[PATCH 01/13] libata-hp: implement ata_eh_detach_dev()

[Tejun Heo <htejun@gmail.com>]

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>

---

 drivers/scsi/libata-eh.c   |   28 ++++++++++++++++++++++++++++
 drivers/scsi/libata-scsi.c |   24 ++++++++++++++++++++++++
 drivers/scsi/libata.h      |    1 +
 3 files changed, 53 insertions(+), 0 deletions(-)

f4a6e5240b58132212fe837bd7d59c71497033fd
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index c76fab0..99222dd 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -629,6 +629,34 @@ void ata_eh_qc_retry(struct ata_queued_c
 }
 
 /**
+ *	ata_eh_detach_dev - detach ATA device
+ *	@dev: ATA device to detach
+ *
+ *	Detach @dev.
+ *
+ *	LOCKING:
+ *	None.
+ */
+static void ata_eh_detach_dev(struct ata_device *dev)
+{
+	struct ata_port *ap = dev->ap;
+	unsigned long flags;
+
+	ata_dev_disable(dev);
+
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+
+	dev->flags &= ~ATA_DFLAG_DETACH;
+
+	if (ata_scsi_offline_dev(dev)) {
+		dev->flags |= ATA_DFLAG_DETACHED;
+		ap->flags |= ATA_FLAG_SCSI_HOTPLUG;
+	}
+
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+}
+
+/**
  *	ata_eh_about_to_do - about to perform eh_action
  *	@ap: target ATA port
  *	@action: action about to be performed
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index d24e091..5f46b11 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -2757,3 +2757,27 @@ void ata_scsi_scan_host(struct ata_port 
 		}
 	}
 }
+
+/**
+ *	ata_scsi_offline_dev - offline attached SCSI device
+ *	@dev: ATA device to offline attached SCSI device for
+ *
+ *	This function is called from ata_eh_hotplug() and responsible
+ *	for taking the SCSI device attached to @dev offline.  This
+ *	function is called with host_set lock which protects dev->sdev
+ *	against clearing.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host_set lock)
+ *
+ *	RETURNS:
+ *	1 if attached SCSI device exists, 0 otherwise.
+ */
+int ata_scsi_offline_dev(struct ata_device *dev)
+{
+	if (dev->sdev) {
+		scsi_device_set_state(dev->sdev, SDEV_OFFLINE);
+		return 1;
+	}
+	return 0;
+}
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index d728fd5..c8a3350 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -75,6 +75,7 @@ extern int ata_cmd_ioctl(struct scsi_dev
 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);
 
-- 
1.3.2