From 55a650c35fea7cfdf989647f37960dfaf76da737 Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Sun, 7 Jun 2020 21:41:05 -0700 Subject: [PATCH] mm/gup: frame_vector: convert get_user_pages() --> pin_user_pages() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This code was using get_user_pages*(), and all of the callers so far were in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Signed-off-by: John Hubbard Signed-off-by: Andrew Morton Acked-by: David Hildenbrand Cc: Daniel Vetter Cc: Jérôme Glisse Cc: Vlastimil Babka Cc: Jan Kara Cc: Dave Chinner Cc: Pankaj Gupta Cc: Souptick Joarder Link: http://lkml.kernel.org/r/20200527223243.884385-3-jhubbard@nvidia.com Signed-off-by: Linus Torvalds --- mm/frame_vector.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/frame_vector.c b/mm/frame_vector.c index c431ca81dad5..4107dbca0056 100644 --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -72,7 +72,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { vec->got_ref = true; vec->is_pfns = false; - ret = get_user_pages_locked(start, nr_frames, + ret = pin_user_pages_locked(start, nr_frames, gup_flags, (struct page **)(vec->ptrs), &locked); goto out; } @@ -122,7 +122,6 @@ EXPORT_SYMBOL(get_vaddr_frames); */ void put_vaddr_frames(struct frame_vector *vec) { - int i; struct page **pages; if (!vec->got_ref) @@ -135,8 +134,8 @@ void put_vaddr_frames(struct frame_vector *vec) */ if (WARN_ON(IS_ERR(pages))) goto out; - for (i = 0; i < vec->nr_frames; i++) - put_page(pages[i]); + + unpin_user_pages(pages, vec->nr_frames); vec->got_ref = false; out: vec->nr_frames = 0;