summaryrefslogtreecommitdiff
path: root/usr/src/uts/common/sys/lofi.h
blob: cea712381584dfce56d45675563fd09a0ade6842 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


#ifndef	_SYS_LOFI_H
#define	_SYS_LOFI_H

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/types.h>
#include <sys/time.h>
#include <sys/taskq.h>
#include <sys/vtoc.h>
#include <sys/dkio.h>
#include <sys/vnode.h>

#ifdef	__cplusplus
extern "C" {
#endif

/*
 * /dev names:
 *	/dev/lofictl	- master control device
 *	/dev/lofi	- block devices, named by minor number
 *	/dev/rlofi	- character devices, named by minor number
 */
#define	LOFI_DRIVER_NAME	"lofi"
#define	LOFI_CTL_NODE		"ctl"
#define	LOFI_CTL_NAME		LOFI_DRIVER_NAME LOFI_CTL_NODE
#define	LOFI_BLOCK_NAME		LOFI_DRIVER_NAME
#define	LOFI_CHAR_NAME		"r" LOFI_DRIVER_NAME

#define	SEGHDR		1
#define	COMPRESSED	1
#define	UNCOMPRESSED	0
#define	MAXALGLEN	36

/*
 *
 * Use is:
 *	ld = open("/dev/lofictl", O_RDWR | O_EXCL);
 *
 * lofi must be opened exclusively. Access is controlled by permissions on
 * the device, which is 644 by default. Write-access is required for ioctls
 * that change state, but only read-access is required for the ioctls that
 * return information. Basically, only root can add and remove files, but
 * non-root can look at the current lists.
 *
 * ioctl usage:
 *
 * kernel ioctls
 *
 *	strcpy(li.li_filename, "somefilename");
 *	ioctl(ld, LOFI_MAP_FILE, &li);
 *	newminor = li.li_minor;
 *
 *	strcpy(li.li_filename, "somefilename");
 *	ioctl(ld, LOFI_UNMAP_FILE, &li);
 *
 *	strcpy(li.li_filename, "somefilename");
 *	li.li_minor = minor_number;
 *	ioctl(ld, LOFI_MAP_FILE_MINOR, &li);
 *
 *	li.li_minor = minor_number;
 *	ioctl(ld, LOFI_UNMAP_FILE_MINOR, &li);
 *
 *	li.li_minor = minor_number;
 *	ioctl(ld, LOFI_GET_FILENAME, &li);
 *
 *	strcpy(li.li_filename, "somefilename");
 *	ioctl(ld, LOFI_GET_MINOR, &li);
 *
 *	li.li_minor = 0;
 *	ioctl(ld, LOFI_GET_MAXMINOR, &li);
 *	maxminor = li.li_minor;
 *
 *	strcpy(li.li_filename, "somefilename");
 *	li.li_minor = 0;
 *	ioctl(ld, LOFI_CHECK_COMPRESSED, &li);
 *
 * If the 'li_force' flag is set for any of the LOFI_UNMAP_* commands, then if
 * the device is busy, the underlying vnode will be closed, and any subsequent
 * operations will fail.  It will behave as if the device had been forcibly
 * removed, so the DKIOCSTATE ioctl will return DKIO_DEV_GONE.  When the device
 * is last closed, it will be torn down.
 *
 * Oh, and last but not least: these ioctls are totally private and only
 * for use by lofiadm(1M).
 *
 */

struct lofi_ioctl {
	uint32_t 	li_minor;
	boolean_t	li_force;
	char	li_filename[MAXPATHLEN + 1];
	char	li_algorithm[MAXALGLEN];
};

#define	LOFI_IOC_BASE		(('L' << 16) | ('F' << 8))

