Since there is no test yet in the blktests repository for a device mapper
driver stacked on top of a zoned block device, add such a test. This test
triggers the following deadlock in kernel versions 6.10..6.14:
Call Trace:
<TASK>
__schedule+0x43f/0x12f0
schedule+0x27/0xf0
__bio_queue_enter+0x10e/0x230
__submit_bio+0xf0/0x280
submit_bio_noacct_nocheck+0x185/0x3d0
blk_zone_wplug_bio_work+0x1ad/0x1f0
process_one_work+0x17b/0x330
worker_thread+0x2ce/0x3f0
kthread+0xec/0x220
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1a/0x30
</TASK>
Call Trace:
<TASK>
__schedule+0x43f/0x12f0
schedule+0x27/0xf0
blk_mq_freeze_queue_wait+0x6f/0xa0
queue_attr_store+0x14f/0x1b0
kernfs_fop_write_iter+0x13b/0x1f0
vfs_write+0x253/0x420
ksys_write+0x64/0xe0
do_syscall_64+0x82/0x160
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
tests/zbd/013 | 110 ++++++++++++++++++++++++++++++++++++++++++++++
tests/zbd/013.out | 2 +
2 files changed, 112 insertions(+)
create mode 100755 tests/zbd/013
create mode 100644 tests/zbd/013.out
diff --git a/tests/zbd/013 b/tests/zbd/013
new file mode 100755
index 000000000000..88aea23ee68a
--- /dev/null
+++ b/tests/zbd/013
@@ -0,0 +1,110 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2025 Google LLC
+
+. tests/zbd/rc
+. common/null_blk
+
+DESCRIPTION="test stacked drivers and queue freezing"
+QUICK=1
+
+requires() {
+ _have_driver dm-crypt
+ _have_fio
+ _have_module null_blk
+ _have_program cryptsetup
+}
+
+# Trigger blk_mq_freeze_queue() repeatedly because there is a bug in the
+# Linux kernel 6.10..6.14 zoned block device code that triggers a deadlock
+# between zoned writes and queue freezing.
+queue_freeze_loop() {
+ while true; do
+ echo 4 >"$1"
+ sleep .1
+ echo 8 >"$1"
+ sleep .1
+ done
+}
+
+test() {
+ set -e
+
+ echo "Running ${TEST_NAME}"
+
+ _init_null_blk nr_devices=0 queue_mode=2
+
+ # A small conventional block device for the LUKS header.
+ local null_blk_params=(
+ blocksize=4096
+ completion_nsec=0
+ memory_backed=1
+ size=4 # MiB
+ submit_queues=1
+ power=1
+ )
+ _configure_null_blk nullb0 "${null_blk_params[@]}"
+ local hdev=/dev/nullb0
+
+ # A larger zoned block device for the data.
+ local null_blk_params=(
+ blocksize=4096
+ completion_nsec=0
+ memory_backed=1
+ size=1024 # MiB
+ submit_queues=1
+ zoned=1
+ power=1
+ )
+ _configure_null_blk nullb1 "${null_blk_params[@]}"
+ local zdev=/dev/nullb1
+
+ local luks_passphrase=this-passphrase-is-not-secret
+ { echo "${luks_passphrase}" |
+ cryptsetup luksFormat --batch-mode ${zdev} \
+ --header ${hdev}; }
+ local luks_vol_name=zbd-013
+ { echo "${luks_passphrase}" |
+ cryptsetup luksOpen \
+ --batch-mode "${zdev}" "${luks_vol_name}" \
+ --header ${hdev}; }
+ local luksdev="/dev/mapper/${luks_vol_name}"
+ local dmdev
+ dmdev="$(basename "$(readlink "${luksdev}")")"
+ ls -ld "${hdev}" "${zdev}" "${luksdev}" "/dev/${dmdev}" >>"${FULL}"
+ local zdev_basename
+ zdev_basename=$(basename "$zdev")
+ local max_sectors_zdev
+ max_sectors_zdev=/sys/block/"${zdev_basename}"/queue/max_sectors_kb
+ echo 4 > "${max_sectors_zdev}"
+ echo "${zdev_basename}: max_sectors_kb=$(<"${max_sectors_zdev}")" >>"${FULL}"
+ local max_sectors_dm
+ max_sectors_dm=/sys/block/"${dmdev}"/queue/max_sectors_kb
+ echo "${dmdev}: max_sectors_kb=$(<"${max_sectors_dm}")" >>"${FULL}"
+ queue_freeze_loop /sys/block/"$dmdev"/queue/read_ahead_kb &
+ local loop_pid=$!
+ local fio_args=(
+ --bs=64M
+ --direct=1
+ --filename="${luksdev}"
+ --runtime="$TIMEOUT"
+ --time_based
+ --zonemode=zbd
+ )
+ if ! _run_fio_verify_io "${fio_args[@]}" >>"${FULL}" 2>&1; then
+ fail=true
+ fi
+
+ set +e
+
+ kill "${loop_pid}"
+ cryptsetup luksClose "${luks_vol_name}"
+ _exit_null_blk
+
+ if [ -z "$fail" ]; then
+ echo "Test complete"
+ else
+ echo "Test failed"
+ return 1
+ fi
+}
diff --git a/tests/zbd/013.out b/tests/zbd/013.out
new file mode 100644
index 000000000000..afc2364a9b73
--- /dev/null
+++ b/tests/zbd/013.out
@@ -0,0 +1,2 @@
+Running zbd/013
+Test complete
