Commit 4cb2ea28 authored by john cooper's avatar john cooper Committed by Rusty Russell
Browse files

Add virtio disk identification support 



Add virtio-blk device id (s/n) support via virtio request.

Signed-off-by: default avatarjohn cooper <john.cooper@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 537b60d1

drivers/block/virtio_blk.c

+30 −0
Original line number Diff line number Diff line
@@ -70,6 +70,8 @@ static void blk_done(struct virtqueue *vq) 
			vbr->req->sense_len = vbr->in_hdr.sense_len;

			vbr->req->errors = vbr->in_hdr.errors;

		}

		if (blk_special_request(vbr->req))

			vbr->req->errors = (error != 0);



		__blk_end_request_all(vbr->req, error);

		list_del(&vbr->list);
@@ -103,6 +105,11 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, 
		vbr->out_hdr.sector = 0;

		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);

		break;

	case REQ_TYPE_SPECIAL:

		vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;

		vbr->out_hdr.sector = 0;

		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);

		break;

	case REQ_TYPE_LINUX_BLOCK:

		if (req->cmd[0] == REQ_LB_OP_FLUSH) {

			vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
@@ -189,6 +196,29 @@ static void virtblk_prepare_flush(struct request_queue *q, struct request *req) 
	req->cmd[0] = REQ_LB_OP_FLUSH;

}



/* return id (s/n) string for *disk to *id_str

 */

static int virtblk_get_id(struct gendisk *disk, char *id_str)

{

	struct virtio_blk *vblk = disk->private_data;

	struct request *req;

	struct bio *bio;



	bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,

			   GFP_KERNEL);

	if (IS_ERR(bio))

		return PTR_ERR(bio);



	req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);

	if (IS_ERR(req)) {

		bio_put(bio);

		return PTR_ERR(req);

	}



	req->cmd_type = REQ_TYPE_SPECIAL;

	return blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);

}



static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,

			 unsigned cmd, unsigned long data)

{

include/linux/virtio_blk.h

+5 −0
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
#define VIRTIO_BLK_F_FLUSH	9	/* Cache flush command support */

#define VIRTIO_BLK_F_TOPOLOGY	10	/* Topology information is available */



#define VIRTIO_BLK_ID_BYTES	20	/* ID string length */



struct virtio_blk_config {

	/* The capacity (in 512-byte sectors). */

	__u64 capacity;
@@ -67,6 +69,9 @@ struct virtio_blk_config { 
/* Cache flush command */

#define VIRTIO_BLK_T_FLUSH	4



/* Get device ID command */

#define VIRTIO_BLK_T_GET_ID    8



/* Barrier before this op. */

#define VIRTIO_BLK_T_BARRIER	0x80000000