1 /*
2 * devname.c - get a dev by its device inode name
3 *
4 * Copyright (C) Andries Brouwer
5 * Copyright (C) 1999, 2000, 2001, 2002, 2003 Theodore Ts'o
6 * Copyright (C) 2001 Andreas Dilger
7 *
8 * %Begin-Header%
9 * This file may be redistributed under the terms of the
10 * GNU Lesser General Public License.
11 * %End-Header%
12 */
13
14 #define _GNU_SOURCE 1
15
16 #include <stdio.h>
17 #include <string.h>
18 #include <limits.h>
19 #if HAVE_UNISTD_H
20 #include <unistd.h>
21 #endif
22 #include <stdlib.h>
23 #include <string.h>
24 #include <ctype.h>
25 #if HAVE_SYS_TYPES_H
26 #include <sys/types.h>
27 #endif
28 #if HAVE_SYS_STAT_H
29 #include <sys/stat.h>
30 #endif
31 #if HAVE_ERRNO_H
32 #include <errno.h>
33 #endif
34 #if HAVE_SYS_MKDEV_H
35 #include <sys/mkdev.h>
36 #endif
37 #include <time.h>
38
39 #include "blkidP.h"
40
41 #ifdef HAVE_DEVMAPPER
42 #include <libdevmapper.h>
43 #endif
44
45 /*
46 * Find a dev struct in the cache by device name, if available.
47 *
48 * If there is no entry with the specified device name, and the create
49 * flag is set, then create an empty device entry.
50 */
blkid_get_dev(blkid_cache cache,const char * devname,int flags)51 blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags)
52 {
53 blkid_dev dev = NULL, tmp;
54 struct list_head *p;
55
56 if (!cache || !devname)
57 return NULL;
58
59 list_for_each(p, &cache->bic_devs) {
60 tmp = list_entry(p, struct blkid_struct_dev, bid_devs);
61 if (strcmp(tmp->bid_name, devname))
62 continue;
63
64 DBG(DEBUG_DEVNAME,
65 printf("found devname %s in cache\n", tmp->bid_name));
66 dev = tmp;
67 break;
68 }
69
70 if (!dev && (flags & BLKID_DEV_CREATE)) {
71 dev = blkid_new_dev();
72 if (!dev)
73 return NULL;
74 dev->bid_time = INT_MIN;
75 dev->bid_name = blkid_strdup(devname);
76 dev->bid_cache = cache;
77 list_add_tail(&dev->bid_devs, &cache->bic_devs);
78 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
79 }
80
81 if (flags & BLKID_DEV_VERIFY)
82 dev = blkid_verify(cache, dev);
83 return dev;
84 }
85
86 #ifdef HAVE_DEVMAPPER
87 static int dm_device_is_leaf(const dev_t dev);
88 #endif
89
90 /*
91 * Probe a single block device to add to the device cache.
92 */
probe_one(blkid_cache cache,const char * ptname,dev_t devno,int pri,int only_if_new)93 static void probe_one(blkid_cache cache, const char *ptname,
94 dev_t devno, int pri, int only_if_new)
95 {
96 blkid_dev dev = NULL;
97 struct list_head *p;
98 const char **dir;
99 char *devname = NULL;
100
101 /* See if we already have this device number in the cache. */
102 list_for_each(p, &cache->bic_devs) {
103 blkid_dev tmp = list_entry(p, struct blkid_struct_dev,
104 bid_devs);
105 #ifdef HAVE_DEVMAPPER
106 if (!dm_device_is_leaf(devno))
107 continue;
108 #endif
109 if (tmp->bid_devno == devno) {
110 if (only_if_new)
111 return;
112 dev = blkid_verify(cache, tmp);
113 break;
114 }
115 }
116 if (dev && dev->bid_devno == devno)
117 goto set_pri;
118
119 /*
120 * Take a quick look at /dev/ptname for the device number. We check
121 * all of the likely device directories. If we don't find it, or if
122 * the stat information doesn't check out, use blkid_devno_to_devname()
123 * to find it via an exhaustive search for the device major/minor.
