[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>

3 files changed, 53 insertions, 0 deletions

diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 8ecb8424d7ba..a049bffdf770 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -667,6 +667,34 @@ void ata_eh_qc_retry(struct ata_queued_cmd *qc)
 }
 
 /**
+ *      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 da9689b70826..3dc6188af0e8 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -2762,3 +2762,27 @@ void ata_scsi_scan_host(struct ata_port *ap)
                 }
         }
 }
+
+/**
+ *      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 2d704be355cc..e38759fdc183 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -75,6 +75,7 @@ extern int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg);
 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);