On Fri, Mar 22, 2019 at 7:07 PM Marcin Dziegielewski
<marcin.dziegielewski@xxxxxxxxx> wrote:
>
> Currently if we issue reboot to the system pblk will close
> ungracefully and in consequence it will need recovery on load.
>
> This patch propose utilize of reboot notifier feature to trigger
> gracefull pblk shutdown on reboot.
To put in my two-penny worth, this seems unmotivated.
If user-land chooses to reboot, why should we delay the reboot in the
order of second(s)?
Recovering should be faster than padding anyway, so why not take the hit there?
Also, It's nice to be able to test OOB recovery by just rebooting the
system, and I have not found this sort of thing being done anywhere
else in the block layer.
/ Hans
>
> Signed-off-by: Marcin Dziegielewski <marcin.dziegielewski@xxxxxxxxx>
> ---
> drivers/lightnvm/core.c | 65 ++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 51 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index 5f82036..4a421f5 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -27,6 +27,7 @@
> #include <linux/miscdevice.h>
> #include <linux/lightnvm.h>
> #include <linux/sched/sysctl.h>
> +#include <linux/reboot.h>
>
> static LIST_HEAD(nvm_tgt_types);
> static DECLARE_RWSEM(nvm_tgtt_lock);
> @@ -1138,9 +1139,52 @@ struct nvm_dev *nvm_alloc_dev(int node)
> }
> EXPORT_SYMBOL(nvm_alloc_dev);
>
> +static void _nvm_unregister(struct nvm_dev *dev, bool graceful)
> +{
> + struct nvm_target *t, *tmp;
> +
> + mutex_lock(&dev->mlock);
> + list_for_each_entry_safe(t, tmp, &dev->targets, list) {
> + if (t->dev->parent != dev)
> + continue;
> + __nvm_remove_target(t, graceful);
> + }
> + mutex_unlock(&dev->mlock);
> +
> + list_del(&dev->devices);
> +
> + nvm_free(dev);
> +}
> +
> +static int nvm_notify_reboot(struct notifier_block *this,
> + unsigned long code, void *x)
> +{
> + struct nvm_dev *dev, *t;
> +
> + down_write(&nvm_lock);
> + if (list_empty(&nvm_devices)) {
> + up_write(&nvm_lock);
> + return NOTIFY_DONE;
> + }
> +
> + list_for_each_entry_safe(dev, t, &nvm_devices, devices)
> + _nvm_unregister(dev, true);
> +
> + up_write(&nvm_lock);
> +
> + return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block nvm_notifier = {
> + .notifier_call = nvm_notify_reboot,
> + .next = NULL,
> + .priority = INT_MAX, /* before any real devices */
> +};
> +
> int nvm_register(struct nvm_dev *dev)
> {
> int ret, exp_pool_size;
> + bool is_first;
>
> if (!dev->q || !dev->ops)
> return -EINVAL;
> @@ -1161,32 +1205,25 @@ int nvm_register(struct nvm_dev *dev)
> return -ENOMEM;
> }
>
> - /* register device with a supported media manager */
> down_write(&nvm_lock);
> + is_first = list_empty(&nvm_devices);
> +
> + /* register device with a supported media manager */
> list_add(&dev->devices, &nvm_devices);
> up_write(&nvm_lock);
>
> + if (is_first)
> + register_reboot_notifier(&nvm_notifier);
> +
> return 0;
> }
> EXPORT_SYMBOL(nvm_register);
>
> void nvm_unregister(struct nvm_dev *dev)
> {
> - struct nvm_target *t, *tmp;
> -
> - mutex_lock(&dev->mlock);
> - list_for_each_entry_safe(t, tmp, &dev->targets, list) {
> - if (t->dev->parent != dev)
> - continue;
> - __nvm_remove_target(t, false);
> - }
> - mutex_unlock(&dev->mlock);
> -
> down_write(&nvm_lock);
> - list_del(&dev->devices);
> + _nvm_unregister(dev, false);
> up_write(&nvm_lock);
> -
> - nvm_free(dev);
> }
> EXPORT_SYMBOL(nvm_unregister);
>
> --
> 1.8.3.1
>
