freebsd-dev/sys/geom/geom.h
Poul-Henning Kamp 07107de9bc Introduce the concept of "magic spaces", and implement them in most of
the relevant classes.

Some methods may implement various "magic spaces", this is reserved
or magic areas on the disk, set a side for various and sundry purposes.
A good example is the BSD disklabel and boot code on i386 which occupies
a total of four magic spaces: boot1, the disklabel, the padding behind
the disklabel and boot2.  The reason we don't simply tell people to
write the appropriate stuff on the underlying device is that (some of)
the magic spaces might be real-time modifiable.  It is for instance
possible to change a disklabel while partitions are open, provided
the open partitions do not get trampled in the process.

Sponsored by:	DARPA & NAI Labs.
2002-05-21 20:33:49 +00:00

333 lines
9.7 KiB
C

/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* 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.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
*
* $FreeBSD$
*/
#ifndef _GEOM_GEOM_H_
#define _GEOM_GEOM_H_
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/queue.h>
#include <sys/ioccom.h>
#include <sys/sbuf.h>
#ifdef KERNELSIM
/*
* The GEOM subsystem makes a few concessions in order to be able to run as a
* user-land simulation as well as a kernel component.
*/
#include <geom_sim.h>
#endif
struct g_class;
struct g_geom;
struct g_consumer;
struct g_provider;
struct g_event;
struct thread;
struct bio;
struct sbuf;
struct g_magicspaces;
typedef struct g_geom * g_create_geom_t (struct g_class *mp,
struct g_provider *pp, char *name);
typedef struct g_geom * g_taste_t (struct g_class *, struct g_provider *,
int flags);
#define G_TF_NORMAL 0
#define G_TF_INSIST 1
#define G_TF_TRANSPARENT 2
typedef int g_access_t (struct g_provider *, int, int, int);
/* XXX: not sure about the thread arg */
typedef void g_orphan_t (struct g_consumer *);
typedef void g_start_t (struct bio *);
typedef void g_spoiled_t (struct g_consumer *);
typedef void g_dumpconf_t (struct sbuf *, char *indent, struct g_geom *,
struct g_consumer *, struct g_provider *);
/*
* The g_class structure describes a transformation class. In other words
* all BSD disklabel handlers share one g_class, all MBR handlers share
* one common g_class and so on.
* Certain operations are instantiated on the class, most notably the
* taste and create_geom functions.
*/
struct g_class {
char *name;
g_taste_t *taste;
g_create_geom_t *create_geom;
/*
* The remaning elements are private and classes should use
* the G_CLASS_INITSTUFF macro to initialize them.
*/
LIST_ENTRY(g_class) class;
LIST_HEAD(,g_geom) geom;
struct g_event *event;
u_int protect;
};
#define G_CLASS_INITSTUFF { 0, 0 }, { 0 }, 0, 0
/*
* The g_geom is an instance of a g_class.
*/
struct g_geom {
u_int protect;
char *name;
struct g_class *class;
LIST_ENTRY(g_geom) geom;
LIST_HEAD(,g_consumer) consumer;
LIST_HEAD(,g_provider) provider;
TAILQ_ENTRY(g_geom) geoms; /* XXX: better name */
int rank;
g_start_t *start;
g_spoiled_t *spoiled;
g_dumpconf_t *dumpconf;
g_access_t *access;
g_orphan_t *orphan;
void *softc;
struct g_event *event;
unsigned flags;
struct g_magicspaces *magicspaces;
#define G_GEOM_WITHER 1
};
/*
* The g_bioq is a queue of struct bio's.
* XXX: possibly collection point for statistics.
* XXX: should (possibly) be collapsed with sys/bio.h::bio_queue_head.
*/
struct g_bioq {
TAILQ_HEAD(, bio) bio_queue;
struct mtx bio_queue_lock;
int bio_queue_length;
};
/*
* A g_consumer is an attachment point for a g_provider. One g_consumer
* can only be attached to one g_provider, but multiple g_consumers
* can be attached to one g_provider.
*/
struct g_consumer {
u_int protect;
struct g_geom *geom;
LIST_ENTRY(g_consumer) consumer;
struct g_provider *provider;
LIST_ENTRY(g_consumer) consumers; /* XXX: better name */
int acr, acw, ace;
struct g_event *event;
int biocount;
int spoiled;
};
/*
* A g_provider is a "logical disk".
*/
struct g_provider {
u_int protect;
char *name;
LIST_ENTRY(g_provider) provider;
struct g_geom *geom;
LIST_HEAD(,g_consumer) consumers;
int acr, acw, ace;
int error;
struct g_event *event;
TAILQ_ENTRY(g_provider) orphan;
int index;
off_t mediasize;
};
/*
* Some methods may implement various "magic spaces", this is reserved
* or magic areas on the disk, set a side for various and sundry purposes.
