From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Ming Lei To: Jens Axboe , Christoph Hellwig , Alexander Viro , Kent Overstreet Cc: David Sterba , Huang Ying , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Theodore Ts'o , "Darrick J . Wong" , Coly Li , Filipe Manana , Ming Lei Subject: [RESEND PATCH V5 15/33] block: introduce bio_clone_seg_bioset() Date: Fri, 25 May 2018 11:46:03 +0800 Message-Id: <20180525034621.31147-16-ming.lei@redhat.com> In-Reply-To: <20180525034621.31147-1-ming.lei@redhat.com> References: <20180525034621.31147-1-ming.lei@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: There is one use case(DM) which requires to clone bio segment by segement, so introduce this API. Signed-off-by: Ming Lei --- block/bio.c | 56 +++++++++++++++++++++++++++++++++++++++-------------- include/linux/bio.h | 1 + 2 files changed, 43 insertions(+), 14 deletions(-) diff --git a/block/bio.c b/block/bio.c index d0debb22ee34..63d4fe85f42e 100644 --- a/block/bio.c +++ b/block/bio.c @@ -644,21 +644,13 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) } EXPORT_SYMBOL(bio_clone_fast); -/** - * bio_clone_bioset - clone a bio - * @bio_src: bio to clone - * @gfp_mask: allocation priority - * @bs: bio_set to allocate from - * - * Clone bio. Caller will own the returned bio, but not the actual data it - * points to. Reference count of returned bio will be one. - */ -struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, - struct bio_set *bs) +static struct bio *__bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, + struct bio_set *bs, bool page) { struct bvec_iter iter; struct bio_vec bv; struct bio *bio; + int nr_vecs = page ? bio_pages(bio_src) : bio_segments(bio_src); /* * Pre immutable biovecs, __bio_clone() used to just do a memcpy from @@ -682,7 +674,7 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, * __bio_clone_fast() anyways. */ - bio = bio_alloc_bioset(gfp_mask, bio_pages(bio_src), bs); + bio = bio_alloc_bioset(gfp_mask, nr_vecs, bs); if (!bio) return NULL; bio->bi_disk = bio_src->bi_disk; @@ -700,8 +692,13 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0]; break; default: - bio_for_each_page(bv, bio_src, iter) - bio->bi_io_vec[bio->bi_vcnt++] = bv; + if (page) { + bio_for_each_page(bv, bio_src, iter) + bio->bi_io_vec[bio->bi_vcnt++] = bv; + } else { + bio_for_each_segment(bv, bio_src, iter) + bio->bi_io_vec[bio->bi_vcnt++] = bv; + } break; } @@ -719,9 +716,40 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, return bio; } + +/** + * bio_clone_bioset - clone a bio + * @bio_src: bio to clone + * @gfp_mask: allocation priority + * @bs: bio_set to allocate from + * + * Clone bio. Caller will own the returned bio, but not the actual data it + * points to. Reference count of returned bio will be one. + */ +struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, + struct bio_set *bs) +{ + return __bio_clone_bioset(bio_src, gfp_mask, bs, true); +} EXPORT_SYMBOL(bio_clone_bioset); /** + * bio_clone_seg_bioset - clone a bio segment by segment + * @bio_src: bio to clone + * @gfp_mask: allocation priority + * @bs: bio_set to allocate from + * + * Clone bio. Caller will own the returned bio, but not the actual data it + * points to. Reference count of returned bio will be one. + */ +struct bio *bio_clone_seg_bioset(struct bio *bio_src, gfp_t gfp_mask, + struct bio_set *bs) +{ + return __bio_clone_bioset(bio_src, gfp_mask, bs, false); +} +EXPORT_SYMBOL(bio_clone_seg_bioset); + +/** * bio_add_pc_page - attempt to add page to bio * @q: the target queue * @bio: destination bio diff --git a/include/linux/bio.h b/include/linux/bio.h index b24c00f99c9c..61a04c131641 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -475,6 +475,7 @@ extern void bio_put(struct bio *); extern void __bio_clone_fast(struct bio *, struct bio *); extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs); +extern struct bio *bio_clone_seg_bioset(struct bio *, gfp_t, struct bio_set *bs); extern struct bio_set fs_bio_set; -- 2.9.5