It might be inconvenient that direct open/accept deviates from the update semantics and fails if the slot is taken instead of removing a file sitting there. Implement the auto-removal.
Note that removal might need to allocate and so may fail. However, if an empty slot is specified, it's guaraneed to not fail on the fd installation side. It's needed for users that can't tolerate spuriously closed files, e.g. accepts where the other end doesn't expect it.
Signed-off-by: Pavel Begunkov firstname.lastname@example.org Signed-off-by: Franz-B. Tuneke