From 401a18e92ce32cd0ddfa5738899ca2b8114f2bbf Mon Sep 17 00:00:00 2001
From: Jens Axboe <jaxboe@fusionio.com>
Date: Fri, 25 Mar 2011 16:57:52 +0100
Subject: [PATCH] block: fix bug with inserting flush requests as sort/merge
With the introduction of the on-stack plugging, we would assume
that any request being inserted was a normal file system request.
As flush/fua requires a special insert mode, this caused problems.
Fix this up by checking for this in flush_plug_list() and use
the appropriate insert mechanism.
Big thanks goes to Markus Tripplesdorf for tirelessly testing
patches, and to Sergey Senozhatsky for helping find the real
issue.
Reported-by: Markus Tripplesdorf <markus@trippelsdorf.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
---
block/blk-core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 59b5c00c0126..64e96ee1d6af 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2702,7 +2702,10 @@ static void flush_plug_list(struct blk_plug *plug)
/*
* rq is already accounted, so use raw insert
*/
- __elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE);
+ if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA))
+ __elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH);
+ else
+ __elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE);
}
if (q) {
--
GitLab