#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2017 Liu Bo.  All Rights Reserved.
#
# FS QA Test 142
#
# Regression test for btrfs DIO read's repair during read without checksum.
#
# Commit 2dabb3248453 ("Btrfs: Direct I/O read: Work on sectorsized blocks")
# introduced this regression.  It'd cause 'Segmentation fault' error.
#
# The upstream fix is
#	commit 97bf5a5589aa ("Btrfs: fix segmentation fault when doing dio read")
#
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
. ./common/filter
. ./common/dmdust

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

# real QA test starts here

# Modify as appropriate.
_supported_fs btrfs
_require_scratch_dev_pool 2
_require_dm_target dust

_require_btrfs_command inspect-internal dump-tree
_require_command "$FILEFRAG_PROG" filefrag

_scratch_dev_pool_get 2
# step 1, create a raid1 btrfs which contains one 128k file.
echo "step 1......mkfs.btrfs" >>$seqres.full

mkfs_opts="-d raid1 -b 1G"
_scratch_pool_mkfs $mkfs_opts >>$seqres.full 2>&1

# -o nospace_cache makes sure data is written to the start position of the data
# chunk
_scratch_mount -o nospace_cache,nodatasum

$XFS_IO_PROG -f -d -c "pwrite -S 0xaa -b 128K 0 128K" "$SCRATCH_MNT/foobar" |\
	_filter_xfs_io_offset

# step 2, corrupt the first 64k of stripe #1
echo "step 2......corrupt file extent" >>$seqres.full

${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar >> $seqres.full
logical_in_btrfs=`${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar | _filter_filefrag | cut -d '#' -f 1`
echo "Logical offset is $logical_in_btrfs" >>$seqres.full
_scratch_unmount

read -r stripe physical < <(
$BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 "$SCRATCH_DEV" |
	grep "$logical_in_btrfs" -A 6 |
	$AWK_PROG '$1 == "stripe" && $3 == "devid" && $4 == 1 { print $2 " " $6; exit }')
echo "Physical offset of stripe $stripe is $physical on devid 1" >> $seqres.full

$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 64K $physical 64K" "$SCRATCH_DEV" > /dev/null

_init_dust
_mount_dust

# step 3, 128k dio read (this read can repair bad copy)
echo "step 3......repair the bad copy" >>$seqres.full

$DMSETUP_PROG message dust-test 0 addbadblock $((physical / 512))
$DMSETUP_PROG message dust-test 0 enable
while [[ -z $( (( BASHPID % 2 == stripe )) &&
	       exec $XFS_IO_PROG -d -c "pread -b 128K 0 128K" "$SCRATCH_MNT/foobar") ]]; do
	:
done

_cleanup_dust

# check if the repair works
$XFS_IO_PROG -c "pread -v -b 512 $physical 512" "$SCRATCH_DEV" |
	_filter_xfs_io_offset

_scratch_dev_pool_put
# success, all done
status=0
exit