partition: add support for sysv68 partitions

Add support for the Motorola sysv68 disk partition (slices in motorola
doc).

Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 92 insertions, 0 deletions

diff --git a/fs/partitions/sysv68.c b/fs/partitions/sysv68.c
new file mode 100644
index 000000000000..4eba27b78643
--- /dev/null
+++ b/fs/partitions/sysv68.c
@@ -0,0 +1,92 @@
+/*
+ *  fs/partitions/sysv68.c
+ *
+ *  Copyright (C) 2007 Philippe De Muyter <phdm@macqel.be>
+ */
+
+#include "check.h"
+#include "sysv68.h"
+
+/*
+ *      Volume ID structure: on first 256-bytes sector of disk
+ */
+
+struct volumeid {
+        u8      vid_unused[248];
+        u8      vid_mac[8];     /* ASCII string "MOTOROLA" */
+};
+
+/*
+ *      config block: second 256-bytes sector on disk
+ */
+
+struct dkconfig {
+        u8      ios_unused0[128];
+        __be32  ios_slcblk;     /* Slice table block number */
+        __be16  ios_slccnt;     /* Number of entries in slice table */
+        u8      ios_unused1[122];
+};
+
+/*
+ *      combined volumeid and dkconfig block
+ */
+
+struct dkblk0 {
+        struct volumeid dk_vid;
+        struct dkconfig dk_ios;
+};
+
+/*
+ *      Slice Table Structure
+ */
+
+struct slice {
+        __be32  nblocks;                /* slice size (in blocks) */
+        __be32  blkoff;                 /* block offset of slice */
+};
+
+
+int sysv68_partition(struct parsed_partitions *state, struct block_device *bdev)
+{
+        int i, slices;
+        int slot = 1;
+        Sector sect;
+        unsigned char *data;
+        struct dkblk0 *b;
+        struct slice *slice;
+
+        data = read_dev_sector(bdev, 0, &sect);
+        if (!data)
+                return -1;
+
+        b = (struct dkblk0 *)data;
+        if (memcmp(b->dk_vid.vid_mac, "MOTOROLA", sizeof(b->dk_vid.vid_mac))) {
+                put_dev_sector(sect);
+                return 0;
+        }
+        slices = be16_to_cpu(b->dk_ios.ios_slccnt);
+        i = be32_to_cpu(b->dk_ios.ios_slcblk);
+        put_dev_sector(sect);
+
+        data = read_dev_sector(bdev, i, &sect);
+        if (!data)
+                return -1;
+
+        slices -= 1; /* last slice is the whole disk */
+        printk("sysV68: %s(s%u)", state->name, slices);
+        slice = (struct slice *)data;
+        for (i = 0; i < slices; i++, slice++) {
+                if (slot == state->limit)
+                        break;
+                if (be32_to_cpu(slice->nblocks)) {
+                        put_partition(state, slot,
+                                be32_to_cpu(slice->blkoff),
+                                be32_to_cpu(slice->nblocks));
+                        printk("(s%u)", i);
+                }
+                slot++;
+        }
+        printk("\n");
+        put_dev_sector(sect);
+        return 1;
+}