Re: [PATCH v2 3/3] common/rc: notrun if io_uring is disabled by sysctl

Darrick J. Wong
2024-03-11T16:29:36Z

On Tue, Mar 12, 2024 at 12:20:29AM +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 notrun
> if io_uring is disabled by that way.
>
> Signed-off-by: Zorro Lang <zlang@kernel.org>

Looks fine to me,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> README | 6 ++++++
> common/rc | 10 ++++++++++
> src/feature.c | 19 ++++++++++++-------
> 3 files changed, 28 insertions(+), 7 deletions(-)
>
> diff --git a/README b/README
> index c46690c4..477136de 100644
> --- a/README
> +++ b/README
> @@ -142,6 +142,12 @@ Setup Environment
> https://www.lscdweb.com/registered/udf_verifier.html, then copy the udf_test
> binary to xfstests/src/.
>
> +8. (optional) To do io_uring related testing, please make sure below 3 things:
> + 1) kernel is built with CONFIG_IO_URING=y
> + 2) sysctl -w kernel.io_uring_disabled=0 (or set it to 2 to disable io_uring
> + testing dynamically if kernel supports)
> + 3) install liburing development package contains liburing.h before building
> + fstests
>
> For example, to run the tests with loopback partitions:
>
> diff --git a/common/rc b/common/rc
> index 50dde313..1406d8d9 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -2317,6 +2317,8 @@ _require_aiodio()
> # this test requires that the kernel supports IO_URING
> _require_io_uring()
> {
> + local n
> +
> $here/src/feature -R
> case $? in
> 0)
> @@ -2324,6 +2326,14 @@ _require_io_uring()
> 1)
> _notrun "kernel does not support IO_URING"
> ;;
> + 2)
> + n=$(sysctl -n kernel.io_uring_disabled 2>/dev/null)
> + if [ "$n" != "0" ];then
> + _notrun "io_uring isn't enabled totally by admin"
> + else
> + _fail "unexpected EPERM error, please check selinux or something else"
> + fi
> + ;;
> *)
> _fail "unexpected error testing for IO_URING support"
> ;;
> diff --git a/src/feature.c b/src/feature.c
> index 941f96fb..7e474ce5 100644
> --- a/src/feature.c
> +++ b/src/feature.c
> @@ -232,15 +232,20 @@ check_uring_support(void)
> int err;
>
> err = io_uring_queue_init(1, &ring, 0);
> - if (err == 0)
> + switch (err) {
> + case 0:
> return 0;
> -
> - if (err == -ENOSYS) /* CONFIG_IO_URING=n */
> + case -ENOSYS:
> + /* CONFIG_IO_URING=n */
> return 1;
> -
> - fprintf(stderr, "unexpected error from io_uring_queue_init(): %s\n",
> - strerror(-err));
> - return 2;
> + case -EPERM:
> + /* Might be due to sysctl io_uring_disabled isn't 0 */
> + return 2;
> + default:
> + fprintf(stderr, "unexpected error from io_uring_queue_init(): %s\n",
> + strerror(-err));
> + return 100;
> + }
> #else
> /* liburing is unavailable, assume IO_URING is unsupported */
> return 1;
> --
> 2.43.0
>
>