124 */
125 for (dir = blkid_devdirs; *dir; dir++) {
126 struct stat st;
127 char device[256];
128
129 sprintf(device, "%s/%s", *dir, ptname);
130 if ((dev = blkid_get_dev(cache, device, BLKID_DEV_FIND)) &&
131 dev->bid_devno == devno)
132 goto set_pri;
133
134 if (stat(device, &st) == 0 && S_ISBLK(st.st_mode) &&
135 st.st_rdev == devno) {
136 devname = blkid_strdup(device);
137 break;
138 }
139 }
140 if (!devname) {
141 devname = blkid_devno_to_devname(devno);
142 if (!devname)
143 return;
144 }
145 dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
146 free(devname);
147
148 set_pri:
149 if (!pri && !strncmp(ptname, "md", 2))
150 pri = BLKID_PRI_MD;
151 if (dev)
152 dev->bid_pri = pri;
153 return;
154 }
155
156 #ifdef HAVE_DEVMAPPER
dm_quiet_log(int level __BLKID_ATTR ((unused)),const char * file __BLKID_ATTR ((unused)),int line __BLKID_ATTR ((unused)),const char * f __BLKID_ATTR ((unused)),...)157 static void dm_quiet_log(int level __BLKID_ATTR((unused)),
158 const char *file __BLKID_ATTR((unused)),
159 int line __BLKID_ATTR((unused)),
160 const char *f __BLKID_ATTR((unused)), ...)
161 {
162 return;
163 }
164
165 /*
166 * device-mapper support
167 */
dm_device_has_dep(const dev_t dev,const char * name)168 static int dm_device_has_dep(const dev_t dev, const char *name)
169 {
170 struct dm_task *task;
171 struct dm_deps *deps;
172 struct dm_info info;
173 unsigned int i;
174 int ret = 0;
175
176 task = dm_task_create(DM_DEVICE_DEPS);
177 if (!task)
178 goto out;
179
180 if (!dm_task_set_name(task, name))
181 goto out;
182
183 if (!dm_task_run(task))
184 goto out;
185
186 if (!dm_task_get_info(task, &info))
187 goto out;
188
189 if (!info.exists)
190 goto out;
191
192 deps = dm_task_get_deps(task);
193 if (!deps || deps->count == 0)
194 goto out;
195
196 for (i = 0; i < deps->count; i++) {
197 dev_t dep_dev = deps->device[i];
198
199 if (dev == dep_dev) {
200 ret = 1;
201 goto out;
202 }
203 }
204
205 out:
206 if (task)
207 dm_task_destroy(task);
208
209 return ret;
210 }
211
dm_device_is_leaf(const dev_t dev)212 static int dm_device_is_leaf(const dev_t dev)
213 {
214 struct dm_task *task;
215 struct dm_names *names;
216 unsigned int next = 0;
217 int n, ret = 1;
218
219 dm_log_init(dm_quiet_log);
220 task = dm_task_create(DM_DEVICE_LIST);
221 if (!task)
222 goto out;
223
224 dm_log_init(0);
225
226 if (!dm_task_run(task))
227 goto out;
228
229 names = dm_task_get_names(task);
230 if (!names || !names->dev)
231 goto out;
232
233 n = 0;
234 do {
235 names = (struct dm_names *) ((char *)names + next);
236
237 if (dm_device_has_dep(dev, names->name))
238 ret = 0;
239
240 next = names->next;
241 } while (next);
242
243 out:
244 if (task)
245 dm_task_destroy(task);
246
247 return ret;
248 }
249
dm_get_devno(const char * name)250 static dev_t dm_get_devno(const char *name)
251 {
252 struct dm_task *task;
253 struct dm_info info;
254 dev_t ret = 0;
255
256 task = dm_task_create(DM_DEVICE_INFO);
257 if (!task)
258 goto out;
