search for: dax_supported

Hi Dan, While testing device mapper with DAX, I faced a bug with the commit: commit ad428cdb525a97d15c0349fdc80f3d58befb50df Author: Dan Williams <dan.j.williams at intel.com> Date: Wed Feb 20 21:12:50 2019 -0800 When I reverted the condition to old code[1] it worked for me. I am thinking when we map two different devices (e.g with device mapper), will start & end pfn still point

Hi Dan, While testing device mapper with DAX, I faced a bug with the commit: commit ad428cdb525a97d15c0349fdc80f3d58befb50df Author: Dan Williams <dan.j.williams at intel.com> Date: Wed Feb 20 21:12:50 2019 -0800 When I reverted the condition to old code[1] it worked for me. I am thinking when we map two different devices (e.g with device mapper), will start & end pfn still point

...would either need a way to have a multi-level pfn to pagemap lookup for composite devices, or a way to discern that even though the pagemap is different that the result is still valid / not an indication that we have leaked into an unassociated address range. Perhaps a per-daxdev callback for ->dax_supported() so that device-mapper internals can be used for this validation. We need to get that fixed up, but I don't see it as a blocker / pre-requisite for virtio-pmem.