The actual recaculation of segments in __blk_recalc_rq_segments will do this check, so there is no point in forcing it if we know it won't succeed. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- block/bio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/bio.c b/block/bio.c index 7f7230140b66..d15a228d1bfc 100644 --- a/block/bio.c +++ b/block/bio.c @@ -729,7 +729,9 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page } /* If we may be able to merge these biovecs, force a recount */ - if (bio->bi_vcnt > 1 && biovec_phys_mergeable(bvec-1, bvec)) + if (bio->bi_vcnt > 1 && + biovec_phys_mergeable(bvec - 1, bvec) && + BIOVEC_SEG_BOUNDARY(q, bvec - 1, bvec)) bio_clear_flag(bio, BIO_SEG_VALID); done: -- 2.18.0