Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Since there's no defined schema for the XML that's generated by the
kern.geom.confxml sysctl, it's silly to warn about tags in libgeom,
especially since libgeom exists simply to build a tree out of the conf
information.

Obtained from: Netflix
MFC after: 3 days

Back out r233646. Although it fixed most libgeom consumers under 32-bit
compatibility, it broke programs using devstat, under 32-bit compatibility and
not.

It's very difficult to fix the identifiers used by devstat, so this change is
simply being backed out. Since changes to 3rd-party code seem likely, and may be
necessary to properly fix 32-bit binaries on 64-bit kernel, it would seem better
to make more invasive changes to fix GEOM's problems with 32-bit compatibility in
general.

The right thing to do is to replace all of the use of pointers as opaque
identifiers with a fixed-size (64-bit or even 32-bit should be enough for tracking
unique GEOM elments) field. That probably maintains source compatibility with
most GEOM consumers, and allows xml2tree to make better assumptions about how to
decode the identifiers.

Submitted by: Anton Yuzhaninov

Fix 32-bit libgeom consumers run on 64-bit kernels with COMPAT_FREEBSD32.

Kernel pointer values are used as opaque unique identifiers, which are then
used to reconstruct references between various providers, classes, etc., inside
libgeom from the source XML. Unfortunately, they're converted to pointer-width
integers (in the form of pointers) to do this, and 32-bit userland pointers
cannot hold sensible representations (however opaque) of 64-bit kernel pointers
on all systems.

In the case where the leading bits are zero and 32 distinct bits of pointer can
be identified, this will happen to work. On systems where the upper 32-bits of
kernel pointers are non-zero and the same for all kernel pointers, this will
result in double frees and all kinds of bizarre crashes and linkage between
objects inside libgeom.

To mitigate this problem, treat the opaque identifiers in the XML as C strings
instead, and internalize them to give unique and consistent per-object pointer
values in userland for each identifier in the XML. This allows us to keep the
libgeom logic the same with only minor changes to initial setup and parsing.

It might be more sensible for speed reasons to treat the identifiers as numbers
of a large size (uintmax_t, say) rather than strings, but strings seem fine for
now.

(As an added side-effect, this makes it slightly easier to identify unresolved
references, but nothing has been added to inform the user of those.)

Expose stripe offset and stripe size through libgeom and geom(8) userland
utilities.

Reviewed by: pjd, mav (earlier version)

- Add a new ioctl for getting the provider name of a geom provider.
- Add a routine for looking up a device and checking if it is a valid geom
provider given a partial or full path to its device node.

Reviewed by: phk
Approved by: pjd (mentor)

Remove parameter names from prototypes to avoid namespace issues.

Implement and document some utility functions that can be used to communicate
with GEOM providers.

OK'ed by: phk

Make libgeom usable by C++ programs:
- Add DECL wrappers to libgeom.h.
- Rename structure members in libgeom.h to use a lg_ prefix for member
names. This is required because a few structures had members named
'class' which made g++ very unhappy.
- Catch gstat(8) and gconcat(8) up to these API changes.

Reviewed by: phk

Add the part of the last commit which cvs appearantly didn't like
the first time.

Collapse the meta arguments into normal arguments, trying to distinguish
just makes our own life harder.

Run a revision on the OAM api.

Use prefix gctl_ systematically.
Add flag with access perms for each argument.
Add ro/rw versions of argument building functions.
General cleanup.

Add marshalling functions for OAM api.

Use devstat instead of GEOM private statistics structure.

Constify arg to geom_lookupid().

Improve a diagnostic printf.

Leak more stuff into libgeom.

Include <sys/time.h>, it's not the users problem that we use bintime
internally.

Add libgeom to the system.

Initially this only contains the functions for accessing the I/O
statistics data.