[PATCH RFC v3 10/11] nvmet: command tracking

[Maurizio Lombardi]

From: Chris Leech <cleech at redhat.com>

Enable tracking of all outstanding requests in an XArray

Signed-off-by: Chris Leech <cleech at redhat.com>
---
 drivers/nvme/target/core.c  | 29 ++++++++++++++++++++++++++++-
 drivers/nvme/target/nvmet.h |  4 ++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 5622b0608d55..b446db3804f1 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -809,10 +809,23 @@ static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
 		nvmet_put_namespace(ns);
 }
 
+#if IS_ENABLED(CONFIG_NVME_TARGET_DELAY_REQUESTS)
+static void nvmet_delayed_execute_req(struct work_struct *work);
+#endif
+
 void nvmet_req_complete(struct nvmet_req *req, u16 status)
 {
 	struct nvmet_sq *sq = req->sq;
+#if IS_ENABLED(CONFIG_NVME_TARGET_DELAY_REQUESTS)
+	unsigned long flags;
 
+	/* only need to update the xarray if this was a delayed request */
+	if (req->req_work.work.func == nvmet_delayed_execute_req) {
+		xa_lock_irqsave(&sq->outstanding_requests, flags);
+		__xa_erase(&sq->outstanding_requests, req->cmd->common.command_id);
+		xa_unlock_irqrestore(&sq->outstanding_requests, flags);
+	}
+#endif
 	__nvmet_req_complete(req, status);
 	percpu_ref_put(&sq->ref);
 }
@@ -984,7 +997,9 @@ int nvmet_sq_init(struct nvmet_sq *sq)
 	init_completion(&sq->free_done);
 	init_completion(&sq->confirm_done);
 	nvmet_auth_sq_init(sq);
-
+#if IS_ENABLED(CONFIG_NVME_TARGET_DELAY_REQUESTS)
+	xa_init_flags(&sq->outstanding_requests, XA_FLAGS_LOCK_IRQ);
+#endif
 	return 0;
 }
 EXPORT_SYMBOL_GPL(nvmet_sq_init);
@@ -1766,6 +1781,7 @@ void nvmet_execute_request(struct nvmet_req *req) {
 	struct nvmet_ctrl *ctrl = req->sq->ctrl;
 	int delay_count;
 	u32 delay_msec;
+	unsigned long flags;
 
 	if (unlikely(req->sq->qid == 0))
 		return req->execute(req);
@@ -1777,6 +1793,17 @@ void nvmet_execute_request(struct nvmet_req *req) {
 	if (!(ctrl && delay_count && delay_msec))
 		return req->execute(req);
 
+	xa_lock_irqsave(&req->sq->outstanding_requests, flags);
+	int ret = __xa_insert(&req->sq->outstanding_requests,
+			    req->cmd->common.command_id, req, GFP_KERNEL);
+	xa_unlock_irqrestore(&req->sq->outstanding_requests, flags);
+
+	if (ret) {
+		pr_err("nvmet: failure to delay command %d",
+		       req->cmd->common.command_id);
+		return req->execute(req);
+	}
+
 	INIT_DELAYED_WORK(&req->req_work, nvmet_delayed_execute_req);
 	queue_delayed_work(nvmet_wq, &req->req_work, msecs_to_jiffies(delay_msec));
 }
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 1bfdddceda15..fc61f28c63da 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -172,6 +172,9 @@ struct nvmet_sq {
 #endif
 	struct completion	free_done;
 	struct completion	confirm_done;
+#if IS_ENABLED(CONFIG_NVME_TARGET_DELAY_REQUESTS)
+	struct xarray		outstanding_requests;
+#endif
 };
 
 struct nvmet_ana_group {
@@ -573,6 +576,7 @@ size_t nvmet_req_transfer_len(struct nvmet_req *req);
 bool nvmet_check_transfer_len(struct nvmet_req *req, size_t len);
 bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len);
 void nvmet_req_complete(struct nvmet_req *req, u16 status);
+void nvmet_req_complete_delayed(struct nvmet_req *req, u16 status);
 int nvmet_req_alloc_sgls(struct nvmet_req *req);
 void nvmet_req_free_sgls(struct nvmet_req *req);
 
-- 
2.43.5