On Fri, Apr 2, 2021 at 2:26 AM Vaibhav Jain <[email protected]> wrote: > > In case a platform doesn't provide explicit flush-hints but provides an > explicit flush callback via ND_REGION_ASYNC region flag, then > nvdimm_has_flush() still returns '0' indicating that writes do not > require flushing. This happens on PPC64 with patch at [1] applied, > where 'deep_flush' of a region was denied even though an explicit > flush function was provided. > > Fix this by adding a condition to nvdimm_has_flush() to test for the > ND_REGION_ASYNC flag on the region and see if a 'region->flush' > callback is assigned.
Looks good. > > References: > [1] "powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall" > https://lore.kernel.org/linux-nvdimm/161703936121.36.7260632399 > 582101498.stgit@e1fbed493c87 Looks like a typo happened in that link, I can fix that up. I'll also change this to the canonical "Link:" tag for references. > > Reported-by: Shivaprasad G Bhat <[email protected]> > Signed-off-by: Vaibhav Jain <[email protected]> > --- > drivers/nvdimm/region_devs.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c > index ef23119db574..e05cc9f8a9fd 100644 > --- a/drivers/nvdimm/region_devs.c > +++ b/drivers/nvdimm/region_devs.c > @@ -1239,6 +1239,11 @@ int nvdimm_has_flush(struct nd_region *nd_region) > || !IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API)) > return -ENXIO; > > + /* Test if an explicit flush function is defined */ > + if (test_bit(ND_REGION_ASYNC, &nd_region->flags) && nd_region->flush) > + return 1; > + > + /* Test if any flush hints for the region are available */ > for (i = 0; i < nd_region->ndr_mappings; i++) { > struct nd_mapping *nd_mapping = &nd_region->mapping[i]; > struct nvdimm *nvdimm = nd_mapping->nvdimm; > @@ -1249,8 +1254,8 @@ int nvdimm_has_flush(struct nd_region *nd_region) > } > > /* > - * The platform defines dimm devices without hints, assume > - * platform persistence mechanism like ADR > + * The platform defines dimm devices without hints nor explicit flush, > + * assume platform persistence mechanism like ADR > */ > return 0; > } > -- > 2.30.2 > _______________________________________________ Linux-nvdimm mailing list -- [email protected] To unsubscribe send an email to [email protected]
