MFC r332426: allow ZFS pool to have temporary name for duration of current import

The change adds -t <name> option to zpool create and -t option to zpool
import in its form with an old name and a new name. This allows to
import (or create) a pool under a name that's different from its real,
permanent name without affecting that name. This is useful when working
with VM images or images of other physical systems if they happen to
have a ZFS pool with the same name as the host system.

Sponsored by: Panzura (porting)

MFC r308089: zfsbootcfg: a simple tool to set next boot (one time)
options for zfsboot

There is a branch-specific change in sbin/zfsbootcfg/Makefile because of
LIBADD vs LDADD/DPADD.

MFC r305331: MFV r304155:
7090 zfs should improve allocation order and throttle allocations

illumos/illumos-gate@0f7643c7376dd69a08acbfc9d1d7d548b10c846a
https://github.com/illumos/illumos-gate/commit/0f7643c7376dd69a08acbfc9d1d7d548b
10c846a

https://www.illumos.org/issues/7090
When write I/Os are issued, they are issued in block order but the ZIO pipelin
e
will drive them asynchronously through the allocation stage which can result i
n
blocks being allocated out-of-order. It would be nice to preserve as much of
the logical order as possible.
In addition, the allocations are equally scattered across all top-level VDEVs
but not all top-level VDEVs are created equally. The pipeline should be able t
o
detect devices that are more capable of handling allocations and should
allocate more blocks to those devices. This allows for dynamic allocation
distribution when devices are imbalanced as fuller devices will tend to be
slower than empty devices.
The change includes a new pool-wide allocation queue which would throttle and
order allocations in the ZIO pipeline. The queue would be ordered by issued
time and offset and would provide an initial amount of allocation of work to
each top-level vdev. The allocation logic utilizes a reservation system to
reserve allocations that will be performed by the allocator. Once an allocatio
n
is successfully completed it's scheduled on a given top-level vdev. Each top-
level vdev maintains a maximum number of allocations that it can handle
(mg_alloc_queue_depth). The pool-wide reserved allocations (top-levels *
mg_alloc_queue_depth) are distributed across the top-level vdevs metaslab
groups and round robin across all eligible metaslab groups to distribute the
work. As top-levels complete their work, they receive additional work from the
pool-wide allocation queue until the allocation queue is emptied.

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: George Wilson <george.wilson@delphix.com>

MFC r305222: MFV r302993: 7104 increase indirect block size

illumos/illumos-gate@4b5c8e93cab28d3c65ba9d407fd8f46e3be1db1c
https://github.com/illumos/illumos-gate/commit/4b5c8e93cab28d3c65ba9d407fd8f46e3
be1db1c

https://www.illumos.org/issues/7104
The current default indirect block size is 16KB. We can improve
performance by increasing it to 128KB. This is especially helpful for
any workload that needs to read most of the metadata, e.g.
scrub/resilver, file deletion, filesystem deletion, and zfs send.
We also need to fix a few space estimation errors to make the tests
pass.

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>

MFC r305209: MFV r302660: 6314 buffer overflow in dsl_dataset_name

illumos/illumos-gate@9adfa60d484ce2435f5af77cc99dcd4e692b6660
https://github.com/illumos/illumos-gate/commit/9adfa60d484ce2435f5af77cc99dcd4e6
92b6660

https://www.illumos.org/issues/6314
Callers of dsl_dataset_name pass a buffer of size ZFS_MAXNAMELEN, but
dsl_dataset_name copies the datasets' name PLUS the snapshot name to it,
resulting in a max of 2 * ZFS_MAXNAMELEN + '@'.

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Matthew Ahrens <mahrens@delphix.com>

MFC r298472: MFV r298471: 6052 decouple lzc_create() from the
implementation details

MFC r297763: MFV r297760: 6418 zpool should have a label clearing command

Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Author: Will Andrews <will@firepipe.net>

Closes #83
Closes #32

openzfs/openzfs@9663688425131744221ea99f9e66b9ed964492ae

FreeBSD already had `zpool labelclear` functionality, so this is mostly
just a diff reduction.

MFC r296519: MFV r296518: 5027 zfs large block support (add copyright)

Author: Matthew Ahrens <matt@mahrens.org>

illumos/illumos-gate@c3d26abc9ee97b4f60233556aadeb57e0bd30bb9

MFC r289362, r289445: 2605 want to resume interrupted zfs send

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Reviewed by: Arne Jansen <sensille@gmx.net>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@9c3fd1216fa7fb02cfbc78a2518a686d54b48ab8

For more info, see:
- slides http://www.slideshare.net/MatthewAhrens/openzfs-send-and-receive
- video https://www.youtube.com/watch?v=iY44jPMvxog
- manpage changes (for zfs resume -s and zfs send -t)
- upcoming talk at the OpenZFS Developer Summit

The TL;DR is:
Use "zfs receive -s" to save the partially received state on failure.
On failure, get the receive token with "zfs get receive_resume_token <fs>"
Resume the send with "zfs send -t <token_value>"

Relnotes: yes

MFC r274337,r274673,274681,r275515:

ZFS large block support. The default recordsize remains at 128KB.

A new tunable/sysctl variable, vfs.zfs.max_recordsize is added to
allow adjusting the permitted maximum record size, or
zfs_max_recordsize, with a default of 1MB. ZFS will not allow
setting recordsize greater than zfs_max_recordsize as a safety
belt, because larger recordsize means greater read and write
latency and more memory usage.

Please note that booting from datasets that have recordsize greater
than 128KB is not supported (but it's Okay to enable the feature on
the pool).

