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`).
[zj: update crypttab(5) too, making "discard" the default.]
<variablelist class='crypttab-options'>
<varlistentry>
- <term><varname>allow-discards</varname></term>
+ <term><varname>discard</varname></term>
<listitem><para>Allow discard requests to be
passed through the encrypted block device. This
opt_readonly = true;
else if (streq(option, "verify"))
opt_verify = true;
- else if (streq(option, "allow-discards"))
+ else if (streq(option, "allow-discards") || streq(option, "discard"))
opt_discards = true;
else if (streq(option, "luks"))
opt_type = CRYPT_LUKS1;