Re: [PATCH 3/3] common/rc: force enable io_uring in _require_io_uring

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Mar 06, 2024 at 05:19:35PM +0800, Zorro Lang wrote:
> If kernel supports io_uring, userspace still can/might disable that
> supporting by set /proc/sys/kernel/io_uring_disabled=2. Let's set
> it to 0, to always enable io_uring (ignore error if there's not
> that file).
> 
> Signed-off-by: Zorro Lang <zlang@kernel.org>
> ---
>  common/rc | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/common/rc b/common/rc
> index 50dde313..966c92e3 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -2317,6 +2317,9 @@ _require_aiodio()
>  # this test requires that the kernel supports IO_URING
>  _require_io_uring()
>  {
> +	# Force enable io_uring if kernel supports it
> +	sysctl -w kernel.io_uring_disabled=0 &> /dev/null

_require_XXX functions are supposed to be predicates that _notrun the
test if XXX isn't configured or available.  Shouldn't this be:

	local io_uring_knob="$(sysctl --values kernel.io_uring_disabled)"
	test "$io_uring_knob" -ne 0 && _notrun "io_uring disabled by admin"

Alternately -- if it _is_ ok to turn this knob, then there should be a
cleanup method to put it back after the test.

--D

> +
>  	$here/src/feature -R
>  	case $? in
>  	0)
> -- 
> 2.43.0
> 
>