block: bio: pass bvec table to bio_init()

Some drivers often use external bvec table, so introduce
this helper for this case. It is always safe to access the
bio->bi_io_vec in this way for this case.

After converting to this usage, it will becomes a bit easier
to evaluate the remaining direct access to bio->bi_io_vec,
so it can help to prepare for the following multipage bvec
support.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Fixed up the new O_DIRECT cases.

Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index e51644e503a5..69e1ae59cab8 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -106,14 +106,13 @@ static void dirty_init(struct keybuf_key *w)
         struct dirty_io *io = w->private;
         struct bio *bio = &io->bio;
 
-        bio_init(bio);
+        bio_init(bio, bio->bi_inline_vecs,
+                 DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS));
         if (!io->dc->writeback_percent)
                 bio_set_prio(bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
 
         bio->bi_iter.bi_size    = KEY_SIZE(&w->key) << 9;
-        bio->bi_max_vecs        = DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS);
         bio->bi_private         = w;
-        bio->bi_io_vec          = bio->bi_inline_vecs;
         bch_bio_map(bio, NULL);
 }