add tests for file system on devices using protection information

add tests for file system on devices using protection information

[Christoph Hellwig]

Hi all,

this series adds support to exercise I/O on file systems using protection
information in the device, including that corruption is properly
reported.

The second test requires a patch to inject corruption into scsi_debug
that was posted to the linux-scsi list.

[PATCH 1/4] common/scsi_debug: don't slow down I/O

[Christoph Hellwig]

scsi_debug by defaults delays I/O and doesn't support multi-page I/O.
Flipping these defaults speed up each test using scsi_debug by more than
an order of magnitute on my test systems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 common/scsi_debug | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/common/scsi_debug b/common/scsi_debug
index c3fe7be623fa..91665547bc0c 100644
--- a/common/scsi_debug
+++ b/common/scsi_debug
@@ -59,7 +59,9 @@ _get_scsi_debug_dev()
 		let physical=physical/2
 		let phys_exp=phys_exp+1
 	done
-	opts="sector_size=$logical physblk_exp=$phys_exp lowest_aligned=$unaligned dev_size_mb=$size $@"
+	opts="sector_size=$logical physblk_exp=$phys_exp"
+	opts="${opts} lowest_aligned=$unaligned dev_size_mb=$size"
+	opts="${opts} delay=0 clustering=1 $@"
 	echo "scsi_debug options $opts" >> $seqres.full
 	modprobe scsi_debug $opts
 	[ $? -eq 0 ] || _fail "scsi_debug modprobe failed"
-- 
2.53.0

[PATCH 2/4] common: add a _sysfs_block_integrity_path helper

[Christoph Hellwig]

Add a helper function to find the sysfs integrity directory for a given
block device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 common/rc | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/common/rc b/common/rc
index 106f044adc2d..96e74cfd4e5b 100644
--- a/common/rc
+++ b/common/rc
@@ -5254,6 +5254,31 @@ _sysfs_queue_path()
 	fi
 }
 
+# Get the sysfs block device integrity/ path for a block device, handling
+# partitions correctly.
+_sysfs_block_integrity_path()
+{
+	local dev parent
+	dev=$(_short_dev "$1")
+
+	# For partitions, integrity details are in the parent device's sysfs dir
+	if [ -e "/sys/class/block/$dev/partition" ]; then
+		parent=$(basename "$(readlink -f /sys/class/block/$dev/..)")
+	else
+		parent="$dev"
+	fi
+
+	local integrity_path="/sys/block/$parent/integrity"
+
+	# Verify the path exists before returning
+	if [ -e "$integrity_path" ]; then
+		echo "$integrity_path"
+		return 0
+	fi
+
+	return 1
+}
+
 # Get the minimum block size of a file.  Usually this is the
 # minimum fs block size, but some filesystems (ocfs2) do block
 # mappings in larger units.
-- 
2.53.0

[PATCH 3/4] generic: test I/O on devices with T10 protection information

[Christoph Hellwig]

Add a test that runs fsx in buffered and direct I/O mode on T10 PI
type 1, 2, 3 with and without strip/insert using scsi_debug.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 tests/generic/2301     | 90 ++++++++++++++++++++++++++++++++++++++++++
 tests/generic/2301.out | 73 ++++++++++++++++++++++++++++++++++
 2 files changed, 163 insertions(+)
 create mode 100755 tests/generic/2301
 create mode 100644 tests/generic/2301.out

