Re: [PATCH v6] btrfs: Add new test for setting the chunk size.

Eryu Guan
2021-11-28T15:57:43Z

On Wed, Nov 24, 2021 at 01:12:30PM -0800, Stefan Roesch wrote:
> Add new testcase for testing the new btrfs sysfs knob to change the
> chunk size. The new knob uses /sys/fs/btrfs/<UUID>/allocation/<block
> type>/chunk_size.
>
> The test case implements three different cases:
> - Test allocation with the default chunk size
> - Test allocation after increasing the chunk size
> - Test allocation when the free space is smaller than the chunk size.
>
> Note: this test needs to force the allocation of space. It uses the
> /sys/fs/btrfs/<UUID>/allocation/<block type>/force_chunk_alloc knob.
>
> Testing:
> The test has been run with volumes of different sizes.
>
> Signed-off-by: Stefan Roesch <shr@fb.com>
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> ---
> V6: - renamed test case from 248 to 251
> - use _require_fs_sysfs
> - use device name in _get_fs_sysfs_attr and _set_fs_sysfs_attr
> V5: - Modify _get_fs_sysfs_attr and _set_fs_sysfs_attr to support btrfs
> - Use _get_fs_sysfs_attr and _set_fs_sysfs_attr
> - Remove _get_btrfs_sysfs_attr and _set_btrfs_fsysfs_attr
> - Rename local functions to not use "_"
> - use $AWK_PROG and $BTRFS_UTIL_PROG
> - remove call to _require_scratch_size
> - fixes for coding convention
> - replace fail calls with echo
> V4: - fixed indentation in common/btrfs
> - Removed UUID code, which is no longer necessary (provided
> by helper function)
> - Used new helper _get_btrfs_sysfs_attr
> - Direct output to /dev/null
> V3: - removed tests for system block type.
> - added failure case for system block type.
> - renamed stripe_size to chunk_size
> V2: - added new functions to common/btrfs and use them in the new test
> - _require_btrfs_sysfs_attr - Make sure btrfs supports a sysfs
> setting
> - _get_btrfs_sysfs_attr - Read sysfs value
> - _set_btrfs_sysfs_attr - Write sysfs value
> - create file system of required size with _scratch_mkfs_sized
> - use shortened error message
> - Remove last logging message
> ---
> common/rc | 29 ++++-
> tests/btrfs/251 | 287 ++++++++++++++++++++++++++++++++++++++++++++
> tests/btrfs/251.out | 11 ++
> 3 files changed, 323 insertions(+), 4 deletions(-)
> create mode 100755 tests/btrfs/251
> create mode 100644 tests/btrfs/251.out
>
> diff --git a/common/rc b/common/rc
> index 0a30a842..9522ba2e 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -4401,7 +4401,14 @@ run_fsx()
> _require_fs_sysfs()
> {
> local attr=$1
> - local dname=$(_short_dev $TEST_DEV)
> + local dname
> +
> + case "$FSTYP" in
> + btrfs)
> + dname=$(findmnt -n -o UUID $TEST_DEV) ;;
> + *)
> + dname=$(_short_dev $TEST_DEV) ;;
> + esac
>
> if [ -z "$attr" -o -z "$dname" ];then
> _fail "Usage: _require_fs_sysfs <sysfs_attr_path>"
> @@ -4436,10 +4443,17 @@ _set_fs_sysfs_attr()
> local content="$*"
>
> if [ ! -b "$dev" -o -z "$attr" -o -z "$content" ];then
> - _fail "Usage: _set_fs_sysfs_attr <mounted_device> <attr> <content>"
> + _fail "Usage: _set_fs_sysfs_attr <mounted_device> <attr> <content>"

What is this change? Seems it adds a space between the first two tabs,
and causes git am to complain about whitespace damange.

