[BLOCK] Unify the seperate read/write io stat fields into arrays

Instead of having ->read_sectors and ->write_sectors, combine the two
into ->sectors[2] and similar for the other fields. This saves a branch
several places in the io path, since we don't have to care for what the
actual io direction is. On my x86-64 box, that's 200 bytes less text in
just the core (not counting the various drivers).

Signed-off-by: Jens Axboe <axboe@suse.de>

1 files changed, 3 insertions, 7 deletions

diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index bb279fad2fd2..946efef3a8f5 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -271,6 +271,7 @@ static int linear_stop (mddev_t *mddev)
 
 static int linear_make_request (request_queue_t *q, struct bio *bio)
 {
+        const int rw = bio_data_dir(bio);
         mddev_t *mddev = q->queuedata;
         dev_info_t *tmp_dev;
         sector_t block;
@@ -280,13 +281,8 @@ static int linear_make_request (request_queue_t *q, struct bio *bio)
                 return 0;
         }
 
-        if (bio_data_dir(bio)==WRITE) {
-                disk_stat_inc(mddev->gendisk, writes);
-                disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bio));
-        } else {
-                disk_stat_inc(mddev->gendisk, reads);
-                disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bio));
-        }
+        disk_stat_inc(mddev->gendisk, ios[rw]);
+        disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
 
         tmp_dev = which_dev(mddev, bio->bi_sector);
         block = bio->bi_sector >> 1;