Bug 54210 - RFE: add device-timeout option for /etc/crypttab
Summary: RFE: add device-timeout option for /etc/crypttab
Status: RESOLVED FIXED
Alias: None
Product: systemd
Classification: Unclassified
Component: general (show other bugs)
Version: unspecified
Hardware: x86 (IA32) Linux (All)
: medium normal
Assignee: systemd-bugs
QA Contact: systemd-bugs
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-08-29 13:26 UTC by seschwar
Modified: 2014-07-11 02:56 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments

Description seschwar 2012-08-29 13:26:02 UTC
I have an external USB drive with an encrypted LUKS partition, which should be unlocked at boot if attached.  If it is not attached systemd should just ignore the missing device, not throw any errors, and continue booting without waiting for the device.

This seems to be a usecase for the nofail crypttab option, as it is described in the manual page:

> nofail
>     The system will not wait for the device to show up and be unlocked at boot, and not fail the boot if it doesn't show up.

Thus the relevant line in /etc/crypttab looks like this:

> onetouch3 UUID=e3c24abf-143a-4d84-92b1-113f02a49a16 /root/luks/onetouch3 nofail

For testing purposes the unlocked partition was not mounted in fstab nor by a unit.  But still, using the option does not have the desired effect.  systemd waits for the device until it times out, as indicated by two entries in journalctl -b:

> Aug 29 14:57:10 pineapple systemd[1]: Job dev-disk-by\x2duuid-e3c24abf\x2d143a\x2d4d84\x2d92b1\x2d113f02a49a16.device/start timed out.
> Aug 29 14:57:10 pineapple systemd[1]: Job dev-mapper-onetouch3.device/start failed with result 'dependency'.
> Aug 29 14:57:10 pineapple systemd[1]: Job systemd-cryptsetup@onetouch3.service/start failed with result 'dependency'.
> Aug 29 14:57:10 pineapple systemd[1]: Job dev-disk-by\x2duuid-e3c24abf\x2d143a\x2d4d84\x2d92b1\x2d113f02a49a16.device/start failed with result 'timeout'.

> Aug 29 14:58:44 pineapple systemd[1]: Job dev-disk-by\x2duuid-e3c24abf\x2d143a\x2d4d84\x2d92b1\x2d113f02a49a16.device/start timed out.
> Aug 29 14:58:44 pineapple systemd[1]: Job dev-mapper-onetouch3.device/start failed with result 'dependency'.
> Aug 29 14:58:44 pineapple systemd[1]: Job systemd-cryptsetup@onetouch3.service/start failed with result 'dependency'.
> Aug 29 14:58:44 pineapple systemd[1]: Job dev-disk-by\x2duuid-e3c24abf\x2d143a\x2d4d84\x2d92b1\x2d113f02a49a16.device/start failed with result 'timeout'.

I am using Arch Linux and the following packages and their versions might be relevant:

linux 3.5.3-1
systemd 189-3
cryptsetup 1.5.0-2
Comment 1 Matthew Monaco 2012-09-26 20:57:46 UTC
It looks like "nofail" applies to cryptsetup.target. So while your device failed, cryptsetup.target succeeded without it.

It seems like what you want to do is reduce the timeout for dev/disk/by/uuid/e3c24abf-143a-4d84-92b1-113f02a49a16.device
Comment 2 seschwar 2012-09-29 18:59:15 UTC
On 2012-09-26 at 20:57 +0000 Matthew Monaco <dgbaley27@0x01b.net> wrote:
> It looks like "nofail" applies to cryptsetup.target. So while
> your device failed, cryptsetup.target succeeded without it.

I had missed that.  With the nofail option the status of
cryptsetup.target is "active" and without it it is "inactive
(dead)".  However in both cases the boot process is the same.
systemd waits until the device times out and then continues
booting normally.

> It seems like what you want to do is reduce the timeout for
> dev/disk/by/uuid/e3c24abf-143a-4d84-92b1-113f02a49a16.device

How do I do that?  The timeout option described in
man:crypttab(5) is for the timeout of the password prompt
and not of the device.  Is there something like fstab's
x-systemd.device-timeout for crypttab?

Moreover I think that crypttab's manual page suggests that the
nofail already implies an immediate timeout:

> The system will not wait for the device to show up (...)

As I see it this is a mismatch between the documentation and the
implementation and probably the source of my confusion.
Comment 3 seschwar 2013-03-14 18:10:42 UTC
After having used systemd for a while I now have a better grasp
of this issue.  In the meantime systemd has also improved in
this respect.  For example the timeout for a non-existing device
seems to be shorter and there is more and more accurate status
output.

Generally the nofail option causes the generated units to
be added to systemd-cryptsetup.target.wants instead of
systemd-cryptsetup.target.requires.  It doesn't change any
timeouts.  If the device is not present the job times out
after the default 1.5 minutes.  This is all just fine.  But
a device-timeout option for crypttab analogous to fstab's
x-systemd.device-timeout is clearly missing in order to decrease
the timeout for removable storage devices.
Comment 4 Zbigniew Jedrzejewski-Szmek 2014-07-02 01:20:11 UTC
Fixed in http://cgit.freedesktop.org/systemd/systemd/commit/?id=8eea868708.
Comment 5 seschwar 2014-07-10 17:43:49 UTC
Thanks, Zbigniew.  x-systemd.device-timeout isn't documented in crypttab's manual page, yet.
Comment 6 Zbigniew Jedrzejewski-Szmek 2014-07-11 02:56:34 UTC
http://cgit.freedesktop.org/systemd/systemd/commit/?id=dc5cd2b772


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