SSD TRIM not working on encrypted root partition

[o-alquimista]

What Happened?

After performing an encrypted install of elementary on an SSD, the TRIM command will not work on the root partition because it's missing a configuration option.

Steps to Reproduce

1. Install elementary, selecting the default encrypted setup the installer offers.
2. Boot the newly installed system and run sudo fstrim -av

Expected Behavior

Expected output of sudo fstrim -av:

/boot/efi: 251,7 MiB (263872512 bytes) trimmed on /dev/nvme0n1p1
/boot: 11,2 MiB (11714560 bytes) trimmed on /dev/nvme0n1p2
/: 3,3 GiB (3517906944 bytes) trimmed on /dev/mapper/data-root

Actual output of sudo fstrim -av:

/boot/efi: 251,7 MiB (263872512 bytes) trimmed on /dev/nvme0n1p1
/boot: 11,2 MiB (11714560 bytes) trimmed on /dev/nvme0n1p2

Expected contents of /etc/crypttab:

cryptdata UUID=51f61b21-5e03-4446-a244-6c399769f909 none luks,discard

Actual contents of /etc/crypttab:

cryptdata UUID=51f61b21-5e03-4446-a244-6c399769f909 none luks

Currently TRIM is only working on the boot partitions. It's important to let the TRIM command pass through to the root partition too. Ubuntu and Fedora are already doing this.

To fix this:

1. Edit /etc/crypttab and add the missing discard option to the cryptdata entry.
2. Rebuild the initramfs sudo update-initramfs -u -k all (reference).
3. Reboot.

OS Version

6.1 (Jólnir)

Software Version

Latest release (I have run all updates)

Log Output

No response

Hardware Info

No response

[o-alquimista]

This is reproducible on elementary 7.1