block: Convert bs->backing_hd to BdrvChild
This is the final step in converting all of the BlockDriverState
pointers that block drivers use to BdrvChild.
After this patch, bs->children contains the full list of child nodes
that are referenced by a given BDS, and these children are only
referenced through BdrvChild, so that updating the pointer in there is
enough for changing edges in the graph.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/block/qcow.c b/block/qcow.c
index 42f888c..635085e 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -597,13 +597,13 @@
}
if (!cluster_offset) {
- if (bs->backing_hd) {
+ if (bs->backing) {
/* read from the base image */
hd_iov.iov_base = (void *)buf;
hd_iov.iov_len = n * 512;
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
qemu_co_mutex_unlock(&s->lock);
- ret = bdrv_co_readv(bs->backing_hd, sector_num,
+ ret = bdrv_co_readv(bs->backing->bs, sector_num,
n, &hd_qiov);
qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
