Now it allow updating cluster nodes without specify --nodes. It can write superblock with zero nodes. It can break the current cluster. Add this check to avoid this problem. Signed-off-by: Xiao Ni <xni@xxxxxxxxxx> --- mdadm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mdadm.c b/mdadm.c index 51e16f3..884dc48 100644 --- a/mdadm.c +++ b/mdadm.c @@ -1341,6 +1341,11 @@ int main(int argc, char *argv[]) } } + if (strcmp(c.update, "nodes") == 0 && c.nodes == 0) { + pr_err("Please specify nodes number with --nodes\n"); + exit(1); + } + if (c.backup_file && data_offset != INVALID_SECTORS) { pr_err("--backup-file and --data-offset are incompatible\n"); exit(2); -- 2.7.5