block: introduce blk_flush_queue to drive flush machinery

This patch introduces 'struct blk_flush_queue' and puts all
flush machinery related fields into this structure, so that

	- flush implementation details aren't exposed to driver
	- it is easy to convert to per dispatch-queue flush machinery

This patch is basically a mechanical replacement.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e267bf0db559..49f3461e4272 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -36,6 +36,7 @@ struct request;
 struct sg_io_hdr;
 struct bsg_job;
 struct blkcg_gq;
+struct blk_flush_queue;
 
 #define BLKDEV_MIN_RQ   4
 #define BLKDEV_MAX_RQ   128     /* Default maximum */
@@ -455,14 +456,7 @@ struct request_queue {
          */
         unsigned int            flush_flags;
         unsigned int            flush_not_queueable:1;
-        unsigned int            flush_queue_delayed:1;
-        unsigned int            flush_pending_idx:1;
-        unsigned int            flush_running_idx:1;
-        unsigned long           flush_pending_since;
-        struct list_head        flush_queue[2];
-        struct list_head        flush_data_in_flight;
-        struct request          *flush_rq;
-        spinlock_t              mq_flush_lock;
+        struct blk_flush_queue  *fq;
 
         struct list_head        requeue_list;
         spinlock_t              requeue_lock;