Commit 7589ad67 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: remove __blk_rq_map_user_iov 



Just duplicate a small amount of code in the low-level map into the bio
and copy to the bio routines, leading to much easier to follow and
maintain code, and better shared error handling.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 7b63c052

block/blk-map.c

+54 −90
Original line number Diff line number Diff line
@@ -127,24 +127,12 @@ static int bio_uncopy_user(struct bio *bio) 
	return ret;

}



/**

 *	bio_copy_user_iov	-	copy user data to bio

 *	@q:		destination block queue

 *	@map_data:	pointer to the rq_map_data holding pages (if necessary)

 *	@iter:		iovec iterator

 *	@gfp_mask:	memory allocation flags

 *

 *	Prepares and returns a bio for indirect user io, bouncing data

 *	to/from kernel pages as necessary. Must be paired with

 *	call bio_uncopy_user() on io completion.

 */

static struct bio *bio_copy_user_iov(struct request_queue *q,

		struct rq_map_data *map_data, struct iov_iter *iter,

		gfp_t gfp_mask)

static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,

		struct iov_iter *iter, gfp_t gfp_mask)

{

	struct bio_map_data *bmd;

	struct page *page;

	struct bio *bio;

	struct bio *bio, *bounce_bio;

	int i = 0, ret;

	int nr_pages;

	unsigned int len = iter->count;
@@ -152,7 +140,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, 


	bmd = bio_alloc_map_data(iter, gfp_mask);

	if (!bmd)

		return ERR_PTR(-ENOMEM);

		return -ENOMEM;



	/*

	 * We need to do a deep copy of the iov_iter including the iovecs.
@@ -169,8 +157,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, 
	bio = bio_kmalloc(gfp_mask, nr_pages);

	if (!bio)

		goto out_bmd;



	ret = 0;

	bio->bi_opf |= req_op(rq);



	if (map_data) {

		nr_pages = 1 << map_data->page_order;
@@ -187,7 +174,7 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, 
		if (map_data) {

			if (i == map_data->nr_entries * nr_pages) {

				ret = -ENOMEM;

				break;

				goto cleanup;

			}



			page = map_data->pages[i / nr_pages];
@@ -195,14 +182,14 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, 


			i++;

		} else {

			page = alloc_page(q->bounce_gfp | gfp_mask);

			page = alloc_page(rq->q->bounce_gfp | gfp_mask);

			if (!page) {

				ret = -ENOMEM;

				break;

				goto cleanup;

			}

		}



		if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {

		if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) {

			if (!map_data)

				__free_page(page);

			break;
@@ -212,9 +199,6 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, 
		offset = 0;

	}



	if (ret)

		goto cleanup;



	if (map_data)

		map_data->offset += bio->bi_iter.bi_size;
@@ -236,39 +220,42 @@ static struct bio *bio_copy_user_iov(struct request_queue *q, 
	bio->bi_private = bmd;

	if (map_data && map_data->null_mapped)

		bmd->is_null_mapped = true;

	return bio;



	bounce_bio = bio;

	ret = blk_rq_append_bio(rq, &bounce_bio);

	if (ret)

		goto cleanup;



	/*

	 * We link the bounce buffer in and could have to traverse it later, so

	 * we have to get a ref to prevent it from being freed

	 */

	bio_get(bounce_bio);

	return 0;

cleanup:

	if (!map_data)

		bio_free_pages(bio);

	bio_put(bio);

out_bmd:

	kfree(bmd);

	return ERR_PTR(ret);

	return ret;

}



/**

 *	bio_map_user_iov - map user iovec into bio

 *	@q:		the struct request_queue for the bio

 *	@iter:		iovec iterator

 *	@gfp_mask:	memory allocation flags

 *

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

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

 */

static struct bio *bio_map_user_iov(struct request_queue *q,

		struct iov_iter *iter, gfp_t gfp_mask)

static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,

		gfp_t gfp_mask)

