Allow enabling soft updates (with -U) on a new filesystem.

[I first added this functionality, and thought to check prior art.  Seeing
OpenBSD had already done this, I changed my addition to reduce the diffs
between the two and went with their option letter.]
Obtained from:	OpenBSD

3 files changed, 18 insertions, 6 deletions

diff --git a/sbin/newfs/mkfs.c b/sbin/newfs/mkfs.c
index 4cf854b..daa5bae 100644
--- a/sbin/newfs/mkfs.c
+++ b/sbin/newfs/mkfs.c
@@ -95,6 +95,7 @@ extern char	*mfs_mtpt;	/* mount point for mfs          */
 extern struct stat mfs_mtstat;	/* stat prior to mount          */
 extern int	Nflag;		/* run mkfs without writing file system */
 extern int	Oflag;		/* format as an 4.3BSD file system */
+extern int	Uflag;		/* enable soft updates for file system */
 extern int	fssize;		/* file system size */
 extern int	ntracks;	/* # tracks/cylinder */
 extern int	nsectors;	/* # sectors/track */
@@ -253,6 +254,9 @@ mkfs(pp, fsys, fi, fo)
 		sblock.fs_inodefmt = FS_44INODEFMT;
 		sblock.fs_maxsymlinklen = MAXSYMLINKLEN;
 	}
+	if (Uflag) {
+		sblock.fs_flags |= FS_DOSOFTDEP;
+	}
 	/*
 	 * Validate the given file system size.
 	 * Verify that its last block can actually be accessed.
@@ -673,11 +677,12 @@ next:
 		    fsys, sblock.fs_size * NSPF(&sblock), sblock.fs_ncyl,
 		    "cylinders", sblock.fs_ntrak, sblock.fs_nsect);
 #define B2MBFACTOR (1 / (1024.0 * 1024.0))
-		printf("\t%.1fMB in %d cyl groups (%d c/g, %.2fMB/g, %d i/g)\n",
+		printf("\t%.1fMB in %d cyl groups (%d c/g, %.2fMB/g, %d i/g)%s\n",
 		    (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
 		    sblock.fs_ncg, sblock.fs_cpg,
 		    (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
-		    sblock.fs_ipg);
+		    sblock.fs_ipg,
+			sblock.fs_flags & FS_DOSOFTDEP ? " SOFTUPDATES" : "");
 #undef B2MBFACTOR
 	}
 	/*
diff --git a/sbin/newfs/newfs.8 b/sbin/newfs/newfs.8
index ef90f88..d39ea4d 100644
--- a/sbin/newfs/newfs.8
+++ b/sbin/newfs/newfs.8
@@ -41,7 +41,7 @@
 .Nd construct a new file system
 .Sh SYNOPSIS
 .Nm
-.Op Fl NO
+.Op Fl NOU
 .Op Fl S Ar sector-size
 .Op Fl T Ar disktype
 .Op Fl a Ar maxcontig
@@ -65,7 +65,7 @@
 .Op Fl x Ar sectors
 .Ar special
 .Nm mount_mfs
-.Op Fl N
+.Op Fl NU
 .Op Fl F Ar file
 .Op Fl T Ar disktype
 .Op Fl a Ar maxcontig
@@ -148,6 +148,8 @@ Cause the file system parameters to be printed out
 without really creating the file system.
 .It Fl O
 Create a
+.It Fl U
+Enables soft updates on the new filesystem.
 .Bx 4.3
 format filesystem.
 This options is primarily used to build root filesystems
diff --git a/sbin/newfs/newfs.c b/sbin/newfs/newfs.c
index b006a8a..e755993 100644
--- a/sbin/newfs/newfs.c
+++ b/sbin/newfs/newfs.c
@@ -173,6 +173,7 @@ char	*mfs_mtpt;		/* mount point for mfs		*/
 struct stat mfs_mtstat;		/* stat prior to mount		*/
 int	Nflag;			/* run without writing file system */
 int	Oflag;			/* format as an 4.3BSD file system */
+int	Uflag;			/* enable soft updates for file system */
 int	fssize;			/* file system size */
 int	ntracks = NTRACKS;	/* # tracks/cylinder */
 int	nsectors = NSECTORS;	/* # sectors/track */
@@ -255,8 +256,8 @@ main(argc, argv)
 	}
 
 	opstring = mfs ?
-	    "NF:T:a:b:c:d:e:f:i:m:o:s:" :
-	    "NOS:T:a:b:c:d:e:f:i:k:l:m:n:o:p:r:s:t:u:vx:";
+	    "NF:T:Ua:b:c:d:e:f:i:m:o:s:" :
+	    "NOS:T:Ua:b:c:d:e:f:i:k:l:m:n:o:p:r:s:t:u:vx:";
 	while ((ch = getopt(argc, argv, opstring)) != -1)
 		switch (ch) {
 		case 'N':
@@ -277,6 +278,9 @@ main(argc, argv)
 		case 'F':
 			filename = optarg;
 			break;
+		case 'U':
+			Uflag = 1;
+			break;
 		case 'a':
 			if ((maxcontig = atoi(optarg)) <= 0)
 				fatal("%s: bad maximum contiguous blocks",
@@ -757,6 +761,7 @@ usage()
 #ifdef COMPAT
 	fprintf(stderr, "\t-T disktype\n");
 #endif
+	fprintf(stderr, "\t-U enable soft updates\n");
 	fprintf(stderr, "\t-a maximum contiguous blocks\n");
 	fprintf(stderr, "\t-b block size\n");
 	fprintf(stderr, "\t-c cylinders/group\n");