> fi
>
> - local dname=$(_short_dev $dev)
> + local dname
> + case "$FSTYP" in
> + btrfs)
> + dname=$(findmnt -n -o UUID ${dev}) ;;
> + *)
> + dname=$(_short_dev $dev) ;;
> + esac
> +
> echo "$content" > /sys/fs/${FSTYP}/${dname}/${attr}
> }
>
> @@ -4460,7 +4474,14 @@ _get_fs_sysfs_attr()
> _fail "Usage: _get_fs_sysfs_attr <mounted_device> <attr>"
> fi
>
> - local dname=$(_short_dev $dev)
> + local dname
> + case "$FSTYP" in
> + btrfs)
> + dname=$(findmnt -n -o UUID ${dev}) ;;
> + *)
> + dname=$(_short_dev $dev) ;;
> + esac
> +
> cat /sys/fs/${FSTYP}/${dname}/${attr}
> }
>
> diff --git a/tests/btrfs/251 b/tests/btrfs/251
> new file mode 100755
> index 00000000..b5c4b623
> --- /dev/null
> +++ b/tests/btrfs/251
> @@ -0,0 +1,287 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2021 Facebook. All Rights Reserved.
> +#
> +# FS QA Test 250
> +#
> +# Test the new /sys/fs/btrfs/<uuid>/allocation/<block-type>/chunk_size
> +# setting. This setting allows the admin to change the chunk size
> +# setting for the next allocation.
> +#
> +# Test 1:
> +# Allocate storage for all three block types (data, metadata and system)
> +# with the default chunk size.
> +#
> +# Test 2:
> +# Set a new chunk size to double the default size and allocate space
> +# for all new block types with the new chunk size.
> +#
> +# Test 3:
> +# Pick an allocation size that is used in a loop and make sure the last
> +# allocation cannot be partially fullfilled.
> +#
> +# Note: Variable naming uses the following convention: if a variable name
> +# ends in "_B" then its a byte value, if it ends in "_MB" then the
> +# value is in megabytes.
> +#
> +. ./common/preamble
> +_begin_fstest auto
> +
> +test_file="${TEST_DIR}/${seq}"

Seems it's not used in the test?

> +seq=`basename $0`
> +seqres="${RESULT_DIR}/${seq}"
> +
> +# Override the default cleanup function.
> +_cleanup()
> +{
> + cd /
> + rm -f "$test_file"

Then there's no need to remove it in cleanup

> +}
> +
> +# Parse a size string which is in the format "XX.XXMib".
> +#
> +# Parameters:
> +# - (IN) Block group type (Data, Metadata, System)
> +# - (INOUT) Variable to store block group size in MB
> +#
> +parse_size_string() {
> + local SIZE=$(echo "$1" | $AWK_PROG 'match($0, /([0-9.]+)/) { print substr($0, RSTART, RLENGTH) }')
> + eval $2="${SIZE%.*}"

The above "eval" line uses spaces as indentions not tab.

> +}
> +
> +# Determine the size of the device in MB.
> +#
> +# Parameters:
> +# - (INOUT) Variable to store device size in MB
> +#
> +device_size() {
> + btrfs fi show ${SCRATCH_MNT} --mbytes | grep devid >> $seqres.full
> + local SIZE=$($BTRFS_UTIL_PROG filesystem show ${SCRATCH_MNT} --mbytes | grep devid)
> + parse_size_string $(echo "${SIZE}" | awk '{print $4}') SIZE_ALLOC
> + eval $1=${SIZE_ALLOC%.*}
> +}
> +
> +# Determine the free space of a block group in MB.
> +#
> +# Parameters:
> +# - (INOUT) Variable to store free space in MB
> +#
> +free_space() {
> + local SIZE=$($BTRFS_UTIL_PROG filesystem show ${SCRATCH_MNT} --mbytes | grep devid)
> + parse_size_string $(echo "${SIZE}" | awk '{print $4}') SIZE_ALLOC
> + parse_size_string $(echo "${SIZE}" | awk '{print $6}') SIZE_USED
> + eval $1=$(expr ${SIZE_ALLOC} - ${SIZE_USED})
> +}
> +
> +# Determine how much space in MB has been allocated to a block group.
> +#
> +# Parameters:
> +# - (IN) Block group type (Data, Metadata, System)
> +# - (INOUT) Variable to store block group size in MB
> +#
> +alloc_size() {
> + local SIZE_STRING=$($BTRFS_UTIL_PROG filesystem df ${SCRATCH_MNT} -m | grep "$1" | awk '{print $3}')
> + parse_size_string ${SIZE_STRING} BLOCK_GROUP_SIZE
> + eval $2="${BLOCK_GROUP_SIZE}"
> +}
> +
> +. ./common/filter
> +_supported_fs btrfs
> +_require_test
> +_require_scratch
> +_require_btrfs_fs_sysfs

Looks like we could drop this require, as _require_fs_sysfs below
ensures this requirement must be met.

