Corrupt Filesystem after Hibernation

Question

After each hibernation process I get a corrupted root filesystem. My setup is a LUKS encrypted root and swap partition on LVM. I use a GPG encrypted key for the root filesystem and a unencrypted key file on the root partition for swap decryption. The initramfs is generated by genkernel with

genkernel --lvm --luks --gpg initramfs

For the hibernation setup I followed the Gentoo Wiki. I tried using

pm-hibernate
s2disk -r /dev/mapper/swap
echo disk > /sys/power/state

but all result in a corrupted root partition. I am not using tuxonice as (afaik) I would need to switch to other kernel sources or apply patches.

System:

Gentoo
Kernel 4.9.6-gentoo-r1
genkernel 3.4.52.4-r2
pm-utils 1.4.1-r7

Disk layout:

NAME         MAJ:MIN RM  SIZE RO TYPE  MOUNTPOINT
sda            8:0    0  477G  0 disk  
├─sda2         8:2    0  128M  0 part  /boot
├─sda3         8:3    0  410G  0 part  
│ ├─vg1-swap 253:1    0   30G  0 lvm   
│ │ └─swap   253:3    0   30G  0 crypt [SWAP]
│ └─vg1-root 253:0    0  380G  0 lvm   
│   └─root   253:2    0  380G  0 crypt /
└─sda1         8:1    0    2M  0 part  

Answer 1

I use a GPG encrypted key for the root filesystem and a unencrypted key file on the root partition for swap decryption.

Does that mean you have to mount the root filesystem in order to be able to decrypt swap? If so, this could likely be the cause of your problems. You're not allowed to access (write) filesystems while in hibernation (because they are "still mounted" by the hibernated system).

https://www.kernel.org/doc/Documentation/power/swsusp.txt

 * BIG FAT WARNING *********************************************************
 *
 * If you touch anything on disk between suspend and resume...
 *              ...kiss your data goodbye.
 *
 * If you do resume from initrd after your filesystems are mounted...
 *              ...bye bye root partition.
 *          [this is actually same case as above]
 *

Hibernation is very chancy business, basically you have to hope for whatever your Initramfs flavour to handle all cases properly. It's best to use a plain swap partition that can be reached without any shenanigans.