Fix comment of __get_user_pages() and make it more clear. Suggested-by: John Hubbard <jhubbard@xxxxxxxxxx> Signed-off-by: Liu Xiang <liuxiang_1999@xxxxxxx> --- Changes in v2: as suggested by John, rewrite the comment about return value. mm/gup.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 8f236a3..bc6a254 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -734,11 +734,17 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags) * Or NULL if the caller does not require them. * @nonblocking: whether waiting for disk IO or mmap_sem contention * - * Returns number of pages pinned. This may be fewer than the number - * requested. If nr_pages is 0 or negative, returns 0. If no pages - * were pinned, returns -errno. Each page returned must be released - * with a put_page() call when it is finished with. vmas will only - * remain valid while mmap_sem is held. + * Returns either number of pages pinned (which may be less than the + * number requested), or an error. Details about the return value: + * + * -- If nr_pages is 0, returns 0. + * -- If nr_pages is >0, but no pages were pinned, returns -errno. + * -- If nr_pages is >0, and some pages were pinned, returns the number of + * pages pinned. Again, this may be less than nr_pages. + * + * The caller is responsible for releasing returned @pages, via put_page(). + * + * @vmas are valid only as long as mmap_sem is held. * * Must be called with mmap_sem held. It may be released. See below. * -- 1.9.1
