From: Ming Lei <tom.leiming@gmail.com>
To: Jens Axboe <axboe@fb.com>, linux-kernel@vger.kernel.org
Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
Ming Lei <tom.leiming@gmail.com>,
Alasdair Kergon <agk@redhat.com>,
Mike Snitzer <snitzer@redhat.com>,
dm-devel@redhat.com (maintainer:DEVICE-MAPPER (LVM)),
Shaohua Li <shli@kernel.org>,
linux-raid@vger.kernel.org (open list:SOFTWARE RAID (Multiple
Disks) SUPPORT)
Subject: [PATCH 07/12] dm: use bvec iterator helpers to implement .get_page and .next_page
Date: Fri, 11 Nov 2016 20:05:35 +0800 [thread overview]
Message-ID: <1478865957-25252-8-git-send-email-tom.leiming@gmail.com> (raw)
In-Reply-To: <1478865957-25252-1-git-send-email-tom.leiming@gmail.com>
Firstly we have mature bvec/bio iterator helper for iterate each
page in one bio, not necessary to reinvent a wheel to do that.
Secondly the coming multipage bvecs requires this patch.
Also add comments about the direct access to bvec table.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
drivers/md/dm-io.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 0bf1a12e35fe..2ef573c220fc 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -162,7 +162,10 @@ struct dpages {
struct page **p, unsigned long *len, unsigned *offset);
void (*next_page)(struct dpages *dp);
- unsigned context_u;
+ union {
+ unsigned context_u;
+ struct bvec_iter context_bi;
+ };
void *context_ptr;
void *vma_invalidate_address;
@@ -204,25 +207,36 @@ static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offse
static void bio_get_page(struct dpages *dp, struct page **p,
unsigned long *len, unsigned *offset)
{
- struct bio_vec *bvec = dp->context_ptr;
- *p = bvec->bv_page;
- *len = bvec->bv_len - dp->context_u;
- *offset = bvec->bv_offset + dp->context_u;
+ struct bio_vec bv = bvec_iter_bvec((struct bio_vec *)dp->context_ptr,
+ dp->context_bi);
+
+ *p = bv.bv_page;
+ *len = bv.bv_len;
+ *offset = bv.bv_offset;
+
+ /* avoid to figure out it in bio_next_page() again */
+ dp->context_bi.bi_sector = (sector_t)bv.bv_len;
}
static void bio_next_page(struct dpages *dp)
{
- struct bio_vec *bvec = dp->context_ptr;
- dp->context_ptr = bvec + 1;
- dp->context_u = 0;
+ unsigned int len = (unsigned int)dp->context_bi.bi_sector;
+
+ bvec_iter_advance((struct bio_vec *)dp->context_ptr,
+ &dp->context_bi, len);
}
static void bio_dp_init(struct dpages *dp, struct bio *bio)
{
dp->get_page = bio_get_page;
dp->next_page = bio_next_page;
- dp->context_ptr = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
- dp->context_u = bio->bi_iter.bi_bvec_done;
+
+ /*
+ * We just use bvec iterator to retrieve pages, so it is ok to
+ * access the bvec table directly here
+ */
+ dp->context_ptr = bio->bi_io_vec;
+ dp->context_bi = bio->bi_iter;
}
/*
--
2.7.4
next prev parent reply other threads:[~2016-11-11 12:06 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-11 12:05 [PATCH 00/12] block: cleanup direct access to bvec table Ming Lei
2016-11-11 12:05 ` [PATCH 01/12] block: bio: pass bvec table to bio_init() Ming Lei
2016-11-12 17:59 ` Christoph Hellwig
2016-11-11 12:05 ` [PATCH 02/12] block: drbd: remove impossible failure handling Ming Lei
2016-11-11 12:05 ` [PATCH 03/12] block: floppy: use bio_add_page() Ming Lei
2016-11-12 18:00 ` Christoph Hellwig
2016-11-11 12:05 ` [PATCH 04/12] target: avoid to access .bi_vcnt directly Ming Lei
2016-11-12 21:37 ` Sagi Grimberg
2016-11-11 12:05 ` [PATCH 05/12] bcache: debug: avoid to access .bi_io_vec directly Ming Lei
2016-11-22 7:30 ` Christoph Hellwig
2016-11-11 12:05 ` [PATCH 06/12] dm: crypt: use bio_add_page() Ming Lei
2016-11-21 14:49 ` Mike Snitzer
2016-11-11 12:05 ` Ming Lei [this message]
2016-11-15 1:01 ` [PATCH 07/12] dm: use bvec iterator helpers to implement .get_page and .next_page Ming Lei
2016-11-15 18:55 ` Christoph Hellwig
2016-11-15 18:57 ` Mike Snitzer
2016-11-21 14:49 ` Mike Snitzer
2016-11-22 0:26 ` Ming Lei
2016-11-22 7:28 ` Christoph Hellwig
2016-11-11 12:05 ` [PATCH 08/12] dm: dm.c: replace 'bio->bi_vcnt == 1' with !bio_multiple_segments Ming Lei
2016-11-15 1:03 ` Ming Lei
2016-11-21 14:50 ` Mike Snitzer
2016-11-11 12:05 ` [PATCH 09/12] fs: logfs: convert to bio_add_page() in sync_request() Ming Lei
2016-11-11 12:05 ` [PATCH 10/12] fs: logfs: use bio_add_page() in __bdev_writeseg() Ming Lei
2016-11-11 12:05 ` [PATCH 11/12] fs: logfs: use bio_add_page() in do_erase() Ming Lei
2016-11-11 12:05 ` [PATCH 12/12] fs: logfs: remove unnecesary check Ming Lei
2016-11-22 15:53 ` [PATCH 00/12] block: cleanup direct access to bvec table Jens Axboe
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