LUKS2 and other device types allow stacking of dm devices
underneath public top level device.
The new type identifies clearly those private devices in respective
device stack so that they can be easily removed while removing
top level public device.
Switch LUKS2 reencryption device stack to use SUBDEV type immmediately
for hotzone and overlay devices. Other devices will follow in later
releases.
It's useful to reencrypt only initial device part only.
For example with golden image reencryption it may be useful
to reencrypt only first X bytes of device because we know
the rest of device is empty.
This is very ugly workaround for situation when multiple
devices are being activated in parallel (systemd crypttab)
and system instead of returning ENOMEM use OOM killer
to randomly kill processes.
This flag is intended to be used only in very specific situations.
crypt_drop_keyring_key function allow to drop all keys in keyring
assocatiated with passed volume key list.
crypt_drop_keyring_key_by_description is used to drop independent key.
Support for multi-segment devices is requirement for online
reencryption to work. Introducing modififed dm backend that
splits data structures describing active device and individual
dm target (or segment).
The new flag is supposed to refresh (reload) active dm-crypt
mapping with new set of activation flags. CRYPT_ACTIVATE_READONLY
can not be switched for already active device.
The flag is silently ignored for tcrypt, verity and integrity
devices. LUKS2 with authenticated encryption support is added in
later commit.
auto-recovery triggers any time when only single correct LUKS2
header instance was found. That may be dangerous.
We should suppress auto-recovery in case blkid decided the
device is no longer LUKS device. For example if secondary (intact)
LUKS2 header was left behind and blkid declares the device is LVM2
member.
Moreover if at least one header instance is corrupted and blkid
declares device non-empty and non-LUKS in the same time, header load
operation will be aborted with error.
The code scan for the second header only if primary is corrrupted.
Let's set the possible offsets more clear.
This patch also removes 8kB header offset (that was not supported anyway).
This change makes the declaration of logger() match its definition,
it also avoids the use of the "class" C++ keyword. This is useful for
importing cryptsetup into Bazel/Blaze.
Move all keyring functions to one place and separate LUKS2 specific
code to generic handling.
Also fix possible mismatch if volume key is in keyring but it is not native
LUKS2 device (libarary cannot process such a device properly).
When loading first dm-crypt table (or action that triggers dm-crypt
module load) we do not know dm-crypt version yet. Let's assume all
kernels before 4.15.0 are flawed and reject VK load via kernel keyring
service.
When dm-crypt is already in kernel, check for correct target version
instead (v1.18.1 or later).
On some systems the requested amount of memory causes OOM killer
to kill the process (instead of returning ENOMEM).
For now, we never try to use more than half of available
physical memory.
