tests/generic/679

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2022 SUSE Linux Products GmbH.  All Rights Reserved.
#
# FS QA Test 679
#
# Test that if we call fallocate against a file range that has a mix of holes
# and written extents, the fallocate succeeds if the filesystem has enough free
# space to allocate extents for the holes.
#
. ./common/preamble
_begin_fstest auto quick prealloc

. ./common/rc
. ./common/filter
. ./common/punch

# real QA test starts here

_require_scratch
_require_xfs_io_command "falloc"
_require_xfs_io_command "fiemap"

# This test is currently not valid for xfs, see the following thread for details:
#
#   https://lore.kernel.org/linux-btrfs/20220315164011.GF8241@magnolia/
#
_supported_fs ^xfs

rm -f $seqres.full

# Create a 1G filesystem.
_scratch_mkfs_sized $((1024 * 1024 * 1024)) >>$seqres.full 2>&1
_scratch_mount

# Create a file with a size of 600M and two holes, each with a size of 1M and
# at file ranges [200, 201M[ and [401M, 402M[.
$XFS_IO_PROG -f -c "pwrite -S 0xab 0 200M" \
                -c "pwrite -S 0xcd 201M 200M" \
                -c "pwrite -S 0xef 402M 198M" \
		$SCRATCH_MNT/foobar | _filter_xfs_io

# Now call fallocate against the whole file range.
# It should succeed, because only 2M of data space needs to be allocated,
# and not 600M (which isn't available since our fs has a size of 1G).
$XFS_IO_PROG -c "falloc 0 600M" $SCRATCH_MNT/foobar

# Unmount and mount again the filesystem. We want to verify that the fallocate
# results were persisted and that all the file data on disk are also correct.
_scratch_cycle_mount

echo -n "Number of unwritten extents in the file: "
$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foobar | _filter_fiemap | \
    grep "unwritten" | wc -l

# Verify we don't have any corruption caused by the fallocate.
echo "File content after fallocate:"
od -A d -t x1 $SCRATCH_MNT/foobar

# success, all done
status=0
exit