Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753689Ab3C0Rk4 (ORCPT ); Wed, 27 Mar 2013 13:40:56 -0400 Received: from mail-da0-f41.google.com ([209.85.210.41]:36140 "EHLO mail-da0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753617Ab3C0Rkv (ORCPT ); Wed, 27 Mar 2013 13:40:51 -0400 From: Kent Overstreet To: axboe@kernel.dk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, dm-devel@vger.kernel.org Cc: tj@kernel.org, neilb@suse.de, Kent Overstreet , Yehuda Sadeh , Alex Elder , ceph-devel@vger.kernel.org Subject: [PATCH 16/22] rbd: Refactor bio cloning, don't clone biovecs Date: Wed, 27 Mar 2013 10:39:46 -0700 Message-Id: <1364405992-28424-17-git-send-email-koverstreet@google.com> X-Mailer: git-send-email 1.8.1.3 In-Reply-To: <1364405992-28424-1-git-send-email-koverstreet@google.com> References: <1364405992-28424-1-git-send-email-koverstreet@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2772 Lines: 101 Now that we've got drivers converted to the new immutable bvec primitives, bio splitting becomes much easier. In a few patches, bio_clone() will be changed to share the old bio's bvec instead of copying it, by default. Signed-off-by: Kent Overstreet Cc: Yehuda Sadeh Cc: Alex Elder Cc: ceph-devel@vger.kernel.org --- drivers/block/rbd.c | 64 ++--------------------------------------------------- 1 file changed, 2 insertions(+), 62 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index d1e4fd8..d4e2406 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -929,73 +929,13 @@ static struct bio *bio_clone_range(struct bio *bio_src, unsigned int len, gfp_t gfpmask) { - struct bio_vec bv; - struct bvec_iter iter; - struct bvec_iter end_iter; - unsigned int resid; - unsigned int voff; - unsigned short vcnt; struct bio *bio; - /* Handle the easy case for the caller */ - - if (!offset && len == bio_src->bi_iter.bi_size) - return bio_clone(bio_src, gfpmask); - - if (WARN_ON_ONCE(!len)) - return NULL; - if (WARN_ON_ONCE(len > bio_src->bi_iter.bi_size)) - return NULL; - if (WARN_ON_ONCE(offset > bio_src->bi_iter.bi_size - len)) - return NULL; - - /* Find first affected segment... */ - - resid = offset; - bio_for_each_segment(bv, bio_src, iter) { - if (resid < bv.bv_len) - break; - resid -= bv.bv_len; - } - voff = resid; - - /* ...and the last affected segment */ - - resid += len; - __bio_for_each_segment(bv, bio_src, end_iter, iter) { - if (resid <= bv.bv_len) - break; - resid -= bv.bv_len; - } - vcnt = end_iter.bi_idx = iter.bi_idx + 1; - - /* Build the clone */ - - bio = bio_alloc(gfpmask, (unsigned int) vcnt); + bio = bio_clone(bio_src, gfpmask); if (!bio) return NULL; /* ENOMEM */ - bio->bi_bdev = bio_src->bi_bdev; - bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector + - (offset >> SECTOR_SHIFT); - bio->bi_rw = bio_src->bi_rw; - bio->bi_flags |= 1 << BIO_CLONED; - - /* - * Copy over our part of the bio_vec, then update the first - * and last (or only) entries. - */ - memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[iter.bi_idx], - vcnt * sizeof (struct bio_vec)); - bio->bi_io_vec[0].bv_offset += voff; - if (vcnt > 1) { - bio->bi_io_vec[0].bv_len -= voff; - bio->bi_io_vec[vcnt - 1].bv_len = resid; - } else { - bio->bi_io_vec[0].bv_len = len; - } - - bio->bi_vcnt = vcnt; + bio_advance(bio, offset); bio->bi_iter.bi_size = len; return bio; -- 1.8.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/