[dm-devel] [PATCH 57/74] libmultipath: update_mpp_paths(): handle INIT_REMOVED

[mwilck at suse.com]

From: Martin Wilck <mwilck at suse.com>

Since the ancient commit b96dead ("[multipathd] remove the retry login in
uev_remove_path()"), update_mpp_paths() was used to check whether devices
found in disassembled maps were still in the pathvec, and to skip them
while re-assembling the new params string on reload. The reason was to
deal with failed reloads. With the introduction of INIT_REMOVED, we
need to skip paths in that state, too. Moreover, past reloads may have
succeeded in removing REMOVED paths from the map, so check if any
INIT_REMOVED paths can now be deleted for good. This is the right
place to do this check, because update_mpp_paths() is called after
obtaining the current kernel state, and before reloading.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 libmultipath/structs_vec.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/libmultipath/structs_vec.c b/libmultipath/structs_vec.c
index 27d6547..8999552 100644
--- a/libmultipath/structs_vec.c
+++ b/libmultipath/structs_vec.c
@@ -29,6 +29,7 @@ int update_mpp_paths(struct multipath *mpp, vector pathvec)
 	struct pathgroup * pgp;
 	struct path * pp;
 	int i,j;
+	bool store_failure = false;
 
 	if (!mpp || !mpp->pg)
 		return 0;
@@ -39,13 +40,23 @@ int update_mpp_paths(struct multipath *mpp, vector pathvec)
 
 	vector_foreach_slot (mpp->pg, pgp, i) {
 		vector_foreach_slot (pgp->paths, pp, j) {
-			if (!find_path_by_devt(mpp->paths, pp->dev_t) &&
-			    (find_path_by_devt(pathvec, pp->dev_t)) &&
-			    store_path(mpp->paths, pp))
-				return 1;
+			if (!find_path_by_devt(mpp->paths, pp->dev_t)) {
+				struct path *pp1;
+
+				/*
+				 * Avoid adding removed paths to the map again
+				 * when we reload it. Such paths may exist if
+				 * domap fails in ev_remove_path().
+				 */
+				pp1 = find_path_by_devt(pathvec, pp->dev_t);
+				if (pp1 && pp->initialized != INIT_REMOVED &&
+				    store_path(mpp->paths, pp))
+					store_failure = true;
+			}
 		}
 	}
-	return 0;
+
+	return store_failure;
 }
 
 int adopt_paths(vector pathvec, struct multipath *mpp)
-- 
2.26.2