Re: [PATCH V2 blktests] nvme: Add new test case about nvme rescan/reset/remove during IO

[Chaitanya Kulkarni <Chaitanya.Kulkarni@xxxxxxx>]

On 09/09/2019 09:47 AM, Yi Zhang wrote:
> Add one test to cover NVMe SSD rescan/reset/remove operation during
> IO, the steps found several issues during my previous testing, check
> them here:
> http://lists.infradead.org/pipermail/linux-nvme/2017-February/008358.html
> http://lists.infradead.org/pipermail/linux-nvme/2017-May/010259.html
>
> Signed-off-by: Yi Zhang <yi.zhang@xxxxxxxxxx>
> ---
>
> changes from v1:
>   - add variable for "/sys/bus/pci/devices/${pdev}"
>   - add kill $!; wait; for background fio
>   - add rescan/reset/remove sysfs node check
>   - add loop checking for nvme reinitialized
>
> ---
> ---
>   tests/nvme/031     | 71 ++++++++++++++++++++++++++++++++++++++++++++++
>   tests/nvme/031.out |  2 ++
>   2 files changed, 73 insertions(+)
>   create mode 100755 tests/nvme/031
>   create mode 100644 tests/nvme/031.out
>
> diff --git a/tests/nvme/031 b/tests/nvme/031
> new file mode 100755
> index 0000000..db163a2
> --- /dev/null
> +++ b/tests/nvme/031
> @@ -0,0 +1,71 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +# Copyright (C) 2019 Yi Zhang <yi.zhang@xxxxxxxxxx>
> +#
> +# Test nvme pci adapter rescan/reset/remove operation during I/O
> +#
> +# Regression test for bellow two commits:
> +# http://lists.infradead.org/pipermail/linux-nvme/2017-May/010367.html
> +# 986f75c876db nvme: avoid to use blk_mq_abort_requeue_list()
> +# 806f026f9b90 nvme: use blk_mq_start_hw_queues() in nvme_kill_queues()
> +
> +. tests/nvme/rc
> +
> +DESCRIPTION="test nvme pci adapter rescan/reset/remove during I/O"
> +TIMED=1
> +
> +requires() {
> +	_have_fio
> +}
> +
> +device_requires() {
> +	_test_dev_is_nvme
> +}
> +
> +test_device() {
> +	echo "Running ${TEST_NAME}"
> +
> +	pdev="$(_get_pci_dev_from_blkdev)"
> +	local sysfs="/sys/bus/pci/devices/${pdev}"
> +
> +	# start fio job
> +	_run_fio_rand_io --filename="$TEST_DEV" --size=1g \
> +		--group_reporting  &> /dev/null &
> +
> +	sleep 5
> +
> +	# do rescan/reset/remove operation
> +	if [[ -f "${sysfs}"/rescan ]]; then
> +		echo 1 > "${sysfs}"/rescan
> +	else
> +		echo "${sysfs}/rescan doesn't exist!"
> +	fi
> +	# QEMU VM doesn't have the "reset" attribute, skip it
> +	if [[ -f "${sysfs}"/reset ]]; then
> +		echo 1 > "${sysfs}"/reset
> +	fi

> +	if [[ -f "${sysfs}"/remove ]]; then
> +		echo 1 > "${sysfs}"/remove
> +	else
> +		echo "${sysfs}/remove doesn't exist!"
> +
> +	fi

This is a lot of code repetition. You should be creating one helper
and passing just file names. (No need to check the return value).
something like this :-

check_sysfs()
{
	local sysfs_attr=$1

	if [[ -f "${sysfs_attr}" ]]; then
		echo 1 > "${sysfs_attr}"
	else
		#TODO : add a check to not print if sysfs_attr is not
                 #reset
		echo "${sysfs_attr] doesn't exist!"
	fi
}
and call above function here :-

	for i in rescan remove reset; do
		check_sysfs_attr $i
	done

> +
> +	{ kill $!; wait; } &> /dev/null
> +
> +	echo 1 > /sys/bus/pci/rescan
> +
> +	# wait nvme reinitialized
> +	local m
Please declare all the local variables at the start of the function.

Do we need to call udevadm settle here ?

> +	for ((m = 0; m < 10; m++)); do
> +		if [[ -b "${TEST_DEV}" ]]; then
> +			break
> +		fi
> +		sleep 0.5
> +	done
> +        if (( m > 9 )); then
> +                echo "nvme still not reinitialized after 5 seconds!"
> +        fi
Please recheck the alignment in the above if.

> +
> +	echo "Test complete"
> +}
> diff --git a/tests/nvme/031.out b/tests/nvme/031.out
> new file mode 100644
> index 0000000..ae902bd
> --- /dev/null
> +++ b/tests/nvme/031.out
> @@ -0,0 +1,2 @@
> +Running nvme/031
> +Test complete
>