Re: [PATCH v2] fstests: test premature ENOSPC in zoned garbage collection

On 4/14/26 4:23 PM, Filipe Manana wrote:
> On Tue, Apr 14, 2026 at 2:50 PM Johannes Thumshirn
> <[email protected]> wrote:
>> This test stresses garbage collection in zoned file systems by
>> constantly overwriting the same file. It is inspired by a reproducer for
>> a btrfs bugifx.
>>
>> Signed-off-by: Johannes Thumshirn <[email protected]>
>> ---
>> Changes to v1:
>> - Rebased onto patches-in-queue
>> - Use "generic/999" to avoid any conflicts
>> - Change the number of loops to number of seq zones
>> - Remove bogus "2>&1"
>>
>> Link to v1:
>> https://lore.kernel.org/all/[email protected]/
>>
>>
>>   tests/generic/999     | 48 +++++++++++++++++++++++++++++++++++++++++++
>>   tests/generic/999.out |  2 ++
>>   2 files changed, 50 insertions(+)
>>   create mode 100755 tests/generic/999
>>   create mode 100644 tests/generic/999.out
>>
>> diff --git a/tests/generic/999 b/tests/generic/999
>> new file mode 100755
>> index 000000000000..4ac6c0ff935c
>> --- /dev/null
>> +++ b/tests/generic/999
>> @@ -0,0 +1,48 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2026 Western Digital Corporation.  All Rights Reserved.
>> +#
>> +# FS QA Test 999
>> +#
>> +# This test stresses garbage collection in zoned file systems by constantly
>> +# overwriting the same file. It is inspired by a reproducer for a btrfs bugifx.
>> +
>> +. ./common/preamble
>> +_begin_fstest auto quick zone
>> +
>> +. ./common/filter
>> +
>> +_require_scratch_size $((16 * 1024 * 1024))
>> +_require_zoned_device "$SCRATCH_DEV"
>> +
>> +# This test requires specific data space usage, skip if we have compression
>> +# enabled.
>> +_require_no_compress
>> +
>> +
>> +_fixed_by_fs_commit XXXXXXXXXXXX \
>> +       "btrfs: zoned: cap delayed refs metadata reservation to avoid overcommit"
>> +_fixed_by_fs_commit XXXXXXXXXXXX \
>> +       "btrfs: zoned: move partially zone_unusable block groups to reclaim list"
> Already in Linus' tree, commit hash 258e46a6385c.
>
>> +_fixed_by_fs_commit XXXXXXXXXXXX \
>> +       "btrfs: zoned: add zone reclaim flush state for DATA space_info"
> Also in Linus' tree, commit hash e2a7fd22378f.
>
>> +
>> +
>> +_scratch_mkfs_sized $((16 * 1024 * 1024 * 1024)) &>>$seqres.full
>> +_scratch_mount
>> +
>> +blocks="$(df -TB 1G $SCRATCH_DEV |\
>> +       $AWK_PROG -v fstyp="$FSTYP" 'match($2, fstyp) {print $3}')"
>> +
>> +loops=$(echo "$blocks * 4 - 2" | bc)
> nit: why pipe to bc? Wouldn't a simple bash expression like the following work?
>
> loops=$(( blocks * 4 - 2 ))
>
> Otherwise it looks fine to me, thanks.
Disregard that, stupid me forgot to git commit --amend...