[LTP] [PATCH v2] copy_file_range03: comparing timestamp in tst_timespec_diff

[xuyang2018.jy@fujitsu.com <xuyang2018.jy@fujitsu.com>]

Hi Li

Looks good to me.
Acked-by: Yang Xu <xuyang2018.jy@fujitsu.com>


Best Regards
Yang Xu
> The st_mtime field is defined as st_mtim.tv_sec for backward
> compatibility in struct stat, which might not precise enough
> for timestamp comparing.
>
> Here switch to timespec diff (with compare nanosecond as well) to
> get rid of this kind of rare faliure:
>
>     7	tst_test.c:1345: TINFO: Timeout per run is 0h 05m 00s
>     8	copy_file_range.h:36: TINFO: Testing libc copy_file_range()
>     9	copy_file_range03.c:48: TPASS: copy_file_range sucessfully updated the timestamp
>     10	tst_test.c:1345: TINFO: Timeout per run is 0h 05m 00s
>     11	copy_file_range.h:39: TINFO: Testing __NR_copy_file_range syscall
>     12	copy_file_range03.c:46: TFAIL: copy_file_range did not update timestamp.
>
> Also, raise the sleep time to 1.5 sec to make test more robust.
>
> Signed-off-by: Li Wang<liwang@redhat.com>
> ---
>   .../copy_file_range/copy_file_range03.c         | 17 ++++++++++-------
>   1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/testcases/kernel/syscalls/copy_file_range/copy_file_range03.c b/testcases/kernel/syscalls/copy_file_range/copy_file_range03.c
> index 253eb57ad..5950c80c1 100644
> --- a/testcases/kernel/syscalls/copy_file_range/copy_file_range03.c
> +++ b/testcases/kernel/syscalls/copy_file_range/copy_file_range03.c
> @@ -12,26 +12,27 @@
>   #define _GNU_SOURCE
>
>   #include "tst_test.h"
> +#include "tst_timer.h"
>   #include "copy_file_range.h"
>
>   static int fd_src;
>   static int fd_dest;
>
> -unsigned long get_timestamp(int fd)
> +struct timespec get_timestamp(int fd)
>   {
>   	struct stat filestat;
>
>   	fstat(fd,&filestat);
> -	return filestat.st_mtime;
> +	return filestat.st_mtim;
>   }
>
>   static void verify_copy_file_range_timestamp(void)
>   {
>   	loff_t offset;
> -	unsigned long timestamp, updated_timestamp;
> +	struct timespec timestamp1, timestamp2, diff;
>
> -	timestamp = get_timestamp(fd_dest);
> -	usleep(1000000);
> +	timestamp1 = get_timestamp(fd_dest);
> +	usleep(1500000);
>
>   	offset = 0;
>   	TEST(sys_copy_file_range(fd_src,&offset,
> @@ -40,9 +41,11 @@ static void verify_copy_file_range_timestamp(void)
>   		tst_brk(TBROK | TTERRNO,
>   				"copy_file_range unexpectedly failed");
>
> -	updated_timestamp = get_timestamp(fd_dest);
> +	timestamp2 = get_timestamp(fd_dest);
>
> -	if (timestamp == updated_timestamp)
> +	diff = tst_timespec_diff(timestamp1, timestamp2);
> +
> +	if (!diff.tv_sec&&  !diff.tv_nsec)
>   		tst_brk(TFAIL, "copy_file_range did not update timestamp.");
>
>   	tst_res(TPASS, "copy_file_range sucessfully updated the timestamp");