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Commit 26e49cfc authored by Kent Overstreet's avatar Kent Overstreet Committed by Jens Axboe
Browse files

block: pass iov_iter to the BLOCK_PC mapping functions 



Make use of a new interface provided by iov_iter, backed by
scatter-gather list of iovec, instead of the old interface based on
sg_iovec. Also use iov_iter_advance() instead of manual iteration.

This commit should contain only literal replacements, without
functional changes.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
[dpark: add more description in commit message]
Signed-off-by: default avatarDongsu Park <dongsu.park@profitbricks.com>
[hch: fixed to do a deep clone of the iov_iter, and to properly use
      the iov_iter direction]
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMing Lei <tom.leiming@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 1dfa0f68

block/bio.c

+67 −79
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ 
#include <linux/mempool.h>

#include <linux/workqueue.h>

#include <linux/cgroup.h>

#include <scsi/sg.h>		/* for struct sg_iovec */



#include <trace/events/block.h>
@@ -1022,21 +1021,11 @@ void bio_copy_data(struct bio *dst, struct bio *src) 
EXPORT_SYMBOL(bio_copy_data);



struct bio_map_data {

	int nr_sgvecs;

	int is_our_pages;

	struct sg_iovec sgvecs[];

	struct iov_iter iter;

	struct iovec iov[];

};



static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,

			     const struct sg_iovec *iov, int iov_count,

			     int is_our_pages)

{

	memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);

	bmd->nr_sgvecs = iov_count;

	bmd->is_our_pages = is_our_pages;

	bio->bi_private = bmd;

}



static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count,

					       gfp_t gfp_mask)

{
@@ -1044,36 +1033,33 @@ static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count, 
		return NULL;



	return kmalloc(sizeof(struct bio_map_data) +

		       sizeof(struct sg_iovec) * iov_count, gfp_mask);

		       sizeof(struct iovec) * iov_count, gfp_mask);

}



static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_count,

static int __bio_copy_iov(struct bio *bio, const struct iov_iter *iter,

			  int to_user, int from_user)

{

	int ret = 0, i;

	struct bio_vec *bvec;

	int iov_idx = 0;

	unsigned int iov_off = 0;

	struct iov_iter iov_iter = *iter;



	bio_for_each_segment_all(bvec, bio, i) {

		char *bv_addr = page_address(bvec->bv_page);

		unsigned int bv_len = bvec->bv_len;



		while (bv_len && iov_idx < iov_count) {

			unsigned int bytes;

			char __user *iov_addr;



			bytes = min_t(unsigned int,

				      iov[iov_idx].iov_len - iov_off, bv_len);

			iov_addr = iov[iov_idx].iov_base + iov_off;

		while (bv_len && iov_iter.count) {

			struct iovec iov = iov_iter_iovec(&iov_iter);

			unsigned int bytes = min_t(unsigned int, bv_len,

						   iov.iov_len);



			if (!ret) {

				if (to_user)

					ret = copy_to_user(iov_addr, bv_addr,

							   bytes);

					ret = copy_to_user(iov.iov_base,

							   bv_addr, bytes);



				if (from_user)

					ret = copy_from_user(bv_addr, iov_addr,

					ret = copy_from_user(bv_addr,

							     iov.iov_base,

							     bytes);



				if (ret)
@@ -1082,13 +1068,7 @@ static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_c 


			bv_len -= bytes;

			bv_addr += bytes;

			iov_addr += bytes;

			iov_off += bytes;



			if (iov[iov_idx].iov_len == iov_off) {

				iov_idx++;

				iov_off = 0;

			}

			iov_iter_advance(&iov_iter, bytes);

		}

	}
@@ -1122,7 +1102,7 @@ int bio_uncopy_user(struct bio *bio) 
		 * don't copy into a random user address space, just free.

		 */

		if (current->mm)

			ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs,

			ret = __bio_copy_iov(bio, &bmd->iter,

					     bio_data_dir(bio) == READ, 0);

		if (bmd->is_our_pages)

			bio_free_pages(bio);
@@ -1137,9 +1117,7 @@ EXPORT_SYMBOL(bio_uncopy_user); 
 *	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)

 *	@iov:	the iovec.

