2 * probe.c - identify a block device by its contents, and return a dev
3 * struct with the details
5 * Copyright (C) 1999 by Andries Brouwer
6 * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
7 * Copyright (C) 2001 by Andreas Dilger
10 * This file may be redistributed under the terms of the
11 * GNU Lesser General Public License.
20 #include <sys/types.h>
21 #ifdef HAVE_SYS_STAT_H
24 #ifdef HAVE_SYS_MKDEV_H
25 #include <sys/mkdev.h>
31 #include "uuid/uuid.h"
35 * This is a special case code to check for an MDRAID device. We do
36 * this special since it requires checking for a superblock at the end
39 static int check_mdraid(int fd, unsigned char *ret_uuid)
41 struct mdp_superblock_s *md;
46 return -BLKID_ERR_PARAM;
48 offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
50 if (blkid_llseek(fd, offset, 0) < 0 ||
51 read(fd, buf, 4096) != 4096)
54 /* Check for magic number */
55 if (memcmp("\251+N\374", buf, 4))
56 return -BLKID_ERR_PARAM;
62 /* The MD UUID is not contiguous in the superblock, make it so */
63 md = (struct mdp_superblock_s *)buf;
64 if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
65 memcpy(ret_uuid, &md->set_uuid0, 4);
66 memcpy(ret_uuid, &md->set_uuid1, 12);
71 static void set_uuid(blkid_dev dev, uuid_t uuid)
75 if (!uuid_is_null(uuid)) {
76 uuid_unparse(uuid, str);
77 blkid_set_tag(dev, "UUID", str, sizeof(str));
81 static void get_ext2_info(blkid_dev dev, unsigned char *buf)
83 struct ext2_super_block *es = (struct ext2_super_block *) buf;
84 const char *label = 0;
86 DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
87 blkid_le32(es->s_feature_compat),
88 blkid_le32(es->s_feature_incompat),
89 blkid_le32(es->s_feature_ro_compat)));
91 if (strlen(es->s_volume_name))
92 label = es->s_volume_name;
93 blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
95 set_uuid(dev, es->s_uuid);
98 static int probe_ext3(int fd __BLKID_ATTR((unused)),
99 blkid_cache cache __BLKID_ATTR((unused)),
101 struct blkid_magic *id __BLKID_ATTR((unused)),
104 struct ext2_super_block *es;
106 es = (struct ext2_super_block *)buf;
108 /* Distinguish between jbd and ext2/3 fs */
109 if (blkid_le32(es->s_feature_incompat) &
110 EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
111 return -BLKID_ERR_PARAM;
113 /* Distinguish between ext3 and ext2 */
114 if (!(blkid_le32(es->s_feature_compat) &
115 EXT3_FEATURE_COMPAT_HAS_JOURNAL))
116 return -BLKID_ERR_PARAM;
118 get_ext2_info(dev, buf);
120 blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2"));
125 static int probe_ext2(int fd __BLKID_ATTR((unused)),
126 blkid_cache cache __BLKID_ATTR((unused)),
128 struct blkid_magic *id __BLKID_ATTR((unused)),
131 struct ext2_super_block *es;
133 es = (struct ext2_super_block *)buf;
135 /* Distinguish between jbd and ext2/3 fs */
136 if (blkid_le32(es->s_feature_incompat) &
137 EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
138 return -BLKID_ERR_PARAM;
140 /* Distinguish between ext3 and ext2 */
141 if ((blkid_le32(es->s_feature_compat) &
142 EXT3_FEATURE_COMPAT_HAS_JOURNAL))
