crypttab options are ignored

[baybal]

Hello, it seems that udisks can't understand discard option in crypttab

bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 UUID=40C85337C8532A84 none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 UUID=12d663c1-e3ff-44ff-9c88-c0d4c2b20624 none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 PARTUUID=95527122-430a-4646-a747-f5aa68b8cbe4 none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 LABEL=OS none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 LABEL=ZENBOOK-S-16\x20OS\x2016\x2f06\x2f2025 none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 UUID=CRYPT-BITLK-bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 PARTLABEL=Basic\040data\040partition none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 /dev/nvme0n1p3 none discard,allow_discards
bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 PARTLABEL=Basic\x20data\x20partition none discard,allow_discards

sudo lsblk -D  
Password: 
NAME                                       DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO
nvme0n1                                           0        4K       2T         0
├─nvme0n1p1                                       0        4K       2T         0
├─nvme0n1p2                                       0        4K       2T         0
├─nvme0n1p3                                       0        4K       2T         0
│ └─bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624
│                                                 0        0B       0B         0
├─nvme0n1p4                                       0        4K       2T         0
├─nvme0n1p5                                       0        4K       2T         0
├─nvme0n1p6                                       0        4K       2T         0
└─nvme0n1p7

[baybal]

The bitlk-12d663c1-e3ff-44ff-9c88-c0d4c2b20624 entry is clearly shown to have DISC-MAX of 0, which means discard is not enabled. If I use cryptsetup manually sudo cryptsetup --allow-discards open --type=bitlk --allow-discards /dev/nvme0n1p3 windows, discards will work, and lsblk -D will show correct discard info.

[axet]

All mounted LUKS devices by udisks does not enable discard:

# dmsetup table luks-7d54b477-c994-4081-ae19-f63882342c37
0 466909184 crypt aes-xts-plain64 :64:logon:cryptsetup:7d54b477-c994-4081-ae19-f63882342c37-d0 0 259:2 4096

Here is no option for LUKS allow_discards in udisks2.conf

[axet]

workaround:

cryptsetup --allow-discards --persistent refresh luks

[baybal]

workaround:

cryptsetup --allow-discards --persistent refresh luks

Unfortunately, not an option for bitlocker

[vojtechtrefny]

Yes, we are currently ignoring options from crypttab, unfortunately it's not as easy to support these as fstab options, where we can just take the string a pass it to (lib)mount. With crypttab some of the options are crypttab/systemd specific options and only a small subset is actually something we can use/set when opening the device with (lib)cryptsetup. discard is one of the options (the only other one is probably read-only) we can support and pass as flag to cryptsetup. This will unfortunately require change in libblockdev so it will take some time to implement.