s390/scm: use common completion path

Since commit caf7df122721 ("block: remove the errors field from struct request")
rq->errors can't be (mis)used by block device drivers to store the error
condition for usage during async completion. Because of that I simply used
async completion only for the non-error paths.

This patch places the error within the private data of struct request and
uses async completion for all paths again.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index 0071febac9e6..2e7fd966c515 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -249,13 +249,13 @@ static void scm_request_requeue(struct scm_request *scmrq)
 static void scm_request_finish(struct scm_request *scmrq)
 {
         struct scm_blk_dev *bdev = scmrq->bdev;
+        int *error;
         int i;
 
         for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++) {
-                if (scmrq->error)
-                        blk_mq_end_request(scmrq->request[i], scmrq->error);
-                else
-                        blk_mq_complete_request(scmrq->request[i]);
+                error = blk_mq_rq_to_pdu(scmrq->request[i]);
+                *error = scmrq->error;
+                blk_mq_complete_request(scmrq->request[i]);
         }
 
         atomic_dec(&bdev->queued_reqs);
@@ -415,7 +415,9 @@ void scm_blk_irq(struct scm_device *scmdev, void *data, blk_status_t error)
 
 static void scm_blk_request_done(struct request *req)
 {
-        blk_mq_end_request(req, 0);
+        int *error = blk_mq_rq_to_pdu(req);
+
+        blk_mq_end_request(req, *error);
 }
 
 static const struct block_device_operations scm_blk_devops = {
@@ -448,6 +450,7 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
         atomic_set(&bdev->queued_reqs, 0);
 
         bdev->tag_set.ops = &scm_mq_ops;
+        bdev->tag_set.cmd_size = sizeof(int);
         bdev->tag_set.nr_hw_queues = nr_requests;
         bdev->tag_set.queue_depth = nr_requests_per_io * nr_requests;
         bdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;