 *	@iov_count: number of elements in the iovec

 *	@write_to_vm: bool indicating writing to pages or not

 *	@iter:		iovec iterator

 *	@gfp_mask:	memory allocation flags

 *

 *	Prepares and returns a bio for indirect user io, bouncing data
@@ -1148,24 +1126,25 @@ EXPORT_SYMBOL(bio_uncopy_user); 
 */

struct bio *bio_copy_user_iov(struct request_queue *q,

			      struct rq_map_data *map_data,

			      const struct sg_iovec *iov, int iov_count,

			      int write_to_vm, gfp_t gfp_mask)

			      const struct iov_iter *iter,

			      gfp_t gfp_mask)

{

	struct bio_map_data *bmd;

	struct page *page;

	struct bio *bio;

	int i, ret;

	int nr_pages = 0;

	unsigned int len = 0;

	unsigned int len = iter->count;

	unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;



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

	for (i = 0; i < iter->nr_segs; i++) {

		unsigned long uaddr;

		unsigned long end;

		unsigned long start;



		uaddr = (unsigned long)iov[i].iov_base;

		end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;

		uaddr = (unsigned long) iter->iov[i].iov_base;

		end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1)

			>> PAGE_SHIFT;

		start = uaddr >> PAGE_SHIFT;



		/*
@@ -1175,22 +1154,31 @@ struct bio *bio_copy_user_iov(struct request_queue *q, 
			return ERR_PTR(-EINVAL);



		nr_pages += end - start;

		len += iov[i].iov_len;

	}



	if (offset)

		nr_pages++;



	bmd = bio_alloc_map_data(iov_count, gfp_mask);

	bmd = bio_alloc_map_data(iter->nr_segs, gfp_mask);

	if (!bmd)

		return ERR_PTR(-ENOMEM);



	/*

	 * We need to do a deep copy of the iov_iter including the iovecs.

	 * The caller provided iov might point to an on-stack or otherwise

	 * shortlived one.

	 */

	bmd->is_our_pages = map_data ? 0 : 1;

	memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs);

	iov_iter_init(&bmd->iter, iter->type, bmd->iov,

			iter->nr_segs, iter->count);



	ret = -ENOMEM;

	bio = bio_kmalloc(gfp_mask, nr_pages);

	if (!bio)

		goto out_bmd;



	if (!write_to_vm)

	if (iter->type & WRITE)

		bio->bi_rw |= REQ_WRITE;



	ret = 0;
@@ -1238,14 +1226,14 @@ struct bio *bio_copy_user_iov(struct request_queue *q, 
	/*

	 * success

	 */

	if ((!write_to_vm && (!map_data || !map_data->null_mapped)) ||

	if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) ||

	    (map_data && map_data->from_user)) {

		ret = __bio_copy_iov(bio, iov, iov_count, 0, 1);

		ret = __bio_copy_iov(bio, iter, 0, 1);

		if (ret)

			goto cleanup;

	}



	bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1);

	bio->bi_private = bmd;

	return bio;

cleanup:

	if (!map_data)
@@ -1258,19 +1246,21 @@ struct bio *bio_copy_user_iov(struct request_queue *q, 


static struct bio *__bio_map_user_iov(struct request_queue *q,

				      struct block_device *bdev,

				      const struct sg_iovec *iov, int iov_count,

				      int write_to_vm, gfp_t gfp_mask)

				      const struct iov_iter *iter,

				      gfp_t gfp_mask)

{

	int i, j;

	int j;

	int nr_pages = 0;

	struct page **pages;

	struct bio *bio;

	int cur_page = 0;

	int ret, offset;

	struct iov_iter i;

	struct iovec iov;



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

		unsigned long uaddr = (unsigned long)iov[i].iov_base;

		unsigned long len = iov[i].iov_len;

	iov_for_each(iov, i, *iter) {

		unsigned long uaddr = (unsigned long) iov.iov_base;

		unsigned long len = iov.iov_len;

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

		unsigned long start = uaddr >> PAGE_SHIFT;
@@ -1300,16 +1290,17 @@ static struct bio *__bio_map_user_iov(struct request_queue *q, 
	if (!pages)

		goto out;



