[SCSI] zfcp: Use SCSI device data zfcp_scsi_dev instead of zfcp_unit

This is the large change to switch from using the data in
zfcp_unit to zfcp_scsi_dev. Keeping everything working requires doing
the switch in one piece. To ensure that no code keeps using the data
in zfcp_unit, this patch also removes the data from zfcp_unit that is
now being replaced with zfcp_scsi_dev.

For zfcp, the scsi_device together with zfcp_scsi_dev exist from the
call of slave_alloc to the call of slave_destroy. The data in
zfcp_scsi_dev is initialized in zfcp_scsi_slave_alloc and the LUN is
opened; the final shutdown for the LUN is run from slave_destroy.

Where the scsi_device or zfcp_scsi_dev is needed, the pointer to the
scsi_device is passed as function argument and inside the function
converted to the pointer to zfcp_scsi_dev; this avoids back and forth
conversion betweeen scsi_device and zfcp_scsi_dev.

While changing the function arguments from zfcp_unit to scsi_device,
the functions names are renamed form "unit" to "lun". This is to have
a seperation between zfcp_scsi_dev/LUN and the zfcp_unit; only code
referring to the remaining configuration information in zfcp_unit
struct uses "unit".

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/s390/scsi/zfcp_dbf.h b/drivers/s390/scsi/zfcp_dbf.h
index 2bcc340..6a48c19 100644
--- a/drivers/s390/scsi/zfcp_dbf.h
+++ b/drivers/s390/scsi/zfcp_dbf.h
@@ -60,7 +60,7 @@
 	u8 need;
 	u32 as;
 	u32 ps;
-	u32 us;
+	u32 ls;
 	u64 ref;
 	u64 action;
 	u64 wwpn;
@@ -350,16 +350,16 @@
 /**
  * zfcp_dbf_scsi_devreset - trace event for Logical Unit or Target Reset
  * @tag: tag indicating success or failure of reset operation
+ * @scmnd: SCSI command which caused this error recovery
  * @flag: indicates type of reset (Target Reset, Logical Unit Reset)
- * @unit: unit that needs reset
- * @scsi_cmnd: SCSI command which caused this error recovery
  */
 static inline
-void zfcp_dbf_scsi_devreset(const char *tag, u8 flag, struct zfcp_unit *unit,
-			    struct scsi_cmnd *scsi_cmnd)
+void zfcp_dbf_scsi_devreset(const char *tag, struct scsi_cmnd *scmnd, u8 flag)
 {
+	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scmnd->device);
+
 	zfcp_dbf_scsi(flag == FCP_TMF_TGT_RESET ? "trst" : "lrst", tag, 1,
-			    unit->port->adapter->dbf, scsi_cmnd, NULL, 0);
+		      zfcp_sdev->port->adapter->dbf, scmnd, NULL, 0);
 }
 
 #endif /* ZFCP_DBF_H */