haraldwolff/qemu-patch-raspberry4
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

block: Introduce bdrv_replace_child()

Browse source 
This adds a common function that is called when attaching a new child to
a parent, removing a child from a parent and when reconfiguring the
graph so that an existing child points to a different node now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
This commit is contained in:
Kevin Wolf 2016-05-23 15:52:26 +02:00
parent 109525ad6a
commit e9740bc6d4
1 changed files with 20 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
block.c
View file

@ -1150,18 +1150,32 @@ static int bdrv_fill_options(QDict **options, const char *filename,
return 0;
}
static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs)
{
BlockDriverState *old_bs = child->bs;
if (old_bs) {
QLIST_REMOVE(child, next_parent);
}
if (new_bs) {
QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
}
child->bs = new_bs;
}
BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
const char *child_name,
const BdrvChildRole *child_role)
{
BdrvChild *child = g_new(BdrvChild, 1);
*child = (BdrvChild) {
.bs = child_bs,
.bs = NULL,
.name = g_strdup(child_name),
.role = child_role,
};
QLIST_INSERT_HEAD(&child_bs->parents, child, next_parent);
bdrv_replace_child(child, child_bs);
return child;
}
@ -1182,7 +1196,9 @@ static void bdrv_detach_child(BdrvChild *child)
QLIST_REMOVE(child, next);
child->next.le_prev = NULL;
}
QLIST_REMOVE(child, next_parent);
bdrv_replace_child(child, NULL);
g_free(child->name);
g_free(child);
}
@ -2203,10 +2219,8 @@ static void change_parent_backing_link(BlockDriverState *from,
QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
assert(c->role != &child_backing);
c->bs = to;
QLIST_REMOVE(c, next_parent);
QLIST_INSERT_HEAD(&to->parents, c, next_parent);
bdrv_ref(to);
bdrv_replace_child(c, to);
bdrv_unref(from);
}
}