mirror of
https://github.com/linux-apfs/apfstests.git
synced 2026-05-01 15:01:44 -07:00
Qu Wenruo
88231c0c0b
Ancient commit f4c697e6406d ("btrfs: return EINVAL if start >
total_bytes in fitrim ioctl") introduced a regression where btrfs
may fail to trim any free space in existing block groups.
It's caused by confusion with btrfs_super_block->total_bytes and
btrfs logical address space.
Unlike physical address, any aligned bytenr in range [0, U64_MAX) is
valid in btrfs logical address space, and it's chunk mapping
mechanism of btrfs to handle the logical<->physical mapping.
The test case will craft a btrfs with the following features:
0) Single data/meta profile
Make trimmed bytes reporting and chunk allocation more predictable.
1) All chunks start beyond super_block->total_bytes (1G)
By relocating these blocks several times.
2) Unallocated space is less than 50% of the whole fs
3) Fragmented data chunks
Data chunks will be full of fragments, 50% of data chunks will be
free space.
So in theory fstrim should be able to trim over 50% space of the fs.
(after fix, 64% of the fs can be trimmed)
While the regression makes btrfs only able to trim unallocated
space, which is less than 50% of the total space.
(without fix, it's only 31%)
Fixed by patch named "btrfs: Ensure btrfs_trim_fs can trim the whole
fs".
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
121 lines
3.7 KiB
Bash
Executable File
121 lines
3.7 KiB
Bash
Executable File
#! /bin/bash
|
|
# FS QA Test 156
|
|
#
|
|
# Check if btrfs can correctly trim free space in block groups
|
|
#
|
|
# An ancient regression prevent btrfs from trimming free space inside
|
|
# existing block groups, if bytenr of block group starts beyond
|
|
# btrfs_super_block->total_bytes.
|
|
# However all bytenr in btrfs is in btrfs logical address space,
|
|
# where any bytenr in range [0, U64_MAX] is valid.
|
|
#
|
|
# Fixed by patch named "btrfs: Ensure btrfs_trim_fs can trim the whole fs".
|
|
#
|
|
#-----------------------------------------------------------------------
|
|
# Copyright (c) 2017 SUSE Linux Products GmbH. All Rights Reserved.
|
|
#
|
|
# This program is free software; you can redistribute it and/or
|
|
# modify it under the terms of the GNU General Public License as
|
|
# published by the Free Software Foundation.
|
|
#
|
|
# This program is distributed in the hope that it would be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program; if not, write the Free Software Foundation,
|
|
# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
#-----------------------------------------------------------------------
|
|
#
|
|
|
|
seq=`basename $0`
|
|
seqres=$RESULT_DIR/$seq
|
|
echo "QA output created by $seq"
|
|
|
|
here=`pwd`
|
|
tmp=/tmp/$$
|
|
status=1 # failure is the default!
|
|
trap "_cleanup; exit \$status" 0 1 2 3 15
|
|
|
|
_cleanup()
|
|
{
|
|
cd /
|
|
rm -f $tmp.*
|
|
}
|
|
|
|
# get standard environment, filters and checks
|
|
. ./common/rc
|
|
. ./common/filter
|
|
|
|
# remove previous $seqres.full before test
|
|
rm -f $seqres.full
|
|
|
|
# real QA test starts here
|
|
|
|
# Modify as appropriate.
|
|
_supported_fs btrfs
|
|
_supported_os Linux
|
|
_require_scratch
|
|
_require_fstrim
|
|
|
|
# 1024fs size
|
|
fs_size=$((1024 * 1024 * 1024))
|
|
|
|
# Use small files to fill half of the fs
|
|
file_size=$(( 1024 * 1024 ))
|
|
nr_files=$(( $fs_size / $file_size / 2))
|
|
|
|
# Force to use single data and meta profile.
|
|
# Since the test relies on fstrim output, which will differ for different
|
|
# profiles
|
|
_scratch_mkfs -b $fs_size -m single -d single > /dev/null
|
|
_scratch_mount
|
|
|
|
_require_batched_discard "$SCRATCH_MNT"
|
|
|
|
for n in $(seq -w 0 $(( $nr_files - 1))); do
|
|
$XFS_IO_PROG -f -c "pwrite 0 $file_size" "$SCRATCH_MNT/file_$n" \
|
|
> /dev/null
|
|
done
|
|
|
|
# Flush all buffer data into disk, to trigger chunk allocation
|
|
sync
|
|
|
|
# Now we have take at least 50% of the filesystem, relocate all chunks twice
|
|
# so all chunks will start after 1G in logical space.
|
|
# (Btrfs chunk allocation will not rewind to reuse lower space)
|
|
_run_btrfs_util_prog balance start --full-balance "$SCRATCH_MNT"
|
|
|
|
# To avoid possible false ENOSPC alert on v4.15-rc1, seems to be a
|
|
# reserved space related bug (maybe related to outstanding space rework?),
|
|
# but that's another story.
|
|
sync
|
|
|
|
_run_btrfs_util_prog balance start --full-balance "$SCRATCH_MNT"
|
|
|
|
# Now remove half of the files to make some holes for later trim.
|
|
# While still keep the chunk space fragmented, so no chunk will be freed
|
|
rm $SCRATCH_MNT/file_*[13579] -f
|
|
|
|
# Make sure space is freed
|
|
sync
|
|
|
|
trimmed=$($FSTRIM_PROG -v "$SCRATCH_MNT" | _filter_fstrim)
|
|
echo "Trimmed=$trimmed total_size=$fs_size ratio=$(($trimmed * 100 / $fs_size))%" \
|
|
>> $seqres.full
|
|
|
|
# For correct full fs trim, both unallocated space (less than 50%)
|
|
# and free space in existing block groups (about 25%) should be trimmed.
|
|
# If less than 50% is trimmed, then only unallocated space is trimmed.
|
|
# BTW, without fix only 31% can be trimmed, while after fix it's 64%.
|
|
if [ $trimmed -lt $(( $fs_size / 2)) ]; then
|
|
echo "Free space in block groups not trimmed"
|
|
echo "Trimmed=$trimmed total_size=$fs_size ratio=$(($trimmed * 100 / $fs_size))%"
|
|
fi
|
|
|
|
echo "Silence is golden"
|
|
# success, all done
|
|
status=0
|
|
exit
|