[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_def.h b/drivers/s390/scsi/zfcp_def.h
index 22e418db4518..a0318630f047 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -3,7 +3,7 @@
  *
  * Global definitions for the zfcp device driver.
  *
- * Copyright IBM Corporation 2002, 2008
+ * Copyright IBM Corporation 2002, 2009
  */
 
 #ifndef ZFCP_DEF_H
@@ -512,6 +512,8 @@ struct zfcp_port {
         u32                    supported_classes;
         struct work_struct     gid_pn_work;
         struct work_struct     test_link_work;
+        struct work_struct     rport_work;
+        enum { RPORT_NONE, RPORT_ADD, RPORT_DEL }  rport_task;
 };
 
 struct zfcp_unit {