scsi: smartpqi: Update RAID bypass handling

Simplify AIO retry management by removing retry list and list
management. Need to retry is already set in the response status. Also
remove the bypass worker thread.

Accelerated I/O requests bypass the RAID engine and go directly to either
an HBA disk or to a physical component of a RAID volume.

Link: https://lore.kernel.org/r/161549380976.25025.11776487034357231156.stgit@brunhilda
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Signed-off-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 19 insertions, 157 deletions

diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h
index fa1ebeea777d..1b9aa6e9e04c 100644
--- a/drivers/scsi/smartpqi/smartpqi.h
+++ b/drivers/scsi/smartpqi/smartpqi.h
@@ -1347,10 +1347,6 @@ struct pqi_ctrl_info {
 	atomic_t	num_blocked_threads;
 	wait_queue_head_t block_requests_wait;
 
-	struct list_head raid_bypass_retry_list;
-	spinlock_t	raid_bypass_retry_list_lock;
-	struct work_struct raid_bypass_retry_work;
-
 	struct pqi_ofa_memory *pqi_ofa_mem_virt_addr;
 	dma_addr_t	pqi_ofa_mem_dma_handle;
 	void		**pqi_ofa_chunk_virt_addr;
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index 4f7a38b96356..b44de3e25541 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -5280,12 +5280,6 @@ static inline int pqi_raid_submit_scsi_cmd(struct pqi_ctrl_info *ctrl_info,
 		device, scmd, queue_group);
 }
 
-static inline void pqi_schedule_bypass_retry(struct pqi_ctrl_info *ctrl_info)
-{
-	if (!pqi_ctrl_blocked(ctrl_info))
-		schedule_work(&ctrl_info->raid_bypass_retry_work);
-}
-
 static bool pqi_raid_bypass_retry_needed(struct pqi_io_request *io_request)
 {
 	struct scsi_cmnd *scmd;
@@ -5302,7 +5296,7 @@ static bool pqi_raid_bypass_retry_needed(struct pqi_io_request *io_request)
 		return false;
 
 	device = scmd->device->hostdata;
-	if (pqi_device_offline(device))
+	if (pqi_device_offline(device) || pqi_device_in_remove(device))
 		return false;
 
 	ctrl_info = shost_to_hba(scmd->device->host);
@@ -5312,132 +5306,6 @@ static bool pqi_raid_bypass_retry_needed(struct pqi_io_request *io_request)
 	return true;
 }
 
-static inline void pqi_add_to_raid_bypass_retry_list(
-	struct pqi_ctrl_info *ctrl_info,
-	struct pqi_io_request *io_request, bool at_head)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&ctrl_info->raid_bypass_retry_list_lock, flags);
-	if (at_head)
-		list_add(&io_request->request_list_entry,
-			&ctrl_info->raid_bypass_retry_list);
-	else
-		list_add_tail(&io_request->request_list_entry,
-			&ctrl_info->raid_bypass_retry_list);
-	spin_unlock_irqrestore(&ctrl_info->raid_bypass_retry_list_lock, flags);
-}
-
-static void pqi_queued_raid_bypass_complete(struct pqi_io_request *io_request,
-	void *context)
-{
-	struct scsi_cmnd *scmd;
-
-	scmd = io_request->scmd;
-	pqi_free_io_request(io_request);
-	pqi_scsi_done(scmd);
-}
-
-static void pqi_queue_raid_bypass_retry(struct pqi_io_request *io_request)
-{
-	struct scsi_cmnd *scmd;
-	struct pqi_ctrl_info *ctrl_info;
-
-	io_request->io_complete_callback = pqi_queued_raid_bypass_complete;
-	scmd = io_request->scmd;
-	scmd->result = 0;
-	ctrl_info = shost_to_hba(scmd->device->host);
-
-	pqi_add_to_raid_bypass_retry_list(ctrl_info, io_request, false);
-	pqi_schedule_bypass_retry(ctrl_info);
-}
-
-static int pqi_retry_raid_bypass(struct pqi_io_request *io_request)
-{
-	struct scsi_cmnd *scmd;
-	struct pqi_scsi_dev *device;
-	struct pqi_ctrl_info *ctrl_info;
-	struct pqi_queue_group *queue_group;
-
-	scmd = io_request->scmd;
-	device = scmd->device->hostdata;
-	if (pqi_device_in_reset(device)) {
-		pqi_free_io_request(io_request);
-		set_host_byte(scmd, DID_RESET);
-		pqi_scsi_done(scmd);
-		return 0;
-	}
-
-	ctrl_info = shost_to_hba(scmd->device->host);
-	queue_group = io_request->queue_group;
-
-	pqi_reinit_io_request(io_request);
-
-	return pqi_raid_submit_scsi_cmd_with_io_request(ctrl_info, io_request,
-		device, scmd, queue_group);
-}
-
-static inline struct pqi_io_request *pqi_next_queued_raid_bypass_request(
-	struct pqi_ctrl_info *ctrl_info)
-{
-	unsigned long flags;
-	struct pqi_io_request *io_request;
-
-	spin_lock_irqsave(&ctrl_info->raid_bypass_retry_list_lock, flags);
-	io_request = list_first_entry_or_null(
-		&ctrl_info->raid_bypass_retry_list,
-		struct pqi_io_request, request_list_entry);
-	if (io_request)
-		list_del(&io_request->request_list_entry);
-	spin_unlock_irqrestore(&ctrl_info->raid_bypass_retry_list_lock, flags);
-
-	return io_request;
-}
-
-static void pqi_retry_raid_bypass_requests(struct pqi_ctrl_info *ctrl_info)
-{
-	int rc;
-	struct pqi_io_request *io_request;
-
-	pqi_ctrl_busy(ctrl_info);
-
-	while (1) {
-		if (pqi_ctrl_blocked(ctrl_info))
-			break;
-		io_request = pqi_next_queued_raid_bypass_request(ctrl_info);
-		if (!io_request)
-			break;
-		rc = pqi_retry_raid_bypass(io_request);
-		if (rc) {
-			pqi_add_to_raid_bypass_retry_list(ctrl_info, io_request,
-				true);
-			pqi_schedule_bypass_retry(ctrl_info);
-			break;
-		}
-	}
-
-	pqi_ctrl_unbusy(ctrl_info);
-}
-
-static void pqi_raid_bypass_retry_worker(struct work_struct *work)
-{
-	struct pqi_ctrl_info *ctrl_info;
-
-	ctrl_info = container_of(work, struct pqi_ctrl_info,
-		raid_bypass_retry_work);
-	pqi_retry_raid_bypass_requests(ctrl_info);
-}
-
-static void pqi_clear_all_queued_raid_bypass_retries(
-	struct pqi_ctrl_info *ctrl_info)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&ctrl_info->raid_bypass_retry_list_lock, flags);
-	INIT_LIST_HEAD(&ctrl_info->raid_bypass_retry_list);
-	spin_unlock_irqrestore(&ctrl_info->raid_bypass_retry_list_lock, flags);
-}
-
 static void pqi_aio_io_complete(struct pqi_io_request *io_request,
 	void *context)
 {
@@ -5445,12 +5313,11 @@ static void pqi_aio_io_complete(struct pqi_io_request *io_request,
 
