diff --git a/mm/rmap.c b/mm/rmap.c index dce74a9efdd672ac7d361fcf4ec6c0918c0a946f..f5d6799b8a744356873c4e20b67ee492b06c6dc3 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -767,14 +767,20 @@ static void __page_set_anon_rmap(struct page *page, * If the page isn't exclusively mapped into this vma, * we must use the _oldest_ possible anon_vma for the * page mapping! - * - * So take the last AVC chain entry in the vma, which is - * the deepest ancestor, and use the anon_vma from that. */ if (!exclusive) { - struct anon_vma_chain *avc; - avc = list_entry(vma->anon_vma_chain.prev, struct anon_vma_chain, same_vma); - anon_vma = avc->anon_vma; + if (PageAnon(page)) + return; + anon_vma = anon_vma->root; + } else { + /* + * In this case, swapped-out-but-not-discarded swap-cache + * is remapped. So, no need to update page->mapping here. + * We convice anon_vma poitned by page->mapping is not obsolete + * because vma->anon_vma is necessary to be a family of it. + */ + if (PageAnon(page)) + return; } anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;