> +
> +# Delete log file if it exists.
> +rm -f "${seqres}.full"
> +
> +# Make filesystem.
> +_scratch_mkfs_sized $((10 * 1024 * 1024 * 1024)) >> $seqres.full 2>&1

Any reason we need a 10G filesystem? Some comments would be good.

> +_scratch_mount >> $seqres.full 2>&1
> +
> +# Check if there is sufficient sysfs support.
> +_require_fs_sysfs allocation/metadata/chunk_size
> +_require_fs_sysfs allocation/metadata/force_chunk_alloc
> +
> +# Get free space.
> +free_space FREE_SPACE_MB
> +device_size DEVICE_SIZE_MB
> +
> +echo "free space = ${FREE_SPACE_MB}MB" >> ${seqres}.full
> +
> +# If device is a symbolic link, get block device.
> +SCRATCH_BDEV=${SCRATCH_DEV}
> +if [[ -h ${SCRATCH_DEV} ]]; then
> + SCRATCH_BDEV=$(readlink -f $SCRATCH_DEV)
> +fi
> +
> +# Get chunk sizes.
> +echo "Capture default chunk sizes."
> +FIRST_DATA_CHUNK_SIZE_B=$(_get_fs_sysfs_attr ${SCRATCH_BDEV} allocation/data/chunk_size)
> +FIRST_METADATA_CHUNK_SIZE_B=$(_get_fs_sysfs_attr ${SCRATCH_BDEV} allocation/metadata/chunk_size)
> +
> +echo "Orig Data chunk size = ${FIRST_DATA_CHUNK_SIZE_B}" >> ${seqres}.full
> +echo "Orig Metaata chunk size = ${FIRST_METADATA_CHUNK_SIZE_B}" >> ${seqres}.full
> +
> +INIT_ALLOC_SIZE_MB=$(expr \( ${FIRST_DATA_CHUNK_SIZE_B} + ${FIRST_METADATA_CHUNK_SIZE_B} \) / 1024 / 1024)
> +echo "Allocation size for initial allocation = ${INIT_ALLOC_SIZE_MB}MB" >> $seqres.full
> +
> +#
> +# Do first allocation with the default chunk sizes for the different block
> +# types.
> +#
> +echo "First allocation."
> +alloc_size "Data" DATA_SIZE_START_MB
> +alloc_size "Metadata" METADATA_SIZE_START_MB
> +
> +echo "Block group Data alloc size = ${DATA_SIZE_START_MB}MB" >> $seqres.full
> +echo "Block group Metadata alloc size = ${METADATA_SIZE_START_MB}MB" >> $seqres.full
> +
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/data/force_chunk_alloc 1
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/metadata/force_chunk_alloc 1
> +
> +alloc_size "Data" FIRST_DATA_SIZE_MB
> +alloc_size "Metadata" FIRST_METADATA_SIZE_MB
> +
> +echo "First block group Data alloc size = ${FIRST_DATA_SIZE_MB}MB" >> ${seqres}.full
> +echo "First block group Metadata alloc size = ${FIRST_METADATA_SIZE_MB}MB" >> ${seqres}.full
> +
> +free_space FREE_SPACE_AFTER
> +echo "Free space after first allocation = ${FREE_SPACE_AFTER}MB" >> ${seqres}.full
> +
> +#
> +# Do allocation with the doubled chunk sizes for the different block types.
> +#
> +echo "Second allocation."
> +SECOND_DATA_CHUNK_SIZE_B=$(expr ${FIRST_DATA_CHUNK_SIZE_B} \* 2)
> +SECOND_METADATA_CHUNK_SIZE_B=$(expr ${FIRST_METADATA_CHUNK_SIZE_B} \* 2)
> +
> +echo "Second block group Data calc alloc size = ${SECOND_DATA_CHUNK_SIZE_B}" >> $seqres.full
> +echo "Second block group Metadata calc alloc size = ${SECOND_METADATA_CHUNK_SIZE_B}" >> $seqres.full
> +
> +# Stripe size is limited to 10% of device size.
> +if [[ ${SECOND_DATA_CHUNK_SIZE_B} -gt $(expr ${DEVICE_SIZE_MB} \* 10 \* 1024 \* 1024 / 100) ]]; then
> + SECOND_DATA_CHUNK_SIZE_B=$(expr ${DEVICE_SIZE_MB} \* 10 / 100 \* 1024 \* 1024)
> +fi
