generic: Test races between mmap and normal writes

Add test which spawns two threads one writing to file via normal write
and one via mmap and checks the result. This is mainly interesting to
uncover races between DAX fault handling and write path.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

tests/generic/346

@@ -0,0 +1,58 @@
+#! /bin/bash
+# FSQA Test No. 346
+#
+# Test races between mmap and normal writes from racing threads
+#
+#-----------------------------------------------------------------------
+#
+# Copyright (C) 2016 SUSE Linux Products GmbH. All Rights Reserved.
+# Author: Jan Kara <jack@suse.cz>
+#
+# 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
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment and checks
+. ./common/rc
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_scratch
+_require_test_program "holetest"
+
+rm -f $seqres.full
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+src/holetest -f -w $SCRATCH_MNT/testfile 1
+src/holetest -f -w $SCRATCH_MNT/testfile 16
+src/holetest -f -w $SCRATCH_MNT/testfile 256
+
+status=0
+exit

tests/generic/346.out

@@ -0,0 +1,55 @@
+QA output created by 346
+
+INFO: zero-filled test...
+INFO: sz = 1048576
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: posix_fallocate test...
+INFO: sz = 1048576
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: ftruncate test...
+INFO: sz = 1048576
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: zero-filled test...
+INFO: sz = 16777216
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: posix_fallocate test...
+INFO: sz = 16777216
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: ftruncate test...
+INFO: sz = 16777216
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: zero-filled test...
+INFO: sz = 268435456
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: posix_fallocate test...
+INFO: sz = 268435456
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected
+
+INFO: ftruncate test...
+INFO: sz = 268435456
+INFO: thread 0 created
+INFO: thread 1 created
+INFO: 0 error(s) detected

tests/generic/group

@@ -346,6 +346,7 @@
 341 auto quick metadata
 342 auto quick metadata
 343 auto quick metadata
+346 auto
 705 blockdev quick rw
 706 blockdev quick rw
 707 blockdev quick rw