sftp-server rename and handling of EXDEV

[Mike Garrison]

Greetings,

One of the complaints we've commonly gotten from users is that modern  
versions of OpenSSH do not allow users to rename files in AFS across  
directories. Since OpenAFS only allows hardlinks in the parent  
directory, you can rename in the same directory but not across  
directory boundaries.

This is the same behavior when you try to rename across regular  
partition boundaries, as a hardlink will fail. I understand that  
renaming was changed a while back so it would not be racy, but is  
there any reason it shouldn't fall back to a racy rename if EXDEV is  
returned?

I know currently that if LINK_OPNOTSUPP_ERRNO is returned, we'll try a  
racy rename. Can this be extended to conditions where EXDEV is returned?

--
Mike Garrison