[dm-devel] [PATCH 3/3] multipathd: Handle losing all path in update_map

[Benjamin Marzinski]

Its possible that when a multipath device is being updated, it will end
up that all the paths for it are gone. This can happen if paths are
added and then removed again before multipathd processes the uevent for
the newly created multipath device. In this case multipathd wasn't
taking the proper action for the case where all the paths had been
removed. If flush_on_last_del was set, multipathd wasn't disabling
flushing and if deferred_remove was set, it wasn't doing a deferred
remove. Multipathd should call flush_map_nopaths(), just like
ev_remove_path() does when the last path is removed.

Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
---
 multipathd/main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/multipathd/main.c b/multipathd/main.c
index 1380dd8b..f2890842 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -602,6 +602,10 @@ retry:
 		goto fail;
 	}
 	verify_paths(mpp);
+	if (VECTOR_SIZE(mpp->paths) == 0 &&
+	    flush_map_nopaths(mpp, vecs))
+		return 1;
+
 	mpp->action = ACT_RELOAD;
 
 	if (mpp->prflag) {
-- 
2.17.2