Re: [PATCH -next v2 02/28] md: use 'mddev->suspended' for is_md_suspended()
From: Xiao Ni <hidden>
Date: 2023-09-20 08:47:44
Also in:
dm-devel, lkml
On Mon, Aug 28, 2023 at 10:04 AM Yu Kuai [off-list ref] wrote:
From: Yu Kuai <redacted> 'pers->prepare_suspend' is introduced to prevent a deadlock for raid456, this change prepares to clean this up in later patches while refactoring mddev_suspend(). Specifically allow reshape to make progress while waiting for 'active_io' to be 0.
Hi Kuai From my side, I can't understand the comments. The change has relationship with pers->prepare_suspend? And why this change can affect reshape? If this change indeed can affect these two things, can you explain more?
quoted hunk ↗ jump to hunk
Signed-off-by: Yu Kuai <redacted> --- drivers/md/md.c | 2 +- drivers/md/md.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/md/md.c b/drivers/md/md.c index 9d8dff9d923c..7fa311a14317 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c@@ -355,7 +355,7 @@ static DEFINE_SPINLOCK(all_mddevs_lock); */ static bool is_suspended(struct mddev *mddev, struct bio *bio) { - if (is_md_suspended(mddev)) + if (is_md_suspended(mddev) || percpu_ref_is_dying(&mddev->active_io))
If we use mddev->suspended to judge if the raid is suspended, it should be enough? Because mddev->suspended must be true when active_io is dying. Best Regards Xiao
quoted hunk ↗ jump to hunk
return true; if (bio_data_dir(bio) != WRITE) return false;diff --git a/drivers/md/md.h b/drivers/md/md.h index b628c292506e..fb3b123f16dd 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h@@ -584,7 +584,7 @@ static inline bool md_is_rdwr(struct mddev *mddev) static inline bool is_md_suspended(struct mddev *mddev) { - return percpu_ref_is_dying(&mddev->active_io); + return READ_ONCE(mddev->suspended); } static inline int __must_check mddev_lock(struct mddev *mddev) --2.39.2