259
260 if (!dm_task_set_name(task, name))
261 goto out;
262
263 if (!dm_task_run(task))
264 goto out;
265
266 if (!dm_task_get_info(task, &info))
267 goto out;
268
269 if (!info.exists)
270 goto out;
271
272 ret = makedev(info.major, info.minor);
273
274 out:
275 if (task)
276 dm_task_destroy(task);
277
278 return ret;
279 }
280
dm_probe_all(blkid_cache cache,int only_if_new)281 static void dm_probe_all(blkid_cache cache, int only_if_new)
282 {
283 struct dm_task *task;
284 struct dm_names *names;
285 unsigned int next = 0;
286 int n;
287
288 dm_log_init(dm_quiet_log);
289 task = dm_task_create(DM_DEVICE_LIST);
290 if (!task)
291 goto out;
292 dm_log_init(0);
293
294 if (!dm_task_run(task))
295 goto out;
296
297 names = dm_task_get_names(task);
298 if (!names || !names->dev)
299 goto out;
300
301 n = 0;
302 do {
303 int rc;
304 char *device = NULL;
305 dev_t dev = 0;
306
307 names = (struct dm_names *) ((char *)names + next);
308
309 rc = asprintf(&device, "mapper/%s", names->name);
310 if (rc < 0)
311 goto try_next;
312
313 dev = dm_get_devno(names->name);
314 if (dev == 0)
315 goto try_next;
316
317 if (!dm_device_is_leaf(dev))
318 goto try_next;
319
320 probe_one(cache, device, dev, BLKID_PRI_DM, only_if_new);
321
322 try_next:
323 free(device);
324 next = names->next;
325 } while (next);
326
327 out:
328 if (task)
329 dm_task_destroy(task);
330 }
331 #endif /* HAVE_DEVMAPPER */
332
333 #define PROC_PARTITIONS "/proc/partitions"
334 #define VG_DIR "/proc/lvm/VGs"
335
336 /*
337 * This function initializes the UUID cache with devices from the LVM
338 * proc hierarchy. We currently depend on the names of the LVM
339 * hierarchy giving us the device structure in /dev. (XXX is this a
340 * safe thing to do?)
341 */
342 #ifdef VG_DIR
343 #include <dirent.h>
lvm_get_devno(const char * lvm_device)344 static dev_t lvm_get_devno(const char *lvm_device)
345 {
346 FILE *lvf;
347 char buf[1024];
348 int ma, mi;
349 dev_t ret = 0;
350
351 DBG(DEBUG_DEVNAME, printf("opening %s\n", lvm_device));
352 if ((lvf = fopen(lvm_device, "r")) == NULL) {
353 DBG(DEBUG_DEVNAME, printf("%s: (%d) %s\n", lvm_device, errno,
354 strerror(errno)));
355 return 0;
356 }
357
358 while (fgets(buf, sizeof(buf), lvf)) {
359 if (sscanf(buf, "device: %d:%d", &ma, &mi) == 2) {
360 ret = makedev(ma, mi);
361 break;
362 }
363 }
364 fclose(lvf);
365
366 return ret;
367 }
368
lvm_probe_all(blkid_cache cache,int only_if_new)369 static void lvm_probe_all(blkid_cache cache, int only_if_new)
370 {
371 DIR *vg_list;
372 struct dirent *vg_iter;
373 int vg_len = strlen(VG_DIR);
374 dev_t dev;
375
376 if ((vg_list = opendir(VG_DIR)) == NULL)
377 return;
378
379 DBG(DEBUG_DEVNAME, printf("probing LVM devices under %s\n", VG_DIR));
380
381 while ((vg_iter = readdir(vg_list)) != NULL) {
382 DIR *lv_list;
383 char *vdirname;
384 char *vg_name;
385 struct dirent *lv_iter;
386
387 vg_name = vg_iter->d_name;
388 if (!strcmp(vg_name, ".") || !strcmp(vg_name, ".."))
