On (24/10/03 06:43), Christoph Hellwig wrote:
> .. actually, we still clear QUEUE_FLAG_DYING early. Something like
> the pathc below (plus proper comments) should sort it out:
>
> diff --git a/block/genhd.c b/block/genhd.c
> index 1c05dd4c6980b5..9a1e18fbb136cf 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -589,9 +589,6 @@ static void __blk_mark_disk_dead(struct gendisk *disk)
> if (test_and_set_bit(GD_DEAD, &disk->state))
> return;
>
> - if (test_bit(GD_OWNS_QUEUE, &disk->state))
> - blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);
> -
> /*
> * Stop buffered writers from dirtying pages that can't be written out.
> */
> @@ -673,6 +670,9 @@ void del_gendisk(struct gendisk *disk)
> drop_partition(part);
> mutex_unlock(&disk->open_mutex);
>
> + if (test_bit(GD_OWNS_QUEUE, &disk->state))
> + blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);
So that mutex_lock(&disk->open_mutex) right before it potentially can
deadlock (I think it will).
My idea, thus far, was to
if (test_bit(GD_OWNS_QUEUE, &disk->state)) }
blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);
blk_kick_queue_enter(disk->queue); // this one simply wake_up_all(&q->mq_freeze_wq);
// if the queue has QUEUE_FLAG_DYING
}
in del_gendisk() before the very first time del_gendisk() attempts to
mutex_lock(&disk->open_mutex), because that mutex is already locked
forever.
> if (!(disk->flags & GENHD_FL_HIDDEN)) {
> sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
