Fix write_init_super usage when hot-adding a spare

Using write_init_super to add a spare to an active array is quite
different to how it is used when creating an array.

It mostly works, but if we are adding two devices to an array,
then when we add the second, there are still traces of the first
which confuse write_init_super.

So get write_init_super to ignore those traces.  Longer term, we
probably want to do this differently as for DDF, hot-adding to
an active array will have to be quite different - it will want to
write to all metadata, possibly via mdmon.

1 files changed, 2 insertions, 0 deletions

diff --git a/super0.c b/super0.c
index 1ca35368..e8cc3f3f 100644
--- a/super0.c
+++ b/super0.c
@@ -698,6 +698,8 @@ static int write_init_super0(struct supertype *st)
 
 		if (di->disk.state == 1)
 			continue;
+		if (di->fd == -1)
+			continue;
 		Kill(di->devname, 0, 1, 1);
 		Kill(di->devname, 0, 1, 1);