389 continue;
390 vdirname = malloc(vg_len + strlen(vg_name) + 8);
391 if (!vdirname)
392 goto exit;
393 sprintf(vdirname, "%s/%s/LVs", VG_DIR, vg_name);
394
395 lv_list = opendir(vdirname);
396 free(vdirname);
397 if (lv_list == NULL)
398 continue;
399
400 while ((lv_iter = readdir(lv_list)) != NULL) {
401 char *lv_name, *lvm_device;
402
403 lv_name = lv_iter->d_name;
404 if (!strcmp(lv_name, ".") || !strcmp(lv_name, ".."))
405 continue;
406
407 lvm_device = malloc(vg_len + strlen(vg_name) +
408 strlen(lv_name) + 8);
409 if (!lvm_device) {
410 closedir(lv_list);
411 goto exit;
412 }
413 sprintf(lvm_device, "%s/%s/LVs/%s", VG_DIR, vg_name,
414 lv_name);
415 dev = lvm_get_devno(lvm_device);
416 sprintf(lvm_device, "%s/%s", vg_name, lv_name);
417 DBG(DEBUG_DEVNAME, printf("LVM dev %s: devno 0x%04X\n",
418 lvm_device,
419 (unsigned int) dev));
420 probe_one(cache, lvm_device, dev, BLKID_PRI_LVM,
421 only_if_new);
422 free(lvm_device);
423 }
424 closedir(lv_list);
425 }
426 exit:
427 closedir(vg_list);
428 }
429 #endif
430
431 #define PROC_EVMS_VOLUMES "/proc/evms/volumes"
432
433 static int
evms_probe_all(blkid_cache cache,int only_if_new)434 evms_probe_all(blkid_cache cache, int only_if_new)
435 {
436 char line[100];
437 int ma, mi, sz, num = 0;
438 FILE *procpt;
439 char device[110];
440
441 procpt = fopen(PROC_EVMS_VOLUMES, "r");
442 if (!procpt)
443 return 0;
444 while (fgets(line, sizeof(line), procpt)) {
445 if (sscanf (line, " %d %d %d %*s %*s %[^\n ]",
446 &ma, &mi, &sz, device) != 4)
447 continue;
448
449 DBG(DEBUG_DEVNAME, printf("Checking partition %s (%d, %d)\n",
450 device, ma, mi));
451
452 probe_one(cache, device, makedev(ma, mi), BLKID_PRI_EVMS,
453 only_if_new);
454 num++;
455 }
456 fclose(procpt);
457 return num;
458 }
459
460 /*
461 * Read the device data for all available block devices in the system.
462 */
probe_all(blkid_cache cache,int only_if_new)463 static int probe_all(blkid_cache cache, int only_if_new)
464 {
465 FILE *proc;
466 char line[1024];
467 char ptname0[128], ptname1[128], *ptname = 0;
468 char *ptnames[2];
469 dev_t devs[2];
470 int ma, mi;
471 unsigned long long sz;
472 int lens[2] = { 0, 0 };
473 int which = 0, last = 0;
474
475 ptnames[0] = ptname0;
476 ptnames[1] = ptname1;
477
478 if (!cache)
479 return -BLKID_ERR_PARAM;
480
481 if (cache->bic_flags & BLKID_BIC_FL_PROBED &&
482 time(0) - cache->bic_time < BLKID_PROBE_INTERVAL)
483 return 0;
484
485 blkid_read_cache(cache);
486 #ifdef HAVE_DEVMAPPER
487 dm_probe_all(cache, only_if_new);
488 #endif
489 evms_probe_all(cache, only_if_new);
490 #ifdef VG_DIR
491 lvm_probe_all(cache, only_if_new);
492 #endif
493
494 proc = fopen(PROC_PARTITIONS, "r");
495 if (!proc)
496 return -BLKID_ERR_PROC;
497
498 while (fgets(line, sizeof(line), proc)) {
499 last = which;
500 which ^= 1;
501 ptname = ptnames[which];
502
503 if (sscanf(line, " %d %d %llu %128[^\n ]",
504 &ma, &mi, &sz, ptname) != 4)
505 continue;
506 devs[which] = makedev(ma, mi);
507
508 DBG(DEBUG_DEVNAME, printf("read partition name %s\n", ptname));
509
510 /* Skip whole disk devs unless they have no partitions.
