storvsc: Use the specified target ID in device lookup

BugLink: http://bugs.launchpad.net/bugs/1583357

The current code assumes that there is only one target in device lookup.
Fix this bug. This will alow us to correctly handle hot reomoval of
LUNs.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Alex Ng <alexng@microsoft.com>
Tested-by: Vivek Yadav <vyadav@microsoft.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 98441221)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/scsi/storvsc_drv.c

@@ -478,19 +478,18 @@ struct hv_host_device {
 struct storvsc_scan_work {
 	struct work_struct work;
 	struct Scsi_Host *host;
-	uint lun;
+	u8 lun;
+	u8 tgt_id;
 };
 
 static void storvsc_device_scan(struct work_struct *work)
 {
 	struct storvsc_scan_work *wrk;
-	uint lun;
 	struct scsi_device *sdev;
 
 	wrk = container_of(work, struct storvsc_scan_work, work);
-	lun = wrk->lun;
 
-	sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
+	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 	if (!sdev)
 		goto done;
 	scsi_rescan_device(&sdev->sdev_gendev);
@@ -541,7 +540,7 @@ static void storvsc_remove_lun(struct work_struct *work)
 	if (!scsi_host_get(wrk->host))
 		goto done;
 
-	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
+	sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 
 	if (sdev) {
 		scsi_remove_device(sdev);
@@ -942,6 +941,7 @@ static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 
 	wrk->host = host;
 	wrk->lun = vm_srb->lun;
+	wrk->tgt_id = vm_srb->target_id;
 	INIT_WORK(&wrk->work, process_err_fn);
 	schedule_work(&wrk->work);
 }