Re: RFC: renameat(): Add a RENAME_REMOVE flag to unlink hardlinks

On Fri, Nov 21, 2014 at 10:20:54PM +0000, Pádraig Brady wrote:

quoted

quoted

That said, would you still like me to take a stab at a proposal to the
POSIX folks that would relax the requirements to allow
implementation-defined behavior when the two arguments to rename
describe the same file but via different directory entries?

I guess there is no point discussing in POSIX and adding extra
implementation options if no implementations do/will act accordingly.

Linux can decide to do that independently, if appropriate.
This is one of those borderline cases where we balance
accretion of cruft vs incompatibility.
On consideration, I'm OK with keeping the existing
rename() behavior for compat and adding the new flag.
That said I still can't think of anything depending
rename() doing nothing with hardlinked source and dest.

You do realize that it opens a very nasty can of worms for filesystems that
are e.g. case-insensitive to some extent?  How do you tell links from
alternative equivalent spellings of the name?