143 return -BLKID_ERR_PARAM;
145 get_ext2_info(dev, buf);
150 static int probe_jbd(int fd __BLKID_ATTR((unused)),
151 blkid_cache cache __BLKID_ATTR((unused)),
153 struct blkid_magic *id __BLKID_ATTR((unused)),
156 struct ext2_super_block *es = (struct ext2_super_block *) buf;
158 if (!(blkid_le32(es->s_feature_incompat) &
159 EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
160 return -BLKID_ERR_PARAM;
162 get_ext2_info(dev, buf);
167 static int probe_vfat(int fd __BLKID_ATTR((unused)),
168 blkid_cache cache __BLKID_ATTR((unused)),
170 struct blkid_magic *id __BLKID_ATTR((unused)),
173 struct vfat_super_block *vs;
175 const char *label = 0;
178 vs = (struct vfat_super_block *)buf;
180 if (strncmp(vs->vs_label, "NO NAME", 7)) {
181 char *end = vs->vs_label + sizeof(vs->vs_label) - 1;
183 while (*end == ' ' && end >= vs->vs_label)
185 if (end >= vs->vs_label) {
186 label = vs->vs_label;
187 label_len = end - vs->vs_label + 1;
191 /* We can't just print them as %04X, because they are unaligned */
192 sprintf(serno, "%02X%02X-%02X%02X", vs->vs_serno[3], vs->vs_serno[2],
193 vs->vs_serno[1], vs->vs_serno[0]);
194 blkid_set_tag(dev, "LABEL", label, label_len);
195 blkid_set_tag(dev, "UUID", serno, sizeof(serno));
200 static int probe_msdos(int fd __BLKID_ATTR((unused)),
201 blkid_cache cache __BLKID_ATTR((unused)),
203 struct blkid_magic *id __BLKID_ATTR((unused)),
206 struct msdos_super_block *ms = (struct msdos_super_block *) buf;
208 const char *label = 0;
211 if (strncmp(ms->ms_label, "NO NAME", 7)) {
212 char *end = ms->ms_label + sizeof(ms->ms_label) - 1;
214 while (*end == ' ' && end >= ms->ms_label)
216 if (end >= ms->ms_label) {
217 label = ms->ms_label;
218 label_len = end - ms->ms_label + 1;
222 /* We can't just print them as %04X, because they are unaligned */
223 sprintf(serno, "%02X%02X-%02X%02X", ms->ms_serno[3], ms->ms_serno[2],
224 ms->ms_serno[1], ms->ms_serno[0]);
225 blkid_set_tag(dev, "UUID", serno, 0);
226 blkid_set_tag(dev, "LABEL", label, label_len);
227 blkid_set_tag(dev, "SEC_TYPE", "msdos", sizeof("msdos"));
232 static int probe_xfs(int fd __BLKID_ATTR((unused)),
233 blkid_cache cache __BLKID_ATTR((unused)),
235 struct blkid_magic *id __BLKID_ATTR((unused)),
238 struct xfs_super_block *xs;
239 const char *label = 0;
241 xs = (struct xfs_super_block *)buf;
243 if (strlen(xs->xs_fname))
244 label = xs->xs_fname;
245 blkid_set_tag(dev, "LABEL", label, sizeof(xs->xs_fname));
246 set_uuid(dev, xs->xs_uuid);
250 static int probe_reiserfs(int fd __BLKID_ATTR((unused)),
251 blkid_cache cache __BLKID_ATTR((unused)),
253 struct blkid_magic *id, unsigned char *buf)
255 struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
256 unsigned int blocksize;
257 const char *label = 0;
259 blocksize = blkid_le16(rs->rs_blocksize);
261 /* If the superblock is inside the journal, we have the wrong one */
262 if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
263 return -BLKID_ERR_BIG;
265 /* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
