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>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2138a7a..759dee8 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -70,6 +70,8 @@
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 @@
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 @@
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)
{
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
index e52029e..167720d 100644
--- a/include/linux/virtio_blk.h
+++ b/include/linux/virtio_blk.h
@@ -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 @@
/* 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