Re: [PATCH] zfs module update

[Andrei Borzenkov]

В Tue, 14 Apr 2015 02:17:43 +0300
Toomas Soome <address@hidden> 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?