commit 20018e12cfde4847a0e90f0f9942804c20c14894
author Kevin Wolf <kwolf@redhat.com> Mon May 23 18:46:59 2016 +0200
committer Kevin Wolf <kwolf@redhat.com> Wed May 25 19:04:11 2016 +0200
tree 2bbc1194536dd1f177c8ea37aeabc18882ea336c
parent 36fe13317bfc3414745528c6c08cea2904ca49ec

block: Propagate .drained_begin/end callbacks

When draining intermediate nodes (i.e. nodes that aren't the root node
for at least one of their parents; with node references, the user can
always configure the graph to create this situation), we need to
propagate the .drained_begin/end callbacks all the way up to the root
for the drain to be effective.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>

block.c

diff --git a/block.c b/block.c
index 598624f..45cddd6 100644
--- a/block.c
+++ b/block.c
@@ -659,6 +659,18 @@
     return 0;
 }
 
+static void bdrv_child_cb_drained_begin(BdrvChild *child)
+{
+    BlockDriverState *bs = child->opaque;
+    bdrv_drained_begin(bs);
+}
+
+static void bdrv_child_cb_drained_end(BdrvChild *child)
+{
+    BlockDriverState *bs = child->opaque;
+    bdrv_drained_end(bs);
+}
+
 /*
  * Returns the options and flags that a temporary snapshot should get, based on
  * the originally requested flags (the originally requested image will have
@@ -705,6 +717,8 @@
 
 const BdrvChildRole child_file = {
     .inherit_options = bdrv_inherited_options,
+    .drained_begin   = bdrv_child_cb_drained_begin,
+    .drained_end     = bdrv_child_cb_drained_end,
 };
 
 /*
@@ -723,6 +737,8 @@
 
 const BdrvChildRole child_format = {
     .inherit_options = bdrv_inherited_fmt_options,
+    .drained_begin   = bdrv_child_cb_drained_begin,
+    .drained_end     = bdrv_child_cb_drained_end,
 };
 
 /*
@@ -750,6 +766,8 @@
 
 static const BdrvChildRole child_backing = {
     .inherit_options = bdrv_backing_options,
+    .drained_begin   = bdrv_child_cb_drained_begin,
+    .drained_end     = bdrv_child_cb_drained_end,
 };
 
 static int bdrv_open_flags(BlockDriverState *bs, int flags)
@@ -1195,7 +1213,7 @@
                              const BdrvChildRole *child_role)
 {
     BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role,
-                                              NULL);
+                                              parent_bs);
     QLIST_INSERT_HEAD(&parent_bs->children, child, next);
     return child;
 }