 	scmd = io_request->scmd;
 	scsi_dma_unmap(scmd);
-	if (io_request->status == -EAGAIN)
+	if (io_request->status == -EAGAIN || pqi_raid_bypass_retry_needed(io_request)) {
 		set_host_byte(scmd, DID_IMM_RETRY);
-	else if (pqi_raid_bypass_retry_needed(io_request)) {
-		pqi_queue_raid_bypass_retry(io_request);
-		return;
+		scmd->SCp.this_residual++;
 	}
+
 	pqi_free_io_request(io_request);
 	pqi_scsi_done(scmd);
 }
@@ -5667,6 +5534,14 @@ static inline u16 pqi_get_hw_queue(struct pqi_ctrl_info *ctrl_info,
 	return hw_queue;
 }
 
+static inline bool pqi_is_bypass_eligible_request(struct scsi_cmnd *scmd)
+{
+	if (blk_rq_is_passthrough(scmd->request))
+		return false;
+
+	return scmd->SCp.this_residual == 0;
+}
+
 /*
  * This function gets called just before we hand the completed SCSI request
  * back to the SML.
@@ -5792,9 +5667,7 @@ static int pqi_scsi_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scm
 		return 0;
 	}
 
-	pqi_ctrl_busy(ctrl_info);
-	if (pqi_ctrl_blocked(ctrl_info) || pqi_device_in_reset(device) ||
-	    pqi_ctrl_in_ofa(ctrl_info) || pqi_ctrl_in_shutdown(ctrl_info)) {
+	if (pqi_ctrl_blocked(ctrl_info)) {
 		rc = SCSI_MLQUEUE_HOST_BUSY;
 		goto out;
 	}
@@ -5811,13 +5684,12 @@ static int pqi_scsi_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scm
 	if (pqi_is_logical_device(device)) {
 		raid_bypassed = false;
 		if (device->raid_bypass_enabled &&
-			!blk_rq_is_passthrough(scmd->request)) {
-			if (!pqi_is_parity_write_stream(ctrl_info, scmd)) {
-				rc = pqi_raid_bypass_submit_scsi_cmd(ctrl_info, device, scmd, queue_group);
-				if (rc == 0 || rc == SCSI_MLQUEUE_HOST_BUSY) {
-					raid_bypassed = true;
-					atomic_inc(&device->raid_bypass_cnt);
-				}
+			pqi_is_bypass_eligible_request(scmd) &&
+			!pqi_is_parity_write_stream(ctrl_info, scmd)) {
+			rc = pqi_raid_bypass_submit_scsi_cmd(ctrl_info, device, scmd, queue_group);
+			if (rc == 0 || rc == SCSI_MLQUEUE_HOST_BUSY) {
+				raid_bypassed = true;
+				atomic_inc(&device->raid_bypass_cnt);
 			}
 		}
 		if (!raid_bypassed)
@@ -8255,11 +8127,6 @@ static struct pqi_ctrl_info *pqi_alloc_ctrl_info(int numa_node)
 		PQI_RESERVED_IO_SLOTS_SYNCHRONOUS_REQUESTS);
 	init_waitqueue_head(&ctrl_info->block_requests_wait);
 
-	INIT_LIST_HEAD(&ctrl_info->raid_bypass_retry_list);
-	spin_lock_init(&ctrl_info->raid_bypass_retry_list_lock);
-	INIT_WORK(&ctrl_info->raid_bypass_retry_work,
-		pqi_raid_bypass_retry_worker);
-
 	ctrl_info->ctrl_id = atomic_inc_return(&pqi_controller_count) - 1;
 	ctrl_info->irq_mode = IRQ_MODE_NONE;
 	ctrl_info->max_msix_vectors = PQI_MAX_MSIX_VECTORS;
@@ -8585,7 +8452,6 @@ static void pqi_take_ctrl_offline_deferred(struct pqi_ctrl_info *ctrl_info)
 	pqi_cancel_update_time_worker(ctrl_info);
 	pqi_ctrl_wait_until_quiesced(ctrl_info);
 	pqi_fail_all_outstanding_requests(ctrl_info);
-	pqi_clear_all_queued_raid_bypass_retries(ctrl_info);
 	pqi_ctrl_unblock_requests(ctrl_info);
 }