block: Introduce bdrv_co_flush_to_os
qcow2 has a writeback metadata cache, so flushing a qcow2 image actually
consists of writing back that cache to the protocol and only then flushes the
protocol in order to get everything stable on disk.
This introduces a separate bdrv_co_flush_to_os to reflect the split.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/qcow2.c b/block/qcow2.c
index f7f73fe..5c784ee 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1105,7 +1105,7 @@
return ret;
}
-static int qcow2_co_flush(BlockDriverState *bs)
+static int qcow2_co_flush_to_os(BlockDriverState *bs)
{
BDRVQcowState *s = bs->opaque;
int ret;
@@ -1124,6 +1124,11 @@
}
qemu_co_mutex_unlock(&s->lock);
+ return 0;
+}
+
+static int qcow2_co_flush_to_disk(BlockDriverState *bs)
+{
return bdrv_co_flush(bs->file);
}
@@ -1245,7 +1250,8 @@
.bdrv_co_readv = qcow2_co_readv,
.bdrv_co_writev = qcow2_co_writev,
- .bdrv_co_flush_to_disk = qcow2_co_flush,
+ .bdrv_co_flush_to_os = qcow2_co_flush_to_os,
+ .bdrv_co_flush_to_disk = qcow2_co_flush_to_disk,
.bdrv_co_discard = qcow2_co_discard,
.bdrv_truncate = qcow2_truncate,
