Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r225773, r225781, r225782, r225783, r225784, 225785, r225786, r225787,
r225830, r225831, r225832, r225835, r226461, r226462, r226463, r226842,
r226851, r226852, r226854, r226855, r226856, r226857, r226859, r226861,
r228542, r228542, r228543, r228544, r228695, r228696:

r225773 (pjd):

Ensure that pjdlog functions don't modify errno.

r225781 (pjd):

No need to use KEEP_ERRNO() macro around pjdlog functions, as they don't
modify errno.

r225782 (pjd):

Prefer PJDLOG_ASSERT() and PJDLOG_ABORT() over assert() and abort().
pjdlog versions will log problem to syslog when application is running in
background.

r225783 (pjd):

Correct two mistakes when converting asserts to PJDLOG_ASSERT()/PJDLOG_ABORT().

r225784 (pjd):

- Convert some impossible conditions into assertions.
- Add missing 'if' in comment.

r225785 (pjd):

Prefer PJDLOG_ASSERT()/PJDLOG_ABORT() over assert().

r225786 (pjd):

No need to wrap pjdlog functions around with KEEP_ERRNO() macro.

r225787 (pjd):

Use PJDLOG_ASSERT() and PJDLOG_ABORT() everywhere instead of assert().

r225830 (pjd):

After every activemap change flush disk's write cache, so that write
reordering won't make the actual write to be committed before marking
the coresponding extent as dirty.

It can be disabled in configuration file.

If BIO_FLUSH is not supported by the underlying file system we log a warning
and never send BIO_FLUSH again to that GEOM provider.

r225831 (pjd):

Break a bit earlier.

r225832 (pjd):

If the underlying provider doesn't support BIO_FLUSH, log it only once
and don't bother trying in the future.

r225835 (pjd):

Correct typo.

r226461 (pjd):

When path to the configuration file is relative, obtain full path,
so we can always find the file, even after daemonizing and changing
working directory to /.

r226462 (pjd):

Remove redundant space.

r226463 (pjd):

Allow to specify pidfile in HAST configuration file.

r226842 (pjd):

Correct comments.

r226851 (pjd):

Delay resuid generation until first connection to secondary, not until first
write. This way on first connection we will synchronize only the extents that
were modified during the lifetime of primary node, not entire GEOM provider.

r226852 (pjd):

Minor cleanups.

r226854 (pjd):

- Eliminate the need for hio_nv.
- Introduce hio_clear() function for clearing hio before returning it
onto free queue.

r226855 (pjd):

Improve comment so it doesn't suggest race is possible, but that we handle
the race.

r226856 (pjd):

Reduce indentation.

r226857 (pjd):

Minor cleanups.

r226859 (pjd):

Implement 'async' mode for HAST.

r226861 (pjd):

Remove redundant space.

r228542 (pjd):

Remove redundant setting of the error variable.

Found by: Clang Static Analyzer

r228543 (pjd):

Simplify code by changing functions types from int to avoid, as the functions
always return 0.

Found by: Clang Static Analyzer

r228544 (pjd):

Remove redundant assignment.

Found by: Clang Static Analyzer

r228695 (pjd):

Don't use function name as format string.

Detected by: clang

r228696 (pjd):

Use lex's standard way of not generating unused function.

Inspired by: r228555

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

- Add support for AF_INET6 sockets for %S format character.
- Use inet_ntop(3) instead of reimplementing it.
- Use %hhu for unsigned char instead of casting it to unsigned int and
using %u.

MFC after: 1 week

Unbreak the build.

MFC after: 2 weeks

- Turn on printf extentions.
- Load support for %T for pritning time.
- Add support for %N for printing number in human readable form.
- Add support for %S for printing sockaddr structure (currently only AF_INET
family is supported, as this is all we need in HAST).
- Disable gcc compile-time format checking as this will no longer work.

MFC after: 2 weeks

Provides three states for pjdlog_initialized, so we can also tell that
this is fist initialization ever.

MFC after: 2 weeks

Rename pjdlog_verify() to pjdlog_abort() as it better describes what the
the function does and mark it with __dead2.

MFC after: 1 week

Initialize all global variables on pjdlog_init().

MFC after: 1 week

Extend pjdlog_verify() to support the following additional macros:
PJDLOG_RVERIFY() - always check expression and on false log the given message
and exit.
PJDLOG_RASSERT() - check expression when NDEBUG is not defined and on false log
given message and exit.
PJDLOG_ABORT() - log the given message and exit.

MFC after: 1 week

Add functions to initialize/finalize pjdlog. This allows to open/close log
file at will.

MFC after: 1 week

Use my copyright for 2011 work.

MFC after: 1 week

Add LOG_NDELAY flag to openlog(3) - we want descriptor to be immediately open
so there are no surprises once we start chrooting or using capsicum.

MFC after: 1 week

- Remove obvious NOTREACHED comment after abort() call.
- Remove redundant newline at the end of the file.

MFC after: 1 week

Use more consistent function name with the others (pjdlogv_prefix_set()
instead of pjdlog_prefix_setv()).

MFC after: 1 week

Use one fprintf() instead of two.

MFC after: 3 days

Include process PID in log messages.

Submitted by: Mikolaj Golub <to.my.trociny@gmail.com>
MFC after: 2 weeks

When logging to stdout/stderr, flush after each log.

MFC after: 2 weeks
Obtained from: Wheel Systems Sp. z o.o. http://www.wheelsystems.com

Problem with assertion is that it logs on stderr. Add two macros:
PJDLOG_ASSERT() and PJDLOG_VERIFY() that will check the given condition
and log the problem where appropriate. The difference between those
two is that PJDLOG_VERIFY() always work and PJDLOG_ASSERT() can be
turned off by defining NDEBUG.

MFC after: 1 month

Keep $FreeBSD$ in __FBSDID() only for C files.

MFC after: 1 month

Mark two more places that we won't reach.

MFC after: 1 month

Fix log size calculation which caused message truncation.

Submitted by: Mikolaj Golub <to.my.trociny@gmail.com>
MFC after: 3 days

Please welcome HAST - Highly Avalable Storage.

HAST allows to transparently store data on two physically separated machines
connected over the TCP/IP network. HAST works in Primary-Secondary
(Master-Backup, Master-Slave) configuration, which means that only one of the
cluster nodes can be active at any given time. Only Primary node is able to
handle I/O requests to HAST-managed devices. Currently HAST is limited to two
cluster nodes in total.

HAST operates on block level - it provides disk-like devices in /dev/hast/
directory for use by file systems and/or applications. Working on block level
makes it transparent for file systems and applications. There in no difference
between using HAST-provided device and raw disk, partition, etc. All of them
are just regular GEOM providers in FreeBSD.

For more information please consult hastd(8), hastctl(8) and hast.conf(5)
manual pages, as well as http://wiki.FreeBSD.org/HAST.

Sponsored by: FreeBSD Foundation
Sponsored by: OMCnet Internet Service GmbH
Sponsored by: TransIP BV