511 * If base name of device has changed, also
512 * check previous dev to see if it didn't have a partn.
513 * heuristic: partition name ends in a digit, & partition
514 * names contain whole device name as substring.
515 *
516 * Skip extended partitions.
517 * heuristic: size is 1
518 *
519 * FIXME: skip /dev/{ida,cciss,rd} whole-disk devs
520 */
521
522 lens[which] = strlen(ptname);
523
524 /* ends in a digit, clearly a partition, so check */
525 if (isdigit(ptname[lens[which] - 1])) {
526 DBG(DEBUG_DEVNAME,
527 printf("partition dev %s, devno 0x%04X\n",
528 ptname, (unsigned int) devs[which]));
529
530 if (sz > 1)
531 probe_one(cache, ptname, devs[which], 0,
532 only_if_new);
533 lens[which] = 0; /* mark as checked */
534 }
535
536 /*
537 * If last was not checked because it looked like a whole-disk
538 * dev, and the device's base name has changed,
539 * check last as well.
540 */
541 if (lens[last] && strncmp(ptnames[last], ptname, lens[last])) {
542 DBG(DEBUG_DEVNAME,
543 printf("whole dev %s, devno 0x%04X\n",
544 ptnames[last], (unsigned int) devs[last]));
545 probe_one(cache, ptnames[last], devs[last], 0,
546 only_if_new);
547 lens[last] = 0;
548 }
549 }
550
551 /* Handle the last device if it wasn't partitioned */
552 if (lens[which])
553 probe_one(cache, ptname, devs[which], 0, only_if_new);
554
555 fclose(proc);
556 blkid_flush_cache(cache);
557 return 0;
558 }
559
blkid_probe_all(blkid_cache cache)560 int blkid_probe_all(blkid_cache cache)
561 {
562 int ret;
563
564 DBG(DEBUG_PROBE, printf("Begin blkid_probe_all()\n"));
565 ret = probe_all(cache, 0);
566 cache->bic_time = time(0);
567 cache->bic_flags |= BLKID_BIC_FL_PROBED;
568 DBG(DEBUG_PROBE, printf("End blkid_probe_all()\n"));
569 return ret;
570 }
571
blkid_probe_all_new(blkid_cache cache)572 int blkid_probe_all_new(blkid_cache cache)
573 {
574 int ret;
575
576 DBG(DEBUG_PROBE, printf("Begin blkid_probe_all_new()\n"));
577 ret = probe_all(cache, 1);
578 DBG(DEBUG_PROBE, printf("End blkid_probe_all_new()\n"));
579 return ret;
580 }
581
582
583 #ifdef TEST_PROGRAM
main(int argc,char ** argv)584 int main(int argc, char **argv)
585 {
586 blkid_cache cache = NULL;
587 int ret;
588
589 blkid_debug_mask = DEBUG_ALL;
590 if (argc != 1) {
591 fprintf(stderr, "Usage: %s\n"
592 "Probe all devices and exit\n", argv[0]);
593 exit(1);
594 }
595 if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
596 fprintf(stderr, "%s: error creating cache (%d)\n",
597 argv[0], ret);
598 exit(1);
599 }
600 if (blkid_probe_all(cache) < 0)
601 printf("%s: error probing devices\n", argv[0]);
602
603 blkid_put_cache(cache);
604 return (0);
605 }
606 #endif
607