[PATCH] xfs: add a test for number of open zones on conventional devices

[PATCH] xfs: add a test for number of open zones on conventional devices

[Christoph Hellwig]

Test that mounts of zoned file systems on conventional devices don't
create more open zones than allowed when the last blocks in one or more
zones have been invalidated.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 tests/xfs/4201     | 65 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/xfs/4201.out |  1 +
 2 files changed, 66 insertions(+)
 create mode 100755 tests/xfs/4201
 create mode 100644 tests/xfs/4201.out

diff --git a/tests/xfs/4201 b/tests/xfs/4201
new file mode 100755
index 000000000000..a1f30cb7e739
--- /dev/null
+++ b/tests/xfs/4201
@@ -0,0 +1,65 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2026 Christoph Hellwig.
+#
+# FS QA Test No. 4201
+#
+# Test that mounts of zoned file systems on conventional devices don't create
+# more open zones than allowed when the last blocks in one or more zones have
+# been invalidated.
+#
+
+. ./common/preamble
+_begin_fstest auto quick zone
+
+_require_scratch
+_require_odirect
+_require_non_zoned_device $SCRATCH_DEV
+_require_non_zoned_device $SCRATCH_RTDEV
+
+open_zones=5
+blocks=65536
+bsize=4096
+
+zone_size_mib=$((blocks * bsize / 1024 / 1024))
+file_size_mib=$((zone_size_mib / 2))
+nr_files=$((open_zones * 3 - 1))
+
+echo "zone size: $zone_size_mib" >>$seqres.full
+echo "file size: $file_size_mib" >>$seqres.full
+echo "nr files: $nr_files" >>$seqres.full
+
+_scratch_mkfs -b size=${bsize} -r zoned=1,rgsize=${blocks}b \
+	> "$seqres.full" 2>&1
+_scratch_mount -o max_open_zones=${open_zones}
+
+_require_fs_sysfs zoned/nr_open_zones
+
+for i in $(seq 1 $nr_files); do
+	dd if=/dev/zero of=$SCRATCH_MNT/$i bs=1M count=$file_size_mib \
+		 oflag=direct > /dev/null 2>&1
+done
+
+rm $SCRATCH_MNT/4
+rm $SCRATCH_MNT/5
+rm $SCRATCH_MNT/6
+rm $SCRATCH_MNT/7
+
+_scratch_unmount
+_scratch_mount -o max_open_zones=${open_zones}
+
+max_open=$(_get_fs_sysfs_attr $SCRATCH_DEV zoned/max_open_zones)
+nr_open=$(_get_fs_sysfs_attr $SCRATCH_DEV zoned/nr_open_zones)
+
+if [ ${max_open} -ne $((open_zones - 1)) ]; then
+	_fail "Test needs adjustments for multiple open GC zones"
+fi
+
+if [ ${nr_open} -gt ${max_open} ]; then
+	_fail "Too many open zones: $nr_open/$max_open"
+fi
+
+_scratch_unmount
+
+status=0
+exit
diff --git a/tests/xfs/4201.out b/tests/xfs/4201.out
new file mode 100644
index 000000000000..32e395dd4d6d
--- /dev/null
+++ b/tests/xfs/4201.out
@@ -0,0 +1 @@
+QA output created by 4201
-- 
2.47.3

Re: [PATCH] xfs: add a test for number of open zones on conventional devices

[Damien Le Moal]

On 3/30/26 22:00, Christoph Hellwig wrote:
> Test that mounts of zoned file systems on conventional devices don't
> create more open zones than allowed when the last blocks in one or more
> zones have been invalidated.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  tests/xfs/4201     | 65 ++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/4201.out |  1 +
>  2 files changed, 66 insertions(+)
>  create mode 100755 tests/xfs/4201
>  create mode 100644 tests/xfs/4201.out
> 
> diff --git a/tests/xfs/4201 b/tests/xfs/4201
> new file mode 100755
> index 000000000000..a1f30cb7e739
> --- /dev/null
> +++ b/tests/xfs/4201
> @@ -0,0 +1,65 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2026 Christoph Hellwig.
> +#
> +# FS QA Test No. 4201
> +#
> +# Test that mounts of zoned file systems on conventional devices don't create
> +# more open zones than allowed when the last blocks in one or more zones have
> +# been invalidated.
> +#
> +
> +. ./common/preamble
> +_begin_fstest auto quick zone
> +
> +_require_scratch
> +_require_odirect
> +_require_non_zoned_device $SCRATCH_DEV
> +_require_non_zoned_device $SCRATCH_RTDEV
> +
> +open_zones=5
> +blocks=65536
> +bsize=4096
> +
> +zone_size_mib=$((blocks * bsize / 1024 / 1024))
> +file_size_mib=$((zone_size_mib / 2))
> +nr_files=$((open_zones * 3 - 1))
> +
> +echo "zone size: $zone_size_mib" >>$seqres.full
> +echo "file size: $file_size_mib" >>$seqres.full
> +echo "nr files: $nr_files" >>$seqres.full
> +
> +_scratch_mkfs -b size=${bsize} -r zoned=1,rgsize=${blocks}b \
> +	> "$seqres.full" 2>&1
> +_scratch_mount -o max_open_zones=${open_zones}
> +
> +_require_fs_sysfs zoned/nr_open_zones
> +
> +for i in $(seq 1 $nr_files); do
> +	dd if=/dev/zero of=$SCRATCH_MNT/$i bs=1M count=$file_size_mib \
> +		 oflag=direct > /dev/null 2>&1
> +done
> +
> +rm $SCRATCH_MNT/4
> +rm $SCRATCH_MNT/5
> +rm $SCRATCH_MNT/6
> +rm $SCRATCH_MNT/7

Hmmm. I think you should delete odd numbered files only since they are going to
be written at the end of a zone. Otherwise, you make the zone empty, and it will
thus not be considered as open.

Something like:

for (( i=0; i<$nr_files; i=$(( i + 2 )) )); do
	rm $SCRATCH_MNT/$(( i + 1))
done

should generate enough open zones.

> +
> +_scratch_unmount
> +_scratch_mount -o max_open_zones=${open_zones}
> +
> +max_open=$(_get_fs_sysfs_attr $SCRATCH_DEV zoned/max_open_zones)
> +nr_open=$(_get_fs_sysfs_attr $SCRATCH_DEV zoned/nr_open_zones)
> +
> +if [ ${max_open} -ne $((open_zones - 1)) ]; then
> +	_fail "Test needs adjustments for multiple open GC zones"
> +fi
> +
> +if [ ${nr_open} -gt ${max_open} ]; then
> +	_fail "Too many open zones: $nr_open/$max_open"
> +fi
> +
> +_scratch_unmount
> +
> +status=0
> +exit
> diff --git a/tests/xfs/4201.out b/tests/xfs/4201.out
> new file mode 100644
> index 000000000000..32e395dd4d6d
> --- /dev/null
> +++ b/tests/xfs/4201.out
> @@ -0,0 +1 @@
> +QA output created by 4201


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH] xfs: add a test for number of open zones on conventional devices

[Christoph Hellwig]

On Tue, Mar 31, 2026 at 07:00:39PM +0900, Damien Le Moal wrote:
> Hmmm. I think you should delete odd numbered files only since they are going to
> be written at the end of a zone. Otherwise, you make the zone empty, and it will
> thus not be considered as open.

Yes, but due to the unevent number I did reproduce the bug even
with this version.  I tried your loop and this overshoots the open
zone limit even more without the fix, so I'll switch to that.