nvme: properly free resources for cancelled command

BugLink: http://bugs.launchpad.net/bugs/1531539

We need to move freeing of resources to the ->complete handler to ensure
they are also freed when we cancel the command.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
(cherry picked from commit eee417b0)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/nvme/host/pci.c

@@ -82,11 +82,9 @@ static wait_queue_head_t nvme_kthread_wait;
 
 struct nvme_dev;
 struct nvme_queue;
-struct nvme_iod;
 
 static int nvme_reset(struct nvme_dev *dev);
 static void nvme_process_cq(struct nvme_queue *nvmeq);
-static void nvme_unmap_data(struct nvme_dev *dev, struct nvme_iod *iod);
 static void nvme_remove_dead_ctrl(struct nvme_dev *dev);
 static void nvme_dev_shutdown(struct nvme_dev *dev);
 
@@ -491,41 +489,6 @@ static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
 }
 #endif
 
-static void req_completion(struct nvme_queue *nvmeq, struct nvme_completion *cqe)
-{
-	struct request *req = blk_mq_tag_to_rq(*nvmeq->tags, cqe->command_id);
-	struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
-	struct nvme_iod *iod = cmd_rq->iod;
-	u16 status = le16_to_cpup(&cqe->status) >> 1;
-	int error = 0;
-
-	if (unlikely(status)) {
-		if (nvme_req_needs_retry(req, status)) {
-			nvme_unmap_data(nvmeq->dev, iod);
-			nvme_requeue_req(req);
-			return;
-		}
-
-		if (req->cmd_type == REQ_TYPE_DRV_PRIV)
-			error = status;
-		else
-			error = nvme_error_status(status);
-	}
-
-	if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
-		u32 result = le32_to_cpup(&cqe->result);
-		req->special = (void *)(uintptr_t)result;
-	}
-
-	if (cmd_rq->aborted)
-		dev_warn(nvmeq->dev->dev,
-			"completing aborted command with status:%04x\n",
-			error);
-
-	nvme_unmap_data(nvmeq->dev, iod);
-	blk_mq_complete_request(req, error);
-}
-
 static bool nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
 		int total_len)
 {
@@ -726,7 +689,7 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (ns && ns->ms && !blk_integrity_rq(req)) {
 		if (!(ns->pi_type && ns->ms == 8) &&
 					req->cmd_type != REQ_TYPE_DRV_PRIV) {
-			blk_mq_complete_request(req, -EFAULT);
+			blk_mq_end_request(req, -EFAULT);
 			return BLK_MQ_RQ_QUEUE_OK;
 		}
 	}
@@ -767,6 +730,35 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 	return ret;
 }
 
+static void nvme_complete_rq(struct request *req)
+{
+	struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
+	struct nvme_dev *dev = cmd->nvmeq->dev;
+	int error = 0;
+
+	nvme_unmap_data(dev, cmd->iod);
+
+	if (unlikely(req->errors)) {
+		if (nvme_req_needs_retry(req, req->errors)) {
+			nvme_requeue_req(req);
+			return;
+		}
+
+		if (req->cmd_type == REQ_TYPE_DRV_PRIV)
+			error = req->errors;
+		else
+			error = nvme_error_status(req->errors);
+	}
+
+	if (unlikely(cmd->aborted)) {
+		dev_warn(dev->dev,
+			"completing aborted command with status: %04x\n",
+			req->errors);
+	}
+
+	blk_mq_end_request(req, error);
+}
+
 static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 {
 	u16 head, phase;
@@ -777,6 +769,7 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 	for (;;) {
 		struct nvme_completion cqe = nvmeq->cqes[head];
 		u16 status = le16_to_cpu(cqe.status);
+		struct request *req;
 
 		if ((status & 1) != phase)
 			break;
@@ -808,7 +801,13 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 			continue;
 		}
 
-		req_completion(nvmeq, &cqe);
+		req = blk_mq_tag_to_rq(*nvmeq->tags, cqe.command_id);
+		if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
+			u32 result = le32_to_cpu(cqe.result);
+			req->special = (void *)(uintptr_t)result;
+		}
+		blk_mq_complete_request(req, status >> 1);
+
 	}
 
 	/* If the controller ignores the cq head doorbell and continuously
@@ -1278,6 +1277,7 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
 
 static struct blk_mq_ops nvme_mq_admin_ops = {
 	.queue_rq	= nvme_queue_rq,
+	.complete	= nvme_complete_rq,
 	.map_queue	= blk_mq_map_queue,
 	.init_hctx	= nvme_admin_init_hctx,
 	.exit_hctx      = nvme_admin_exit_hctx,
@@ -1287,6 +1287,7 @@ static struct blk_mq_ops nvme_mq_admin_ops = {
 
 static struct blk_mq_ops nvme_mq_ops = {
 	.queue_rq	= nvme_queue_rq,
+	.complete	= nvme_complete_rq,
 	.map_queue	= blk_mq_map_queue,
 	.init_hctx	= nvme_init_hctx,
 	.init_request	= nvme_init_request,