2 files changed, 30 insertions, 4 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a0b225eb4ac4..118e0f69f224 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -737,9 +737,22 @@ static void wait_barrier(struct r1conf *conf)
         spin_lock_irq(&conf->resync_lock);
         if (conf->barrier) {
                 conf->nr_waiting++;
-                wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
+                /* Wait for the barrier to drop.
+                 * However if there are already pending
+                 * requests (preventing the barrier from
+                 * rising completely), and the
+                 * pre-process bio queue isn't empty,
+                 * then don't wait, as we need to empty
+                 * that queue to get the nr_pending
+                 * count down.
+                 */
+                wait_event_lock_irq(conf->wait_barrier,
+                                    !conf->barrier ||
+                                    (conf->nr_pending &&
+                                     current->bio_list &&
+                                     !bio_list_empty(current->bio_list)),
                                     conf->resync_lock,
-                                    );
+                        );
                 conf->nr_waiting--;
         }
         conf->nr_pending++;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index f4f3edcdaf8d..2ae7021320e1 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -863,9 +863,22 @@ static void wait_barrier(struct r10conf *conf)
         spin_lock_irq(&conf->resync_lock);
         if (conf->barrier) {
                 conf->nr_waiting++;
-                wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
+                /* Wait for the barrier to drop.
+                 * However if there are already pending
+                 * requests (preventing the barrier from
+                 * rising completely), and the
+                 * pre-process bio queue isn't empty,
+                 * then don't wait, as we need to empty
+                 * that queue to get the nr_pending
+                 * count down.
+                 */
+                wait_event_lock_irq(conf->wait_barrier,
+                                    !conf->barrier ||
+                                    (conf->nr_pending &&
+                                     current->bio_list &&
+                                     !bio_list_empty(current->bio_list)),
                                     conf->resync_lock,
-                                    );
+                        );
                 conf->nr_waiting--;
         }
         conf->nr_pending++;