md: load/store badblock list from v1.x metadata

Space must have been allocated when array was created.
A feature flag is set when the badblock list is non-empty, to
ensure old kernels don't load and trust the whole device.

We only update the on-disk badblocklist when it has changed.
If the badblocklist (or other metadata) is stored on a bad block, we
don't cope very well.

If metadata has no room for bad block, flag bad-blocks as disabled,
and do the same for 0.90 metadata.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 85af8433f8b8..aea9e9ff8a33 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -55,7 +55,7 @@ struct mdk_rdev_s
         struct block_device *meta_bdev;
         struct block_device *bdev;      /* block device handle */
 
-        struct page     *sb_page;
+        struct page     *sb_page, *bb_page;
         int             sb_loaded;
         __u64           sb_events;
         sector_t        data_offset;    /* start of data in array */
@@ -127,6 +127,9 @@ struct mdk_rdev_s
                 u64     *page;          /* badblock list */
                 int     changed;
                 seqlock_t lock;
+
+                sector_t sector;
+                sector_t size;          /* in sectors */
         } badblocks;
 };