From: Milan Broz <mbroz@redhat.com>
Date: Sat, 16 Aug 2008 01:51:51 +0200
Subject: [md] dm mpath: fix bugs in error paths
Message-id: 48A61697.7080206@redhat.com
O-Subject: [RHEL5.3 PATCH] dm mpath: fix bugs in error paths (#459092)
Bugzilla: 459092
RH-Acked-by: Alasdair G Kergon <agk@redhat.com>
RH-Acked-by: Alasdair G Kergon <agk@redhat.com>

RHEL5.3 dm mpath: fix several problems in dm-mpath target error paths
Resolves: rhbz#459092
Patches are upstream, commits
def052d21c4e77975bb75cf212f018ec913f8e2f
148acff615b403168cdf39e55bfcfaa6e4a7d233
371b2e348b7731a548b0a7432ca2ba32e90dd16f

These are trivial bugfixes in multipath dm target:
- Fix test for reinstate_path method before attempting to use it.
- Return a specific error message if there are an invalid number
  of multipath arguments.
- Free path selector if the arguments are invalid.

Kernel with patch compiled and tested.

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 679bc96..2412c5a 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -524,8 +524,10 @@ static int parse_path_selector(struct arg_set *as, struct priority_group *pg,
 	}
 
 	r = read_param(_params, shift(as), &ps_argc, &ti->error);
-	if (r)
+	if (r) {
+		dm_put_path_selector(pst);
 		return -EINVAL;
+	}
 
 	r = pst->create(&pg->ps, ps_argc, as->argv);
 	if (r) {
@@ -622,8 +624,10 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
 		struct pgpath *pgpath;
 		struct arg_set path_args;
 
-		if (as->argc < nr_params)
+		if (as->argc < nr_params) {
+			ti->error = "not enough path parameters";
 			goto bad;
+		}
 
 		path_args.argc = nr_params;
 		path_args.argv = as->argv;
@@ -881,7 +885,7 @@ static int reinstate_path(struct pgpath *pgpath)
 	if (pgpath->path.is_active)
 		goto out;
 
-	if (!pgpath->pg->ps.type) {
+	if (!pgpath->pg->ps.type->reinstate_path) {
 		DMWARN("Reinstate path not supported by path selector %s",
 		       pgpath->pg->ps.type->name);
 		r = -EINVAL;