return sector_size;
}
+/************************************************************
+ * lcm
+ * Requires:
+ * - numbers of which to find the lowest common multiple
+ * Modifies: nothing
+ * Returns:
+ * lowest common multiple of x and y
+ ************************************************************/
+unsigned int
+lcm(unsigned int x, unsigned int y)
+{
+ unsigned int m = x, n = y, o;
+
+ while ((o = m % n)) {
+ m = n;
+ n = o;
+ }
+
+ return (x / n) * y;
+}
+
/**
* disk_get_partition_info()
* @fd - open file descriptor to disk
uint8_t *mbr_type, uint8_t *signature_type)
{
legacy_mbr *mbr;
- void *mbr_unaligned;
+ void *mbr_sector;
+ size_t mbr_size;
off_t offset;
int this_bytes_read = 0;
int gpt_invalid=0, mbr_invalid=0;
int rc=0;
int sector_size = get_sector_size(fd);
- if (sizeof(*mbr) != sector_size)
- return 1;
- mbr_unaligned = malloc(sizeof(*mbr)+sector_size-1);
- mbr = (legacy_mbr *)
- (((unsigned long)mbr_unaligned + sector_size - 1) &
- ~(unsigned long)(sector_size-1));
- memset(mbr, 0, sizeof(*mbr));
+
+ mbr_size = lcm(sizeof(*mbr), sector_size);
+ if ((rc = posix_memalign(&mbr_sector, sector_size, mbr_size)) != 0)
+ goto error;
+ memset(mbr_sector, '\0', mbr_size);
+
offset = lseek(fd, 0, SEEK_SET);
- this_bytes_read = read(fd, mbr, sizeof(*mbr));
+ this_bytes_read = read(fd, mbr_sector, mbr_size);
if (this_bytes_read < sizeof(*mbr)) {
rc=1;
goto error_free_mbr;
}
+ mbr = (legacy_mbr *)mbr_sector;
gpt_invalid = gpt_disk_get_partition_info(fd, num,
start, size,
signature,
}
}
error_free_mbr:
- free(mbr_unaligned);
+ free(mbr_sector);
+ error:
return rc;
}