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

[tridge at samba.org]

Hi Ted,

 > Does it literally mean "file creation time" in terms of when the OS
 > created the file, or does it mean "file" in the sense of
 > application contents.  For example, if an application edits the
 > file and saves it out using "write file to foo.new; sync; rename
 > foo to foo.bak; rename foo.new to foo", should the creation time
 > for the newly written file "foo" be the time when the editor saved
 > out the file (i.e., when "foo.new" was created), or copied from the
 > original file "foo"'s creation time.

In Windows this is can be controlled by applications, but it also is
done at the filesystem level in NTFS using a technique that Microsoft
call "File System Tunneling". If you create a file with the same name
within a short time (default 15s and settable in the registry) of when
the file previously existed then it will get the same CreationTime as
the previous file.

For details see http://support.microsoft.com/kb/172190

Some applications also do this regardless of the registry setting for
MaximumTunnelEntryAgeInSeconds. They use the ability to set the
CreationTime to get the same behaviour.

Cheers, Tridge