[PATCH] nvme: don't create block device for inactive namespace

[Bin Meng]

+ML

On Fri, Jun 18, 2021 at 1:47 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Heinrich,
>
> On Thu, Jun 17, 2021 at 7:04 PM Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
> >
> > QEMU returns the highest supported namespace number NN as 255. This does
> > not imply that there are 255 active namespaces.
> >
> > If a namespace is not active, the namespace identify command returns a zero
> > filled data structure. We can use field NSZE (namespace size) to decide if
> > a block device should be created.
>
> Thanks for the fix. Apparently QEMU has changed its behavior of namespaces.
>
> >
> > Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> > ---
> >  drivers/nvme/nvme-uclass.c | 30 +++++++++++++++++++++++++++++-
> >  1 file changed, 29 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/nvme/nvme-uclass.c b/drivers/nvme/nvme-uclass.c
> > index 277e31e1f3..f7861f5287 100644
> > --- a/drivers/nvme/nvme-uclass.c
> > +++ b/drivers/nvme/nvme-uclass.c
> > @@ -4,22 +4,50 @@
> >   * Copyright (C) 2017 Bin Meng <bmeng.cn at gmail.com>
> >   */
> >
> > +#define LOG_CATEGORY UCLASS_NVME
> > +
> >  #include <common.h>
> >  #include <blk.h>
> >  #include <errno.h>
> >  #include <dm.h>
> >  #include <dm/device.h>
> > +#include <log.h>
> > +#include <memalign.h>
> > +#include <nvme.h>
> >  #include "nvme.h"
> >
> > +/**
> > + * nvme_probe_namespace() - check if namespace is active
> > + *
> > + * @dev:       NVMe controller device
> > + * @ns_id:     namespace ID
> > + * Return:     0 if namespace exists, -ve on error
> > + */
> > +static int nvme_probe_namespace(struct nvme_dev *dev, unsigned int ns_id)
> > +{
> > +       ALLOC_CACHE_ALIGN_BUFFER(char, buf_ns, sizeof(struct nvme_id_ns));
> > +       struct nvme_id_ns *id = (struct nvme_id_ns *)buf_ns;
> > +
> > +       if (nvme_identify(dev, ns_id, 0, (dma_addr_t)(long)id))
> > +               return -EIO;
> > +       log_debug("ns_id %u, nsze %llu\n", ns_id, id->nsze);
> > +       if (!id->nsze)
> > +               return -ENOENT;
> > +       return 0;
> > +}
> > +
> >  static int nvme_uclass_post_probe(struct udevice *udev)
> >  {
> >         char name[20];
> >         struct udevice *ns_udev;
> > -       int i, ret;
> > +       unsigned int i;
> > +       int ret;
> >         struct nvme_dev *ndev = dev_get_priv(udev);
> >
> >         /* Create a blk device for each namespace */
> >         for (i = 0; i < ndev->nn; i++) {
>
> I suggest we assign correct number of namespaces in
> nvme_get_info_from_identify() instead.
>
> > +               if (nvme_probe_namespace(ndev, i + 1))
> > +                       continue;
> >                 /*
> >                  * Encode the namespace id to the device name so that
> >                  * we can extract it when doing the probe.
>
> Regards,
> Bin