Creation time in XFS

Creation time in XFS

[Martin Steigerwald]

Hi!

Does XFS support creation time too or are there plans to support it?

Ext3 seems to do since 2.6.23:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ef7f38359ea8b3e9c7f2cae9a4d4935f55ca9e80

http://tinyurl.com/3drb65

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

Re: Creation time in XFS

[Timothy Shimmin]

Martin Steigerwald wrote:
> Hi!
> 
> Does XFS support creation time too or are there plans to support it?
> 
> Ext3 seems to do since 2.6.23:
> 
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ef7f38359ea8b3e9c7f2cae9a4d4935f55ca9e80
> 
> http://tinyurl.com/3drb65
> 
> Ciao,

Hi Martin,

No XFS does not support creation time. It just has the regular
atime,mtime and ctime.
There are no plans that I've heard to support it.
Not much involved to support it AFAICT but it would either involve
changing the ondisk format of the inode or storing it in an EA.
Storing it in an EA would be yet another one for the EA creation
on inode allocation scenarios (done presently for default ACLs and
and also in other future data).

I wonder how this creation time is being exported currently?

--Tim

Re: Creation time in XFS

[Andi Kleen]

Timothy Shimmin <tes@sgi.com> writes:

> No XFS does not support creation time. It just has the regular
> atime,mtime and ctime.
> There are no plans that I've heard to support it.
> Not much involved to support it AFAICT but it would either involve
> changing the ondisk format of the inode or storing it in an EA.

If you ever change the on disk format adding a file type similar to ext3
to directories could also greatly speed up find in many cases.

> I wonder how this creation time is being exported currently?

I don't think it is at all currently:

% gid i_crtime
fs/udf/udf_i.h:21:#define UDF_I_CRTIME(X)               ( UDF_I(X)->i_crtime )
include/linux/ext4_fs.h:344:    __le32  i_crtime;       /* File Creation time */
include/linux/ext4_fs_i.h:160:  struct timespec i_crtime;
include/linux/udf_fs_i.h:20:    struct timespec         i_crtime;
fs/ext4/ialloc.c:566:   inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
fs/ext4/inode.c:2705:   EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
fs/ext4/inode.c:2792:   EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);

-Andi

Re: Creation time in XFS

[Timothy Shimmin]

Andi Kleen wrote:
> Timothy Shimmin <tes@sgi.com> writes:
> 
>> No XFS does not support creation time. It just has the regular
>> atime,mtime and ctime.
>> There are no plans that I've heard to support it.
>> Not much involved to support it AFAICT but it would either involve
>> changing the ondisk format of the inode or storing it in an EA.
> 
> If you ever change the on disk format adding a file type similar to ext3
> to directories could also greatly speed up find in many cases.
> 
Sounds a good idea.
In that case a new ondisk directory format (at v2 at the moment).
I think Dave (dgc) might have been mentioning something about that
recently.

--Tim

Re: Creation time in XFS

[David Chinner]

On Mon, Oct 01, 2007 at 11:30:01AM +0200, Andi Kleen wrote:
> Timothy Shimmin <tes@sgi.com> writes:
> 
> > No XFS does not support creation time. It just has the regular
> > atime,mtime and ctime.
> > There are no plans that I've heard to support it.
> > Not much involved to support it AFAICT but it would either involve
> > changing the ondisk format of the inode or storing it in an EA.
> 
> If you ever change the on disk format adding a file type similar to ext3
> to directories could also greatly speed up find in many cases.

Sure, but that's the directory structure, not inode structure.
They have different versioning methods, and so can be modified
independently.

FWIW, I haven't forgotten abou thtis request, Andi ;) I'll be
modifying the directory structure for CRCs relatively soon, and I
plan to do that modification at the same time so I only need a
single version bump for both....

> > I wonder how this creation time is being exported currently?
> 
> I don't think it is at all currently:

So what is the point? Forensic analysis?

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group

Re: Creation time in XFS

[Christoph Hellwig]

On Tue, Oct 02, 2007 at 07:25:10PM +1000, David Chinner wrote:
> > I don't think it is at all currently:
> 
> So what is the point? Forensic analysis?

Windows wants it, so I guess they added when they had to bump the inode
version anyway in preparation of a user interface for samba.  We probably
should do the same for XFS when bumping the inode version for the crcs.

Re: Creation time in XFS

[David Chinner]

On Tue, Oct 02, 2007 at 10:38:22AM +0100, Christoph Hellwig wrote:
> On Tue, Oct 02, 2007 at 07:25:10PM +1000, David Chinner wrote:
> > > I don't think it is at all currently:
> > 
> > So what is the point? Forensic analysis?
> 
> Windows wants it, so I guess they added when they had to bump the inode
> version anyway in preparation of a user interface for samba.

<groan>

Can you point me to whatever list this was discussed on? This
is exactly the sort of stuff that needs to be discussed on -fsdevel.

> We probably
> should do the same for XFS when bumping the inode version for the crcs.

Perhaps. I don't really like the idea of adding unused fields to
the on disk structure just in case it is needed in the future....

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group

Re: Creation time in XFS

[Eric Sandeen]

Martin Steigerwald wrote:
> Hi!
> 
> Does XFS support creation time too or are there plans to support it?
> 
> Ext3 seems to do since 2.6.23:
> 
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ef7f38359ea8b3e9c7f2cae9a4d4935f55ca9e80

well, that's ext4, not ext3, just FWIW.

-Eric