Commit Graph

54 Commits

Author SHA1 Message Date
Colin Percival
bd4fcf75ee Remove whitespace which accidentaly snuck into r364831. 2020-08-26 19:28:30 +00:00
Colin Percival
437bab4828 Add -w option to lockf(1).
By default, lockf(1) opens its lock file O_RDONLY|O_EXLOCK.  On NFS, if the
file already exists, this is split into opening the file read-only and then
requesting an exclusive lock -- and the second step fails because NFS does
not permit exclusive locking on files which are opened read-only.

The new -w option changes the open flags to O_WRONLY|O_EXLOCK, allowing it
to work on NFS -- at the cost of not working if the file cannot be opened
for writing.

(Whether the traditional BSD behaviour of allowing exclusive locks to be
obtained on a file which cannot be opened for writing is a good idea is
perhaps questionable since it may allow less-privileged users to perform
a local denial of service; however this behaviour has been present for a
long time and changing it now seems like it would cause problems.)

Reviewed by:	rmacklem
Differential Revision:	https://reviews.freebsd.org/D26005
2020-08-26 19:26:48 +00:00
Fernando Apesteguía
15597d5df2 lockf(1): Add EXAMPLES section
* Add pretty small EXAMPLES section
 * While here, fix a warning in line 98 (new sentence in new line)

Approved by:	bcr@
Differential Revision:	https://reviews.freebsd.org/D25205
2020-06-18 08:31:04 +00:00
Andriy Voskoboinyk
d614ded66a lockf(1): return EX_UNAVAILABLE if -n is used and the lock file does not
exist

Apply EX_UNAVAILABLE patch part from PR 170775 to match the documentation.

Checked with a command from PR 210770:
lockf -n /tmp/doesnotexist echo; echo $?

PR:		210770
MFC after:	1 week
2019-03-20 07:40:38 +00:00
Pedro F. Giffuni
1de7b4b805 various: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

No functional change intended.
2017-11-27 15:37:16 +00:00
Bryan Drewery
ea825d0274 DIRDEPS_BUILD: Update dependencies.
Sponsored by:	Dell EMC Isilon
2017-10-31 00:07:04 +00:00
Simon J. Gerraty
ccfb965433 Add META_MODE support.
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.

Still need to add real targets under targets/ to build packages.

Differential Revision:       D2796
Reviewed by: brooks imp
2015-06-13 19:20:56 +00:00
Simon J. Gerraty
44d314f704 dirdeps.mk now sets DEP_RELDIR 2015-06-08 23:35:17 +00:00
Simon J. Gerraty
98e0ffaefb Merge sync of head 2015-05-27 01:19:58 +00:00
Bryan Drewery
90e8186404 Remove extra flags from r250462.
MFC after:	1 week
2015-04-16 02:24:40 +00:00
Mark Johnston
bef6922b96 lockf(1): add a reference to lockf(3).
Submitted by:	Conrad Meyer
MFC after:	1 week
2015-04-06 22:53:23 +00:00
Simon J. Gerraty
ee7b0571c2 Merge head from 7/28 2014-08-19 06:50:54 +00:00
Baptiste Daroussin
2b7af31cf5 use .Mt to mark up email addresses consistently (part3)
PR:		191174
Submitted by:	Franco Fichtner  <franco at lastsummer.de>
2014-06-23 08:23:05 +00:00
Simon J. Gerraty
fae50821ae Updated dependencies 2014-05-16 14:09:51 +00:00
Simon J. Gerraty
76b28ad6ab Updated dependencies 2014-05-10 05:16:28 +00:00
Simon J. Gerraty
d1d0158641 Merge from head 2013-09-05 20:18:59 +00:00
Eitan Adler
b5be420a7c 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
2013-05-10 17:30:29 +00:00
Simon J. Gerraty
7cf3a1c6b2 Updated dependencies 2013-03-11 17:21:52 +00:00
Simon J. Gerraty
f5f7c05209 Updated dependencies 2013-02-16 01:23:54 +00:00
Marcel Moolenaar
7750ad47a9 Sync FreeBSD's bmake branch with Juniper's internal bmake branch.
Requested by: Simon Gerraty <sjg@juniper.net>
2012-08-22 19:25:57 +00:00
Eitan Adler
50d675f7a9 Remove trailing whitespace per mdoc lint warning
Disussed with:	gavin
No objection from:	doc
Approved by:	joel
MFC after:	3 days
2012-03-29 05:02:12 +00:00
Ulrich Spörlein
aa12cea2cc 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)
2010-04-14 19:08:06 +00:00
David Malone
7f15c32d76 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
2008-08-21 07:36:17 +00:00
Ruslan Ermilov
8931e1d50e Also fix a "blank line" issue that sneaked in from rev. 1.19.
Submitted by:	John Hein
2007-10-31 19:26:01 +00:00
Ruslan Ermilov
de8f7dcbae Remove newly acquired hard sentence breaks. 2007-10-30 19:23:42 +00:00
Christian S.J. Peron
6a53f0a52b 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
2007-10-12 14:56:52 +00:00
Ruslan Ermilov
c8c3587578 Markup cosmetics. 2006-12-20 16:57:13 +00:00
Christian S.J. Peron
cc2a9f52a7 Finish off style(9) fixes which I started two revisions ago. This basically
changes the indentation style from 4 spaces to 8 spaces which we expect to
see in other FreeBSD source files.
2005-10-09 04:45:41 +00:00
Christian S.J. Peron
45edbdccd7 Do not ignore ENOENT
Pointed out by:	Amir Shalem
2005-10-07 11:49:27 +00:00
Christian S.J. Peron
4ccbe0c50d Un-break handling of -t 0 which was broken in my previous commit.
Add a flags argument to wait_for_lock so that O_NONBLOCK can be
passed to open if a user doesn't want the open to sleep until the
lock becomes available.

