Revise r197763 which fixes filesystem corruption when extending

into un-zeroed storage.

The original patch was questioned by Kirk as it forces the filesystem
to do excessive work initialising inodes on first use, and was never
MFC'd.  This change mimics the newfs(8) approach of zeroing two
blocks of inodes for each new cylinder group.

Reviewed by:	mckusick
MFC after:	3 weeks

3 files changed, 102 insertions, 0 deletions

diff --git a/tools/regression/sbin/Makefile b/tools/regression/sbin/Makefile
new file mode 100644
index 0000000..33d158e
--- /dev/null
+++ b/tools/regression/sbin/Makefile
@@ -0,0 +1,5 @@
+# $FreeBSD$
+
+SUBDIR=	growfs
+
+.include <bsd.subdir.mk>
diff --git a/tools/regression/sbin/growfs/Makefile b/tools/regression/sbin/growfs/Makefile
new file mode 100644
index 0000000..dc9fa67
--- /dev/null
+++ b/tools/regression/sbin/growfs/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+all test:
+	prove -vmw regress.t
+
+clean:
diff --git a/tools/regression/sbin/growfs/regress.t b/tools/regression/sbin/growfs/regress.t
new file mode 100755
index 0000000..9dbdd85
--- /dev/null
+++ b/tools/regression/sbin/growfs/regress.t
@@ -0,0 +1,91 @@
+#! /usr/bin/perl
+#
+# $FreeBSD$
+
+use strict;
+use warnings;
+use Test::More tests => 19;
+use Fcntl qw(:DEFAULT :seek);
+
+use constant BLK => 512;
+use constant BLKS_PER_MB => 2048;
+
+my $unit;
+END { system "mdconfig -du$unit" if defined $unit };
+
+sub setsize {
+    my ($partszMB, $unitszMB) = @_;
+
+    open my $fd, "|-", "disklabel -R md$unit /dev/stdin" or die;
+    print $fd "a: ", ($partszMB * BLKS_PER_MB), " 0 4.2BSD 1024 8192\n";
+    print $fd "c: ", ($unitszMB * BLKS_PER_MB), " 0 unused 0 0\n";
+    close $fd;
+}
+
+sub fill {
+    my ($start, $size, $content) = @_;
+
+    my $content512 = $content x (int(512 / length $content) + 1);
+    substr($content512, 512) = "";
+    sysopen my $fd, "/dev/md$unit", O_RDWR or die "/dev/md$unit: $!";
+    seek($fd, $start * BLK, SEEK_SET);
+    while ($size) {
+	syswrite($fd, $content512) == 512 or die "write: $!";
+	$size--;
+    }
+}
+
+SKIP: {
+    skip "Cannot test without UID 0", 19 if $<;
+
+    chomp(my $md = `mdconfig -s40m`);
+    like($md, qr/^md\d+$/, "Created $md with size 40m") or die;
+    $unit = substr $md, 2;
+
+    for my $type (1..2) {
+
+	initialise: {
+	    ok(setsize(10, 40), "Sized ${md}a to 10m");
+	    system "newfs -O $type -U ${md}a >/dev/null";
+	    is($?, 0, "Initialised the filesystem on ${md}a as UFS$type");
+	    chomp(my @out = `fsck -tufs -y ${md}a`);
+	    ok(!grep(/MODIFIED/, @out), "fsck says ${md}a is clean, " .
+		scalar(@out) . " lines of output");
+	}
+
+	extend20_zeroed: {
+	    ok(setsize(20, 40), "Sized ${md}a to 20m");
+	    diag "Filling the extent with zeros";
+	    fill(10 * BLKS_PER_MB, 10 * BLKS_PER_MB, chr(0));
+	    my $out = `growfs -y ${md}a`;
+	    is($?, 0, "Extended the filesystem on ${md}a") or print $out;
+
+	    my ($unallocated) = $out =~ m{\d+ sectors cannot be allocated};
+	    fill(30 * BLKS_PER_MB - $unallocated, $unallocated, chr(0))
+		if $unallocated;
+
+	    chomp(my @out = `fsck -tufs -y ${md}a`);
+	    ok(!grep(/MODIFIED/, @out), "fsck says ${md}a is clean, " .
+		scalar(@out) . " lines of output");
+	}
+
+	extend30_garbaged: {
+	    ok(setsize(30, 40), "Sized ${md}a to 30m");
+	    diag "Filling the extent with garbage";
+	    fill(20 * BLKS_PER_MB, 10 * BLKS_PER_MB, chr(0xaa) . chr(0x55));
+	    my $out = `growfs -y ${md}a`;
+	    is($?, 0, "Extended the filesystem on ${md}a") or print $out;
+
+	    my ($unallocated) = $out =~ m{\d+ sectors cannot be allocated};
+	    fill(30 * BLKS_PER_MB - $unallocated, $unallocated, chr(0))
+		if $unallocated;
+
+	    chomp(my @out = `fsck -tufs -y ${md}a`);
+	    ok(!grep(/MODIFIED/, @out), "fsck says ${md}a is clean, " .
+		scalar(@out) . " lines of output");
+	}
+    }
+
+    system "mdconfig -du$unit";
+    undef $unit;
+}