Add test cases for msdosfs bug

Add a test that writes a big file, reads it again, and compares the result.
This detects the bug that briefly was in msdosfs.

Also add tests that create lots of files in a directory. Do this in the root
dir and a subdir because these work completely differently on msdosfs.  Need to
enlarge the used disk images for this test.

ok bluhm@

2 files changed, 123 insertions, 4 deletions

diff --git a/regress/sys/fileops/Makefile.inc b/regress/sys/fileops/Makefile.inc
index 410817a63b9..d6d2c05781e 100644
--- a/regress/sys/fileops/Makefile.inc
+++ b/regress/sys/fileops/Makefile.inc
@@ -1,6 +1,10 @@
-# $OpenBSD: Makefile.inc,v 1.2 2017/05/29 13:49:40 bluhm Exp $
+# $OpenBSD: Makefile.inc,v 1.3 2017/08/15 17:16:39 sf Exp $
 
-TESTS=		create read mmap
+PERL_REQUIRE != perl -e 'eval { require File::Slurp } or print $$@'
+
+TESTS1=		create read mmap
+TESTS2=		many_files_root many_files_subdir file_write
+TESTS= ${TESTS1} ${TESTS2}
 
 FILEOPS_MNT=	/mnt/regress-fileops
 FILEOPS_PROG=	${.OBJDIR}/../fileops
@@ -12,7 +16,7 @@ CLEANFILES=	diskimage stamp-*
 .PHONY: disk mount unconfig clean
 
 disk: unconfig
-	dd if=/dev/urandom of=diskimage bs=1M count=32
+	dd if=/dev/urandom of=diskimage bs=1M count=64
 	vnconfig vnd0 diskimage
 	${NEWFS} /dev/rvnd0c
 
@@ -34,7 +38,7 @@ stamp-setup:
 ${.OBJDIR}/../fileops:
 	${.MAKE} -C ${.CURDIR}/.. fileops
 
-.for t in ${TESTS}
+.for t in ${TESTS1}
 REGRESS_TARGETS+=	run-regress-${t}
 run-regress-${t}: stamp-setup ${.OBJDIR}/../fileops
 	@echo '\n======== $@ ========'
@@ -42,6 +46,20 @@ run-regress-${t}: stamp-setup ${.OBJDIR}/../fileops
 	    ${FILEOPS_PROG} ${t} ${FILEOPS_MNT}/file
 .endfor
 
+.for t in ${TESTS2}
+REGRESS_TARGETS+=	run-regress-${t}
+.if ! empty(PERL_REQUIRE)
+run-regress-${t}:
+	@echo "${PERL_REQUIRE}"
+	@echo "Install the p5-File-Slurp package to run the fileops ${t} subtest"
+	@echo SKIPPED
+.else
+run-regress-${t}: stamp-setup
+	@echo '\n======== $@ ========'
+	perl ${.CURDIR}/../fileops2.pl ${t} ${FILEOPS_MNT}
+.endif
+.endfor
+
 REGRESS_TARGETS+=	run-regress-cleanup
 run-regress-cleanup:
 	@echo '\n======== $@ ========'
diff --git a/regress/sys/fileops/fileops2.pl b/regress/sys/fileops/fileops2.pl
new file mode 100644
index 00000000000..7136ad978a9
--- /dev/null
+++ b/regress/sys/fileops/fileops2.pl
@@ -0,0 +1,101 @@
+#!/usr/bin/perl
+
+use warnings;
+use strict;
+
+
+# File::Slurp does things differently than a simple print $fh and $foo = <$fh>
+# Only with File::Slurp, the issue caused by denode.h,v 1.31
+# msdosfs_vnops.c,v 1.114 is reproducible with file_write_test().
+# XXX One should do some ktrace analysis and rewrite the test to exactly do
+# XXX what is required to trigger the issue.
+use File::Slurp;
+
+my $test = $ARGV[0] or usage();
+my $basedir = $ARGV[1] or usage();
+
+if ($test eq 'many_files_root') {
+	many_files_test($basedir, 500);
+} elsif ($test eq 'many_files_subdir') {
+	my $dir = "$basedir/subdir";
+	mkdir($dir) or die "could not create $dir";
+	[ -d $dir ] or die "mkdir($dir) did not work?";
+	many_files_test("$dir", 2000);
+} elsif ($test eq 'file_write') {
+	file_write_test("$basedir/file");
+} else {
+	usage();
+}
+
+exit 0;
+
+### sub routines
+
+# create lots of files in a dir an check that they can be read again
+sub many_files_test {
+	my $dir = shift;
+	my $nfiles = shift;
+
+
+	for my $i (1 .. $nfiles) {
+		write_file("$dir/$i", "x$i\n")
+		    or die "Could not writ file $dir/$i: $!";
+	}
+
+	foreach my $i (1 .. $nfiles) {
+		my $file = "$dir/$i";
+		my $content = read_file($file);
+		defined $content or die "could not read $file: $!";
+		if ($content ne "x$i\n") {
+			die "$file has wrong content:'$content' instead of 'x$i\n'";
+		}
+		unlink($file) or die "could not unlink $file";
+	}
+	foreach my $i (1 .. $nfiles) {
+		my $file = "$dir/$i";
+		if (-e $file) {
+			die "$file still exists?";
+		}
+	}
+}
+
+# create one ~ 500K file and check that reading gives the same contents
+sub file_write_test {
+	my $file = shift;
+	my $content = '';
+
+	for my $i (1 .. 100000) {
+		$content .= "$i\n";
+	}
+	write_file($file, $content) or die "Could not write $file: $!";
+
+	my $got = read_file($file) or die "Could not write $file: $!";
+	if (length $got != length $content) {
+		die "File $file is " . length $got . " bytes, expected "
+		    . length $content;
+	}
+
+	if ($got ne $content) {
+		my $i = 0;
+		do {
+			if (substr($got, $i, 1) ne substr($content, $i, 1)) {
+				die "Got wrong content at pos $i in $file";
+			}
+			$i++;
+		} while ($i < length($got));
+		die "BUG";
+	}
+
+	unlink $file or die "can't delet $file: $!";
+}
+
+sub usage {
+	print << "EOF";
+usage: $0 <test> <mount-point>
+
+	test can be one of:
+		file_write
+		many_files_root
+		many_files_subdir
+EOF
+}