parallels: update used bitmap in allocate_cluster

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

@@ -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;