Commit d8207640 authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Jens Axboe
Browse files

iov_iter: introduce iov_iter_get_pages_[alloc_]flags() 



Add iov_iter_get_pages_flags() and iov_iter_get_pages_alloc_flags()
which take a flags argument that is passed to get_user_pages_fast().

This is so that FOLL_PCI_P2PDMA can be passed when appropriate.

Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221021174116.7200-4-logang@deltatee.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4003f107

include/linux/uio.h

+6 −0
Original line number Diff line number Diff line
@@ -247,8 +247,14 @@ void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode 
void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count);

void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray,

		     loff_t start, size_t count);

ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,

		size_t maxsize, unsigned maxpages, size_t *start,

		unsigned gup_flags);

ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages,

			size_t maxsize, unsigned maxpages, size_t *start);

ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,

		struct page ***pages, size_t maxsize, size_t *start,

		unsigned gup_flags);

ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages,

			size_t maxsize, size_t *start);

int iov_iter_npages(const struct iov_iter *i, int maxpages);

lib/iov_iter.c

+24 −8
Original line number Diff line number Diff line
@@ -1430,7 +1430,8 @@ static struct page *first_bvec_segment(const struct iov_iter *i, 


static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,

		   struct page ***pages, size_t maxsize,

		   unsigned int maxpages, size_t *start)

		   unsigned int maxpages, size_t *start,

		   unsigned int gup_flags)

{

	unsigned int n;
@@ -1442,7 +1443,6 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, 
		maxsize = MAX_RW_COUNT;



	if (likely(user_backed_iter(i))) {

		unsigned int gup_flags = 0;

		unsigned long addr;

		int res;
@@ -1492,33 +1492,49 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, 
	return -EFAULT;

}



ssize_t iov_iter_get_pages2(struct iov_iter *i,

ssize_t iov_iter_get_pages(struct iov_iter *i,

		   struct page **pages, size_t maxsize, unsigned maxpages,

		   size_t *start)

		   size_t *start, unsigned gup_flags)

{

	if (!maxpages)

		return 0;

	BUG_ON(!pages);



	return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, start);

	return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages,

					  start, gup_flags);

}

EXPORT_SYMBOL_GPL(iov_iter_get_pages);



ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages,

		size_t maxsize, unsigned maxpages, size_t *start)

{

	return iov_iter_get_pages(i, pages, maxsize, maxpages, start, 0);

}

EXPORT_SYMBOL(iov_iter_get_pages2);



ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i,

ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,

		   struct page ***pages, size_t maxsize,

		   size_t *start)

		   size_t *start, unsigned gup_flags)

{

	ssize_t len;



	*pages = NULL;



	len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start);

	len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start,

					 gup_flags);

	if (len <= 0) {

		kvfree(*pages);

		*pages = NULL;

	}

	return len;

}

EXPORT_SYMBOL_GPL(iov_iter_get_pages_alloc);



ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i,

		struct page ***pages, size_t maxsize, size_t *start)

{

	return iov_iter_get_pages_alloc(i, pages, maxsize, start, 0);

}

EXPORT_SYMBOL(iov_iter_get_pages_alloc2);



size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,