From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@infradead.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Kent Overstreet <kent.overstreet@gmail.com>
Cc: David Sterba <dsterba@suse.cz>, Huang Ying <ying.huang@intel.com>,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
Theodore Ts'o <tytso@mit.edu>,
"Darrick J . Wong" <darrick.wong@oracle.com>,
Coly Li <colyli@suse.de>, Filipe Manana <fdmanana@gmail.com>,
Randy Dunlap <rdunlap@infradead.org>,
Ming Lei <ming.lei@redhat.com>
Subject: [PATCH V6 08/30] block: introduce chunk_last_segment()
Date: Sat, 9 Jun 2018 20:29:52 +0800 [thread overview]
Message-ID: <20180609123014.8861-9-ming.lei@redhat.com> (raw)
In-Reply-To: <20180609123014.8861-1-ming.lei@redhat.com>
BTRFS and guard_bio_eod() need to get the last singlepage segment
from one multipage chunk, so introduce this helper to make them happy.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
include/linux/bvec.h | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 9e082d023392..aac75d87d884 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -219,4 +219,29 @@ static inline bool bvec_iter_chunk_advance(const struct bio_vec *bv,
.bi_bvec_done = 0, \
}
+/*
+ * Get the last singlepage segment from the multipage bvec and store it
+ * in @seg
+ */
+static inline void chunk_last_segment(const struct bio_vec *bvec,
+ struct bio_vec *seg)
+{
+ unsigned total = bvec->bv_offset + bvec->bv_len;
+ unsigned last_page = total / PAGE_SIZE;
+
+ if (last_page * PAGE_SIZE == total)
+ last_page--;
+
+ 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:[~2018-06-09 12:29 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-09 12:29 [PATCH V6 00/30] block: support multipage bvec Ming Lei
2018-06-09 12:29 ` [PATCH V6 01/30] block: simplify bio_check_pages_dirty Ming Lei
2018-06-09 12:29 ` [PATCH V6 02/30] block: bio_set_pages_dirty can't see NULL bv_page in a valid bio_vec Ming Lei
2018-06-09 12:29 ` [PATCH V6 03/30] block: use bio_add_page in bio_iov_iter_get_pages Ming Lei
2018-06-09 12:29 ` [PATCH V6 04/30] block: introduce multipage page bvec helpers Ming Lei
2018-06-09 12:29 ` [PATCH V6 05/30] block: introduce bio_for_each_chunk() Ming Lei
2018-06-09 12:29 ` [PATCH V6 06/30] block: use bio_for_each_chunk() to compute multipage bvec count Ming Lei
2018-06-09 12:29 ` [PATCH V6 07/30] block: use bio_for_each_chunk() to map sg Ming Lei
2018-06-09 12:29 ` Ming Lei [this message]
2018-06-11 17:19 ` [PATCH V6 08/30] block: introduce chunk_last_segment() Christoph Hellwig
2018-06-12 3:24 ` Ming Lei
2018-06-09 12:29 ` [PATCH V6 09/30] fs/buffer.c: use bvec iterator to truncate the bio Ming Lei
2018-06-09 12:29 ` [PATCH V6 10/30] btrfs: use chunk_last_segment to get bio's last page Ming Lei
2018-06-09 12:29 ` [PATCH V6 11/30] block: implement bio_pages_all() via bio_for_each_segment_all() Ming Lei
2018-06-13 14:44 ` Christoph Hellwig
2018-06-14 1:23 ` Ming Lei
2018-06-14 6:20 ` Christoph Hellwig
2018-06-09 12:29 ` [PATCH V6 12/30] block: introduce bio_chunks() Ming Lei
2018-06-13 14:47 ` Christoph Hellwig
2018-06-13 14:57 ` Kent Overstreet
2018-06-09 12:29 ` [PATCH V6 13/30] block: introduce rq_for_each_chunk() Ming Lei
2018-06-13 14:48 ` Christoph Hellwig
2018-06-14 1:52 ` Ming Lei
2018-06-09 12:29 ` [PATCH V6 14/30] block: loop: pass multipage chunks to iov_iter Ming Lei
2018-06-09 12:29 ` [PATCH V6 15/30] block: introduce bio_clone_chunk_bioset() Ming Lei
2018-06-13 14:56 ` Christoph Hellwig
2018-06-14 2:01 ` Ming Lei
2018-06-14 6:39 ` Christoph Hellwig
2018-06-14 7:28 ` Ming Lei
2018-06-09 12:30 ` [PATCH V6 16/30] dm: clone bio via bio_clone_chunk_bioset Ming Lei
2018-06-09 12:30 ` [PATCH V6 17/30] block: introduce bio_for_each_chunk_all and bio_for_each_chunk_segment_all Ming Lei
2018-06-09 12:30 ` [PATCH V6 18/30] block: convert to bio_for_each_chunk_segment_all() Ming Lei
2018-06-09 12:30 ` [PATCH V6 19/30] md/dm/bcache: conver to bio_for_each_chunk_segment_all and bio_for_each_chunk_all Ming Lei
2018-06-10 12:38 ` Coly Li
2018-06-13 14:57 ` Christoph Hellwig
2018-06-09 12:30 ` [PATCH V6 20/30] fs: conver to bio_for_each_chunk_segment_all() Ming Lei
2018-06-09 12:30 ` [PATCH V6 21/30] btrfs: conver to bio_for_each_chunk_segment_all Ming Lei
2018-06-09 12:30 ` [PATCH V6 22/30] ext4: " Ming Lei
2018-06-09 12:30 ` [PATCH V6 23/30] f2fs: " Ming Lei
2018-06-09 12:30 ` [PATCH V6 24/30] xfs: " Ming Lei
2018-06-09 12:30 ` [PATCH V6 25/30] exofs: " Ming Lei
2018-06-09 12:30 ` [PATCH V6 26/30] gfs2: " Ming Lei
2018-06-09 12:30 ` [PATCH V6 27/30] block: kill bio_for_each_segment_all() Ming Lei
2018-06-09 12:30 ` [PATCH V6 28/30] block: enable multipage bvecs Ming Lei
2018-06-09 12:30 ` [PATCH V6 29/30] block: always define BIO_MAX_PAGES as 256 Ming Lei
2018-06-09 12:30 ` [PATCH V6 30/30] block: document usage of bio iterator helpers Ming Lei
2018-06-15 15:43 ` Gi-Oh Kim
2018-06-11 16:48 ` [PATCH V6 00/30] block: support multipage bvec Christoph Hellwig
2018-06-12 3:42 ` Ming Lei
2018-06-13 14:42 ` Christoph Hellwig
2018-06-14 1:18 ` Ming Lei
2018-06-14 6:18 ` Christoph Hellwig
2018-06-13 14:59 ` Kent Overstreet
2018-06-14 1:20 ` Ming Lei
2018-06-15 12:59 ` Gi-Oh Kim
2018-06-21 1:17 ` Ming Lei
2018-06-21 8:40 ` Gi-Oh Kim
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