Add virtio disk identification support

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

Signed-off-by: john cooper <john.cooper@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
john cooper 2010-03-25 01:33:33 -04:00 committed by Rusty Russell
parent 537b60d178
commit 4cb2ea28c5
2 changed files with 35 additions and 0 deletions

View File

@ -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)
{

View File

@ -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