NAME¶
g_new_geomf
,
g_destroy_geom
—
geom management
SYNOPSIS¶
#include
<geom/geom.h>
struct g_geom *
g_new_geomf
(
struct
g_class *mp,
const char *fmt,
...);
void
g_destroy_geom
(
struct
g_geom *gp);
DESCRIPTION¶
The geom (do not confuse “geom” with “GEOM”) is an
instance of a GEOM class. For example: in a typical i386
FreeBSD system, there will be one geom of class MBR
for each disk. The geom's name is not really important, it is only used in the
XML dump and for debugging purposes. There can be many geoms with the same
name.
The
g_new_geomf
() function creates a new
geom, which will be an instance of the class
mp. The geom's name is created in a
printf(3)-like way from the rest of the
arguments.
The
g_destroy_geom
() function destroys the
given geom immediately and cancels all related pending events.
The
g_geom structure contains fields that
should be set by the caller after geom creation, but before creating any
providers or consumers related to this geom (not all are required):
- g_start_t *
start
- Pointer to a function used for I/O processing.
- g_spoiled_t *
spoiled
- Pointer to a function used for consumers spoiling.
- g_dumpconf_t *
dumpconf
- Pointer to a function used for configuration in XML format dumping.
- g_access_t *
access
- Pointer to a function used for access control.
- g_orphan_t *
orphan
- Pointer to a function used to inform about orphaned consumer.
- g_ioctl_t *
ioctl
- Pointer to a function used for handling ioctl requests.
- void *
softc
- Field for private use.
RESTRICTIONS/CONDITIONS¶
If you intend to use providers in this geom you must set field
start of your geom.
If you are planning to use consumers in your geom you must set fields
orphan and
access for it.
g_new_geomf
():
- Class mp must be valid (registered in
GEOM).
- The topology lock has to be held.
g_destroy_geom
():
- The geom cannot possess any providers.
- The geom cannot possess any consumers.
- The topology lock has to be held.
RETURN VALUES¶
The
g_new_geomf
() function returns a pointer
to the newly created geom.
EXAMPLES¶
Create an example geom.
static struct geom *
g_example_start(struct bio *bp)
{
[...]
}
static void
g_example_orphan(struct g_consumer *cp)
{
g_topology_assert();
[...]
}
static void
g_example_spoiled(struct g_consumer *cp)
{
g_topology_assert();
[...]
}
static void
g_example_access(struct g_provider *pp, int dr, int dw, int de)
{
[...]
}
static struct g_geom *
create_example_geom(struct g_class *myclass)
{
struct g_geom *gp;
g_topology_lock();
gp = g_new_geomf(myclass, "example_geom");
g_topology_unlock();
gp->start = g_example_start;
gp->orphan = g_example_orphan;
gp->spoiled = g_example_spoiled;
gp->access = g_example_access;
gp->softc = NULL;
return (gp);
}
static int
destroy_example_geom(struct g_geom *gp)
{
g_topology_lock();
if (!LIST_EMPTY(&gp->provider) ||
!LIST_EMPTY(&gp->consumer)) {
g_topology_unlock();
return (EBUSY);
}
g_destroy_geom(gp);
g_topology_unlock();
return (0);
}
SEE ALSO¶
geom(4),
DECLARE_GEOM_CLASS(9),
g_access(9),
g_attach(9),
g_bio(9),
g_consumer(9),
g_data(9),
g_event(9),
g_provider(9),
g_provider_by_name(9),
g_wither_geom(9)
AUTHORS¶
This manual page was written by
Pawel Jakub
Dawidek ⟨pjd@FreeBSD.org⟩.