Initial import

1 files changed, 157 insertions, 0 deletions

diff --git a/fs/hfsplus/part_tbl.c b/fs/hfsplus/part_tbl.c
new file mode 100644
index 000000000..eb355d81e
--- /dev/null
+++ b/fs/hfsplus/part_tbl.c
@@ -0,0 +1,157 @@
+/*
+ * 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 <linux/slab.h>
+#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;
+
+static int hfs_parse_old_pmap(struct super_block *sb, struct old_pmap *pm,
+		sector_t *part_start, sector_t *part_size)
+{
+	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+	int i;
+
+	for (i = 0; i < 42; i++) {
+		struct old_pmap_entry *p = &pm->pdEntry[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);
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+static int hfs_parse_new_pmap(struct super_block *sb, void *buf,
+		struct new_pmap *pm, sector_t *part_start, sector_t *part_size)
+{
+	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+	int size = be32_to_cpu(pm->pmMapBlkCnt);
+	int buf_size = hfsplus_min_io_size(sb);
+	int res;
+	int i = 0;
+
+	do {
+		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);
+			return 0;
+		}
+
+		if (++i >= size)
+			return -ENOENT;
+
+		pm = (struct new_pmap *)((u8 *)pm + HFSPLUS_SECTOR_SIZE);
+		if ((u8 *)pm - (u8 *)buf >= buf_size) {
+			res = hfsplus_submit_bio(sb,
+						 *part_start + HFS_PMAP_BLK + i,
+						 buf, (void **)&pm, READ);
+			if (res)
+				return res;
+		}
+	} while (pm->pmSig == cpu_to_be16(HFS_NEW_PMAP_MAGIC));
+
+	return -ENOENT;
+}
+
+/*
+ * Parse the partition map looking for the start and length of a
+ * HFS/HFS+ partition.
+ */
+int hfs_part_find(struct super_block *sb,
+		sector_t *part_start, sector_t *part_size)
+{
+	void *buf, *data;
+	int res;
+
+	buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	res = hfsplus_submit_bio(sb, *part_start + HFS_PMAP_BLK,
+				 buf, &data, READ);
+	if (res)
+		goto out;
+
+	switch (be16_to_cpu(*((__be16 *)data))) {
+	case HFS_OLD_PMAP_MAGIC:
+		res = hfs_parse_old_pmap(sb, data, part_start, part_size);
+		break;
+	case HFS_NEW_PMAP_MAGIC:
+		res = hfs_parse_new_pmap(sb, buf, data, part_start, part_size);
+		break;
+	default:
+		res = -ENOENT;
+		break;
+	}
+out:
+	kfree(buf);
+	return res;
+}