We should extend the bitmap if the file is extended and set the bit in
the image used bitmap once the cluster is allocated. Sanity check at
that moment also looks like a good idea.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
---
 block/parallels.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/block/parallels.c b/block/parallels.c
index b6505fcc5b..3beb18e44f 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -282,6 +282,8 @@ allocate_clusters(BlockDriverState *bs, int64_t sector_num,
         return len;
     }
     if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
+        uint32_t new_usedsize;
+
         space += s->prealloc_size;
         /*
          * We require the expanded size to read back as zero. If the
@@ -305,6 +307,12 @@ allocate_clusters(BlockDriverState *bs, int64_t sector_num,
         if (ret < 0) {
             return ret;
         }
+
+        new_usedsize = s->used_bmap_size +
+                       (space << BDRV_SECTOR_BITS) / s->cluster_size;
+        s->used_bmap = bitmap_zero_extend(s->used_bmap, s->used_bmap_size,
+                                          new_usedsize);
+        s->used_bmap_size = new_usedsize;
     }
 
     /*
@@ -336,6 +344,12 @@ allocate_clusters(BlockDriverState *bs, int64_t sector_num,
         }
     }
 
+    ret = mark_used(bs, s->used_bmap, s->used_bmap_size,
+                    s->data_end << BDRV_SECTOR_BITS, to_allocate);
+    if (ret < 0) {
+        /* Image consistency is broken. Alarm! */
+        return ret;
+    }
     for (i = 0; i < to_allocate; i++) {
         parallels_set_bat_entry(s, idx + i, s->data_end / s->off_multiplier);
         s->data_end += s->tracks;
-- 
2.34.1