freebsd-skq/lib/libc/sys/fsync.2

.\" Copyright (c) 1983, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)fsync.2	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd June 4, 1993
.Dt FSYNC 2
.Os
.Sh NAME
.Nm fsync
.Nd "synchronise changes to a file"
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn fsync "int fd"
.Sh DESCRIPTION
.Fn Fsync
causes all modified data and attributes of
.Fa fd
to be moved to a permanent storage device.
This normally results in all in-core modified copies
of buffers for the associated file to be written to a disk.
.Pp
.Fn Fsync
should be used by programs that require a file to be
in a known state, for example, in building a simple transaction
facility.
.Sh IMPLEMENTATION NOTES
In the non-threaded library
.Fn fsync
is implemented as the
.Va fsync
syscall.
.Pp
In the threaded library, the
.Va fsync
syscall is assembled to
.Fn _thread_sys_fsync
and
.Fn fsync
is implemented as a function which locks
.Fa fd
for read and write, then calls
.Fn _thread_sys_fsync .
Before returning,
.Fn fsync
unlocks
.Fa fd .
.Sh RETURN VALUES
.Rv -std fsync
.Sh ERRORS
The
.Fn fsync
fails if:
.Bl -tag -width Er
.It Bq Er EBADF
.Fa fd
is not a valid descriptor.
.It Bq Er EINVAL
.Fa fd
refers to a socket, not to a file.
.It Bq Er EIO
An I/O error occurred while reading from or writing to the file system.
.El
.Sh SEE ALSO
.Xr sync 2 ,
.Xr syncer 4 ,
.Xr sync 8
.Sh HISTORY
The
.Fn fsync
function call appeared in
.Bx 4.2 .
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\" Copyright (c) 1983, 1993`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\" 3. All advertising materials mentioning features or use of this software`
			`.\" must display the following acknowledgement:`
			`.\" This product includes software developed by the University of`
			`.\" California, Berkeley and its contributors.`
			`.\" 4. Neither the name of the University nor the names of its contributors`
			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
			`.\" @(#)fsync.2 8.1 (Berkeley) 6/4/93`
$Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00			`.\" $FreeBSD$`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\"`
			`.Dd June 4, 1993`
			`.Dt FSYNC 2`
mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 13:41:46 +00:00			`.Os`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh NAME`
			`.Nm fsync`
Make the NAME section a bit less confusing. PR: 19262 Submitted by: NOKUBI Hirotaka <nokubi@ff.iij4u.or.jp> Reviewed by: sheldonh 2000-07-15 13:04:33 +00:00			`.Nd "synchronise changes to a file"`
Introduce ".Lb" macro to libc manpages. More libraries manpages updates following. 2000-04-21 09:42:15 +00:00			`.Sh LIBRARY`
			`.Lb libc`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh SYNOPSIS`
mdoc(7) police: Use the new .In macro for #include statements. 2001-10-01 16:09:29 +00:00			`.In unistd.h`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Ft int`
			`.Fn fsync "int fd"`
			`.Sh DESCRIPTION`
			`.Fn Fsync`
			`causes all modified data and attributes of`
			`.Fa fd`
			`to be moved to a permanent storage device.`
			`This normally results in all in-core modified copies`
			`of buffers for the associated file to be written to a disk.`
			`.Pp`
			`.Fn Fsync`
			`should be used by programs that require a file to be`
			`in a known state, for example, in building a simple transaction`
			`facility.`
Reviewed by: julian and (hsu?) Submitted by: John Birrel(L?) changes for threadsafe operations 1996-01-22 00:02:33 +00:00			`.Sh IMPLEMENTATION NOTES`
			`In the non-threaded library`
			`.Fn fsync`
			`is implemented as the`
			`.Va fsync`
			`syscall.`
			`.Pp`
			`In the threaded library, the`
			`.Va fsync`
			`syscall is assembled to`
			`.Fn _thread_sys_fsync`
			`and`
			`.Fn fsync`
			`is implemented as a function which locks`
Replace .Va, .Ar and .Nm with .Fa or .Va where necessary, examples: ``.Ar errno'' -> ``.Va errno'' ``.Nm ops'' -> ``.Fa ops'' ``.Va fd'' -> ``.Fa fd'' 2000-06-23 05:05:44 +00:00			`.Fa fd`
Reviewed by: julian and (hsu?) Submitted by: John Birrel(L?) changes for threadsafe operations 1996-01-22 00:02:33 +00:00			`for read and write, then calls`
			`.Fn _thread_sys_fsync .`
			`Before returning,`
			`.Fn fsync`
			`unlocks`
Replace .Va, .Ar and .Nm with .Fa or .Va where necessary, examples: ``.Ar errno'' -> ``.Va errno'' ``.Nm ops'' -> ``.Fa ops'' ``.Va fd'' -> ``.Fa fd'' 2000-06-23 05:05:44 +00:00			`.Fa fd .`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh RETURN VALUES`
Use the ``.Rv -std'' mdoc(7) macro in appropriate cases. Reviewed by: ru 2001-08-09 13:32:13 +00:00			`.Rv -std fsync`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh ERRORS`
			`The`
			`.Fn fsync`
			`fails if:`
			`.Bl -tag -width Er`
			`.It Bq Er EBADF`
Prepare for mdoc(7)NG. 2000-12-29 14:08:20 +00:00			`.Fa fd`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`is not a valid descriptor.`
			`.It Bq Er EINVAL`
Prepare for mdoc(7)NG. 2000-12-29 14:08:20 +00:00			`.Fa fd`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`refers to a socket, not to a file.`
			`.It Bq Er EIO`
			`An I/O error occurred while reading from or writing to the file system.`
			`.El`
			`.Sh SEE ALSO`
			`.Xr sync 2 ,`
Update stale references to update(4) with references to the new syncer(4) manual page. 2000-07-19 07:39:08 +00:00			`.Xr syncer 4 ,`
Added a update(4) man page to describe the kernel initiated update process and changed all of the old references to update(8) to update(4). 1996-02-12 00:45:47 +00:00			`.Xr sync 8`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh HISTORY`
			`The`
Correctly use .Fn instead of .Nm to reference function names in a bunch of man pages. Use the correct .Bx (BSD UNIX) or .At (AT&T UNIX) macros instead of explicitly specifying the version in the text in a bunch of man pages. 1996-08-22 23:31:07 +00:00			`.Fn fsync`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`function call appeared in`
			`.Bx 4.2 .`