[SCSI] zfcp: Block FC transport rports early on errors

Use the I/O blocking mechanism in the FC transport class to allow
faster failovers for multipathing:
- Call fc_remote_port_delete early to set the rport to BLOCKED.
- Check the rport status in queuecommand with fc_remote_portchkready
  to no longer accept new I/O for this port and fail the I/O with the
  appropriate scsi_cmnd result.
- Implement the terminate_rport_io handler to abort all pending I/O
  requests
- Return SCSI commands with DID_TRANSPORT_DISRUPTED while erp is
  running.
- When updating the remote port status, check for late changes and
  update the remote ports status accordingly.

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

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 69a31187e54..b2be6593b56 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -3,7 +3,7 @@
  *
  * Module interface and handling of zfcp data structures.
  *
- * Copyright IBM Corporation 2002, 2008
+ * Copyright IBM Corporation 2002, 2009
  */
 
 /*
@@ -606,10 +606,12 @@ struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 	INIT_LIST_HEAD(&port->unit_list_head);
 	INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);
 	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
+	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
 
 	port->adapter = adapter;
 	port->d_id = d_id;
 	port->wwpn = wwpn;
+	port->rport_task = RPORT_NONE;
 
 	/* mark port unusable as long as sysfs registration is not complete */
 	atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);