Support new raid6 layouts needed for DDF

DDF raid6 layouts are subtly different from the standard 'md' layouts.
From 2.6.30 the kernel knows about these.
Teach mdadm about them, and also allow 'ddf' to set an appropriate default.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 31 insertions, 8 deletions

diff --git a/super-ddf.c b/super-ddf.c
index 6c75998..b021801 100644
--- a/super-ddf.c
+++ b/super-ddf.c
@@ -1759,20 +1759,25 @@ static int layout_to_rlq(int level, int layout, int raiddisks)
 		}
 		break;
 	case 5:
-	case 6:
 		switch(layout) {
 		case ALGORITHM_LEFT_ASYMMETRIC:
 			return DDF_RAID5_N_RESTART;
 		case ALGORITHM_RIGHT_ASYMMETRIC:
-			if (level == 5)
-				return DDF_RAID5_0_RESTART;
-			else
-				return DDF_RAID6_0_RESTART;
+			return DDF_RAID5_0_RESTART;
 		case ALGORITHM_LEFT_SYMMETRIC:
 			return DDF_RAID5_N_CONTINUE;
 		case ALGORITHM_RIGHT_SYMMETRIC:
 			return -1; /* not mentioned in standard */
 		}
+	case 6:
+		switch(layout) {
+		case ALGORITHM_ROTATING_N_RESTART:
+			return DDF_RAID5_N_RESTART;
+		case ALGORITHM_ROTATING_ZERO_RESTART:
+			return DDF_RAID6_0_RESTART;
+		case ALGORITHM_ROTATING_N_CONTINUE:
+			return DDF_RAID5_N_CONTINUE;
+		}
 	}
 	return -1;
 }
@@ -1807,11 +1812,11 @@ static int rlq_to_layout(int rlq, int prl, int raiddisks)
 	case DDF_RAID6:
 		switch(rlq) {
 		case DDF_RAID5_N_RESTART:
-			return ALGORITHM_LEFT_ASYMMETRIC;
+			return ALGORITHM_ROTATING_N_RESTART;
 		case DDF_RAID6_0_RESTART:
-			return ALGORITHM_RIGHT_ASYMMETRIC;
+			return ALGORITHM_ROTATING_ZERO_RESTART;
 		case DDF_RAID5_N_CONTINUE:
-			return ALGORITHM_LEFT_SYMMETRIC;
+			return ALGORITHM_ROTATING_N_CONTINUE;
 		default:
 			return -1;
 		}
@@ -3537,6 +3542,23 @@ static struct mdinfo *ddf_activate_spare(struct active_array *a,
 }
 #endif /* MDASSEMBLE */
 
+static int ddf_level_to_layout(int level)
+{
+	switch(level) {
+	case 0:
+	case 1:
+		return 0;
+	case 5:
+		return ALGORITHM_LEFT_SYMMETRIC;
+	case 6:
+		return ALGORITHM_ROTATING_N_CONTINUE;
+	case 10:
+		return 0x102;
+	default:
+		return UnSet;
+	}
+}
+
 struct superswitch super_ddf = {
 #ifndef	MDASSEMBLE
 	.examine_super	= examine_super_ddf,
@@ -3562,6 +3584,7 @@ struct superswitch super_ddf = {
 	.free_super	= free_super_ddf,
 	.match_metadata_desc = match_metadata_desc_ddf,
 	.container_content = container_content_ddf,
+	.default_layout	= ddf_level_to_layout,
 
 	.external	= 1,