source: mainline/uspace/srv/bd/file_bd/file_bd.c@ 1433ecda

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 1433ecda was 1433ecda, checked in by Jiri Svoboda <jiri@…>, 7 years ago

Fix cstyle: make ccheck-fix and commit only files where all the changes are good.
  • Property mode set to 100644
File size: 7.5 KB
Line 
1/*
2 * Copyright (c) 2009 Jiri Svoboda
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 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup bd
30 * @{
31 */
32
33/**
34 * @file
35 * @brief File-backed block device driver
36 *
37 * Allows accessing a file as a block device. Useful for, e.g., mounting
38 * a disk image.
39 */
40
41#include <stdio.h>
42#include <async.h>
43#include <as.h>
44#include <bd_srv.h>
45#include <fibril_synch.h>
46#include <loc.h>
47#include <stddef.h>
48#include <stdint.h>
49#include <errno.h>
50#include <str_error.h>
51#include <stdbool.h>
52#include <task.h>
53#include <macros.h>
54#include <str.h>
55
56#define NAME "file_bd"
57
58#define DEFAULT_BLOCK_SIZE 512
59
60static size_t block_size;
61static aoff64_t num_blocks;
62static FILE *img;
63
64static service_id_t service_id;
65static bd_srvs_t bd_srvs;
66static fibril_mutex_t dev_lock;
67
68static void print_usage(void);
69static errno_t file_bd_init(const char *fname);
70static void file_bd_connection(cap_call_handle_t icall_handle, ipc_call_t *icall, void *);
71
72static errno_t file_bd_open(bd_srvs_t *, bd_srv_t *);
73static errno_t file_bd_close(bd_srv_t *);
74static errno_t file_bd_read_blocks(bd_srv_t *, aoff64_t, size_t, void *, size_t);
75static errno_t file_bd_write_blocks(bd_srv_t *, aoff64_t, size_t, const void *, size_t);
76static errno_t file_bd_get_block_size(bd_srv_t *, size_t *);
77static errno_t file_bd_get_num_blocks(bd_srv_t *, aoff64_t *);
78
79static bd_ops_t file_bd_ops = {
80 .open = file_bd_open,
81 .close = file_bd_close,
82 .read_blocks = file_bd_read_blocks,
83 .write_blocks = file_bd_write_blocks,
84 .get_block_size = file_bd_get_block_size,
85 .get_num_blocks = file_bd_get_num_blocks
86};
87
88int main(int argc, char **argv)
89{
90 errno_t rc;
91 char *image_name;
92 char *device_name;
93 category_id_t disk_cat;
94
95 printf(NAME ": File-backed block device driver\n");
96
97 block_size = DEFAULT_BLOCK_SIZE;
98
99 ++argv;
100 --argc;
101 while (*argv != NULL && (*argv)[0] == '-') {
102 /* Option */
103 if (str_cmp(*argv, "-b") == 0) {
104 if (argc < 2) {
105 printf("Argument missing.\n");
106 print_usage();
107 return -1;
108 }
109
110 rc = str_size_t(argv[1], NULL, 10, true, &block_size);
111 if (rc != EOK || block_size == 0) {
112 printf("Invalid block size '%s'.\n", argv[1]);
113 print_usage();
114 return -1;
115 }
116 ++argv;
117 --argc;
118 } else {
119 printf("Invalid option '%s'.\n", *argv);
120 print_usage();
121 return -1;
122 }
123 ++argv;
124 --argc;
125 }
126
127 if (argc < 2) {
128 printf("Missing arguments.\n");
129 print_usage();
130 return -1;
131 }
132
133 image_name = argv[0];
134 device_name = argv[1];
135
136 if (file_bd_init(image_name) != EOK)
137 return -1;
138
139 rc = loc_service_register(device_name, &service_id);
140 if (rc != EOK) {
141 printf("%s: Unable to register device '%s': %s.\n",
142 NAME, device_name, str_error(rc));
143 return rc;
144 }
145
146 rc = loc_category_get_id("disk", &disk_cat, IPC_FLAG_BLOCKING);
147 if (rc != EOK) {
148 printf("%s: Failed resolving category 'disk': %s\n", NAME, str_error(rc));
149 return rc;
150 }
151
152 rc = loc_service_add_to_cat(service_id, disk_cat);
153 if (rc != EOK) {
154 printf("%s: Failed adding %s to category: %s",
155 NAME, device_name, str_error(rc));
156 return rc;
157 }
158
159 printf("%s: Accepting connections\n", NAME);
