From b7e54dd751fad5163efc63fd2de9be30eb417720 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 10 Mar 2020 13:07:46 -0400 Subject: [PATCH] blk-iocost: fix incorrect vtime comparison in iocg_is_idle() commit dcd6589b11d3b1e71f516a87a7b9646ed356b4c0 upstream. vtimes may wrap and time_before/after64() should be used to determine whether a given vtime is before or after another. iocg_is_idle() was incorrectly using plain "<" comparison do determine whether done_vtime is before vtime. Here, the only thing we're interested in is whether done_vtime matches vtime which indicates that there's nothing in flight. Let's test for inequality instead. Signed-off-by: Tejun Heo Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/blk-iocost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 27ca68621137..9a599cc28c29 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1318,7 +1318,7 @@ static bool iocg_is_idle(struct ioc_gq *iocg) return false; /* is something in flight? */ - if (atomic64_read(&iocg->done_vtime) < atomic64_read(&iocg->vtime)) + if (atomic64_read(&iocg->done_vtime) != atomic64_read(&iocg->vtime)) return false; return true;