Submitted by:	Amir Shalem (partially modified)
2005-10-05 22:02:07 +00:00
Christian S.J. Peron
031469eb27 Fix long standing race condition associated with how lockf uses open(2)
for mutual exclusion:

A brief description of the problem:

	1) Proc A picks up non-blocking lock on file X
	2) Proc B attempts to pickup lock, fails then waits
	3) Proc C attempts to pickup lock, fails then waits
	4) Proc A releases lock
	5) Proc B acquires lock, release it to pickup a non-blocking version
	6) Proc C acquires lock, release it to pickup a non-blocking version
	7) Both process B and C race each other to pickup lock again

This occurs mainly because the processes do not keep the lock after they have
been waiting on it. They drop it, attempt to re-acquire it. (They use the wait
to notify when the lock has become available then race to pick it up). This
results in additional CPU utilization during the race, and can also result
in processes picking locks up out of order.

This change attempts to correct this problem by eliminating the test/acquire
race and having the operating system handle it.

Reported by:	kris
Tested by:	kris
MFC after:	1 week
2005-10-05 17:39:15 +00:00
Giorgos Keramidas
6fb9b618f5 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.
2005-07-31 03:30:48 +00:00
Ruslan Ermilov
39c59153e9 Markup and wording fixes.
Approved by:	re (blanket)
2005-06-14 11:50:53 +00:00
Eivind Eklund
f2839e75f6 Document a couple of gotchas. 2005-05-26 22:30:12 +00:00
Ruslan Ermilov
a866e17077 Added the EXIT STATUS section where appropriate. 2005-01-17 07:44:44 +00:00
Tim J. Robbins
208f2fd1ed Use warn() instead of perror(). 2004-07-15 04:51:21 +00:00
Ruslan Ermilov
6a3e8b0adc Mechanically kill hard sentence breaks. 2004-07-02 22:22:35 +00:00
David E. O'Brien
e026a48c34 Consistently use FBSDID 2002-06-30 05:25:07 +00:00
Philippe Charnier
e8937ba009 Use `The .Nm utility' 2002-04-20 12:18:28 +00:00
Mark Murray
91bd71d206 Remove leaf node WARNS?=2 (that mainly I added). This should
help the GCC3 transition and CURRENT in general.
2002-02-08 22:31:43 +00:00
David Malone
9ff5e898db Warns cleanups. 2001-12-03 21:07:23 +00:00
Ruslan Ermilov
753d686d34 mdoc(7) police: s/BSD/.Bx/ where appropriate. 2001-08-14 10:01:54 +00:00
Dima Dorfman
f247324df7 Remove whitespace at EOL. 2001-07-15 08:06:20 +00:00
Ruslan Ermilov
625003720a mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 14:16:33 +00:00
David E. O'Brien
9c8efe99eb Add history. 2000-12-10 01:10:54 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
John Polstra
2f278eac1f Add a "-k" option, to specify that the lock file should be kept
rather than removed.

Submitted by:	Nick Barnes <Nick.Barnes@pobox.com>
1998-07-08 05:29:05 +00:00
Philippe Charnier
306005e78c .Sh AUTHOR -> .Sh AUTHORS. Use .An/.Aq. 1998-03-23 07:48:45 +00:00
Philippe Charnier
3ec665d482 lockf: usage : lockf -> usage: lockf by using fprintf instead of errx. 1997-07-22 07:32:23 +00:00
Warner Losh
1c8af87873 compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.
1997-03-29 04:34:07 +00:00