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 r261892: zpool.8: fix typo in option description of labelclear command

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 r269100:

Diff reduction against Illumos.

MFC r268621 (smh) + r268625:

Don't report non-native block-size pools under zpool status -x

zpool status -x is used to identify pools that are exhibiting
errors or are otherwise unavailable, therefore non-native
block-size pools shouldn't be reported.

Also update man page to clarify other additional conditions
which won't cause a pool to be displayed under zpool status -x.

Sponsored by: Multiplay

MFC the cddl/contrib/opensolaris/cmd/zpool portion of r267803 (joel):

mdoc: remove superfluous paragraph macros.

MFC r263889 (MFV r263887):

3993 zpool(1M) and zfs(1M) should support -p for "list" and "get"
4700 "zpool get" doesn't support -H or -o options

MFC r263459: MFV 263436-263438:

3947 zpool(1M) references nonexistent zfs-features(5)
4540 zpool(1M) man page doesn't describe "readonly" property
3948 zfs sync=default is not accepted
4611 zfs(1M) still mentions 'send -r' in synopsis
4415 zpool(1M) man page missing "import -m" description
4570 Document dedupditto pool property
4572 Dedup-related documentation additions for zpool and zdb.
1371 Add -D option description to zpool(1M) manpage
4571 Add documentation for -T and interval to "zpool list"

MFC r260138: MFV r242733:

3306 zdb should be able to issue reads in parallel
3321 'zpool reopen' command should be documented in the man page
and help message

illumos/illumos-gate@31d7e8fa33fae995f558673adb22641b5aa8b6e1

FreeBSD porting notes: the kernel part of this changeset depends
on Solaris buf(9S) interfaces and are not really applicable for
our use. vdev_disk.c is patched as-is to reduce diverge from
upstream, but vdev_file.c is left intact.

MFC r261774 by feld:

Add caveat to zpool manpage indicating that we do not automatically activate
hot spares. This should be MFC'd to all STABLE branches.

Upon the availability of zfsd, the zpool manpage on relevant branches should
be updated to remove this caveat and document hot spare's reliance on zfsd.

Requested by: feld

MFC r261892: zpool.8: fix typo in option description of labelclear command

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 r269100:

Diff reduction against Illumos.

MFC r268621 (smh) + r268625:

Don't report non-native block-size pools under zpool status -x

zpool status -x is used to identify pools that are exhibiting
errors or are otherwise unavailable, therefore non-native
block-size pools shouldn't be reported.

Also update man page to clarify other additional conditions
which won't cause a pool to be displayed under zpool status -x.

Sponsored by: Multiplay

MFC the cddl/contrib/opensolaris/cmd/zpool portion of r267803 (joel):

mdoc: remove superfluous paragraph macros.

MFC r263889 (MFV r263887):

3993 zpool(1M) and zfs(1M) should support -p for "list" and "get"
4700 "zpool get" doesn't support -H or -o options

MFC r263459: MFV 263436-263438:

3947 zpool(1M) references nonexistent zfs-features(5)
4540 zpool(1M) man page doesn't describe "readonly" property
3948 zfs sync=default is not accepted
4611 zfs(1M) still mentions 'send -r' in synopsis
4415 zpool(1M) man page missing "import -m" description
4570 Document dedupditto pool property
4572 Dedup-related documentation additions for zpool and zdb.
1371 Add -D option description to zpool(1M) manpage
4571 Add documentation for -T and interval to "zpool list"

MFC r260138: MFV r242733:

3306 zdb should be able to issue reads in parallel
3321 'zpool reopen' command should be documented in the man page
and help message

illumos/illumos-gate@31d7e8fa33fae995f558673adb22641b5aa8b6e1

FreeBSD porting notes: the kernel part of this changeset depends
on Solaris buf(9S) interfaces and are not really applicable for
our use. vdev_disk.c is patched as-is to reduce diverge from
upstream, but vdev_file.c is left intact.

MFC r261774 by feld:

Add caveat to zpool manpage indicating that we do not automatically activate
hot spares. This should be MFC'd to all STABLE branches.

Upon the availability of zfsd, the zpool manpage on relevant branches should
be updated to remove this caveat and document hot spare's reliance on zfsd.

Requested by: feld