md: don't account sync_io if iostats of the disk is disabled

If iostats is disabled, disk_stats will not be updated and
part_stat_read_accum() only returns a constant value. In this case,
continuing to count sync_io and to check is_mddev_idle() is no longer
meaningful.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240117031946.2324519-3-linan666@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index f28e41f9ac4aa2461c2673a211ab2ff0fa3ae069..00bbafcd27bbddd18b64434217a759370cdbb23f 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8583,6 +8583,10 @@ static int is_mddev_idle(struct mddev *mddev, int init)
        rcu_read_lock();
        rdev_for_each_rcu(rdev, mddev) {
                struct gendisk *disk = rdev->bdev->bd_disk;
+
+               if (!init && !blk_queue_io_stat(disk->queue))
+                       continue;
+
                curr_events =
                        (long long)part_stat_read_accum(disk->part0, sectors) -
                        atomic64_read(&disk->sync_io);

diff --git a/drivers/md/md.h b/drivers/md/md.h
index d0db98c0d33bea08a0a29b8225a2cca3db712fe7..029dd0491a36612bfa38159972e14312cccfbc8a 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -621,7 +621,8 @@ extern void mddev_unlock(struct mddev *mddev);
 
 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
 {
-       atomic64_add(nr_sectors, &bdev->bd_disk->sync_io);
+       if (blk_queue_io_stat(bdev->bd_disk->queue))
+               atomic64_add(nr_sectors, &bdev->bd_disk->sync_io);
 }
 
 static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)