[PATCH V4 18/31] smartpqi: synchronize device resets with mutex

[Don Brace <don.brace@xxxxxxxxxxxxx>]

From: Kevin Barnett <kevin.barnett@xxxxxxxxxxxxx>

Synchronize device reset operations with a mutex.
 * Remove some flags used to check for device resets
   already in progress.
 * Allow only 1 reset operation at a time for the host.

Reviewed-by: Scott Benesh <scott.benesh@xxxxxxxxxxxxx>
Reviewed-by: Mike McGowen <mike.mcgowen@xxxxxxxxxxxxx>
Reviewed-by: Scott Teel <scott.teel@xxxxxxxxxxxxx>
Signed-off-by: Kevin Barnett <kevin.barnett@xxxxxxxxxxxxx>
Signed-off-by: Don Brace <don.brace@xxxxxxxxxxxxx>
---
 drivers/scsi/smartpqi/smartpqi.h      |    1 -
 drivers/scsi/smartpqi/smartpqi_init.c |   48 +++++++++------------------------
 2 files changed, 13 insertions(+), 36 deletions(-)

diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h
index a18c1f9afb37..ba7d26364b84 100644
--- a/drivers/scsi/smartpqi/smartpqi.h
+++ b/drivers/scsi/smartpqi/smartpqi.h
@@ -1295,7 +1295,6 @@ struct pqi_ctrl_info {
 	struct mutex	ofa_mutex; /* serialize ofa */
 	bool		controller_online;
 	bool		block_requests;
-	bool		block_device_reset;
 	bool		in_ofa;
 	bool		in_shutdown;
 	u8		inbound_spanning_supported : 1;
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index f1f90c21045d..7436df0d55f2 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -247,12 +247,12 @@ static inline void pqi_save_ctrl_mode(struct pqi_ctrl_info *ctrl_info,
 
 static inline void pqi_ctrl_block_device_reset(struct pqi_ctrl_info *ctrl_info)
 {
-	ctrl_info->block_device_reset = true;
+	mutex_lock(&ctrl_info->lun_reset_mutex);
 }
 
-static inline bool pqi_device_reset_blocked(struct pqi_ctrl_info *ctrl_info)
+static inline void pqi_ctrl_unblock_device_reset(struct pqi_ctrl_info *ctrl_info)
 {
-	return ctrl_info->block_device_reset;
+	mutex_unlock(&ctrl_info->lun_reset_mutex);
 }
 
 static inline bool pqi_ctrl_blocked(struct pqi_ctrl_info *ctrl_info)
@@ -297,16 +297,6 @@ static inline bool pqi_device_offline(struct pqi_scsi_dev *device)
 	return device->device_offline;
 }
 
-static inline void pqi_device_reset_start(struct pqi_scsi_dev *device)
-{
-	device->in_reset = true;
-}
-
-static inline void pqi_device_reset_done(struct pqi_scsi_dev *device)
-{
-	device->in_reset = false;
-}
-
 static inline bool pqi_device_in_reset(struct pqi_scsi_dev *device)
 {
 	return device->in_reset;
@@ -6098,7 +6088,7 @@ static int pqi_lun_reset(struct pqi_ctrl_info *ctrl_info,
 #define PQI_LUN_RESET_RETRY_INTERVAL_MSECS	10000
 #define PQI_LUN_RESET_PENDING_IO_TIMEOUT_SECS	120
 
-static int _pqi_device_reset(struct pqi_ctrl_info *ctrl_info,
+static int pqi_lun_reset_with_retries(struct pqi_ctrl_info *ctrl_info,
 	struct pqi_scsi_dev *device)
 {
 	int rc;
@@ -6124,23 +6114,15 @@ static int pqi_device_reset(struct pqi_ctrl_info *ctrl_info,
 {
 	int rc;
 
-	mutex_lock(&ctrl_info->lun_reset_mutex);
-
 	pqi_ctrl_block_requests(ctrl_info);
 	pqi_ctrl_wait_until_quiesced(ctrl_info);
 	pqi_fail_io_queued_for_device(ctrl_info, device);
 	rc = pqi_wait_until_inbound_queues_empty(ctrl_info);
-	pqi_device_reset_start(device);
-	pqi_ctrl_unblock_requests(ctrl_info);
-
 	if (rc)
 		rc = FAILED;
 	else
-		rc = _pqi_device_reset(ctrl_info, device);
-
-	pqi_device_reset_done(device);
-
-	mutex_unlock(&ctrl_info->lun_reset_mutex);
+		rc = pqi_lun_reset_with_retries(ctrl_info, device);
+	pqi_ctrl_unblock_requests(ctrl_info);
 
 	return rc;
 }
@@ -6156,29 +6138,25 @@ static int pqi_eh_device_reset_handler(struct scsi_cmnd *scmd)
 	ctrl_info = shost_to_hba(shost);
 	device = scmd->device->hostdata;
 
+	mutex_lock(&ctrl_info->lun_reset_mutex);
+
 	dev_err(&ctrl_info->pci_dev->dev,
 		"resetting scsi %d:%d:%d:%d\n",
 		shost->host_no, device->bus, device->target, device->lun);
 
 	pqi_check_ctrl_health(ctrl_info);
-	if (pqi_ctrl_offline(ctrl_info) ||
-		pqi_device_reset_blocked(ctrl_info)) {
+	if (pqi_ctrl_offline(ctrl_info))
 		rc = FAILED;
-		goto out;
-	}
-
-	pqi_wait_until_ofa_finished(ctrl_info);
-
-	atomic_inc(&ctrl_info->sync_cmds_outstanding);
-	rc = pqi_device_reset(ctrl_info, device);
-	atomic_dec(&ctrl_info->sync_cmds_outstanding);
+	else
+		rc = pqi_device_reset(ctrl_info, device);
 
-out:
 	dev_err(&ctrl_info->pci_dev->dev,
 		"reset of scsi %d:%d:%d:%d: %s\n",
 		shost->host_no, device->bus, device->target, device->lun,
 		rc == SUCCESS ? "SUCCESS" : "FAILED");
 
+	mutex_unlock(&ctrl_info->lun_reset_mutex);
+
 	return rc;
 }