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diff --git a/share/man/man9/DECLARE_GEOM_CLASS.9 b/share/man/man9/DECLARE_GEOM_CLASS.9 new file mode 100644 index 0000000..a6dc969 --- /dev/null +++ b/share/man/man9/DECLARE_GEOM_CLASS.9 @@ -0,0 +1,179 @@ +.\" +.\" Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org> +.\" All rights reserved. +.\" +.\" 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 DEVELOPERS ``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 DEVELOPERS 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 INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd August 13, 2007 +.Dt DECLARE_GEOM_CLASS 9 +.Os +.Sh NAME +.Nm DECLARE_GEOM_CLASS +.Nd "GEOM class declaration macro" +.Sh SYNOPSIS +.In geom/geom.h +.Fn DECLARE_GEOM_CLASS "class" "mod_name" +.Sh DESCRIPTION +The +.Fn DECLARE_GEOM_CLASS +macro registers a GEOM class in GEOM. +A GEOM class itself implements one particular kind of transformation. +Typical examples are: MBR disk partition, +.Bx +disklabel and RAID5 classes. +.Fn DECLARE_GEOM_CLASS +can be used both for compiled in and loaded as +.Xr kld 4 +modules GEOM classes and it is the only official way for class registration. +.Pp +The arguments to +.Fn DECLARE_GEOM_CLASS +are: +.Bl -tag -offset indent -width Fa +.It Fa class +The +.Vt g_class +structure which describes a GEOM class. +.It Fa mod_name +A kernel module name (not a class name!). +.El +.Pp +Structure +.Vt g_class +contains data describing the class. +They are: +.Bl -tag -offset indent -width indent +.It Vt "const char *" Va name +Class name. +.It Vt "g_taste_t *" Va taste +Pointer to function used for taste event handling. +If it is +.Pf non- Dv NULL +it is called in three situations: +.Pp +.Bl -dash -compact +.It +On class activation, all existing providers are offered for tasting. +.It +When new provider is created it is offered for tasting. +.It +After last write access to a provider is closed it is offered for retasting +(on first write open event +.Dq spoil +was sent). +.El +.It Vt "g_config_t *" Va config +This field is not used anymore, its functionality was replaced by the +.Va ctlreq +field. +.It Vt "g_ctl_req_t *" Va ctlreq +Pointer to function used for handling events from userland applications. +.It Vt "g_init_t *" Va init +Pointer to function which is called right after class registration. +.It Vt "g_fini_t *" Va fini +Pointer to function which is called right before class deregistration. +.It Vt "g_ctl_destroy_geom_t *" Va destroy_geom +Pointer to a function which is called for every geom on class unload. +If this field is not set, the class can not be unloaded. +.El +.Pp +Only a +.Fa name +field is required; the rest are optional. +.Sh RESTRICTIONS/CONDITIONS +The fields of +.Vt g_class +should always be initialized using C99-style field naming +(see the initialization of +.Va example_class +below). +.Sh EXAMPLES +Example class declaration. +.Bd -literal -offset indent +static struct g_geom * +g_example_taste(struct g_class *mp, struct g_provider *pp, + int flags __unused) +{ + g_topology_assert(); + + [...] +} + +static void +g_example_ctlreq(struct gctl_req *req, struct g_class *cp, + char const *verb) +{ + + [...] +} + +static int +g_example_destroy_geom(struct gctl_req *req, struct g_class *cp, + struct g_geom *gp) +{ + + g_topology_assert(); + + [...] +} + +static void +g_example_init(struct g_class *mp) +{ + + [...] +} + +static void +g_example_fini(struct g_class *mp) +{ + + [...] +} + +struct g_class example_class = { + .name = "EXAMPLE", + .taste = g_example_taste, + .ctlreq = g_example_ctlreq, + .init = g_example_init, + .fini = g_example_fini, + .destroy_geom = g_example_destroy_geom +}; + +DECLARE_GEOM_CLASS(example_class, g_example); +.Ed +.Sh SEE ALSO +.Xr geom 4 , +.Xr g_attach 9 , +.Xr g_bio 9 , +.Xr g_consumer 9 , +.Xr g_data 9 , +.Xr g_event 9 , +.Xr g_geom 9 , +.Xr g_provider 9 , +.Xr g_provider_by_name 9 , +.Xr g_wither_geom 9 +.Sh AUTHORS +.An -nosplit +This manual page was written by +.An Pawel Jakub Dawidek Aq Mt pjd@FreeBSD.org . |
