On Thu, Jan 17, 2019 at 9:03 PM Wei Yang <[email protected]> wrote: > > On Thu, Jan 17, 2019 at 08:31:56PM -0800, Dan Williams wrote: > >On Thu, Jan 17, 2019 at 7:36 PM Wei Yang <[email protected]> > >wrote: > >> > >> In current implementation, we might re-allocate nd_pfn->pfn_sb. > >> > >> For example: > >> > >> nd_dax_probe() > >> nd_pfn->pfn_sb = devm_kzalloc() > >> > >> dax_pmem_probe() > >> nvdimm_setup_pfn() > >> nd_pfn_init() > >> nd_pfn->pfn_sb = devm_kzalloc() > >> > >> This patch checks nd_pfn->pfn_sb before allocating it in nd_pfn_init(). > > > >Ugh, this patch is unfortunately uncovering a deeper problem. > >nvdimm_setup_pfn() should not be calling nd_pfn_init(). This > >effectively is always re-initializing the info-block, benign but > >unnecessary. Instead it needs to be using nd_pfn_validate() followed > >by an __nvdimm_setup_pfn() in the dax_pmem_probe() path. > > > >Good find! > > So we should fix this like: > > dax_pmem_probe() > nd_pfn_validate() > __nvdimm_setup_pfn() > > Is my understanding correct?
Yes, at first glance, but it would need a deeper review and testing. The usage of nvdimm_setup_pfn() in drivers/nvdimm/pmem.c needs a similar fixup. _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
