drbd: Removed checks for REQ_HARDBARRIER on incomming BIOs

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_int.h

@@ -832,7 +832,6 @@ enum {
 				 * Gets cleared when the state.conn
 				 * goes into C_CONNECTED state. */
 	WRITE_BM_AFTER_RESYNC,	/* A kmalloc() during resync failed */
-	NO_BARRIER_SUPP,	/* underlying block device doesn't implement barriers */
 	CONSIDER_RESYNC,
 
 	MD_NO_FUA,		/* Users wants us to not use FUA/FLUSH on meta data dev */

drivers/block/drbd/drbd_main.c

@@ -2788,11 +2788,6 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
 
 	drbd_set_defaults(mdev);
 
-	/* for now, we do NOT yet support it,
-	 * even though we start some framework
-	 * to eventually support barriers */
-	set_bit(NO_BARRIER_SUPP, &mdev->flags);
-
 	atomic_set(&mdev->ap_bio_cnt, 0);
 	atomic_set(&mdev->ap_pending_cnt, 0);
 	atomic_set(&mdev->rs_pending_cnt, 0);

drivers/block/drbd/drbd_req.c

@@ -1032,20 +1032,6 @@ int drbd_make_request_26(struct request_queue *q, struct bio *bio)
 		return 0;
 	}
 
-	/* Reject barrier requests if we know the underlying device does
-	 * not support them.
-	 * XXX: Need to get this info from peer as well some how so we
-	 * XXX: reject if EITHER side/data/metadata area does not support them.
-	 *
-	 * because of those XXX, this is not yet enabled,
-	 * i.e. in drbd_init_set_defaults we set the NO_BARRIER_SUPP bit.
-	 */
-	if (unlikely(bio->bi_rw & REQ_HARDBARRIER) && test_bit(NO_BARRIER_SUPP, &mdev->flags)) {
-		/* dev_warn(DEV, "Rejecting barrier request as underlying device does not support\n"); */
-		bio_endio(bio, -EOPNOTSUPP);
-		return 0;
-	}
-
 	/*
 	 * what we "blindly" assume:
 	 */