On Mon, 9 Aug 2021 15:28:08 -0700 Dan Williams <[email protected]> wrote:
> In preparation for LIBNVDIMM to manage labels on CXL devices deploy > helpers that abstract the label type from the implementation. The CXL > label format is mostly similar to the EFI label format with concepts / > fields added, like dynamic region creation and label type guids, and > other concepts removed like BLK-mode and interleave-set-cookie ids. > > CXL labels support checksums by default, but early versions of the EFI > labels did not. Add a validate function that can return true in the case > the label format does not implement a checksum. > > Signed-off-by: Dan Williams <[email protected]> Reviewed-by: Jonathan Cameron <[email protected]> > --- > drivers/nvdimm/label.c | 68 > +++++++++++++++++++++++++----------------------- > 1 file changed, 35 insertions(+), 33 deletions(-) > > diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c > index b40a4eda1d89..3f73412dd438 100644 > --- a/drivers/nvdimm/label.c > +++ b/drivers/nvdimm/label.c > @@ -346,29 +346,45 @@ static bool preamble_next(struct nvdimm_drvdata *ndd, > free, nslot); > } > > +static bool nsl_validate_checksum(struct nvdimm_drvdata *ndd, > + struct nd_namespace_label *nd_label) > +{ > + u64 sum, sum_save; > + > + if (!namespace_label_has(ndd, checksum)) > + return true; > + > + sum_save = nsl_get_checksum(ndd, nd_label); > + nsl_set_checksum(ndd, nd_label, 0); > + sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > + nsl_set_checksum(ndd, nd_label, sum_save); > + return sum == sum_save; > +} > + > +static void nsl_calculate_checksum(struct nvdimm_drvdata *ndd, > + struct nd_namespace_label *nd_label) > +{ > + u64 sum; > + > + if (!namespace_label_has(ndd, checksum)) > + return; > + nsl_set_checksum(ndd, nd_label, 0); > + sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > + nsl_set_checksum(ndd, nd_label, sum); > +} > + > static bool slot_valid(struct nvdimm_drvdata *ndd, > struct nd_namespace_label *nd_label, u32 slot) > { > + bool valid; > + > /* check that we are written where we expect to be written */ > if (slot != nsl_get_slot(ndd, nd_label)) > return false; > - > - /* check checksum */ > - if (namespace_label_has(ndd, checksum)) { > - u64 sum, sum_save; > - > - sum_save = nsl_get_checksum(ndd, nd_label); > - nsl_set_checksum(ndd, nd_label, 0); > - sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > - nsl_set_checksum(ndd, nd_label, sum_save); > - if (sum != sum_save) { > - dev_dbg(ndd->dev, "fail checksum. slot: %d expect: > %#llx\n", > - slot, sum); > - return false; > - } > - } > - > - return true; > + valid = nsl_validate_checksum(ndd, nd_label); > + if (!valid) > + dev_dbg(ndd->dev, "fail checksum. slot: %d\n", slot); > + return valid; > } > > int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd) > @@ -812,13 +828,7 @@ static int __pmem_label_update(struct nd_region > *nd_region, > guid_copy(&nd_label->abstraction_guid, > to_abstraction_guid(ndns->claim_class, > &nd_label->abstraction_guid)); > - if (namespace_label_has(ndd, checksum)) { > - u64 sum; > - > - nsl_set_checksum(ndd, nd_label, 0); > - sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1); > - nsl_set_checksum(ndd, nd_label, sum); > - } > + nsl_calculate_checksum(ndd, nd_label); > nd_dbg_dpa(nd_region, ndd, res, "\n"); > > /* update label */ > @@ -1049,15 +1059,7 @@ static int __blk_label_update(struct nd_region > *nd_region, > guid_copy(&nd_label->abstraction_guid, > to_abstraction_guid(ndns->claim_class, > &nd_label->abstraction_guid)); > - > - if (namespace_label_has(ndd, checksum)) { > - u64 sum; > - > - nsl_set_checksum(ndd, nd_label, 0); > - sum = nd_fletcher64(nd_label, > - sizeof_namespace_label(ndd), 1); > - nsl_set_checksum(ndd, nd_label, sum); > - } > + nsl_calculate_checksum(ndd, nd_label); > > /* update label */ > offset = nd_label_offset(ndd, nd_label); >
