[PATCH v2 42/49] multipathd: implement add_map_without_path() with libmp_mapinfo()

[Martin Wilck <martin.wilck@xxxxxxxx>]

Also, change the return value to int, as this is more expressive and
the returned struct multipath isn't used by the caller.

Also remove the call to sync_map_state() in ev_add_map(), which is
redundant because add_map_without_path() would have called update_map()
and thus sync_map_state() already.

Note: this removes the call to remove_map() at the end of the function,
which doesn't make sense anyway, because update_multipath_table()
would not return error unless the table disassembly failed, in which
case nothing would have been added the the mpvec or pathvec yet.
It should be sufficient to just cleanup the local data structures when
add_map_without_path() fails.

Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
 multipathd/main.c | 79 ++++++++++++++++++++++++-----------------------
 1 file changed, 41 insertions(+), 38 deletions(-)

diff --git a/multipathd/main.c b/multipathd/main.c
index 1e7a6ac..536974c 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -707,51 +707,57 @@ fail:
 	return 0;
 }
 
-static struct multipath *
-add_map_without_path (struct vectors *vecs, const char *alias)
+static int add_map_without_path (struct vectors *vecs, const char *alias)
 {
-	struct multipath * mpp = alloc_multipath();
+	struct multipath __attribute__((cleanup(cleanup_multipath_and_paths)))
+		*mpp = alloc_multipath();
+	char __attribute__((cleanup(cleanup_charp))) *params = NULL;
+	char __attribute__((cleanup(cleanup_charp))) *status = NULL;
 	struct config *conf;
+	char uuid[DM_UUID_LEN];
+	int rc = DMP_ERR;
 
-	if (!mpp)
-		return NULL;
-	if (!alias) {
-		free(mpp);
-		return NULL;
-	}
+	if (!mpp || !(mpp->alias = strdup(alias)))
+		return DMP_ERR;
 
-	mpp->alias = strdup(alias);
+	if ((rc = libmp_mapinfo(DM_MAP_BY_NAME | MAPINFO_MPATH_ONLY,
+				(mapid_t) { .str = mpp->alias },
+				(mapinfo_t) {
+					.uuid = uuid,
+					.dmi = &mpp->dmi,
+					.size = &mpp->size,
+					.target = &params,
+					.status = &status,
+				})) != DMP_OK)
+		return rc;
+
+	if (!is_mpath_uuid(uuid))
+		return DMP_NO_MATCH;
+	else
+		strlcpy(mpp->wwid, uuid + UUID_PREFIX_LEN, sizeof(mpp->wwid));
 
-	if (dm_get_info(mpp->alias, &mpp->dmi) != DMP_OK) {
-		condlog(3, "%s: cannot access table", mpp->alias);
-		goto out;
-	}
-	if (!strlen(mpp->wwid) &&
-	    dm_get_wwid(mpp->alias, mpp->wwid, WWID_SIZE) != DMP_OK) {
-		condlog(3, "%s: cannot obtain WWID", mpp->alias);
-		goto out;
-	}
 	if (!strlen(mpp->wwid))
 		condlog(1, "%s: adding map with empty WWID", mpp->alias);
+
 	conf = get_multipath_config();
 	mpp->mpe = find_mpe(conf->mptable, mpp->wwid);
 	put_multipath_config(conf);
 
-	if (update_multipath_table(mpp, vecs->pathvec, 0) != DMP_OK)
-		goto out;
+	if ((rc = update_multipath_table__(mpp, vecs->pathvec, 0, params, status)) != DMP_OK)
+		return DMP_ERR;
 
 	if (!vector_alloc_slot(vecs->mpvec))
-		goto out;
+		return DMP_ERR;
+	vector_set_slot(vecs->mpvec, steal_ptr(mpp));
 
-	vector_set_slot(vecs->mpvec, mpp);
+	/*
+	 * We can pass mpp here, steal_ptr() has just nullified it.
+	 * vector_set_slot() just set the last slot, use that.
+	 */
+	if (update_map(VECTOR_LAST_SLOT(vecs->mpvec), vecs, 1) != 0) /* map removed */
+		return DMP_ERR;
 
-	if (update_map(mpp, vecs, 1) != 0) /* map removed */
-		return NULL;
-
-	return mpp;
-out:
-	remove_map(mpp, vecs->pathvec, vecs->mpvec);
-	return NULL;
+	return DMP_OK;
 }
 
 static int
@@ -865,14 +871,9 @@ int
 ev_add_map (char * dev, const char * alias, struct vectors * vecs)
 {
 	struct multipath * mpp;
-	int reassign_maps;
+	int reassign_maps, rc;
 	struct config *conf;
 
-	if (dm_is_mpath(alias) != DM_IS_MPATH_YES) {
-		condlog(4, "%s: not a multipath map", alias);
-		return 0;
-	}
-
 	mpp = find_mp_by_alias(vecs->mpvec, alias);
 
 	if (mpp) {
@@ -910,10 +911,12 @@ ev_add_map (char * dev, const char * alias, struct vectors * vecs)
 	/*
 	 * now we can register the map
 	 */
-	if ((mpp = add_map_without_path(vecs, alias))) {
-		sync_map_state(mpp);
+	if ((rc = add_map_without_path(vecs, alias)) == DMP_OK) {
 		condlog(2, "%s: devmap %s registered", alias, dev);
 		return 0;
+	} else if (rc == DMP_NO_MATCH) {
+		condlog(4, "%s: not a multipath map", alias);
+		return 0;
 	} else {
 		condlog(2, "%s: ev_add_map failed", dev);
 		return 1;
-- 
2.45.2