Re: [PATCH] cowlinks v2

Linus Torvalds
2004-03-25T20:39:08Z

On Thu, 25 Mar 2004, Jamie Lokier wrote:
>
> That is not useful for me or the other people who want to use this to
> duplicate large source trees and run "diff" between trees.
>
> "diff" depends on being able to check if files in the two trees are
> identical -- by checking whether the inode number and device (and
> maybe other stat data) are identical. This allows "diff -ur" between
> two cloned trees the size of linux to be quite fast. Without that
> optimisation, it's very slow indeed.

I think the correct thing to do is to just admit that cowlinks aren't
POSIX, and instead see the inode number as a way to see whether the link
has been broken or not. Ie just accept the inode number potentially
changing.

That would make "diff" (adn most other uses) ok with this, and anythign
that isn't, just couldn't be used with cowlinked files.

Linus