[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, 5 insertions, 1 deletions

diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 569d2437e99..f6399ca97bc 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -3,7 +3,7 @@
  *
  * External function declarations.
  *
- * Copyright IBM Corporation 2002, 2008
+ * Copyright IBM Corporation 2002, 2009
  */
 
 #ifndef ZFCP_EXT_H
@@ -154,6 +154,10 @@ extern int zfcp_adapter_scsi_register(struct zfcp_adapter *);
 extern void zfcp_adapter_scsi_unregister(struct zfcp_adapter *);
 extern char *zfcp_get_fcp_sns_info_ptr(struct fcp_rsp_iu *);
 extern struct fc_function_template zfcp_transport_functions;
+extern void zfcp_scsi_rport_work(struct work_struct *);
+extern void zfcp_scsi_schedule_rport_register(struct zfcp_port *);
+extern void zfcp_scsi_schedule_rport_block(struct zfcp_port *);
+extern void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *);
 
 /* zfcp_sysfs.c */
 extern struct attribute_group zfcp_sysfs_unit_attrs;