[pkg-cryptsetup-devel] Bug#902449: cryptsetup-initramfs: auto-detection of zfs pool(s)

[Michal Humpula]

Hi Guilhem,

I can see the point against implementing the specific FS quirks. I'm might be 
able to send some patches upstream to make the ZFS more discoverable, but I 
need some more input from you.

On my machine I see that Btrfs propagates one of the devices to the /proc/
mounts, even if the actual FS is constructed from multiple devices in whatever 
manner the user wanted. Personally this seems confusing to me as user of /
proc/mounts, though it might be more reasonable approach for Btrfs users 
(don't know). I can see that cryptsetup hook uses this to get the UUID of the 
device and from that discover all the devices forming the Btrfs FS instance.

Entry in /proc/mounts for ZFS is different as it refers to the actual ZFS 
filesystem not to the devices of the underlying zpool. Which, from my point of 
view, makes more sense. Do you see a way to export all the required 
information in sysfs that would be acceptable by you? From top of my head, I 
can think of something like `/sys/fs/zfs/$FS/devices` where $FS can be 
something like `tank/my/fs`.

I think few other upcoming filesystems will have similar problems, e.g. 
bcachefs.

Cheers
Michal