From b53e24c4f6bcc5f38b79c1c344e643bd54b69964 Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Mon, 22 May 2023 17:43:09 -0700 Subject: mm: call arch_swap_restore() from unuse_pte() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We would like to move away from requiring architectures to restore metadata from swap in the set_pte_at() implementation, as this is not only error-prone but adds complexity to the arch-specific code. This requires us to call arch_swap_restore() before calling swap_free() whenever pages are restored from swap. We are currently doing so everywhere except in unuse_pte(); do so there as well. Link: https://lkml.kernel.org/r/20230523004312.1807357-3-pcc@google.com Link: https://linux-review.googlesource.com/id/I68276653e612d64cde271ce1b5a99ae05d6bbc4f Signed-off-by: Peter Collingbourne Suggested-by: David Hildenbrand Acked-by: David Hildenbrand Acked-by: "Huang, Ying" Reviewed-by: Steven Price Acked-by: Catalin Marinas Cc: Alexandru Elisei Cc: Chinwen Chang Cc: Evgenii Stepanov Cc: Greg Kroah-Hartman Cc: kasan-dev Cc: "Kuan-Ying Lee (李冠穎)" Cc: Qun-Wei Lin Cc: Suren Baghdasaryan Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton --- mm/swapfile.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index cad0209ac67f..d996c335fc3c 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1778,6 +1778,13 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, goto setpte; } + /* + * Some architectures may have to restore extra metadata to the page + * when reading from swap. This metadata may be indexed by swap entry + * so this must be called before swap_free(). + */ + arch_swap_restore(entry, page_folio(page)); + /* See do_swap_page() */ BUG_ON(!PageAnon(page) && PageMappedToDisk(page)); BUG_ON(PageAnon(page) && PageAnonExclusive(page)); -- cgit