Commit c7d57ab1 authored by Al Viro's avatar Al Viro
Browse files

hugetlbfs: copy_page_to_iter() can deal with compound pages 



... since April 2021

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent f0f6b614

fs/hugetlbfs/inode.c

+1 −30
Original line number Diff line number Diff line
@@ -284,35 +284,6 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 
}

#endif



static size_t

hugetlbfs_read_actor(struct page *page, unsigned long offset,

			struct iov_iter *to, unsigned long size)

{

	size_t copied = 0;

	int i, chunksize;



	/* Find which 4k chunk and offset with in that chunk */

	i = offset >> PAGE_SHIFT;

	offset = offset & ~PAGE_MASK;



	while (size) {

		size_t n;

		chunksize = PAGE_SIZE;

		if (offset)

			chunksize -= offset;

		if (chunksize > size)

			chunksize = size;

		n = copy_page_to_iter(&page[i], offset, chunksize, to);

		copied += n;

		if (n != chunksize)

			return copied;

		offset = 0;

		size -= chunksize;

		i++;

	}

	return copied;

}



/*

 * Support for read() - Find the page attached to f_mapping and copy out the

 * data. Its *very* similar to generic_file_buffered_read(), we can't use that
@@ -363,7 +334,7 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to) 
			/*

			 * We have the page, copy it to user space buffer.

			 */

			copied = hugetlbfs_read_actor(page, offset, to, nr);

			copied = copy_page_to_iter(page, offset, nr, to);

			put_page(page);

		}

		offset += copied;