new file mode 100644
@@ -0,0 +1,35 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2023 Ming Lei
+#
+# ublk_drv helper functions.
+
+. common/shellcheck
+
+_have_ublk() {
+ _have_driver ublk_drv
+ _have_src_program miniublk
+}
+
+_remove_ublk_devices() {
+ src/miniublk del -a
+}
+
+_init_ublk() {
+ _remove_ublk_devices
+
+ modprobe -rq ublk_drv
+ if ! modprobe ublk_drv; then
+ SKIP_REASONS+=("requires ublk_drv")
+ return 1
+ fi
+
+ udevadm settle
+ return 0
+}
+
+_exit_ublk() {
+ _remove_ublk_devices
+ udevadm settle
+ modprobe -r -q ublk_drv
+}
new file mode 100755
@@ -0,0 +1,41 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2023 Ming Lei
+#
+# Test if gendisk is leaked, and regression in the following commit
+# c43332fe028c ("blk-cgroup: delay calling blkcg_exit_disk until disk_release")
+# can be covered
+
+. tests/block/rc
+. common/ublk
+
+DESCRIPTION="add & delete ublk device and test if gendisk is leaked"
+QUICK=1
+
+requires() {
+ _have_ublk
+}
+
+test() {
+ local ublk_prog="src/miniublk"
+
+ echo "Running ${TEST_NAME}"
+
+ if ! _init_ublk; then
+ return 1
+ fi
+
+ ${ublk_prog} add -t null -n 0 > "$FULL"
+ udevadm settle
+ if ! ${ublk_prog} list -n 0 >> "$FULL"; then
+ echo "fail to list dev"
+ fi
+ if ! dd if=/dev/ublkb0 iflag=direct of=/dev/null bs=1M count=512 >> "$FULL" 2>&1; then
+ echo "fail io"
+ fi
+ ${ublk_prog} del -n 0 >> "$FULL"
+
+ _exit_ublk
+
+ echo "Test complete"
+}
new file mode 100644
@@ -0,0 +1,2 @@
+Running block/033
+Test complete
So far only sync ublk removal is supported, and the device's last reference is dropped in gendisk's ->free_disk(), so it can be used to test gendisk leak issue. Signed-off-by: Ming Lei <ming.lei@redhat.com> --- common/ublk | 35 +++++++++++++++++++++++++++++++++++ tests/block/033 | 41 +++++++++++++++++++++++++++++++++++++++++ tests/block/033.out | 2 ++ 3 files changed, 78 insertions(+) create mode 100644 common/ublk create mode 100755 tests/block/033 create mode 100644 tests/block/033.out