From: Ming Lei <tom.leiming@gmail.com>
To: Jens Axboe <axboe@fb.com>, linux-kernel@vger.kernel.org
Cc: linux-block@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
Ming Lei <tom.leiming@gmail.com>,
Mike Christie <mchristi@redhat.com>,
Hannes Reinecke <hare@suse.com>,
Kent Overstreet <kent.overstreet@gmail.com>,
Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com>,
Shaun Tancheff <shaun.tancheff@seagate.com>,
Johannes Thumshirn <jthumshirn@suse.de>,
Bart Van Assche <bart.vanassche@sandisk.com>
Subject: [PATCH v1 30/54] block: bio: introduce single/multi page version of bio_for_each_segment_all()
Date: Tue, 27 Dec 2016 23:56:19 +0800 [thread overview]
Message-ID: <1482854250-13481-31-git-send-email-tom.leiming@gmail.com> (raw)
In-Reply-To: <1482854250-13481-1-git-send-email-tom.leiming@gmail.com>
This patches introduce bio_for_each_segment_all_sp() and
bio_for_each_segment_all_mp().
bio_for_each_segment_all_sp() is for replacing bio_for_each_segment_all()
in case that the returned bvec has to be single page bvec.
bio_for_each_segment_all_mp() is for replacing bio_for_each_segment_all()
in case that user wants to update the returned bvec via the pointer.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
include/linux/bio.h | 24 ++++++++++++++++++++++++
include/linux/blk_types.h | 6 ++++++
2 files changed, 30 insertions(+)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 79079bc5a1be..efa0b3627735 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -217,6 +217,30 @@ static inline void bio_advance_iter_mp(struct bio *bio, struct bvec_iter *iter,
#define bio_for_each_segment_mp(bvl, bio, iter) \
__bio_for_each_segment_mp(bvl, bio, iter, (bio)->bi_iter)
+/*
+ * This helper returns each bvec stored in bvec table directly,
+ * so the returned bvec points to one multipage bvec in the table
+ * and caller can update the bvec via the returnd pointer.
+ */
+#define bio_for_each_segment_all_mp(bvl, bio, i) \
+ bio_for_each_segment_all((bvl), (bio), (i))
+
+/*
+ * This helper returns singlepage bvec to caller, and the sp bvec
+ * is generated in-flight from multipage bvec stored in bvec table.
+ * So we can _not_ change the bvec stored in bio->bi_io_vec[] via
+ * this helper.
+ *
+ * If someone need to update bvec in the table, please use
+ * bio_for_each_segment_all_mp() and make sure it is correctly used
+ * since the bvec points to one multipage bvec.
+ */
+#define bio_for_each_segment_all_sp(bvl, bio, i, bi) \
+ for ((bi).iter = BVEC_ITER_ALL_INIT, i = 0, bvl = &(bi).bv; \
+ (bi).iter.bi_idx < (bio)->bi_vcnt && \
+ (((bi).bv = bio_iter_iovec((bio), (bi).iter)), 1); \
+ bio_advance_iter((bio), &(bi).iter, (bi).bv.bv_len), i++)
+
#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
static inline unsigned __bio_segments(struct bio *bio, bool mp)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 519ea2c9df61..ef8e30abb099 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -89,6 +89,12 @@ struct bio {
#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
+/* this iter is only for implementing bio_for_each_segment_rd() */
+struct bvec_iter_all {
+ struct bvec_iter iter;
+ struct bio_vec bv; /* in-flight singlepage bvec */
+};
+
/*
* bio flags
*/
--
2.7.4
