Re: [PATCH blktests v2 1/6] common/rc: avoid module load in _have_driver()

[Bart Van Assche <bart.vanassche@gmail.com>]

On 8/17/22 18:26, Shin'ichiro Kawasaki wrote:
> The helper function _have_driver() checks availability of the specified
> driver, or module, regardless whether it is loadable or not. When the
> driver is loadable, it loads the module for checking, but does not
> unload it. This makes following test cases fail.
> 
> Such failure happens when nvmeof-mp test group is executed after nvme
> test group with tcp transport. _have_driver() for tcp transport loads
> nvmet and nvmet-tcp modules. nvmeof-mp test group tries to unload the
> nvmet module but it fails because of dependency to the nvmet-tcp module.
> 
> To avoid the failure, do not load module in _have_driver() using -n
> dry run option of the modprobe command. While at it, fix a minor problem
> of modname '-' replacement. Currently, only the first '-' in modname is
> replaced with '_'. Replace all '-'s.
> 
> Fixes: e9645877fbf0 ("common: add a helper if a driver is available")
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
>   common/rc | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/common/rc b/common/rc
> index 01df6fa..8150fee 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -30,9 +30,10 @@ _have_root() {
>   
>   _have_driver()
>   {
> -	local modname="${1/-/_}"
> +	local modname="${1//-/_}"
>   
> -	if [ ! -d "/sys/module/${modname}" ] && ! modprobe -q "${modname}"; then
> +	if [[ ! -d "/sys/module/${modname}" ]] &&
> +		   ! modprobe -qn "${modname}"; then
>   		SKIP_REASONS+=("driver ${modname} is not available")
>   		return 1
>   	fi

There are two (unrelated?) changes in this patch but only one change has 
been explained in the patch description :-(

Bart.