This is similar to uid_range_load_userns() but instead of reading the
uid_map off a process it reads it off a userns fd.
(Of course the kernel has no API for this right now, hence we fork off a
throw-away process which joins the user namespace, and then read off the
data from there.)
We don't "uncapitalize" parts of an already-capitalized name when concatenating
words. In particular, we had UidRange in basic/uid-range.h and UGIDAllocationRange
in basic/uid-alloc-range.h, which is annoying.
This renames UidRange -> UidRangeEntry, and reintroduces UidRange which
contains the array of UidRangeEntry and its size.
No fucntional changes, just refactoring.
Mike Yuan
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Yu Watanabe