Hi First submitted an xfstest (generic/080) that demonstrates our current problem. When run on ext4-dax mount, and I'd imagine Dave's xfs-dax mount this test fails, on regular mount it works just fine. then 2 patches to fix it. The main problem is that current mm/memory.c will no call us with page_mkwrite if we do not have an actual page mapping, which is what DAX uses. The solution presented here introduces a new pfn_mkwrite to solve this problem. Please see patch-2 for details. I've been running with this patch for 4 month both HW and VMs with no apparent danger, but see patch-2 I played it safe. List of patches: [PATCH 1/2] generic: 080 test that mmap-write updates c/mtime This one is for Dave Chinner to submit to xfstests [PATCH 1/2] mm: New pfn_mkwrite same as page_mkwrite for VM_PFNMAP This patch I need help with please look into it? [PATCH 2/2] dax: use pfn_mkwrite to update mtime Please review and comment. Thanks Boaz -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>