Remove $FreeBSD$: two-line .h pattern

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

Optimize telldir(3)

Currently each call to telldir() requires a malloc and adds an entry to a
linked list which must be traversed on future telldir(), seekdir(),
closedir(), and readdir() calls. Applications that call telldir() for every
directory entry incur O(n^2) behavior in readdir() and O(n) in telldir() and
closedir().

This optimization eliminates the malloc() and linked list in most cases by
packing the relevant information into a single long. On 64-bit architectures
msdosfs, NFS, tmpfs, UFS, and ZFS can all use the packed representation. On
32-bit architectures msdosfs, NFS, and UFS can use the packed
representation, but ZFS and tmpfs can only use it for about the first 128
files per directory. Memory savings is about 50 bytes per telldir(3) call.
Speedup for telldir()-heavy directory traversals is about 20-30x for one
million files per directory.

Reviewed by: kib, mav, mckusick
MFC after: 3 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D13385

General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

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.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Commit the 64-bit inode project.

Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment. Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks. Unfortunately, not everything can be
fixed, especially outside the base system. For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING. Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver. Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by: The FreeBSD Foundation (emaste, kib)
Differential revision: https://reviews.freebsd.org/D10439

Tweak seekdir, telldir and readdir so that when htere are deletes going on,
as seek to teh last location saved will still work. This is needed for Samba
to be able to correctly handle delete requests from windows. This does not
completely fix seekdir when deletes are present but fixes the worst of the
problems. The real solution must involve some changes to the API for eh VFS
and getdirentries(2).

Obtained from: Panzura inc
MFC after: 1 week

Fix some edge cases with rewinddir():
- In the unionfs case, opendir() and fdopendir() read the directory's full
contents and cache it. This cache is not refreshed when rewinddir() is
called, so rewinddir() will not notice updates to a directory. Fix this
by splitting the code to fetch a directory's contents out of
__opendir_common() into a new _filldir() function and call this from
rewinddir() when operating on a unionfs directory.
- If rewinddir() is called on a directory opened with fdopendir() before
any directory entries are fetched, rewinddir() will not adjust the seek
location of the backing file descriptor. If the file descriptor passed
to fdopendir() had a non-zero offset, the rewinddir() will not rewind to
the beginning. Fix this by always seeking back to 0 in rewinddir().
This means the dd_rewind hack can also be removed.

While here, add missing locking to rewinddir().

CR: https://phabric.freebsd.org/D312
Reviewed by: jilles
MFC after: 1 week

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

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

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

Do not read away the target directory entry when encountering deleted
files after a seekdir().

The seekdir shall set the position for the next readdir operation.
When the _readdir_unlocked() encounters deleted entry, dd_loc is
already advanced. Continuing the loop leads to premature read of
the target entry.

Submitted by: Marc Balmer <mbalmer at openbsd org>
Obtained from: OpenBSD
MFC after: 2 weeks

Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by: -arch

Move telldir position recording type definitions and prototypes
to "telldir.h" in order to prevent namespace pollution in
<dirent.h> (which was including <sys/queue.h>).

Add $FreeBSD$ to rewinddir.c and seekdir.c.