parallels: create parallels_set_bat_entry_helper() to assign BAT value

This helper will be reused in next patches during parallels_co_check
rework to simplify its code.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230424093147.197643-5-alexander.ivanov@virtuozzo.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

block/parallels.c

@@ -165,6 +165,13 @@ static int64_t block_status(BDRVParallelsState *s, int64_t sector_num,
     return start_off;
 }
 
+static void parallels_set_bat_entry(BDRVParallelsState *s,
+                                    uint32_t index, uint32_t offset)
+{
+    s->bat_bitmap[index] = cpu_to_le32(offset);
+    bitmap_set(s->bat_dirty_bmap, bat_entry_off(index) / s->bat_dirty_block, 1);
+}
+
 static int64_t coroutine_fn GRAPH_RDLOCK
 allocate_clusters(BlockDriverState *bs, int64_t sector_num,
                   int nb_sectors, int *pnum)
@@ -251,10 +258,8 @@ allocate_clusters(BlockDriverState *bs, int64_t sector_num,
     }
 
     for (i = 0; i < to_allocate; i++) {
-        s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
+        parallels_set_bat_entry(s, idx + i, s->data_end / s->off_multiplier);
         s->data_end += s->tracks;
-        bitmap_set(s->bat_dirty_bmap,
-                   bat_entry_off(idx + i) / s->bat_dirty_block, 1);
     }
 
     return bat2sect(s, idx) + sector_num % s->tracks;