/*
* zero_blocks()
*
* Zeros-out 'num' allocation blocks beginning with 'start'.
*/
static int zero_blocks(struct hfs_mdb *mdb, int start, int num) {
hfs_buffer buf;
int end;
int j;
start = mdb->fs_start + start * mdb->alloc_blksz;
end = start + num * mdb->alloc_blksz;
for (j=start; j<end; ++j) {
if (hfs_buffer_ok(buf = hfs_buffer_get(mdb->sys_mdb, j, 0))) {
memset(hfs_buffer_data(buf), 0, HFS_SECTOR_SIZE);
hfs_buffer_dirty(buf);
hfs_buffer_put(buf);
}
}
return 0;
}
/*
* parse_new_part_table()
*
* Parse a new style partition map looking for the
* start and length of the 'part'th HFS partition.
*/
static int parse_new_part_table(hfs_sysmdb sys_mdb, hfs_buffer buf,
int part, hfs_s32 *size, hfs_s32 *start)
{
struct new_pmap *pm = (struct new_pmap *)hfs_buffer_data(buf);
hfs_u32 pmap_entries = hfs_get_hl(pm->pmMapBlkCnt);
int hfs_part = 0;
int entry;
for (entry = 0; (entry < pmap_entries) && !(*start); ++entry) {
if (entry) {
/* read the next partition map entry */
buf = hfs_buffer_get(sys_mdb, HFS_PMAP_BLK + entry, 1);
if (!hfs_buffer_ok(buf)) {
hfs_warn("hfs_fs: unable to "
"read partition map.\n");
goto bail;
}
pm = (struct new_pmap *)hfs_buffer_data(buf);
if (hfs_get_ns(pm->pmSig) !=
htons(HFS_NEW_PMAP_MAGIC)) {
hfs_warn("hfs_fs: invalid "
"entry in partition map\n");
hfs_buffer_put(buf);
goto bail;
}
}
/* look for an HFS partition */
if (!memcmp(pm->pmPartType,"Apple_HFS",9) &&
((hfs_part++) == part)) {
/* Found it! */
*start = hfs_get_hl(pm->pmPyPartStart);
*size = hfs_get_hl(pm->pmPartBlkCnt);
}
hfs_buffer_put(buf);
}
return 0;
bail:
return 1;
}
/*
* hfs_part_find()
*
* Parse the partition map looking for the
* start and length of the 'part'th HFS partition.
*/
int hfs_part_find(hfs_sysmdb sys_mdb, int part, int silent,
hfs_s32 *size, hfs_s32 *start)
{
hfs_buffer buf;
hfs_u16 sig;
int dd_found = 0;
int retval = 1;
/* Read block 0 to see if this media is partitioned */
buf = hfs_buffer_get(sys_mdb, HFS_DD_BLK, 1);
if (!hfs_buffer_ok(buf)) {
hfs_warn("hfs_fs: Unable to read block 0.\n");
goto done;
}
sig = hfs_get_ns(((struct hfs_drvr_desc *)hfs_buffer_data(buf))->ddSig);
hfs_buffer_put(buf);
if (sig == htons(HFS_DRVR_DESC_MAGIC)) {
/* We are definitely on partitioned media. */
dd_found = 1;
}
buf = hfs_buffer_get(sys_mdb, HFS_PMAP_BLK, 1);
if (!hfs_buffer_ok(buf)) {
hfs_warn("hfs_fs: Unable to read block 1.\n");
goto done;
}
*size = *start = 0;
switch (hfs_get_ns(hfs_buffer_data(buf))) {
case __constant_htons(HFS_OLD_PMAP_MAGIC):
retval = parse_old_part_table(sys_mdb, buf, part, size, start);
break;
case __constant_htons(HFS_NEW_PMAP_MAGIC):
retval = parse_new_part_table(sys_mdb, buf, part, size, start);
break;
default:
if (dd_found) {
/* The media claimed to have a partition map */
if (!silent) {
hfs_warn("hfs_fs: This disk has an "
"unrecognized partition map type.\n");
}
} else {
/* Conclude that the media is not partitioned */
retval = 0;
}
goto done;
}
if (!retval) {
if (*start == 0) {
if (part) {
hfs_warn("hfs_fs: unable to locate "
"HFS partition number %d.\n", part);
} else {
hfs_warn("hfs_fs: unable to locate any "
"HFS partitions.\n");
}
retval = 1;
} else if (*size < 0) {
hfs_warn("hfs_fs: Partition size > 1 Terabyte.\n");
retval = 1;
} else if (*start < 0) {
hfs_warn("hfs_fs: Partition begins beyond 1 "
"Terabyte.\n");
retval = 1;
}
}
done:
return retval;
}
