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

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

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

Approved by: re (implicit)

- Simplify code by using g_*() API.
- Don't use u_char and u_int in userland.
- Change 'unsigned' to 'unsigned int'.
- Update copyright years.

MFC after: 1 week

Check for overflow before it occurs. Also add check for
negative numbers.

Suggested by: ache
Approved by: kib (mentor)

Remove G_TYPE_ASCLBA type and replace it with G_TYPE_STRING in gpart.
Move code that converts params from humanized numbers to sectors count
to subr.c and adjust comment.
Add post-processing for "size" and "start offset" params in gpart,
now they are properly converted to sectors count with known sector size
that can be greater that 512 bytes.
Also replace "unsigned long long" type to "off_t" for unify code since
it used for medium size in libgeom(3) and DIOCGMEDIASIZE ioctl.

PR: bin/146277
Reviewed by: marcel (previous version)
Approved by: kib (mentor)
MFC after: 1 month

bgeom(3) does strdup of param name.
Don't leak memory when deleting param from gctl_req.

Reviewed by: marcel
Approved by: mav (mentor)
MFC after: 2 weeks

Flush disk write cache after storing and clearing metadata.

- Back out r186038. Rather than changing the intent of the caller, the problem
should be handled internally in gvinum.

Suggested by: pjd

- When writing metadata to a geom provider, open the it as read-write since it
might do subsequent reads from other providers. This stopped geli (and
probably other classes using g_metadata_store as well) from being put on top
of gvinum raid5 volumes.

Note:
The reason it fails in the gvinum raid5 case is that gvinum will read back the
old parity stripe before calculating the new parity stripe to be written out
again. The write will then fail because the underlying disk to be read is
opened write only.

MFC after: 1 week

Add two support functions:
o gctl_delete_param() -- intended for parameters that are consumed
by geom(8) itself and which should not be passed to the kernel.
o gctl_has_param() -- intended to check if optional parameters are
present.

Both are needed by gpart(8) to process the optional parameter for
writing bootcode to a partition (as part of the bootcode verb).
However, the kernel is itself not involved in this matter and the
parameter needs to be removed from the request destined for the
kernel.

Implement gctl_change_param() function, which changes value of existing
parameter.

MFC after: 1 week

Add __printflike() attribute to various functions.

Remove trailing spaces.

- The geom(8) utility only uses three types of arguments: string (char *),
value (intmax_t) and boolean (int).
Based on that provide three functions:
- gctl_get_ascii()
- gctl_get_int()
- gctl_get_intmax()
- Hide gctl_get_param() function, as it is only used internally in
subr.c.
- Allow to provide argument name as (fmt, ...).
- Assert geom(8) bugs (missing argument is a geom(8) bug).

- Clean-up and simplify the code by using new functions and assumtions
(no more checking for missing argument).

Tested by: regression tests

Move function for calculating number of bits into more central place.
I want to use it so more.

MFC after: 3 days

MFp4: gmirror(8) is coming soon, and we need g_metadata_read() there.

Implement 3 new functions:
- g_lcm() - calculates Least Common Multiple of two given values,
it is helpful when we need to find sector size for provider
which is based on disks with different sector size;
- g_get_mediasize() - returns media size of given provider;
- g_get_sectorsize() - returns sector size of given provider;
Those function aren't used now, but are used by geom_mirror which will be
committed soon.

Bring in geom(8) utility. It is an universal utility for operating on
GEOM classes. It works by loading a shared library via dlopen(3) mechanism
with class-specific code, it is also responsible for communicating with
GEOM via libgeom(3).
Per-class shared libraries are going to be stored in /lib/geom/ directory.
It provides also few standard commands like 'list', 'load' and 'unload'
for existing classes which aren't aware of geom(8).
More info will be send on freebsd-current@ mailing list.

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