MFC r307755: swapoff: Remove only late devices with -aL.

Currently, '/etc/rc.d/swaplate stop' removes all swap devices. This can be
very slow and may not even be possible if there is a lot of swap space in
use. However, removing swap devices is only needed for late swap devices
that may depend on daemons that subsequent shutdown steps stop. Normal swap
devices such as hard disk partitions will remain available throughout the
shutdown process and need not be removed.

In swapoff, interpret -aL to remove late swap devices only, and use this in
etc/rc.d/swaplate. The meaning of -aL in swapon remains unchanged (add all
swap devices, both normal and late).

PR: 187081

MFC r306585: swapon(8): Update to reality: swapoff ignores -L and the late
option in fstab.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

- Purge one more reference to ad(4)[1].
- NSWAPDEV limit has gone.

Noticed by: Sergey V. Dyatko [1]
MFC after: 1 week

- Add vnode-backed swap space specification support. This is enabled when
device names "md" or "md[0-9]*" and a "file" option are specified in
/etc/fstab like this:

md none swap sw,file=/swap.bin 0 0

- Add GBDE/GELI encrypted swap space specification support, which
rc.d/encswap supported. The /etc/fstab lines are like the following:

/dev/ada1p1.bde none swap sw 0 0
/dev/ada1p2.eli none swap sw 0 0

.eli devices accepts aalgo, ealgo, keylen, and sectorsize as options.

swapctl(8) can understand an encrypted device in the command line
like this:

# swapctl -a /dev/ada2p1.bde

- "-L" flag is added to support "late" option to defer swapon until
rc.d/mountlate runs.

- rc.d script change:

rc.d/encswap -> removed
rc.d/addswap -> just display a warning message if $swapfile is defined
rc.d/swap1 -> renamed to rc.d/swap
rc.d/swaplate -> newly added to support "late" option

These changes alleviate a race condition between device creation/removal
and swapon/swapoff.

MFC after: 1 week
Reviewed by: wblock (manual page)

Add new option -F to specify alternative location of the /etc/fstab
file.

MFC after: 1 month

Add a -q flag to swapon(8) to suppress informational messages. Use it in
rc.d.
Note: errors are not affected by this flag.

- Change the meaning of -h flag from giving the output in megabytes to
giving the output in a human-readable form. This behaviour is consistent
with most of system tools.
- Add -m and -g options to give output in megabytes and gigabytes
respectively.

Sync program's usage() with manpage's SYNOPSIS.

Sort sections.

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core, imp

Spell "utilities" correctly.

More fixes.

Submitted by: Andy Farkas <andyf@speednet.com.au>
Reviewed by: das

mdoc(7) police: Tidy up.

Clarify about NSWAPDEV, add a DIAGNOSTICS section pointing to
swapon(2), and correct HISTORY.

Reviewed by: mike (mentor)

Add 'swapctl' - as a hardlink to swapon/swapoff, and augment swapon with
swapctl functionality. The idea is to create a swapctl command that is
fairly close to the OpenBSD and NetBSD version. FreeBSD does not implement
swap priority (and it would be a mistake if we did) so we didn't bother with
that part of it.

Submitted by: Eirik Nygaard <eirikn@bluezone.no>
Augmented by: dillon (extensively)
Reviewed by: David Schultz <dschultz@uclink.Berkeley.EDU>

This is David Schultz's swapoff code which I am finally able to commit.
This should be considered highly experimental for the moment.

Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU>
MFC after: 3 weeks

s/filesystem/file system/g as discussed on -developers

The .Nm utility.

mdoc(7) police: removed HISTORY info from the .Os call.

vnconfig(8) -> mdconfig(8).

mdoc(7) police: use the new features of the Nm macro.

correct wording in BUGS section; it's not possible to dismount swap
devices, but it's certainly possible to make use of them.

PR: 17013
Submitted by: Giorgos Keramidas <keramida@ceid.upatras.gr>

Mention /dev/vn0b and /dev/vntab. ascii -> ASCII transform had
already happened in an earlier commit.

PR: docs/13645
Submitted by: Stephen Roznowski <sjr@home.com>

Correct spelling : ascii -> ASCII

PR: docs/13702
Submitted by: Stephen J. Roznowski <sjr@home.com>
Reviewed by: mpp

$Id$ -> $FreeBSD$

Refer to current names for swap partitions in the `FILES' section.

PR: docs/11709
Submitted by: Matthew D. Fuller <fullermd@over-yonder.net>

.Nm swapon -> .Nm.
Sort #includes. Add rcsid.

Revert last commit and SEE ALSO pstat(8) instead.

Submitted by: Bruce Evans

SEE ALSO swapinfo(8).

PR: 5447
Submitted by: Craig Leres <leres@ee.lbl.gov>

.Xr vnconfig 8. This was suggested by Dworkin Muller <dworkin@village.org>
when he tried to figure out how to swap to a file and had to ask me for
help.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

add missing comma(s) in .Xr macros

Make the noauto flag usable for swap devices too. Closes PR#1542
Submitted-By: David Leonard <d@scry.dstc.edu.au>

fstab is in section 5, not section 8.
Obtained from: NetBSD

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.