drbd: Fixed race condition in drbd_queue_bitmap_io

May only test for ap_bio_cnt == 0 under req_lock. It can increase
only under req_lock.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Philipp Reisner 2010-11-16 15:30:44 +01:00
parent 8869d683b7
commit 22afd7ee94

View File

@ -3849,11 +3849,13 @@ void drbd_queue_bitmap_io(struct drbd_conf *mdev,
mdev->bm_io_work.done = done;
mdev->bm_io_work.why = why;
spin_lock_irq(&mdev->req_lock);
set_bit(BITMAP_IO, &mdev->flags);
if (atomic_read(&mdev->ap_bio_cnt) == 0) {
if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags))
drbd_queue_work(&mdev->data.work, &mdev->bm_io_work.w);
}
spin_unlock_irq(&mdev->req_lock);
}
/**