There is a hole at the end of 'struct bvec_iter', so put a new field here and we can save cookie returned from submit_bio() here for supporting bio based polling.
This way can avoid to extend bio unnecessarily. Meantime add two helpers to get/set this field. Reviewed-by: Hannes Reinecke <[email protected]> Signed-off-by: Ming Lei <[email protected]> --- block/blk.h | 10 ++++++++++ include/linux/bvec.h | 8 ++++++++ 2 files changed, 18 insertions(+) diff --git a/block/blk.h b/block/blk.h index 35901cee709d..c1d8456656df 100644 --- a/block/blk.h +++ b/block/blk.h @@ -395,4 +395,14 @@ static inline void blk_create_io_poll_context(struct request_queue *q) bio_poll_ctx_alloc(ioc); } +static inline unsigned int bio_get_private_data(struct bio *bio) +{ + return bio->bi_iter.bi_private_data; +} + +static inline void bio_set_private_data(struct bio *bio, unsigned int data) +{ + bio->bi_iter.bi_private_data = data; +} + #endif /* BLK_INTERNAL_H */ diff --git a/include/linux/bvec.h b/include/linux/bvec.h index ff832e698efb..547ad7526960 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -43,6 +43,14 @@ struct bvec_iter { unsigned int bi_bvec_done; /* number of bytes completed in current bvec */ + + /* + * There is a hole at the end of bvec_iter, add one new field to hold + * something which isn't related with 'bvec_iter', so that we can + * avoid extending bio. So far this new field is used for bio based + * polling, we will store returning value of submit_bio() here. + */ + unsigned int bi_private_data; }; struct bvec_iter_all { -- 2.29.2 -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
