First, this enables checks on DragonFly BSD, which partially works since
CL 589496 (except two things: atime is not supported on hammer2 fs, and
when both times are omitted, it doesn't work due to a kernel bug).
Second, there are a few problems with TestChtimesWithZeroTimes:
- test cases are interdependent (former cases influence the latter ones),
making the test using too many different times and also hard to read;
- time is changed forward not backward which could be racy;
- if the test has failed, it hard to see which exact case is failing.
Plus, there are issues with the error exclusion code in
TestChtimesWithZeroTimes:
- the atime comparison is done twice for the default ("unix") case;
- the atime exclusion caused by noatime mount flag applies to all
unixes rather than netbsd only as it should;
- the atime exclusion tries to read wrong files (/bin/mounts and
/etc/mtab instead of /proc/mounts);
- the exclusion for netbsd is only applied for 64-bit arches, which
seems wrong (and I've reproduced noatime issue on NetBSD 9.4/i386).
Let's rewrite it, fixing all these issues, and rename to
TestChtimesOmit.
NB: TestChtimes can now be removed.
Change-Id: If9020256ca920b4db836a1f0b2e055b5fce4a552
Reviewed-on: https://go-review.googlesource.com/c/go/+/591535
Auto-Submit: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Joedian Reid <joedian@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>