diff --git a/tests/generic/2301 b/tests/generic/2301
new file mode 100755
index 000000000000..db984051430d
--- /dev/null
+++ b/tests/generic/2301
@@ -0,0 +1,90 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2026 Christoph Hellwig
+#
+# FS QA Test No. 2301
+#
+# Basix FSX sanity check when using T10 protection information
+#
+. ./common/preamble
+_begin_fstest auto rw
+
+_cleanup()
+{
+	cd /
+	rm -r -f $tmp.*
+	[ -d "$SCSI_DEBUG_MNT" ] && _unmount $SCSI_DEBUG_MNT 2>/dev/null
+	_put_scsi_debug_dev
+}
+
+. ./common/scsi_debug
+
+_require_scsi_debug
+# If TEST_DEV is block device, make sure current fs is a localfs which can be
+# written on scsi_debug device
+_require_test
+_require_block_device $TEST_DEV
+
+size=$(_small_fs_size_mb 256)
+
+# like run_fsx(), but using a custom path
+fsx_run()
+{
+	_run_fsx_on_file $SCSI_DEBUG_MNT/junk $@ || _exit 1
+}
+
+test_dif()
+{
+	local pi_type=$1
+	local pi_enable="$2"
+
+	scsi_debug_pi_opts="write_same_length=0 dif=${pi_type} dix=1"
+	SCSI_DEBUG_DEV=`_get_scsi_debug_dev 512 512 0 $size $scsi_debug_pi_opts`
+
+	SCSI_DEBUG_MNT="$TEST_DIR/scsi_debug_$seq"
+	rm -rf $SCSI_DEBUG_MNT
+	mkdir $SCSI_DEBUG_MNT
+
+	_mkfs_dev $SCSI_DEBUG_DEV || \
+		_fail "Can't make $FSTYP on DIF-enabled scsi_debug device"
+	run_check _mount $SCSI_DEBUG_DEV $SCSI_DEBUG_MNT
+	bsize=$($here/src/min_dio_alignment $SCSI_DEBUG_MNT $SCSI_DEBUG_DEV)
+
+	local integrity_path="$(_sysfs_block_integrity_path $SCSI_DEBUG_DEV)"
+	echo $pi_enable > $integrity_path/read_verify
+	echo $pi_enable > $integrity_path/write_generate
+
+	# fsx load similar to generic/091
+	echo "Testing direct I/O for DIF type $pi_type (enabled: $pi_enable)"
+	local dio_opts="-r PSIZE -t BSIZE -w BSIZE"
+	fsx_run -N 10000            -l 500000 -r BSIZE -w BSIZE -Z -R -W
+	fsx_run -N 10000  -o 8192   -l 500000 -r BSIZE -w BSIZE -Z -R -W
+	fsx_run -N 10000  -o 32768  -l 500000 -r BSIZE -w BSIZE -Z -R -W
+	fsx_run -N 10000  -o 8192   -l 500000 -r BSIZE -w BSIZE -Z -R -W
+	fsx_run -N 10000  -o 32768  -l 500000 -r BSIZE -w BSIZE -Z -R -W
+	fsx_run -N 10000  -o 128000 -l 500000 -r BSIZE -w BSIZE -Z -W
+
+	# fsx load similar to generic/091 but using buffered I/O
+	echo "Testing buffered I/O for DIF type $pi_type (enabled: $pi_enable)"
+	fsx_run -N 10000            -l 500000
+	fsx_run -N 10000  -o 8192   -l 500000
+	fsx_run -N 10000  -o 32768  -l 500000
+	fsx_run -N 10000  -o 128000 -l 500000
+
+	[ -d "$SCSI_DEBUG_MNT" ] && _unmount $SCSI_DEBUG_MNT 2>/dev/null
+	_put_scsi_debug_dev
+}
