Merge branch 'linus' into x86/pebs

1 files changed, 7 insertions, 1 deletions

diff --git a/block/blk-settings.c b/block/blk-settings.c
index bb93d4c32775..8dd86418f35d 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -286,8 +286,14 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
         t->max_hw_segments = min(t->max_hw_segments, b->max_hw_segments);
         t->max_segment_size = min(t->max_segment_size, b->max_segment_size);
         t->hardsect_size = max(t->hardsect_size, b->hardsect_size);
-        if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags))
+        if (!t->queue_lock)
+                WARN_ON_ONCE(1);
+        else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {
+                unsigned long flags;
+                spin_lock_irqsave(t->queue_lock, flags);
                 queue_flag_clear(QUEUE_FLAG_CLUSTER, t);
+                spin_unlock_irqrestore(t->queue_lock, flags);
+        }
 }
 EXPORT_SYMBOL(blk_queue_stack_limits);