geom.h revision 102500
1/*-
2 * Copyright (c) 2002 Poul-Henning Kamp
3 * Copyright (c) 2002 Networks Associates Technology, Inc.
4 * All rights reserved.
5 *
6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7 * and NAI Labs, the Security Research Division of Network Associates, Inc.
8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9 * DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The names of the authors may not be used to endorse or promote
20 *    products derived from this software without specific prior written
21 *    permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * $FreeBSD: head/sys/geom/geom.h 98066 2002-06-09 10:57:34Z phk $
36 */
37
38#ifndef _GEOM_GEOM_H_
39#define _GEOM_GEOM_H_
40
41#include <sys/lock.h>
42#include <sys/mutex.h>
43#include <sys/sx.h>
44#include <sys/queue.h>
45#include <sys/ioccom.h>
46#include <sys/sbuf.h>
47
48#ifdef KERNELSIM
49/*
50 * The GEOM subsystem makes a few concessions in order to be able to run as a
51 * user-land simulation as well as a kernel component.
52 */
53#include <geom_sim.h>
54#endif
55
56struct g_class;
57struct g_geom;
58struct g_consumer;
59struct g_provider;
60struct g_event;
61struct thread;
62struct bio;
63struct sbuf;
64struct g_magicspaces;
65
66
67typedef struct g_geom * g_create_geom_t (struct g_class *mp,
68    struct g_provider *pp, char *name);
69typedef struct g_geom * g_taste_t (struct g_class *, struct g_provider *,
70    int flags);
71#define G_TF_NORMAL		0
72#define G_TF_INSIST		1
73#define G_TF_TRANSPARENT	2
74typedef int g_access_t (struct g_provider *, int, int, int);
75/* XXX: not sure about the thread arg */
76typedef void g_orphan_t (struct g_consumer *);
77
78typedef void g_start_t (struct bio *);
79typedef void g_spoiled_t (struct g_consumer *);
80typedef void g_dumpconf_t (struct sbuf *, char *indent, struct g_geom *,
81    struct g_consumer *, struct g_provider *);
82
83/*
84 * The g_class structure describes a transformation class.  In other words
85 * all BSD disklabel handlers share one g_class, all MBR handlers share
86 * one common g_class and so on.
87 * Certain operations are instantiated on the class, most notably the
88 * taste and create_geom functions.
89 */
90struct g_class {
91	char			*name;
92	g_taste_t		*taste;
93	g_create_geom_t		*create_geom;
94	/*
95	 * The remaning elements are private and classes should use
96	 * the G_CLASS_INITIALIZER macro to initialize them.
97         */
98	LIST_ENTRY(g_class)	class;
99	LIST_HEAD(,g_geom)	geom;
100	struct g_event		*event;
101	u_int			protect;
102};
103
104#define G_CLASS_INITIALIZER { 0, 0 }, { 0 }, 0, 0
105
106/*
107 * The g_geom is an instance of a g_class.
108 */
109struct g_geom {
110	u_int			protect;
111	char			*name;
112	struct g_class		*class;
113	LIST_ENTRY(g_geom)	geom;
114	LIST_HEAD(,g_consumer)	consumer;
115	LIST_HEAD(,g_provider)	provider;
116	TAILQ_ENTRY(g_geom)	geoms;	/* XXX: better name */
117	int			rank;
118	g_start_t		*start;
119	g_spoiled_t		*spoiled;
120	g_dumpconf_t		*dumpconf;
121	g_access_t		*access;
122	g_orphan_t		*orphan;
123	void			*softc;
124	struct g_event		*event;
125	unsigned		flags;
126	struct g_magicspaces	*magicspaces;
127#define	G_GEOM_WITHER		1
128};
129
130/*
131 * The g_bioq is a queue of struct bio's.
132 * XXX: possibly collection point for statistics.
133 * XXX: should (possibly) be collapsed with sys/bio.h::bio_queue_head.
134 */
135struct g_bioq {
136	TAILQ_HEAD(, bio)	bio_queue;
137	struct mtx		bio_queue_lock;
138	int			bio_queue_length;
139};
140
141/*
142 * A g_consumer is an attachment point for a g_provider.  One g_consumer
143 * can only be attached to one g_provider, but multiple g_consumers
144 * can be attached to one g_provider.
145 */
146
147struct g_consumer {
148	u_int			protect;
149	struct g_geom		*geom;
150	LIST_ENTRY(g_consumer)	consumer;
151	struct g_provider	*provider;
152	LIST_ENTRY(g_consumer)	consumers;	/* XXX: better name */
153	int			acr, acw, ace;
154	struct g_event		*event;
155
156	int			biocount;
157	int			spoiled;
158};
159
160/*
161 * A g_provider is a "logical disk".
162 */
163struct g_provider {
164	u_int			protect;
165	char			*name;
166	LIST_ENTRY(g_provider)	provider;
167	struct g_geom		*geom;
168	LIST_HEAD(,g_consumer)	consumers;
169	int			acr, acw, ace;
170	int			error;
171	struct g_event		*event;
172	TAILQ_ENTRY(g_provider)	orphan;
173	int			index;
174	off_t			mediasize;
175};
176
177/*
178 * Some methods may implement various "magic spaces", this is reserved
179 * or magic areas on the disk, set a side for various and sundry purposes.
180 * A good example is the BSD disklabel and boot code on i386 which occupies
181 * a total of four magic spaces: boot1, the disklabel, the padding behind
182 * the disklabel and boot2.  The reason we don't simply tell people to
183 * write the appropriate stuff on the underlying device is that (some of)
184 * the magic spaces might be real-time modifiable.  It is for instance
185 * possible to change a disklabel while partitions are open, provided
186 * the open partitions do not get trampled in the process.
