rdev_dec_pending(rdev, mddev);
if (atomic_dec_and_test(&mddev->flush_pending)) {
+ /* The pair is percpu_ref_get() from md_flush_request() */
+ percpu_ref_put(&mddev->active_io);
+
/* The pre-request flush has finished */
queue_work(md_wq, &mddev->flush_work);
}
rdev_for_each_rcu(rdev, mddev)
if (rdev->raid_disk >= 0 &&
!test_bit(Faulty, &rdev->flags)) {
- /* Take two references, one is dropped
- * when request finishes, one after
- * we reclaim rcu_read_lock
- */
struct bio *bi;
- atomic_inc(&rdev->nr_pending);
+
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
bi = bio_alloc_bioset(rdev->bdev, 0,
atomic_inc(&mddev->flush_pending);
submit_bio(bi);
rcu_read_lock();
- rdev_dec_pending(rdev, mddev);
}
rcu_read_unlock();
if (atomic_dec_and_test(&mddev->flush_pending))
/* new request after previous flush is completed */
if (ktime_after(req_start, mddev->prev_flush_start)) {
WARN_ON(mddev->flush_bio);
+ /*
+ * Grab a reference to make sure mddev_suspend() will wait for
+ * this flush to be done.
+ *
+ * md_flush_reqeust() is called under md_handle_request() and
+ * 'active_io' is already grabbed, hence percpu_ref_is_zero()
+ * won't pass, percpu_ref_tryget_live() can't be used because
+ * percpu_ref_kill() can be called by mddev_suspend()
+ * concurrently.
+ */
+ WARN_ON(percpu_ref_is_zero(&mddev->active_io));
+ percpu_ref_get(&mddev->active_io);
mddev->flush_bio = bio;
bio = NULL;
}