266 if (!strcmp(id->bim_magic, "ReIsEr2Fs") ||
267 !strcmp(id->bim_magic, "ReIsEr3Fs")) {
268 if (strlen(rs->rs_label))
269 label = rs->rs_label;
270 set_uuid(dev, rs->rs_uuid);
272 blkid_set_tag(dev, "LABEL", label, sizeof(rs->rs_label));
277 static int probe_jfs(int fd __BLKID_ATTR((unused)),
278 blkid_cache cache __BLKID_ATTR((unused)),
280 struct blkid_magic *id __BLKID_ATTR((unused)),
283 struct jfs_super_block *js;
284 const char *label = 0;
286 js = (struct jfs_super_block *)buf;
288 if (strlen((char *) js->js_label))
289 label = (char *) js->js_label;
290 blkid_set_tag(dev, "LABEL", label, sizeof(js->js_label));
291 set_uuid(dev, js->js_uuid);
295 static int probe_romfs(int fd __BLKID_ATTR((unused)),
296 blkid_cache cache __BLKID_ATTR((unused)),
298 struct blkid_magic *id __BLKID_ATTR((unused)),
301 struct romfs_super_block *ros;
302 const char *label = 0;
304 ros = (struct romfs_super_block *)buf;
306 if (strlen((char *) ros->ros_volume))
307 label = (char *) ros->ros_volume;
308 blkid_set_tag(dev, "LABEL", label, 0);
312 static int probe_cramfs(int fd __BLKID_ATTR((unused)),
313 blkid_cache cache __BLKID_ATTR((unused)),
315 struct blkid_magic *id __BLKID_ATTR((unused)),
318 struct cramfs_super_block *csb;
319 const char *label = 0;
321 csb = (struct cramfs_super_block *)buf;
323 if (strlen((char *) csb->name))
324 label = (char *) csb->name;
325 blkid_set_tag(dev, "LABEL", label, 0);
329 static int probe_swap0(int fd __BLKID_ATTR((unused)),
330 blkid_cache cache __BLKID_ATTR((unused)),
332 struct blkid_magic *id __BLKID_ATTR((unused)),
333 unsigned char *buf __BLKID_ATTR((unused)))
335 blkid_set_tag(dev, "UUID", 0, 0);
336 blkid_set_tag(dev, "LABEL", 0, 0);
340 static int probe_swap1(int fd,
341 blkid_cache cache __BLKID_ATTR((unused)),
343 struct blkid_magic *id __BLKID_ATTR((unused)),
344 unsigned char *buf __BLKID_ATTR((unused)))
346 struct swap_id_block *sws;
348 probe_swap0(fd, cache, dev, id, buf);
350 * Version 1 swap headers are always located at offset of 1024
351 * bytes, although the swap signature itself is located at the
352 * end of the page (which may vary depending on hardware
355 if (lseek(fd, 1024, SEEK_SET) < 0) return 1;
356 if (!(sws = (struct swap_id_block *)malloc(1024))) return 1;
357 if (read(fd, sws, 1024) != 1024) {
362 /* arbitrary sanity check.. is there any garbage down there? */
363 if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0) {
364 if (sws->sws_volume[0])
365 blkid_set_tag(dev, "LABEL", sws->sws_volume,
366 sizeof(sws->sws_volume));
367 if (sws->sws_uuid[0])
368 set_uuid(dev, sws->sws_uuid);
376 *udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
377 "NSR03", "TEA01", 0 };
379 static int probe_udf(int fd, blkid_cache cache __BLKID_ATTR((unused)),
380 blkid_dev dev __BLKID_ATTR((unused)),
381 struct blkid_magic *id __BLKID_ATTR((unused)),
382 unsigned char *buf __BLKID_ATTR((unused)))
385 struct iso_volume_descriptor isosb;
388 /* determine the block size by scanning in 2K increments
389 (block sizes larger than 2K will be null padded) */
