#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2019 Red Hat, Inc.  All Rights Reserved.
#
# FS QA Test No. 536
#
# Test a some write patterns for stale data exposure after a crash.  XFS is
# historically susceptible to this problem in the window between delalloc to
# physical extent conversion and writeback completion.
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

here=`pwd`
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, filters and checks
. ./common/rc

# remove previous $seqres.full before test
rm -f $seqres.full

# real QA test starts here

# Modify as appropriate.
_supported_fs generic
_require_scratch
_require_scratch_shutdown

# create a small fs and initialize free blocks with a unique pattern
_scratch_mkfs_sized $((1024 * 1024 * 100)) >> $seqres.full 2>&1
_scratch_mount
$XFS_IO_PROG -f -c "pwrite -S 0xab 0 100m" -c fsync $SCRATCH_MNT/spc \
	>> $seqres.full 2>&1
rm -f $SCRATCH_MNT/spc
$XFS_IO_PROG -c fsync $SCRATCH_MNT

# Write a couple files with particular writeback sequences. The first writes a
# delalloc extent and triggers writeback on the last page. The second triggers
# post-eof preallocation (on XFS), write extends into the preallocation and
# triggers writeback of the last written page.
$XFS_IO_PROG -fc "pwrite 0 256k" -c "sync_range -w 252k 4k" \
	-c "sync_range -a 252k 4k" $SCRATCH_MNT/file.1 >> $seqres.full 2>&1
$XFS_IO_PROG -fc "pwrite 0 260k" -c fsync -c "pwrite 1536k 4k" \
	-c "sync_range -w 1536k 4k" -c "sync_range -a 1536k 4k" \
	$SCRATCH_MNT/file.2 >> $seqres.full 2>&1

# Shut down before any other writeback completes. Flush the log to persist inode
# size updates.
_scratch_shutdown -f

# Now search both files for stale bytes. The region prior to the last page in
# the first file should be zero filled. The region between the two writes to the
# second file should also be zero filled.
_scratch_cycle_mount
echo file.1 | tee -a $seqres.full
hexdump $SCRATCH_MNT/file.1 | tee -a $seqres.full | grep ab
echo file.2 | tee -a $seqres.full
hexdump $SCRATCH_MNT/file.2 | tee -a $seqres.full | grep ab

status=0
exit