+
+# Test with PI fully enabled
+test_dif 1 1
+test_dif 2 1
+test_dif 3 1
+
+# Test with strip / insert in the HBA
+test_dif 1 0
+test_dif 2 0
+test_dif 3 0
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/2301.out b/tests/generic/2301.out
new file mode 100644
index 000000000000..dda88676a219
--- /dev/null
+++ b/tests/generic/2301.out
@@ -0,0 +1,73 @@
+QA output created by 2301
+Testing direct I/O for DIF type 1 (enabled: 1)
+fsx -N 10000 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 128000 -l 500000 -r BSIZE -w BSIZE -Z -W
+Testing buffered I/O for DIF type 1 (enabled: 1)
+fsx -N 10000 -l 500000
+fsx -N 10000 -o 8192 -l 500000
+fsx -N 10000 -o 32768 -l 500000
+fsx -N 10000 -o 128000 -l 500000
+Testing direct I/O for DIF type 2 (enabled: 1)
+fsx -N 10000 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 128000 -l 500000 -r BSIZE -w BSIZE -Z -W
+Testing buffered I/O for DIF type 2 (enabled: 1)
+fsx -N 10000 -l 500000
+fsx -N 10000 -o 8192 -l 500000
+fsx -N 10000 -o 32768 -l 500000
+fsx -N 10000 -o 128000 -l 500000
+Testing direct I/O for DIF type 3 (enabled: 1)
+fsx -N 10000 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 128000 -l 500000 -r BSIZE -w BSIZE -Z -W
+Testing buffered I/O for DIF type 3 (enabled: 1)
+fsx -N 10000 -l 500000
+fsx -N 10000 -o 8192 -l 500000
+fsx -N 10000 -o 32768 -l 500000
+fsx -N 10000 -o 128000 -l 500000
+Testing direct I/O for DIF type 1 (enabled: 0)
+fsx -N 10000 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 128000 -l 500000 -r BSIZE -w BSIZE -Z -W
+Testing buffered I/O for DIF type 1 (enabled: 0)
+fsx -N 10000 -l 500000
+fsx -N 10000 -o 8192 -l 500000
+fsx -N 10000 -o 32768 -l 500000
+fsx -N 10000 -o 128000 -l 500000
+Testing direct I/O for DIF type 2 (enabled: 0)
+fsx -N 10000 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 128000 -l 500000 -r BSIZE -w BSIZE -Z -W
+Testing buffered I/O for DIF type 2 (enabled: 0)
+fsx -N 10000 -l 500000
+fsx -N 10000 -o 8192 -l 500000
+fsx -N 10000 -o 32768 -l 500000
+fsx -N 10000 -o 128000 -l 500000
+Testing direct I/O for DIF type 3 (enabled: 0)
+fsx -N 10000 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 8192 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 32768 -l 500000 -r BSIZE -w BSIZE -Z -R -W
+fsx -N 10000 -o 128000 -l 500000 -r BSIZE -w BSIZE -Z -W
+Testing buffered I/O for DIF type 3 (enabled: 0)
+fsx -N 10000 -l 500000
+fsx -N 10000 -o 8192 -l 500000
+fsx -N 10000 -o 32768 -l 500000
+fsx -N 10000 -o 128000 -l 500000
-- 
2.53.0

