Re: [ndctl PATCH v4 10/17] libcxl: add label_size to cxl_memdev, and an API to retrieve it

["Verma, Vishal L" <vishal.l.verma@intel.com>]

On Thu, 2021-10-14 at 11:24 -0700, Dan Williams wrote:
> On Thu, Oct 7, 2021 at 1:22 AM Vishal Verma <vishal.l.verma@intel.com> wrote:
> > 
> > Size of the Label Storage Area (LSA) is available as a sysfs attribute
> > called 'label_storage_size'. Add that to libcxl's memdev so that it is available
> > for label related commands.
> > 
> > Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> > ---
> >  cxl/lib/private.h  |  1 +
> >  cxl/lib/libcxl.c   | 12 ++++++++++++
> >  cxl/libcxl.h       |  1 +
> >  cxl/lib/libcxl.sym |  5 +++++
> >  4 files changed, 19 insertions(+)
> > 
> > diff --git a/cxl/lib/private.h b/cxl/lib/private.h
> > index 9c6317b..671f12f 100644
> > --- a/cxl/lib/private.h
> > +++ b/cxl/lib/private.h
> > @@ -21,6 +21,7 @@ struct cxl_memdev {
> >         unsigned long long pmem_size;
> >         unsigned long long ram_size;
> >         int payload_max;
> > +       size_t lsa_size;
> >         struct kmod_module *module;
> >  };
> > 
> > diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
> > index 33cc462..de3a8f7 100644
> > --- a/cxl/lib/libcxl.c
> > +++ b/cxl/lib/libcxl.c
> > @@ -247,6 +247,13 @@ static void *add_cxl_memdev(void *parent, int id, const char *cxlmem_base)
> >         if (memdev->payload_max < 0)
> >                 goto err_read;
> > 
> > +       sprintf(path, "%s/label_storage_size", cxlmem_base);
> > +       if (sysfs_read_attr(ctx, path, buf) < 0)
> > +               goto err_read;
> > +       memdev->lsa_size = strtoull(buf, NULL, 0);
> > +       if (memdev->lsa_size == ULLONG_MAX)
> > +               goto err_read;
> > +
> >         memdev->dev_path = strdup(cxlmem_base);
> >         if (!memdev->dev_path)
> >                 goto err_read;
> > @@ -350,6 +357,11 @@ CXL_EXPORT const char *cxl_memdev_get_firmware_verison(struct cxl_memdev *memdev
> >         return memdev->firmware_version;
> >  }
> > 
> > +CXL_EXPORT size_t cxl_memdev_get_label_size(struct cxl_memdev *memdev)
> > +{
> > +       return memdev->lsa_size;
> > +}
> > +
> >  CXL_EXPORT void cxl_cmd_unref(struct cxl_cmd *cmd)
> >  {
> >         if (!cmd)
> > diff --git a/cxl/libcxl.h b/cxl/libcxl.h
> > index 7408745..d3b97a1 100644
> > --- a/cxl/libcxl.h
> > +++ b/cxl/libcxl.h
> > @@ -42,6 +42,7 @@ struct cxl_ctx *cxl_memdev_get_ctx(struct cxl_memdev *memdev);
> >  unsigned long long cxl_memdev_get_pmem_size(struct cxl_memdev *memdev);
> >  unsigned long long cxl_memdev_get_ram_size(struct cxl_memdev *memdev);
> >  const char *cxl_memdev_get_firmware_verison(struct cxl_memdev *memdev);
> > +size_t cxl_memdev_get_label_size(struct cxl_memdev *memdev);
> > 
> >  #define cxl_memdev_foreach(ctx, memdev) \
> >          for (memdev = cxl_memdev_get_first(ctx); \
> > diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
> > index 1b608d8..b9feb93 100644
> > --- a/cxl/lib/libcxl.sym
> > +++ b/cxl/lib/libcxl.sym
> > @@ -75,3 +75,8 @@ global:
> >         cxl_cmd_new_read_label;
> >         cxl_cmd_read_label_get_payload;
> >  } LIBCXL_2;
> > +
> > +LIBCXL_4 {
> > +global:
> > +       cxl_memdev_get_label_size;
> 
> Since we never made a release with the v2 symbols, why do we need a new v3 set?

Hm, yeah - I think I just logically separated them, but from a libtool
versioning standpoint, I agree there is no need. I'll put them all into
the v1 group.

> 
> Other than that, looks good to me:
> 
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
>