sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Pass BIO_SPEEDUP through all the geom layers

While some geom layers pass unknown commands down, not all do. For the ones that
don't, pass BIO_SPEEDUP down to the providers that constittue the geom, as
applicable. No changes to vinum or virstor because I was unsure how to add this
support, and I'm also unsure how to test these. gvinum doesn't implement
BIO_FLUSH either, so it may just be poorly maintained. gvirstor is for testing
and not supportig BIO_SPEEDUP is fine.

Reviewed by: chs
Differential Revision: https://reviews.freebsd.org/D23183

Add a "count_until_fail" option to gnop, which says to start failing
I/O requests after the given number have been allowed though.

Approved by: imp (mentor)
Reviewed by: rpokala kib 0mp mckusick
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21593

GEOM: Reduce unnecessary log interleaving with sbufs

Similar to what was done for device_printfs in r347229.

Convert g_print_bio() to a thin shim around g_format_bio(), which acts on an
sbuf; documented in g_bio.9.

Reviewed by: markj
Discussed with: rlibby
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D21165

gnop: Introduce requests delay.

This allows to simulated disk that is responding slowly to the IO requests.

Reviewed by: markj, bcr, pjd (previous version)
Differential Revision: https://reviews.freebsd.org/D21052

gnop(8): add the ability to set a nop provider's physical path

While I'm here, expand the existing tests a bit.

MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D13579

sys/geom: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Make geom_nop(4) collect statistics on all types of BIOs, not just
reads and writes.

PR: kern/198405
Submitted by: Matthew D. Fuller <fullermd at over-yonder dot net>
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3679

Add a way to specify stripesize and stripeoffset to gnop(8). This makes
it possible to "simulate" 4K media, to eg test alignment handling.

Reviewed by: mav@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3664

Merge GEOM direct dispatch changes from the projects/camlock branch.

When safety requirements are met, it allows to avoid passing I/O requests
to GEOM g_up/g_down thread, executing them directly in the caller context.
That allows to avoid CPU bottlenecks in g_up/g_down threads, plus avoid
several context switches per I/O.

The defined now safety requirements are:
- caller should not hold any locks and should be reenterable;
- callee should not depend on GEOM dual-threaded concurency semantics;
- on the way down, if request is unmapped while callee doesn't support it,
the context should be sleepable;
- kernel thread stack usage should be below 50%.

To keep compatibility with GEOM classes not meeting above requirements
new provider and consumer flags added:
- G_CF_DIRECT_SEND -- consumer code meets caller requirements (request);
- G_CF_DIRECT_RECEIVE -- consumer code meets callee requirements (done);
- G_PF_DIRECT_SEND -- provider code meets caller requirements (done);
- G_PF_DIRECT_RECEIVE -- provider code meets callee requirements (request).
Capable GEOM class can set them, allowing direct dispatch in cases where
it is safe. If any of requirements are not met, request is queued to
g_up or g_down thread same as before.

Such GEOM classes were reviewed and updated to support direct dispatch:
CONCAT, DEV, DISK, GATE, MD, MIRROR, MULTIPATH, NOP, PART, RAID, STRIPE,
VFS, ZERO, ZFS::VDEV, ZFS::ZVOL, all classes based on g_slice KPI (LABEL,
MAP, FLASHMAP, etc).

To declare direct completion capability disk(9) KPI got new flag equivalent
to G_PF_DIRECT_SEND -- DISKFLAG_DIRECT_COMPLETION. da(4) and ada(4) disk
drivers got it set now thanks to earlier CAM locking work.

This change more then twice increases peak block storage performance on
systems with manu CPUs, together with earlier CAM locking changes reaching
more then 1 million IOPS (512 byte raw reads from 16 SATA SSDs on 4 HBAs to
256 user-level threads).

Sponsored by: iXsystems, Inc.
MFC after: 2 months

move the error report to a lower log level... Now you can see when it
returns an error without getting every single io that went through it..

MFC after: 1 week

Add trivial resize handling to gnop(8).

Reviewed by: mav
Sponsored by: FreeBSD Foundation

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

- Import the HEAD csup code which is the basis for the cvsmode work.

Remove trailing spaces.

- Split failure probability configuration into read failure probability and
write failure probability.
- Allow to specify an error number to return of failure.

MFC after: 3 days

Teach NOP GEOM class how to gather the following statistics:
- number of read I/O requests,
- number of write I/O requests,
- number of read bytes,
- number of written bytes.
Add 'reset' subcommand for resetting statistics.

- Add '-S' option, which allow to specify sector size for transparent
provider.
- Bump version number.

This allows for a quite interesting trick. One can setup a stripe with
stripe size of 512 bytes and create transparent provider on top of it
with sector size equal to <ndisks> * 512. The result will be something
like RAID3 without parity disk (every access will touch all disks).

MFp4: Add two options for gnop(8)'s 'create' command:
-o offset - specifies where to start on the original provider
-s size - specifies size of the transparent provider

- Change command name from 'config' to 'configure'.
- Bump version number.

Introduce NOP GEOM class. This is totally transparent GEOM class, but
it is very useful for tests. One is able to destroy its provider
forcibly if wants to test how other class handle such events.
One is also able to specify failure probability to check how other
classes handle I/O errors.

Supported by: Wheel - Open Technologies - http://www.wheel.pl