Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Close a race between libzfs and mountd when updating NFS exports.
- Flush the file descriptor for the new ZFS exports file before
sending a SIGHUP to mountd.

Reviewed by: pjd
Approved by: ken
MFC after: 3 days

Finally... Import the latest open-source ZFS version - (SPA) 28.

Few new things available from now on:

- Data deduplication.
- Triple parity RAIDZ (RAIDZ3).
- zfs diff.
- zpool split.
- Snapshot holds.
- zpool import -F. Allows to rewind corrupted pool to earlier
transaction group.
- Possibility to import pool in read-only mode.

MFC after: 1 month

- Add support for the "sec" option to "zfs set sharenfs"

Submitted by: Dmitry Morozovsky <marck@FreeBSD.org>
Approved by: delphij (mentor)
MFC after: 3 days

Forced commit to note that these files were repo copied.

Improve sharenfs option handling, so it is possible to give hosts list.
Before the change the command above:

# zfs set sharenfs=freefall.freebsd.org,69.147.83.54 tank/foo

was translated to:

/tank/foo -freefall.freebsd.org -69.147.83.54

instead of:

/tank/foo freefall.freebsd.org 69.147.83.54

This commit corrects this.

Please welcome ZFS - The last word in file systems.

ZFS file system was ported from OpenSolaris operating system. The code in under
CDDL license.

I'd like to thank all SUN developers that created this great piece of software.

Supported by: Wheel LTD (http://www.wheel.pl/)
Supported by: The FreeBSD Foundation (http://www.freebsdfoundation.org/)
Supported by: Sentex (http://www.sentex.net/)