[PATCH] block: implement elv_insert and use it (fix ordcolor flipping bug)

q->ordcolor must only be flipped on initial queueing of a hardbarrier
request.

Constructing ordered sequence and requeueing used to pass through
__elv_add_request() which flips q->ordcolor when it sees a barrier
request.

This patch separates out elv_insert() from __elv_add_request() and uses
elv_insert() when constructing ordered sequence and requeueing.
elv_insert() inserts the given request at the specified position and
does nothing else.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index ee5ed98db4cd..03d9c82b0fe7 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -454,7 +454,7 @@ static void queue_flush(request_queue_t *q, unsigned which)
         rq->end_io = end_io;
         q->prepare_flush_fn(q, rq);
 
-        __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+        elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
 }
 
 static inline struct request *start_ordered(request_queue_t *q,
@@ -490,7 +490,7 @@ static inline struct request *start_ordered(request_queue_t *q,
         else
                 q->ordseq |= QUEUE_ORDSEQ_POSTFLUSH;
 
-        __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+        elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
 
         if (q->ordered & QUEUE_ORDERED_PREFLUSH) {
                 queue_flush(q, QUEUE_ORDERED_PREFLUSH);