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

["Darrick J. Wong" <djwong@kernel.org>]

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?

--D

> +
> +if [[ $orig_dcnt != $dcnt ]]; then
> +	echo "Corrupt data extent counter"
> +	exit 1
> +fi
> +
> +if [[ $orig_acnt != $acnt ]]; then
> +	echo "Corrupt attr extent counter"
> +	exit 1
> +fi
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/548.out b/tests/xfs/548.out
> new file mode 100644
> index 00000000..19a7f907
> --- /dev/null
> +++ b/tests/xfs/548.out
> @@ -0,0 +1,12 @@
> +QA output created by 548
> +Add blocks to file's data fork
> +Consume free space
> +Create fragmented filesystem
> +Inject bmap_alloc_minlen_extent error tag
> +Add blocks to file's attr fork
> +Unmount filesystem
> +Upgrade filesystem to support large extent counters
> +Mount filesystem
> +Modify inode core
> +Unmount filesystem
> +Verify inode extent counter values after fs upgrade
> -- 
> 2.35.1
>