Re: [PATCH 1/3] src/feature: add IO_URING feature checking

[Brian Foster <bfoster@redhat.com>]

On Thu, Sep 17, 2020 at 01:14:41AM +0800, Zorro Lang wrote:
> IO_URING is a new feature for GNU/Linux system, if someone case of
> xfstests tests this feature, better to check if current system
> supports it, or need _notrun.
> 
> Signed-off-by: Zorro Lang <zlang@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  src/Makefile  |  4 ++++
>  src/feature.c | 41 ++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 42 insertions(+), 3 deletions(-)
> 
> diff --git a/src/Makefile b/src/Makefile
> index 643c1916..f1422c5c 100644
> --- a/src/Makefile
> +++ b/src/Makefile
> @@ -65,6 +65,10 @@ SUBDIRS += aio-dio-regress
>  LLDLIBS += -laio
>  endif
>  
> +ifeq ($(HAVE_URING), true)
> +LLDLIBS += -luring
> +endif
> +
>  CFILES = $(TARGETS:=.c)
>  LDIRT = $(TARGETS) fssum
>  
> diff --git a/src/feature.c b/src/feature.c
> index a7eb7595..df550cf6 100644
> --- a/src/feature.c
> +++ b/src/feature.c
> @@ -19,6 +19,7 @@
>   *
>   * Test for machine features
>   *   -A  test whether AIO syscalls are available
> + *   -R  test whether IO_URING syscalls are available
>   *   -o  report a number of online cpus
>   *   -s  report pagesize
>   *   -w  report bits per long
> @@ -39,6 +40,10 @@
>  #include <libaio.h>
>  #endif
>  
> +#ifdef HAVE_LIBURING_H
> +#include <liburing.h>
> +#endif
> +
>  #ifndef USRQUOTA
>  #define USRQUOTA  0
>  #endif
> @@ -59,7 +64,7 @@ usage(void)
>  	fprintf(stderr, "Usage: feature [-v] -<q|u|g|p|U|G|P> <filesystem>\n");
>  	fprintf(stderr, "       feature [-v] -c <file>\n");
>  	fprintf(stderr, "       feature [-v] -t <file>\n");
> -	fprintf(stderr, "       feature -A | -o | -s | -w\n");
> +	fprintf(stderr, "       feature -A | -R | -o | -s | -w\n");
>  	exit(1);
>  }
>  
> @@ -215,6 +220,29 @@ check_aio_support(void)
>  #endif
>  }
>  
> +static int
> +check_uring_support(void)
> +{
> +#ifdef HAVE_LIBURING_H
> +	struct io_uring ring;
> +	int err;
> +
> +	err = io_uring_queue_init(1, &ring, 0);
> +	if (err == 0)
> +		return 0;
> +
> +	if (err == -ENOSYS) /* CONFIG_IO_URING=n */
> +		return 1;
> +
> +	fprintf(stderr, "unexpected error from io_uring_queue_init(): %s\n",
> +		strerror(-err));
> +	return 2;
> +#else
> +	/* liburing is unavailable, assume IO_URING is unsupported */
> +	return 1;
> +#endif
> +}
> +
>  
>  int
>  main(int argc, char **argv)
> @@ -228,6 +256,7 @@ main(int argc, char **argv)
>  	int	pflag = 0;
>  	int	Pflag = 0;
>  	int	qflag = 0;
> +	int	Rflag = 0;
>  	int	sflag = 0;
>  	int	uflag = 0;
>  	int	Uflag = 0;
> @@ -235,7 +264,7 @@ main(int argc, char **argv)
>  	int	oflag = 0;
>  	char	*fs = NULL;
>  
> -	while ((c = getopt(argc, argv, "ActgGopPqsuUvw")) != EOF) {
> +	while ((c = getopt(argc, argv, "ActgGopPqRsuUvw")) != EOF) {
>  		switch (c) {
>  		case 'A':
>  			Aflag++;
> @@ -264,6 +293,9 @@ main(int argc, char **argv)
>  		case 'q':
>  			qflag++;
>  			break;
> +		case 'R':
> +			Rflag++;
> +			break;
>  		case 's':
>  			sflag++;
>  			break;
> @@ -289,7 +321,7 @@ main(int argc, char **argv)
>  		if (optind != argc-1)	/* need a device */
>  			usage();
>  		fs = argv[argc-1];
> -	} else if (Aflag || wflag || sflag || oflag) {
> +	} else if (Aflag || Rflag || wflag || sflag || oflag) {
>  		if (optind != argc)
>  			usage();
>  	} else 
> @@ -317,6 +349,9 @@ main(int argc, char **argv)
>  	if (Aflag)
>  		return(check_aio_support());
>  
> +	if (Rflag)
> +		return(check_uring_support());
> +
>  	if (sflag) {
>  		printf("%d\n", getpagesize());
>  		exit(0);
> -- 
> 2.20.1
>