[PARTITION] MSDOS: Fix Sun num_partitions handling.

Correct the Solaris x86 number of partitions (slices) is a way that is
backward compatible with the earlier size.

This works without a new VTOC structure definition as the timestamp
and v_asciilabel fields in the VTOC are not used by the kernel yet.

Signed-off-by: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 5 insertions, 2 deletions

diff --git a/fs/partitions/msdos.c b/fs/partitions/msdos.c
index 4ccec4cd1367..5567ec0d03a3 100644
--- a/fs/partitions/msdos.c
+++ b/fs/partitions/msdos.c
@@ -203,6 +203,7 @@ parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,
         Sector sect;
         struct solaris_x86_vtoc *v;
         int i;
+        short max_nparts;
 
         v = (struct solaris_x86_vtoc *)read_dev_sector(bdev, offset+1, &sect);
         if (!v)
@@ -218,7 +219,9 @@ parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,
                 put_dev_sector(sect);
                 return;
         }
-        for (i=0; i<SOLARIS_X86_NUMSLICE && state->next<state->limit; i++) {
+        /* Ensure we can handle previous case of VTOC with 8 entries gracefully */
+        max_nparts = le16_to_cpu (v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
+        for (i=0; i<max_nparts && state->next<state->limit; i++) {
                 struct solaris_x86_slice *s = &v->v_slice[i];
                 if (s->s_size == 0)
                         continue;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 9756fc102a83..a47b8025d399 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -264,7 +264,7 @@ static inline void set_capacity(struct gendisk *disk, sector_t size)
 
 #ifdef CONFIG_SOLARIS_X86_PARTITION
 
-#define SOLARIS_X86_NUMSLICE    8
+#define SOLARIS_X86_NUMSLICE    16
 #define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 
 struct solaris_x86_slice {