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-rw-r--r--kernel/fs/hfsplus/part_tbl.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/kernel/fs/hfsplus/part_tbl.c b/kernel/fs/hfsplus/part_tbl.c
new file mode 100644
index 000000000..eb355d81e
--- /dev/null
+++ b/kernel/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;
+}