Re: [PATCH] zfs module update

[Andrei Borzenkov <arvidjaar@gmail.com>]

В Tue, 14 Apr 2015 02:17:43 +0300
Toomas Soome <tsoome@me.com> пишет:

> hi!
> 
> this is the major update to grub2 zfs module; the work is based on Oracle code drops from Solaris 11, and Illumos.

IANAL but I suspect such changes require at least submission from
someone with Oracle E-Mail

+ *  Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved

> I am including here two separate patch sets, first is zfs itself, second one is update to allow embedding.
> 
> supports:
> - all current OpenZFS features
> - Solaris 11 zpool versions (including reading encrypted datasets)
> - can recognise and boot all pool configurations with exception that log device is not inspected (thats something to be investigated in future, while this code does not mind log device, its still probably not good idea to actually have one).
> - pool is readable as long as there is enough parity to reconstruct data from
> - supports multiple vdevs
> - supports both mirror and raidz
> - supports bootloader embedding as long as it will fit to 3.5MB space reserved for bootblock.
> - using negative cache for non-zfs devices
> 
> limitations: 
> - no writes. at all. never will be;)
> - actual pool configuration is limited by disks visibility for grub, and that depends on actual system. if grub can see 4 disks, that will set the limit.
> - browsing encryped datasets by tree levels is not supported, full path needs to be used; as writing the encrypred datasets is possible only with solaris 11 and it has its own grub implementation, I just left encryption support as is, at least for now.
> - mount cache code is there but not enabled; enabling it did trigger artefacts with grub graphical menu, reasons yet unknown - so far all checks with libumem for memory usage and integrity have been all OK.
> 
> tests done: booting with different zpool configurations, single disk, mirror, raidz, multiple vdev, 512B and 4096B sector sizes, missing disks (zpool offline and physically removed), tests are performed on illumos and unknown amount of linux systems - this code is already used by debian grub2 packages.
> 
> the embedding support adds zfs GPT partition tag to allow grub to be embedded directly to zfs partition, without the need for BIOS boot partition. If BIOS boot partition exists, it will be used. This functionality is already implemented in Illumos (with legacy grub), so, there is no reason not to support his with grub 2 as well. 

GRUB already has embedding support for ZFS; why second patch is needed?

> 
> as zfs update is pretty large, i include it compressed…
> 

Any chance to split it in series of incremental self-contained patches?