Revert r250907 from releng/9.2:

 Reports of NFS deadlocks on -stable@ suggest that reverting
 this change resolves the problem.

 This is a direct reverse-merge to releng/9.2, pending further
 review and analysis on the stable/9 branch.

Approved by:	re (marius)
Discussed on:	stable
MF9 r254783: Correct implementation of atomic_flag_test_and_set

Approved by:	re
MFS r254728:

  Pull in r182983 from upstream clang trunk:

    Fix handling of braced-init-list as reference initializer within
    aggregate initialization. Previously we would incorrectly require an
    extra set of braces around such initializers.

  Pull in r188718 from upstream clang trunk:

    Handle init lists and _Atomic fields.

    Fixes PR16931.

  These fixes are needed for the atomic_flag type to work correctly in our
  stdatomic.h.

Approved by:	re
Default net.inet.tcp.experimental.initcwnd10 to 0 in releng/9.2.

Concerns have been raised regarding enabling initcwnd10 by default
in the stable/ branch, so as a cautionary measure, turn this off
for the 9.2-RELEASE.  This sysctl is still available for those
who want to enable this on their own systems.

This is a direct commit to releng/9.2.

Discussed with:	re
Approved by:	re (marius)
Update releng/9.2 to -RC3.

Approved by:	re (implicit)
MFS9 r254966:
Add missing mergeinfo from head for stabe/9 revisions: 252995 253168 253169

Reviewed by:	gjb
Approved by:	re (gjb)
MFS9 r254953, itself an MFC of r254942 and r254952:
Make alternate layout ``opt-in'' and add support for named releases.
Minor edit to version.4th(8) manual and stack-leak fixes while here.

Approved by:	re (gjb)
Reduce the disc1.iso image size by setting WITHOUT_CLANG=1 for the
'system' target.  Since clang is not enabled by default for releng/9.2,
this has no user visible changes by default.

This brings 9.2-R* well enough below the 700MB mark so that we do not
need to be concerned with it fitting on standard CD-ROM medium.

This is a direct commit to releng/9.2, pending further review for head/
and stable/9/.

Discussed with:	delphij, hrs
Approved by:	re (marius)
Sponsored by:	The FreeBSD Foundation
MFS of 255104:
MFC of 253998:

This bug fix is in a code path in rename taken when there is a
collision between a rename and an open system call for the same
target file. Here, rename releases its vnode references, waits for
the open to finish, and then restarts by reacquiring its needed
vnode locks. In this case, rename was unlocking but failing to
release its reference to one of its held vnodes. The effect was
that even after all the actual references to the vnode had gone,
the vnode still showed active references. For files that had been
removed, their space was not reclaimed until the filesystem was
forcibly unmounted.

This bug manifested itself in the Postgres server which would
leak/lose hundreds of files per day amounting to many gigabytes of
disk space. This bug required shutting down Postgres, forcibly
unmounting its filesystem, remounting its filesystem and restarting
Postgres every few days to recover the lost space.

Reported by: Dan Thomas and Palle Girgensohn
Bug-fix by:  kib
Tested by:   Dan Thomas and Palle Girgensohn

Approved by: re@ (Marius Strobl <marius@freebsd.org>)
MFS9 r255306:
MFC r245428:

Add CLOCK_PROCESS_CPUTIME_ID to <time.h>, to synchronize the CLOCK_*
values with those in <sys/time.h>.  Otherwise, if a program includes
<time.h> before <sys/time.h>, the CLOCK_PROCESS_CPUTIME_ID macro never
gets defined.

Reviewed by:	davidxu
Approved by:	re (kib)
MFH (r254684, r254955): fix segfault on reload.
MFH (r255156): silence an error message on non-IPv6 interfaces.

Approved by:    re (glebius)
MFH (r255243): create /var/authpf with correct ownership and permissions.

Approved by:	re (glebius)
MFS r255435: MFC r255320:

Return BUS_PROBE_DEFAULT instead of BUS_PROBE_SPECIFIC.

Approved by:	re (hrs)
In IPv6 and NetATM, stop SIOCSIFADDR, SIOCSIFBRDADDR, SIOCSIFDSTADDR
and SIOCSIFNETMASK at the socket layer rather than pass them on to the
link layer without validation or credential checks.  [SA-13:12]

Prevent cross-mount hardlinks between different nullfs mounts of the
same underlying filesystem.  [SA-13:13]

Security:	CVE-2013-5691
Security:	FreeBSD-SA-13:12.ifioctl
Security:	CVE-2013-5710
Security:	FreeBSD-SA-13:13.nullfs
Approved by:	re
Reintegrate r250907 (previously reverted as r254754) plus MFS r254947,
r255443:

r250907 (scottl):
  MFC r248830, r250027, r250409: Several fixes and improvements
  to sendfile()

r254947 (kib):
  NFS implementation of VOP_READ() sometimes upgrades the vnode lock,
  which causes drop of the shared lock and sleep for exclusive.  As
  result, busying of the page before the call to vn_rdwr() makes NFS
  code to wait for vnode lock while page is busy, which contradicts the
  proper order of vnode lock -> busy.

r255443 (des):
  Fix the length calculation for the final block of a sendfile(2)
  transmission which could be tricked into rounding up to the nearest
  page size, leaking up to a page of kernel memory.  [13:11]

Approved by:	re (delphij)
Sponsored by:	The FreeBSD Foundation
Update releng/9.2 to -RC4.

Approved by:	re (implicit)
- Bump Copyright year
- Trim old entries from the releng/9.1 branch

Approved by:	re (implicit)
- Bump Copyright year
- Trim old entries from releng/9.1
- Update URLs for 9.2 where needed
- Note CVS/cvsup are not supported methods to update src/

Approved by:	re (implicit)
- Bump Copyright year

Approved by:	re (implicit)
- Bump Copyright year
- Trim old entries from releng/9.1

Approved by:	re (implicit)