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 253433:

In this GRN, Marcel Moolenaar overhauled the logic for mounting
the root file system on bootup:

|------------------------------------------------------------------------
|r214006 | marcel | 2010-10-17 22:01:53 -0700 (Sun, 17 Oct 2010) | 20 lines
|
| Re-implement the root mount logic using a recursive approach, whereby each
|root file system (starting with devfs and a synthesized configuration) can
|contain directives for mounting another file system as root.
|------------------------------------------------------------------------

This commit adds a mount.conf(8) man page which documents
the root mount logic. mount.conf(8) also provides some examples
for the /.mount.conf file, which can be used to change the root mount behavior.

Reviewed by: marcel bjk

MFC: 253445:

Minor mdoc fixes

Approved by: re (gjb)

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

Approved by: re (implicit)

Switch the default WARNS level for sbin/ to 6.

Submitted by: Ulrich Spörlein

Use pidfile(3) API to restart mountd(8) on success mount.
This why we won't kill random process if there is a stale PID in
/var/run/mountd.pid.

Remove UFS-specific parts from mount(8).
For mounting UFS, all mount options are passed directly to nmount(),
without any UFS-specific logic.

- Minor fixes to raise WARNS level to 6.
- Teach the mount program to call the nmount() syscall directly
- Preserve existing method of calling mount() for UFS, until we clean things
up.
- Preserve existing method of forking and calling external mount programs for
mfs, msdosfs, nfs, nfs4, ntfs, nwfs, nullfs, portalfs, reiserfs, smbfs,
udf, umapfs, unionfs
- devfs, linprocfs, procfs, ext2fs call nmount() syscall directly, since
that is all those external mount programs were doing

Reviewed by: phk
Discussed on: arch

Bump WARNS up to 3.

The previous change to mount(8) to report ufs or ufs2 used
libufs, which only works for Charlie root.

This change reverts the introduction of libufs and moves the
check into the kernel. Since the f_fstypename is the same
for both ufs and ufs2, we check fs_magic for presence of
ufs2 and copy "ufs2" explicitly instead.

Submitted by: Christian S.J. Peron <maneo@bsdpro.com>

Report the difference between ufs and ufs2.

Submitted by: "Christian S.J. Peron" <maneo@bsdpro.com>

style.Makefile: Add a '?' before '=' in WARNS.

Default to WARNS=2.
Binary builds that cannot handle this must explicitly set WARNS=0.

Reviewed by: mike

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Set the default manual section for sbin/ to 8.

$Id$ -> $FreeBSD$

Removed ROOTSLICE_HUNT. The root device is now found better by
getvfsent() in most cases. (The main exception is when /etc/fstab
still hasn't been converted to use a slice for the root device, the
root device is a SCSI device, and the /dev/sd* inode for this device
still hasn't been renamed to /dev/da*.)

If we are mounting the root filesystem, and we're accessing it through
something that might refer to the compatability slice rather than the
correct slice entry, try all the possible slice entries first.

This is a compatability hack to deal with the case where the kernel has
correctly mounted the root filesystem out of its slice, but the user
has not updated their /etc/fstab file to reflect this. A diagnostic
is emitted if the mount succeeds, indicating that the file should be
updated.

This is a prelude to fixing the kernel to behave as alluded to above.
Reviewed by: (discussed with) julian, phk

Removed definition of _NEW_VFSCONF. The new vfsconf interface is now
the default.

Backed out previous commit - don't clobber the (normally equivalent)
default for NOSHARED.

Try to avoid mounting filesystems multiple times. Also while
I'm here do some -Wall cleaning.

PR: kern/1839
Reviewed and corrected by: joerg

Merge from Lite2
- use new getvfsbyname() interface and mount(2) interface

**DANGER WILL ROBINSON!!** You must be running a -current kernel
from within a week or so in order for this to work!

Convert to our man installation style. Also fixed long-standing bug
in `fastboot'/`fasthalt' in which the interpreter would hang around
after `reboot' or `halt' is run, causing an irritating ``Killed'' message.

This commit was generated by cvs2svn to compensate for changes in r1558,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite sbin Sources

Note: XNSrouted and routed NOT imported here, they shall be imported with
usr.sbin.