[PATCH 07/12] libata-hp-prep: store attached SCSI device

[Tejun Heo <htejun@gmail.com>]

Add device persistent field dev->sdev and store the attached SCSI
device.  With hotplug, libata needs to know the attached SCSI device
to offline and detach it, but scsi_device_lookup() cannot be used
because libata will reuse SCSI ID numbers - dead but not gone devices
(due to zombie opens, etc...) interfere with the lookup.

dev->sdev doesn't hold reference to the SCSI device.  It's cleared
when the SCSI device goes away.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-scsi.c |   14 ++++++++++----
 include/linux/libata.h     |    1 +
 2 files changed, 11 insertions(+), 4 deletions(-)

16098cb84a40faee6726ff51371e9aa17e018a5f
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 95e5c23..a1caf3f 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -2743,16 +2743,22 @@ void ata_scsi_simulate(struct ata_device
 
 void ata_scsi_scan_host(struct ata_port *ap)
 {
-	struct ata_device *dev;
 	unsigned int i;
 
 	if (ap->flags & ATA_FLAG_DISABLED)
 		return;
 
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
-		dev = &ap->device[i];
+		struct ata_device *dev = &ap->device[i];
+		struct scsi_device *sdev;
+
+		if (!ata_dev_enabled(dev) || dev->sdev)
+			continue;
 
-		if (ata_dev_enabled(dev))
-			scsi_scan_target(&ap->host->shost_gendev, 0, i, 0, 0);
+		sdev = __scsi_add_device(ap->host, 0, i, 0, NULL);
+		if (!IS_ERR(sdev)) {
+			dev->sdev = sdev;
+			scsi_device_put(sdev);
+		}
 	}
 }
diff --git a/include/linux/libata.h b/include/linux/libata.h
index c42ea93..54b2259 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -412,6 +412,7 @@ struct ata_device {
 	struct ata_port		*ap;
 	unsigned int		devno;		/* 0 or 1 */
 	unsigned long		flags;		/* ATA_DFLAG_xxx */
+	struct scsi_device	*sdev;		/* attached SCSI device */
 	/* n_sector is used as CLEAR_OFFSET, read comment above CLEAR_OFFSET */
 	u64			n_sectors;	/* size of device, if ATA */
 	unsigned int		class;		/* ATA_DEV_xxx */
-- 
1.3.2