rbd: don't print warning if not mapping a parent
The presence of the LAYERING bit in an rbd image's feature mask does
not guarantee the image actually has a parent image. Currently that
bit is set only when a clone (i.e., image with a parent) is created,
but it is (currently) not cleared if that clone gets flattened back
into a "normal" image. A "parent_id" query will leave the
parent_spec for the image being mapped a null pointer, but will not
return an error.
Currently, whenever an image with the LAYERED feature gets mapped, a
warning about the use of layered images gets printed. But we don't
want to do this for a flattened image, so print the warning only
if we find there is a parent spec after the probe.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4c98695..2d34aea 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4567,13 +4567,14 @@
ret = rbd_dev_v2_parent_info(rbd_dev);
if (ret)
goto out_err;
-
/*
- * Don't print a warning for parent images. We can
- * tell this point because we won't know its pool
- * name yet (just its pool id).
+ * Print a warning if this image has a parent.
+ * Don't print it if the image now being probed
+ * is itself a parent. We can tell at this point
+ * because we won't know its pool name yet (just its
+ * pool id).
*/
- if (rbd_dev->spec->pool_name)
+ if (rbd_dev->parent_spec && rbd_dev->spec->pool_name)
rbd_warn(rbd_dev, "WARNING: kernel layering "
"is EXPERIMENTAL!");
}