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-rw-r--r--block/cfq-iosched.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4b4217d9be7..07b70624377 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -577,9 +577,9 @@ static int cfq_allow_merge(request_queue_t *q, struct request *rq,
pid_t key;
/*
- * Disallow merge, if bio and rq aren't both sync or async
+ * Disallow merge of a sync bio into an async request.
*/
- if (!!bio_sync(bio) != !!rq_is_sync(rq))
+ if ((bio_data_dir(bio) == READ || bio_sync(bio)) && !rq_is_sync(rq))
return 0;
/*
@@ -592,7 +592,7 @@ static int cfq_allow_merge(request_queue_t *q, struct request *rq,
if (cfqq == RQ_CFQQ(rq))
return 1;
- return 1;
+ return 0;
}
static inline void