sh: Fix LINENO and prompt after $'\0 and newline.
Refactor ZFS ARC reclaim checks and limits

Remove previously added kmem methods in favour of defines which
allow diff minimisation between upstream code base.

Rebalance ARC free target to be vm_pageout_wakeup_thresh by default
which eliminates issue where ARC gets minimised instead of balancing
with VM pageout. The restores the target point prior to r270759.

Bring in missing upstream only changes which move unused code to
further eliminate code differences.

Add additional DTRACE probe to aid monitoring of ARC behaviour.

Enable upstream i386 code paths on platforms which don't define
UMA_MD_SMALL_ALLOC.

Fix mixture of byte an page values in arc_memory_throttle i386 code
path value assignment of available_memory.

PR:		187594
Review:		D702
Reviewed by:	avg
MFC after:	1 week
X-MFC-With:	r270759 & r270861
Sponsored by:	Multiplay
Add dependencies to various libraries to libzfs and libzpool.

Submitted by:	sef
Add mkimg_chs() for those schemes that need the LBA broken down into
cylinder, head and track numbers. Return ~0U for these values when
mkimg wasn't given both -T and -H (i.e. no geometry) or the cylinder
would be larger than the provided maximum.

Use mkimgs_chs() for the EBR, MBR and PC98 schemes to fill in the
appropriate fields. Make sure to use a "rounded" size so that the
partition is always a multiple of the track size. We reserved the
room for it in the metadata callback so that's a valid thing to
do.

Bump the mkimg version number.
While doing that again: have mkimg.o depend on the Makefile so that
a version change triggers a rebuild as needed.
Update baseline files for EBR, MBR and PC98 now that mkimg fills in
the CHS fields appropriately when -T and -H are given on the command
line.
Add GUID of FreeBSD slice to GPT scheme.

MFC after:	1 week
Hook up support for userland CTF support in DTrace. This required some
modifications to libproc to support fetching the CTF info for a given file.

With this change, dtrace(1) is able to resolve type info for function and
USDT probe arguments, and function return values. In particular, the args[n]
syntax should now work for referencing arguments of userland probes,
provided that the requisite CTF info is available.

The uctf tests pass if the test programs are compiled with CTF info. The
current infrastructure around the DTrace test suite doesn't support this
yet.

Differential Revision:	https://reviews.freebsd.org/D891
MFC after:		1 month
Relnotes:		yes
Sponsored by:		EMC / Isilon Storage Division
Remove an incorrect and useless debug print.

X-MFC-With:	r272488
- MFi386: Add compile-with option for tau32-ddk.c.
- Whitespace change.
- Remove duplicate line.
Reduce diffs against i386.
Merge pc98's machdep.c into i386/i386/machdep.c.
MFV r272493:

Show individual disk capacity when doing zpool list -v.

Illumos issue:
    5147 zpool list -v should show individual disk capacity

MFC after:	1 week
Add sequence counters with memory barriers.

Current implementation is somewhat simplistic and hackish,
will be improved later after possible memory barrier overhaul.

Reviewed by:	kib
MFC after:	3 weeks
MFV r272494:

Make space_map_truncate() always do space_map_reallocate().  Without
this, setting space_map_max_blksz would cause panic for existing pool,
as dmu_objset_set_blocksize would fail if the object have multiple blocks.

Illumos issues:
   5164 space_map_max_blksz causes panic, does not work
   5165 zdb fails assertion when run on pool with recently-enabled
	spacemap_histogram feature

MFC after:	2 weeks
Plug capability races.

fp and appropriate capability lookups were not atomic, which could result in
improper capabilities being checked.

This could result either in protection bypass or in a spurious ENOTCAPABLE.

Make fp + capability check atomic with the help of sequence counters.

Reviewed by:	kib
MFC after:	3 weeks
MFV r272495:

In arc_kmem_reap_now(), reap range_seg_cache too to reclaim memory in
response of memory pressure.

Illumos issue:
    5163 arc should reap range_seg_cache

MFC after:	1 week
MFV r272496:

Add tunable for number of metaslabs per vdev
(vfs.zfs.vdev.metaslabs_per_vdev).  The default remains
at 200.

Illumos issue:
    5161 add tunable for number of metaslabs per vdev

MFC after:	2 weeks
Add in decode for the AR9300 RX descriptor.
Diff reduction with upstream.  The code change is not really applicable
to FreeBSD.

Illumos issue:
    5148 zvol's DKIOCFREE holds zfsdev_state_lock too long

MFC after:	1 month
Add a new sysctl, vfs.zfs.vol.unmap_enabled, which allows the system
administrator to toggle whether ZFS should ignore UNMAP requests.

Illumos issue:
    5149 zvols need a way to ignore DKIOCFREE

MFC after:	2 weeks