[PATCH] cfq-iosched: bad accounting on non-fs requests

Current cfq can cause hangs with non-fs requests, because the accounting
goes bad.  This fixes it.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/block/cfq-iosched.c

@@ -867,6 +867,9 @@ static inline void cfq_account_dispatch(struct cfq_rq *crq)
 	struct cfq_data *cfqd = cfqq->cfqd;
 	unsigned long now, elapsed;
 
+	if (!blk_fs_request(crq->request))
+		return;
+
 	/*
 	 * accounted bit is necessary since some drivers will call
 	 * elv_next_request() many times for the same request (eg ide)
@@ -912,6 +915,9 @@ cfq_account_completion(struct cfq_queue *cfqq, struct cfq_rq *crq)
 {
 	struct cfq_data *cfqd = cfqq->cfqd;
 
+	if (!crq->accounted)
+		return;
+
 	WARN_ON(!cfqd->rq_in_driver);
 	cfqd->rq_in_driver--;