David Noel <david.i.noel@gmail.com> writes:
> Ugh. It turns out I had security.bsd.hardlink_check_gid=1 and
> security.bsd.hardlink_check_uid=1 in sysctl.conf. Setting them to 0
> fixed everything. That's frustrating. Sorry for all the trouble. Many
> thanks for helping resolve this.
Hah, I wondered if it might be something like that. Still, it's hard to
see how this link() would fail any security check that didn't amount to
disabling link() altogether. The UID and GID of the process, the old
file, and the directory will all match --- so exactly what rule are we
falling foul of? (Or IOW, this still seems like a kernel bug, though
perhaps of a design rather than implementation kind.)
regards, tom lane