#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2021 Chandan Babu R.  All Rights Reserved.
#
# FS QA Test 537
#
# Verify that XFS does not cause inode fork's extent count to overflow when
# swapping forks between files
. ./common/preamble
_begin_fstest auto quick collapse swapext

# Import common functions.
. ./common/filter
. ./common/inject

# real QA test starts here

_supported_fs xfs
_require_scratch
_require_xfs_debug
_require_xfs_scratch_rmapbt
_require_xfs_io_command "fcollapse"
_require_xfs_io_command "swapext"
_require_xfs_io_error_injection "reduce_max_iextents"

echo "* Swap extent forks"

echo "Format and mount fs"
_scratch_mkfs >> $seqres.full
_scratch_mount >> $seqres.full

bsize=$(_get_file_block_size $SCRATCH_MNT)

srcfile=${SCRATCH_MNT}/srcfile
donorfile=${SCRATCH_MNT}/donorfile

echo "Create \$donorfile having an extent of length 67 blocks"
$XFS_IO_PROG -f -s -c "pwrite -b $((17 * bsize)) 0 $((17 * bsize))" $donorfile \
       >> $seqres.full

# After the for loop the donor file will have the following extent layout
# | 0-4 | 5 | 6 | 7 | 8 | 9 | 10 |
echo "Fragment \$donorfile"
for i in $(seq 5 10); do
	start_offset=$((i * bsize))
	$XFS_IO_PROG -f -c "fcollapse $start_offset $bsize" $donorfile >> $seqres.full
done

echo "Create \$srcfile having an extent of length 18 blocks"
$XFS_IO_PROG -f -s -c "pwrite -b $((18 * bsize)) 0 $((18 * bsize))" $srcfile \
       >> $seqres.full

echo "Fragment \$srcfile"
# After the for loop the src file will have the following extent layout
# | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7-10 |
for i in $(seq 1 7); do
	start_offset=$((i * bsize))
	$XFS_IO_PROG -f -c "fcollapse $start_offset $bsize" $srcfile >> $seqres.full
done

echo "Collect \$donorfile's extent count"
donor_nr_exts=$(_xfs_get_fsxattr nextents $donorfile)

echo "Collect \$srcfile's extent count"
src_nr_exts=$(_xfs_get_fsxattr nextents $srcfile)

echo "Inject reduce_max_iextents error tag"
_scratch_inject_error reduce_max_iextents 1

echo "Swap \$srcfile's and \$donorfile's extent forks"
$XFS_IO_PROG -f -c "swapext $donorfile" $srcfile >> $seqres.full 2>&1

echo "Check for \$donorfile's extent count overflow"
nextents=$(_xfs_get_fsxattr nextents $donorfile)

if (( $nextents == $src_nr_exts )); then
	echo "\$donorfile: Extent count overflow check failed"
fi

echo "Check for \$srcfile's extent count overflow"
nextents=$(_xfs_get_fsxattr nextents $srcfile)

if (( $nextents == $donor_nr_exts )); then
	echo "\$srcfile: Extent count overflow check failed"
fi

# success, all done
status=0
exit