The procfs mmu files such as smaps and pagemap currently ignore devdax and fsdax pages because these pages are considered special. A future change will start treating these as normal pages, meaning they can be exposed via smaps and pagemap. The only difference is that devdax and fsdax pages can never be pinned for DMA via FOLL_LONGTERM, so add an explicit check in pte_is_pinned() to reflect that. Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx> --- Changes for v5: - After discussion with David remove the checks for DAX pages for smaps and pagemap walkers. This means DAX pages will now appear in those procfs files. --- fs/proc/task_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 38a5a3e..9a8a7d3 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1378,7 +1378,7 @@ static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))) return false; folio = vm_normal_folio(vma, addr, pte); - if (!folio) + if (!folio || folio_is_devdax(folio) || folio_is_fsdax(folio)) return false; return folio_maybe_dma_pinned(folio); } -- git-series 0.9.1
