md: Increment version for clustered bitmaps

Add BITMAP_MAJOR_CLUSTERED as 5, in order to prevent older kernels
to assemble a clustered device.

In order to maximize compatibility, the major version is set to
BITMAP_MAJOR_CLUSTERED *only* if the bitmap is clustered.

Added MD_FEATURE_CLUSTERED in order to return error for older
kernels which would assemble MD even if the bitmap is corrupted.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index 2ae6131e69a5..867ee874fa80 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -302,6 +302,7 @@ struct mdp_superblock_1 {
 #define MD_FEATURE_RECOVERY_BITMAP      128 /* recovery that is happening
                                              * is guided by bitmap.
                                              */
+#define MD_FEATURE_CLUSTERED            256 /* clustered MD */
 #define MD_FEATURE_ALL                  (MD_FEATURE_BITMAP_OFFSET       \
                                         |MD_FEATURE_RECOVERY_OFFSET     \
                                         |MD_FEATURE_RESHAPE_ACTIVE      \
@@ -310,6 +311,7 @@ struct mdp_superblock_1 {
                                         |MD_FEATURE_RESHAPE_BACKWARDS   \
                                         |MD_FEATURE_NEW_OFFSET          \
                                         |MD_FEATURE_RECOVERY_BITMAP     \
+                                        |MD_FEATURE_CLUSTERED           \
                                         )
 
 #endif