/*
* This function is used by MBR partition table parser to avoid
* misinterpretation of FAT filesystem.
*/
int blkid_probe_is_vfat(blkid_probe pr)
{
struct vfat_super_block *vs;
struct msdos_super_block *ms;
const struct blkid_idmag *mag = NULL;
if (blkid_probe_get_idmag(pr, &vfat_idinfo, NULL, &mag) || !mag)
return 0;
ms = blkid_probe_get_sb(pr, mag, struct msdos_super_block);
if (!ms)
return 0;
vs = blkid_probe_get_sb(pr, mag, struct vfat_super_block);
if (!vs)
return 0;
return fat_valid_superblock(mag, ms, vs, NULL, NULL);
}
/*
* This function is used by MBR partition table parser to avoid
* misinterpretation of FAT filesystem.
*/
int blkid_probe_is_vfat(blkid_probe pr)
{
struct vfat_super_block *vs;
struct msdos_super_block *ms;
const struct blkid_idmag *mag = NULL;
int rc;
rc = blkid_probe_get_idmag(pr, &vfat_idinfo, NULL, &mag);
if (rc < 0)
return rc; /* error */
if (rc != BLKID_PROBE_OK || !mag)
return 0;
ms = blkid_probe_get_sb(pr, mag, struct msdos_super_block);
if (!ms)
return errno ? -errno : 0;
vs = blkid_probe_get_sb(pr, mag, struct vfat_super_block);
if (!vs)
return errno ? -errno : 0;
return fat_valid_superblock(pr, mag, ms, vs, NULL, NULL);
}
/*
* The blkid_do_probe() backend.
*/
static int superblocks_probe(blkid_probe pr, struct blkid_chain *chn)
{
size_t i;
int rc = BLKID_PROBE_NONE;
if (!pr || chn->idx < -1)
return -EINVAL;
blkid_probe_chain_reset_values(pr, chn);
if (pr->flags & BLKID_FL_NOSCAN_DEV)
return BLKID_PROBE_NONE;
if (pr->size <= 0 || (pr->size <= 1024 && !S_ISCHR(pr->mode)))
/* Ignore very very small block devices or regular files (e.g.
* extended partitions). Note that size of the UBI char devices
* is 1 byte */
return BLKID_PROBE_NONE;
DBG(LOWPROBE, ul_debug("--> starting probing loop [SUBLKS idx=%d]",
chn->idx));
i = chn->idx < 0 ? 0 : chn->idx + 1U;
for ( ; i < ARRAY_SIZE(idinfos); i++) {
const struct blkid_idinfo *id;
const struct blkid_idmag *mag = NULL;
uint64_t off = 0;
chn->idx = i;
id = idinfos[i];
if (chn->fltr && blkid_bmp_get_item(chn->fltr, i)) {
DBG(LOWPROBE, ul_debug("filter out: %s", id->name));
rc = BLKID_PROBE_NONE;
continue;
}
if (id->minsz && id->minsz > pr->size) {
rc = BLKID_PROBE_NONE;
continue; /* the device is too small */
}
/* don't probe for RAIDs, swap or journal on CD/DVDs */
if ((id->usage & (BLKID_USAGE_RAID | BLKID_USAGE_OTHER)) &&
blkid_probe_is_cdrom(pr)) {
rc = BLKID_PROBE_NONE;
continue;
}
/* don't probe for RAIDs on floppies */
if ((id->usage & BLKID_USAGE_RAID) && blkid_probe_is_tiny(pr)) {
rc = BLKID_PROBE_NONE;
continue;
}
DBG(LOWPROBE, ul_debug("[%zd] %s:", i, id->name));
rc = blkid_probe_get_idmag(pr, id, &off, &mag);
if (rc < 0)
break;
if (rc != BLKID_PROBE_OK)
continue;
/* final check by probing function */
if (id->probefunc) {
DBG(LOWPROBE, ul_debug("\tcall probefunc()"));
rc = id->probefunc(pr, mag);
if (rc != BLKID_PROBE_OK) {
blkid_probe_chain_reset_values(pr, chn);
if (rc < 0)
break;
continue;
}
}
/* all cheks passed */
if (chn->flags & BLKID_SUBLKS_TYPE)
rc = blkid_probe_set_value(pr, "TYPE",
(unsigned char *) id->name,
strlen(id->name) + 1);
if (!rc)
rc = blkid_probe_set_usage(pr, id->usage);
if (!rc && mag)
rc = blkid_probe_set_magic(pr, off, mag->len,
(unsigned char *) mag->magic);
if (rc) {
blkid_probe_chain_reset_values(pr, chn);
DBG(LOWPROBE, ul_debug("failed to set result -- ignore"));
continue;
}
DBG(LOWPROBE, ul_debug("<-- leaving probing loop (type=%s) [SUBLKS idx=%d]",
id->name, chn->idx));
return BLKID_PROBE_OK;
}
DBG(LOWPROBE, ul_debug("<-- leaving probing loop (failed=%d) [SUBLKS idx=%d]",
rc, chn->idx));
return rc;
}
