From b2387ddcced8de3e6471a2fb16a409577063016f Mon Sep 17 00:00:00 2001
From: Shaohua Li <shli@fb.com>
Date: Fri, 1 May 2015 09:59:44 -0700
Subject: [PATCH] blk-mq: fix FUA request hang
When a FUA request enters its DATA stage of flush pipeline, the
request is added to mq requeue list, the request will then be added to
ctx->rq_list. blk_mq_attempt_merge() might merge the request with a bio.
Later when the request is finished the flush pipeline, the
request->__data_len is 0. Then I only saw the bio gets endio called, the
original request never finish.
Adding REQ_FLUSH_SEQ into REQ_NOMERGE_FLAGS looks an easy fix.
stable: 3.15+
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
include/linux/blk_types.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index a1b25e35ea5f9..b7299febc4b4a 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -220,7 +220,7 @@ enum rq_flag_bits {
/* This mask is used for both bio and request merge checking */
#define REQ_NOMERGE_FLAGS \
- (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
+ (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA | REQ_FLUSH_SEQ)
#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
#define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
--
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