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

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>

2 files changed, 11 insertions, 4 deletions

diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 05090768d9a8..da9689b70826 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -2743,16 +2743,22 @@ void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd,
 
 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 10dc235ad8bc..c0513c752751 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -413,6 +413,7 @@ 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 */