[PATCH 4/4] generic: test corruption detection using T10 protection information

[Christoph Hellwig]

Add a test that simulates bit flips in data and misdirected writes and
checks that file systems detect it when run on devices using protection
information.

This requires the new scsi_debug corruption injection.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 tests/generic/2302     | 143 +++++++++++++++++++++++++++++++++++++++++
 tests/generic/2302.out |  21 ++++++
 2 files changed, 164 insertions(+)
 create mode 100755 tests/generic/2302
 create mode 100644 tests/generic/2302.out

diff --git a/tests/generic/2302 b/tests/generic/2302
new file mode 100755
index 000000000000..5fff1f5e5015
--- /dev/null
+++ b/tests/generic/2302
@@ -0,0 +1,143 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2026 Christoph Hellwig
+#
+# FS QA Test No. 2302
+#
+# Test that T10 DIF detects bitflips and misplaced writes.
+#
+. ./common/preamble
+_begin_fstest auto rw
+
+_cleanup()
+{
+	cd /
+	rm -r -f $tmp.*
+	[ -d "$SCSI_DEBUG_MNT" ] && _unmount $SCSI_DEBUG_MNT 2>/dev/null
+	_put_scsi_debug_dev
+}
+
+. ./common/scsi_debug
+. ./common/filter
+
+_require_scsi_debug
+# If TEST_DEV is block device, make sure current fs is a localfs which can be
+# written on scsi_debug device
+_require_test
+_require_block_device $TEST_DEV
+
+# FIEMAP on Btrfs returns logical addresses within the filesystem's address
+# space, not physical device offsets. Writing to these offsets on $SCRATCH_DEV
+# would corrupt the filesystem in multi-device setups.
+_exclude_fs btrfs
+
+size=$(_small_fs_size_mb 256)
+
+# Get the physical block offset (in bytes) of the file's first block on device
+get_phys_blk()
+{
+	local file="$1"
+	local fiemap_output
+	local phys_blk
+
+	fiemap_output=$($XFS_IO_PROG -r -c "fiemap -v" "$file" 2>/dev/null)
+	phys_blk=$(echo "$fiemap_output" | _filter_xfs_io_fiemap | head -1 | awk '{print $3}')
+	if [ -z "$phys_blk" ]; then
+		echo ""
+		return
+	fi
+	echo $phys_blk
+}
+
+test_dif()
+{
+	local pi_type=$1
+	local last=$2
+	local bit_errors=$3
+	local reftag_adjust=$4
+
+	echo -n "Testing DIF type $pi_type "
+	if [ "$bit_errors" -gt "0" ]; then
+		echo -n "bit errors ($bit_errors) in "
+	fi
+	if [ "$reftag_adjust" -ne "0" ]; then
+		echo -n "reftag adjustment by $reftag_adjust in "
+	fi
+	if [ "$last" -eq 1 ]; then
+		echo "last sector"
+	else
+		echo "first sector"
+	fi
+
+	scsi_debug_pi_opts="write_same_length=0 dif=${pi_type} dix=1"
+	SCSI_DEBUG_DEV=`_get_scsi_debug_dev 512 512 0 $size $scsi_debug_pi_opts`
+
+	SCSI_DEBUG_MNT="$TEST_DIR/scsi_debug_$seq"
+	rm -rf $SCSI_DEBUG_MNT
+	mkdir $SCSI_DEBUG_MNT
+
+	_mkfs_dev $SCSI_DEBUG_DEV || \
+		_fail "Can't make $FSTYP on DIF-enabled scsi_debug device"
+	run_check _mount $SCSI_DEBUG_DEV $SCSI_DEBUG_MNT
+
+	local blksz=$(_get_block_size $SCSI_DEBUG_MNT)
+	local testfile="$SCSI_DEBUG_MNT/test"
+
+	$XFS_IO_PROG -d -f \
+		-c "pwrite -S 0x66 0 $((128 * blksz))" \
+		-c fsync \
+		$testfile >> $seqres.full 2>&1
+
+	local phys_blk=$(get_phys_blk $testfile)
+	if [ -z "$phys_blk" ]; then
+		_fail "$test_name: failed to get physical block offset via fiemap"
+	fi
+
+	local dev=$(_short_dev $SCSI_DEBUG_DEV)
+	local debugfs_dir=$(ls /sys/block/$dev/device/scsi_device/)
+	local debugfs_file="/sys/kernel/debug/scsi_debug/$debugfs_dir/corrupt"
+
+	if [ ! -f "$debugfs_file" ]; then
+		_notrun "scsi_debug corruption injection not supported"
+	fi
+
+	if [ "$last" -eq 1 ]; then
+		echo "adding to $phys_blk" >> $seqres.full
+		phys_blk=$((phys_blk + 127))
+	fi
+
+	echo "lba=$phys_blk,num=1,bit_errors=$bit_errors,reftag_adjust=$reftag_adjust" \
+		 > $debugfs_file
+
+	$XFS_IO_PROG -d -f \
+		-c "pread 0 $((128 * blksz))" \
+		$testfile
+
+	[ -d "$SCSI_DEBUG_MNT" ] && _unmount $SCSI_DEBUG_MNT 2>/dev/null
+	_put_scsi_debug_dev
+}
+
+# test data corruption in first block
+test_dif 1 0 2 0
+test_dif 2 0 2 0
+test_dif 3 0 2 0
+
+# test data corruption in last block
+test_dif 1 1 2 0
+test_dif 2 1 2 0
+test_dif 3 1 2 0
+
+
+# Note: Type 3 doesn't have a refrag, so don't test it
+
+# reftag mismatch in first block
+test_dif 1 0 0 8
+test_dif 2 0 0 8
+
+# reftag mismatch in last block
+test_dif 1 1 0 8
+test_dif 2 1 0 8
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/2302.out b/tests/generic/2302.out
new file mode 100644
index 000000000000..03b68d904943
--- /dev/null
+++ b/tests/generic/2302.out
@@ -0,0 +1,21 @@
+QA output created by 2302
+Testing DIF type 1 bit errors (2) in first sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 2 bit errors (2) in first sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 3 bit errors (2) in first sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 1 bit errors (2) in last sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 2 bit errors (2) in last sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 3 bit errors (2) in last sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 1 reftag adjustment by 8 in first sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 2 reftag adjustment by 8 in first sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 1 reftag adjustment by 8 in last sector
+pread: Invalid or incomplete multibyte or wide character
+Testing DIF type 2 reftag adjustment by 8 in last sector
+pread: Invalid or incomplete multibyte or wide character
-- 
2.53.0

Re: [PATCH 1/4] common/scsi_debug: don't slow down I/O

[Zorro Lang]

