Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-3-Clause-FreeBSD identifier never was, drop -FreeBSD

There never was a BSD-3-Clause-FreeBSD SPDX identifier. Replace it
with BSD-3-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

GEOM: Introduce partial confxml API

Traditionally the GEOM's primary channel of information from kernel to
user-space was confxml, fetched by libgeom through kern.geom.confxml
sysctl. It is convenient and informative, representing full state of
GEOM in a single XML document. But problems start to arise on systems
with hundreds of disks, where the full confxml size reaches many
megabytes, taking significant time to first write it and then parse.

This patch introduces alternative solution, allowing to fetch much
smaller XML document, subset of the full confxml, limited to 64KB and
representing only one specified geom and optionally its parents. It
uses existing GEOM control interface, extended with new "getxml" verb.
In case of any error, such as the buffer overflow, it just transparently
falls back to traditional full confxml. This patch uses the new API in
user-space GEOM tools where it is possible.

Reviewed by: imp
MFC after: 2 month
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D34529

[skip ci] correct a few SPDX license tags

These were all incorrectly labeled as 2-clause BSD licenses by a
semi-automated process, when in fact they are 3-clause.

Discussed with: pfg, imp
MFC after: 2 weeks
Sponsored by: Axcient

lib: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Systems with lots of geom providers can end up with a kern.geom.confxml
value too large for the buffer allocated. Work around this by retrying
a few times with larger buffer sizes.

Submitted by: Scott Ferris <scott.ferris@isilon.com>
Reviewed by: mlaier, ngie
Sponsored by: EMC Isilon Storage Division

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

Add missing `void' keyword.

- Import the HEAD csup code which is the basis for the cvsmode work.

- Simplify the procedure of retrieving XML-data from the kernel.
- Fix a number of potential memory leaks in libgeom related to doing realloc
without freeing old pointer if things go wrong.
- Fix a number of places in libgeom where malloc and calloc return values
were not checked.
- Check malloc return value and provide sufficient warning messages when XML
parsing fails.

PR: kern/83464
Submitted by: Dan Lukes <dan - at - obluda.cz>
Approved by: kib (mentor)

Second call of sysctl() is used to gather a proper size of a memory chunk
needed to hold the GEOM tree. At this point, pointer 'p' has an improper
value (as it was used previously), and we're getting EFAULT. Fix this
functionality by passing NULL instead of 'p'.

This fixes mdconfig(8) -l output with high number of md(4) devices.

Found by: kris
Reviewed by: phk

Leak more stuff into libgeom.