On 2015-10-14 14:53, Andy Lutomirski wrote:
> On Wed, Oct 14, 2015 at 11:49 AM, Christoph Hellwig <hch@infradead.org> wrote:
>> On Wed, Oct 14, 2015 at 11:38:13AM -0700, Andy Lutomirski wrote:
>>> One might argue that reflink is like copy + immediate dedupe.
>>
>> Not, it's not.  It's all that and more, because it is an operation that
>> is atomic vs other writes to the file and it's an operation that either
>> clones the whole range or nothing.  That's a very important difference.
>
> Fair enough.
>
> Would copy_file_range without the reflink option removed still be
> permitted to link blocks on supported filesystems (btrfs and maybe
> XFS)?
I would argue that it should have such functionality, but not do so by 
default (maybe add some option to tell it to ask the FS to accelerate 
the copy operation?).