Hi, 在 2023/09/27 8:15, Song Liu 写道:
On Mon, Sep 25, 2023 at 8:04 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:From: Yu Kuai <yukuai3@xxxxxxxxxx> There are no functional changes, the new helper will still hold 'all_mddevs_lock' after putting mddev, and it will be used to simplify md_seq_ops. Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> --- drivers/md/md.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 10cb4dfbf4ae..a5ef6f7da8ec 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -616,10 +616,15 @@ static inline struct mddev *mddev_get(struct mddev *mddev) static void mddev_delayed_delete(struct work_struct *ws); -void mddev_put(struct mddev *mddev) +static void __mddev_put(struct mddev *mddev, bool locked) { - if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock)) + if (locked) { + spin_lock(&all_mddevs_lock); + if (!atomic_dec_and_test(&mddev->active)) + return; + } else if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock)) return; +This condition is indeed very confusing. No matter whether we call the flag "locked" or "do_lock", it is not really accurate. How about we factor out a helper with the following logic: if (!mddev->raid_disks && list_empty(&mddev->disks) && mddev->ctime == 0 && !mddev->hold_active) { /* Array is not configured at all, and not held active, * so destroy it */ set_bit(MD_DELETED, &mddev->flags); /* * Call queue_work inside the spinlock so that * flush_workqueue() after mddev_find will succeed in waiting * for the work to be done. */ queue_work(md_misc_wq, &mddev->del_work); } and then use it at the two callers? Does this make sense?
Yes, that sounds great. I'll do this in v3. Thanks, Kuai
Thanks, Song .
