From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Theodore Ts'o <tytso@mit.edu>,
Omar Sandoval <osandov@fb.com>, Sagi Grimberg <sagi@grimberg.me>,
Dave Chinner <dchinner@redhat.com>,
Kent Overstreet <kent.overstreet@gmail.com>,
Mike Snitzer <snitzer@redhat.com>,
dm-devel@redhat.com, Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, linux-raid@vger.kernel.org,
David Sterba <dsterba@suse.com>,
linux-btrfs@vger.kernel.org,
"Darrick J . Wong" <darrick.wong@oracle.com>,
linux-xfs@vger.kernel.org, Gao Xiang <gaoxiang25@huawei.com>,
Christoph Hellwig <hch@lst.de>,
linux-ext4@vger.kernel.org, Coly Li <colyli@suse.de>,
linux-bcache@vger.kernel.org, Boaz Harrosh <ooo@electrozaur.com>,
Bob Peterson <rpeterso@redhat.com>,
cluster-devel@redhat.com, Ming Lei <ming.lei@redhat.com>
Subject: [PATCH V15 08/18] block: introduce mp_bvec_last_segment()
Date: Fri, 15 Feb 2019 19:13:14 +0800 [thread overview]
Message-ID: <20190215111324.30129-9-ming.lei@redhat.com> (raw)
In-Reply-To: <20190215111324.30129-1-ming.lei@redhat.com>
BTRFS and guard_bio_eod() need to get the last singlepage segment
from one multipage bvec, so introduce this helper to make them happy.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
include/linux/bvec.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 0ae729b1c9fe..21f76bad7be2 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -131,4 +131,26 @@ static inline bool bvec_iter_advance(const struct bio_vec *bv,
.bi_bvec_done = 0, \
}
+/*
+ * Get the last single-page segment from the multi-page bvec and store it
+ * in @seg
+ */
+static inline void mp_bvec_last_segment(const struct bio_vec *bvec,
+ struct bio_vec *seg)
+{
+ unsigned total = bvec->bv_offset + bvec->bv_len;
+ unsigned last_page = (total - 1) / PAGE_SIZE;
+
+ seg->bv_page = nth_page(bvec->bv_page, last_page);
+
+ /* the whole segment is inside the last page */
+ if (bvec->bv_offset >= last_page * PAGE_SIZE) {
+ seg->bv_offset = bvec->bv_offset % PAGE_SIZE;
+ seg->bv_len = bvec->bv_len;
+ } else {
+ seg->bv_offset = 0;
+ seg->bv_len = total - last_page * PAGE_SIZE;
+ }
+}
+
#endif /* __LINUX_BVEC_ITER_H */
--
2.9.5
next prev parent reply other threads:[~2019-02-15 11:15 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 11:13 [PATCH V15 00/18] block: support multi-page bvec Ming Lei
2019-02-15 11:13 ` [PATCH V15 01/18] btrfs: look at bi_size for repair decisions Ming Lei
2019-02-15 11:13 ` [PATCH V15 02/18] block: don't use bio->bi_vcnt to figure out segment number Ming Lei
2019-02-15 11:13 ` [PATCH V15 03/18] block: remove bvec_iter_rewind() Ming Lei
2019-02-15 11:13 ` [PATCH V15 04/18] block: introduce multi-page bvec helpers Ming Lei
2019-02-15 11:13 ` [PATCH V15 05/18] block: introduce bio_for_each_bvec() and rq_for_each_bvec() Ming Lei
2019-02-15 11:13 ` [PATCH V15 06/18] block: use bio_for_each_bvec() to compute multi-page bvec count Ming Lei
2019-02-15 11:13 ` [PATCH V15 07/18] block: use bio_for_each_bvec() to map sg Ming Lei
2019-02-15 11:13 ` Ming Lei [this message]
2019-02-15 11:13 ` [PATCH V15 09/18] fs/buffer.c: use bvec iterator to truncate the bio Ming Lei
2019-02-15 11:13 ` [PATCH V15 10/18] btrfs: use mp_bvec_last_segment to get bio's last page Ming Lei
2019-02-15 11:13 ` [PATCH V15 11/18] block: loop: pass multi-page bvec to iov_iter Ming Lei
2019-02-15 11:13 ` [PATCH V15 12/18] bcache: avoid to use bio_for_each_segment_all() in bch_bio_alloc_pages() Ming Lei
2019-02-15 11:13 ` [PATCH V15 13/18] block: allow bio_for_each_segment_all() to iterate over multi-page bvec Ming Lei
2019-02-15 11:13 ` [PATCH V15 14/18] block: enable multipage bvecs Ming Lei
[not found] ` <CGME20190221084301eucas1p11e8841a62b4b1da3cccca661b6f4c29d@eucas1p1.samsung.com>
2019-02-21 8:42 ` Marek Szyprowski
2019-02-21 9:57 ` Ming Lei
2019-02-21 10:08 ` Marek Szyprowski
2019-02-21 10:16 ` Ming Lei
2019-02-21 10:22 ` Marek Szyprowski
2019-02-21 10:38 ` Ming Lei
2019-02-21 11:42 ` Marek Szyprowski
2019-02-27 20:47 ` Jon Hunter
2019-02-27 23:29 ` Ming Lei
2019-02-28 7:51 ` Marek Szyprowski
2019-02-28 12:39 ` Jon Hunter
2019-02-15 11:13 ` [PATCH V15 15/18] block: always define BIO_MAX_PAGES as 256 Ming Lei
2019-02-15 11:13 ` [PATCH V15 16/18] block: document usage of bio iterator helpers Ming Lei
2019-02-15 11:13 ` [PATCH V15 17/18] block: kill QUEUE_FLAG_NO_SG_MERGE Ming Lei
2019-02-15 11:13 ` [PATCH V15 18/18] block: kill BLK_MQ_F_SG_MERGE Ming Lei
2019-02-15 14:51 ` [PATCH V15 00/18] block: support multi-page bvec Christoph Hellwig
2019-02-17 13:10 ` Ming Lei
2019-02-15 15:49 ` Jens Axboe
2019-02-15 17:14 ` [dm-devel] " Bart Van Assche
2019-02-15 17:59 ` Jens Axboe
2019-02-17 13:13 ` Ming Lei
2019-02-18 7:49 ` Ming Lei
2019-02-17 13:11 ` Ming Lei
2019-02-19 16:28 ` Bart Van Assche
2019-02-20 1:17 ` Ming Lei
2019-02-20 2:37 ` Bart Van Assche
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190215111324.30129-9-ming.lei@redhat.com \
--to=ming.lei@redhat.com \
--cc=axboe@kernel.dk \
--cc=cluster-devel@redhat.com \
--cc=colyli@suse.de \
--cc=darrick.wong@oracle.com \
--cc=dchinner@redhat.com \
--cc=dm-devel@redhat.com \
--cc=dsterba@suse.com \
--cc=gaoxiang25@huawei.com \
--cc=hch@lst.de \
--cc=kent.overstreet@gmail.com \
--cc=linux-bcache@vger.kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-raid@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
--cc=ooo@electrozaur.com \
--cc=osandov@fb.com \
--cc=rpeterso@redhat.com \
--cc=sagi@grimberg.me \
--cc=snitzer@redhat.com \
--cc=tytso@mit.edu \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).