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

[Jan Engelhardt]

On Thursday 2010-07-22 17:47, Linus Torvalds wrote:
>On Thu, Jul 22, 2010 at 8:36 AM, Volker Lendecke
><Volker.Lendecke at sernet.de> wrote:
>>
>> The nice thing about this is also that if this is supposed
>> to be fully usable for Windows clients, the birthtime needs
>> to be changeable. That's what NTFS semantics gives you, thus
>> Windows clients tend to require it.
>
>Ok. So it's not really a creation date, exactly the same way ctime
>isn't at all a creation date. [...]
>Tell me why we shouldn't just do this right?

Nobody said the c in ctime stands for creation. It stands for
change (you probably knew that).

$ touch this
$ stat this
  File: `this'
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fh/15d  Inode: 106777647   Links: 1
Access: (0644/-rw-r--r--)  Uid: (25121/ jengelh)   Gid: (  100/   users)
Access: 2010-07-22 18:18:52.665480058 +0200
Modify: 2010-07-22 18:18:52.665480058 +0200
Change: 2010-07-22 18:18:52.665480058 +0200

# Only change inode, not content
$ chmod 600 this
$ stat this
  File: `this'
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fh/15d  Inode: 106777647   Links: 1
Access: (0600/-rw-------)  Uid: (25121/ jengelh)   Gid: (  100/   users)
Access: 2010-07-22 18:18:52.665480058 +0200
Modify: 2010-07-22 18:18:52.665480058 +0200
Change: 2010-07-22 18:18:58.533436339 +0200


(Solaris exhibits the very same kind of behavior.)