Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / hfs / part_tbl.c

diff --git a/kernel/fs/hfs/part_tbl.c b/kernel/fs/hfs/part_tbl.c
new file mode 100644 (file)
index 0000000..36add53
--- /dev/null
+++ b/kernel/fs/hfs/part_tbl.c
@@ -0,0 +1,117 @@
+/*
+ *  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;
+}