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

		unsigned long uaddr = (unsigned long)iov[i].iov_base;

		unsigned long len = iov[i].iov_len;

	iov_for_each(iov, i, *iter) {

		unsigned long uaddr = (unsigned long) iov.iov_base;

		unsigned long len = iov.iov_len;

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

		unsigned long start = uaddr >> PAGE_SHIFT;

		const int local_nr_pages = end - start;

		const int page_limit = cur_page + local_nr_pages;



		ret = get_user_pages_fast(uaddr, local_nr_pages,

				write_to_vm, &pages[cur_page]);

				(iter->type & WRITE) != WRITE,

				&pages[cur_page]);

		if (ret < local_nr_pages) {

			ret = -EFAULT;

			goto out_unmap;
@@ -1349,7 +1340,7 @@ static struct bio *__bio_map_user_iov(struct request_queue *q, 
	/*

	 * set data direction, and check if mapped pages need bouncing

	 */

	if (!write_to_vm)

	if (iter->type & WRITE)

		bio->bi_rw |= REQ_WRITE;



	bio->bi_bdev = bdev;
@@ -1357,10 +1348,10 @@ static struct bio *__bio_map_user_iov(struct request_queue *q, 
	return bio;



 out_unmap:

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

		if(!pages[i])

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

		if (!pages[j])

			break;

		page_cache_release(pages[i]);

		page_cache_release(pages[j]);

	}

 out:

	kfree(pages);
@@ -1369,25 +1360,22 @@ static struct bio *__bio_map_user_iov(struct request_queue *q, 
}



/**

 *	bio_map_user_iov - map user sg_iovec table into bio

 *	bio_map_user_iov - map user iovec into bio

 *	@q:		the struct request_queue for the bio

 *	@bdev:		destination block device

 *	@iov:	the iovec.

 *	@iov_count: number of elements in the iovec

 *	@write_to_vm: bool indicating writing to pages or not

 *	@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.

 */

struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,

			     const struct sg_iovec *iov, int iov_count,

			     int write_to_vm, gfp_t gfp_mask)

			     const struct iov_iter *iter,

			     gfp_t gfp_mask)

{

	struct bio *bio;



	bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,

				 gfp_mask);

	bio = __bio_map_user_iov(q, bdev, iter, gfp_mask);

	if (IS_ERR(bio))

		return bio;

block/blk-map.c

+19 −19
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 
#include <linux/module.h>

#include <linux/bio.h>

#include <linux/blkdev.h>

#include <scsi/sg.h>		/* for struct sg_iovec */

#include <linux/uio.h>



#include "blk.h"
@@ -44,9 +44,7 @@ static int __blk_rq_unmap_user(struct bio *bio) 
 * @q:		request queue where request should be inserted

 * @rq:		request to map data to

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

 * @iov:	pointer to the iovec

 * @iov_count:	number of elements in the iovec

 * @len:	I/O byte count

 * @iter:	iovec iterator

 * @gfp_mask:	memory allocation flags

 *

 * Description:
@@ -63,20 +61,21 @@ static int __blk_rq_unmap_user(struct bio *bio) 
 *    unmapping.

 */

int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,

			struct rq_map_data *map_data, const struct sg_iovec *iov,

			int iov_count, unsigned int len, gfp_t gfp_mask)

			struct rq_map_data *map_data,

			const struct iov_iter *iter, gfp_t gfp_mask)

{

	struct bio *bio;

	int i, read = rq_data_dir(rq) == READ;

	int unaligned = 0;

	struct iov_iter i;

	struct iovec iov;



	if (!iov || iov_count <= 0)

	if (!iter || !iter->count)

		return -EINVAL;



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

		unsigned long uaddr = (unsigned long)iov[i].iov_base;

	iov_for_each(iov, i, *iter) {

		unsigned long uaddr = (unsigned long) iov.iov_base;



		if (!iov[i].iov_len)

		if (!iov.iov_len)

			return -EINVAL;



		/*
@@ -86,16 +85,15 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, 
			unaligned = 1;

	}



	if (unaligned || (q->dma_pad_mask & len) || map_data)

		bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,

					gfp_mask);

	if (unaligned || (q->dma_pad_mask & iter->count) || map_data)

