Alistair Popple wrote: > dax_layout_busy_page_range() is used by file systems to scan the DAX > page-cache to unmap mapping pages from user-space and to determine if > any pages in the given range are busy, either due to ongoing DMA or > other get_user_pages() usage. > > Currently it checks to see the file mapping is mapped into user-space > with mapping_mapped() and returns early if not, skipping the check for > DMA busy pages. This is wrong as pages may still be undergoing DMA > access even if they have subsequently been unmapped from > user-space. Fix this by dropping the check for mapping_mapped(). > > Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx> > Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx> Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>