xref: /freebsd/stand/userboot/userboot/userboot_disk.c (revision 8df8b2d3e51d1b816201d8a1fe8bc29fe192e562)
1 /*-
2  * Copyright (c) 2011 Google, Inc.
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 AUTHOR 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 AUTHOR 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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * Userboot disk image handling.
32  */
33 
34 #include <sys/disk.h>
35 #include <stand.h>
36 #include <stdarg.h>
37 #include <bootstrap.h>
38 
39 #include "disk.h"
40 #include "libuserboot.h"
41 
42 struct userdisk_info {
43 	uint64_t	mediasize;
44 	uint16_t	sectorsize;
45 	int		ud_open;	/* reference counter */
46 	void		*ud_bcache;	/* buffer cache data */
47 };
48 
49 int userboot_disk_maxunit = 0;
50 
51 static int userdisk_maxunit = 0;
52 static struct userdisk_info	*ud_info;
53 
54 static int	userdisk_init(void);
55 static void	userdisk_cleanup(void);
56 static int	userdisk_strategy(void *devdata, int flag, daddr_t dblk,
57 		    size_t size, char *buf, size_t *rsize);
58 static int	userdisk_realstrategy(void *devdata, int flag, daddr_t dblk,
59 		    size_t size, char *buf, size_t *rsize);
60 static int	userdisk_open(struct open_file *f, ...);
61 static int	userdisk_close(struct open_file *f);
62 static int	userdisk_ioctl(struct open_file *f, u_long cmd, void *data);
63 static int	userdisk_print(int verbose);
64 
65 struct devsw userboot_disk = {
66 	"disk",
67 	DEVT_DISK,
68 	userdisk_init,
69 	userdisk_strategy,
70 	userdisk_open,
71 	userdisk_close,
72 	userdisk_ioctl,
73 	userdisk_print,
74 	userdisk_cleanup
75 };
76 
77 /*
78  * Initialize userdisk_info structure for each disk.
79  */
80 static int
81 userdisk_init(void)
82 {
83 	off_t mediasize;
84 	u_int sectorsize;
85 	int i;
86 
87 	userdisk_maxunit = userboot_disk_maxunit;
88 	if (userdisk_maxunit > 0) {
89 		ud_info = malloc(sizeof(*ud_info) * userdisk_maxunit);
90 		if (ud_info == NULL)
91 			return (ENOMEM);
92 		for (i = 0; i < userdisk_maxunit; i++) {
93 			if (CALLBACK(diskioctl, i, DIOCGSECTORSIZE,
94 			    &sectorsize) != 0 || CALLBACK(diskioctl, i,
95 			    DIOCGMEDIASIZE, &mediasize) != 0)
96 				return (ENXIO);
97 			ud_info[i].mediasize = mediasize;
98 			ud_info[i].sectorsize = sectorsize;
99 			ud_info[i].ud_open = 0;
100 			ud_info[i].ud_bcache = NULL;
101 		}
102 	}
103 	bcache_add_dev(userdisk_maxunit);
104 	return(0);
105 }
106 
107 static void
108 userdisk_cleanup(void)
109 {
110 
111 	if (userdisk_maxunit > 0)
112 		free(ud_info);
113 }
114 
115 /*
116  * Print information about disks
117  */
118 static int
119 userdisk_print(int verbose)
120 {
121 	struct disk_devdesc dev;
122 	char line[80];
123 	int i, ret = 0;
124 
125 	if (userdisk_maxunit == 0)
126 		return (0);
127 
128 	printf("%s devices:", userboot_disk.dv_name);
129 	if ((ret = pager_output("\n")) != 0)
130 		return (ret);
131 
132 	for (i = 0; i < userdisk_maxunit; i++) {
133 		snprintf(line, sizeof(line),
134 		    "    disk%d:   Guest drive image\n", i);
135 		ret = pager_output(line);
136 		if (ret != 0)
137 			break;
138 		dev.dd.d_dev = &userboot_disk;
139 		dev.dd.d_unit = i;
140 		dev.d_slice = -1;
141 		dev.d_partition = -1;
142 		if (disk_open(&dev, ud_info[i].mediasize,
143 		    ud_info[i].sectorsize) == 0) {
144 			snprintf(line, sizeof(line), "    disk%d", i);
145 			ret = disk_print(&dev, line, verbose);
146 			disk_close(&dev);
147 			if (ret != 0)
148 				break;
149 		}
150 	}
151 	return (ret);
152 }
153 
154 /*
155  * Attempt to open the disk described by (dev) for use by (f).
