The unit of the -c options is fragments, so adjust man page and

variable name; correct the loop packing more inodes into the cg:
in some cases it could put more fragments into the cg than requested;
give an error if the -c option cannot be honoured. ok millert@ pedro@

3 files changed, 24 insertions, 28 deletions

diff --git a/sbin/newfs/mkfs.c b/sbin/newfs/mkfs.c
index a99ecc8be57..154271dd127 100644
--- a/sbin/newfs/mkfs.c
+++ b/sbin/newfs/mkfs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mkfs.c,v 1.60 2007/05/18 18:57:06 otto Exp $	*/
+/*	$OpenBSD: mkfs.c,v 1.61 2007/05/18 19:08:16 otto Exp $	*/
 /*	$NetBSD: mkfs.c,v 1.25 1995/06/18 21:35:38 cgd Exp $	*/
 
 /*
@@ -88,7 +88,7 @@ extern int	fssize;		/* file system size */
 extern int	sectorsize;	/* bytes/sector */
 extern int	fsize;		/* fragment size */
 extern int	bsize;		/* block size */
-extern int	maxblkspercg;	/* maximum blocks per cylinder group */
+extern int	maxfrgspercg;	/* maximum fragments per cylinder group */
 extern int	minfree;	/* free space threshold */
 extern int	opt;		/* optimization preference (space or time) */
 extern int	density;	/* number of bytes per inode */
@@ -359,8 +359,8 @@ mkfs(struct partition *pp, char *fsys, int fi, int fo, mode_t mfsmode,
 	 * install media which needs to pack 2 files very tightly.
 	 */
 	mincylgrps = MINCYLGRPS;
-	if (maxblkspercg != INT_MAX) {
-		i = sblock.fs_size / maxblkspercg;
+	if (maxfrgspercg != INT_MAX) {
+		i = sblock.fs_size / maxfrgspercg;
 		if (i < MINCYLGRPS)
 			mincylgrps = i <= 0 ? 1 : i;
 	}
@@ -370,25 +370,21 @@ mkfs(struct partition *pp, char *fsys, int fi, int fo, mode_t mfsmode,
 	 * grow any larger, the number of cylinder groups drops below
 	 * mincylgrps, or we reach the requested size.
 	 */
-	for (; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
+	for (;;) {
+		sblock.fs_fpg += sblock.fs_frag;
 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 		    INOPB(&sblock));
 
-		if (sblock.fs_size / sblock.fs_fpg < mincylgrps)
-			break;
-
-		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
-			continue;
-
-		if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
+		if (sblock.fs_fpg > maxfrgspercg ||
+		    sblock.fs_size / sblock.fs_fpg < mincylgrps ||
+		    CGSIZE(&sblock) > (unsigned long)sblock.fs_bsize)
 			break;
-
-		sblock.fs_fpg -= sblock.fs_frag;
-		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
-		    INOPB(&sblock));
-
-		break;
 	}
+	sblock.fs_fpg -= sblock.fs_frag;
+	sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
+	    INOPB(&sblock));
+	if (sblock.fs_fpg > maxfrgspercg)
+		errx(22, "can't honour -c: minimum is %d", sblock.fs_fpg);
 
 	/*
 	 * Check to be sure that the last cylinder group has enough blocks to
diff --git a/sbin/newfs/newfs.8 b/sbin/newfs/newfs.8
index 2a7c8a01644..7506e5249b2 100644
--- a/sbin/newfs/newfs.8
+++ b/sbin/newfs/newfs.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: newfs.8,v 1.55 2007/04/13 20:20:54 jmc Exp $
+.\"	$OpenBSD: newfs.8,v 1.56 2007/05/18 19:08:16 otto Exp $
 .\"	$NetBSD: newfs.8,v 1.12 1995/03/18 14:58:41 cgd Exp $
 .\"
 .\" Copyright (c) 1983, 1987, 1991, 1993, 1994
@@ -41,7 +41,7 @@
 .Bk -words
 .Op Fl Nq
 .Op Fl b Ar block-size
-.Op Fl c Ar blocks-per-cylinder-group
+.Op Fl c Ar fragments-per-cylinder-group
 .Op Fl e Ar maxbpg
 .Op Fl f Ar frag-size
 .Op Fl g Ar avgfilesize
@@ -59,7 +59,7 @@
 .Nm mount_mfs
 .Bk -words
 .Op Fl b Ar block-size
-.Op Fl c Ar blocks-per-cylinder-group
+.Op Fl c Ar fragments-per-cylinder-group
 .Op Fl e Ar maxbpg
 .Op Fl f Ar frag-size
 .Op Fl i Ar bytes
@@ -131,8 +131,8 @@ The following options define the general layout policies:
 .It Fl b Ar block-size
 The block size of the file system, in bytes.
 The default is 16KB.
-.It Fl c Ar blocks-per-cylinder-group
-The number of blocks per cylinder group in a file system.
+.It Fl c Ar fragments-per-cylinder-group
+The number of fragments per cylinder group in a file system.
 The default is to compute the maximum allowed by the other parameters.
 This value is dependent on a number of other parameters,
 in particular the block size and the number of bytes per inode.
diff --git a/sbin/newfs/newfs.c b/sbin/newfs/newfs.c
index 4c667e1413c..7d6a24c9c76 100644
--- a/sbin/newfs/newfs.c
+++ b/sbin/newfs/newfs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: newfs.c,v 1.60 2007/05/15 09:35:47 thib Exp $	*/
+/*	$OpenBSD: newfs.c,v 1.61 2007/05/18 19:08:16 otto Exp $	*/
 /*	$NetBSD: newfs.c,v 1.20 1996/05/16 07:13:03 thorpej Exp $	*/
 
 /*
@@ -116,7 +116,7 @@ int	sectorsize;		/* bytes/sector */
 int	realsectorsize;		/* bytes/sector in hardware */
 int	fsize = 0;		/* fragment size */
 int	bsize = 0;		/* block size */
-int	maxblkspercg = INT_MAX;	/* maximum blocks per cylinder group */
+int	maxfrgspercg = INT_MAX;	/* maximum fragments per cylinder group */
 int	minfree = MINFREE;	/* free space threshold */
 int	opt = DEFAULTOPT;	/* optimization preference (space or time) */
 int	reqopt = -1;		/* opt preference has not been specified */
@@ -205,9 +205,9 @@ main(int argc, char *argv[])
 				fatal("block size is %s: %s", errstr, optarg);
 			break;
 		case 'c':
-			maxblkspercg = strtonum(optarg, 1, INT_MAX, &errstr);
+			maxfrgspercg = strtonum(optarg, 1, INT_MAX, &errstr);
 			if (errstr)
-				fatal("blocks per cylinder group is %s: %s",
+				fatal("fragments per cylinder group is %s: %s",
 				    errstr, optarg);
 			break;
 		case 'e':
@@ -668,7 +668,7 @@ usage(void)
 	} else {
 	    fprintf(stderr,
 	        "usage: %s [-Nq] [-b block-size] "
-		"[-c blocks-per-cylinder-group] [-e maxbpg]\n"
+		"[-c fragments-per-cylinder-group] [-e maxbpg]\n"
 		"\t[-f frag-size] [-g avgfilesize] [-h avgfpdir] [-i bytes]\n"
 		"\t[-m free-space] [-O filesystem-format] [-o optimization]\n"
 		"\t[-S sector-size] [-s size] [-t fstype] special\n",