187 */
188
189struct g_magicspace {
190	char			name[8];
191	off_t			offset;
192	u_int			len;
193	u_int			flags;
194};
195
196struct g_magicspaces {
197	uintptr_t		geom_id;
198	char			class[8];
199	uint			nmagic;
200	uint			nspace;
201	struct g_magicspace	*magicspace;
202};
203
204/* geom_dump.c */
205void g_hexdump(void *ptr, int length);
206void g_trace(int level, char *, ...);
207#	define G_T_TOPOLOGY	1
208#	define G_T_BIO		2
209#	define G_T_ACCESS	4
210
211/* geom_enc.c */
212uint32_t g_dec_be2(u_char *p);
213uint32_t g_dec_be4(u_char *p);
214uint32_t g_dec_le2(u_char *p);
215uint32_t g_dec_le4(u_char *p);
216void g_enc_le4(u_char *p, uint32_t u);
217
218/* geom_event.c */
219void g_orphan_provider(struct g_provider *pp, int error);
220void g_waitidle(void);
221void g_silence(void);
222
223/* geom_subr.c */
224int g_access_abs(struct g_consumer *cp, int read, int write, int exclusive);
225int g_access_rel(struct g_consumer *cp, int read, int write, int exclusive);
226void g_add_class(struct g_class *mp);
227int g_add_magicspace(struct g_geom *gp, const char *name, off_t start, u_int len, u_int flags);
228int g_attach(struct g_consumer *cp, struct g_provider *pp);
229struct g_geom *g_create_geomf(char *class, struct g_provider *, char *fmt, ...);
230void g_destroy_consumer(struct g_consumer *cp);
231void g_destroy_geom(struct g_geom *pp);
232void g_destroy_provider(struct g_provider *pp);
233void g_detach(struct g_consumer *cp);
234void g_error_provider(struct g_provider *pp, int error);
235int g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len);
236#define g_getattr(a, c, v) g_getattr__((a), (c), (v), sizeof *(v))
237int g_handleattr(struct bio *bp, char *attribute, void *val, int len);
238int g_handleattr_int(struct bio *bp, char *attribute, int val);
239int g_handleattr_off_t(struct bio *bp, char *attribute, off_t val);
240struct g_geom * g_insert_geom(char *class, struct g_consumer *cp);
241struct g_consumer * g_new_consumer(struct g_geom *gp);
242struct g_geom * g_new_geomf(struct g_class *mp, char *fmt, ...);
243struct g_provider * g_new_providerf(struct g_geom *gp, char *fmt, ...);
244void g_sanity(void *ptr);
245void g_spoil(struct g_provider *pp, struct g_consumer *cp);
246int g_std_access(struct g_provider *pp, int dr, int dw, int de);
247void g_std_done(struct bio *bp);
248void g_std_spoiled(struct g_consumer *cp);
249
250/* geom_io.c */
251struct bio * g_clone_bio(struct bio *);
252void g_destroy_bio(struct bio *);
253void g_io_deliver(struct bio *bp);
254void g_io_fail(struct bio *bp, int error);
255int g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr);
256void g_io_request(struct bio *bp, struct g_consumer *cp);
257int g_io_setattr(const char *attr, struct g_consumer *cp, int len, void *ptr);
258struct bio *g_new_bio(void);
259void * g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error);
260
261/* geom_kern.c / geom_kernsim.c */
262
263struct g_ioctl {
264	u_long		cmd;
265	void		*data;
266	int		fflag;
267	struct thread	*td;
268};
269
270#ifdef _KERNEL
271
272struct g_kerneldump {
273	off_t		offset;
274	off_t		length;
275};
276
277MALLOC_DECLARE(M_GEOM);
278
279static __inline void *
280g_malloc(int size, int flags)
281{
282	void *p;
283
284	p = malloc(size, M_GEOM, flags);
285	g_sanity(p);
286	/* printf("malloc(%d, %x) -> %p\n", size, flags, p); */
287	return (p);
288}
289
290static __inline void
291g_free(void *ptr)
292{
293	g_sanity(ptr);
294	/* printf("free(%p)\n", ptr); */
295	free(ptr, M_GEOM);
296}
297
298extern struct sx topology_lock;
299
300#define g_topology_lock() 					\
301	do {							\
302		mtx_assert(&Giant, MA_NOTOWNED);		\
303		sx_xlock(&topology_lock);			\
304	} while (0)
305
306#define g_topology_unlock()					\
307	do {							\
308		g_sanity(NULL);					\
309		sx_xunlock(&topology_lock);			\
310	} while (0)
311
312#define g_topology_assert()					\
313	do {							\
314		g_sanity(NULL);					\
315		sx_assert(&topology_lock, SX_XLOCKED);		\
316	} while (0)
317
318#define DECLARE_GEOM_CLASS(class, name) 	\
319	static void				\
320	name##init(void)			\
321	{					\
322		mtx_unlock(&Giant);		\
323		g_add_class(&class);		\
324		mtx_lock(&Giant);		\
325	}					\
326	SYSINIT(name, SI_SUB_PSEUDO, SI_ORDER_FIRST, name##init, NULL);
327
328#endif /* _KERNEL */
329
330#define GEOMGETCONF _IOWR('G',  0, struct sbuf)
331
332#endif /* _GEOM_GEOM_H_ */
333