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 r245456:
Allow to insert new component to geom_raid3 without specifying number.

PR: kern/160562

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

Approved by: re (implicit)

Sector size can not be greater than MAXPHYS. Since GRAID3 calculates
sector size from user-specified block size, report to user about
big blocksize.

PR: kern/147851
MFC after: 1 week

Replace strlen(_PATH_DEV) with sizeof(_PATH_DEV) - 1.

Suggested by: kib
Approved by: kib (mentor)
MFC after: 5 days

- Remove gc_argname field. It was introduced for gpart(8), but if I
understand everything correctly, we don't really need it.
- Provide default numeric value as strings. This allows to simplify
a lot of code.
- Bump version number.

For completeness, add -s argument, manually specifying array block size.

Add gpart(8).

In order to support gpart(8), geom(8) needs to support a named
argument. Also, optional string parameters are a requirement.
Both have been added to the infrastructure. The former required
all existing classes to be adjusted.

Now, that we have gjournal in the tree add possibility to configure
gmirror and graid3 in a way that it is not resynchronized after a
power failure or system crash.
It is safe when gjournal is running on top of gmirror/graid3.

Be sure to not create devices with (mediasize % sectorsize) != 0.

Reported by: xride
MFC after: 1 week

Be sure to not create device which

MFp4: G_TYPE_BOOL sounds much better than G_TYPE_NONE.

Changes: 98722

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

Don't forget to initialize 'id' field.

MFC after: 3 days

Define subcommands' usage inside g_command structure.

MFC after: 1 week

- Add md_provsize field to metadata, which will help with
shared-last-sector problem.
After this change, even if there is more than one provider with the same
last sector, the proper one will be chosen based on its size.
It still doesn't fix the 'c' partition problem (when da0s1 can be confused
with da0s1c) and situation when 'a' partition starts at offset 0
(then da0s1a can be confused with da0s1 and da0s1c). One can use '-h'
option there, when creating device or avoid sharing last sector.
Actually, when providers share the same last sector and their size is equal,
they provide exactly the same data, so the name (da0s1, da0s1a, da0s1c)
isn't important at all.
- Provide backward compatibility.
- Update copyright's year.

MFC after: 1 week

Fix arguments syntax.

Manual pages fixes by: ru
MFC after: 3 days

- Add genid field to the metadata which will allow to improve reliability a bit.
After this change, when component is disconnected because of an I/O error,
it will not be connected and synchronized automatically, it will be logged
as broken and skipped. Autosynchronization can occur, when component is
disconnected (on orphan event) and connected again - there were no I/O
error, so there is no need to not connected the component, but when there were
writes while it wasn't connected, it will be synchronized.
This fix cases, when component is disconnected because of I/O error and can be
connected again and again.
- Bump version number.
- Implement backward compatibility mechanism. After this change when metadata in
old version is detected, it is automatically upgraded to the new (current)
version.

Do not exit after printing usage, give geom(8) a chance to show standard
commands.

When configuring RAID3 with verification option, force synchronization
of parity component, because we can't return an EIO error for read of
every sector which wasn't written first.

Discussed with: phk

Warn the user if we are not going to use whole provider space.

Requested by: Michael Handler <handler@grendel.net>

Implementation of 'verify reading' algorithm, which uses parity data for
verification of regular data when device is in complete state.
On verification error, EIO error is returned for the bio and sysctl
kern.geom.raid3.stat.parity_mismatch is increased.

Suggested by: phk

Implement new reading algorithm, which will use parity component for reading
as well, even if device is in complete state.
I observe 40% of speed-up with this option for random read operations,
but slowdown for sequential reads.
Basically, without this option reading from a RAID3 device built from 5
components (c0-c4) looks like this:

Request no. Used components
1 c0+c1+c2+c3
2 c0+c1+c2+c3
3 c0+c1+c2+c3

With the new feature:

Request no. Used components
1 c0+c1+c2+c3
2 (c1^c2^c3^c4)+c1+c2+c3
3 c0+(c0^c2^c3^c4)+c2+c3
4 c0+c1+(c0^c1^c3^c4)+c3
5 c0+c1+c2+(c0^c1^c2^c4)
6 c0+c1+c2+c3
[...]

Actually one can specify more than one device to stop.

Introduce GEOM RAID3 class, i.e. kernel module, which implements RAID3
transformation and graid3(8) userland utility, which can be used for
configuration. No manual page yet, sorry.

Hardware provided by: Daniel Seuffert