Remove useless getpwnam() call.

Submitted by:	Arthur Mesh <amesh@juniper.net>
MFC after:	1 week
In the "Too many open files" edge cases don't try to preserve old
number for non-std* descriptors, but close old file and retry.

Obtained from:  inspired by Apple's change from pfg@
MFC after:      2 weeks
Make sysctls under vfs.zfs.zfetch writeable.

I don't see any reason for them to be read-only, while tuning them without
reboot is much more convenient for experiments.

MFC after:	2 weeks
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 after:	2 weeks
Fix obvious off by one error: prefix[1] should be set to the path of the
newcons specific keymap files, not prefix[2]. The result of this bug was
that kbdcontrol ignored the files in the syscons keymap directory, which
apparently still work under newcons, for most locales.

MFC after:	1 week
The previous commit (r269119) introduced a regression: It removed the
ability to specify the the full path name of the keymap file.

Instead leave the original search order intact, but insert the path for
newcons-specific fonts (if run on a system using newcons):

	- KEYMAP_PATH in environment
	- full path name
	- /usr/share/vt/keymaps		(only if newcons is in use!)
	- /usr/share/syscons/keymaps	(also as fall-back for newcons)

MFC after:	1 week
Fix infinite loop, when doing WRITE SAME on file-backed LUN.

MFC after:	3 days
Implement separate I/O dispatch method for ZVOLs in "dev" mode.

Unlike disk devices ZVOLs process all requests synchronously.  That makes
impossible sending multiple requests to them from single thread.  From the
other side ZVOLs have real d_read/d_write methods, which unlike d_strategy
can handle uio scatter/gather and have no strict I/O size limitations.

So, if ZVOL in "dev" mode is detected, use of d_read/d_write methods instead
of d_strategy allows to avoid pointless splitting of large requests into
MAXPHYS (128K) sized chunks.

MFC after:	1 week
strftime() xlocale cleanups.

Replace fprintf_l with fputs when output is unformatted.
Use locale_t in _conv() since it was using sprintf (now sprintf_l)
Use locale_t on _yconv() sinci it calls _conv()

Obtained from:	Apple Inc. (Libc 997.90.3)
CR:		D482
Reviewed by:	theraven
MFC after:	1 week
In r232153, libarchive 3.0.3 was imported, replacing the archive_hash.h
header with archive_crypto_private.h, and its ARCHIVE_HASH_xxx macros
were renamed to ARCHIVE_CRYPTO_xxx.

Rename these macros in lib/libarchive/config_freebsd.h, to re-enable the
hashes for libarchive again.  This affects the mtree format writer, and
the xar format reader and writer modules.

This also requires changes in the library order for statically linking
rescue, otherwise ld would complain about redefined symbols.  Thanks to
jkim for pointing out the solution.

Reviewed by:	kientzle
MFC after:	1 week
Don't return ERESTART when the device is gone. In ttydev_leave() ERESTART
is the indication that draining got interrupted due to a revoke(2) and
that tty_drain() is to be called again for draining to complete. If the
device is flagged as gone, then waiting/draining is not possible. Only
return ERESTART when waiting is still possible.

Obtained from:	Juniper Networks, Inc.
Fix for division by zero.

MFC after:	3 days
Create 32-bit core files for 32-bit processes on 64-bit machines.
The 64-bit machine supported right now is amd64, but it's not too
hard to add powerpc64.

Obtained from:	Juniper Networks, Inc.
Fix relocations related to dpcpu and vnet sets. The address is
rebased to point to the allocated memory, but for architectures
that have non-zero relocation addends, the address comparison
happens on the "unfinalized" address.
After the addend is taken into account, call elf_relocaddr() to
make sure we rebase properly.
Avoid using ${.CURDIR} so that the module can be built from multiple
directories.

Obtained from:	Juniper Networks, Inc.
Do not fail the low-level device probe simply because the kernel
doesn't have support for the Z8530. Embedded PowerPC platforms
typically don't. Fail when the device class we actually need is
not present.

Obtained from:	Juniper Networks, Inc.
Remove bogus module dependencies.
Build tsec(4) as a module.

Obtained from:	Juniper Networks, Inc.
When unwiring a region of an address space, do not assume that the
underlying physical pages are mapped by the pmap.  If, for example, the
application has performed an mprotect(..., PROT_NONE) on any part of the
wired region, then those pages will no longer be mapped by the pmap.
So, using the pmap to lookup the wired pages in order to unwire them
doesn't always work, and when it doesn't work wired pages are leaked.

To avoid the leak, introduce and use a new function vm_object_unwire()
that locates the wired pages by traversing the object and its backing
objects.

At the same time, switch from using pmap_change_wiring() to the recently
introduced function pmap_unwire() for unwiring the region's mappings.
pmap_unwire() is faster, because it operates a range of virtual addresses
rather than a single virtual page at a time.  Moreover, by operating on
a range, it is superpage friendly.  It doesn't waste time performing
unnecessary demotions.

Reported by:	markj
Reviewed by:	kib
Tested by:	pho, jmg (arm)
Sponsored by:	EMC / Isilon Storage Division
Remove completely bogus alignment check -- it's the physical address that
needs to be aligned, not the virtual, and it doesn't seem worth the cost
of a vtophys() call just to see if kmem_alloc_contig() works properly.