block: Add flush callback

Some block devices need an explicit callback for flushing written
blocks. Add this callback.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/common/block.c b/common/block.c
index e522ee425a..0edc8619ef 100644
--- a/common/block.c
+++ b/common/block.c
@@ -55,6 +55,9 @@ static int writebuffer_flush(struct block_device *blk)
 		}
 	}
 
+	if (blk->ops->flush)
+		return blk->ops->flush(blk);
+
 	return 0;
 }