Merge branches 'depends/rmk/io', 'depends/rmk/l2x0' and 'depends/rmk/gpio' into highb...

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

diff --git a/block/blk-flush.c b/block/blk-flush.c
index bb21e4c..491eb30 100644 (file)
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -95,11 +95,12 @@ static unsigned int blk_flush_policy(unsigned int fflags, struct request *rq)
 {
        unsigned int policy = 0;
 
+       if (blk_rq_sectors(rq))
+               policy |= REQ_FSEQ_DATA;
+
        if (fflags & REQ_FLUSH) {
                if (rq->cmd_flags & REQ_FLUSH)
                        policy |= REQ_FSEQ_PREFLUSH;
-               if (blk_rq_sectors(rq))
-                       policy |= REQ_FSEQ_DATA;
                if (!(fflags & REQ_FUA) && (rq->cmd_flags & REQ_FUA))
                        policy |= REQ_FSEQ_POSTFLUSH;
        }
@@ -122,7 +123,7 @@ static void blk_flush_restore_request(struct request *rq)
 
        /* make @rq a normal request */
        rq->cmd_flags &= ~REQ_FLUSH_SEQ;
-       rq->end_io = NULL;
+       rq->end_io = rq->flush.saved_end_io;
 }
 
 /**
@@ -300,9 +301,6 @@ void blk_insert_flush(struct request *rq)
        unsigned int fflags = q->flush_flags;   /* may change, cache */
        unsigned int policy = blk_flush_policy(fflags, rq);
 
-       BUG_ON(rq->end_io);
-       BUG_ON(!rq->bio || rq->bio != rq->biotail);
-
        /*
         * @policy now records what operations need to be done.  Adjust
         * REQ_FLUSH and FUA for the driver.
@@ -311,6 +309,19 @@ void blk_insert_flush(struct request *rq)
        if (!(fflags & REQ_FUA))
                rq->cmd_flags &= ~REQ_FUA;
 
+       /*
+        * An empty flush handed down from a stacking driver may
+        * translate into nothing if the underlying device does not
+        * advertise a write-back cache.  In this case, simply
+        * complete the request.
+        */
+       if (!policy) {
+               __blk_end_bidi_request(rq, 0, 0, 0);
+               return;
+       }
+
+       BUG_ON(!rq->bio || rq->bio != rq->biotail);
+
        /*
         * If there's data but flush is not necessary, the request can be
         * processed directly without going through flush machinery.  Queue
@@ -319,6 +330,7 @@ void blk_insert_flush(struct request *rq)
        if ((policy & REQ_FSEQ_DATA) &&
            !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) {
                list_add_tail(&rq->queuelist, &q->queue_head);
+               blk_run_queue_async(q);
                return;
        }
 
@@ -329,6 +341,7 @@ void blk_insert_flush(struct request *rq)
        memset(&rq->flush, 0, sizeof(rq->flush));
        INIT_LIST_HEAD(&rq->flush.list);
        rq->cmd_flags |= REQ_FLUSH_SEQ;
+       rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
        rq->end_io = flush_data_end_io;
 
        blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0);