block: Stop abusing csd.list for fifo_time

Block layer currently abuses rq->csd.list.next for storing fifo_time.
That is a terrible hack and completely unnecessary as well. Union
achieves the same space saving in a cleaner way.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4afa4f8f6090..1e1fa3f93d5f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -99,6 +99,7 @@ struct request {
         union {
                 struct call_single_data csd;
                 struct work_struct mq_flush_work;
+                unsigned long fifo_time;
         };
 
         struct request_queue *q;