Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Add option to lockf to avoid creating a file if it does not exist.

PR: bin/170775
Submitted by: Matthew Story <matthewstory@gmail.com>
Reviewed by: scottl
MFC after: 1 week

Remove trailing whitespace per mdoc lint warning

Disussed with: gavin
No objection from: doc
Approved by: joel
MFC after: 3 days

mdoc: order prologue macros consistently by Dd/Dt/Os

Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.

Reviewed by: ru
Approved by: philip, ed (mentors)

Lockf was exiting with status 1 if the command did not exit normally.
This is easy to confuse with the actual exit status of the program.
Instead exit with EX_SOFTWARE if the command doesn't exit normally.

MFC after: 1 month

Also fix a "blank line" issue that sneaked in from rev. 1.19.

Submitted by: John Hein

Remove newly acquired hard sentence breaks.

Revision 1.12 of lockf.c fixed a "thundering herd" scenario when the
lock experienced contention a number of processes would race to acquire
lock when it was released. This problem resulted in a lot of CPU
load as well as locks being picked up out of order.

Unfortunately, a regression snuck in which allowed multiple threads
to pickup the same lock when -k was not used. This could occur when
multiple processes open a file descriptor to inode X (one process
will be blocked) and the file is unlinked on unlock (thereby removing
the directory entry allow another process to create a new directory
entry for the same file name and lock it).

This changes restores the old algorithm of: wait for the lock, then
acquire lock when we want to unlink the file on exit (specifically
when -k is not used) and keeps the new algorithm for when -k is used,
which yields fairness and improved performance.

Also, update the man page to inform users that if lockf(1) is being
used to facilitate concurrency between a number of processes, it
is recommended that -k be used to reduce CPU load and yeld
fairness with regard to lock ordering.

Collaborated with: jdp
PR: bin/114341
PR: bin/116543
PR: bin/111101
MFC after: 1 week

Markup cosmetics.

Fix all the spelling mistakes I could find in the man pages for words
that have at least 3 characters.

MFC after: 1 week
Thanks to: Music band ``Chingon''
for keeping me company while searching for these.

Markup and wording fixes.

Approved by: re (blanket)

Document a couple of gotchas.

Added the EXIT STATUS section where appropriate.

Mechanically kill hard sentence breaks.

Use `The .Nm utility'

mdoc(7) police: s/BSD/.Bx/ where appropriate.

Remove whitespace at EOL.

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

Add history.

$Id$ -> $FreeBSD$

Add a "-k" option, to specify that the lock file should be kept
rather than removed.

Submitted by: Nick Barnes <Nick.Barnes@pobox.com>

.Sh AUTHOR -> .Sh AUTHORS. Use .An/.Aq.

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.

On failure, return various exit codes from <sysexits.h>. In particular,
return EX_TEMPFAIL if the file was already locked. This makes it easier
to distinguish between lock collisions and failures within the command
being executed.

Also, don't complain if the unlink() fails in the cleanup handler. It
doesn't matter anyway, and it obscured the exit status returned from
the command that was executed.

This commit was generated by cvs2svn to compensate for changes in r21439,
which included commits to RCS files with non-trunk default branches.

Initial import of the lockf utility. It executes an arbitrary command
while holding an exclusive lock on a file.