Re: [PATCH 2/2] blktests/033: add test to cover gendisk leak

[Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>]

I suggest the commit title:

    block/033: add test to cover gendisk leak

On Feb 16, 2023 / 11:01, Ming Lei wrote:
> 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         | 32 ++++++++++++++++++++++++++++++++
>  tests/block/033     | 33 +++++++++++++++++++++++++++++++++
>  tests/block/033.out |  2 ++
>  3 files changed, 67 insertions(+)
>  create mode 100644 common/ublk
>  create mode 100755 tests/block/033
>  create mode 100644 tests/block/033.out
> 
> diff --git a/common/ublk b/common/ublk
> new file mode 100644
> index 0000000..66b3a58
> --- /dev/null
> +++ b/common/ublk
> @@ -0,0 +1,32 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +# Copyright (C) 2023 Ming Lei
> +#
> +# null_blk helper functions.

I think you meant s/null_blk/ublk/

> +
> +. common/shellcheck
> +
> +_have_ublk() {
> +	_have_driver ublk_drv

The _init_ublk() below looks assuming the ublk_drv modules is loadable. If so,
the live above should be:

    _have_module ublk_drv

Of note is that some of the blkteste users run tests with all drivers as
built-in modules. So it is the better that the new test case can run with
built-in ublk_drv, if possible. (Or it can be a left work.)

> +	_have_src_program ublk/miniublk
> +}
> +
> +_remove_ublk_devices() {
> +	src/ublk/miniublk del -a
> +}
> +
> +_init_ublk() {
> +	if ! modprobe -r ublk_drv || ! modprobe ublk_drv "${args[@]}" ; then
> +		SKIP_REASONS+=("requires modular ublk_drv")
> +		return 1
> +	fi
> +
> +	udevadm settle
> +	return 0
> +}
> +
> +_exit_ublk() {
> +	_remove_ublk_devices
> +	udevadm settle
> +	modprobe -r -q ublk_drv
> +}
> diff --git a/tests/block/033 b/tests/block/033
> new file mode 100755
> index 0000000..342ccf3
> --- /dev/null
> +++ b/tests/block/033
> @@ -0,0 +1,33 @@
> +#!/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/ublk/miniublk"
> +	echo "Running ${TEST_NAME}"
> +
> +	if ! _init_ublk; then
> +		return 1
> +	fi
> +
> +	local ublk_dev=`$ublk_prog add -t null --quiet`
> +	$ublk_prog del --disk=$ublk_dev > /dev/null 2>&1
> +
> +	_exit_ublk
> +
> +	echo "Test complete"
> +}
> diff --git a/tests/block/033.out b/tests/block/033.out
> new file mode 100644
> index 0000000..067846a
> --- /dev/null
> +++ b/tests/block/033.out
> @@ -0,0 +1,2 @@
> +Running block/033
> +Test complete
> -- 
> 2.31.1
> 

-- 
Shin'ichiro Kawasaki