156  */
157 static int
158 userdisk_open(struct open_file *f, ...)
159 {
160 	va_list			ap;
161 	struct disk_devdesc	*dev;
162 
163 	va_start(ap, f);
164 	dev = va_arg(ap, struct disk_devdesc *);
165 	va_end(ap);
166 
167 	if (dev->dd.d_unit < 0 || dev->dd.d_unit >= userdisk_maxunit)
168 		return (EIO);
169 	ud_info[dev->dd.d_unit].ud_open++;
170 	if (ud_info[dev->dd.d_unit].ud_bcache == NULL)
171 		ud_info[dev->dd.d_unit].ud_bcache = bcache_allocate();
172 	return (disk_open(dev, ud_info[dev->dd.d_unit].mediasize,
173 	    ud_info[dev->dd.d_unit].sectorsize));
174 }
175 
176 static int
177 userdisk_close(struct open_file *f)
178 {
179 	struct disk_devdesc *dev;
180 
181 	dev = (struct disk_devdesc *)f->f_devdata;
182 	ud_info[dev->dd.d_unit].ud_open--;
183 	if (ud_info[dev->dd.d_unit].ud_open == 0) {
184 		bcache_free(ud_info[dev->dd.d_unit].ud_bcache);
185 		ud_info[dev->dd.d_unit].ud_bcache = NULL;
186 	}
187 	return (disk_close(dev));
188 }
189 
190 static int
191 userdisk_strategy(void *devdata, int rw, daddr_t dblk, size_t size,
192     char *buf, size_t *rsize)
193 {
194 	struct bcache_devdata bcd;
195 	struct disk_devdesc *dev;
196 
197 	dev = (struct disk_devdesc *)devdata;
198 	bcd.dv_strategy = userdisk_realstrategy;
199 	bcd.dv_devdata = devdata;
200 	bcd.dv_cache = ud_info[dev->dd.d_unit].ud_bcache;
201 	return (bcache_strategy(&bcd, rw, dblk + dev->d_offset,
202 	    size, buf, rsize));
203 }
204 
205 static int
206 userdisk_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
207     char *buf, size_t *rsize)
208 {
209 	struct disk_devdesc *dev = devdata;
210 	uint64_t	off;
211 	size_t		resid;
212 	int		rc;
213 
214 	rw &= F_MASK;
215 	if (rw == F_WRITE)
216 		return (EROFS);
217 	if (rw != F_READ)
218 		return (EINVAL);
219 	if (rsize)
220 		*rsize = 0;
221 	off = dblk * ud_info[dev->dd.d_unit].sectorsize;
222 	rc = CALLBACK(diskread, dev->dd.d_unit, off, buf, size, &resid);
223 	if (rc)
224 		return (rc);
225 	if (rsize)
226 		*rsize = size - resid;
227 	return (0);
228 }
229 
230 static int
231 userdisk_ioctl(struct open_file *f, u_long cmd, void *data)
232 {
233 	struct disk_devdesc *dev;
234 	int rc;
235 
236 	dev = (struct disk_devdesc *)f->f_devdata;
237 	rc = disk_ioctl(dev, cmd, data);
238 	if (rc != ENOTTY)
239 		return (rc);
240 
241 	return (CALLBACK(diskioctl, dev->dd.d_unit, cmd, data));
242 }
243