Hi,
在 2025/04/16 17:44, Xiao Ni 写道:
On Wed, Apr 16, 2025 at 5:29 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
Hi,
在 2025/04/16 15:42, Yu Kuai 写道:
Hi,
在 2025/04/16 14:20, Xiao Ni 写道:
+static bool is_rdev_idle(struct md_rdev *rdev, bool init)
+{
+ unsigned long last_events = rdev->last_events;
+
+ if (!bdev_is_partition(rdev->bdev))
+ return true;
For md array, I think is_rdev_idle is not useful. Because
mddev->last_events must be increased while upper ios come in and idle
will be set to false. For dm array, mddev->last_events can't work. So
is_rdev_idle is for dm array. If member disk is one partition,
is_rdev_idle alwasy returns true, and is_mddev_idle always return
true. It's a bug here. Do we need to check bdev_is_partition here?
is_rdev_idle() is not used for current array, for example:
sda1 is used for array md0, and user doesn't issue IO to md0, while
user issues IO to sda2. In this case, is_mddev_idle() still fail for
array md0 because is_rdev_idle() fail.
Thanks very much for the explanation. It makes sense :)
Perhaps the name is_rdev_holder_idle() is better.
Your suggestion is better. And it's better to add some comments before
this function.
But how about dm-raid? Can this patch work for dm-raid?
is_rdev_holder_idle() can work for dm-raid, however, the part to
check if normal IO is inflight or completed can't work for dm-raid,
currently there is no way to grab dm gendisk from mddev. However, I
think there won't be regression since the old buggy is_mddev_idle()
almost always return false.
Thanks,
Kuai
Regards
Xiao
Thanks,
Kuai
This is just inherited from the old behaviour.
Thanks,
Kuai
Best Regards
Xiao
.
.
