123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118 |
- /*
- * linux/fs/hfs/part_tbl.c
- *
- * Copyright (C) 1996-1997 Paul H. Hargrove
- * (C) 2003 Ardis Technologies <roman@ardistech.com>
- * This file may be distributed under the terms of the GNU General Public License.
- *
- * Original code to handle the new style Mac partition table based on
- * a patch contributed by Holger Schemel (aeglos@valinor.owl.de).
- */
- #include "hfs_fs.h"
- /*
- * The new style Mac partition map
- *
- * For each partition on the media there is a physical block (512-byte
- * block) containing one of these structures. These blocks are
- * contiguous starting at block 1.
- */
- struct new_pmap {
- __be16 pmSig; /* signature */
- __be16 reSigPad; /* padding */
- __be32 pmMapBlkCnt; /* partition blocks count */
- __be32 pmPyPartStart; /* physical block start of partition */
- __be32 pmPartBlkCnt; /* physical block count of partition */
- u8 pmPartName[32]; /* (null terminated?) string
- giving the name of this
- partition */
- u8 pmPartType[32]; /* (null terminated?) string
- giving the type of this
- partition */
- /* a bunch more stuff we don't need */
- } __packed;
- /*
- * The old style Mac partition map
- *
- * The partition map consists for a 2-byte signature followed by an
- * array of these structures. The map is terminated with an all-zero
- * one of these.
- */
- struct old_pmap {
- __be16 pdSig; /* Signature bytes */
- struct old_pmap_entry {
- __be32 pdStart;
- __be32 pdSize;
- __be32 pdFSID;
- } pdEntry[42];
- } __packed;
- /*
- * hfs_part_find()
- *
- * Parse the partition map looking for the
- * start and length of the 'part'th HFS partition.
- */
- int hfs_part_find(struct super_block *sb,
- sector_t *part_start, sector_t *part_size)
- {
- struct buffer_head *bh;
- __be16 *data;
- int i, size, res;
- res = -ENOENT;
- bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data);
- if (!bh)
- return -EIO;
- switch (be16_to_cpu(*data)) {
- case HFS_OLD_PMAP_MAGIC:
- {
- struct old_pmap *pm;
- struct old_pmap_entry *p;
- pm = (struct old_pmap *)bh->b_data;
- p = pm->pdEntry;
- size = 42;
- for (i = 0; i < size; p++, i++) {
- if (p->pdStart && p->pdSize &&
- p->pdFSID == cpu_to_be32(0x54465331)/*"TFS1"*/ &&
- (HFS_SB(sb)->part < 0 || HFS_SB(sb)->part == i)) {
- *part_start += be32_to_cpu(p->pdStart);
- *part_size = be32_to_cpu(p->pdSize);
- res = 0;
- }
- }
- break;
- }
- case HFS_NEW_PMAP_MAGIC:
- {
- struct new_pmap *pm;
- pm = (struct new_pmap *)bh->b_data;
- size = be32_to_cpu(pm->pmMapBlkCnt);
- for (i = 0; i < size;) {
- if (!memcmp(pm->pmPartType,"Apple_HFS", 9) &&
- (HFS_SB(sb)->part < 0 || HFS_SB(sb)->part == i)) {
- *part_start += be32_to_cpu(pm->pmPyPartStart);
- *part_size = be32_to_cpu(pm->pmPartBlkCnt);
- res = 0;
- break;
- }
- brelse(bh);
- bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK + ++i, pm);
- if (!bh)
- return -EIO;
- if (pm->pmSig != cpu_to_be16(HFS_NEW_PMAP_MAGIC))
- break;
- }
- break;
- }
- }
- brelse(bh);
- return res;
- }
|