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 6bf9523451f3fd1f57c0d5c6c7f1a59ad38000c7..879e0d5a678a84c122f4875cbb3b13cee070c314 100644 (file)
--- 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