[PATCH] lightnvm: deprecated OCSSD support and schedule it for removal in Linux 5.15

[Hans Holmberg]

On Mon, Apr 12, 2021 at 12:20 PM Matias Bjørling <mb at lightnvm.io> wrote:
>
> On 12/04/2021 11.49, Javier González wrote:
> > On 12.04.2021 11:26, Matias Bjørling wrote:
> >> On 12/04/2021 11.21, Matias Bjørling wrote:
> >>> On 12/04/2021 10.12, Christoph Hellwig wrote:
> >>>> Lightnvm was an innovative idea to expose more low-level control
> >>>> over SSDs.
> >>>> But it failed to get properly standardized and remains a
> >>>> non-standarized
> >>>> extension to NVMe that requires vendor specific quirks for a few
> >>>> now mostly
> >>>> obsolete SSD devices.  The standardized ZNS command set for NVMe
> >>>> has take
> >>>> over a lot of the approaches and allows for fully standardized
> >>>> operation.
> >>>>
> >>>> Remove the Linux code to support open channel SSDs as the few
> >>>> production
> >>>> deployments of the above mentioned SSDs are using userspace driver
> >>>> stacks
> >>>> instead of the fairly limited Linux support.
> >>>>
> >>>> Signed-off-by: Christoph Hellwig <hch at lst.de>
> >>>> ---
> >>>>   drivers/lightnvm/Kconfig | 4 +++-
> >>>>   drivers/lightnvm/core.c  | 2 ++
> >>>>   2 files changed, 5 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/drivers/lightnvm/Kconfig b/drivers/lightnvm/Kconfig
> >>>> index 4c2ce210c1237d..04caa0f2d445c7 100644
> >>>> --- a/drivers/lightnvm/Kconfig
> >>>> +++ b/drivers/lightnvm/Kconfig
> >>>> @@ -4,7 +4,7 @@
> >>>>   #
> >>>>     menuconfig NVM
> >>>> -    bool "Open-Channel SSD target support"
> >>>> +    bool "Open-Channel SSD target support (DEPRECATED)"
> >>>>       depends on BLOCK
> >>>>       help
> >>>>         Say Y here to get to enable Open-channel SSDs.
> >>>> @@ -15,6 +15,8 @@ menuconfig NVM
> >>>>         If you say N, all options in this submenu will be skipped
> >>>> and disabled
> >>>>         only do this if you know what you are doing.
> >>>>   +      This code is deprecated and will be removed in Linux 5.15.
> >>>> +
> >>>>   if NVM
> >>>>     config NVM_PBLK
> >>>> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> >>>> index 28ddcaa5358b14..4394f47c81296a 100644
> >>>> --- a/drivers/lightnvm/core.c
> >>>> +++ b/drivers/lightnvm/core.c
> >>>> @@ -1174,6 +1174,8 @@ int nvm_register(struct nvm_dev *dev)
> >>>>   {
> >>>>       int ret, exp_pool_size;
> >>>>   +    pr_warn_once("lightnvm support is deprecated and will be
> >>>> removed in Linux 5.15.\n");
> >>>> +
> >>>>       if (!dev->q || !dev->ops) {
> >>>>           kref_put(&dev->ref, nvm_free);
> >>>>           return -EINVAL;
> >>>
> >>> Thanks, Christoph.
> >>>
> >>> I'll send it to Jens with today's lightnvm PR.
> >>
> >> Javier, can I add your reviewed-by?
> >>
> >
> > Yes, please.
> >
> > I'll crack a beer and cheer on it tonight. Good times :)

All those patches lost in time, like tears in rain..

Cheers to everyone involved!

Hans

> >
> > Javier
>
> Thank you.
>