From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Benjamin Marzinski <bmarzins@redhat.com>

Date: Tue, 11 May 2021 11:15:47 -0500

Subject: [PATCH] multipathd: don't fail to remove path once the map is removed

In ev_remove_path(), if update_mpp_paths() fails, we delete the entire

map. However, since update_mpp_paths() happens before we call

set_path_removed(), pp->initialized isn't set to INIT_REMOVED, so

remove_map_and_stop_waiter() doesn't remove the path when in removes the

map.  But with the map removed, there's nothing to keep us from removing

the path.

Call set_path_removed() before update_mpp_paths() to avoid the odd case

of ev_remove_path() removing the map but not the path.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

---

 libmultipath/structs_vec.c |  4 ++--

 multipathd/main.c          | 13 ++++++++-----

 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/libmultipath/structs_vec.c b/libmultipath/structs_vec.c

index d242c06b..75390198 100644

--- a/libmultipath/structs_vec.c

+++ b/libmultipath/structs_vec.c

@@ -45,8 +45,8 @@ int update_mpp_paths(struct multipath *mpp, vector pathvec)

 				/*

 				 * Avoid adding removed paths to the map again

-				 * when we reload it. Such paths may exist if

-				 * domap fails in ev_remove_path().

+				 * when we reload it. Such paths may exist in

+				 * ev_remove_paths() or if it returns failure.

 				 */

 				pp1 = find_path_by_devt(pathvec, pp->dev_t);

 				if (pp1 && pp->initialized != INIT_REMOVED &&

diff --git a/multipathd/main.c b/multipathd/main.c

index 102946bf..449ce384 100644

--- a/multipathd/main.c

+++ b/multipathd/main.c

@@ -1199,6 +1199,13 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map)

 	 * avoid referring to the map of an orphaned path

 	 */

 	if ((mpp = pp->mpp)) {

+		/*

+		 * Mark the path as removed. In case of success, we

+		 * will delete it for good. Otherwise, it will be deleted

+		 * later, unless all attempts to reload this map fail.

+		 */

+		set_path_removed(pp);

+

 		/*

 		 * transform the mp->pg vector of vectors of paths

 		 * into a mp->params string to feed the device-mapper

@@ -1210,13 +1217,9 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map)

 		}

 		/*

-		 * Mark the path as removed. In case of success, we

-		 * will delete it for good. Otherwise, it will be deleted

-		 * later, unless all attempts to reload this map fail.

-		 * Note: we have to explicitly remove pp from mpp->paths,

+		 * we have to explicitly remove pp from mpp->paths,

 		 * update_mpp_paths() doesn't do that.

 		 */

-		set_path_removed(pp);

 		i = find_slot(mpp->paths, pp);

 		if (i != -1)

 			vector_del_slot(mpp->paths, i);