From: Guoqing Jiang <gqjiang@suse.com>
Date: Wed, 11 May 2016 09:31:36 +0000 (+0800)
Subject: super1: add more checks for NodeNumUpdate option
X-Git-Tag: mdadm-4.0~87
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=45a87c2f31335a759190dff663a881bc78ca5443;p=mdadm.git

super1: add more checks for NodeNumUpdate option

There are some cases which didn't need to check the space
is enough or not for NodeNumUpdate option.

1. for array which does not have clustered bitmap.
2. "--nodes" parameter is 0 (eg, add a disk to clustered raid).
3. if "--nodes" parameter is set to a smaller num than
   current bms->nodes.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
---

diff --git a/super1.c b/super1.c
index 6bf95234..879e0d5a 100644
--- a/super1.c
+++ b/super1.c
@@ -2394,9 +2394,25 @@ static int write_bitmap1(struct supertype *st, int fd, enum bitmap_update update
 			return -EINVAL;
 		}
 
-		if (bms->version == BITMAP_MAJOR_CLUSTERED && st->nodes <= 1) {
-			pr_err("Warning: cluster-md at least needs two nodes\n");
-			return -EINVAL;
+		if (bms->version == BITMAP_MAJOR_CLUSTERED) {
+			if (st->nodes == 1) {
+				/* the parameter for nodes is not valid */
+				pr_err("Warning: cluster-md at least needs two nodes\n");
+				return -EINVAL;
+			} else if (st->nodes == 0)
+				/* --nodes is not specified */
+				break;
+			else if (__cpu_to_le32(st->nodes) < bms->nodes) {
+				/* Since the nodes num is not increased, no need to check the space
+				 * is enough or not, just update bms->nodes */
+				bms->nodes = __cpu_to_le32(st->nodes);
+				break;
+			}
+		} else {
+			/* no need to change bms->nodes for other bitmap types */
+			if (st->nodes)
+				pr_err("Warning: --nodes option is only suitable for clustered bitmap\n");
+			break;
 		}
 
 		/* Each node has an independent bitmap, it is necessary to calculate the