[SCSI] zfcp: add queue_full sysfs attribute

Adds a new sysfs attribute queue_full for adapters that records the number
of incidents where a requests could not be submitted due to insufficient
free space on the request queue.

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: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 17 insertions, 7 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 49dbeb754e5f..9e083a5e2c4e 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -717,6 +717,14 @@ static int zfcp_fsf_sbal_check(struct zfcp_qdio_queue *queue)
         return 0;
 }
 
+static int zfcp_fsf_sbal_available(struct zfcp_adapter *adapter)
+{
+        unsigned int count = atomic_read(&adapter->req_q.count);
+        if (!count)
+                atomic_inc(&adapter->qdio_outb_full);
+        return count > 0;
+}
+
 static int zfcp_fsf_req_sbal_get(struct zfcp_adapter *adapter)
 {
         long ret;
@@ -727,6 +735,8 @@ static int zfcp_fsf_req_sbal_get(struct zfcp_adapter *adapter)
                                         zfcp_fsf_sbal_check(req_q), 5 * HZ);
         if (ret > 0)
                 return 0;
+        if (!ret)
+                atomic_inc(&adapter->qdio_outb_full);
 
         spin_lock_bh(&req_q->lock);
         return -EIO;
@@ -984,7 +994,7 @@ struct zfcp_fsf_req *zfcp_fsf_abort_fcp_command(unsigned long old_req_id,
         struct zfcp_fsf_req *req = NULL;
 
         spin_lock(&adapter->req_q.lock);
-        if (!atomic_read(&adapter->req_q.count))
+        if (!zfcp_fsf_sbal_available(adapter))
                 goto out;
         req = zfcp_fsf_req_create(adapter, FSF_QTCB_ABORT_FCP_CMND,
                                   req_flags, adapter->pool.fsf_req_abort);
@@ -1219,7 +1229,7 @@ int zfcp_fsf_send_els(struct zfcp_send_els *els)
                 return -EBUSY;
 
         spin_lock(&adapter->req_q.lock);
-        if (!atomic_read(&adapter->req_q.count))
+        if (!zfcp_fsf_sbal_available(adapter))
                 goto out;
         req = zfcp_fsf_req_create(adapter, FSF_QTCB_SEND_ELS,
                                   ZFCP_REQ_AUTO_CLEANUP, NULL);
@@ -1264,7 +1274,7 @@ int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
         int retval = -EIO;
 
         spin_lock_bh(&adapter->req_q.lock);
-        if (!atomic_read(&adapter->req_q.count))
+        if (!zfcp_fsf_sbal_available(adapter))
                 goto out;
         req = zfcp_fsf_req_create(adapter,
                                   FSF_QTCB_EXCHANGE_CONFIG_DATA,
@@ -1360,7 +1370,7 @@ int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *erp_action)
                 return -EOPNOTSUPP;
 
         spin_lock_bh(&adapter->req_q.lock);
-        if (!atomic_read(&adapter->req_q.count))
+        if (!zfcp_fsf_sbal_available(adapter))
                 goto out;
         req = zfcp_fsf_req_create(adapter, FSF_QTCB_EXCHANGE_PORT_DATA,
                                   ZFCP_REQ_AUTO_CLEANUP,
@@ -1406,7 +1416,7 @@ int zfcp_fsf_exchange_port_data_sync(struct zfcp_adapter *adapter,
                 return -EOPNOTSUPP;
 
         spin_lock_bh(&adapter->req_q.lock);
-        if (!atomic_read(&adapter->req_q.count))
+        if (!zfcp_fsf_sbal_available(adapter))
                 goto out;
 
         req = zfcp_fsf_req_create(adapter, FSF_QTCB_EXCHANGE_PORT_DATA, 0,
@@ -2224,7 +2234,7 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
                 return -EBUSY;
 
         spin_lock(&adapter->req_q.lock);
-        if (!atomic_read(&adapter->req_q.count))
+        if (!zfcp_fsf_sbal_available(adapter))
                 goto out;
         req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND, req_flags,
                                   adapter->pool.fsf_req_scsi);
@@ -2347,7 +2357,7 @@ struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_adapter *adapter,
                 return NULL;
 
         spin_lock(&adapter->req_q.lock);
-        if (!atomic_read(&adapter->req_q.count))
+        if (!zfcp_fsf_sbal_available(adapter))
                 goto out;
         req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND, req_flags,
                                   adapter->pool.fsf_req_scsi);