On Thu, Jul 23, 2026 at 04:28:44PM +0200, Christoph Hellwig wrote:
> scsi_debug by defaults delays I/O and doesn't support multi-page I/O.
> Flipping these defaults speed up each test using scsi_debug by more than
> an order of magnitute on my test systems.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  common/scsi_debug | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/common/scsi_debug b/common/scsi_debug
> index c3fe7be623fa..91665547bc0c 100644
> --- a/common/scsi_debug
> +++ b/common/scsi_debug
> @@ -59,7 +59,9 @@ _get_scsi_debug_dev()
>  		let physical=physical/2
>  		let phys_exp=phys_exp+1
>  	done
> -	opts="sector_size=$logical physblk_exp=$phys_exp lowest_aligned=$unaligned dev_size_mb=$size $@"
> +	opts="sector_size=$logical physblk_exp=$phys_exp"
> +	opts="${opts} lowest_aligned=$unaligned dev_size_mb=$size"
> +	opts="${opts} delay=0 clustering=1 $@"
>  	echo "scsi_debug options $opts" >> $seqres.full
>  	modprobe scsi_debug $opts

While this is syntactically correct, especially when leaving $opts unquoted.
But as this patch is trying to to improve code readability, so how about:

local opts=(
    "sector_size=$logical"
    "physblk_exp=$phys_exp"
    "lowest_aligned=$unaligned"
    "dev_size_mb=$size"
    "delay=0"
    "clustering=1"
)
opts+=("$@")
echo "scsi_debug options ${opts[*]}" >> $seqres.full
modprobe scsi_debug "${opts[@]}"

Thanks,
Zorro

>  	[ $? -eq 0 ] || _fail "scsi_debug modprobe failed"
> -- 
> 2.53.0
> 

Re: [PATCH 4/4] generic: test corruption detection using T10 protection information

[Zorro Lang]

On Thu, Jul 23, 2026 at 04:28:47PM +0200, Christoph Hellwig wrote:
> Add a test that simulates bit flips in data and misdirected writes and
> checks that file systems detect it when run on devices using protection
> information.
> 
> This requires the new scsi_debug corruption injection.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  tests/generic/2302     | 143 +++++++++++++++++++++++++++++++++++++++++
>  tests/generic/2302.out |  21 ++++++
>  2 files changed, 164 insertions(+)
>  create mode 100755 tests/generic/2302
>  create mode 100644 tests/generic/2302.out
> 
> diff --git a/tests/generic/2302 b/tests/generic/2302
> new file mode 100755
> index 000000000000..5fff1f5e5015
> --- /dev/null
> +++ b/tests/generic/2302
> @@ -0,0 +1,143 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2026 Christoph Hellwig
> +#
> +# FS QA Test No. 2302
> +#
> +# Test that T10 DIF detects bitflips and misplaced writes.
> +#
> +. ./common/preamble
> +_begin_fstest auto rw
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -r -f $tmp.*
> +	[ -d "$SCSI_DEBUG_MNT" ] && _unmount $SCSI_DEBUG_MNT 2>/dev/null
> +	_put_scsi_debug_dev
> +}
> +
> +. ./common/scsi_debug
> +. ./common/filter
> +
> +_require_scsi_debug
> +# If TEST_DEV is block device, make sure current fs is a localfs which can be
> +# written on scsi_debug device
> +_require_test
> +_require_block_device $TEST_DEV
> +
> +# FIEMAP on Btrfs returns logical addresses within the filesystem's address
> +# space, not physical device offsets. Writing to these offsets on $SCRATCH_DEV
> +# would corrupt the filesystem in multi-device setups.
> +_exclude_fs btrfs
> +
> +size=$(_small_fs_size_mb 256)
> +
> +# Get the physical block offset (in bytes) of the file's first block on device
> +get_phys_blk()
> +{
> +	local file="$1"
> +	local fiemap_output
> +	local phys_blk
> +
> +	fiemap_output=$($XFS_IO_PROG -r -c "fiemap -v" "$file" 2>/dev/null)

_require_xfs_io_command fiemap

> +	phys_blk=$(echo "$fiemap_output" | _filter_xfs_io_fiemap | head -1 | awk '{print $3}')

This logic looks like common/rc:_get_file_extent_sector(), can this
function help?

