xfstests: check block truncation after write failure

Extraced from  https://bugzilla.kernel.org/show_bug.cgi?id=22452
"data corruption after mmap()ing a file and writev() some data to another file"

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Dave Chinner <david@fromorbit.com>

246

@@ -0,0 +1,60 @@
+#! /bin/bash
+# FS QA Test No. 246
+#
+# Check that truncation after failed writes does not zero too much data.
+#
+# Based on a bug report and testcase from
+# Marius Tolzmann <tolzmann@molgen.mpg.de>
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2010 Christoph Hellwig.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+#-----------------------------------------------------------------------
+#
+# creator
+owner=hch@lst.de
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+
+file=$TEST_DIR/mmap-writev
+
+_cleanup()
+{
+	rm -rf $file
+	rm -rf $file.NEW
+}
+
+trap "_cleanup ; exit \$status" 0 1 2 3 15
+
+echo -n "cccccccccc" > $file
+$here/src/t_mmap_writev $file $file.NEW
+od -t x2 $file.NEW
+
+status=0
+exit $status

246.out

@@ -0,0 +1,4 @@
+QA output created by 246
+0000000 6161 6161 6161 6161 6161 6262 6262 6262
+0000020 6262 6262 6363 6363 6363 6363 6363
+0000036

group

@@ -359,3 +359,4 @@ deprecated
 243 auto quick prealloc
 244 auto quota quick
 245 auto quick dir
+246 auto quick rw

src/Makefile

@@ -10,7 +10,8 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
 	mmapcat append_reader append_writer dirperf metaperf \
 	devzero feature alloc fault fstest t_access_root \
 	godown resvtest writemod makeextents itrash rename \
-	multi_open_unlink dmiperf unwritten_sync genhashnames t_holes
+	multi_open_unlink dmiperf unwritten_sync genhashnames t_holes \
+	t_mmap_writev
 
 LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
 	preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \

src/t_mmap_writev.c

@@ -0,0 +1,70 @@
+/*
+    mmap() a file and writev() back to another file
+         - kernel bug #22452 testcase
+
+    Copyright (C) 2010
+         by D.Buczek - Max Planck Institute for Molecular Genetics Berlin
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include <sys/types.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <sys/mman.h>
+#include <string.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+int main(int argc, char **argv)
+{
+	char *file = argv[1];
+	char *new_file = argv[2];
+	int fd;
+	int fd_new;
+	void *base;
+
+	struct iovec iovec[3]=
+	{
+		{ "aaaaaaaaaa" , 10 },
+		{ "bbbbbbbbbb" , 10 },
+	 	{ NULL , 10 }
+	};
+
+	int i;
+
+	fd=open(file, O_RDONLY);
+	if (fd==-1) {perror("open");exit(1);}
+
+	base = mmap(NULL,16384,PROT_READ,MAP_SHARED,fd,0);
+	if  (base == (void *)-1) { perror("mmap");exit(1); }
+
+	unlink(new_file);
+
+	fd_new=open(new_file,O_RDWR|O_CREAT,0666);
+	if (fd_new==-1) {perror("creat");exit(1);}
+
+	iovec[2].iov_base=(char *)base;
+	i=writev(fd_new,iovec,sizeof(iovec)/sizeof(*iovec));
+	if (i==-1) {perror("writev");exit(1);}
+
+	close(fd_new);
+	munmap(base,16384);
+	close(fd);
+
+	return 0;
+}