Merge tag 'md/4.0-rc7-fix' of git://neil.brown.name/md

Pull md fixes from Neil Brown:
 "Two regression fixes for md, one fairly recent and minor (diskstats
  has confusing data) and one older and more serious - RAID0 with
  non-power-of-2 chunksize corrupts data.

  I guess (almost) no-one uses non-power-of-2 chunks.

  Summary:

   - Revert recent change which broke IO accounting.

   - Fix bug with RAID0 arrays with non-power-of-2 chunk size"

* tag 'md/4.0-rc7-fix' of git://neil.brown.name/md:
  md/raid0: fix bug with chunksize not a power of 2.
  md: fix md io stats accounting broken

2 files changed, 7 insertions, 2 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 717daad71fb1..e6178787ce3d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -249,6 +249,7 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
         const int rw = bio_data_dir(bio);
         struct mddev *mddev = q->queuedata;
         unsigned int sectors;
+        int cpu;
 
         if (mddev == NULL || mddev->pers == NULL
             || !mddev->ready) {
@@ -284,7 +285,10 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
         sectors = bio_sectors(bio);
         mddev->pers->make_request(mddev, bio);
 
-        generic_start_io_acct(rw, sectors, &mddev->gendisk->part0);
+        cpu = part_stat_lock();
+        part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+        part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
+        part_stat_unlock();
 
         if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
                 wake_up(&mddev->sb_wait);
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 3ed9f42ddca6..3b5d7f704aa3 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -313,7 +313,7 @@ static struct strip_zone *find_zone(struct r0conf *conf,
 
 /*
  * remaps the bio to the target device. we separate two flows.
- * power 2 flow and a general flow for the sake of perfromance
+ * power 2 flow and a general flow for the sake of performance
 */
 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
                                 sector_t sector, sector_t *sector_offset)
@@ -524,6 +524,7 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
                         split = bio;
                 }
 
+                sector = bio->bi_iter.bi_sector;
                 zone = find_zone(mddev->private, &sector);
                 tmp_dev = map_sector(mddev, zone, sector, &sector);
                 split->bi_bdev = tmp_dev->bdev;