From 274a5843ff2f08a89464589d90c64eb65f2c0847 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@fb.com>
Date: Fri, 15 Aug 2014 12:44:08 -0600
Subject: [PATCH] blk-mq: don't allow merges if turned off for the queue

blk-mq uses BLK_MQ_F_SHOULD_MERGE, as set by the driver at init time,
to determine whether it should merge IO or not. However, this could
also be disabled by the admin, if merging is switched off through
sysfs. So check the general queue state as well before attempting
to merge IO.

Reported-by: Rob Elliott <Elliott@hp.com>
Tested-by: Rob Elliott <Elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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