virtio_blk: SG_IO passthru support (1cde26f9) · Commits · 戴 / test

drivers/block/virtio_blk.c

+50 −14

Original line number	Diff line number	Diff line
		@@ -37,6 +37,7 @@ struct virtblk_req
		struct list_head list;
		struct request *req;
		struct virtio_blk_outhdr out_hdr;
		struct virtio_scsi_inhdr in_hdr;
		u8 status;
		};

		@@ -49,7 +50,9 @@ static void blk_done(struct virtqueue *vq)

		spin_lock_irqsave(&vblk->lock, flags);
		while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) {
		unsigned int nr_bytes;
		int error;

		switch (vbr->status) {
		case VIRTIO_BLK_S_OK:
		error = 0;
		@@ -62,6 +65,12 @@ static void blk_done(struct virtqueue *vq)
		break;
		}

		if (blk_pc_request(vbr->req)) {
		vbr->req->resid_len = vbr->in_hdr.residual;
		vbr->req->sense_len = vbr->in_hdr.sense_len;
		vbr->req->errors = vbr->in_hdr.errors;
		}

		__blk_end_request_all(vbr->req, error);
		list_del(&vbr->list);
		mempool_free(vbr, vblk->pool);
		@@ -74,7 +83,7 @@ static void blk_done(struct virtqueue *vq)
		static bool do_req(struct request_queue q, struct virtio_blk vblk,
		struct request *req)
		{
		unsigned long num, out, in;
		unsigned long num, out = 0, in = 0;
		struct virtblk_req *vbr;

		vbr = mempool_alloc(vblk->pool, GFP_ATOMIC);
		@@ -99,18 +108,36 @@ static bool do_req(struct request_queue q, struct virtio_blk vblk,
		if (blk_barrier_rq(vbr->req))
		vbr->out_hdr.type \|= VIRTIO_BLK_T_BARRIER;

		sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr));
		num = blk_rq_map_sg(q, vbr->req, vblk->sg+1);
		sg_set_buf(&vblk->sg[num+1], &vbr->status, sizeof(vbr->status));
		sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));

		/*
		* If this is a packet command we need a couple of additional headers.
		* Behind the normal outhdr we put a segment with the scsi command
		* block, and before the normal inhdr we put the sense data and the
		* inhdr with additional status information before the normal inhdr.
		*/
		if (blk_pc_request(vbr->req))
		sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len);

		num = blk_rq_map_sg(q, vbr->req, vblk->sg + out);

		if (blk_pc_request(vbr->req)) {
		sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, 96);
		sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr,
		sizeof(vbr->in_hdr));
		}

		sg_set_buf(&vblk->sg[num + out + in++], &vbr->status,
		sizeof(vbr->status));

		if (num) {
		if (rq_data_dir(vbr->req) == WRITE) {
		vbr->out_hdr.type \|= VIRTIO_BLK_T_OUT;
		out = 1 + num;
		in = 1;
		out += num;
		} else {
		vbr->out_hdr.type \|= VIRTIO_BLK_T_IN;
		out = 1;
		in = 1 + num;
		in += num;
		}
		}

		if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr)) {
		@@ -148,8 +175,16 @@ static void do_virtblk_request(struct request_queue *q)
		static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
		unsigned cmd, unsigned long data)
		{
		return scsi_cmd_ioctl(bdev->bd_disk->queue,
		bdev->bd_disk, mode, cmd,
		struct gendisk *disk = bdev->bd_disk;
		struct virtio_blk *vblk = disk->private_data;

		/*
		* Only allow the generic SCSI ioctls if the host can support it.
		*/
		if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
		return -ENOIOCTLCMD;

		return scsi_cmd_ioctl(disk->queue, disk, mode, cmd,
		(void __user *)data);
		}

		@@ -356,6 +391,7 @@ static struct virtio_device_id id_table[] = {
		static unsigned int features[] = {
		VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
		VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
		VIRTIO_BLK_F_SCSI,
		};

		static struct virtio_driver virtio_blk = {

include/linux/virtio_blk.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */
		#define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
		#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
		#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */

		struct virtio_blk_config
		{
		@@ -55,6 +56,13 @@ struct virtio_blk_outhdr
		__u64 sector;
		};

		struct virtio_scsi_inhdr {
		__u32 errors;
		__u32 data_len;
		__u32 sense_len;
		__u32 residual;
		};

		/* And this is the final byte of the write scatter-gather list. */
		#define VIRTIO_BLK_S_OK 0
		#define VIRTIO_BLK_S_IOERR 1

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