On 4/29/24 7:17 PM, Jeremy Allison wrote:
On Mon, Apr 29, 2024 at 10:51:21AM +0200, Ralph Boehme wrote:Hi Steve, On 4/28/24 9:41 PM, Steve French via samba-technical wrote:I did another test of the Samba server ctime bug on Samba master (4.21.0pre1) and Samba server is still broken in how it reports ctime. An example scenario is simple, creating a hardlink is supposed to update ctime on a file (and this works fine to Windows server and ksmbd etc) but Samba server mistakenly reports ctime as mtime (unless you mount with the "posix" mount option). This e.g. breaks xfstest generic/236 when run to Samba More information is at: https://bugzilla.samba.org/show_bug.cgi?id=10883I wonder if this is a bug going back as far as c9dca82ed7757f4745edf6ee6048bd94d86c4dbc@Jeremy: do you remember why you chose to return mtime in get_change_timespec() and not ctime?If you look closely at that commit, you'll see that it's actually not changing the logic that previously existed :-).
yeah, sure, but it was a decent refactoring so I was wondering whether you'd considered the actual logic you were touching was correct. :)
- put_long_date_timespec(p, m_timespec); /* change time */
+ put_long_date_timespec(p, c_timespec); /* change time */
Previously we were using m_timespec as change time,
and c_timespec in this change now comes from:
+ c_timespec = get_change_timespec(fsp, smb_fname);
+struct timespec get_change_timespec(struct files_struct *fsp,
+ const struct smb_filename *smb_fname)
+{
+ return smb_fname->st.st_ex_mtime;
+}
So I actually wasn't changing what we already were
doing :-).
Now as to *why* we were using m_time instead of c_time,
my guess is that we were trying to emulate NTFS
semantics which were not documented or well understood at the
time (where "the time" is probably prior to 2009 :-).
Hm, so what do we do? MS-FSA seems to indicate NTFS ctime has pretty much the same semantics as POSIX ctime:
2.1.1.3 Per FileLastChangeTime: The time that identifies when the file metadata or contents were last changed in the FILETIME format specified in [MS-FSCC] section 2.1.1.
Let's see how many tests complain: <https://gitlab.com/samba-team/devel/samba/-/pipelines/1272333543>
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