xref: /freebsd/sys/geom/multipath/g_multipath.h (revision 70e0bbedef95258a4dadc996d641a9bebd3f107d)
1 /*-
2  * Copyright (c) 2006-2007 Matthew Jacob <mjacob@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 AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 /*
29  * Based upon work by Pawel Jakub Dawidek <pjd@FreeBSD.org> for all of the
30  * fine geom examples, and by Poul Henning Kamp <phk@FreeBSD.org> for GEOM
31  * itself, all of which is most gratefully acknowledged.
32  */
33 
34 #ifndef	_G_MULTIPATH_H_
35 #define	_G_MULTIPATH_H_
36 
37 #define	G_MULTIPATH_CLASS_NAME	"MULTIPATH"
38 #define	G_MULTIPATH_VERSION	1
39 #define	G_MULTIPATH_MAGIC	"GEOM::MULTIPATH"
40 
41 #include <sys/endian.h>
42 
43 #ifdef	_KERNEL
44 
45 struct g_multipath_softc {
46 	struct g_provider *	sc_pp;
47 	struct g_consumer *	sc_active;
48 	struct mtx		sc_mtx;
49 	char			sc_name[16];
50 	char			sc_uuid[40];
51 	int			sc_opened;
52 	int			sc_stopping;
53 	int			sc_ndisks;
54 	int			sc_active_active; /* Active/Active mode */
55 };
56 #endif	/* _KERNEL */
57 
58 struct g_multipath_metadata {
59 	char		md_magic[16];	/* Magic Value */
60 	char 		md_uuid[40];	/* more magic */
61 	char		md_name[16];	/* a friendly name */
62 	uint32_t	md_version;	/* version */
63 	uint32_t	md_sectorsize;	/* sectorsize of provider */
64 	uint64_t	md_size;	/* absolute size of provider */
65 	uint8_t		md_active_active; /* Active/Active mode */
66 };
67 
68 static __inline void
69 multipath_metadata_encode(const struct g_multipath_metadata *, u_char *);
70 
71 static __inline void
72 multipath_metadata_decode(u_char *, struct g_multipath_metadata *);
73 
74 static __inline void
75 multipath_metadata_encode(const struct g_multipath_metadata *md, u_char *data)
76 {
77 	bcopy(md->md_magic, data, sizeof(md->md_magic));
78 	data += sizeof(md->md_magic);
79 	bcopy(md->md_uuid, data, sizeof(md->md_uuid));
80 	data += sizeof(md->md_uuid);
81 	bcopy(md->md_name, data, sizeof(md->md_name));
82 	data += sizeof(md->md_name);
83 	le32enc(data, md->md_version);
84 	data += sizeof(md->md_version);
85 	le32enc(data, md->md_sectorsize);
86 	data += sizeof(md->md_sectorsize);
87 	le64enc(data, md->md_size);
88 	data += sizeof(md->md_size);
89 	*data = md->md_active_active;
90 }
91 
92 static __inline void
93 multipath_metadata_decode(u_char *data, struct g_multipath_metadata *md)
94 {
95 	bcopy(data, md->md_magic, sizeof(md->md_magic));
96 	data += sizeof(md->md_magic);
97 	bcopy(data, md->md_uuid, sizeof(md->md_uuid));
98 	data += sizeof(md->md_uuid);
99 	bcopy(data, md->md_name, sizeof(md->md_name));
100 	data += sizeof(md->md_name);
101 	md->md_version = le32dec(data);
102 	data += sizeof(md->md_version);
103 	md->md_sectorsize = le32dec(data);
104 	data += sizeof(md->md_sectorsize);
105 	md->md_size = le64dec(data);
106 	data += sizeof(md->md_size);
107 	md->md_active_active = *data;
108 }
109 #endif	/* _G_MULTIPATH_H_ */
110