On Thu, Jul 30, 2020 at 1:18 PM Qu Wenruo <wqu@xxxxxxxx> wrote:
>
> There is a bug in trim code which leads to fstrim accessing beyond
> device boundary.
>
> The test case will check if fstrim, then shrink, then fstrim, all of
> them works without problem.
>
> The fix is titled "btrfs: trim: fix underflow in trim length to prevent
> access beyond device boundary".
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
Looks good, thanks.
> ---
> tests/btrfs/214 | 62 +++++++++++++++++++++++++++++++++++++++++++++
> tests/btrfs/214.out | 2 ++
> tests/btrfs/group | 1 +
> 3 files changed, 65 insertions(+)
> create mode 100755 tests/btrfs/214
> create mode 100644 tests/btrfs/214.out
>
> diff --git a/tests/btrfs/214 b/tests/btrfs/214
> new file mode 100755
> index 00000000..6cd9f444
> --- /dev/null
> +++ b/tests/btrfs/214
> @@ -0,0 +1,62 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2020 SUSE Linux Products GmbH. All Rights Reserved.
> +#
> +# FS QA Test 214
> +#
> +# Test if the following workload would cause problem:
> +# - fstrim
> +# - shrink device
> +# - fstrim
> +#
> +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_size $((5 * 1024 * 1024)) #kB
> +_require_fstrim
> +
> +# Create a 5G fs
> +_scratch_mkfs_sized $((5 * 1024 * 1024 * 1024)) >> $seqres.full
> +_scratch_mount
> +
> +# Fstrim to populate the device->alloc_status CHUNK_TRIMMED bits
> +$FSTRIM_PROG -v $SCRATCH_MNT >> $seqres.full 2>&1 || \
> + _notrun "FSTRIM not supported"
> +
> +
> +# Shrink the fs to 4G, so the existing CHUNK_TRIMMED bits are beyond
> +# device boundary
> +$BTRFS_UTIL_PROG filesystem resize 1:-1G "$SCRATCH_MNT" >> $seqres.full
> +
> +# Do fstrim again to trigger the bug
> +$FSTRIM_PROG -v $SCRATCH_MNT >> $seqres.full
> +
> +echo "Silence is golden"
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/btrfs/214.out b/tests/btrfs/214.out
> new file mode 100644
> index 00000000..dafb6086
> --- /dev/null
> +++ b/tests/btrfs/214.out
> @@ -0,0 +1,2 @@
> +QA output created by 214
> +Silence is golden
> diff --git a/tests/btrfs/group b/tests/btrfs/group
> index 59e8ecce..e306fea5 100644
> --- a/tests/btrfs/group
> +++ b/tests/btrfs/group
> @@ -216,3 +216,4 @@
> 211 auto quick log prealloc
> 212 auto balance dangerous
> 213 auto quick balance dangerous
> +214 auto quick trim dangerous
> --
> 2.27.0
>
--
Filipe David Manana,
“Whether you think you can, or you think you can't — you're right.”
