setfacl and mtime

[Tim Kientzle]

Craig Reyenga wrote:
> 
> I've been toying with ACLs lately, and I noticed that ACL operations change
> the mtime of the file, whereas chmod does not. Is this functionality
> intentional? More importantly, can it be turned off?

In particular, this is yet another way that the following two
commands seem to differ, even though (by my understanding), they
should be exactly interchangable:

   chmod u=rw file
   setfacl -m user::rw- file

The second changes the mtime, the first does not.
The second does not work on all filesystems, the first does.

The ACL routines I wrote for bsdtar (long story why
this was necessary...)  are careful to convert changes
to basic ACL entries (such as the second example above)
to the equivalent chmod.  It seems to me that the
library/kernel acl routines should also behave this way?

Tim