mirror of
https://github.com/torvalds/linux.git
synced 2024-11-11 06:31:49 +00:00
dd73a01a30
HFSPLUS_SB doesn't return a pointer to the hfsplus-specific superblock information like all other FOO_SB macros, but dereference the pointer in a way that made it look like a direct struct derefence. This only works as long as the HFSPLUS_SB macro is used directly and prevents us from keepig a local hfsplus_sb_info pointer. Fix the calling convention and introduce a local sbi variable in all functions that use it constantly. Signed-off-by: Christoph Hellwig <hch@tuxera.com>
135 lines
3.6 KiB
C
135 lines
3.6 KiB
C
/*
|
|
* linux/fs/hfsplus/part_tbl.c
|
|
*
|
|
* Copyright (C) 1996-1997 Paul H. Hargrove
|
|
* 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).
|
|
*
|
|
* In function preconditions the term "valid" applied to a pointer to
|
|
* a structure means that the pointer is non-NULL and the structure it
|
|
* points to has all fields initialized to consistent values.
|
|
*
|
|
*/
|
|
|
|
#include "hfsplus_fs.h"
|
|
|
|
/* offsets to various blocks */
|
|
#define HFS_DD_BLK 0 /* Driver Descriptor block */
|
|
#define HFS_PMAP_BLK 1 /* First block of partition map */
|
|
#define HFS_MDB_BLK 2 /* Block (w/i partition) of MDB */
|
|
|
|
/* magic numbers for various disk blocks */
|
|
#define HFS_DRVR_DESC_MAGIC 0x4552 /* "ER": driver descriptor map */
|
|
#define HFS_OLD_PMAP_MAGIC 0x5453 /* "TS": old-type partition map */
|
|
#define HFS_NEW_PMAP_MAGIC 0x504D /* "PM": new-type partition map */
|
|
#define HFS_SUPER_MAGIC 0x4244 /* "BD": HFS MDB (super block) */
|
|
#define HFS_MFS_SUPER_MAGIC 0xD2D7 /* MFS MDB (super block) */
|
|
|
|
/*
|
|
* 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 hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
|
|
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"*/ &&
|
|
(sbi->part < 0 || sbi->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) &&
|
|
(sbi->part < 0 || sbi->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;
|
|
}
|