390 for (bs = 1; bs < 16; bs++) {
391 lseek(fd, bs*2048+32768, SEEK_SET);
392 if (read(fd, (char *)&isosb, sizeof(isosb)) != sizeof(isosb))
398 /* Scan up to another 64 blocks looking for additional VSD's */
399 for (j = 1; j < 64; j++) {
401 lseek(fd, j*bs*2048+32768, SEEK_SET);
402 if (read(fd, (char *)&isosb, sizeof(isosb))
406 /* If we find NSR0x then call it udf:
409 NSR03 for UDF 2.00 */
410 if (!strncmp(isosb.id, "NSR0", 4))
412 for (m = udf_magic; *m; m++)
413 if (!strncmp(*m, isosb.id, 5))
421 static int probe_ocfs(int fd __BLKID_ATTR((unused)),
422 blkid_cache cache __BLKID_ATTR((unused)),
424 struct blkid_magic *id __BLKID_ATTR((unused)),
427 struct ocfs_volume_header ovh;
428 struct ocfs_volume_label ovl;
431 memcpy(&ovh, buf, sizeof(ovh));
432 memcpy(&ovl, buf+512, sizeof(ovl));
434 major = ocfsmajor(ovh);
436 blkid_set_tag(dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
438 blkid_set_tag(dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
440 blkid_set_tag(dev, "LABEL", ovl.label, ocfslabellen(ovl));
441 blkid_set_tag(dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
442 set_uuid(dev, ovl.vol_id);
446 static int probe_ocfs2(int fd __BLKID_ATTR((unused)),
447 blkid_cache cache __BLKID_ATTR((unused)),
449 struct blkid_magic *id __BLKID_ATTR((unused)),
452 struct ocfs2_super_block *osb;
454 osb = (struct ocfs2_super_block *)buf;
456 blkid_set_tag(dev, "LABEL", osb->s_label, sizeof(osb->s_label));
457 set_uuid(dev, osb->s_uuid);
461 static int probe_oracleasm(int fd __BLKID_ATTR((unused)),
462 blkid_cache cache __BLKID_ATTR((unused)),
464 struct blkid_magic *id __BLKID_ATTR((unused)),
467 struct oracle_asm_disk_label *dl;
469 dl = (struct oracle_asm_disk_label *)buf;
471 blkid_set_tag(dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
476 * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
477 * in the type_array table below + bim_kbalign.
479 * When probing for a lot of magics, we handle everything in 1kB buffers so
480 * that we don't have to worry about reading each combination of block sizes.
482 #define BLKID_BLK_OFFS 64 /* currently reiserfs */
485 * Various filesystem magics that we can check for. Note that kboff and
486 * sboff are in kilobytes and bytes respectively. All magics are in
487 * byte strings so we don't worry about endian issues.
489 static struct blkid_magic type_array[] = {
490 /* type kboff sboff len magic probe */
491 { "oracleasm", 0, 32, 8, "ORCLDISK", probe_oracleasm },
492 { "ntfs", 0, 3, 8, "NTFS ", 0 },
493 { "jbd", 1, 0x38, 2, "\123\357", probe_jbd },
494 { "ext3", 1, 0x38, 2, "\123\357", probe_ext3 },
495 { "ext2", 1, 0x38, 2, "\123\357", probe_ext2 },
496 { "reiserfs", 8, 0x34, 8, "ReIsErFs", probe_reiserfs },
497 { "reiserfs", 64, 0x34, 9, "ReIsEr2Fs", probe_reiserfs },
498 { "reiserfs", 64, 0x34, 9, "ReIsEr3Fs", probe_reiserfs },
499 { "reiserfs", 64, 0x34, 8, "ReIsErFs", probe_reiserfs },
500 { "reiserfs", 8, 20, 8, "ReIsErFs", probe_reiserfs },
501 { "vfat", 0, 0x52, 5, "MSWIN", probe_vfat },
