[PATCH 1/5] blk-mq: define max_order for allocating rqs pages as macro

[Ming Lei <ming.lei@redhat.com>]

Inside blk_mq_alloc_rqs(), 'max_order' is actually one const local
variable, define it as macro, and this macro will be re-used
in following patch.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 77d885805699..f9da2d803c18 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2360,10 +2360,12 @@ static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
 	return 0;
 }
 
+#define MAX_RQS_PAGE_ORDER 4
+
 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 		     unsigned int hctx_idx, unsigned int depth)
 {
-	unsigned int i, j, entries_per_page, max_order = 4;
+	unsigned int i, j, entries_per_page;
 	size_t rq_size, left;
 	int node;
 
@@ -2382,7 +2384,7 @@ int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 	left = rq_size * depth;
 
 	for (i = 0; i < depth; ) {
-		int this_order = max_order;
+		int this_order = MAX_RQS_PAGE_ORDER;
 		struct page *page;
 		int to_do;
 		void *p;
-- 
2.25.2