On Mon, May 13, 2019 at 08:37:47AM +0200, Christoph Hellwig wrote:
> We fundamentally do not have a maximum segement size for devices with a
> virt boundary. So don't bother checking it, especially given that the
> existing checks didn't properly work to start with as we never update
> bi_seg_back_size after a successful merge, and for front merges would
.bi_seg_back_size is only needed to update in case of single segment
request.
However, ll_new_hw_segment() does not merge segment, so the existing
check works fine.
> have had to check bi_seg_front_size anyway.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> block/blk-merge.c | 19 +------------------
> 1 file changed, 1 insertion(+), 18 deletions(-)
>
> diff --git a/block/blk-merge.c b/block/blk-merge.c
> index 80a5a0facb87..eee2c02c50ce 100644
> --- a/block/blk-merge.c
> +++ b/block/blk-merge.c
> @@ -12,23 +12,6 @@
>
> #include "blk.h"
>
> -/*
> - * Check if the two bvecs from two bios can be merged to one segment. If yes,
> - * no need to check gap between the two bios since the 1st bio and the 1st bvec
> - * in the 2nd bio can be handled in one segment.
> - */
> -static inline bool bios_segs_mergeable(struct request_queue *q,
> - struct bio *prev, struct bio_vec *prev_last_bv,
> - struct bio_vec *next_first_bv)
> -{
> - if (!biovec_phys_mergeable(q, prev_last_bv, next_first_bv))
> - return false;
> - if (prev->bi_seg_back_size + next_first_bv->bv_len >
> - queue_max_segment_size(q))
> - return false;
> - return true;
> -}
> -
> static inline bool bio_will_gap(struct request_queue *q,
> struct request *prev_rq, struct bio *prev, struct bio *next)
> {
> @@ -60,7 +43,7 @@ static inline bool bio_will_gap(struct request_queue *q,
> */
> bio_get_last_bvec(prev, &pb);
> bio_get_first_bvec(next, &nb);
> - if (bios_segs_mergeable(q, prev, &pb, &nb))
> + if (biovec_phys_mergeable(q, &pb, &nb))
> return false;
> return __bvec_gap_to_prev(q, &pb, nb.bv_offset);
> }
> --
> 2.20.1
>
The patch itself is good, if the commit log is fixed:
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
thanks,
Ming
