Re: New reflink(2) syscall

[Joel Becker <Joel.Becker@oracle.com>]

On Tue, May 05, 2009 at 01:44:11PM -0400, Stephen Smalley wrote:
> > Both use cases are equally valid, and I imagine there would be
> > interest in using reflinks both for snapshots and as a very
> > lightweight copy operation by commands like /bin/cp.

	Sure, but you can start with a reflink and then do what you want
to it.

> Not arguing against this, but just to note:  the security model will
> differ depending on these flags, as the link-like case doesn't require
> the caller to have read access to the file (the data is no more
> accessible than it was before), whereas the copy-like case requires the
> caller to have read access to the original file since the data "leaks"
> into a container with potentially different access constraints.

	Yeah, another reason why I don't want to complicate the
behavior.  I defined it as "the operation is like link(2)" for a reason
:-)

Joel

-- 

"I inject pure kryptonite into my brain.
 It improves my kung fu, and it eases the pain."


Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127