LSM: Whiteout chardev creation sidesteps mknod hook

[Miklos Szeredi]

On Tue, 14 Apr 2026 at 15:42, Mickaël Salaün <mic at digikod.net> wrote:

> BTW, I don't understand why only the renameat2(2) syscall can
> (indirectly) create this file type; why not also unlink(2) or rmdir(2)?

The reason is that the same effect is possible with first creating the
whiteout in the work directory with mknod, then renaming it over the
target.  Since the work directory is needed anyway, this spares
filesystems from having to implement yet another overlayfs specific
operation.

Thanks,
Miklos