> +	if [ -z "$phys_blk" ]; then
> +		echo ""
> +		return
> +	fi
> +	echo $phys_blk
> +}
> +
> +test_dif()
> +{
> +	local pi_type=$1
> +	local last=$2
> +	local bit_errors=$3
> +	local reftag_adjust=$4
> +
> +	echo -n "Testing DIF type $pi_type "
> +	if [ "$bit_errors" -gt "0" ]; then
> +		echo -n "bit errors ($bit_errors) in "
> +	fi
> +	if [ "$reftag_adjust" -ne "0" ]; then
> +		echo -n "reftag adjustment by $reftag_adjust in "
> +	fi
> +	if [ "$last" -eq 1 ]; then
> +		echo "last sector"
> +	else
> +		echo "first sector"
> +	fi
> +
> +	scsi_debug_pi_opts="write_same_length=0 dif=${pi_type} dix=1"
> +	SCSI_DEBUG_DEV=`_get_scsi_debug_dev 512 512 0 $size $scsi_debug_pi_opts`
> +
> +	SCSI_DEBUG_MNT="$TEST_DIR/scsi_debug_$seq"
> +	rm -rf $SCSI_DEBUG_MNT
> +	mkdir $SCSI_DEBUG_MNT
> +
> +	_mkfs_dev $SCSI_DEBUG_DEV || \
> +		_fail "Can't make $FSTYP on DIF-enabled scsi_debug device"
> +	run_check _mount $SCSI_DEBUG_DEV $SCSI_DEBUG_MNT
> +
> +	local blksz=$(_get_block_size $SCSI_DEBUG_MNT)
> +	local testfile="$SCSI_DEBUG_MNT/test"
> +
> +	$XFS_IO_PROG -d -f \

_require_odirect ?

> +		-c "pwrite -S 0x66 0 $((128 * blksz))" \
> +		-c fsync \
> +		$testfile >> $seqres.full 2>&1
> +
> +	local phys_blk=$(get_phys_blk $testfile)
> +	if [ -z "$phys_blk" ]; then
> +		_fail "$test_name: failed to get physical block offset via fiemap"
> +	fi
> +
> +	local dev=$(_short_dev $SCSI_DEBUG_DEV)
> +	local debugfs_dir=$(ls /sys/block/$dev/device/scsi_device/)
> +	local debugfs_file="/sys/kernel/debug/scsi_debug/$debugfs_dir/corrupt"

_require_debugfs

> +
> +	if [ ! -f "$debugfs_file" ]; then
> +		_notrun "scsi_debug corruption injection not supported"
> +	fi
> +
> +	if [ "$last" -eq 1 ]; then
> +		echo "adding to $phys_blk" >> $seqres.full
> +		phys_blk=$((phys_blk + 127))
> +	fi
> +
> +	echo "lba=$phys_blk,num=1,bit_errors=$bit_errors,reftag_adjust=$reftag_adjust" \
> +		 > $debugfs_file
> +
> +	$XFS_IO_PROG -d -f \
> +		-c "pread 0 $((128 * blksz))" \
> +		$testfile
> +
> +	[ -d "$SCSI_DEBUG_MNT" ] && _unmount $SCSI_DEBUG_MNT 2>/dev/null
> +	_put_scsi_debug_dev
> +}
> +
> +# test data corruption in first block
> +test_dif 1 0 2 0
> +test_dif 2 0 2 0
> +test_dif 3 0 2 0
> +
> +# test data corruption in last block
> +test_dif 1 1 2 0
> +test_dif 2 1 2 0
> +test_dif 3 1 2 0
> +
> +
> +# Note: Type 3 doesn't have a refrag, so don't test it
> +
> +# reftag mismatch in first block
> +test_dif 1 0 0 8
> +test_dif 2 0 0 8
> +
> +# reftag mismatch in last block
> +test_dif 1 1 0 8
> +test_dif 2 1 0 8
> +
> +# success, all done
> +status=0
> +exit

_exit 0

> diff --git a/tests/generic/2302.out b/tests/generic/2302.out
> new file mode 100644
> index 000000000000..03b68d904943
> --- /dev/null
> +++ b/tests/generic/2302.out
> @@ -0,0 +1,21 @@
> +QA output created by 2302
> +Testing DIF type 1 bit errors (2) in first sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 2 bit errors (2) in first sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 3 bit errors (2) in first sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 1 bit errors (2) in last sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 2 bit errors (2) in last sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 3 bit errors (2) in last sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 1 reftag adjustment by 8 in first sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 2 reftag adjustment by 8 in first sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 1 reftag adjustment by 8 in last sector
> +pread: Invalid or incomplete multibyte or wide character
> +Testing DIF type 2 reftag adjustment by 8 in last sector
> +pread: Invalid or incomplete multibyte or wide character
> -- 
> 2.53.0
>