502 { "vfat", 0, 0x52, 8, "FAT32 ", probe_vfat },
503 { "vfat", 0, 0x36, 5, "MSDOS", probe_msdos },
504 { "vfat", 0, 0x36, 8, "FAT16 ", probe_msdos },
505 { "vfat", 0, 0x36, 8, "FAT12 ", probe_msdos },
506 { "minix", 1, 0x10, 2, "\177\023", 0 },
507 { "minix", 1, 0x10, 2, "\217\023", 0 },
508 { "minix", 1, 0x10, 2, "\150\044", 0 },
509 { "minix", 1, 0x10, 2, "\170\044", 0 },
510 { "vxfs", 1, 0, 4, "\365\374\001\245", 0 },
511 { "xfs", 0, 0, 4, "XFSB", probe_xfs },
512 { "romfs", 0, 0, 8, "-rom1fs-", probe_romfs },
513 { "bfs", 0, 0, 4, "\316\372\173\033", 0 },
514 { "cramfs", 0, 0, 4, "E=\315\050", probe_cramfs },
515 { "qnx4", 0, 4, 6, "QNX4FS", 0 },
516 { "udf", 32, 1, 5, "BEA01", probe_udf },
517 { "udf", 32, 1, 5, "BOOT2", probe_udf },
518 { "udf", 32, 1, 5, "CD001", probe_udf },
519 { "udf", 32, 1, 5, "CDW02", probe_udf },
520 { "udf", 32, 1, 5, "NSR02", probe_udf },
521 { "udf", 32, 1, 5, "NSR03", probe_udf },
522 { "udf", 32, 1, 5, "TEA01", probe_udf },
523 { "iso9660", 32, 1, 5, "CD001", 0 },
524 { "iso9660", 32, 9, 5, "CDROM", 0 },
525 { "jfs", 32, 0, 4, "JFS1", probe_jfs },
526 { "hfs", 1, 0, 2, "BD", 0 },
527 { "ufs", 8, 0x55c, 4, "T\031\001\000", 0 },
528 { "hpfs", 8, 0, 4, "I\350\225\371", 0 },
529 { "sysv", 0, 0x3f8, 4, "\020~\030\375", 0 },
530 { "swap", 0, 0xff6, 10, "SWAP-SPACE", probe_swap0 },
531 { "swap", 0, 0xff6, 10, "SWAPSPACE2", probe_swap1 },
532 { "swsuspend", 0, 0xff6, 9, "S1SUSPEND", probe_swap1 },
533 { "swsuspend", 0, 0xff6, 9, "S2SUSPEND", probe_swap1 },
534 { "swap", 0, 0x1ff6, 10, "SWAP-SPACE", probe_swap0 },
535 { "swap", 0, 0x1ff6, 10, "SWAPSPACE2", probe_swap1 },
536 { "swsuspend", 0, 0x1ff6, 9, "S1SUSPEND", probe_swap1 },
537 { "swsuspend", 0, 0x1ff6, 9, "S2SUSPEND", probe_swap1 },
538 { "swap", 0, 0x3ff6, 10, "SWAP-SPACE", probe_swap0 },
539 { "swap", 0, 0x3ff6, 10, "SWAPSPACE2", probe_swap1 },
540 { "swsuspend", 0, 0x3ff6, 9, "S1SUSPEND", probe_swap1 },
541 { "swsuspend", 0, 0x3ff6, 9, "S2SUSPEND", probe_swap1 },
542 { "swap", 0, 0x7ff6, 10, "SWAP-SPACE", probe_swap0 },
543 { "swap", 0, 0x7ff6, 10, "SWAPSPACE2", probe_swap1 },
544 { "swsuspend", 0, 0x7ff6, 9, "S1SUSPEND", probe_swap1 },
545 { "swsuspend", 0, 0x7ff6, 9, "S2SUSPEND", probe_swap1 },
546 { "swap", 0, 0xfff6, 10, "SWAP-SPACE", probe_swap0 },
547 { "swap", 0, 0xfff6, 10, "SWAPSPACE2", probe_swap1 },
548 { "swsuspend", 0, 0xfff6, 9, "S1SUSPEND", probe_swap1 },
549 { "swsuspend", 0, 0xfff6, 9, "S2SUSPEND", probe_swap1 },
550 { "ocfs", 0, 8, 9, "OracleCFS", probe_ocfs },
551 { "ocfs2", 1, 0, 6, "OCFSV2", probe_ocfs2 },
552 { "ocfs2", 2, 0, 6, "OCFSV2", probe_ocfs2 },
553 { "ocfs2", 4, 0, 6, "OCFSV2", probe_ocfs2 },
554 { "ocfs2", 8, 0, 6, "OCFSV2", probe_ocfs2 },
555 { NULL, 0, 0, 0, NULL, NULL }
559 * Verify that the data in dev is consistent with what is on the actual
560 * block device (using the devname field only). Normally this will be
561 * called when finding items in the cache, but for long running processes
562 * is also desirable to revalidate an item before use.
