Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 865b58c0 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by James Bottomley
Browse files

[SCSI] virtio-scsi: support online resizing of disks 



Support the LUN parameter change event.  Currently, the host fires this event
when the capacity of a disk is changed from the virtual machine monitor.
The resize then appears in the kernel log like this:

  sd 0:0:0:0: [sda] 46137344 512-byte logical blocks: (23.6 GB/22.0 GIb)
  sda: detected capacity change from 22548578304 to 23622320128

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent 9da5f5ac

drivers/scsi/virtio_scsi.c

+30 −1
Original line number Diff line number Diff line
@@ -279,6 +279,31 @@ static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 
	}

}



static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,

					 struct virtio_scsi_event *event)

{

	struct scsi_device *sdev;

	struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);

	unsigned int target = event->lun[1];

	unsigned int lun = (event->lun[2] << 8) | event->lun[3];

	u8 asc = event->reason & 255;

	u8 ascq = event->reason >> 8;



	sdev = scsi_device_lookup(shost, 0, target, lun);

	if (!sdev) {

		pr_err("SCSI device %d 0 %d %d not found\n",

			shost->host_no, target, lun);

		return;

	}



	/* Handle "Parameters changed", "Mode parameters changed", and

	   "Capacity data has changed".  */

	if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))

		scsi_rescan_device(&sdev->sdev_gendev);



	scsi_device_put(sdev);

}



static void virtscsi_handle_event(struct work_struct *work)

{

	struct virtio_scsi_event_node *event_node =
@@ -297,6 +322,9 @@ static void virtscsi_handle_event(struct work_struct *work) 
	case VIRTIO_SCSI_T_TRANSPORT_RESET:

		virtscsi_handle_transport_reset(vscsi, event);

		break;

	case VIRTIO_SCSI_T_PARAM_CHANGE:

		virtscsi_handle_param_change(vscsi, event);

		break;

	default:

		pr_err("Unsupport virtio scsi event %x\n", event->event);

	}
@@ -737,7 +765,8 @@ static struct virtio_device_id id_table[] = { 
};



static unsigned int features[] = {

	VIRTIO_SCSI_F_HOTPLUG

	VIRTIO_SCSI_F_HOTPLUG,

	VIRTIO_SCSI_F_CHANGE,

};



static struct virtio_driver virtio_scsi_driver = {

include/linux/virtio_scsi.h

+2 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ struct virtio_scsi_config { 
/* Feature Bits */

#define VIRTIO_SCSI_F_INOUT                    0

#define VIRTIO_SCSI_F_HOTPLUG                  1

#define VIRTIO_SCSI_F_CHANGE                   2



/* Response codes */

#define VIRTIO_SCSI_S_OK                       0
@@ -108,6 +109,7 @@ struct virtio_scsi_config { 
#define VIRTIO_SCSI_T_NO_EVENT                 0

#define VIRTIO_SCSI_T_TRANSPORT_RESET          1

#define VIRTIO_SCSI_T_ASYNC_NOTIFY             2

#define VIRTIO_SCSI_T_PARAM_CHANGE             3



/* Reasons of transport reset event */

#define VIRTIO_SCSI_EVT_RESET_HARD             0