mkisofs hardlink detection broken on HAMMER
Running mkisofs on a directory with hard links will count each hard link as a separate file when that directory is on a HAMMER file system and the .iso will be larger than if the directory had been on a UFS. It seems mkisofs's hard link detection (it goes by identical inodes, I guess) isn't working on HAMMER.
A very unpleasant side effect of this is that our ISOs are much larger than they could be. In fact, the x86_64 ISO is already exceeding the 750MB mark. This is because /usr/pkg/libexec/git-core has a large number of hard links (over 100) for a >2MB file.
I don't think HAMMER is really at fault here and the only thing I can think of right now (without having looked at cdrtools source) is that it could have to do with HAMMER's inodes being 64 bit (?) vs. 32 on UFS.