1 files changed, 12 insertions, 6 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 3c8121072507..78b7b0cb7216 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2662,17 +2662,23 @@ static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b)
         return !(rqa->q <= rqb->q);
 }
 
+/*
+ * If 'from_schedule' is true, then postpone the dispatch of requests
+ * until a safe kblockd context. We due this to avoid accidental big
+ * additional stack usage in driver dispatch, in places where the originally
+ * plugger did not intend it.
+ */
 static void queue_unplugged(struct request_queue *q, unsigned int depth,
-                            bool force_kblockd)
+                            bool from_schedule)
 {
-        trace_block_unplug_io(q, depth);
-        __blk_run_queue(q, force_kblockd);
+        trace_block_unplug(q, depth, !from_schedule);
+        __blk_run_queue(q, from_schedule);
 
         if (q->unplugged_fn)
                 q->unplugged_fn(q);
 }
 
-void blk_flush_plug_list(struct blk_plug *plug, bool force_kblockd)
+void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 {
         struct request_queue *q;
         unsigned long flags;
@@ -2707,7 +2713,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool force_kblockd)
                 BUG_ON(!rq->q);
                 if (rq->q != q) {
                         if (q) {
-                                queue_unplugged(q, depth, force_kblockd);
+                                queue_unplugged(q, depth, from_schedule);
                                 spin_unlock(q->queue_lock);
                         }
                         q = rq->q;
@@ -2728,7 +2734,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool force_kblockd)
         }
 
         if (q) {
-                queue_unplugged(q, depth, force_kblockd);
+                queue_unplugged(q, depth, from_schedule);
                 spin_unlock(q->queue_lock);
         }