[PATCH] libata-hp: implement ata_eh_detach_dev()

Implement ata_eh_detach_dev().  This function is responsible for
detaching an ATA device and offlining the associated SCSI device
atomically so that the detached device is not accessed after ATA
detach is complete.

Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index 2d704be..e38759f 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -75,6 +75,7 @@
 extern struct scsi_transport_template ata_scsi_transport_template;
 
 extern void ata_scsi_scan_host(struct ata_port *ap);
+extern int ata_scsi_offline_dev(struct ata_device *dev);
 extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,
 			       unsigned int buflen);