dm: set DM_TARGET_WILDCARD feature on "error" target

The DM_TARGET_WILDCARD feature indicates that the "error" target may
replace any target; even immutable targets.  This feature will be useful
to preserve the ability to replace the "multipath" target even once it
is formally converted over to having the DM_TARGET_IMMUTABLE feature.

Also, implicit in the DM_TARGET_WILDCARD feature flag being set is that
.map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined
in the target_type.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 80a439543259..4763c4ae30e4 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1291,7 +1291,8 @@ static int table_load(struct dm_ioctl *param, size_t param_size)
 
         immutable_target_type = dm_get_immutable_target_type(md);
         if (immutable_target_type &&
-            (immutable_target_type != dm_table_get_immutable_target_type(t))) {
+            (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
+            !dm_table_get_wildcard_target(t)) {
                 DMWARN("can't replace immutable target type %s",
                        immutable_target_type->name);
                 r = -EINVAL;