Re: [PATCH v2 1/2] md: factor out a new helper to put mddev
From: Mariusz Tkaczyk <hidden>
Date: 2023-09-26 12:45:52
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On Tue, 26 Sep 2023 10:58:26 +0800 Yu Kuai [off-list ref] wrote:
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From: Yu Kuai <redacted> 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 <redacted> --- 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;
It is "locked" and we are taking lock? It seems weird to me. Perhaps "do_lock" would be better? Do you meant "lockdep_assert_held(&all_mddevs_lock);" Something is wrong here, we have two paths and in both cases we are taking lock.
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+ } else if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock)) return; + if (!mddev->raid_disks && list_empty(&mddev->disks) && mddev->ctime == 0 && !mddev->hold_active) { /* Array is not configured at all, and not held active,@@ -633,7 +638,14 @@ void mddev_put(struct mddev *mddev) */ queue_work(md_misc_wq, &mddev->del_work); } - spin_unlock(&all_mddevs_lock); + + if (!locked) + spin_unlock(&all_mddevs_lock);
As above, I'm not sure if it is correct. Thanks, Mariusz