[PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6]

[Greg Freemyer]

On Thu, Jul 22, 2010 at 2:21 PM, Benny Halevy <bhalevy at panasas.com> wrote:
> On Jul. 22, 2010, 20:24 +0300, Linus Torvalds <torvalds at linux-foundation.org> wrote:
>> On Thu, Jul 22, 2010 at 10:03 AM, Jan Engelhardt <jengelh at medozas.de> wrote:
>>>
>>> I beg to differ. ctime is not completely useless. It reflects changes on
>>> the inode for when you don't you change the content.
>>
>> Uh. Yes. Except that why is file metadata really different from file
>> data? Most people really don't care. And a lot of people have asked
>> for creation dates - and I seriously doubt that Windows people
>> complain a lot about the fact that there you have mtime for metadata
>> changes too.
>>
>> The point being that Unix ctime semantics certainly have well-defined
>> semantics, but they are in no way "better" than having a real creation
>> time, and are often worse.
>
> Yeah, having create time would be important.
> That said, having a non user-settable modify timestamp is crucial
> for quickly determining whether a file has changed.

How would "cp --archive" and a host of backup/restore tools work
without user-settable modify timestamps?

Or are you proposing another timestamp?  I do computer forensics, I
like timestamps, but enough is enough.

Greg