* A good example is the BSD disklabel and boot code on i386 which occupies
* a total of four magic spaces: boot1, the disklabel, the padding behind
* the disklabel and boot2. The reason we don't simply tell people to
* write the appropriate stuff on the underlying device is that (some of)
* the magic spaces might be real-time modifiable. It is for instance
* possible to change a disklabel while partitions are open, provided
* the open partitions do not get trampled in the process.
*/
struct g_magicspace {
char name[8];
off_t offset;
u_int len;
u_int flags;
};
struct g_magicspaces {
uintptr_t geom_id;
char class[8];
uint nmagic;
struct g_magicspace *magicspace;
};
/* geom_dump.c */
void g_hexdump(void *ptr, int length);
void g_trace(int level, char *, ...);
# define G_T_TOPOLOGY 1
# define G_T_BIO 2
# define G_T_ACCESS 4
/* geom_enc.c */
uint32_t g_dec_be2(u_char *p);
uint32_t g_dec_be4(u_char *p);
uint32_t g_dec_le2(u_char *p);
uint32_t g_dec_le4(u_char *p);
void g_enc_le4(u_char *p, uint32_t u);
/* geom_event.c */
void g_orphan_provider(struct g_provider *pp, int error);
void g_rattle(void);
void g_silence(void);
/* geom_subr.c */
int g_access_abs(struct g_consumer *cp, int read, int write, int exclusive);
int g_access_rel(struct g_consumer *cp, int read, int write, int exclusive);
void g_add_class(struct g_class *mp);
int g_add_magicspace(struct g_geom *gp, u_int index, const char *name, off_t start, u_int len, u_int flags);
int g_attach(struct g_consumer *cp, struct g_provider *pp);
struct g_geom *g_create_geomf(char *class, struct g_provider *, char *fmt, ...);
void g_destroy_consumer(struct g_consumer *cp);
void g_destroy_geom(struct g_geom *pp);
void g_destroy_provider(struct g_provider *pp);
void g_dettach(struct g_consumer *cp);
void g_error_provider(struct g_provider *pp, int error);
int g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len);
#define g_getattr(a, c, v) g_getattr__((a), (c), (v), sizeof *(v))
int g_haveattr(struct bio *bp, char *attribute, void *val, int len);
int g_haveattr_int(struct bio *bp, char *attribute, int val);
int g_haveattr_off_t(struct bio *bp, char *attribute, off_t val);
struct g_geom * g_insert_geom(char *class, struct g_consumer *cp);
struct g_consumer * g_new_consumer(struct g_geom *gp);
struct g_geom * g_new_geomf(struct g_class *mp, char *fmt, ...);
int g_new_magicspaces(struct g_geom *gp, int nspaces);
struct g_provider * g_new_providerf(struct g_geom *gp, char *fmt, ...);
void g_sanity(void *ptr);
void g_spoil(struct g_provider *pp, struct g_consumer *cp);
int g_std_access(struct g_provider *pp, int dr, int dw, int de);
void g_std_done(struct bio *bp);
void g_std_spoiled(struct g_consumer *cp);
/* geom_io.c */
struct bio * g_clone_bio(struct bio *);
void g_destroy_bio(struct bio *);
void g_io_deliver(struct bio *bp);
void g_io_fail(struct bio *bp, int error);
int g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr);
void g_io_request(struct bio *bp, struct g_consumer *cp);
int g_io_setattr(const char *attr, struct g_consumer *cp, int len, void *ptr);
struct bio *g_new_bio(void);
void * g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error);
/* geom_kern.c / geom_kernsim.c */
struct g_ioctl {
u_long cmd;
void *data;
int fflag;
struct thread *td;
};
#ifdef _KERNEL
struct g_kerneldump {
off_t offset;
off_t length;
};
MALLOC_DECLARE(M_GEOM);
static __inline void *
g_malloc(int size, int flags)
{
void *p;
p = malloc(size, M_GEOM, flags);
g_sanity(p);
/* printf("malloc(%d, %x) -> %p\n", size, flags, p); */
return (p);
}
static __inline void
g_free(void *ptr)
{
g_sanity(ptr);
/* printf("free(%p)\n", ptr); */
free(ptr, M_GEOM);
}
extern struct sx topology_lock;
#define g_topology_lock() \
do { \
mtx_assert(&Giant, MA_NOTOWNED); \
sx_xlock(&topology_lock); \
} while (0)
#define g_topology_unlock() \
do { \
g_sanity(NULL); \
sx_xunlock(&topology_lock); \
} while (0)
#define g_topology_assert() \
do { \
g_sanity(NULL); \
sx_assert(&topology_lock, SX_XLOCKED); \
} while (0)
#define DECLARE_GEOM_CLASS(class, name) \
static void \
name##init(void) \
{ \
mtx_unlock(&Giant); \
g_add_class(&class); \
mtx_lock(&Giant); \
} \
SYSINIT(name, SI_SUB_PSEUDO, SI_ORDER_FIRST, name##init, NULL);
#endif /* _KERNEL */
#define GEOMGETCONF _IOWR('G', 0, struct sbuf)
#endif /* _GEOM_GEOM_H_ */