[PATCH V10 09/19] block: introduce bio_bvecs()

Ming Lei
2018-11-15T08:55:49Z

There are still cases in which we need to use bio_bvecs() for get the
number of multi-page segment, so introduce it.

Cc: Dave Chinner <dchinner@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Shaohua Li <shli@kernel.org>
Cc: linux-raid@vger.kernel.org
Cc: linux-erofs@lists.ozlabs.org
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Cc: Coly Li <colyli@suse.de>
Cc: linux-bcache@vger.kernel.org
Cc: Boaz Harrosh <ooo@electrozaur.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: cluster-devel@redhat.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
include/linux/bio.h | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 1f0dcf109841..3496c816946e 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -196,7 +196,6 @@ static inline unsigned bio_segments(struct bio *bio)
* We special case discard/write same/write zeroes, because they
* interpret bi_size differently:
*/
-
switch (bio_op(bio)) {
case REQ_OP_DISCARD:
case REQ_OP_SECURE_ERASE:
@@ -205,13 +204,34 @@ static inline unsigned bio_segments(struct bio *bio)
case REQ_OP_WRITE_SAME:
return 1;
default:
- break;
+ bio_for_each_segment(bv, bio, iter)
+ segs++;
+ return segs;
}
+}

- bio_for_each_segment(bv, bio, iter)
- segs++;
+static inline unsigned bio_bvecs(struct bio *bio)
+{
+ unsigned bvecs = 0;
+ struct bio_vec bv;
+ struct bvec_iter iter;

- return segs;
+ /*
+ * We special case discard/write same/write zeroes, because they
+ * interpret bi_size differently:
+ */
+ switch (bio_op(bio)) {
+ case REQ_OP_DISCARD:
+ case REQ_OP_SECURE_ERASE:
+ case REQ_OP_WRITE_ZEROES:
+ return 0;
+ case REQ_OP_WRITE_SAME:
+ return 1;
+ default:
+ bio_for_each_bvec(bv, bio, iter)
+ bvecs++;
+ return bvecs;
+ }
}

/*
--
2.9.5