[Qemu-devel] [PATCH 1/2] vhdx: DIV_ROUND_UP() in vhdx_calc_bat_entries()

[Max Reitz <mreitz@redhat.com>]

We have DIV_ROUND_UP(), so we can use it to produce more easily readable
code. It may be slower than the bit shifting currently performed
(because it actually performs a division), but since
vhdx_calc_bat_entries() is never used in a hot path, this is completely
fine.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/vhdx.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/block/vhdx.c b/block/vhdx.c
index 2fe9a5e..3955f7f 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -856,14 +856,8 @@ static void vhdx_calc_bat_entries(BDRVVHDXState *s)
 {
     uint32_t data_blocks_cnt, bitmap_blocks_cnt;
 
-    data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits;
-    if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) {
-        data_blocks_cnt++;
-    }
-    bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits;
-    if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) {
-        bitmap_blocks_cnt++;
-    }
+    data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size);
+    bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio);
 
     if (s->parent_entries) {
         s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1);
-- 
2.6.4