svn commit: r308089 - in head

[Andriy Gapon]

On 07/03/2017 07:25, Lawrence Stewart wrote:
> I've just taken Allan Jude's & co-conspirators' work for a spin that
> allows gptzfsboot to boot from a geli + ZFS partition. Everything is
> working amazingly well, but I see the above "failed to read pad2 area of
> primary vdev" message on every boot.
> 
> It doesn't appear to cause any problems per se and the system
> boots/works fine. I assume that message is printed to signal an
> unexpected situation though, so figured I'd get in touch to get your
> thoughts.
> 
> 
> 
> I installed the KVM-based virtual machine system manually from the live
> shell of:
> 
> FreeBSD-12.0-CURRENT-amd64-20170301-r314495-disc1.iso
> 
> 
> 
> The partitioning is very simple:
> 
> gpart create -s gpt /dev/vtbd0
> gpart add -t freebsd-boot -a 8 -b 40 -s 512k vtbd0
> gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 vtbd0
> gpart add -t freebsd-zfs -b 2088 vtbd0
> 
>   root# gpart show
>   =>      40  83886000  vtbd0  GPT  (40G)
> 	  40      1024      1  freebsd-boot  (512K)
> 	1064      1024         - free -  (512K)
> 	2088  83883952      2  freebsd-zfs  (40G)
> 
> 
> 
> geli was inited/attached to vtbd0p2 and the zpool was created with command:
> 
> zpool create -o altroot=/tmp/zroot -o cachefile=/tmp/zpool.cache -O
> checksum=skein -O compression=lz4 <pool> vtbd0p2.eli
> 
> i.e. the entire pool including bootfs is using skein for checksumming
> and lz4 for compression.
> 
> 
> 
> I hit another boot bug using skein previously which Toomas (CCed) fixed,
> and am wondering if this issue might also be related to the skein
> implementation.
> 
> I haven't tested if the zfsbootcfg functionality works for fear that the
> printf is indicating a low level problem with the zpool. I can test
> potentially destructive things and break the pool though if that would
> be helpful.
> 
> Any thoughts?

I think that Toomas explained the situation rather well.
vdev_read_pad2() and vdev_clear_pad2() are not aware of GELI as of now, so the
former does not even try to decrypt anything and, obviously, gets some garbage
as a result.  It's that simple.  If it's possible to make it understand that it
deals with encrypted data, then it would be great.

-- 
Andriy Gapon