[PATCH] Block: blk-throttle: set low_valid immediately once one cgroup has io.low configured

[Liu Bo]

Once one cgroup has io.low configured, @low_valid becomes true and other
cgroups won't switch it back whatsoever.

Signed-off-by: Liu Bo <bo....@linux.alibaba.com>
---
 block/blk-throttle.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 8bd54118dc0a..479c6b9dcf10 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -579,8 +579,10 @@ static void blk_throtl_update_limit_valid(struct 
throtl_data *td)
                struct throtl_grp *tg = blkg_to_tg(blkg);
 
                if (tg->bps[READ][LIMIT_LOW] || tg->bps[WRITE][LIMIT_LOW] ||
-                   tg->iops[READ][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW])
+                   tg->iops[READ][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) {
                        low_valid = true;
+                       break;
+               }
        }
        rcu_read_unlock();
 
-- 
1.8.3.1