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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>,
	Johannes Berg <johannes.berg@intel.com>
Subject: [PATCH v1 15/54] block: implement sp version of bvec iterator helpers
Date: Tue, 27 Dec 2016 23:56:04 +0800	[thread overview]
Message-ID: <1482854250-13481-16-git-send-email-tom.leiming@gmail.com> (raw)
In-Reply-To: <1482854250-13481-1-git-send-email-tom.leiming@gmail.com>

This patch implements singlepage version of the following
3 helpers:
	- bvec_iter_offset_sp()
	- bvec_iter_len_sp()
	- bvec_iter_page_sp()

So that one multipage bvec can be splited to singlepage
bvec, and make users of current bvec iterator happy.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 include/linux/bvec.h | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 307a387eb29c..d77c3cabce8c 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -22,6 +22,7 @@
 
 #include <linux/kernel.h>
 #include <linux/bug.h>
+#include <linux/mm.h>
 
 /*
  * What is multipage bvecs(segment)?
@@ -95,14 +96,25 @@ struct bvec_iter {
 #define bvec_iter_offset_mp(bvec, iter)				\
 	(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
 
+#define bvec_iter_page_idx_mp(bvec, iter)			\
+	(bvec_iter_offset_mp((bvec), (iter)) / PAGE_SIZE)
+
+
 /*
  * <page, offset,length> of singlepage(sp) segment.
  *
  * This helpers will be implemented for building sp bvec in flight.
  */
-#define bvec_iter_offset_sp(bvec, iter)	bvec_iter_offset_mp((bvec), (iter))
-#define bvec_iter_len_sp(bvec, iter)	bvec_iter_len_mp((bvec), (iter))
-#define bvec_iter_page_sp(bvec, iter)	bvec_iter_page_mp((bvec), (iter))
+#define bvec_iter_offset_sp(bvec, iter)					\
+	(bvec_iter_offset_mp((bvec), (iter)) % PAGE_SIZE)
+
+#define bvec_iter_len_sp(bvec, iter)					\
+	min_t(unsigned, bvec_iter_len_mp((bvec), (iter)),		\
+	    (PAGE_SIZE - (bvec_iter_offset_sp((bvec), (iter)))))
+
+#define bvec_iter_page_sp(bvec, iter)					\
+	nth_page(bvec_iter_page_mp((bvec), (iter)),			\
+		 bvec_iter_page_idx_mp((bvec), (iter)))
 
 /* current interfaces support sp style at default */
 #define bvec_iter_page(bvec, iter)	bvec_iter_page_sp((bvec), (iter))
-- 
2.7.4

  parent reply	other threads:[~2016-12-27 16:08 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 ` Ming Lei [this message]
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 ` [PATCH v1 30/54] block: bio: introduce single/multi page version of bio_for_each_segment_all() Ming Lei
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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