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

MFC r260236:
In dmu_zfetch_stream_reclaim() replace division with multiplication and
move it out of the loop and lock.

MFC r258632,258704: MFV r255255: 4045 zfs write throttle & i/o scheduler
performance work

Sponsored by: HybridCluster [merge]

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

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

MFV r251619:

ZFS needs better comments.

Illumos ZFS issues:
3741 zfs needs better comments

MFC after: 2 weeks

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

Re-commit the zfs sysctl(9) type-safety changes.

Thanks to dim and pjd for the pointer to zfs_context.h for building
userland.

Revert cddl changes for sysctl(9) until I understand why this isn't
building on universe.

sysctl(9) cleanup checkpoint: amd64 GENERIC builds cleanly.

Commit the zfs piece.

Fix perfomance problem with ZFS prefetch caching [1]
Add statistics for ZFS prefetch (sysctl kstat.zfs.misc.zfetchstats)

Partial import of OpenSolaris onnv revision 10474:0e96dd3b905a

Reported by: jhell@dataix.net (private e-mail) [1]
Approved by: pjd, delphij (mentor)
Obtained from: OpenSolaris (Bug ID 6859997, 6868951)
MFC after: 3 days

Don't bottleneck on acquiring the stream locks - this avoids a massive
drop off in throughput with large numbers of simultaneous reads

MFC after: 7 days

pjd has requested that I keep the tunable as zfs_prefetch_disable to minimize gratuitous
differences with Opensolaris' ZFS

Sorry for the churn

check against prefetch_enable

use default policy for enabling prefetching unless the TUNABLE is set

As far as I can tell systems that have less than 4GB are more often hurt
by prefetched than helped. On i386 systems and systems with less than 4GB,
prefetch is now disabled by default. I've added a prefetch enable tunable, to
enable prefetching for those systems. The prefetch disable tunable will continue
to unconditionally disable prefetching.

Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes.

This bring huge amount of changes, I'll enumerate only user-visible changes:

- Delegated Administration

Allows regular users to perform ZFS operations, like file system
creation, snapshot creation, etc.

- L2ARC

Level 2 cache for ZFS - allows to use additional disks for cache.
Huge performance improvements mostly for random read of mostly
static content.

- slog

Allow to use additional disks for ZFS Intent Log to speed up
operations like fsync(2).

- vfs.zfs.super_owner

Allows regular users to perform privileged operations on files stored
on ZFS file systems owned by him. Very careful with this one.

- chflags(2)

Not all the flags are supported. This still needs work.

- ZFSBoot

Support to boot off of ZFS pool. Not finished, AFAIK.

Submitted by: dfr

- Snapshot properties

- New failure modes

Before if write requested failed, system paniced. Now one
can select from one of three failure modes:
- panic - panic on write error
- wait - wait for disk to reappear
- continue - serve read requests if possible, block write requests

- Refquota, refreservation properties

Just quota and reservation properties, but don't count space consumed
by children file systems, clones and snapshots.

- Sparse volumes

ZVOLs that don't reserve space in the pool.

- External attributes

Compatible with extattr(2).

- NFSv4-ACLs

Not sure about the status, might not be complete yet.

Submitted by: trasz

- Creation-time properties

- Regression tests for zpool(8) command.

Obtained from: OpenSolaris

We want to use LBOLT instead of lbolt on FreeBSD.
I've this already fixed in p4, but the fix was never integrated into HEAD.

Reported by: ed

Forced commit to note that these files were repo copied.

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/)