1 files changed, 38 insertions, 18 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index c57658f3d34f..47795fbf081f 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -670,8 +670,11 @@ static int zfcp_fsf_req_sbal_get(struct zfcp_adapter *adapter)
                                zfcp_fsf_sbal_check(adapter), 5 * HZ);
         if (ret > 0)
                 return 0;
-        if (!ret)
+        if (!ret) {
                 atomic_inc(&adapter->qdio_outb_full);
+                /* assume hanging outbound queue, try queue recovery */
+                zfcp_erp_adapter_reopen(adapter, 0, "fsrsg_1", NULL);
+        }
 
         spin_lock_bh(&adapter->req_q_lock);
         return -EIO;
@@ -722,7 +725,7 @@ static struct zfcp_fsf_req *zfcp_fsf_req_create(struct zfcp_adapter *adapter,
                 req = zfcp_fsf_alloc_qtcb(pool);
 
         if (unlikely(!req))
-                return ERR_PTR(-EIO);
+                return ERR_PTR(-ENOMEM);
 
         if (adapter->req_no == 0)
                 adapter->req_no++;
@@ -1010,6 +1013,23 @@ skip_fsfstatus:
                 send_ct->handler(send_ct->handler_data);
 }
 
+static void zfcp_fsf_setup_ct_els_unchained(struct qdio_buffer_element *sbale,
+                                            struct scatterlist *sg_req,
+                                            struct scatterlist *sg_resp)
+{
+        sbale[0].flags |= SBAL_FLAGS0_TYPE_WRITE_READ;
+        sbale[2].addr   = sg_virt(sg_req);
+        sbale[2].length = sg_req->length;
+        sbale[3].addr   = sg_virt(sg_resp);
+        sbale[3].length = sg_resp->length;
+        sbale[3].flags |= SBAL_FLAGS_LAST_ENTRY;
+}
+
+static int zfcp_fsf_one_sbal(struct scatterlist *sg)
+{
+        return sg_is_last(sg) && sg->length <= PAGE_SIZE;
+}
+
 static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req,
                                        struct scatterlist *sg_req,
                                        struct scatterlist *sg_resp,
@@ -1020,30 +1040,30 @@ static int zfcp_fsf_setup_ct_els_sbals(struct zfcp_fsf_req *req,
         int bytes;
 
         if (!(feat & FSF_FEATURE_ELS_CT_CHAINED_SBALS)) {
-                if (sg_req->length > PAGE_SIZE || sg_resp->length > PAGE_SIZE ||
-                    !sg_is_last(sg_req) || !sg_is_last(sg_resp))
+                if (!zfcp_fsf_one_sbal(sg_req) || !zfcp_fsf_one_sbal(sg_resp))
                         return -EOPNOTSUPP;
 
-                sbale[0].flags |= SBAL_FLAGS0_TYPE_WRITE_READ;
-                sbale[2].addr   = sg_virt(sg_req);
-                sbale[2].length = sg_req->length;
-                sbale[3].addr   = sg_virt(sg_resp);
-                sbale[3].length = sg_resp->length;
-                sbale[3].flags |= SBAL_FLAGS_LAST_ENTRY;
+                zfcp_fsf_setup_ct_els_unchained(sbale, sg_req, sg_resp);
+                return 0;
+        }
+
+        /* use single, unchained SBAL if it can hold the request */
+        if (zfcp_fsf_one_sbal(sg_req) && zfcp_fsf_one_sbal(sg_resp)) {
+                zfcp_fsf_setup_ct_els_unchained(sbale, sg_req, sg_resp);
                 return 0;
         }
 
         bytes = zfcp_qdio_sbals_from_sg(req, SBAL_FLAGS0_TYPE_WRITE_READ,
                                         sg_req, max_sbals);
         if (bytes <= 0)
-                return -ENOMEM;
+                return -EIO;
         req->qtcb->bottom.support.req_buf_length = bytes;
         req->sbale_curr = ZFCP_LAST_SBALE_PER_SBAL;
 
         bytes = zfcp_qdio_sbals_from_sg(req, SBAL_FLAGS0_TYPE_WRITE_READ,
                                         sg_resp, max_sbals);
         if (bytes <= 0)
-                return -ENOMEM;
+                return -EIO;
         req->qtcb->bottom.support.resp_buf_length = bytes;
 
         return 0;
@@ -1607,10 +1627,10 @@ static void zfcp_fsf_open_wka_port_handler(struct zfcp_fsf_req *req)
         case FSF_ACCESS_DENIED:
                 wka_port->status = ZFCP_WKA_PORT_OFFLINE;
                 break;
-        case FSF_PORT_ALREADY_OPEN:
-                break;
         case FSF_GOOD:
                 wka_port->handle = header->port_handle;
+                /* fall through */
+        case FSF_PORT_ALREADY_OPEN:
                 wka_port->status = ZFCP_WKA_PORT_ONLINE;
         }
 out:
@@ -1731,15 +1751,16 @@ static void zfcp_fsf_close_physical_port_handler(struct zfcp_fsf_req *req)
                 zfcp_fsf_access_denied_port(req, port);
                 break;
         case FSF_PORT_BOXED:
-                zfcp_erp_port_boxed(port, "fscpph2", req);
-                req->status |= ZFCP_STATUS_FSFREQ_ERROR |
-                               ZFCP_STATUS_FSFREQ_RETRY;
                 /* can't use generic zfcp_erp_modify_port_status because
                  * ZFCP_STATUS_COMMON_OPEN must not be reset for the port */
                 atomic_clear_mask(ZFCP_STATUS_PORT_PHYS_OPEN, &port->status);
                 list_for_each_entry(unit, &port->unit_list_head, list)
                         atomic_clear_mask(ZFCP_STATUS_COMMON_OPEN,
                                           &unit->status);
+                zfcp_erp_port_boxed(port, "fscpph2", req);
+                req->status |= ZFCP_STATUS_FSFREQ_ERROR |
+                               ZFCP_STATUS_FSFREQ_RETRY;
+
                 break;
         case FSF_ADAPTER_STATUS_AVAILABLE:
                 switch (header->fsf_status_qual.word[0]) {
@@ -2541,7 +2562,6 @@ struct zfcp_fsf_req *zfcp_fsf_control_file(struct zfcp_adapter *adapter,
         bytes = zfcp_qdio_sbals_from_sg(req, direction, fsf_cfdc->sg,
                                         FSF_MAX_SBALS_PER_REQ);
         if (bytes != ZFCP_CFDC_MAX_SIZE) {
-                retval = -ENOMEM;
                 zfcp_fsf_req_free(req);
                 goto out;
         }