#define	LOFI_MAP_FILE		(LOFI_IOC_BASE | 0x01)
#define	LOFI_MAP_FILE_MINOR	(LOFI_IOC_BASE | 0x02)
#define	LOFI_UNMAP_FILE		(LOFI_IOC_BASE | 0x03)
#define	LOFI_UNMAP_FILE_MINOR	(LOFI_IOC_BASE | 0x04)
#define	LOFI_GET_FILENAME	(LOFI_IOC_BASE | 0x05)
#define	LOFI_GET_MINOR		(LOFI_IOC_BASE | 0x06)
#define	LOFI_GET_MAXMINOR	(LOFI_IOC_BASE | 0x07)
#define	LOFI_CHECK_COMPRESSED	(LOFI_IOC_BASE | 0x08)

/*
 * file types that might be usable with lofi, maybe. Only regular
 * files are documented though.
 */
#define	S_ISLOFIABLE(mode) \
	(S_ISREG(mode) || S_ISBLK(mode) || S_ISCHR(mode))

#if defined(_KERNEL)

/*
 * We limit the maximum number of active lofi devices to 128, which seems very
 * large. You can tune this by changing lofi_max_files in /etc/system.
 * If you change it dynamically, which you probably shouldn't do, make sure
 * to only _increase_ it.
 */
#define	LOFI_MAX_FILES	128
extern uint32_t lofi_max_files;

#define	V_ISLOFIABLE(vtype) \
	((vtype == VREG) || (vtype == VBLK) || (vtype == VCHR))

struct lofi_state {
	char		*ls_filename;	/* filename to open */
	size_t		ls_filename_sz;
	struct vnode	*ls_vp;		/* open vnode */
	kmutex_t	ls_vp_lock;	/* protects ls_vp */
	kcondvar_t	ls_vp_cv;	/* signal changes to ls_vp */
	uint32_t	ls_vp_iocount;	/* # pending I/O requests */
	boolean_t	ls_vp_closereq;	/* force close requested */
	u_offset_t	ls_vp_size;
	uint32_t	ls_blk_open;
	uint32_t	ls_chr_open;
	uint32_t	ls_lyr_open_count;
	int		ls_openflag;
	taskq_t		*ls_taskq;
	kstat_t		*ls_kstat;
	kmutex_t	ls_kstat_lock;
	struct dk_geom	ls_dkg;
	struct vtoc	ls_vtoc;
	struct dk_cinfo	ls_ci;

	/* the following fields are required for compression support */
	int		ls_comp_algorithm_index; /* idx into compress_table */
	char		ls_comp_algorithm[MAXALGLEN];
	uint32_t	ls_uncomp_seg_sz; /* sz of uncompressed segment */
	uint32_t	ls_comp_index_sz; /* number of index entries */
	uint32_t	ls_comp_seg_shift; /* exponent for byte shift */
	uint32_t	ls_uncomp_last_seg_sz; /* sz of last uncomp segment */
	uint64_t	ls_comp_offbase; /* offset of actual compressed data */
	uint64_t	*ls_comp_seg_index; /* array of index entries */
	caddr_t		ls_comp_index_data; /* index pages loaded from file */
	uint32_t	ls_comp_index_data_sz;
	u_offset_t	ls_vp_comp_size; /* actual compressed file size */
};

#endif	/* _KERNEL */

/*
 * Common signature for all lofi compress functions
 */
typedef int lofi_compress_func_t(void *src, size_t srclen, void *dst,
	size_t *destlen, int level);

/*
 * Information about each compression function
 */
typedef struct lofi_compress_info {
	lofi_compress_func_t	*l_decompress;
	lofi_compress_func_t	*l_compress;
	int			l_level;
	char			*l_name;	/* algorithm name */
} lofi_compress_info_t;

enum lofi_compress {
	LOFI_COMPRESS_GZIP = 0,
	LOFI_COMPRESS_GZIP_6 = 1,
	LOFI_COMPRESS_GZIP_9 = 2,
	LOFI_COMPRESS_FUNCTIONS
};

#ifdef	__cplusplus
}
#endif

#endif	/* _SYS_LOFI_H */