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charset="utf-8" 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 Signed-off-by: Logan Gunthorpe Signed-off-by: Martin Oliveira Acked-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 25 ++----------------------- 1 file changed, 2 insertions(+), 23 deletions(-) diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 8502ef68459b..90603664de7f 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -386,28 +386,6 @@ static vm_fault_t kernfs_vma_fault(struct vm_fault *vm= f) return ret; } =20 -static vm_fault_t kernfs_vma_page_mkwrite(struct vm_fault *vmf) -{ - struct file *file =3D vmf->vma->vm_file; - struct kernfs_open_file *of =3D kernfs_of(file); - vm_fault_t ret; - - if (!of->vm_ops) - return VM_FAULT_SIGBUS; - - if (!kernfs_get_active(of->kn)) - return VM_FAULT_SIGBUS; - - ret =3D 0; - if (of->vm_ops->page_mkwrite) - ret =3D of->vm_ops->page_mkwrite(vmf); - else - file_update_time(file); - - kernfs_put_active(of->kn); - return ret; -} - static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long add= r, void *buf, int len, int write) { @@ -432,7 +410,6 @@ static int kernfs_vma_access(struct vm_area_struct *vma= , unsigned long addr, static const struct vm_operations_struct kernfs_vm_ops =3D { .open =3D kernfs_vma_open, .fault =3D kernfs_vma_fault, - .page_mkwrite =3D kernfs_vma_page_mkwrite, .access =3D kernfs_vma_access, }; =20 @@ -482,6 +459,8 @@ static int kernfs_fop_mmap(struct file *file, struct vm= _area_struct *vma) if (vma->vm_ops && vma->vm_ops->close) goto out_put; =20 + WARN_ON(vma->vm_ops && vma->vm_ops->page_mkwrite); + rc =3D 0; if (!of->mmapped) { of->mmapped =3D true; --=20 2.34.1