#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2017 Liu Bo.  All Rights Reserved.
#
# FS QA Test 143
#
# Regression test for btrfs buffered read's repair during read without checksum.
#
# This is to test whether buffered read retry-repair code is able to work in
# raid1 case as expected.
#
# Please note that without checksum, btrfs doesn't know if the data used to
# repair is correct, so repair is more of resync which makes sure that both
# of the copy has the same content.
#
# Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed and drop
# checks") introduced the regression.
#
# The upstream fix is
#	commit 9d0d1c8b1c9d ("Btrfs: bring back repair during read")
#
. ./common/preamble
_begin_fstest auto quick read_repair

. ./common/filter
. ./common/dmdust

_supported_fs btrfs
_require_scratch_dev_pool 2
_require_dm_target dust

_require_btrfs_command inspect-internal dump-tree

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

_check_minimal_fs_size $(( 1024 * 1024 * 1024 ))
mkfs_opts="-d raid1 -b 1G"
_scratch_pool_mkfs $mkfs_opts >>$seqres.full 2>&1

# make sure data is written to the start position of the data chunk
_scratch_mount -o nodatasum $(_btrfs_no_v1_cache_opt)

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

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

logical_in_btrfs=$(_btrfs_get_first_logical $SCRATCH_MNT/foobar)
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 buffered 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

_btrfs_buffered_read_on_mirror $stripe 2 "$SCRATCH_MNT/foobar" 0 128K

_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