{

	unsigned int max_sectors = queue_max_hw_sectors(q);

	int j;

	struct bio *bio;

	unsigned int max_sectors = queue_max_hw_sectors(rq->q);

	struct bio *bio, *bounce_bio;

	int ret;

	int j;



	if (!iov_iter_count(iter))

		return ERR_PTR(-EINVAL);

		return -EINVAL;



	bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES));

	if (!bio)

		return ERR_PTR(-ENOMEM);

		return -ENOMEM;

	bio->bi_opf |= req_op(rq);



	while (iov_iter_count(iter)) {

		struct page **pages;
@@ -284,7 +271,7 @@ static struct bio *bio_map_user_iov(struct request_queue *q, 


		npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);



		if (unlikely(offs & queue_dma_alignment(q))) {

		if (unlikely(offs & queue_dma_alignment(rq->q))) {

			ret = -EINVAL;

			j = 0;

		} else {
@@ -296,7 +283,7 @@ static struct bio *bio_map_user_iov(struct request_queue *q, 
				if (n > bytes)

					n = bytes;



				if (!bio_add_hw_page(q, bio, page, n, offs,

				if (!bio_add_hw_page(rq->q, bio, page, n, offs,

						     max_sectors, &same_page)) {

					if (same_page)

						put_page(page);
@@ -323,18 +310,30 @@ static struct bio *bio_map_user_iov(struct request_queue *q, 
	bio_set_flag(bio, BIO_USER_MAPPED);



	/*

	 * subtle -- if bio_map_user_iov() ended up bouncing a bio,

	 * it would normally disappear when its bi_end_io is run.

	 * however, we need it for the unmap, so grab an extra

	 * reference to it

	 * Subtle: if we end up needing to bounce a bio, it would normally

	 * disappear when its bi_end_io is run.  However, we need the original

	 * bio for the unmap, so grab an extra reference to it

	 */

	bio_get(bio);

	return bio;



	bounce_bio = bio;

	ret = blk_rq_append_bio(rq, &bounce_bio);

	if (ret)

		goto out_put_orig;



	/*

	 * We link the bounce buffer in and could have to traverse it

	 * later, so we have to get a ref to prevent it from being freed

	 */

	bio_get(bounce_bio);

	return 0;



 out_put_orig:

	bio_put(bio);

 out_unmap:

	bio_release_pages(bio, false);

	bio_put(bio);

	return ERR_PTR(ret);

	return ret;

}



/**
@@ -558,44 +557,6 @@ int blk_rq_append_bio(struct request *rq, struct bio **bio) 
}

EXPORT_SYMBOL(blk_rq_append_bio);



static int __blk_rq_map_user_iov(struct request *rq,

		struct rq_map_data *map_data, struct iov_iter *iter,

		gfp_t gfp_mask, bool copy)

{

	struct request_queue *q = rq->q;

	struct bio *bio, *orig_bio;

	int ret;



	if (copy)

		bio = bio_copy_user_iov(q, map_data, iter, gfp_mask);

	else

		bio = bio_map_user_iov(q, iter, gfp_mask);



	if (IS_ERR(bio))

		return PTR_ERR(bio);



	bio->bi_opf &= ~REQ_OP_MASK;

	bio->bi_opf |= req_op(rq);



	orig_bio = bio;



	/*

	 * We link the bounce buffer in and could have to traverse it

	 * later so we have to get a ref to prevent it from being freed

	 */

	ret = blk_rq_append_bio(rq, &bio);

	if (ret) {

		if (copy)

			bio_uncopy_user(orig_bio);

		else

			bio_unmap_user(orig_bio);

		return ret;

	}

	bio_get(bio);



	return 0;

}



/**

 * blk_rq_map_user_iov - map user data to a request, for passthrough requests

 * @q:		request queue where request should be inserted
@@ -639,7 +600,10 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, 


	i = *iter;

	do {

		ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy);

		if (copy)

			ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask);

		else

			ret = bio_map_user_iov(rq, &i, gfp_mask);

		if (ret)

			goto unmap_rq;

		if (!bio)

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