[v3,1/4] multipathd: monitor new multipath dev even if we can't update it

Commit Message

Benjamin Marzinski April 2, 2025, 11:13 p.m. UTC

If a multipath device was created by the multipath command, multipathd
might not agree with how the device was created. ev_add_map() can reload
the device with a different table by calling add_map_without_path() ->
update_map(). If this reloading of the map failed, multipathd was simply
ignoring the multipath device, even though it still existed.

One way that reloading can fail is if a path that multipathd already has
initialized goes offline. If a multipath device is created by the
multipath command while the path is offline, it will not use the offline
path, since multipath won't be able to get the necessary pathinfo.
However, multipathd will already have the pathinfo for the path, and may
not even know that it's offline, since the path is an orphan. When it
tries to reload the device, it will include the offline path, and the
reload will fail.

Instead of ignoring the device if it can't reload it, multipathd should
just montior it as it is. When the path device is no longer offline, it
can be added back to the multipath device by calling
"multipathd reconfigure" or "multipathd add path <path>".

Signed-off-by: Benjamin Marzinski <[e-mail]>
Reviewed-by: Martin Wilck  <[e-mail]>
---
 multipathd/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/multipathd/main.c b/multipathd/main.c
index e63b6aa7..7aaae773 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -679,7 +679,7 @@  retry:
 	}
 
 fail:
-	if (new_map && (retries < 0 || wait_for_events(mpp, vecs))) {
+	if (new_map && wait_for_events(mpp, vecs)) {
 		condlog(0, "%s: failed to create new map", mpp->alias);
 		remove_map(mpp, vecs->pathvec, vecs->mpvec);
 		return 1;