From: Khazhismel Kumykov <khazhy@google.com> stable inclusion from stable-v5.10.112 commit 504c15f07f541f87185113ccd485a814adf31e4f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5HL0X Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit ce40426fdc3c92acdba6b5ca74bc7277ffaa6a3d ] Mixing sched_clock() and ktime_get_ns() usage will give bad results. Switch hst_select_path() from using sched_clock() to ktime_get_ns(). Also rename path_service_time()'s 'sched_now' variable to 'now'. Fixes: 2613eab11996 ("dm mpath: add Historical Service Time Path Selector") Signed-off-by: Khazhismel Kumykov <khazhy@google.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- drivers/md/dm-historical-service-time.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/md/dm-historical-service-time.c b/drivers/md/dm-historical-service-time.c index 186f91e2752c..06fe43c13ba3 100644 --- a/drivers/md/dm-historical-service-time.c +++ b/drivers/md/dm-historical-service-time.c @@ -429,7 +429,7 @@ static struct dm_path *hst_select_path(struct path_selector *ps, { struct selector *s = ps->context; struct path_info *pi = NULL, *best = NULL; - u64 time_now = sched_clock(); + u64 time_now = ktime_get_ns(); struct dm_path *ret = NULL; unsigned long flags; @@ -470,7 +470,7 @@ static int hst_start_io(struct path_selector *ps, struct dm_path *path, static u64 path_service_time(struct path_info *pi, u64 start_time) { - u64 sched_now = ktime_get_ns(); + u64 now = ktime_get_ns(); /* if a previous disk request has finished after this IO was * sent to the hardware, pretend the submission happened @@ -479,11 +479,11 @@ static u64 path_service_time(struct path_info *pi, u64 start_time) if (time_after64(pi->last_finish, start_time)) start_time = pi->last_finish; - pi->last_finish = sched_now; - if (time_before64(sched_now, start_time)) + pi->last_finish = now; + if (time_before64(now, start_time)) return 0; - return sched_now - start_time; + return now - start_time; } static int hst_end_io(struct path_selector *ps, struct dm_path *path, -- 2.20.1