On Thu, May 14, 2020 at 01:53:16AM +0530, Souptick Joarder wrote: > First, when memory allocation for sg_list_unaligned failed, there > is no point of calling put_pages() as we haven't pinned any pages. > > Second, if get_user_pages_fast() failed we should unpinned num_pinned > pages, no point of checking till num_pages. > > This will address both. > > Signed-off-by: Souptick Joarder <jrdr.li...@gmail.com>
If gup_flags were | FOLL_LONGTERM then this patch would fix a double free because of the put_page() in __gup_longterm_locked(). mm/gup.c 1786 if (check_dax_vmas(vmas_tmp, rc)) { 1787 for (i = 0; i < rc; i++) 1788 put_page(pages[i]); ^^^^^^^^^^^^^^^^^^^ put_page() here and also in the caller. 1789 rc = -EOPNOTSUPP; 1790 goto out; 1791 } But since this isn't FOLL_LONGTERM the patch is a nice cleanup which doesn't affect run time. Reviewed-by: Dan Carpenter <dan.carpen...@oracle.com> regards, dan carpenter