Merge branch 'for-linus' of ../linux-2.6-block into block-for-2.6.39/core

[pandora-kernel.git] / block / blk-flush.c

diff --git a/block/blk-flush.c b/block/blk-flush.c
index a867e3f..0bd8c9c 100644 (file)
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -212,9 +212,14 @@ static void flush_end_io(struct request *flush_rq, int error)
                queued |= blk_flush_complete_seq(rq, seq, error);
        }
 
-       /* after populating an empty queue, kick it to avoid stall */
+       /*
+        * Moving a request silently to empty queue_head may stall the
+        * queue.  Kick the queue in those cases.  This function is called
+        * from request completion path and calling directly into
+        * request_fn may confuse the driver.  Always use kblockd.
+        */
        if (queued && was_empty)
-               __blk_run_queue(q);
+               __blk_run_queue(q, true);
 }
 
 /**
@@ -257,7 +262,7 @@ static bool blk_kick_flush(struct request_queue *q)
        q->flush_rq.end_io = flush_end_io;
 
        q->flush_pending_idx ^= 1;
-       elv_insert(q, &q->flush_rq, ELEVATOR_INSERT_FRONT);
+       elv_insert(q, &q->flush_rq, ELEVATOR_INSERT_REQUEUE);
        return true;
 }
 
@@ -266,9 +271,12 @@ static void flush_data_end_io(struct request *rq, int error)
        struct request_queue *q = rq->q;
        bool was_empty = elv_queue_empty(q);
 
-       /* after populating an empty queue, kick it to avoid stall */
+       /*
+        * After populating an empty queue, kick it to avoid stall.  Read
+        * the comment in flush_end_io().
+        */
        if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error) && was_empty)
-               __blk_run_queue(q);
+               __blk_run_queue(q, true);
 }
 
 /**