[PATCH 1/3] rbd: fix up the layering warning message

[Alex Elder <elder@inktank.com>]

A warning gets spewed for any image being probed, including parent
images.  Set up a condition such that the warning message only gets
printed for the image being mapped, not any of its parents.

Also, I didn't like the way the warning ended up being so long.
Make it a terse warning instead.  People experimenting with layering
will know what the message means.

This is part of:
    http://tracker.ceph.com/issues/4867

Signed-off-by: Alex Elder <elder@inktank.com>
---
 drivers/block/rbd.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 8b30d83..176a3d7 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4624,8 +4624,15 @@ static int rbd_dev_v2_probe(struct rbd_device
*rbd_dev)
 		ret = rbd_dev_v2_parent_info(rbd_dev);
 		if (ret)
 			goto out_err;
-		rbd_warn(rbd_dev, "WARNING: kernel support for "
-					"layered rbd images is EXPERIMENTAL!");
+
+		/*
+		 * 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).
+		 */
+		if (rbd_dev->spec->pool_name)
+			rbd_warn(rbd_dev, "WARNING: kernel layering "
+					"is EXPERIMENTAL!");
 	}

 	/* If the image supports fancy striping, get its parameters */
-- 
1.7.9.5