byte offset of the directory entry for the inode number for all types
of files except directories, although this breaks hard links for
non-directories even if it doesn't cause overflow. Just ignore this
broken inode number for stat() and readdir() and return a less broken
one (the block offset of the file), so that applications normally can't
see the brokenness.
This leaves at least the following brokenness:
- extra inodes, vnodes and caching for hard links.
- various overflow bugs. cd9660 supports 64-bit block numbers, but we
silently ignore the top 32 bits in isonum_733() and then drop another
10 bits for our broken inode numbers. We may also have sign extension
bugs from storing 32-bit extents in ints and longs even if ints are
32-bits. These bugs affect DVDs. mkisofs apparently limits them
by writing directory entries first.
Inode numbers were broken mainly in 4.4BSD-Lite2. FreeBSD-1.1.5 seems
to have a correct implementation modulo the overflow bugs. We need
to look up directory entries from inodes for symlinks only. FreeBSD-1.1.5
use separate fields (iso_parent_extent, iso_parent) to point to the
directory entry. 4.4BSD-Lite doesn't have these, and abuses i_ino to
point to the directory entry. Correct pointers are impossible for
hard links, but symlinks can't be hard links.