CONFIG_ARCH_EPHEMERAL_INODES (not configurable)

configname: CONFIG_ARCH_EPHEMERAL_INODES

Linux Kernel Configuration
└─>General architecture-dependent options
└─>ARCH_EPHEMERAL_INODES
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
An arch should select this symbol if it doesn't keep track of inode
instances on its own, but instead relies on something else (e.g. the
host kernel for an UML kernel).

is selected by
CONFIG_SECURITY_LANDLOCK