11:20 a.m.
Hello Dave Jiang,
The patch 006358b35c73: "libnvdimm: add support for clear poison list
and badblocks for device dax" from Apr 7, 2017, leads to the
following static checker warning:
drivers/nvdimm/bus.c:852 nd_pmem_forget_poison_check()
warn: we tested 'nd_dax' before and it was 'false'
drivers/nvdimm/bus.c
835 static int nd_pmem_forget_poison_check(struct device *dev, void *data)
836 {
837 struct nd_cmd_clear_error *clear_err =
838 (struct nd_cmd_clear_error *)data;
839 struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
840 struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
841 struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
^^^^^^
nd_dax is set here.
842 struct nd_namespace_common *ndns = NULL;
843 struct nd_namespace_io *nsio;
844 resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
845
846 if (nd_dax || !dev->driver)
^^^^^^
We return if it's non-NULL
847 return 0;
848
849 start = clear_err->address;
850 end = clear_err->address + clear_err->cleared - 1;
851
852 if (nd_btt || nd_pfn || nd_dax) {
853 if (nd_btt)
854 ndns = nd_btt->ndns;
855 else if (nd_pfn)
856 ndns = nd_pfn->ndns;
857 else if (nd_dax)
^^^^^^
but the rest of the function assumes it can be true. Perhaps we plan
to enable it in the future? It's not clear to me.
858 ndns = nd_dax->nd_pfn.ndns;
859
860 if (!ndns)
861 return 0;
862 } else
863 ndns = to_ndns(dev);
864
865 nsio = to_nd_namespace_io(&ndns->dev);
866 pstart = nsio->res.start + offset;
867 pend = nsio->res.end - end_trunc;
868
869 if ((pstart >= start) && (pend <= end))
870 return -EBUSY;
871
872 return 0;
873
874 }
regards,
dan carpenter