160 task_retval(0);
161 async_manager();
162
163 /* Not reached */
164 return 0;
165}
166
167static void print_usage(void)
168{
169 printf("Usage: " NAME " [-b <block_size>] <image_file> <device_name>\n");
170}
171
172static errno_t file_bd_init(const char *fname)
173{
174 bd_srvs_init(&bd_srvs);
175 bd_srvs.ops = &file_bd_ops;
176
177 async_set_fallback_port_handler(file_bd_connection, NULL);
178 errno_t rc = loc_server_register(NAME);
179 if (rc != EOK) {
180 printf("%s: Unable to register driver.\n", NAME);
181 return rc;
182 }
183
184 img = fopen(fname, "rb+");
185 if (img == NULL)
186 return EINVAL;
187
188 if (fseek(img, 0, SEEK_END) != 0) {
189 fclose(img);
190 return EIO;
191 }
192
193 off64_t img_size = ftell(img);
194 if (img_size < 0) {
195 fclose(img);
196 return EIO;
197 }
198
199 num_blocks = img_size / block_size;
200
201 fibril_mutex_initialize(&dev_lock);
202
203 return EOK;
204}
205
206static void file_bd_connection(cap_call_handle_t icall_handle, ipc_call_t *icall, void *arg)
207{
208 bd_conn(icall_handle, icall, &bd_srvs);
209}
210
211/** Open device. */
212static errno_t file_bd_open(bd_srvs_t *bds, bd_srv_t *bd)
213{
214 return EOK;
215}
216
217/** Close device. */
218static errno_t file_bd_close(bd_srv_t *bd)
219{
220 return EOK;
221}
222
223/** Read blocks from the device. */
224static errno_t file_bd_read_blocks(bd_srv_t *bd, uint64_t ba, size_t cnt, void *buf,
225 size_t size)
226{
227 size_t n_rd;
228
229 if (size < cnt * block_size)
230 return EINVAL;
231
232 /* Check whether access is within device address bounds. */
233 if (ba + cnt > num_blocks) {
234 printf(NAME ": Accessed blocks %" PRIuOFF64 "-%" PRIuOFF64 ", while "
235 "max block number is %" PRIuOFF64 ".\n", ba, ba + cnt - 1,
236 num_blocks - 1);
237 return ELIMIT;
238 }
239
240 fibril_mutex_lock(&dev_lock);
241
242 clearerr(img);
243 if (fseek(img, ba * block_size, SEEK_SET) < 0) {
244 fibril_mutex_unlock(&dev_lock);
245 return EIO;
246 }
247
248 n_rd = fread(buf, block_size, cnt, img);
249
250 if (ferror(img)) {
251 fibril_mutex_unlock(&dev_lock);
252 return EIO; /* Read error */
253 }
254
255 fibril_mutex_unlock(&dev_lock);
256
257 if (n_rd < cnt)
258 return EINVAL; /* Read beyond end of device */
259
260 return EOK;
261}
262
263/** Write blocks to the device. */
264static errno_t file_bd_write_blocks(bd_srv_t *bd, uint64_t ba, size_t cnt,
265 const void *buf, size_t size)
266{
267 size_t n_wr;
268
269 if (size < cnt * block_size)
270 return EINVAL;
271
272 /* Check whether access is within device address bounds. */
273 if (ba + cnt > num_blocks) {
274 printf(NAME ": Accessed blocks %" PRIuOFF64 "-%" PRIuOFF64 ", while "
275 "max block number is %" PRIuOFF64 ".\n", ba, ba + cnt - 1,
276 num_blocks - 1);
277 return ELIMIT;
278 }
279
280 fibril_mutex_lock(&dev_lock);
281
282 clearerr(img);
283 if (fseek(img, ba * block_size, SEEK_SET) < 0) {
284 fibril_mutex_unlock(&dev_lock);
285 return EIO;
286 }
287
288 n_wr = fwrite(buf, block_size, cnt, img);
289
290 if (ferror(img) || n_wr < cnt) {
291 fibril_mutex_unlock(&dev_lock);
292 return EIO; /* Write error */
293 }
294
295 if (fflush(img) != 0) {
296 fibril_mutex_unlock(&dev_lock);
297 return EIO;
298 }
299
300 fibril_mutex_unlock(&dev_lock);
301
302 return EOK;
303}
304
305/** Get device block size. */
306static errno_t file_bd_get_block_size(bd_srv_t *bd, size_t *rsize)
307{
308 *rsize = block_size;
309 return EOK;
310}
311
312/** Get number of blocks on device. */
313static errno_t file_bd_get_num_blocks(bd_srv_t *bd, aoff64_t *rnb)
314{
315 *rnb = num_blocks;
316 return EOK;
317}
318
319/**
320 * @}
321 */
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