From 6b2ff10390b19a2364af622b6666b690443f9f3f Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Thu, 1 Feb 2024 17:25:51 +0800 Subject: md: Fix missing release of 'active_io' for flush commit 855678ed8534518e2b428bcbcec695de9ba248e8 upstream. submit_flushes atomic_set(&mddev->flush_pending, 1); rdev_for_each_rcu(rdev, mddev) atomic_inc(&mddev->flush_pending); bi->bi_end_io = md_end_flush submit_bio(bi); /* flush io is done first */ md_end_flush if (atomic_dec_and_test(&mddev->flush_pending)) percpu_ref_put(&mddev->active_io) -> active_io is not released if (atomic_dec_and_test(&mddev->flush_pending)) -> missing release of active_io For consequence, mddev_suspend() will wait for 'active_io' to be zero forever. Fix this problem by releasing 'active_io' in submit_flushes() if 'flush_pending' is decreased to zero. Fixes: fa2bbff7b0b4 ("md: synchronize flush io with array reconfiguration") Cc: stable@vger.kernel.org # v6.1+ Reported-by: Blazej Kucman Closes: https://lore.kernel.org/lkml/20240130172524.0000417b@linux.intel.com/ Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240201092559.910982-7-yukuai1@huaweicloud.com Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/md') diff --git a/drivers/md/md.c b/drivers/md/md.c index c7efe1522951..846bdee4daa0 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -564,8 +564,12 @@ static void submit_flushes(struct work_struct *ws) rcu_read_lock(); } rcu_read_unlock(); - if (atomic_dec_and_test(&mddev->flush_pending)) + if (atomic_dec_and_test(&mddev->flush_pending)) { + /* The pair is percpu_ref_get() from md_flush_request() */ + percpu_ref_put(&mddev->active_io); + queue_work(md_wq, &mddev->flush_work); + } } static void md_submit_flush_data(struct work_struct *ws) -- cgit v1.2.3