From 4cb2ea28c55cf5e5ef83aec535099ffce3c583df Mon Sep 17 00:00:00 2001 From: john cooper Date: Thu, 25 Mar 2010 01:33:33 -0400 Subject: [PATCH] Add virtio disk identification support Add virtio-blk device id (s/n) support via virtio request. Signed-off-by: john cooper Signed-off-by: Rusty Russell --- drivers/block/virtio_blk.c | 30 ++++++++++++++++++++++++++++++ include/linux/virtio_blk.h | 5 +++++ 2 files changed, 35 insertions(+) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 2138a7ae050c..759dee8330ac 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -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) { diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index e52029e98919..167720d695ed 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 @@ 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 -- 2.39.2