drbd: Track the numbers of sectors in flight

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index ab2bd09d54b4..69d350fe7c1e 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -338,19 +338,21 @@ static inline int _req_mod(struct drbd_request *req, enum drbd_req_event what)
         return rv;
 }
 
-/* completion of master bio is outside of spinlock.
- * If you need it irqsave, do it your self!
- * Which means: don't use from bio endio callback. */
+/* completion of master bio is outside of our spinlock.
+ * We still may or may not be inside some irqs disabled section
+ * of the lower level driver completion callback, so we need to
+ * spin_lock_irqsave here. */
 static inline int req_mod(struct drbd_request *req,
                 enum drbd_req_event what)
 {
+        unsigned long flags;
         struct drbd_conf *mdev = req->mdev;
         struct bio_and_error m;
         int rv;
 
-        spin_lock_irq(&mdev->req_lock);
+        spin_lock_irqsave(&mdev->req_lock, flags);
         rv = __req_mod(req, what, &m);
-        spin_unlock_irq(&mdev->req_lock);
+        spin_unlock_irqrestore(&mdev->req_lock, flags);
 
         if (m.bio)
                 complete_master_bio(mdev, &m);