Fix --grow --add for linear arrays.

The new superblock needs to have a new disk.number.  This is a bit of a hack...
Fix handling of negative bitmap offsets on 64bit hosts.

The bitmap offset is a signed 32bit number, so casting to (long)
isn't sufficient.  We must cast to (int32_t).
Fix various problems with --grow --add for linear.

The code to add a drive to a live linear array had never
been tested properly and so was buggy.  This tidies it up
and means that the new regression-test passes.

1 files changed, 10 insertions, 3 deletions

diff --git a/super0.c b/super0.c
index 5828e15..30da8aa 100644
--- a/super0.c
+++ b/super0.c
@@ -459,7 +459,16 @@ static int update_super0(struct mdinfo *info, void *sbv, char *update,
 			rv = 1;
 		}
 	}
-	if (strcmp(update, "grow") == 0) {
+	if (strcmp(update, "linear-grow-new") == 0) {
+		memset(&sb->disks[info->disk.number], 0, sizeof(sb->disks[0]));
+		sb->disks[info->disk.number].number = info->disk.number;
+		sb->disks[info->disk.number].major = info->disk.major;
+		sb->disks[info->disk.number].minor = info->disk.minor;
+		sb->disks[info->disk.number].raid_disk = info->disk.raid_disk;
+		sb->disks[info->disk.number].state = info->disk.state;
+		sb->this_disk = sb->disks[info->disk.number];
+	}
+	if (strcmp(update, "linear-grow-update") == 0) {
 		sb->raid_disks = info->array.raid_disks;
 		sb->nr_disks = info->array.nr_disks;
 		sb->active_disks = info->array.active_disks;
@@ -470,8 +479,6 @@ static int update_super0(struct mdinfo *info, void *sbv, char *update,
 		sb->disks[info->disk.number].minor = info->disk.minor;
 		sb->disks[info->disk.number].raid_disk = info->disk.raid_disk;
 		sb->disks[info->disk.number].state = info->disk.state;
-		if (sb->this_disk.number == info->disk.number)
-			sb->this_disk = sb->disks[info->disk.number];
 	}
 	if (strcmp(update, "resync") == 0) {
 		/* make sure resync happens */