[PATCH v2 11/20] multipathd: resync map after setup_map in ev_remove_path

[Benjamin Marzinski <bmarzins@xxxxxxxxxx>]

In ev_remove_path() it was possible to exit after calling setup_map()
without resyncing the mpp state with the kernel. This meant that the
mpp state in multipathd might not match with the kernel state at all.

It's safe to exit before calling setup_map() if either wait_for_udev
or need_do_map is set. In both cases, setup_map() will later be called,
either by a uevent or by the calling function.

Once setup_map() has been called, setup_multipath() and sync_map_state()
are now always called, to make sure the mpp matches the kernel state.

Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
---
 multipathd/main.c | 40 +++++++++++++++++++---------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/multipathd/main.c b/multipathd/main.c
index d7c87039..aa3c7eb6 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -1395,6 +1395,8 @@ 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)) {
+		char devt[BLK_DEV_SIZE];
+
 		/*
 		 * Mark the path as removed. In case of success, we
 		 * will delete it for good. Otherwise, it will be deleted
@@ -1428,12 +1430,6 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map)
 		    flush_map_nopaths(mpp, vecs))
 			goto out;
 
-		if (setup_map(mpp, &params, vecs)) {
-			condlog(0, "%s: failed to setup map for"
-				" removal of path %s", mpp->alias, pp->dev);
-			goto fail;
-		}
-
 		if (mpp->wait_for_udev) {
 			mpp->wait_for_udev = 2;
 			retval = REMOVE_PATH_DELAY;
@@ -1444,6 +1440,12 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map)
 			retval = REMOVE_PATH_DELAY;
 			goto out;
 		}
+
+		if (setup_map(mpp, &params, vecs)) {
+			condlog(0, "%s: failed to setup map for"
+				" removal of path %s", mpp->alias, pp->dev);
+			goto fail;
+		}
 		/*
 		 * reload the map
 		 */
@@ -1453,24 +1455,20 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map)
 				"removal of path %s",
 				mpp->alias, pp->dev);
 			retval = REMOVE_PATH_FAILURE;
-		} else {
-			/*
-			 * update our state from kernel
-			 */
-			char devt[BLK_DEV_SIZE];
-
-			strlcpy(devt, pp->dev_t, sizeof(devt));
-
-			/* setup_multipath will free the path
-			 * regardless of whether it succeeds or
-			 * fails */
-			if (setup_multipath(vecs, mpp))
-				return REMOVE_PATH_MAP_ERROR;
-			sync_map_state(mpp);
+		}
+		/*
+		 * update mpp state from kernel even if domap failed.
+		 * If the path was removed from the mpp, setup_multipath will
+		 * free the path regardless of whether it succeeds or fails
+		 */
+		strlcpy(devt, pp->dev_t, sizeof(devt));
+		if (setup_multipath(vecs, mpp))
+			return REMOVE_PATH_MAP_ERROR;
+		sync_map_state(mpp);
 
+		if (retval == REMOVE_PATH_SUCCESS)
 			condlog(2, "%s: path removed from map %s",
 				devt, mpp->alias);
-		}
 	} else {
 		/* mpp == NULL */
 		if ((i = find_slot(vecs->pathvec, (void *)pp)) != -1)
-- 
2.45.0