On Thu, Jul 04, 2024 at 10:37:22AM -0600, Martin Oliveira wrote: > The .page_mkwrite operator of kernfs just calls file_update_time(). > This is the same behaviour that the fault code does if .page_mkwrite is > not set. > > Furthermore, having the page_mkwrite() operator causes > writable_file_mapping_allowed() to fail due to > vma_needs_dirty_tracking() on the gup flow, which is a pre-requisite for > enabling P2PDMA over RDMA. > > There are no users of .page_mkwrite and no known valid use cases, so > just remove the .page_mkwrite from kernfs_ops and WARN_ON() if an mmap() > implementation sets .page_mkwrite. > > Co-developed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Signed-off-by: Martin Oliveira <martin.oliveira@xxxxxxxxxxxxx> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>