[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp

When the SCSI midlayer is running error recovery, the low-level error
recovery in zfcp could be running and preventing the SCSI midlayer to
issue error recovery requests. To avoid unnecessary error recovery
escalation, wait for the zfcp erp to finish and retry if necessary.

While reworking the SCSI eh handlers, alsa cleanup the code and
simplify the interface from zfcp_scsi to the fsf layer.

Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 14 insertions, 25 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 1b25158..cc69db3 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -12,6 +12,9 @@
 #include <linux/blktrace_api.h>
 #include "zfcp_ext.h"
 
+#define ZFCP_REQ_AUTO_CLEANUP	0x00000002
+#define ZFCP_REQ_NO_QTCB	0x00000008
+
 static void zfcp_fsf_request_timeout_handler(unsigned long data)
 {
 	struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
@@ -913,27 +916,22 @@ static void zfcp_fsf_abort_fcp_command_handler(struct zfcp_fsf_req *req)
 /**
  * zfcp_fsf_abort_fcp_command - abort running SCSI command
  * @old_req_id: unsigned long
- * @adapter: pointer to struct zfcp_adapter
  * @unit: pointer to struct zfcp_unit
- * @req_flags: integer specifying the request flags
  * Returns: pointer to struct zfcp_fsf_req
- *
- * FIXME(design): should be watched by a timeout !!!
  */
 
 struct zfcp_fsf_req *zfcp_fsf_abort_fcp_command(unsigned long old_req_id,
-						struct zfcp_adapter *adapter,
-						struct zfcp_unit *unit,
-						int req_flags)
+						struct zfcp_unit *unit)
 {
 	struct qdio_buffer_element *sbale;
 	struct zfcp_fsf_req *req = NULL;
+	struct zfcp_adapter *adapter = unit->port->adapter;
 
 	spin_lock_bh(&adapter->req_q_lock);
 	if (zfcp_fsf_req_sbal_get(adapter))
 		goto out;
 	req = zfcp_fsf_req_create(adapter, FSF_QTCB_ABORT_FCP_CMND,
-				  req_flags, adapter->pool.fsf_req_abort);
+				  0, adapter->pool.fsf_req_abort);
 	if (IS_ERR(req)) {
 		req = NULL;
 		goto out;
@@ -2309,21 +2307,17 @@ static void zfcp_set_fcp_dl(struct fcp_cmnd_iu *fcp_cmd, u32 fcp_dl)
 
 /**
  * zfcp_fsf_send_fcp_command_task - initiate an FCP command (for a SCSI command)
- * @adapter: adapter where scsi command is issued
  * @unit: unit where command is sent to
  * @scsi_cmnd: scsi command to be sent
- * @timer: timer to be started when request is initiated
- * @req_flags: flags for fsf_request
  */
-int zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
-				   struct zfcp_unit *unit,
-				   struct scsi_cmnd *scsi_cmnd,
-				   int use_timer, int req_flags)
+int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
+				   struct scsi_cmnd *scsi_cmnd)
 {
 	struct zfcp_fsf_req *req;
 	struct fcp_cmnd_iu *fcp_cmnd_iu;
 	unsigned int sbtype;
 	int real_bytes, retval = -EIO;
+	struct zfcp_adapter *adapter = unit->port->adapter;
 
 	if (unlikely(!(atomic_read(&unit->status) &
 		       ZFCP_STATUS_COMMON_UNBLOCKED)))
@@ -2332,7 +2326,8 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
 	spin_lock(&adapter->req_q_lock);
 	if (!zfcp_fsf_sbal_available(adapter))
 		goto out;
-	req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND, req_flags,
+	req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND,
+				  ZFCP_REQ_AUTO_CLEANUP,
 				  adapter->pool.fsf_req_scsi);
 	if (IS_ERR(req)) {
 		retval = PTR_ERR(req);
@@ -2414,9 +2409,6 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
 
 	zfcp_set_fcp_dl(fcp_cmnd_iu, real_bytes);
 
-	if (use_timer)
-		zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
-
 	retval = zfcp_fsf_req_send(req);
 	if (unlikely(retval))
 		goto failed_scsi_cmnd;
@@ -2434,19 +2426,16 @@ out:
 
 /**
  * zfcp_fsf_send_fcp_ctm - send SCSI task management command
- * @adapter: pointer to struct zfcp-adapter
  * @unit: pointer to struct zfcp_unit
  * @tm_flags: unsigned byte for task management flags
- * @req_flags: int request flags
  * Returns: on success pointer to struct fsf_req, NULL otherwise
  */
-struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_adapter *adapter,
-					   struct zfcp_unit *unit,
-					   u8 tm_flags, int req_flags)
+struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_unit *unit, u8 tm_flags)
 {
 	struct qdio_buffer_element *sbale;
 	struct zfcp_fsf_req *req = NULL;
 	struct fcp_cmnd_iu *fcp_cmnd_iu;
+	struct zfcp_adapter *adapter = unit->port->adapter;
 
 	if (unlikely(!(atomic_read(&unit->status) &
 		       ZFCP_STATUS_COMMON_UNBLOCKED)))
@@ -2455,7 +2444,7 @@ struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_adapter *adapter,
 	spin_lock_bh(&adapter->req_q_lock);
 	if (zfcp_fsf_req_sbal_get(adapter))
 		goto out;
-	req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND, req_flags,
+	req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND, 0,
 				  adapter->pool.fsf_req_scsi);
 	if (IS_ERR(req)) {
 		req = NULL;