next prev parent reply other threads:[~2016-12-27 16:10 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1482854250-13481-1-git-send-email-tom.leiming@gmail.com>
2016-12-27 15:55 ` [PATCH v1 01/54] block: drbd: comment on direct access bvec table Ming Lei
2016-12-27 15:55 ` [PATCH v1 02/54] block: loop: comment on direct access to " Ming Lei
2016-12-27 15:55 ` [PATCH v1 03/54] kernel/power/swap.c: " Ming Lei
2016-12-27 15:55 ` [PATCH v1 04/54] mm: page_io.c: " Ming Lei
2016-12-27 15:55 ` [PATCH v1 05/54] fs/buffer: " Ming Lei
2016-12-27 15:55 ` [PATCH v1 06/54] f2fs: f2fs_read_end_io: " Ming Lei
2016-12-27 15:55 ` [PATCH v1 07/54] bcache: " Ming Lei
2016-12-30 16:56 ` Coly Li
2016-12-27 15:55 ` [PATCH v1 08/54] block: comment on bio_alloc_pages() Ming Lei
2016-12-30 10:40 ` Coly Li
2016-12-30 11:06 ` Coly Li
2016-12-27 15:55 ` [PATCH v1 09/54] block: comment on bio_iov_iter_get_pages() Ming Lei
2016-12-27 15:55 ` [PATCH v1 10/54] block: introduce flag QUEUE_FLAG_NO_MP Ming Lei
2016-12-27 15:56 ` [PATCH v1 11/54] md: set NO_MP for request queue of md Ming Lei
2016-12-27 15:56 ` [PATCH v1 12/54] dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE Ming Lei
2017-01-03 16:43 ` Mike Snitzer
2017-01-06 3:30 ` Ming Lei
2016-12-27 15:56 ` [PATCH v1 13/54] block: comments on bio_for_each_segment[_all] Ming Lei
2016-12-27 15:56 ` [PATCH v1 14/54] block: introduce multipage/single page bvec helpers Ming Lei
2016-12-27 15:56 ` [PATCH v1 15/54] block: implement sp version of bvec iterator helpers Ming Lei
2016-12-27 15:56 ` [PATCH v1 16/54] block: introduce bio_for_each_segment_mp() Ming Lei
2016-12-27 15:56 ` [PATCH v1 17/54] block: introduce bio_clone_sp() Ming Lei
2016-12-27 15:56 ` [PATCH v1 18/54] bvec_iter: introduce BVEC_ITER_ALL_INIT Ming Lei
2016-12-27 15:56 ` [PATCH v1 19/54] block: bounce: avoid direct access to bvec table Ming Lei
2016-12-27 15:56 ` [PATCH v1 20/54] block: bounce: don't access bio->bi_io_vec in copy_to_high_bio_irq Ming Lei
2016-12-27 15:56 ` [PATCH v1 21/54] block: introduce bio_can_convert_to_sp() Ming Lei
2016-12-27 15:56 ` [PATCH v1 22/54] block: bounce: convert multipage bvecs into singlepage Ming Lei
2016-12-27 15:56 ` [PATCH v1 23/54] bcache: handle bio_clone() & bvec updating for multipage bvecs Ming Lei
2016-12-30 11:01 ` Coly Li
2016-12-31 10:29 ` Ming Lei
2016-12-27 15:56 ` [PATCH v1 24/54] blk-merge: compute bio->bi_seg_front_size efficiently Ming Lei
2016-12-27 15:56 ` [PATCH v1 25/54] block: blk-merge: try to make front segments in full size Ming Lei
2016-12-27 15:56 ` [PATCH v1 26/54] block: blk-merge: remove unnecessary check Ming Lei
2016-12-27 15:56 ` [PATCH v1 27/54] block: use bio_for_each_segment_mp() to compute segments count Ming Lei
2016-12-27 15:56 ` [PATCH v1 28/54] block: use bio_for_each_segment_mp() to map sg Ming Lei
2016-12-27 15:56 ` [PATCH v1 29/54] block: introduce bvec_for_each_sp_bvec() Ming Lei
2016-12-27 15:56 ` Ming Lei [this message]
2016-12-27 15:56 ` [PATCH v1 31/54] block: introduce bio_segments_all() Ming Lei
2017-01-16 3:19 ` [PATCH v1 00/54] block: support multipage bvec Ming Lei
2017-01-16 15:18 ` Christoph Hellwig
2017-01-17 2:40 ` Ming Lei
2017-01-17 7:50 ` Christoph Hellwig
2017-01-17 8:13 ` Ming Lei
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