minix/lib/libc/sys/fdatasync.2
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

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Groff

.\" $NetBSD: fdatasync.2,v 1.16 2008/04/30 13:10:51 martin Exp $
.\"
.\" Copyright (c) 1998 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Klaus Klein.
.\"
.\" 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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
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.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd October 25, 2003
.Dt FDATASYNC 2
.Os
.Sh NAME
.Nm fdatasync
.Nd synchronize the data of a file
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn fdatasync "int fd"
.Sh DESCRIPTION
The
.Fn fdatasync
function forces all modified data associated with the file descriptor
.Fa fd
to be flushed to stable storage.
.Pp
The functionality is as described for
.Xr fsync 2 ,
with the exception that file status information need not be synchronized,
which may result in a performance gain, compared to
.Xr fsync 2 .
This behaviour is commonly known as
.Bf -symbolic
synchronized I/O data integrity completion.
.Ef
.Sh RETURN VALUES
A value of 0 is returned on success.
Otherwise, a value \-1 is returned and
.Va errno
is set to indicate the error.
.Sh ERRORS
The
.Fn fdatasync
function will fail if:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid file descriptor open for writing.
.It Bq Er EINVAL
This implementation does not support synchronized I/O for this file.
.It Bq Er ENOSYS
The
.Fn fdatasync
function is not supported by this implementation.
.El
.Pp
In the event that any of the I/O operations to be performed fail,
.Fn fdatasync
returns the error conditions defined for
.Xr read 2
and
.Xr write 2 ,
and outstanding I/O operations are not guaranteed to have been completed.
.Sh SEE ALSO
.Xr fsync 2 ,
.Xr open 2 ,
.Xr read 2 ,
.Xr write 2
.Sh STANDARDS
The
.Fn fdatasync
function conforms to
.St -p1003.1b-93 .