block: Allow bdrv_flush to return errors

This changes bdrv_flush to return 0 on success and -errno in case of failure.
It's a requirement for implementing proper error handle in users of bdrv_flush.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/block/raw-win32.c b/block/raw-win32.c
index 503ed3959a..7f32778612 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -150,7 +150,14 @@ static int raw_write(BlockDriverState *bs, int64_t sector_num,
 static void raw_flush(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;
-    FlushFileBuffers(s->hfile);
+    int ret;
+
+    ret = FlushFileBuffers(s->hfile);
+    if (ret != 0) {
+        return -EIO;
+    }
+
+    return 0;
 }
 
 static void raw_close(BlockDriverState *bs)