On Mon, Jun 27, 2022 at 10:30:03PM +0800, Yang Xu wrote:
> This case is a regression test for xfsprogs commit
> f4afdcb0a ("xfs_db: clean up the salvage read callsites in set_cur()").
>
> I found this because xfs/270 on older xfsprogs can hit this bug.
> The code is pasted from xfs/270 but remove mount rw/ro test.
>
> Signed-off-by: Yang Xu <xuyang2018.jy@xxxxxxxxxxx>
> ---
> tests/xfs/082 | 67 +++++++++++++++++++++++++++++++++++++++++++++++
> tests/xfs/082.out | 2 ++
> 2 files changed, 69 insertions(+)
> create mode 100755 tests/xfs/082
> create mode 100644 tests/xfs/082.out
>
> diff --git a/tests/xfs/082 b/tests/xfs/082
> new file mode 100755
> index 00000000..7a5ece8f
> --- /dev/null
> +++ b/tests/xfs/082
> @@ -0,0 +1,67 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2022 FUJITSU LIMITED. All rights reserved.
> +#
> +# FS QA Test 082
> +#
> +# Today xfs_db set_cur whether clean up the LIBXFS_READBUF_SALVAGE
> +# call sites so that we use the return value directly instead of
> +# scraping it out later.
> +#
> +# It is a regression test for xfsprogs
> +# f4afdcb0a ("xfs_db: clean up the salvage read callsites in set_cur()").
> +#
> +
> +. ./common/preamble
> +_begin_fstest auto quick mount
> +
> +# Import common functions.
> +. ./common/filter
> +
> +# real QA test starts here
> +_supported_fs xfs
> +# skip fs check because superblock contains unknown ro-compat features
> +_require_scratch_nocheck
> +# Only V5 XFS disallow rw mount/remount with unknown ro-compat features
> +_require_scratch_xfs_crc
> +
> +_scratch_mkfs_xfs >>$seqres.full 2>&1
> +
> +# set the highest bit of features_ro_compat, use it as an unknown
> +# feature bit. If one day this bit become known feature, please
> +# change this case.
> +
> +ro_compat=$(_scratch_xfs_get_metadata_field "features_ro_compat" "sb 0")
> +echo $ro_compat | grep -q -E '^0x[[:xdigit:]]$'
> +if [[ $? != 0 ]]; then
> + echo "features_ro_compat has an invalid value."
> +fi
> +
> +ro_compat=$(echo $ro_compat | \
> + awk '/^0x[[:xdigit:]]+/ {
> + printf("0x%x\n", or(strtonum($1), 0x80000000))
> + }')
> +
> +# write the new ro compat field to the superblock
> +_scratch_xfs_set_metadata_field "features_ro_compat" "$ro_compat" "sb 0" \
> + > $seqres.full 2>&1
> +
> +# read the newly set ro compat filed for verification
> +new_ro_compat=$(_scratch_xfs_get_metadata_field "features_ro_compat" "sb 0" \
> + >$seqres.full 2>&1)
Hi,
Although you hit this issue by xfs/270, but that doesn't mean you need to do the
same complicated calculation.
You nearly can corrupt many fields to trigger that xfs_db bug, due to
you don't need to test xfs mount. For example corrupt the features_ro_compat
simply:
# xfs_db -x -c "sb 0" -c "write -d features_ro_compat 0x80000000" /dev/sda3
Allowing write of corrupted data with good CRC
features_ro_compat = 0x80000000
# xfs_db -c "sb 0" -c "print features_ro_compat" /dev/sda3
Superblock has unknown read-only compatible features (0x80000000) enabled.
Attempted to mount read-only compatible filesystem read-write.
Filesystem can only be safely mounted read only.
no current type
cache_purge: shake on cache 0x562ed6463a70 left 1 nodes!?
cache_purge: shake on cache 0x562ed6463a70 left 1 nodes!?
cache_zero_check: refcount is 1, not zero (node=0x562ed6478110)
Or even corrupt the sb magicnum (sb 0 need -F) directly:
# xfs_db -x -c "sb 1" -c "write -d magicnum 0" /dev/sda3
Allowing write of corrupted data and bad CRC
magicnum = 0
# xfs_db -c "sb 1" -c "print magicnum" /dev/sda3
bad magic number
no current type
cache_purge: shake on cache 0x5589a86a9a70 left 1 nodes!?
cache_purge: shake on cache 0x5589a86a9a70 left 1 nodes!?
cache_zero_check: refcount is 1, not zero (node=0x5589a86be110)
Or choose other fields you feel good.
> +
> +# verify the new ro_compat field is empty
> +# Without xfsprog patch, xfs_db set_cur function doesn't return directly when
> +# meeting error by using LIBXFS_READBUF_SALVAGE flag. So cache_purge will complain
> +# about this.
> +if [ -z $new_ro_compat ]; then
> + grep -q "cache_purge: shake on cache" $seqres.full && \
> + echo "Hit xfsprogs set_cur bug"
> + echo "Unable to get new ro compat filed"
Let those "cache_purge ..." things break golden image (.out2 file) directly.
> +fi
> +
> +echo "Silence is golden."
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/082.out b/tests/xfs/082.out
> new file mode 100644
> index 00000000..6ed56cb1
> --- /dev/null
> +++ b/tests/xfs/082.out
> @@ -0,0 +1,2 @@
> +QA output created by 082
> +Silence is golden.
> --
> 2.27.0
>