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

	else

		bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);

		bio = bio_map_user_iov(q, NULL, iter, gfp_mask);



	if (IS_ERR(bio))

		return PTR_ERR(bio);



	if (bio->bi_iter.bi_size != len) {

	if (bio->bi_iter.bi_size != iter->count) {

		/*

		 * Grab an extra reference to this bio, as bio_unmap_user()

		 * expects to be able to drop it twice as it happens on the
@@ -121,12 +119,14 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq, 
		    struct rq_map_data *map_data, void __user *ubuf,

		    unsigned long len, gfp_t gfp_mask)

{

	struct sg_iovec iov;

	struct iovec iov;

	struct iov_iter i;



	iov.iov_base = (void __user *)ubuf;

	iov.iov_base = ubuf;

	iov.iov_len = len;

	iov_iter_init(&i, rq_data_dir(rq), &iov, 1, len);



	return blk_rq_map_user_iov(q, rq, map_data, &iov, 1, len, gfp_mask);

	return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask);

}

EXPORT_SYMBOL(blk_rq_map_user);

block/scsi_ioctl.c

+4 −13
Original line number Diff line number Diff line
@@ -332,7 +332,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, 


	ret = 0;

	if (hdr->iovec_count) {

		size_t iov_data_len;

		struct iov_iter i;

		struct iovec *iov = NULL;



		ret = rw_copy_check_uvector(-1, hdr->dxferp, hdr->iovec_count,
@@ -342,20 +342,11 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, 
			goto out_free_cdb;

		}



		iov_data_len = ret;

		ret = 0;



		/* SG_IO howto says that the shorter of the two wins */

		if (hdr->dxfer_len < iov_data_len) {

			hdr->iovec_count = iov_shorten(iov,

						       hdr->iovec_count,

						       hdr->dxfer_len);

			iov_data_len = hdr->dxfer_len;

		}

		iov_iter_init(&i, rq_data_dir(rq), iov, hdr->iovec_count,

			      min_t(unsigned, ret, hdr->dxfer_len));



		ret = blk_rq_map_user_iov(q, rq, NULL, (struct sg_iovec *) iov,

					  hdr->iovec_count,

					  iov_data_len, GFP_KERNEL);

		ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);

		kfree(iov);

	} else if (hdr->dxfer_len)

		ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,

drivers/scsi/sg.c

+6 −9
Original line number Diff line number Diff line
@@ -1734,22 +1734,19 @@ sg_start_req(Sg_request *srp, unsigned char *cmd) 
	}



	if (iov_count) {

		int len, size = sizeof(struct sg_iovec) * iov_count;

		int size = sizeof(struct iovec) * iov_count;

		struct iovec *iov;

		struct iov_iter i;



		iov = memdup_user(hp->dxferp, size);

		if (IS_ERR(iov))

			return PTR_ERR(iov);



		len = iov_length(iov, iov_count);

		if (hp->dxfer_len < len) {

			iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);

			len = hp->dxfer_len;

		}

		iov_iter_init(&i, rw, iov, iov_count,

			      min_t(size_t, hp->dxfer_len,

				    iov_length(iov, iov_count)));



		res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,

					  iov_count,

					  len, GFP_ATOMIC);

		res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);

		kfree(iov);

	} else

		res = blk_rq_map_user(q, rq, md, hp->dxferp,

include/linux/bio.h

+3 −4
Original line number Diff line number Diff line
@@ -428,11 +428,10 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); 
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,

			   unsigned int, unsigned int);

extern int bio_get_nr_vecs(struct block_device *);

struct sg_iovec;

struct rq_map_data;

extern struct bio *bio_map_user_iov(struct request_queue *,

				    struct block_device *,

				    const struct sg_iovec *, int, int, gfp_t);

				    const struct iov_iter *, gfp_t);

extern void bio_unmap_user(struct bio *);

extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,

				gfp_t);
@@ -462,8 +461,8 @@ extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); 


extern struct bio *bio_copy_user_iov(struct request_queue *,

				     struct rq_map_data *,

				     const struct sg_iovec *,

				     int, int, gfp_t);

				     const struct iov_iter *,

				     gfp_t);

extern int bio_uncopy_user(struct bio *);

void zero_fill_bio(struct bio *bio);

extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);