generic: regression test for ext4 crash consistency bug

This test is motivated by this inconsistency found in ext4 during random
crash consistency tests:

 *** fsck.ext4 output ***
 fsck from util-linux 2.27.1
 e2fsck 1.42.13 (17-May-2015)
 Pass 1: Checking inodes, blocks, and sizes
 Inode 12, end of extent exceeds allowed value
         (logical block 33, physical block 33817, len 7)
 Clear? no

 Inode 12, i_blocks is 240, should be 184.  Fix? no

This test uses device mapper flakey target to demonstrate the bug
found using device mapper log-writes target.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/generic/501

@@ -0,0 +1,80 @@
+#! /bin/bash
+# FS QA Test No. 501
+#
+# This test is motivated by a bug found in ext4 during random crash
+# consistency tests.
+#
+#-----------------------------------------------------------------------
+# Copyright (C) 2017 CTERA Networks. All Rights Reserved.
+# Author: Amir Goldstein <amir73il@gmail.com>
+#
+# 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"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_flakey
+	cd /
+	rm -f $tmp.*
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/dmflakey
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_scratch
+_require_dm_target flakey
+
+rm -f $seqres.full
+
+_scratch_mkfs >> $seqres.full 2>&1
+_require_metadata_journaling $SCRATCH_DEV
+
+_init_flakey
+_mount_flakey
+
+fsxops=$tmp.fsxops
+cat <<EOF > $fsxops
+write 0x137dd 0xdc69 0x0
+fallocate 0xb531 0xb5ad 0x21446
+collapse_range 0x1c000 0x4000 0x21446
+write 0x3e5ec 0x1a14 0x21446
+zero_range 0x20fac 0x6d9c 0x40000 keep_size
+mapwrite 0x216ad 0x274f 0x40000
+EOF
+run_check $here/ltp/fsx -d --replay-ops $fsxops $SCRATCH_MNT/testfile
+
+_flakey_drop_and_remount
+_unmount_flakey
+_cleanup_flakey
+_check_scratch_fs
+
+echo "Silence is golden"
+
+status=0
+exit

tests/generic/501.out

@@ -0,0 +1,2 @@
+QA output created by 501
+Silence is golden

tests/generic/group

@@ -458,3 +458,4 @@
 453 auto quick dir
 454 auto quick attr
 500 auto log replay
+501 auto quick metadata