> +if [[ ${SECOND_METADATA_CHUNK_SIZE_B} -gt $(expr ${DEVICE_SIZE_MB} \* 10 \* 1024 \* 1024 / 100) ]]; then
> + SECOND_METADATA_CHUNK_SIZE_B=$(expr ${DEVICE_SIZE_MB} \* 10 / 100 \* 1024 \* 1024)
> +fi
> +
> +echo "Second block group Data alloc size = ${SECOND_DATA_CHUNK_SIZE_B}" >> $seqres.full
> +echo "Second block group Metadata alloc size = ${SECOND_METADATA_CHUNK_SIZE_B}" >> $seqres.full
> +
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/data/chunk_size ${SECOND_DATA_CHUNK_SIZE_B}
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/metadata/chunk_size ${SECOND_METADATA_CHUNK_SIZE_B}
> +
> +SECOND_DATA_CHUNK_SIZE_READ_B=$(_get_fs_sysfs_attr ${SCRATCH_BDEV} allocation/data/chunk_size)
> +SECOND_METADATA_CHUNK_SIZE_READ_B=$(_get_fs_sysfs_attr ${SCRATCH_BDEV} allocation/metadata/chunk_size)
> +
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/data/force_chunk_alloc 1
> +echo "Allocated data chunk" >> $seqres.full
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/metadata/force_chunk_alloc 1
> +echo "Allocated metadata chunk" >> $seqres.full
> +
> +alloc_size "Data" SECOND_DATA_SIZE_MB
> +alloc_size "Metadata" SECOND_METADATA_SIZE_MB
> +alloc_size "System" SECOND_SYSTEM_SIZE_MB
> +
> +echo "Calculate request size so last memory allocation cannot be completely fullfilled."
> +free_space FREE_SPACE_MB
> +
> +# Find request size whose space allocation cannot be completely fullfilled.
> +THIRD_DATA_CHUNK_SIZE_MB=$(expr 256)
> +until [ ${THIRD_DATA_CHUNK_SIZE_MB} -gt $(expr 7 \* 1024) ]; do
> + if [ $((FREE_SPACE_MB%THIRD_DATA_CHUNK_SIZE_MB)) -ne 0 ]; then
> + break
> + fi
> + THIRD_DATA_CHUNK_SIZE_MB=$((THIRD_DATA_CHUNK_SIZE_MB+256))
> +done
> +
> +if [[ ${THIRD_DATA_CHUNK_SIZE_MB} -eq $(expr 7 \* 1024) ]]; then
> + _fail "Cannot find allocation size for partial block allocation."
> +fi
> +
> +THIRD_DATA_CHUNK_SIZE_B=$(expr ${THIRD_DATA_CHUNK_SIZE_MB} \* 1024 \* 1024)
> +echo "Allocation size in mb = ${THIRD_DATA_CHUNK_SIZE_MB}" >> ${seqres}.full
> +echo "Allocation size in bytes = ${THIRD_DATA_CHUNK_SIZE_B}" >> ${seqres}.full
> +
> +#
> +# Do allocation until free space is exhausted.
> +#
> +echo "Third allocation."
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/data/chunk_size ${THIRD_DATA_CHUNK_SIZE_B}
> +
> +free_space FREE_SPACE_MB
> +while [ $FREE_SPACE_MB -gt $THIRD_DATA_CHUNK_SIZE_MB ]
> +do
> + alloc_size "Data" THIRD_DATA_SIZE_MB
> + _set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/data/force_chunk_alloc 1
> +
> + free_space FREE_SPACE_MB
> +done
> +
> +alloc_size "Data" FOURTH_DATA_SIZE_MB
> +
> +#
> +# Force chunk allocation of system block type must fail.
> +#
> +echo "Force allocation of system block type must fail."
> +_set_fs_sysfs_attr ${SCRATCH_BDEV} allocation/system/force_chunk_alloc 1 2>/dev/null
> +if [ $? -ne 0 ]; then
> + _dump_err "_set_fs_sysfs_attr cannot write allocation/system/force_chunk_alloc"
> +fi

I don't think we need this check. We could just remove the
"2 > /dev/null" part from the above _set_fs_sysfs_attr and it will print
error message and break golden image on error.

