`rename(2)` entry handler is invalid

[fvalasiad]

rename(2) makes changes to our data structures without validation that said system call has exited successfully(something we cannot know before we reach syscall exit).

Generally speaking the whole mechanism feels awkward and I'd rather find a better way to do it. Will look into it.

[fvalasiad]

Well after thinking about it the solution was rather simple:

The only thing that rename_exit cannot access when compared with its rename_entry counterpart is the absolute path of the oldpath. oldpath itself is actually accessible, and the hash is the same as the newpath hash.

Well speaking in terms of absolutepath that is.