block: Introduce bdrv_dirty_bitmap_granularity()

This returns the granularity (in bytes) of dirty bitmap,
which matches the QMP interface and the existing query
interface.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1429314609-29776-6-git-send-email-jsnow@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -5575,8 +5575,7 @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
         BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
         BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
         info->count = bdrv_get_dirty_count(bs, bm);
-        info->granularity =
-            ((uint32_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap));
+        info->granularity = bdrv_dirty_bitmap_granularity(bm);
         info->has_name = !!bm->name;
         info->name = g_strdup(bm->name);
         entry->value = info;
@@ -5616,6 +5615,11 @@ uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)
     return granularity;
 }
 
+uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap)
+{
+    return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
+}
+
 void bdrv_dirty_iter_init(BlockDriverState *bs,
                           BdrvDirtyBitmap *bitmap, HBitmapIter *hbi)
 {

include/block/block.h

@@ -460,6 +460,7 @@ void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
 void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
 uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs);
+uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap);
 int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector);
 void bdrv_set_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
                            int64_t cur_sector, int nr_sectors);