Commit 2c9ecdf4 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Jens Axboe
Browse files

bsg: add bidi support 



bsg uses the rq->next_rq pointer for a bidi request.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent abae1fde

block/bsg.c

+49 −25
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ struct bsg_command { 
	struct list_head list;

	struct request *rq;

	struct bio *bio;

	struct bio *bidi_bio;

	int err;

	struct sg_io_v4 hdr;

	struct sg_io_v4 __user *uhdr;
@@ -243,16 +244,6 @@ bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw) 
	if (hdr->protocol || hdr->subprotocol)

		return -EINVAL;



	/*

	 * looks sane, if no data then it should be fine from our POV

	 */

	if (!hdr->dout_xfer_len && !hdr->din_xfer_len)

		return 0;



	/* not supported currently */

	if (hdr->dout_xfer_len && hdr->din_xfer_len)

		return -EINVAL;



	*rw = hdr->dout_xfer_len ? WRITE : READ;



	return 0;
@@ -265,7 +256,7 @@ static struct request * 
bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)

{

	request_queue_t *q = bd->queue;

	struct request *rq;

	struct request *rq, *next_rq = NULL;

	int ret, rw = 0; /* shut up gcc */

	unsigned int dxfer_len;

	void *dxferp = NULL;
@@ -282,11 +273,30 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr) 
	 * map scatter-gather elements seperately and string them to request

	 */

	rq = blk_get_request(q, rw, GFP_KERNEL);

	if (!rq)

		return ERR_PTR(-ENOMEM);

	ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,

						       &bd->flags));

	if (ret) {

		blk_put_request(rq);

		return ERR_PTR(ret);

	if (ret)

		goto out;



	if (rw == WRITE && hdr->din_xfer_len) {

		if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {

			ret = -EOPNOTSUPP;

			goto out;

		}



		next_rq = blk_get_request(q, READ, GFP_KERNEL);

		if (!next_rq) {

			ret = -ENOMEM;

			goto out;

		}

		rq->next_rq = next_rq;



		dxferp = (void*)(unsigned long)hdr->din_xferp;

		ret =  blk_rq_map_user(q, next_rq, dxferp, hdr->din_xfer_len);

		if (ret)

			goto out;

	}



	if (hdr->dout_xfer_len) {
@@ -300,14 +310,17 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr) 


	if (dxfer_len) {

		ret = blk_rq_map_user(q, rq, dxferp, dxfer_len);

		if (ret) {

			dprintk("failed map at %d\n", ret);

			blk_put_request(rq);

			rq = ERR_PTR(ret);

		}

		if (ret)

			goto out;

	}



	return rq;

out:

	blk_put_request(rq);

	if (next_rq) {

		blk_rq_unmap_user(next_rq->bio);

		blk_put_request(next_rq);

	}

	return ERR_PTR(ret);

}



/*
@@ -346,6 +359,8 @@ static void bsg_add_command(struct bsg_device *bd, request_queue_t *q, 
	 */

	bc->rq = rq;

	bc->bio = rq->bio;

	if (rq->next_rq)

		bc->bidi_bio = rq->next_rq->bio;

	bc->hdr.duration = jiffies;

	spin_lock_irq(&bd->lock);

	list_add_tail(&bc->list, &bd->busy_list);
@@ -402,7 +417,7 @@ static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd) 
}



static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,

				    struct bio *bio)

				    struct bio *bio, struct bio *bidi_bio)

{

	int ret = 0;
@@ -431,6 +446,11 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, 
			ret = -EFAULT;

	}



	if (rq->next_rq) {

		blk_rq_unmap_user(bidi_bio);

		blk_put_request(rq->next_rq);

	}



	blk_rq_unmap_user(bio);

	blk_put_request(rq);
@@ -477,7 +497,8 @@ static int bsg_complete_all_commands(struct bsg_device *bd) 
		if (IS_ERR(bc))

			break;



		tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio);

		tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,

						bc->bidi_bio);

		if (!ret)

			ret = tret;
@@ -511,7 +532,8 @@ __bsg_read(char __user *buf, size_t count, struct bsg_device *bd, 
		 * after completing the request. so do that here,

		 * bsg_complete_work() cannot do that for us

		 */

		ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio);

		ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,

					       bc->bidi_bio);



		if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr)))

			ret = -EFAULT;
@@ -868,7 +890,7 @@ bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 
	}

	case SG_IO: {

		struct request *rq;

		struct bio *bio;

		struct bio *bio, *bidi_bio = NULL;

		struct sg_io_v4 hdr;



		if (copy_from_user(&hdr, uarg, sizeof(hdr)))
@@ -879,8 +901,10 @@ bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 
			return PTR_ERR(rq);



		bio = rq->bio;

		if (rq->next_rq)

			bidi_bio = rq->next_rq->bio;

		blk_execute_rq(bd->queue, NULL, rq, 0);

		blk_complete_sgv4_hdr_rq(rq, &hdr, bio);

		blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);



		if (copy_to_user(uarg, &hdr, sizeof(hdr)))

			return -EFAULT;