> Random side note: on MacOS, the kernel does know all the filenames of a hardlink, because hardlinks are secretly implemented as fancy symlink-like data struct

> Random side note: on MacOS, the kernel does know all the filenames of a hardlink, because hardlinks are secretly implemented as fancy symlink-like data structures. You normally don't see any symptoms of this except that hardlinks are suspiciously slow on MacOS. But in exchange for the slowness, the kernel actually can look up all filenames of a hardlink if it wants. I think this has something to do with Aliases and finding .app files even if they move around, or something. This reads weird to me. As the author points out, a directory entry (hardlink) is just a filename pointing to an inode. When you first create a file, and there is only one filename for that file, that entry is a hardlink. So in that text the first occurrence of "hardlink" should probably read "the kernel does know all the filenames of an inode". But then it gets weird. When the author says "hardlinks are suspiciously slow on MacOS", it sounds like they're saying "accessing files is suspiciously slow on MacOS" - because accessing any file in the filesystem goes through hardlinks. All links to a file, including the first, are hardlinks.