[PATCH v2] blk-cgroup: remove unused blk_queue_for_each_rl stub

[Tao Cui <cui.tao@linux.dev>]

From: Tao Cui <cuitao@kylinos.cn>

blk_queue_for_each_rl() was added by commit a051661ca6d1 ("blkcg:
implement per-blkg request allocation") to iterate over the root request
list and per-blkg request lists for the legacy (non-blk-mq) request
allocation path.  The request_list code, including q->root_rl from
struct request_queue, was later removed in 2018 by commit db6d99523560
("block: remove request_list code").

The macro definition left behind in the !CONFIG_BLK_CGROUP fallback
branch of the private block/blk-cgroup.h header now references the
removed q->root_rl field, and has no callers in-tree (it would fail to
compile if expanded, so it cannot have any out-of-tree users either).

Remove the dead stub.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Reviewed-by: Yu Kuai <yukuai@fygo.io>
Reviewed-by: Tang Yizhou <yizhou.tang@shopee.com>

---
Changes in v2:
- Rebase onto current linux-next head (no code change).
- Add the Reviewed-by tags collected on v1 (Yu Kuai, Tang Yizhou).
- Link to v1: https://lore.kernel.org/r/20260717102049.2080768-1-cui.tao@linux.dev
---
 block/blk-cgroup.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index e67c69839129..ceca6647a5e5 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -517,9 +517,6 @@ static inline void blkg_put(struct blkcg_gq *blkg) { }
 static inline void blk_cgroup_bio_start(struct bio *bio) { }
 static inline bool blk_cgroup_mergeable(struct request *rq, struct bio *bio) { return true; }
 
-#define blk_queue_for_each_rl(rl, q)	\
-	for ((rl) = &(q)->root_rl; (rl); (rl) = NULL)
-
 #endif	/* CONFIG_BLK_CGROUP */
 
 #endif /* _BLK_CGROUP_PRIVATE_H */
-- 
2.43.0