1.\" 2.\" Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 15.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 18.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd January 16, 2004 28.Dt g_provider 9 29.Os 30.Sh NAME 31.Nm g_new_providerf , 32.Nm g_destroy_provider , 33.Nm g_error_provider 34.Nd "GEOM providers management" 35.Sh SYNOPSIS 36.In geom/geom.h 37.Ft "struct g_provider *" 38.Fn g_new_providerf "struct g_geom *gp" "const char *fmt" ... 39.Ft void 40.Fn g_destroy_provider "struct g_provider *pp" 41.Ft void 42.Fn g_error_provider "struct g_provider *pp" "int error" 43.Sh DESCRIPTION 44A GEOM provider is the front gate at which a geom offers service. 45A provider is 46.Dq a disk\-like thing which appears in Pa /dev 47\- a logical disk in other words. 48All providers have three main properties: name, sectorsize and size. 49.Pp 50The 51.Fn g_new_providerf 52function creates a new provider on given geom 53.Fa gp . 54The name of the provider, which will appear as device in devfs, is created 55in a printf-like way from the rest of 56the arguments. 57After creation, the caller has to set the provider's 58.Va mediasize 59and 60.Va sectorsize , 61as well as other desired initializations, and then call 62.Fn g_error_provider 63to reset the provider's error, which is initially set to 64.Er ENXIO . 65.Pp 66The 67.Fn g_destroy_provider 68function destroys the given provider, cancels all related pending events and 69removes the corresponding devfs entry. 70.Pp 71The 72.Fn g_error_provider 73function is used to set the provider's error value. 74If set to a nonzero, all I/O requests will be denied, 75as well as increasing its access count will not be possible (error 76.Fa error 77will be returned). 78.Sh RESTRICTIONS/CONDITIONS 79.Fn g_new_provider : 80.Bl -item -offset indent 81.It 82The provider name should be unique, but this is not enforced by GEOM. 83If the name is not unique, one will end up with two (or more) files 84with the same name, which is a programmer error. 85.It 86The geom 87.Fa gp 88has to have a 89.Fa start 90method defined. 91.It 92The topology lock has to be held. 93.El 94.Pp 95.Fn g_destroy_provider : 96.Bl -item -offset indent 97.It 98The provider must not have consumers attached. 99.It 100The access count has to be 0. 101.It 102The topology lock has to be held. 103.El 104.Sh RETURN VALUES 105The 106.Fn g_new_providerf 107function returns a pointer to the newly created provider. 108.Sh EXAMPLES 109Create an example provider, set its parameters and make it usable. 110.Bd -literal -offset indent 111struct g_provider * 112create_example_provider(struct g_geom *gp) 113{ 114 struct g_provider *pp; 115 116 g_topology_lock(); 117 pp = g_new_providerf(gp, "example_provider"); 118 g_topology_unlock(); 119 pp->mediasize = 65536; 120 pp->sectorsize = 512; 121 g_error_provider(pp, 0); 122 123 return (pp); 124} 125.Ed 126.Sh SEE ALSO 127.Xr DECLARE_GEOM_CLASS 9 , 128.Xr geom 4 , 129.Xr g_access 9 , 130.Xr g_attach 9 , 131.Xr g_bio 9 , 132.Xr g_consumer 9 , 133.Xr g_data 9 , 134.Xr g_event 9 , 135.Xr g_geom 9 , 136.Xr g_provider_by_name 9 , 137.Xr g_wither_geom 9 138.Sh AUTHORS 139.An -nosplit 140This manual page was written by 141.An Pawel Jakub Dawidek Aq pjd@FreeBSD.org . 142