[PATCH 1/6] scsi: libsas: Add sas_task_find_rq()

[John Garry <john.garry@huawei.com>]

blk-mq already provides a unique tag per request. Some libsas LLDDs - like
hisi_sas - already use this tag as the unique per-IO HW tag.

Add a common function to provide the request associated with a sas_task
for all libsas LLDDs.

Signed-off-by: John Garry <john.garry@huawei.com>
---
 include/scsi/libsas.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index f86b56bf7833..bc51756a3317 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -644,6 +644,28 @@ static inline bool sas_is_internal_abort(struct sas_task *task)
 	return task->task_proto == SAS_PROTOCOL_INTERNAL_ABORT;
 }
 
+static inline struct request *sas_task_find_rq(struct sas_task *task)
+{
+	struct scsi_cmnd *scmd;
+
+	if (!task || !task->uldd_task)
+		return NULL;
+
+	if (task->task_proto & SAS_PROTOCOL_STP_ALL) {
+		struct ata_queued_cmd *qc;
+
+		qc = task->uldd_task;
+		scmd = qc->scsicmd;
+	} else {
+		scmd = task->uldd_task;
+	}
+
+	if (!scmd)
+		return NULL;
+
+	return scsi_cmd_to_rq(scmd);
+}
+
 struct sas_domain_function_template {
 	/* The class calls these to notify the LLDD of an event. */
 	void (*lldd_port_formed)(struct asd_sas_phy *);
-- 
2.35.3