sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

vfs: use __enum_uint8 for vtype and vstate

This whacks hackery around only reading v_type once.

Bump __FreeBSD_version to 1400093

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

Drop "All rights reserved" from all my stuff. This includes
Foundation copyrights, approved by emaste@. It does not include
files which carry other people's copyrights; if you're one
of those people, feel free to make similar change.

Reviewed by: emaste, imp, gbe (manpages)
Differential Revision: https://reviews.freebsd.org/D26980

Fix some signed/unsigned comparison warnings in NFS

Reviewed by: rmacklem
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26533

vfs: remove the obsolete privused argument from vaccess

This brings argument count down to 6, which is passable without the
stack on amd64.

Remove unused argument to priv_check_cred.

Patch mostly generated with cocinnelle:

@@
expression E1,E2;
@@

- priv_check_cred(E1,E2,0)
+ priv_check_cred(E1,E2)

Sponsored by: The FreeBSD Foundation

sys/kern: 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.

Expose an interface to determine if an ACE is inherited.

Submitted by: sef
Reviewed by: trasz
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D3540

Fix bug where NFSv4 ACL enforcement code wouldn't unconditionally
allow the owner to read and write ACL and file attributes when there
was no entry with subject matching the owner. In other words,
'getfacl meh' shouldn't fail for the owner if the ACL looks like this:

# file: meh
# owner: trasz
# group: wheel
user:root:------a-------:------:allow

Reported by: kientzle

Add module load/unload stubs.

Remove assertion against empty NFSv4 ACLs. An empty ACL is not exactly
valid - we don't allow for setting it on a file, for example - but it's
not something we should assert on.

For STABLE kernel, it changes nothing, because it's not compiled with
INVARIANTS. If it was, it would fix crashes. It also fixes an assert
in libc encountered with NFSv4 without nfsuserd(8) running.

Submitted by: Yuri Pankov (earlier version)
MFC after: 1 month

Make UFS use PSARC/2010/029 NFSv4 ACL semantics by default, bringing
it in line with ZFSv28.

X-MFC-After: ZFSv28.

Move the code around so that libc behaviour does not depend on a variable
that was supposed to be kernel-only. There should be no functional changes.

Temporarily revert r219272; it breaks acl_is_trivial_np(3).

Make UFS use PSARC/2010/029 NFSv4 ACL semantics by default, just like
ZFSv28 does.

MFC after: 2 months

Adapt filesystem-independent NFSv4 ACL code (used by UFS, but not by ZFS)
to PSARC/2010/029. In short, the semantics is simplified - "weird stuff"
no longer happens after chmod, entries don't get duplicated during
inheritance, and trivial ACLs no longer contain three "DENY" entries,
which is also more friendly to MS Windows.

By default, UFS keeps using old semantics. To change it, set sysctl
vfs.acl_nfs4_old_semantics to 0. I'll flip the switch when ZFSv28
hits the tree, to keep these two in sync - ZFS v28 uses PSARC semantics,
and ZFS v15 uses the old one.

Fix uninitialized variable.

Found with: Coverity Prevent(tm)
CID: 8632

Remove workaround for ZFS bug; fix was committed to the //depot/user/pjd/zfs/...
branch some time ago.

MFC after: two weeks

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

First step at adopting FreeBSD to support PSARC/2010/029. This makes
acl_is_trivial_np(3) properly recognize the new trivial ACLs. From
the user point of view, that means "ls -l" no longer shows plus signs
for all the files when running ZFS v28.

execve(2) has a special check for file permissions: a file must have at
least one execute bit set, otherwise execve(2) will return EACCES even
for an user with PRIV_VFS_EXEC privilege.

Add the check also to vaccess(9), vaccess_acl_nfs4(9) and
vaccess_acl_posix1e(9). This makes access(2) to better agree with
execve(2). Because ZFS doesn't use vaccess(9) for VEXEC, add the check
to zfs_freebsd_access() too. There may be other file systems which are
not using vaccess*() functions and need to be handled separately.

PR: kern/125009
Reviewed by: bde, trasz
Approved by: pjd (ZFS part)

The acl_cnt field is unsigned; no point in checking if it's >= 0.

Found with: Coverity Prevent
CID: 3683

MFC r200723:

Interpret VAPPEND correctly in vaccess_acl_nfs4(9).

MFC r197405:

Add pieces of infrastructure required for NFSv4 ACL support in UFS.

Reviewed by: rwatson

Fix comments.

Now that all the callers seem to be fixed, add KASSERTs to make sure VAPPEND
is not being used improperly.

Interpret VAPPEND correctly in vaccess_acl_nfs4(9).

Add pieces of infrastructure required for NFSv4 ACL support in UFS.

Reviewed by: rwatson

Add part of NFSv4 ACL kernel support code that is required for the upcoming
libc changes to work. Not connected to the kernel build yet; for now,
it will be compiled into libc.

Reviewed by: rwatson