[Pkg-systemd-maintainers] Bug#719167: systemd-cryptsetup: Encountered unknown /etc/crypttab option 'discard', ignoring.

[Ondrej Balaz]

On Fri, Aug 9, 2013 at 9:32 AM, Michael Biebl <biebl at debian.org> wrote:
> Am 09.08.2013 00:41, schrieb Ondrej Balaz:
>> Package: systemd
>> Version: 204-2
>> Severity: normal
>> Tags: patch
>>
>> systemd-cryptsetup recognizes option 'allow-discards' in /etc/crypttab
>> to enable TRIM passthrough to underlying encrypted device. In Debian
>> this option was changed to 'discard' to avoid hyphen in option name
>> (see: #648868 and `man crypttab`).
>>
>> Attached is a simple patch that changes systemd-cryptsetup to recognize
>> 'discard' option instead of 'allow-discards'.
>
> If the two options are really equivalent, we should accept both and not
> just change allow-discards -> discard.
>

Both options have same effect (they enable TRIM passthrough) but
'allow-discards' is ignored by other Debian tools (most notably cryptroot in
initramfs). IMHO we should fail at 'allow-discards' as it is not supported
by Debian's /etc/crypttab. Supporting both may lead to situations where
TRIM is successfully enabled on devices unlocked by systemd itself but
not on devices unlocked by cryptroot (systemd+initramfstools scenario).

If you still want to support both please let me know, I'll modify the patch.

-- 
Ondrej Balaz

e-mail: blami at blami.net