dm array: fix bug in growing array

Entries would be lost if the old tail block was partially filled.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c
index 172147eb1d40..af96e24ec328 100644
--- a/drivers/md/persistent-data/dm-array.c
+++ b/drivers/md/persistent-data/dm-array.c
@@ -509,15 +509,18 @@ static int grow_add_tail_block(struct resize *resize)
 static int grow_needs_more_blocks(struct resize *resize)
 {
         int r;
+        unsigned old_nr_blocks = resize->old_nr_full_blocks;
 
         if (resize->old_nr_entries_in_last_block > 0) {
+                old_nr_blocks++;
+
                 r = grow_extend_tail_block(resize, resize->max_entries);
                 if (r)
                         return r;
         }
 
         r = insert_full_ablocks(resize->info, resize->size_of_block,
-                                resize->old_nr_full_blocks,
+                                old_nr_blocks,
                                 resize->new_nr_full_blocks,
                                 resize->max_entries, resize->value,
                                 &resize->root);