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 r228259:
Support domain-search in dhclient(8)

The "domain-search" option (option 119) allows a DHCP server to publish
a list of implicit domain suffixes used during name lookup. This option
is described in RFC 3397.

For instance, if the domain-search option says:
".example.org .example.com"
and one wants to resolve "foobar", the resolver will try:
1. "foobar.example.org"
2. "foobar.example.com"

The file /etc/resolv.conf is updated with a "search" directive if the
DHCP server provides "domain-search".

A regression test suite is included in this patch under
tools/regression/sbin/dhclient.

PR: bin/151940
Sponsored by: Yakaz (http://www.yakaz.com)

MFC r229000:
Invalid Domain Search option isn't considered as a fatal error

In the original Domain Search option patch, an invalid option value
would cause the whole lease to be rejected. However, DHCP servers who
emit such an invalid value are more common than I thought. With this new
patch, just the option is rejected, not the entire lease.

PR: bin/163431
Submitted by: Fabian Keil <fk@fabiankeil.de> (earlier version)
Reviewed by: Fabian Keil <fk@fabiankeil.de>
Sponsored by: Yakaz (http://www.yakaz.com)

MFC r229001:
Adapt testsuite following change in Domain Search error handling

In this testsuite, warning() and error() have the same behaviour.

PR: bin/163431
Sponsored by: Yakaz (http://www.yakaz.com)

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

Approved by: re (implicit)

Revise r197763 which fixes filesystem corruption when extending
into un-zeroed storage.

The original patch was questioned by Kirk as it forces the filesystem
to do excessive work initialising inodes on first use, and was never
MFC'd. This change mimics the newfs(8) approach of zeroing two
blocks of inodes for each new cylinder group.

Reviewed by: mckusick
MFC after: 3 weeks