From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: [PATCH v2 06/14] block: Add bio_reset() Date: Wed, 23 May 2012 17:02:43 -0700 Message-ID: <1337817771-25038-7-git-send-email-koverstreet@google.com> References: <1337817771-25038-1-git-send-email-koverstreet@google.com> Cc: Kent Overstreet , tj@kernel.org, axboe@kernel.dk, agk@redhat.com, neilb@suse.de, drbd-dev@lists.linbit.com, bharrosh@panasas.com, vgoyal@redhat.com, mpatocka@redhat.com, sage@newdream.net, yehuda@hq.newdream.net To: linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:47332 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753924Ab2EXAD1 (ORCPT ); Wed, 23 May 2012 20:03:27 -0400 Received: by mail-pb0-f46.google.com with SMTP id rp8so10598371pbb.19 for ; Wed, 23 May 2012 17:03:27 -0700 (PDT) In-Reply-To: <1337817771-25038-1-git-send-email-koverstreet@google.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Reusing bios is something that's been highly frowned upon in the past, but driver code keeps doing it anyways. If it's going to happen anyways, we should provide a generic method. This'll help with getting rid of bi_destructor - drivers/block/pktcdvd.c was open coding it, by doing a bio_init() and resetting bi_destructor. Signed-off-by: Kent Overstreet Change-Id: Ib0a43dfcb3f6c22a54da513d4a86be544b5ffd95 --- fs/bio.c | 8 ++++++++ include/linux/bio.h | 1 + include/linux/blk_types.h | 6 ++++++ 3 files changed, 15 insertions(+) diff --git a/fs/bio.c b/fs/bio.c index de0733e..7d8c29d 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -259,6 +259,14 @@ void bio_init(struct bio *bio) } EXPORT_SYMBOL(bio_init); +void bio_reset(struct bio *bio) +{ + memset(bio, 0, BIO_RESET_BYTES); + bio->bi_flags = 1 << BIO_UPTODATE; + +} +EXPORT_SYMBOL(bio_reset); + /** * bio_alloc_bioset - allocate a bio for I/O * @gfp_mask: the GFP_ mask given to the slab allocator diff --git a/include/linux/bio.h b/include/linux/bio.h index b27f16b..35f7c4d 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -228,6 +228,7 @@ extern struct bio *bio_clone(struct bio *, gfp_t); struct bio *bio_clone_kmalloc(struct bio *, gfp_t); extern void bio_init(struct bio *); +extern void bio_reset(struct bio *); extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index dc0e399..6b7daf3 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -57,6 +57,10 @@ struct bio { unsigned int bi_seg_front_size; unsigned int bi_seg_back_size; + /* + * Everything starting with bi_max_vecs will be preserved by bio_reset() + */ + unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ atomic_t bi_cnt; /* pin count */ @@ -83,6 +87,8 @@ struct bio { struct bio_vec bi_inline_vecs[0]; }; +#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) + /* * bio flags */ -- 1.7.9.3.327.g2980b