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\[en] 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 55.Xr devfs 5 , 56is created 57in a 58.Xr printf 3 Ns 59-like way from the rest of 60the arguments. 61After creation, the caller has to set the provider's 62.Va mediasize 63and 64.Va sectorsize , 65as well as other desired initializations, and then call 66.Fn g_error_provider 67to reset the provider's error, which is initially set to 68.Er ENXIO . 69.Pp 70The 71.Fn g_destroy_provider 72function destroys the given provider, cancels all related pending events and 73removes the corresponding devfs entry. 74.Pp 75The 76.Fn g_error_provider 77function is used to set the provider's error value. 78If set to a nonzero, all I/O requests will be denied, 79as well as increasing its access count will not be possible (error 80.Fa error 81will be returned). 82.Sh RESTRICTIONS/CONDITIONS 83.Fn g_new_provider : 84.Bl -item -offset indent 85.It 86The provider name should be unique, but this is not enforced by GEOM. 87If the name is not unique, one will end up with two (or more) files 88with the same name, which is a programmer error. 89.It 90The geom 91.Fa gp 92has to have a 93.Fa start 94method defined. 95.It 96The topology lock has to be held. 97.El 98.Pp 99.Fn g_destroy_provider : 100.Bl -item -offset indent 101.It 102The provider must not have consumers attached. 103.It 104The access count has to be 0. 105.It 106The topology lock has to be held. 107.El 108.Sh RETURN VALUES 109The 110.Fn g_new_providerf 111function returns a pointer to the newly created provider. 112.Sh EXAMPLES 113Create an example provider, set its parameters and make it usable. 114.Bd -literal -offset indent 115struct g_provider * 116create_example_provider(struct g_geom *gp) 117{ 118 struct g_provider *pp; 119 120 g_topology_lock(); 121 pp = g_new_providerf(gp, "example_provider"); 122 g_topology_unlock(); 123 pp->mediasize = 65536; 124 pp->sectorsize = 512; 125 g_error_provider(pp, 0); 126 127 return (pp); 128} 129.Ed 130.Sh SEE ALSO 131.Xr geom 4 , 132.Xr DECLARE_GEOM_CLASS 9 , 133.Xr g_access 9 , 134.Xr g_attach 9 , 135.Xr g_bio 9 , 136.Xr g_consumer 9 , 137.Xr g_data 9 , 138.Xr g_event 9 , 139.Xr g_geom 9 , 140.Xr g_provider_by_name 9 , 141.Xr g_wither_geom 9 142.Sh AUTHORS 143.An -nosplit 144This manual page was written by 145.An Pawel Jakub Dawidek Aq Mt pjd@FreeBSD.org . 146