[PATCH 3/5] loop: add helper loop_queue_work_prep

[Ming Lei <ming.lei@xxxxxxxxxx>]

Add helper loop_queue_work_prep() for making loop_queue_rq() more
readable.

Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
 drivers/block/loop.c | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index eae38cd38b7b..9f8d32d2dc4d 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -859,6 +859,27 @@ static inline int queue_on_root_worker(struct cgroup_subsys_state *css)
 }
 #endif
 
+static void loop_queue_work_prep(struct loop_cmd *cmd)
+{
+	struct request *rq = blk_mq_rq_from_pdu(cmd);
+
+	/* always use the first bio's css */
+	cmd->blkcg_css = NULL;
+	cmd->memcg_css = NULL;
+#ifdef CONFIG_BLK_CGROUP
+	if (rq->bio) {
+		cmd->blkcg_css = bio_blkcg_css(rq->bio);
+#ifdef CONFIG_MEMCG
+		if (cmd->blkcg_css) {
+			cmd->memcg_css =
+				cgroup_get_e_css(cmd->blkcg_css->cgroup,
+						&memory_cgrp_subsys);
+		}
+#endif
+	}
+#endif
+}
+
 static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd)
 {
 	struct rb_node **node, *parent = NULL;
@@ -866,6 +887,8 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd)
 	struct work_struct *work;
 	struct list_head *cmd_list;
 
+	loop_queue_work_prep(cmd);
+
 	spin_lock_irq(&lo->lo_work_lock);
 
 	if (queue_on_root_worker(cmd->blkcg_css))
@@ -1903,21 +1926,6 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 		break;
 	}
 
-	/* always use the first bio's css */
-	cmd->blkcg_css = NULL;
-	cmd->memcg_css = NULL;
-#ifdef CONFIG_BLK_CGROUP
-	if (rq->bio) {
-		cmd->blkcg_css = bio_blkcg_css(rq->bio);
-#ifdef CONFIG_MEMCG
-		if (cmd->blkcg_css) {
-			cmd->memcg_css =
-				cgroup_get_e_css(cmd->blkcg_css->cgroup,
-						&memory_cgrp_subsys);
-		}
-#endif
-	}
-#endif
 	loop_queue_work(lo, cmd);
 
 	return BLK_STS_OK;
-- 
2.47.0