From 6245e8ee5d457d233fb72a46eebf244ed11eb71d Mon Sep 17 00:00:00 2001
From: Shaohua Li <shli@fusionio.com>
Date: Fri, 9 Nov 2012 08:44:27 +0100
Subject: [PATCH] --- yaml --- r: 345663 b: refs/heads/master c:
 bee0393cc12b6d8f10e884e555a095e050e0b2b9 h: refs/heads/master i:   345661:
 b3e15202dd1b7c1bc28b694995e503316f696856   345659:
 f68891b60fb1db51e0c530575bfda3c0e6b2b345   345655:
 571dde4c5b7c60783a8f00419352c5d7d811be5a   345647:
 e1a113fc778a02fdf95ac4521b23a75bd9964a59   345631:
 bb62c21321dd8c2fad9b692efdae2257fe93798e   345599:
 aaac4fa127fbdcc862eac359156af6c7be553b4b v: v3

---
 [refs]                 |  2 +-
 trunk/block/elevator.c | 16 ++++++++++++----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index fdc3e8206ff5..cb4d232335fb 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3d106fba2e7eb6967b1e2cc147a6894ec4307cef
+refs/heads/master: bee0393cc12b6d8f10e884e555a095e050e0b2b9
diff --git a/trunk/block/elevator.c b/trunk/block/elevator.c
index 9b1d42b62f20..9edba1b8323e 100644
--- a/trunk/block/elevator.c
+++ b/trunk/block/elevator.c
@@ -458,6 +458,7 @@ static bool elv_attempt_insert_merge(struct request_queue *q,
 				     struct request *rq)
 {
 	struct request *__rq;
+	bool ret;
 
 	if (blk_queue_nomerges(q))
 		return false;
@@ -471,14 +472,21 @@ static bool elv_attempt_insert_merge(struct request_queue *q,
 	if (blk_queue_noxmerges(q))
 		return false;
 
+	ret = false;
 	/*
 	 * See if our hash lookup can find a potential backmerge.
 	 */
-	__rq = elv_rqhash_find(q, blk_rq_pos(rq));
-	if (__rq && blk_attempt_req_merge(q, __rq, rq))
-		return true;
+	while (1) {
+		__rq = elv_rqhash_find(q, blk_rq_pos(rq));
+		if (!__rq || !blk_attempt_req_merge(q, __rq, rq))
+			break;
 
-	return false;
+		/* The merged request could be merged with others, try again */
+		ret = true;
+		rq = __rq;
+	}
+
+	return ret;
 }
 
 void elv_merged_request(struct request_queue *q, struct request *rq, int type)