[SCSI] zfcp: Fix port reference counting

If this problem appears zfcp ports cannot be de-queued since it is
checked for a zero refcount. The port reference counting is wrong for
existing zfcp ports when e.g. an adapter gets on-line again. During
port scanning the reference counting for existing ports should not be
changed.

Signed-off-by: Martin Petermann <martin.petermann@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, 4 insertions, 3 deletions

diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index db409684e06f..19ae0842047c 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -539,6 +539,9 @@ static void zfcp_validate_port(struct zfcp_port *port)
 {
         struct zfcp_adapter *adapter = port->adapter;
 
+        if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC))
+                return;
+
         atomic_clear_mask(ZFCP_STATUS_COMMON_NOESC, &port->status);
 
         if ((port->supported_classes != 0) ||
@@ -599,10 +602,8 @@ static int zfcp_scan_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
                 if (acc->wwpn == fc_host_port_name(adapter->scsi_host))
                         continue;
                 port = zfcp_get_port_by_wwpn(adapter, acc->wwpn);
-                if (port) {
-                        zfcp_port_get(port);
+                if (port)
                         continue;
-                }
 
                 port = zfcp_port_enqueue(adapter, acc->wwpn,
                                          ZFCP_STATUS_COMMON_NOESC, d_id);