[PATCH] New ZFS features from Illumos (13514, 13524, 13525)

[Martin Matuska]

I have ported the recent changes from Illumos for our tree.

The patch can be downloaded here:
http://people.freebsd.org/~mm/patches/zfs/head-illumos-13514-13524-13525.patch

What is it all about?

It is three revisions covering 7 features. There are no changes to the
on-disk format. There three new IOCTL's and one has been changed.
I have written some compatibility code for the changed IOCTL
(ZFS_IOC_DESTROY_SNAPS) so that it detects if the given argument is a
nvlist.
This way the recursive destroy of ZFS snapshots works with the older
binaries on the new kernel.

The other way (new binaries, old kernel) is little more problematic.
If using the new flags to zfs send there may be (some) crambled output
and it is not possible to destroy snapshots.
The problem is I cannot properly detect (in another way than osversion)
what utiliy versions are we running. But if this isn't such a big
problem (new binary, old kernel) we could go with this version.

Here is a list of the features, for detailed descriptions see links
underneath:

1644 add ZFS "clones" property
https://www.illumos.org/issues/1644

1645 add ZFS "written" and "written at ..." properties
https://www.illumos.org/issues/1645

1646 "zfs send" should estimate size of stream
https://www.illumos.org/issues/1646

1647 "zfs destroy" should determine space reclaimed by destroying
multiple snapshots
https://www.illumos.org/issues/1647

1693 persistent 'comment' field for a zpool
https://www.illumos.org/issues/1693

1708 adjust size of zpool history data
https://www.illumos.org/issues/1708

1748 desire support for reguid in zfs
https://www.illumos.org/issues/1748

Illumos changesets::
13514:
http://hg.openindiana.org/upstream/illumos/illumos-gate/rev/417c34452f03
(1748)
13524:
http://hg.openindiana.org/upstream/illumos/illumos-gate/rev/417c34452f03
(1644, 1645, 1646, 1647, 1708)
13525:
http://hg.openindiana.org/upstream/illumos/illumos-gate/rev/7059b67f1bc2
(1693)

Please review and/or test my patch, comments and suggestions are welcome.
http://people.freebsd.org/~mm/patches/zfs/head-illumos-13514-13524-13525.patch

-- 
Martin Matuska
FreeBSD committer
http://blog.vx.sk