scsi: make 'state' device attribute pollable

While the 'state' attribute can (and will) change occasionally,
calling 'poll()' or 'select()' on it fails as sysfs is never
notified that the state has changed.
With this patch calling 'poll()' or 'select()' will work
properly.
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_lib.c

@@ -2654,6 +2654,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
 
 	}
 	sdev->sdev_state = state;
+	sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
 	return 0;
 
  illegal:
@@ -3077,6 +3078,7 @@ int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
 	case SDEV_BLOCK:
 	case SDEV_TRANSPORT_OFFLINE:
 		sdev->sdev_state = new_state;
+		sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
 		break;
 	case SDEV_CREATED_BLOCK:
 		if (new_state == SDEV_TRANSPORT_OFFLINE ||
@@ -3084,6 +3086,7 @@ int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
 			sdev->sdev_state = new_state;
 		else
 			sdev->sdev_state = SDEV_CREATED;
+		sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
 		break;
 	case SDEV_CANCEL:
 	case SDEV_OFFLINE:

drivers/scsi/scsi_transport_srp.c

@@ -556,8 +556,11 @@ int srp_reconnect_rport(struct srp_rport *rport)
 		 */
 		shost_for_each_device(sdev, shost) {
 			mutex_lock(&sdev->state_mutex);
-			if (sdev->sdev_state == SDEV_OFFLINE)
+			if (sdev->sdev_state == SDEV_OFFLINE) {
 				sdev->sdev_state = SDEV_RUNNING;
+				sysfs_notify(&sdev->sdev_gendev.kobj,
+					     NULL, "state");
+			}
 			mutex_unlock(&sdev->state_mutex);
 		}
 	} else if (rport->state == SRP_RPORT_RUNNING) {