Limited safety belt is provided for mounted root filesystem but use
caution when using a larger value.

Illumos issue:
5027 zfs large block support

MFC r269118: MFV r269010:

Import Illumos changes to address the following Illumos issues:
4976 zfs should only avoid writing to a failing non-redundant
top-level vdev
4978 ztest fails in get_metaslab_refcount()
4979 extend free space histogram to device and pool
4980 metaslabs should have a fragmentation metric
4981 remove fragmented ops vector from block allocator
4982 space_map object should proactively upgrade when feature
is enabled
4984 device selection should use fragmentation metric

MFC r268128: MFV r268122:

4929 want prevsnap property

MFC r268079: MFV r267566:

4390 i/o errors when deleting filesystem/zvol can lead to space map
corruption

MFC r266771: MFV r266766:

Add a new zfs property, "redundant_metadata" which can have values "all" or
"most". The default will be "all", which is the current behavior. When set
to all, ZFS stores an extra copy of all metadata. If a single on-disk block
is corrupt, at worst a single block of user data (which is recordsize bytes
long) can be lost.

Setting to "most" will cause us to only store 1 copy of level-1 indirect
blocks of user data files. This can improve performance of random writes,
because less metadata has to be written. In practice, at worst about
100 blocks (of recordsize bytes each) of user data can be lost if a single
on-disk block is corrupt.

The exact behavior of which metadata blocks are stored redundantly may change
in future releases.

Illumos issue: 3835 zfs need not store 2 copies of all metadata

MFC r264835 (MFV r264829):

3897 zfs filesystem and snapshot limits

MFC r264145:
Add property and sysctl to control how ZVOLs are exposed to OS.

New ZFS property volmode and sysctl vfs.zfs.vol.mode allow switching ZVOL
between three modes:
geom -- existing fully functional behavior (default);
dev -- exposing volumes only as raw disk device file in devfs;
none -- not exposing volumes outside ZFS.

The "dev" mode is less functional (can't be partitioned, mounted, etc),
but it is faster, and in some scenarios with untrusted consumers safer.
It can be useful for NAS, VM block storages, etc.
The "none" mode may be convenient for backup servers, etc. that don't
need direct data access.

Due to the way ZVOL is integrated with main ZFS code, those property
and sysctl are checked only during pool import and volume creation.

MFC r260183: MFV r260154 + 260182:

4369 implement zfs bookmarks
4368 zfs send filesystems from readonly pools

Illumos/illumos-gate@78f171005391b928aaf1642b3206c534ed644332

MFC r274337,r274673,274681,r275515:

ZFS large block support. The default recordsize remains at 128KB.

A new tunable/sysctl variable, vfs.zfs.max_recordsize is added to
allow adjusting the permitted maximum record size, or
zfs_max_recordsize, with a default of 1MB. ZFS will not allow
setting recordsize greater than zfs_max_recordsize as a safety
belt, because larger recordsize means greater read and write
latency and more memory usage.

Please note that booting from datasets that have recordsize greater
than 128KB is not supported (but it's Okay to enable the feature on
the pool).

Limited safety belt is provided for mounted root filesystem but use
caution when using a larger value.

Illumos issue:
5027 zfs large block support

MFC r269118: MFV r269010:

Import Illumos changes to address the following Illumos issues:
4976 zfs should only avoid writing to a failing non-redundant
top-level vdev
4978 ztest fails in get_metaslab_refcount()
4979 extend free space histogram to device and pool
4980 metaslabs should have a fragmentation metric
4981 remove fragmented ops vector from block allocator
4982 space_map object should proactively upgrade when feature
is enabled
4984 device selection should use fragmentation metric

MFC r268128: MFV r268122:

4929 want prevsnap property

MFC r268079: MFV r267566:

4390 i/o errors when deleting filesystem/zvol can lead to space map
corruption

MFC r266771: MFV r266766:

Add a new zfs property, "redundant_metadata" which can have values "all" or
"most". The default will be "all", which is the current behavior. When set
to all, ZFS stores an extra copy of all metadata. If a single on-disk block
is corrupt, at worst a single block of user data (which is recordsize bytes
long) can be lost.

Setting to "most" will cause us to only store 1 copy of level-1 indirect
blocks of user data files. This can improve performance of random writes,
because less metadata has to be written. In practice, at worst about
100 blocks (of recordsize bytes each) of user data can be lost if a single
on-disk block is corrupt.

The exact behavior of which metadata blocks are stored redundantly may change
in future releases.

Illumos issue: 3835 zfs need not store 2 copies of all metadata

MFC r264835 (MFV r264829):

3897 zfs filesystem and snapshot limits

MFC r264145:
Add property and sysctl to control how ZVOLs are exposed to OS.

New ZFS property volmode and sysctl vfs.zfs.vol.mode allow switching ZVOL
between three modes:
geom -- existing fully functional behavior (default);
dev -- exposing volumes only as raw disk device file in devfs;
none -- not exposing volumes outside ZFS.

The "dev" mode is less functional (can't be partitioned, mounted, etc),
but it is faster, and in some scenarios with untrusted consumers safer.
It can be useful for NAS, VM block storages, etc.
The "none" mode may be convenient for backup servers, etc. that don't
need direct data access.

Due to the way ZVOL is integrated with main ZFS code, those property
and sysctl are checked only during pool import and volume creation.

MFC r260183: MFV r260154 + 260182:

4369 implement zfs bookmarks
4368 zfs send filesystems from readonly pools

Illumos/illumos-gate@78f171005391b928aaf1642b3206c534ed644332