blk-throttle: fix unused variable warning with BLK_DEV_THROTTLING_LOW=n

We trigger this warning:

block/blk-throttle.c: In function ‘blk_throtl_bio’:
block/blk-throttle.c:2042:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]
  int ret;
      ^~~

since we only assign 'ret' if BLK_DEV_THROTTLING_LOW is off, we never
check it.

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index c82bf9b1fe7224c049aea2248726ee8576d898c6..b78db2e5fdff1e158ea52c179313ff3eba282015 100644 (file)
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -2030,6 +2030,20 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td)
 }
 #endif
 
+static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio)
+{
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+       int ret;
+
+       ret = bio_associate_current(bio);
+       if (ret == 0 || ret == -EBUSY)
+               bio->bi_cg_private = tg;
+       blk_stat_set_issue(&bio->bi_issue_stat, bio_sectors(bio));
+#else
+       bio_associate_current(bio);
+#endif
+}
+
 bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
                    struct bio *bio)
 {
@@ -2039,7 +2053,6 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
        bool rw = bio_data_dir(bio);
        bool throttled = false;
        struct throtl_data *td = tg->td;
-       int ret;
 
        WARN_ON_ONCE(!rcu_read_lock_held());
 
@@ -2054,12 +2067,7 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
        if (unlikely(blk_queue_bypass(q)))
                goto out_unlock;
 
-       ret = bio_associate_current(bio);
-#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
-       if (ret == 0 || ret == -EBUSY)
-               bio->bi_cg_private = tg;
-       blk_stat_set_issue(&bio->bi_issue_stat, bio_sectors(bio));
-#endif
+       blk_throtl_assoc_bio(tg, bio);
        blk_throtl_update_idletime(tg);
 
        sq = &tg->service_queue;