SquashFS Gains Support For IDMAPPED Mounts With Linux 6.2

Introduced nearly two years ago with Linux 5.12 was IDMAPPED mounts for many innovative use-cases from containers to systemd-homed. With the Linux 6.2 kernel, SquashFS is the latest file-system adding support for IDMAPPED mounts.

In simple terms, IDMAPPED mounts allow for different mounts to expose the same file or directory under different ownership rights. IDMAPPED mounts make it easier to share files between multiple users or even multiple machines, sharing files with unprivileged containers without having to permanently change the ownership rights, and a variety of other improvements and capabilities around better managing file rights.

EXT4 and FAT were among the initial adopters for supporting IDMAPPED mounts and on kernel releases since there has been Btrfs support, F2FS, OverlayFS, EROFS, and others. With Linux 6.2, SquashFS is joining the party.

Christian Brauner of Microsoft presented at Kernel Recipes 2022 on IDMAPPED mounts for those wanting to learn more about it and user-space software already able to make use of this functionality.

SquashFS is commonly used on embedded systems, live Linux environments, and elsewhere while now can be enjoyed in conjunction with IDMAPPED mounts. This pull request that was merged this week for Linux 6.2 enables the IDMAPPED mounts support.