Add nodes option while creating md

Specifies the maximum number of nodes in the cluster that may use
this device simultaneously. This is equivalent to the number of
bitmaps created in the internal superblock (patches to follow).

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

1 files changed, 32 insertions, 1 deletions

diff --git a/mdadm.c b/mdadm.c
index 3e8c49b5..2ab006ab 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -588,7 +588,14 @@ int main(int argc, char *argv[])
 			}
 			ident.raid_disks = s.raiddisks;
 			continue;
-
+		case O(CREATE, Nodes):
+			c.nodes = parse_num(optarg);
+			if (c.nodes <= 0) {
+				pr_err("invalid number for the number of cluster nodes: %s\n",
+					optarg);
+				exit(2);
+			}
+			continue;
 		case O(CREATE,'x'): /* number of spare (eXtra) disks */
 			if (s.sparedisks) {
 				pr_err("spare-devices set twice: %d and %s\n",
@@ -1097,6 +1104,15 @@ int main(int argc, char *argv[])
 				s.bitmap_file = optarg;
 				continue;
 			}
+			if (strcmp(optarg, "clustered")== 0) {
+				s.bitmap_file = optarg;
+				/* Set the default number of cluster nodes
+				 * to 4 if not already set by user
+				 */
+				if (c.nodes < 1)
+					c.nodes = 4;
+				continue;
+			}
 			/* probable typo */
 			pr_err("bitmap file must contain a '/', or be 'internal', or 'none'\n"
 				"       not '%s'\n", optarg);
@@ -1377,6 +1393,21 @@ int main(int argc, char *argv[])
 	case CREATE:
 		if (c.delay == 0)
 			c.delay = DEFAULT_BITMAP_DELAY;
+
+		if (c.nodes) {
+			if (!s.bitmap_file || strcmp(s.bitmap_file, "clustered") != 0) {
+				pr_err("--nodes argument only compatible with --bitmap=clustered\n");
+				rv = 1;
+				break;
+			}
+
+			if (s.level != 1) {
+				pr_err("--bitmap=clustered is currently supported with RAID mirror only\n");
+				rv = 1;
+				break;
+			}
+		}
+
 		if (s.write_behind && !s.bitmap_file) {
 			pr_err("write-behind mode requires a bitmap.\n");
 			rv = 1;