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 r246922 (pjd):

- Add support for 'memsync' mode. This is the fastest replication mode that's
why it will now be the default.
- Bump protocol version to 2 and add backward compatibility for version 1.
- Allow to specify hosts by kern.hostid as well (in addition to hostname and
kern.hostuuid) in configuration file.

Sponsored by: Panzura

MFC r229699, r229744, r229778, r229944, r229945, r229946, r230092, r230395,
r230396, r230436, r230457, r230515, r230976:

r229744 (pjd):

fork(2) returns -1 on failure, not some random negative number.

r229699 (pjd):

Constify argument.

r229778 (uqs):

Spelling fixes for sbin/

r229944 (pjd):

Don't touch pidfiles when running in foreground. Before that change we
would create an empty pidfile on start and check if it changed on SIGHUP.

r229945 (pjd):

For functions that return -1 on failure check exactly for -1 and not for
any negative number.

r229946 (pjd):

- Fix a bug where pidfile was removed in SIGHUP when it hasn't changed in
configuration file.
- Log the fact that pidfile has changed.

r230092 (pjd):

Style cleanups.

r230395 (pjd):

Remove unused token 'port'.

r230396 (pjd):

Remove another unused token.

r230436 (pjd):

Fix minor memory leak.

r230457 (pjd):

Free memory that won't be used in child.

r230515 (pjd):

- Fix documentation to note that /etc/hast.conf is the default configuration
file for hastd(8) and hastctl(8) and not hast.conf.
- In copyright statement correct that this file is documentation, not software.
- Bump date.

r230976 (pjd):

Fix typo in comment.

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 missing ifdef. This fixes build with NO_OPENSSL.

Reported by: Pawel Tyll <ptyll@nitronet.pl>
Approved by: pjd (mentor)
MFC after: 1 week

Remove hast_proto_recv(). It was used only in one place, where
hast_proto_recv_hdr() may be used. This also fixes the issue
(introduced by r220523) with hastctl, which crashed on assert in
hast_proto_recv_data().

Suggested and approved by: pjd (mentor)

In hast_proto_recv() remove unnecessary check. The size is checked
later in hast_proto_recv_data().

Approved by: pjd (mentor)
MFC after: 1 week

In hast_proto_recv_data() check that the size of the data to be
received does not exceed the buffer size.

Approved by: pjd (mentor)
MFC after: 1 week

Allow to compress on-the-wire data using two algorithms:
- HOLE - it simply turns all-zero blocks into few bytes header;
it is extremely fast, so it is turned on by default;
it is mostly intended to speed up initial synchronization
where we expect many zeros;
- LZF - very fast algorithm by Marc Alexander Lehmann, which shows
very decent compression ratio and has BSD license.

MFC after: 2 weeks

Allow to checksum on-the-wire data using either CRC32 or SHA256.

MFC after: 2 weeks

Constify arguments we can constify.

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

Eliminate dead code.

Found by: Coverity Prevent
CID: 5158
MFC after: 3 days

Fix compilation with WITHOUT_CRYPT or WITHOUT_OPENSSL options.

Reported by: Andrei V. Lavreniyuk <andy.lavr@reactor-xg.kiev.ua>
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