenBSD: installboot.8,v 1.6 2022/08/19 08:27:48 kn Exp $
 .\"
 .\" Copyright (c) 2013, 2014 Joel Sing
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: July 20 2021 $
+.Dd $Mdocdate: August 19 2022 $
 .Dt INSTALLBOOT 8
 .Os
 .Sh NAME
@@ -22,10 +22,14 @@
 .Nd install bootstrap on a disk
 .Sh SYNOPSIS
 .Nm installboot
-.Op Fl npv
+.Op Fl nv
 .Op Fl r Ar root
 .Ar disk
 .Op Ar stage1 Op Ar stage2
+.Nm
+.Op Fl nv
+.Fl p
+.Ar disk
 .Sh DESCRIPTION
 .Nm
 installs bootstrap on the specified disk.
@@ -38,7 +42,7 @@ the beginning of the disk.
 The options are as follows:
 .Bl -tag -width Ds
 .It Fl n
-Perform a dry run - do not actually write any bootstrap to the disk.
+Perform a dry run - do not actually write to the disk.
 .It Fl p
 Prepare filesystem.
 This will create a new filesystem on the partition reserved for the
diff --git a/usr.sbin/installboot/installboot.c b/usr.sbin/installboot/installboot.c
index 6f79d397886..824a5ad9179 100644
--- a/usr.sbin/installboot/installboot.c
+++ b/usr.sbin/installboot/installboot.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: installboot.c,v 1.14 2021/07/20 14:51:56 kettenis Exp $	*/
+/*	$OpenBSD: installboot.c,v 1.15 2022/08/19 08:27:48 kn Exp $	*/
 
 /*
  * Copyright (c) 2012, 2013 Joel Sing <jsing@openbsd.org>
@@ -31,17 +31,16 @@ int	prepare;
 int	stages;
 int	verbose;
 
-char	*root = "/";
+char	*root;
 char	*stage1;
 char	*stage2;
 
 static __dead void
 usage(void)
 {
-	extern char *__progname;
-
-	fprintf(stderr, "usage: %s [-npv] [-r root] disk [stage1%s]\n",
-	    __progname, (stages >= 2) ? " [stage2]" : "");
+	fprintf(stderr, "usage:\t%1$s [-nv] [-r root] disk [stage1%2$s]\n"
+	    "\t%1$s [-nv] -p disk\n",
+	    getprogname(), (stages >= 2) ? " [stage2]" : "");
 
 	exit(1);
 }
@@ -63,9 +62,7 @@ main(int argc, char **argv)
 			prepare = 1;
 			break;
 		case 'r':
-			root = strdup(optarg);
-			if (root == NULL)
-				err(1, "strdup");
+			root = optarg;
 			break;
 		case 'v':
 			verbose = 1;
@@ -80,6 +77,8 @@ main(int argc, char **argv)
 
 	if (argc < 1 || argc > stages + 1)
 		usage();
+	if (prepare && (root != NULL || argc > 1))
+		usage();
 
 	dev = argv[0];
 	if (argc > 1)
@@ -87,7 +86,18 @@ main(int argc, char **argv)
 	if (argc > 2)
 		stage2 = argv[2];
 
+	if ((devfd = opendev(dev, (nowrite ? O_RDONLY : O_RDWR), OPENDEV_PART,
+	    &realdev)) == -1)
+		err(1, "open: %s", realdev);
+
+	if (prepare) {
+		md_prepareboot(devfd, realdev);
+		return 0;
+	}
+
 	/* Prefix stages with root, unless they were user supplied. */
+	if (root == NULL)
+		root = "/";
 	if (verbose)
 		fprintf(stderr, "Using %s as root\n", root);
 	if (argc <= 1 && stage1 != NULL) {
@@ -101,10 +111,6 @@ main(int argc, char **argv)
 			exit(1);
 	}
 
-	if ((devfd = opendev(dev, (nowrite ? O_RDONLY : O_RDWR), OPENDEV_PART,
-	    &realdev)) == -1)
-		err(1, "open: %s", realdev);
-
         if (verbose) {
 		fprintf(stderr, "%s bootstrap on %s\n",
 		    (nowrite ? "would install" : "installing"), realdev);
@@ -119,11 +125,6 @@ main(int argc, char **argv)
 
 	md_loadboot();
 
-	if (prepare) {
-		md_prepareboot(devfd, realdev);
-		return 0;
-	}
-
 #ifdef SOFTRAID
 	sr_installboot(devfd, dev);
 #else
-- 
2.20.1