[Bug 36958] New: Wine emulates file creation time instead of fetching it from the underlying filesystem

http://bugs.winehq.org/show_bug.cgi?id=36958

Bug ID: 36958
           Summary: Wine emulates file creation time instead of fetching
                    it from the underlying filesystem
           Product: Wine
           Version: 1.7.22
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P5
         Component: ntdll
          Assignee: [e-mail]
          Reporter: [e-mail]

Created attachment 49071
  --> http://bugs.winehq.org/attachment.cgi?id=49071
Far2 showing file modification/creation/lass access times.

In Linux at least ext4 supports file creation time field (crtime), but Wine
doesn't use it. Instead it uses mtime.

Please, implement crtime for filesystems which impelement this field.

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

http://bugs.winehq.org/show_bug.cgi?id=36958

Jonas Jelten  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

https://bugs.winehq.org/show_bug.cgi?id=36958

--- Comment #1 from Austin English  ---
This is your friendly reminder that there has been no bug activity for over a
year. Is this still an issue in current (1.7.51 or newer) wine?

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

https://bugs.winehq.org/show_bug.cgi?id=36958

--- Comment #2 from Artem S. Tashkinov  ---
(In reply to Austin English from comment #1)
> This is your friendly reminder that there has been no bug activity for over
> a year. Is this still an issue in current (1.7.51 or newer) wine?

Yep.

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=36958

Ken Sharp  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |download, source

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=36958

--- Comment #3 from Artem S. Tashkinov  ---
statx() does that https://man7.org/linux/man-pages/man2/statx.2.html

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=36958

--- Comment #4 from Artem S. Tashkinov  ---
This is still relevant.

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=36958

--- Comment #5 from Artem S. Tashkinov  ---
Alexandre, it must be relatively easy to fix.

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=36958

Damjan Jovanovic  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |[e-mail]

--- Comment #6 from Damjan Jovanovic  ---
On FreeBSD and OSX, Wine got support for creation time back in 2012:

commit 5da1eaf2131f29264b734bdf4cde072115b0762f
Author: Charles Davis 
Date:   Thu Nov 29 21:50:46 2012 -0700

ntdll: Add support for BSD-style creation ("birth") time.

It's just Linux that's been a disaster:
https://blog.marbu.eu/posts/2019-02-17-btime/

If this was implemented via a new field in "struct stat", it would be easy to
#ifdef. But it uses a new "struct statx" instead, which means that many
functions in dlls/ntdll/unix/file.c which take "struct stat" parameters need to
be changed just for Linux.

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=36958

Martin Bukatovič  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

--- Comment #7 from Martin Bukatovič  ---
(In reply to Damjan Jovanovic from comment #6)
> It's just Linux that's been a disaster:
> https://blog.marbu.eu/posts/2019-02-17-btime/
>
> If this was implemented via a new field in "struct stat", it would be easy
> to #ifdef. But it uses a new "struct statx" instead, which means that many
> functions in dlls/ntdll/unix/file.c which take "struct stat" parameters need
> to be changed just for Linux.

Additional problem mentioned in the blog post is that Linux kernel doesn't
allow creation time field to be changed from user space (there is no syscall
for that) while Windows allows that.

This means that even if the creation time is fetched from statx structure, the
semantics will differ and use cases involving updating this field won't be even
possible.

This is not a problem for operating systems from BSD family, because there the
creation time field handling comes from design of FreeBSD's UFS2 file system,
which assumed that the field can be changed to allow preservation of this
information during backup restoration (eg. while extracting a tarball).

[Bug 36958] Wine emulates file creation time instead of fetching it from the underlying filesystem

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=36958

--- Comment #8 from Artem S. Tashkinov  ---
Ted Ts'o wrote:

POSIX and Single Unix Specification also doesn't provide a way to
allow userspace to set ctime (inode change time).  That's because the
definition of "change time" is defined to include the time to change
anything about the inode metadata --- including the inode timestamps.

Simply, the definition of "birth time" is about the time that the
inode was "birthed", and that's not something that you can change.
The problem is that DOS has a concept of "creation time", which seems
to mean "the time that the abstract concept of the file was created".
So if a file was created somewhere in a build farm in Redmond,
Washington, that's the time that the file should have, according to
Microsoft.  So Windows allows the "creation time" to be set to any
arbitrary file, since installers need to be able to set the "abstract
creation time".

You can debate whether "birth time" (which can't be set) or a
"abstract creation time" (which can set to any arbitrary value), is
"better" but that's why Linux doesn't support a way to set the "birth
time".

Whether you think we should bow to what Microsoft dictates probably
depends on how much you believe Windows is a legacy operating system
or not.  ????  Personally, it's not something I really care about, and
if someone really wants to add a Windows-compatible "Creation Time",
my suggestion would be to define an extended attribute where this
could be stored.

We *could* allocate space in the on-disk inode to store this
timestamp, but since I would estimate 99.9% of deployed Linux systems
don't care about Windows compatibility, it's not a good use of
resources.  We could also add a mount option which changes the
semantics of birth time, but that adds extra complexity, and again, I
would estimate that 99.9% of Linux systems (where I include all of the
Linux deployments in Cloud VM's) don't care about Windows
compatibility in this way.

Cheers,

- Ted