Merge tag 'for-4.16/dm-fixes-4' of...

Merge tag 'for-4.16/dm-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix a DM multipath regression introduced in a v4.16-rc6 commit:
   restore support for loading, and attaching, scsi_dh modules during
   multipath table load. Otherwise some users may find themselves unable
   to boot, as was reported today:

     https://marc.info/?l=linux-scsi&m=152231276114962&w=2

 - Fix a DM core ioctl permission check regression introduced in a
   v4.16-rc5 commit.

* tag 'for-4.16/dm-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: fix dropped return code from dm_get_bdev_for_ioctl
  dm mpath: fix support for loading scsi_dh modules during table load

drivers/md/dm-mpath.c

@@ -887,7 +887,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
 
 	q = bdev_get_queue(p->path.dev->bdev);
 	attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
-	if (attached_handler_name) {
+	if (attached_handler_name || m->hw_handler_name) {
 		INIT_DELAYED_WORK(&p->activate_path, activate_path_work);
 		r = setup_scsi_dh(p->path.dev->bdev, m, attached_handler_name, &ti->error);
 		if (r) {

drivers/md/dm.c

@@ -466,7 +466,7 @@ static int dm_get_bdev_for_ioctl(struct mapped_device *md,
 {
 	struct dm_target *tgt;
 	struct dm_table *map;
-	int srcu_idx, r;
+	int srcu_idx, r, r2;
 
 retry:
 	r = -ENOTTY;
@@ -492,9 +492,11 @@ static int dm_get_bdev_for_ioctl(struct mapped_device *md,
 		goto out;
 
 	bdgrab(*bdev);
-	r = blkdev_get(*bdev, *mode, _dm_claim_ptr);
-	if (r < 0)
+	r2 = blkdev_get(*bdev, *mode, _dm_claim_ptr);
+	if (r2 < 0) {
+		r = r2;
 		goto out;
+	}
 
 	dm_put_live_table(md, srcu_idx);
 	return r;