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.Dd January 16, 2004 26.Dt G_PROVIDER 9 27.Os 28.Sh NAME 29.Nm g_new_providerf , 30.Nm g_destroy_provider , 31.Nm g_error_provider 32.Nd "GEOM providers management" 33.Sh SYNOPSIS 34.In geom/geom.h 35.Ft "struct g_provider *" 36.Fn g_new_providerf "struct g_geom *gp" "const char *fmt" ... 37.Ft void 38.Fn g_destroy_provider "struct g_provider *pp" 39.Ft void 40.Fn g_error_provider "struct g_provider *pp" "int error" 41.Sh DESCRIPTION 42A GEOM provider is the front gate at which a geom offers service. 43A provider is 44.Dq a disk-like thing which appears in Pa /dev 45\[en] a logical disk in other words. 46All providers have three main properties: name, sectorsize and size. 47.Pp 48The 49.Fn g_new_providerf 50function creates a new provider on given geom 51.Fa gp . 52The name of the provider, which will appear as device in 53.Xr devfs 5 , 54is created 55in a 56.Xr printf 3 Ns 57-like way from the rest of 58the arguments. 59After creation, the caller has to set the provider's 60.Va mediasize 61and 62.Va sectorsize , 63as well as other desired initializations, and then call 64.Fn g_error_provider 65to reset the provider's error, which is initially set to 66.Er ENXIO . 67.Pp 68The 69.Fn g_destroy_provider 70function destroys the given provider, cancels all related pending events and 71removes the corresponding devfs entry. 72.Pp 73The 74.Fn g_error_provider 75function is used to set the provider's error value. 76If set to a nonzero, all I/O requests will be denied, 77as well as increasing its access count will not be possible (error 78.Fa error 79will be returned). 80.Sh RESTRICTIONS/CONDITIONS 81.Fn g_new_provider : 82.Bl -item -offset indent 83.It 84The provider name should be unique, but this is not enforced by GEOM. 85If the name is not unique, one will end up with two (or more) files 86with the same name, which is a programmer error. 87.It 88The geom 89.Fa gp 90has to have a 91.Fa start 92method defined. 93.It 94The topology lock has to be held. 95.El 96.Pp 97.Fn g_destroy_provider : 98.Bl -item -offset indent 99.It 100The provider must not have consumers attached. 101.It 102The access count has to be 0. 103.It 104The topology lock has to be held. 105.El 106.Sh RETURN VALUES 107The 108.Fn g_new_providerf 109function returns a pointer to the newly created provider. 110.Sh EXAMPLES 111Create an example provider, set its parameters and make it usable. 112.Bd -literal -offset indent 113struct g_provider * 114create_example_provider(struct g_geom *gp) 115{ 116 struct g_provider *pp; 117 118 g_topology_lock(); 119 pp = g_new_providerf(gp, "example_provider"); 120 g_topology_unlock(); 121 pp->mediasize = 65536; 122 pp->sectorsize = 512; 123 g_error_provider(pp, 0); 124 125 return (pp); 126} 127.Ed 128.Sh SEE ALSO 129.Xr geom 4 , 130.Xr DECLARE_GEOM_CLASS 9 , 131.Xr g_access 9 , 132.Xr g_attach 9 , 133.Xr g_bio 9 , 134.Xr g_consumer 9 , 135.Xr g_data 9 , 136.Xr g_event 9 , 137.Xr g_geom 9 , 138.Xr g_provider_by_name 9 , 139.Xr g_wither_geom 9 140.Sh AUTHORS 141.An -nosplit 142This manual page was written by 143.An Pawel Jakub Dawidek Aq Mt pjd@FreeBSD.org . 144