[PATCH 4/6] bcache: clean up bio reuse for struct dirty_io

Christoph Hellwig
2018-06-11T19:48:04Z

Instead of reinitializing the bio everytime we can call bio_reuse when
reusing it. Also moves the private data initialization out of
dirty_init, which is renamed to suit the remaining functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/md/bcache/writeback.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index ad45ebe1a74b..986e50f069d6 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -179,19 +179,12 @@ struct dirty_io {
struct bio bio;
};

-static void dirty_init(struct keybuf_key *w)
+static void dirty_init_prio(struct keybuf_key *w)
{
struct dirty_io *io = w->private;
- struct bio *bio = &io->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_private = w;
- bch_bio_map(bio, NULL);
+ bio_set_prio(&io->bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
}

static void dirty_io_destructor(struct closure *cl)
@@ -285,10 +278,12 @@ static void write_dirty(struct closure *cl)
* to clean up.
*/
if (KEY_DIRTY(&w->key)) {
- dirty_init(w);
- bio_set_op_attrs(&io->bio, REQ_OP_WRITE, 0);
+ bio_reuse(&io->bio);
+ dirty_init_prio(w);
+ io->bio.bi_opf = REQ_OP_WRITE;
io->bio.bi_iter.bi_sector = KEY_START(&w->key);
bio_set_dev(&io->bio, io->dc->bdev);
+ io->bio.bi_private = w;
io->bio.bi_end_io = dirty_endio;

/* I/O request sent to backing device */
@@ -399,13 +394,18 @@ static void read_dirty(struct cached_dev *dc)
io->dc = dc;
io->sequence = sequence++;

- dirty_init(w);
- bio_set_op_attrs(&io->bio, REQ_OP_READ, 0);
+ bio_init(&io->bio, io->bio.bi_inline_vecs,
+ DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS));
+ dirty_init_prio(w);
+ io->bio.bi_opf = REQ_OP_READ;
+ io->bio.bi_iter.bi_size = KEY_SIZE(&w->key) << 9;
io->bio.bi_iter.bi_sector = PTR_OFFSET(&w->key, 0);
bio_set_dev(&io->bio,
PTR_CACHE(dc->disk.c, &w->key, 0)->bdev);
+ io->bio.bi_private = w;
io->bio.bi_end_io = read_dirty_endio;

+ bch_bio_map(&io->bio, NULL);
if (bch_bio_alloc_pages(&io->bio, GFP_KERNEL))
goto err_free;

--
2.17.1