Commit 1fe0640f authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

rnbd-srv: simplify bio mapping in process_rdma 



The memory mapped in process_rdma is contiguous, so there is no need
to loop over bio_add_page.  Remove rnbd_bio_map_kern and just open code
the bio allocation and mapping in the caller.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJack Wang <jinpu.wang@ionons.com>
Tested-by: default avatarJack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20220124091107.642561-11-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4b1dc86d

drivers/block/rnbd/rnbd-srv-dev.c

+0 −57
Original line number Diff line number Diff line
@@ -44,60 +44,3 @@ void rnbd_dev_close(struct rnbd_dev *dev) 
	blkdev_put(dev->bdev, dev->blk_open_flags);

	kfree(dev);

}
 


void rnbd_dev_bi_end_io(struct bio *bio)

{

	struct rnbd_dev_blk_io *io = bio->bi_private;



	rnbd_endio(io->priv, blk_status_to_errno(bio->bi_status));

	bio_put(bio);

}



/**

 *	rnbd_bio_map_kern	-	map kernel address into bio

 *	@data: pointer to buffer to map

 *	@bs: bio_set to use.

 *	@len: length in bytes

 *	@gfp_mask: allocation flags for bio allocation

 *

 *	Map the kernel address into a bio suitable for io to a block

 *	device. Returns an error pointer in case of error.

 */

struct bio *rnbd_bio_map_kern(void *data, struct bio_set *bs,

			      unsigned int len, gfp_t gfp_mask)

{

	unsigned long kaddr = (unsigned long)data;

	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;

	unsigned long start = kaddr >> PAGE_SHIFT;

	const int nr_pages = end - start;

	int offset, i;

	struct bio *bio;



	bio = bio_alloc_bioset(gfp_mask, nr_pages, bs);

	if (!bio)

		return ERR_PTR(-ENOMEM);



	offset = offset_in_page(kaddr);

	for (i = 0; i < nr_pages; i++) {

		unsigned int bytes = PAGE_SIZE - offset;



		if (len <= 0)

			break;



		if (bytes > len)

			bytes = len;



		if (bio_add_page(bio, virt_to_page(data), bytes,

				    offset) < bytes) {

			/* we don't support partial mappings */

			bio_put(bio);

			return ERR_PTR(-EINVAL);

		}



		data += bytes;

		len -= bytes;

		offset = 0;

	}



	return bio;

}

drivers/block/rnbd/rnbd-srv-dev.h

+0 −5
Original line number Diff line number Diff line
@@ -41,11 +41,6 @@ void rnbd_dev_close(struct rnbd_dev *dev); 


void rnbd_endio(void *priv, int error);



void rnbd_dev_bi_end_io(struct bio *bio);



struct bio *rnbd_bio_map_kern(void *data, struct bio_set *bs,

			      unsigned int len, gfp_t gfp_mask);



static inline int rnbd_dev_get_max_segs(const struct rnbd_dev *dev)

{

	return queue_max_segments(bdev_get_queue(dev->bdev));

drivers/block/rnbd/rnbd-srv.c

+16 −7
Original line number Diff line number Diff line
@@ -114,6 +114,14 @@ rnbd_get_sess_dev(int dev_id, struct rnbd_srv_session *srv_sess) 
	return sess_dev;

}



static void rnbd_dev_bi_end_io(struct bio *bio)

{

	struct rnbd_dev_blk_io *io = bio->bi_private;



	rnbd_endio(io->priv, blk_status_to_errno(bio->bi_status));

	bio_put(bio);

}



static int process_rdma(struct rnbd_srv_session *srv_sess,

			struct rtrs_srv_op *id, void *data, u32 datalen,

			const void *usr, size_t usrlen)
@@ -144,12 +152,12 @@ static int process_rdma(struct rnbd_srv_session *srv_sess, 
	priv->sess_dev = sess_dev;

	priv->id = id;



	/* Generate bio with pages pointing to the rdma buffer */

	bio = rnbd_bio_map_kern(data, sess_dev->rnbd_dev->ibd_bio_set, datalen, GFP_KERNEL);

	if (IS_ERR(bio)) {

		err = PTR_ERR(bio);

		rnbd_srv_err(sess_dev, "Failed to generate bio, err: %d\n", err);

		goto sess_dev_put;

	bio = bio_alloc_bioset(GFP_KERNEL, 1, sess_dev->rnbd_dev->ibd_bio_set);

	if (bio_add_page(bio, virt_to_page(data), datalen,

			offset_in_page(data)) != datalen) {

		rnbd_srv_err(sess_dev, "Failed to map data to bio\n");

		err = -EINVAL;

		goto bio_put;

	}



	io = container_of(bio, struct rnbd_dev_blk_io, bio);
@@ -170,7 +178,8 @@ static int process_rdma(struct rnbd_srv_session *srv_sess, 


	return 0;



sess_dev_put:

bio_put:

	bio_put(bio);

	rnbd_put_sess_dev(sess_dev);

err:

	kfree(priv);