[SCSI] zfcp: fix device registration issues

The patch fixes following issues:

(1) Replace scsi_add_device with scsi_scan_target.
(Thus the rport instead of the scsi_host becomes parent of a
scsi_target again.)

(2) Avoid scsi_device allocation during registration of an remote port.
(Would be done during fc_scsi_scan_rport.)

(3) Fix queuecommand behaviour when an zfcp unit is blocked.
(Call scsi_done with DID_NO_CONNECT instead of returning
SCSI_MLQUEUE_DEVICE_BUSY otherwise we might end up waiting
for completion in blk_execute_rq for ever.)

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

3 files changed, 12 insertions, 6 deletions

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 7f551d66f47f..6eba56cd89ba 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -664,6 +664,7 @@ do { \
 #define ZFCP_STATUS_UNIT_TEMPORARY              0x00000002
 #define ZFCP_STATUS_UNIT_SHARED                 0x00000004
 #define ZFCP_STATUS_UNIT_READONLY               0x00000008
+#define ZFCP_STATUS_UNIT_REGISTERED             0x00000010
 
 /* FSF request status (this does not have a common part) */
 #define ZFCP_STATUS_FSFREQ_NOT_INIT             0x00000000
diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index e3c4bdd29a60..57cb628a05aa 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -3391,10 +3391,13 @@ zfcp_erp_action_cleanup(int action, struct zfcp_adapter *adapter,
                     && (!atomic_test_mask(ZFCP_STATUS_UNIT_TEMPORARY,
                                           &unit->status))
                     && !unit->device
-                    && port->rport)
-                        scsi_add_device(port->adapter->scsi_host, 0,
-                                        port->rport->scsi_target_id,
-                                        unit->scsi_lun);
+                    && port->rport) {
+                        atomic_set_mask(ZFCP_STATUS_UNIT_REGISTERED,
+                                        &unit->status);
+                        scsi_scan_target(&port->rport->dev, 0,
+                                         port->rport->scsi_target_id,
+                                         unit->scsi_lun, 0);
+                }
                 zfcp_unit_put(unit);
                 break;
         case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index a2de3c9afe49..9e6d07d7b3c8 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -183,7 +183,8 @@ zfcp_scsi_slave_alloc(struct scsi_device *sdp)
 
         read_lock_irqsave(&zfcp_data.config_lock, flags);
         unit = zfcp_unit_lookup(adapter, sdp->channel, sdp->id, sdp->lun);
-        if (unit) {
+        if (unit && atomic_test_mask(ZFCP_STATUS_UNIT_REGISTERED,
+                                     &unit->status)) {
                 sdp->hostdata = unit;
                 unit->device = sdp;
                 zfcp_unit_get(unit);
@@ -208,6 +209,7 @@ zfcp_scsi_slave_destroy(struct scsi_device *sdpnt)
         struct zfcp_unit *unit = (struct zfcp_unit *) sdpnt->hostdata;
 
         if (unit) {
+                atomic_clear_mask(ZFCP_STATUS_UNIT_REGISTERED, &unit->status);
                 sdpnt->hostdata = NULL;
                 unit->device = NULL;
                 zfcp_unit_put(unit);
@@ -291,7 +293,7 @@ zfcp_scsi_command_async(struct zfcp_adapter *adapter, struct zfcp_unit *unit,
                                "on port 0x%016Lx in recovery\n",
                                zfcp_get_busid_by_unit(unit),
                                unit->fcp_lun, unit->port->wwpn);
-                retval = SCSI_MLQUEUE_DEVICE_BUSY;
+                zfcp_scsi_command_fail(scpnt, DID_NO_CONNECT);
                 goto out;
         }