block: Report data child for query-blockstats

It makes no sense to report the block stats of a purely metadata-storing
child in query-blockstats.  So if the primary child does not have any
data, try to find a unique data-storing child.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2019-11-28 09:49:22 +01:00 committed by Kevin Wolf
parent 7cc734a9ea
commit 3f26191c73

View File

@ -526,6 +526,7 @@ static void bdrv_query_blk_stats(BlockDeviceStats *ds, BlockBackend *blk)
static BlockStats *bdrv_query_bds_stats(BlockDriverState *bs,
bool blk_level)
{
BdrvChild *parent_child;
BlockStats *s = NULL;
s = g_malloc0(sizeof(*s));
@ -555,9 +556,35 @@ static BlockStats *bdrv_query_bds_stats(BlockDriverState *bs,
s->has_driver_specific = true;
}
if (bs->file) {
parent_child = bdrv_primary_child(bs);
if (!parent_child ||
!(parent_child->role & (BDRV_CHILD_DATA | BDRV_CHILD_FILTERED)))
{
BdrvChild *c;
/*
* Look for a unique data-storing child. We do not need to look for
* filtered children, as there would be only one and it would have been
* the primary child.
*/
parent_child = NULL;
QLIST_FOREACH(c, &bs->children, next) {
if (c->role & BDRV_CHILD_DATA) {
if (parent_child) {
/*
* There are multiple data-storing children and we cannot
* choose between them.
*/
parent_child = NULL;
break;
}
parent_child = c;
}
}
}
if (parent_child) {
s->has_parent = true;
s->parent = bdrv_query_bds_stats(bs->file->bs, blk_level);
s->parent = bdrv_query_bds_stats(parent_child->bs, blk_level);
}
if (blk_level && bs->backing) {