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

[Li Wang <liwang@redhat.com>]

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");
-- 
2.31.1