On 10/9/20 12:59 AM, Daniel Vetter wrote:
...
@@ -48,40 +47,25 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
start = untagged_addr(start);
- mmap_read_lock(mm);
- locked = 1;
- vma = find_vma_intersection(mm, start, start + 1);
- if (!vma) {
- ret = -EFAULT;
- goto out;
- }
-
- /*
- * While get_vaddr_frames() could be used for transient (kernel
- * controlled lifetime) pinning of memory pages all current
- * users establish long term (userspace controlled lifetime)
- * page pinning. Treat get_vaddr_frames() like
- * get_user_pages_longterm() and disallow it for filesystem-dax
- * mappings.
- */
- if (vma_is_fsdax(vma)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
-
- if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
+ ret = pin_user_pages_fast(start, nr_frames,
+ FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
+ (struct page **)(vec->ptrs));
+ if (ret > 0) {
None of the callers that we have today will accept anything less than
ret == nr_frames. And the whole partially pinned region idea turns out
to be just not useful for almost everyone, from what I recall of the gup/pup
call sites. So I wonder if we should just have get_vaddr_frames do the
cleanup here and return -EFAULT, if ret != nr_frames ?
thanks,
--
John Hubbard
NVIDIA
