On Wed, Feb 02, 2022 at 07:15:08PM +0800, Qu Wenruo wrote:
> Despite the regular file defragging, "btrfs filesystem defragment" provides
> an option, -c, to convert all data extents (except holes and
> preallocated ranges) to a new compression algorithm.
>
> The special behavior here is, unlike regular defrag which is not going to
> touch extents which are adjacent to preallocated/hole ranges, with -c, all
> non-hole/non-preallocated extents should be defragged and converted to
> the new compression algorithm.
>
> This test case will ensure the old behavior is properly kept.
>
> Currently both old kernels (v5.15 and older) and newer kernel with
> refactored defrag (v5.16 and newer) can pass the tests.
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Looks good now, thanks.
Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
> ---
> Changelog:
> v2:
> - Add the test into prealloc group
> - Add explicit requirement for ranged fiemap and prealloc of xfs_io
> - Fix a typo in commit message
> - Use full "btrfs filesystem defragment" in the test case
> - Remove unnecessary compress-force mount option
> - Remove unnecessary -f option for xfs_io falloc command
> Which is working on an existing file.
> ---
> tests/btrfs/258 | 158 ++++++++++++++++++++++++++++++++++++++++++++
> tests/btrfs/258.out | 2 +
> 2 files changed, 160 insertions(+)
> create mode 100755 tests/btrfs/258
> create mode 100644 tests/btrfs/258.out
>
> diff --git a/tests/btrfs/258 b/tests/btrfs/258
> new file mode 100755
> index 00000000..360bb5f5
> --- /dev/null
> +++ b/tests/btrfs/258
> @@ -0,0 +1,158 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2022 SUSE Linux Products GmbH. All Rights Reserved.
> +#
> +# FS QA Test 258
> +#
> +# Make sure "btrfs filesystem defragment" can still convert the compression
> +# algorithm of all regular extents.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick defrag compress prealloc
> +
> +# Override the default cleanup function.
> +# _cleanup()
> +# {
> +# cd /
> +# rm -r -f $tmp.*
> +# }
> +
> +# Import common functions.
> +. ./common/filter
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_supported_fs btrfs
> +_require_scratch
> +_require_xfs_io_command "fiemap" "ranged"
> +_require_xfs_io_command "falloc"
> +_require_btrfs_command inspect-internal dump-tree
> +
> +get_inode_number()
> +{
> + local file="$1"
> +
> + stat -c "%i" "$file"
> +}
> +
> +get_file_extent()
> +{
> + local file="$1"
> + local offset="$2"
> + local ino=$(get_inode_number "$file")
> + local file_extent_key="($ino EXTENT_DATA $offset)"
> +
> + $BTRFS_UTIL_PROG inspect-internal dump-tree -t 5 $SCRATCH_DEV |\
> + grep -A4 "$file_extent_key"
> +}
> +
> +check_file_extent()
> +{
> + local file="$1"
> + local offset="$2"
> + local expected="$3"
> +
> + echo "=== file extent at file '$file' offset $offset ===" >> $seqres.full
> + get_file_extent "$file" "$offset" > $tmp.output
> + cat $tmp.output >> $seqres.full
> + grep -q "$expected" $tmp.output ||\
> + echo "file \"$file\" offset $offset doesn't have expected string \"$expected\""
> +}
> +
> +# Unlike file extents whose btrfs specific attributes need to be grabbed from
> +# dump-tree, we can check holes by fiemap. And mkfs enables no-holes feature by
> +# default in recent versions of btrfs-progs, preventing us from grabbing holes
> +# from dump-tree.
> +check_hole()
> +{
> + local file="$1"
> + local offset="$2"
> + local len="$3"
> +
> + output=$($XFS_IO_PROG -c "fiemap $offset $len" "$file" |\
> + _filter_xfs_io_fiemap | head -n1)
> + if [ -z $output ]; then
> + echo "=== file extent at file '$file' offset $offset is a hole ===" \
> + >> $seqres.full
> + else
> + echo "=== file extent at file '$file' offset $offset is not a hole ==="
> + fi
> +}
> +
> +# Needs 4K sectorsize as the test is crafted using that sectorsize
> +_require_btrfs_support_sectorsize 4096
> +
> +_scratch_mkfs -s 4k >> $seqres.full 2>&1
> +
> +# Initial data is compressed using lzo
> +_scratch_mount -o compress=lzo
> +
> +# file 'large' has all of its compressed extents at their maximum size
> +$XFS_IO_PROG -f -c "pwrite 0 1m" "$SCRATCH_MNT/large" >> $seqres.full
> +
> +# file 'fragment' has all of its compressed extents adjacent to
> +# preallocated/hole ranges, which should not be defragged with regular
> +# defrag ioctl, but should still be defragged by
> +# "btrfs filesystem defragment -c"
> +$XFS_IO_PROG -f -c "pwrite 0 16k" \
> + -c "pwrite 32k 16k" -c "pwrite 64k 16k" \
> + "$SCRATCH_MNT/fragment" >> $seqres.full
> +sync
> +# We only do the falloc after the compressed data reached disk.
> +# Or the inode could have PREALLOC flag, and prevent the
> +# data from being compressed.
> +$XFS_IO_PROG -c "falloc 16k 16k" "$SCRATCH_MNT/fragment"
> +sync
> +
> +echo "====== Before the defrag ======" >> $seqres.full
> +
> +# Should be lzo compressed
> +check_file_extent "$SCRATCH_MNT/large" 0 "compression 2"
> +
> +# Should be lzo compressed
> +check_file_extent "$SCRATCH_MNT/fragment" 0 "compression 2"
> +
> +# Should be preallocated
> +check_file_extent "$SCRATCH_MNT/fragment" 16384 "type 2"
> +
> +# Should be lzo compressed
> +check_file_extent "$SCRATCH_MNT/fragment" 32768 "compression 2"
> +
> +# Should be hole
> +check_hole "$SCRATCH_MNT/fragment" 49152 16384
> +
> +# Should be lzo compressed
> +check_file_extent "$SCRATCH_MNT/fragment" 65536 "compression 2"
> +
> +$BTRFS_UTIL_PROG filesystem defragment "$SCRATCH_MNT/large" -czstd \
> + "$SCRATCH_MNT/fragment" >> $seqres.full
> +# Need to commit the transaction or dump-tree won't grab the new
> +# metadata on-disk.
> +sync
> +
> +echo "====== After the defrag ======" >> $seqres.full
> +
> +# Should be zstd compressed
> +check_file_extent "$SCRATCH_MNT/large" 0 "compression 3"
> +
> +# Should be zstd compressed
> +check_file_extent "$SCRATCH_MNT/fragment" 0 "compression 3"
> +
> +# Should be preallocated
> +check_file_extent "$SCRATCH_MNT/fragment" 16384 "type 2"
> +
> +# Should be zstd compressed
> +check_file_extent "$SCRATCH_MNT/fragment" 32768 "compression 3"
> +
> +# Should be hole
> +check_hole "$SCRATCH_MNT/fragment" 49152 16384
> +
> +# Should be zstd compressed
> +check_file_extent "$SCRATCH_MNT/fragment" 65536 "compression 3"
> +
> +echo "Silence is golden"
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/btrfs/258.out b/tests/btrfs/258.out
> new file mode 100644
> index 00000000..9d47016c
> --- /dev/null
> +++ b/tests/btrfs/258.out
> @@ -0,0 +1,2 @@
> +QA output created by 258
> +Silence is golden
> --
> 2.34.1
>
