Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block

[linux-2.6-microblaze.git] / block / blk-iolatency.c

diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 9568bf8..e285152 100644 (file)
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -401,7 +401,6 @@ static void check_scale_change(struct iolatency_grp *iolat)
        unsigned int cur_cookie;
        unsigned int our_cookie = atomic_read(&iolat->scale_cookie);
        u64 scale_lat;
-       unsigned int old;
        int direction = 0;
 
        if (lat_to_blkg(iolat)->parent == NULL)
@@ -422,11 +421,10 @@ static void check_scale_change(struct iolatency_grp *iolat)
        else
                return;
 
-       old = atomic_cmpxchg(&iolat->scale_cookie, our_cookie, cur_cookie);
-
-       /* Somebody beat us to the punch, just bail. */
-       if (old != our_cookie)
+       if (!atomic_try_cmpxchg(&iolat->scale_cookie, &our_cookie, cur_cookie)) {
+               /* Somebody beat us to the punch, just bail. */
                return;
+       }
 
        if (direction < 0 && iolat->min_lat_nsec) {
                u64 samples_thresh;
@@ -633,8 +631,8 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
                        window_start = atomic64_read(&iolat->window_start);
                        if (now > window_start &&
                            (now - window_start) >= iolat->cur_win_nsec) {
-                               if (atomic64_cmpxchg(&iolat->window_start,
-                                            window_start, now) == window_start)
+                               if (atomic64_try_cmpxchg(&iolat->window_start,
+                                                        &window_start, now))
                                        iolatency_check_latencies(iolat, now);
                        }
                }
@@ -773,19 +771,23 @@ int blk_iolatency_init(struct request_queue *q)
        rqos->ops = &blkcg_iolatency_ops;
        rqos->q = q;
 
-       rq_qos_add(q, rqos);
-
+       ret = rq_qos_add(q, rqos);
+       if (ret)
+               goto err_free;
        ret = blkcg_activate_policy(q, &blkcg_policy_iolatency);
-       if (ret) {
-               rq_qos_del(q, rqos);
-               kfree(blkiolat);
-               return ret;
-       }
+       if (ret)
+               goto err_qos_del;
 
        timer_setup(&blkiolat->timer, blkiolatency_timer_fn, 0);
        INIT_WORK(&blkiolat->enable_work, blkiolatency_enable_work_fn);
 
        return 0;
+
+err_qos_del:
+       rq_qos_del(q, rqos);
+err_free:
+       kfree(blkiolat);
+       return ret;
 }
 
 static void iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)