On Thu, Jan 28, 2021 at 03:31:40PM -0600, Eric Sandeen wrote:
> We might have URING #defined at build time, but be running on a kernel
> which does not support it.
>
> For that reason, we should not exit with an error if
> io_uring_queue_init() fails with ENOSYS. We can just note the lack of
> support and skip all future io_uring operations.
>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
>
> diff --git a/ltp/fsstress.c b/ltp/fsstress.c
> index 22df5e38..73751935 100644
> --- a/ltp/fsstress.c
> +++ b/ltp/fsstress.c
> @@ -35,6 +35,7 @@ io_context_t io_ctx;
> #include <liburing.h>
> #define URING_ENTRIES 1
> struct io_uring ring;
> +bool have_io_uring; /* to indicate runtime availability */
> #endif
> #include <sys/syscall.h>
> #include <sys/xattr.h>
> @@ -706,9 +707,15 @@ int main(int argc, char **argv)
> }
> #endif
> #ifdef URING
> + have_io_uring = true;
> + /* If ENOSYS, just ignore uring, other errors are fatal. */
Yes, I thought about if we should do this since rhel8 kernel removed io_uring
support from kernel, but left userspace liburing. But if we do this for io_uring,
should we do the same check the others which can be disabled from kernel? Likes: AIO?
Thanks,
Zorro
> if (io_uring_queue_init(URING_ENTRIES, &ring, 0)) {
> - fprintf(stderr, "io_uring_queue_init failed\n");
> - exit(1);
> + if (errno == ENOSYS) {
> + have_io_uring = false;
> + } else {
> + fprintf(stderr, "io_uring_queue_init failed\n");
> + exit(1);
> + }
> }
> #endif
> for (i = 0; !loops || (i < loops); i++)
> @@ -720,7 +727,8 @@ int main(int argc, char **argv)
> }
> #endif
> #ifdef URING
> - io_uring_queue_exit(&ring);
> + if (have_io_uring)
> + io_uring_queue_exit(&ring);
> #endif
> cleanup_flist();
> free(freq_table);
> @@ -2208,6 +2216,9 @@ do_uring_rw(int opno, long r, int flags)
> struct iovec iovec;
> int iswrite = (flags & (O_WRONLY | O_RDWR)) ? 1 : 0;
>
> + if (!have_io_uring)
> + return;
> +
> init_pathname(&f);
> if (!get_fname(FT_REGFILE, r, &f, NULL, NULL, &v)) {
> if (v)
>