564 * If we are unable to revalidate the data, we return the old data and
565 * do not set the BLKID_BID_FL_VERIFIED flag on it.
567 blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
569 struct blkid_magic *id;
570 unsigned char *bufs[BLKID_BLK_OFFS + 1], *buf;
580 diff = now - dev->bid_time;
582 if ((now < dev->bid_time) ||
583 (diff < BLKID_PROBE_MIN) ||
584 (dev->bid_flags & BLKID_BID_FL_VERIFIED &&
585 diff < BLKID_PROBE_INTERVAL))
589 printf("need to revalidate %s (time since last check %lu)\n",
590 dev->bid_name, diff));
592 if (((fd = open(dev->bid_name, O_RDONLY)) < 0) ||
593 (fstat(fd, &st) < 0)) {
594 if (errno == ENXIO || errno == ENODEV || errno == ENOENT) {
598 /* We don't have read permission, just return cache data. */
600 printf("returning unverified data for %s\n",
605 memset(bufs, 0, sizeof(bufs));
608 * Iterate over the type array. If we already know the type,
609 * then try that first. If it doesn't work, then blow away
610 * the type information, and try again.
615 if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
618 if (check_mdraid(fd, uuid) == 0) {
624 for (id = type_array; id->bim_type; id++) {
626 strcmp(id->bim_type, dev->bid_type))
629 idx = id->bim_kboff + (id->bim_sboff >> 10);
630 if (idx > BLKID_BLK_OFFS || idx < 0)
634 if (lseek(fd, idx << 10, SEEK_SET) < 0)
637 if (!(buf = (unsigned char *)malloc(1024)))
640 if (read(fd, buf, 1024) != 1024) {
647 if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
651 if ((id->bim_probe == NULL) ||
652 (id->bim_probe(fd, cache, dev, id, buf) == 0)) {
658 if (!id->bim_type && dev->bid_type) {
660 * Zap the device filesystem type and try again
662 blkid_set_tag(dev, "TYPE", 0, 0);
663 blkid_set_tag(dev, "SEC_TYPE", 0, 0);
664 blkid_set_tag(dev, "LABEL", 0, 0);
665 blkid_set_tag(dev, "UUID", 0, 0);
669 if (!dev->bid_type) {
676 dev->bid_devno = st.st_rdev;
677 dev->bid_time = time(0);
678 dev->bid_flags |= BLKID_BID_FL_VERIFIED;
679 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
681 blkid_set_tag(dev, "TYPE", type, 0);
683 DBG(DEBUG_PROBE, printf("%s: devno 0x%04llx, type %s\n",
684 dev->bid_name, st.st_rdev, type));
692 int blkid_known_fstype(const char *fstype)
694 struct blkid_magic *id;
696 for (id = type_array; id->bim_type; id++) {
697 if (strcmp(fstype, id->bim_type) == 0)
704 int main(int argc, char **argv)
710 blkid_debug_mask = DEBUG_ALL;
712 fprintf(stderr, "Usage: %s device\n"
713 "Probe a single device to determine type\n", argv[0]);
716 if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
717 fprintf(stderr, "%s: error creating cache (%d)\n",
721 dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
723 printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
726 printf("%s is type %s\n", argv[1], dev->bid_type ?
727 dev->bid_type : "(null)");
729 printf("\tlabel is '%s'\n", dev->bid_label);
731 printf("\tuuid is %s\n", dev->bid_uuid);