blktrace: pass zfcp driver data

This patch writes the channel and fabric latencies in nanoseconds per
request via blktrace for later analysis. The utilization of the inbound
and outbound adapter queue is also reported.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 739356a5c123..5ae1d497e5ed 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -6,6 +6,7 @@
  * Copyright IBM Corporation 2002, 2008
  */
 
+#include <linux/blktrace_api.h>
 #include "zfcp_ext.h"
 
 static void zfcp_fsf_request_timeout_handler(unsigned long data)
@@ -777,6 +778,7 @@ static int zfcp_fsf_req_send(struct zfcp_fsf_req *req)
         list_add_tail(&req->list, &adapter->req_list[idx]);
         spin_unlock(&adapter->req_list_lock);
 
+        req->qdio_outb_usage = atomic_read(&req_q->count);
         req->issued = get_clock();
         if (zfcp_qdio_send(req)) {
                 /* Queues are down..... */
@@ -2082,6 +2084,36 @@ static void zfcp_fsf_req_latency(struct zfcp_fsf_req *req)
         spin_unlock_irqrestore(&unit->latencies.lock, flags);
 }
 
+#ifdef CONFIG_BLK_DEV_IO_TRACE
+static void zfcp_fsf_trace_latency(struct zfcp_fsf_req *fsf_req)
+{
+        struct fsf_qual_latency_info *lat_inf;
+        struct scsi_cmnd *scsi_cmnd = (struct scsi_cmnd *)fsf_req->data;
+        struct request *req = scsi_cmnd->request;
+        struct zfcp_blk_drv_data trace;
+        int ticks = fsf_req->adapter->timer_ticks;
+
+        trace.flags = 0;
+        trace.magic = ZFCP_BLK_DRV_DATA_MAGIC;
+        if (fsf_req->adapter->adapter_features & FSF_FEATURE_MEASUREMENT_DATA) {
+                trace.flags |= ZFCP_BLK_LAT_VALID;
+                lat_inf = &fsf_req->qtcb->prefix.prot_status_qual.latency_info;
+                trace.channel_lat = lat_inf->channel_lat * ticks;
+                trace.fabric_lat = lat_inf->fabric_lat * ticks;
+        }
+        if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR)
+                trace.flags |= ZFCP_BLK_REQ_ERROR;
+        trace.inb_usage = fsf_req->qdio_inb_usage;
+        trace.outb_usage = fsf_req->qdio_outb_usage;
+
+        blk_add_driver_data(req->q, req, &trace, sizeof(trace));
+}
+#else
+static inline void zfcp_fsf_trace_latency(struct zfcp_fsf_req *fsf_req)
+{
+}
+#endif
+
 static void zfcp_fsf_send_fcp_command_task_handler(struct zfcp_fsf_req *req)
 {
         struct scsi_cmnd *scpnt = req->data;
@@ -2114,6 +2146,8 @@ static void zfcp_fsf_send_fcp_command_task_handler(struct zfcp_fsf_req *req)
         if (req->adapter->adapter_features & FSF_FEATURE_MEASUREMENT_DATA)
                 zfcp_fsf_req_latency(req);
 
+        zfcp_fsf_trace_latency(req);
+
         if (unlikely(fcp_rsp_iu->validity.bits.fcp_rsp_len_valid)) {
                 if (fcp_rsp_info[3] == RSP_CODE_GOOD)
                         set_host_byte(scpnt, DID_OK);