[SCSI] zfcp: Do not wait for SBALs on stopped queue

Trying to read the FC host statistics on an offline adapter results in
a 5 seconds wait. Reading the statistics tries to issue an exchange
port data request which first waits up to 5 seconds for an entry in
the request queue.

Change the strategy for getting a free SBAL to exit when the queue is
stopped. Reading the statistics will then fail without the wait.

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

2 files changed, 9 insertions, 6 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 4e15361a83b9..229795f190e8 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -719,11 +719,6 @@ static struct zfcp_fsf_req *zfcp_fsf_req_create(struct zfcp_qdio *qdio,
         zfcp_qdio_req_init(adapter->qdio, &req->qdio_req, req->req_id, sbtype,
                            req->qtcb, sizeof(struct fsf_qtcb));
 
-        if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)) {
-                zfcp_fsf_req_free(req);
-                return ERR_PTR(-EIO);
-        }
-
         return req;
 }
 
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index 28117e130e2c..6fa5e0453176 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -251,7 +251,8 @@ static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
         struct zfcp_qdio_queue *req_q = &qdio->req_q;
 
         spin_lock_bh(&qdio->req_q_lock);
-        if (atomic_read(&req_q->count))
+        if (atomic_read(&req_q->count) ||
+            !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
                 return 1;
         spin_unlock_bh(&qdio->req_q_lock);
         return 0;
@@ -274,8 +275,13 @@ int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
         spin_unlock_bh(&qdio->req_q_lock);
         ret = wait_event_interruptible_timeout(qdio->req_q_wq,
                                zfcp_qdio_sbal_check(qdio), 5 * HZ);
+
+        if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
+                return -EIO;
+
         if (ret > 0)
                 return 0;
+
         if (!ret) {
                 atomic_inc(&qdio->req_q_full);
                 /* assume hanging outbound queue, try queue recovery */
@@ -375,6 +381,8 @@ void zfcp_qdio_close(struct zfcp_qdio *qdio)
         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
         spin_unlock_bh(&qdio->req_q_lock);
 
+        wake_up(&qdio->req_q_wq);
+
         qdio_shutdown(qdio->adapter->ccw_device,
                       QDIO_FLAG_CLEANUP_USING_CLEAR);