Re: [PATCH 4/4] xfs/548: Verify correctness of upgrading an fs to support large extent counters

[Chandan Babu R <chandan.babu@oracle.com>]

On Mon, Jun 06, 2022 at 08:35:19 AM -0700, Darrick J. Wong wrote:
> On Mon, Jun 06, 2022 at 06:11:01PM +0530, Chandan Babu R wrote:
>> This commit adds a test to verify upgrade of an existing V5 filesystem to
>> support large extent counters.
>> 
>> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
>> ---
>>  tests/xfs/548     | 109 ++++++++++++++++++++++++++++++++++++++++++++++
>>  tests/xfs/548.out |  12 +++++
>>  2 files changed, 121 insertions(+)
>>  create mode 100755 tests/xfs/548
>>  create mode 100644 tests/xfs/548.out
>> 
>> diff --git a/tests/xfs/548 b/tests/xfs/548
>> new file mode 100755
>> index 00000000..6c577584
>> --- /dev/null
>> +++ b/tests/xfs/548
>> @@ -0,0 +1,109 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2022 Oracle.  All Rights Reserved.
>> +#
>> +# FS QA Test 548
>> +#
>> +# Test to verify upgrade of an existing V5 filesystem to support large extent
>> +# counters.
>> +#
>> +. ./common/preamble
>> +_begin_fstest auto quick metadata
>> +
>> +# Import common functions.
>> +. ./common/filter
>> +. ./common/attr
>> +. ./common/inject
>> +. ./common/populate
>> +
>> +# real QA test starts here
>> +_supported_fs xfs
>> +_require_scratch
>> +_require_scratch_xfs_nrext64
>> +_require_attrs
>> +_require_xfs_debug
>> +_require_test_program "punch-alternating"
>> +_require_xfs_io_error_injection "bmap_alloc_minlen_extent"
>> +
>> +_scratch_mkfs -d size=$((512 * 1024 * 1024)) >> $seqres.full
>> +_scratch_mount >> $seqres.full
>> +
>> +bsize=$(_get_file_block_size $SCRATCH_MNT)
>> +
>> +testfile=$SCRATCH_MNT/testfile
>> +
>> +nr_blks=20
>> +
>> +echo "Add blocks to file's data fork"
>> +$XFS_IO_PROG -f -c "pwrite 0 $((nr_blks * bsize))" $testfile \
>> +	     >> $seqres.full
>> +$here/src/punch-alternating $testfile
>> +
>> +echo "Consume free space"
>> +fillerdir=$SCRATCH_MNT/fillerdir
>> +nr_free_blks=$(stat -f -c '%f' $SCRATCH_MNT)
>> +nr_free_blks=$((nr_free_blks * 90 / 100))
>> +
>> +_fill_fs $((bsize * nr_free_blks)) $fillerdir $bsize 0 \
>> +	 >> $seqres.full 2>&1
>> +
>> +echo "Create fragmented filesystem"
>> +for dentry in $(ls -1 $fillerdir/); do
>> +	$here/src/punch-alternating $fillerdir/$dentry >> $seqres.full
>> +done
>> +
>> +echo "Inject bmap_alloc_minlen_extent error tag"
>> +_scratch_inject_error bmap_alloc_minlen_extent 1
>> +
>> +echo "Add blocks to file's attr fork"
>> +nr_blks=10
>> +attr_len=255
>> +nr_attrs=$((nr_blks * bsize / attr_len))
>> +for i in $(seq 1 $nr_attrs); do
>> +	attr="$(printf "trusted.%0247d" $i)"
>> +	$SETFATTR_PROG -n "$attr" $testfile >> $seqres.full 2>&1
>> +	[[ $? != 0 ]] && break
>> +done
>> +
>> +testino=$(stat -c '%i' $testfile)
>> +
>> +echo "Unmount filesystem"
>> +_scratch_unmount >> $seqres.full
>> +
>> +orig_dcnt=$(_scratch_xfs_get_metadata_field core.nextents "inode $testino")
>> +orig_acnt=$(_scratch_xfs_get_metadata_field core.naextents "inode $testino")
>> +
>> +echo "Upgrade filesystem to support large extent counters"
>> +_scratch_xfs_admin -O nrext64=1 >> $seqres.full 2>&1
>> +if [[ $? != 0 ]]; then
>> +	_notrun "Filesystem geometry is not suitable for upgrading"
>> +fi
>> +
>> +
>> +echo "Mount filesystem"
>> +_scratch_mount >> $seqres.full
>> +
>> +echo "Modify inode core"
>> +touch $testfile
>> +
>> +echo "Unmount filesystem"
>> +_scratch_unmount >> $seqres.full
>> +
>> +dcnt=$(_scratch_xfs_get_metadata_field core.nextents "inode $testino")
>> +acnt=$(_scratch_xfs_get_metadata_field core.naextents "inode $testino")
>> +
>> +echo "Verify inode extent counter values after fs upgrade"
>
> Is there a scenario where the inode counters would become corrupt after
> enabling the superblock feature bit?  IIRC repair doesn't rewrite the
> inodes during the upgrade... so is this test merely being cautious?  Or
> is this covering a failure you found somewhere while writing the feature?
>

I was just being cautious w.r.t "Large extent counters" functionality working
correctly. I used this test during my development to make sure that I was able
to capture failures before I ran the entire xfstests suite.

-- 
chandan