Thanks,
Eryu

> +
> +#
> +# Verification of initial allocation.
> +#
> +echo "Verify first allocation."
> +FIRST_DATA_CHUNK_SIZE_MB=$(expr ${FIRST_DATA_CHUNK_SIZE_B} / 1024 / 1024)
> +FIRST_METADATA_CHUNK_SIZE_MB=$(expr ${FIRST_METADATA_CHUNK_SIZE_B} / 1024 / 1024)
> +
> +# if [[ $(expr ${FIRST_DATA_CHUNK_SIZE_MB} + ${DATA_SIZE_START_MB}) -ne $(expr ${FIRST_DATA_SIZE_MB}) ]]; then
> +if [[ $(expr ${FIRST_DATA_CHUNK_SIZE_MB} + ${DATA_SIZE_START_MB}) -ne ${FIRST_DATA_SIZE_MB} ]]; then
> + echo "tInitial data allocation not correct."
> +fi
> +
> +if [[ $(expr ${FIRST_METADATA_CHUNK_SIZE_MB} + ${METADATA_SIZE_START_MB}) -ne ${FIRST_METADATA_SIZE_MB} ]]; then
> + echo "Initial metadata allocation not correct."
> +fi
> +
> +#
> +# Verification of second allocation.
> +#
> +echo "Verify second allocation."
> +SECOND_DATA_CHUNK_SIZE_MB=$(expr ${SECOND_DATA_CHUNK_SIZE_B} / 1024 / 1024)
> +SECOND_METADATA_CHUNK_SIZE_MB=$(expr ${SECOND_METADATA_CHUNK_SIZE_B} / 1024 / 1024)
> +
> +if [[ ${SECOND_DATA_CHUNK_SIZE_B} -ne ${SECOND_DATA_CHUNK_SIZE_READ_B} ]]; then
> + echo "Value written to allocation/data/chunk_size and read value are different."
> +fi
> +
> +if [[ ${SECOND_METADATA_CHUNK_SIZE_B} -ne ${SECOND_METADATA_CHUNK_SIZE_READ_B} ]]; then
> + echo "Value written to allocation/metadata/chunk_size and read value are different."
> +fi
> +
> +if [[ $(expr ${SECOND_DATA_CHUNK_SIZE_MB} + ${FIRST_DATA_SIZE_MB}) -ne ${SECOND_DATA_SIZE_MB} ]]; then
> + echo "Data allocation after chunk size change not correct."
> +fi
> +
> +if [[ $(expr ${SECOND_METADATA_CHUNK_SIZE_MB} + ${FIRST_METADATA_SIZE_MB}) -ne ${SECOND_METADATA_SIZE_MB} ]]; then
> + echo "Metadata allocation after chunk size change not correct."
> +fi
> +
> +#
> +# Verification of third allocation.
> +#
> +echo "Verify third allocation."
> +if [[ ${FREE_SPACE_MB} -gt ${THIRD_DATA_CHUNK_SIZE_MB} ]]; then
> + echo "Free space after allocating over memlimit is too high."
> +fi
> +
> +# The + 1 is required as 1MB is always kept as free space.
> +if [[ $(expr ${THIRD_DATA_CHUNK_SIZE_MB} + ${THIRD_DATA_SIZE_MB} + 1) -le $(expr ${FOURTH_DATA_SIZE_MB}) ]]; then
> + echo "Allocation until out of memory: last memory allocation size is not correct."
> +fi
> +
> +status=0
> +exit
> +
> diff --git a/tests/btrfs/251.out b/tests/btrfs/251.out
> new file mode 100644
> index 00000000..bb7b45d8
> --- /dev/null
> +++ b/tests/btrfs/251.out
> @@ -0,0 +1,11 @@
> +QA output created by 248
> +Capture default chunk sizes.
> +First allocation.
> +Second allocation.
> +Calculate request size so last memory allocation cannot be completely fullfilled.
> +Third allocation.
> +Force allocation of system block type must fail.
> +_set_fs_sysfs_attr cannot write allocation/system/force_chunk_alloc
> +Verify first allocation.
> +Verify second allocation.
> +Verify third allocation.
> --
> 2.30.2