[Ocfs2-devel] [PATCH 1/3] fs: Document the reflink(2) system call.

[Jamie Lokier <jamie@shareable.org>]

Theodore Tso wrote:
> 1) If someone other than the owner of a file uses reflink to "make a
> copy" of the file, is it new inode, with the new inode number, owned
> by the original owner (making it look more like a link), or owned by
> the person creating the reflink (making it look more like a copy).
> 
> 2) Does changing the metadata --- atime, user/group ownership, ctime,
> etc., break the COW link and cause a copy?
> 
> (2) could be a per-filesystem implementation detail, but (1) goes to
> the semantics of the how the reflink() system call will work, so I
> think we need to have a common answer which is the same across all
> filesystems.  

I agree on both.

user/group ownership seems to raise the most questions.

Can we settle the hopefully simpler question of ctime, atime, mode changes?

-- Jamie