Commit ae29333f authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by David Sterba
Browse files

block: add bio_add_zone_append_page 



Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which
is intended to be used by file systems that directly add pages to a bio
instead of using bio_iov_iter_get_pages().

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 72c9925f

block/bio.c

+33 −0
Original line number Diff line number Diff line
@@ -851,6 +851,39 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, 
}

EXPORT_SYMBOL(bio_add_pc_page);



/**

 * bio_add_zone_append_page - attempt to add page to zone-append bio

 * @bio: destination bio

 * @page: page to add

 * @len: vec entry length

 * @offset: vec entry offset

 *

 * Attempt to add a page to the bio_vec maplist of a bio that will be submitted

 * for a zone-append request. This can fail for a number of reasons, such as the

 * bio being full or the target block device is not a zoned block device or

 * other limitations of the target block device. The target block device must

 * allow bio's up to PAGE_SIZE, so it is always possible to add a single page

 * to an empty bio.

 *

 * Returns: number of bytes added to the bio, or 0 in case of a failure.

 */

int bio_add_zone_append_page(struct bio *bio, struct page *page,

			     unsigned int len, unsigned int offset)

{

	struct request_queue *q = bio->bi_disk->queue;

	bool same_page = false;



	if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_ZONE_APPEND))

		return 0;



	if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))

		return 0;



	return bio_add_hw_page(q, bio, page, len, offset,

			       queue_max_zone_append_sectors(q), &same_page);

}

EXPORT_SYMBOL_GPL(bio_add_zone_append_page);



/**

 * __bio_try_merge_page - try appending data to an existing bvec.

 * @bio: destination bio

include/linux/bio.h

+2 −0
Original line number Diff line number Diff line
@@ -455,6 +455,8 @@ void bio_chain(struct bio *, struct bio *); 
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);

int bio_add_zone_append_page(struct bio *bio, struct page *page,

			     unsigned int len, unsigned int offset);

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,