[PATCH 1/9] block: export __bio_iov_append_get_pages()

[Damien Le Moal]

On 2020/11/26 11:42, Chaitanya Kulkarni wrote:
> In this prep patch we exoprt the __bio_iov_append_get_pages() so that
> NVMeOF target can use the core logic of building Zone Append bios for
> REQ_OP_ZONE_APPEND without repeating the code.
> 
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
> ---
>  block/bio.c         | 3 ++-
>  include/linux/bio.h | 1 +
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/block/bio.c b/block/bio.c
> index fa01bef35bb1..de356fa28315 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -1033,7 +1033,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
>  	return 0;
>  }
>  
> -static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
> +int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
>  {
>  	unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;
>  	unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
> @@ -1079,6 +1079,7 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
>  	iov_iter_advance(iter, size - left);
>  	return ret;
>  }
> +EXPORT_SYMBOL_GPL(__bio_iov_append_get_pages);

Why not use bio_iov_iter_get_pages() which is already exported ? As long as the
bio op is set to REQ_OP_ZONE_APPEND when bio_iov_iter_get_pages() is called,
__bio_iov_append_get_pages() will be used in that function.

>  
>  /**
>   * bio_iov_iter_get_pages - add user or kernel pages to a bio
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index c6d765382926..47247c1b0b85 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -446,6 +446,7 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page,
>  		unsigned int len, unsigned int off, bool *same_page);
>  void __bio_add_page(struct bio *bio, struct page *page,
>  		unsigned int len, unsigned int off);
> +int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter);
>  int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
>  void bio_release_pages(struct bio *bio, bool mark_dirty);
>  extern void bio_set_pages_dirty(struct bio *bio);
> 


-- 
Damien Le Moal
Western Digital Research