drbd: fix potential deadlock during "restart" of conflicting writes

[mirror_ubuntu-zesty-kernel.git] / drivers / block / drbd / drbd_receiver.c

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 8a7f61ba74a89e08406f150de0393f0df116313c..b159ad15abe5f8a60fa5b311ccba730a276a95b9 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1748,30 +1748,6 @@ static int receive_RSDataReply(struct drbd_tconn *tconn, struct packet_info *pi)
        return err;
 }
 
-static int w_restart_write(struct drbd_work *w, int cancel)
-{
-       struct drbd_request *req = container_of(w, struct drbd_request, w);
-       struct drbd_conf *mdev = w->mdev;
-       struct bio *bio;
-       unsigned long start_time;
-       unsigned long flags;
-
-       spin_lock_irqsave(&mdev->tconn->req_lock, flags);
-       if (!expect(req->rq_state & RQ_POSTPONED)) {
-               spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
-               return -EIO;
-       }
-       bio = req->master_bio;
-       start_time = req->start_time;
-       /* Postponed requests will not have their master_bio completed!  */
-       __req_mod(req, DISCARD_WRITE, NULL);
-       spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
-
-       while (__drbd_make_request(mdev, bio, start_time))
-               /* retry */ ;
-       return 0;
-}
-
 static void restart_conflicting_writes(struct drbd_conf *mdev,
                                       sector_t sector, int size)
 {
@@ -1785,11 +1761,9 @@ static void restart_conflicting_writes(struct drbd_conf *mdev,
                if (req->rq_state & RQ_LOCAL_PENDING ||
                    !(req->rq_state & RQ_POSTPONED))
                        continue;
-               if (expect(list_empty(&req->w.list))) {
-                       req->w.mdev = mdev;
-                       req->w.cb = w_restart_write;
-                       drbd_queue_work(&mdev->tconn->data.work, &req->w);
-               }
+               /* as it is RQ_POSTPONED, this will cause it to
+                * be queued on the retry workqueue. */
+               __req_mod(req, DISCARD_WRITE, NULL);
        }
 }