1 files changed, 31 insertions, 16 deletions

diff --git a/drivers/s390/block/scm_blk_cluster.c b/drivers/s390/block/scm_blk_cluster.c
index 2fd01320b978..09db45296eed 100644
--- a/drivers/s390/block/scm_blk_cluster.c
+++ b/drivers/s390/block/scm_blk_cluster.c
@@ -57,39 +57,52 @@ void scm_request_cluster_init(struct scm_request *scmrq)
 	scmrq->cluster.state = CLUSTER_NONE;
 }
 
-static bool clusters_intersect(struct scm_request *A, struct scm_request *B)
+static bool clusters_intersect(struct request *A, struct request *B)
 {
 	unsigned long firstA, lastA, firstB, lastB;
 
-	firstA = ((u64) blk_rq_pos(A->request) << 9) / CLUSTER_SIZE;
-	lastA = (((u64) blk_rq_pos(A->request) << 9) +
-		    blk_rq_bytes(A->request) - 1) / CLUSTER_SIZE;
+	firstA = ((u64) blk_rq_pos(A) << 9) / CLUSTER_SIZE;
+	lastA = (((u64) blk_rq_pos(A) << 9) +
+		    blk_rq_bytes(A) - 1) / CLUSTER_SIZE;
 
-	firstB = ((u64) blk_rq_pos(B->request) << 9) / CLUSTER_SIZE;
-	lastB = (((u64) blk_rq_pos(B->request) << 9) +
-		    blk_rq_bytes(B->request) - 1) / CLUSTER_SIZE;
+	firstB = ((u64) blk_rq_pos(B) << 9) / CLUSTER_SIZE;
+	lastB = (((u64) blk_rq_pos(B) << 9) +
+		    blk_rq_bytes(B) - 1) / CLUSTER_SIZE;
 
 	return (firstB <= lastA && firstA <= lastB);
 }
 
 bool scm_reserve_cluster(struct scm_request *scmrq)
 {
+	struct request *req = scmrq->request[scmrq->aob->request.msb_count];
 	struct scm_blk_dev *bdev = scmrq->bdev;
 	struct scm_request *iter;
+	int pos, add = 1;
 
 	if (write_cluster_size == 0)
 		return true;
 
 	spin_lock(&bdev->lock);
 	list_for_each_entry(iter, &bdev->cluster_list, cluster.list) {
-		if (clusters_intersect(scmrq, iter) &&
-		    (rq_data_dir(scmrq->request) == WRITE ||
-		     rq_data_dir(iter->request) == WRITE)) {
-			spin_unlock(&bdev->lock);
-			return false;
+		if (iter == scmrq) {
+			/*
+			 * We don't have to use clusters_intersect here, since
+			 * cluster requests are always started separately.
+			 */
+			add = 0;
+			continue;
+		}
+		for (pos = 0; pos <= iter->aob->request.msb_count; pos++) {
+			if (clusters_intersect(req, iter->request[pos]) &&
+			    (rq_data_dir(req) == WRITE ||
+			     rq_data_dir(iter->request[pos]) == WRITE)) {
+				spin_unlock(&bdev->lock);
+				return false;
+			}
 		}
 	}
-	list_add(&scmrq->cluster.list, &bdev->cluster_list);
+	if (add)
+		list_add(&scmrq->cluster.list, &bdev->cluster_list);
 	spin_unlock(&bdev->lock);
 
 	return true;
@@ -118,7 +131,7 @@ static int scm_prepare_cluster_request(struct scm_request *scmrq)
 {
 	struct scm_blk_dev *bdev = scmrq->bdev;
 	struct scm_device *scmdev = bdev->gendisk->private_data;
-	struct request *req = scmrq->request;
+	struct request *req = scmrq->request[0];
 	struct msb *msb = &scmrq->aob->msb[0];
 	struct req_iterator iter;
 	struct aidaw *aidaw;
@@ -183,10 +196,12 @@ static int scm_prepare_cluster_request(struct scm_request *scmrq)
 
 bool scm_need_cluster_request(struct scm_request *scmrq)
 {
-	if (rq_data_dir(scmrq->request) == READ)
+	int pos = scmrq->aob->request.msb_count;
+
+	if (rq_data_dir(scmrq->request[pos]) == READ)
 		return false;
 
-	return blk_rq_bytes(scmrq->request) < CLUSTER_SIZE;
+	return blk_rq_bytes(scmrq->request[pos]) < CLUSTER_SIZE;
 }
 
 /* Called with queue lock held. */