dm mpath: avoid attempting to activate null path
Path activation code is called even when the pgpath is NULL. This could
lead to a panic in activate_path(). Such a panic is seen in -rt kernel.
This problem has been there before the pg_init() was moved to a
workqueue.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 4840733..58b1015 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -441,13 +441,13 @@
__choose_pgpath(m);
pgpath = m->current_pgpath;
- m->pgpath_to_activate = m->current_pgpath;
if ((pgpath && !m->queue_io) ||
(!pgpath && !m->queue_if_no_path))
must_queue = 0;
- if (m->pg_init_required && !m->pg_init_in_progress) {
+ if (m->pg_init_required && !m->pg_init_in_progress && pgpath) {
+ m->pgpath_to_activate = pgpath;
m->pg_init_count++;
m->pg_init_required = 0;
m->pg_init_in_progress = 1;