From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932590Ab2KNDId (ORCPT ); Tue, 13 Nov 2012 22:08:33 -0500 Received: from mail-pb0-f46.google.com ([209.85.160.46]:34572 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932446Ab2KNDIc (ORCPT ); Tue, 13 Nov 2012 22:08:32 -0500 MIME-Version: 1.0 In-Reply-To: <1348111122-27400-2-git-send-email-robin.k.dong@gmail.com> References: <1348111122-27400-1-git-send-email-robin.k.dong@gmail.com> <1348111122-27400-2-git-send-email-robin.k.dong@gmail.com> Date: Wed, 14 Nov 2012 11:08:31 +0800 Message-ID: Subject: Re: [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it From: Robin Dong To: linux-kernel@vger.kernel.org, dm-devel@redhat.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ping 2012/9/20 Robin Dong : > From: Robin Dong > > When trying to modify flashcache to request based (current it's bio based), we need > to make request from bios by ourselves, but dm_io() will submit these bios directly, > so we propose to modify the dm_io() to return bios instead of submiting it. > > This could also improve the flexibility of dm_io(). > > Signed-off-by: Robin Dong > --- > drivers/md/dm.c | 11 +++++++++++ > include/linux/device-mapper.h | 3 +++ > 2 files changed, 14 insertions(+), 0 deletions(-) > > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > index 4e09b6f..bf6e3bb 100644 > --- a/drivers/md/dm.c > +++ b/drivers/md/dm.c > @@ -1459,11 +1459,22 @@ static int dm_request_based(struct mapped_device *md) > static void dm_request(struct request_queue *q, struct bio *bio) > { > struct mapped_device *md = q->queuedata; > + struct dm_table *map = dm_get_live_table(md); > + struct dm_target *ti = dm_table_find_target(map, bio->bi_sector); > + > + if (ti->type->mk_rq) { > + ti->type->mk_rq(ti, q, bio); > + goto out; > + } > > if (dm_request_based(md)) > blk_queue_bio(q, bio); > else > _dm_request(q, bio); > + > +out: > + dm_table_put(map); > + return; > } > > void dm_dispatch_request(struct request *rq) > diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h > index 38d27a1..2386389 100644 > --- a/include/linux/device-mapper.h > +++ b/include/linux/device-mapper.h > @@ -50,6 +50,8 @@ typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, > union map_info *map_context); > typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, > union map_info *map_context); > +typedef int (*dm_make_request_fn) (struct dm_target *ti, > + struct request_queue *q, struct bio *bio); > > /* > * Returns: > @@ -136,6 +138,7 @@ struct target_type { > dm_dtr_fn dtr; > dm_map_fn map; > dm_map_request_fn map_rq; > + dm_make_request_fn mk_rq; > dm_endio_fn end_io; > dm_request_endio_fn rq_end_io; > dm_presuspend_fn presuspend; > -- > 1.7.1 > -- -- Best Regard Robin Dong