generic/528: take fs timestamps granularity into account in tolerance interval

Filesystems timestamps granularity can cause spurious test failures:

  QA output created by 528
  btime has value of 1635818936
  btime is NOT in range 1635818937 .. 1635818942

This test output makes it looks like $testfile was created *before* the
'date' command was executed.  What really happen was that btime was
truncated according to the granularity defined by filesystem (I've seen
this with both ext4 and xfs, but I guess others are also affected).

Since granularity can't be worse than a second, simply adjust the test
tolerance interval by 1 second.

Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

diff --git a/tests/generic/528 b/tests/generic/528
index 24d1ee0e5ec7be69e41aea51341dfd23c0259816..a63827b1139b14c8b1f8ffef28b706161a5f6715 100755 (executable)
--- a/tests/generic/528
+++ b/tests/generic/528
@@ -41,7 +41,7 @@ btime=$(date +%s -d "$($XFS_IO_PROG -c "statx -v -m $STATX_BTIME" $testfile | \
        grep 'stat.btime =' | cut -d '=' -f 2)")
 test -n "$btime" || echo "error: did not see btime in output??"
 
-_within_tolerance "btime" "$btime" "$now" 0 5 -v
+_within_tolerance "btime" "$btime" "$now" 1 5 -v
 
 status=0
 exit