Added first part of GEOM kernel API manuals pages.
Documented function and macros are:
- DECLARE_GEOM_CLASS(),
- g_attach(),
- g_detach(),
- g_new_bio(),
- g_clone_bio(),
- g_destroy_bio(),
- g_new_consumer(),
- g_destroy_consumer(),
- g_read_data(),
- g_write_data(),
- g_post_event(),
- g_waitfor_event(),
- g_cancel_event(),
- g_new_geomf(),
- g_destroy_geom(),
- g_new_providerf(),
- g_destroy_provider(),
- g_error_provider(),
- g_provider_by_name(),
- g_wither_geom().
and more to come.
I want to thanks following people for help with those documents:
Slawek Zak <zaks@prioris.mini.pw.edu.pl>
Simon L. Nielsen <simon@FreeBSD.org>
Pieter de Boer <g.p.de.boer@st.hanze.nl>
and of course
Poul-Henning Kamp <phk@FreeBSD.org>
Reviewed by: phk, scottl
Approved by: phk, scottl (mentor)
2004-02-11 10:06:18 +00:00
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.\"
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.\" Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd January 16, 2004
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.Dt g_data 9
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.Os
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.Sh NAME
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.Nm g_read_data ,
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.Nm g_write_data
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.Nd "read/write data through consumer"
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.Sh SYNOPSIS
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.In geom/geom.h
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.Ft "void *"
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.Fn g_read_data "struct g_consumer *cp" "off_t offset" "off_t length" "int *error"
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.Ft int
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.Fn g_write_data "struct g_consumer *cp" "off_t offset" "void *ptr" "off_t length"
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.Sh DESCRIPTION
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The
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.Fn g_read_data
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reads
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.Fa length
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bytes of data from a provider through attached consumer
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.Fa cp
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starting at offset
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.Fa offset .
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Memory for data is allocated inside
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.Fn g_read_data
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with
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.Fn g_malloc ,
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and should therefor be freed by the caller with the
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.Fn g_free
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function after use.
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If the operation fails, an error value will be stored in the
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.Fa error
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argument if it is not
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.Dv NULL .
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.Pp
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The
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.Fn g_write_data
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writes
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.Fa length
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bytes of data from address
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.Fa ptr
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starting at offset
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.Fa offset
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to a provider through the attached consumer
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.Fa cp .
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.Sh RESTRICTIONS/CONDITIONS
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Length of data should be a multiple of the sectorsize for the provider
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and less than or equal to
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.Dv DFLTPHYS
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.Dv ( DFLTPHYS is defined in
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.In sys/param.h ) .
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.Pp
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The topology lock must not be held.
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.Sh RETURN VALUES
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.Fn g_read_data
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returns a pointer to the read data or
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.Dv NULL
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if an error occured.
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In that case an error value is stored in the
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.Fa error
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argument unsless it is
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.Dv NULL .
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.Pp
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.Fn g_write_data
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returns the value 0 if successful; otherwise an error code is returned.
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.Sh ERRORS
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Possible errors:
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.Bl -tag -width Er
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.It Bq Er EIO
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Can not read data.
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.El
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.Sh SEE ALSO
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.Xr DECLARE_GEOM_CLASS 9 ,
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.Xr geom 4 ,
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2004-03-11 19:53:22 +00:00
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.Xr g_access 9 ,
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Added first part of GEOM kernel API manuals pages.
Documented function and macros are:
- DECLARE_GEOM_CLASS(),
- g_attach(),
- g_detach(),
- g_new_bio(),
- g_clone_bio(),
- g_destroy_bio(),
- g_new_consumer(),
- g_destroy_consumer(),
- g_read_data(),
- g_write_data(),
- g_post_event(),
- g_waitfor_event(),
- g_cancel_event(),
- g_new_geomf(),
- g_destroy_geom(),
- g_new_providerf(),
- g_destroy_provider(),
- g_error_provider(),
- g_provider_by_name(),
- g_wither_geom().
and more to come.
I want to thanks following people for help with those documents:
Slawek Zak <zaks@prioris.mini.pw.edu.pl>
Simon L. Nielsen <simon@FreeBSD.org>
Pieter de Boer <g.p.de.boer@st.hanze.nl>
and of course
Poul-Henning Kamp <phk@FreeBSD.org>
Reviewed by: phk, scottl
Approved by: phk, scottl (mentor)
2004-02-11 10:06:18 +00:00
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.Xr g_attach 9 ,
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.Xr g_bio 9 ,
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.Xr g_consumer 9 ,
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.Xr g_event 9 ,
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.Xr g_geom 9 ,
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.Xr g_provider 9 ,
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.Xr g_provider_by_name 9 ,
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.Xr g_wither_geom 9
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.Sh AUTHORS
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.An -nosplit
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This manual page was written by
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.An Pawel Jakub Dawidek Aq pjd@FreeBSD.org .
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