Re: [PATCH] hfsplus: disable rename of directory hardlinks

[Gustav Munkby <grddev@gmail.com>]

>> +    /* Renaming directory hardlinks to could create loops.
>> +     * Conservatively prevent any hardlink renaming.
>> +     */
> 
> It should also be safe to rename a directory hard link if the source and target parent directories are the same. 
> 
> This would allow the case of changing the directory name without moving it to another location.  

Theoretically, yes. In fact, it seems the implementation on OS X is even more
liberal by alos allowing moves into other directories as long as the target is
not already beneath another hardlink.

However, for that to make sense, proper support for renaming hardlinks (files as
well as directories) must first be implemented. The way I understand the hfsplus
code both rename and unlink is currently broken for any type of hardlink,
because it operates on the link target rather than the link source. Hardlinks in
HFS+ are represented much like low-level soft links, with one target
file/directory in a private system directory, and several link sources.
Operating on the link target would invalidate all link sources on rename/unlink,
which is clearly not desired.